Science.gov

Sample records for crawler tractors

  1. Miniature pipe crawler tractor

    DOEpatents

    McKay, Mark D.; Anderson, Matthew O.; Ferrante, Todd A.; Willis, W. David

    2000-01-01

    A pipe crawler tractor may comprise a half tractor assembly having a first base drive wheel, a second base drive wheel, and a top drive wheel. The drive wheels are mounted in spaced-apart relation so that the top drive wheel is positioned between the first and second base drive wheels. The mounting arrangement is also such that the first and second base drive wheels contact the inside surface of the pipe at respective first and second positions and so that the top drive wheel contacts the inside surface of the pipe at a third position, the third position being substantially diametrically opposed to the first and second positions. A control system connected to the half tractor assembly controls the rotation of the first base wheel, the second base wheel, and the top drive wheel to move the half tractor assembly within the pipe.

  2. Self-Pacing a Gross Motor Skills Course: Crawler Tractor Operator, MOS 62E20.

    ERIC Educational Resources Information Center

    Brennan, Mark F.; Taylor, John E.

    As part of the Army's emphasis on performance-oriented instruction in training centers, a study was conducted to determine the feasibility of using self-paced instruction in a gross motor skills course. The Crawler Tractor Operator Course, a seven-week heavy equipment course conducted at Fort Leonard Wood, Missouri was selected for the study…

  3. Pipe crawlers: Versatile adaptations for real applications

    SciTech Connect

    Hapstack, M.; Talarek, T.R.

    1990-01-01

    A problem at the Savannah River Site requires the unique application of a pipe crawler. A number of stainless steel pipes buried in concrete require ultrasonic inspection of the heat affected zones of the welds for detection of flaws or cracks. The paper describes the utilization of an inch-worm motion pipe crawler which negotiates a 90 degree reducing elbow with significant changes in diameter and vertical sections before entering the area of concern. After a discussion of general considerations and problem description, special requirements to meet the objectives and the design approach regarding the tractor, control system, instrument carriage, and radiation protection are discussed. 2 refs., 11 figs. (MB)

  4. Crawler Transporter 2 Trek

    NASA Image and Video Library

    2016-03-23

    An American flag flutters in the breeze as NASA’s upgraded crawler-transporter 2 (CT-2) travels along the crawlerway during its trek to Launch Pad 39B at the agency’s Kennedy Space Center in Florida, to test recently completed upgrades and modifications for NASA’s journey to Mars. The Ground Systems Development and Operations Program at Kennedy oversaw upgrades to the crawler in the Vehicle Assembly Building. The crawler will carry the mobile launcher with Orion atop the Space Launch System rocket to Pad 39B for Exploration Mission-1, scheduled for 2018.

  5. Crawler Transporter 2 Trek

    NASA Image and Video Library

    2016-03-23

    Technicians walk alongside NASA’s upgraded crawler-transporter 2 (CT-2) as it continues the trek on the crawlerway from the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida to Launch Pad 39B to test recently completed upgrades and modifications for NASA’s journey to Mars. The Ground Systems Development and Operations Program at Kennedy oversaw upgrades to the crawler in the VAB. The crawler will carry the mobile launcher with Orion atop the Space Launch System rocket to Pad 39B for Exploration Mission-1, scheduled for 2018.

  6. Crawler Transporter 2 Trek

    NASA Image and Video Library

    2016-03-23

    NASA’s upgraded crawler-transporter 2 (CT-2) travels along the crawlerway from the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida on its trek to Launch Pad 39B to test recently completed upgrades and modifications for NASA’s journey to Mars. The Ground Systems Development and Operations Program at Kennedy oversaw upgrades to the crawler in the VAB. The crawler will carry the mobile launcher with Orion atop the Space Launch System rocket to Pad 39B for Exploration Mission-1, scheduled for 2018.

  7. Crawler Transporter 2 Trek

    NASA Image and Video Library

    2016-03-23

    Technicians walk alongside NASA’s upgraded crawler-transporter 2 (CT-2) as it continues the trek along the crawlerway from the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida to Launch Pad 39B to test recently completed upgrades and modifications for NASA’s journey to Mars. The Ground Systems Development and Operations Program at Kennedy oversaw upgrades to the crawler in the VAB. The crawler will carry the mobile launcher with Orion atop the Space Launch System rocket to Pad 39B for Exploration Mission-1, scheduled for 2018.

  8. Crawler Transporter 2 Trek

    NASA Image and Video Library

    2016-03-23

    NASA’s upgraded crawler-transporter 2 (CT-2) has exited the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida for its trek along the crawlerway to Launch Pad 39B to test recently completed upgrades and modifications for NASA’s journey to Mars. The Ground Systems Development and Operations Program at Kennedy oversaw upgrades to the crawler in the VAB. The crawler will carry the mobile launcher with Orion atop the Space Launch System rocket to Pad 39B for Exploration Mission-1, scheduled for 2018.

  9. Crawler Transporter 2 Trek

    NASA Image and Video Library

    2016-03-23

    NASA’s upgraded crawler-transporter 2 (CT-2) begins its trek from the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida to Launch Pad 39B to test recently completed upgrades and modifications for NASA’s journey to Mars. The Ground Systems Development and Operations Program at Kennedy oversaw upgrades to the crawler in the VAB. The crawler will carry the mobile launcher with Orion atop the Space Launch System rocket to Pad 39B for Exploration Mission-1, scheduled for 2018.

  10. Crawler Transporter 2 Trek

    NASA Image and Video Library

    2016-03-23

    A truck sprays water in front of NASA’s upgraded crawler-transporter 2 (CT-2) to control dust as it begins the trek from the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida to Launch Pad 39B to test recently completed upgrades and modifications for NASA’s journey to Mars. The Ground Systems Development and Operations Program at Kennedy oversaw upgrades to the crawler in the VAB. The crawler will carry the mobile launcher with Orion atop the Space Launch System rocket to Pad 39B for Exploration Mission-1, scheduled for 2018.

  11. Crawler Transporter 2 Trek

    NASA Image and Video Library

    2016-03-23

    NASA’s upgraded crawler-transporter 2 (CT-2) travels along the crawlerway during its trek to Launch Pad 39B at the agency’s Kennedy Space Center in Florida, to test recently completed upgrades and modifications for NASA’s journey to Mars. The Ground Systems Development and Operations Program at Kennedy oversaw upgrades to the crawler in the Vehicle Assembly Building. The crawler will carry the mobile launcher with Orion atop the Space Launch System rocket to Pad 39B for Exploration Mission-1, scheduled for 2018.

  12. Extendable pipe crawler

    DOEpatents

    Hapstack, M.

    1991-05-28

    A pipe crawler is described having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by inchworm'-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward. 5 figures.

  13. Extendable pipe crawler

    DOEpatents

    Hapstack, Mark

    1991-01-01

    A pipe crawler having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by "inchworm"-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward.

  14. Jacking Up Crawler

    NASA Image and Video Library

    2014-02-27

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, the B and D truck sections of crawler-transporter 2, or CT-2, are being raised up to prepare for installation of new roller bearing assemblies. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  15. GSDO Crawler 2 Refurbishment

    NASA Image and Video Library

    2014-03-18

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, ground support technicians assist with removal of bearings from the B truck tread of crawler-transporter 2, or CT-2. New roller bearing assemblies will be installed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  16. GSDO Crawler 2 Refurbishment

    NASA Image and Video Library

    2014-03-18

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, a ground support technician assists with removal of bearings from the B truck tread of crawler-transporter 2, or CT-2. New roller bearing assemblies will be installed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  17. GSDO Crawler 2 Refurbishment

    NASA Image and Video Library

    2014-03-18

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, a ground support technician assists with removal of a bearing from the B truck tread of crawler-transporter 2, or CT-2. New roller bearing assemblies will be installed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  18. Pipe crawler apparatus

    DOEpatents

    Hovis, Gregory L.; Erickson, Scott A.; Blackmon, Bruce L.

    2002-01-01

    A pipe crawler apparatus particularly useful for 3-inch and 4-inch diameter pipes is provided. The pipe crawler apparatus uses a gripping apparatus in which a free end of a piston rod is modified with a bearing retaining groove. Bearings, placed within the groove, are directed against a camming surface of three respective pivoting support members. The non-pivoting ends of the support members carry a foot-like gripping member that, upon pivoting of the support member, engages the interior wall of the pipe.

  19. Uses for lunar crawler transporters

    NASA Astrophysics Data System (ADS)

    Kaden, Richard A.

    This article discusses state-of-the-art crawler transporters and expresses the need for additional research and development for lunar crawlers. The thrust of the paper illustrates how the basic crawler technology has progressed to a point where extremely large modules can be shop fabricated and move to some distant location at a considerable savings. Also, extremely heavy loads may be lifted by large crawler cranes and placed in designed locations. The Transi-Lift Crawler crane with its traveling counterweight is an attractive concept for lunar construction.

  20. Crawler Solids Unknown Analysis

    NASA Technical Reports Server (NTRS)

    Frandsen, Athela

    2016-01-01

    Crawler Transporter (CT) #2 has been undergoing refurbishment to carry the Space Launch System (SLS). After returning to normal operation, multiple filters of the gear box lubrication system failed/clogged and went on bypass during a test run to the launch pad. Analysis of the filters was done in large part with polarized light microscopy (PLM) to identify the filter contaminates and the source of origin.

  1. Crawler Bearing Replacement

    NASA Image and Video Library

    2014-02-28

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, ground support technicians monitor the progress as the B and D truck sections of crawler-transporter 2, or CT-2, are being raised up to prepare for installation of new roller bearing assemblies. Sections of the crawler’s large metal tracks have been removed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  2. Crawler Bearing Replacement

    NASA Image and Video Library

    2014-02-28

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, a technician monitors the progress as the B and D truck sections of crawler-transporter 2, or CT-2, are raised up to prepare for installation of new roller bearing assemblies. Sections of the crawler’s large metal tracks have been removed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  3. Crawler Bearing Replacement

    NASA Image and Video Library

    2014-02-28

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, the B and D truck sections of crawler-transporter 2, or CT-2, are being raised up to prepare for installation of new roller bearing assemblies. Sections of the crawler’s large metal tracks have been removed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  4. Crawler Bearing Replacement

    NASA Image and Video Library

    2014-02-28

    CAPE CANAVERAL, Fla. – Inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, the B and D truck sections of crawler-transporter 2, or CT-2, have been raised up to prepare for installation of new roller bearing assemblies. Sections of the crawler’s large metal tracks have been removed. Work continues in high bay 2 to upgrade CT-2. The modifications are designed to ensure CT-2’s ability to transport launch vehicles currently in development, such as the agency’s Space Launch System, to the launch pad. The Ground Systems Development and Operations Program office at Kennedy is overseeing the upgrades. For more than 45 years the crawler-transporters were used to transport the mobile launcher platform and the Apollo-Saturn V rockets and, later, space shuttles to Launch Pads 39A and B. For more information, visit: http://www.nasa.gov/exploration/systems/ground/crawler-transporter. Photo credit: NASA/Dimitri Gerondidakis

  5. Tether Elevator Crawler Systems (TECS)

    NASA Technical Reports Server (NTRS)

    Swenson, Frank R.

    1987-01-01

    One of the needs of the experimenters on the space station is access to steady and controlled-variation microgravity environments. A method of providing these environments is to place the experiment on a tether attached to the space station. This provides a high degree of isolation from structural oscillations and vibrations. Crawlers can move these experiments along the tethers to preferred locations, much like an elevator. This report describes the motion control laws developed for these crawlers and the testing of laboratory models of these tether elevator crawlers.

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

    NASA Astrophysics Data System (ADS)

    Bertelsen, W. R.

    1987-06-01

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

  7. Pipe crawler with extendable legs

    DOEpatents

    Zollinger, William T.

    1992-01-01

    A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler.

  8. Pipe crawler with extendable legs

    DOEpatents

    Zollinger, W.T.

    1992-06-16

    A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs.

  9. [Vibration on agricultural tractors].

    PubMed

    Peretti, Alessandro; Delvecchio, Simone; Bonomini, Francesco; di Bisceglie, Anita Pasqua; Colosio, Claudio

    2013-01-01

    In the article, details related to the diffusion of agricultural tractors in Italy are given and considerations about the effects of vibration on operators, the sources of vibration and suggestions to reduce them are presented. The acceleration values observed in Italy amongst 244 tractors and levels of worker exposure are shown by means of histograms. The relevant data variability is discussed.

  10. Pipe crawler with stabilizing midsection

    DOEpatents

    Zollinger, W.T.; Treanor, R.C.

    1994-12-27

    A pipe crawler is described having a midsection that provides the stability and flexibility to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in ''inch worm'' fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting. 5 figures.

  11. Pipe crawler with stabilizing midsection

    DOEpatents

    Zollinger, William T.; Treanor, Richard C.

    1994-01-01

    A pipe crawler having a midsection that provides the stability and flexibty to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in "inch worm" fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting.

  12. H-Canyon Recovery Crawler

    SciTech Connect

    Kriikku, E. M.; Hera, K. R.; Marzolf, A. D.; Phillips, M. H.

    2015-08-01

    The Nuclear Material Disposition Project group asked the Savannah River National Lab (SRNL) Research and Development Engineering (R&DE) department to help procure, test, and deploy a remote crawler to recover the 2014 Inspection Crawler (IC) that tipped over in the H-Canyon Air Exhaust Tunnel. R&DE wrote a Procurement Specification for a Recovery Crawler (RC) and SRNS Procurement Department awarded the contract to Power Equipment Manufacturing Inc. (PEM). The PEM RC was based on their standard sewer inspection crawler with custom arms and forks added to the front. The arms and forks would be used to upright the 2014 Inspection Crawler. PEM delivered the RC and associated cable reel, 2014 Inspection Crawler mockup, and manuals in late April 2015. R&DE and the team tested the crawler in May of 2015 and made modifications based on test results and Savannah River Site (SRS) requirements. R&DE delivered the RC to H-Area at the end of May. The team deployed the RC on June 9, 10, and 11, 2015 in the H-Canyon Air Exhaust Tunnel. The RC struggled with some obstacles in the tunnel, but eventually made it to the IC. The team spent approximately five hours working to upright the IC and eventually got it on its wheels. The IC travelled approximately 20 feet and struggled to drive over debris on the air tunnel floor. Unfortunately the IC tripped over trying to pass this obstacle. The team decided to leave the IC in this location and inspect the tunnel with the RC. The RC passed the IC and inspected the tunnel as it travelled toward H-Canyon. The team turned the RC around when it was about 20 feet from the H-Canyon crossover tunnel. From that point, the team drove the RC past the manway towards the new sand filter and stopped approximately 20 feet from the new sand filter. The team removed the RC from the tunnel, decontaminated the RC, and stored it the manway building, 294-2H. The RC deployment confirmed the IC was not in a condition to perform useful tunnel inspections and

  13. Tractor & Machinery Safety. 1984 Revision.

    ERIC Educational Resources Information Center

    Montana State Office of Public Instruction, Helena. Dept. of Vocational Education Services.

    This curriculum guide is intended for use in teaching an instructional unit in tractor and machinery safety that is geared toward college freshmen. Addressed in the individual lessons of the unit are the following topics: understanding the importance of safe and efficient tractor operation, understanding the characteristics of tractors, preparing…

  14. Tractor Operation and Daily Care.

    ERIC Educational Resources Information Center

    Fore, J. M.; And Others

    Written for the tractor operator, the manual describes, with the aid of colored illustrations and diagrams, the tasks involved in the proper operation and daily maintenance of tractors. It offers explanations for the desirability of the various servicing and adjustment operations, as well as guidelines for tractor operation and safety. The…

  15. Acoustic Tractor Beam

    NASA Astrophysics Data System (ADS)

    Démoré, Christine E. M.; Dahl, Patrick M.; Yang, Zhengyi; Glynne-Jones, Peter; Melzer, Andreas; Cochran, Sandy; MacDonald, Michael P.; Spalding, Gabriel C.

    2014-05-01

    Negative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (>1 cm) to demonstrate the negative radiation forces and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to nonconservative forces, produced by redirection of a momentum flux from the angled sides of a target and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams and demonstrates continuous attraction towards the source, against a net momentum flux in the system.

  16. Acoustic tractor beam.

    PubMed

    Démoré, Christine E M; Dahl, Patrick M; Yang, Zhengyi; Glynne-Jones, Peter; Melzer, Andreas; Cochran, Sandy; MacDonald, Michael P; Spalding, Gabriel C

    2014-05-02

    Negative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (>1 cm) to demonstrate the negative radiation forces and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to nonconservative forces, produced by redirection of a momentum flux from the angled sides of a target and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams and demonstrates continuous attraction towards the source, against a net momentum flux in the system.

  17. Vegetable oils for tractors

    SciTech Connect

    Moroney, M.

    1981-11-14

    Preliminary tests by the Agricultural Institute, show that tractors can be run on a 50:50 rape oil-diesel mixture or on pure rape oil. In fact, engine power actually increased slightly with the 50:50 blend but decreased fractionally with pure rape oil. Research at the North Dakota State University on using sunflower oil as an alternative to diesel fuel is also noted.

  18. Crawler-Transporter Time-Lapse

    NASA Image and Video Library

    Time-lapse video shows crawler-transporter No. 2 traveling from the Vehicle Assembly Building to Launch Pad 39A at NASA's Kennedy Space Center in Florida. The move was performed by the Ground Syste...

  19. Seatbelt use during tractor overturns.

    PubMed

    Myers, M L; Cole, H P; Westneat, S C

    2006-02-01

    In 2002, the Kentucky Farm Tractor Overturn Survey was administered, in which 6,063 randomly selected farm operators responded to questions that addressed the presence and use of seatbelts in the event of a tractor overturn. Data were analyzed to determine the proportion of seatbelt presence and use on tractors that overturned differentiated by whether they were equipped or not equipped with a rollover protective structure (ROPS). In 537 overturns reported for which the ROPS status was known, 92 involved ROPS-equipped tractors, of which 60 had a functioning seatbelt, and 19 operators of these tractors used the seatbelt that was present during the overturn. However, of the 445 overturns of non-ROPS tractors, eight had a functioning seatbelt, and three of these operators wore the seatbelt. Two of the three operators that wore seatbelts on non-ROPS tractors suffered a permanent disability. In contrast, of the 19 operators who wore a seatbelt on ROPS-equipped tractors, 18 experienced no or minor injuries, and one required outpatient care. Seatbelts are known to save lives but are a secondary safety device to ROPS, for ROPS alone saves lives and is a necessary pre-condition for seatbelt presence and use.

  20. Tractor Safety. Unit A-9.

    ERIC Educational Resources Information Center

    Luft, Vernon D.; Backlund, Paul

    This document is a teacher's guide for a unit in tractor and machinery safety for college freshmen. It is intended to be used for 10 hours of instruction for freshmen who are intending to work on or around machinery. Safety hazards directly and indirectly related to many types of machinery are covered in addition to tractors. The objectives of the…

  1. Dynamic acoustic tractor beams

    SciTech Connect

    Mitri, F. G.

    2015-03-07

    Pulling a sphere and vibrating it around an equilibrium position by amplitude-modulation in the near-field of a single finite circular piston transducer is theoretically demonstrated. Conditions are found where a fluid hexane sphere (with arbitrary radius) chosen as an example, centered on the axis of progressive propagating waves and submerged in non-viscous water, experiences an attractive (steady) force pulling it towards the transducer, as well as an oscillatory force forcing it to vibrate back-and-forth. Numerical predictions for the dynamic force illustrate the theory and suggest an innovative method in designing dynamic acoustical tractor beams.

  2. Aerial view of the KSC crawler transporters

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In this aerial view the Crawler Transporter Maintenance Building (center) sits between two crawler transporters. The KSC crawlers are the largest tracked vehicles known. Once used to move assembled Apollo/Saturn from the VAB to the launch pad, they are now used for transporting Shuttle vehicles. They move the Mobile Launcher Platform into the Vehicle Assembly Building and then to the Launch Pad with an assembled space vehicle. Maximum speed is 1.6 km (one mile) per hour loaded, about 3.2 km (2 miles) per hour unloaded. Launch Pad to VAB trip time with the Mobile Launch Platform is about 5 hours. The crawler burns 568 liters (150 gallons) of diesel oil per mile. KSC's two crawlers have accumulated 1,243 miles since 1977. Including the Apollo years, the transporters have racked up 2,526 miles, about the same distance as a one-way trip from KSC to Los Angeles by interstate highway or a round trip between KSC and New York City.

  3. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05761, Marion Power Shovel Company, October 1963. CRAWLER TRUCK ASSEMBLY-FIELD WELDMENT SECTIONS & DETAILS. Sheet 4 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  4. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05761, Marion Power Shovel Company, October 1963. CRAWLER TRUCK ASSEMBLY-PLAN VIEW. Sheet 2 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  5. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05761, Marion Power Shovel Company, October 1963. CRAWLER TRUCK ASSEMBLY-SIDE VIEW. Sheet 3 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  6. MLP-1 on Crawler Transporter 2 (CT-2)

    NASA Image and Video Library

    2017-03-22

    NASA's upgraded crawler-transporter 2 (CT-2), carrying mobile launcher platform 1, moves slowly along the crawlerway toward the Vehicle Assembly Building at the agency's Kennedy Space Center in Florida. The crawler's upgrades and modifications were monitored and tested during a loaded test to the crawlerway Pad A/B split. CT-2 will return to the crawler yard. The crawler is being tested to confirm it is ready to support the load of the mobile launcher carrying the Space Launch System with Orion atop for the first test flight, Exploration Mission 1. The Ground Systems Development and Operations Program at Kennedy is managing upgrades to the crawler.

  7. Crawler transporter nears the Mobile Launch Platform

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The crawler transporter nears the Mobile Launch Platform and Space Shuttle Discovery to await possible orders for a rollback. KSC managers developed a precautionary plan to roll back Discovery to the Vehicle Assembly Building in the event that Hurricane Georges threatens Central Florida. The decision was made to minimize risk and provide protection to the Space Shuttle national asset

  8. Evaluation of farm tractor-related fatalities.

    PubMed

    Dogan, Kamil H; Demirci, Serafettin; Sunam, Guven S; Deniz, Idris; Gunaydin, Gursel

    2010-03-01

    Farm tractors are the major cause of occupational fatalities in agricultural regions. Fatalities typically result from being run over or crushed by the tractor, becoming entangled in the moving parts of the tractor, accidents on roadways, and tractor rollovers, which involve the tractor tipping sideways or backwards and crushing the operator. In this study, tractor-related fatalities in the Konya province of Turkey are retrospectively evaluated. Out of the 3940 cases on which a death examination and/or autopsy was performed between the years 2000 and 2007 at The Konya Branch of Forensic Medicine Council, 86 (2.2%) of the death cases were caused by tractor accidents and are included in this study. The ages of the victims varied between 3 and 80 years old with a mean age of 31.7 + or - 22.3. Sixty-eight (79.1%) of the cases involved males, while 18 (20.9%) of the cases involved females. In 32 (37.2%) of the cases, the deaths due to tractor accidents occurred when the tractor overturned. In 37 (43.0%) of the cases, the tractor-related fatalities involved the passengers and the drivers were involved in 34 (39.5%) of the cases. In conclusion, tractor accidents are preventable and deaths from tractor accidents can be significantly reduced if drivers are required to wear safety belts and helmets and frequent checks are implemented to enforce the ban on carrying passengers.

  9. ROPS deficiency of gray-market tractors.

    PubMed

    Myers, M L; Purschwitz, M A

    2012-04-01

    Many used tractors that are imported from Japan are adding to the current national inventory in the U.S. and Canada of farm tractors that lack a rollover protective structure (ROPS). Gray-market tractors are built for use by the manufacturer for a certain country but are imported against the manufacture's wishes to a second country for use there, usually as a used tractor. Gray-market tractors may lack ROPS and seatbelts, depending on the date of manufacturer. The objective of this investigation is to describe the gray market for tractors imported from Japan into the U.S. and the policy implications regarding the hazards associated with these imports. Operator manuals and warning labels are typically not written in English. Foreign manufacturers that market tractors in the U.S. have established a variety of disincentives for the importation of gray-market tractors, including issuing warnings, not servicing or providing parts for these tractors, and banning their importation through actions by the U.S. International Trade Commission. Nonetheless, a U.S. market has developed that imports and provides services and parts for gray-market tractors, and some companies provide certified ROPS on the tractors that they sell. A product safety perspective and related policies are presented as an approach to ensuring that these imports are equipped with ROPS and seatbelts.

  10. Space Shuttle Crawler Transporter Sound Attenuation Study

    NASA Technical Reports Server (NTRS)

    Margasahayam, Ravi N.; MacDonald, Rod; Faszer, Clifford

    2004-01-01

    The crawler transporter (CT) is the world's largest tracked vehicle known, weighing 6 million pounds with a length of 131 feet and a width of 113 feet. The Kennedy Space Center (KSC) has two CTs that were designed and built for the Apollo program in the 1960's, maintained and retrofitted for use in the Space Shuttle program. As a key element of the Space Shuttle ground systems, the crawler transports the entire 12-million-pound stack comprising the orbiter, the mobile launch platform (MLP), the external tank (ET), and the solid rocket boosters (SRB) from the Vehicle Assembly Building (VAB) to the launch pad. This rollout, constituting a 3.5-5.0-mile journey at a top speed of 0.9 miles-per-hour, requires over 8 hours to reach either Launch Complex 39A or B. This activity is only a prelude to the spectacle of sound and fury of the Space Shuttle launch to orbit in less than 10 minutes and traveling at orbital velocities of Mach 24. This paper summarizes preliminary results from the Crawler Transporter Sound Attenuation Study, encompassing test and engineering analysis of significant sound sources to measure and record full frequency spectrum and intensity of the various noise sources and to analyze the conditions of vibration. Additionally, data such as ventilation criteria, plus operational procedures were considered to provide a comprehensive noise suppression design for implementation. To date, sound attenuation study and results on Crawler 2 have shown significant noise reductions ranging from 5 to 24 dBA.

  11. Matter-Wave Tractor Beams

    NASA Astrophysics Data System (ADS)

    Gorlach, Alexey A.; Gorlach, Maxim A.; Lavrinenko, Andrei V.; Novitsky, Andrey

    2017-05-01

    Optical and acoustic tractor beams are currently the focus of intense research due to their counterintuitive property of exerting a pulling force on small scattering objects. In this Letter we propose a matter-wave tractor beam and utilize the de Broglie waves of nonrelativistic matter particles in analogy to "classical" tractor beams. We reveal the presence of the quantum-mechanical pulling force for the variety of quantum mechanical potentials observing the resonant enhancement of the pulling effect under the conditions of the suppressed scattering known as the Ramsauer-Townsend effect. We also derive the sufficient conditions on the scattering potential for the emergence of the pulling force and show that, in particular, a Coulomb scatterer is always shoved, while a Yukawa (screened Coulomb) scatterer can be drawn. Pulling forces in optics, acoustics, quantum mechanics, and classical mechanics are compared, and the matter-wave pulling force is found to have exclusive properties of dragging slow particles in short-range potentials. We envisage that the use of tractor beams could lead to the unprecedented precision in manipulation with atomic-scale quantum objects.

  12. Tractor Transmissions. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Agricultural Engineering and Vocational Agriculture, Athens, GA.

    The manual was developed as a reference for teaching students about transmissions in farm tractors. The manual is divided into five sections: (1) transmission history, (2) gears and bearings in transmission, (3) sliding-gear transmissions, (4) planetary gearing, and (5) glossary. The working principles of the sliding-gear transmission, the most…

  13. Matter-Wave Tractor Beams.

    PubMed

    Gorlach, Alexey A; Gorlach, Maxim A; Lavrinenko, Andrei V; Novitsky, Andrey

    2017-05-05

    Optical and acoustic tractor beams are currently the focus of intense research due to their counterintuitive property of exerting a pulling force on small scattering objects. In this Letter we propose a matter-wave tractor beam and utilize the de Broglie waves of nonrelativistic matter particles in analogy to "classical" tractor beams. We reveal the presence of the quantum-mechanical pulling force for the variety of quantum mechanical potentials observing the resonant enhancement of the pulling effect under the conditions of the suppressed scattering known as the Ramsauer-Townsend effect. We also derive the sufficient conditions on the scattering potential for the emergence of the pulling force and show that, in particular, a Coulomb scatterer is always shoved, while a Yukawa (screened Coulomb) scatterer can be drawn. Pulling forces in optics, acoustics, quantum mechanics, and classical mechanics are compared, and the matter-wave pulling force is found to have exclusive properties of dragging slow particles in short-range potentials. We envisage that the use of tractor beams could lead to the unprecedented precision in manipulation with atomic-scale quantum objects.

  14. MLP-1 on Crawler Transporter 2 (CT-2)

    NASA Image and Video Library

    2017-03-22

    NASA's upgraded crawler-transporter 2 (CT-2), carrying mobile launcher platform 1, moves slowly along the crawlerway at the agency's Kennedy Space Center in Florida. The crawler's upgrades and modifications will be monitored and tested under loaded conditions during its travel to the crawlerway Pad A/B split and back to the crawler yard to confirm it is ready to support the load of the mobile launcher carrying the Space Launch System with Orion atop for the first test flight, Exploration Mission 1. The Ground Systems Development and Operations Program at Kennedy is managing upgrades to the crawler.

  15. MLP-1 on Crawler Transporter 2 (CT-2)

    NASA Image and Video Library

    2017-03-22

    NASA's upgraded crawler-transporter 2 (CT-2) picks up mobile launcher platform 1 (MLP1) at the MLP park site near the Vehicle Assembly at the agency's Kennedy Space Center in Florida. The crawler's upgrades and modifications will be monitored and tested under loaded conditions during its travel to the crawlerway Pad A/B split and back to the crawler yard to confirm it is ready to support the load of the mobile launcher carrying the Space Launch System with Orion atop for the first test flight, Exploration Mission 1. The Ground Systems Development and Operations Program at Kennedy is managing upgrades to the crawler.

  16. MLP-1 on Crawler Transporter 2 (CT-2)

    NASA Image and Video Library

    2017-03-22

    NASA's upgraded crawler-transporter 2 (CT-2) travels slowly along the crawlerway, carrying the mobile launcher platform at the agency's Kennedy Space Center in Florida. The crawler's upgrades and modifications will be monitored and tested under loaded conditions during its travel to the crawlerway Pad A/B split and back to the crawler yard to confirm it is ready to support the load of the mobile launcher carrying the Space Launch System with Orion atop for the first test flight, Exploration Mission 1. The Ground Systems Development and Operations Program at Kennedy is managing upgrades to the crawler.

  17. MLP-1 on Crawler Transporter 2 (CT-2)

    NASA Image and Video Library

    2017-03-22

    During a load test of NASA's upgraded crawler-transporter 2 (CT-2), a ground support technician watches as the giant vehicle travels along the crawlerway at the agency’s Kennedy Space Center in Florida. The crawler's upgrades and modifications will be monitored and tested under loaded conditions during its travel to the crawlerway Pad A/B split and back to the crawler yard to confirm it is ready to support the load of the mobile launcher carrying the Space Launch System with Orion atop for the first test flight, Exploration Mission 1. The Ground Systems Development and Operations Program at Kennedy is managing upgrades to the crawler.

  18. MLP-1 on Crawler Transporter 2 (CT-2)

    NASA Image and Video Library

    2017-03-22

    Ground support technicians walk alongside NASA's upgraded crawler-transporter 2 (CT-2), carrying mobile launcher platform 1, as it slowly travels on the crawlerway at the agency's Kennedy Space Center in Florida. The crawler's upgrades and modifications will be monitored and tested under loaded conditions during its travel to the crawlerway Pad A/B split and back to the crawler yard to confirm it is ready to support the load of the mobile launcher carrying the Space Launch System with Orion atop for the first test flight, Exploration Mission 1. The Ground Systems Development and Operations Program at Kennedy is managing upgrades to the crawler.

  19. Microhole Drilling Tractor Technology Development

    SciTech Connect

    Western Well Tool

    2007-07-09

    In an effort to increase the U.S. energy reserves and lower costs for finding and retrieving oil, the USDOE created a solicitation to encourage industry to focus on means to operate in small diameter well-Microhole. Partially in response to this solicitation and because Western Well Tool's (WWT) corporate objective to develop small diameter coiled tubing drilling tractor, WWT responded to and was awarded a contract to design, prototype, shop test, and field demonstrate a Microhole Drilling Tractor (MDT). The benefit to the oil industry and the US consumer from the project is that with the MDT's ability to facilitate Coiled Tubing drilled wells to be 1000-3000 feet longer horizontally, US brown fields can be more efficiently exploited resulting in fewer wells, less environmental impact, greater and faster oil recovery, and lower drilling costs. Shortly after award of the contract, WWT was approached by a major oil company that strongly indicated that the specified size of a tractor of 3.0 inches diameter was inappropriate and that immediate applications for a 3.38-inch diameter tractor would substantially increase the usefulness of the tool to the oil industry. Based on this along with an understanding with the oil company to use the tractor in multiple field applications, WWT applied for and was granted a no-cost change-of-scope contract amendment to design, manufacture, assemble, shop test and field demonstrate a prototype a 3.38 inch diameter MDT. Utilizing existing WWT tractor technology and conforming to an industry developed specification for the tool, the Microhole Drilling Tractor was designed. Specific features of the MDT that increase it usefulness are: (1) Operation on differential pressure of the drilling fluid, (2) On-Off Capability, (3) Patented unique gripping elements (4) High strength and flexibility, (5) Compatibility to existing Coiled Tubing drilling equipment and operations. The ability to power the MDT with drilling fluid results in a highly

  20. Plane waves as tractor beams

    NASA Astrophysics Data System (ADS)

    Forgács, Péter; Lukács, Árpád; Romańczukiewicz, Tomasz

    2013-12-01

    It is shown that in a large class of systems, plane waves act as tractor beams: i.e., an incident plane wave can exert a pulling force on the scatterer. The underlying physical mechanism for the pulling force is due to the sufficiently strong scattering of the incoming wave into another mode carrying more momentum, in which case excess momentum is created behind the scatterer. This tractor beam or negative radiation pressure (NRP) effect, is found to be generic in systems with multiple scattering channels. In a birefringent medium, electromagnetic plane waves incident on a thin plate exert NRP of the same order of magnitude as optical radiation pressure, while in artificial dielectrics (metamaterials), the magnitude of NRP can even be macroscopic. In two dimensions, we study various scattering situations on vortices, and NRP is shown to occur by the scattering of heavy baryons into light leptons off cosmic strings, and by neutron scattering off vortices in the XY model.

  1. Optical tractor Bessel polarized beams

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.; Li, R. X.; Guo, L. X.; Ding, C. Y.

    2017-01-01

    Axial and transverse radiation force cross-sections of optical tractor Bessel polarized beams are theoretically investigated for a dielectric sphere with particular emphasis on the beam topological charge (or order), half-cone angle and polarization. The angular spectrum decomposition method (ASDM) is used to derive the non-paraxial electromagnetic (EM) field components of the Bessel beams. The multipole expansion method using vector spherical harmonics is utilized and appropriate beam-shape coefficients are derived in order to compute the radiation force cross-sections. The analysis has no limitation to a particular range of frequencies such that the Rayleigh, Mie or geometrical optics regimes can all be considered effectively using the present rigorous formalism. The focus of this investigation is to identify some of the tractor beam conditions so as to achieve retrograde motion of a dielectric sphere located arbitrarily in space. Numerical computations for the axial and transverse radiation force cross-sections are presented for linear, right-circular, radial, azimuthal and mixed polarizations of the individual plane waves forming the Bessel beams of zeroth- and first-order (with positive or negative helicity), respectively. As the sphere shifts off the beam's axis, the axial pulling (tractor) force is weakened. Moreover, the transverse radiation force cross-section field changes with the sphere's size factor ka (where k is the wavenumber and a is the sphere radius). Both stable and unstable equilibrium regions around the beam's axis are found, depending on the choice of ka and the half-cone angle α0. These results are particularly important in the development of emergent technologies for the photophoretic assembly of optically-engineered (meta)materials with designed properties using optical tractor (vortex) beams, particle manipulation, levitation and positioning, and other applications.

  2. Tractors, mass, and Weyl invariance

    NASA Astrophysics Data System (ADS)

    Gover, A. R.; Shaukat, A.; Waldron, A.

    2009-05-01

    Deser and Nepomechie established a relationship between masslessness and rigid conformal invariance by coupling to a background metric and demanding local Weyl invariance, a method which applies neither to massive theories nor theories which rely upon gauge invariances for masslessness. We extend this method to describe massive and gauge invariant theories using Weyl invariance. The key idea is to introduce a new scalar field which is constant when evaluated at the scale corresponding to the metric of physical interest. This technique relies on being able to efficiently construct Weyl invariant theories. This is achieved using tractor calculus—a mathematical machinery designed for the study of conformal geometry. From a physics standpoint, this amounts to arranging fields in multiplets with respect to the conformal group but with novel Weyl transformation laws. Our approach gives a mechanism for generating masses from Weyl weights. Breitenlohner-Freedman stability bounds for Anti-de Sitter theories arise naturally as do direct derivations of the novel Weyl invariant theories given by Deser and Nepomechie. In constant curvature spaces, partially massless theories—which rely on the interplay between mass and gauge invariance—are also generated by our method. Another simple consequence is conformal invariance of the maximal depth partially massless theories. Detailed examples for spins s⩽2 are given including tractor and component actions, on-shell and off-shell approaches and gauge invariances. For all spins s⩾2 we give tractor equations of motion unifying massive, massless, and partially massless theories.

  3. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 79K00088, John F. Kennedy Space Center, November 1969. SYS FUNCTIONAL DRAWING. Sheet 5 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  4. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05770, Marion Power Shovel Company, February 1964. OPERATOR'S CAB ASSY. Sheet 1 of 1 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  5. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05760, KSC-Launch Support Equipment Engineering Division, January 1967. GENERAL ARRANGEMENT. Sheet 1 of 4 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  6. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05762, Marion Power Shovel Company, December 1964. CHASSIS STRUCTURE ASSEMBLY. Sheet 2 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  7. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05760, Marion Power Shovel Company, January 1965. GENERAL ARRANGEMENT. Sheet 3 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  8. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 79K00088, John F. Kennedy Space Center, November 1969. SYS FUNCTIONAL DRAWING. Sheet 6 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  9. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 79K00081, John F. Kennedy Space Center, December 1969. SYS FUNCTIONAL DRAWING. Sheet 3 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  10. MLP-1 on Crawler Transporter 2 (CT-2)

    NASA Image and Video Library

    2017-03-22

    NASA’s upgraded crawler-transporter 2 (CT-2) travels slowly along the crawlerway carrying mobile launcher platform 1 at the agency’s Kennedy Space Center in Florida. The crawler's upgrades and modifications were being monitored and tested under loaded conditions during its travel to the Pad A/B split and back to the crawler yard to confirm it is ready to support the load of the mobile launcher carrying the Space Launch System with Orion atop for the first test flight, Exploration Mission 1. A truck sprays water in front of the crawler to control dust as the large vehicle moves along. The Ground Systems Development and Operations Program at Kennedy is managing upgrades to the crawler.

  11. Simplified overturn stability monitoring of agricultural tractors.

    PubMed

    Nichol, C I; Sommer, H J; Murphy, D J

    2005-02-01

    Agricultural tractors are the most common source of farm work fatalities in the U.S., with overturns the most common type of incident. For the year 2001, there were 15 tractor-related fatalities in Pennsylvania, 9 of which were due to tractor rollover. A new device using low-cost sensors and microcomputers was developed around a simplified mathematical model of an agricultural tractor to inform the operator of potential tractor instability. This device communicates the current rollover potential, along with a recent history of rollover potential, to the operator of the tractor via a simple bar-graph display. The device uses a single-chip accelerometer to sense the current rollover potential and a small microprocessor to analyze the accelerometer data, compensate for variations due to temperature, and then send this information to a visual display. The use of these low-cost "off the shelf" components enabled the fabrication of a very inexpensive sensor system. Because agricultural tractors have a long service life, it was important to make the device low cost and flexible. This could enable it to be sold as an aftermarket add-on for a variety of tractor models. The device is also capable of interfacing with newer on-board tractor systems via a CAN bus to make it more attractive to tractor manufacturers who may want to incorporate this device into new models. Work is continuing on the development of an improved display to inform the tractor operator of possible instability, including display ergonomic studies, investigation of threshold levels for alerting an operator of potential instability, and investigation into audible warning signals.

  12. Optimizing Crawler4j using MapReduce Programming Model

    NASA Astrophysics Data System (ADS)

    Siddesh, G. M.; Suresh, Kavya; Madhuri, K. Y.; Nijagal, Madhushree; Rakshitha, B. R.; Srinivasa, K. G.

    2017-06-01

    World wide web is a decentralized system that consists of a repository of information on the basis of web pages. These web pages act as a source of information or data in the present analytics world. Web crawlers are used for extracting useful information from web pages for different purposes. Firstly, it is used in web search engines where the web pages are indexed to form a corpus of information and allows the users to query on the web pages. Secondly, it is used for web archiving where the web pages are stored for later analysis phases. Thirdly, it can be used for web mining where the web pages are monitored for copyright purposes. The amount of information processed by the web crawler needs to be improved by using the capabilities of modern parallel processing technologies. In order to solve the problem of parallelism and the throughput of crawling this work proposes to optimize the Crawler4j using the Hadoop MapReduce programming model by parallelizing the processing of large input data. Crawler4j is a web crawler that retrieves useful information about the pages that it visits. The crawler Crawler4j coupled with data and computational parallelism of Hadoop MapReduce programming model improves the throughput and accuracy of web crawling. The experimental results demonstrate that the proposed solution achieves significant improvements with respect to performance and throughput. Hence the proposed approach intends to carve out a new methodology towards optimizing web crawling by achieving significant performance gain.

  13. Optimizing Crawler4j using MapReduce Programming Model

    NASA Astrophysics Data System (ADS)

    Siddesh, G. M.; Suresh, Kavya; Madhuri, K. Y.; Nijagal, Madhushree; Rakshitha, B. R.; Srinivasa, K. G.

    2016-08-01

    World wide web is a decentralized system that consists of a repository of information on the basis of web pages. These web pages act as a source of information or data in the present analytics world. Web crawlers are used for extracting useful information from web pages for different purposes. Firstly, it is used in web search engines where the web pages are indexed to form a corpus of information and allows the users to query on the web pages. Secondly, it is used for web archiving where the web pages are stored for later analysis phases. Thirdly, it can be used for web mining where the web pages are monitored for copyright purposes. The amount of information processed by the web crawler needs to be improved by using the capabilities of modern parallel processing technologies. In order to solve the problem of parallelism and the throughput of crawling this work proposes to optimize the Crawler4j using the Hadoop MapReduce programming model by parallelizing the processing of large input data. Crawler4j is a web crawler that retrieves useful information about the pages that it visits. The crawler Crawler4j coupled with data and computational parallelism of Hadoop MapReduce programming model improves the throughput and accuracy of web crawling. The experimental results demonstrate that the proposed solution achieves significant improvements with respect to performance and throughput. Hence the proposed approach intends to carve out a new methodology towards optimizing web crawling by achieving significant performance gain.

  14. How crawler track-mounted conveyors improve bulk handling's economics

    SciTech Connect

    Hawkins, G.P.

    1984-11-01

    Crawler track-mounted conveyors can be used in most applications formerly requiring stacking, reclaiming or movement from excavators to bench conveyors. The crawler track-mounted conveyor has been automated for push button operation and allows mobilization of in-pit operations for the movement of overburden, minerals and coal. In-pit mobilization of crushers, the use of mobilized steep angle conveyor for the removal of coal from the pit, and the movement of overburden from excavation to spoil can all be done more economically when a combination of a crawler track mounted conveyor is used in conjunction with a shiftable or fixed conveyor.

  15. Assessment of controls layout of Indian tractors.

    PubMed

    Kumar, Adarsh; Bhaskar, Gaikwad; Singh, J K

    2009-01-01

    Tractors in low-income countries are used both for farm and non-farm activities. Most of the tractors being manufactured in India are products of collaboration with other countries. The design of tractors manufactured in India has not changed much in the past five decades especially from an ergonomics point of view, because of economic considerations. This paper describes a tractor control layout assessment with respect to the Indian population and compares the location of controls with workspace envelopes and the IS12343 standard for commonly used tractors on Indian farms. Controls like steering, foot clutch, foot brake, foot accelerator are located in areas defined by IS12343 standard in some tractors but these are not placed in the workspace envelopes of the Indian population. This results in a mismatch between the workspace envelope and location of controls as defined by the standard. The controls need a complete change in their layout to be in the workspace envelopes, as this cannot be achieved by providing seat movement in the horizontal and vertical directions in the present tractor design.

  16. DETAIL VIEW OF CONNECTOR FOR MATING TO THE CRAWLER TRANSPORTER ...

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

    DETAIL VIEW OF CONNECTOR FOR MATING TO THE CRAWLER TRANSPORTER - Cape Canaveral Air Force Station, Launch Complex 39, Mobile Launcher Platforms, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  17. Improving tractor safety warnings: readability is missing.

    PubMed

    Tebeaux, E

    2010-07-01

    Research on tractor safety has not focused on user manuals. This study focuses on tractor operator manuals, specifically safety warnings, selected from the files of the Tractor Test facility at University of Nebraska-Lincoln. Analysis of many common warnings, based on readability and legibility research, shows that many warnings contain excessive information, confusing visuals and safety icons, poor document design, and illegible typefaces. The result is unreadable warnings that do not communicate quickly and correctly, and discourage readers rather than clarify critical information. Many tractor operator warnings are cluttered, "over-written," and contain information needed to protect the manufacturer rather than to inform operators. What is needed is a careful analysis and revision of many safety warnings with the goal of encouraging operators to read the warnings and follow their message.

  18. Keys to Successful Tractor Maintenance Units.

    ERIC Educational Resources Information Center

    Doerr, William A.

    1979-01-01

    To prevent problems with teaching plans, supplement class instruction, and stimulate use of the operator's manual, the teacher can use a series of leaflets. The first leaflet describes the activities and what is expected of the tractor operator's manual. (LRA)

  19. Making 'Tractor Beams' a Reality (Eventually)

    NASA Image and Video Library

    Tractor beams -- the ability to trap and move objects using laser light -- are the stuff of science fiction, but a team of NASA scientists has won funding to study the concept for remotely capturin...

  20. Liquid crystal elastomer strips as soft crawlers

    NASA Astrophysics Data System (ADS)

    DeSimone, Antonio; Gidoni, Paolo; Noselli, Giovanni

    2015-11-01

    In this paper, we speculate on a possible application of Liquid Crystal Elastomers to the field of soft robotics. In particular, we study a concept for limbless locomotion that is amenable to miniaturisation. For this purpose, we formulate and solve the evolution equations for a strip of nematic elastomer, subject to directional frictional interactions with a flat solid substrate, and cyclically actuated by a spatially uniform, time-periodic stimulus (e.g., temperature change). The presence of frictional forces that are sensitive to the direction of sliding transforms reciprocal, 'breathing-like' deformations into directed forward motion. We derive formulas quantifying this motion in the case of distributed friction, by solving a differential inclusion for the displacement field. The simpler case of concentrated frictional interactions at the two ends of the strip is also solved, in order to provide a benchmark to compare the continuously distributed case with a finite-dimensional benchmark. We also provide explicit formulas for the axial force along the crawler body.

  1. Tractors and rollover protection in the United States.

    PubMed

    Murphy, Dennis J; Myers, John; McKenzie, E A; Cavaletto, Richard; May, John; Sorensen, Julie

    2010-07-01

    There are approximately 4.2 million tractors on farms and ranches across the United States. The average age of tractors is over 25 years and some of the oldest models are the most popular. Older tractors are less safe than newer tractors, and many older tractors are operated by individuals with increased risk of being injured or killed on a tractor. A key tractor safety device, a rollover protective structure (ROPS), is missing from most tractors manufactured before 1985. Data from the US Department of Labor's Census of Fatal Occupational Injuries (CFOI) suggest that the production agriculture sector accounts for approximately 70.3% of the 3299 work deaths in the Agriculture, Forestry, and Fishing industry between 2003 and 2007. Nearly 900 of these incidents involve farm tractors and of these, approximately 43% were from tractor overturns. Efforts to reduce both the number of tractor overturn fatalities and injuries have been underway for years. These efforts primarily encompass worker education/training programs and activities, ROPS design and engineering applications, and research on more effective ways of encouraging tractor owners to retrofit their older tractors with ROPS. This paper reviews various approaches available to reduce the fatalities, serious injuries, and economic burden associated with tractor overturns. Past and current efforts to promote ROPS in the United States and in other countries, current safe tractor operations education and training programs, and ROPS-related safety engineering projects are discussed. Recommendations for advancing safe tractor operation and the number of tractors protected by ROPS are given. This review was prepared for the Agricultural Safety and Health Council of America/National Institute for Occupational Safety and Health conference, "Be Safe, Be Profitable: Protecting Workers in Agriculture," January 2010.

  2. INNOVATIVE ELECTROMAGNETIC SENSORS FOR PIPELINE CRAWLERS

    SciTech Connect

    J. Bruce Nestleroth

    2004-11-05

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they encounter. Recent development efforts include a new generation of powered inspection platforms that crawl slowly inside a pipeline and are able to maneuver past the physical barriers that can limit inspection. At Battelle, innovative electromagnetic sensors are being designed and tested for these new pipeline crawlers. The various sensor types can be used to assess a wide range of pipeline anomalies including corrosion, mechanical damage, and cracks. The Applied Energy Systems Group at Battelle is concluding the first year of work on a projected three-year development effort. In this first year, two innovative electromagnetic inspection technologies were designed and tested. Both were based on moving high-strength permanent magnets to generate inspection energy. One system involved translating permanent magnets towards the pipe. A pulse of electric current would be induced in the pipe to oppose the magnetization according to Lenz's Law. The decay of this pulse would indicate the presence of defects in the pipe wall. This inspection method is similar to pulsed eddy current inspection methods, with the fundamental difference being the manner in which the current is generated. Details of this development effort were reported in the first semiannual report on this project. This second semiannual report focuses on the development of a second inspection methodology, based on rotating permanent magnets. During this period, a rotating permanent magnet exciter was designed and built. The exciter unit produces strong eddy currents in the pipe wall. The tests have shown that at distances of a pipe diameter or more, the currents flow circumferentially, and that these circumferential

  3. North and east elevations of tractor shed facing southwest ...

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

    North and east elevations of tractor shed facing southwest - Norris Farm, Tractor Shed-Combine Barn, .5 mile west of County Road 857 & .25 mile east of County Road 88/1, Cheat Neck, Monongalia County, WV

  4. South and west elevations of tractor shed facing northeast ...

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

    South and west elevations of tractor shed facing northeast - Norris Farm, Tractor Shed-Combine Barn, .5 mile west of County Road 857 & .25 mile east of County Road 88/1, Cheat Neck, Monongalia County, WV

  5. Lube rack of Automotive and Tractor Repair Shops with Warehousefield ...

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

    Lube rack of Automotive and Tractor Repair Shops with Warehouse-field Equipment Repair Shop Building's wall to the right, looking from the south - Kekaha Sugar Company, Automotive and Tractor Repair Shops, 8315 Kekaha Road, Kekaha, Kauai County, HI

  6. View of south elevation of Automotive and Tractor Repair Shops ...

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

    View of south elevation of Automotive and Tractor Repair Shops with the Warehouse Fabrication Shop and Stack in the background, looking from the southwest - Kekaha Sugar Company, Automotive and Tractor Repair Shops, 8315 Kekaha Road, Kekaha, Kauai County, HI

  7. Miniature Tractor Pull Helps Teach Mechanical Power Transmission.

    ERIC Educational Resources Information Center

    Waggoner, Todd C.

    1996-01-01

    A miniature tractor pull was developed as a high school activity, enabling students to assess a tractor's pulling capabilities and determine subsequent horsepower. The activity takes the textbook concept of horsepower and makes it come alive. (JOW)

  8. Tractor Mechanics: Learning Activity Packages 1-19.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    Learning activity packages are presented for teaching tractor mechanics. The first of two sections deals with miscellaneous tasks and contains learning activity packages on cleaning the tractor and receiving new tractor parts. Section 2 is concerned with maintaining and servicing the electrical system, and it includes the following learning…

  9. 30 CFR 77.409 - Shovels, draglines, and tractors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shovels, draglines, and tractors. 77.409... COAL MINES Safeguards for Mechanical Equipment § 77.409 Shovels, draglines, and tractors. (a) Shovels, draglines, and tractors shall not be operated in the presence of any person exposed to a hazard from...

  10. Tractor Mechanic--Teacher's Guide. Competency Based Education Curriculum.

    ERIC Educational Resources Information Center

    McCann, Edward W.

    This teacher's guide is designed to accompany the Tractor Mechanic Competency Based Education (CBE) Curriculum (CE 022 480). The following information is included: a discussion of the uses of the Tractor Mechanic CBE curriculum; definitions of related terms; the table of contents for the Tractor Mechanic CBE curriculum; a list of competencies by…

  11. Effectiveness of the Indiana 4-H Tractor Program: Alumni Perceptions.

    ERIC Educational Resources Information Center

    Carrabba, James J., Jr.; Talbert, B. Allen; Field, William E.; Tormoehlen, Roger

    2001-01-01

    Responses from Indiana 4-H tractor driving contestants 1982-197 (n=139) showed that 74% were employed on farms; most felt the contests effectively taught tractor safety and made them generally aware of safety. However, many still engaged in risky behaviors such as not wearing seatbelts in tractors with rollover protective structures or allowing…

  12. Tractor Mechanics: Learning Activity Packages 1-19.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    Learning activity packages are presented for teaching tractor mechanics. The first of two sections deals with miscellaneous tasks and contains learning activity packages on cleaning the tractor and receiving new tractor parts. Section 2 is concerned with maintaining and servicing the electrical system, and it includes the following learning…

  13. Massive higher spins from BRST and tractors

    NASA Astrophysics Data System (ADS)

    Grigoriev, Maxim; Waldron, Andrew

    2011-12-01

    We obtain the higher spin tractor equations of motion conjectured by Gover et al. from a BRST approach and use those methods to prove that they describe massive, partially massless and massless higher spins in conformally flat backgrounds. The tractor description makes invariance under local choices of unit systems manifest. In this approach, physical models are described by conformal, rather than (pseudo-)Riemannian geometry. In particular masses become geometric quantities, namely the weights of tractor fields. Massive models can therefore be handled in a unified and simple manner mimicking the gauge principle usually employed for massless models. From a holographic viewpoint, these models describe both the bulk and boundary theories in terms of conformal geometry. This is an important advance, because tying the boundary conformal structure to that of the bulk theory gives greater control over a bulk-boundary correspondence.

  14. Evaluation of mechanical tractor pedal extensions.

    PubMed

    Kelso, S A; Stangherlin, A M; Mann, D D

    2008-10-01

    Many farmers with disabilities choose to modify their work environments to accommodate their personal abilities; however, modified tractors may present greater risk to the operator as they are often one-of-a-kind designs that have not been subjected to rigorous safety testing. The objective of this research was to evaluate mechanical tractor pedal , extensions from a safety perspective. This objective was achieved by identifying potential hazards associated with the introduction of a pedal extension into the cab environment so that both existing and novel designs could be compared using a common methodology. Based on review of the published literature, 19 potential hazards associated with the introduction of a pedal extension into the cab of a tractor were identified. A hazard self-assessment worksheet (HSAW), created based on the 19 hazards, was validated through a pilot study. The overall inter-rater reliability and concurrent criterion validity proved to be acceptable. With the use of the HSAW six pedal extensions (three existing designs and three novel designs) were evaluated by 14 experts. Statistical analysis of the results did not identify a "best" design; however, several important trends were observed. Four of the six designs tended to block access to the exit path. The two designs that did not block access to the exit path might be considered to be the best designs for the tractors used in this study, but other designs likely would have been acceptable if they had been custom-fit for these tractors. The results of this research suggest that custom fabrication of pedal extensions for each specific tractor will likely yield the safest work environment for those who choose to use this assistive technology.

  15. Workmen and Crawler Crane pouring roof slab and parapet wall ...

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

    Workmen and Crawler Crane pouring roof slab and parapet wall of building - looking northwest. Taken Nov. 15, 1929. 14th Naval District Photo Collection Item No. 7165 - U.S. Naval Base, Pearl Harbor, Exterior Cranes, Waterfront Crane Track System, Pearl City, Honolulu County, HI

  16. The Organization of Wariness of Heights in Experienced Crawlers

    ERIC Educational Resources Information Center

    Ueno, Mika; Uchiyama, Ichiro; Campos, Joseph J.; Dahl, Audun; Anderson, David I.

    2012-01-01

    Most infants with more than 6 weeks of crawling experience completely avoid the deep side of a visual cliff (Campos, Bertenthal, & Kermoian, 1992; Gibson & Walk, 1960). However, some experienced crawlers do move onto the transparent surface suspended several feet above the ground. An important question is whether these "nonavoiders" lack wariness…

  17. The Organization of Wariness of Heights in Experienced Crawlers

    ERIC Educational Resources Information Center

    Ueno, Mika; Uchiyama, Ichiro; Campos, Joseph J.; Dahl, Audun; Anderson, David I.

    2012-01-01

    Most infants with more than 6 weeks of crawling experience completely avoid the deep side of a visual cliff (Campos, Bertenthal, & Kermoian, 1992; Gibson & Walk, 1960). However, some experienced crawlers do move onto the transparent surface suspended several feet above the ground. An important question is whether these "nonavoiders" lack wariness…

  18. Herbaceous Weed Control Trials with a Planting Machine Sprayer and a Crawler-Tractor Sprayer--Fourth Year Pine Response.

    Treesearch

    James Miller

    1990-01-01

    Operational trials of herbaceous weed control treatments by machine application were studied at two southern alabama locations for establishing loblolly pine (Pinus taeda). The first study tested the feasibility of a spray attachment for planting machines to apply banded treatments while planting in February and March. Two rates of sulfometuron (Oust...

  19. INNOVATIVE ELECTROMAGNETIC SENSORS FOR PIPELINE CRAWLERS

    SciTech Connect

    J. Bruce Nestleroth; Richard J. Davis

    2005-05-23

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they encounter. Recent development efforts include a new generation of powered inspection platforms that crawl slowly inside a pipeline and are able to maneuver past the physical barriers that can limit inspection. At Battelle, innovative electromagnetic sensors are being designed and tested for these new pipeline crawlers. The various sensor types can be used to assess a wide range of pipeline anomalies including corrosion, mechanical damage, and cracks. The Applied Energy Systems Group at Battelle is in the second year of work on a projected three-year development effort. In the first year, two innovative electromagnetic inspection technologies were designed and tested. Both were based on moving high-strength permanent magnets to generate inspection energy. One system involved translating permanent magnets towards the pipe. A pulse of electric current would be induced in the pipe to oppose the magnetization according to Lenz's Law. The decay of this pulse would indicate the presence of defects in the pipe wall. This inspection method is similar to pulsed eddy current inspection methods, with the fundamental difference being the manner in which the current is generated. Details of this development effort were reported in the first semiannual report on this project. The second inspection methodology is based on rotating permanent magnets. The rotating exciter unit produces strong eddy currents in the pipe wall. At distances of a pipe diameter or more from the rotating exciter, the currents flow circumferentially. These circumferential currents are deflected by pipeline defects such as corrosion and axially aligned cracks. Simple sensors are used to detect the change in current

  20. Sonic tractor beam costs less than 90

    NASA Astrophysics Data System (ADS)

    2017-02-01

    A single-sided sonic tractor beam that can levitate objects without the need for complex phase-shifting electronics has been developed by researchers in the UK, who say that it can be made for less than 90 with readily available components and a 3D printer.

  1. Plans for Learning Stations. Tractor Mechanics.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This shop guide gives graphic illustration of twenty-eight learning stations in a tractor mechanics shop, at each of which a specific learning activity occurs. The authors suggest that each station (most of them constructed of plywood or sheet metal and angle iron) be self-contained, having its own appropriate tools, supplies, parts, and set of…

  2. Extra-safe tractor-trailer coupling

    NASA Technical Reports Server (NTRS)

    Albrecht, W. P.; Sparks, R. H.

    1979-01-01

    Built-in safety mechanism for tractor-trailer "fifth-wheel" coupling keeps rig together in case kingpin failure. Modified coupling utilizes all standard components, such as two wear plates, kingpin, and kingpin latch. It is modified by adding semicircular lip to top wear plate, matching semicircular slot to bottom wear plate, and two latching stop mechanisms.

  3. The Tractor Electrical System. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Vocational Instructional Materials, Athens, GA.

    The fundamental principles underlying the application of electricity to tractors and farm equipment are presented. An understanding of the material in the basic manual will enable the service man to understand better the service procedures covered in service manuals on electrical equipment. Topics dealt with are fundamentals of electricity,…

  4. Polyhedron tracking and gravity tractor asteroid deflection

    NASA Astrophysics Data System (ADS)

    Ummen, N.; Lappas, V.

    2014-11-01

    In the wake of the Chelyabinsk airburst, the defense against hazardous asteroids is becoming a topic of high interest. This work improves the gravity tractor asteroid deflection approach by tracking realistic small body shapes with tilted ion engines. An algorithm for polyhedron tracking was evaluated in a fictitious impact scenario. The simulations suggest a capability increase up to 38.2% with such improved tilting strategies. The long- and short-term effects within polyhedron tracking are illustrated. In particular, the orbital reorientation effect is influential when realistic asteroid shapes and rotations are accounted for. Also analyzed is the subject of altitude profiles, a way to tailor the gravity tractor performance, and to achieve a steering ability within the B-plane. A novel analytical solution for the classic gravity tractor is derived. It removes the simulation need for classic tractor designs to obtain comparable two body model Δv figures. This paper corroborates that the asteroid shape can be exploited for maximum performance. Even a single engine tilt adjustment at the beginning of deflection operations yields more deflection than a fixed preset tilt.

  5. Goods handling: tugs, trailers and tractors.

    PubMed

    Grayson, H

    1980-09-26

    Ease of handling ought to be a priority in any supply and disposal system. Hazel Grayson, senior research officer at the Medical Architecture Research Unit, Polytechnic of North London, suggests that even where driver-operated electric tow tractors cannot be used, other types of electric pulling device should be considered.

  6. Plans for Learning Stations. Tractor Mechanics.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This shop guide gives graphic illustration of twenty-eight learning stations in a tractor mechanics shop, at each of which a specific learning activity occurs. The authors suggest that each station (most of them constructed of plywood or sheet metal and angle iron) be self-contained, having its own appropriate tools, supplies, parts, and set of…

  7. V-TECS Guide for Tractor Mechanic.

    ERIC Educational Resources Information Center

    Benson, Robert T.

    This guide contains a course outline for a tractor mechanic course. The outline is organized by 15 duties: performing general skills and maintaining and servicing storage battery, ignition circuit, the cooling system, the charging circuit, the starting circuit, gasoline fuel system, diesel fuel system, basic engine, lubrication system, clutches,…

  8. Tractor Mechanic Check Sheets for Modules.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    Forms for student self-checks and the instructor's final checklist (student evaluation) are provided for use with thirty-three learning modules on maintaining and servicing fuel and electrical systems in tractor mechanics. The student self-check asks the students questions about their understanding of the modules' content. The instructor's…

  9. Tractor Trailer Driver's Training Programs. Performance Report.

    ERIC Educational Resources Information Center

    New Hampshire Vocational Technical Coll., Nashua.

    This document describes a project to develop a 320-hour tractor trailer driver training program and a 20-hour commercial driver licensing upgrade training program. Of 34 graduates from the training program, 28 secured employment in the trucking industry. From August 1989 to June 1990, 725 students were trained in the upgrade training program with…

  10. Large Crawler Crane for new lightning protection system

    NASA Image and Video Library

    2007-10-25

    A large crawler crane moves past the Vehicle Assembly Building on its way to Launch Pad 39B. The crane with its 70-foot boom will be used to construct a new lightning protection system for the Constellation Program and Ares/Orion launches. Pad B will be the site of the first Ares vehicle launch, including Ares I-X which is scheduled for April 2009.

  11. Large Crawler Crane for new lightning protection system

    NASA Image and Video Library

    2007-10-25

    A large crawler crane travels along one of the crawlerway tracks on its way to Launch Pad 39B. The crane with its 70-foot boom will be used to construct a new lightning protection system for the Constellation Program and Ares/Orion launches. Pad B will be the site of the first Ares vehicle launch, including Ares I-X which is scheduled for April 2009.

  12. Large Crawler Crane for new lightning protection system

    NASA Image and Video Library

    2007-10-25

    A large crawler crane arrives at the turn basin at the Launch Complex 39 Area on NASA's Kennedy Space Center. The crane with its 70-foot boom will be moved to Launch Pad 39B and used to construct a new lightning protection system for the Constellation Program and Ares/Orion launches. Pad B will be the site of the first Ares vehicle launch, including Ares I-X which is scheduled for April 2009.

  13. Large Crawler Crane for new lightning protection system

    NASA Image and Video Library

    2007-10-25

    A large crawler crane begins moving away from the turn basin at the Launch Complex 39 Area on NASA's Kennedy Space Center. The crane with its 70-foot boom will be moved to Launch Pad 39B and used to construct a new lightning protection system for the Constellation Program and Ares/Orion launches. Pad B will be the site of the first Ares vehicle launch, including Ares I-X which is scheduled for April 2009.

  14. Large Crawler Crane for new lightning protection system

    NASA Image and Video Library

    2007-10-25

    A large crawler crane traveling long one of the crawlerway tracks makes the turn toward Launch Pad 39B. The crane with its 70-foot boom will be used to construct a new lightning protection system for the Constellation Program and Ares/Orion launches. Pad B will be the site of the first Ares vehicle launch, including Ares I-X which is scheduled for April 2009.

  15. ROBOTIC CRAWLER PROVIDES RADIOLOGICAL PROTECTION IN HAZARDOUS ENVIRONMENT

    SciTech Connect

    HAM, J.E.

    2002-01-31

    A robotic crawler was deployed into the process cells at the 224-T Building to perform cell characterization. The most significant hazard was the potential for criticality upon introduction of a moderating material. Due to the unknown fissile inventory in the cells and the potential moderation affects of a person, manned entry was considered too high of a risk, and a robotic crawler was determined to be the best option for the initial characterization. The robotic crawler provided maneuverability, allowing access to areas in the cells where debris was found. It provided visual inspection in areas with little light, using a low lux pan and tilt camera system. Also, it provided fissile inventory measurements using a non-destructive assay (NDA) detector. The NDA detector supplied real-time data to maintain criticality control. Other technologies used during the cell characterization were water-cooled suits and a thin water resistant synthetic anti-contamination coverall, used for heat stress reduction. Also, an aluminum framed shelter provided a weather barrier, allowing work to continue under conditions which would have stopped work without it.

  16. Tractor beam in micro-scale

    NASA Astrophysics Data System (ADS)

    Brzobohatý, O.; Karásek, V.; Šiler, M.; Chvátal, L.; Čižmár, T.; Zemánek, P.

    2014-12-01

    Following the Keplerian idea of radiative forces one would intuitively expect that an object illuminated by sunlight radiation or a laser beam is accelerated along the direction of the photon flow. Such radiation pressure forms the basis for the concept of solar sail, or laser acceleration of micro-particles. In contrast, a hypothetical optical field known from the realm of science-fiction as the "tractor" beam attracts the matter from large distances against the beam propagation. We present a geometry of such"tractor" beam in micro-scale and experimentally demonstrate how it acts upon spherical micro-particles of various sizes or optically self-arranged structures of micro-particles.

  17. A stochastic analysis of tractor overturn costs on catfish farms.

    PubMed

    Ibendahl, G A; Stephens, W B; Myers, M L

    2012-10-01

    An area of health and safety risk in agriculture that can be especially dangerous is catfish farming. One of the potential sources of injuries on catfish farms is tractor overturns that often result in crushing injuries. There is likely a higher probability of tractor overturns on a catfish farm than on a traditional crop farm due to the conditions that prevail on catfish farms. A catfish farm requires tractor movement near pond levees and water, and these levees have steep banks. Many of the activities on a catfish farm, such as mowing, feeding, and pond maintenance, require operating a tractor near a pond levee. Rollover protection structures (ROPS) on tractors can help to minimize the injuries caused by tractor overturns. ROPS do not lessen the probability of overturns, but ROPS mitigate the expected injury severity and lower the associated costs of an overturn. Despite the benefits of ROPS, not every tractor is so equipped. Some earlier work indicated that the cost to retrofit older tractors might outweigh the expected benefits. This article uses stochastic (i.e., randomly determined) analysis to determine if risk-averse farmers are more likely than risk-neutral farmers to retrofit tractors with ROPS. For this analysis, a distribution function of injury costs should an overturn occur was developed for both ROPS and non-ROPS tractors, and a Monte Carlo simulation was conducted. Results indicate that many risk-averse producers would be willing to retrofit older tractors with ROPS. However producers who are risk-neutral probably will not retrofit. These results might explain why not all tractors have been retrofitted despite the long-term availability of retrofit kits.

  18. Potential exposure to hazardous work activities: tractor usage among farmwomen.

    PubMed

    Carruth, Ann K; Skarke, Lana; Gilmore, Karen; Brown, Elizabeth R

    2006-01-01

    Farmwomen are often an unacknowledged workforce, leading to a lack of targeted safety interventions. This study examined the involvement and work patterns of 665 women in Texas and 657 women in Louisiana who were 18 years old and older and whose family participated in farming operations. Surveys were used to gather specific data regarding tractor work patterns, tractor knowledge, sources of information about tractors, and demographic information in two southern states in which cattle and dairy were the major agricultural commodity. Among the sample of 1,322 women, 577 (43.6%) reported driving tractors at least one day a year. This subset was used to describe characteristics of tractors and tractor-related activities. Findings indicate that women learn to drive tractors in their 20s, use husbands as the primary source of their information about tractors, engage in a wide variety of farm activities including bush-hogging and plowing, and acknowledge knowing an average or less than an average amount about driving tractors. Women most often reported driving between 1 to 12 days/year (n = 321, 55.6%). When examining patterns of ROPS-equipped tractor use, women were 1.47 times more likely to drive a tractor without ROPS or enclosed when driving less than 12 days a year as opposed to 13-103 days/year or greater than 104 days/year. The results of this study support the need for health care professionals and safety specialists to design appropriate interventions that target women to become more knowledgeable regarding the injury risks associated with farm work while driving tractors.

  19. Ability of youth operators to reach farm tractor controls.

    PubMed

    Fathallah, F A; Chang, J H; Pickett, W; Marlenga, B

    2009-06-01

    Farm tractor work is commonly assigned to young people on North American farms, where tractors account for the majority of deaths and major portions of non-fatal trauma to working youths. However, little is known about the potential mismatch between the anthropometric and physical characteristics of children and tractor characteristics. The purpose of this study was to evaluate the ability of children of varying ages and percentiles to reach major controls on 45 tractors in common use in the US. The main study finding was that many tractor controls, especially those that are hand-operated, may not be effectively reached by the majority of youth operators aged 12 to 16 years. The study raises further serious questions about the ability of children to safely operate tractors in common use on US farms and calls for reconsideration of age guidelines for the assignment of children to tractor work on farms. This study provides novel ergonomic evidence about the ability of children to reach controls inside agricultural tractor cabins. The approach could be applied in similar situations where youths may operate other vehicles or machines. Study findings support the establishment and refinement of policies and guidelines related to youth tractor operation.

  20. Agricultural Tractor Safety on Public Roads and Farms.

    ERIC Educational Resources Information Center

    Department of Transportation, Washington, DC.

    This study investigated the extent, causes, and means of preventing agricultural tractor accidents. The report includes an estimate of annual tractor-related deaths, an identification of the primary causes of such accidents with consideration of the major hazards causing death or injury, and recommendations or means for preventing the occurrence…

  1. Single wheel testers, single track testers, and instrumented tractors

    USDA-ARS?s Scientific Manuscript database

    Single wheel testers and single track testers are used for determining tractive performance characteristics of tires and tracks. Instrumented tractors are useful in determining the tractive performance of tractors. These machines are also used for determining soil-tire and soil-track interactions,...

  2. Protecting young workers in agriculture: participation in tractor certification training.

    PubMed

    Heaney, C A; Wilkins, J R; Dellinger, W; McGonigle, H; Elliott, M; Bean, T L; Jepsen, S D

    2006-08-01

    Tractor-related injuries among youth are an important public health problem. The major objectives of this study were to (1) provide a rigorous estimate of the number of youth operating tractors in Ohio and (2) assess the extent to which these youth are participating in federally mandated tractor safety training. A self-administered questionnaire was completed by approximately 4,000 students ages 14 or 15 years who were enrolled in a stratified cluster sample of 99 Ohio schools. Almost one-third of the youth (30%) reported having operated tractors, with 19% having operated a tractor on a farm not owned by a parent or guardian. More than half of the youth (52%) reported having operated a tractor and/or other hazardous machinery, with 25% having operated the machinery on a farm not owned or operated by a parent or guardian. Extrapolating from 4-H records and Ohio census data, fewer than 1% of the youth who are operating tractors or other hazardous machinery have participated in tractor certification training. Increasing participation in mandated training may be an important step in protecting the health of our nation's young agricultural workers.

  3. Development of a small high-thrust tractor rocket motor

    SciTech Connect

    Carr, C.E.; Oberlander, W.F.

    1986-01-01

    This paper summarizes the parachute extraction tractor rocket motor design and test efforts conducted during the Sandia ASW/SOW development program. The prime contractor was Sandia National Laboratories, Albuquerque, New Mexico; the tractor rocket motor subcontractor was Morton Thiokol, Inc., Elkton, Maryland.

  4. Farm Tractor Tune-Up and Service Specifications.

    ERIC Educational Resources Information Center

    Bryant, J. G.; And Others

    Tune-up and service specifications for 10 major tractor manufacturers are presented in the handbook. In addition, the following tables are included: (1) spark plug heat-range comparisons, (2) freezing protection, (3) pressures for farm tractor tires, (4) use of calcium chloride for liquid weighting, (5) comparisons of American Petroleum Institute…

  5. Farm Tractor Tune-Up and Service Specifications.

    ERIC Educational Resources Information Center

    Bryant, J. G.; And Others

    Tune-up and service specifications for 10 major tractor manufacturers are presented in the handbook. In addition, the following tables are included: (1) spark plug heat-range comparisons, (2) freezing protection, (3) pressures for farm tractor tires, (4) use of calcium chloride for liquid weighting, (5) comparisons of American Petroleum Institute…

  6. 40 CFR 1037.630 - Special purpose tractors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Special purpose tractors. 1037.630 Section 1037.630 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION... tractors intended for intra-city pickup and delivery, such as those that deliver bottled beverages...

  7. Injury severity related to overturn characteristics of tractors.

    PubMed

    Myers, Melvin L; Cole, Henry P; Westneat, Susan C

    2009-01-01

    Early studies of injuries associated with overturns indicate that more fatalities occurred when a tractor overturned beyond 90 degrees (continuous roll) relative to the impact plane. Recently, the principle of preventing continuous rolls has re-emerged for the protection of riding lawnmower operators. Related to tractors, a population-based study was conducted that compared the severity of fatal and nonfatal injuries between a 90 degrees and continuous roll for tractors equipped with rollover protective structures (ROPS) and not equipped with a ROPS (non- ROPS). In 2002, the Kentucky Farm Tractor Overturn Survey was administered to an 8% random sample (6,063) of Kentucky farm operators. The farmers responded to questions that differentiated between the types of overturns and operator injury outcomes for ROPS-equipped and non-ROPS tractors during overturn events. Overturn characteristics were collected that included 90 degrees to the side, beyond 90 degrees to the side, and to the rear for both ROPS-equipped and non-ROPS tractors. Of the 541 overturns reported in this study, 535 (99%) of the respondents reported the most recent overturn characteristics of the tractor: 92 (17%) were ROPS-equipped and 443 (83%) were non-ROPS. For side overturns, 67% of the rolls occurred with ROPS-equipped tractors, and 54% occurred with non-ROPS tractors. The percentages of deaths related to rolls to the side for ROPS-equipped and non-ROPS tractors were, respectively, 1.6% and 3.7%. There was one (2%) deaths related to 90 degrees rolls for ROPS-equipped tractors, whereas for continuous rolls there were 6.4% fatalities related to side overturns, 13% resulted in non-fatal injuries with an average of 1 day of hospitalization for ROPS-equipped tractors, and 39% resulted in non-fatal injuries with an average of 18 days of hospitalization for non-ROPS tractors. The results from this study indicated that a ROPS was more effective at stopping an overturn at 90 degrees than no ROPS, with an

  8. Realization of compact tractor beams using acoustic delay-lines

    NASA Astrophysics Data System (ADS)

    Marzo, A.; Ghobrial, A.; Cox, L.; Caleap, M.; Croxford, A.; Drinkwater, B. W.

    2017-01-01

    A method for generating stable ultrasonic levitation of physical matter in air using single beams (also known as tractor beams) is demonstrated. The method encodes the required phase modulation in passive unit cells into which the ultrasonic sources are mounted. These unit cells use waveguides such as straight and coiled tubes to act as delay-lines. It is shown that a static tractor beam can be generated using a single electrical driving signal, and a tractor beam with one-dimensional movement along the propagation direction can be created with two signals. Acoustic tractor beams capable of holding millimeter-sized polymer particles of density 1.25 g/cm3 and fruit-flies (Drosophila) are demonstrated. Based on these design concepts, we show that portable tractor beams can be constructed with simple components that are readily available and easily assembled, enabling applications in industrial contactless manipulation and biophysics.

  9. Reducing costs with well tractors for horizontal wells

    SciTech Connect

    Hallundbaek, J.

    1995-12-31

    The Well Tractor is a new concept for a down hole tool that significantly reduces operation costs for servicing horizontal wells. The Well Tractor is a cost effective alternative to the very expensive and time consuming conventional drill pipe conveyed operations. The Well Tractor is capable of pulling coiled tubing and/or wireline horizontally beyond 10,000 ft. The Well Tractor is capable of pulling more then 25,000 ft of coiled tubing and/or wireline into a highly deviated well. Furthermore the tool is designed for pushing other tools into the hole, e.g. logging tools, video cameras. The lateral reach capacity with coiled tubing is therefore increased considerably. Time consuming production logging operations of horizontal wells utilizing jointed pipe can be carried out by the Well Tractor as a wireline job.

  10. Development of an ergonomic evaluation facility for Indian tractors.

    PubMed

    Patel, R; Kumar, A; Mohan, D

    2000-06-01

    The design of tractors manufactured in low-income countries like India has not changed much in the past two decades, especially from an ergonomic point of view. Moreover, in these countries tractors are used for transportation purposes in addition to farming operations. Therefore, the design criteria for these tractors need to be different from those in high-income countries. This paper describes the development of an ergonomic facility for improvement of tractor design. An ergonomic evaluation facility has been developed consisting of a work place envelope for the Indian population, a layout measuring device and an ergonomic rig. This facility can be used for comparative evaluation of the display and control layouts of different tractors in order to develop an optimum layout. The ergonomic rig has the facility to simulate the improved layout for subjective evaluation.

  11. Enhanced Gravity Tractor Technique for Planetary Defense

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Reeves, David M.; Hopkins, Joshua B.; Wade, Darren W.; Tantardini, Marco; Shen, Haijun

    2015-01-01

    Given sufficient warning time, Earth-impacting asteroids and comets can be deflected with a variety of different "slow push/pull" techniques. The gravity tractor is one technique that uses the gravitational attraction of a rendezvous spacecraft to the impactor and a low-thrust, high-efficiency propulsion system to provide a gradual velocity change and alter its trajectory. An innovation to this technique, known as the Enhanced Gravity Tractor (EGT), uses mass collected in-situ to augment the mass of the spacecraft, thereby greatly increasing the gravitational force between the objects. The collected material can be a single boulder, multiple boulders, regolith or a combination of different sources. The collected mass would likely range from tens to hundreds of metric tons depending on the size of the impactor and warning time available. Depending on the propulsion system's capability and the mass collected, the EGT approach can reduce the deflection times by a factor of 10 to 50 or more, thus reducing the deflection times of several decades to years or less and overcoming the main criticism of the traditional gravity tractor approach. Additionally, multiple spacecraft can orbit the target in formation to provide the necessary velocity change and further reduce the time needed by the EGT technique to divert hazardous asteroids and comets. The robotic segment of NASA's Asteroid Redirect Mission (ARM) will collect a multi-ton boulder from the surface of a large Near-Earth Asteroid (NEA) and will provide the first ever demonstration of the EGT technique and validate one method of collecting in-situ mass on an asteroid of hazardous size.

  12. Well tractors for highly deviated and horizontal wells

    SciTech Connect

    Hallundbaek, J.

    1994-12-31

    This paper introduces the oil industry to a new type of downhole tools--the Well Tractors with modular power source designed for running in open hole and inside the completions of horizontal and highly deviated wells. The Well Tractors are used for cleaning, setting and pulling of plugs, operating sliding sleeves, open hole logging, running of production logs, drilling, perforation guns, cement bond logs, etc. Horizontally the Well Tractors pull coiled tubing and/or wireline beyond 10,000 ft. The Well Tractors are capable of pulling more than 25,000 ft of coiled tubing and/or wireline into a highly deviated well. Furthermore the tools are designed for pushing other tools into the hole, e.g., logging tools, video cameras, etc. The Well Tractors with modular power source are designed in two versions: A fluid driven version for coiled tubing operations, powered by brine, water, mud, etc., which is pumped down through standard coiled tubing. The tool is controlled from the surface via a wireline running inside the tubing. Through the wireline measurements can be transmitted to the surface. Alternatively the tool can also operate without the wireline which enables it to run with a smaller size of coiled tubing or have a higher flow rate for cleaning jobs. An electric driven version of the Well Tractor for wireline operations, powered and controlled through the wireline. The Well Tractors are designed in 3 different sizes. A Tractor with an outside diameter of 3 1/8 in. A Tractor with an outside diameter of 4 3/4 in. and a Tractor with an outside diameter of 2 1/8 in.

  13. A mathematical equation for quantifying control functionality in agricultural tractors.

    PubMed

    Drakopoulos, D; Mann, D D

    2008-10-01

    The overall accessibility of controls is one of the most important issues to consider when designing a control layout. Well-arranged controls, whose operational characteristics are based on both design guidelines and on human factors considerations, allow the operator to efficiently interact with the system in question. The objective of this article is to introduce a numerical index, referred to as the "index of functionality", capable of comparing, on a mathematical basis, different control arrangements in agricultural tractors. The model is based on information that has been gleaned from the published literature, with input from both professional ergonomists and experienced agricultural tractor operators. The numerical index may take any value between 0 and +1, with +1 being defined as an optimum value in terms of the functionality of a workstation. Data were collected from six old (pre-1982) and six modern (post-2003) tractor workstations to determine whether the model would recognize improvements that have occurred in the ergonomic design of tractor control layouts over the past 20 years. An average score of 0.19 +/- 0.07 was calculated for the pre-1982 tractor workstations. By contrast, an average score of 0.63 +/- 0.10 was calculated for the post-2003 tractor workstations. A number of limitations have been identified with the current model; despite these limitations, the index of functionality clearly recognized the ergonomic improvements in tractor workstations that have occurred over the past 20 years.

  14. Accident rates for heavy truck-tractors in Michigan.

    PubMed

    Blower, D; Campbell, K L; Green, P E

    1993-06-01

    Accident rates of heavy truck-tractors are modelled using log-linear methods. The accident data used are a census of truck-tractor involvements in Michigan from May 1987 to April 1988. Travel data used to calculate the rates were produced by a survey of truck-tractors in Michigan covering the same time period. Both the accident and travel data were limited to Michigan-registered tractors operating in Michigan. Log-linear models of casualty and property-damage-only accident rates were developed using number of trailers, road type, area type, and time of day as predictor variables. Overall, differences between tractors with one and two trailers were not significant. Tractors with no trailers (bobtails) have significantly higher accident rates. Characteristics of the operating environment were found to have larger effects on the accident rate than tractor configuration (except for the bobtail). Rates varied by a factor of up to 6.8, depending on the road type. Casualty accident risk at night was 1.4 times the risk during the day. The risk of a casualty accident in rural areas was 1.6 times that of urban areas.

  15. A simple method to improve autonomous GPS positioning for tractors.

    PubMed

    Gomez-Gil, Jaime; Alonso-Garcia, Sergio; Gómez-Gil, Francisco Javier; Stombaugh, Tim

    2011-01-01

    Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Navigation Systems (INS). However, both are complex and expensive solutions. In contrast, this article presents a simple and low cost method to improve tractor positioning when only a GPS receiver is used as the positioning sensor. The method is based on placing the GPS receiver ahead of the tractor, and on applying kinematic laws of tractor movement, or a geometric approximation, to obtain the midpoint position and orientation of the tractor rear axle more precisely. This precision improvement is produced by the fusion of the GPS data with tractor kinematic control laws. Our results reveal that the proposed method effectively reduces the guidance GPS error along a straight trajectory.

  16. A Simple Method to Improve Autonomous GPS Positioning for Tractors

    PubMed Central

    Gomez-Gil, Jaime; Alonso-Garcia, Sergio; Gómez-Gil, Francisco Javier; Stombaugh, Tim

    2011-01-01

    Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Navigation Systems (INS). However, both are complex and expensive solutions. In contrast, this article presents a simple and low cost method to improve tractor positioning when only a GPS receiver is used as the positioning sensor. The method is based on placing the GPS receiver ahead of the tractor, and on applying kinematic laws of tractor movement, or a geometric approximation, to obtain the midpoint position and orientation of the tractor rear axle more precisely. This precision improvement is produced by the fusion of the GPS data with tractor kinematic control laws. Our results reveal that the proposed method effectively reduces the guidance GPS error along a straight trajectory. PMID:22163917

  17. Risk analysis of tractor overturns on catfish farms.

    PubMed

    Stephens, Walter B; Ibendahl, Gregory A; Myers, Melvin L; Cole, Henry P

    2010-10-01

    Fatal and nonfatal injuries occur on catfish farms as a result of tractor overturns, but these injuries can be greatly mitigated when a tractor is equipped with a rollover protective structure (ROPS) and seatbelt. This study analyzed the proportion of tractors on catfish farms in Mississippi not equipped with ROPS and the cost of retrofitting those tractors with a ROPS and seatbelt as compared to the expected benefits gained from adding the protection. To determine if farmers have the financial incentive to retrofit older tractors, a net present value framework was used because the expected benefits occur over a number of years. The ROPS retrofit is a one-time cost that occurs immediately, and thus the present value does not need to be calculated, i.e., time period 0. According to this study adding ROPS will provide a net benefit of $22,877 in the event of an overturn. When dealing with small farms (<125 acres) where an average tractor is used for approximately twice as many hours compared to an average tractor on large farms, the extra hours worked by a single tractor resulted in total benefits of retrofitting ROPS of $9.45 per year, whereas for large farms the net benefit is $4.70 (=125 acres). Given that the least expensive retrofit is $147, it would take 15.5 years of tractor use on the small farms for the expected benefits to outweigh the cost. Given the large range of costs that could occur due to an overturn, there could be a significant premium for not having ROPS protection. In other words, there likely is a smaller range of costs from an overturn with ROPS than without ROPS because ROPS reduces the more serious incidents.

  18. Narrow-track wheeled agricultural tractor parameter variation.

    PubMed

    Guzzomi, A; Rondelli, V

    2013-10-01

    Despite a general consensus among farmers, manufacturers, and researchers that wheeled agricultural tractor design has changed over time, there is little published evidence. There is debate as to whether the standardized rollover protective structure (ROPS) energy and force requirements, based on a tractor reference mass and pertaining to studies conducted more than 40 years ago, are appropriate for modern tractors. This article investigated the physical parameters of 326 modern narrow-track tractors, measured according to OECD Code 6 over 16 years (1993 to 2008 inclusive): 252 (-77%) were fixed-chassis tractors and 74 (-23%) were articulated. To understand the significance of design changes, the data were analyzed with respect to time and as a function of tractor mass. Articulated and fixed-chassis data were treated separately. The time data allowed qualitative analysis, while the mass data allowed quantitative analysis. The parameters show some changes over time and clearly indicate differences between articulated and fixed-chassis types. The parameter changes, along with the differences between types, may have important safety ramifications for ROPS energy absorption requirements, and these aspects are discussed. Regression lines with R2 values were fitted to the mass-related data for fixed-chassis and articulated tractors to determine the suitability of fit. The mass relations also displayed differences between fixed-chassis and articulated tractors. Thus, the most significant recommendation from this study is that the standardized testing procedure for narrow-track wheeled agricultural tractor category should be split into two groups: fixed-chassis and articulated.

  19. Tractor Mechanics. Maintaining and Servicing the Engine, Learning Activity Packages 78-89; Lubricating the Tractor, Learning Activity Packages 90-94; Painting the Tractor, Learning Activity Packages 95-96.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This series of learning activity packages focuses on three areas of tractor mechanics: (1) maintaining and servicing the engine, (2) lubricating the tractor, and (3) painting the tractor. Each of the nineteen illustrated learning activity packages follows a typical format: introduction, directions, objectives, learning activities, tools and…

  20. DETAIL VIEW OF STEAM TRACTOR "OLD DINAH," LOOKING NORTHWEST. THIS ...

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

    DETAIL VIEW OF STEAM TRACTOR "OLD DINAH," LOOKING NORTHWEST. THIS STEAM TRACTOR WAS USED TO REPLACE THE HORSE WAGON TRAINS THAT CARRIED SUPPLIES AND CRUDE OIL THE 26 MILES FROM BEATTY, NEVADA TO KEANE WONDER. THE TRACTOR ONLY MADE ONE RUN IN 1909 BEFORE THE BOILER EXPLODED ENROUTE, AND IT WAS ABANDONED THERE ON THE TRAIL TODAY IT STANDS ON DISPLAY AT THE FURNACE CREEK RANCH IN DEATH VALLEY NATIONAL PARK, AS SEEN IN THE PHOTOGRAPH. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  1. [Ergonomic evaluation of assembly line of tractors].

    PubMed

    Dellera, L; Buratti, G

    2012-01-01

    In the assembly lines in the engineering sector, ever more guided by the theories of lean production, is increasingly important ergonomic factor working conditions to preserve the health of workers and ensuring the performance. This analysis has focused on the study of biomechanical and postural stress of work tasks of an assembly line of the tractor, characterized by different weights and volumes from that of the car. Comparison with the technical standard of EN 1005-4 has allowed the identification as the machining assembly of small components result in conditions of acceptability, while most of the other processes aren't reliable. The emergence of these problems pushed to find several ergonomic solutions including the development of a special reclining seat to enable a proper posture during the working.

  2. 17. TRACTOR ENGINE POWERING SHAFT SYSTEM IN FOREGROUND, BELT CONNECTS ...

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

    17. TRACTOR ENGINE POWERING SHAFT SYSTEM IN FOREGROUND, BELT CONNECTS WITH MAIN SHAFT LOOKING EAST. - W. A. Young & Sons Foundry & Machine Shop, On Water Street along Monongahela River, Rices Landing, Greene County, PA

  3. Environmental perspective facing south showing chicken house, tractor shed, and ...

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

    Environmental perspective facing south showing chicken house, tractor shed, and homestead - Norris Farm, .5 mile west of County Road 857 & .25 mile east of County Road 88/1, Cheat Neck, Monongalia County, WV

  4. VIEW OF STACK WITH AUTOMOBILE AND TRACTOR REPAIR SHOP TO ...

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

    VIEW OF STACK WITH AUTOMOBILE AND TRACTOR REPAIR SHOP TO THE FAR RIGHT. WAREHOUSE WITH ITS RIDGELINE ROTARY VENTS TO RIGHT OF STACK. VIEW FROM THE WEST - Kekaha Sugar Company, Sugar Mill Building, 8315 Kekaha Road, Kekaha, Kauai County, HI

  5. Learn about SmartWay Tractors and Trailers

    EPA Pesticide Factsheets

    Companies that lease or purchase tractors or trailers that meet EPA's designated SmartWay standards are using more efficient equipment and may be eligible to put the SmartWay logo on the exterior of their equipment.

  6. SmartWay Tractor and Trailer Logo Usage Instructions

    EPA Pesticide Factsheets

    View a presentation provides guidelines for SmartWay Partners on tractor and trailer logo usage, including SmartWay designated technical specifications and requirements, importance of logo display, how to obtain the logo, and logo placement.

  7. Safe tractor access platforms: from guidance material to implementation.

    PubMed

    Day, L; Rechnitzer, G

    2004-08-01

    This article reports on the implementation of published guidelines for retrofitting tractors with safe access platforms, which were developed to reduce the risk of serious injuries and deaths associated with mounting and dismounting. Farmer interviews and engineering-based inspections of ten retrofitted tractors were conducted to gather information regarding benefits and disadvantages of the retrofitting and to assess the construction of the platforms. A scoring system was developed for platform retrofitting, and weighted scores between zero and ten were calculated for tractor access before and after retrofitting. Access was improved on all tractors, although to varying degrees. The average post-retrofit weighted score was 6.3 (range 2.6 to 9.7), compared with the pre-retrofit average of 0.9 (range 0.3 to 1.6). Five tractors received a post-retrofit score of 8.0 or higher. None of the lower-scoring tractors fully met the specifications for placement of the bottom step or rear wheel guard, two key characteristics for runover prevention. Other characteristics associated with a lower post-retrofit score included a low bottom step, high step rises, absence of colored nosing, and the front handrail space not being filled in. Platform retrofitting had little effect on tractor operations and substantially improved ease of access. This is the first published evaluation of a design-based solution for tractor runover injuries. This study shows that general guidelines for retrofitting of safe access platforms can be successfully applied. Mechanisms to increase adherence to the key criteria of bottom step positioning and rear wheel guarding should be included in future promotion.

  8. Apparatus for extending the frame of a tractor

    SciTech Connect

    Bulmahn, G.L.

    1987-07-14

    This patent describes an apparatus for extending the frame of an agricultural tractor adapted for pulling farm implements for adaptation to ridge or till farming. The tractor includes a set of rear wheels, a frame, a set of front wheels, and an engine mounted between the front and rear wheels, the apparatus comprises: a longitudinal extension frame; extension frame attaching means connected to the extension frame for attaching to tractor frame along with removal of the tractor front wheels; pivoting means secured to the extension frame to enable pivoting of at least a portion relative to the tractor frame about a substantially vertical axis; front wheel attaching means for attaching at least two front wheels to the extension frame; a hydraulically operated steering apparatus operably secured to the front wheels and to the extension frame pivoting means; hydraulic fluid hose extension means for connecting the tractor hydraulic steering control means to the hydraulic steering apparatus; and a three point hitch connected for attaching an agricultural implement at a position intermediate the front wheel.

  9. 78 FR 42800 - Certain Crawler Cranes and Components Thereof; Institution of Investigation Pursuant to United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-17

    ... certain crawler cranes and components thereof by reason of trade secret misappropriation, the threat or... secrets, the threat or effect of which is to destroy or substantially injure an industry in the...

  10. Tractor overturn concerns in Iowa: perspectives from the Keokuk county rural health study.

    PubMed

    Sanderson, W T; Madsen, M D; Rautiainen, R; Kelly, K M; Zwerling, C; Taylor, C D; Reynolds, S J; Stromquist, A M; Burmeister, L F; Merchant, J A

    2006-02-01

    Agriculture remains one of the most hazardous industries in the U.S., with tractor overturns producing the greatest number of agricultural machinery-related fatalities. Rollover protective structures (ROPS) and seatbelts effectively reduce tractor overturn deaths. However, a large proportion of tractors in use in American agriculture are older tractors without ROPS and seatbelts. This article describes the tractor-related responses from participants in a population-based study conducted in Keokuk County, Iowa. This study was designed to measure rural and agricultural adverse health and injury outcomes and their respective risk factors. Questionnaires were partially developed from well-documented national surveys. Questions about agricultural machinery use, presence of safety equipment on the machinery, work practices, and attitudes about farm safety were included. Study participants on farms who owned tractors had an average of 3.1 tractors with an average age of 27 years. Only 39% of the 665 tractors had ROPS. Tractor age was associated with the presence of ROPS; 84% of tractors manufactured after 1984 were ROPS-equipped, whereas only 3% of tractors manufactured before 1960 were ROPS-equipped. ROPS-equipped tractors were significantly more common on larger farms and households with higher income. Only 4% of the farmers reported that their tractors had seatbelts and they wore them when operating their tractors. The results of this study support the findings of other studies, which indicate that many older tractors without ROPS and seatbelts remain in use in American agriculture. Until a dramatic reduction in the number of tractors in the U.S. operated without ROPS and seatbelts is achieved, the annual incidence of 120 to 130 deaths associated with tractor overturns will persist.

  11. The influence of tractor-seat height above the ground on lateral vibrations.

    PubMed

    Gomez-Gil, Jaime; Gomez-Gil, Francisco Javier; Martin-de-Leon, Rebeca

    2014-10-22

    Farmers experience whole-body vibrations when they drive tractors. Among the various factors that influence the vibrations to which the driver is exposed are terrain roughness, tractor speed, tire type and pressure, rear axle width, and tractor seat height above the ground. In this paper the influence of tractor seat height above the ground on the lateral vibrations to which the tractor driver is exposed is studied by means of a geometrical and an experimental analysis. Both analyses show that: (i) lateral vibrations experienced by a tractor driver increase linearly with tractor-seat height above the ground; (ii) lateral vibrations to which the tractor driver is exposed can equal or exceed vertical vibrations; (iii) in medium-size tractors, a feasible 30 cm reduction in the height of the tractor seat, which represents only 15% of its current height, will reduce the lateral vibrations by around 20%; and (iv) vertical vibrations are scarcely influenced by tractor-seat height above the ground. The results suggest that manufacturers could increase the comfort of tractors by lowering tractor-seat height above the ground, which will reduce lateral vibrations.

  12. Mission Designs for Demonstrating Gravity Tractor Asteroid Deflection

    NASA Astrophysics Data System (ADS)

    Busch, M.; Faber, N.; Eggl, S.; Morrison, D.; Clark, A.; Frost, C.; Jaroux, B. A.; Khetawat, V.

    2015-12-01

    Gravity tractor asteroid deflection relies on the gravitational attraction between the target and a nearby spacecraft; using low-thrust propulsion to change the target's trajectory slowly but continuously. Our team, based at the NASA Ames Mission Design Center, prepared designs for a Gravity Tractor Demonstration Mission (GTDM) for the European Commission's NEOShield initiative. We found five asteroids with well-known orbits and opportunities for efficient stand-alone demonstrations in the 2020s. We selected one object, 2000 FJ10, for a detailed design analysis. Our GTDM design has a 4 kW solar-electric propulsion system and launch mass of 1150 kg. For a nominal asteroid mass of 3 x 109 kg and diameter 150 m, and a hovering altitude 125 m above the asteroid's surface, GTDM would change FJ10's semi-major axis by 10 km over 2 years. To measure the deflection clearly and to permit safe hovering by the spacecraft, several months of survey and characterization are required prior to the active tractoring phase of the mission. Accurate tracking is also required after the tractoring phase, to ensure that the asteroid has indeed been deflected as intended. The GTDM design includes both spacecraft and Earth-based observations of FJ10 to verify the deflection. The estimated cost of GTDM is $280 million. Trajectory analysis for GTDM confirmed that the outcome of a deflection of any asteroid depends on when that deflection is performed. Compared to kinetic impactor deflection, the gradual deflection from a gravity tractor produces comparable results for a given total momentum transfer. However, a gravity tractor can have greater flexibility in the direction in which the target asteroid can be deflected. Asteroid deflection scenarios must be modeled carefully on a case-to-case basis. We will review implications of the results of the GTDM study to other proposed gravity tractor demonstrations, such as that included in NASA's Asteroid Redirect Mission.

  13. Ensuring Machine and Tractor Aggregates Operability

    NASA Astrophysics Data System (ADS)

    Redreev, G. V.

    2016-08-01

    the operability of the machine and tractor aggregates is ensured by processes which occur in machine units and considered as technical systems. In order to develop theoretical understanding of the processes in technical systems as the basis and purpose of the repairserving actions, the author's concept is presented which relies on on the basic concepts of "processes in technical systems", "maintenance and repair of performers", "maintenance and repair of technology" "objectives of the maintenance and repair". Analysis of the basic concepts of "processes in technical systems" made possible to distinguishing four types of relations: of order, stipulation, exactingness, and non-contradiction. It is shown that the implementation of maintenance and repair of technology should be conducted according to the assessment of the effectiveness of processes in technical systems, revealed in complex diagnosis. The perfection of the design of the machine in terms of its technical operation can be estimated according to the degree of consistency of processes in technical systems, purposes of maintenance and repair. In order to increase the efficiency of the lubrication system,the modernised design of the centrifugal oil filter with permanent control of its cleaning power is offered, which allows changing the technology of the maintenance of engine lubrication system by separating the operations of crankcase oil replacement and the rotor filter cleaning.

  14. Assessing farm tractor incidents and awareness levels of operators for tractor safety issues in the Hatay province of Turkey.

    PubMed

    Keskin, S Görücü; Keskin, M; Soysal, Y

    2012-04-01

    Studies and statistical data on safety issues related to farm tractors and machinery are very limited in developing countries, including Turkey. This study was carried out to investigate tractor-related incidents in the Hatay province, located in the mid-south of Turkey. A questionnaire was conducted with 107 tractor operators using face-to-face interviews. Data were evaluated according to the incident type, machinery involved, and mechanism of injury or fatality. A total of 101 incidents were reported by 77 of the 107 respondents. Most of the incidents were due to tractor rollovers (65.4%), 14.8% of the incidents were due to entanglement of body parts in moving machinery, and 12.9% involved crashing into other vehicles or obstacles. The leading cause of the incidents was personal mistakes (60.4%). Fatalities resulted from 25.7% of the incidents, while 45.5% of the incidents caused non-fatal injuries. Only 5.6% of the tractors had a ROPS-enclosed cab. The percentage of ROPS-equipped tractors was 19.6%, while 41.3% of the tractors had a shade cover and 33.6% had no protective structure. Only one of the respondents used a seatbelt, although 44.9% of them stated that seatbelts should be used. It was also found that only 13.5% of the operators had training in work safety, while 95.1% stated that incidents might be reduced if people were trained. Development of appropriate policies and training programs are needed for safer operation of agricultural machinery to reduce injuries and fatalities due to farm accidents.

  15. Design and Analysis of an Active Helical Drive Downhole Tractor

    NASA Astrophysics Data System (ADS)

    LI, Yujia; LIU, Qingyou; CHEN, Yonghua; REN, Tao

    2017-03-01

    During oil-gas well drilling and completion, downhole tools and apparatus should be conveyed to the destination to complete a series of downhole works. Downhole tractors have been used to convey tools in complex wellbores, however a very large tractive force is needed to carry more downhole tools to accomplish works with high efficiency. A novel serial active helical drive downhole tractor which has significantly improved performance compared with previous work is proposed. All previously reported helical drive downhole tractors need stators to balance the torque generated by the rotator. By contrast, the proposed serial downhole tractor does not need a stator; several rotator-driven units should only be connected to one another to achieve a tractive force multifold higher than that was previously reported. As a result, the length of a single unit is shortened, and the motion flexibility of the downhole tractor is increased. The major performance indicators, namely, gear ratio, velocity, and tractive force, are analyzed. Experimental results show that the maximum tractive force of a single-unit prototype with a length of 900 mm is 165.3 kg or 1620 N. The analysis and experimental results show that the proposed design has considerable potential for downhole works.

  16. Design and Analysis of an Active Helical Drive Downhole Tractor

    NASA Astrophysics Data System (ADS)

    LI, Yujia; LIU, Qingyou; CHEN, Yonghua; REN, Tao

    2017-03-01

    During oil-gas well drilling and completion, downhole tools and apparatus should be conveyed to the destination to complete a series of downhole works. Downhole tractors have been used to convey tools in complex wellbores, however a very large tractive force is needed to carry more downhole tools to accomplish works with high efficiency. A novel serial active helical drive downhole tractor which has significantly improved performance compared with previous work is proposed. All previously reported helical drive downhole tractors need stators to balance the torque generated by the rotator. By contrast, the proposed serial downhole tractor does not need a stator; several rotator-driven units should only be connected to one another to achieve a tractive force multifold higher than that was previously reported. As a result, the length of a single unit is shortened, and the motion flexibility of the downhole tractor is increased. The major performance indicators, namely, gear ratio, velocity, and tractive force, are analyzed. Experimental results show that the maximum tractive force of a single-unit prototype with a length of 900 mm is 165.3 kg or 1620 N. The analysis and experimental results show that the proposed design has considerable potential for downhole works.

  17. The Organization of Wariness of Heights in Experienced Crawlers

    PubMed Central

    Ueno, Mika; Uchiyama, Ichiro; Campos, Joseph J.; Dahl, Audun; Anderson, David I.

    2011-01-01

    Most infants with more than 6 weeks of crawling experience completely avoid the deep side of a visual cliff (Campos et al., 1992; Gibson & Walk, 1960). However, some experienced crawlers do move onto the transparent surface suspended several feet above the ground. An important question is whether these non-avoiders lack wariness of heights or whether they have a qualitatively different way of showing their wariness than do avoiders of the deep side. The current study addressed this question by measuring heart rate (HR) acceleration upon being lowered on the deep and shallow sides of the visual cliff, latency to crawl toward the mother, and tactile exploration of the cliff surface. Non-avoiders and avoiders had indistinguishable patterns of HR acceleration, showing greater HR acceleration when lowered onto the deep than when lowered onto the shallow side of the cliff. Non-avoiders also showed more tactile exploration and longer latencies than did a comparable group of infants tested on the shallow side. This study illustrates how the same emotion, wariness of heights, can be shown by qualitatively different behaviors, all serving the same function of protecting the individual from falling over a drop-off. PMID:24817830

  18. The Organization of Wariness of Heights in Experienced Crawlers.

    PubMed

    Ueno, Mika; Uchiyama, Ichiro; Campos, Joseph J; Dahl, Audun; Anderson, David I

    2012-07-01

    Most infants with more than 6 weeks of crawling experience completely avoid the deep side of a visual cliff (Campos et al., 1992; Gibson & Walk, 1960). However, some experienced crawlers do move onto the transparent surface suspended several feet above the ground. An important question is whether these non-avoiders lack wariness of heights or whether they have a qualitatively different way of showing their wariness than do avoiders of the deep side. The current study addressed this question by measuring heart rate (HR) acceleration upon being lowered on the deep and shallow sides of the visual cliff, latency to crawl toward the mother, and tactile exploration of the cliff surface. Non-avoiders and avoiders had indistinguishable patterns of HR acceleration, showing greater HR acceleration when lowered onto the deep than when lowered onto the shallow side of the cliff. Non-avoiders also showed more tactile exploration and longer latencies than did a comparable group of infants tested on the shallow side. This study illustrates how the same emotion, wariness of heights, can be shown by qualitatively different behaviors, all serving the same function of protecting the individual from falling over a drop-off.

  19. 4-H Tractor Operator Program Teaches Employability Skills and Safety to Youth

    ERIC Educational Resources Information Center

    Barrett, Debra K.

    2013-01-01

    For Michigan State University Extension, the Berrien County 4-H Tractor Operator Program has provided tractor safety education to teens for over 30 years. The certification training satisfies current requirements for operation of a 20 PTO HP or greater agricultural tractor by 14- and 15-year-old youth employed on property "not" owned,…

  20. A survey of tractors and rollover protective structures in Washington State.

    PubMed

    Spielholz, P; Sjostrom, T; Clark, R E; Adams, D A

    2006-11-01

    A survey of farms in Washington State was conducted to determine tractor characteristics and the presence of rollover protective structures (ROPS) in a state with more inclusive rules on tractor retrofitting than federal regulations. A total of 544 valid surveys were completed from a proportional random sample across different types of farms. Responders indicated that 58% of tractors overall were equipped with ROPS, and 42% of the tractors without ROPS were exempt from the state rules. Seatbelts on tractors equipped with ROPS were reportedly used "sometimes" or more 30% of the time, and 17% of these tractors had no seatbelt installed. Tractors used for row crop farming were significantly more likely to be equipped with ROPS than those used for tree, vine, or hops farming. Older tractors were used for fewer hours, were less likely to be ROPS-equipped, and were less likely to be operated while wearing a seatbelt. The results were consistent with a positive effect of the Washington State ROPS requirements, demonstrated by the increased percentage of ROPS-equipped pre-1976 tractors, as compared to other states, and by the difference between ROPS-equipped tractors in exempt and non-exempt types of farming. The results point to the need for prevention activities to increase seatbelt use on ROPS-equipped tractors, and for further development of practical protection for tractors operating under overhead obstacles.

  1. 49 CFR 393.61 - Truck and truck tractor window construction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Truck and truck tractor window construction. 393... REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Glazing and Window Construction § 393.61 Truck and truck tractor window construction. Each truck and truck tractor (except trucks engaged in armored...

  2. 49 CFR 393.61 - Truck and truck tractor window construction.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Truck and truck tractor window construction. 393... REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Glazing and Window Construction § 393.61 Truck and truck tractor window construction. Each truck and truck tractor (except trucks engaged in armored...

  3. 75 FR 2153 - Certificate of Alternative Compliance for the Tractor Tug FORTE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ... SECURITY Coast Guard Certificate of Alternative Compliance for the Tractor Tug FORTE AGENCY: Coast Guard... was issued for the tractor tug FORTE as required by 33 U.S.C. 1605(c) and 33 CFR 81.18. DATES: The... Purpose The tractor tug FORTE will be used for offshore supply operations. The horizontal distance...

  4. 49 CFR 393.61 - Truck and truck tractor window construction.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Truck and truck tractor window construction. 393... REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Glazing and Window Construction § 393.61 Truck and truck tractor window construction. Each truck and truck tractor (except trucks engaged in...

  5. 49 CFR 393.61 - Truck and truck tractor window construction.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Truck and truck tractor window construction. 393... REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Glazing and Window Construction § 393.61 Truck and truck tractor window construction. Each truck and truck tractor (except trucks engaged in...

  6. 75 FR 52255 - Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-802A Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-25

    ...; AD 2010-17-18] RIN 2120-AA64 Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT- 802A... all Air Tractor, Inc. (Air Tractor) Models AT-802 and AT-802A airplanes. AD 2010-13-08 currently... both of the wing main spar lower caps at the center splice joint for cracks and repair or replace...

  7. Path-tracking control of a tractor-aircraft system

    NASA Astrophysics Data System (ADS)

    Wang, Nengjian; Liu, Hongbo; Yang, Wanhui

    2012-12-01

    An aircraft tractor plays a significant role as a kind of important marine transport and support equipment. It's necessary to study its controlling and manoeuvring stability to improve operation efficiency. A virtual prototyping model of the tractor-aircraft system based on Lagrange's equation of the first kind with Lagrange mutipliers was established in this paper. According to the towing characteristics, a path-tracking controller using fuzzy logic theory was designed. Direction control herein was carried out through a compensatory tracking approach. Interactive co-simulation was performed to validate the path-tracking behavior in closed-loop. Simulation results indicated that the tractor followed the reference courses precisely on a flat ground.

  8. Tractor controls actuating force limits for Indian operators.

    PubMed

    Mehta, C R; Pandey, M M; Tiwari, P S; Gite, L P; Khadatkar, Abhijit

    2011-01-01

    In four-wheel tractors, proper design of controls is important for comfortable and safe operation of the tractor. The design involves location and dimensions of controls as well as strength limits for operating these controls. The present study was aimed to quantify human strength for operation of tractor controls and to recommend the maximum control actuating forces for normal operation of tractors based on strength capability of 3,423 Indian male agricultural workers. The 5th percentile values of strength parameters i.e. leg strength sitting (left and right), foot strength sitting (right), torque strength (both hands) sitting, push strength (left hand and right hand) sitting and pull strength (left hand and right hand) sitting of agricultural workers collected using a strength measurement set-up were taken into consideration for the study. It was recommended that the maximum actuating forces for normal operation of frequently operated brake and clutch pedals of tractors should not exceed 260 N and 125 N based on 5th percentile values of right and left leg strength of male agricultural workers, respectively. The maximum actuating force required in steering wheel operation should not exceed 51 N based on 5th percentile value of torque strength (both hands) sitting of workers. The maximum actuating forces required for operating frequently operated levers viz. gear selection, speed selection, hydraulic control and hand throttle of Indian tractors should not exceed 46 N, 46 N, 25 N and 25 N, respectively. It may be concluded that the maximum actuating force limits as given in Bureau of Indian Standards IS 10703 are very high as compared to the findings of the study based on strength data of Indian male operators, which highlight the need to revise the standard.

  9. Characterizing particle pairs optically bound in "tractor beam"

    NASA Astrophysics Data System (ADS)

    Damková, Jana; Chvátal, LukáÅ.¡; Brzobohatý, Oto; Svak, Vojtěch; Å iler, Martin; Simpson, Stephen; Zemánek, Pavel

    2016-09-01

    We report on an experimental and theoretical study of optical binding of polystyrene sphere pairs illuminated by retro-reflected wide Gaussian beam, so-called "tractor beam". We show that depending on configuration of particle pairs, optically bound structure in the "tractor beam" can be pushed or pulled against the beam propagation. We employ holographic video microscopy to analyse object positions in three dimensions and their time evolution. In such a way, we investigate their dynamics in dependence on the geometrical configuration that is compared with numerical simulations. We observe strong dependence of the particle pair motion on the relative distance of the particles.

  10. Design and Development of a Robotic Crawler for CANDU Fuel Channel Inspection

    NASA Astrophysics Data System (ADS)

    Shukla, Shivam

    For the design of a new robotic crawler drive unit for CANDU fuel channel inspection, a complete design and screening process was done in order to fulfil the objective of this research. A brief explanation of CANDU reactors is provided along with a discussion of the inspection systems that are currently in use. A study of some existing inspection systems is presented which was used for the development of the new robotic crawler design. A number of concepts were generated which underwent a screening process with the help of two design tools. With the help of these tools, a concept was chosen as the final design and details of it are presented. To demonstrate a proof-of-concept, the physical prototype of the robotic crawler was manufactured and assembled. A speed controller was implemented in the final design of the robotic crawler. A set of test procedures were performed on the final design and the results are discussed. Some improvements that can be done on the final design of the robotic crawler are also discussed in the final section of this thesis.

  11. Public health focus: effectiveness of rollover protective structures for preventing injuries associated with agricultural tractors.

    PubMed

    1993-01-29

    Agriculture ranks fourth among U.S. industries for work-related fatalities (1). Fatalities associated with agricultural machinery commonly involve farm tractors, and rollover incidents (i.e., the tractor tips sideways or backward and overturns, crushing the operator) account for 46% (Minnesota) to 76% (Georgia) of all farm tractor-related fatalities (2). Annually, agricultural tractor rollovers result in approximately 132 work-related deaths among persons aged > or = 16 years* (3). This report summarizes information regarding the efficacy, effectiveness, and cost-effectiveness of rollover protective structures (ROPS) on agricultural tractors.

  12. The rod of Aesculapios: John Haygarth (1740-1827) and Perkins' metallic tractors.

    PubMed

    Booth, Christopher

    2005-08-01

    James Gillray's cartoon Metallic Tractors, published in 1801, portrays Benjamin Perkins treating a boil on the nose of an alcoholic John Bull with a pair of metallic tractors. The tractors had been invented by his father, Elisha Perkins of Connecticut, and were supposed to relieve pain and other symptoms through the agency of animal magnetism. The tractors were revealed as nothing more than an expensive sham by Dr John Haygarth in Bath, who showed that wooden tractors were equally effective. Thus, he was one of the first to use a placebo in a single-blind clinical trial.

  13. Mission concepts and operations for asteroid mitigation involving multiple gravity tractors

    NASA Astrophysics Data System (ADS)

    Foster, Cyrus; Bellerose, Julie; Mauro, David; Jaroux, Belgacem

    2013-09-01

    The gravity tractor concept is a proposed method to deflect an imminent asteroid impact through gravitational tugging over a time scale of years. In this study, we present mission scenarios and operational considerations for asteroid mitigation efforts involving multiple gravity tractors. We quantify the deflection performance improvement provided by a multiple gravity tractor campaign and assess its sensitivity to staggered launches. We next explore several proximity operation strategies to accommodate multiple gravity tractors at a single asteroid including formation-flying and mechanically-docked configurations. Finally, we utilize 99942 Apophis as an illustrative example to assess the performance of a multiple gravity tractor campaign.

  14. Mission Concepts and Operations for Asteroid Mitigation Involving Multiple Gravity Tractors

    NASA Technical Reports Server (NTRS)

    Foster, Cyrus; Bellerose, Julie; Jaroux, Belgacem; Mauro, David

    2012-01-01

    The gravity tractor concept is a proposed method to deflect an imminent asteroid impact through gravitational tugging over a time scale of years. In this study, we present mission scenarios and operational considerations for asteroid mitigation efforts involving multiple gravity tractors. We quantify the deflection performance improvement provided by a multiple gravity tractor campaign and assess its sensitivity to staggered launches. We next explore several proximity operation strategies to accommodate multiple gravity tractors at a single asteroid including formation-flying and mechanically-docked configurations. Finally, we utilize 99942 Apophis as an illustrative example to assess the performance of a multiple gravity tractor campaign.

  15. A spatial cluster analysis of tractor overturns in Kentucky from 1960 to 2002

    USGS Publications Warehouse

    Saman, D.M.; Cole, H.P.; Odoi, A.; Myers, M.L.; Carey, D.I.; Westneat, S.C.

    2012-01-01

    Background: Agricultural tractor overturns without rollover protective structures are the leading cause of farm fatalities in the United States. To our knowledge, no studies have incorporated the spatial scan statistic in identifying high-risk areas for tractor overturns. The aim of this study was to determine whether tractor overturns cluster in certain parts of Kentucky and identify factors associated with tractor overturns. Methods: A spatial statistical analysis using Kulldorff's spatial scan statistic was performed to identify county clusters at greatest risk for tractor overturns. A regression analysis was then performed to identify factors associated with tractor overturns. Results: The spatial analysis revealed a cluster of higher than expected tractor overturns in four counties in northern Kentucky (RR = 2.55) and 10 counties in eastern Kentucky (RR = 1.97). Higher rates of tractor overturns were associated with steeper average percent slope of pasture land by county (p = 0.0002) and a greater percent of total tractors with less than 40 horsepower by county (p<0.0001). Conclusions: This study reveals that geographic hotspots of tractor overturns exist in Kentucky and identifies factors associated with overturns. This study provides policymakers a guide to targeted county-level interventions (e.g., roll-over protective structures promotion interventions) with the intention of reducing tractor overturns in the highest risk counties in Kentucky. ?? 2012 Saman et al.

  16. Dealing with pre-ROPS tractors: is a trade-in program the solution?

    PubMed

    Sorensen, Julie A; Conway, George A; DeSpain, Michael S; Wyckoff, Sherry; Bayes, Barbara; May, John J

    2011-01-01

    Tractor overturns are the leading cause of work-related death in an industry with the highest occupational fatality rate. Rollover protective structures (ROPS) and seatbelts are 99% effective in reducing the risk of an overturn fatality. However, kits are not available for 20% of tractors currently lacking ROPS. For these tractor owners, two potential solutions have been discussed: (1) technology for reinforcing tractor axles to accommodate ROPS and (2) a pre-ROPS tractor removal program. The purpose of this study was to conduct preliminary research to assess the feasibility of a tractor trade-in program. Focus groups were conducted with pre-ROPS tractor owners and tractor dealers. The data were analyzed using a concept development analytical approach and results were reviewed in an industry stakeholder's workgroup session. Data from the research indicates that tractor owners and dealers would need persuasive financial incentives to participate in a trade-in program. The workgroup session also indicated that it would be difficult to fund or support a large-scale initiative, and the economics of removing a large group of older tractors from the marketplace may exacerbate financial roadblocks. However, the data from this study could be used to pilot test a small-scale, focused, tractor buy-back program.

  17. A Spatial Cluster Analysis of Tractor Overturns in Kentucky from 1960 to 2002

    PubMed Central

    Saman, Daniel M.; Cole, Henry P.; Odoi, Agricola; Myers, Melvin L.; Carey, Daniel I.; Westneat, Susan C.

    2012-01-01

    Background Agricultural tractor overturns without rollover protective structures are the leading cause of farm fatalities in the United States. To our knowledge, no studies have incorporated the spatial scan statistic in identifying high-risk areas for tractor overturns. The aim of this study was to determine whether tractor overturns cluster in certain parts of Kentucky and identify factors associated with tractor overturns. Methods A spatial statistical analysis using Kulldorff's spatial scan statistic was performed to identify county clusters at greatest risk for tractor overturns. A regression analysis was then performed to identify factors associated with tractor overturns. Results The spatial analysis revealed a cluster of higher than expected tractor overturns in four counties in northern Kentucky (RR = 2.55) and 10 counties in eastern Kentucky (RR = 1.97). Higher rates of tractor overturns were associated with steeper average percent slope of pasture land by county (p = 0.0002) and a greater percent of total tractors with less than 40 horsepower by county (p<0.0001). Conclusions This study reveals that geographic hotspots of tractor overturns exist in Kentucky and identifies factors associated with overturns. This study provides policymakers a guide to targeted county-level interventions (e.g., roll-over protective structures promotion interventions) with the intention of reducing tractor overturns in the highest risk counties in Kentucky. PMID:22291980

  18. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    Brad Lawarre, a crawler engineer and driver on the Test and Operations Support Contract, monitors the progress from one of the crawler-transporter 2 (CT-2) cabs as the vehicle moves slowly along the crawlerway toward the Vehicle Assembly Building at NASA's Kennedy Space Center Florida. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  19. STS-101 Atlantis aboard the crawler-transporter on way to LC-39A

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Passing by a palm tree, the Space Shuttle Atlantis aboard the crawler-transporter makes its way to Launch Pad 39A. The crawler- transporter carries its cargo at 1 mph, taking about five hours to cover the 3.4 miles from the Vehicle Assembly Building to the launch pad. A leveling system on the crawler-transporter keeps the top of the Space Shuttle vertical, especially negotiating the ramp leading to the launch pads and when it is raised and lowered on pedestals at the pad. Liftoff of Atlantis on mission STS-101 is scheduled for April 17 at 7:03 p.m. EDT. STS-101 is a logistics and resupply mission for the International Space Station, to restore full redundancy to the International Space Station power system in preparation for the arrival of the next pressurized module, the Russian-built Zvezda.

  20. Side slope stability of articulated-frame logging tractors

    Treesearch

    H.G. Gibson; K.C. Elliott; S.P.E. Persson

    1971-01-01

    Many log or pulpwood transporting machines have hinged or articulated frames for steering. The articulated frame offers advantages for these machines, but the design introduces some problems in stability. We formulated and analyzed a mathematical model simulating stability of a 4-wheel-drive, articulated frame logging tractor (wheeled skidder) at static or low constant...

  1. Tractor Mechanic--Student Material. Competency Based Education Curriculum.

    ERIC Educational Resources Information Center

    McCann, Edward W.

    Developed to assist vocational agricultural mechanics students in learning to be tractor mechanics, this curriculum guide contains all the student competency sheets which comprise this competency-based curriculum. These competency sheets are categorized under sixteen instructional units. The first two units cover employment opportunities and…

  2. Tractor Mechanic--Student Material. Competency Based Education Curriculum.

    ERIC Educational Resources Information Center

    McCann, Edward W.

    Developed to assist vocational agricultural mechanics students in learning to be tractor mechanics, this curriculum guide contains all the student competency sheets which comprise this competency-based curriculum. These competency sheets are categorized under sixteen instructional units. The first two units cover employment opportunities and…

  3. Math on the Job. Tractor-Trailer Driver.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This booklet is intended to help mainstreamed mentally retarded, emotionally disturbed, or learning disabled high school students acquire a basic understanding of the responsibilities and working conditions of tractor-trailer drivers and to practice basic math skills necessary in the occupation. The first section provides a brief introduction to…

  4. SmartWay Mark Signature Page: Tractors & Trailers

    EPA Pesticide Factsheets

    This SmartWay agreement is for companies and organizations who wish to comply with the SmartWay Graphic Standards and Usage Guide guidelines and requirements for using the SmartWay logos on SmartWay designated Tractors and Trailers.

  5. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    Crawler-transporter 2 (CT-2) moves slowly along the crawlerway on its way back to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  6. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    Crawler-transporter 2 (CT-2) moves slowly along the crawlerway toward the Vehicle Assembly Building (in the background) at NASA's Kennedy Space Center in Florida. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  7. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    Crawler-transport 2 (CT-2) moves slowly along the crawlerway on its way back to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The crawler took a trip to the pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  8. Safety status of farm tractors that operate on public highways in four rural Kentucky counties.

    PubMed

    Cole, H P; Piercy, L R; Heinz, K L; Westneat, S C; Arrowsmith, H E; Raymond, K M

    2009-07-01

    Kentucky FFA students inspected 153 farm tractors for safety features that prevent operator injuries during tractor overturns, highway collisions, runovers, and power take-off (PTO) entanglements. Tractor mean age was 23.6 years (SD = 20.9). Rollover protective structures (ROPS) were present on 50.66% of tractors, but only 33.33% of these had functional seatbelts. Loose and damaged seats were found on 30.46% of tractors. In 38.99% of cases, tractor rear-wheel fenders exposed operators to moving tractor tires, and 48.67% of tractors had dangerously worn or damaged tires. Tractors with a narrow front-end stance comprised 16.11% of the total. Only 53.06% of the tractors had starters with secure hard cover by-pass starting shields that fully covered the starter terminals, and 37.37% had fully exposed terminals with no cover. PTO master shields with all parts present and undamaged were present on only 29.27% of the tractors, and in 39.02% of cases the entire shield was missing. Only 44.67% of the tractors had properly mounted and fully functional mounting and dismounting access steps and handholds. SMV emblems were missing on 53.64% of tractors and in the proper place and condition in only 25.83% of cases. Tractors with properly mounted and fully functional head and tail lights comprised 40.94% of the sample, and tractors with no functional lights comprised 24.16%. Properly mounted, clean, and functional rearview mirrors were present on only 19.87% of the tractors, and 69.54% had no rearview mirrors. The project increased farming and non-farming students' awareness of tractor safety issues, provided empirical data about the safety status of a sample of tractors that frequently travel public highways in four rural Kentucky farming counties, and promoted dialog about these issues with adult farmers and other community members with whom the students interacted.

  9. Design and experimental validation of a simple controller for a multi-segment magnetic crawler robot

    NASA Astrophysics Data System (ADS)

    Kelley, Leah; Ostovari, Saam; Burmeister, Aaron B.; Talke, Kurt A.; Pezeshkian, Narek; Rahimi, Amin; Hart, Abraham B.; Nguyen, Hoa G.

    2015-05-01

    A novel, multi-segmented magnetic crawler robot has been designed for ship hull inspection. In its simplest version, passive linkages that provide two degrees of relative motion connect front and rear driving modules, so the robot can twist and turn. This permits its navigation over surface discontinuities while maintaining its adhesion to the hull. During operation, the magnetic crawler receives forward and turning velocity commands from either a tele-operator or high-level, autonomous control computer. A low-level, embedded microcomputer handles the commands to the driving motors. This paper presents the development of a simple, low-level, leader-follower controller that permits the rear module to follow the front module. The kinematics and dynamics of the two-module magnetic crawler robot are described. The robot's geometry, kinematic constraints and the user-commanded velocities are used to calculate the desired instantaneous center of rotation and the corresponding central-linkage angle necessary for the back module to follow the front module when turning. The commands to the rear driving motors are determined by applying PID control on the error between the desired and measured linkage angle position. The controller is designed and tested using Matlab Simulink. It is then implemented and tested on an early two-module magnetic crawler prototype robot. Results of the simulations and experimental validation of the controller design are presented.

  10. Personal noise exposures of operators of agricultural tractors.

    PubMed

    Aybek, Ali; Kamer, H Atil; Arslan, Selçuk

    2010-03-01

    Approximately one million agricultural tractors are used in Turkey for crop production and about one-third of the population lives in rural areas. The objectives of this study were to determine sound pressure levels, A-weighted sound pressure levels, and the permissible exposure time for tractors without cabins, field-installed cabins, and original cabins at ear level of agricultural tractor operators for following machines: plows, cultivators, top soil cultivators, rotary tillers, tool combinations (harrow+roller), mechanical drills, pneumatic drills, chemical applicators, fertilizer applicators, drum mowers, balers, and forage harvesters. Variance analyses showed that type of operation, type of cabins, and operation x cabin interactions were statistically significant (P<0.01) both for sound pressure levels and equivalent (A-weighted) sound pressure levels. The use of original cabins had a greater effect in decreasing average sound pressures and resulted in more efficient noise insulation, especially at higher center frequencies compared to field-installed cabins whereas field-installed cabins proved to be more favorable compared to tractors without cabins. Sound pressure levels at 4000Hz center frequency was reduced 2-13dB and 4-18dB by using a field-installed cabin and an original cabin, respectively. The measured A-weighted equivalent sound pressure levels were compared to the threshold limit level, and was concluded that depending on the cabin types used, the operators could usually work from 4 to 6h a day without suffering from noise induced inconveniences while 2-3h is permissible for plowing and forage harvesting on tractors without cabins. Due to timeliness considerations in agricultural machine operations, a farmer would not be willing to interrupt the operation based on permissible exposure time set by the standards. Based on the findings of this study, particularly an original cabin is recommended to reduce machine-induced noise below the danger limit

  11. Farm tractors, and the use of seat belts and roll-over protective structures.

    PubMed

    Kelsey, T W; May, J J; Jenkins, P L

    1996-10-01

    Roll-over protective structures (ROPS) on farm tractors could significantly reduce the rate of fatal occupational injury on farms, but comparatively few tractors have them. Many of the policy discussions have focused on trying to identify the percentage of tractors that do not have ROPS, even though such a focus probably does not accurately represent effective protection by ROPS. This study investigates whether including differences in hours of usage, tractor activities, and seat belt use affects estimates of farm operators' protection by ROPS. In general, tractors used more hours a year were more likely to have ROPS. ROPS status also varied by tractor activity. When adjusting for seat belt use, effective ROPS protection is much less than when considering just ROPS status. Measures of the effective coverage of ROPS and policy responses should reflect these differences in hours, activities, and seat belt use.

  12. Helical tractor beam: analytical solution of Rayleigh particle dynamics.

    PubMed

    Carretero, Luis; Acebal, Pablo; Garcia, Celia; Blaya, Salvador

    2015-08-10

    We analyze particle dynamics in an optical force field generated by helical tractor beams obtained by the interference of a cylindrical beam with a topological charge and a co-propagating temporally de-phased plane wave. We show that, for standard experimental conditions, it is possible to obtain analytical solutions for the trajectories of particles in such force field by using of some approximations. These solutions show that, in contrast to other tractor beams described before, the intensity becomes a key parameter for the control of particle trajectories. Therefore, by tuning the intensity value the particle can describe helical trajectories upstream and downstream, a circular trajectory in a fixed plane, or a linear displacement in the propagation direction. The approximated analytical solutions show good agreement to the corresponding numerical solutions of the exact dynamical differential equations.

  13. Development and testing of an electric farm tractor

    SciTech Connect

    Christianson, L.L.; Alcock, R.; Froehlich, D.; Knabach, W.; Endahl, L.

    1985-01-01

    The battery-powered tractor, Electric Choremaster I, designed, built, and tested at South Dakota State University, is an 80 hp, high-clearance vehicle intended for all-weather applications and for commercial and industrial applications which require a loader/backhoe. Electric Choremaster II is a skid-steer tractor of 40 hp for in-building work and commercial applications requiring compact size and sharp-turning capability. Following a review of the literature on electric vehicles, the authors describe the technology and design and the results of performance tests and cost comparisons. Design changes on the basis of these tests will improve life-cycle costs. 8 references, 3 figures, 3 tables.

  14. Rollover protection on New York tractors and farmers' readiness for change.

    PubMed

    May, J J; Sorensen, J A; Burdick, P A; Earle-Richardson, G B; Jenkins, P L

    2006-08-01

    Tractor overturns contribute significantly to fatalities in New York State agriculture. On-site inspections a decade ago indicated that approximately 60% of tractors were without effective rollover protection. Our objectives were: to describe the current prevalence and distribution of rollover protective structures (ROPS) on New York farm tractors, to identify characteristics associated with the absence of ROPS, to explore segmenting the New York farm community on readiness for ROPS retrofitting, and to identify demographic characteristics that might assist in this segmenting. A random selection of 644 livestock, dairy, fruit, cash crop, vegetable, and organic farms were contacted for a telephone survey. Of 562 farms (87%) participating, 102 (18.1%) had all tractors equipped with ROPS and 138 (24.6%) had none. A disproportionate number of livestock, cash crop, and organic operations had no ROPS. Rates of ROPS-equipped tractors correlated directly with farm size and annual hours of tractor operation. Older farmers had a lower proportion of ROPS tractors. The presence of a child operator did not affect the proportion of ROPS tractors. After weighting the sample, the total number of non-ROPS tractors in New York is estimated at more than 80,000. In addition to providing key farm demographics, the survey enabled placement of farmers on a "stage of change" continuum related to readiness for retrofitting. Three-quarters of New York farmers are in the "precontemplation" stage of change relative to ROPS retrofitting, and this varies little by size of operation, age of farmer, or the presence of child tractor operators. Stage of change may relate to hours of tractor operation (p = 0.05) and does relate to commodity (p = 0.003) due primarily to the higher proportion of crop farmers in the earliest stage of change. The goal of retrofitting all New York farm tractors with ROPS appears nearly as daunting as it did a decade ago.

  15. [The differential diagnosis of the types of trauma caused by wheeled tractors].

    PubMed

    Zaval'niuk, A Kh

    1993-01-01

    Examinations of 23 corpses and study of 282 expert conclusions concerning the deaths of subjects aged 6 to 78 dead because of wheeled tractor injuries under agricultural conditions helped detect the specific characteristic signs of tractor injury types. Mathematical method of analysis of the characteristic features' quantitative parameters permitted the author to find statistically reliable criteria for differential diagnosis of the types of injuries inflicted by wheeled tractors. The possibility of correct conclusions of an expert using this method is at least 95%.

  16. Operational characteristics of tractors driven by children on farms in the United States and Canada.

    PubMed

    Marlenga, B; Pickett, W; Berg, R L; Murphy, D

    2004-01-01

    Farm tractors are an important source of traumatic injury for children on farms. There is, however, no documentation about the age and size of tractors that children are operating and little information about the frequency with which rollover protective structures (ROPS) are used. This study described tractors that children on farms in the U.S. and Canada were operating by age, horsepower, and the presence of ROPS, according to the age and gender of the farm children involved. As a sub-analysis of data compiled during a randomized controlled trial, a descriptive analysis was completed on work exposure data collected by telephone interview. Of the 1,113 children involved in the trial, 522 (47%) were reported to perform at least one job that involved the operation of a farm tractor, and 408 (36.7%) were operating tractors of at least 20 horsepower. The majority of these children were male. There was a wide range of ages and sizes of tractors operated. However, the majority of tractors were between 20 and 70 horsepower and manufactured after 1970. Nearly one-half of the tractors were equipped with ROPS, and these tended to be newer and larger tractors. This analysis provides new data about the broad range of tractors driven by farm children in the U.S. and Canada. The findings point to a need to re-examine the reliance on a single voluntary standard to mitigate the hazard of tractor rollovers and the need for an enhanced safety policy requiring all tractors operated by children be equipped with ROPS.

  17. Alcohol fueled farm tractors compete favorably, with diesel in Brazil tests

    SciTech Connect

    Finch, E.O.; Brandini, A.

    1984-08-01

    Heavy duty alcohol powered engines are suitable to tractors. In Brazil diesel and alcohol tractors of the same configuration, weight, and engine size running side by side, indicated superior field performance of the alcohol tractor and a time saving of about 5-10% for the same work schedule. Lifetime and maintenance factors, chemical energy to mechanical work conversion efficiencies, thermal efficiency, fuel consumption, starting procedure and other considerations are discussed.

  18. System identification, adaptive control and formation driving of farm tractors

    NASA Astrophysics Data System (ADS)

    Rekow, Andrew Karl Wilhelm

    Great increases in agricultural productivity and profitability can be gained by increasing the navigational control accuracy of a farm tractor. To maximize accuracy in the presence of environmental uncertainties, a novel technique for on-line parameter identification has been developed. This method combines the Extended Kalman Filter (EKF) and the Least Mean Square (LMS) algorithms and is used to identify key parameters which describe the dynamics of a farm tractor. This algorithm provides a 15:1 improvement in computational efficiency over the traditional EKF, while offering comparable convergence rates and noise rejection properties. Experimental data on a full-sized John Deere tractor shows a 25 percent improvement in lateral accuracy when using then adaptive controller versus a fixed controller over identical trajectories. In addition to parameter identification, farmers require formation driving capability for routine operations. Multiple farm vehicles work cooperatively together to accomplish a common goal. Several formation driving algorithms were developed for these varying requirements. An experimental implementation of a fully autonomous farm vehicle following a human operated lead vehicle demonstrated an accuracy of 10 centimeters in the in-track direction and 10 centimeters in the cross track direction.

  19. High-speed optimal steering of a tractor-semitrailer

    NASA Astrophysics Data System (ADS)

    Cheng, Caizhen; Roebuck, Richard; Odhams, Andrew; Cebon, David

    2011-04-01

    A high-speed optimal trailer steering controller for a tractor-semitrailer is discussed. A linear model of a tractor-semitrailer with steered trailer axles is described, and an optimal trailer steering controller is introduced. A path-following controller is derived to minimise the path-tracking error in steady-state manoeuvres using active trailer steering. A roll stability controller is introduced by adding the lateral acceleration of trailer centre of gravity as another objective in the steering controller, so as to improve roll stability in transient manoeuvres. A strategy to switch between these two control modes is demonstrated. Simulation results show that the steering controller can ensure good path tracking of articulated vehicles in steady-state manoeuvres and improve roll stability significantly in transient manoeuvres, while maintaining the path-tracking deviation within an acceptable range. Tests with an experimental tractor-semitrailer equipped with a high-bandwidth active steering system validate the controller design and simulation results. The roll stability controller reduces the measured rearward amplification by 27%.

  20. Innovative Sensors for Pipeline Crawlers: Rotating Permanent Magnet Inspection

    SciTech Connect

    J. Bruce Nestleroth; Richard J. Davis; Stephanie Flamberg

    2006-09-30

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they may encounter. To facilitate inspection of these ''unpiggable'' pipelines, recent inspection development efforts have focused on a new generation of powered inspection platforms that are able to crawl slowly inside a pipeline and can maneuver past the physical barriers that limit internal inspection applicability, such as bore restrictions, low product flow rate, and low pressure. The first step in this research was to review existing inspection technologies for applicability and compatibility with crawler systems. Most existing inspection technologies, including magnetic flux leakage and ultrasonic methods, had significant implementation limitations including mass, physical size, inspection energy coupling requirements and technology maturity. The remote field technique was the most promising but power consumption was high and anomaly signals were low requiring sensitive detectors and electronics. After reviewing each inspection technology, it was decided to investigate the potential for a new inspection method. The new inspection method takes advantage of advances in permanent magnet strength, along with their wide availability and low cost. Called rotating permanent magnet inspection (RPMI), this patent pending technology employs pairs of permanent magnets rotating around the central axis of a cylinder to induce high current densities in the material under inspection. Anomalies and wall thickness variations are detected with an array of sensors that measure local changes in the magnetic field produced by the induced current flowing in the material. This inspection method is an alternative to the common concentric coil remote field technique that induces low-frequency eddy

  1. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    A ground support technician walks alongside crawler-transporter 2 (CT-2) as the vehicle moves slowly along the crawlerway toward the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  2. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    A full view of crawler-transporter 2 (CT-2) as it moves slowly along the crawlerway on its way back to the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  3. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    Crawler-transporter 2 (CT-2) moves slowly along the crawlerway on its way back to the Vehicle Assembly Building (in view in the background) at NASA's Kennedy Space Center in Florida. Water sprayed by a truck in front to reduce dust creates a small rainbow. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  4. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    Ground support technicians walks alongside crawler-transporter 2 (CT-2) as the vehicle moves slowly along the crawlerway toward the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  5. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    A ground support technician checks the new hydraulic cylinders on crawler-transporter 2 (CT-2) as the vehicle moves slowly along the crawlerway toward the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  6. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    Ground support technicians check out the treads on crawler-transporter 2 (CT-2) as the vehicle moves slowly along the crawlerway toward the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  7. Crawler Transporter 2 (CT-2) Trek from Pad 39B to VAB

    NASA Image and Video Library

    2017-03-21

    A ground support technician checks the giant treads on crawler-transporter 2 (CT-2) as the vehicle moves slowly along the crawlerway toward the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The crawler took a trip to the pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.

  8. 29 CFR 1926.1001 - Minimum performance criteria for rollover protective structures for designated scrapers, loaders...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-tired dozers, and motor graders; and Figure W-4 for crawler tractors and crawler-type loaders. (2) Table... structures for designated scrapers, loaders, dozers, graders, and crawler tractors. 1926.1001 Section 1926... designated scrapers, loaders, dozers, graders, and crawler tractors. (a) General. This section...

  9. 29 CFR 1926.1003 - Overhead protection for operators of agricultural and industrial tractors used in construction.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... industrial tractors used in construction. 1926.1003 Section 1926.1003 Labor Regulations Relating to Labor... protection for operators of agricultural and industrial tractors used in construction. (a) General—(1) Purpose. When overhead protection is provided on wheel-type agricultural and industrial tractors, the...

  10. 29 CFR 1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Front end weight shall be at least 25 percent of the tractor test weight. In case power take-off... tractors shall meet the test and performance requirements of 29 CFR 1928.52, 1928.53, or 1926.1002 as appropriate. A ROPS used on track-type tractors shall meet the test and performance requirements of 29...

  11. A Tractor or an Automobile? A 1920s Farm Family Faces a Decision.

    ERIC Educational Resources Information Center

    Kunze, Joel P.

    1991-01-01

    Outlines a lesson plan in which students role play a 1920s farm family deciding whether to buy an automobile or a tractor. Other students act as automobile and tractor sales groups. Explains how the lesson illuminates relationships between technological advance and social history. Includes handouts identifying benefits of purchasing cars or…

  12. Forces required to operate controls on farm tractors: implications for young operators.

    PubMed

    Fathallah, F A; Chang, J H; Berg, R L; Pickett, W; Marlenga, B

    2008-07-01

    Farm tractors account for the majority of fatal injuries to adolescents working in agriculture and therefore remain a leading occupational priority. The question of whether these injuries occur because adolescents are assigned tractor jobs beyond their physical capabilities has not been answered. The purpose of this study was to estimate the activation forces required to operate controls on 40 tractors in common use in the US and compare them with existing estimates of physical strength for children of varying ages and with recommended ergonomic force limits for repeatedly engaging controls. Activation forces for steering, brakes and clutch were measured on each tractor. The main study finding was that the activation forces required to operate tractors typically exceeded the physical abilities of most children aged 13 to 17 years. This raises serious questions about the ability of children to safely operate tractors in common use on US farms. This study provides an ergonomic approach for evaluating the potential mismatch between young people's strength capabilities and forces required in operating farm tractors. This approach could be used in similar situations where adolescents may operate vehicles (e.g. all-terrain vehicles), machinery or other mechanical devices requiring activation of levers and controls. Study findings potentially inform the establishment of occupational policies surrounding tractor operation by young people.

  13. Evaluation of a policy to reduce youth tractor crashes on public roads.

    PubMed

    Marlenga, B; Doty, B C; Berg, R L; Linneman, J G

    2006-02-01

    Evaluate the effectiveness of a United States state law, Wisconsin Act 455, in reducing highway tractor crashes involving youth operators. Policy outcome evaluation involving review of a retrospective case series. Youth highway tractor crashes from Wisconsin for the years 1994-2003 that resulted in a fatality, injury, and/or property damage. One hundred and forty six tractor crash cases involving operators younger than 16 years. Describe and model the tractor crash patterns before and after enactment of the law, and examine the relation between the contributing circumstances identified in the crash reports and the content covered in the mandated tractor certification course. There was neither a significant change in the number of youth tractor crashes after the law was passed, nor any reduction in the proportion of crashes where the youth operator was designated at fault. The tractor certification course did not cover the major factors contributing to youth tractor crashes on public roads. No significant effect of the law was detected and crash rates at the end of the study period were similar to those before Wisconsin Act 455. The authors'findings should not be construed to suggest that public policy, in general, is an ineffective strategy for the prevention of pediatric agricultural injuries. Negotiating a balance in public policy debates will be a challenge, but it is clear that future policy initiatives need to identify and implement the right policy for the right problem.

  14. 75 FR 82219 - Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-802A Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-30

    .... Models AT-802 and AT- 802A Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... Tractor, Inc. (Air Tractor) Models AT-802 and AT-802A airplanes. That AD currently requires you to... spar lower caps at the center splice joint for cracks and repair or replace any cracked spar,...

  15. 76 FR 9495 - Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-802A Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-18

    .... Models AT-802 and AT- 802A Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... Directive (AD) 2010-17-18, which applied to these products: Air Tractor, Inc. (Air ] Tractor) Models AT-802... at the center splice joint for cracks and repair or replace any cracked spar, and changes the...

  16. 75 FR 35616 - Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-802A Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    .... Models AT-802 and AT- 802A Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... supersede AD 2006-08-09, which applies to all Air Tractor, Inc. (Air Tractor) Models AT-802 and AT-802A... two outboard fastener holes in both of the wing main spar lower caps at the center splice joint...

  17. Research on preprocessing method of tractor wheel speed signal based on wavelet transform

    NASA Astrophysics Data System (ADS)

    Zhili, Zhou; Yao, Liu; Liyou, Xu

    2017-09-01

    As one of the most important parameters in the measurement of tractor slip ratio, wheel speed signal must ensure its accuracy in order to accurately measure the tractor slip ratio. Noises make tractor wheel speed signal a significant fluctuation, which may cause control system failure. Fault points elimination method suitable for tractor wheel speed signal was determined based on the characteristics of tractor wheel speed signal during working process. Meanwhile, soft-hard compromise threshold function wavelet denoising method is designed according to the characteristics of tractor wheel speed signal and trials. We use Carsim simulation software to get actual tractor wheel speed signal, and add white noise which SNR (signal to noise ratio) is 60 to the original signal. From the results of several wavelet denoising methods we can conclude that the soft-hard compromise threshold function wavelet denoising method is better than any other ordinary wavelet denoising methods. The SNR of denoised signal is 56.440 and the MSE (mean square error) is 0.0042. The wavelet transform denoising method is feasible to remove noise from tractor driving wheel speed signal.

  18. Design and implementation of a GPS guidance system for agricultural tractors using augmented reality technology.

    PubMed

    Santana-Fernández, Javier; Gómez-Gil, Jaime; del-Pozo-San-Cirilo, Laura

    2010-01-01

    Current commercial tractor guidance systems present to the driver information to perform agricultural tasks in the best way. This information generally includes a treated zones map referenced to the tractor's position. Unlike actual guidance systems where the tractor driver must mentally associate treated zone maps and the plot layout, this paper presents a guidance system that using Augmented Reality (AR) technology, allows the tractor driver to see the real plot though eye monitor glasses with the treated zones in a different color. The paper includes a description of the system hardware and software, a real test done with image captures seen by the tractor driver, and a discussion predicting that the historical evolution of guidance systems could involve the use of AR technology in the agricultural guidance and monitoring systems.

  19. CO{sub 2} Laser Ablation Propulsion Tractor Beams

    SciTech Connect

    Sinko, John E.; Schlecht, Clifford A.

    2010-05-06

    Manipulation of objects at a distance has already been achieved with no small measure of success in the realm of microscopic objects on the scale size of nanometers to micrometers in applications including laser trapping and laser tweezers. However, there has been relatively little effort to apply such remote control to macroscopic systems. A space tractor beam could be applied to a wide range of applications, including removal of orbital debris, facilitation of spacecraft docking, adjustment of satellite attitude or orbital position, etc. In this paper, an ablative laser propulsion tractor beam is demonstrated based on radiation from a CO{sub 2} laser. Cooperative, layered polymer targets were used for remote impulse generation using a CO{sub 2} laser. The use of a structured ablatant enabling switching between thrust directional parity (i.e., forward or reverse) and imparting torque to a remote target. Fluence-dependent results are presented in the context of polymer ablation modeling work and with consideration of confined ablation effects.

  20. Retrofitting tractors with rollover protective structures: perspective of equipment dealers.

    PubMed

    Tonelli, S M; Donham, K J; Leedom-Larson, K; Sanderson, W; Purschwitz, M

    2009-10-01

    This study was one of a cluster of studies that originated via requests for proposals from the NIOSH National Agricultural Tractor Safety Initiative. The present study design consisted of several steps: (1) formation of an advisory group, (2) development and testing of a standard paper self-responding survey instrument, (3) sample selection of farm equipment dealers, (4) administration of the survey, (5) assessment and analysis of the survey, and (6) in-person response panel of dealers (n = 80) to review results of the questionnaire for further definition and sharpening of the recommendations from the survey. A key finding is that most dealers do not currently sell or install ROPS retrofit kits. Barriers cited by dealers included (1) actual or perceived lack of farmer demand, (2) injury liability, (3) expensive freight for ordering ROPS, (4) lack of dealer awareness of the magnitude of deaths from tractor overturns and the high life-protective factor of ROPS, and (5) difficulty and incursion of non-recoverable expenses in locating and obtaining specific ROPS. Despite not currently selling or installing ROPS, dealers responded favorably about their future potential role in ROPS promotion and sales. Dealers were willing to further promote, sell, and install ROPS if there was demand from farmers. Recommendations include establishing a ROPS "clearing house" that dealers could contact to facilitate locating and obtaining ROPS orders from customers. Additional recommendations include education and social marketing targeting farm machinery dealers as well farmers, manufacturers, and policy makers.

  1. Prevalence of ROPS-equipped tractors in U.S. aquaculture.

    PubMed

    Myers, M L; Westneat, S C; Myers, J R; Cole, H P

    2009-04-01

    Aquaculture involves the production of plant and animal products that are cultured in water. The principal freshwater fishes raised in the U.S. are catfish (raised mainly in ponds) and trout (raised mostly in concrete raceways), and the principal crustaceans grown are shrimp, crayfish, oysters, and clams. Tractors are used on aquaculture farms mostly in pond culture. Ponds present overturn hazards because of the slopes of levees, slippery conditions, and nighttime driving. Protection is afforded to the tractor operator when a rollover protective structure (ROPS) is attached to the tractor. The purpose of this study was to analyze and describe the prevalence of ROPS-equipped tractors on farms engaged in aquaculture in the U.S. The analysis concluded that 78% of tractors used in aquaculture were equipped with a ROPS, in contrast with the prevalence of ROPS at 49% for all of agriculture. Moreover, 91% of the tractors in the South used for aquaculture were equipped with a ROPS. The national sample for aquaculture included 75 farms and 137 tractors, which is small, but nonetheless, several hypotheses can be generated as a result of this descriptive study.

  2. Parental knowledge of child development and the assignment of tractor work to children.

    PubMed

    Pickett, William; Marlenga, Barbara; Berg, Richard L

    2003-07-01

    Many childhood farm tractor injuries occur during the performance of work that was assigned by parents, and some tractor work is beyond the developmental capabilities of children. This has been highlighted recently by a policy statement authored by the American Academy of Pediatrics. The objective of this study was 1) to assess child development knowledge of farm parents who received a new resource, the North American Guidelines for Children's Agricultural Tasks (NAGCAT), and 2) to determine whether this knowledge was associated with use of NAGCAT in the assignment of tractor jobs and with compliance with 2 aspects of the NAGCAT tractor guideline. Secondary analysis of data collected during a randomized controlled trial that involved 450 farms in the United States and Canada was conducted. Variables assessed included 1) parental knowledge of child development across several age groups and 3 domains of child development (physical, cognitive, and psychosocial), 2) documentation of the most common tractor jobs assigned to each child, and 3) a report of whether NAGCAT was used in assigning these tractor jobs. High parental knowledge of child development was associated with enhanced use of NAGCAT and fewer violations when assigning tractor work to children. However, even in the presence of high knowledge, some farm parents still assigned to their children work that was in violation of NAGCAT. Educational interventions by themselves are not sufficient to remove many farm children from known occupational hazards. These findings are discussed in light of the recent policy statement on agricultural injuries from the American Academy of Pediatrics.

  3. Action Learning: a new method to increase tractor rollover protective structure (ROPS) adoption.

    PubMed

    Biddle, Elyce Anne; Keane, Paul R

    2012-01-01

    Action Learning is a problem-solving process that is used in various industries to address difficult problems. This project applied Action Learning to a leading problem in agricultural safety. Tractor overturns are the leading cause of fatal injury to farmworkers. This cause of injury is preventable using rollover protective structures (ROPS), protective equipment that functions as a roll bar structure to protect the operator in the event of an overturn. For agricultural tractors manufactured after 1976 and employee operated, Occupational Safety and Health Administration (OSHA) regulation requires employers to equip them with ROPS and seat belts. By the mid-1980s, US tractor manufacturers began adding ROPS on all farm tractors over 20 horsepower sold in the United States (http://www.nasdonline.org/document/113/d001656/rollover-protection-for-farm-tractor-operators.html). However, many older tractors remain in use without ROPS, putting tractor operators at continued risk for traumatic injury and fatality. For many older tractor models ROPS are available for retrofit, but for a variety of reasons, tractor owners have not chosen to retrofit those ROPS. The National Institute for Occupational Safety and Health (NIOSH) attempted various means to ameliorate this occupational safety risk, including the manufacture of a low-cost ROPS for self-assembly. Other approaches address barriers to adoption. An Action Learning approach to increasing adoption of ROPS was followed in Virginia and New York, with mixed results. Virginia took action to increase the manufacturing and adoption of ROPS, but New York saw problems that would be insurmountable. Increased focus on team composition might be needed to establish effective Action Learning teams to address this problem.

  4. Action Learning: A New Method to Increase Tractor Rollover Protective Structure (ROPS) Adoption

    PubMed Central

    Biddle, Elyce Anne; Keane, Paul R.

    2016-01-01

    Action Learning is a problem-solving process that is used in various industries to address difficult problems. This project applied Action Learning to a leading problem in agricultural safety. Tractor overturns are the leading cause of fatal injury to farmworkers. This cause of injury is preventable using rollover protective structures (ROPS), protective equipment that functions as a roll bar structure to protect the operator in the event of an overturn. For agricultural tractors manufactured after 1976 and employee operated, Occupational Safety and Health Administration (OSHA) regulation requires employers to equip them with ROPS and seat belts. By the mid-1980s, US tractor manufacturers began adding ROPS on all farm tractors over 20 horsepower sold in the United States (http://www.nasdonline.org/document/113/d001656/rollover-protection-for-farm-tractor-operators.html). However, many older tractors remain in use without ROPS, putting tractor operators at continued risk for traumatic injury and fatality. For many older tractor models ROPS are available for retrofit, but for a variety of reasons, tractor owners have not chosen to retrofit those ROPS. The National Institute for Occupational Safety and Health (NIOSH) attempted various means to ameliorate this occupational safety risk, including the manufacture of a low-cost ROPS for self-assembly. Other approaches address barriers to adoption. An Action Learning approach to increasing adoption of ROPS was followed in Virginia and New York, with mixed results. Virginia took action to increase the manufacturing and adoption of ROPS, but New York saw problems that would be insurmountable. Increased focus on team composition might be needed to establish effective Action Learning teams to address this problem. PMID:22994641

  5. Fatalities associated with improper hitching to farm tractors--New York, 1991-1995.

    PubMed

    1996-04-19

    Approximately half of all injury-related fatalities in the agricultural industry are associated with farm tractors (1). Since April 1991, the New York State Department of Health's Occupational Health Nurses in Agricultural Communities (OHNAC) program has investigated 27 incidents of sudden rear rollover of farm tractors (i.e., incidents in which the tractor flips backward, rotating around its rear axle); these incidents resulted in 15 fatalities. This report describes four of these incidents, summarizes the characteristics of the 16 incidents that involved improper hitching, and outlines strategies for reducing the risk for their occurrence.

  6. ANNULUS CLOSURE TECHNOLOGY DEVELOPMENT INSPECTION/SALT DEPOSIT CLEANING MAGNETIC WALL CRAWLER

    SciTech Connect

    Minichan, R; Russell Eibling, R; James Elder, J; Kevin Kane, K; Daniel Krementz, D; Rodney Vandekamp, R; Nicholas Vrettos, N

    2008-06-01

    The Liquid Waste Technology Development organization is investigating technologies to support closure of radioactive waste tanks at the Savannah River Site (SRS). Tank closure includes removal of the wastes that have propagated to the tank annulus. Although amounts and types of residual waste materials in the annuli of SRS tanks vary, simple salt deposits are predominant on tanks with known leak sites. This task focused on developing and demonstrating a technology to inspect and spot clean salt deposits from the outer primary tank wall located in the annulus of an SRS Type I tank. The Robotics, Remote and Specialty Equipment (RRSE) and Materials Science and Technology (MS&T) Sections of the Savannah River National Laboratory (SRNL) collaborated to modify and equip a Force Institute magnetic wall crawler with the tools necessary to demonstrate the inspection and spot cleaning in a mock-up of a Type I tank annulus. A remote control camera arm and cleaning head were developed, fabricated and mounted on the crawler. The crawler was then tested and demonstrated on a salt simulant also developed in this task. The demonstration showed that the camera is capable of being deployed in all specified locations and provided the views needed for the planned inspection. It also showed that the salt simulant readily dissolves with water. The crawler features two different techniques for delivering water to dissolve the salt deposits. Both water spay nozzles were able to dissolve the simulated salt, one is more controllable and the other delivers a larger water volume. The cleaning head also includes a rotary brush to mechanically remove the simulated salt nodules in the event insoluble material is encountered. The rotary brush proved to be effective in removing the salt nodules, although some fine tuning may be required to achieve the best results. This report describes the design process for developing technology to add features to a commercial wall crawler and the results of the

  7. The BCube Crawler: Web Scale Data and Service Discovery for EarthCube.

    NASA Astrophysics Data System (ADS)

    Lopez, L. A.; Khalsa, S. J. S.; Duerr, R.; Tayachow, A.; Mingo, E.

    2014-12-01

    Web-crawling, a core component of the NSF-funded BCube project, is researching and applying the use of big data technologies to find and characterize different types of web services, catalog interfaces, and data feeds such as the ESIP OpenSearch, OGC W*S, THREDDS, and OAI-PMH that describe or provide access to scientific datasets. Given the scale of the Internet, which challenges even large search providers such as Google, the BCube plan for discovering these web accessible services is to subdivide the problem into three smaller, more tractable issues. The first, to be able to discover likely sites where relevant data and data services might be found, the second, to be able to deeply crawl the sites discovered to find any data and services which might be present. Lastly, to leverage the use of semantic technologies to characterize the services and data found, and to filter out everything but those relevant to the geosciences. To address the first two challenges BCube uses an adapted version of Apache Nutch (which originated Hadoop), a web scale crawler, and Amazon's ElasticMapReduce service for flexibility and cost effectiveness. For characterization of the services found, BCube is examining existing web service ontologies for their applicability to our needs and will re-use and/or extend these in order to query for services with specific well-defined characteristics in scientific datasets such as the use of geospatial namespaces. The original proposal for the crawler won a grant from Amazon's academic program, which allowed us to become operational; we successfully tested the Bcube Crawler at web scale obtaining a significant corpus, sizeable enough to enable work on characterization of the services and data found. There is still plenty of work to be done, doing "smart crawls" by managing the frontier, developing and enhancing our scoring algorithms and fully implementing the semantic characterization technologies. We describe the current status of the project

  8. Detection of the relevant type of locomotion in infancy: crawlers versus walkers.

    PubMed

    Sanefuji, Wakako; Ohgami, Hidehiro; Hashiya, Kazuhide

    2008-12-01

    Human infants show a preference for individuals who are similar to them. Using point-light displays of human walkers and crawlers as stimuli, we examined whether infants' preference for the motions of crawling and walking changes between, before, and after the onset of bipedal walking. The results show that crawling and walking infants prefer the types of locomotion that are similar to their own, respectively. These indicate that the infants detect the similarities between the motions they performed and they observed, which provides the behavioral evidence that the production of a particular motion is connected to its perception in infancy.

  9. Metallurgical Design and Development of NASA Crawler/Transporter Tread Belt Shoe Castings

    NASA Technical Reports Server (NTRS)

    Parker, Donald S.

    2006-01-01

    The NASA Crawler/Transporters (CT-1 and CT-2) used to transport the Space Shuffles are one of the largest tracked vehicles in existence today. Two of these machines have been used to move space flight vehicles at Kennedy Space Center since the Apollo missions of the 1960's and relatively few modifications have been made to keep them operational. In September of 2003 during normal Crawler/Transporter operations cracks were observed along the roller pad surfaces of several tread belt shoes. Further examination showed 20 cracked shoes on CT-1 and 40 cracked shoes on CT-2 and a formal failure analysis investigation was undertaken while the cracked shoes were replaced. Six shoes were cross-sectioned with the fracture surfaces exposed and it was determined that the cracks were due to fatigue that initiated on the internal casting web channels at pre-existing casting defects and propagated through thickness both transgranularly and intergranularly between internal shrinkage cavities, porosity, and along austenitic and ferritic grain boundaries. The original shoes were cast during the 1960's using a modified 861330 steel with slightly higher levels of chromium, nickel and molybdenum followed by heat treatment to achieve a minimum tensile strength of 11 Oksi. Subsequent metallurgical analysis of the tread belt shoes after multiple failures showed excessive internal defects, alloy segregation, a nonuniform ferritic/ bainitic/martensitic microstructure, and low average tensile properties indicative of poor casting and poor heat-treatment. As a result, NASA funded an initiative to replace all of the tread belt shoes on both crawler/transporters along with a redesign of the alloy, manufacturing, and heat-treatment to create a homogeneous cast structure with uniform mechanical and metallurgical properties. ME Global, a wholly owned subsidiary of ME Elecmetal based in Minneapolis, MN was selected as manufacturing and design partner to develop the new shoes and this paper

  10. The smooth (tractor) operator: insights of knowledge engineering.

    PubMed

    Cullen, Ralph H; Smarr, Cory-Ann; Serrano-Baquero, Daniel; McBride, Sara E; Beer, Jenay M; Rogers, Wendy A

    2012-11-01

    The design of and training for complex systems requires in-depth understanding of task demands imposed on users. In this project, we used the knowledge engineering approach (Bowles et al., 2004) to assess the task of mowing in a citrus grove. Knowledge engineering is divided into four phases: (1) Establish goals. We defined specific goals based on the stakeholders involved. The main goal was to identify operator demands to support improvement of the system. (2) Create a working model of the system. We reviewed product literature, analyzed the system, and conducted expert interviews. (3) Extract knowledge. We interviewed tractor operators to understand their knowledge base. (4) Structure knowledge. We analyzed and organized operator knowledge to inform project goals. We categorized the information and developed diagrams to display the knowledge effectively. This project illustrates the benefits of knowledge engineering as a qualitative research method to inform technology design and training. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  11. Soil compaction and structural morphology under tractor wheelings

    NASA Astrophysics Data System (ADS)

    Shanahan, Peter; Quinton, John; Binley, Andrew; Silgram, Martyn

    2010-05-01

    Compaction of cultivated soils is a major problem for agriculture in terms of yield decline and sustainable soil resource management. Tramline wheelings exacerbate runoff and increase erosion from arable land. The UK Department for Environment, Food and Rural Affairs (Defra) LINK Project - a joint venture between agri-business, land managers and research groups - is currently evaluating a number of methods for alleviating compaction in tractor wheelings across a range of soil types in England. Using innovative applications of agri-geophysics (e.g. ground penetrating radar, electrical resistivity, acoustics and x-ray tomography), this current project aims to determine relationships between properties derived from geophysical methods (e.g. soil moisture, porosity), soil compaction and structural morphology. Such relationships are important for a clearer understanding of hydrological and biogeochemical processes in compacted soils, to address land management practices and develop cost-effective mitigation measures. Our poster will present some early results of this study.

  12. An investigation of drag reduction for tractor trailer vehicles

    NASA Technical Reports Server (NTRS)

    Muirhead, V. U.

    1978-01-01

    Force and moment data were obtained from a one-twenty-fifth scale wind tunnel model of a cab-over-engine tractor trailer combination. The tests define the aerodynamic characteristics of the baseline (unmodified) vehicle and several modified configurations. The primary modifications consist of: (1) greatly increased forebody corner radii, (2) a smooth fairing over the cab-to-trailer gap, (3) a smoothed underbody, and (4) rear streamlining (boattailing)of the trailer. Tests were conducted for yaw angles from 0 deg to 30 deg. The reduction in drag, relative to the baseline, obtained by combining the modifications are compared for the zero yaw condition with full scale coast down drag results for similar configurations. The drag reductions obtained from the model and full scale tests are in good agreement.

  13. Machine-Tractor Aggregates Operation Assurance by Mobile Maintenance Teams

    NASA Astrophysics Data System (ADS)

    Redreev, G. V.; Myalo, O. V.; Prokopov, S. P.; Solomkin, A. P.; Okunev, G. A.

    2017-07-01

    operability of machine-tractor aggregates (MTA) is ensured by purposeful activity of maintenance and repair performers. MTAs operation assurance can provide achievement of absolutely different goals. For further development of technical service formation concept concretization in the part of determining locations of maintenance and repair performers and their area of expertise is suggested, as well as of arising peculiarities of equipment. The theoretical task is reduced to the type of tasks of distribution of recourses or transportation tasks. Mobile maintenance teams of regional agricultural equipment manufacturers’ dealers have experience of technical service performance. The formed stream of requests from agricultural plants determines the direction of correcting of existing theoretical provisions, confirming necessity of further development of centralized method of technical service by efforts and means of manufacturers’ dealers.

  14. Prevalence of drug use in commercial tractor-trailer drivers.

    PubMed

    Couper, Fiona J; Pemberton, Melissa; Jarvis, Anjanette; Hughes, Marty; Logan, Barry K

    2002-05-01

    An enforcement emphasis project, "Operation Trucker Check," was established in order to determine the extent to which commercial tractor-trailer drivers were operating their vehicles while impaired by drugs. A total of 1079 drivers and their vehicles were assessed for driver and equipment violations, and drivers additionally underwent preliminary field sobriety tests conducted by drug recognition expert (DRE) officers. Anonymous urine specimens for drug analysis were requested, and 822 urine specimens were obtained in total. Compliance with the drug-testing portion was voluntary, and there was a 19% refusal rate. Overall, 21% of the urine specimens tested positive for either illicit, prescription, and/or over-the-counter drugs, and 7% tested positive for more than one drug. Excluding caffeine and nicotine, the largest number of positive findings (9.5%) were for CNS stimulants, such as methamphetamine, amphetamine, phentermine, ephedrine/pseudoephedrine, and cocaine. The second most frequently encountered drug class were the cannabinoids, with 4.3% of drivers testing positive for marijuana metabolites. Only 11 drivers (1.3%) were positive for alcohol. Sixteen truck drivers (1.6%) were charged with driving under the influence of drugs after a full DRE evaluation was conducted. The results indicate that in spite of comprehensive drug testing in the trucking industry, some tractor-trailer drivers are continuing to take illicit and other drugs with the potential of having a negative effect on their driving ability. On the other hand, only a few drivers were, in fact, deemed to be under the influence of drugs at the time of driving when evaluated by DRE officers.

  15. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide.

    PubMed

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-07-21

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold (23)Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry.

  16. Summary of NREL's Recent Class 8 Tractor Trailer Platooning Testing (Presentation)

    SciTech Connect

    Lammert, M.; Kelly, K.; Walkowicz, K.

    2014-08-01

    This presentation summarizes NREL's recent class 8 tractor trailer platooning testing, including analysis of SAE J1321 Type II fuel consumption testing, fuel consumption improvement, fuel economy and platooning position accuracy.

  17. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide

    PubMed Central

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-01-01

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold 23Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry. PMID:27440516

  18. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide

    NASA Astrophysics Data System (ADS)

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-07-01

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold 23Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry.

  19. Design and Implementation of a GPS Guidance System for Agricultural Tractors Using Augmented Reality Technology

    PubMed Central

    Santana-Fernández, Javier; Gómez-Gil, Jaime; del-Pozo-San-Cirilo, Laura

    2010-01-01

    Current commercial tractor guidance systems present to the driver information to perform agricultural tasks in the best way. This information generally includes a treated zones map referenced to the tractor’s position. Unlike actual guidance systems where the tractor driver must mentally associate treated zone maps and the plot layout, this paper presents a guidance system that using Augmented Reality (AR) technology, allows the tractor driver to see the real plot though eye monitor glasses with the treated zones in a different color. The paper includes a description of the system hardware and software, a real test done with image captures seen by the tractor driver, and a discussion predicting that the historical evolution of guidance systems could involve the use of AR technology in the agricultural guidance and monitoring systems. PMID:22163479

  20. [Risk of noise-induced hearing loss in farm tractor operators].

    PubMed

    Solecki, L

    2001-01-01

    Studies of noise at work site of tractor operators showed that this parameter exceeds allowable values. In order to evaluate the risk of hearing loss in this occupational group, noise-induced permanent threshold shift (NIPTS) values were determined. This parameter is a function of the audiometric frequency, duration of occupational exposure and noise exposure level (LEX,8 h). The procedure recommended by ISO-1999/1990 was used for calculations. The study covered two groups of operators: operators of ZM "Ursus" medium-power tractors (noise exposure level: LEX,8 h = 96.6 dB) and operators of high-power tractors of the same manufacture (LEX,8 h = 89.6 dB) The risk of hearing impairment was determined for the group of men aged 50 years, occupationally exposed to noise for a period of 30 years. The calculation was based on the mean value of expected hearing loss for three selected audiometric frequencies: 1000; 2000; and 4000 Hz. The study showed that the average (median; N0.50) expected hearing loss, excluding that associated with age, after 30 years of employment was 15 dB for operators of medium-power farm tractors, and 6 dB for operators of high-power tractors. The risk of hearing impairment due to occupational exposure to noise (exceeding the maximum allowable hearing loss of 27 dB; according to ISO-1999/1990) that may cause an acoustic trauma was 37.9% for medium-power tractors and 13.0% for high-power tractors. The results of the study show that noise at workplaces of farm tractor operators creates a high risk of hearing impairment.

  1. Exposure to audible and infrasonic noise by modern agricultural tractors operators.

    PubMed

    Bilski, Bartosz

    2013-03-01

    The wheeled agricultural tractor is one of the most prominent sources of noise in agriculture. This paper presents the assessment of the operator's exposure to audible and infrasonic noise in 32 selected modern wheeled agricultural tractors designed and produced by world-renowned companies in normal working conditions. The tractors have been in use for no longer than 4 years, with rated power of 51 kW to up to 228 kW (as per 97/68 EC). Audible and infrasonic noise level measurements and occupational exposure analysis to noise were performed according to ISO 9612:2009 (strategy 1 - task-based measurements). The measurements were made in different typical work conditions inside and outside of tractors cabs. The results indicated that exposure levels to noise perceived by the operators (L(ex,Te) between 62,3 and 84,7 dB-A) and can make a small risk of potential adversely effects on hearing during tasks performed inside the closed cab. It should be remarked that uncertainty interval is wider and in in some conditions can occur transgression of audible noise occupational exposure limits. The measured audible noise levels can potentially develop the non-auditory effects. Analysed tractors emit considerable infrasonic noise levels that tend to exceed the occupational exposure limits (both inside and outside the driver's cab). The levels of infrasound: 83,8-111,4 dB-G. All tractors introduced for sale should be subjected to tests in terms of infrasonic noise levels. The applicable standards for low frequency noise and its measurement methods for vehicles, including agricultural tractors, should be scientifically revised. In the last years there has been a noticeable technical progress in reduction of audible noise exposure at the tractors operators workplaces with simultaneously lack of important works for limitation of exposure to infrasound. Author discuss possible health and ergonomic consequencies of such exposure.

  2. Investigation of Tractor Base Bleeding for Heavy Vehicle Aerodynamic Drag Reduction

    SciTech Connect

    Ortega, J; Salari, K; Storms, B

    2007-10-25

    One of the main contributors to the aerodynamic drag of a heavy vehicle is tractor-trailer gap drag, which arises when the vehicle operates within a crosswind. Under this operating condition, freestream flow is entrained into the tractor-trailer gap, imparting a momentum exchange to the vehicle and subsequently increasing the aerodynamic drag. While a number of add-on devices, including side extenders, splitter plates, vortex stabilizers, and gap sealers, have been previously tested to alleviate this source of drag, side extenders remain the primary add-on device of choice for reducing tractor-trailer gap drag. However, side extenders are not without maintenance and operational issues. When a heavy vehicle pivots sharply with respect to the trailer, as can occur during loading or unloading operations, the side extenders can become crushed against the trailer. Consequently, fleet operators are forced to incur additional costs to cover the repair or replacement of the damaged side extenders. This issue can be overcome by either shortening the side extenders or by devising an alternative drag reduction concept that can perform just as effectively as side extenders. To explore such a concept, we investigate tractor base bleeding as a means of reducing gap drag. Wind tunnel measurements are made on a 1:20 scale heavy vehicle model at a vehicle width-based Reynolds number of 420,000. The tractor bleeding flow, which is delivered through a porous material embedded within the tractor base, is introduced into the tractor-trailer gap at bleeding coefficients ranging from 0.0-0.018. To determine the performance of tractor base bleeding under more realistic operating conditions, computational fluid dynamics simulations are performed on a full-scale heavy vehicle within a crosswind for bleeding coefficients ranging from 0.0-0.13.

  3. TRACTOR_DB: a database of regulatory networks in gamma-proteobacterial genomes

    PubMed Central

    González, Abel D.; Espinosa, Vladimir; Vasconcelos, Ana T.; Pérez-Rueda, Ernesto; Collado-Vides, Julio

    2005-01-01

    Experimental data on the Escherichia coli transcriptional regulatory system has been used in the past years to predict new regulatory elements (promoters, transcription factors (TFs), TFs' binding sites and operons) within its genome. As more genomes of gamma-proteobacteria are being sequenced, the prediction of these elements in a growing number of organisms has become more feasible, as a step towards the study of how different bacteria respond to environmental changes at the level of transcriptional regulation. In this work, we present TRACTOR_DB (TRAnscription FaCTORs' predicted binding sites in prokaryotic genomes), a relational database that contains computational predictions of new members of 74 regulons in 17 gamma-proteobacterial genomes. For these predictions we used a comparative genomics approach regarding which several proof-of-principle articles for large regulons have been published. TRACTOR_DB may be currently accessed at http://www.bioinfo.cu/Tractor_DB, http://www.tractor.lncc.br/ or at http://www.cifn.unam.mx/Computational_Genomics/tractorDB. Contact Email id is tractor@cifn.unam.mx. PMID:15608293

  4. A summary of state laws regulating youth operating farm tractors on highways.

    PubMed

    Doty, B C; Marlenga, B

    2006-02-01

    Driving farm tractors on highways is hazardous for youth due to the large speed differential between motor vehicles and agricultural vehicles, as well as recent increases in traffic volume on many rural roads. In 1994, the state of Wisconsin enacted legislation requiring youth who operate farm tractors on highways to complete a tractor and machinery certification course. We were interested in finding out whether other states have similar requirements. The purpose of this project was to collect and summarize state laws regulating youth who operate farm tractors on highways in the U.S. A systematic method was used that included an initial Lexis-Nexis database search followed by internet searches in combination with follow-up email and telephone communications when missing or unclear results were obtained. The findings show that 14 states have legislation addressing youth who operate farm tractors on highways. The content of these statutes varies, but includes driver's license or educational requirements, as well as regulations concerning the ages, locations, and/or times of day when youth may drive farm machinery on highways. This compilation of state laws will be useful information for agricultural safety professionals in designing effective outreach programs. A synthesis of the findings may also lead to the development of model legislation or inform future research efforts aimed at preventing youth farm tractor crashes on highways.

  5. TRACTOR_DB: a database of regulatory networks in gamma-proteobacterial genomes.

    PubMed

    González, Abel D; Espinosa, Vladimir; Vasconcelos, Ana T; Pérez-Rueda, Ernesto; Collado-Vides, Julio

    2005-01-01

    Experimental data on the Escherichia coli transcriptional regulatory system has been used in the past years to predict new regulatory elements (promoters, transcription factors (TFs), TFs' binding sites and operons) within its genome. As more genomes of gamma-proteobacteria are being sequenced, the prediction of these elements in a growing number of organisms has become more feasible, as a step towards the study of how different bacteria respond to environmental changes at the level of transcriptional regulation. In this work, we present TRACTOR_DB (TRAnscription FaCTORs' predicted binding sites in prokaryotic genomes), a relational database that contains computational predictions of new members of 74 regulons in 17 gamma-proteobacterial genomes. For these predictions we used a comparative genomics approach regarding which several proof-of-principle articles for large regulons have been published. TRACTOR_DB may be currently accessed at http://www.bioinfo.cu/Tractor_DB, http://www.tractor.lncc.br/ or at http://www.cifn.unam.mx/Computational_Genomics/tractorDB. Contact Email id is tractor@cifn.unam.mx.

  6. The Social Marketing of Safety Behaviors: A Quasi–Randomized Controlled Trial of Tractor Retrofitting Incentives

    PubMed Central

    Jenkins, Paul L.; Emmelin, Maria; Stenlund, Hans; Weinehall, Lars; Earle-Richardson, Giulia B.; May, John J.

    2011-01-01

    Objectives. We assessed the effect of social marketing incentives on dispositions toward retrofitting and retrofitting behavior among farmers whose tractors lacked rollover protective structures. Methods. From 2006 to 2007, we conducted a quasi–randomized controlled trial with 391 farm owners in New York and Pennsylvania surveyed before and after exposure to 1 of 3 tractor retrofitting incentive combinations. These combinations were offered in 3 trial regions; region 1 received rebates; region 2 received rebates, messages, and promotion and was considered the social marketing region; and region 3 received messages and promotion. A fourth region served as a control. Results. The social marketing region generated the greatest increases in readiness to retrofit, intentions to retrofit, and message recall. In addition, postintervention stage of change, intentions, attitudes, subjective norms, and perceived behavioral control levels were higher among farmers who had retrofitted tractors. Conclusions. Our results showed that a social marketing approach (financial incentives, tailored messages, and promotion) had the greatest influence on message recall, readiness to retrofit tractors, and intentions to retrofit tractors and that behavioral measures were fairly good predictors of tractor retrofitting behaviors. PMID:21330581

  7. The social marketing of safety behaviors: a quasi-randomized controlled trial of tractor retrofitting incentives.

    PubMed

    Sorensen, Julie A; Jenkins, Paul L; Emmelin, Maria; Stenlund, Hans; Weinehall, Lars; Earle-Richardson, Giulia B; May, John J

    2011-04-01

    We assessed the effect of social marketing incentives on dispositions toward retrofitting and retrofitting behavior among farmers whose tractors lacked rollover protective structures. From 2006 to 2007, we conducted a quasi-randomized controlled trial with 391 farm owners in New York and Pennsylvania surveyed before and after exposure to 1 of 3 tractor retrofitting incentive combinations. These combinations were offered in 3 trial regions; region 1 received rebates; region 2 received rebates, messages, and promotion and was considered the social marketing region; and region 3 received messages and promotion. A fourth region served as a control. The social marketing region generated the greatest increases in readiness to retrofit, intentions to retrofit, and message recall. In addition, postintervention stage of change, intentions, attitudes, subjective norms, and perceived behavioral control levels were higher among farmers who had retrofitted tractors. Our results showed that a social marketing approach (financial incentives, tailored messages, and promotion) had the greatest influence on message recall, readiness to retrofit tractors, and intentions to retrofit tractors and that behavioral measures were fairly good predictors of tractor retrofitting behaviors.

  8. Formation flying solar-sail gravity tractors in displaced orbit for towing near-Earth asteroids

    NASA Astrophysics Data System (ADS)

    Gong, Shengping; Li, Junfeng; Baoyin, Hexi

    2009-11-01

    Several methods of asteroid deflection have been proposed in literature and the gravitational tractor is a new method using gravitational coupling for near-Earth object orbit modification. One weak point of gravitational tractor is that the deflection capability is limited by the mass and propellant of the spacecraft. To enhance the deflection capability, formation flying solar sail gravitational tractor is proposed and its deflection capability is compared with that of a single solar sail gravitational tractor. The results show that the orbital deflection can be greatly increased by increasing the number of the sails. The formation flying solar sail gravitational tractor requires several sails to evolve on a small displaced orbit above the asteroid. Therefore, a proper control should be applied to guarantee that the gravitational tractor is stable and free of collisions. Two control strategies are investigated in this paper: a loose formation flying realized by a simple controller with only thrust modulation and a tight formation realized by the sliding-mode controller and equilibrium shaping method. The merits of the loose and tight formations are the simplicity and robustness of their controllers, respectively.

  9. A user-oriented web crawler for selectively acquiring online content in e-health research

    PubMed Central

    Xu, Songhua; Yoon, Hong-Jun; Tourassi, Georgia

    2014-01-01

    Motivation: Life stories of diseased and healthy individuals are abundantly available on the Internet. Collecting and mining such online content can offer many valuable insights into patients’ physical and emotional states throughout the pre-diagnosis, diagnosis, treatment and post-treatment stages of the disease compared with those of healthy subjects. However, such content is widely dispersed across the web. Using traditional query-based search engines to manually collect relevant materials is rather labor intensive and often incomplete due to resource constraints in terms of human query composition and result parsing efforts. The alternative option, blindly crawling the whole web, has proven inefficient and unaffordable for e-health researchers. Results: We propose a user-oriented web crawler that adaptively acquires user-desired content on the Internet to meet the specific online data source acquisition needs of e-health researchers. Experimental results on two cancer-related case studies show that the new crawler can substantially accelerate the acquisition of highly relevant online content compared with the existing state-of-the-art adaptive web crawling technology. For the breast cancer case study using the full training set, the new method achieves a cumulative precision between 74.7 and 79.4% after 5 h of execution till the end of the 20-h long crawling session as compared with the cumulative precision between 32.8 and 37.0% using the peer method for the same time period. For the lung cancer case study using the full training set, the new method achieves a cumulative precision between 56.7 and 61.2% after 5 h of execution till the end of the 20-h long crawling session as compared with the cumulative precision between 29.3 and 32.4% using the peer method. Using the reduced training set in the breast cancer case study, the cumulative precision of our method is between 44.6 and 54.9%, whereas the cumulative precision of the peer method is between 24.3 and

  10. Nematoelastic crawlers

    NASA Astrophysics Data System (ADS)

    Zakharov, A. P.; Pismen, L. M.

    2016-02-01

    A propagating "beam" triggering a local phase transition in a nematic elastomer sets it into a crawling motion, which may morph due to buckling. We consider the motion of the various configurations of slender rods and thin stripes with both uniform and splayed nematic order in cross-section and detect the dependence of the gait and speed on flexural rigidity and substrate friction.

  11. 78 FR 33860 - Crawler, Locomotive, and Truck Cranes Standard; Extension of the Office of Management and Budget...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    .... OSHA-2010-0015] Crawler, Locomotive, and Truck Cranes Standard; Extension of the Office of Management..., Locomotive, and Truck cranes (29 CFR 1910.180). DATES: Comments must be submitted (postmarked, sent, or... it. The purpose of each of these requirements is to prevent workers from using unsafe cranes and...

  12. Risk exposure to vibration and noise in the use of agricultural track-laying tractors.

    PubMed

    Vallone, Mariangela; Bono, Filippa; Quendler, Elisabeth; Febo, Pierluigi; Catania, Pietro

    2016-12-23

    Human exposure to mechanical vibration may represent a significant risk factor for exposed workers in the agricultural sector. Also, noise in agriculture is one of the risk factors to be taken into account in the evaluation of workers' health and safety. One of the major sources of discomfort for the workers operating a tractors is the noise to which they are exposed during work. The aim of this study was to evaluate the risk of exposure to whole-body vibration for the operator driving track-laying tractors in vineyard orchard and the noise level. The experimental tests were performed with six different track-laying tractors coupled with the same rototilling machine. The results showed that the vibration values of track-laying tractors coupled to rototilling machine, referred to the 8-hour working day, were always higher than 0.5 m s(-2), the daily exposure action value established by Directive 2002/44/EC of the European Parliament. The daily noise exposure levels always exceeded the exposure limit value of 87 dB(A) established by Directive 2003/10/EC of the European Parliament. The ANOVA repeated measures model showed that the factor 'site', namely, the soil characteristics, did not influence the vibration level on the X and Y-axes of the tractors measured, regardless of their age. In the Z-axis, the vibration level was enhanced as the soil structure increased. As tractor age increased, the influence of soil characteristics was less important. In term of the age of the tractor and the number of hours worked, it was possible to identify three risk classes, which were up to 3,000 hours worked and offered a low risk; from 3,000 - 6,000 hours worked with a medium risk, and over 6,000 hours with a high risk level.

  13. Nonfatal tractor-related injuries presenting to a state trauma system.

    PubMed

    Swanton, Amanda R; Young, Tracy L; Leinenkugel, Kathy; Torner, James C; Peek-Asa, Corinne

    2015-06-01

    To identify tractor-related injuries using data from a statewide trauma system, to characterize the mechanisms of nonfatal tractor-related injury, and to determine which injuries are associated with higher severity injury. A retrospective observational study was conducted using the Iowa State Trauma Registry to identify cases of nonfatal tractor-related injuries over an 11-year period from 2002 to 2012. Frequency of injury was reported by age, sex, severity, and nature. Injuries were classified by mechanism and a polytomous regression model was used to predict injury severity adjusting for sex and age. Five-hundred thirteen nonfatal tractor-related injuries were identified with 18% classified as severe. Injuries were most frequent among males and among those ≥45years of age. Rollovers were the most frequent mechanism of both total (25%) and severe injury (38%), although the frequency of injury mechanism varied by age. Falls were the next most frequent mechanism of injury (20%) but resulted in fewer high-severity injuries. Collision (adjOR=1.89, 95% CI=1.01-3.51), rollover (adjOR=2.03, 95% CI=1.21-3.40), and run over/rolled on (adjOR=2.06, 95% CI=1.17-3.62) injuries were significantly associated with higher injury severity. Advanced age was also a significant predictor of higher severity injury (adjOR=1.82, 95% CI=1.06-3.12). Mechanisms of nonfatal tractor-related injuries are heterogeneous, differ by age, and are associated with varying level of severity. This work shows the burden of nonfatal tractor injuries on a rural state trauma system. These findings also demonstrate the heterogeneous nature of nonfatal tractor injuries and underscore the need for a multi-level approaches to injury prevention. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Frequency and severity of injuries to operators during overturns of farm tractors.

    PubMed

    Cole, H P; Myers, M L; Westneat, S C

    2006-05-01

    Previous estimates of operator death from farm tractor overturn events range from 0.03 to 0.68. This study provided population-based estimates of the denominator of total farm tractor overturns and the frequency of six classes of overturn injury outcomes for tractors with and without rollover protective structures (ROPS). A 40-item telephone survey collected information from a random sample of 6,063 (8.0%) Kentucky farms about each farm's most recent overturn. A total of 551 (9.1%) farms reported overturns, and 5,512 (90.1%) reported no overturns. Injury outcomes for 443 overturns of non-ROPS tractors and 89 ROPS tractors were distributed as follows: no or minor injury (non-ROPS: 70.43%; ROPS: 82.02%), outpatient treatment (non-ROPS: 21.90%; ROPS: 9.00%), hospital admission (non-ROPS: 15.35%; ROPS: 3.37%), temporary disability (non-ROPS: 13.54%; ROPS: 14.61%), permanent disability (non-ROPS: 3.16%; ROPS: 0.00%), and death (non-ROPS: 5.42%; ROPS: 1.12%). (Percents total to more than 100 because some operators treated as outpatients were subsequently hospitalized, disabled, or died.) The observed 0.054 probability of death from overturn of non-ROPS tractors in this sample was corrected for the proportion of farms that went out of business prior to the survey and thus were excluded from the sampling frame. The adjusted 0.08 probability of death from overturn of a non-ROPS tractor is five times smaller than the NIOSH estimate of 0.40. The discrepancy lies in the much larger denominator of all non-fatal and fatal overturns than assumed previously.

  15. Using Data Crawlers and Semantic Web to Build Financial XBRL Data Generators: The SONAR Extension Approach

    PubMed Central

    Rodríguez-García, Miguel Ángel; Rodríguez-González, Alejandro; Valencia-García, Rafael; Gómez-Berbís, Juan Miguel

    2014-01-01

    Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach. PMID:24587726

  16. Using data crawlers and semantic Web to build financial XBRL data generators: the SONAR extension approach.

    PubMed

    Rodríguez-García, Miguel Ángel; Rodríguez-González, Alejandro; Colomo-Palacios, Ricardo; Valencia-García, Rafael; Gómez-Berbís, Juan Miguel; García-Sánchez, Francisco

    2014-01-01

    Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach.

  17. Optimization of motion control laws for tether crawler or elevator systems

    NASA Technical Reports Server (NTRS)

    Swenson, Frank R.; Von Tiesenhausen, Georg

    1988-01-01

    Based on the proposal of a motion control law by Lorenzini (1987), a method is developed for optimizing motion control laws for tether crawler or elevator systems in terms of the performance measures of travel time, the smoothness of acceleration and deceleration, and the maximum values of velocity and acceleration. The Lorenzini motion control law, based on powers of the hyperbolic tangent function, is modified by the addition of a constant-velocity section, and this modified function is then optimized by parameter selections to minimize the peak acceleration value for a selected travel time or to minimize travel time for the selected peak values of velocity and acceleration. It is shown that the addition of a constant-velocity segment permits further optimization of the motion control law performance.

  18. Space Shuttle Crawler Transporter Vibration Analysis in Support of Rollout Fatigue Load Spectra Verification Program

    NASA Technical Reports Server (NTRS)

    Margasahayam, Ravi N.; Meyer, Karl A.; Nerolich, Shaun M.; Burton, Roy C.; Gosselin, Armand M.

    2004-01-01

    The Crawler Transporter (CT), designed and built for the Apollo Program in the 1960's and surpassing its initial operational life, has become an integral part of the Space Shuttle Program (SSP). The CT transports the Space Shuttle Vehicle (SSV) stack, atop the Mobile Launch Platform (MLP), from the Vehicle Assembly Building (VAB) to the launch pad. This support structure provides hydraulic jacking, leveling and load equalization for the 12 million pound stack on its 3.5-5.0 mile rollout to the launch pad. Major elements of the SSV, consisting of the orbiter, solid rocket boosters (SRB) and external tank (ET) have required fatigue analyses as part of the mission life certification. Compared to rollout vibration, the SSV sees relatively high vibration loads during launch, ascent, descent and landing phases of the mission. Although preliminary measured SRB vibration levels during rollout were of low amplitude and frequency, the duration of the rollout phase is typically high, from 5-6 hours. As part of an expanded mission life assessment, additional certification effort was initiated to define fatigue load spectra for rollout. This study addresses the CT vibration analyses in support of the rollout fatigue study. Structural models developed for modal and vibration analyses were used to identify unique CT, CT/MLP and CT/MLP/SRB vibration characteristics for comparison to instrumented rollout tests. Whereas the main structural and vibration characteristics of the SSV are well defined, minimum analytical and vibration test data on the Crawler Transporter were available. Unique vibration characteristics of the CT are attributable to the drive mechanism, hydraulic jacking system, structural framing and the CT-to-MLP support pad restraints. Initial tests performed on the CT/MLP/SRB configuration showed reasonable correlation with predicted mode shapes and frequencies.

  19. A Kalman Filter Implementation for Precision Improvement in Low-Cost GPS Positioning of Tractors

    PubMed Central

    Gomez-Gil, Jaime; Ruiz-Gonzalez, Ruben; Alonso-Garcia, Sergio; Gomez-Gil, Francisco Javier

    2013-01-01

    Low-cost GPS receivers provide geodetic positioning information using the NMEA protocol, usually with eight digits for latitude and nine digits for longitude. When these geodetic coordinates are converted into Cartesian coordinates, the positions fit in a quantization grid of some decimeters in size, the dimensions of which vary depending on the point of the terrestrial surface. The aim of this study is to reduce the quantization errors of some low-cost GPS receivers by using a Kalman filter. Kinematic tractor model equations were employed to particularize the filter, which was tuned by applying Monte Carlo techniques to eighteen straight trajectories, to select the covariance matrices that produced the lowest Root Mean Square Error in these trajectories. Filter performance was tested by using straight tractor paths, which were either simulated or real trajectories acquired by a GPS receiver. The results show that the filter can reduce the quantization error in distance by around 43%. Moreover, it reduces the standard deviation of the heading by 75%. Data suggest that the proposed filter can satisfactorily preprocess the low-cost GPS receiver data when used in an assistance guidance GPS system for tractors. It could also be useful to smooth tractor GPS trajectories that are sharpened when the tractor moves over rough terrain. PMID:24217355

  20. Complementing computationally predicted regulatory sites in Tractor_DB using a pattern matching approach.

    PubMed

    Guía, Marylens Hernández; Pérez, Abel González; Angarica, Vladimir Espinosa; Vasconcelos, Ana T; Collado-Vides, Julio

    2005-01-01

    Prokaryotic genomes annotation has focused on genes location and function. The lack of regulatory information has limited the knowledge on cellular transcriptional regulatory networks. However, as more phylogenetically close genomes are sequenced and annotated, the implementation of phylogenetic footprinting strategies for the recognition of regulators and their regulons becomes more important. In this paper we describe a comparative genomics approach to the prediction of new gamma-proteobacterial regulon members. We take advantage of the phylogenetic proximity of Escherichia coli and other 16 organisms of this subdivision and the intensive search of the space sequence provided by a pattern-matching strategy. Using this approach we complement predictions of regulatory sites made using statistical models currently stored in Tractor_DB, and increase the number of transcriptional regulators with predicted binding sites up to 86. All these computational predictions may be reached at Tractor_DB (www.bioinfo.cu/Tractor_DB, www.tractor.lncc.br, www.ccg.unam.mx/Computational_Genomics/tractorDB/). We also take a first step in this paper towards the assessment of the conservation of the architecture of the regulatory network in the gamma-proteobacteria through evaluating the conservation of the overall connectivity of the network.

  1. A Kalman filter implementation for precision improvement in low-cost GPS positioning of tractors.

    PubMed

    Gomez-Gil, Jaime; Ruiz-Gonzalez, Ruben; Alonso-Garcia, Sergio; Gomez-Gil, Francisco Javier

    2013-11-08

    Low-cost GPS receivers provide geodetic positioning information using the NMEA protocol, usually with eight digits for latitude and nine digits for longitude. When these geodetic coordinates are converted into Cartesian coordinates, the positions fit in a quantization grid of some decimeters in size, the dimensions of which vary depending on the point of the terrestrial surface. The aim of this study is to reduce the quantization errors of some low-cost GPS receivers by using a Kalman filter. Kinematic tractor model equations were employed to particularize the filter, which was tuned by applying Monte Carlo techniques to eighteen straight trajectories, to select the covariance matrices that produced the lowest Root Mean Square Error in these trajectories. Filter performance was tested by using straight tractor paths, which were either simulated or real trajectories acquired by a GPS receiver. The results show that the filter can reduce the quantization error in distance by around 43%. Moreover, it reduces the standard deviation of the heading by 75%. Data suggest that the proposed filter can satisfactorily preprocess the low-cost GPS receiver data when used in an assistance guidance GPS system for tractors. It could also be useful to smooth tractor GPS trajectories that are sharpened when the tractor moves over rough terrain.

  2. Tractor Supply Company Agrees to Implement Company-Wide Compliance Program to Resolve Clean Air Act Violations

    EPA Pesticide Factsheets

    WASHINGTON -- The U.S. Environmental Protection Agency (EPA) and the U.S. Department of Justice today announced a settlement with Tractor Supply Company Inc. and Tractor Supply Company of Texas L.P., that resolves allegations that the companies impor

  3. 40 CFR 1037.106 - Exhaust emission standards for CO2 for tractors above 26,000 pounds GVWR.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Exhaust emission standards for CO2 for... Emission Standards and Related Requirements § 1037.106 Exhaust emission standards for CO2 for tractors above 26,000 pounds GVWR. (a) The CO2 standards of this section apply for tractors above 26,000...

  4. 40 CFR 1037.106 - Exhaust emission standards for CO2 for tractors above 26,000 pounds GVWR.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Exhaust emission standards for CO2 for... Emission Standards and Related Requirements § 1037.106 Exhaust emission standards for CO2 for tractors above 26,000 pounds GVWR. (a) The CO2 standards of this section apply for tractors above 26,000...

  5. 40 CFR 1037.106 - Exhaust emission standards for CO2 for tractors above 26,000 pounds GVWR.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Exhaust emission standards for CO2 for... Emission Standards and Related Requirements § 1037.106 Exhaust emission standards for CO2 for tractors above 26,000 pounds GVWR. (a) The CO2 standards of this section apply for tractors above 26,000...

  6. Cycle-time equations for five small tractors operating in low-volume small-diameter hardwood stands

    Treesearch

    Chris B. LeDoux; Neil K. Huyler; Neil K. Huyler

    1992-01-01

    Prediction equations for estimating cycle time were developed for five small tractors studied under various silvicultural treatments and operating conditions. The tractors studied included the Pasquali 933, a Holder A60F, a Forest Ant Forwarder (Skogsman), a Massey-Ferguson, and a Sam4 Minitarus. Skidding costs were estimated based on the cycle-time equations. Using...

  7. 29 CFR 1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Motor Vehicle Seat Belt Assemblies, 2 except as noted hereafter: 2 Copies may be obtained from the... operations, and while their use is incidental to the work performed therein. (ii) Low profile tractors while... ROPS equipped tractor to operate, and while their use is incidental to the work performed therein....

  8. Tractors and twistors from conformal Cartan geometry: a gauge theoretic approach II. Twistors

    NASA Astrophysics Data System (ADS)

    Attard, J.; François, J.

    2017-04-01

    Tractor and Twistor bundles provide natural conformally covariant calculi on 4D-Riemannian manifolds. They have different origins but are closely related, and usually constructed bottom–up through prolongation of defining differential equations. We propose alternative top–down gauge theoretic constructions, starting from the conformal Cartan bundle P and its vectorial E and spinorial {E associated bundles. Our key ingredient is the dressing field method of gauge symmetry reduction, which allows tractors and twistors and their associated connections to exhibit as gauge fields of a non-standard kind as far as Weyl rescaling transformation is concerned. By non-standard we mean that they implement the gauge principle of physics, but are of a different geometric nature than the well-known differential geometric objects usually underlying gauge theories. We provide the corresponding BRST treatment. In a companion paper we dealt with tractors, in the present one we address the case of twistors.

  9. Farm tractors and mandatory roll-over protection retrofits: potential costs of the policy in New York.

    PubMed

    Kelsey, T W; Jenkins, P L

    1991-07-01

    Tractor roll-overs are the leading cause of fatal farm accidents, accounting for more than one-fourth of all agriculturally related deaths. Most of these deaths could be prevented if the tractors were equipped with roll-over protective structures (ROPS). This study estimates the number of tractors in New York without ROPS, projects their retirement, and then estimates the number of lives which would be saved if ROPS were retrofitted on old tractors. The basic costs associated with mandating ROPS are calculated from these estimates. The minimum economic cost of mandating ROPS is $511,136 per life saved for the retrofits, and an additional $253,254 per life saved for every $1 million spent annually on enforcement. It is concluded that a policy mandating ROPS on all tractors would be expensive, but should be considered with particular attention to the need for and cost effectiveness of enforcement.

  10. Evaluation of Corrosion Failure in Tractor-Trailer Brake System

    SciTech Connect

    Wilson, DF

    2002-10-22

    As reported to ORNL, concomitant with the introduction of different deicing and anti-icing compounds, there was an increase in the brake failure rate of tractor-trailer trucks. A forensic evaluation of a failed brake system was performed. Optical and scanning electron microscopic evaluation showed corrosion to be mostly confined to the brake table/lining interface. The corrosion is non-uniform as is to be expected for plain carbon steel in chloride environments. This initial analysis found no evidence for the chlorides of calcium and magnesium, which are the newly introduced deicing and antiicing compounds and are less soluble in water than the identified chlorides of sodium and potassium, in the scale. The result could be as a result of non-exposure of the examined brake table to calcium and magnesium chloride. The mechanisms for the increased failure rate are postulated as being an increased rate of corrosion due to positive shifts in the corrosion potential, and an increased amount of corrosion due to an increased ''time of wetness'' that results from the presence of hygroscopic salts. Laboratory scale evaluation of the corrosion of plain carbon steel in simulated deicing and anti-icing solutions need to be performed to determine corrosion rates and morphological development of corrosion product, to compare laboratory data to in-service data, and to rank economically feasible replacement materials for low carbon steel. In addition, the mechanical behavior of the lining attached to the brake shoe table needs to be assessed. It is opined that an appropriate adjustment of materials could easily allow for a doubling of a brake table/lining lifetime. Suggestions for additional work, to clarify the mechanisms of rust jacking and to develop possible solutions, are described.

  11. Towing Asteroids with Gravity Tractors Enhanced by Tethers and Solar Sails

    NASA Technical Reports Server (NTRS)

    Shen, Haijun; Roithmayr, Carlos M.

    2015-01-01

    Material collected from an asteroid's surface can be used to increase gravitational attraction between the asteroid and a Gravity Tractor (GT); the spacecraft therefore operates more effectively and is referred to as an Enhanced Gravity Tractor (EGT). The use of tethers and solar sails to further improve effectiveness and simplify operations is investigated. By employing a tether, the asteroidal material can be placed close to the asteroid while the spacecraft is stationed farther away, resulting in a better safety margin and improved thruster efficiency. A solar sail on a spacecraft can naturally provide radial offset and inter-spacecraft separation required for multiple EGTs.

  12. A three body dynamic simulation of a seated tractor rocket escape system for the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Ondler, R. M.

    1989-01-01

    In the tractor-rocket seated-extraction candidate system for Space Shuttle Orbiter crew escape, the crewmember is pulled from his seat and away from the Orbiter via an elastic pendant, using a system of rails to guide the extraction trajectory through an opening on the window frame for flight deck crew and through the side hatch for the middeck crew. A three-body simulation has been developed to model the flight-mechanics aspects of the concept, where the three bodies are the astronaut (six DOF), the tractor rocket (six DOF), and the Shuttle Orbiter (three DOF); attention is given to crewmembers' clearance of the Orbiter structure and engine plumes.

  13. Prevalence of ROPS--equipped tractors and farm/farmer characteristics.

    PubMed

    Wilkins, J R; Engelhardt, H L; Bean, T L; Byers, M V; Crawford, J M

    2003-05-01

    Data were collected on tractor safety status and the prevalence of ROPS as part of the Ohio Farm Family Health and Hazard Surveillance Program (FFHHSP) "walk-around" hazard assessments of cash grain farms in central Ohio. Principal operator (PO) characteristics thought a priori to have a possible association with ROPS utilization included age, education, percent time spent farming, total years in agriculture, and previous training in occupational injury prevention. Farm characteristics of interest were farm size, acres of cropland in use, sales value during the past 12 months, and current number of farm workers. Descriptive and logistic regression analyses were conducted to evaluate potential associations between these factors and ROPS utilization patterns. Of 1,044 tractors encountered on 306 farms, 359 (34.4%) were equipped with ROPS, 29 (9.5%) had nothing but ROPS-equipped tractors, and 117 (38.2%) did not have any ROPS-equipped tractors. The absence/presence of ROPS-equipped tractors in our sample was found to vary by several factors, and over a wide range. Results of invariable logistic regression analyses (excluding the relatively small number of tractors manufactured after 1985) indicated that younger POs with at least a high school education who spent more than half their time working in agriculture, employed three or more workers, had 500 or more acres of total farm land and cropland in use, and had a 12-month sales value exceeding $250,000 were more likely to have at least one ROPS-equipped tractor on their farms. However, time spent farming, number of workers, and the 12-month sales value were not strongly predictive in multivariable models. Although more than 20% of the POs in our sample reported having had training in occupational injury prevention, this factor had essentially no value in predicting the absence/presence of ROPS-equipped tractors on their farms. The results of this study illustrate the need for interventions to encourage ROPS

  14. Quantitative evaluation of recall and precision of CAT Crawler, a search engine specialized on retrieval of Critically Appraised Topics

    PubMed Central

    Dong, Peng; Wong, Ling Ling; Ng, Sarah; Loh, Marie; Mondry, Adrian

    2004-01-01

    Background Critically Appraised Topics (CATs) are a useful tool that helps physicians to make clinical decisions as the healthcare moves towards the practice of Evidence-Based Medicine (EBM). The fast growing World Wide Web has provided a place for physicians to share their appraised topics online, but an increasing amount of time is needed to find a particular topic within such a rich repository. Methods A web-based application, namely the CAT Crawler, was developed by Singapore's Bioinformatics Institute to allow physicians to adequately access available appraised topics on the Internet. A meta-search engine, as the core component of the application, finds relevant topics following keyword input. The primary objective of the work presented here is to evaluate the quantity and quality of search results obtained from the meta-search engine of the CAT Crawler by comparing them with those obtained from two individual CAT search engines. From the CAT libraries at these two sites, all possible keywords were extracted using a keyword extractor. Of those common to both libraries, ten were randomly chosen for evaluation. All ten were submitted to the two search engines individually, and through the meta-search engine of the CAT Crawler. Search results were evaluated for relevance both by medical amateurs and professionals, and the respective recall and precision were calculated. Results While achieving an identical recall, the meta-search engine showed a precision of 77.26% (±14.45) compared to the individual search engines' 52.65% (±12.0) (p < 0.001). Conclusion The results demonstrate the validity of the CAT Crawler meta-search engine approach. The improved precision due to inherent filters underlines the practical usefulness of this tool for clinicians. PMID:15588311

  15. Quantitative evaluation of recall and precision of CAT Crawler, a search engine specialized on retrieval of Critically Appraised Topics.

    PubMed

    Dong, Peng; Wong, Ling Ling; Ng, Sarah; Loh, Marie; Mondry, Adrian

    2004-12-10

    Critically Appraised Topics (CATs) are a useful tool that helps physicians to make clinical decisions as the healthcare moves towards the practice of Evidence-Based Medicine (EBM). The fast growing World Wide Web has provided a place for physicians to share their appraised topics online, but an increasing amount of time is needed to find a particular topic within such a rich repository. A web-based application, namely the CAT Crawler, was developed by Singapore's Bioinformatics Institute to allow physicians to adequately access available appraised topics on the Internet. A meta-search engine, as the core component of the application, finds relevant topics following keyword input. The primary objective of the work presented here is to evaluate the quantity and quality of search results obtained from the meta-search engine of the CAT Crawler by comparing them with those obtained from two individual CAT search engines. From the CAT libraries at these two sites, all possible keywords were extracted using a keyword extractor. Of those common to both libraries, ten were randomly chosen for evaluation. All ten were submitted to the two search engines individually, and through the meta-search engine of the CAT Crawler. Search results were evaluated for relevance both by medical amateurs and professionals, and the respective recall and precision were calculated. While achieving an identical recall, the meta-search engine showed a precision of 77.26% (+/-14.45) compared to the individual search engines' 52.65% (+/-12.0) (p < 0.001). The results demonstrate the validity of the CAT Crawler meta-search engine approach. The improved precision due to inherent filters underlines the practical usefulness of this tool for clinicians.

  16. Space Shuttle Crawler Transporter Truck Shoe Qualification Tests and Analyses for Return-to-Flight

    NASA Technical Reports Server (NTRS)

    Margasahayam, Ravi N.; Meyer, Karl A.; Burton, Roy C.; Gosselin, Armand M.

    2005-01-01

    A vital element to Launch Complex 39 (LC39) and NASA's Kennedy Space Center (KSC) mobile launch transfer operation is a 3 million kilogram behemoth known as the Crawler Transporter (CT). Built in the 1960's, two CT's have accumulated over 1700+ miles each and have been used for the Apollo and the Space Shuttle programs. Recent observation of fatigue cracks on the CT shoes led to a comprehensive engineering, structural and metallurgical evaluation to assess the root cause that necessitated procurement of over 1000 new shoes. This paper documents the completed dynamic and compression tests on the old and new shoes respectively, so as to certify them for Space Shuttle's return-to-flight (RTF). Measured strain data from the rollout tests was used to develop stress/loading spectra and static equivalent load for qualification testing of the new shoes. Additionally, finite element analysis (FEA) was used to conduct sensitivity analyses of various contact parameters and structural characteristics for acceptance of new shoes.

  17. 78 FR 51724 - California State Motor Vehicle Pollution Control Standards; Tractor-Trailer Greenhouse Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ...: The California Air Resources Board (CARB) has notified EPA that it has adopted a tractor-trailer... Regulation). By letter dated June 20, 2013, CARB submitted a request that EPA grant a waiver of preemption of... comment on the request. DATES: EPA has scheduled a public hearing concerning CARB's request on September...

  18. Vocational Agriculture Training Program: Safe Tractor and Farm Machinery Operation. Special Paper No. 8. Second Revision.

    ERIC Educational Resources Information Center

    Bobbitt, Frank; Doss, Howard

    The publication was prepared for the United States Office of Education for use by teachers who direct agricultural training programs in safe tractor operation and safe farm machinery operation that comply with the United States Department of Labor regulations on hazardous occupations in agriculture. Upon successful completion of these training…

  19. GASOLINE TRACTOR ENGINE SYSTEMS. AGRICULTURAL MACHINERY--SERVICE OCCUPATIONS, MODULE NUMBER 14.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    ONE OF A SERIES DESIGNED TO HELP TEACHERS PREPARE POSTSECONDARY STUDENTS FOR AGRICULTURAL MACHINERY SERVICE OCCUPATIONS AS PARTS MEN, MECHANICS, MECHANIC'S HELPERS, AND SERVICE SUPERVISORS, THIS GUIDE AIMS TO DEVELOP STUDENT UNDERSTANDING OF THE OPERATION, COMPONENTS, AND FUNCTIONS OF VARIOUS GASOLINE TRACTOR ENGINE SYSTEMS. IT WAS DEVELOPED BY A…

  20. Tractor Mechanics: Maintaining and Servicing the Fuel System. Learning Activity Packages 20-33.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    Learning activity packages are presented for instruction in tractor mechanics. The packages deal with the duties involved in maintaining the fuel system. The following fourteen learning activity packages are included: servicing fuel and air filters, servicing fuel tanks and lines, adjusting a carburetor, servicing a carburetor, servicing the…

  1. A History of the Caterpillar Tractor Company's Use of Motion Pictures.

    ERIC Educational Resources Information Center

    Veeder, Gerry A.

    Film historians have tended to overlook the industrial film even though it has been widely used as a sales tool since early in this century. The Caterpillar Tractor Company was one of the first to adopt this medium as a means of demonstrating what its machines could do in a variety of situations. While other types of films have been made by…

  2. Residual stand damage survey for three small tractors used in harvesting northern hardwoods

    Treesearch

    Neil K. Huyler; George D. Aiken; Chris B. LeDoux

    1994-01-01

    There have always been concerns about the impact of timber harvesting with conventional ground-based harvesting equipment on many parts of the forest ecosystem. One of these parts, which is easily measured, is the residual stand. The interest in small tractors (less than 60 horsepower) has increased in recent years because private landowners are concerned that large...

  3. The Development of Procedural Knowledge in Adults Engaged in a Tractor-Trailer Task.

    ERIC Educational Resources Information Center

    Moses, Nelson

    1994-01-01

    Studied development of procedural knowledge in 14 adults, aged 18 to 35 years, engaged in a novel task using a toy tractor-trailer rig. Results revealed three phases of development in subjects' knowledge of steering procedures and the rig's movement patterns, and their use of feedback information. Subjects also manifested different levels of…

  4. 49 CFR 393.61 - Truck and truck tractor window construction.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Truck and truck tractor window construction. 393.61 Section 393.61 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... inches). The maximum radius of the corner arcs shall not exceed 152 mm (6 inches). The long axis of...

  5. Tractor Mechanics: Maintaining and Servicing the Fuel System. Learning Activity Packages 20-33.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    Learning activity packages are presented for instruction in tractor mechanics. The packages deal with the duties involved in maintaining the fuel system. The following fourteen learning activity packages are included: servicing fuel and air filters, servicing fuel tanks and lines, adjusting a carburetor, servicing a carburetor, servicing the…

  6. Off-axial acoustic radiation force of repulsor and tractor bessel beams on a sphere.

    PubMed

    Silva, Glauber T; Lopes, J Henrique; Mitri, Farid G

    2013-06-01

    Acoustic Bessel beams are known to produce an axial radiation force on a sphere centered on the beam axis (on-axial configuration) that exhibits both repulsor and tractor behaviors. The repulsor and the tractor forces are oriented along the beam's direction of propagation and opposite to it, respectively. The behavior of the acoustic radiation force generated by Bessel beams when the sphere lies outside the beam's axis (off-axial configuration) is unknown. Using the 3-D radiation force formulas given in terms of the partial wave expansion coefficients for the incident and scattered waves, both axial and transverse components of the force exerted on a silicone- oil sphere are obtained for a zero- and a first-order Bessel vortex beam. As the sphere departs from the beam's axis, the tractor force becomes weaker. Moreover, the behavior of the transverse radiation force field may vary with the sphere's size factor ka (where k is the wavenumber and a is the sphere radius). Both stable and unstable equilibrium regions around the beam's axis are found, depending on ka values. These results are particularly important for the design of acoustical tractor beam devices operating with Bessel beams.

  7. A History of the Caterpillar Tractor Company's Use of Motion Pictures.

    ERIC Educational Resources Information Center

    Veeder, Gerry A.

    Film historians have tended to overlook the industrial film even though it has been widely used as a sales tool since early in this century. The Caterpillar Tractor Company was one of the first to adopt this medium as a means of demonstrating what its machines could do in a variety of situations. While other types of films have been made by…

  8. Analysis of bifurcation and stability for a tractor semi-trailer in planar motion

    NASA Astrophysics Data System (ADS)

    Ding, Nenggen; Shi, Xiaobo; Zhang, Yipeng; Chen, Wen

    2014-12-01

    This paper is intended for bifurcation analysis of a nonlinear tractor semi-trailer vehicle model in planar motion and for investigating its stability under constant running conditions. Bifurcation analysis shows that bifurcation diagrams of a tractor semi-trailer are quite different from those of a single-unit vehicle. Some instability phenomena of the vehicle system such as jackknifing, sideslip, and spinning are explained by correlating them with the behaviour in the neighbourhood of unstable fixed points based on analysis of eigenvectors, phase trajectories, and status of lateral tyre force saturation. It is also found that yaw planar instability of a tractor semi-trailer is caused by lateral tyre force saturation of the tractor's rear axles and/or the trailer's axles. Moreover, the stability region in the state space is demarcated, and a stability index for evaluating size of the stability region in a feasible domain is proposed. Yaw stability under constant driving conditions is analysed by using the proposed stability index.

  9. Evaluation of a tractor cab using real-time aerosol counting instrumentation.

    PubMed

    Hall, Ronald M; Heitbrink, William A; Reed, Laurence D

    2002-01-01

    Aerosol instrumentation was used to evaluate air infiltration into tractor cabs that are used to protect the agricultural worker during pesticide applications. Preliminary surveys were conducted on three different manufactured agriculture enclosures. The results of these preliminary surveys indicated that aerosols are entering the cab through leak sources or are being generated inside the cab. These results identified the need for in-depth field evaluations of tractor cabs to identify any leak sources. To evaluate the ability of tractor cabs to reduce operator air contaminant exposure, field evaluations were conducted on two tractor cabs. Specifically, we evaluated: 1) the particle size distribution and the effectiveness of the filter system; and 2) air infiltration into the cab. These evaluations were also conducted to demonstrate the ease and practicality of using optical particle counters to evaluate the ability of cabin filtration systems. Pesticide particle size distribution during an air blast spray operation was also evaluated during the study. The field tests were conducted on a John Deere 7000 series tractor cab (tractor manufacturer's cab) and a Nelson spraycab (retrofit cab). Both cabs were equipped with high efficiency particulate air (HEPA) filter media which were assumed to be 99.97 percent efficient at removing the test aerosol, atmospheric condensation nuclei. Thus, the major source of aerosols inside the cab was assumed to be leakage around filters at the seals. Using a portable dust monitor (PDM), the ratio of the outside to inside aerosol measurements was used to calculate a cab protection factor. During the evaluations, one PDM was placed inside the tractor cab (near the tractor operator) and one PDM was placed outside (near the air intake) to count particles. During the evaluations, the instruments were switched to prevent instrument bias from affecting the findings. The ratio of the two measurements (i.e., protection factor = outside

  10. 29 CFR 1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Tractors while used with mounted equipment which is incompatible with ROPS (e.g. cornpickers, cotton... dictated by the work environment. Such information shall be provided at the time of initial assignment and...

  11. Bioactivities of crude mucus proteins from Eudrilus eugeniae (African night crawler) and Perionyx excavatus (Blue worm).

    PubMed

    Prem-U-Domkit, K; Muangman, T; Klungsupya, P; Chantsavang, S; Kubera, A

    2017-01-01

    This study aimed to investigate the enzymatic anti-oxidative, hemolytic and cytotoxic activities of crude mucus proteins from the two earthworms including Eudrilus eugeniae (African night crawler) and Perionyx excavatus (Blue worm). The bioactivities were determined by hemolytic activity, cytotoxic activity using HepG2 human hepatocellular carcinoma cells, L-929 mouse fibroblast and TK6 human lymphoblast cell lines and antioxidant activity. The results indicated that the hemolytic activity of mucus proteins of P. excavatus was higher than that of E. eugeniae. The cytotoxic activity of the mucus proteins of E. eugeniae could inhibit the growth of HepG2 with the IC50 at 144.2 ± 0.18 µg/mL but showed no effect on L-929 and TK6. On the other hand, the crude proteins of P. excavatus decreased cell viability of both L-929 and HepG2 with their IC50 respectively were 6.87 ± 0.16 and 174.3 ± 0.19 µg/mL but they did not reduce the growth of TK6 cell line. The SOD-like activity of P. excavatus and E. eugeniae crude proteins were found with the IC50 at 149 µg/mL and 386.2 µg/mL, respectively. For GPx-like activity, crude proteins of P. excavatus exhibited significant (p ≤ 0.05) greater activity than those of E. eugeniae when tested at the concentration 100 µg/mL. This study revealed the bioactivities of crude mucus of earthworms which served as alternative natural proteins for the prophylaxis or treatment of free radical-related diseases as well as development of dietary supplements and cosmetics.

  12. a Decade of Improvement in Whole-Body Vibration and Low Back Pain for Freight Container Tractor Drivers

    NASA Astrophysics Data System (ADS)

    Nishiyama, K.; Taoda, K.; Kitahara, T.

    1998-08-01

    The authors' study in 1983 revealed that the whole-body vibration of the tractor units of freight containers was most hazardous in the back-to-chest directions (x-axis). The allowable exposure time was considerably shorter than that for heavy duty trucks. The low back pain (LBP) among the drivers seemed to be due to the long working hours and the ergonomically unsound tractor design, as well as the vibration. A preventative measure was the introduction of a tractor cab suspended by an air spring instead of a steel spring. In 1992, a follow-up field study was conducted. A personal vibration exposure meter developed by us measured the whole-body vibration on eight tractors. Eighty-nine triplets matched with the age and the years of driving tractors answered a questionnaire evaluation of the ergonomics of their tractor units.The comparison of the newest steel suspension vehicles to the old ones produced by the same motor company revealed that in thex-axis the vibration level had decreased by as much as 4 to 9 dB. Some tractors showed an increase in vibration in the buttocks-to-head direction (z-axis). However, such adverse changes seemed not to affect evaluations according to the fatigue-decreased proficiency boundary (FDP) and the exposure limit (EL) recommended in ISO 2631-1978. The present models, regardless of the type of suspension, changed the direction of the most hazardous vibration from thex-axis to thez-axis. However, the effect of the air-suspension was not so remarkable as expected. Among 40% of drivers seemed to exceed the FDP boundary during a day.The questionnaire study showed an improvement in the ergonomic evaluation of the tractors. The air suspension models seemed to induce less LBP than the steel suspension models.

  13. Wind-drag estimation in a traffic accident involving a motor scooter and a tractor-trailer.

    PubMed

    Park, Chan-Seong; Jeon, Seung-Won; Lee, Kyu-Jung; Kim, Jun-Suk; Oh, Jae-Geun; Park, Jong-Chan; Lee, Hong-Seok; Choi, Young-Shik

    2012-07-01

    This case report describes a noncontact traffic accident involving a motor scooter and a tractor-trailer with a focus on the wind-drag effect. We used load cells to measure the drag force acting on a substantially similar motor scooter when a substantially similar tractor-trailer passes by it, taking into consideration various speeds of the tractor-trailer and distances between the two vehicles. A three-dimensional steady-state flow analysis was also performed by using the CFX program for computational fluid dynamics to examine the streamlines and the pressure distribution around the tractor-trailer at various speeds. From the experiment, for a separation distance of 1.0 m (3.28 ft) and a speed of 90 km/h (55.9 mph), the maximum resultant drag force is 124.5 N (28 lb); this constitutes a degree of force that could abruptly disrupt the stability in maneuvering by an operator who is unaware of the approaching tractor-trailer. In addition, a single equation that relates the tractor-trailer speed to the drag force that acts on the motor scooter was derived on the basis of the Reynolds number (Re) and the wind-drag coefficient (C(d)): C(d) = 1.298 × 10(-7) Re.

  14. Quantifying driver's field-of-view in tractors: methodology and case study.

    PubMed

    Gilad, Issachar; Byran, Eyal

    2015-01-01

    When driving a car, the visual awareness is important for operating and controlling the vehicle. When operating a tractor, it is even more complex. This is because the driving is always accompanied with another task (e.g., plough) that demands constant changes of body postures, to achieve the needed Field-of-View (FoV). Therefore, the cockpit must be well designed to provide best FoV. Today, the driver's FoV is analyzed mostly by computer simulations of a cockpit model and a Digital Human Model (DHM) positioned inside. The outcome is an 'Eye view' that displays what the DHM 'sees'. This paper suggests a new approach that adds quantitative information to the current display; presented on three tractor models as case studies. Based on the results, the design can be modified. This may assist the engineer, to analyze, compare and improve the design, for better addressing the driver needs.

  15. Co-Simulation Research of the Mechanical-Hydraulic-Control Coupling System of ITER Tractor

    NASA Astrophysics Data System (ADS)

    Yang, Xiuqing; Luo, Minzhou; Mei, Tao; Yao, Damao

    2009-06-01

    The virtual prototyping models of the mechanical, hydraulic and control system of the ITER tractor were built with CATIA, ADAMS and MATLAB/Simulink respectively according to its heavy load and high precision characteristics, and the data transfer between the different models was accomplished by the integration interface between different software. Consequently the virtual experimental platform for the multi-disciplinary co-simulation was established. A co-simulation study of the mechanical-hydraulic-control coupling system of the ITER tractor was carried out. The synchronization servo control of parallel hydraulic cylinders was implemented, and the tracking control of the preconcerted trajectory of the hydraulic cylinders was realized on the established experimental platform. This paper presents the optimization design and technology rebuilding for the complicated coupling system with its theoretic foundation and co-simulation virtual experimental platform.

  16. Lubricant flow analysis for effective lubrication of tractor forward/reverse clutch.

    PubMed

    Noh, Daekyung; Kim, Soochul; Kim, Yongjoo; Jang, Joosup

    2017-04-01

    Owing to the high power requirements of tractors, their low-power transmission gears often experience durability problems such as burning of the clutch. The operation of tractors under high load conditions also causes clutch slip, with the consequent longer operation duration exacerbating the burning of the friction plate. Solving this problem requires effective lubricant distribution. This was achieved in the present study by the development of an analysis model for predicting the lubricant flow rate. The reliability of the model was verified by comparing its predictions for various operation conditions with experimental measurements. Using the model, it was determined that effective distribution of the lubricant could be achieved without significant modification of the system, by only adjusting the gaps between the clutch piston and the housing, and between the separation plates and the case.

  17. A Benchmark of Tractor Trailer Operator Training Between the United States Army’s 37th Transportation Command and a Selected Civilian Industry Leader

    DTIC Science & Technology

    1993-09-01

    ELECTE n "FEB 22 1994j3 A BENCHMARK OF TRACTOR TRAILER OPERATOR TRAINING BETWEEN THE UNITED STATES ARMY’S 37TH TRANSPORTATION COMMAND AND , 4 !*-" A...TRACTOR TRAILER OPERATOR TRAINING BETWEEN THE UNITED STATES ARMY’S 37TH TRANSPORTATION COMMAND AND A SELECTED CIVILIAN INDUSTRY LEADER THESIS Stephen J...LAL/93S-29 A BENCHMARK OF TRACTOR TRAILER OPERATOR TRAINING BETWEEN THE UNITED STATES ARMY’S 37TH TRANSPORTATION COMMAND AND A SELECTED CIVILIAN

  18. Tractor tire aspect ratio effects on soil bulk density and cone index

    USDA-ARS?s Scientific Manuscript database

    A 580/70R38 tractor drive tire with an aspect ratio of 0.756 and a 650/75R32 tire with an aspect ratio of 0.804 were operated at two dynamic loads and two inflation pressures on a sandy loam and a clay loam with loose soil above a hardpan. Soil bulk density and cone index were measured just above t...

  19. Optical pulling force on a magneto-dielectric Rayleigh sphere in Bessel tractor polarized beams

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.; Li, R. X.; Yang, R. P.; Guo, L. X.; Ding, C. Y.

    2016-11-01

    The optical radiation force induced by Bessel (vortex) beams on a magneto-dielectric subwavelength sphere is investigated with particular emphasis on the beam polarization and order l (or topological charge). The analysis is focused on identifying the regions and some of the conditions to achieve retrograde motion of the sphere centered on the axis of wave propagation of the incident beam, or shifted off-axially. Exact non-paraxial analytical solutions are established, and computations for linear, circular, radial, azimuthal and mixed polarizations of the individual plane wave components forming the Bessel (vortex) beams by means of the angular spectrum decomposition method (ASDM) illustrate the theory with particular emphasis on the tractor (i.e. reversal) behavior of the force. This effect results in the pulling of the magneto-dielectric sphere against the forward linear momentum density flux associated with the incoming waves. Should some conditions related to the choice of the beam parameters as well as the permittivity and permeability of the sphere be met, the optical force vanishes and reverses sign. Moreover, the beam polarization is shown to affect differently the axial negative pulling force for either the zeroth- or the first-order Bessel beam. When the sphere is centered on the beam‧s axis, the axial force component is always negative for the zeroth-order Bessel beam except for the radial and azimuthal polarization configurations. Nonetheless, for the first-order Bessel beam, the axial force is negative for the radial polarization case only. Additional tractor beam effects arise when the sphere departs from the center of the beam. It is also demonstrated that the tractor beam effect arises from the force component originating from the cross-interaction between the electric and magnetic dipoles. Potential applications are in particle manipulation, optical levitation, tractor beam tweezers, and other emergent technologies using polarized Bessel beams on

  20. Factors affecting the cost of tractor logging in the California Pine Region

    Treesearch

    M.E. Krueger

    1929-01-01

    The past five years have seen a very rapid expansion in the use of tractors for logging in the pine region of California. In 1923, when a previous bulletin of this series was published, steam donkey yarding, with which that study treated, was the prevailing method of yarding. During the season of 1928 probably not less than 60 percent of the timber output of this...

  1. [Accident prevention in agriculture in the ASL1 Abruzzo Local Health Service: protection facilities for tractors].

    PubMed

    Pompei, Domenico; Rossi, Roberta; Vecchiola, Rita; Angelone, Anna Maria; Fabiani, Leila

    2015-07-08

    The ASL1 workplace prevention and safety service in Abruzzo has been conducting workplace inspections on agricultural and livestock farms in the province of L'Aquila since 2011, mainly in the areas of Avezzano, Sulmona and L'Aquila. The agricultural sector in Abruzzo is characterized by high rates of accidents and the ratio of fatal injuries/total injuries is higher than the industry and services sector. To evaluate the presence or absence of safety devices , i.e. compliance or otherwise with regulations for tractors, and of any variable factor that could be associated with the safety of the vehicle. Between 2011 and 2013, 98 farms in the province of L'Aquila were inspected. The data resulting from the inspections was collected by the use of a checklist. An univariate logistic regression analysis was conducted in which the vehicles that complied with regulations were considered as the dependant variable, and the age of the tractor owner, the acres of worked land and the type of farm were considered as explanatory variables. Statistical elaboration was carried out using the Stata 12 programme. Out of a total of 298 tractors that were checked, 64.8% did not comply with regulations due to absence or unsuitability of one or more safety devices such as: a protective device in case of overturning; retention system of the driver; mounting and dismounting from the vehicle; protection of moving parts and hot parts; PTO (Power Take Off) protection device. A significant association between non-compliance of vehicles and the age of the owner and acres worked was observed, whereas no statistical significance was observed for the association with the farm type variable. Our study showed that farms where the owner's age is between 50 and 64 years and where more acres of land are worked are those where the agricultural or forestry tractors had lower levels of compliance with regulations.

  2. Adoption of rollover protective structures (ROPS) on U.S. farm tractors by state: 1993-1995, 2001, and 2004.

    PubMed

    Hard, D L; Myers, J R

    2011-04-01

    This research compares state-level rollover protective structure (ROPS) prevalence rates from the early and mid-1990s to those observed in the years 2001 and 2004. In addition, state-level ROPS prevalence rates are compared to state-level tractor overturn fatality rates. Tractor data for 1993-1995 and for 2001 and 2004 for all tractors and ROPS-equipped tractors in use on U.S. farms were derived from surveys conducted for NIOSH by the USDA-NASS. Changes in ROPS prevalence rates at the state level between the two time periods were assessed using a two-sample paired t-test with unequal sample sizes. Poisson regression was used to assess the association between ROPS prevalence rates and tractor overturn fatality rates at the state level. Overall, 49 of the 50 states had an observed increase in the percentage of farm tractors equipped with ROPS from 1993-1995 to 2001 and 2004. This increase was statistically significant for 34 states. Large shifts in ROPS prevalence were found within individual states and in clusters of states. These include a major increase in the southeastern U.S. and some western states. However, a core of states in the northeast (many of them in or near the Appalachian Mountains) through the upper midwest remain in the bottom quartile for ROPS prevalence. For the years 1992 through 2004, the highest fatality rates were observed in many of the same states that were identified previously as having persistently low ROPS prevalence rates. There is a clear relationship between low state-level ROPS prevalence rates and high state-specific tractor overturn fatality rates. While progress has been made in increasing the percentage of ROPS-equipped farm tractors, it is projected that ROPS prevalence rates will not reach a protective level nationally until after 2015. Regionally, the northeast and midwest will not reach protective levels of ROPS-equipped tractors until after 2020. Based on the adoption rates observed, tractor overturn rates will likely

  3. Aerodynamic performance of a drag reduction device on a full-scale tractor/trailer

    NASA Technical Reports Server (NTRS)

    Lanser, Wendy R.; Ross, James C.; Kaufman, Andrew E.

    1991-01-01

    The effectiveness of an aerodynamic boattail on a tractor/trailer road vehicle was measured in the NASA Ames Research Center 80- by 120-Foot Wind Tunnel. Results are examined for the tractor/trailer with and without the drag reduction device. Pressure measurements and flow visualization show that the aerodynamic boattail traps a vortex or eddy in the corner formed between the device and the rear corner of the trailer. This recirculating flow turns the flow inward as it separates from the edges of the base of the trailer. This modified flow behavior increases the pressure acting over the base area of the truck, thereby reducing the net aerodynamic drag of the vehicle. Drag measurements and pressure distributions in the region of the boattail device are presented for selected configurations. The optimum configuration reduces the overall drag of the tractor/trailer combination by about 10 percent at a zero yaw angle. Unsteady pressure measurements do not indicate strong vortex shedding, although the addition of the boattail plates increases high frequency content of the fluctuating pressure.

  4. Coca-Cola Refreshments Class 8 Diesel Electric Hybrid Tractor Evaluation: 13-Month Final Report

    SciTech Connect

    Walkowicz, K.; Lammert, M.; Curran, P.

    2012-08-01

    This 13-month evaluation used five Kenworth T370 hybrid tractors and five Freightliner M2106 standard diesel tractors at a Coca Cola Refreshments facility in Miami, Florida. The primary objective was to evaluate the fuel economy, emissions, and operational field performance of hybrid electric vehicles when compared to similar-use conventional diesel vehicles. A random dispatch system ensures the vehicles are used in a similar manner. GPS logging, fueling, and maintenance records and laboratory dynamometer testing are used to evaluate the performance of these hybrid tractors. Both groups drive similar duty cycles with similar kinetic intensity (0.95 vs. 0.69), average speed (20.6 vs. 24.3 mph), and stops per mile (1.9 vs. 1.5). The study demonstrated the hybrid group had a 13.7% fuel economy improvement over the diesel group. Laboratory fuel economy and field fuel economy study showed similar trends along the range of KI and stops per mile. Hybrid maintenance costs were 51% lower per mile; hybrid fuel costs per mile were 12% less than for the diesels; and hybrid vehicle total cost of operation per mile was 24% less than the cost of operation for the diesel group.

  5. Local unit invariance, back-reacting tractors and the cosmological constant problem

    NASA Astrophysics Data System (ADS)

    Bonezzi, R.; Corradini, O.; Waldron, A.

    2012-02-01

    When physics is expressed in a way that is independent of local choices of unit systems, Riemannian geometry is replaced by conformal geometry. Moreover masses become geometric, appearing as Weyl weights of tractors (conformal multiplets of fields necessary to keep local unit invariance manifest). The relationship between these weights and masses is through the scalar curvature. As a consequence mass terms are spacetime dependent for off-shell gravitational backgrounds, but happily constant for physical, Einstein manifolds. Unfortunately this introduces a naturalness problem because the scalar curvature is proportional to the cosmological constant. By writing down tractor stress tensors (multiplets built from the standard stress tensor and its first and second derivatives), we show how back-reaction solves this naturalness problem. We also show that classical back-reaction generates an interesting potential for scalar fields. We speculate that a proper description of how physical systems couple to scale, could improve our understanding of naturalness problems caused by the disparity between the particle physics and observed, cosmological constants. We further give some ideas how an ambient description of tractor calculus could lead to a Ricci-flat/CFT correspondence which generalizes the AdS side of Maldacena's duality to a Ricci-flat space of one higher dimension.

  6. Self-reported back pain in tractor drivers exposed to whole-body vibration.

    PubMed

    Boshuizen, H C; Bongers, P M; Hulshof, C T

    1990-01-01

    A postal questionnaire on symptoms of ill health and exposure to whole-body vibration was completed by 577 workers (response rate 79%) who were employed in certain functions by two companies 11 years before. The relation between the occupational history of driving vibrating vehicles (mainly agricultural tractors) and back pain has been analyzed. The prevalence of reported back pain is approximately 10% higher in the tractor drivers than in workers not exposed to vibration. The increase is mainly due to more pain in the lower back and more pain lasting at least several days. A vibration dose was calculated by assigning each vehicle driven a vibration magnitude, estimated on the base of vibration measurements. The prevalence of back pain increases with the vibration dose. The highest prevalence odds ratios are found for the more severe types of back pain. These prevalence odds ratios do not increase with the vibration dose. This might be due to health-related selection which is more pronounced for severe back pain than for back pain in general. The two components of the vibration dose, duration of exposure and estimated mean vibration magnitude, have also been considered separately. Back pain increases with duration of exposure but it does not increase with the estimated mean magnitude of vibration. This is probably due to the inaccuracy of this estimate. The higher prevalence of back pain in tractor drivers might be (partly) caused by whole-body vibration, but prolonged sitting and posture might also be of influence.

  7. Risk perceptions, barriers, and motivators to tractor ROPS retrofitting in the New York state farm community.

    PubMed

    Sorensen, J A; May, J J; Jenkins, P L; Jones, A M; Earle-Richardson, G B

    2006-08-01

    The prevalence of tractor rollovers among agricultural workers has made the retrofitting of tractors with rollover protective structures (ROPS) and seat belts a public health priority for agricultural health and safety specialists. To address this concern, the New York Center for Agricultural Medicine and Health (NYCAMH) developed a seven-question survey, designed to assess perceptions of risk as well as potential motivators and barriers to retrofitting. Data from 465 phone surveys were gathered from New York State farmers representing various commodities and farm sizes. Analysis of responses to three qualitative questions contained in the survey indicated that most farmers in New York understand the importance of ROPS but lack the proper motivation to consider retrofitting. It appears that more convenient safety strategies, cost, and age of the tractor compete with a farmer's initiative to retrofit. In addition, survey responses illustrate that although many farmers believe ROPS are important in a general sense, many believe that this safety measure is not necessary for them in particular. Frequent motivators to retrofitting are concerns about safety, although the authors conclude that a more thorough analysis of these "general safety concerns" in qualitative interviews is important.

  8. Aerodynamic performance of a drag reduction device on a full-scale tractor/trailer

    NASA Astrophysics Data System (ADS)

    Lanser, Wendy R.; Ross, James C.; Kaufman, Andrew E.

    1991-09-01

    The effectiveness of an aerodynamic boattail on a tractor/trailer road vehicle was measured in the NASA Ames Research Center 80- by 120-Foot Wind Tunnel. Results are examined for the tractor/trailer with and without the drag reduction device. Pressure measurements and flow visualization show that the aerodynamic boattail traps a vortex or eddy in the corner formed between the device and the rear corner of the trailer. This recirculating flow turns the flow inward as it separates from the edges of the base of the trailer. This modified flow behavior increases the pressure acting over the base area of the truck, thereby reducing the net aerodynamic drag of the vehicle. Drag measurements and pressure distributions in the region of the boattail device are presented for selected configurations. The optimum configuration reduces the overall drag of the tractor/trailer combination by about 10 percent at a zero yaw angle. Unsteady pressure measurements do not indicate strong vortex shedding, although the addition of the boattail plates increases high frequency content of the fluctuating pressure.

  9. Aerodynamic performance of a drag reduction device on a full-scale tractor/trailer

    NASA Technical Reports Server (NTRS)

    Lanser, Wendy R.; Ross, James C.; Kaufman, Andrew E.

    1991-01-01

    The effectiveness of an aerodynamic boattail on a tractor/trailer road vehicle was measured in the NASA Ames Research Center 80- by 120-Foot Wind Tunnel. Results are examined for the tractor/trailer with and without the drag reduction device. Pressure measurements and flow visualization show that the aerodynamic boattail traps a vortex or eddy in the corner formed between the device and the rear corner of the trailer. This recirculating flow turns the flow inward as it separates from the edges of the base of the trailer. This modified flow behavior increases the pressure acting over the base area of the truck, thereby reducing the net aerodynamic drag of the vehicle. Drag measurements and pressure distributions in the region of the boattail device are presented for selected configurations. The optimum configuration reduces the overall drag of the tractor/trailer combination by about 10 percent at a zero yaw angle. Unsteady pressure measurements do not indicate strong vortex shedding, although the addition of the boattail plates increases high frequency content of the fluctuating pressure.

  10. Gravity, two times, tractors, Weyl invariance, and six-dimensional quantum mechanics

    NASA Astrophysics Data System (ADS)

    Bonezzi, R.; Latini, E.; Waldron, A.

    2010-09-01

    Fefferman and Graham showed some time ago that four-dimensional conformal geometries could be analyzed in terms of six-dimensional, ambient, Riemannian geometries admitting a closed homothety. Recently, it was shown how conformal geometry provides a description of physics manifestly invariant under local choices of unit systems. Strikingly, Einstein’s equations are then equivalent to the existence of a parallel scale tractor (a six-component vector subject to a certain first order covariant constancy condition at every point in four-dimensional spacetime). These results suggest a six-dimensional description of four-dimensional physics, a viewpoint promulgated by the 2 times physics program of Bars. The Fefferman-Graham construction relies on a triplet of operators corresponding, respectively, to a curved six-dimensional light cone, the dilation generator and the Laplacian. These form an sp(2) algebra which Bars employs as a first class algebra of constraints in a six-dimensional gauge theory. In this article four-dimensional gravity is recast in terms of six-dimensional quantum mechanics by melding the 2 times and tractor approaches. This parent formulation of gravity is built from an infinite set of six-dimensional fields. Successively integrating out these fields yields various novel descriptions of gravity including a new four-dimensional one built from a scalar doublet, a tractor-vector multiplet and a conformal class of metrics.

  11. Using Web Crawler Technology for Text Analysis of Geo-Events: A Case Study of the Huangyan Island Incident

    NASA Astrophysics Data System (ADS)

    Hu, H.; Ge, Y. J.

    2013-11-01

    With the social networking and network socialisation have brought more text information and social relationships into our daily lives, the question of whether big data can be fully used to study the phenomenon and discipline of natural sciences has prompted many specialists and scholars to innovate their research. Though politics were integrally involved in the hyperlinked word issues since 1990s, automatic assembly of different geospatial web and distributed geospatial information systems utilizing service chaining have explored and built recently, the information collection and data visualisation of geo-events have always faced the bottleneck of traditional manual analysis because of the sensibility, complexity, relativity, timeliness and unexpected characteristics of political events. Based on the framework of Heritrix and the analysis of web-based text, word frequency, sentiment tendency and dissemination path of the Huangyan Island incident is studied here by combining web crawler technology and the text analysis method. The results indicate that tag cloud, frequency map, attitudes pie, individual mention ratios and dissemination flow graph based on the data collection and processing not only highlight the subject and theme vocabularies of related topics but also certain issues and problems behind it. Being able to express the time-space relationship of text information and to disseminate the information regarding geo-events, the text analysis of network information based on focused web crawler technology can be a tool for understanding the formation and diffusion of web-based public opinions in political events.

  12. Effects of tractor loads and tyre pressures on soil compaction in Tunisia under different moisture conditions

    NASA Astrophysics Data System (ADS)

    Khemis, Chiheb; Abrougui, Khaoula; Ren, Lidong; Mutuku, Eunice Ann; Chehaibi, Sayed; Cornelis, Wim

    2017-04-01

    Vegetables in Tunisia demand frequent tractor traffic for soil tillage, cultural operations and phytosanitary treatment, resulting in soil compaction. This study evaluates the effects of four levels of compaction by using different loads and tyre pressures of tractors, i.e., load 1 (C1) = 1460 kg, load 2 (C2) = 3100 kg, tyre pressure 1 (C3) = 800 kg cm-2, tyre pressure 2 (C4) = 1500 kg cm-2 on the hydraulic and physical properties of a sandy loam (10% clay, 20% silt, 68% sand) under three natural moisture conditions H0, H1 (15 days later), H2 (30 days later). At H0 average water content between 0 and 30 cm depth varied from 0.04 to 0.06 kg kg-1, at H1 between 0.13 and 0.07 kg kg-1, and at H2 between 0.10 and 0.09 kg kg-1. Each test run was limited to one pass. Undisturbed soil cores were collected in the topsoil (0-10 cm), at 10-20 cm and in the subsoil (20-30 cm) below the trace of the wheel at sites in the Higher Institute of Agronomy of Chott Mariam, Sousse, Tunisia. Soil compaction level was determined by penetration resistance using a penetrologger. Porosity, bulk density and permeability were then determined to evaluate the impact of the four load/tyre pressure combinations at the three moisture conditions on soil compaction. Prior to the experiment (C0), bulk density was 1.4 Mg m-3. After the tractor pass, the highest degree of compaction was observed with tractor load C2 and tyre pressure C4 which significantly changed soil bulk density resulting in values of up to 1.71 Mg m-3 in the topsoil and compacted subsoil under H2, which is significantly above the critical value of 1.6 Mg m-3 for soils with clay content below 17.5%. The high degree of compaction significantly affected penetration resistance and porosity of both topsoil and subsoil layers accordingly. Permeability was significantly reduced as a result of the induced compaction. The results demonstrate that different degrees of soil compaction under different moisture levels could greatly influence

  13. 30 CFR 56.14130 - Roll-over protective structures (ROPS) and seat belts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) and seat belts shall be installed on— (1) Crawler tractors and crawler loaders; (2) Graders; (3) Wheel loaders and wheel tractors; (4) The tractor portion of semi-mounted scrapers, dumpers, water wagons... when operating graders from a standing position, the grader operator shall wear safety lines and...

  14. 30 CFR 56.14130 - Roll-over protective structures (ROPS) and seat belts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) and seat belts shall be installed on— (1) Crawler tractors and crawler loaders; (2) Graders; (3) Wheel loaders and wheel tractors; (4) The tractor portion of semi-mounted scrapers, dumpers, water wagons... when operating graders from a standing position, the grader operator shall wear safety lines and...

  15. 30 CFR 56.14130 - Roll-over protective structures (ROPS) and seat belts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) and seat belts shall be installed on— (1) Crawler tractors and crawler loaders; (2) Graders; (3) Wheel loaders and wheel tractors; (4) The tractor portion of semi-mounted scrapers, dumpers, water wagons... when operating graders from a standing position, the grader operator shall wear safety lines and...

  16. A newly developed snow vehicle (SM100S) for Antarctica. Part 4: Low temperature properties of crawler belt

    NASA Astrophysics Data System (ADS)

    Maekawa, Etsuji; Terayama, Yoshihide

    1992-11-01

    In order to discover a high cold-resistance material for use in the crawler belt of snow vehicles, the physical properties at very low temperatures of a recently developed material, isoprene/butadiene (70/30) random copolymer filled with carbon black, was investigated in comparison with a blended rubber NR (Natural Rubber) / BR (Butadiene Rubber) (65/35) as well as a currently used NR. It has been found that this material can keep rubber elasticity even at low temperatures below - 70 C, though it is somewhat inferior to the other two materials as to strengths such as stress-at-break and tear; and hence, it is considered as quite worthy of a practical test for a snow vehicle in the Antarctic area.

  17. Initial rollover effectiveness evaluation of an alternative seat belt design for agricultural tractors.

    PubMed

    Rains, G C

    2000-02-01

    A test program was conducted to determine the effectiveness of a seat belt restraint in preventing occupant movement in a rollover accident. A baseline type-2 seat belt (pelvic and torso restraint), and an improved type-2 seat belt restraint, both designed to restrict occupant motion in a rollover accident, were tested in a rollover restraints tester (RRT). Each seat belt was placed on a H-III 50th percentile male dummy and testing conducted at a single roll rate and two D-ring adjustment positions. Each test simulated what was approximately a 260 degrees per second rollover parallel to the longitudinal axis of the tractor with the top of the ROPS impacting the ground after 180 degrees of roll. Forces on the dummy's head and neck were measured, and video was taken to measure the head motion in the x-, y-, and z-axis of the dummy. The average vertical, forward, and lateral head movement in the baseline seat belt was 144, 222, and 184 mm, respectively, when the adjustable D-ring anchorage supporting the shoulder belt was in its lowest position. At the lowest D-ring height, the shoulder belt became ineffective and the seat belt performance became similar to a type-1 restraint (required for tractors with ROPS) resulting in increased vertical, forward, and lateral movement. The improved restraint reduced vertical head movement by as much as 75% without increasing head and neck loads above established injury criteria. Testing seat belts for rollover effectiveness will become increasingly important as seat belt usage on tractors with ROPS increases.

  18. Optical pulling force and torques on Rayleigh semiconductor prolate and oblate spheroids in Bessel tractor beams

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.

    2017-07-01

    Optical tractor Bessel beams are gaining increased interest where a negative attractive force acting in opposite direction of wave propagation is harnessed for particle manipulation in opto-fluidics, the manufacturing of periodic composite metamaterials and other related applications. Previous works considered the spherical geometry, however, it is of some importance to develop improved models to investigate objects of more complex shapes and study the tractor beam effect on them. The aim of this work is therefore directed toward this goal, where the dipole approximation method is used to compute the optical force, spin and orbital torques on a subwavelength semiconductor spheroid illuminated by a zeroth-order Bessel vector beam. Numerical computations for the Cartesian components of the optical radiation force on prolate and oblate spheroids with arbitrary orientation are performed, with emphasis on the emergence of a negative pulling force and its dependence on the half-cone angle of the beam, the aspect ratio of the spheroid, and its orientation in space. Moreover, the Cartesian components of the spin radiation torque are computed where a negative spin torque can arise, which causes a rotational twisting effect of the spheroid around its center of mass in either the counterclockwise or the clockwise (negative) direction of spinning. In addition, the axial component of the orbital radiation torque is computed which also shows sign reversal. The results of this analysis provide a priori information for the design and development of novel optical tweezers devices and tractor beams, with potential applications in the manipulation and handling of elongated particles.

  19. Determination of influence factors and accident rates for the Armored Tractor/Safe Secure Trailer

    SciTech Connect

    Phillips, J.S.; Clauss, D.B.; Blower, D.F.

    1994-04-01

    Operating environments, such as road type, road location, and time of day, play an important role in the observed accident rates of heavy trucks used in general commerce. These same factors influence the accident rate of the Armored Tractor/Safe Secure Trailer (AT/SST) used by the Department of Energy to transport hazardous cargos within the continental United States. This report discusses the development of accident rate influence factors. These factors, based on heavy trucks used in general commerce, are used to modify the observed overall AT/SST accident rate to account for the different operating environments.

  20. Structural dynamics modeling and testing of the Department of Energy tractor/trailer combination

    SciTech Connect

    Field, R.V. Jr.; Hurtado, J.E.; Carne, T.G.; Dohrmann, C.R.

    1996-12-31

    This study presents a combined analytical and experimental effort to characterize and improve the ride quality of the Department of Energy tractor/trailer combination. The focus is to augment the experimental test results with the use of a high quality computer model. The discussion includes an overview of the finite element model of the vehicle and experimental modal test results. System identification techniques are employed to update the mathematical model. The validated model is then used to illustrate the benefits of incorporating two major design changes, namely the switch from a separate cab/sleeper configuration to an integrated cab, and the use of a cab suspension system.

  1. Whole-Body Vibration Assessment of the M915A2 Truck Tractor

    DTIC Science & Technology

    1994-01-01

    lam, s Pd ImJ V: T* am U.34. embalm b*t Z..Vag" Febnmry 14, IM M915Z2 buck Xxpnut h :•lIFb haS I 1 0.0t/0.391 1.0 2 Y 0.04/0.191 .. ’• >:T: Z 0,03...15 Appendix A: List of manufacturers .............. 16 Appendix B: ISO tables and graphs ... ........... .. 17 List of figures Figure Page 1 ...M915A2 truck tractor .............. ............... 4 2. Data acquisition system ............. .............. 7 List of tables Table Page 1 . WBV test

  2. The analysis of work-related injuries in a tractor factory.

    PubMed

    Nikoli, N; Mavrić, T

    1994-05-01

    An analysis of work-related injuries and absenteeism was carried out in a steel production and tractor manufacturing factory from 1982 to 1986. During that period there were 1152 injuries and 16,798 working days lost. Foundry workers were the most frequently injured; fists and fingers were the most frequently affected parts of the body. The number of injuries at work as well as the number of lost working days were highly influenced by the low socio-economic position of workers and by a general recession.

  3. KENNEDY SPACE CENTER, FLA. - Framed between palm trees, solid rocket boosters loom above the Mobile Launcher Platform (MLP) as the crawler transporter slowly moves it along the crawlerway. The journey is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - Framed between palm trees, solid rocket boosters loom above the Mobile Launcher Platform (MLP) as the crawler transporter slowly moves it along the crawlerway. The journey is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  4. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  5. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The view reveals the river gravel surface that is 4 inches thick on the straightaway sections and 8 inches thick on curves. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The view reveals the river gravel surface that is 4 inches thick on the straightaway sections and 8 inches thick on curves. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  6. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  7. KENNEDY SPACE CENTER, FLA. - Carrying a set of twin solid rocket boosters, the crawler transporter slowly moves the Mobile Launcher Platform (MLP) past the NASA-KSC News Center where the U.S. flag flies daily. The journey is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - Carrying a set of twin solid rocket boosters, the crawler transporter slowly moves the Mobile Launcher Platform (MLP) past the NASA-KSC News Center where the U.S. flag flies daily. The journey is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  8. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (on the horizon at right; Pad 39B is at far left), and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (on the horizon at right; Pad 39B is at far left), and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  9. KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician walks towards the intersection of the crawlerway beside a crawler-transporter moving Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A, and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician walks towards the intersection of the crawlerway beside a crawler-transporter moving Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A, and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  10. KENNEDY SPACE CENTER, FLA. - As the crawler transporter slowly moves the Mobile Launcher Platform (MLP) out of the Vehicle Assembly Building, the two solid rocket boosters on top are framed in the doorway. The move is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - As the crawler transporter slowly moves the Mobile Launcher Platform (MLP) out of the Vehicle Assembly Building, the two solid rocket boosters on top are framed in the doorway. The move is in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  11. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (framed between the boosters), and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (framed between the boosters), and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  12. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, along the crawlerway in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, along the crawlerway in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  13. KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician inspects the shoes on one of eight tracks of a crawler-transporter (CT). The CT is moving Mobile Launcher Platform (MLP) number 3 with a set of twin solid rocket boosters bolted on top to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician inspects the shoes on one of eight tracks of a crawler-transporter (CT). The CT is moving Mobile Launcher Platform (MLP) number 3 with a set of twin solid rocket boosters bolted on top to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  14. KENNEDY SPACE CENTER, FLA. - The crawler transporter has slowly moved the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter has slowly moved the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  15. KENNEDY SPACE CENTER, FLA. - Seen across the water of the Launch Complex 39 turn basin, a crawler-transporter, carrying Mobile Launcher Platform (MLP) number 3 with a set of twin solid rocket boosters bolted atop, crawls out of the 525-foot-tall Vehicle Assembly Building during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Seen across the water of the Launch Complex 39 turn basin, a crawler-transporter, carrying Mobile Launcher Platform (MLP) number 3 with a set of twin solid rocket boosters bolted atop, crawls out of the 525-foot-tall Vehicle Assembly Building during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  16. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, crawl out of the Vehicle Assembly Building (VAB) in support of the second engineering analysis vibration test on the crawler and MLP. In the background is another MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, crawl out of the Vehicle Assembly Building (VAB) in support of the second engineering analysis vibration test on the crawler and MLP. In the background is another MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  17. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (on the horizon) and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A (on the horizon) and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  18. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, crawls away from the Vehicle Assembly Building in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, crawls away from the Vehicle Assembly Building in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  19. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. In the distance, at left, is Launch Pad 39A. The water on the right of the crawlerway is the Banana River. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. In the distance, at left, is Launch Pad 39A. The water on the right of the crawlerway is the Banana River. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  20. KENNEDY SPACE CENTER, FLA. - As the crawler transporter slowly moves the Mobile Launcher Platform (MLP) out of the Vehicle Assembly Building, the driver of the front control cab can be seen. The MLP is carrying two solid rocket boosters for engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - As the crawler transporter slowly moves the Mobile Launcher Platform (MLP) out of the Vehicle Assembly Building, the driver of the front control cab can be seen. The MLP is carrying two solid rocket boosters for engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  1. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, along the crawlerway in support of engineering analysis vibration tests on the crawler and MLP. In the distance, at left, is Launch Pad 39A. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, along the crawlerway in support of engineering analysis vibration tests on the crawler and MLP. In the distance, at left, is Launch Pad 39A. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  2. KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. On either side of the boosters on the horizon can be seen the two launch pads. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. On either side of the boosters on the horizon can be seen the two launch pads. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  3. KENNEDY SPACE CENTER, FLA. - Viewed across the turn basin in the Launch Complex 39 Area, the crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB). The journey is in support of engineering analysis vibration tests on the crawler and MLP. The water on the right of the crawlerway is the Banana River. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - Viewed across the turn basin in the Launch Complex 39 Area, the crawler transporter slowly moves the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, away from the Vehicle Assembly Building (VAB). The journey is in support of engineering analysis vibration tests on the crawler and MLP. The water on the right of the crawlerway is the Banana River. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  4. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters bolted to it, atop the crawler-transporter, crawl to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. In the background are Launch Pads 39A (right) and 39B (left). The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters bolted to it, atop the crawler-transporter, crawl to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. In the background are Launch Pads 39A (right) and 39B (left). The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  5. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters bolted to it, atop the crawler-transporter, inches along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The MLP is viewed from the KSC News Center across the turn basin. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters bolted to it, atop the crawler-transporter, inches along the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. The MLP is viewed from the KSC News Center across the turn basin. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  6. KENNEDY SPACE CENTER, FLA. - The crawler transporter is slowly moving the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-17

    KENNEDY SPACE CENTER, FLA. - The crawler transporter is slowly moving the Mobile Launcher Platform (MLP), carrying a set of twin solid rocket boosters, out of the Vehicle Assembly Building (VAB) in support of engineering analysis vibration tests on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  7. KENNEDY SPACE CENTER, FLA. - The crawler-transporter carrying Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, crawls to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. From this perspective, the Launch Control Center (left) and the 525-foot-tall Vehicle Assembly Building (right) in the background appear dwarfed by the 184-foot-tall boosters. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - The crawler-transporter carrying Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, crawls to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. From this perspective, the Launch Control Center (left) and the 525-foot-tall Vehicle Assembly Building (right) in the background appear dwarfed by the 184-foot-tall boosters. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  8. KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch away from the Vehicle Assembly Building (VAB) in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Mobile Launcher Platform (MLP) number 3 and a set of twin solid rocket boosters, atop the crawler-transporter, inch away from the Vehicle Assembly Building (VAB) in support of the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  9. KENNEDY SPACE CENTER, FLA. - A crawler-transporter carrying Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, crawls to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. From this perspective, the Launch Control Center (left) and the 525-foot-tall Vehicle Assembly Building (right) in the background appear dwarfed by the 184-foot-tall boosters. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A crawler-transporter carrying Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, crawls to the intersection in the crawlerway in support of the second engineering analysis vibration test on the crawler and MLP. From this perspective, the Launch Control Center (left) and the 525-foot-tall Vehicle Assembly Building (right) in the background appear dwarfed by the 184-foot-tall boosters. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  10. KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician monitors the performance of a crawler-transporter as it moves Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, to the intersection in the crawlerway during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A, and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A Kennedy Space Center technician monitors the performance of a crawler-transporter as it moves Mobile Launcher Platform (MLP) number 3, with a set of twin solid rocket boosters bolted atop, to the intersection in the crawlerway during the second engineering analysis vibration test on the crawler and MLP. The crawler is moving at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it leaves the VAB, travels toward Launch Pad 39A, and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  11. Reduction of aerodynamic drag and fuel consumption for tractor-trailer vehicles

    NASA Technical Reports Server (NTRS)

    Muirhead, V. U.; Saltzman, E. J.

    1979-01-01

    Wind-tunnel tests were performed on a scale model of a cab-over-engine tractor-trailer vehicle and several modifications of the model. Results from two of the model configurations were compared with full-scale drag data obtained from similar configurations during coast-down tests. Reductions in fuel consumption derived from these tests are presented in terms of fuel quantity and dollar savings per vehicle year, based on an annual driving distance of 160,900 km (100,000 mi.). The projected savings varied from 13,001 (3435) to 25,848 (6829) liters (gallons) per year which translated to economic savings from $3435 to about $6829 per vehicle year for an operating speed of 88.5 km/h (55 mph) and wind speeds near the national average of 15.3 km/h (9.5 mph). The estimated cumulative fuel savings for the entire U.S. fleet of cab-over-engine tractor, van-type trailer combinations ranged from 4.18 million kl (26.3 million bbl) per year for a low-drag configuration to approximately twice that amount for a more advanced configuration.

  12. Acoustic control in a tractor cabin using two optimally designed Helmholtz resonators

    NASA Astrophysics Data System (ADS)

    Driesch, Patricia L.; Koopmann, Gary H.

    2003-10-01

    A virtual design methodology is developed to minimize the noise in enclosures with optimally designed, passive, 20 acoustic absorbers (Helmholtz resonators). A series expansion of eigenfunctions is used to represent the acoustic=20 absorbers as external volume velocities, eliminating the need for a solution of large matrix eigenvalue problems. A determination of this type (efficient model/reevaluation approach) significantly increases the design possibilities when optimization techniques are implemented. As a full-scale demonstration, the acoustic response from 90-190 Hz of a tractor cabin was investigated. The lowest cabin mode proposes a significant challenge to a noise control engineer since its anti-node is located near the head of the operator and often generates unacceptable sound-pressure levels. Exploiting the low-frequency capability of Helmholtz resonators, lumped parameter models of these resonators were coupled to the enclosure via an experimentally determined acoustic model of the tractor cabin. The virtual design methodology uses gradient optimization techniques as a post-processor for the modeling and analysis of the unmodified acoustic interior to determine optimal resonator characteristics. Using two optimally designed Helmholtz resonators, potential energy was experimentally reduced by 3.4 and 10.3 dB at 117 and 167 Hz, respectively.

  13. Prevalence of ROPS-equipped tractors on minority operated farms in the US.

    PubMed

    Myers, John R

    2009-05-01

    Tractor overturns kill an average of 100 farmers and farm workers per year. Roll-over protective structures (ROPS) are a proven intervention, but are not on a sufficient number of tractors in the US to reduce these deaths. Little has been reported on ROPS use by racial minority farm operators. Data from the NIOSH OISPA survey were used to assess ROPS prevalence rates from a random sample of racial minority farm operators for the year 2003, and ROPS prevalence rates from a random sample of all US farms for the year 2004. ROPS prevalence rates on minority farming operations follow similar patterns to ROPS prevalence rates on all US farms. A low prevalence of ROPS on farms was associated with operators over the age of 65 years, farms with small acreages, and farms operated on a part-time basis. The race of the operator had little impact on ROPS prevalence rates. Factors such as acreage, farm operator age, region of the US, and full- or part-time farming status influence ROPS prevalence rates on farms more than the race of the operator. Understanding how ROPS prevalence differs across these farm and farm operator characteristics has the potential to efficiently target areas for ROPS promotion programs across the US. Copyright 2009 Wiley-Liss, Inc.

  14. Preventing tractor rollover fatalities: performance of the NIOSH autoROPS.

    PubMed

    Powers, J R; Harris, J R; Etherton, J R; Ronaghi, M; Snyder, K A; Lutz, T J; Newbraugh, B H

    2001-09-01

    Approximately 132 agricultural tractor overturn fatalities occur per year. The use of rollover protective structures (ROPS), along with seat belts, is the best known method for preventing these fatalities. One impediment to ROPS use, however, is low clearance situations, such as orchards and animal confinement buildings. To address the need for ROPS that are easily adapted to low clearance situations, the Division of Safety Research, National Institute for Occupational Safety and Health (NIOSH), developed an automatically deploying, telescoping ROPS (Auto-ROPS). The NIOSH AutoROPS consists of two subsystems. The first is a retractable ROPS that is normally latched in its lowered position for day-to-day use. The second subsystem is a sensor that monitors the operating angle of the tractor. Ifa rollover condition is detected by the sensor, the retracted ROPS will deploy and lock in the full upright position before ground contact. Static load testing and field upset tests of the NIOSH AutoROPS have been conducted in accordance with SAE standard J2194. Additionally, timed trials of the AutoROPS deployment mechanism were completed. The design of the retractable ROPS and sensor, as well as the results of the different testing phases are discussed.

  15. Reduction of aerodynamic drag and fuel consumption for tractor-trailer vehicles

    NASA Technical Reports Server (NTRS)

    Muirhead, V. U.; Saltzman, E. J.

    1979-01-01

    Wind-tunnel tests were performed on a scale model of a cab-over-engine tractor-trailer vehicle and several modifications of the model. Results from two of the model configurations were compared with full-scale drag data obtained from similar configurations during coast-down tests. Reductions in fuel consumption derived from these tests are presented in terms of fuel quantity and dollar savings per vehicle year, based on an annual driving distance of 160,900 km (100,000 mi.). The projected savings varied from 13,001 (3435) to 25,848 (6829) liters (gallons) per year which translated to economic savings from $3435 to about $6829 per vehicle year for an operating speed of 88.5 km/h (55 mph) and wind speeds near the national average of 15.3 km/h (9.5 mph). The estimated cumulative fuel savings for the entire U.S. fleet of cab-over-engine tractor, van-type trailer combinations ranged from 4.18 million kl (26.3 million bbl) per year for a low-drag configuration to approximately twice that amount for a more advanced configuration.

  16. Rearward Visibility Issues Related to Agricultural Tractors and Self-Propelled Machinery: Contributing Factors, Potential Solutions.

    PubMed

    Ehlers, S G; Field, W E

    2016-01-01

    As the size, complexity, and speed of agricultural tractors and self-propelled machinery have increased, so have the visibility-related issues, placing significant importance on the visual skills, alertness, and reactive abilities of the operator. Rearward movement of large agricultural equipment has been identified in the literature as causing both fatalities and injuries to bystanders who were not visible to the operator and damage to both the machine and stationary objects. The addition of monitoring assistance, while not a new concept, has advanced significantly, offering agricultural machinery operators greater options for increasing their awareness of the area surrounding the machine. In this research, we attempt to (1) identify and describe the key contributors to agricultural machinery visibility issues, i.e., operator-related and machine-related factors, and (2) enumerate and evaluate the potential solutions being offered that address these factors. Enhanced operator safety and efficiency should result from a better understanding of the efforts to solve the visibility problems inherent in large tractors and self-propelled agricultural machinery.

  17. Piezoelectric-based actuators for improved tractor-trailer performance (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Menicovich, David; Amitay, Michael; Gallardo, Daniele

    2017-04-01

    The application of piezo-electrically-driven synthetic-jet-based active flow control to reduce drag on tractor-trailers and to improve thermal mixing in refrigerated trailers was explored on full-scale tests. The active flow control technique that is being used relies on a modular system comprised of distributed, small, highly efficient actuators. These actuators, called synthetic jets, are jets that are synthesized at the edge of an orifice by a periodic motion of a piezoelectric diaphragm(s) mounted on one (or more) walls of a sealed cavity. The synthetic jet is zero net mass flux (ZNMF), but it allows momentum transfer to flow. It is typically driven near diaphragm and/or cavity resonance, and therefore, small electric input [O(10W)] is required. Another advantage of this actuator is that no plumbing is required. The system doesn't require changes to the body of the truck, can be easily reconfigured to various types of vehicles, and consumes small amounts of electrical power from the existing electrical system of the truck. The actuators are operated in a closed feedback loop based on inputs received from the tractor's electronic control unit, various system components and environmental sensors. The data are collected and processed on-board and transmitted to a cloud-based data management platform for further big data analytics and diagnostics. The system functions as a smart connected product through the interchange of data between the physical truck-mounted system and its cloud platform.

  18. Generating a stationary infinite range tractor force via a multimode optical fibre

    NASA Astrophysics Data System (ADS)

    Ebongue, C. A.; Holzmann, D.; Ostermann, S.; Ritsch, H.

    2017-06-01

    Optical fibres confine and guide light almost unattenuated and thus convey light forces to polarizable nano-particles over very long distances. Radiation pressure forces arise from scattering of guided photons into free space while gradient forces are based on coherent scattering between different fibre modes or propagation directions. Interestingly, even scattering between co-propagating modes induces longitudinal forces as the transverse confinement of the light modes creates mode dependent longitudinal wave-vectors and photon momenta. We generalize a proven scattering matrix based approach to calculate single as well as inter-particle forces to include several forward and backward propagating modes. We show that an injection of the higher order mode only in a two mode fibre will induce a stationary tractor force against the injection direction, when the mode coupling to the lower order mode dominates against backscattering and free space losses. Generically this arises for non-absorbing particles at the centre of a waveguide. The model also gives improved predictions for inter-particle forces in evanescent nanofibre fields as experimentally observed recently. Surprisingly strong tractor forces can also act on whole optically bound arrays.

  19. Preventing tractor rollover fatalities: performance of the NIOSH AutoROPS

    PubMed Central

    Powers, J; Harris, J; Etherton, J; Ronaghi, M; Snyder, K; Lutz, T; Newbraugh, B

    2001-01-01

    Approximately 132 agricultural tractor overturn fatalities occur per year. The use of rollover protective structures (ROPS), along with seat belts, is the best known method for preventing these fatalities. One impediment to ROPS use, however, is low clearance situations, such as orchards and animal confinement buildings. To address the need for ROPS that are easily adapted to low clearance situations, the Division of Safety Research, National Institute for Occupational Safety and Health (NIOSH), developed an automatically deploying, telescoping ROPS (AutoROPS). The NIOSH AutoROPS consists of two subsystems. The first is a retractable ROPS that is normally latched in its lowered position for day-to-day use. The second subsystem is a sensor that monitors the operating angle of the tractor. If a rollover condition is detected by the sensor, the retracted ROPS will deploy and lock in the full upright position before ground contact. Static load testing and field upset tests of the NIOSH AutoROPS have been conducted in accordance with SAE standard J2194. Additionally, timed trials of the AutoROPS deployment mechanism were completed. The design of the retractable ROPS and sensor, as well as the results of the different testing phases are discussed. PMID:11565973

  20. Evaluating tractor performance and exhaust gas emissions using biodiesel from cotton seed oil

    NASA Astrophysics Data System (ADS)

    Al-lwayzy, Saddam H.; Yusaf, Talal; Jensen, Troy

    2012-09-01

    Alternative fuels for diesel engines, such as biodiesel, have attracted much attention recently due to increasing fuel prices and the imperative to reduce emissions. The exhaust gas emissions from tractors and other agricultural machinery make a significant contribution to these emissions. The use of biodiesel in internal combustion engines (ICE) has been reported to give comparable performance to conventional diesel (CD), but with generally lower emissions. There is however, contradictory evidence of NO emissions being both higher and lower from the use of biodiesel. In this work, agriculture tractor engine performance and its emission using both CD and biodiesel from cotton seed oil (CSO-B20) mixed at a 20% blend ration has been evaluated and compared. The PTO test results showed comparable exhaust emissions between CD and CSO-B20. However, the use of CSO-B20 led to reductions in the thermal efficiency and exhaust temperature and an increase in the brake specific fuel consumption (BSFC), when compared to CD.

  1. 29 CFR 1926.1003 - Overhead protection for operators of agricultural and industrial tractors used in construction.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... REGULATIONS FOR CONSTRUCTION Rollover Protective Structures; Overhead Protection § 1926.1003 Overhead...) Purpose. When overhead protection is provided on wheel-type agricultural and industrial tractors, the... accidental upset. (2) Applicability. This standard applies to wheel-type agricultural and industrial...

  2. 29 CFR 1926.1003 - Overhead protection for operators of agricultural and industrial tractors used in construction.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... REGULATIONS FOR CONSTRUCTION Rollover Protective Structures; Overhead Protection § 1926.1003 Overhead...) Purpose. When overhead protection is provided on wheel-type agricultural and industrial tractors, the... accidental upset. (2) Applicability. This standard applies to wheel-type agricultural and industrial...

  3. 29 CFR 1926.1003 - Overhead protection for operators of agricultural and industrial tractors used in construction.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... REGULATIONS FOR CONSTRUCTION Rollover Protective Structures; Overhead Protection § 1926.1003 Overhead...) Purpose. When overhead protection is provided on wheel-type agricultural and industrial tractors, the... accidental upset. (2) Applicability. This standard applies to wheel-type agricultural and industrial...

  4. 29 CFR 1926.1003 - Overhead protection for operators of agricultural and industrial tractors used in construction.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... REGULATIONS FOR CONSTRUCTION Rollover Protective Structures; Overhead Protection § 1926.1003 Overhead...) Purpose. When overhead protection is provided on wheel-type agricultural and industrial tractors, the... accidental upset. (2) Applicability. This standard applies to wheel-type agricultural and industrial...

  5. A powered roller/crimper for walk-behind tractors to terminate cover crops in conservation agriculture

    USDA-ARS?s Scientific Manuscript database

    Roller/crimper implements have been used in large conservation farming systems to terminate cover crops near maturity and flatten them down to create a mulch through which cash crops can be planted directly into the cover residue. On small farms, tractors are usually small and less powerful relative...

  6. 29 CFR 1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... tractor means a two-or four-wheel drive type vehicle, or track vehicle, of more than 20 engine horsepower, designed to furnish the power to pull, carry, propel, or drive implements that are designed for agriculture... following characteristics: (1) The front wheel spacing is equal to the rear wheel spacing, as measured from...

  7. Tracking the prevalence of rollover protective structures on U.S. farm tractors: 1993, 2001, and 2004.

    PubMed

    Loringer, Kelly A; Myers, John R

    2008-01-01

    Between 1992 and 2005, 1412 workers on farms died from tractor overturns. A Rollover Protective Structure (ROPS) is a proven intervention to reduce overturn deaths. However, farm characteristics that are associated with the adoption of ROPS are not well understood. ROPS prevalence statistics were derived from National Institute for Occupational Safety and Health (NIOSH) surveys that tracked ROPS use on farms. Data were from the years 1993, 2001, and 2004. In 1993, 38% of tractors were equipped with ROPS. This increased to 51% by 2004. ROPS prevalence rates were higher on farms in the Southern region of the United States, on farms where the operator was 25-34 years old, and on farms with $100,000 or more of farm sales. Low ROPS prevalence rates were associated with farm operators 65 years old or older and with farms with less than $10,000 of farm product sales. The increase in ROPS prevalence between 1993 and 2004 has not been sufficient to decrease the rate of tractor overturn deaths on farms. Incentive programs targeting older farm operators and low-income farm operations are suggested to increase ROPS use on tractors. The study provides farm characteristics associated with low ROPS prevalence rates. The results can be used to target farms for future ROPS promotion activities.

  8. Repower and Regear on an M915 Line Haul Tractor to Demonstrate Feasibility of Commercial Electronic Controls and Air Starters

    DTIC Science & Technology

    1989-02-01

    traction limit coefficient 1.4000 road surface factor 13.50 x 8.00 ft. vehicle height x width 0.7500 air resistance coefficient DIESEL ENGINE: CUMM NTC...MILITARY WHEELED VEHICLE-SUPPORT TACOM PROPULSION LAB. M915A1 LINEHAUL TRACTOR Engine CUMM NTC-400 CYSO, CYSI (20163) (Clutch fan ENGAGED) (engine

  9. Improved third generation peristaltic crawler for removal of high-level waste plugs in United States department of energy Hanford site pipelines

    SciTech Connect

    Vazquez, Gabriela; Pribanic, Tomas

    2013-07-01

    There are approximately 56 million gallons (212 km{sup 3}) of high level waste (HLW) at the U.S. Department of Energy (DOE) Hanford Site. It is scheduled that by the year 2040, the HLW is to be completely transferred to secure double-shell tanks (DST) from the leaking single-tanks (SST) via transfer pipeline system. Blockages have formed inside the pipes during transport because of the variety in composition and characteristics of the waste. These full and partial plugs delay waste transfers and require manual intervention to repair, therefore are extremely expensive, consuming millions of dollars and further threatening the environment. To successfully continue the transfer of waste through the pipelines, DOE site engineers are in need of a technology that can accurately locate the blockages and unplug the pipelines. In this study, the proposed solution to remediate blockages formed in pipelines is the use of a peristaltic crawler: a pneumatically/hydraulically operated device that propels itself in a worm-like motion through sequential fluctuations of pressure in its air cavities. The crawler is also equipped with a high-pressure water nozzle used to clear blockages inside the pipelines. The crawler is now in its third generation. Previous generations showed limitations in its durability, speed, and maneuverability. Latest improvements include an automation of sequence that prevents kickback, a front-mounted inspection camera for visual feedback, and a thinner wall outer bellow for improved maneuverability. Different experimental tests were conducted to evaluate the improvements of crawler relative to its predecessors using a pipeline test-bed assembly. Anchor force tests, unplugging tests, and fatigue testing for both the bellow and rubber rims have yet to be conducted and thus results are not presented in this research. Experiments tested bellow force and response, cornering maneuverability, and straight line navigational speed. The design concept and

  10. Factors associated with the prevalence of non-ROPS tractors on farms in the U.S.

    PubMed

    Myers, J R

    2010-10-01

    Rollover protective structures (ROPS) are an effective engineering control known to prevent tractor overturn deaths, the leading cause of occupational fatalities for farmers and farm workers in the U.S. However, the use of ROPS is known to vary greatly from farm to farm. A national sample of 11,458 farm operators from the 2004 Occupational Injury Surveillance of Production Agriculture (OISPA) survey was used to assess the association between the prevalence of ROPS and ten farm operator and farm demographic variables using logistic regression. The variable were: operator's age, operator's sex, operator's education, farm sales, full- or part-time farming, acreage, type of operation, number of hired workers, number of injuries, and region. All ten variables were found to have significant associations with the prevalence of non-ROPS tractors on farms in the univariate logistic regressions. For the multivariate model, all variables except for the sex of the farm operator remained significant. Farms with less than three adult injuries, no hired workers, less than 300 acres in size, a Midwest location, and a primary farm type of tobacco, fruit and nuts, dairy, or poultry and eggs all had adjusted odds ratios of 2 or greater. Increasing the prevalence of ROPS-equipped tractors is essential for reducing the leading cause of death on farms, tractor overturns. Economic factors play a major role in the prevalence and distribution of non-ROPS tractors on farms. The identified associations can be used to effectively target areas of the U.S. for ROPS promotion activities.

  11. Enhanced Gravity Tractor Derived from the Asteroid Redirect Mission for Deflecting Hypothetical Asteroid 2017 PDC

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Reeves, David M.; Abell, Paul A.; Shen, Haijun; Qu, Min

    2017-01-01

    The Asteroid Redirect Mission (ARM) concept would robotically visit a hazardous-size near-Earth asteroid (NEA) with a rendezvous spacecraft, collect a multi-ton boulder and regolith samples from its surface, demonstrate an innovative planetary defense technique known as the Enhanced Gravity Tractor (EGT), and return the asteroidal material to a stable orbit around the Moon, allowing astronauts to explore the returned material in the mid-2020s. Launch of the robotic vehicle to rendezvous with the ARM reference target, NEA (341843) 2008 EV5, would occur in late 2021 [1,2]. The robotic segment of the ARM concept uses a 40 kW Solar Electric Propulsion (SEP) system with a specific impulse (Isp) of 2600 s, and would provide the first ever demonstration of the EGT technique on a hazardous-size asteroid and validate one method of collecting mass in-situ. The power, propellant, and thrust capability of the ARM robotic spacecraft can be scaled from a 40 kW system to 150 kW and 300 kW, which represent a likely future power level progression. The gravity tractor technique uses the gravitational attraction of a station-keeping spacecraft with the asteroid to provide a velocity change and gradually alter the trajectory of the asteroid. EGT utilizes a spacecraft with a high-efficiency propulsion system, such as Solar Electric Propulsion (SEP), along with mass collected in-situ to augment the mass of the spacecraft, thereby increasing the gravitational force between the objects [3]. As long as the spacecraft has sufficient thrust and propellant capability, the EGT force is only limited by the amount of in-situ mass collected and can be increased several orders of magnitude compared to the traditional gravity tractor technique in which only the spacecraft mass is used to generate the gravitational attraction force. This increase in available force greatly reduces the required deflection time. The collected material can be a single boulder, multiple boulders, regolith, or a

  12. A Second New Species of Ice Crawlers from China (Insecta: Grylloblattodea), with Thorax Evolution and the Prediction of Potential Distribution

    PubMed Central

    Bai, Ming; Jarvis, Karl; Wang, Shu-Yong; Song, Ke-Qing; Wang, Yan-Ping; Wang, Zhi-Liang; Li, Wen-Zhu; Wang, Wei; Yang, Xing-Ke

    2010-01-01

    Modern grylloblattids are one of the least diverse of the modern insect orders. The thorax changes in morphology might be associated with the changes of the function of the forelegs, wing loss, changes in behavior and adaptation to habitat. As temperature is the main barrier for migration of modern grylloblattids, the range of each species is extremely limited. The potential distribution areas of grylloblattids remain unclear. A second new species of ice crawlers (Insecta: Grylloblattodea), Grylloblattella cheni Bai, Wang et Yang sp. nov., is described from China. The distribution map and key to species of Grylloblattella are given. A comparison of the thorax of extant and extinct Grylloblattodea is presented, with an emphasis on the pronotum using geometric morphometric analysis, which may reflect thorax adaptation and the evolution of Grylloblattodea. Potential global distribution of grylloblattids is inferred. Highly diversified pronota of extinct Grylloblattodea may reflect diverse habitats and niches. The relatively homogeneous pronota of modern grylloblattids might be explained by two hypotheses: synapomorphy or convergent evolution. Most fossils of Grylloblattodea contain an obviously longer meso- and metathorax than prothorax. The length of the meso- and metathorax of modern grylloblattids is normally shorter than the prothorax. This may be associated with the wing loss, which is accompanied by muscle reduction and changes to the thoracic skeleton system. Threats to grylloblattids and several conservation comments are also provided. PMID:20877572

  13. 30 CFR 57.14130 - Roll-over protective structures (ROPS) and seat belts for surface equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and crawler loaders; (2) Graders; (3) Wheel loaders and wheel tractors; (4) The tractor portion of... operating graders from a standing position, the grader operator shall wear safety lines and a harness...

  14. 30 CFR 57.14130 - Roll-over protective structures (ROPS) and seat belts for surface equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and crawler loaders; (2) Graders; (3) Wheel loaders and wheel tractors; (4) The tractor portion of... operating graders from a standing position, the grader operator shall wear safety lines and a harness...

  15. 30 CFR 57.14130 - Roll-over protective structures (ROPS) and seat belts for surface equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and crawler loaders; (2) Graders; (3) Wheel loaders and wheel tractors; (4) The tractor portion of... operating graders from a standing position, the grader operator shall wear safety lines and a harness...

  16. EPA Nonregulatory Nonroad Duty Cycles

    EPA Pesticide Factsheets

    EPA nonregulatory, nonroad duty cycles for equipment such as agricultural tractors, backhoe loaders,crawlers tractors, excavators, arc welding skid steer loaders, and wheel loaders. Also,test procedures, laboratory methods, and emissions for this equipmen

  17. Aerodynamic drag reduction apparatus for gap-divided bluff bodies such as tractor-trailers

    SciTech Connect

    Ortega, Jason M.; Salari, Kambiz

    2006-07-11

    An apparatus for reducing the aerodynamic drag of a bluff-bodied vehicle such as a tractor-trailer in a flowstream, the bluff-bodied vehicle of a type having a leading portion, a trailing portion connected to the leading portion, and a gap between the leading and trailing portions defining a recirculation zone. The apparatus is preferably a baffle assembly, such as a vertical panel, adapted to span a width of the gap between the leading and trailing portions so as to impede cross-flow through the gap, with the span of the baffle assembly automatically adjusting for variations in the gap width when the leading and trailing portions pivot relative to each other.

  18. Computational Flow Modeling of a Simplified Integrated Tractor-Trailer Geometry

    SciTech Connect

    Salari, K; McWherter-Payne, M

    2003-09-15

    For several years, Sandia National Laboratories and Lawrence Livermore National Laboratory have been part of a consortium funded by the Department of Energy to improve fuel efficiency of heavy vehicles such as Class 8 trucks through aerodynamic drag reduction. The objective of this work is to demonstrate the feasibility of using the steady Reynolds-Averaged Navier-Stokes (RANS) approach to predict the flow field around heavy vehicles, with special emphasis on the base region of the trailer, and to compute the aerodynamic forces. In particular, Sandia's computational fluid dynamics code, SACCARA, was used to simulate the flow on a simplified model of a tractor-trailer vehicle. The results are presented and compared with NASA Ames experimental data to assess the predictive capability of RANS to model the flow field and predict the aerodynamic forces.

  19. Computational flow modeling of a simplified integrated tractor-trailer geometry.

    SciTech Connect

    McWherter-Payne, Mary Anna; Salari, Kambiz

    2003-09-01

    For several years, Sandia National Laboratories and Lawrence Livermore National Laboratory have been part of a consortium funded by the Department of Energy to improve fuel efficiency of heavy vehicles such as Class 8 trucks through aerodynamic drag reduction. The objective of this work is to demonstrate the feasibility of using the steady Reynolds-Averaged Navier-Stokes (RANS) approach to predict the flow field around heavy vehicles, with special emphasis on the base region of the trailer, and to compute the aerodynamic forces. In particular, Sandia's computational fluid dynamics code, SACCARA, was used to simulate the flow on a simplified model of a tractor-trailer vehicle. The results are presented and compared with NASA Ames experimental data to assess the predictive capability of RANS to model the flow field and predict the aerodynamic forces.

  20. Acoustical pulling force on rigid spheroids in single Bessel vortex tractor beams

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.

    2015-11-01

    The theoretical formalism for acoustical Bessel vortex (helicoidal) tractor beams and results presented here are the first to demonstrate the emergence of a pulling force of attraction on non-spherical oblate and prolate rigid spheroidal particles centered on the beam's axis of wave propagation. Numerical predictions for the axial acoustic radiation force illustrate the theory with particular emphasis on the aspect ratio of the spheroid, the half-cone angle and order of the beam, as well as the dimensionless size parameter. It is demonstrated here that the Bessel vortex beam parameters may be tailored in such a way that the spheroid is pulled against the forward linear momentum density flux associated with the incoming waves. Those results potentially suggest the use of Bessel vortex beams in the development of emergent technologies for non-contact remote sampling and particle characterization.

  1. The Effect of Propellers and Nacelles on the Landing Speeds of Tractor Monoplanes

    NASA Technical Reports Server (NTRS)

    Windler, Ray

    1932-01-01

    This paper reports wind-tunnel tests giving the lift coefficients of large-scale wing-nacelle combinations both with and without the propeller. The tests were made to show the effect of nacelles, and idling and stopped propellers on the landing speeds of tractor monoplanes. Four types of nacelles with various cowlings were used in numerous positions with respect to both a Clark Y and a thick airfoil. The effect of both the idling and stopped propeller on lift, and consequently on landing speed, was negligible. A nacelle with exposed engine cylinders when placed directly in front of an airfoil caused a slight reduction in lift, consequently an increase in landing speed, over the condition with the wing alone. With this exception no appreciable effect on landing speed was indicated for any of the other combinations.

  2. Maximum forces sustained during various methods of exiting commercial tractors, trailers and trucks.

    PubMed

    Fathallah, F A; Cotnam, J P

    2000-02-01

    Many commercial vehicles have steps and grab-rails to assist the driver in safely entering/exiting the vehicle. However, many drivers do not use these aids. The purpose of this study was to compare impact forces experienced during various exit methods from commercial equipment. The study investigated impact forces of ten male subjects while exiting two tractors, a step-van, a box-trailer, and a cube-van. The results showed that exiting from cab-level or trailer-level resulted in impact forces as high as 12 times the subject's body weight; whereas, fully utilizing the steps and grab-rails resulted in impact forces less than two times body weight. An approach that emphasizes optimal design of entry/exit aids coupled with driver training and education is expected to minimize exit-related injuries.

  3. [The potentials for errors in the hygienic assessment of the general vibrations in tractors].

    PubMed

    Ivanovich, E; Goranova, L; Enev, S

    1991-01-01

    The data for the parameters of the general vibrations in tractors are comparatively scanty and contradictory. In the present work are analyzed the most frequently met omissions and errors in the measurement and evaluation of the general vibrations, as well as the factors, which can effect the intensity of the general vibrations; constructive and technological peculiarities, technical state, rate of machine amortization, construction, damping qualities, and regulation of the seat, motion velocity, relief, type of the performed agricultural activity. The necessity for taking under consideration these factors in measuring the general vibrations and the hygiene interpretation of the data, as well as precise report on the daily, weekly and general exposure, in view of defining the total vibration loading, is underlined.

  4. A statistical description of the types and severities of accidents involving tractor semi-trailers

    SciTech Connect

    Clauss, D.B.; Wilson, R.K.; Blower, D.F.; Campbell, K.L.

    1994-06-01

    This report provides a statistical description of the types and severities of tractor semi-trailer accidents involving at least one fatality. The data were developed for use in risk assessments of hazardous materials transportation. Several accident databases were reviewed to determine their suitability to the task. The TIFA (Trucks Involved in Fatal Accidents) database created at the University of Michigan Transportation Research Institute was extensively utilized. Supplementary data on collision and fire severity, which was not available in the TIFA database, were obtained by reviewing police reports for selected TIFA accidents. The results are described in terms of frequencies of different accident types and cumulative distribution functions for the peak contact velocity, rollover skid distance, fire temperature, fire size, fire separation, and fire duration.

  5. Steering a tractor by means of an EMG-based human-machine interface.

    PubMed

    Gomez-Gil, Jaime; San-Jose-Gonzalez, Israel; Nicolas-Alonso, Luis Fernando; Alonso-Garcia, Sergio

    2011-01-01

    An electromiographic (EMG)-based human-machine interface (HMI) is a communication pathway between a human and a machine that operates by means of the acquisition and processing of EMG signals. This article explores the use of EMG-based HMIs in the steering of farm tractors. An EPOC, a low-cost human-computer interface (HCI) from the Emotiv Company, was employed. This device, by means of 14 saline sensors, measures and processes EMG and electroencephalographic (EEG) signals from the scalp of the driver. In our tests, the HMI took into account only the detection of four trained muscular events on the driver's scalp: eyes looking to the right and jaw opened, eyes looking to the right and jaw closed, eyes looking to the left and jaw opened, and eyes looking to the left and jaw closed. The EMG-based HMI guidance was compared with manual guidance and with autonomous GPS guidance. A driver tested these three guidance systems along three different trajectories: a straight line, a step, and a circumference. The accuracy of the EMG-based HMI guidance was lower than the accuracy obtained by manual guidance, which was lower in turn than the accuracy obtained by the autonomous GPS guidance; the computed standard deviations of error to the desired trajectory in the straight line were 16 cm, 9 cm, and 4 cm, respectively. Since the standard deviation between the manual guidance and the EMG-based HMI guidance differed only 7 cm, and this difference is not relevant in agricultural steering, it can be concluded that it is possible to steer a tractor by an EMG-based HMI with almost the same accuracy as with manual steering.

  6. Steering a Tractor by Means of an EMG-Based Human-Machine Interface

    PubMed Central

    Gomez-Gil, Jaime; San-Jose-Gonzalez, Israel; Nicolas-Alonso, Luis Fernando; Alonso-Garcia, Sergio

    2011-01-01

    An electromiographic (EMG)-based human-machine interface (HMI) is a communication pathway between a human and a machine that operates by means of the acquisition and processing of EMG signals. This article explores the use of EMG-based HMIs in the steering of farm tractors. An EPOC, a low-cost human-computer interface (HCI) from the Emotiv Company, was employed. This device, by means of 14 saline sensors, measures and processes EMG and electroencephalographic (EEG) signals from the scalp of the driver. In our tests, the HMI took into account only the detection of four trained muscular events on the driver’s scalp: eyes looking to the right and jaw opened, eyes looking to the right and jaw closed, eyes looking to the left and jaw opened, and eyes looking to the left and jaw closed. The EMG-based HMI guidance was compared with manual guidance and with autonomous GPS guidance. A driver tested these three guidance systems along three different trajectories: a straight line, a step, and a circumference. The accuracy of the EMG-based HMI guidance was lower than the accuracy obtained by manual guidance, which was lower in turn than the accuracy obtained by the autonomous GPS guidance; the computed standard deviations of error to the desired trajectory in the straight line were 16 cm, 9 cm, and 4 cm, respectively. Since the standard deviation between the manual guidance and the EMG-based HMI guidance differed only 7 cm, and this difference is not relevant in agricultural steering, it can be concluded that it is possible to steer a tractor by an EMG-based HMI with almost the same accuracy as with manual steering. PMID:22164006

  7. Quantitative Estimate of the Relation Between Rolling Resistance on Fuel Consumption of Class 8 Tractor Trailers Using Both New and Retreaded Tires (SAE Paper 2014-01-2425)

    EPA Science Inventory

    Road tests of class 8 tractor trailers were conducted by the US Environmental Protection Agency on new and retreaded tires of varying rolling resistance in order to provide estimates of the quantitative relationship between rolling resistance and fuel consumption.

  8. Quantitative Estimate of the Relation Between Rolling Resistance on Fuel Consumption of Class 8 Tractor Trailers Using Both New and Retreaded Tires (SAE Paper 2014-01-2425)

    EPA Science Inventory

    Road tests of class 8 tractor trailers were conducted by the US Environmental Protection Agency on new and retreaded tires of varying rolling resistance in order to provide estimates of the quantitative relationship between rolling resistance and fuel consumption.

  9. Audible and infrasonic noise levels in the cabins of modern agricultural tractors--does the risk of adverse, exposure-dependent effects still exist?

    PubMed

    Bilski, Bartosz

    2013-06-01

    The agricultural tractor is one of the most commonly used vehicles on farms and one of the most prominent sources of noise. This article presents an exemplary assessment of the audible and infrasonic noise levels in the cabins of selected modern wheeled agricultural tractors. Operator-perceived audible and infrasonic noise levels in the cabins were examined for 20 types of modern tractors during typical conditions of work. The tractors had been in use for no longer than 3 years, with rated power between 96 kW and 227 kW, designed and produced by world-renowned companies. Noise level measurements were performed in accordance with PN-EN ISO 9612:2011 (ISO 9612:2009). Audible noise levels (A-weighted) ranged from 62.1 to 87.4 dB-A (average: 68.2 to 83.8 dB-A) for different work tasks. The factors influencing noise levels include performed tasks, soil, weather conditions and the skills of individual drivers. In spectrum analysis, the highest noise levels occurred at frequencies 250 Hz, 1 and 2 kHz. Infrasound noise levels (G-weighted) ranged from 87.3 to 111.3 dB-G. The driver-experienced exposure to infrasound was found to increase significantly when the vehicle was in motion. Average audible noise levels have no potential to adversely affect the hearing organ during tasks performed inside the closed cabins of the analysed modern agricultural tractors. Due to the relatively low audible noise levels inside the cabins of modern agricultural tractors, non-auditory effects are the only adverse symptoms that can develop. Modern agricultural tractors emit considerable infrasonic noise levels. All tractors introduced into the market should be subjected to tests with regard to infrasonic noise levels.

  10. A Demonstration Project in New York and Virginia: Retrofitting Cost-Effective Roll-over Protective Structures (CROPS) on Tractors.

    PubMed

    Hard, D L; McKenzie, E A; Cantis, D; May, J; Sorensen, J; Bayes, B; Madden, E; Wyckoff, S; Stone, B; Maass, J

    2015-07-01

    The NIOSH cost-effective roll-over protective structure (CROPS) demonstration project sought to determine whether three prototype roll-over protective structures (ROPS) designed to be retrofitted on Ford 8N, Ford 3000, Ford 4000, and Massey Ferguson 135 tractors could be installed in the field and whether they would be acceptable by the intended end users (farmers). There were a total of 50 CROPS. demonstrators (25 in New York and 25 in Virginia), with 45 observers attending the New York CROPS demonstrations and 36 observers attending the Virginia CROPS demonstrations, for a total of 70 participants in New York and 61 in Virginia. The oldest retrofitted tractors were 77 to 62 years old, while the newest retrofitted tractors were 40 to 37 years old. The most frequently retrofitted tractor in the CROPS demonstration project was a Ford 3000 series tractor (n = 19; 38%), followed by Ford 4000 (n = 11; 22%), Massey Ferguson 135 (n = 11; 22%), and Ford 8N (n = 9; 18%). A major issue of CROPS retrofitting was the rear wheel fenders. The effort involved in disassembling the fenders (removing the old bolts was often faster by cutting them with a torch), modifying the fender mounting brackets, and then reinstalling the fenders with the CROPS generally required the most time. In addition, various other semi-permanent equipment attachments, such as front-end loaders, required additional time and effort to fit with the CROPS. Demonstrators were asked to rank the reasons why they had not retrofitted their tractors with ROPS until they had enrolled in the CROPS demonstration program. ROPS "cost too much" was ranked as the primary reason for participants in both states (80% for New York and 88% for Virginia). The second highest ranked reasons were "ROPS wasn't available" for Virginia (80%) and "hassle to find ROPS" for New York (69%). The third highest ranked reasons were "not enough time to find ROPS" for New York (67%) and "hassle to find ROPS" for Virginia (79%). All

  11. A Demonstration Project in New York and Virginia: Retrofitting Cost-Effective Roll-over Protective Structures (CROPS) on Tractors

    PubMed Central

    Hard, David L.; McKenzie, E. A.; Cantis, Douglas; May, John; Sorensen, Julie; Bayes, Barbara; Madden, Erin; Wyckoff, Sherry; Stone, Bruce; Maass, Jimmy

    2015-01-01

    The NIOSH cost-effective roll-over protective structure (CROPS) demonstration project sought to determine whether three prototype roll-over protective structures (ROPS) designed to be retrofitted on Ford 8N, Ford 3000, Ford 4000, and Massey Ferguson 135 tractors could be installed in the field and whether they would be acceptable by the intended end users (farmers). There were a total of 50 CROPS demonstrators (25 in New York and 25 in Virginia), with 45 observers attending the New York CROPS demonstrations and 36 observers attending the Virginia CROPS demonstrations, for a total of 70 participants in New York and 61 in Virginia. The oldest retrofitted tractors were 77 to 62 years old, while the newest retrofitted tractors were 40 to 37 years old. The most frequently retrofitted tractor in the CROPS demonstration project was a Ford 3000 series tractor (n = 19; 38%), followed by Ford 4000 (n = 11; 22%), Massey Ferguson 135 (n = 11; 22%), and Ford 8N (n = 9; 18%). A major issue of CROPS retrofitting was the rear wheel fenders. The effort involved in disassembling the fenders (removing the old bolts was often faster by cutting them with a torch), modifying the fender mounting brackets, and then reinstalling the fenders with the CROPS generally required the most time. In addition, various other semi-permanent equipment attachments, such as front-end loaders, required additional time and effort to fit with the CROPS. Demonstrators were asked to rank the reasons why they had not retrofitted their tractors with ROPS until they had enrolled in the CROPS demonstration program. ROPS “cost too much” was ranked as the primary reason for participants in both states (80% for New York and 88% for Virginia). The second highest ranked reasons were “ROPS wasn’t available” for Virginia (80%) and “hassle to find ROPS” for New York (69%). The third highest ranked reasons were “not enough time to find ROPS” for New York (67%) and “hassle to find ROPS” for Virginia

  12. Calibration and Algorithm Development for Estimation of Nitrogen in Wheat Crop Using Tractor Mounted N-Sensor

    PubMed Central

    Singh, Manjeet; Kumar, Rajneesh; Sharma, Ankit; Singh, Bhupinder; Thind, S. K.

    2015-01-01

    The experiment was planned to investigate the tractor mounted N-sensor (Make Yara International) to predict nitrogen (N) for wheat crop under different nitrogen levels. It was observed that, for tractor mounted N-sensor, spectrometers can scan about 32% of total area of crop under consideration. An algorithm was developed using a linear relationship between sensor sufficiency index (SIsensor) and SISPAD to calculate the Napp as a function of SISPAD. There was a strong correlation among sensor attributes (sensor value, sensor biomass, and sensor NDVI) and different N-levels. It was concluded that tillering stage is most prominent stage to predict crop yield as compared to the other stages by using sensor attributes. The algorithms developed for tillering and booting stages are useful for the prediction of N-application rates for wheat crop. N-application rates predicted by algorithm developed and sensor value were almost the same for plots with different levels of N applied. PMID:25811039

  13. Influence on operator's health of hand-transmitted vibrations from handles of a single-axle tractor.

    PubMed

    Goglia, Vlado; Gospodaric, Zlatko; Filipovic, Dubravko; Djukic, Igor

    2006-01-01

    The operators of the single-axle tractors are especially exposed to hand-arm transmitted vibrations. These vibrations can cause the complex of vascular, neurological and musculoskeletal disorders, collectively named hand-arm vibration syndrome. Among these, the most common disorder is vibration-induced white finger (Raynaud's phenomenon). The vibration levels were measured in three tractor's working conditions, namely idling, transportation and soil tillage. The vibration level on the handles was measured and analysed and the frequency spectra for the chosen working conditions were obtained. The frequency-weighted acceleration, given in m/s2, was calculated and the obtained values are graphically presented. The measured vibration levels are then discussed with regard to the operator's daily exposure limits recommended by the ISO 5349. The vibration levels were much higher in the x and y directions than the z-direction in all working conditions. The vibration total values in idling, transportation and soil tillage were 3.37, 8.37 and 9.62 m/s2, respectively. Results showed that the 10% of workers are exposed to a risk of vibration-induced white finger disorder of the hands after relatively short periods (3-4 years), if the tractor is used 8 hour per day in soil tillage and transportation at full load. Considering the criteria of the ISO 5349, the daily working time with the single-axle tractor should be limited in order to protect the operator and work schedules should be arranged to include vibration-free periods.

  14. Hand-transmitted vibration from the steering wheel to drivers of a small four-wheel drive tractor.

    PubMed

    Goglia, V; Gospodarić, Z; Kosutić, S; Filipović, D

    2003-01-01

    The paper presents research results of the vibration transmitted from the steering wheel of the small tractor with a 4-wheel drive to the driver's hands. The vibration measurements were carried out on the tractor randomly chosen from the producer's store-house. Before testing the tractor was examined and adjusted following the producer's recommendations. The vibration levels were measured at idling and at full load. The vibration level on the steering wheel was measured and analyzed and the frequency spectra for the chosen working conditions were obtained. The frequency-weighted acceleration, given in m/s(-2), was calculated. The vibration total value was defined as the root-mean-square of the three component values. The obtained values are graphically represented in accordance with ISO/DIS 5349-1979 and ISO5349-1-2001. The vibration exposure for the predicted 10% prevalance of vibration-induced white finger in accordance with Annex C of the same standard was also tested.

  15. Analytical evaluation of the protection offered by sealed tractor cabins during crop pulverization with fenitrothion.

    PubMed

    Barcellos, Michelle; Faletti, Milena Michele; Madureira, Luiz Augusto Dos Santos; Bauer, Fernando Cesar

    2016-12-01

    The practice of large-scale agriculture requires the use of pesticides in order to maximize production. This activity has gained increasing attention in recent years, especially from rural workers, due to the risks associated with long-term exposure to pesticides. To minimize these risks, personal protection equipment (e.g., covers, gloves, and goggles) and collective protection equipment (e.g., agricultural tractors with sealed cabins) have been developed. In general, these approaches are intended to reduce the contact of farmers and agricultural machinery operators with the more toxic and stable compounds, an example of which is fenitrothion. In this study, fenitrothion was used as a marker to evaluate the protection afforded inside a sealed tractor cabin. To simulate the pesticide exposure, tests were performed using artificial cotton targets as passive adsorptive agents inside the cabin during the pesticide application. Samples were extracted according to the US Environmental Protection Agency (USEPA) procedure using ultrasonic extraction and as proposed by the Brazilian Standard for Solid Waste Classification (NBR 10004). The extracts were analyzed by high-performance liquid chromatography with diode array detection (HPLC-DAD). The chromatographic method was optimized using a factorial design. The combined results indicated that the best conditions were achieved using a mobile phase with a water/acetonitrile ratio of 35:65, a column temperature of 40 °C, and a flow rate of 1.0 mL/min, with a total analysis time of <10 min. The method was evaluated in the linear range of 0.50 to 2.01 mg/kg, with a determination coefficient of 0.9886. The precision was evaluated on different days and the relative standard deviations were between 0.17 and 3.41 %. In relation to the accuracy, recovery values of 95 to 104 % were obtained. The detection and quantification limits were 0.18 and 0.50 mg/kg, respectively. None of the target cottons showed concentrations of

  16. Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

    SciTech Connect

    Lascurain, Mary Beth; Capps, Gary J; Franzese, Oscar

    2013-10-01

    The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data

  17. Space Weather Influence on Relative Motion Control using the Touchless Electrostatic Tractor

    NASA Astrophysics Data System (ADS)

    Hogan, Erik A.; Schaub, Hanspeter

    2016-09-01

    With recent interest in the use of electrostatic forces for contactless tugging and attitude control of noncooperative objects for orbital servicing and active debris mitigation, the need for a method of remote charge control arises. In this paper, the use of a directed electron beam for remote charge control is considered in conjunction with the relative motion control. A tug vehicle emits an electron beam onto a deputy object, charging it negatively. At the same time, the tug is charged positively due to beam emission, resulting in an attractive electrostatic force. The relative position feedback control between the tug and the passive debris object is studied subject to the charging being created through an electron beam. Employing the nominal variations of the GEO space weather conditions across longitude slots, two electrostatic tugging strategies are considered. First, the electron beam current is adjusted throughout the orbit in order to maximize this resulting electrostatic force. This open-loop control strategy compensates for changes in the nominally expected local space weather environment in the GEO region to adjust for fluctuations in the local plasma return currents. Second, the performance impact of using a fixed electron beam current on the electrostatic tractor is studied if the same natural space weather variations are assumed. The fixed electron beam current shows a minor performance penalty (<5 %) while providing a much simpler implementation that does not require any knowledge of local space weather conditions.

  18. Occupation and chronic obstructive pulmonary disease in Minsk tractor plant workers.

    PubMed

    Vinnikov, Denis; Semizhon, Sergey; Rybina, Tatsyana; Savich, Ludmila; Scherbitsky, Vicktor; Manichev, Igor

    2017-09-20

    The aim of this study was to measure the association of exposure to dust at workplace with COPD using objective methods of exposure and outcome classification. Forced expiratory volume in one second (FEV1 ) to forced vital capacity (FVC) <70%; FVC below LLN, and FEV1 below LLN from the annual screening of Minsk Tractor Plant workers (N = 458) were tested for predictors in an adjusted logistic regression model. In a regression model, adjusted for pack-years of smoking, age, sex, and work duration, work in highly exposed workplaces was associated with FEV1 /FVC<70% (odds ratio (OR) 2.10 (95% confidence interval (CI) 1.16;3.83); and FEV1

  19. Enhanced fuel efficiency on tractor-trailers using synthetic jet-based active flow control

    NASA Astrophysics Data System (ADS)

    Amitay, Michael; Menicovich, David; Gallardo, Daniele

    2016-04-01

    The application of piezo-electrically-driven synthetic-jet-based active flow control to reduce drag on tractor-trailers was explored experimentally in wind tunnel testing as well as full-scale road tests. Aerodynamic drag accounts for more than 50% of the usable energy at highway speeds, a problem that applies primarily to trailer trucks. Therefore, a reduction in aerodynamic drag results in large saving of fuel and reduction in CO2 emissions. The active flow control technique that is being used relies on a modular system comprised of distributed, small, highly efficient actuators. These actuators, called synthetic jets, are jets that are synthesized at the edge of an orifice by a periodic motion of a piezoelectric diaphragm(s) mounted on one (or more) walls of a sealed cavity. The synthetic jet is zero net mass flux (ZNMF), but it allows momentum transfer to flow. It is typically driven near diaphragm and/or cavity resonance, and therefore, small electric input [O(10W)] is required. Another advantage of this actuator is that no plumbing is required. The system doesn't require changes to the body of the truck, can be easily reconfigured to various types of vehicles, and consumes small amounts of electrical power from the existing electrical system of the truck. Preliminary wind tunnel results showed up to 18% reduction in fuel consumption, whereas road tests also showed very promising results.

  20. Wear of Spheroidal Graphite Cast Irons for Tractor Drive Train Components

    SciTech Connect

    Beltowski, Mark F; Blau, Peter Julian; Qu, Jun

    2009-01-01

    The study was prompted by a desire to improve the wear resistance of power transmission components in rear axle drives on commercial farm tractors. Reciprocating wear tests were conducted under lubricated and non-lubricated conditions on three spheroidal cast irons which varied in strength and hardness (designated GGG450, GGG600, and GGG700). Hemispherically-tipped steel pins (designed 42CrMoS4/ 41CrS4) were used as the sliders. Except for the test duration, test procedures were similar to those described in ASTM Standard Test Method G133 for linearly-reciprocating sliding. Among the three cast irons tested, the harder and stronger the alloy, the lower was its wear rate. Wear factors were approximately four orders of magnitude lower for experiments lubricated in fresh, fully-formulated lubricating oil. There was a linear relationship between Brinell hardness of the alloys and the negative logarithm of the wear factors that were expressed in (mm3/N-m). Wear of lubricated test pins was not measurable due to the presence of deposits; however under non-lubricated sliding, the ratio of the wear of the flat specimen to that of the pin decreased as the hardness of the flat specimens approached that of the pin specimen.

  1. Steels for parts of the propulsion system of industrial caterpillar tractors

    SciTech Connect

    Spirkina, G.V.; Efimova, L.B.

    1988-05-01

    New steels were developed for the track shoes and track links of tractors used for the mining of ore, coal, and gold and for the construction of gas and oil lines in the Soviet Union. Steels 40KhFR (for the shoes) and 40GMFR (for the links), alloyed with chromium (up to 1.0%) or manganese (up to 1.2%) with additional microalloying with boron, titanium, and aluminum and with small additions of vanadium (up to 0.10%) and molybdenum (up to 0.16%), were used as base steels. The influence of microalloying was revealed in increases in the depth of hardenability and in impact strength. The steels are fine grained with increased cold resistance both in the high strength and hardened and tempered conditions. Optimum final heat-treat cycles were determined. An analysis of service data showed that the life of parts of the new steels is more than twice as long as of parts of the previously used steels.

  2. 29 CFR 1926.1000 - Rollover protective structures (ROPS) for material handling equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... material handling equipment: To all rubber-tired, self-propelled scrapers, rubber-tired front-end loaders, rubber-tired dozers, wheel-type agricultural and industrial tractors, crawler tractors, crawler-type... rollover protective structures for compactors and rubber-tired skid-steer equipment is reserved...

  3. A numerical study of scale effects on performance of a tractor type podded propeller

    NASA Astrophysics Data System (ADS)

    Choi, Jung-Kyu; Park, Hyoung-Gil; Kim, Hyoung-Tae

    2014-06-01

    In this study, the scale effect on the performance of the podded propeller of tractor type is investigated. Turbulent flow computations are carried out for Reynolds numbers increasing progressively from model scale to full scale using the CFD analysis. The result of the flow calculation for model scale Reynolds numbers agrees well with that of the experiment of a large cavitation tunnel. The existing numerical analysis indicates that the performance of the podded propeller blades is mainly influenced by the advance coefficient and relatively little by the Reynolds number. However, the drag of pod housing with propeller in operation is different from that of pod housing without propeller due to the acceleration and swirl of propeller slipstream which is altered by propeller loading as well as the pressure recovery and friction according to Reynolds number, which suggests that the pod housing drag under the condition of propeller in operation is the key factor of the scale effect on the performance between model and full scale podded propellers. The so called `drag ratio', which is the ratio of pod housing drag to total thrust of podded propeller, increases as the advance coefficient increases due to accelerated flow in the slipstream of the podded propeller. However, the increasing rate of the drag ratio reduces continuously as the Reynolds number increases from model to full scale progressively. The contribution of hydrodynamic forces, which acts on the parts composed of the pod housing with propeller operating in various loading conditions, to the thrust and the torque of the total propeller unit are presented for a range of Reynolds numbers from model to full scales.

  4. Aerodynamic drag reduction tests on a full-scale tractor-trailer combination with several add-on devices

    NASA Technical Reports Server (NTRS)

    Montoya, L. C.; Steers, L. L.

    1974-01-01

    Aerodynamic drag tests were performed on a conventional cab-over-engine tractor with a 45-foot trailer and five commercially available or potentially available add-on devices using the coast-down method. The tests ranged in velocity from approximately 30 miles per hour to 65 miles per hour and included some flow visualization. A smooth, level runway at Edwards Air Force Base was used for the tests, and deceleration measurements were taken with both accelerometers and stopwatches. An evaluation of the drag reduction results obtained with each of the five add-on devices is presented.

  5. Structural Characterization of the 216-Z-9 Crib Prior to Decontamination and Demolition Using Robot Crawler and High Resolution Photography

    SciTech Connect

    Hopkins, A.; Sutter, C.; Klos, D.B.; Teal, J.A.; Oates, L.; Bond, F.W.; Mattlin, E.; Clarke, S.

    2008-07-01

    The Department of Energy, Richland Operations Office is preparing to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action for the decontamination and demolition of the above-grade mining structures and equipment at the 216-Z-9 Crib. An investigation of the condition of the mining complex was initiated to determine constraints necessary for safely conducting the removal of the buildings. While crib headspace chemical analysis and nondestructive analysis of the interior of the buildings was completed to address radiological contamination concerns, the primary concern regarding the removal of the above-grade structures located on the crib cover involves determining the loading capacity and structural integrity of the crib cover slab. Additional concerns included headspace gases and radionuclide contamination. Until the structural analysis was completed, loading limits on the crib cover had been restricted. Photographic documentation revealed the loss of protective tiles and acid resistant coating from the underside of the cover raising a question of concrete stability. The investigation relied heavily on the use of high resolution photography with high intensity lighting for photographic documentation of the underside of the crib cover, followed by structural analysis of the documentation by a team of qualified engineers. Deployment of a robot crawler with attached camera and positioning of a fixed camera were integral to this structural characterization effort. Results of the photographic documentation were of sufficient quality to allow for bounding decisions to be made regarding the loading of the crib cover while performing the demolition of the mining structures (glovebox, excavator, bucket) and the associated buildings. The 216-Z-9 Crib, also known as the 216 Z-9 Recuplex CAW (CA column waste) Waste Disposal Cavern, the Z-9 Trench and the Z-9 Crib was constructed as an engineered trench with an open area beneath

  6. Silent geographical spread of the H7N9 virus by online knowledge analysis of the live bird trade with a distributed focused crawler.

    PubMed

    Chen, Chen; Lu, Shan; Du, Pengcheng; Wang, Haiyin; Yu, Weiwen; Song, Huawen; Xu, Jianguo

    2013-12-01

    Unlike those infected by H5N1, birds infected by the newly discovered H7N9 virus have no observable clinical symptoms. Public health workers in China do not know where the public health threat lies. In this study, we used a distributed focused crawler to analyze online knowledge of the live bird trade in first-wave provinces, namely, Jiangsu, Zhejiang, Anhui, and Shanghai, to track the new H7N9 virus and predict its spread. Of the 18 provinces proposed to be at high risk of infection, 10 reported human infections and one had poultry specimens that tested positive. Five provinces (Xinjiang, Yunnan, Guizhou, Shaanxi, and Tibet) as well as Hong Kong, Macao, and Taiwan were proposed to have no risk of H7N9 virus infection from the live bird trade. These data can help health authorities and the public to respond rapidly to reduce damage related to the spread of the virus.

  7. Silent geographical spread of the H7N9 virus by online knowledge analysis of the live bird trade with a distributed focused crawler

    PubMed Central

    Chen, Chen; Lu, Shan; Du, Pengcheng; Wang, Haiyin; Yu, Weiwen; Song, Huawen; Xu, Jianguo

    2013-01-01

    Unlike those infected by H5N1, birds infected by the newly discovered H7N9 virus have no observable clinical symptoms. Public health workers in China do not know where the public health threat lies. In this study, we used a distributed focused crawler to analyze online knowledge of the live bird trade in first-wave provinces, namely, Jiangsu, Zhejiang, Anhui, and Shanghai, to track the new H7N9 virus and predict its spread. Of the 18 provinces proposed to be at high risk of infection, 10 reported human infections and one had poultry specimens that tested positive. Five provinces (Xinjiang, Yunnan, Guizhou, Shaanxi, and Tibet) as well as Hong Kong, Macao, and Taiwan were proposed to have no risk of H7N9 virus infection from the live bird trade. These data can help health authorities and the public to respond rapidly to reduce damage related to the spread of the virus. PMID:26038450

  8. Prevalence of roll-over protective structure (ROPS)-equipped tractors on Hispanic-operated farms in the United States.

    PubMed

    Myers, John R

    2010-04-01

    Roll-over protective structures (ROPS) are known to prevent tractor overturn deaths, but not enough tractors are equipped with them in the United States to reduce the rate of these deaths to levels seen in several European countries. Recent literature has defined the use of ROPS on US farms in general, but little is known about ROPS use on Hispanic farm operations. Data from a national survey for the calendar year 2003 were used to assess the prevalence of ROPS use on Hispanic-operated farms. Farm characteristics previously identified to be associated with low ROPS prevalence rates on other farming operations were examined for these Hispanic farming operations. The overall ROPS prevalence rate on Hispanic farms was 52.2%. Adjusted odds ratios of potential risk factors found that the region where the farm was located and the acreage of the farm appeared to be the most significant indicators of the prevalence of ROPS on Hispanic farms. In addition, the age of the farm operator, the farm status as a full- or part-time operation, and the type of farm operation were also important factors. These findings were similar to those seen for racial minority farms and the general farming population. These results can be used to target ROPS promotion programs for Hispanic farmers across the United States.

  9. Mapping out tractor beams: topological angular momentum and reduced axial flux; gradient versus non-conservative forces

    NASA Astrophysics Data System (ADS)

    Spalding, Gabriel C.; Dahl, Patrick M.; Démoré, Christine E.; Yang, Zhengi; Glynne-Jones, Peter; Melzer, Andreas; Cochran, Sandy; MacDonald, Michael P.

    2013-09-01

    We experimentally demonstrate continuous attraction of macroscopic targets (> 1 cm) towards the source, against a net momentum flux in the system. Use of a simple setup provides an easily understood illustration of the negative radiation pressure concept for tractor beam, and how these are distinct from the gradient force acting in conventional optical tweezers. Here, we map out regimes over which negative radiation forces dominate, and (favorably) compare the thresholds observed to those that emerge from simulations. Theoretical explorations of tractor beam action commonly invoke higher-order Bessel beams, and here we make clear that the reason for this is because of the reduction in axial momentum associated with such hollow-core beams, which allows effects associated with off-axis "skew" momentum to become dominant. Ultimately, there is interest in exploring the language used for describing such effects: radiation pressure versus gradient force (which we suggest might be better described in terms of non-conservative versus conservative forces), and "orbital" angular momentum (which we suggest might be more appropriately termed "topological" angular momentum).

  10. Tractor Mechanics. Maintaining and Servicing the Cooling System, Learning Activity Packages 34-40; Maintaining and Servicing Hydraulic Systems, Learning Activity Packages 41-48.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This series of learning activity packages focuses on two areas of tractor mechanics: (1) maintaining and servicing the cooling system and (2) maintaining and servicing hydraulic systems. Each of the fifteen illustrated learning activity packages follows a typical format: introduction, directions, objectives, learning activities, tools and…

  11. Tests of Nacelle-Propeller Combinations in Various Positions with Reference to Wings V : Clark Y Biplane Cellule - NACA Cowled Nacelle - Tractor Propeller

    NASA Technical Reports Server (NTRS)

    Valentine, E Floyd

    1935-01-01

    This report is the fifth of a series giving the results obtained from wind tunnel tests on the interference drag and propulsive efficiency of nacelle-propeller-wing combinations. This report gives results of tests of an NACA cowled air-cooled engine nacelle with tractor propeller located in 12 positions with reference to a Clark Y biplane cellule.

  12. Dairy barns and roll-over protection on farm tractors: work environment impacts on the adoption of roll-over protective structures.

    PubMed

    Kelsey, T W; Dennis, J W; Jenkins, P L

    1994-04-01

    A mailed survey of one group of dairy farmers supports the informal perception that roll-over protective structure (ROPS)-equipped tractors are considered unusable for in-barn tasks. This attitude must be addressed in order to achieve greater use of safety equipment.

  13. Tractor-Maintenance: Operation & Daily Care [and] Servicing Air Cleaner & Lubrication. Student Materials. V. A. III. [V-C-1 through V-C-4].

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Vocational Instructional Services.

    Designed for use by students in vocational agricultural classes, this manual deals with tractor maintenance. Operation and daily care are the topics of the first section. Safety is also covered. In the final part of the manual, servicing the air cleaner and lubricating the engine are discussed. Both sections conclude with a quiz. (PLB)

  14. Tractor-Maintenance: Operation & Daily Care [and] Servicing Air Cleaner & Lubrication. Student Materials. V. A. III. [V-C-1 through V-C-4].

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Vocational Instructional Services.

    Designed for use by students in vocational agricultural classes, this manual deals with tractor maintenance. Operation and daily care are the topics of the first section. Safety is also covered. In the final part of the manual, servicing the air cleaner and lubricating the engine are discussed. Both sections conclude with a quiz. (PLB)

  15. An approach for modeling the influence of wheel tractor loads and vibration frequencies on soil compaction

    NASA Astrophysics Data System (ADS)

    Verotti, M.; Servadio, P.; Belfiore, N. P.; Bergonzoli, S.

    2012-04-01

    Both soil compaction and ground vibration are forms of environmental degradation that may be understood in the context of the vehicle-soil interaction process considered (Hildebrand et al., 2008). The transit of tractors on agricultural soil is often the main cause of soil compaction increasing. As known, this can be a serious problems for tillage and sowing and therefore the influence of all the affecting factors have been extensively studied in the last decades in order to understand their impact on the biosystem. There are factors related to the climate, namely to the rainfalls and temperature, and many others. Hence, it is not simple to figure out a complete model for predicting an index of compaction, for a given situation. Soil compaction models are important tools for controlling soil compaction due to agricultural field traffic and they are potentially useful technique to provide information concerning correct soil management. By means of such models, strategies and recommendations for prevention of soil compaction may be developed and specific advice may be given to farmers and advisers. In order to predict field wheeled and tracked vehicle performance, some empirical methods, used for off-road vehicle, were applied by Servadio (2010) on agricultural soil. The empirical indexes included, besides the soil strength, the load carried by the tire or track, some technical characteristics of the tire or track of the vehicle (tire or track width, tire or track wheel diameter, unloaded tire section height, number of wheel station in one track, tire deflection, total length of the belt track, the track pitch) as well as the vehicle passes. They have been validated with the tests results of agricultural vehicles over a range of soil in central Italy. Among the parameters which affect soil compaction, the water content of the soil, the axle load and number of vehicle passes proved to be the most important ones. The present paper concerns mainly vehicle

  16. EXPERIMENTAL STUDY ON CLASSIFICATION OF LAYOUT METHODS OF A STEEL PLATE AND EFFECT OF DECREASE IN ACTING PRESSURE ON BEARING GROUND THROUGH THE CRAWLERS OF DRILL RIGS.

    NASA Astrophysics Data System (ADS)

    Hori, Tomohito; Tamate, Satoshi; Kikkawa, Naotaka; Itoh, Kazuya

    Drill rigs are large pieces of construction machinery, used to build pile foundations and improve ground stability. In recent years, there have been several reports of accidents where drill rigs have toppled over. Two potential causes for these accidents are related to drill rigs becoming unstable. One cause is structural instability, where the body is composed of a top heavy weight distribution. The other is concerned with the supporting ground. During the construction process, rig sites are excavated and overlaid by reclaimed soil. These works produce uneven surfaces, as well as a distribution of different stiffnesses in the supporting ground. In this study, we first classify layout methods of a steel plate and conduct loading tests with several layout patterns while decreasing the acting pressure on the bearing ground through the crawlers. Secondly, a series of experimental simulations using a 1/25 scale model of a drill rig are performed in a centrifuge, in order to investigate the cause of drill rig instability with motion-image sequence analysis. Finally, we discuss the optimum layout methods of the steel plate.

  17. Tests of Nacelle-Propeller Combinations in Various Positions with Reference to Wings III : Clark Y Wing - Various Radial-engine Cowlings - Tractor Propeller

    NASA Technical Reports Server (NTRS)

    Wood, Donald H

    1933-01-01

    This report is the third of a series giving the results obtained in the 20-foot wind tunnel on the interference drag, and propulsive efficiency of nacelle-propeller-wing combinations. The first report gave the results of the tests of an NACA cowled air-cooled engine nacelle with tractor propeller located in 21 positions with reference to a thick wing. The second report gave the results for several engine cowlings and nacelles with tractor propeller located in four positions with reference to same wing. The present report gives results of tests of the same nacelles and cowlings in the same positions with reference to a smaller wing of Clark y section. The lift, drag, and propulsive efficiency were determined at several angles of attack for each cowling and in each nacelle location.

  18. EVALUATION OF THE EFFECTIVENESS OF TRUCK EFFICIENCY TECHNOLOGIES IN CLASS 8 TRACTOR-TRAILERS BASED ON A TRACTIVE ENERGY ANALYSIS USING MEASURED DRIVE CYCLE DATA

    SciTech Connect

    LaClair, Tim J; Gao, Zhiming; Fu, Joshua S.; Calcagno, Jimmy; Yun, Jeongran

    2014-01-01

    Quantifying the fuel savings that can be achieved from different truck fuel efficiency technologies for a fleet s specific usage allows the fleet to select the combination of technologies that will yield the greatest operational efficiency and profitability. This paper presents an analysis of vehicle usage in a commercial vehicle fleet and an assessment of advanced efficiency technologies using an analysis of measured drive cycle data for a class 8 regional commercial shipping fleet. Drive cycle measurements during a period of a full year from six tractor-trailers in normal operations in a less-than-truckload (LTL) carrier were analyzed to develop a characteristic drive cycle that is highly representative of the fleet s usage. The vehicle mass was also estimated to account for the variation of loads that the fleet experienced. The drive cycle and mass data were analyzed using a tractive energy analysis to quantify the fuel efficiency and CO2 emissions benefits that can be achieved on class 8 tractor-trailers when using advanced efficiency technologies, either individually or in combination. Although differences exist among class 8 tractor-trailer fleets, this study provides valuable insight into the energy and emissions reduction potential that various technologies can bring in this important trucking application.

  19. Health risk evaluation of whole-body vibration by ISO 2631-5 and ISO 2631-1 for operators of agricultural tractors and recreational vehicles.

    PubMed

    Park, Min-Soo; Fukuda, Takabumi; Kim, Tae-Gu; Maeda, Setsuo

    2013-01-01

    This paper presents experimental research evaluation of the vibration exposure for the health risk prediction during vehicle operation. The vibration measurements were carried out on a recreational vehicle and two types of agricultural tractors. The vibration levels were measured for different surfaces and vehicle speed conditions. Based on the analysis of the results in the small agricultural tractor operated in the workplace (frameworks), Sed exceeded 0.80 MPa by ISO2631-5:2004, and Av exceeded 0.89 m/s(2) by ISO2631-1:1997. That means that operators driving small agricultural tractors more than 8 h a day have a high probability of adverse health effects. However, the exposure value for the recreational vehicle had Sed < 0.5 MPa by ISO2631-5:2004 and Av < 0.5 m/s(2) by ISO2631-1:1997 on highways and local roads. That means Recreational Vehicle operators driving more than 8 h a day, have a low probability of adverse health effects. Also, for the recreational vehicle, vibration was taken at different speeds (40-60 km/h, 80 km/h, 100-120 km/h). However, the speed change did not appear to affect the vibration dose variation while driving a vehicle on the highway and road. Finally, the health effect index of ISO2631-5:2004 are almost the same as assessment of health effect by ISO2631-1:1997.

  20. Truck Rollover Characterization for Class-8 Tractor-Trailers Utilizing Standard Dual Tires and New-Generation Single Tires

    SciTech Connect

    Capps, Gary; Knee, Bill; Franzese, Oscar; Pollock, Paul; Coleman, Daniel; Janajreh, Ibrahim; Haas, Steven; Frey, Norm; Law, Harry; Johnson, Eric; Lawson, Robert; Petrolino, Joe; Rice, Dave

    2005-07-30

    The Heavy Truck Rollover Characterization Project is a major research effort conducted by the National Transportation Research Center, Inc. (NTRCI) in partnership with Oak Ridge National Laboratory (ORNL), Dana Corporation (Dana), Michelin Americas Research and Development Corporation (Michelin) and Clemson University (Clemson), under the NTRCIs Heavy Vehicle Safety Research Center (HVSRC) for the Federal Highway Administration (FHWA). ORNL provided the day-to-day management of the project. The expertise mix of this team coupled with complementary research needs and interests, and a positive can-do attitude provided an extremely positive experimental research opportunity for all involved. Furthermore, this team supplied significant and valuable resources that provided a strong positive benchmark regarding the ability to conduct research within a public-private partnership. The work conducted by this team focused on initial efforts to generate data and information on heavy truck rollover not currently available in the industry. It reflects efforts within Phases 1 and 2 of a longer-term four-phase research program. A 1999 Peterbilt 379 class-8 tractor and 2004 Wabash dry freight van trailer were the test vehicles utilized in this effort. Both were instrumented with a number of sensors to capture the dynamics of the tractor and trailer as it engaged in various testing maneuvers that included: an evasive maneuver, swept sine, constant radius, and a run-off-the-road maneuver. The run-off-the-road maneuver was discontinued because the test track could not safety accommodate such a maneuver. These maneuvers were carried out utilizing both standard dual tires and new-generation dual tires in six test series. Two test series also included the use of a wider-slider suspension. Outriggers were placed on the test vehicle to assure that an actual rollover would not occur, however, the tests were designed to generate lift-off of tires during the tests. One of the main objectives

  1. Evaluating the protective capacity of two-post ROPS for a seat-belted occupant during a farm tractor overturn.

    PubMed

    Guan, J; Hsiao, H; Zwiener, J V; Current, R S; Lutz, T J; Cantis, D M; Powers, J R; Newbraugh, B H; Spahr, J S

    2011-01-01

    This study evaluated the effectiveness of a commercial rollover protective structure (ROPS) and size-extended ROPS in protecting a 95th percentile male operator during tractor overturns. Six rear upset tests (commercial ROPS) and ten side upset tests (commercial and size-extended ROPS) were conducted. A 95th percentile instrumented male manikin was used in all tests. Head injury criterion (HIC15), 80 g limit on resultant head acceleration, neck injury criterion (Nij), and peak axial force (extension-compression) were employed to evaluate injury potential. In all rear tests, the manikin's head impact with the ground was within the tolerance limits for head/neck injuries. Based on limited trials in the side tests, the study observed a small to moderate chance of neck injuries under the commercial and size-extended ROPS conditions; the injury risk was not statistically significant between these two test conditions. This study identified a risk of non-fatal injuries for large-size operators in side overturns, although the prevention effectiveness of commercial versus size-extended ROPS cannot be determined without further testing. These findings may have implications for future ROPS designs.

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

    NASA Technical Reports Server (NTRS)

    Muirhead, V. U.

    1981-01-01

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

  3. Using mobile, internet connected deep sea crawlers for spatial and temporal analysis of cold seep ecosystems and the collection of real-time classroom data for extreme environment education.

    NASA Astrophysics Data System (ADS)

    Purser, Autun; Kwasnitschka, Tom; Duda, Alexander; Schwendner, Jakob; Bamberg, Marlene; Sohl, Frank; Doya, Carol; Aguzzi, Jacopo; Best, Mairi; Llovet, Neus Campanya I.; Scherwath, Martin; Thomsen, Laurenz

    2015-04-01

    Cabled internet and power connectivity with the deep sea allow instruments to operate in the deep sea at higher temporal resolutions than was possible historically, with the reliance on battery life and data storage capacities. In addition to the increase in sensor temporal frequency, cabled infrastructures now allow remote access to and control of mobile platforms on the seafloor. Jacobs University Bremen, in combination with collaborators from the Robotic Exploration of Extreme Environments (ROBEX) project, CSIC Barcelona and Ocean Networks Canada have been operating tracked deep sea crawler vehicles at ~890 m depth at the dynamic Barkley Canyon methane seep site, Pacific Canada during the last ~4 years. The vehicle has been able to explore an area of ~50 m radius, allowing repeated visits to numerous microhabitats. Mounting a range of sensors, including temperature, pressure, conductivity, fluorescence, turbidity, flow and methane concentration sensors, as well as various camera systems a large dataset has been compiled. Several methane pockmarks are present in the survey area, and geological, biological and oceanographic changes have been monitored over a range of timescales. Several publications have been produced, and in this presentation we introduce further data currently under analysis. Cabled internet connectivity further allows mobile platforms to be used directly in education. As part of the ROBEX project, researchers and students from both terrestrial and planetary sciences are using the crawler in an ongoing study project. Students are introduced to statistical methods from both fields during the course and in later stages they can plan their own research using the in-situ crawler, and follow the progress of their investigations live, then analyse the collected data using the techniques introduced during the course. Cabled infrastructures offer a unique facility for spatial investigation of extreme ecosystems over time, and for the 'hands on

  4. Development of a Short-Duration Drive Cycle to Represent Long-Term Measured Drive Cycle Data: Evaluation of Truck Efficiency Technologies in Class 8 Tractor Trailers

    SciTech Connect

    LaClair, Tim; Gao, Zhiming; Fu, Joshua; Calcagno, Jimmy; Yun, Jeongran

    2014-12-01

    Quantifying the fuel savings and emissions reductions that can be achieved from truck fuel efficiency technologies for a fleet's specific usage allows the fleet to select a combination of technologies that will yield the greatest operational efficiency and profitability. An accurate characterization of usage for the fleet is critical for such an evaluation; however, short-term measured drive cycle data do not generally reflect overall usage very effectively. This study presents a detailed analysis of vehicle usage in a commercial vehicle fleet and demonstrates the development of a short-duration synthetic drive cycle with measured drive cycle data collected over an extended period of time. The approach matched statistical measures of the vehicle speed with acceleration history and integrated measured grade data to develop a compressed drive cycle that accurately represents total usage. Drive cycle measurements obtained during a full year from six tractor trailers in normal operations in a less-than-truckload carrier were analyzed to develop a synthetic drive cycle. The vehicle mass was also estimated to account for the variation of loads that the fleet experienced. These drive cycle and mass data were analyzed with a tractive energy analysis to quantify the benefits in terms of fuel efficiency and reduced carbon dioxide emissions that can be achieved on Class 8 tractor trailers by using advanced efficiency technologies, either individually or in combination. Although differences exist between Class 8 tractor trailer fleets, this study provides valuable insight into the energy and emissions reduction potential that various technologies can bring in this important trucking application. Finally, the methodology employed for generating the synthetic drive cycle serves as a rigorous approach to develop an accurate usage characterization that can be used to effectively compress large quantities of drive cycle data.

  5. Development of a Short-Duration Drive Cycle to Represent Long-Term Measured Drive Cycle Data: Evaluation of Truck Efficiency Technologies in Class 8 Tractor Trailers

    DOE PAGES

    LaClair, Tim; Gao, Zhiming; Fu, Joshua; ...

    2014-12-01

    Quantifying the fuel savings and emissions reductions that can be achieved from truck fuel efficiency technologies for a fleet's specific usage allows the fleet to select a combination of technologies that will yield the greatest operational efficiency and profitability. An accurate characterization of usage for the fleet is critical for such an evaluation; however, short-term measured drive cycle data do not generally reflect overall usage very effectively. This study presents a detailed analysis of vehicle usage in a commercial vehicle fleet and demonstrates the development of a short-duration synthetic drive cycle with measured drive cycle data collected over an extendedmore » period of time. The approach matched statistical measures of the vehicle speed with acceleration history and integrated measured grade data to develop a compressed drive cycle that accurately represents total usage. Drive cycle measurements obtained during a full year from six tractor trailers in normal operations in a less-than-truckload carrier were analyzed to develop a synthetic drive cycle. The vehicle mass was also estimated to account for the variation of loads that the fleet experienced. These drive cycle and mass data were analyzed with a tractive energy analysis to quantify the benefits in terms of fuel efficiency and reduced carbon dioxide emissions that can be achieved on Class 8 tractor trailers by using advanced efficiency technologies, either individually or in combination. Although differences exist between Class 8 tractor trailer fleets, this study provides valuable insight into the energy and emissions reduction potential that various technologies can bring in this important trucking application. Finally, the methodology employed for generating the synthetic drive cycle serves as a rigorous approach to develop an accurate usage characterization that can be used to effectively compress large quantities of drive cycle data.« less

  6. Narrative text analysis of accident reports with tractors, self-propelled harvesting machinery and materials handling machinery in Austrian agriculture from 2008 to 2010 - a comparison.

    PubMed

    Mayrhofer, Hannes; Quendler, Elisabeth; Boxberger, Josef

    2014-01-01

    The aim of this study was the identification of accident scenarios and causes by analysing existing accident reports of recognized agricultural occupational accidents with tractors, self-propelled harvesting machinery and materials handling machinery from 2008 to 2010. As a result of a literature-based evaluation of past accident analyses, the narrative text analysis was chosen as an appropriate method. A narrative analysis of the text fields of accident reports that farmers used to report accidents to insurers was conducted to obtain detailed information about the scenarios and causes of accidents. This narrative analysis of reports was made the first time and yielded first insights for identifying antecedents of accidents and potential opportunities for technical based intervention. A literature and internet search was done to discuss and confirm the findings. The narrative text analysis showed that in more than one third of the accidents with tractors and materials handling machinery the vehicle rolled or tipped over. The most relevant accident scenarios with harvesting machinery were being trapped and falling down. The direct comparison of the analysed machinery categories showed that more than 10% of the accidents in each category were caused by technical faults, slippery or muddy terrain and incorrect or inappropriate operation of the vehicle. Accidents with tractors, harvesting machinery and materials handling machinery showed similarities in terms of causes, circumstances and consequences. Certain technical and communicative measures for accident prevention could be used for all three machinery categories. Nevertheless, some individual solutions for accident prevention, which suit each specific machine type, would be necessary.

  7. Wind-Tunnel Tests of Several Model Tractor-Propeller and Pusher-Propeller Wing Extension-Shaft Arrangements, Special Report

    NASA Technical Reports Server (NTRS)

    Harmon, Hubert N.

    1941-01-01

    Tests were made in the 20-foot propeller-research tunnel to investigate the possibility of obtaining increased net efficiencies of propeller-nacelle units by enclosing the engines in the wings and by using extension shafts. A wing of 5-foot chord was fitted with a propeller drive assembly providing for several axial locations of tractor propellers and pusher propellers. A three-blade 4-foot propeller and a three-blade 3 1/2-foot propeller of special design were tested in this wing with spinners and fairings ranging in diameter from 6 to 16 inches. A 16-inch NACA cowling was tested for comparative purposes. Two types of cuffs were also employed. It was found that the net efficiency of a conventional round-shank propeller mounted on an extension shaft in front of or behind a wing increased with an increase in the diameter of the spinner and the shaft housing within the scope of the tests. The largest spinner used had a diameter that might favorably compare with that of a radial engine cowling. The efficiencies for the pusher position appeared to be more critically affected by spinner size than those for the tractor position. The spinners with large diameters for the pusher position resulted in a higher efficiency than those for the corresponding tractor arrangements; the reverse was true for the small spinners. The use of propeller cuffs in combination with a spinner of small diameter generally resulted in net efficiencies that were comparable with those found for the large-spinner combinations.

  8. Prediction of the effects of propeller operation on the static longitudinal stability of single-engine tractor monoplanes with flaps retracted

    NASA Technical Reports Server (NTRS)

    Weil, Joseph; Sleeman, William C , Jr

    1949-01-01

    The effects of propeller operation on the static longitudinal stability of single-engine tractor monoplanes are analyzed, and a simple method is presented for computing power-on pitching-moment curves for flap-retracted flight conditions. The methods evolved are based on the results of powered-model wind-tunnel investigations of 28 model configurations. Correlation curves are presented from which the effects of power on the downwash over the tail and the stabilizer effectiveness can be rapidly predicted. The procedures developed enable prediction of power-on longitudinal stability characteristics that are generally in very good agreement with experiment.

  9. The U.S. Department of Labor's Tractor and Machinery Certification Program: management styles and perceptions held by community stakeholders and instructors.

    PubMed

    Jepsen, S D

    2012-07-01

    A mixed-mode, descriptive study was conducted on the U.S. Department of Labor's (DOL) Tractor and Machinery Certification Program. Legislated by the Fair Labors Standards Act, the Hazardous Occupations Order in Agriculture (HOOA) was enacted in 1968 as a public policy measure to reduce the number of injuries to youth on farms. An educational exemption allows youth 14 and 15 years of age to work for hire after they successfully complete a training program. In the 40+ years since the legislation went into effect prescribing such training exemptions, deficiencies and variations have occurred in the quality of the educational program and the system by which agencies certify young people. To gain a better understanding of the DOL Tractor and Machinery Certification program, community stakeholders were asked to identify management practices, curriculum resources, and perceptions of the DOL program. The study design used qualitative data from 49 agricultural representatives participating in regional focus groups and quantitative data from 330 community instructors responding to an electronic-formatted questionnaire (representing a 70.7% response rate) in an effort to answer the question: "What is the current status of the DOL Tractor and Machinery Certification program in the United States?" The findings revealed that 55.2% of the instructors taught a qualifying DOL program. Of these, the certification was administered through an Extension or 4-H program (68.7%), an agricultural education program (24.7%), or as a combination of Extension and agricultural education (6.0%). Course instructors believed the training was beneficial to students and had opportunity to attract more students than currently enrolled These instructors placed a higher value on standardized teaching materials than on standardized testing procedures; they also supported the need for additional teaching aids, which included hands-on activities, videotapes, student workbooks, and DVDs. Study participants

  10. An Analysis of Once-per-revolution Oscillating Aerodynamic Thrust Loads on Single-Rotation Propellers on Tractor Airplanes at Zero Yaw

    NASA Technical Reports Server (NTRS)

    Rogallo, Vernon L; Yaggy, Paul F; Mccloud, John L , III

    1956-01-01

    A simplified procedure is shown for calculating the once-per-revolution oscillating aerodynamic thrust loads on propellers of tractor airplanes at zero yaw. The only flow field information required for the application of the procedure is a knowledge of the upflow angles at the horizontal center line of the propeller disk. Methods are presented whereby these angles may be computed without recourse to experimental survey of the flow field. The loads computed by the simplified procedure are compared with those computed by a more rigorous method and the procedure is applied to several airplane configurations which are believed typical of current designs. The results are generally satisfactory.

  11. A Summary of the Experimental Results for a Generic Tractor-Trailer in the Ames Research Center 7- by 10-Foot and 12-Foot Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Storms, Bruce L.; Satran, Dale R.; Heineck, James T.; Walker, Stephen M.

    2006-01-01

    Experimental measurements of a generic tractor-trailer were obtained in two wind tunnels at Ames Research Center. After a preliminary study at atmospheric conditions in the 7- by 10-Foot Wind Tunnel, additional testing was conducted at Reynolds numbers corresponding to full-scale highway speeds in the 12-Foot Pressure Wind Tunnel. To facilitate computational modeling, the 1:8-scale geometry, designated the Generic Conventional Model, included a simplified underbody and omitted many small-scale details. The measurements included overall and component forces and moments, static and dynamic surface pressures, and three-component particle image velocimetry. This summary report highlights the effects of numerous drag reduction concepts and provides details of the model installation in both wind tunnels. To provide a basis for comparison, the wind-averaged drag coefficient was tabulated for all configurations tested. Relative to the baseline configuration representative of a modern class-8 tractor-trailer, the most effective concepts were the trailer base flaps and trailer belly box providing a drag-coefficient reduction of 0.0855 and 0.0494, respectively. Trailer side skirts were less effective yielding a drag reduction of 0.0260. The database of this experimental effort is publicly available for further analysis.

  12. Wind tunnel measurements of the dilution of tailpipe emissions downstream of a car, a light-duty truck, and a heavy-duty truck tractor head.

    PubMed

    Chang, Victor W C; Hildemann, Lynn M; Chang, Cheng-hisn

    2009-06-01

    The particle and gaseous pollutants in vehicle exhaust emissions undergo rapid dilution with ambient air after exiting the tailpipe. The rate and extent of this dilution can greatly affect both the size evolution of primary exhaust particles and the potential for formation of ultrafine particles. Dilution ratios were measured inside of a wind tunnel in the region immediately downstream of the tailpipe using model vehicles (approximately one-fifth to one-seventh scale models) representing a light-duty truck, a passenger car, and a heavy-duty tractor head (without the trailer). A tracer gas (ethene) was released at a measured flow rate from the tailpipe, and 60 sampling probes placed downstream of the vehicle simultaneously sampled gas tracer concentrations in the near-wake (first few vehicle heights) and far-wake regions (beyond 10 vehicle heights). Tests using different tunnel wind speeds show the range of dilution ratios that can be expected as a function of vehicle type and downstream distance (i.e., time). The vehicle shape quite strongly influences dilution profiles in the near-wake region but is much less important in the far-wake region. The tractor generally produces higher dilution rates than the automobile and light-duty truck under comparable conditions.

  13. Encouraging farmers to retrofit tractors: a qualitative analysis of risk perceptions among a group of high-risk farmers in New York.

    PubMed

    Sorensen, J A; May, J J; Paap, K; Purschwitz, M A; Emmelin, M

    2008-01-01

    Tractor rollovers continue to be one of the most frequent causes of agricultural fatalities. Despite knowledge of rollovers and the efficacy of rollover protective structures (ROPS), few New York farmers have considered installing ROPS on their unprotected tractors. Qualitative interviews conducted with an "at-risk" segment of the New York farming community indicate that there are a number of barriers to safety in general and to retrofitting, in particular. The following themes and categories emerged in relation to safety and risk taking: constant exposures to risk with positive outcomes normalizes risk; the modeling of risk by significant others positions risk as part of a farming identity; and the pressure to reduce costs, save time, and accept risk frames risk-taking as the cost-effective option (especially in regard to retrofitting, which farmers believe is both expensive and time-consuming). Recommendations for researchers planning retrofitting interventions would be to focus safety messages on the risk to significant others or on the financial impact of rollovers, and to provide financial incentives and assistance to farmers considering retrofitting.

  14. Test, Evaluation, and Demonstration of Practical Devices/Systems to Reduce Aerodynamic Drag of Tractor/Semitrailer Combination Unit Trucks

    SciTech Connect

    Scott Smith; Karla Younessi; Matt Markstaller; Dan Schlesinger; Bhaskar Bhatnagar; Donald Smith; Bruno Banceu; Ron Schoon; V.K. Sharma; Mark Kachmarsky; Srikant Ghantae; Michael Sorrels; Conal Deedy; Justin Clark; Skip Yeakel; Michael D. Laughlin; Charlotte Seigler; Sidney Diamond

    2007-04-30

    Class 8 heavy-duty trucks account for over three-quarters of the total diesel fuel used by commercial trucks (trucks with GVWRs more than 10,000 pounds) in the United States each year. At the highway speeds at which these trucks travel (i.e., 60 mph or greater), aerodynamic drag is a major part of total horsepower needed to move the truck down the highway, Reductions in aerodynamic drag can yield measurable benefits in fuel economy through the use of relatively inexpensive and simple devices. The goal of this project was to examine a number of aerodynamic drag reduction devices and systems and determine their effectiveness in reducing aerodynamic drag of Class 8 tractor/semitrailer combination-units, thus contributing to DOE's goal of reducing transportation petroleum use. The project team included major heavy truck manufacturers in the United States, along with the management and industry expertise of the Truck Manufacturers Association as the lead investigative organization. The Truck Manufacturers Association (TMA) is the national trade association representing the major North American manufacturers of Class 6-8 trucks (GVWRs over 19,500 lbs). Four major truck manufacturers participated in this project with TMA: Freightliner LLC; International Truck and Engine Corporation; Mack Trucks Inc.; and Volvo Trucks North America, Inc. Together, these manufacturers represent over three-quarters of total Class 8 truck sales in the United States. These four manufacturers pursued complementary research efforts as part of this project. The project work was separated into two phases conducted over a two-year period. In Phase I, candidate aerodynamic devices and systems were screened to focus research and development attention on devices that offered the most potential. This was accomplished using full-size vehicle tests, scale model tests, and computational fluid dynamics analyses. In Phase II, the most promising devices were installed on full-size trucks and their effect on

  15. STS-27 Atlantis, Orbiter Vehicle (OV) 104, rolls out to KSC LC pad 39B

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-27 Atlantis, Orbiter Vehicle (OV) 104, atop the mobile launcher platform rolls out to Kennedy Space Center (KSC) Launch Complex (LC) pad 39B via the crawler transporter. In this profile view, the tractor tracks of the crawler transporter, the mobile launcher platform, and the underside of OV-104 attached to the external tank (ET) are visible.

  16. Design of a new sensor for determination of the effects of tractor field usage in southern Spain: soil sinkage and alterations in the cone index and dry bulk density.

    PubMed

    Valera, Diego L; Gil, Jesús; Agüera, Juan

    2012-10-08

    Variations in sinkage and cone index are of crucial importance when planning fieldwork, and for determining the trafficability of farm machinery. Many studies have highlighted the link between higher values of these parameters and dramatic decreases in crop yield. Variations in the dry bulk density and cone index of clayey soil in Southern Spain were measured following each of five successive passes over the same land with the three types of tractor most widely used in the area (tracked, two-wheel drive and four-wheel drive). In addition, sinkage (rut depth) of the running gear was measured using a laser microrelief profile meter. This device, which integrates three sensors, was specifically designed for these experiments, as was an electrical penetrometer to determine the cone index, and both instruments proved reliable and accurate in the field. The main goal of this study was to design, manufacture and test these new devices. The first pass caused most soil alteration when compared to successive passes for all types of tractor tested and soil conditions prevailing during the tests. (Heavier) four-wheel drive tractors were found to cause greater soil damage (sinkage, cone index and dry bulk density) than two-wheel drive and track tractors. There was no statistically significant difference between the two latter types. The greatest alterations were recorded in the top 10 cm of the soil. The results show that soil compaction should be avoided as much as possible. This can be achieved by ensuring that tractors always travel along the same tracks, especially in the wet season. At present these aspects are not considered by farmers in this area.

  17. A Statistical Description of the Types and Severities of Accidents Involving Tractor Semi-Trailers, Updated Results for 1992-1996

    SciTech Connect

    BLOWER,DANIEL F.; CLAUSS,DAVID B.

    1999-10-01

    This report provides a statistical description of the types and severities of tractor semi-trailer accidents involving at least one fatality. The data were developed for use in risk assessments of hazardous materials transportation. A previous study (SAND93-2580) reviewed the availability of accident data, identified the TIFA (Trucks Involved in Fatal Accidents) as the best source of accident data for accidents involving heavy trucks, and provided statistics on accident data collected between 1980 and 1990. The current study is an extension of the previous work and describes data collected for heavy truck accidents occurring between 1992 and 1996. The TIFA database created at the University of Michigan Transportation Research Institute was extensively utilized. Supplementary data on collision and fire severity, which was not available in the TIFA database, were obtained by reviewing police reports and interviewing responders and witnesses for selected TEA accidents. The results are described in terms of frequencies of different accident types and cumulative distribution functions for the peak contact velocity, rollover skid distance, effective fire temperature, fire size, fire separation, and fire duration.

  18. KENNEDY SPACE CENTER, FLA. - A high-flying bird takes a closer look at the Mobile Launcher Platform (MLP) number 3 with twin solid rocket boosters bolted to it as it crawls toward Launch Pad 39A, in the background. The crawler is moving along the crawlerway at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - A high-flying bird takes a closer look at the Mobile Launcher Platform (MLP) number 3 with twin solid rocket boosters bolted to it as it crawls toward Launch Pad 39A, in the background. The crawler is moving along the crawlerway at various speeds up to 1 mph in an effort to achieve vibration data gathering goals as it travels toward Launch Pad 39A and then returns. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  19. KENNEDY SPACE CENTER, FLA. -Crawler-transporter (CT) number 2, moves away from the Vehicle Assembly Building, with a Mobile Launcher Platform on top, on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT moves Space Shuttle vehicles between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds.

    NASA Image and Video Library

    2003-08-18

    KENNEDY SPACE CENTER, FLA. -Crawler-transporter (CT) number 2, moves away from the Vehicle Assembly Building, with a Mobile Launcher Platform on top, on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT moves Space Shuttle vehicles between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds.

  20. KENNEDY SPACE CENTER, FLA. - Inside the cab of crawler-transporter (CT) number 2, driver Sam Dove, with United Space Alliance, operates the vehicle on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT is transporting a Mobile Launch Platform (MLP). The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

    NASA Image and Video Library

    2003-08-18

    KENNEDY SPACE CENTER, FLA. - Inside the cab of crawler-transporter (CT) number 2, driver Sam Dove, with United Space Alliance, operates the vehicle on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT is transporting a Mobile Launch Platform (MLP). The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

  1. KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transportation (CT) number 2 shows the new muffler system on the vehicle. The CT also recently underwent modifications to the cab. The CT is transporting a Mobile Launch Platform (MLP). The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

    NASA Image and Video Library

    2003-08-18

    KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transportation (CT) number 2 shows the new muffler system on the vehicle. The CT also recently underwent modifications to the cab. The CT is transporting a Mobile Launch Platform (MLP). The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

  2. KENNEDY SPACE CENTER, FLA. - Crawler-transporter (CT) number 2 nears the launch pad with a Mobile Launcher Platform (MLP) on top. After recent modifications to the cab and muffler system, the CT was taken on a test run. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

    NASA Image and Video Library

    2003-08-19

    KENNEDY SPACE CENTER, FLA. - Crawler-transporter (CT) number 2 nears the launch pad with a Mobile Launcher Platform (MLP) on top. After recent modifications to the cab and muffler system, the CT was taken on a test run. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

  3. KENNEDY SPACE CENTER, FLA. - Crawler-transporter (CT) number 2, moves away from the Vehicle Assembly Building with a Mobile Launcher Platform (MLP) on top on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

    NASA Image and Video Library

    2003-08-18

    KENNEDY SPACE CENTER, FLA. - Crawler-transporter (CT) number 2, moves away from the Vehicle Assembly Building with a Mobile Launcher Platform (MLP) on top on a test run to the launch pad. The CT recently underwent modifications to the cab. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

  4. KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transporter (CT) number 2 shows the cab, at left, that recently underwent modifications. The CT is transporting a Mobile Launch Platform (MLP) on a test run to the pad. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

    NASA Image and Video Library

    2003-08-18

    KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transporter (CT) number 2 shows the cab, at left, that recently underwent modifications. The CT is transporting a Mobile Launch Platform (MLP) on a test run to the pad. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

  5. KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transporter (CT) number 2 shows the cab (left, above the tracks) that recently underwent modifications. The CT is transporting a Mobile Launch Platform (MLP) on a test run to the pad. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

    NASA Image and Video Library

    2003-08-18

    KENNEDY SPACE CENTER, FLA. - A closeup of crawler-transporter (CT) number 2 shows the cab (left, above the tracks) that recently underwent modifications. The CT is transporting a Mobile Launch Platform (MLP) on a test run to the pad. The CT moves Space Shuttle vehicles, situated on the MLP, between the VAB and launch pad. Moving on four double-tracked crawlers, the CT uses a laser guidance system and a leveling system for the journey that keeps the top of a Space Shuttle vertical within plus- or minus-10 minutes of arc. The system enables the CT-MLP-Shuttle to negotiate the ramp leading to the launch pads and keep the load level. Unloaded, the CT weighs 6 million pounds. Seen on top of the MLP are two tail service masts that support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft umbilicals.

  6. Tractor Mechanics. Maintaining and Servicing the Power Train, Learning Activity Packages 49-53; Maintaining and Servicing the Clutch, Learning Activity Packages 54-59; Maintaining and Servicing the Transmission and Differential, Learning Activity Packages 60-68; Maintaining and Servicing the Final Drive, Learning Activity Packages 69-77.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This series of learning activity packages focuses on four areas of tractor mechanics: (1) maintaining and servicing the power train, (2) maintaining and servicing the clutch, (3) maintaining and servicing the transmission and differential, and (4) maintaining and servicing the final drive. Each of the twenty-nine illustrated learning activity…

  7. Methodologies for Crawler Based Web Surveys.

    ERIC Educational Resources Information Center

    Thelwall, Mike

    2002-01-01

    Describes Web survey methodologies used to study the content of the Web, and discusses search engines and the concept of crawling the Web. Highlights include Web page selection methodologies; obstacles to reliable automatic indexing of Web sites; publicly indexable pages; crawling parameters; and tests for file duplication. (Contains 62…

  8. An Intelligent Crawler for a Virtual World

    ERIC Educational Resources Information Center

    Eno, Joshua

    2010-01-01

    Virtual worlds, which allow users to create and interact with content in a 3D, multi-user environment, growing and becoming more integrated with the traditional flat web. However, little is empirically known about the content users create in virtual world and how it can be indexed and searched effectively. In order to gain a better understanding…

  9. Dynamic Scheduling for Web Monitoring Crawler

    DTIC Science & Technology

    2009-02-27

    publication changes in web pages caused by particular events, such as accidents, financial crisis, and sports games . 2. A group of web pages P = {P1, P2, P3...Period We monitored sports news web pages during Beijing Olympic Games . As each game held in the Olympic can be regarded as an event, it is possible to...expect articles about the games would be published according to progresses of the games . For example, if some Olympians won or lost in the game , the

  10. An Intelligent Crawler for a Virtual World

    ERIC Educational Resources Information Center

    Eno, Joshua

    2010-01-01

    Virtual worlds, which allow users to create and interact with content in a 3D, multi-user environment, growing and becoming more integrated with the traditional flat web. However, little is empirically known about the content users create in virtual world and how it can be indexed and searched effectively. In order to gain a better understanding…

  11. Tractor Hydraulics. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Vocational Instructional Materials, Athens, GA.

    The manual was developed to help provide a better understanding of how and why hydraulic principles serve the purposes of weight reduction, increase of physical effort, and more precise control to machines of all types. The four components that are necessary to have a workable hydraulic system--a reservoir, a pump, a valve, and a motor (cylinder)…

  12. Logging damage using an individual tree selection practice in Appalachian hardwood stands

    Treesearch

    Neil I. Lamson; H. Clay Smith; Gary W. Miller

    1985-01-01

    Four West Virginia hardwood stands, managed using individual-tree selection for the past 30 years, were examined after the third and, in one instance, the fourth periodic harvest to determine the severity of logging damage. On existing skid roads, trees were removed with a rubber-tired skidder or a crawler tractor with a rubber-tired arch. Logging damage reduced...

  13. 29 CFR 1926.1001 - Minimum performance criteria for rollover protective structures for designated scrapers, loaders...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... assembled vehicle is not required. However, the vehicle structure and frame which support the ROPS must...-Type Loaders; and SAE J396, Minimum Performance Criteria for Roll-Over Protective Structure for Motor... structures for designated scrapers, loaders, dozers, graders, and crawler tractors. 1926.1001 Section...

  14. 29 CFR 1926.1001 - Minimum performance criteria for rollover protective structures for designated scrapers, loaders...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... assembled vehicle is not required. However, the vehicle structure and frame which support the ROPS must...-Type Loaders; and SAE J396, Minimum Performance Criteria for Roll-Over Protective Structure for Motor... structures for designated scrapers, loaders, dozers, graders, and crawler tractors. 1926.1001 Section...

  15. 29 CFR 1926.1001 - Minimum performance criteria for rollover protective structures for designated scrapers, loaders...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... assembled vehicle is not required. However, the vehicle structure and frame which support the ROPS must...-Type Loaders; and SAE J396, Minimum Performance Criteria for Roll-Over Protective Structure for Motor... structures for designated scrapers, loaders, dozers, graders, and crawler tractors. 1926.1001 Section...

  16. 29 CFR 1926.1001 - Minimum performance criteria for rollover protective structures for designated scrapers, loaders...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... assembled vehicle is not required. However, the vehicle structure and frame which support the ROPS must...-Type Loaders; and SAE J396, Minimum Performance Criteria for Roll-Over Protective Structure for Motor... structures for designated scrapers, loaders, dozers, graders, and crawler tractors. 1926.1001 Section...

  17. Mechanized systems for harvesting eastern hardwoods

    Treesearch

    Chris B. LeDoux

    2010-01-01

    In the central Appalachian region, hardwoods traditionally have been harvested by chainsaw felling with trees and logs extracted from the forest to landings by rubber-tired skidders, bulldozers, and crawler tractors. In recent years, mechanized systems that include feller bunchers and cut-to-length (CTL) processors coupled with forwarders and clambunk and grapple...

  18. KENNEDY SPACE CENTER, FLA. - Like candles embedded in a sculptured “cake,” the Mobile Launcher Platform (MLP) number 3 with twin solid rocket boosters bolted to it inches along the crawlerway at various speeds up to 1 mph in an effort to achieve vibration data gathering goals. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

    NASA Image and Video Library

    2003-11-21

    KENNEDY SPACE CENTER, FLA. - Like candles embedded in a sculptured “cake,” the Mobile Launcher Platform (MLP) number 3 with twin solid rocket boosters bolted to it inches along the crawlerway at various speeds up to 1 mph in an effort to achieve vibration data gathering goals. The boosters are braced at the top for stability. The primary purpose of these rollout tests is to gather data to develop future maintenance requirements on the transport equipment and the flight hardware. Various parts of the MLP and crawler transporter have been instrumented with vibration data collection equipment.

  19. KENNEDY SPACE CENTER, FLA. - The rising sun and some scattered clouds provide a picturesque backdrop for the Space Shuttle Discovery as it travels along the crawlerway toward Launch Pad 39A in preparation for the STS-82 mission. The Shuttle is on a Mobile Launcher Platform, and the entire assemblage is being carried by a large, tracked vehicle called the crawler transporter. A seven-member crew will perform the second servicing of the orbiting Hubble Space Telescope (HST) during the 10-day STS-82 flight, whcih is targeted for a Feb. 11 liftoff.

    NASA Image and Video Library

    1997-01-17

    KENNEDY SPACE CENTER, FLA. - The rising sun and some scattered clouds provide a picturesque backdrop for the Space Shuttle Discovery as it travels along the crawlerway toward Launch Pad 39A in preparation for the STS-82 mission. The Shuttle is on a Mobile Launcher Platform, and the entire assemblage is being carried by a large, tracked vehicle called the crawler transporter. A seven-member crew will perform the second servicing of the orbiting Hubble Space Telescope (HST) during the 10-day STS-82 flight, whcih is targeted for a Feb. 11 liftoff.

  20. Optical tractor beam with chiral light

    NASA Astrophysics Data System (ADS)

    Fernandes, David E.; Silveirinha, Mário G.

    2015-06-01

    We suggest a novel mechanism to induce the motion of a chiral material body towards an optical source with no optical traps. Our solution is based on the interference between a chiral light beam and its reflection on an opaque mirror. Surprisingly, it is theoretically shown that the electromagnetic response of the material may be tailored in such a way that independent of the specific body location with respect to the mirror, it is always pulled upstream against the photon flow associated with the incoming wave. Moreover, it is proven that by controlling the handedness of the incoming light it may be possible to harness the sign of the optical force, switching from a pulling force to a pushing force.

  1. Optical Pulling Force and Tractor Beams

    NASA Astrophysics Data System (ADS)

    Paul, Nayan Kumar

    Light-matter interaction has been an interesting subject of intense analytical and experimental research since the formulation of Maxwell's electromagnetic wave theory. Optical forces exerted on particles excited by incident light waves have been studied for the last few decades. The interaction of light with materials gives rise to light scattering from the particle in the form of energy. The divergence of the Maxwell stress tensor provides a good approximation of the total optical forces on a particle. The divergence of the stress tensor is mathematically equal to the time average Lorentz force since [special characters omitted]. Others have claimed that the stress tensor is "fraught with danger," but it is a matter of application. The stress tensor approach is computationally simpler since application of the divergence theorem allows for a reduction of dimension in the integration. For example, you can either integrate the force density over the volume of an object (3-D), or integrate the divergence of the stress tensor on a surface (2-D) enclosing the volume. It gives a straightforward prediction of the total optical forces on a particle, but may be challenging in the case of multiple particles or for larger particles. The Rayleigh approximation estimates the radiation pressure on small particles in the propagation direction of light, but may be inappropriate for larger particles in comparison to the wavelength of the incident light waves. Light waves exert radiation pressure on a particle and pushes it away from the light source toward the direction of propagation. It is shown that plane waves propagating in a rectangular waveguide not only push a passive particle toward the propagation direction, but also pull it toward the light source. The particle remains trapped in the transverse direction of the rectangular waveguide. The Lorentz force and the Rayleigh approximation are applied to calculate the total force on the particle. The push-pull phenomenon depends on the frequency of the incident light wave. Optical pulling of a spherical Rayleigh particle along the surface of a dielectric slab waveguide is also shown. The particle is trapped in the transverse direction near the surface of the slab and can be pushed or pulled in the longitudinal direction along the surface of the slab. The pushing and pulling forces switch near the switching frequency of the slab. The manipulation of a small particle on the surface of a material due to the control of standing waves generated on the surface is presented. Evanescent waves pull the particle toward the surface of the material and the particle is trapped by the standing waves. Two mirrors are used and the adjustments of the mirrors allows precise and arbitrary manipulation of the trapped particle on the surface of the material. The magnitude of the pulling force on the particle depends on the angle of incident of light waves.

  2. Slash disposal and seedbed preparation by tractor

    Treesearch

    Donald T. Gordon

    1956-01-01

    Creating ground conditions favorable to regeneration immediately after the final harvest cutting is basic to forest management wherever advance growth is deficient. Ponderosa (Pinus ponderosa Laws) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.) seeds require bare mineral soil for satisfactory germination. Pine seedlings,...

  3. Linear tractor dry coal extrusion pump

    DOEpatents

    Sprouse, Kenneth M.; Matthews, David R.

    2011-10-18

    A pump for transporting particulate material includes an inlet, an outlet, a passageway, a first and second load beam, a first and second scraper seal, and a first and second drive assembly. The inlet introduces the particulate material into the passageway and the outlet expels the particulate material from the passageway. The passageway is defined by a first belt assembly and a second belt assembly that are opposed to each other. The first and second load beams are positioned within the first belt assembly and the second belt assembly, respectively. The first scraper seal and a second scraper seal are positioned proximate the passageway and the outlet. The first drive assembly is positioned within an interior section of the first belt assembly and drives the first belt assembly and the second drive assembly is positioned within an interior section of the second belt assembly and drives the second belt assembly.

  4. Linear tractor dry coal extrusion pump

    DOEpatents

    Sprouse, Kenneth M.; Matthews, David R.

    2008-06-17

    A pump for transporting particulate material includes an inlet, an outlet, a passageway, a first and second load beam, a first and second scraper seal, and a first and second drive assembly. The inlet introduces the particulate material into the passageway and the outlet expels the particulate material from the passageway. The passageway is defined by a first belt assembly and a second belt assembly that are opposed to each other. The first and second load beams are positioned within the first belt assembly and the second belt assembly, respectively. The first scraper seal and a second scraper seal are positioned proximate the passageway and the outlet. The first drive assembly is positioned within an interior section of the first belt assembly and drives the first belt assembly and the second drive assembly is positioned within an interior section of the second belt assembly and drives the second belt assembly.

  5. 29 CFR 1910.180 - Crawler locomotive and truck cranes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... (iv) The effectiveness of these preceding stability factors will be influenced by such additional factors as freely suspended loads, track, wind, or ground conditions, condition and inflation of rubber... diameter due to loss of core support, internal or external corrosion, or wear of outside wires. (ii)...

  6. 29 CFR 1910.180 - Crawler locomotive and truck cranes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... (iv) The effectiveness of these preceding stability factors will be influenced by such additional factors as freely suspended loads, track, wind, or ground conditions, condition and inflation of rubber... diameter due to loss of core support, internal or external corrosion, or wear of outside wires. (ii)...

  7. Tank 19F Folding Crawler Final Evaluation, Rev. 0

    SciTech Connect

    Nance, T.

    2000-10-25

    The Department of Energy (DOE) is committed to removing millions of gallons of high-level radioactive waste from 51 underground waste storage tanks at the Savannah River Site (SRS). The primary radioactive waste constituents are strontium, plutonium,and cesium. It is recognized that the continued storage of this waste is a risk to the public, workers, and the environment. SRS was the first site in the DOE complex to have emptied and operationally closed a high-level radioactive waste tank. The task of emptying and closing the rest of the tanks will be completed by FY28.

  8. Enhancing a Web Crawler with Arabic Search Capability

    DTIC Science & Technology

    2010-09-01

    contribution to the higher level of ambiguity is that sometimes vowels (diacritics) are omitted in written Arabic, which may change the meaning of the words...two parts: Normalization and Stemmer. The Normalization process is used to normalize the orthography—the writing system—of the queries and corpus... vowels ). (4). Remove non letters. (5). Replace آ (ALEF with MADDA above), أ (ALEF with HAMZA above), and إ (ALEF with HAZA below) with ا (ALEF

  9. A new twist on old ideas: How sitting reorients crawlers

    PubMed Central

    Soska, Kasey C.; Robinson, Scott R.; Adolph, Karen E.

    2014-01-01

    Traditionally, crawling and sitting are considered distinct motor behaviors with different postures and functions. Ten- to 12-month-old infants were observed in the laboratory or in their homes while being coaxed to crawl continuously over long, straight walkways (Study 1; N = 20) and during spontaneous crawling during free play (Study 2; N = 20). In every context, infants stopped crawling to sit 3-6 times per minute. Transitions from crawling to sitting frequently turned infants’ bodies away from the direction of heading; subsequent transitions back to crawling were offset by as much as 180° from the original direction of heading. Apparently, body reorientations result from the biomechanics of transitioning between crawling and sitting. Findings indicate that sustained, linear crawling is likely an epiphenomenon of how gait is studied in standard paradigms. Postural transitions between crawling and sitting are ubiquitous and can represent a functional unit of action. These transitions and the accompanying body reorientations likely have cascading effects for infants’ exploration, visual perception, and spatial cognition. PMID:25041056

  10. A new twist on old ideas: how sitting reorients crawlers.

    PubMed

    Soska, Kasey C; Robinson, Scott R; Adolph, Karen E

    2015-03-01

    Traditionally, crawling and sitting are considered distinct motor behaviors with different postures and functions. Ten- to 12-month-old infants were observed in the laboratory or in their homes while being coaxed to crawl continuously over long, straight walkways (Study 1; N = 20) and during spontaneous crawling during free play (Study 2; N = 20). In every context, infants stopped crawling to sit 3-6 times per minute. Transitions from crawling to sitting frequently turned infants' bodies away from the direction of heading; subsequent transitions back to crawling were offset by as much as 180° from the original direction of heading. Apparently, body reorientations result from the biomechanics of transitioning between crawling and sitting. Findings indicate that sustained, linear crawling is likely an epiphenomenon of how gait is studied in standard paradigms. Postural transitions between crawling and sitting are ubiquitous and can represent a functional unit of action. These transitions and the accompanying body reorientations likely have cascading effects for infants' exploration, visual perception, and spatial cognition.

  11. 29 CFR 1910.180 - Crawler locomotive and truck cranes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... function and usefulness of a machine. (6) Appointed means assigned specific responsibilities by the... machine in providing stability for lifting working loads. (21) Designated means selected or assigned by.... (23) Dynamic (loading) means loads introduced into the machine or its components by forces in...

  12. 29 CFR 1910.180 - Crawler locomotive and truck cranes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... function and usefulness of a machine. (6) Appointed means assigned specific responsibilities by the... machine in providing stability for lifting working loads. (21) Designated means selected or assigned by.... (23) Dynamic (loading) means loads introduced into the machine or its components by forces in...

  13. 29 CFR 1910.180 - Crawler locomotive and truck cranes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... base, which rest on supports at the outer ends. (32) Rail clamp means a tong-like metal device, mounted... consists of a rotating superstructure with power plant, operating machinery, and boom, mounted on a base..., mounted on a base or car equipped for travel on railroad track. It may be self-propelled or propelled by...

  14. Crawlers as Robotic Scanner Platform for Miniature NDT Instruments

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Y.

    1998-01-01

    The current use of aging aircraft significantly longer than their design life added a great degree of urgency to the ongoing need for low-cost, rapid, simple-to-operate, reliable and efficient NDE methods for detection and characterization of flaws.

  15. KSC-04PD-2134

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. A tractor-trailer arrives at the Crawler Transporter (CT) area with a new shipment of crawler shoes. The new shoes were manufactured by ME Global in Duluth, Minn. The CT transports the Mobile Launcher Platform, with the assembled Space Shuttle aboard, between the refurbishment area, the VAB and Launch Complex Pads 39A and 39B. The crawlers have 456 shoes, 57 per belt (8 belts in all). Each shoe weighs 2,200 pounds. The original shoes were manufactured for the Apollo Program. Cracks appeared in the shoes in recent years spurring a need for replacement. The new manufacturer, in Duluth, Minn., has improved the design for Return to Flight and use through the balance of the Space Shuttle Program.

  16. KSC-04PD-2135

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. A tractor-trailer arrives at the Crawler Transporter (CT) area with a new shipment of crawler shoes. In the background is the Vehicle Assembly Building. The new shoes were manufactured by ME Global in Duluth, Minn. The CT transports the Mobile Launcher Platform, with the assembled Space Shuttle aboard, between the refurbishment area, the VAB and Launch Complex Pads 39A and 39B. The crawlers have 456 shoes, 57 per belt (8 belts in all). Each shoe weighs 2,200 pounds. The original shoes were manufactured for the Apollo Program. Cracks appeared in the shoes in recent years spurring a need for replacement. The new manufacturer, in Duluth, Minn., has improved the design for Return to Flight and use through the balance of the Space Shuttle Program.

  17. KSC-2012-6200

    NASA Image and Video Library

    2012-11-06

    CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a tractor levels out the gravel after the six-million-pound crawler-transporter passed by on its way from the Vehicle Assembly Building to Launch Pad 39A. The test drive is designed to check out recently completed modifications to ensure the crawler-transporter's ability to carry launch vehicles such as the space agency's Space Launch System heavy-lift rocket to the pad. NASA's Ground Systems Development and Operations Program is leading the 20-year life-extension project for the crawler. A pair of behemoth machines called crawler-transporters has carried the load of taking rockets and spacecraft to the launch pad for more than 40 years at NASA’s Kennedy Space Center in Florida. Each the size of a baseball infield and powered by locomotive and large electrical power generator engines, the crawler-transporters will stand ready to keep up the work for the next generation of launch vehicles projects to lift astronauts into space. For more information, visit http://www.nasa.gov/exploration/systems/ground/index.html Photo credit: NASA/Ben Smegelsky

  18. Class 8 Tractor Trailer Platooning: Effects, Impacts, and Improvements

    SciTech Connect

    Lammert, Mike; Gonder, Jeff; Kelly, Kenneth; Salari, Kambiz; Ortega, Jason

    2016-07-19

    This poster provides information about NREL's evaluation of the fuel savings potential of semi-automated truck platooning. Platooning involves reducing aerodynamic drag by grouping vehicles together and decreasing the distance between them through the use of electronic coupling, which allows multiple vehicles to accelerate or brake simultaneously. The U.S. Department of Energy's interest in platooning stems from the opportunity to reduce petroleum consumption. This work addresses the need for data and analysis on what aspects of operation can impact platooning savings and what can be done to maximize the savings realized.

  19. A comparison of small tractors for thinning central hardwoods

    Treesearch

    N. Huyler; C.B. LeDoux

    1991-01-01

    Young-growth hardwood forests in the central hardwood region will require intensive management if they are to help meet the Nation's increasing demand for wood. Such management generally will require entries into the stands when the trees are small. Many small-scale machines are available for harvesting small wood. Time and motion studies were conducted on small-...

  20. Saving Space and Time: The Tractor That Einstein Built

    NASA Technical Reports Server (NTRS)

    2006-01-01

    In 1984, NASA initiated the Gravity Probe B (GP-B) program to test two unverified predictions of Albert Einstein s theory of general relativity, hypotheses about the ways space, time, light, and gravity relate to each other. To test these predictions, the Space Agency and researchers at Stanford University developed an experiment that would check, with extreme precision, tiny changes in the spin direction of four gyroscopes contained in an Earth satellite orbiting at a 400-mile altitude directly over the Earth s poles. When the program first began, the researchers assessed using Global Positioning System (GPS) technology to control the attitude of the GP-B spacecraft accurately. At that time, the best GPS receivers could only provide accuracy to nearly 1 meter, but the GP-B spacecraft required a system 100 times more accurate. To address this concern, researchers at Stanford designed high-performance, attitude-determining hardware that used GPS signals, perfecting a high-precision form of GPS called Carrier-Phase Differential GPS that could provide continuous real-time position, velocity, time, and attitude sensor information for all axes of a vehicle. The researchers came to the realization that controlling the GP-B spacecraft with this new system was essentially no different than controlling an airplane. Their thinking took a new direction: If this technology proved successful, the airlines and the Federal Aviation Administration (FAA) were ready commercial markets. They set out to test the new technology, the "Integrity Beacon Landing System," using it to automatically land a commercial Boeing 737 over 100 times successfully through Real-Time Kinematic (RTK) GPS technology. The thinking of the researchers shifted again, from automatically landing aircraft, to automating precision farming and construction equipment.

  1. GREEN TRACTORS AND HOUSES FROM SOYBEANS. (R829576)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  2. Erosion associated with cable and tractor logging in northwestern California

    Treesearch

    R. M. Rice; P. A. Datzman

    1981-01-01

    Abstract - Erosion and site conditions were measured at 102 logged plots in northwestern California. Erosion averaged 26.8 m 3 /ha. A log-normal distribution was a better fit to the data. The antilog of the mean of the logarithms of erosion was 3.2 m 3 /ha. The Coast District Erosion Hazard Rating was a poor predictor of erosion related to logging. In a new equation...

  3. TRACTOR REPAIR. AGRICULTURAL MACHINERY--SERVICE OCCUPATIONS, MODULE NUMBER 16.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    THE PURPOSE OF THIS GUIDE IS TO HELP TEACHERS PREPARE POSTSECONDARY STUDENTS FOR THE AGRICULTURAL MACHINERY SERVICE OCCUPATIONS AS PARTS MEN, MECHANICS, MECHANIC'S HELPERS, AND SERVICE SUPERVISORS. IT WAS DESIGNED BY A NATIONAL TASK FORCE ON THE BASIS OF RESEARCH FROM STATE STUDIES. THE MAJOR OBJECTIVE IS TO DEVELOP (1) AN UNDERSTANDING OF THE…

  4. USSR INDUSTRIAL DEVELOPMENT: SOVIET TRACTORS AND AGRICULTURAL MACHINERY NO. 57.

    DTIC Science & Technology

    by I. I. Trepenenkov The conditions and prospects of work on the development of mechanization means for harvest ing ensilage crops, by K. Klement’ev PPN-30 picker loader, by I. P. Shvetsov and A. V. Petrovskii

  5. GREEN TRACTORS AND HOUSES FROM SOYBEANS. (R829576)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  6. Improving Performance in Constructing specific Web Directory using Focused Crawler: An Experiment on Botany Domain

    NASA Astrophysics Data System (ADS)

    Khalilian, Madjid; Boroujeni, Farsad Zamani; Mustapha, Norwati

    Nowadays the growth of the web causes some difficulties to search and browse useful information especially in specific domains. However, some portion of the web remains largely underdeveloped, as shown in lack of high quality contents. An example is the botany specific web directory, in which lack of well-structured web directories have limited user's ability to browse required information. In this research we propose an improved framework for constructing a specific web directory. In this framework we use an anchor directory as a foundation for primary web directory. This web directory is completed by information which is gathered with automatic component and filtered by experts. We conduct an experiment for evaluating effectiveness, efficiency and satisfaction.

  7. Spiders and Worms and Crawlers, Oh My: Searching on the World Wide Web.

    ERIC Educational Resources Information Center

    Eagan, Ann; Bender, Laura

    Searching on the world wide web can be confusing. A myriad of search engines exist, often with little or no documentation, and many of these search engines work differently from the standard search engines people are accustomed to using. Intended for librarians, this paper defines search engines, directories, spiders, and robots, and covers basics…

  8. 78 FR 36572 - Certain Crawler Cranes and Components Thereof Notice of Receipt of Complaint; Solicitation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-18

    ... complainant in this investigation would affect the public health and welfare in the United States, competitive conditions in the United States economy, the production of like or directly competitive articles in the... United States; (ii) Identify any public health, safety, or welfare concerns in the United States...

  9. 78 FR 69448 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Crawler...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-19

    ... requirements. The Standard requires performance of a monthly inspection on cranes and running ropes and preparation of a certification record for each inspection. A rope that has been idle for a month or more must... Number. In addition, notwithstanding any other provisions of law, no person shall generally be subject...

  10. Countermine Operations in Very Shallow Water and Surf Zone: The Role of Bottom Crawlers

    DTIC Science & Technology

    2003-09-01

    Vehicle Fest (AUV Fest) in October 2001. In that event, the TAR robots were outfitted with acoustic modems, magneto-inductive receivers, metal detector , and...configurations used during UUV Fest 2001. Left: TAR with cameras, shape tracers, bumper, and Pulse Eddy Induction Coil (PEIC) metal detector . Right

  11. Connecting the Science User With Science Data and Services via the BCube Broker and Crawler

    NASA Astrophysics Data System (ADS)

    Khalsa, S. J. S.

    2015-12-01

    BCube, an NSF EarthCube Building Block project, aims to improve efficiency and productivity of geoscientists who work across disciplinary boundaries by facilitating discovery and access of geoscience data, linking major data facilities, and creating a new paradigm for data advertising and discovery. In this presentation we describe the achievements to date of the BCube brokering and web crawling efforts, addressing focus areas and outcomes in both cyberinfrastructure and geocsciences. We describe science scenarios illustrating the research in the ocean, climate, hydrology and polar domains that is being supported by the BCube Broker. By providing mediation between a diversity of standards and protocols the broker makes it possible for the geoscientists working in these demains to discover and access high-value datasets via a cloud-based interface. An Accessor Development Kit (ADK) enables the community to develop modules that extend the capabilities of the broker. In addition, we describe the web crawling and semantic technologies that are being applied to find new geoscience-relevant datasets and services on the web.

  12. Design and Experimental Validation of a Simple Controller for a Multi-Segment Magnetic Crawler Robot

    DTIC Science & Technology

    2015-04-01

    high-level, autonomous control computer . A low-level, embedded microcomputer handles the commands to the driving motors. This paper presents the...receives forward and turning velocity commands from either a tele-operator or high-level, autonomous control computer . A low-level, embedded...ACKNOWLEDGEMENT This project was supported by the SPAWAR Systems Center Pacific’s Naval Innovative Science and Engineering (NISE) program and the U.S

  13. Initial Production Test of Crane-Shovel, Crawler Mounted, 12-1/2-Ton, FSN 3810-926-1031.

    DTIC Science & Technology

    crane shovel could be adequately maintained at operator and organizational maintenance level with tools and manuals available. Two test items were operated a total of 935 test hours on typical crane-shovel missions.

  14. 75 FR 20005 - Crawler, Locomotive, and Truck Cranes Standard; Extension of the Office of Management and Budget...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-16

    ...) burden, conducts a pre- clearance consultation program to provide the public with an opportunity to... hard copy. All comments, attachments, and other material must identify the Agency name and the...

  15. Mapping wide row crops with video sequences acquired from a tractor moving at treatment speed.

    PubMed

    Sainz-Costa, Nadir; Ribeiro, Angela; Burgos-Artizzu, Xavier P; Guijarro, María; Pajares, Gonzalo

    2011-01-01

    This paper presents a mapping method for wide row crop fields. The resulting map shows the crop rows and weeds present in the inter-row spacing. Because field videos are acquired with a camera mounted on top of an agricultural vehicle, a method for image sequence stabilization was needed and consequently designed and developed. The proposed stabilization method uses the centers of some crop rows in the image sequence as features to be tracked, which compensates for the lateral movement (sway) of the camera and leaves the pitch unchanged. A region of interest is selected using the tracked features, and an inverse perspective technique transforms the selected region into a bird's-eye view that is centered on the image and that enables map generation. The algorithm developed has been tested on several video sequences of different fields recorded at different times and under different lighting conditions, with good initial results. Indeed, lateral displacements of up to 66% of the inter-row spacing were suppressed through the stabilization process, and crop rows in the resulting maps appear straight.

  16. Reducing Fuel Consumption through Semi-Automated Platooning with Class 8 Tractor Trailer Combinations (Poster)

    SciTech Connect

    Lammert, M.; Gonder, J.

    2014-07-01

    This poster describes the National Renewable Energy Laboratory's evaluation of the fuel savings potential of semi-automated truck platooning. Platooning involves reducing aerodynamic drag by grouping vehicles together and decreasing the distance between them through the use of electronic coupling, which allows multiple vehicles to accelerate or brake simultaneously. The NREL study addressed the need for data on American style line-haul sleeper cabs with modern aerodynamics and over a range of trucking speeds common in the United States.

  17. Three-dimensional analysis of optical forces generated by an active tractor beam using radial polarization.

    PubMed

    Carretero, Luis; Acebal, Pablo; Blaya, Salvador

    2014-02-10

    We theoretically study the three-dimensional behavior of nanoparticles in an active optical conveyor. To do this, we solved the Langevin equation when the forces are generated by a focusing system at the near field. Analytical expressions for the optical forces generated by the optical conveyor were obtained by solving the Richards and Wolf vectorial diffraction integrals in an approximated form when a mask of two annular pupils is illuminated by a radially polarized Hermite-Gauss beam. Trajectories, in both the transverse plane and the longitudinal direction, are analyzed showing that the behavior of the optical conveyor can be optimized by conveniently choosing the configuration of the mask of the two annular pupils (inner and outer radius of the two rings) in order to trap and transport all particles at the focal plane.

  18. A Study of Caterpillar Tractor Company’s Equipment Investment Analysis Method.

    DTIC Science & Technology

    1987-01-01

    costs, and financial management strategy are three areas that contribute to the actual cost of heavy equipment and they are areas that require...criticality, that they can be grouped within the four combined Effecting solid marketing strategy by knowing what the competition’s pricing is and...34own 50 ,𔃼 or more machines." This implies that firms with less than 50 machines do not employ investment analysis models for financial strategy . I

  19. Tractor-logging costs and production in old-growth redwood forests

    Treesearch

    Kenneth N. Boe

    1963-01-01

    A cost accounting analysis of full-scale logging operations in old-growth redwood during 2 years revealed that it cost $12.24 per M bd. ft. (gross Scribner log scale) to get logs on trucks. Road development costs averaged another $5.19 per M bd. ft. Felling-bucking production was calculated by average tree d.b.h. Both skidding and loading outputs per hour were...

  20. Multivariable feedback design to improve tracking performance on tractor vibration test rig

    NASA Astrophysics Data System (ADS)

    Vaes, D.; Engelen, K.; Anthonis, J.; Swevers, J.; Sas, P.

    2007-02-01

    The multivariable tracking accuracy on an automotive vibration test rig can be improved by extending the current industrial off-line iterative feedforward procedure with a real-time multiple-input-multiple-output (MIMO) feedback controller. This paper shows that for the considered 4×4 application, the two most common approaches, namely full MIMO identification and μ-synthesis on one hand and decentralised control on the other hand fail to design a robust MIMO controller with acceptable performance. Therefore, a control design based on static decoupling is applied. This is a combination of (1) a transformation of the inputs and the outputs to decouple the system, and (2) independent single-input-single-output (SISO) controllers designed for the diagonal elements of the transformed system, using standard SISO identification and H∞-techniques. To optimise the closed-loop performance, a new decoupling algorithm is developed. The new presented algorithm outperforms the existing decoupling algorithms, yielding satisfactory multivariable closed-loop performance.