Sample records for elevated guideways

  1. Multispan Elevated Guideway Design for Passenger Transport Vehicles : Volume 1. Text.

    DOT National Transportation Integrated Search

    1975-04-01

    Analysis techniques, a design procedure and design data are described for passenger vehicle, simply supported, single span and multiple span elevated guideway structures. Analyses and computer programs are developed to determine guideway deflections,...

  2. Elevated guideway cost-ride quality studies for group rapid transit systems

    DOT National Transportation Integrated Search

    1977-10-01

    A methodology is developed for relating cost to ride quality in elevated guideway : system design, based upon directly relating guideway structural properties and : construction tolerances to both cost and ride quality. It is illustrated in detail : ...

  3. Design and validation of a slender guideway for Maglev vehicle by simulation and experiment

    NASA Astrophysics Data System (ADS)

    Han, Jong-Boo; Han, Hyung-Suk; Kim, Sung-Soo; Yang, Seok-Jo; Kim, Ki-Jung

    2016-03-01

    Normally, Maglev (magnetic levitation) vehicles run on elevated guideways. The elevated guideway must satisfy various load conditions of the vehicle, and has to be designed to ensure ride quality, while ensuring that the levitation stability of the vehicle is not affected by the deflection of the guideway. However, because the elevated guideways of Maglev vehicles in South Korea and other countries fabricated so far have been based on over-conservative design criteria, the size of the structures has increased. Further, from the cost perspective, they are unfavourable when compared with other light rail transits such as monorail, rubber wheel, and steel wheel automatic guided transit. Therefore, a slender guideway that does have an adverse effect on the levitation stability of the vehicle is required through optimisation of design criteria. In this study, to predict the effect of various design parameters of the guideway on the dynamic behaviour of the vehicle, simulations were carried out using a dynamics model similar to the actual vehicle and guideway, and a limiting value of deflection ratio of the slender guideway to ensure levitation control is proposed. A guideway that meets the requirement as per the proposed limit for deflection ratio was designed and fabricated, and through a driving test of the vehicle, the validity of the slender guideway was verified. From the results, it was confirmed that although some increase in airgap and cabin acceleration was observed with the proposed slender guideway when compared with the conventional guideway, there was no notable adverse effect on the levitation stability and ride quality of the vehicle. Therefore, it can be inferred that the results of this study will become the basis for establishing design criteria for slender guideways of Maglev vehicles in future.

  4. Multispan Elevated Guideway Design for Passenger Transport Vehicles : Volume 2. Appendixes.

    DOT National Transportation Integrated Search

    1975-04-01

    Contents: Appendix A - derivation of vehicle-guideway interaction equations; Appendix B - evaluation of pier support dynamics; Appendix C - computer simulation program of two-dimensional vehicle over a multi-span guideway; Appendix D - computer progr...

  5. Coupled vibration analysis of Maglev vehicle-guideway while standing still or moving at low speeds

    NASA Astrophysics Data System (ADS)

    Kim, Ki-Jung; Han, Jong-Boo; Han, Hyung-Suk; Yang, Seok-Jo

    2015-04-01

    Dynamic instability, that is, resonance, may occur on an electromagnetic suspension-type Maglev that runs over the elevated guideway, particularly at very low speeds, due to the flexibility of the guideway. An analysis of the dynamic interaction between the vehicle and guideway is required at the design stage to investigate such instability, setting slender guideway in design direction for reducing construction costs. In addition, it is essential to design an effective control algorithm to solve the problem of instability. In this article, a more detailed model for the dynamic interaction of vehicle/guideway is proposed. The proposed model incorporates a 3D full vehicle model based on virtual prototyping, flexible guideway by a modal superposition method and levitation electromagnets including feedback controller into an integrated model. By applying the proposed model to an urban Maglev vehicle newly developed for commercial application, an analysis of the instability phenomenon and an investigation of air gap control performance are carried out through a simulation.

  6. Interactions between Magnetically Levitated Vehicles and Elevated Guideway Structures

    DOT National Transportation Integrated Search

    1992-07-01

    The dynamic performance characteristic of magnetically levitated vehicles and vehicle trains relating to ride quality and magnetic gap variations have been determined using computer simulation models for one-dimensional, two-dimensional and finite le...

  7. Design criteria for maglev structures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sandberg, H.R.; Williams, J.R.

    1997-05-01

    Maglev systems represent an entirely new concept in transportation. They will not operate on nor share the right-of-way with any other system. It is important, therefore, that the guideways be designed and constructed so as to be economical, constructable, durable, adaptable, reliable, and readily maintained. Comparisons should be made with the current transportation systems, especially highways and railroads. Since most of the guideway will be elevated, the comparison should be with the bridges. The object of the comparisons should be to avoid the shortcomings of the other systems while building on their strengths. This paper develops in some detail designmore » and construction criteria that will ensure a good, long-lived performance of the maglev guideway. The importance of beauty should have a low priority in comparison to the other design criteria. Clean, simple details meeting other criteria will ensure an acceptable appearance. These criteria were used in evaluating the four maglev concepts developed for the National Maglev Initiative.« less

  8. Upper internals arrangement for a pressurized water reactor

    DOEpatents

    Singleton, Norman R; Altman, David A; Yu, Ching; Rex, James A; Forsyth, David R

    2013-07-09

    In a pressurized water reactor with all of the in-core instrumentation gaining access to the core through the reactor head, each fuel assembly in which the instrumentation is introduced is aligned with an upper internals instrumentation guide-way. In the elevations above the upper internals upper support assembly, the instrumentation is protected and aligned by upper mounted instrumentation columns that are part of the instrumentation guide-way and extend from the upper support assembly towards the reactor head in hue with a corresponding head penetration. The upper mounted instrumentation columns are supported laterally at one end by an upper guide tube and at the other end by the upper support plate.

  9. Open tube guideway for high speed air cushioned vehicles

    NASA Technical Reports Server (NTRS)

    Goering, R. S. (Inventor)

    1974-01-01

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

  10. Vibration analysis of the maglev guideway with the moving load

    NASA Astrophysics Data System (ADS)

    Wang, H. P.; Li, J.; Zhang, K.

    2007-09-01

    The response of the guideway induced by moving maglev vehicle is investigated in this paper. The maglev vehicle is simplified as evenly distributed force acting on the guideway at constant speed. According to the experimental line, the guideway structure of rail-sleeper-bridge is simplified as Bernoulli-Euler (B-E) beam—evenly distributed spring—simply supported B-E beam structure; thus, double deck model of the maglev guideway is constructed which can more accurately reflect the dynamic characteristic of the experimental line. The natural frequency and mode are deduced based on the theoretical model. The relationship between structural parameters and natural frequency are exploited by employing the numerical calculation method. The way to suppress the vehicle-guideway interaction by regulating the structural parameter is also discussed here. Using the normal coordinate transformation method, the coupled differential equations of motion of the maglev guideway are converted into a set of uncoupled equations. The closed-form solutions for the response of the guideway subjecting the moving load are derived. It is noted that the moving load would not induce the vehicle-guideway interaction oscillation. The analysis of the guideway impact factor implies that at some position of the guideway, the deflection may decrease with the increase of the speed of the load; several extreme value of the guideway displacement will appear induced by different speeds, with different acting place, the speeds are different either. The final numerical simulation verifies these conclusions.

  11. Maglev guideway design issues

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Plotkin, D.; Kim, S.

    1997-05-01

    This paper reports results from guideway analyses conducted as part of the National Maglev Initiative (NMI), a government-industry effort from 1989 to 1994, formed to encourage the development of US maglev technology and to assess its potential application within the US transportation system. Covered here are some key guideway design issues that were common to the designs assessed for the NMI, and to maglev guideways in general. They represent aspects that will need additional attention in future efforts to produce structurally sound and economical maglev guideways. These recommendations come from the analyses conducted by a team from the US Armymore » Construction Engineering Research Laboratories, the Civil Engineering Department of the University of Illinois, and Alfred Benesch and Company. The recommendations focus on design philosophy and the development of general design criteria, guideway maintenance and the provision for future alignment adjustment in both the guideway and the magnets, foundation design, and the long-term performance of guideway materials and reinforcement. Generally, one of the main challenges to guideway designers is to produce a structure that will be easily maintainable to the narrow tolerances and precise alignment required for practical high-speed maglev operation.« less

  12. 49 CFR 38.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Automated guideway transit vehicles and systems... DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 38.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and...

  13. 49 CFR 38.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Automated guideway transit vehicles and systems... DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 38.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and...

  14. 49 CFR 38.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Automated guideway transit vehicles and systems... DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 38.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and...

  15. 49 CFR 38.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Automated guideway transit vehicles and systems... DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 38.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and...

  16. 49 CFR 38.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Automated guideway transit vehicles and systems... DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 38.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and...

  17. 36 CFR 1192.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and systems, sometimes called “people movers”, operated in... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Automated guideway transit...

  18. 36 CFR 1192.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and systems, sometimes called “people movers”, operated in... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Automated guideway transit...

  19. 36 CFR § 1192.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and systems, sometimes called “people movers”, operated in... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Automated guideway transit...

  20. 36 CFR 1192.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and systems, sometimes called “people movers”, operated in... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Automated guideway transit...

  1. 36 CFR 1192.173 - Automated guideway transit vehicles and systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.173 Automated guideway transit vehicles and systems. (a) Automated Guideway Transit (AGT) vehicles and systems, sometimes called “people movers”, operated in... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Automated guideway transit...

  2. Experiments and Identification of the Unbalance of Aerostatic Guideways on the Micro-Scale

    PubMed Central

    Chen, Dongju; Bian, Yanhua; Fan, Jinwei

    2014-01-01

    In order to diagnose the unbalance of aerostatic guideways, displacement and acceleration sensors were used to measure the vibration signals of the unbalance of the aerostatic guideways caused by the gas fluctuation. The frequency characteristics for the unbalance of aerostatic guideways caused by gas fluctuation has been extracted from the measured signals by power spectral density, and the basic frequencies of the guideway system have been diagnosed according to spectral characteristics, in agreement with the results calculated by the corresponding motion equations and the finite element method. PMID:24603638

  3. Dynamics and controls in maglev systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai, Y.; Chen, S.S.; Rote, D.M.

    1992-09-01

    The dynamic response of magnetically levitated (maglev) ground transportation systems has important consequences for safety and ride quality, guideway design, and system costs. Ride quality is determined by vehicle response and by environmental factors such as humidity and noise. The dynamic response of the vehicles is the key element in determining ride quality, and vehicle stability is an important safety-related element. To design a proper guideway that provides acceptable ride quality in the stable region, vehicle dynamics must be understood. Furthermore the trade-off between guideway smoothness and the levitation and control systems must be considered if maglev systems are tomore » be economically feasible. The link between the guideway and the other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. In this study, the role of dynamics and controls in maglev vehicle/guideway interactions is discussed, and the literature on modeling the dynamic interactions of vehicle/guideway and suspension controls for ground vehicles is reviewed. Particular emphasis is placed on modeling vehicle/guideway interactions and response characteristics of maglev systems for a multicar, multiload vehicle traveling on a single- or doublespan flexible guideway, including coupling effects of vehicle/guideway, comparison of concentrated and distributed loads, and ride comfort. Different control-law designs are introduced into vehicle suspensions when a simple two-degree-of-freedom vehicle model is applied. Active and semiactive control designs for primary and secondary suspensions do improve the response of vehicle and provide acceptable ride comfort. Finally, future research associated with dynamics and controls of vehicle/guideway systems is identified.« less

  4. Expansion joint for guideway for magnetic levitation transportation system

    DOEpatents

    Rossing, Thomas D.

    1993-01-01

    An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The sidewalls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging sidewalls so that the cuts have a substantially dove-tail shape.

  5. Expansion joint for guideway for magnetic levitation transportation system

    DOEpatents

    Rossing, T.D.

    1993-02-09

    An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The side walls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging side walls so that the cuts have a substantially dove-tail shape.

  6. Assessment of Operational Automated Guideway Systems - Airtrans (Phase II)

    DOT National Transportation Integrated Search

    1980-01-01

    This study, Phase II, completes the assessment of AIRTRANS, the automated guideway system located at the Dallas-Fort Worth Airport. The Phase I assessment report: "Assessment of Operational Automated Guideway Systems--AIRTRANS (Phase I)" (PB-261 339)...

  7. Preliminary design for a maglev development facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coffey, H.T.; He, J.L.; Chang, S.L.

    1992-04-01

    A preliminary design was made of a national user facility for evaluating magnetic-levitation (maglev) technologies in sizes intermediate between laboratory experiments and full-scale systems. A technical advisory committee was established and a conference was held to obtain advice on the potential requirements of operational systems and how the facility might best be configured to test these requirements. The effort included studies of multiple concepts for levitating, guiding, and propelling maglev vehicles, as well as the controls, communications, and data-acquisition and -reduction equipment that would be required in operating the facility. Preliminary designs for versatile, dual 2-MVA power supplies capable ofmore » powering attractive or repulsive systems were developed. Facility site requirements were identified. Test vehicles would be about 7.4 m (25 ft) long, would weigh form 3 to 7 metric tons, and would operate at speeds up to 67 m/s (150 mph) on a 3.3-km (2.05-mi) elevated guideway. The facility would utilize modular vehicles and guideways, permitting the substitution of levitation, propulsion, and guideway components of different designs and materials for evaluation. The vehicle would provide a test cell in which individual suspension or propulsion components or subsystems could be tested under realistic conditions. The system would allow economical evaluation of integrated systems under varying weather conditions and in realistic geometries.« less

  8. System Operations Studies for Automated Guideway Transit Systems : Discrete Event Simulation Model Programmer's Manual

    DOT National Transportation Integrated Search

    1982-07-01

    In order to examine specific automated guideway transit (AGT) developments and concepts, UMTA undertook a program of studies and technology investigations called Automated Guideway Transit Technology (AGTT) Program. The objectives of one segment of t...

  9. Systems Operations Studies for Automated Guideway Transit Systems : System Availability Model Programmer's Manual

    DOT National Transportation Integrated Search

    1981-07-01

    In order to examine specific automated guideway transit (AGT) developments and concepts, UMTA undertook a program of studies and technology investigations called Automated Guideway Transit Technology (AGTT) Program. The objectives of one segment of t...

  10. Dynamics, stability, and control of maglev systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai, Y.; Chen, S.S.; Rote, D.M.

    1993-06-01

    The dynamic response of maglev systems is important in several respects: Safety and ride quality, guideway design, and system costs. The dynamic response of vehicles is the key element in the determination of ride quality, and vehicle stability is one of the important elements relative to safety. To design a proper guideway that provides acceptable ride quality in the stable region, the vehicle dynamics must be understood. The trade-off between guideway smoothness and the levitation and control systems must be considered if maglev systems are to be economically feasible. This paper is a summary of our previous work on dynamics,more » stability and control of maglev systems. First of all, the importance of dynamics of vehicle/guideway of maglev systems is discussed. Emphasis is placed on the modeling vehicle/guideway interactions of maglev systems with a multicar, or multiload vehicle traversing on a single or double-span flexible guideway. Coupled effects of vehicle/guideway interactions in wide range of vehicle speeds with various vehicle and guideway parameters for maglev systems are investigated. Secondly, the alternative control designs of maglev vehicle suspension systems are investigated in this study to achieve safe, stable operation and acceptable ride comfort requires some form of vehicle motion control. Active and semi-active control law designs are introduced into primary and secondary suspensions of maglev vehicles. Finally, this paper discusses the stability of maglev systems based on experimental data, scoping calculations, and simple mathematical models. Divergence and flutter are obtained for coupled vibration of a three-degree-of-freedom maglev vehicle on a guideway consisting of double L-shaped aluminum segments. The theory and analysis developed in this study provides basic stability characteristics and identifies future research needs for maglev systems.« less

  11. Dynamics, stability, and control of maglev systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai, Y.; Chen, S.S.; Rote, D.M.

    1993-01-01

    The dynamic response of maglev systems is important in several respects: Safety and ride quality, guideway design, and system costs. The dynamic response of vehicles is the key element in the determination of ride quality, and vehicle stability is one of the important elements relative to safety. To design a proper guideway that provides acceptable ride quality in the stable region, the vehicle dynamics must be understood. The trade-off between guideway smoothness and the levitation and control systems must be considered if maglev systems are to be economically feasible. This paper is a summary of our previous work on dynamics,more » stability and control of maglev systems. First of all, the importance of dynamics of vehicle/guideway of maglev systems is discussed. Emphasis is placed on the modeling vehicle/guideway interactions of maglev systems with a multicar, or multiload vehicle traversing on a single or double-span flexible guideway. Coupled effects of vehicle/guideway interactions in wide range of vehicle speeds with various vehicle and guideway parameters for maglev systems are investigated. Secondly, the alternative control designs of maglev vehicle suspension systems are investigated in this study to achieve safe, stable operation and acceptable ride comfort requires some form of vehicle motion control. Active and semi-active control law designs are introduced into primary and secondary suspensions of maglev vehicles. Finally, this paper discusses the stability of maglev systems based on experimental data, scoping calculations, and simple mathematical models. Divergence and flutter are obtained for coupled vibration of a three-degree-of-freedom maglev vehicle on a guideway consisting of double L-shaped aluminum segments. The theory and analysis developed in this study provides basic stability characteristics and identifies future research needs for maglev systems.« less

  12. 49 CFR 611.105 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... public transportation and other high occupancy vehicles, or uses a fixed catenary system and a right of... rail, commuter rail, automated guideway transit, people movers, ferry boat service, and fixed-guideway facilities for buses (such as bus rapid transit) and other high occupancy vehicles. A new fixed guideway...

  13. 49 CFR 611.105 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... public transportation and other high occupancy vehicles, or uses a fixed catenary system and a right of... rail, commuter rail, automated guideway transit, people movers, ferry boat service, and fixed-guideway facilities for buses (such as bus rapid transit) and other high occupancy vehicles. A new fixed guideway...

  14. Vehicle/Guideway Interaction in Maglev Systems

    DTIC Science & Technology

    1992-03-01

    Technology Division Materials and Components in Maglev Systems Technology Division Materials and Components Technology Division byY. Cai, S. S. Chen, and D. M...Transportation Systems Reports (UC-330, Vehicle/Guideway Interaction in Maglev Systems by Y. Cai and S. S. Chen Materials and Components Technology Division D. M...Surface Irregularities ...................................... 32 4 Vehicle/Guideway Interaction in Transrapid Maglev System .................. 34 4.1

  15. Guideway structural design and power/propulsion/braking in relation to guideways. Volume 3: Appendix B: Maglev guideway structural design

    NASA Astrophysics Data System (ADS)

    Falkowski, K. M.; Key, F. S.; Kuznetsov, S. B.

    1993-01-01

    This final report summarizes work completed in the investigation of the power, propulsion, and braking systems for five different electrodynamic (EDS) Maglev configurations. System requirements and recommendations, including a cost analysis, are determined for each configuration. The analysis considers variations in vehicle length, acceleration'/deceleration criteria, airgap clearance, and maximum propulsion thrust. Five different guideway configurations have been considered, each of which is based on air-core magnets made from low-temperature superconductors (LTSC) - (NbTi, Nb3Sn) or the newer high-T(sub c) ceramic superconductors (HTSCs). The material requirements and cost of the guideway electrical components were studied as a function of the energy conversion efficiency, the stator block length, armature current density, stator temperature rise, and other parameters. The propulsion design focused on a dual-parallel, linear synchronous motor (LSM) with thrust modulation achieved by applying a variable frequency and voltage along the guideway. Critical design parameters were estimated using a three-dimensional computer model for the inductances, magnetic fields, and electromagnetic forces. The study also addressed the conceptual design of the magnet, cryostat, and refrigeration subsystems. Magnetic fields, forces, AC losses, superconductor stability, heat loading, and refrigeration demands were analyzed; a specific design shows limits of passive shielding.

  16. The concept of the mechanically active guideway as a novel approach to maglev

    NASA Technical Reports Server (NTRS)

    Horwath, T. G.

    1992-01-01

    A maglev system that is suitable for operation in the United States will have to meet unique requirements which determine the major systems characteristics. Maglev configurations presently developed in Germany and Japan are based on conventional maglev concepts and as such do not meet all of the requirements. A novel maglev guideway concept is introduced as a solution. This concept, the mechanically active guideway, is articulated in three degrees of freedom and assumes system functions which normally reside in the maglev vehicle. The mechanically active guideway contains spatially distributed actuators which are energized under computer control at the time of vehicle passage to achieve bank angle adjustment and ride quality control. A typical realization of the concept is outlined.

  17. 49 CFR 239.7 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... vehicles operating on rails or electromagnetic guideways which are expressly identified in a railroad's... or electromagnetic guideways, including— (i) Commuter or other short-haul rail passenger service in a...

  18. 49 CFR 239.7 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... vehicles operating on rails or electromagnetic guideways which are expressly identified in a railroad's... or electromagnetic guideways, including— (i) Commuter or other short-haul rail passenger service in a...

  19. 49 CFR 239.7 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... vehicles operating on rails or electromagnetic guideways which are expressly identified in a railroad's... or electromagnetic guideways, including— (i) Commuter or other short-haul rail passenger service in a...

  20. 49 CFR 239.7 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... vehicles operating on rails or electromagnetic guideways which are expressly identified in a railroad's... or electromagnetic guideways, including— (i) Commuter or other short-haul rail passenger service in a...

  1. Dynamic analysis of the American Maglev system. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Seda-Sanabria, Y.; Ray, J.C.

    1996-06-01

    Understanding the dynamic interaction between a magnetic levitated (Maglev) vehicle and its supporting guideway is essential in the evaluation of the performance of such a system. This interacting coupling, known as vehicle/guideway interaction (VGI), has a significant effect on system parameters such as the required magnetic suspension forces and gaps, vehicular ride quality, and guideway deflections and stresses. This report presents the VGI analyses conducted on an actual Maglev system concept definition (SCD), the American Maglev SCD, using a linear-elastic finite-element (FE) model. Particular interest was focused on the comparison of the ride quality of the vehicle, using two differentmore » suspension systems, and their effect on the guideway structure. The procedure and necessary assumptions in the modeling are discussed.« less

  2. General atomics low speed Maglev technology development program (Supplemental #3)

    DOT National Transportation Integrated Search

    2005-05-01

    This report details accomplishments of the Low Speed Maglev Technology Development Program, Supplemental #3. The 4 major tasks included: guideway foundation construction, fabrication and installation of 7 guideway modules, system integration and test...

  3. Automated Guideway Network Traffic Modeling

    DOT National Transportation Integrated Search

    1972-02-01

    In the literature concerning automated guideway transportation systems, such as dual mode, a great deal of effort has been expended on the use of deterministic reservation schemes and the problem of merging streams of vehicles. However, little attent...

  4. Automated Guideway Ground Transportation Network Simulation

    DOT National Transportation Integrated Search

    1975-08-01

    The report discusses some automated guideway management problems relating to ground transportation systems and provides an outline of the types of models and algorithms that could be used to develop simulation tools for evaluating system performance....

  5. Morgantown People Mover Phase II : Impact Assessment

    DOT National Transportation Integrated Search

    1984-02-01

    This report describes an assessment of the Morgantown People Mover (MPM) system, which is an automated guideway transit system extending over 5,300 meters (3.3 miles) of double lane guideway, connecting West Virginia University's downtown campus with...

  6. Predicting automated guideway transit system station security requirements

    DOT National Transportation Integrated Search

    1980-03-01

    This study addresses the issues of personal security on Automated Guideway Transit (AGT) Systems, as they might be deployed in typical urban residential and non-residential settings. Based upon a literature review, it outlines basic characteristics o...

  7. Braking System Integration in Dual Mode Systems

    DOT National Transportation Integrated Search

    1974-05-01

    An optimal braking system for Dual Mode is a complex product of vast number of multivariate, interdependent parameters that encompass on-guideway and off-guideway operation as well as normal and emergency braking. : Details of, and interralations amo...

  8. Maglev guideway cost and construction schedule assessment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Plotkin, D.; Kim, S.

    1997-05-01

    A summary of construction cost and scheduling information is presented for four maglev guideway designs on an example route from Baltimore, MD to Newark, NJ. This work results from the National Maglev Initiative (NMI), a government-industry effort from 1989 to 1994. The system design concepts used as a basis for developing cost and construction scheduling information, were submitted by four industry consortia solely for this analysis, and represent their own unpublished designs. The detailed cost and construction schedule analyses cover the main guideway only. A summary estimate was made for stations, power distribution systems, maintenance facilities, and other types ofmore » infrastructure. The results of the analyses indicate a number of design aspects which must receive further consideration by future designers. These aspects will affect the practical and economic construction and long-term maintenance of a high-speed maglev guideway.« less

  9. Valve assembly for internal combustion engine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wakeman, R.J.; Shea, S.F.

    1989-09-05

    This patent describes an improvement in a valve assembly for an internal combustion engine of the type including a valve having a valve stem, a valve guideway for mounting this valve for reciprocal strokes between opened and seated position, and spring means for biasing the valve into the seated position. The improvement comprising a valve spool of greater cross-sectional diameter as compared to the valve stem, and a valve spool guideway within which the valve spool is movable during the strokes of the valve, an upper surface of the valve spool and a portion of the spool guideway collectively establishingmore » a damper chamber which varies in volume during the valve strokes. a feed passage for introducing oil into the damper chamber, and a bleed passage for discharging oil from the damper chamber. The bleed passages each laterally opening into the valve spool guideway.« less

  10. 49 CFR 611.301 - Small Starts eligibility.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... extension to a fixed guideway, or a corridor-based bus rapid transit system, a project must: (1) Be a Small... extension to a fixed guideway, or a corridor-based bus rapid system, a project must: (1) Be a Small Starts...

  11. 49 CFR 611.301 - Small Starts eligibility.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... extension to a fixed guideway, or a corridor-based bus rapid transit system, a project must: (1) Be a Small... extension to a fixed guideway, or a corridor-based bus rapid system, a project must: (1) Be a Small Starts...

  12. Extended System Operations Studies for Automated Guideway Transit Systems

    DOT National Transportation Integrated Search

    1982-02-01

    The objectives of the System Operations Studies (SOS) of the Automated Guideway Transit Technology (AGTT) program was to develop models for the analysis of system operations, to evaluate AGT system performance and cost, and to establish guidelines fo...

  13. 49 CFR 268.1 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... TRANSPORTATION MAGNETIC LEVITATION TRANSPORTATION TECHNOLOGY DEPLOYMENT PROGRAM Overview § 268.1 Definitions. As..., including land, piers, guideways, propulsion equipment and other components attached to guideways, power... described in § 268.3. Maglev means transportation systems employing magnetic levitation that would be...

  14. Study to Establish Ride Comfort Criteria for High Speed Magnetically Levitated Transportation Systems

    DOT National Transportation Integrated Search

    1994-06-01

    Advanced high speed fixed guideway transportation systems such as magnetic levitation systems have speed, acceleration, : and banking capabilities which present new guideway design issues. This increased performance results in new concerns : for pass...

  15. Rail fixed guideway systems : state safety oversight : final rule

    DOT National Transportation Integrated Search

    1995-12-27

    As required by the Intermodal Surface Transportation Efficiency Act of 1991, the Federal Transit Administration (FTA) issues a rule requiring states to oversee the safety of rail fixed guideway systems not regulated by the Federal Railroad Administra...

  16. Simulation Models for the Electric Power Requirements in a Guideway Transit System

    DOT National Transportation Integrated Search

    1980-04-01

    This report describes a computer simulation model developed at the Transportation Systems Center to study the electrical power distribution characteristics of Automated Guideway Transit (AGT) systems. The objective of this simulation effort is to pro...

  17. Assessment of Operational Automated Guideway Systems - Airtrans (Phase I)

    DOT National Transportation Integrated Search

    1976-09-01

    This report presents the results of an evaluation study of AIRTRANS, a unique, automated guideway system located at the Dallas/Fort Worth Airport. AIRTRANS was designed to move passengers, employees, baggage, mail, trash and supplies. The newest and ...

  18. Systems Operation Studies for Automated Guideway Transit Systems : Summary Report

    DOT National Transportation Integrated Search

    1980-02-01

    In order to examine specific Automated Guideway Transit (AGT) developments and concepts and to build a better knowledge base for future decision-making, UMTA has undertaken a new program of studies and technology investigations called the Urban Mass ...

  19. Systems Operations Studies for Automated Guideway Transit Systems : Discrete Event Simulation Model User's Manual.

    DOT National Transportation Integrated Search

    1982-06-01

    In order to examine specific Automated Guideway Transit (AGT) developments and concepts, and to build a better knowledge base for future decision-making, the Urban Mass Transportation Administration (UMTA) undertook a new program of studies and techn...

  20. Cost Experience of Automated Guideway Transit Systems (Supplement IV)

    DOT National Transportation Integrated Search

    1982-12-01

    By the end of 1982, automated guideway transit (AGT) systems will have carried over 500 million passengers since their first commercial operation of the Tampa International Airport in 1971. To keep abreast of the domestic use of AGT systems in the U....

  1. Guidelines for the design and evaluation of human factors aspects of automated guideway transit systems

    DOT National Transportation Integrated Search

    1979-03-01

    This report is a summary of human factors considerations for the planning, : deSign, construction, and implementation of Automated Guideway Transit (AGT) Systems : including Downtown People Mover (DPM) systems. Design concepts such as passenger : saf...

  2. Systems Operation Studies for Automated Guideway Transit Systems : Representative Application Areas for AGT

    DOT National Transportation Integrated Search

    1980-11-01

    The purpose of the Application Area Definition task is to define the travel demands and guideway networks for a set of representative AGT system deployments. These demands and networks, when combined with detailed descriptions of the systems and thei...

  3. Guidelines for the design and evaluation of human factors aspects of automated guideway transit systems

    DOT National Transportation Integrated Search

    1979-03-01

    This document has been compiled to provide guidance in the planning, design, fabrication, and evaluation of human factors aspects of Automated Guideway Transit (AGT) Systems, including Downtown People Mover (DPM) systems. It is based on the present s...

  4. Safety of High Speed Magnetic Levitation Transportation Systems : Thermal Effects and Related Safety Issues of Typical Maglev Steel Guideways

    DOT National Transportation Integrated Search

    1994-09-01

    This report presents a theoretical analysis predicting the temperature distribution, thermal deflections, and thermal stresses that may occur in typical steel Maglev guideways under the proposed Orlando FL thermal environment. Transient, finite eleme...

  5. Engineering Safety- and Security-Related Requirements for Software-Intensive Systems

    DTIC Science & Technology

    2007-02-27

    the Zoo Loop Line to enter the inner Great Apes and Monkeys taxi station. Exiting the taxi when the doors open, they head down the elevator and...Carnegie Mellon University Example Overview Very Large New Zoo Zoo Automated Taxi System (ZATS) Example Zoo Habitat Guideway Layout ZATS Context Diagram...Firesmith, 27 February 2007 © 2007 Carnegie Mellon University Very Large New Zoo P a rk in g L o ts Z o o B a c k L o ts R e s ta u ra n ts a n d S h o

  6. Systems Operations Studies for Automated Guideway Transit Systems : Quantitative Analysis of Alternative AGT Operational Control Strategies

    DOT National Transportation Integrated Search

    1981-10-01

    The objectives of the Systems Operation Studies (SOS) for automated guideway transit (AGT) systems are to develop models for the analysis of system operations, to evaluate performance and cost, and to establish guidelines for the design and operation...

  7. The influence of inhomogeneous magnetic field over a NdFeB guideway on levitation force of the HTS bulk maglev system

    NASA Astrophysics Data System (ADS)

    Zhao, Lifeng; Deng, Jiangtao; Li, Linbo; Feng, Ning; Wei, Pu; Lei, Wei; Jiang, Jing; Wang, Xiqin; Zhang, Yong; Zhao, Yong

    2018-04-01

    Dynamic responses of high temperature superconducting bulk to inhomogeneous magnetic field distribution of permanent magnet guideway, as well as enlarged amplitude of magnetic field obtained by partially covering the permanent magnet guideway (PMG) with iron sheets in different thickness, are investigated. Experiments show that the instantaneous levitation force increases with the increase of the variation rate of magnetic field (dB/dt). Meanwhile, inhomogeneous magnetic field from PMG causes the decay of levitation force. The decay of levitation force almost increases linearly with the increase of alternating magnetic field amplitude. It should be very important for the application of high-speed maglev system.

  8. Automated guideway transit : an assessment of PRT and other new systems, including supporting panel reports : prepared at the request of the Senate Committee on Appropriations, Transportation Subcommittee

    DOT National Transportation Integrated Search

    1975-06-01

    This assessment of Personal Rapid Transit and other forms of Automated Guideway : Transportation has been prepared in response to a request from Congress. The : scope of this assessment complements two other studies conducted by the Office : of Techn...

  9. High speed maglev design

    DOEpatents

    Rote, Donald M.; He, Jianliang; Coffey, Howard

    1993-01-01

    A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes dividing the superconducting magnets into two types: a strong field magnet which is located vertically below the vehicle for propulsion and guidance and a weak field superconducting magnet located at the ends of the vehicle for levitation and added guidance. Several proposed embodiments exist for the placement of the magnetic field shielding: locating the shielding on the vehicle, locating the shielding on the guideway, and locating the shielding on the guideway and adding shielding to the vertical undercarriage. In addition, the separation between the vehicle and the guideway can be controlled to reduce the exposure of the passenger cabin to magnetic fields.

  10. High speed maglev design

    DOEpatents

    Rote, D.M.; Jianliang He; Coffey, H.

    1993-10-19

    A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes dividing the superconducting magnets into two types: a strong field magnet which is located vertically below the vehicle for propulsion and guidance and a weak field superconducting magnet located at the ends of the vehicle for levitation and added guidance. Several proposed embodiments exist for the placement of the magnetic field shielding: locating the shielding on the vehicle, locating the shielding on the guideway, and locating the shielding on the guideway and adding shielding to the vertical undercarriage. In addition, the separation between the vehicle and the guideway can be controlled to reduce the exposure of the passenger cabin to magnetic fields. 4 figures.

  11. Computation of magnetic suspension of maglev systems using dynamic circuit theory

    NASA Technical Reports Server (NTRS)

    He, J. L.; Rote, D. M.; Coffey, H. T.

    1992-01-01

    Dynamic circuit theory is applied to several magnetic suspensions associated with maglev systems. These suspension systems are the loop-shaped coil guideway, the figure-eight-shaped null-flux coil guideway, and the continuous sheet guideway. Mathematical models, which can be used for the development of computer codes, are provided for each of these suspension systems. The differences and similarities of the models in using dynamic circuit theory are discussed in the paper. The paper emphasizes the transient and dynamic analysis and computer simulation of maglev systems. In general, the method discussed here can be applied to many electrodynamic suspension system design concepts. It is also suited for the computation of the performance of maglev propulsion systems. Numerical examples are presented in the paper.

  12. Improved high speed maglev design

    DOEpatents

    Rote, D.M.; He, Jianliang; Coffey, H.T.

    1992-01-01

    This report discusses a propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes dividing the superconducting magnets into two types: a strong field magnet which is located vertically below the vehicle for propulsion and guidance and a weak field superconducting magnet located at the ends of the vehicle for levitation and added guidance. Several proposed embodiments exist for the placement of the magnetic field shielding: locating the shielding on the vehicle, locating the shielding on the guideway, and locating the shielding on the guideway and adding shielding to the vertical undercarriage. In addition, the separation between the be vehicle and the guideway can be controlled to reduce the exposure of the passenger cabin to magnetic fields.

  13. Aerodynamic vibrations of a maglev vehicle running on flexible guideways under oncoming wind actions

    NASA Astrophysics Data System (ADS)

    Yau, J. D.

    2010-05-01

    This paper intends to present a computational framework of aerodynamic analysis for a maglev (magnetically levitated) vehicle traveling over flexible guideways under oncoming wind loads. The guideway unit is simulated as a series of simple beams with identical span and the maglev vehicle as a rigid car body supported by levitation forces. To carry out the interaction dynamics of maglev vehicle/guideway system, this study adopts an onboard PID (proportional-integral-derivative) controller based on Ziegler-Nicholas (Z-N) method to control the levitation forces. Interaction of wind with high-speed train is a complicated situation arising from unsteady airflow around the train. In this study, the oncoming wind loads acting on the running maglev vehicle are generated in temporal/spatial domain using digital simulation techniques that can account for the moving effect of vehicle's speed and the spatial correlation of stochastic airflow velocity field. Considering the motion-dependent nature of levitation forces and the non-conservative characteristics of turbulent airflows, an iterative approach is used to compute the interaction response of the maglev vehicle/guideway coupling system under wind actions. For the purpose of numerical simulation, this paper employs Galerkin's method to convert the governing equations containing a maglev vehicle into a set of differential equations in generalized systems, and then solve the two sets of differential equations using an iterative approach with the Newmark method. From the present investigation, the aerodynamic forces may result in a significant amplification on acceleration amplitude of the running maglev vehicle at higher speeds. For this problem, a PID+LQR (linear quadratic regulator) controller is proposed to reduce the vehicle's acceleration response for the ride comfort of passengers.

  14. Anti-terrorist vehicle crash impact energy absorbing barrier

    DOEpatents

    Swahlan, David J.

    1989-01-01

    An anti-terrorist vehicle crash barrier includes side support structures, crushable energy absorbing aluminum honeycomb modules, and an elongated impact-resistant beam extending between, and at its opposite ends through vertical guideways defined by, the side support structures. An actuating mechanism supports the beam at its opposite ends for movement between a lowered barrier-withdrawn position in which a traffic-supporting side of the beam is aligned with a traffic-bearing surface permitting vehicular traffic between the side support structures and over the beam, and a raised barrier-imposed position in which the beam is aligned with horizontal guideways defined in the side support structures above the traffic-bearing surface, providing an obstruction to vehicular traffic between the side support structures. The beam is movable rearwardly in the horizontal guideways with its opposite ends disposed transversely therethrough upon being impacted at its forward side by an incoming vehicle. The crushable modules are replaceably disposed in the horizontal guideways between aft ends thereof and the beam. The beam, replaceable modules, side support structures and actuating mechanism are separate and detached from one another such that the beam and replaceable modules are capable of coacting to disable and stop an incoming vehicle without causing structural damage to the side support structures and actuating mechanism.

  15. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOEpatents

    Coffey, H.T.

    1993-10-19

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.

  16. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOEpatents

    Coffey, Howard T.

    1993-01-01

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

  17. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Levien, Mary

    The Freight Shuttle System (FSS) is designed to provide freight transportation services between those short and intermediate distance locations (within 600 miles) that are currently handling large volumes of freight traffic. Much like trucks, the FSS's transporters are autonomous: each transporter has its own propulsion and travels independently of other transporters. Inspired by railroads, each FSS transporter has steel wheels operating on a steel running surface and can carry either a standardsize freight container or an over-the-road truck trailer. However, unlike either rail or trucks, the FSS runs on an elevated, dedicated guideway to avoid the interference of other transportationmore » systems. The objective of this report is to examine the potential viability for an alternative transportation system for trailers and containers in a multi-national, cross-border setting. The El Paso-Ciudad Juarez region serves as the environment of this analysis.« less

  18. Vibrational Properties of High- Superconductors Levitated Above a Bipolar Permanent Magnetic Guideway

    NASA Astrophysics Data System (ADS)

    Liu, Lu; Wang, Jiasu

    2014-05-01

    A bipolar permanent magnetic guideway (PMG) has a unique magnetic field distribution profile which may introduce a better levitation performance and stability to the high- superconducting (HTS) maglev system. The dynamic vibration properties of multiple YBCO bulks arranged into different arrays positioned above a bipolar PMG and free to levitate were investigated. The acceleration and resonance frequencies were experimentally measured, and the stiffness and damping coefficients were evaluated for dynamic stability. Results indicate that the levitation stiffness is closely related to the field-cooling-height and sample positioning. The damping ratio was found to be low and nonlinear for the Halbach bipolar HTS-PMG system.

  19. Control of maglev vehicles with aerodynamic and guideway disturbances

    NASA Technical Reports Server (NTRS)

    Flueckiger, Karl; Mark, Steve; Caswell, Ruth; Mccallum, Duncan

    1994-01-01

    A modeling, analysis, and control design methodology is presented for maglev vehicle ride quality performance improvement as measured by the Pepler Index. Ride quality enhancement is considered through active control of secondary suspension elements and active aerodynamic surfaces mounted on the train. To analyze and quantify the benefits of active control, the authors have developed a five degree-of-freedom lumped parameter model suitable for describing a large class of maglev vehicles, including both channel and box-beam guideway configurations. Elements of this modeling capability have been recently employed in studies sponsored by the U.S. Department of Transportation (DOT). A perturbation analysis about an operating point, defined by vehicle and average crosswind velocities, yields a suitable linearized state space model for multivariable control system analysis and synthesis. Neglecting passenger compartment noise, the ride quality as quantified by the Pepler Index is readily computed from the system states. A statistical analysis is performed by modeling the crosswind disturbances and guideway variations as filtered white noise, whereby the Pepler Index is established in closed form through the solution to a matrix Lyapunov equation. Data is presented which indicates the anticipated ride quality achieved through various closed-loop control arrangements.

  20. The first man-loading high temperature superconducting Maglev test vehicle in the world

    NASA Astrophysics Data System (ADS)

    Wang, Jiasu; Wang, Suyu; Zeng, Youwen; Huang, Haiyu; Luo, Fang; Xu, Zhipei; Tang, Qixue; Lin, Guobin; Zhang, Cuifang; Ren, Zhongyou; Zhao, Guomin; Zhu, Degui; Wang, Shaohua; Jiang, He; Zhu, Min; Deng, Changyan; Hu, Pengfei; Li, Chaoyong; Liu, Fang; Lian, Jisan; Wang, Xiaorong; Wang, Lianghui; Shen, Xuming; Dong, Xiaogang

    2002-10-01

    The first man-loading high temperature superconducting Maglev test vehicle in the world is reported. This vehicle was first tested successfully on December 31, 2000 in the Applied Superconductivity Laboratory, Southwest Jiaotong University, China. Heretofore over 17,000 passengers took the vehicle, and it operates very well from beginning to now. The function of suspension is separated from one of propulsion. The high temperature superconducting Maglev provides inherent stable forces both in the levitation and in the guidance direction. The vehicle is 3.5 m long, 1.2 m wide, and 0.8 m high. When five people stand on vehicle and the total weight is 530 kg, the net levitation gap is more than 20 mm. The whole vehicle system includes three parts, vehicle body, guideway and controlling system. The high temperature superconducting Maglev equipment on board is the most important for the system. The onboard superconductors are melt-textured YBaCuO bulks. The superconductors are fixed on the bottom of liquid nitrogen vessels and cooled by liquid nitrogen. The guideway consists of two parallel permanent magnetic tracks, whose surface concentrating magnetic field is up to 1.2 T. The guideway is 15.5 m long.

  1. Workshop on technology issues of superconducting Maglev transportation systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wegrzyn, J.E.; Shaw, D.T.

    1991-09-27

    There exists a critical need in the United States to improve its ground transportation system. One suggested system that offers many advantages over the current transportation infrastructure is Maglev. Maglev represents the latest evolution in very high and speed ground transportation, where vehicles are magnetically levitated, guided, and propelled over elevated guideways at speeds of 300 miles per hour. Maglev is not a new concept but is, however, receiving renewed interest. The objective of this workshop was to further promote these interest by bringing together a small group of specialists in Maglev technology to discuss Maglev research needs and tomore » identify key research issues to the development of a successful Maglev system. The workshop was organized into four sessions based on the following technical areas: Materials, Testing, and Shielding; Magnet Design and Cryogenic Systems; Propulsion and Levitation Systems; and, System Control and Integration.« less

  2. The AMT maglev test sled -- EML weapons technology transition to transportation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schaaf, J.C. Jr.; Zowarka, R.C. Jr.; Davey, K.

    1997-01-01

    Technology spinoffs from prior electromagnetic launcher work enhance a magnetic levitation transportation system test bed being developed by American Maglev Technology of Florida. This project uses a series wound linear DC motor and brushes to simplify the magnetic levitation propulsion system. It takes advantage of previous related work in electromagnetic launcher technology to achieve success with this innovative design. Technology and knowledge gained from developments for homopolar generators and proposed railgun arc control are key to successful performance. This contribution supports a cost effective design that is competitive with alternative concepts. Brushes transfer power from the guideway (rail) to themore » vehicle (armature) in a novel design that activates the guideway only under the vehicle, reducing power losses and guideway construction costs. The vehicle carries no power for propulsion and levitation, and acts only as a conduit for the power through the high speed brushes. Brush selection and performance is based on previous EML homopolar generator research. A counterpulse circuit, first introduced in an early EML conference, is used to suppress arcing on the trailing brush and to transfer inductive energy to the next propulsion coil. Isolated static lift and preliminary propulsion tests have been completed, and integrated propulsion and lift tests are scheduled in early 1996.« less

  3. A Concept for the Use and Integration of Super-Conducting Magnets in Structural Systems in General and Maglev Guideway Mega-Structures in Particular

    NASA Technical Reports Server (NTRS)

    Ussery, Wilfred T.; MacCalla, Eric; MacCalla, Johnetta; Elnimeiri, Mahjoub; Goldsmith, Myron; Polk, Sharon Madison; Jenkins, Mozella; Bragg, Robert H.

    1996-01-01

    Recent breakthroughs in several different fields now make it possible to incorporate the use of superconducting magnets in structures in ways which enhance the performance of structural members or components of structural systems in general and Maglev guideway mega-structures in particular. The building of structural systems which connect appropriately scaled superconducting magnets with the post-tensioned tensile components of beams, girders, or columns would, if coupled with 'state of the art' structure monitoring, feedback and control systems, and advanced computer software, constitute a distinct new generation of structures that would possess the unique characteristic of being heuristic and demand or live-load responsive. The holistic integration of powerful superconducting magnets in structures so that they do actual structural work, creates a class of 'technologically endowed' structures that, in part - literally substitute superconductive electric power and magnetism for concrete and steel. The research and development engineering, and architectural design issues associated with such 'technologically endowed' structural system can now be conceptualized, designed, computer simulates built and tested. The Maglev guideway mega-structure delineated herein incorporates these concepts, and is designed for operation in the median strip of U.S. Interstate Highway 5 from San Diego to Seattle an Vancouver, and possibly on to Fairbanks, Alaska. This system also fits in the median strip of U.S. Interstate Highway 55 and 95 North-South, and 80 and 10, East-West. As a Western Region 'Peace Dividend' project, it could become a National or Bi-National research, design and build, super turnkey project that would create thousands of jobs by applying superconducting, material science, electronic aerospace and other defense industry technologies to a multi-vehicle, multi-use Maglev guideway megastructure that integrates urban mass transit Lower Speed (0-100 mph), High Speed (100-200 mph), Super Speed (200-400 mph), and Hypersonic evacuated tube (400-10,000 mph) Maglev systems.

  4. Study on figure-eight-shaped coil electrodynamic suspension magnetic levitation systems without cross-connection

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ribani, P.L.; Urbano, N.

    2000-01-01

    Two figure-eight-shaped coils for electrodynamic suspension (EDS) magnetic levitation (MAGLEV) systems without cross-connection are proposed and analyzed. The guideway coils are positioned under the MAGLEV vehicle; they are parallel to the horizontal plane. The interaction of a magnetic module on the vehicle, composed of three or four superconducting (SC) coils, with a guideway module, comprised of two figure-eight coils, is studied by means of the dynamic circuit theory. The currents in the SC coils are supposed to be constant in time while they move as a rigid body, with a constant velocity. Some results are presented and compared with thosemore » for a standard side-wall cross-connected system.« less

  5. Influence of movement direction on levitation performance and energy dissipation in a superconducting maglev system

    NASA Astrophysics Data System (ADS)

    Huang, Chen-Guang; Yong, Hua-Dong; Zhou, You-He

    2017-11-01

    During the regular operation of a maglev system, the superconducting levitation body may move away from the working position due to the external disturbance and the curved part of the guideway. Based on the A - V formulation of magnetoquasistatic Maxwell's equations, in this paper, a two-dimensional numerical model is applied to study the influence of movement direction on a typical maglev system consisting of an infinitely long high-temperature superconductor and a guideway of two infinitely long parallel permanent magnets with opposite horizontal magnetization. After the highly nonlinear current-voltage characteristic of the superconductor is taken into account, the levitation performance change and the energy dissipation induced by the relative movement of the superconductor and the guideway are discussed. The results show that the levitation force, guidance force and power loss are strongly dependent on the movement direction and speed of the superconductor when it moves away from the working position. If the superconductor moves periodically through the working position, these three physical quantities will change periodically with time. Interestingly, the power loss drastically increases during the first cycle, and after the first cycle it starts to decrease and finally tends to a dynamic steady state. Moreover, an increase in the tilt angle of movement direction will improve the maximum levitation force and, simultaneously, enhance the energy dissipation of the maglev system.

  6. Ride quality criteria and the design process. [standards for ride comfort

    NASA Technical Reports Server (NTRS)

    Ravera, R. J.

    1975-01-01

    Conceptual designs for advanced ground transportation systems often hinge on obtaining acceptable vehicle ride quality while attempting to keep the total guideway cost (initial and subsequent maintenance) as low as possible. Two ride quality standards used extensively in work sponsored by the U.S. Department of Transportation (DOT) are the DOT-Urban Tracked Air Cushion Vehicle (UTACV) standard and the International Standards Organization (ISO) reduced ride comfort criteria. These standards are reviewed and some of the deficiencies, which become apparent when trying to apply them in practice, are noted. Through the use of a digital simulation, the impact of each of these standards on an example design process is examined. It is shown that meeting the ISO specification for the particular vehicle/guideway case investigated is easier than meeting the UTACV standard.

  7. Automated Guideway Transit Service Availability Workshop

    DOT National Transportation Integrated Search

    1978-02-01

    The workshop consisted of four panel sessions: Service Availability Definitions; Operator Experience in Operational Systems; Theoretical Aspects of AGT Service Availability; and User-Manufacturer Relationships. The workshop presented a wide spectrum ...

  8. 49 CFR 659.13 - Overview.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State Oversight Agency § 659.13... oversight agency must oversee the execution of these practices and procedures, to ensure compliance with the...

  9. 23 CFR 771.115 - Classes of actions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... rail, light rail, commuter rail, automated guideway transit). (4) New construction or extension of a separate roadway for buses or high occupancy vehicles not located within an existing highway facility. (b...

  10. 23 CFR 771.115 - Classes of actions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... rail, light rail, commuter rail, automated guideway transit). (4) New construction or extension of a separate roadway for buses or high occupancy vehicles not located within an existing highway facility. (b...

  11. 23 CFR 771.115 - Classes of actions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... rail, light rail, commuter rail, automated guideway transit). (4) New construction or extension of a separate roadway for buses or high occupancy vehicles not located within an existing highway facility. (b...

  12. 49 CFR 611.3 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... TRANSPORTATION MAJOR CAPITAL INVESTMENT PROJECTS § 611.3 Applicability. (a) This part applies to all proposals for Federal capital investment funds under 49 U.S.C. 5309 for new transit fixed guideway systems and...

  13. Automated Guideway Transit System Passenger Security Guidebook

    DOT National Transportation Integrated Search

    1980-03-01

    This uidebook provides AGT system planners, designers and operators with information on available crime countermeasures and their relative effectiveness against transit crime. : Crime countermeasures on current transit systems have been reviewed and ...

  14. 49 CFR 659.7 - Withholding of funds for noncompliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the... withheld formula funds, if compliance is achieved within two years (See 49 U.S.C. 5330). ...

  15. 49 CFR 611.3 - Applicability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... TRANSPORTATION MAJOR CAPITAL INVESTMENT PROJECTS § 611.3 Applicability. (a) This part applies to all proposals for Federal capital investment funds under 49 U.S.C. 5309 for new transit fixed guideway systems and...

  16. 49 CFR 37.3 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., and work. (3) The phrase has a record of such an impairment means has a history of, or has been... guideway, or other advanced technology vehicles, designed to travel at speeds in excess of those possible...

  17. Communication Systems for Dual Mode Transportation

    DOT National Transportation Integrated Search

    1974-02-01

    A program is underway to develop and demonstrate transportation systems based on vehicles which are capable of automatic operation on special guideways and manual operation on conventional roads. Adequate and reliable communications to and from vehic...

  18. Assessment of Operational Automated Guideway Systems - Jetrail

    DOT National Transportation Integrated Search

    1977-12-01

    The report is an assessment and evaluation of the Braniff International Airlines Jetrail system located at Love Field in Dallas, Texas, the first operational completely automated, demand-responsive, group rapid, intra-airport transportation system. I...

  19. Morgantown People Mover Collision Avoidance System Design Summary

    DOT National Transportation Integrated Search

    1980-09-01

    The Morgantown People Mover (MPM) is an automated two-mode (schedule and demand) transit system that consists of a fleet of electrically powered, rubber-tired, passenger-carrying vehicles operating on a dedicated guideway under computer control. The ...

  20. Evacuation and rescue in automated guideway transit. Volume 2 : guidebook

    DOT National Transportation Integrated Search

    1979-12-01

    Evacuation and rescue are significant problems in all transportation systems. : Serious injuries and loss of life can result from situations in which inadequate : means of evacuating and rescuing passengers exist. In conventional transporlation : sys...

  1. Evacuation and Rescue in Automated Guideway Transit : Volume 2. Guidebook.

    DOT National Transportation Integrated Search

    1979-12-01

    Evacuation and rescue are significant problems in all transportation systems. Serious injuries and loss of life can result from situations in which inadequate means of evacuating and rescuing passengers exist. In conventional transporlation systems, ...

  2. Development/Deployment Investigation of Cabintaxi/Cabinlift Systems

    DOT National Transportation Integrated Search

    1977-12-01

    This report presents the results of an investigation of the Cabintaxi/Cabinlift automated guideway transit (AGT) systems under development in the Federal Republic of Germany. These systems have not been conceived and designed for a particular transpo...

  3. Static characteristics design of hydrostatic guide-ways based on fluid-structure interactions

    NASA Astrophysics Data System (ADS)

    Lin, Shuo; Yin, YueHong

    2016-10-01

    With the raising requirements in micro optical systems, the available machines become hard to achieve the process dynamic and accuracy in all aspects. This makes compact design based on fluid/structure interactions (FSI) important. However, there is a difficulty in studying FSI with oil film as fluid domain. This paper aims at static characteristic design of a hydrostatic guide-way with capillary restrictors based on FSI. The pressure distribution of the oil film land is calculated by solving the Reynolds-equation with Galerkin technique. The deformation of structure is calculated by commercial FEM software, MSC. Nastran. A matlab program is designed to realize the coupling progress by modifying the load boundary in the submitting file and reading the deformation result. It's obvious that the stiffness of the hydrostatic bearing decreases with the weakening of the bearing structure. This program is proposed to make more precise prediction of bearing stiffness.

  4. Comprehensive comparison of the levitation performance of bulk YBaCuO arrays above two different types of magnetic guideways

    NASA Astrophysics Data System (ADS)

    Deng, Zigang; Qian, Nan; Che, Tong; Jin, Liwei; Si, Shuaishuai; Zhang, Ya; Zheng, Jun

    2016-12-01

    The permanent magnet guideway (PMG) is an important part of high temperature superconducting (HTS) maglev systems. So far, two types of PMG, the normal PMG and Halbach-type PMG, are widely applied in present maglev transportation systems. In this paper, the levitation performance of high temperature superconductor bulks above the two PMGs was synthetically compared. Both static levitation performance and dynamic response characteristics were investigated. Benefiting from the reasonable magnetic field distribution, the Halbach-type PMG is able to gain larger levitation force, greater levitation force decay during the same relaxation time, bigger resonance frequency and dynamic stiffness for the bulk superconductor levitation unit compared with the normal PMG. Another finding is that the Halbach-type PMG is not sensitive to the levitation performance of the bulk levitation unit with different arrays. These results are helpful for the practical application of HTS maglev systems.

  5. Relationship of the Levitation Force Between Single and Multiple YBCO Bulks Above a Permanent Magnet Guideway Operating Dive-Lift Movement with Different Angles

    NASA Astrophysics Data System (ADS)

    Zeng, R.; Wang, S. Y.; Liao, X. L.; Deng, Z. G.; Wang, J. S.

    2013-04-01

    In practical applications, the acceleration and deceleration motions inevitably happen in the operation of high temperature superconducting (HTS) maglev trains. For further research of the maglev properties of YBaCuO bulk above a permanent magnet guideway (PMG), by moving a fixed vertical distance, this paper studies the relationship of the levitation force between single and multiple YBCO bulks above a PMG operating dive-lift movement with different angles. Experimental results show that the maximal levitation force increment of two bulks than one bulk is smaller than the maximal levitation force increment of three bulks than two bulks. With the degree decreasing, the maximal levitation force increment of three bulks is bigger than the maximal levitation force increment of two bulks and one bulk, and the hysteresis loop of the levitation force of the three-bulk arrangement is getting smaller.

  6. Summary of Downtown People Mover (DPM) Winterization Test Activities

    DOT National Transportation Integrated Search

    1982-01-01

    This report describes and summarizes the test activities and presents the results of a two-year winter operation test program for three technologically-different Automated Guideway Transit (AGT) systems. The basic objective of the program was to dete...

  7. Downtown People Mover (DPM) Winterization Test Demonstration : UMI

    DOT National Transportation Integrated Search

    1982-01-01

    This report describes and summarizes the test activities and presents the results of a two-year winter operation test program for three technologically-different Automated Guideway Transit (AGT) systems. The basic objective of the program was to dete...

  8. Development of Measures of Service Availability : Volume 2. Task Technical Reports.

    DOT National Transportation Integrated Search

    1978-06-01

    The study (a part of UMTA's Automatic Guideway Transit Technology program) is aimed at developing a set of measures for "service availability" which will be meaningful, readily understandable, and acceptable to transit operators, suppliers, and inter...

  9. Development of Measures of Service Availability : Volume 3. Application Guideline Manual.

    DOT National Transportation Integrated Search

    1978-06-01

    The study (a part of UMTA's Automatic Guideway Transit Technology program) is aimed at developing a set of measures for "service availability" which will be meaningful, readily understandable, and acceptable to transit operators, suppliers, and inter...

  10. Implementation Guidelines for State Safety Oversight of Rail Fixed Guideway Systems

    DOT National Transportation Integrated Search

    1996-06-01

    These guidelines will assist states, oversight agencies, and rail transit agencies in developing safety and security programs to satisfy the requirements of the Federal Transit Administration (FTA). These requirements were published in the Federal Re...

  11. 49 CFR 611.9 - Project justification criteria for grants and loans for fixed guideway systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... evaluations and assign ratings for project justification, FTA will evaluate information developed locally... of the criteria will be expressed in terms of descriptive indicators, as follows: “high,” “medium...

  12. 49 CFR 611.9 - Project justification criteria for grants and loans for fixed guideway systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... evaluations and assign ratings for project justification, FTA will evaluate information developed locally... of the criteria will be expressed in terms of descriptive indicators, as follows: “high,” “medium...

  13. 49 CFR 611.9 - Project justification criteria for grants and loans for fixed guideway systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... evaluations and assign ratings for project justification, FTA will evaluate information developed locally... of the criteria will be expressed in terms of descriptive indicators, as follows: “high,” “medium...

  14. Development of Measures of Service Availability : Volume 1. Summary Report.

    DOT National Transportation Integrated Search

    1978-06-01

    The objective of the project was to develop passenger-oriented measures of service availability which could be used to control the failure characteristics of Automated Guideway Transit (AGT) systems throughout their life cycle. A corollary and equall...

  15. Interim Assessment of the VAL Automated Guideway Transit System.

    DOT National Transportation Integrated Search

    1981-11-01

    This report describes an interim assessment of the VAL (Vehicules Automatiques Legers or Light Automated Vehicle) AGT system which is currently under construction in Lille, France, and which is to become fully operational in December 1983. This repor...

  16. Evacuation and rescue in automated guideway transit. Volume 1 : data collection, scenarios, and evaluation

    DOT National Transportation Integrated Search

    1979-12-01

    Evacuation and rescue are significant problems in all transportation systems. Serious injuries and loss of life can result from situations in which inadequate means of evacuating and rescuing passengers exist. In conventional transportation systems, ...

  17. Factors contributing to the retention of seated passengers during emergency stops

    DOT National Transportation Integrated Search

    1980-03-01

    A series of seven experiments was conducted to examine the variables that : could contribute to a safe emergency stop on an automated guideway transit system. : Sixty subjects, conforming to a desired range, experienced emergency decelerations : in a...

  18. Passenger safety and convenience services in automated guideway transit. Volume 1 : data collection, scenarios, and evaluation

    DOT National Transportation Integrated Search

    1980-12-01

    In conventional transit operations, vehicle operators and station attendants : have been assigned' secondary roles connected with passenger safety and convenience : services (PS&CS). Giving directions, offering personal assistance to the ill, the : h...

  19. Parametric Cost Study of AC-DC Wayside Power Systems

    DOT National Transportation Integrated Search

    1975-09-01

    The wayside power system provides all the power requirements of an electric vehicle operating on a fixed guideway. For a given set of specifications there are numerous wayside power supply configurations which will be satisfactory from a technical st...

  20. Systems Operation Studies for Automated Guideway Transit Systems : Detailed Station Model Functional Specifications

    DOT National Transportation Integrated Search

    1981-07-01

    The Detailed Station Model (DSM) is a discrete event model representing the interrelated queueing processes associated with vehicle and passenger activities in an AGT station. The DSM will provide operational and performance measures of alternative s...

  1. Effects of deceleration and rate of deceleration on live seated human subjects

    DOT National Transportation Integrated Search

    1977-10-01

    This report describes the testing of live, seated human subjects to determine : the maximum deceleration and associated rate of change of deceleration (jerk) at : which the majority of potential users of automated guideway transportation (ACT) : syst...

  2. Report on Funding Levels and Allocations of Funds

    DOT National Transportation Integrated Search

    1995-05-01

    This report provides the U.S. Department of Transportation's recommendations to Congress for allocation of funds to be made available for the construction of new fixed guideway systems and extensions for Fiscal Year 1996. The report is required by 49...

  3. Lateral Stability of a Dynamic Ram Air Cushion Vehicle

    DOT National Transportation Integrated Search

    1974-08-01

    The lateral stability derivatives of a dynamic ram air cushion vehicle in a rectangular guideway were measured using a ship model towing tank. Lift and pitching moment are also reported. The primary lateral derivatives are all stabilizing, with signi...

  4. Systems Operation Studies for Automated Guideway Transit Systems - Classification and Definition of AGT Systems

    DOT National Transportation Integrated Search

    1980-02-01

    The report describes the development of an AGT classification structure. Five classes are defined based on three system characteristics: service type, minimum travelling unit capacity, and maximum operating velocity. The five classes defined are: Per...

  5. System Operations Studies for Automated Guideway Transit Systems : Detailed Station Model User's Manual

    DOT National Transportation Integrated Search

    1981-07-01

    The Detailed Station Model (DSM) is a discrete event model representing the interrelated queueing processes associated with vehicle and passenger activities in an AGT station. The DSM will provide operational and performance measures of alternative s...

  6. United States-Federal Republic of Germany cooperative study of advanced ground vehicle ride quality

    DOT National Transportation Integrated Search

    1979-11-01

    In the first phase of this study, the relative comfort : assoiciated with various speed-guideway configurations for a proposed : magnetically levitated vehicle (Figure 1) and for a currently : operating Bundesbahn rail-coach were determined. The ride...

  7. Transit Boardings Estimation and Simulation Tool (TBEST) calibration for guideway and BRT modes.

    DOT National Transportation Integrated Search

    2013-06-01

    This research initiative was motivated by a desire of the Florida Department of Transportation and the : Transit Boardings Estimation and Simulation Tool (TBEST) project team to enhance the value of TBEST to : the planning community by improving its ...

  8. Transit forecasting accuracy : ridership forecasts and capital cost estimates, final research report.

    DOT National Transportation Integrated Search

    2009-01-01

    In 1992, Pickrell published a seminal piece examining the accuracy of ridership forecasts and capital cost estimates for fixed-guideway transit systems in the US. His research created heated discussions in the transit industry regarding the ability o...

  9. Systems Operation Studies for Automated Guideway Transit Systems : Availability Model Functional Specification

    DOT National Transportation Integrated Search

    1981-01-01

    The System Availability Model (SAM) is a system-level model which provides measures of vehicle and passenger availability. The SAM will be used to evaluate the system-level influence of availability concepts employed in AGT systems. This functional s...

  10. Cost Experience of Automated Guideway Transit Systems. (Supplement V) Costs and Trends for the Period 1976-1982.

    DOT National Transportation Integrated Search

    1984-04-01

    This report summarizes the cost experiences and trends of sixteen domestic AGT systems. Capital costs, operation and maintenance costs, system characteristics, operational statistics, and unit cost measures are presented to provide useful information...

  11. 78 FR 74056 - Rail Vehicles Access Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ...-0001] RIN 3014-AA42 Rail Vehicles Access Advisory Committee AGENCY: Architectural and Transportation... Architectural and Transportation Barriers Compliance Board (Access Board), established the Rail Vehicle Access... pursuant to the Americans with Disabilities Act for transportation vehicles that operate on fixed guideway...

  12. Sliding-gate valve

    DOEpatents

    Usnick, George B.; Ward, Gene T.; Blair, Henry O.; Roberts, James W.; Warner, Terry N.

    1979-01-01

    This invention is a novel valve of the slidable-gate type. The valve is designed especially for long-term use with highly abrasive slurries. The sealing surfaces of the gate are shielded by the valve seats when the valve is fully open or closed, and the gate-to-seat clearance is swept with an inflowing purge gas while the gate is in transit. A preferred form of the valve includes an annular valve body containing an annular seat assembly defining a flow channel. The seat assembly comprises a first seat ring which is slidably and sealably mounted in the body, and a second seat ring which is tightly fitted in the body. These rings cooperatively define an annular gap which, together with passages in the valve body, forms a guideway extending normal to the channel. A plate-type gate is mounted for reciprocation in the guideway between positions where a portion of the plate closes the channel and where a circular aperture in the gate is in register with the channel. The valve casing includes opposed chambers which extend outwardly from the body along the axis of the guideway to accommodate the end portions of the gate. The chambers are sealed from atmosphere; when the gate is in transit, purge gas is admitted to the chambers and flows inwardly through the gate-to-seat-ring, clearance, minimizing buildup of process solids therein. A shaft reciprocated by an external actuator extends into one of the sealed chambers through a shaft seal and is coupled to an end of the gate. Means are provided for adjusting the clearance between the first seat ring and the gate while the valve is in service.

  13. 49 CFR 659.5 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT General Provisions § 659.5 Definitions... Transportation. Hazard means any real or potential condition (as defined in the rail transit agency's hazard management process) that can cause injury, illness, or death; damage to or loss of a system, equipment or...

  14. 49 CFR 659.5 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT General Provisions § 659.5 Definitions... Transportation. Hazard means any real or potential condition (as defined in the rail transit agency's hazard management process) that can cause injury, illness, or death; damage to or loss of a system, equipment or...

  15. 49 CFR 659.5 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT General Provisions § 659.5 Definitions... Transportation. Hazard means any real or potential condition (as defined in the rail transit agency's hazard management process) that can cause injury, illness, or death; damage to or loss of a system, equipment or...

  16. 49 CFR 659.5 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT General Provisions § 659.5 Definitions... Transportation. Hazard means any real or potential condition (as defined in the rail transit agency's hazard management process) that can cause injury, illness, or death; damage to or loss of a system, equipment or...

  17. Performance Evaluation of an Air-Levitated, Air-Propelled, Passive Vehicle Personal Rapid Transit System

    DOT National Transportation Integrated Search

    1975-06-01

    An eight-passenger Uniflo vehicle was tested to 30 ft/sec on enclosed guideway through curved straight and switch sections. The following parameters were measured: ride quality, as 3 axis acceleration; noise emission as perceived by passengers and in...

  18. United States-Federal Republic of Germany cooperative study of planned magnetically levitated vehicle ride quality

    DOT National Transportation Integrated Search

    1979-10-01

    The major goal of the second phase was to estimate the absolute comfort levels which would be associated with actual travel on highspeed, interurban, fixed-guideway, transportation systems. To accomplish this goal, the study design incorporated many ...

  19. Systems Operation Studies for Automated Guideway Transit Systems : System Availability Model User's Manual

    DOT National Transportation Integrated Search

    1981-01-01

    The System Availability Model (SAM) is a system-level model which provides measures of vehicle and passenger availability. The SAM operates in conjunction with the AGT discrete Event Simulation Model (DESM). The DESM output is the normal source of th...

  20. Towing Tank Tests on a Ram Wing in a Rectangular Guideway

    DOT National Transportation Integrated Search

    1973-07-01

    The object of the study was to set the theoretical and experimental basis for a preliminary design of a ram wing vehicle. A simplified one-dimensional mathematical model is developed in an attempt to estimate the stability derivatives of this type of...

  1. Transit boardings estimation and simulation tool (TBEST) calibration for guideway and BRT modes : [summary].

    DOT National Transportation Integrated Search

    2013-06-01

    As demand for public transportation grows, planning tools used by Florida Department of Transportation (FDOT) and other transit agencies must evolve to effectively predict changing patterns of ridership. A key tool for this purpose is the Transit Boa...

  2. 78 FR 59316 - Rail Vehicles Access Advisory Committee Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-26

    ...-0001] RIN 3014-AA42 Rail Vehicles Access Advisory Committee Meetings AGENCY: Architectural and... Vehicles Access Advisory Committee (Committee) will hold its first meeting. We, the Architectural and... transportation vehicles that operate on fixed guideway systems (e.g., rapid rail, light rail, commuter rail...

  3. 78 FR 65244 - Rail Vehicles Access Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ...-0001] RIN 3014-AA42 Rail Vehicles Access Advisory Committee AGENCY: Architectural and Transportation Barriers Compliance Board. ACTION: Notice of advisory committee meeting. SUMMARY: The Rail Vehicles Access... vehicles that operate on fixed guideway systems (e.g., rapid rail, light rail, commuter rail, intercity...

  4. Magnetic superelevation design of Halbach permanent magnet guideway for high-temperature superconducting maglev

    NASA Astrophysics Data System (ADS)

    Lei, Wuyang; Qian, Nan; Zheng, Jun; Huang, Huan; Zhang, Ya; Deng, Zigang

    2017-07-01

    To improve the curve negotiating ability of high-temperature superconducting (HTS) maglev system, a special structure of magnetic superelevation for double-pole Halbach permanent magnet guideway (PMG) was designed. The most significant feature of this design is the asymmetrical PMG that forms a slanting magnetic field without affecting the smoothness of the PMG surface. When HTS maglev vehicle runs through curves with magnetic superelevation, the vehicle will slant due to asymmetry in magnetic field and the flux-pinning effect of onboard HTS bulks. At the same time, one component of the levitation force provides a part of the centripetal force that reduces lateral acceleration of the vehicle and thus enhances its curve negotiating ability. Furthermore, the slant angle of magnetic superelevation can be adjusted by changing the materials and the thickness of the added permanent magnets. This magnetic superelevation method, together with orographic uplift, can be applied to different requirements of PMG designs. Besides, the applicability of this method would benefit future development of high-speed HTS maglev system.

  5. Maglev performance of a double-layer bulk high temperature superconductor above a permanent magnet guideway

    NASA Astrophysics Data System (ADS)

    Deng, Z.; Wang, J.; Zheng, J.; Lin, Q.; Zhang, Y.; Wang, S.

    2009-05-01

    In order to improve the performance of the present high temperature superconducting (HTS) maglev vehicle system, the maglev performance of single- and double-layer bulk high temperature superconductors (HTSC) was investigated above a permanent magnet guideway (PMG). It is found that the maglev performance of a double-layer bulk HTSC is not a simple addition of each layer's levitation and guidance force. Moreover, the applied magnetic field at the position of the upper layer bulk HTSC is not completely shielded by the lower layer bulk HTSC either. 53.5% of the levitation force and 27.5% of the guidance force of the upper layer bulk HTSC are excited in the double-layer bulk HTSC arrangement in the applied field-cooling condition and working gap, bringing a corresponding improvement of 16.9% and 8.8% to the conventional single-layer bulk HTSC. The present research implies that the cost performance of upper layer bulk HTSC is a little low for the whole HTS maglev system.

  6. Side-suspended High-Tc Superconducting Maglev Prototype Vehicle Running at a High Speed in an Evacuated Circular Test Track

    NASA Astrophysics Data System (ADS)

    Zhou, Dajin; Zhao, Lifeng; Cui, Chenyu; Zhang, Yong; Guo, Jianqiang; Zhao, Yong

    2017-07-01

    High-T c superconductor (HTS) and permanent magnetic guideway (PMG) based maglev train is intensively studied in China, Japan, Germany and Brazil, mainly through static or vibration test. Amongst these studies, only a few of reports are available for the direct and effective assessment on the dynamic performance of the HTS maglev vehicle by running on a straight or circular PMG track. The highest running speed of these experiments is lower than 50 km/h. In this paper, a side-suspended HTS permanent magnetic guideway maglev system was proposed and constructed in order to increase the running speed in a circular track. By optimizing the arrangement of YBCO bulks besides the PMG, the side-suspended HTS maglev prototype vehicle was successfully running stably at a speed as high as 150 km/h in a circular test track with 6.5 m in diameter, and in an evacuated tube environment, in which the pressure is 5 × 103 Pa.

  7. Composite materials for rail transit systems

    NASA Technical Reports Server (NTRS)

    Griffin, O. Hayden, Jr.; Guerdal, Zafer; Herakovich, Carl T.

    1987-01-01

    The potential is explored for using composite materials in urban mass transit systems. The emphasis was to identify specific advantages of composite materials in order to determine their actual and potential usage for carbody and guideway structure applications. The literature was reviewed, contacts were made with major domestic system operators, designers, and builders, and an analysis was made of potential composite application to railcar construction. Composites were found to be in use throughout the transit industry, usually in secondary or auxiliary applications such as car interior and nonstructural exterior panels. More recently, considerable activity has been initiated in the area of using composites in the load bearing elements of civil engineering structures such as highway bridges. It is believed that new and improved manufacturing refinements in pultrusion and filament winding will permit the production of beam sections which can be used in guideway structures. The inherent corrosion resistance and low maintenance characteristics of composites should result in lowered maintenance costs over a prolonged life of the structure.

  8. Experiment results of high temperature superconducting Maglev vehicle

    NASA Astrophysics Data System (ADS)

    Wang, J. S.; Wang, S. Y.; Ren, Z. Y.; Jiang, H.; Zhu, M.; Wang, X. R.; Shen, X. M.; Song, H. H.

    2003-04-01

    The first man-loading high temperature superconducting (HTS) magnetic levitation (Maglev) test vehicle in the world has normally operated over one year after its birth on December 31, 2000. Heretofore over 23 000 passengers have taken the vehicle, and it operates very well from first running to now. The HTS Maglev vehicle is over guideway, which consists of two parallel permanent magnetic tracks. The levitation force of the entire Maglev vehicle is measured. Three times measurement results on December 24, 2000, July 1, 2001, and December 24, 2001 are reported respectively, it will be seen from this that the levitation forces do not change nearly after long running. Total levitation force of entire vehicle is 1050 kg at the 8 mm net levitation gap, which the gap between the bottom of liquid nitrogen vessels and guideway face. A measuring equipment of the guidance force of the entire Maglev vehicle is designed and manufactured. The guidance force of the vehicle is obtained by the equipment.

  9. Automated transit networks (ATN) : a review of the state of the industry and prospects for the future.

    DOT National Transportation Integrated Search

    2014-09-01

    The concept of Automated Transit Networks (ATN) - in which fully automated vehicles on exclusive, grade-separated guideways : provide on-demand, primarily non-stop, origin-to-destination service over an area network has been around since the 1950...

  10. 49 CFR 268.1 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... environmental impact statement which is required pursuant to §§ 268.3. Eligible project costs means the costs of preconstruction planning activities and the capital cost of the fixed guideway infrastructure of a Maglev project... storage, repair, and maintenance facilities, but eligible project costs do not include the cost of...

  11. Systems Operation Studies for Automated Guideway Transit Systems: Feeder Systems Model Functional Specification

    DOT National Transportation Integrated Search

    1981-01-01

    This document specifies the functional requirements for the AGT-SOS Feeder Systems Model (FSM), the type of hardware required, and the modeling techniques employed by the FSM. The objective of the FSM is to map the zone-to-zone transit patronage dema...

  12. Extended System Operations Studies for Automated Guideway Transit Systems : Plan for Task 5--DPM Failure Management

    DOT National Transportation Integrated Search

    1981-06-01

    The purpose of Task 5 in the Extended System Operations Studies Project, DPM Failure Management, is to enhance the capabilities of the Downtown People Mover Simulation (DPMS) and the Discrete Event Simulation Model (DESM) by increasing the failure mo...

  13. 49 CFR 659.15 - System safety program standard.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false System safety program standard. 659.15 Section 659... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State Oversight Agency § 659.15 System safety program standard. (a) General requirement. Each state...

  14. 49 CFR 1580.203 - Reporting significant security concerns.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... heavy rail transit, light rail transit, automated guideway, cable car, inclined plane, funicular, and... or transit vehicle crew. (2) Bomb threats, specific and non-specific. (3) Reports or discovery of... a train or transit vehicle or inside the facility of a passenger railroad carrier or rail transit...

  15. 49 CFR 1580.203 - Reporting significant security concerns.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... heavy rail transit, light rail transit, automated guideway, cable car, inclined plane, funicular, and... or transit vehicle crew. (2) Bomb threats, specific and non-specific. (3) Reports or discovery of... a train or transit vehicle or inside the facility of a passenger railroad carrier or rail transit...

  16. 49 CFR 1580.203 - Reporting significant security concerns.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... heavy rail transit, light rail transit, automated guideway, cable car, inclined plane, funicular, and... or transit vehicle crew. (2) Bomb threats, specific and non-specific. (3) Reports or discovery of... a train or transit vehicle or inside the facility of a passenger railroad carrier or rail transit...

  17. 49 CFR 1580.203 - Reporting significant security concerns.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... heavy rail transit, light rail transit, automated guideway, cable car, inclined plane, funicular, and... or transit vehicle crew. (2) Bomb threats, specific and non-specific. (3) Reports or discovery of... a train or transit vehicle or inside the facility of a passenger railroad carrier or rail transit...

  18. Aerodynamics of Tracked Ram Air Cushion Vehicles - Effects of Pitch Attitude and Upper Surface Flow

    DOT National Transportation Integrated Search

    1979-12-01

    Three types of experiments were conducted on geometrically similar model of a Tracked Ram Air Cushion Vehicle (TRACV). The first consisted of wind tunnel tests with the vehicle model positioned within a short segment of stationary guideway. In the se...

  19. Investigation of the Dynamics of a Maglev Vehicle Traversing a Flexible Guideway : Theory and Experiment

    DOT National Transportation Integrated Search

    1979-04-01

    This report presents the results of a research program conducted jointly by the United States Department of Transportation and the Federal Republic of Germany Ministry for Research and Technology. The object of this program was to study the dynamics ...

  20. 49 CFR 659.15 - System safety program standard.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... included in the affected rail transit agency's system safety program plan relating to the hazard management... 49 Transportation 7 2011-10-01 2011-10-01 false System safety program standard. 659.15 Section 659... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the...

  1. 49 CFR Appendix A to Part 611 - Description of Measures Used for Project Evaluation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Livable Communities initiatives and local economic activities; (5) Consideration of alternative land use... to fixed guideway systems and extensions may not be limited to a single project). (b) The stability and reliability of the proposed capital financing plan, according to: (i) The stability, reliability...

  2. 49 CFR 659.23 - System security plan: contents.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false System security plan: contents. 659.23 Section 659.23 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State Oversight Agency § 659.23 System security...

  3. 75 FR 62917 - Notice of Request for the Approval of Information Collection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-13

    ...--Major Capital Investment Projects. DATES: Comments must be submitted before December 13, 2010. ADDRESSES.... Part 611--49 CFR Major Capital Investment Projects. OMB Number: 2132-0561. Background: On August 10... the manner in which candidate projects for major capital investment grants for new fixed guideway...

  4. Trends Before the San Diego Trolley: A San Diego Trolley Guideway Implementation Monitoring Study Report

    DOT National Transportation Integrated Search

    1982-07-01

    A substantial amount of interest has been generated in San Diego's new light rail system. This 16 mile system is the first system of its type to become operational in several decades and was constructed entirely without Federal funds. This report pro...

  5. 49 CFR 659.19 - System safety program plan: contents.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false System safety program plan: contents. 659.19... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State Oversight Agency § 659.19 System safety program plan: contents. The system safety plan shall...

  6. 49 CFR 659.19 - System safety program plan: contents.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false System safety program plan: contents. 659.19... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State Oversight Agency § 659.19 System safety program plan: contents. The system safety plan shall...

  7. 49 CFR 659.19 - System safety program plan: contents.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false System safety program plan: contents. 659.19... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State Oversight Agency § 659.19 System safety program plan: contents. The system safety plan shall...

  8. 49 CFR 659.19 - System safety program plan: contents.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false System safety program plan: contents. 659.19... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State Oversight Agency § 659.19 System safety program plan: contents. The system safety plan shall...

  9. 49 CFR 659.19 - System safety program plan: contents.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false System safety program plan: contents. 659.19... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State Oversight Agency § 659.19 System safety program plan: contents. The system safety plan shall...

  10. Review of Aircraft Crash Databases and Evaluation of the Probability of Aircraft Crashes on to a MAGLEV Guide-way: Technical Report

    DOT National Transportation Integrated Search

    1991-12-09

    The System Safety & Security Division at The Volpe National Transportation System Center (VNTSC), Cambridge, MA is participating in an overall risk assessment study on the safety of High Speed Magnetic Levitation Transportation Systems ("MagLev"). Tr...

  11. 49 CFR 659.43 - Certification of compliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Certification of compliance. 659.43 Section 659.43..., DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State Oversight Agency § 659.43 Certification of compliance. (a) Annually, the oversight agency must certify to the FTA...

  12. 49 CFR 659.27 - Internal safety and security reviews.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the..., indicating that the rail transit agency is in compliance with its system safety program plan and system... security reviews indicate that the rail transit agency is not in compliance with its system safety program...

  13. Development/Deployment Investigation of H-Bahn System (H-Bahn Untersuchung von Technologie, Entwicklung und Betrieb)

    DOT National Transportation Integrated Search

    1982-01-01

    This report describes and provides the results of an assessment of the H-Bahn Automated Guideway Transit (AGT) system under development in the Federal Republic of Germany. It is a joint U.S./German technical assessment study that was completed under ...

  14. 49 CFR 659.39 - Oversight agency reporting to the Federal Transit Administration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., must make its initial submission to FTA by May 1, 2006. In states with rail fixed guideway systems... must make a new initial submission to FTA within thirty (30) days of the designation. (b) An initial... must submit the following to FTA: (1) A publicly available annual report summarizing its oversight...

  15. Proceedings of Workshop on Methodology for Evaluating the Effectiveness of Transit Crime Reduction Measures in Automated Guideway Transit Systems

    DOT National Transportation Integrated Search

    1977-07-01

    The workshop focused on current methods of assessing the effectiveness of crime and vandalism reduction methods that are used in conventional urban mass transit systems, and on how they might be applied to new AGT systems. Conventional as well as nov...

  16. Development and Testing of a Completely Passive, Air Suspended, Air Propelled Personal Rapid Transit Vehicle

    DOT National Transportation Integrated Search

    1973-04-01

    A prototype Uniflo vehicle base with mock-up superstructure was tested on 55 ft. of full-scale track. Sound treatment to meet NCA 60 at 25 ft. from the guideway enclosure and within the vehicle was proposed and the costs determined. A heating and coo...

  17. The Shock and Vibration Digest, Volume 18, Number 2

    DTIC Science & Technology

    1986-02-01

    Bounce Response of Canadian 71. McMunn, J.C., "Multi-Parameter Optimum MAGLEV Vehicle under Guideway Excitation. . Damping in Linear Dynamical Systems...Northeast Corridor High-Speed Test Cars," J. "Suspension Bounce Response of Canadian L’,-*’-.-" Engrg. Indus., Trans. ASME, 91B (3), pp 897-907 MAGLEV

  18. Extended System Operations Studies for Automated Guideway Transit Systems : Procedure for the Analysis of Representative AGT Deployments

    DOT National Transportation Integrated Search

    1981-12-01

    The purpose of this report is to present a general procedure for using the SOS software to analyze AGT systems. Data to aid the analyst in specifying input information, required as input to the software, are summarized in the appendices. The data are...

  19. 49 CFR 659.11 - Confidentiality of investigation reports and security plans.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Confidentiality of investigation reports and security plans. 659.11 Section 659.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAIL FIXED GUIDEWAY SYSTEMS; STATE SAFETY OVERSIGHT Role of the State § 659.11...

  20. Influence of radius of cylinder HTS bulk on guidance force in a maglev vehicle system

    NASA Astrophysics Data System (ADS)

    Longcai, Zhang

    2014-07-01

    Bulk superconductors had great potential for various engineering applications, especially in a high-temperature superconducting (HTS) maglev vehicle system. In such a system, the HTS bulks were always exposed to AC external magnetic field, which was generated by the inhomogeneous surface magnetic field of the NdFeB guideway. In our previous work, it was observed that the guidance force of the YBCO bulk over the NdFeB guideway used in the HTS maglev vehicle system was decayed by the application of the AC external magnetic field. In this paper, we investigated the influence of the radius of the cylinder HTS bulk exposed to an AC magnetic field perturbation on the guidance force in the maglev vehicle system. From the results, it was found that the guidance force was stronger for the bulk with bigger radius and the guidance force decay rates of the bulks were approximately equal despite of the different radius in the maglev vehicle system. Therefore, in order to obtain higher guidance force in the maglev vehicle system, we could use the cylinder HTS bulks with the bigger radius.

  1. Dynamic response characteristics of high temperature superconducting maglev systems: Comparison between Halbach-type and normal permanent magnet guideways

    NASA Astrophysics Data System (ADS)

    Wang, B.; Zheng, J.; Che, T.; Zheng, B. T.; Si, S. S.; Deng, Z. G.

    2015-12-01

    The permanent magnet guideway (PMG) is very important for the performance of the high temperature superconducting (HTS) system in terms of electromagnetic force and operational stability. The dynamic response characteristics of a HTS maglev model levitating on two types of PMG, which are the normal PMG with iron flux concentration and Halbach-type PMG, were investigated by experiments. The dynamic signals for different field-cooling heights (FCHs) and loading/unloading processes were acquired and analyzed by a vibration analyzer and laser displacement sensors. The resonant frequency, stiffness and levitation height of the model were discussed. It was found that the maglev model on the Halbach-type PMG has higher resonant frequency and higher vertical stiffness compared with the normal PMG. However, the low lateral stiffness of the model on the Halbach-type PMG indicates poor lateral stability. Besides, the Halbach-type PMG has better loading capacity than the normal PMG. These results are helpful to design a suitable PMG for the HTS system in practical applications.

  2. Optimization of a superconducting linear levitation system using a soft ferromagnet

    NASA Astrophysics Data System (ADS)

    Agramunt-Puig, Sebastia; Del-Valle, Nuria; Navau, Carles; Sanchez, Alvaro

    2013-04-01

    The use of guideways that combine permanent magnets and soft ferromagnetic materials is a common practice in magnetic levitation transport systems (maglevs) with bulk high-temperature superconductors. Theoretical tools to simulate in a realistic way both the behavior of all elements (permanent magnets, soft ferromagnet and superconductor) and their mutual effects are helpful to optimize the designs of real systems. Here we present a systematic study of the levitation of a maglev with translational symmetry consisting of a superconducting bar and a guideway with two identic permanent magnets and a soft ferromagnetic material between them. The system is simulated with a numerical model based on the energy minimization method that allows to analyze the mutual interaction of the superconductor, assumed to be in the critical state, and a soft ferromagnet with infinite susceptibility. Results indicate that introducing a soft ferromagnet within the permanent magnets not only increases the levitation force but also improves the stability. Besides, an estimation of the relative sizes and shapes of the soft ferromagnet, permanent magnets and the superconductor in order to obtain large levitation force with full stability is provided.

  3. Propulsion and stabilization system for magnetically levitated vehicles

    DOEpatents

    Coffey, Howard T.

    1993-06-29

    A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.

  4. Supplement II : Summary of Capital and Operations & Maintenance Cost Experience of Automated Guideway Transit Systems : Costs and Trends for the period 1976-1979

    DOT National Transportation Integrated Search

    1980-03-01

    This report summarizes O&M cost experience and trends for the following AGT systems for the period 1976-1979: AIRTRANS, Sea-Tac, Tampa, Disneyworld (WEDway), and Morgantown (O&M data on the Morgantown system is reported through 1978). Capital cost da...

  5. Dynamic Stability of Maglev Systems,

    DTIC Science & Technology

    1992-04-01

    AD-A259 178 ANL-92/21 Materials and Components Dynamic Stability of Technology Division Materials and Components Maglev Systems Technology Division...of Maglev Systems Y. Cai, S. S. Chen, and T. M. Mulcahy Materials and Components Technology Division D. M. Rote Center for Transportation Research...of Maglev System with L-Shaped Guideway ......................................... 6 3 Stability of M aglev System s

  6. Summary of Capital and Operations & Maintenance Cost Experience of Automated Guideway Transit Systems Costs and Trends for the period 1976-1978. Supplement I

    DOT National Transportation Integrated Search

    1979-10-01

    This costs supplement is presented in the form of a series of tables and figures which summarize the data obtained as well as the results of analysis. Comments and explanatory notes relative to tables/figures are made where appropriate. Also included...

  7. Costs and energy efficiency of a dual-mode system

    NASA Technical Reports Server (NTRS)

    Heft, R. C.

    1977-01-01

    The life cycle costs of a dual mode system for both public and semiprivate ownership are examined, and the costs in terms of levelized required revenue per passenger mile are presented. The energy use of the dual mode vehicle is analyzed by means of a detailed vehicle simulation program for the control policy and guideway system. Several different propulsion systems are considered.

  8. Fault tolerant computer control for a Maglev transportation system

    NASA Technical Reports Server (NTRS)

    Lala, Jaynarayan H.; Nagle, Gail A.; Anagnostopoulos, George

    1994-01-01

    Magnetically levitated (Maglev) vehicles operating on dedicated guideways at speeds of 500 km/hr are an emerging transportation alternative to short-haul air and high-speed rail. They have the potential to offer a service significantly more dependable than air and with less operating cost than both air and high-speed rail. Maglev transportation derives these benefits by using magnetic forces to suspend a vehicle 8 to 200 mm above the guideway. Magnetic forces are also used for propulsion and guidance. The combination of high speed, short headways, stringent ride quality requirements, and a distributed offboard propulsion system necessitates high levels of automation for the Maglev control and operation. Very high levels of safety and availability will be required for the Maglev control system. This paper describes the mission scenario, functional requirements, and dependability and performance requirements of the Maglev command, control, and communications system. A distributed hierarchical architecture consisting of vehicle on-board computers, wayside zone computers, a central computer facility, and communication links between these entities was synthesized to meet the functional and dependability requirements on the maglev. Two variations of the basic architecture are described: the Smart Vehicle Architecture (SVA) and the Zone Control Architecture (ZCA). Preliminary dependability modeling results are also presented.

  9. Design of an ultraprecision computerized numerical control chemical mechanical polishing machine and its implementation

    NASA Astrophysics Data System (ADS)

    Zhang, Chupeng; Zhao, Huiying; Zhu, Xueliang; Zhao, Shijie; Jiang, Chunye

    2018-01-01

    The chemical mechanical polishing (CMP) is a key process during the machining route of plane optics. To improve the polishing efficiency and accuracy, a CMP model and machine tool were developed. Based on the Preston equation and the axial run-out error measurement results of the m circles on the tin plate, a CMP model that could simulate the material removal at any point on the workpiece was presented. An analysis of the model indicated that lower axial run-out error led to lower material removal but better polishing efficiency and accuracy. Based on this conclusion, the CMP machine was designed, and the ultraprecision gas hydrostatic guideway and rotary table as well as the Siemens 840Dsl numerical control system were incorporated in the CMP machine. To verify the design principles of machine, a series of detection and machining experiments were conducted. The LK-G5000 laser sensor was employed for detecting the straightness error of the gas hydrostatic guideway and the axial run-out error of the gas hydrostatic rotary table. A 300-mm-diameter optic was chosen for the surface profile machining experiments performed to determine the CMP efficiency and accuracy.

  10. A Review of Dynamic Characteristics of Magnetically Levitated Vehicle Systems.

    DTIC Science & Technology

    1995-11-01

    The dynamic response of magnetically levitated ( maglev ) ground transportation systems has important consequences for safety and ride quality...smoothness and levitation and control systems must be considered if maglev systems are to be economically feasible. The link between the guideway and the...other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. This report, which

  11. Segmented rail linear induction motor

    DOEpatents

    Cowan, Jr., Maynard; Marder, Barry M.

    1996-01-01

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces.

  12. A novel propulsion method for high- Tc superconducting maglev vehicle

    NASA Astrophysics Data System (ADS)

    Ma, Guangtong; Wang, Jiasu; Wang, Suyu; Liu, Minxian; Jing, Hua; Lu, Yiyun; Lin, Qunxu

    2008-01-01

    High-Tc superconducting (HTS) maglev is considered as a perfect transportation type because of its unique inherent stability. A direct current (DC) linear motor using the permanent magnet guideway (PMG) as the stator and the on-board coil as the rotor instead of the present inductive or synchronous alternate current (AC) linear motor which has an economic disadvantage due to the necessity to lay primary coil along the guideway is proposed in this paper. In order to modulate the magnetic field under the PMG, an inverse E shape ferromagnetic device (IESFD) core is designed. The possible winding method for the on-board coil is listed, and the analytical result shows that a considerable net ampere force and thus the propulsion force can be generated by this special structure. The influence of the concentrated effect of the IESFD on the maglev performance of HTS bulk is studied by a numerical program, and the results show that the levitation force with the IESFD is 90% of that without. It is also indicated that the load capability and lateral performance of the maglev vehicle combined this propulsion method can be improved thanks to the attractive effect between the IESFD and PMG. The cost of the HTS maglev vehicle will be remarkably reduced and then shorten the distance to practical application with this propulsion method.

  13. Maglev guideway route alignment and right-of-way requirements

    NASA Astrophysics Data System (ADS)

    Carlton, S.; Andriola, T.

    1992-12-01

    The use of existing rights-of-way (ROW) is assessed for maglev systems by estimating trip times and land acquisition requirements for potential maglev corridors while meeting passenger comfort limits. Right-of-way excursions improve trip time but incur a cost for purchasing land. The final report documents findings of the eight tasks in establishing right-of-way feasibility by examining three city-pair corridors in detail and developing an approximation method for estimating route length and travel times in 20 additional city-pair corridor portions and 21 new corridors. The use of routes independent of existing railroad or highway right-of-way have trip time advantages and significantly reduce the need for aggressive guideway geometries on intercity corridors. Selection of the appropriate alignment is determined by many corridor specific issues. Use of existing intercity rights-of-way may be appropriate for parts of routes on a corridor-specific basis and for urban penetration where vehicle speeds are likely to be reduced by policy due to noise and safety considerations, and where land acquisition costs are high. Detailed aspects of available rights-of-way, land acquisition costs, geotechnical issues, land use, and population centers must be examined in more detail on a specific corridor basis before the proper or best maglev alignment can be chosen.

  14. Levitation properties of maglev systems using soft ferromagnets

    NASA Astrophysics Data System (ADS)

    Huang, Chen-Guang; Zhou, You-He

    2015-03-01

    Soft ferromagnets are widely used as flux-concentration materials in the design of guideways for superconducting magnetic levitation transport systems. In order to fully understand the influence of soft ferromagnets on the levitation performance, in this work we apply a numerical model based on the functional minimization method and the Bean’s critical state model to study the levitation properties of an infinitely long superconductor immersed in the magnetic field created by a guideway of different sets of infinitely long parallel permanent magnets with soft ferromagnets between them. The levitation force, guidance force, magnetic stiffness and magnetic pole density are calculated considering the coupling between the superconductor and soft ferromagnets. The results show that the levitation performance is closely associated with the permanent magnet configuration and with the location and dimension of the soft ferromagnets. Introducing the soft ferromagnet with a certain width in a few configurations always decreases the levitation force. However, for most configurations, the soft ferromagnets contribute to improve the levitation performance only when they have particular locations and dimensions in which the optimized location and thickness exist to increase the levitation force the most. Moreover, if the superconductor is laterally disturbed, the presence of soft ferromagnets can effectively improve the lateral stability for small lateral displacement and reduce the degradation of levitation force.

  15. Segmented rail linear induction motor

    DOEpatents

    Cowan, M. Jr.; Marder, B.M.

    1996-09-03

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces. 6 figs.

  16. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, Donald M.; He, Jianliang; Johnson, Larry R.

    1994-01-01

    A propulsion and stabilization system comprising a series of FIG. 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the FIG. 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  17. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, D.M.; He, J.; Johnson, L.R.

    1994-01-04

    A propulsion and stabilization system are described comprising a series of coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance, and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension. 8 figures.

  18. A Model for Assessment of Dynamic Interaction Between Magnetically Levitated Vehicles and Their Supporting Guideways

    DTIC Science & Technology

    1994-07-01

    Public Release; Distribution Is Unlimited DTXC QtTAu r V94 8 Prepared for Headquarters, U.S. Army Corps of Engineers National Maglev Initiative and U.S...for public release; distribution is unlimited Prepared for Headquarters, U.S. Army Corps of Engineers Washington, DC 20314-1000 National Maglev ...Corps of Engineers, National Maglev Initiative, and U.S. Army Engineer Division, Huntsville. 73 p. : ill. ; 28 cm. - (Technical report ; SL-94-1 5

  19. Performance of an Automated-Mixed-Traffic-Vehicle /AMTV/ System. [urban people mover

    NASA Technical Reports Server (NTRS)

    Peng, T. K. C.; Chon, K.

    1978-01-01

    This study analyzes the operation and evaluates the expected performance of a proposed automatic guideway transit system which uses low-speed Automated Mixed Traffic Vehicles (AMTV's). Vehicle scheduling and headway control policies are evaluated with a transit system simulation model. The effect of mixed-traffic interference on the average vehicle speed is examined with a vehicle-pedestrian interface model. Control parameters regulating vehicle speed are evaluated for safe stopping and passenger comfort.

  20. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, D.M.; He, Jianliang; Johnson, L.R.

    1992-01-01

    This report discusses a propulsion and stabilization system comprising a series of figure 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the figure 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  1. Correlations Between Magnetic Flux and Levitation Force of HTS Bulk Above a Permanent Magnet Guideway

    NASA Astrophysics Data System (ADS)

    Huang, Huan; Zheng, Jun; Zheng, Botian; Qian, Nan; Li, Haitao; Li, Jipeng; Deng, Zigang

    2017-10-01

    In order to clarify the correlations between magnetic flux and levitation force of the high-temperature superconducting (HTS) bulk, we measured the magnetic flux density on bottom and top surfaces of a bulk superconductor while vertically moving above a permanent magnet guideway (PMG). The levitation force of the bulk superconductor was measured simultaneously. In this study, the HTS bulk was moved down and up for three times between field-cooling position and working position above the PMG, followed by a relaxation measurement of 300 s at the minimum height position. During the whole processes, the magnetic flux density and levitation force of the bulk superconductor were recorded and collected by a multipoint magnetic field measurement platform and a self-developed maglev measurement system, respectively. The magnetic flux density on the bottom surface reflected the induced field in the superconductor bulk, while on the top, it reveals the penetrated magnetic flux. The results show that the magnetic flux density and levitation force of the bulk superconductor are in direct correlation from the viewpoint of inner supercurrent. In general, this work is instructive for understanding the connection of the magnetic flux density, the inner current density and the levitation behavior of HTS bulk employed in a maglev system. Meanwhile, this magnetic flux density measurement method has enriched present experimental evaluation methods of maglev system.

  2. Shock Absorbing System

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A lightweight, inexpensive shock-absorbing system, developed by Langley Research Center 20 years ago, is now in service as safety device for an automated railway at Duke University Medical Center. The transportation system travels at about 25 miles per hour, carrying patients, visitors, staff and cargo. At the end of each guideway of the system are "frangible," (breakable) tube "buffers." If a slowing car fails to make a complete stop at the terminal, it would bump and shatter the tubes, absorbing energy that might otherwise jolt the passengers or damage the vehicle.

  3. Dynamic stability of maglev systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai, Y.; Chen, S.S.; Mulcahy, T.M.

    1994-05-01

    Because dynamic instabilities are not acceptable in any commercial maglev system, it is important to consider dynamic instability in the development of all maglev systems. This study considers the stability of maglev systems based on experimental data, scoping calculations, and simple mathematical models. Divergence and flutter are obtained for coupled vibration of a three-degree-of-freedom maglev vehicle on a guideway consisting of double L-shaped aluminum segments. The theory and analysis developed in this study provides basic stability characteristics and identifies future research needs for maglev systems.

  4. DOT/NASA comparative assessment of Brayton engines for guideway vehicles and busses. Volume 2: Analysis and results

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Gas turbine engines were assessed for application to hear duty transportation. A summary of the assumptions, applications, and methods of analysis is included along with a discussion of the approach taken, the technical program flow chart, and weighting criteria used for performance evaluation. The various engines are compared on the bases of weight, performance, emissions and noise, technology status, and growth potential. The results of the engine screening phase and the conceptual design phase are presented.

  5. Clamp for use in winding large magnet coils

    DOEpatents

    Brown, Robert L.; Kenney, Walter J.

    1983-01-01

    In one aspect, the invention is a novel arrangement for applying forces to urns of a vertically extending helical coil which is wound about a support. The apparatus includes a first rigid member extending towards the turns. A second rigid member extends transversely from the end of the first and has a vertically extending face provided with a generally straight groove extending transversely of the turns. A longitudinal passage in the first member connects to the groove to form therewith a continuous guideway for rollable articles. A rigid lug longitudinally movable in the groove is provided with a projection which extends out of the groove and beneath the bottom of a selected turn of the coil. A train of rigid, rollable articles is disposed in the guideway inwardly of the lug. Means are provided for applying force to that end of the train which is relatively remote from the lug, to urge the latter against the bottom face of the selected turn. As a result, that turn is moved upward along the face of the support, establishing a selected spacing between that turn and the previously formed turn of the coil. When upward movement of the selected turn stops, the force applied to the lug immediately translates to a force which urges the above-mentioned grooved face against all of the formed turns, thus compressing them against the support. The above-mentioned first and second members are swingably mounted so that they can be temporarily moved out of the winding path, thus permitting continuous winding.

  6. Clamp for use in winding large magnet coils

    DOEpatents

    Brown, R.L.; Kenney, W.J.

    1981-05-05

    In one aspect, the invention is a novel arrangement for applying forces to turns of a vertically extending helical coil which is wound about a support. The apparatus includes a first rigid member extending towards the turns. A second rigid member extends transversely from the end of the first and has a vertically extending face provided with a generally straight groove extending transversely of the turns. A longitudinal passage in the first member connects to the groove to form therewith a continuous guideway for rollable articles. A rigid lug longitudinally movable in the groove is provided with a projection which extends out of the groove and beneath the bottom of a selected turn of the coil. A train of rigid, rollable articles is disposed in the guideway inwardly of the lug. Means are provided for applying force to that end of the train which is relatively remote from the lug, to urge the latter against the bottom face of the selected turn. As a result, that turn is moved upward along the face of the support, establishing a selected spacing between that turn and the previously formed turn of the coil. When upward movement of the selected turn stops, the force applied to the lug immediately translates to a force which urges the above-mentioned grooved face against all of the formed turns, thus compressing them against the support. The above-mentioned first and second members are swingably mounted so that they can be temporarily moved out of the winding path, thus permitting continuous winding.

  7. Maglev system concept using 20-K high-temperature superconductors and hyperconductors

    NASA Astrophysics Data System (ADS)

    Hull, J. R.; He, Jianliang

    A magnetically levitated high-speed ground transportation concept is proposed that uses high-temperature superconductors or hyperconductors, cooled by liquid hydrogen at 20 K, to provide levitation. An on-board hydrogen-powered turbine/generator provides electricity for propulsion by linear induction motors. The liquid hydrogen is used to cool the superconductors and the windings of the generator and motors before combusting in the turbine. The principal advantage of this system is the potential to greatly reduce the cost of the guideway, which is completely passive.

  8. Dynamic stability of maglev systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai, Y.; Chen, S.S.; Mulcahy, T.M.

    1992-04-01

    Because dynamic instability is not acceptable for any commercial maglev systems, it is important to consider this phenomenon in the development of all maglev systems. This study considers the stability of maglev systems based on experimental data, scoping calculations, and simple mathematical models. Divergence and flutter are obtained for coupled vibration of a three-degree-of-freedom maglev vehicle on a guideway consisting of double L-shaped aluminum segments attached to a rotating wheel. The theory and analysis developed in this study identifies basic stability characteristics and future research needs of maglev systems.

  9. Dynamic stability of electrodynamic maglev systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai, Y.; Chen, S.S.; Mulcahy, T.M.

    1997-01-01

    Because dynamic instabilities are not acceptable in any commercial maglev system, it is important to consider dynamic instability in the development of all maglev systems. This study considers the stability of maglev systems based on mathematical models and experimental data. Divergence and flutter are obtained for coupled vibration of a three-degree-of-freedom maglev vehicle on a guideway consisting of double L-shaped aluminum segments. The theory and analysis for motion-dependent magnetic-force-induced instability developed in this study provides basic stability characteristics and identifies future research needs for maglev systems.

  10. Modal Interfaces in Hawaii

    NASA Technical Reports Server (NTRS)

    Wright, E. Alvey

    1974-01-01

    Hawaii, an archipelago where transportation distances are short but the interfaces are many, seeks elimination of modal changes by totally-submerged hydrofoil craft operating at the water surface directly between tourist resort destinations, by dual mode rapid transit vehicles operating directly between the deplaning bridges at Honolulu International Airport and hotel porte-cochere at Waikiki, by demand responsive vehicles for collection and distribution operating on fixed guideways for line haul, and by roll-on/roll-off inter-island ferries for all models of manually operated ground vehicles. The paper also describes facilitation of unavoidable interfaces by innovative sub-systems.

  11. Today's research development on the application of the superconductivity transport system in Japan

    NASA Technical Reports Server (NTRS)

    Kyotani, Yoshihiro

    1995-01-01

    At the Miyazaki test track today, the new test vehicle, MLU002N, is under test run to obtain necessary data for Yamanashi test track where the construction is underway, the test vehicle has been ordered and the first tunnel was completed in December 1993. Superconducting magnetohydrodynamic drive ship, MHDS, 'Yamato 1' has completed its experiment in 1992 and it is now under preparation to exhibit to the public in___1994. Furthermore, to promote the research development of MHDS, the detailed discussion is underway on the magnetohydrodynamic drive equipment as well as the research on the future scheme. Neither an automobile nor railway but a new transport system called EQUOS LIM CAR(ELC) has been proposed. By using the rotating magnetic field, it will levitate on the aluminum like reaction plate. On the normal road, it will run by rolling the wheels like an electric car but on the highway, it will levitate on the guideway resulting to less noise, less vibration and pollution free drive. To understand the concept of the ELC, the model was built and experimented by using permanent magnet. The same model was donated to the MUSEUM OF SCIENCE AND INDUSTRY in Chicago and was displayed to the public. Today, the trial superconducting magnet has been made and the research development of the subsystem is underway. Research development of superconducting elevator, equipment for the launching of spaceship, tube transportation system and others are in progress for the superconducting applied transportation system.

  12. Magnetic and levitation characteristics of bulk high-temperature superconducting magnets above a permanent magnet guideway

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Zheng, Botian; He, Dabo; Sun, Ruixue; Deng, Zigang; Xu, Xun; Dou, Shixue

    2016-09-01

    Due to the large levitation force or the large guidance force of bulk high-temperature superconducting magnets (BHTSMs) above a permanent magnet guideway (PMG), it is reasonable to employ pre-magnetized BHTSMs to replace applied-magnetic-field-cooled superconductors in a maglev system. There are two combination modes between the BHTSM and the PMG, distinguished by the different directions of the magnetization. One is the S-S pole mode, and the other is the S-N pole mode combined with a unimodal PMG segment. A multi-point magnetic field measurement platform was employed to acquire the magnetic field signals of the BHTSM surface in real time during the pre-magnetization process and the re-magnetization process. Subsequently, three experimental aspects of levitation, including the vertical movement due to the levitation force, the lateral movement due to the guidance force, and the force relaxation with time, were explored above the PMG segment. Moreover, finite element modeling by COMSOL Multiphysics has been performed to simulate the different induced currents and the potentially different temperature rises with different modes inside the BHTSM. It was found that the S-S pole mode produced higher induced current density and a higher temperature rise inside the BHTSM, which might escalate its lateral instability above the PMG. The S-N pole mode exhibits the opposite characteristics. In general, this work is instructive for understanding and connecting the magnetic flux, the inner current density, the levitation behavior, and the temperature rise of BHTSMs employed in a maglev system.

  13. Automated mixed traffic vehicle control and scheduling study

    NASA Technical Reports Server (NTRS)

    Peng, T. K. C.; Chon, K.

    1976-01-01

    The operation and the expected performance of a proposed automatic guideway transit system which uses low speed automated mixed traffic vehicles (AMTVs) were analyzed. Vehicle scheduling and headway control policies were evaluated with a transit system simulation model. The effect of mixed traffic interference on the average vehicle speed was examined with a vehicle pedestrian interface model. Control parameters regulating vehicle speed were evaluated for safe stopping and passenger comfort. Some preliminary data on the cost and operation of an experimental AMTV system are included. These data were the result of a separate task conducted at JPL, and were included as background information.

  14. Dynamic stability of maglev systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai, Y.; Chen, S.S.; Mulcahy, T.M.

    1992-09-01

    Since the occurrence of dynamic instabilities is not acceptable for any commercial maglev systems, it is important to consider the dynamic instability in the development of all maglev systems. This study is to consider the stability of maglev systems based on experimental data, scoping calculations and simple mathematical models. Divergence and flutter are obtained for coupled vibration of a three-degree-of-freedom maglev vehicle on the guideway which consists of double L-shaped aluminum segments attached to a rotating wheel. The theory and analysis developed in this study provides basic stability characteristics and identifies future research needs for maglev system.

  15. The pitch-heave dynamics of transportation vehicles

    NASA Technical Reports Server (NTRS)

    Sweet, L. M.; Richardson, H. H.

    1975-01-01

    The analysis and design of suspensions for vehicles of finite length using pitch-heave models is presented. Dynamic models for the finite length vehicle include the spatial distribution of the guideway input disturbance over the vehicle length, as well as both pitch and heave degrees-of-freedom. Analytical results relate the vehicle front and rear accelerations to the pitch and heave natural frequencies, which are functions of vehicle suspension geometry and mass distribution. The effects of vehicle asymmetry and suspension contact area are evaluated. Design guidelines are presented for the modification of vehicle and suspension parameters to meet alternative ride quality criteria.

  16. Quality assurance program guidelines for application to and use by manufacturers of rail/guideway vehicles, buses, automatic train control systems, and their major subsystems

    NASA Technical Reports Server (NTRS)

    Witkin, S. A.

    1976-01-01

    Guidelines are presented for a quality assurance system to be implemented by the manufacturer in support of designing, developing, fabricating, assembling, inspecting, testing, handling, and delivery of equipment being procured for use in public urban mass transit systems. The guidelines apply to this equipment when being procured for: (1) use in revenue service; (2) demonstration of systems that will be revenue producing or used by the public; (3) use as a prototype for follow-on operational/revenue producing equipment procurements; and (4) qualification tests.

  17. Today`s research development on the application of the superconductivity transport system in Japan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kyotani, Y.

    1995-04-01

    At the Miyazaki test track today, the new test vehicle, MLU002N, is under test run to obtain necessary data for Yamanashi test track where the construction is underway, the test vehicle has been ordered and the first tunnel was completed in December 1993. Superconducting magnetohydrodynamic drive ship, MHDS, `Yamato 1` has completed its experiment in 1992 and it is now under preparation to exhibit to the public in 1994. Furthermore, to promote the research development of MHDS, the detailed discussion is underway on the magnetohydrodynamic drive equipment as well as the research on the future scheme. Neither an automobile normore » railway but a new transport system called EQUOS LIM CAR(ELC) has been proposed. By using the rotating magnetic field, it will levitate on the aluminum like reaction plate. On the normal road, it will run by rolling the wheels like an electric car but on the highway, it will levitate on the guideway resulting to less noise, less vibration and pollution free drive. To understand the concept of the ELC, the model was built and experimented by using permanent magnet. The same model was donated to the MUSEUM OF SCIENCE AND INDUSTRY in Chicago and was displayed to the public. Today, the trial superconducting magnet has been made and the research development of the subsystem is underway. Research development of superconducting elevator, equipment for the launching of spaceship, tube transportation system and others are in progress for the superconducting applied transportation system.« less

  18. Static and dynamic stability of the guidance force in a side-suspended HTS maglev system

    NASA Astrophysics Data System (ADS)

    Zhou, Dajin; Cui, Chenyu; Zhao, Lifeng; Zhang, Yong; Wang, Xiqing; Zhao, Yong

    2017-02-01

    The static and dynamic stability of the guidance force in a side-suspended HTS-PMG (permanent magnetic guideway) system were studied theoretically and experimentally. It is found that there are two types of guidance force that exist in the HTS-PMG system, which are sensitive to the levitation gap and the arrangement of YBCO bulks around the central axis of the PMG. An optimized YBCO array was used to stabilize the system, which enabled a side-suspended HTS-PMG maglev vehicle to run stably at 102 km h-1 on a circular test track with 6.5 m in diameter.

  19. Assessment of the impact of dipped guideways on urban rail transit systems: Ventilation and safety requirements

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The ventilation and fire safety requirements for subway tunnels with dipped profiles between stations as compared to subway tunnels with level profiles were evaluated. This evaluation is based upon computer simulations of a train fire emergency condition. Each of the tunnel configurations evaluated was developed from characteristics that are representative of modern transit systems. The results of the study indicate that: (1) The level tunnel system required about 10% more station cooling than dipped tunnel systems in order to meet design requirements; and (2) The emergency ventilation requirements are greater with dipped tunnel systems than with level tunnel systems.

  20. Dual-keel electrodynamic maglev system

    DOEpatents

    He, Jianliang; Wang, Zian; Rote, Donald M.; Coffey, Howard T.; Hull, John R.; Mulcahy, Thomas M.; Cal, Yigang

    1996-01-01

    A propulsion and stabilization system with a plurality of superconducting magnetic devices affixed to the dual-keels of a vehicle, where the superconducting magnetic devices produce a magnetic field when energized. The system also includes a plurality of figure-eight shaped null-flux coils affixed to opposing vertical sides of slots in a guideway. The figure-eight shaped null-flux coils are vertically oriented, laterally cross-connected in parallel, longitudinally connected in series, and continue the length of the vertical slots providing levitation and guidance force. An external power source energizes the figure-eight shaped null-flux coils to create a magnetic traveling wave that interacts with the magnetic field produced by the superconducting magnets to impart motion to the vehicle.

  1. Robust levitation control for maglev systems with guaranteed bounded airgap.

    PubMed

    Xu, Jinquan; Chen, Ye-Hwa; Guo, Hong

    2015-11-01

    The robust control design problem for the levitation control of a nonlinear uncertain maglev system is considered. The uncertainty is (possibly) fast time-varying. The system has magnitude limitation on the airgap between the suspended chassis and the guideway in order to prevent undesirable contact. Furthermore, the (global) matching condition is not satisfied. After a three-step state transformation, a robust control scheme for the maglev vehicle is proposed, which is able to guarantee the uniform boundedness and uniform ultimate boundedness of the system, regardless of the uncertainty. The magnitude limitation of the airgap is guaranteed, regardless of the uncertainty. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Field measurements and analyses of environmental vibrations induced by high-speed Maglev.

    PubMed

    Li, Guo-Qiang; Wang, Zhi-Lu; Chen, Suwen; Xu, You-Lin

    2016-10-15

    Maglev, offers competitive journey-times compared to the railway and subway systems in markets for which distance between the stations is 100-1600km owing to its high acceleration and speed; however, such systems may have excessive vibration. Field measurements of Maglev train-induced vibrations were therefore performed on the world's first commercial Maglev line in Shanghai, China. Seven test sections along the line were selected according to the operating conditions, covering speeds from 150 to 430km/h. Acceleration responses of bridge pier and nearby ground were measured in three directions and analyzed in both the time and frequency domain. The effects of Maglev train speed on vibrations of the bridge pier and ground were studied in terms of their peak accelerations. Attenuation of ground vibration was investigated up to 30m from the track centerline. Effects of guideway configuration were also analyzed based on the measurements through two different test sections with same train speed of 300km/h. The results showed that peak accelerations exhibited a strong correlation with both train speed and distance off the track. Guideway configuration had a significant effect on transverse vibration, but a weak impact on vertical and longitudinal vibrations of both bridge pier and ground. Statistics indicated that, contrary to the commonly accepted theory and experience, vertical vibration is not always dominant: transverse and longitudinal vibrations should also be considered, particularly near turns in the track. Moreover, measurements of ground vibration induced by traditional high-speed railway train were carried out with the same testing devices in Bengbu in the Anhui Province. Results showed that the Maglev train generates significantly different vibration signatures as compared to the traditional high-speed train. The results obtained from this paper can provide good insights on the impact of Maglev system on the urban environment and the quality of human life nearby. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Magnetic fields end-face effect investigation of HTS bulk over PMG with 3D-modeling numerical method

    NASA Astrophysics Data System (ADS)

    Qin, Yujie; Lu, Yiyun

    2015-09-01

    In this paper, the magnetic fields end-face effect of high temperature superconducting (HTS) bulk over a permanent magnetic guideway (PMG) is researched with 3D-modeling numerical method. The electromagnetic behavior of the bulk is simulated using finite element method (FEM). The framework is formulated by the magnetic field vector method (H-method). A superconducting levitation system composed of one rectangular HTS bulk and one infinite long PMG is successfully investigated using the proposed method. The simulation results show that for finite geometrical HTS bulk, even the applied magnetic field is only distributed in x-y plane, the magnetic field component Hz which is along the z-axis can be observed interior the HTS bulk.

  4. Dual-keel electrodynamic maglev system

    DOEpatents

    He, J.L.; Wang, Z.; Rote, D.M.; Coffey, H.T.; Hull, J.R.; Mulcahy, T.M.; Cal, Y.

    1996-12-24

    A propulsion and stabilization system is disclosed with a plurality of superconducting magnetic devices affixed to the dual-keels of a vehicle, where the superconducting magnetic devices produce a magnetic field when energized. The system also includes a plurality of figure-eight shaped null-flux coils affixed to opposing vertical sides of slots in a guideway. The figure-eight shaped null-flux coils are vertically oriented, laterally cross-connected in parallel, longitudinally connected in series, and continue the length of the vertical slots providing levitation and guidance force. An external power source energizes the figure-eight shaped null-flux coils to create a magnetic traveling wave that interacts with the magnetic field produced by the superconducting magnets to impart motion to the vehicle. 6 figs.

  5. MagLev Cobra: Test Facilities and Operational Experiments

    NASA Astrophysics Data System (ADS)

    Sotelo, G. G.; Dias, D. H. J. N.; de Oliveira, R. A. H.; Ferreira, A. C.; De Andrade, R., Jr.; Stephan, R. M.

    2014-05-01

    The superconducting MagLev technology for transportation systems is becoming mature due to the research and developing effort of recent years. The Brazilian project, named MagLev-Cobra, started in 1998. It has the goal of developing a superconducting levitation vehicle for urban areas. The adopted levitation technology is based on the diamagnetic and the flux pinning properties of YBa2Cu3O7-δ (YBCO) bulk blocks in the interaction with Nd-Fe-B permanent magnets. A laboratory test facility with permanent magnet guideway, linear induction motor and one vehicle module is been built to investigate its operation. The MagLev-Cobra project state of the art is presented in the present paper, describing some construction details of the new test line with 200 m.

  6. Double row loop-coil configuration for high-speed electrodynamic maglev suspension, guidance, propulsion and guideway directional switching

    DOEpatents

    He, Jianliang; Rote, Donald M.

    1996-01-01

    A stabilization and propulsion system comprising a series of loop-coils arranged in parallel rows wherein two rows combine to form one of two magnetic rails. Levitation and lateral stability are provided when the induced field in the magnetic rails interacts with the superconducting magnets mounted on the magnetic levitation vehicle. The loop-coils forming the magnetic rails have specified dimensions and a specified number of turns and by constructing differently these specifications, for one rail with respect to the other, the angle of tilt of the vehicle can be controlled during directional switching. Propulsion is provided by the interaction of a traveling magnetic wave associated with the coils forming the rails and the super conducting magnets on the vehicle.

  7. Double row loop-coil configuration for high-speed electrodynamic maglev suspension, guidance, propulsion and guideway directional switching

    DOEpatents

    He, J.; Rote, D.M.

    1996-05-21

    A stabilization and propulsion system are disclosed comprising a series of loop-coils arranged in parallel rows wherein two rows combine to form one of two magnetic rails. Levitation and lateral stability are provided when the induced field in the magnetic rails interacts with the superconducting magnets mounted on the magnetic levitation vehicle. The loop-coils forming the magnetic rails have specified dimensions and a specified number of turns and by constructing differently these specifications, for one rail with respect to the other, the angle of tilt of the vehicle can be controlled during directional switching. Propulsion is provided by the interaction of a traveling magnetic wave associated with the coils forming the rails and the superconducting magnets on the vehicle. 12 figs.

  8. Correcting groove error in gratings ruled on a 500-mm ruling engine using interferometric control.

    PubMed

    Mi, Xiaotao; Yu, Haili; Yu, Hongzhu; Zhang, Shanwen; Li, Xiaotian; Yao, Xuefeng; Qi, Xiangdong; Bayinhedhig; Wan, Qiuhua

    2017-07-20

    Groove error is one of the most important factors affecting grating quality and spectral performance. To reduce groove error, we propose a new ruling-tool carriage system based on aerostatic guideways. We design a new blank carriage system with double piezoelectric actuators. We also propose a completely closed-loop servo-control system with a new optical measurement system that can control the position of the diamond relative to the blank. To evaluate our proposed methods, we produced several gratings, including an echelle grating with 79  grooves/mm, a grating with 768  grooves/mm, and a high-density grating with 6000  grooves/mm. The results show that our methods effectively reduce groove error in ruled gratings.

  9. Superconducting Electromagnetic Suspension (EMS) system for Grumman Maglev concept

    NASA Technical Reports Server (NTRS)

    Kalsi, Swarn S.

    1994-01-01

    The Grumman developed Electromagnetic Suspension (EMS) Maglev system has the following key characteristics: a large operating airgap--40 mm; levitation at all speeds; both high speed and low speed applications; no deleterious effects on SC coils at low vehicle speeds; low magnetic field at the SC coil--less than 0.35 T; no need to use non-magnetic/non-metallic rebar in the guideway structure; low magnetic field in passenger cabin--approximately 1 G; low forces on the SC coil; employs state-of-the-art NbTi wire; no need for an active magnet quench protection system; and lower weight than a magnet system with copper coils. The EMS Maglev described in this paper does not require development of any new technologies. The system could be built with the existing SC magnet technology.

  10. Influence of Off-Centre Operation on the Performance of HTS Maglev

    NASA Astrophysics Data System (ADS)

    Gou, Y.; He, D.; Zheng, J.; Ye, C.; Xu, Y.; Sun, R.; Che, T.; Deng, Z.

    2014-03-01

    Owing to instinctive self-stable levitation characteristics, high-temperature superconducting (HTS) maglev using bulk high-temperature superconductors attracts more and more attention from scientists and engineers around the world. In this paper, the levitation force relaxation and guidance force characteristics of a Y-Ba-Cu-O levitation unit with different eccentric distances (EDs) off the center of the permanent magnet guideway were experimentally investigated under field-cooling (FC) conditions. Experimental results indicate that the levitation force slightly increases at small EDs firstly, but degrades with further increasing of EDs. However, the maximum guidance force and its stiffness exhibit enhancement in moderate ED range. The results demonstrate that a properly designed initial FC eccentric distance is important for the practical applications of HTS maglev according to specific requirements like running in curve lines.

  11. Post-TRANSPO test program: summary report. Volume I

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cusick, R.T.; Mooring, E.E.

    1973-06-01

    The report given encompasses the Post-TRANSPO Test Program (PTTP) operation, organization, and instrumentation. The more significant tests are described and a summary of the analyses performed to data is provided for the construction and testing of four prototype Personal Rapid Transit (PRT) Systems at Dulles International Airport. These systems are the Bendix Dashaveyor, the Ford Motor ACT, the Rohr Monocab and the Transportation Technology TTI. Each prototype featured two vehicles with a minimum of 1000 feet of guideway, off-line stations and fully automatic control. The TTI used air cushions for vertical support and a linear induction motor for propulsion. Themore » other systems used rubber tires, two supported from a roadway and the other, the Monocab, suspended from an overhead guidebeam. Conclusions and recommendations for further work are presented.« less

  12. Instrument for the application of controlled mechanical loads to tissues in sterile culture

    DOEpatents

    Lintilhac, Phillip M.; Vesecky, Thompson B.

    1995-01-01

    Apparatus and methods are disclosed facilitating the application of forces and measurement of dimensions of a test subject. In one arrangement the test subject is coupled to a forcing frame and controlled forces applied thereto by a series of guideways and sliders. The sliders, which contact the test subject are in force transmitting relation to a forcing frame. Tension, compression and bending forces can be applied to the test subject. Force applied to the test subject is measured and controlled. A dimensional characteristic of the test subject, such as growth, is measured by a linear variable differential transformer. The growth measurement data can be used to control the force applied. Substantially uniaxial stretching is achieved by placing the test subject on an elastic membrane stretched by an arrangement of members securing the elastic member to the forcing frame.

  13. A method to enhance the curve negotiation performance of HTS Maglev

    NASA Astrophysics Data System (ADS)

    Che, T.; Gou, Y. F.; Deng, Z. G.; Zheng, J.; Zheng, B. T.; Chen, P.

    2015-09-01

    High temperature superconducting (HTS) Maglev has attracted more and more attention due to its special self-stable characteristic, and much work has been done to achieve its actual application, but the research about the curve negotiation is not systematic and comprehensive. In this paper, we focused on the change of the lateral displacements of the Maglev vehicle when going through curves under different velocities, and studied the change of the electromagnetic forces through experimental methods. Experimental results show that setting an appropriate initial eccentric distance (ED), which is the distance between the center of the bulk unit and the center of the permanent magnet guideway (PMG), when cooling the bulks is favorable for the Maglev system’s curve negotiation. This work will provide some available suggestions for improving the curve negotiation performance of the HTS Maglev system.

  14. Design and analysis of an electromagnetic turnout for the superconducting Maglev system

    NASA Astrophysics Data System (ADS)

    Li, Y. J.; Dai, Q.; Zhang, Y.; Wang, H.; Chen, Z.; Sun, R. X.; Zheng, J.; Deng, C. Y.; Deng, Z. G.

    2016-09-01

    Turnout is a crucial track junction device of the ground rail transportation system. For high temperature superconducting (HTS) Maglev system, the permanent magnet guideway (PMG) makes the strong magnetic force existing between rail segments, which may cause moving difficulties and increase the operation cost when switching a PMG. In this paper, a non-mechanical 'Y' shaped Halbach-type electromagnetic turnout was proposed. By replacing the PMs with electromagnets, the turnout can guide the maglev vehicle running into another PMG by simply controlling the current direction of electromagnets. The material and structure parameters of the electromagnets were optimized by simulation. The results show that the optimized electromagnet can keep the magnetic field above it as strong as the PMs', meanwhile feasible for design and manufacture. This work provides valuable references for the future design in non-mechanical PMG turnout.

  15. Maglev-rail intermodal equipment and suspension study. Final report, July 1991-February 1993

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gilcrease, E.E.; Gillam, C.M.

    1993-02-01

    The physical and operational characteristics of four existing and planned maglev systems were surveyed pertinent to the intermodal interface for each system. The maglev systems investigated were: Grumman New York State' (Configuration 002) Maglev; Transrapid Intercity (Transrapid 07) Maglev; HSST Passive Intermediate Speed (HSST-300) Maglev; and Japan Railways Vertical Magnet (Configuration MLU 002) Maglev. The focus of the study was to investigate the feasibility of using existing railroad right-of-way to access center-city terminals in one of three possible methods: Maglev vehicles traveling over existing railroad tracks with the use of steel guide wheels and some means of exterior propulsion; maglevmore » vehicles transferred onto modified railroad flatcars and transported over existing railroad tracks with locomotive power; or new grade-separated maglev guideways on existing railroad rights-of-way.« less

  16. Flux-canceling electrodynamic maglev suspension. Part 1: Test fixture design and modeling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thompson, M.T.; Thornton, R.D.; Kondoleon, A.

    1999-05-01

    The design and analysis of a scale-model suspension test facility for magnetic levitation (maglev) is discussed. The authors describe techniques for the design, construction, and testing of a prototype electrodynamic suspension (EDS) levitation system. The viability of future high-temperature superconducting magnet designs for maglev has been investigated with regard to their application to active secondary suspensions. In order to test the viability of a new flux-canceling EDS suspension, a 1/5-scale suspension magnet and guideway was constructed. The suspension was tested by using a high-speed rotating test wheel facility with linear peripheral speed of up to 84 m/s (300 km/h). Amore » set of approximate design tools and scaling laws has been developed in order to evaluate forces and critical velocities in the suspension.« less

  17. Air Bearings Machined On Ultra Precision, Hydrostatic CNC-Lathe

    NASA Astrophysics Data System (ADS)

    Knol, Pierre H.; Szepesi, Denis; Deurwaarder, Jan M.

    1987-01-01

    Micromachining of precision elements requires an adequate machine concept to meet the high demand of surface finish, dimensional and shape accuracy. The Hembrug ultra precision lathes have been exclusively designed with hydrostatic principles for main spindle and guideways. This concept is to be explained with some major advantages of hydrostatics compared with aerostatics at universal micromachining applications. Hembrug has originally developed the conventional Mikroturn ultra precision facing lathes, for diamond turning of computer memory discs. This first generation of machines was followed by the advanced computer numerically controlled types for machining of complex precision workpieces. One of these parts, an aerostatic bearing component has been succesfully machined on the Super-Mikroturn CNC. A case study of airbearing machining confirms the statement that a good result of the micromachining does not depend on machine performance alone, but also on the technology applied.

  18. Study on the effect of transition curve to the dynamic characteristics of high-temperature superconducting maglev

    NASA Astrophysics Data System (ADS)

    Qian, Nan; Zheng, Botian; Gou, Yanfeng; Chen, Ping; Zheng, Jun; Deng, Zigang

    2015-12-01

    High temperature superconducting (HTS) maglev technology is becoming more and more mature, and many key technologies have been deeply studied. However, the transition curve plays a key role in HTS maglev system, and related studies have not been carried out. In this paper series of simulations were conducted to test the lateral and vertical vibration of HTS maglev when passing through curves. Two magnetic guideways, of which one has transition curves but the other does not, are designed to test the vibration characteristics of a mini HTS maglev model running though curves. Results show that after adding transition curves between straight line and circular curve the vibration of HTS maglev model in lateral and vertical directions are all weakened in different degrees. It proves that adding transition curve into HTS maglev system is favorable and necessary.

  19. Feasibility of low-cost magnetic rail designs by integrating ferrite magnets and NdFeB magnets for HTS Maglev systems

    NASA Astrophysics Data System (ADS)

    Sun, R. X.; Deng, Z. G.; Gou, Y. F.; Li, Y. J.; Zheng, J.; Wang, S. Y.; Wang, J. S.

    2015-09-01

    Permanent magnet guideway (PMG) is an indispensable part of high temperature superconducting (HTS) Maglev systems. Present PMGs are made of NdFeB magnets with excellent performance and cost much. As another permanent magnet material, the ferrite magnet is weak at magnetic energy product and coercive force, but inexpensive. So, it is a possible way to integrate the ferrite and NdFeB magnets for cutting down the cost of present PMGs. In the paper, the equivalent on magnetic field intensity between ferrite magnets and NdFeB magnets was evaluated by finite element simulation. According to the calculation results, the magnetic field of the PMG integrating ferrite magnets and NdFeB magnets can be increased remarkably comparing with the pure ferrite PMG. It indicates that low-cost PMG designs by integrating the two permanent magnet materials are feasible for the practical HTS Maglev system.

  20. Dynamic stability experiment of Maglev systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai, Y.; Mulcahy, T.M.; Chen, S.S.

    1995-04-01

    This report summarizes the research performed on Maglev vehicle dynamic stability at Argonne National Laboratory during the past few years. It also documents magnetic-force data obtained from both measurements and calculations. Because dynamic instability is not acceptable for any commercial Maglev system, it is important to consider this phenomenon in the development of all Maglev systems. This report presents dynamic stability experiments on Maglev systems and compares their numerical simulation with predictions calculated by a nonlinear dynamic computer code. Instabilities of an electrodynamic system (EDS)-type vehicle model were obtained from both experimental observations and computer simulations for a five-degree-of-freedom Maglevmore » vehicle moving on a guideway consisting of double L-shaped aluminum segments attached to a rotating wheel. The experimental and theoretical analyses developed in this study identify basic stability characteristics and future research needs of Maglev systems.« less

  1. Noise from high speed maglev systems: Noise sources, noise criteria, preliminary design guidelines for noise control, recommendations for acoustical test facility for maglev research. Final report, July 1991-October 1992

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hanson, C.E.; Abbot, P.; Dyer, I.

    1993-01-01

    Noise levels from magnetically-levitated trains (maglev) at very high speed may be high enough to cause environmental noise impact in residential areas. Aeroacoustic sources dominate the sound at high speeds and guideway vibrations generate noticeable sound at low speed. In addition to high noise levels, the startle effect as a result of sudden onset of sound from a rapidly moving nearby maglev vehicle may lead to increased annoyance to neighbors of a maglev system. The report provides a base for determining the noise consequences and potential mitigation for a high speed maglev system in populated areas of the United States.more » Four areas are included in the study: (1) definition of noise sources; (2) development of noise criteria; (3) development of design guidelines; and (4) recommendations for a noise testing facility.« less

  2. Instrument for the application of controlled mechanical loads to tissues in sterile culture

    DOEpatents

    Lintilhac, P.M.; Vesecky, T.B.

    1995-04-18

    Apparatus and methods are disclosed facilitating the application of forces and measurement of dimensions of a test subject. In one arrangement the test subject is coupled to a forcing frame and controlled forces applied thereto by a series of guideways and sliders. The sliders, which contact the test subject are in force transmitting relation to a forcing frame. Tension, compression and bending forces can be applied to the test subject. Force applied to the test subject is measured and controlled. A dimensional characteristic of the test subject, such as growth, is measured by a linear variable differential transformer. The growth measurement data can be used to control the force applied. Substantially uniaxial stretching is achieved by placing the test subject on an elastic membrane stretched by an arrangement of members securing the elastic member to the forcing frame. 8 figs.

  3. DOT/NASA comparative assessment of Brayton engines for guideway vehicle and buses. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The Department of Transportation requested that the NASA Office of Aeronautics and Space Technology evaluate and assess the potential of several types of gas turbine engines and fuels for the on-board power and propulsion of a future heavy-duty ground transportation system. The purpose of the investigation was threefold: (1) to provide a definition of the potential for turbine engines to minimize pollution, energy consumption, and noise; (2) to provide a useful means of comparison of the types of engine based on consistent assumptions and a common analytical approach; and (3) to provide a compendium of comparative performance data that would serve as the technical basis for future planning. Emphasis was on establishing comparison trends rather than on absolute values and a definitive engine selection. The primary value of this study is intended to be usefulness of the results to provide a quantitative basis for future judgement.

  4. Automated Mixed Traffic Vehicle (AMTV) technology and safety study

    NASA Technical Reports Server (NTRS)

    Johnston, A. R.; Peng, T. K. C.; Vivian, H. C.; Wang, P. K.

    1978-01-01

    Technology and safety related to the implementation of an Automated Mixed Traffic Vehicle (AMTV) system are discussed. System concepts and technology status were reviewed and areas where further development is needed are identified. Failure and hazard modes were also analyzed and methods for prevention were suggested. The results presented are intended as a guide for further efforts in AMTV system design and technology development for both near term and long term applications. The AMTV systems discussed include a low speed system, and a hybrid system consisting of low speed sections and high speed sections operating in a semi-guideway. The safety analysis identified hazards that may arise in a properly functioning AMTV system, as well as hardware failure modes. Safety related failure modes were emphasized. A risk assessment was performed in order to create a priority order and significant hazards and failure modes were summarized. Corrective measures were proposed for each hazard.

  5. Method and apparatus to control the lateral motion of a long metal bar being formed by a mechanical process such as rolling or drawing

    DOEpatents

    Chang, Tzyy-Shuh [Ann Arbor, MI; Huang, Hsun-Hau [Ann Arbor, MI; Lin, Chang-Hung [Ypsilanti, MI

    2011-01-04

    An apparatus to control lateral motion of a bar moving along a guidance path includes a pair of rotatable hubs each having at least first and second rollers at locations around the perimeter of the hub. The first roller has a first retaining groove of a first radius and the second roller has a second groove of a second radius smaller than the first radius. Each hub further includes at least one guiding element located between the rollers with a guide channel extending in the outer surface. A mounting system allows the hubs to be rotated between first and second positions. In the first position the first rollers oppose each other forming a guideway having a first, enlarged diameter for capturing a free end of an approaching bar. In the second position the second rollers form a second, smaller diameter to match the actual size of the bar.

  6. Coasting characteristic of the flywheel system under anisotropy effect of bulk high temperature superconductors

    NASA Astrophysics Data System (ADS)

    Wu, J. F.; Li, Y.

    2014-10-01

    High-temperature superconductors (HTSCs) array with aligned growth section boundary (GSB) pattern (AGSBP) exhibits larger levitation force and suppression of levitation force decay above a permanent magnet guideway (PMG) compared with misaligned GSB pattern (MGSBP) has been studied in maglev train application (Zheng et al., 2013). This result maybe helpful and support a new way for the HTS bearing design for flywheel systems. So, in this paper, we further examine this growth anisotropy effect on the maglev performance of flywheel system. Levitation force and coasting time were investigated from the point-view of HTS flywheel applications. The GS/GSB alignment of AGSBP bulk HTSCs produces larger levitation force than that of MGSBP, but the coasting time is shorter than that of MGSBP, that is to say, the electric magnetic drag force with AGSBP is larger than that of MGSBP. This result may also exist in the maglev guideline when the maglev train stops freely.

  7. Technical assessment of maglev system concepts. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lever, J.H.

    1998-10-01

    The Government Maglev System Assessment Team operated from 1991 to 1993 as part of the National Maglev Initiative. They assessed the technical viability of four US Maglev system concepts, using the French TGV high speed train and the German TR07 Maglev system as assessment baselines. Maglev in general offers advantages that include high speed potential, excellent system control, high capacity, low energy consumption, low maintenance, modest land requirements, low operating costs, and ability to meet a variety of transportation missions. Further, the US Maglev concepts could provide superior performance to TR07 for similar cost or similar performance for less cost.more » They also could achieve both lower trip times and lower energy consumption along typical US routes. These advantages result generally from the use of large gap magnetic suspensions, more powerful linear synchronous motors and tilting vehicles. Innovative concepts for motors, guideways, suspension, and superconducting magnets all contribute to a potential for superior long term performance of US Maglev systems compared with TGV and TR07.« less

  8. Growth anisotropy effect of bulk high temperature superconductors on the levitation performance in the applied magnetic field

    NASA Astrophysics Data System (ADS)

    Zheng, J.; Liao, X. L.; Jing, H. L.; Deng, Z. G.; Yen, F.; Wang, S. Y.; Wang, J. S.

    2013-10-01

    Growth anisotropies of bulk high temperature superconductors (HTSCs) fabricated by a top-seeded melt texture growth process, that is, different pinning effect in the growth sectors (GSs) and growth sector boundaries (GSBs), possess effect on the macro flux trapping and levitation performance of bulk HTSCs. Previous work (Physics Procedia, 36 (2012) 1043) has found that the bulk HTSC array with aligned GSB pattern (AGSBP) exhibits better capability for levitation and suppression of levitation force decay above a permanent magnet guideway (PMG) compared with misaligned GSB pattern (MGSBP). In this paper, we further examine this growth anisotropy effect on the maglev performance of a double-layer bulk HTSC. In contrast to reported trapped flux cases (Supercond. Sci. Technol. 19 (2006) S466), the two superposed bulk HTSCs with same AGSBP with PMG are found to show better maglev performance. These series of results are helpful and support a new way for the performance optimization of present HTS maglev systems.

  9. Feasibility of introducing ferromagnetic materials to onboard bulk high-Tc superconductors to enhance the performance of present maglev systems

    NASA Astrophysics Data System (ADS)

    Deng, Zigang; Wang, Jiasu; Zheng, Jun; Zhang, Ya; Wang, Suyu

    2013-02-01

    Performance improvement is a long-term research task for the promotion of practical application of promising high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle technologies. We studied the feasibility to enhance the performance of present HTS Maglev systems by introducing ferromagnetic materials to onboard bulk superconductors. The principle here is to make use of the high magnetic permeability of ferromagnetic materials to alter the flux distribution of the permanent magnet guideway for the enhancement of magnetic field density at the position of the bulk superconductors. Ferromagnetic iron plates were added to the upper surface of bulk superconductors and their geometric and positioning effects on the maglev performance were investigated experimentally. Results show that the guidance performance (stability) was enhanced greatly for a particular setup when compared to the present maglev system which is helpful in the application where large guidance forces are needed such as maglev tracks with high degrees of curves.

  10. Wear resistance of ductile irons

    NASA Astrophysics Data System (ADS)

    Lerner, Y. S.

    1994-06-01

    This study was undertaken to evaluate the wear resistance of different grades of ductile iron as alterna-tives to high- tensile- strength alloyed and inoculated gray irons and bronzes for machine- tool and high-pressure hydraulic components. Special test methods were employed to simulate typical conditions of reciprocating sliding wear with and without abrasive- contaminated lubricant for machine and press guideways. Quantitative relationships were established among wear rate, microstructure and micro-hardness of structural constituents, and nodule size of ductile iron. The frictional wear resistance of duc-tile iron as a bearing material was tested with hardened steel shafts using standard test techniques under continuous rotating movement with lubricant. Lubricated sliding wear tests on specimens and compo-nents for hydraulic equipment and apparatus were carried out on a special rig with reciprocating motion, simulating the working conditions in a piston/cylinder unit in a pressure range from 5 to 32 MPa. Rig and field tests on machine- tool components and units and on hydraulic parts have confirmed the test data.

  11. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miller, John M.; Jones, Perry T.; Li, Jan-Mou

    As visionary as dynamic, or in-motion, wireless charging of electric vehicles appears the concept is well over a century old as this paper will show. This is because the concept of magnetic induction dates back to the pioneering work of physicist Michael Faraday in the early 19th century. Today wireless power transfer (WPT) is being standardized for stationary and quasi-stationary charging of electric vehicles (EV). The Society of Automotive Engineers (SAE) has undertaken the standardization of stationary charging and will make this public during 2016. In addition to this the IEEE-SA (Standards Activities) initiated standards development for EV?s in theirmore » EVWPT working group in 2012. This study introduces the many challenges facing EVWPT in not only high power transfer to a moving vehicle and energy management at a utility scale, but communications in a vehicle to infrastructure (V2I) environment and management of high data rates, ultra-low latency, and dealing with communications loss in dense urban areas. Finally, future concepts such as guideway powering of EV?s are presented to illustrate one technical trajectory EVWPT may take.« less

  12. Observation of the Field, Current and Force Distributions in an Optimized Superconducting Levitation with Translational Symmetry

    NASA Astrophysics Data System (ADS)

    Ye, Chang-Qing; Ma, Guang-Tong; Liu, Kun; Wang, Jia-Su

    2017-01-01

    The superconducting levitation realized by immersing the high-temperature superconductors (HTSs) into nonuniform magnetic field is deemed promising in a wide range of industrial applications such as maglev transportation and kinetic energy storage. Using a well-established electromagnetic model to mathematically describe the HTS, we have developed an efficient scheme that is capable of intelligently and globally optimizing the permanent magnet guideway (PMG) with single or multiple HTSs levitated above for the maglev transportation applications. With maximizing the levitation force as the principal objective, we optimized the dimensions of a Halbach-derived PMG to observe how the field, current and force distribute inside the HTSs when the optimized situation is achieved. Using a pristine PMG as a reference, we have analyzed the critical issues for enhancing the levitation force through comparing the field, current and force distributions between the optimized and pristine PMGs. It was also found that the optimized dimensions of the PMG are highly dependent upon the levitated HTS. Moreover, the guidance force is not always contradictory to the levitation force and may also be enhanced when the levitation force is prescribed to be the principle objective, depending on the configuration of levitation system and lateral displacement.

  13. A novel HTS magnetic levitation dining table

    NASA Astrophysics Data System (ADS)

    Lu, Yiyun; Huang, Huiying

    2018-05-01

    High temperature superconducting (HTS) bulk can levitate above or suspend below a permanent magnet stably. Many magnificent potential applications of HTS bulk are proposed by researchers. Until now, few reports have been found for real applications of HTS bulk. A complete set of small-scale HTS magnetic levitation table is proposed in the paper. The HTS magnetic levitation table includes an annular HTS magnetic levitation system which is composed of an annular HTS bulk array and an annular permanent magnet guideway (PMG). The annular PMG and the annular cryogenics vessel which used to maintain low temperature environment of the HTS bulk array are designed. 62 YBCO bulks are used to locate at the bottom of the annular vessel. A 3D-model finite element numerical method is used to design the HTS bulk magnetic levitation system. Equivalent magnetic levitation and guidance forces calculation rules are proposed aimed at the annular HTS magnetic levitation system stability. Based on the proposed method, levitation and guidance forces curves of the one YBCO bulk magnetic above PMG could be obtained. This method also can use to assist PMG design to check whether the designed PMG could reach the basic demand of the HTS magnetic levitation table.

  14. Remagnetization effects due to lateral displacement above a PMG on bulk HTS magnet

    NASA Astrophysics Data System (ADS)

    Liu, W.; Wang, J. S.; Ma, G. T.; Zheng, J.; Ren, J. F.; Li, L. L.; Yang, X. F.; Ye, C. Q.; Wang, S. Y.

    2012-12-01

    For a high-Tc superconducting (HTS) maglev system with large force requirements, the use of magnetized bulk high-Tc superconductor magnets (MBSCMs) is a good candidate because of its strong flux pinning ability and corresponding high trapped flux. Different from the rare-earth permanent magnet (PM), the trapped flux of a MBSCM is sustained by the supercurrent produced by a magnetizing process, so the trapped flux is sensitive to variations of the supercurrent. The lateral displacement of a MBSCM above a PM guideway (PMG) will provide disturbance of the applied field and then alter the supercurrent as a process of remagnetization. Different magnetization histories will bring different remagnetization characteristics and consequently diverse levitation performances for a MBSCM during the lateral displacements. When the MBSCMs are applied into the HTS maglev system, the influence of lateral displacements on levitation performance should be taken into consideration. This article investigates the remagnetization characteristics of a MBSCM when it is subject to the lateral displacements above a PMG with different trapped magnetic flux and opposite magnetization polarities. Relevant analyses about the internal supercurrent configuration based on the critical state model are also included to better understand the remagnetization characteristic of a MBSCM.

  15. ORNL Experience and Challenges Facing Dynamic Wireless Power Charging of EV's

    DOE PAGES

    Miller, John M.; Jones, Perry T.; Li, Jan-Mou; ...

    2015-05-21

    As visionary as dynamic, or in-motion, wireless charging of electric vehicles appears the concept is well over a century old as this paper will show. This is because the concept of magnetic induction dates back to the pioneering work of physicist Michael Faraday in the early 19th century. Today wireless power transfer (WPT) is being standardized for stationary and quasi-stationary charging of electric vehicles (EV). The Society of Automotive Engineers (SAE) has undertaken the standardization of stationary charging and will make this public during 2016. In addition to this the IEEE-SA (Standards Activities) initiated standards development for EV?s in theirmore » EVWPT working group in 2012. This study introduces the many challenges facing EVWPT in not only high power transfer to a moving vehicle and energy management at a utility scale, but communications in a vehicle to infrastructure (V2I) environment and management of high data rates, ultra-low latency, and dealing with communications loss in dense urban areas. Finally, future concepts such as guideway powering of EV?s are presented to illustrate one technical trajectory EVWPT may take.« less

  16. Frequency Characteristics of the MAGLEV Double-layered Propulsion Coil

    NASA Astrophysics Data System (ADS)

    Ema, Satoshi

    The MAGLEV (magnetically levitated vehicle) is now well along in development testing at Yamanashi Test Line. The MAGLEV power source needs to supply a variable voltage and variable frequency to propulsion coils, which installed on outdoor guideway. The output voltage of the electric power converter contains many higher harmonics, which causes many troubles such as inductive interference. Accordingly, it is necessary to clarify the frequency characteristics of the propulsion coils and the power feeding circuit. In view of this situation, experiments and the theoretical analysis concerning the frequency characteristics of the propulsion coils with single-layer arrangement and the power feeding circuit at Miyazaki Test Line had been performed by the author. But the arrangement of the propulsion coils had been changed in Yamanashi Test Line from the single-layered coils to the double-layered coils for the stability of the super-conducting magnet on board. Thus, experiments and investigations concerning the frequency characteristics(resonance characteristics)of the propulsion coils with double-layer arrangement at Yamanashi Test Line have been performed but a theoretical analysis had not been done enough. A theoretical analysis was therefore done in this paper by applying the inverted L equivalent circuit with mutual inductance and capacitance to the propulsion coil, from which the positive and zero phase characteristics of the double-layered propulsion coils were analyzed.

  17. Advanced Concept

    NASA Image and Video Library

    1999-10-21

    This artist’s concept depicts a Magnetic Launch Assist vehicle in orbit. Formerly referred to as the Magnetic Levitation (Maglev) system, the Magnetic Launch Assist system is a launch system developed and tested by engineers at the Marshall Space Flight Center (MSFC) that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using electricity and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. The system is similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway. A full-scale, operational track would be about 1.5-miles long, capable of accelerating a vehicle to 600 mph in 9.5 seconds, and the vehicle would then shift to rocket engines for launch into orbit. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  18. An efficient and economical way to enhance the performance of present HTS Maglev systems by utilizing the anisotropy property of bulk superconductors

    NASA Astrophysics Data System (ADS)

    Deng, Zigang; Wang, Jiasu; Zheng, Jun; Zhang, Ya; Wang, Suyu

    2013-02-01

    We report a simple, efficient and economical way to enhance the levitation or guidance performance of present high-temperature superconducting (HTS) Maglev systems by exploring the anisotropic properties of the critical current density in the a-b plane and along the c-axis of bulk superconductors. In the method, the bulk laying mode with different c-axis directions is designed to match with the magnetic field configuration of the applied permanent magnet guideway (PMG). Experimental results indicate that more than a factor of two improvement in the levitation force or guidance force is achieved when changing the laying mode of bulk superconductors from the traditional fashion of keeping the c-axis vertical to the PMG surface to the studied one of keeping the c-axis parallel to the PMG surface, at the maximum horizontal and vertical magnetic field positions of the PMG, respectively. These phenomena resulted from the physical nature of the generated levitation force and guidance force (electromagnetic forces) and the fact that there are different critical current densities in the a-b plane and along the c axis. Based on the experimental results, new HTS Maglev systems can be designed to meet the requirements of practical heavy-load or curved-route applications.

  19. Development of a simulation model of semi-active suspension for monorail

    NASA Astrophysics Data System (ADS)

    Hasnan, K.; Didane, D. H.; Kamarudin, M. A.; Bakhsh, Qadir; Abdulmalik, R. E.

    2016-11-01

    The new Kuala Lumpur Monorail Fleet Expansion Project (KLMFEP) uses semiactive technology in its suspension system. It is recognized that the suspension system influences the ride quality. Thus, among the way to further improve the ride quality is by fine- tuning the semi-active suspension system on the new KL Monorail. The semi-active suspension for the monorail specifically in terms of improving ride quality could be exploited further. Hence a simulation model which will act as a platform to test the design of a complete suspension system particularly to investigate the ride comfort performance is required. MSC Adams software was considered as the tool to develop the simulation platform, where all parameters and data are represented by mathematical equations; whereas the new KL Monorail being the reference model. In the simulation, the model went through step disturbance on the guideway for stability and ride comfort analysis. The model has shown positive results where the monorail is in stable condition as an outcome from stability analysis. The model also scores a Rating 1 classification in ISO 2631 Ride Comfort performance which is very comfortable as an overall outcome from ride comfort analysis. The model is also adjustable, flexibile and understandable by the engineers within the field for the purpose of further development.

  20. Analysis of Ground Effects on Aerodynamic Characteristics of Aerofoils Using Boundary Layer Approximation

    NASA Astrophysics Data System (ADS)

    Takahashi, Yuji; Kikuchi, Masanori; Hirano, Kimitaka

    A study of a new high-speed zero-emission transportation “Aerotrain” is being carried out in Tohoku University and the University of Miyazaki. Because the aerotrain utilizes the ground effect, research on the aerofoil section, which can harness the ground effect effectively, is important. The aerotrain moves along a U-shaped guideway, which has a ground and sidewalls, so it has many viscous interference elements. In an analysis of the ground effects on the aerodynamic characteristics of aerofoils, the boundary layers on the aerofoil surface must be considered. At first, velocity distributions on the surfaces of aerofoils in potential flows are computed using the vortex method, then the momentum integration equations of the boundary layer are solved with experimental formulas. This procedure has the following advantages: modifications of the aerofoil section are easy because it is not necessary to make complicated computational grids, boundary layer transition and separation can be predicted using empirical procedures. The aerodynamic characteristics of four types of aerofoil sections are investigated to clarify the relationship between aerofoil sections and ground effects. Computational results are compared with experimental results obtained using a towing wind tunnel to verify computational precisions. In addition, aerofoil characteristics at an actual cruise speed are analyzed.

  1. Design, manufacture and performance evaluation of HTS electromagnets for the hybrid magnetic levitation system

    NASA Astrophysics Data System (ADS)

    Chu, S. Y.; Hwang, Y. J.; Choi, S.; Na, J. B.; Kim, Y. J.; Chang, K. S.; Bae, D. K.; Lee, C. Y.; Ko, T. K.

    2011-11-01

    A high speed electromagnetic suspension (EMS) maglev has emerged as the solution to speed limit problem that conventional high-speed railroad has. In the EMS maglev, small levitation gap needs uniform guide-way which leads to increase the construction cost. The large levitation gap can reduce the construction cost. However it is hard for normal conducting electromagnet to produce larger magneto-motive force (MMF) for generating levitation force as increased levitation gap. This is because normal conductors have limited rating current to their specific volume. Therefore, the superconducting electromagnet can be one of the solutions for producing both large levitation gap and sufficient MMF. The superconducting electromagnets have incomparably high allowable current density than what normal conductors have. In this paper, the prototype of high temperature superconducting (HTS) electromagnets were designed and manufactured applicable to hybrid electromagnetic suspension system (H-EMS). The H-EMS consists of control coils for levitation control and superconducting coils for producing MMF for levitation. The required MMF for generating given levitation force was calculated by both equations of ideal U-core magnet and magnetic field analysis using the finite element method (FEM). The HTS electromagnets were designed as double pancakes with Bi-2223/Ag tapes. Experiments to confirm its operating performance were performed in liquid nitrogen (LN2).

  2. Advanced Concept

    NASA Image and Video Library

    1999-01-01

    This artist’s concept depicts a Magnetic Launch Assist vehicle clearing the track and shifting to rocket engines for launch into orbit. The system, formerly referred as the Magnetic Levitation (MagLev) system, is a launch system developed and tested by Engineers at the Marshall Space Flight Center (MSFC) that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using an off-board electric energy source and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. The system is similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway. A full-scale, operational track would be about 1.5-miles long, capable of accelerating a vehicle to 600 mph in 9.5 seconds, and the vehicle would then shift to rocket engines for launch into orbit. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  3. Dynamic levitation performance of Gd-Ba-Cu-O and Y-Ba-Cu-O bulk superconductors under a varying external magnetic field

    NASA Astrophysics Data System (ADS)

    Liao, Hengpei; Zheng, Jun; Jin, Liwei; Huang, Huan; Deng, Zigang; Shi, Yunhua; Zhou, Difan; Cardwell, David A.

    2018-07-01

    We report that the dynamic levitation force of bulk high temperature superconductors (HTS) in motion attenuates when exposed to an inhomogeneous magnetic field. This phenomenon has significant potential implications for the long-term stability and running performance of HTS in maglev applications. In order to suppress the attenuation of the levitation force associated with fluctuations in magnetic field, we compare the dynamic levitation performance of single grain Y-Ba-Cu-O (YBCO) and Gd-Ba-Cu-O (GdBCO) bulk superconductors with relatively high critical current densities. A bespoke HTS maglev dynamic measurement system (SCML-03) incorporating a rotating circular permanent magnet guideway was employed to simulate the movement of HTS in a varying magnetic field at different frequencies (i.e. speed of rotation). The attenuation of the levitation force during dynamic operation, which is key parameter for effective maglev operation, has been evaluated experimentally. It is found that GdBCO bulk superconductors that exhibit superior levitation force properties are more able to resist the attenuation of levitation force compared with YBCO bulk materials under the same operating conditions. This investigation indicates clearly that GdBCO bulk superconductors can play an important role in suppressing attenuation of the levitation force, therefore improving the long-term levitation performance under dynamic operating conditions. This result is potentially significant in the design and application of HTS in maglev systems.

  4. Artist's Concept of Magnetic Launch Assisted Air-Breathing Rocket

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This artist's concept depicts a Magnetic Launch Assist vehicle in orbit. Formerly referred to as the Magnetic Levitation (Maglev) system, the Magnetic Launch Assist system is a launch system developed and tested by engineers at the Marshall Space Flight Center (MSFC) that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using electricity and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. The system is similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway. A full-scale, operational track would be about 1.5-miles long, capable of accelerating a vehicle to 600 mph in 9.5 seconds, and the vehicle would then shift to rocket engines for launch into orbit. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  5. National Maglev initiative: California line electric utility power system requirements

    NASA Technical Reports Server (NTRS)

    Save, Phil

    1994-01-01

    The electrical utility power system requirements were determined for a Maglev line from San Diego to San Francisco and Sacramento with a maximum capacity of 12,000 passengers an hour in each direction at a speed of 300 miles per hour, or one train every 30 seconds in each direction. Basically the Maglev line requires one 50-MVA substation every 12.5 miles. The need for new power lines to serve these substations and their voltage levels are based not only on equipment loading criteria but also on limitations due to voltage flicker and harmonics created by the Maglev system. The resulting power system requirements and their costs depend mostly on the geographical area, urban or suburban with 'strong' power systems, or mountains and rural areas with 'weak' power systems. A reliability evaluation indicated that emergency power sources, such as a 10-MW battery at each substation, were not justified if sufficient redundancy is provided in the design of the substations and the power lines serving them. With a cost of $5.6 M per mile, the power system requirements, including the 12-kV DC cables and the inverters along the Maglev line, were found to be the second largest cost component of the Maglev system, after the cost of the guideway system ($9.1 M per mile), out of a total cost of $23 M per mile.

  6. Magnetic Launch Assist Vehicle-Artist's Concept

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This artist's concept depicts a Magnetic Launch Assist vehicle clearing the track and shifting to rocket engines for launch into orbit. The system, formerly referred as the Magnetic Levitation (MagLev) system, is a launch system developed and tested by Engineers at the Marshall Space Flight Center (MSFC) that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using an off-board electric energy source and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. The system is similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway. A full-scale, operational track would be about 1.5-miles long, capable of accelerating a vehicle to 600 mph in 9.5 seconds, and the vehicle would then shift to rocket engines for launch into orbit. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  7. Levitation and guidance force relaxations of the single-seeded and multi-seeded YBCO superconductors

    NASA Astrophysics Data System (ADS)

    Abdioglu, M.; Ozturk, K.; Kabaer, M.; Ekici, M.

    2018-01-01

    The stable levitation and guidance forces at higher force levels are important parameters for technological applicability of high temperature superconductors (HTSs) in Maglev and Flywheel energy storage systems. In this study, we have investigated the levitation and guidance force relaxation of both the single-seeded and multi-seeded YBCOs for different (HTS)-permanent magnetic guideway (PMG) arrangements in different cooling heights (CH). The measured saturated force values of Halbach PMG arrangements are bigger than the maximum force values of other PMGs. It is determined that the normalized magnetic levitation force (MLF) and normalized guidance force (GF) relaxation rate values decrease while the relaxation rates increase with increasing magnetic pole number and the effective external magnetic field area for both the single-seeded and multi-seeded YBCO. Also it can be said that the force stability at the higher force value of Halbach PMG arrangement indicates that the relaxation quality of Halbach PMG is better than that of the others. Additionally, it can be said that both the MLF and GF relaxation qualities of the multi-seeded YBCOs are better than that of the single-seeded ones. This magnetic force and relaxation results of the single-seeded and multi-seeded YBCOs are useful to optimize the loading capacity and lateral reliability of HTS Maglev and similar magnetic bearing systems.

  8. Magnetic Signals of High-Temperature Superconductor Bulk During the Levitation Force Measurement Process

    NASA Astrophysics Data System (ADS)

    Huang, Huan; Zheng, Jun; Qian, Nan; Che, Tong; Zheng, Botian; Jin, Liwei; Deng, Zigang

    2017-05-01

    In order to study the commonly neglected magnetic field information in the course of levitation force measurement process in a superconducting maglev system, a multipoint magnetic field measurement platform was employed to acquire magnetic signals of a bulk high-Tc superconductor on both the top and the bottom surface. Working conditions including field cooling (FC) and zero field cooling were investigated for these vertical down and up motions above a permanent magnet guideway performed on a HTS maglev measurement system. We have discussed the magnetic flux variation process based on the Bean model. A magnetic hysteresis effect similar to the levitation force hysteresis loop of the bulk superconductor was displayed and analyzed in this paper. What is more valuable, there exists some available magnetic flux on the top surface of the bulk superconductor, and the proportion is as high as 62.42% in the FC condition, which provides an experimental hint to design the superconductor bulk and the applied field for practical use in a more efficient way. In particular, this work reveals real-time magnetic flux variation of the bulk superconductor in the levitation application, which is the other important information in contrast to the macroscopic levitation and guidance force investigations in previous studies, and it enriches the existing research methods. The results are significant for understanding the magnetic characteristic of superconductors, and they can contribute to optimize the present HTS maglev system design.

  9. Modeling dynamic behavior of superconducting maglev systems under external disturbances

    NASA Astrophysics Data System (ADS)

    Huang, Chen-Guang; Xue, Cun; Yong, Hua-Dong; Zhou, You-He

    2017-08-01

    For a maglev system, vertical and lateral displacements of the levitation body may simultaneously occur under external disturbances, which often results in changes in the levitation and guidance forces and even causes some serious malfunctions. To fully understand the effect of external disturbances on the levitation performance, in this work, we build a two-dimensional numerical model on the basis of Newton's second law of motion and a mathematical formulation derived from magnetoquasistatic Maxwell's equations together with a nonlinear constitutive relation between the electric field and the current density. By using this model, we present an analysis of dynamic behavior for two typical maglev systems consisting of an infinitely long superconductor and a guideway of different arrangements of infinitely long parallel permanent magnets. The results show that during the vertical movement, the levitation force is closely associated with the flux motion and the moving velocity of the superconductor. After being disturbed at the working position, the superconductor has a disturbance-induced initial velocity and then starts to periodically vibrate in both lateral and vertical directions. Meanwhile, the lateral and vertical vibration centers gradually drift along their vibration directions. The larger the initial velocity, the faster their vibration centers drift. However, the vertical drift of the vertical vibration center seems to be independent of the direction of the initial velocity. In addition, due to the lateral and vertical drifts, the equilibrium position of the superconductor in the maglev systems is not a space point but a continuous range.

  10. A 2 Tesla Full Scale High Performance Periodic Permanent Magnet Model for Attractive (228 KN) and repulsive Maglev

    NASA Technical Reports Server (NTRS)

    Stekly, Z. J. J.; Gardner, C.; Domigan, P.; Baker, J.; Hass, M.; McDonald, C.; Wu, C.; Farrell, R. A.

    1996-01-01

    Two 214.5 cm. long high performance periodic (26 cm period) permanent magnet half-assemblies were designed and constructed for use as a wiggler using Nd-B-Fe and vanadium permendur as hard and soft magnetic materials by Field Effects, a division of Intermagnetics General Corporation. Placing these assemblies in a supporting structure with a 2.1 cm pole to pole separation resulted in a periodic field with a maximum value of 2.04 T. This is believed to be the highest field ever achieved by this type of device. The attractive force between the two 602 kg magnet assemblies is 228 kN, providing enough force for suspension of a 45,500 kg vehicle. If used in an attractive maglev system with an appropriate flat iron rail, one assembly will generate the same force with a gap of 1.05 cm leading to a lift to weight ratio of 38.6, not including the vehicle attachment structure. This permanent magnet compares well with superconducting systems which have lift to weight ratios in the range of 5 to 10. This paper describes the magnet assemblies and their measured magnetic performance. The measured magnetic field and resulting attractive magnetic force have a negative spring characteristic. Appropriate control coils are necessary to provide stable operation. The estimated performance of the assemblies in a stable repulsive mode, with eddy currents in a conducting guideway, is also discussed.

  11. Lateral motion stability of high-temperature superconducting maglev systems derived from a nonlinear guidance force hysteretic model

    NASA Astrophysics Data System (ADS)

    Li, Haitao; Deng, Zigang; Jin, Li’an; Li, Jipeng; Li, Yanxing; Zheng, Jun

    2018-07-01

    High-temperature superconducting (HTS) maglev, owning to the capability of passive stabilization, is potentially promising for high-speed transportation. The guidance force of bulk HTS materials above a permanent magnetic guideway has a nonlinear response due to the hysteresis effect. As a kind of rail transit, when the vehicle runs along the track, the curve and other disturbances will cause vibrations to the vehicle system. These physical factors will pose dynamic loads on the components, reducing structural reliability as well as affecting the ride comfort. The lateral motion, as an important part of the vehicle system dynamics, needs to be studied in the pursuit of HTS maglev realization. In this paper, we first measured the guidance forces of HTS bulks under different motion conditions, and analyzed the relationship between the lateral displacement, the movement velocity and the guidance force. Then, a mathematical model was built based on these experimental data. The key feature of this mathematical model is that it can describe the hysteresis characteristic of the guidance force. Based on this model, we investigated the lateral motion stability of the HTS levitation system, and found three singular points, one stable focus point, and two unstable saddle points. Lastly, a phase portrait was proposed to indicate the safe working region of the HTS maglev vehicle where the vehicle can automatically return to its equilibrium position. These experimental and simulation results are important to clarify the lateral motion stability under external disturbance or shock, and provide a reference basis for the design of levitation systems.

  12. Magnetic Launch Assist Experimental Track

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In this photograph, a futuristic spacecraft model sits atop a carrier on the Magnetic Launch Assist System, formerly known as the Magnetic Levitation (MagLev) System, experimental track at the Marshall Space Flight Center (MSFC). Engineers at MSFC have developed and tested Magnetic Launch Assist technologies that would use magnetic fields to levitate and accelerate a vehicle along a track at very high speeds. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a Magnetic Launch Assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide, and about 1.5-feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  13. Research Technology

    NASA Image and Video Library

    2001-03-01

    Engineers at the Marshall Space Flight Center (MSFC) have been testing Magnetic Launch Assist Systems, formerly known as Magnetic Levitation (MagLev) technologies. To launch spacecraft into orbit, a Magnetic Launch Assist system would use magnetic fields to levitate and accelerate a vehicle along a track at a very high speed. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, the launch-assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This photograph shows a subscale model of an airplane running on the experimental track at MSFC during the demonstration test. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide, and about 1.5- feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  14. Research Technology

    NASA Image and Video Library

    1999-10-01

    In this photograph, a futuristic spacecraft model sits atop a carrier on the Magnetic Launch Assist System, formerly known as the Magnetic Levitation (MagLev) System, experimental track at the Marshall Space Flight Center (MSFC). Engineers at MSFC have developed and tested Magnetic Launch Assist technologies that would use magnetic fields to levitate and accelerate a vehicle along a track at very high speeds. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a Magnetic Launch Assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide, and about 1.5-feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  15. Magnetic Launch Assist System Demonstration Test

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Engineers at the Marshall Space Flight Center (MSFC) have been testing Magnetic Launch Assist Systems, formerly known as Magnetic Levitation (MagLev) technologies. To launch spacecraft into orbit, a Magnetic Launch Assist system would use magnetic fields to levitate and accelerate a vehicle along a track at a very high speed. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, the launch-assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This photograph shows a subscale model of an airplane running on the experimental track at MSFC during the demonstration test. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide, and about 1.5- feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  16. Effective method to control the levitation force and levitation height in a superconducting maglev system

    NASA Astrophysics Data System (ADS)

    Yang, Peng-Tao; Yang, Wan-Min; Wang, Miao; Li, Jia-Wei; Guo, Yu-Xia

    2015-11-01

    The influence of the width of the middle magnet in the permanent magnet guideways (PMGs) on the levitation force and the levitation height of single-domain yttrium barium copper oxide (YBCO) bulks has been investigated at 77 K under the zero field cooled (ZFC) state. It is found that the largest levitation force can be obtained in the system with the width of the middle magnet of the PMG equal to the size of the YBCO bulk when the gap between the YBCO bulk and PMG is small. Both larger levitation force and higher levitation height can be obtained in the system with the width of the middle magnet of the PMG larger than the size of the YBCO bulk. The stiffness of the levitation force between the PMG and the YBCO bulk is higher in the system with a smaller width of the middle magnet in the PMG. These results provide an effective way to control the levitation force and the levitation height for the superconducting maglev design and applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 51342001 and 50872079), the Key-grant Project of Chinese Ministry of Education (Grant No. 311033), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120202110003), the Innovation Team in Shaanxi Province, China (Grant No. 2014KTC-18), and the Fundamental Research Funds for the Central Universities, China (Grant Nos. GK201101001 and GK201305014), and the Outstanding Doctoral Thesis Foundation Project of Shaanxi Normal University, China (Grant Nos. X2011YB08 and X2012YB05).

  17. Magnetic Launch Assist Demonstration Test

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image shows a 1/9 subscale model vehicle clearing the Magnetic Launch Assist System, formerly referred to as the Magnetic Levitation (MagLev), test track during a demonstration test conducted at the Marshall Space Flight Center (MSFC). Engineers at MSFC have developed and tested Magnetic Launch Assist technologies. To launch spacecraft into orbit, a Magnetic Launch Assist System would use magnetic fields to levitate and accelerate a vehicle along a track at very high speeds. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a launch-assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide and about 1.5-feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  18. Research Technology

    NASA Image and Video Library

    2001-03-01

    This image shows a 1/9 subscale model vehicle clearing the Magnetic Launch Assist System, formerly referred to as the Magnetic Levitation (MagLev), test track during a demonstration test conducted at the Marshall Space Flight Center (MSFC). Engineers at MSFC have developed and tested Magnetic Launch Assist technologies. To launch spacecraft into orbit, a Magnetic Launch Assist System would use magnetic fields to levitate and accelerate a vehicle along a track at very high speeds. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a launch-assist system would electromagnetically drive a space vehicle along the track. A full-scale, operational track would be about 1.5-miles long and capable of accelerating a vehicle to 600 mph in 9.5 seconds. This track is an advanced linear induction motor. Induction motors are common in fans, power drills, and sewing machines. Instead of spinning in a circular motion to turn a shaft or gears, a linear induction motor produces thrust in a straight line. Mounted on concrete pedestals, the track is 100-feet long, about 2-feet wide and about 1.5-feet high. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  19. Fabrication of micro-lens array on convex surface by meaning of micro-milling

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Du, Yunlong; Wang, Bo; Shan, Debin

    2014-08-01

    In order to develop the application of the micro-milling technology, and to fabricate ultra-precision optical surface with complex microstructure, in this paper, the primary experimental research on micro-milling complex microstructure array is carried out. A complex microstructure array surface with vary parameters is designed, and the mathematic model of the surface is set up and simulated. For the fabrication of the designed microstructure array surface, a micro three-axis ultra-precision milling machine tool is developed, aerostatic guideway drove directly by linear motor is adopted in order to guarantee the enough stiffness of the machine, and novel numerical control strategy with linear encoders of 5nm resolution used as the feedback of the control system is employed to ensure the extremely high motion control accuracy. With the help of CAD/CAM technology, convex micro lens array on convex spherical surface with different scales on material of polyvinyl chloride (PVC) and pure copper is fabricated using micro tungsten carbide ball end milling tool based on the ultra-precision micro-milling machine. Excellent nanometer-level micro-movement performance of the axis is proved by motion control experiment. The fabrication is nearly as the same as the design, the characteristic scale of the microstructure is less than 200μm and the accuracy is better than 1μm. It prove that ultra-precision micro-milling technology based on micro ultra-precision machine tool is a suitable and optional method for micro manufacture of microstructure array surface on different kinds of materials, and with the development of micro milling cutter, ultraprecision micro-milling complex microstructure surface will be achieved in future.

  20. 75 FR 43395 - Airworthiness Directives; Aircraft Industries a.s. Model L 23 Super Blanik Gliders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-26

    ... elevator in place and in jamming of the Pilot's elevator control system, and subsequent loss of elevator... elevator in place and in jamming of the Pilot's elevator control system, and subsequent loss of elevator... retaining the elevator in place and in jamming of the Pilot's elevator control system, and subsequent loss...

  1. Elevational gradient in clutch size of Red-faced Warblers

    USGS Publications Warehouse

    Dillon, Kristen G.; Conway, Courtney J.

    2015-01-01

    Our understanding of life history evolution has benefited from debates regarding the underlying causes, and geographic ubiquity, of spatial patterns in avian clutch sizes. Past studies have revealed that birds lay smaller clutch sizes at higher elevation. However, in most previous studies, investigators have failed to adequately control for elevational differences in breeding phenology. To better understand the elevational gradient in avian clutch size, we need to know how clutch size changes across the entire elevational breeding range of a species (i.e., the shape of the relationship between elevation and clutch size), and whether the elevational gradient in clutch size is merely an artifact of elevational gradients in breeding phenology or breeding season length. We examined the relationship between breeding elevation and clutch size of Red-faced Warblers (Cardellina rubrifrons) along a 1000-m elevational gradient in Arizona. Our objectives were to determine how clutch size changed with elevation, and if the relationship between clutch size and elevation merely reflected elevational changes in breeding season length or phenology. The proportion of 5-egg clutches decreased and the proportion of 3- and 4-egg clutches increased non-linearly with increasing elevation, even after controlling for the elevational gradient in nest initiation date. Thus, average clutch size declined across the elevational breeding range of Red-faced Warblers, but this decline was not due to elevational variation in breeding phenology. Timing of breeding changed, but the duration of the breeding season did not change appreciably across the elevational gradient. Hence, elevational differences in breeding season length or breeding phenology cannot explain why Red-faced Warblers (and perhaps other birds) breeding at higher elevations have smaller clutches.

  2. Elevational Gradient of Vascular Plant Species Richness and Endemism in Crete – The Effect of Post-Isolation Mountain Uplift on a Continental Island System

    PubMed Central

    Trigas, Panayiotis; Panitsa, Maria; Tsiftsis, Spyros

    2013-01-01

    Understanding diversity patterns along environmental gradients and their underlying mechanisms is a major topic in current biodiversity research. In this study, we investigate for the first time elevational patterns of vascular plant species richness and endemism on a long-isolated continental island (Crete) that has experienced extensive post-isolation mountain uplift. We used all available data on distribution and elevational ranges of the Cretan plants to interpolate their presence between minimum and maximum elevations in 100-m elevational intervals, along the entire elevational gradient of Crete (0–2400 m). We evaluate the influence of elevation, area, mid-domain effect, elevational Rapoport effect and the post-isolation mountain uplift on plant species richness and endemism elevational patterns. Furthermore, we test the influence of the island condition and the post-isolation mountain uplift to the elevational range sizes of the Cretan plants, using the Peloponnese as a continental control area. Total species richness monotonically decreases with increasing elevation, while endemic species richness has a unimodal response to elevation showing a peak at mid-elevation intervals. Area alone explains a significant amount of variation in species richness along the elevational gradient. Mid-domain effect is not the underlying mechanism of the elevational gradient of plant species richness in Crete, and Rapoport's rule only partly explains the observed patterns. Our results are largely congruent with the post-isolation uplift of the Cretan mountains and their colonization mainly by the available lowland vascular plant species, as high-elevation specialists are almost lacking from the Cretan flora. The increase in the proportion of Cretan endemics with increasing elevation can only be regarded as a result of diversification processes towards Cretan mountains (especially mid-elevation areas), supported by elevation-driven ecological isolation. Cretan plants have experienced elevational range expansion compared to the continental control area, as a result of ecological release triggered by increased species impoverishment with increasing elevation. PMID:23555031

  3. 60. FORWARD AIRPLANE ELEVATOR PIT WITH ELEVATOR IN RAISED POSITION ...

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

    60. FORWARD AIRPLANE ELEVATOR PIT WITH ELEVATOR IN RAISED POSITION AFT LOOKING FORWARD ON CENTERLINE SHOWING ELEVATOR GUIDES, WIREWAYS, SHEAVES, HYDRAULIC OIL TANKS AND ELEVATOR LANDING PADS. - U.S.S. HORNET, Puget Sound Naval Shipyard, Sinclair Inlet, Bremerton, Kitsap County, WA

  4. Groundwater withdrawals 1976, 1990, and 2000--10 and land-surface-elevation changes 2000--10 in Harris, Galveston, Fort Bend, Montgomery, and Brazoria Counties, Texas

    USGS Publications Warehouse

    Kasmarek, Mark C.; Johnson, Michaela R.

    2013-01-01

    Measured land-surface-elevation changes from December 31, 2000, to December 31, 2010, ranged from an elevation increase of 0.06 feet (ft), or an average increase in elevation of 0.006 ft per year, at the Seabrook borehole extensometer located near Seabrook, Tex., to an elevation decrease of 1.28 ft, or an average decrease in elevation of 0.128 ft per year, at a PAM station north of Jersey Village, Tex. (PAM 07). Measured land-surface-elevation changes from December 31, 2005, to December 31, 2010, ranged from an elevation increase of 0.07 ft, or an average increase in elevation of 0.014 ft per year, at PAM 09 in far northeastern Harris County to an elevation decrease of 0.51 ft, or an average decrease in elevation of 0.102 ft per year, at PAM 07.

  5. 74. East elevation of elevated Mainline structure (Section F6) looking ...

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

    74. East elevation of elevated Mainline structure (Section F-6) looking West - along the Arborway toward the masonry bridge carrying the former New Haven R.R. tracks over the Arborway. Arborway overpass is at upper right. - Boston Elevated Railway, Elevated Mainline, Washington Street, Boston, Suffolk County, MA

  6. Global patterns of protection of elevational gradients in mountain ranges.

    PubMed

    Elsen, Paul R; Monahan, William B; Merenlender, Adina M

    2018-05-21

    Protected areas (PAs) that span elevational gradients enhance protection for taxonomic and phylogenetic diversity and facilitate species range shifts under climate change. We quantified the global protection of elevational gradients by analyzing the elevational distributions of 44,155 PAs in 1,010 mountain ranges using the highest resolution digital elevation models available. We show that, on average, mountain ranges in Africa and Asia have the lowest elevational protection, ranges in Europe and South America have intermediate elevational protection, and ranges in North America and Oceania have the highest elevational protection. We use the Convention on Biological Diversity's Aichi Target 11 to assess the proportion of elevational gradients meeting the 17% suggested minimum target and examine how different protection categories contribute to elevational protection. When considering only strict PAs [International Union for Conservation of Nature (IUCN) categories I-IV, n = 24,706], nearly 40% of ranges do not contain any PAs, roughly half fail to meet the 17% target at any elevation, and ∼75% fail to meet the target throughout ≥50% of the elevational gradient. Observed elevational protection is well below optimal, and frequently below a null model of elevational protection. Including less stringent PAs (IUCN categories V-VI and nondesignated PAs, n = 19,449) significantly enhances elevational protection for most continents, but several highly biodiverse ranges require new or expanded PAs to increase elevational protection. Ensuring conservation outcomes for PAs with lower IUCN designations as well as strategically placing PAs to better represent and connect elevational gradients will enhance ecological representation and facilitate species range shifts under climate change. Copyright © 2018 the Author(s). Published by PNAS.

  7. Small-scale topography modulates elevational α-, β- and γ-diversity of Andean leaf beetles.

    PubMed

    Thormann, Birthe; Ahrens, Dirk; Espinosa, Carlos Iván; Armijos, Diego Marín; Wagner, Thomas; Wägele, Johann W; Peters, Marcell K

    2018-05-01

    Elevational diversity gradients are typically studied without considering the complex small-scale topography of large mountains, which generates habitats of strongly different environmental conditions within the same elevational zones. Here we analyzed the importance of small-scale topography for elevational diversity patterns of hyperdiverse tropical leaf beetles (Coleoptera: Chrysomelidae). We compared patterns of elevational diversity and species composition of beetles in two types of forests (on mountain ridges and in valleys) and analyzed whether differences in the rate of species turnover among forest habitats lead to shifts in patterns of elevational diversity when scaling up from the local study site to the elevational belt level. We sampled beetle assemblages at 36 sites in the Podocarpus National Park, Ecuador, which were equally distributed over two forest habitats and three elevational levels. DNA barcoding and Poisson tree processes modelling were used to delimitate putative species. On average, local leaf beetle diversity showed a clear hump-shaped pattern. However, only diversity in forests on mountain ridges peaked at mid-elevation, while beetle diversity in valleys was similarly high at low- and mid-elevation and only declined at highest elevations. A higher turnover of species assemblages at lower than at mid-elevations caused a shift from a hump-shaped diversity pattern found at the local level to a low-elevation plateau pattern (with similar species numbers at low and mid-elevation) at the elevational belt level. Our study reveals an important role of small-scale topography and spatial scale for the inference on gradients of elevational species diversity.

  8. Exposure to Upper Arm Elevation During Work Compared to Leisure Among 12 Different Occupations Measured with Triaxial Accelerometers.

    PubMed

    Palm, Peter; Gupta, Nidhi; Forsman, Mikael; Skotte, Jørgen; Nordquist, Tobias; Holtermann, Andreas

    2018-06-26

    Regarding prevention of neck and shoulder pain (NSP), unsupported arm elevation is one factor that should be taken into account when performing work risk assessment. Triaxial accelerometers can be used to measure arm elevation over several days but it is not possible to differentiate between supported and unsupported arm elevation from accelerometers only. Supported arm elevation is more likely to exist during sitting than standing. The aim of the study was to evaluate the use of whole workday measurements of arm elevation with accelerometers to assess potentially harmful work exposure of arm elevation, by comparing arm elevation at work with arm elevation during leisure, in a population with diverse work tasks, and to assess how the exposure parameters were modified when upper arm elevation during sitting time was excluded. The participants, 197 workers belonging to 12 occupational groups with diverse work tasks, wore triaxial accelerometers on the dominant arm, hip, and back for 1-4 days to measure arm elevation and periods of sitting. None of the groups were found to have higher exposure to arm elevation during work compared to leisure. Even though some occupations where known to have work tasks that forced them to work with elevated arms to a large extent. A high proportion of arm elevation derived from sitting time, especially so during leisure. When arm elevation during sitting time was excluded from the analysis, arm elevation was significantly higher at work than during leisure among construction workers, garbage collectors, manufacturing workers, and domestic cleaners. Together this illustrates that it is not suitable to use whole workday measurments of arm elevation with accelerometer as a sole information source when assessing the risk for NSP due to arm elevation. Information on body posture can provide relevant contextual information in exposure assessments when it is known that the potential harmful exposure is performed in standing or walking.

  9. Elevation leads to altruistic behavior.

    PubMed

    Schnall, Simone; Roper, Jean; Fessler, Daniel M T

    2010-03-01

    Feelings of elevation, elicited by witnessing another person perform a good deed, have been hypothesized to motivate a desire to help others. However, despite growing interest in the determinants of prosocial behavior, there is only limited evidence that elevation leads to increases in altruistic behavior. In two experiments, we tested the relationship between elevation and helping behavior. Prior to measuring helping behavior, we measured elevation among participants in an elevation-inducing condition and control conditions in order to determine whether witnessing altruistic behavior elicited elevation. In Experiment 1, participants experiencing elevation were more likely to volunteer for a subsequent unpaid study than were participants in a neutral state. In Experiment 2, participants experiencing elevation spent approximately twice as long helping the experimenter with a tedious task as participants experiencing mirth or a neutral emotional state. Further, feelings of elevation, but not feelings of amusement or happiness, predicted the amount of helping. Together, these results provide evidence that witnessing another person's altruistic behavior elicits elevation, a discrete emotion that, in turn, leads to tangible increases in altruism.

  10. Research on the ride comfort of elevator monitoring using smartphone

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Sun, Xiaowei; Xie, Zhao; Su, Wensheng; Xue, Zhigang; Zhao, Xuefeng

    2017-04-01

    With the rapid development of high-rise buildings, the requirement of the elevator's speed is growing higher. And the vibration amplitude of elevator will also increasing with the improvement of running speed. The vibration problems of elevator have become the important factors that affect the comfort feeling of elevator. At the same time, the strong vibration will affect the normal work of elevator, and even cause accidents. So it's necessary to study the vibration characteristics of the elevator. In recent years, smartphone has developed rapidly, with a variety of sophisticated sensors; it has the powerful data processing and transmission capacity. In this paper, the author has presented an elevator comfort monitoring method based on smartphone. This method using Monitoring App can monitor the acceleration and inclination information using MEMS sensors embedded in smartphone. Then a confirmatory test for an elevator was designed, experimental results show that elevator comfort monitoring method based on smartphone is stable and reliable.

  11. Growth data for 29 elevational transect years from the California study of ponderosa pine

    Treesearch

    M. Thompson Conkle

    1973-01-01

    Ponderosa pine progenies from parents restricted in latitude but spanning 7.000 feet of elevation show significant growth differences in plantations at low-, mid-, and high-elevation test sites. At low- and mid-elevation sites tree heights and diameters of progenies from high-elevation parents were the smallest; those from the low-elevation parents, intermediate; and...

  12. Variant responses of tree seedling to seasonal drought stress along an elevational transect in tropical montane forests

    PubMed Central

    Song, Xiaoyang; Li, Jieqiong; Zhang, Wenfu; Tang, Yong; Sun, Zhenhua; Cao, Min

    2016-01-01

    Seasonal drought is a common phenomenon in many forests predominated by monsoon climate. The impact of seasonal drought, however, may vary with elevations, and tree species of forests hence may differ in their response to elevations. In this study, we monitored the seasonal variation of seedling species composition, and their relative growth rate (RGR) along an elevational transect in tropical forests of southwest China for two years. We found tree seedling species richness declined with rising elevation. Seedling abundance and species richness increased significantly from dry season to rainy season. In dry season, RGR declined progressively from low to high elevational bands, while positive RGR occurred in each elevation in rainy season. We grouped seedling species into low and high elevation specialists based on their elevational distributions. Seasonal variance in soil moisture may lead to seasonal dynamics of seedling community in this area. Our results suggest that the observed change in local climate over the last 40 years tends to allow the tree species from high elevation to expand their distribution to the lower elevation, while the ranges of those at low elevations could be compressed or at the risk of extinction. PMID:27819274

  13. Plant population differentiation and climate change: responses of grassland species along an elevational gradient.

    PubMed

    Frei, Esther R; Ghazoul, Jaboury; Matter, Philippe; Heggli, Martin; Pluess, Andrea R

    2014-02-01

    Mountain ecosystems are particularly susceptible to climate change. Characterizing intraspecific variation of alpine plants along elevational gradients is crucial for estimating their vulnerability to predicted changes. Environmental conditions vary with elevation, which might influence plastic responses and affect selection pressures that lead to local adaptation. Thus, local adaptation and phenotypic plasticity among low and high elevation plant populations in response to climate, soil and other factors associated with elevational gradients might underlie different responses of these populations to climate warming. Using a transplant experiment along an elevational gradient, we investigated reproductive phenology, growth and reproduction of the nutrient-poor grassland species Ranunculus bulbosus, Trifolium montanum and Briza media. Seeds were collected from low and high elevation source populations across the Swiss Alps and grown in nine common gardens at three different elevations with two different soil depths. Despite genetic differentiation in some traits, the results revealed no indication of local adaptation to the elevation of population origin. Reproductive phenology was advanced at lower elevation in low and high elevation populations of all three species. Growth and reproduction of T. montanum and B. media were hardly affected by garden elevation and soil depth. In R. bulbosus, however, growth decreased and reproductive investment increased at higher elevation. Furthermore, soil depth influenced growth and reproduction of low elevation R. bulbosus populations. We found no evidence for local adaptation to elevation of origin and hardly any differences in the responses of low and high elevation populations. However, the consistent advanced reproductive phenology observed in all three species shows that they have the potential to plastically respond to environmental variation. We conclude that populations might not be forced to migrate to higher elevations as a consequence of climate warming, as plasticity will buffer the detrimental effects of climate change in the three investigated nutrient-poor grassland species. © 2013 John Wiley & Sons Ltd.

  14. Predictors of backrest elevation in critical care.

    PubMed

    Grap, Mary Jo; Munro, Cindy L; Bryant, Sandra; Ashtiani, Brooke

    2003-04-01

    Low backrest and supine positions are associated with increased mortality and ventilator associated pneumonia (VAP). Data are not available across ICU settings about the level of backrest position used and its relationship to enteral feeding and hemodynamic status. The purpose of this descriptive study was to document the level of backrest elevation and position and identify factors associated with and predict positioning in a medical, surgical and neuroscience intensive care unit. Data were collected randomly in each unit over a 6-week period, resulting in 506 observations for170 patients. Backrest elevation was determined by electronic bed read-out or bed frame elevation gauge. BP, HR and enteral feeding status were retrieved from the medical record. Results showed that mean backrest elevation was 19.2 degrees and 70% of subjects were supine. No difference in backrest elevation among units was found. Significant correlations between backrest elevation and systolic BP (r=0.15, P=0.006); and backrest and diastolic BP (r=0.13, P=0.02) were found. There was no difference in backrest elevation between patients being fed and not being fed. Differences in backrest elevation for intubated versus nonintubated patients approached significance (P=0.07) with intubated patients at lower backrest elevations. In summary, use of higher backrest elevations (>30 degrees ) is minimal, is not related to feeding and minimally related to hemodynamic status. Strategies to meet published recommendations for backrest elevation (30-45 degrees ) must include repeated feedback about nurse's use of backrest elevation and estimates of elevation.

  15. elevatr: Access Elevation Data from Various APIs

    EPA Science Inventory

    Several web services are available that provide access to elevation data. This package provides access to several of those services and returns elevation data either as a SpatialPointsDataFrame from point elevation services or as a raster object from raster elevation services. ...

  16. Association of stroke clinical outcomes with coexistence of hyperglycemia and biomarkers of inflammation.

    PubMed

    Zhou, Jingwen; Wu, Jiahui; Zhang, Jintao; Xu, Tan; Zhang, Huan; Zhang, Yonghong; Zhang, Shaoyan

    2015-06-01

    To investigate the association of short-term clinical outcomes with coexistence of hyperglycemia and elevated biomarkers of inflammation among acute ischemic stroke (AIS) patients. We performed a retrospective study of 2675 patients diagnosed with AIS from January 2006 to December 2008. The study outcomes were defined as neurologic deficiency (National Institutes of Health Stroke Scale score ≥5) at discharge or death during hospitalization. Compared with normoglycemia and without any elevated biomarkers, patients with hyperglycemia, elevated white blood cell (WBC) count, elevated neutrophils ratio (NEUR), and elevated erythrocyte sedimentation rate (ESR) had higher rates of study outcomes (all P < .05). Furthermore, patients with coexistence of hyperglycemia with any of elevated WBC count, NEUR, or ESR were more likely to have study outcomes (all P < .05). Compared with subjects with normoglycaemia and without any elevated biomarker, multivariate adjusted odds ratios (95% confidence interval) of study outcomes associated with hyperglycemia, elevated WBC count, elevated NEUR, elevated ESR, coexistences of hyperglycemia with elevated WBC count, elevated NEUR, and elevated ESR were 1.492 (1.139-1.955), 1.404 (1.048-1.881), 1.897 (1.411-2.551), 2.184 (1.339-3.564), 1.963 (1.337-2.883), 2.544(1.715- 3.775), and 2.687 (1.347-5.363), respectively. This study indicated that hyperglycemia and elevated biomarkers of inflammation were associated with short-term clinical outcomes, and individuals with coexistence of hyperglycemia and elevated biomarkers of inflammation had higher risk of poor clinical outcomes among AIS patients. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  17. Comparing elevation and freeboard from IceBridge and four different CryoSat-2 retrackers for coincident sea ice observations

    NASA Astrophysics Data System (ADS)

    Yi, D.; Kurtz, N. T.; Harbeck, J.

    2017-12-01

    The airborne IceBridge and spaceborne Cryosat-2 missions observe polar sea ice at different altitudes with different footprint sizes and often at different time and locations. Many studies use different retrackers to derive Cryosat-2 surface elevation, which we find causes large differences in the elevation and freeboard comparisons of IceBridge and Cryosat-2. In this study, we compare sea ice surface elevation and freeboard using 8 coincident CryoSat-2, ATM, and LVIS observations with IceBridge airplanes under flying the Cryosat-2 ground tracks. We apply identical ellipsoid, geoid model, tide model, and atmospheric correction to CryoSat-2 and IceBridge data to reduce elevation bias due to their differences. IceBridge's ATM and LVIS elevation and freeboard and Snow Radar snow depth are averaged at each CryoSat-2 footprint for comparison. The four different Cryosat-2 retrackers (ESA, GSFC, AWI, and JPL) show distinct differences in mean elevation up to 0.35 meters over leads and over floes, which suggests that systematic elevation bias exists between the retrackers. The mean IceBridge elevation over leads is within the mean elevation distribution of the four Cryosat-2 retrackers. The mean IceBridge elevation over floes is above the mean elevation distribution of the four Cryosat-2 retrackers. After removing the snow depth from IceBridge elevation, over floe, the mean elevation of IceBridge is within the mean elevation distribution of the four Cryosat-2 retrackers. By identifying the strengths and weaknesses of the retrackers, this study provides a mechanism to improve freeboard retrievals from existing methods.

  18. A comparison of bat activity at low and high elevations in the Black Hills of western Washington

    USGS Publications Warehouse

    Erickson, J.; Adams, Michael J.

    2003-01-01

    We examined the differences in activity patterns and community structure of bats between low (<150 m) and high ( ! 575 m) elevation sites in two habitats of the Capitol State Forest, Washington. Total bat activity averaged four times higher at low elevation sites than at high elevation sites. Feeding activity was almost 20 times higher at low elevation sites. However, the non-myotis group had similar activity levels at high and low elevation, whereas myotis group activity decreased at higher elevations. Different levels of activity between elevations could be the result of differences in insect availability, climatic conditions, and morphology of the bat species.

  19. Heart Disease Death Rates in Low Versus High Land Elevation Counties in the U.S.

    PubMed

    Hart, John

    2015-01-01

    Previous research on land elevation and cancer death rates in the U.S. revealed lower cancer death rates in higher elevations. The present study further tests the possible effect of land elevation on a diffident health outcome, namely, heart disease death rates. U.S. counties not overlapping in their land elevations according to their lowest and highest elevation points were identified. Using an ecological design, heart disease death rates for two races (black and white) corresponding to lower elevation counties were compared to heart disease death rates in higher land elevation counties using the two-sample t-test and effect size statistics. Death rates in higher land elevation counties for both races were lower compared to the death rates in lower land elevation counties (p < 0.001) with large effect sizes (of > 0.70). Since this is an observational study, no causal inference is claimed, and further research is indicated to verify these findings.

  20. Heart Disease Death Rates in Low Versus High Land Elevation Counties in the U.S

    PubMed Central

    2015-01-01

    Previous research on land elevation and cancer death rates in the U.S. revealed lower cancer death rates in higher elevations. The present study further tests the possible effect of land elevation on a diffident health outcome, namely, heart disease death rates. U.S. counties not overlapping in their land elevations according to their lowest and highest elevation points were identified. Using an ecological design, heart disease death rates for two races (black and white) corresponding to lower elevation counties were compared to heart disease death rates in higher land elevation counties using the two-sample t-test and effect size statistics. Death rates in higher land elevation counties for both races were lower compared to the death rates in lower land elevation counties (p < 0.001) with large effect sizes (of > 0.70). Since this is an observational study, no causal inference is claimed, and further research is indicated to verify these findings. PMID:26674102

  1. Elevational characteristics of the archaeal community in full-scale activated sludge wastewater treatment plants at a 3,660-meter elevational scale.

    PubMed

    Niu, Lihua; Zhang, Xue; Li, Yi; Wang, Peifang; Zhang, Wenlong; Wang, Chao; Wang, Qing

    2017-07-01

    Due to the important roles of archaea in wastewater treatment processes, archaeal communities have been studied extensively in various anaerobic reactors, but the knowledge of archaeal communities in full-scale activated sludge wastewater treatment plants (WWTPs) remains quite poor. In this study, 454-pyrosequencing was for the first time employed to investigate archaeal communities from 20 full-scale activated sludge WWTPs distributed at a 3,660-meter elevational scale in China. Results showed that archaeal communities from WWTPs were dominated by Methanosarcinales (84.6%). A core archaeal population (94.5%) composed of Methanosaeta, Methanosarcina, Methanogenium and Methanobrevibacter was shared among WWTPs. The elevational pattern of archaeal communities was observed in WWTPs, with an elevational threshold associated with archaeal community richness and structures at approximately 1,500 meters above sea level (masl). A declining trend in community richness with increasing elevation was observed at higher elevations, whereas no trend was presented at lower elevations. Spearman correlation analysis indicated that the archaeal community richness at higher elevations was associated with more environmental variables than that at lower elevations. Redundancy analysis indicated that wastewater variables were the dominant contributors to the variation of community structures at higher elevations, followed by operational variables and elevation.

  2. Elevation trends and shrink-swell response of wetland soils to flooding and drying

    USGS Publications Warehouse

    Cahoon, Donald R.; Perez, Brian C.; Segura, Bradley D.; Lynch, James C.

    2011-01-01

    Given the potential for a projected acceleration in sea-level rise to impact wetland sustainability over the next century, a better understanding is needed of climate-related drivers that influence the processes controlling wetland elevation. Changes in local hydrology and groundwater conditions can cause short-term perturbations to marsh elevation trends through shrink—swell of marsh soils. To better understand the magnitude of these perturbations and their impacts on marsh elevation trends, we measured vertical accretion and elevation dynamics in microtidal marshes in Texas and Louisiana during and after the extreme drought conditions that existed there from 1998 to 2000. In a Louisiana marsh, elevation was controlled by subsurface hydrologic fluxes occurring below the root zone but above the 4 m depth (i.e., the base of the surface elevation table benchmark) that were related to regional drought and local meteorological conditions, with marsh elevation tracking water level variations closely. In Texas, a rapid decline in marsh elevation was related to severe drought conditions, which lowered local groundwater levels. Unfragmented marshes experienced smaller water level drawdowns and more rapid marsh elevation recovery than fragmented marshes. It appears that extended drawdowns lead to increased substrate consolidation making it less resilient to respond to future favorable conditions. Overall, changes in water storage lead to rapid and large short-term impacts on marsh elevation that are as much as five times greater than the long-term elevation trend, indicating the importance of long-term, high-resolution elevation data sets to understand the prolonged effects of water deficits on marsh elevation change.

  3. Support for the elevational Rapoport's rule among seed plants in Nepal depends on biogeographical affinities and boundary effects.

    PubMed

    Feng, Jianmeng; Hu, Xiaokang; Wang, Jie; Wang, Yanmei

    2016-10-01

    As one of the most important hypotheses on biogeographical distribution, Rapoport's rule has attracted attention around the world. However, it is unclear whether the applicability of the elevational Rapoport's Rule differs between organisms from different biogeographical regions. We used Stevens' method, which uses species diversity and the averaged range sizes of all species within each (100 m) elevational band to explore diversity-elevation, range-elevation, and diversity-range relationships. We compared support for the elevational Rapoport's rule between tropical and temperate species of seed plants in Nepal. Neither tropical nor temperate species supported the predictions of the elevational Rapoport's rule along the elevation gradient of 100-6,000 m a.s.l. for any of the studied relationships. However, along the smaller 1,000-5,000 m a.s.l. gradient (4,300 m a.s.l. for range-elevation relationships) which is thought to be less influenced by boundary effects, we observed consistent support for the rule by tropical species, although temperate species did not show consistent support. The degree of support for the elevational Rapoport's rule may not only be influenced by hard boundary effects, but also by the biogeographical affinities of the focal taxa. With ongoing global warming and increasing variability of temperature in high-elevation regions, tropical taxa may shift upward into higher elevations and expand their elevational ranges, causing the loss of temperate taxa diversity. Relevant studies on the elevational Rapoport's rule with regard to biogeographical affinities may be a promising avenue to further our understanding of this rule.

  4. Generation of a precise DEM by interactive synthesis of multi-temporal elevation datasets: a case study of Schirmacher Oasis, East Antarctica

    NASA Astrophysics Data System (ADS)

    Jawak, Shridhar D.; Luis, Alvarinho J.

    2016-05-01

    Digital elevation model (DEM) is indispensable for analysis such as topographic feature extraction, ice sheet melting, slope stability analysis, landscape analysis and so on. Such analysis requires a highly accurate DEM. Available DEMs of Antarctic region compiled by using radar altimetry and the Antarctic digital database indicate elevation variations of up to hundreds of meters, which necessitates the generation of local improved DEM. An improved DEM of the Schirmacher Oasis, East Antarctica has been generated by synergistically fusing satellite-derived laser altimetry data from Geoscience Laser Altimetry System (GLAS), Radarsat Antarctic Mapping Project (RAMP) elevation data and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) global elevation data (GDEM). This is a characteristic attempt to generate a DEM of any part of Antarctica by fusing multiple elevation datasets, which is essential to model the ice elevation change and address the ice mass balance. We analyzed a suite of interpolation techniques for constructing a DEM from GLAS, RAMP and ASTER DEM-based point elevation datasets, in order to determine the level of confidence with which the interpolation techniques can generate a better interpolated continuous surface, and eventually improve the elevation accuracy of DEM from synergistically fused RAMP, GLAS and ASTER point elevation datasets. The DEM presented in this work has a vertical accuracy (≈ 23 m) better than RAMP DEM (≈ 57 m) and ASTER DEM (≈ 64 m) individually. The RAMP DEM and ASTER DEM elevations were corrected using differential GPS elevations as ground reference data, and the accuracy obtained after fusing multitemporal datasets is found to be improved than that of existing DEMs constructed by using RAMP or ASTER alone. This is our second attempt of fusing multitemporal, multisensory and multisource elevation data to generate a DEM of Antarctica, in order to address the ice elevation change and address the ice mass balance. Our approach focuses on the strengths of each elevation data source to produce an accurate elevation model.

  5. Building C west elevation showing south elevation of Building B ...

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

    Building C west elevation showing south elevation of Building B (on left) and north elevation of Building D (on right). The Germantown Dyeworks complex and smoke stack appear in the background. View looking east - Hinckley Knitting Mills, Building C, 21-35 East Wister Street, Philadelphia, Philadelphia County, PA

  6. 1-Meter Digital Elevation Model specification

    USGS Publications Warehouse

    Arundel, Samantha T.; Archuleta, Christy-Ann M.; Phillips, Lori A.; Roche, Brittany L.; Constance, Eric W.

    2015-10-21

    In January 2015, the U.S. Geological Survey National Geospatial Technical Operations Center began producing the 1-Meter Digital Elevation Model data product. This new product was developed to provide high resolution bare-earth digital elevation models from light detection and ranging (lidar) elevation data and other elevation data collected over the conterminous United States (lower 48 States), Hawaii, and potentially Alaska and the U.S. territories. The 1-Meter Digital Elevation Model consists of hydroflattened, topographic bare-earth raster digital elevation models, with a 1-meter x 1-meter cell size, and is available in 10,000-meter x 10,000-meter square blocks with a 6-meter overlap. This report details the specifications required for the production of the 1-Meter Digital Elevation Model.

  7. Ice elevations and surface change on the Malaspina Glacier, Alaska

    USGS Publications Warehouse

    Sauber, J.; Molnia, B.; Carabajal, C.; Luthcke, S.; Muskett, R.

    2005-01-01

    Here we use Ice, Cloud and land Elevation Satellite (ICESat)-derived elevations and surface characteristics to investigate the Malaspina Glacier of southern Alaska. Although there is significant elevation variability between ICESat tracks on this glacier, we were able to discern general patterns in surface elevation change by using a regional digital elevation model (DEM) as a reference surface. Specifically, we report elevation differences between ICESat Laser 1-3 observations (February 2003 - November 2004) and a Shuttle Radar Topography Mission (SRTM)-derived DEM from February 2000. Elevation decreases of up to 20-25 m over a 3-4 year time period were observed across the folded loop moraine on the southern portion of the Malaspina Glacier. Copyright 2005 by the American Geophysical Union.

  8. Intelligent elevator management system using image processing

    NASA Astrophysics Data System (ADS)

    Narayanan, H. Sai; Karunamurthy, Vignesh; Kumar, R. Barath

    2015-03-01

    In the modern era, the increase in the number of shopping malls and industrial building has led to an exponential increase in the usage of elevator systems. Thus there is an increased need for an effective control system to manage the elevator system. This paper is aimed at introducing an effective method to control the movement of the elevators by considering various cases where in the location of the person is found and the elevators are controlled based on various conditions like Load, proximity etc... This method continuously monitors the weight limit of each elevator while also making use of image processing to determine the number of persons waiting for an elevator in respective floors. Canny edge detection technique is used to find out the number of persons waiting for an elevator. Hence the algorithm takes a lot of cases into account and locates the correct elevator to service the respective persons waiting in different floors.

  9. Elevational speciation in action? Restricted gene flow associated with adaptive divergence across an altitudinal gradient

    USGS Publications Warehouse

    Funk, W. C.; Murphy, M.A.; Hoke, K. L.; Muths, Erin L.; Amburgey, Staci M.; Lemmon, Emily M.; Lemmon, A. R.

    2016-01-01

    Evolutionary theory predicts that divergent selection pressures across elevational gradients could cause adaptive divergence and reproductive isolation in the process of ecological speciation. Although there is substantial evidence for adaptive divergence across elevation, there is less evidence that this restricts gene flow. Previous work in the boreal chorus frog (Pseudacris maculata) has demonstrated adaptive divergence in morphological, life history and physiological traits across an elevational gradient from approximately 1500–3000 m in the Colorado Front Range, USA. We tested whether this adaptive divergence is associated with restricted gene flow across elevation – as would be expected if incipient speciation were occurring – and, if so, whether behavioural isolation contributes to reproductive isolation. Our analysis of 12 microsatellite loci in 797 frogs from 53 populations revealed restricted gene flow across elevation, even after controlling for geographic distance and topography. Calls also varied significantly across elevation in dominant frequency, pulse number and pulse duration, which was partly, but not entirely, due to variation in body size and temperature across elevation. However, call variation did not result in strong behavioural isolation: in phonotaxis experiments, low-elevation females tended to prefer an average low-elevation call over a high-elevation call, and vice versa for high-elevation females, but this trend was not statistically significant. In summary, our results show that adaptive divergence across elevation restricts gene flow in P. maculata, but the mechanisms for this potential incipient speciation remain open.

  10. Wood properties of Scots pines (Pinus sylvestris) grown at elevated temperature and carbon dioxide concentration.

    PubMed

    Kilpeläinen, Antti; Peltola, Heli; Ryyppö, Aija; Sauvala, Kari; Laitinen, Kaisa; Kellomäki, Seppo

    2003-09-01

    Impacts of elevated temperature and carbon dioxide concentration ([CO2]) on wood properties of 15-year-old Scots pines (Pinus sylvestris L.) grown under conditions of low nitrogen supply were investigated in open-top chambers. The treatments consisted of (i) ambient temperature and ambient [CO2] (AT+AC), (ii) ambient temperature and elevated [CO2] (AT+EC), (iii) elevated temperature and ambient [CO2] (ET+AC) and (iv) elevated temperature and elevated [CO2] (ET+EC). Wood properties analyzed for the years 1992-1994 included ring width, early- and latewood width and their proportions, intra-ring wood density (minimum, maximum and mean, as well as early- and latewood densities), mean fiber length and chemical composition of the wood (cellulose, hemicellulose, lignin and acetone extractive concentration). Absolute radial growth over the 3-year period was 54% greater in AT+EC trees and 30 and 25% greater in ET+AC and ET+EC trees, respectively, than in AT+AC trees. Neither elevated temperature nor elevated [CO2] had a statistically significant effect on ring width, early- and latewood widths or their proportions. Both latewood density and maximum intra-ring density were increased by elevated [CO2], whereas fiber length was increased by elevated temperature. Hemicellulose concentration decreased and lignin concentration increased significantly in response to elevated temperature. There were no statistically significant interaction effects of elevated temperature and elevated [CO2] on the wood properties, except on earlywood density.

  11. Contrasting Decadal-Scale Changes in Elevation and ...

    EPA Pesticide Factsheets

    Northeastern US salt marshes face multiple co-stressors, including accelerating rates of relative sea level rise (RSLR), elevated nutrient inputs, and low sediment supplies. In order to evaluate how marsh surface elevations respond to such factors, we used surface elevation tables (SETs) and surface elevation pins to measure changes in marsh surface elevation in two eastern Long Island Sound salt marshes, Barn Island and Mamacoke marshes. We compare marsh elevation change at these two systems with recent rates of RSLR and find evidence of differences between the two sites; Barn Island is maintaining its historic rate of elevation gain (2.3 ± 0.24 mm year−1 from 2003 to 2013) and is no longer keeping pace with RSLR, while Mamacoke shows evidence of a recent increase in rates (4.2 ± 0.52 mm year−1 from 1994 to 2014) to maintain its elevation relative to sea level. In addition to data on short-term elevation responses at these marshes, both sites have unusually long and detailed data on historic vegetation species composition extending back more than half a century. Over this study period, vegetation patterns track elevation change relative to sea levels, with the Barn Island plant community shifting towards those plants that are found at lower elevations and the Mamacoke vegetation patterns showing little change in plant composition. We hypothesize that the apparent contrasting trend in marsh elevation at the sites is due to differences in sediment a

  12. Tabletop Experimental Track for Magnetic Launch Assist

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Marshall Space Flight Center's (MSFC's) Advanced Space Transportation Program has developed the Magnetic Launch Assist System, formerly known as the Magnetic Levitation (MagLev) technology that could give a space vehicle a running start to break free from Earth's gravity. A Magnetic Launch Assist system would use magnetic fields to levitate and accelerate a vehicle along a track at speeds up to 600 mph. The vehicle would shift to rocket engines for launch into orbit. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a Magnetic Launch Assist system would electromagnetically propel a space vehicle along the track. The tabletop experimental track for the system shown in this photograph is 44-feet long, with 22-feet of powered acceleration and 22-feet of passive braking. A 10-pound carrier with permanent magnets on its sides swiftly glides by copper coils, producing a levitation force. The track uses a linear synchronous motor, which means the track is synchronized to turn the coils on just before the carrier comes in contact with them, and off once the carrier passes. Sensors are positioned on the side of the track to determine the carrier's position so the appropriate drive coils can be energized. MSFC engineers have conducted tests on the indoor track and a 50-foot outdoor track. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  13. Research Technology

    NASA Image and Video Library

    2000-01-01

    Marshall Space Flight Center’s (MSFC’s) Advanced Space Transportation Program has developed the Magnetic Launch Assist System, formerly known as the Magnetic Levitation (MagLev) technology that could give a space vehicle a running start to break free from Earth’s gravity. A Magnetic Launch Assist system would use magnetic fields to levitate and accelerate a vehicle along a track at speeds up to 600 mph. The vehicle would shift to rocket engines for launch into orbit. Similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway, a Magnetic Launch Assist system would electromagnetically propel a space vehicle along the track. The tabletop experimental track for the system shown in this photograph is 44-feet long, with 22-feet of powered acceleration and 22-feet of passive braking. A 10-pound carrier with permanent magnets on its sides swiftly glides by copper coils, producing a levitation force. The track uses a linear synchronous motor, which means the track is synchronized to turn the coils on just before the carrier comes in contact with them, and off once the carrier passes. Sensors are positioned on the side of the track to determine the carrier’s position so the appropriate drive coils can be energized. MSFC engineers have conducted tests on the indoor track and a 50-foot outdoor track. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  14. Interactive effects of CO2 and O3 on a ponderosa pine plant/litter/soil mesocosm.

    PubMed

    Olszyk, D M; Johnson, M G; Phillips, D L; Seidler, R J; Tingey, D T; Watrud, L S

    2001-01-01

    To study individual and combined impacts of two important atmospheric trace gases, CO2 and O3, on C and N cycling in forest ecosystems; a multi-year experiment using a small-scale ponderosa pine (Pinus ponderosa Laws.) seedling/soil/litter system was initiated in April 1998. The experiment was conducted in outdoor, sun-lit chambers where aboveground and belowground ecological processes could be studied in detail. This paper describes the approach and methodology used, and presents preliminary data for the first two growing seasons. CO2 treatments were ambient and elevated (ambient + 280 ppm). O3 treatments were elevated (hourly averages to 159 ppb, cumulative exposure > 60 ppb O3, SUM 06 approximately 10.37 ppm h), and a low control level (nearly all hourly averages <40 ppb. SUM 06 approximately 0.07 ppm h). Significant (P < 0.05) individual and interactive effects occurred with elevated CO2 and elevated O3. Elevated CO2 increased needle-level net photosynthetic rates over both seasons. Following the first season, the highest photosynthetic rates were for trees which had previously received elevated O3 in addition to elevated CO2. Elevated CO2 increased seedling stem diameters, with the greatest increase at low O3. Elevated CO2 decreased current year needle % N in the summer. For 1-year-old needles measured in the fall there was a decrease in % N with elevated CO2 at low O3, but an increase in % N with elevated CO2 at elevated O3. Nitrogen fixation (measured by acetylene reduction) was low in ponderosa pine litter and there were no significant CO2 or O3 effects. Neither elevated CO2 nor elevated O3 affected standing root biomass or root length density. Elevated O3 decreased the % N in coarse-fine (1-2 mm diameter) but not in fine (< 1 mm diameter) roots. Both elevated CO2 and elevated O3 tended to increase the number of fungal colony forming units (CFUs) in the AC soil horizon, and elevated O3 tended to decrease bacterial CFUs in the C soil horizon. Thus, after two growing seasons we showed interactive effects of O3 and CO2 in combination, in addition to responses to CO2 or O3 alone for a ponderosa pine plant/litter/soil system.

  15. Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise

    USGS Publications Warehouse

    Cherry, J.A.; McKee, K.L.; Grace, J.B.

    2009-01-01

    1. Sea-level rise, one indirect consequence of increasing atmospheric CO2, poses a major challenge to long-term stability of coastal wetlands. An important question is whether direct effects of elevated CO 2 on the capacity of marsh plants to accrete organic material and to maintain surface elevations outweigh indirect negative effects of stressors associated with sea-level rise (salinity and flooding). 2. In this study, we used a mesocosm approach to examine potential direct and indirect effects of atmospheric CO2 concentration, salinity and flooding on elevation change in a brackish marsh community dominated by a C3 species, Schoenoplectus americanus, and a C4 grass, Spartina patens. This experimental design permitted identification of mechanisms and their role in controlling elevation change, and the development of models that can be tested in the field. 3. To test hypotheses related to CO2 and sea-level rise, we used conventional anova procedures in conjunction with structural equation modelling (SEM). SEM explained 78% of the variability in elevation change and showed the direct, positive effect of S. americanus production on elevation. The SEM indicated that C3 plant response was influenced by interactive effects between CO2 and salinity on plant growth, not a direct CO2 fertilization effect. Elevated CO2 ameliorated negative effects of salinity on S. americanus and enhanced biomass contribution to elevation. 4. The positive relationship between S. americanus production and elevation change can be explained by shoot-base expansion under elevated CO 2 conditions, which led to vertical soil displacement. While the response of this species may differ under other environmental conditions, shoot-base expansion and the general contribution of C3 plant production to elevation change may be an important mechanism contributing to soil expansion and elevation gain in other coastal wetlands. 5. Synthesis. Our results revealed previously unrecognized interactions and mechanisms contributing to marsh elevation change, including amelioration of salt stress by elevated CO2 and the importance of plant production and shoot-base expansion for elevation gain. Identification of biological processes contributing to elevation change is an important first step in developing comprehensive models that permit more accurate predictions of whether coastal marshes will persist with continued sea-level rise or become submerged. ?? 2008 The Authors.

  16. Reproductive allocation in plants as affected by elevated carbon dioxide and other environmental changes: a synthesis using meta-analysis and graphical vector analysis.

    PubMed

    Wang, Xianzhong; Taub, Daniel R; Jablonski, Leanne M

    2015-04-01

    Reproduction is an important life history trait that strongly affects dynamics of plant populations. Although it has been well documented that elevated carbon dioxide (CO2) in the atmosphere greatly enhances biomass production in plants, the overall effect of elevated CO2 on reproductive allocation (RA), i.e., the proportion of biomass allocated to reproductive structures, is little understood. We combined meta-analysis with graphical vector analysis to examine the overall effect of elevated CO2 on RA and how other environmental factors, such as low nutrients, drought and elevated atmospheric ozone (O3), interacted with elevated CO2 in affecting RA in herbaceous plants. Averaged across all species of different functional groups and environmental conditions, elevated CO2 had little effect on RA (-0.9%). RA in plants of different reproductive strategies and functional groups, however, differed in response to elevated CO2. For example, RA in iteroparous wild species decreased by 8%, while RA in iteroparous crops increased significantly (+14%) at elevated CO2. RA was unaffected by CO2 in plants grown with no stress or in low-nutrient soils. RA decreased at elevated CO2 and elevated O3, but increased in response to elevated CO2 in drought-stressed plants, suggesting that elevated CO2 could ameliorate the adverse effect of drought on crop production to some extent. Our results demonstrate that elevated CO2 and other global environmental changes have the potential to greatly alter plant community composition through differential effects on RA of different plant species and thus affect the dynamics of natural and agricultural ecosystems in the future.

  17. The space station tethered elevator system

    NASA Technical Reports Server (NTRS)

    Anderson, Loren A.

    1989-01-01

    The optimized conceptual engineering design of a space station tethered elevator is presented. The elevator is an unmanned mobile structure which operates on a ten kilometer tether spanning the distance between the Space Station and a tethered platform. Elevator capabilities include providing access to residual gravity levels, remote servicing, and transportation to any point along a tether. The potential uses, parameters, and evolution of the spacecraft design are discussed. Engineering development of the tethered elevator is the result of work conducted in the following areas: structural configurations; robotics, drive mechanisms; and power generation and transmission systems. The structural configuration of the elevator is presented. The structure supports, houses, and protects all systems on board the elevator. The implementation of robotics on board the elevator is discussed. Elevator robotics allow for the deployment, retrieval, and manipulation of tethered objects. Robotic manipulators also aid in hooking the elevator on a tether. Critical to the operation of the tethered elevator is the design of its drive mechanisms, which are discussed. Two drivers, located internal to the elevator, propel the vehicle along a tether. These modular components consist of endless toothed belts, shunt-wound motors, regenerative power braking, and computer controlled linear actuators. The designs of self-sufficient power generation and transmission systems are reviewed. Thorough research indicates all components of the elevator will operate under power provided by fuel cells. The fuel cell systems will power the vehicle at seven kilowatts continuously and twelve kilowatts maximally. A set of secondary fuel cells provides redundancy in the unlikely event of a primary system failure. Power storage exists in the form of Nickel-Hydrogen batteries capable of powering the elevator under maximum loads.

  18. Creatine kinase elevation, lactacidemia, and metabolic myopathy in adult patients with diabetes mellitus.

    PubMed

    Frank, Marlies; Finsterer, Josef

    2012-01-01

    To determine the frequency of elevated creatine kinase (CK) levels among patients with diabetes mellitus and to determine how often elevated CK is attributable to primary myopathy. In this prospective study, we investigated how often CK, aspartate amino-transferase, alanine aminotransferase, and resting lactate were elevated among consecutive diabetic patients attending our clinic. Those with elevated CK values were offered a neurologic workup. Ninety-nine patients with diabetes mellitus, aged 19 to 87 years, were assessed between May 2008 and April 2010. Seven patients had type 1 diabetes and 92 patients had type 2 diabetes. CK, aspartate aminotransferase, alanine aminotransferase, and resting lactate were elevated in 19 of 99, 25 of 99, 22 of 99, and 24 of 98 patients, respectively. Eleven of 19 patients with increased CK were self-injecting insulin. Ten of 24 patients with elevated serum lactate took metformin. Seven of 19 patients with elevated CK consented to neurologic workup. Two of the 7 had elevated resting lactate. In all 7 patients, the findings from neurologic investigation were indicative of a metabolic defect and further diagnostic evaluation was recommended. In diabetic patients attending our clinic, elevated CK levels occur in one-fifth and lactacidemia occurs in one-quarter. Elevated CK levels are attributable to a primary metabolic myopathy in most cases. Elevated CK levels in the setting of diabetes mellitus require further neurologic evaluation.

  19. 49 CFR 213.59 - Elevation of curved track; runoff.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Elevation of curved track; runoff. 213.59 Section... track; runoff. (a) If a curve is elevated, the full elevation shall be provided throughout the curve, unless physical conditions do not permit. If elevation runoff occurs in a curve, the actual minimum...

  20. 75. Southeast elevation of Forest Hills station looking Northwest ...

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

    75. Southeast elevation of Forest Hills station - looking Northwest from junction of Washington and Walk Hill Streets. At left is the beginning of Section F-7 the exposed steel portion of elevated structure leading to the Forest Hills storage yard (demolished in 1985). - Boston Elevated Railway, Elevated Mainline, Washington Street, Boston, Suffolk County, MA

  1. 76 FR 64038 - Airworthiness Directives; CPAC, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-17

    ... airplane in the elevator spar area or that could have affected the elevator spar. (5) Type of operation... elevator spar for cracks and, if any crack is found, either replace with a serviceable elevator spar that is found free of cracks or repair/modify the elevator spar with an FAA-approved method. That AD also...

  2. [Distribution characteristics of heavy metals along an elevation gradient of montane forest].

    PubMed

    Wan, Jia-rong; Nie, Ming; Zou, Qin; Hu, Shao-chang; Chen, Jia-kuan

    2011-12-01

    In the present paper, the concentrations of fourteen heavy metals (Fe, Al, Ti, Cu, Cr, Mn, V, Zn, Ni, Co, Pb, Se, Cd and As) were determined by ICP-AES and atomic absorption spectroscopy along an elevation gradient of montane forest. The results show that the elevation gradient had significant effects on the concentrations of Fe, Al, Ti, V, Pb and As. And the concentrations of Cu, Cr, Mn, Zn, Ni, Co, Se and Cd were not significantly affected by the elevation gradient. Because the studying area is red soil, the elevation gradient had significant effects on the concentrations of Fe, Al and Ti which are characteristic heavy metals of red soil, suggesting that the red soil at different elevations has different intensities of weathering desilication and bioaccumulation. Other heavy metals have different relationships with the elevation gradient, such as the concentrations of Cr, Zn and Cd were high at relatively high elevation and Pb and As were high at relatively low elevation. These results suggest that the different elevations of montane forest soils were polluted by differently types of heavy metals.

  3. Traction sheave elevator, hoisting unit and machine space

    DOEpatents

    Hakala, Harri; Mustalahti, Jorma; Aulanko, Esko

    2000-01-01

    Traction sheave elevator consisting of an elevator car moving along elevator guide rails, a counterweight moving along counterweight guide rails, a set of hoisting ropes (3) on which the elevator car and counterweight are suspended, and a drive machine unit (6) driving a traction sheave (7) acting on the hoisting ropes (3) and placed in the elevator shaft. The drive machine unit (6) is of a flat construction. A wall of the elevator shaft is provided with a machine space with its open side facing towards the shaft, the essential parts of the drive machine unit (6) being placed in the space. The hoisting unit (9) of the traction sheave elevator consists of a substantially discoidal drive machine unit (6) and an instrument panel (8) mounted on the frame (20) of the hoisting unit.

  4. Elevational Distribution and Conservation Biogeography of Phanaeine Dung Beetles (Coleoptera: Scarabaeinae) in Bolivia

    PubMed Central

    Herzog, Sebastian K.; Hamel-Leigue, A. Caroli; Larsen, Trond H.; Mann, Darren J.; Soria-Auza, Rodrigo W.; Gill, Bruce D.; Edmonds, W. D.; Spector, Sacha

    2013-01-01

    Insect macroecology and conservation biogeography studies are disproportionately scarce, especially in the Neotropics. Dung beetles are an ideal focal taxon for biodiversity research and conservation. Using distribution and body size data on the ecologically important Phanaeini, the best-known Neotropical dung beetle tribe, we determined elevational patterns of species richness, endemism, body size, and elevational range in Bolivia, specifically testing Bergmann’s and Rapoport’s rule. Richness of all 39 species and of 15 ecoregional endemics showed a hump-shaped pattern peaking at 400 m, but overall declined strongly with elevation up to 4000 m. The relationship between endemic and total species richness appeared to be curvilinear, providing only partial support for the null hypothesis that species-rich areas are more likely to be centers of endemism by chance alone. An elevational increase in the proportion of ecoregional endemics suggests that deterministic factors also appear to influence endemism in the Andes. When controlling for the effect of area using different species-area relationships, the statistically significant richness peak became more pronounced and shifted upslope to 750 m. Larger species did not have higher elevational mid-points, and mean body size decreased significantly with elevation, contradicting Bergmann’s rule. Rapoport’s rule was supported: species with higher elevational mid-points had broader elevational ranges, and mean elevational range increased significantly with elevation. The elevational decrease of phanaeine richness is in accordance with studies that demonstrated the combined influence of temperature and water availability on species diversity, but also is consistent with niche conservatism. For invertebrates, confirmation of Rapoport’s and refutation of Bergmann’s rule appear to be scale-invariant general patterns. Analyses of biogeographic patterns across elevational gradients can provide important insights for identifying conservation priorities. Phanaeines with narrow elevational ranges on isolated low-elevation mountains in eastern Bolivia are at greatest climate-change related extinction risk from range-shift gaps and mountaintop extinctions. PMID:23717678

  5. Elevational distribution and conservation biogeography of phanaeine dung beetles (Coleoptera: Scarabaeinae) in Bolivia.

    PubMed

    Herzog, Sebastian K; Hamel-Leigue, A Caroli; Larsen, Trond H; Mann, Darren J; Soria-Auza, Rodrigo W; Gill, Bruce D; Edmonds, W D; Spector, Sacha

    2013-01-01

    Insect macroecology and conservation biogeography studies are disproportionately scarce, especially in the Neotropics. Dung beetles are an ideal focal taxon for biodiversity research and conservation. Using distribution and body size data on the ecologically important Phanaeini, the best-known Neotropical dung beetle tribe, we determined elevational patterns of species richness, endemism, body size, and elevational range in Bolivia, specifically testing Bergmann's and Rapoport's rule. Richness of all 39 species and of 15 ecoregional endemics showed a hump-shaped pattern peaking at 400 m, but overall declined strongly with elevation up to 4000 m. The relationship between endemic and total species richness appeared to be curvilinear, providing only partial support for the null hypothesis that species-rich areas are more likely to be centers of endemism by chance alone. An elevational increase in the proportion of ecoregional endemics suggests that deterministic factors also appear to influence endemism in the Andes. When controlling for the effect of area using different species-area relationships, the statistically significant richness peak became more pronounced and shifted upslope to 750 m. Larger species did not have higher elevational mid-points, and mean body size decreased significantly with elevation, contradicting Bergmann's rule. Rapoport's rule was supported: species with higher elevational mid-points had broader elevational ranges, and mean elevational range increased significantly with elevation. The elevational decrease of phanaeine richness is in accordance with studies that demonstrated the combined influence of temperature and water availability on species diversity, but also is consistent with niche conservatism. For invertebrates, confirmation of Rapoport's and refutation of Bergmann's rule appear to be scale-invariant general patterns. Analyses of biogeographic patterns across elevational gradients can provide important insights for identifying conservation priorities. Phanaeines with narrow elevational ranges on isolated low-elevation mountains in eastern Bolivia are at greatest climate-change related extinction risk from range-shift gaps and mountaintop extinctions.

  6. Determinants of food resource assimilation by stream insects along a tropical elevation gradient.

    PubMed

    Atkinson, Carla L; Encalada, Andrea C; Rugenski, Amanda T; Thomas, Steve A; Landeira-Dabarca, Andrea; Poff, N LeRoy; Flecker, Alexander S

    2018-04-26

    Food resource availability varies along gradients of elevation where riparian vegetative cover exerts control on the relative availability of allochthonous and autochthonous resources in streams. Still, little is known about how elevation gradients can alter the availability and quality of resources and how stream food webs respond. We sampled habitat characteristics, stable isotope signatures (δ 13 C, δ 15 N, δ 2 Η) and the carbon, nitrogen and phosphorus composition of basal food resources and insects in 11 streams of similar size along an elevation gradient from 1260 to 4045 m on the northeastern slope of the Ecuadorian Andean-Amazon region. Algal-based (autochthonous) food resources primarily supported insects occurring at higher elevations, but at low elevations there was a shift to greater allochthony, corresponding with lower light availability and reduced epilithon resource abundance. Additionally, percent phosphorus (%P) of both autochthonous and allochthonous food resources and of body tissue for some abundant insect taxa (stonefly Anacroneuria and mayfly Andesiops) declined with increasing elevation, despite the greater autochthony at high elevation. Allochthonous food resources were always a lower quality food resource, as indicated by higher C:N, N:P, and lower %P, across elevation in comparison to autochthonous resources, but autochthonous resources had higher %P than allochthonous resources across all elevations and comprised a greater portion of high-elevation insect resource assimilation. Aquatic insects may be able to compensate for the lower quality of both resource types at high elevations through altered body stoichiometry, even though higher quality autochthonous-based foods are in high abundance at high elevations.

  7. Rapid warming forces contrasting growth trends of subalpine fir ( Abies fabri ) at higher- and lower-elevations in the eastern Tibetan Plateau

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Wenzhi; Jia, Min; Wang, Genxu

    Tree radial growth is expected to increase at higher elevations under climate warming, while lower elevation tree growth is expected to decline. However, numerous studies have found tree radial growth responds consistently to climate along elevational gradients. Here, we sampled five plots across the subalpine Abies fabri forest belt on Gongga Mountain in the eastern Tibetan Plateau to determine tree radial growth trends and responses to climate. Three commonly used detrending methods all consistently showed that tree radial growth at high elevation (> 3100 m) increased, while tree growth declined at the lower elevations (2700 m–2900 m) over the lastmore » three decades. Increasing late-growing season temperature positively (p < 0.05) correlated to tree radial growth at higher elevations, but the sign of this relationship reversed to become negative at lower elevations. Moving-window correlation analyses indicated the difference between high and low elevations response to temperature variation increased strongly with warming. Placing our result into the global context, 62% of 39 published studies found that trees along elevation gradients respond divergently to warming, and that these are located in warmer and wetter regions of the Earth. Notably, 28% of studies found non-significant responses to temperature at both high and low elevations. Our findings in the subalpine mountain forest in the eastern Tibetan Plateau were consistent with the majority of published datasets, and imply increasing temperature benefit for tree populations at higher elevation, while warming dampens growth at lower elevations.« less

  8. To left of center is freight elevator used to move ...

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

    To left of center is freight elevator used to move materials to the upper floors of the building. This elevator is also powered via the belts and drive shafts which operate the machine tools. Sign on elevator reads 'For Mr. Edison's Personal Use Only;' according to rumor, Edison was encouraged to use the elevator as he grew older, but refused. The elevator is designed for freight only. - Thomas A. Edison Laboratories, Building No. 5, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

  9. Influence of elevated carbon dioxide and temperature on belowground carbon allocation and enzyme activities in tropical flooded soil planted with rice.

    PubMed

    Bhattacharyya, P; Roy, K S; Neogi, S; Manna, M C; Adhya, T K; Rao, K S; Nayak, A K

    2013-10-01

    Changes in the soil labile carbon fractions and soil biochemical properties to elevated carbon dioxide (CO2) and temperature reflect the changes in the functional capacity of soil ecosystems. The belowground root system and root-derived carbon products are the key factors for the rhizospheric carbon dynamics under elevated CO2 condition. However, the relationship between interactive effects of elevated CO2 and temperature on belowground soil carbon accrual is not very clear. To address this issue, a field experiment was laid out to study the changes of carbon allocation in tropical rice soil (Aeric Endoaquept) under elevated CO2 and elevated CO2 + elevated temperature conditions in open top chambers (OTCs). There were significant increase of root biomass by 39 and 44 % under elevated CO2 and elevated CO2 + temperature compared to ambient condition, respectively. A significant increase (55 %) of total organic carbon in the root exudates under elevated CO2 + temperature was noticed. Carbon dioxide enrichment associated with elevated temperature significantly increased soil labile carbon, microbial biomass carbon, and activities of carbon-transforming enzyme like β-glucosidase. Highly significant correlations were noticed among the different soil enzymes and soil labile carbon fractions.

  10. Transcriptional profiling reveals elevated CO2 and elevated O3 alter resistance of soybean (Glycine max) to Japanese beetles (Popillia japonica).

    PubMed

    Casteel, Clare L; O'Neill, Bridget F; Zavala, Jorge A; Bilgin, Damla D; Berenbaum, May R; Delucia, Evan H

    2008-04-01

    The accumulation of CO2 and O3 in the troposphere alters phytochemistry which in turn influences the interactions between plants and insects. Using microarray analysis of field-grown soybean (Glycine max), we found that the number of transcripts in the leaves affected by herbivory by Japanese beetles (Popillia japonica) was greater when plants were grown under elevated CO2, elevated O3 and the combination of elevated CO2 plus elevated O3 than when grown in ambient atmosphere. The effect of herbivory on transcription diminished strongly with time (<1% of genes were affected by herbivory after 3 weeks), and elevated CO2 interacted more strongly with herbivory than elevated O3. The majority of transcripts affected by elevated O3 were related to antioxidant metabolism. Constitutive levels and the induction by herbivory of key transcripts associated with defence and hormone signalling were down-regulated under elevated CO2; 1-aminocyclopropane-1-carboxylate (ACC) synthase, lipoxygenase (LOX), allene oxide synthase (AOS), allene oxide cyclase (AOC), chalcone synthase (CHS), polyphenol oxidase (PPO) and cysteine protease inhibitor (CystPI) were lower in abundance compared with levels under ambient conditions. By suppressing the ability to mount an effective defence, elevated CO2 may decrease resistance of soybean to herbivory.

  11. 4. South Elevation Columbia Island Abutment Four; South Elevation ...

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

    4. South Elevation - Columbia Island Abutment Four; South Elevation - Washington Abutment One - Arlington Memorial Bridge, Spanning Potomac River between Lincoln Memorial & Arlington National Cemetery, Washington, District of Columbia, DC

  12. View southeast, showing front elevation, side (west) elevation and ell. ...

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

    View southeast, showing front elevation, side (west) elevation and ell. Outbuildings and field stretching to west and south - Conner Homestead, Epping Road (State Route 101), Exeter, Rockingham County, NH

  13. Refrigeration Plant, North Elevation, Second Floor Plan, East Elevation, Ground ...

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

    Refrigeration Plant, North Elevation, Second Floor Plan, East Elevation, Ground Floor Plan, Section A-A - Kennecott Copper Corporation, On Copper River & Northwestern Railroad, Kennicott, Valdez-Cordova Census Area, AK

  14. Design of a powered elevator control system. [powered elevator system for modified C-8A aircraft for STOL operation

    NASA Technical Reports Server (NTRS)

    Glende, W. L. B.

    1974-01-01

    The design, fabrication and flight testing of a powered elevator system for the Augmentor Wing Jet STOL Research Aircraft (AWJSRA or Mod C-8A) are discussed. The system replaces a manual spring tab elevator control system that was unsatisfactory in the STOL flight regime. Pitch control in the AWJSRA is by means of a single elevator control surface. The elevator is used for both maneuver and trim control as the stabilizer is fixed. A fully powered, irreversible flight control system powered by dual hydraulic sources was designed. The existing control columns and single mechanical cable system of the AWJSRA have been retained as has been the basic elevator surface, except that the elevator spring tab is modified into a geared balance tab. The control surface is directly actuated by a dual tandem moving body actuator. Control signals are transmitted from the elevator aft quadrant to the actuator by a linkage system that includes a limited authority series servo actuator.

  15. Nitric oxide enhances development of lateral roots in tomato (Solanum lycopersicum L.) under elevated carbon dioxide.

    PubMed

    Wang, Huan; Xiao, Wendan; Niu, Yaofang; Jin, Chongwei; Chai, Rushan; Tang, Caixian; Zhang, Yongsong

    2013-01-01

    Elevated carbon dioxide (CO₂) has been shown to enhance the growth and development of plants, especially of roots. Amongst them, lateral roots play an important role in nutrient uptake, and thus alleviate the nutrient limitation to plant growth under elevated CO₂. This paper examined the mechanism underlying CO₂ elevation-induced lateral root formation in tomato. The endogenous nitric oxide (NO) in roots was detected by the specific probe 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM DA). We suggest that CO₂ elevation-induced NO accumulation was important for lateral root formation. Elevated CO₂ significantly increased the activity of nitric oxide synthase in roots, but not nitrate reductase activity. Moreover, the pharmacological evidence showed that nitric oxide synthase rather than nitrate reductase was responsible for CO₂ elevation-induced NO accumulation. Elevated CO₂ enhanced the activity of nitric oxide synthase and promoted production of NO, which was involved in lateral root formation in tomato under elevated CO₂.

  16. Internalized elevation perception of simple stimuli in cochlear-implant and normal-hearing listeners

    PubMed Central

    Thakkar, Tanvi; Goupell, Matthew J.

    2014-01-01

    In normal-hearing (NH) listeners, elevation perception is produced by the spectral cues imposed by the pinna, head, and torso. Elevation perception in cochlear-implant (CI) listeners appears to be non-existent; this may be a result of poorly encoded spectral cues. In this study, an analog of elevation perception was investigated by having 15 CI and 8 NH listeners report the intracranial location of spectrally simple signals (single-electrode or bandlimited acoustic stimuli, respectively) in both horizontal and vertical dimensions. Thirteen CI listeners and all of the NH listeners showed an association between place of stimulation (i.e., stimulus frequency) and perceived elevation, generally responding with higher elevations for more basal stimulation. This association persisted in the presence of a randomized temporal pitch, suggesting that listeners were not associating pitch with elevation. These data provide evidence that CI listeners might perceive changes in elevation if they were presented stimuli with sufficiently salient elevation cues. PMID:25096117

  17. Feasibility of Shape-Memory Ni/Ti Alloy Wire Containing Tube Elevators for Transcrestal Detaching Maxillary Sinus Mucosa: Ex Vivo Study.

    PubMed

    Li, Yanfeng; Wang, Fuli; Hu, Pin; Fan, Jiadong; Han, Yishi; Liu, Bin; Liu, Tao; Yang, Chunhao; Gu, Xiangmin

    2016-01-01

    Osteotome sinus floor elevation is a less invasive approach to augment an insufficient alveolar bone at the posterior maxilla for dental implantation. However, this approach has some limitations due to the lack of sinus lift tools available for clinical use and the small transcrestal access to the maxillary sinus floor. We recently invented shape-memory Ni/Ti alloy wire containing tube elevators for transcrestal detaching maxillary sinus mucosa, and developed goat ex vivo models for direct visualizing the effectiveness of detaching sinus mucosa in real time during transcrestal maxillary sinus floor elevation. We evaluated our invented elevators, namely elevator 012 and elevator 014, for their effectiveness for transcrestal detaching maxillary sinus mucosa using the goat ex vivo models. We measured the length of sinus mucosa detached in mesial and distal directions or buccal and palatal directions, and the space volume created by detaching maxillary sinus mucosa in mesial, distal, buccal and palatal directions using the invented elevators. Elevator 012 had a shape-memory Ni/Ti alloy wire with a diameter of 0.012 inch, while elevator 014 had its shape-memory Ni/Ti alloy wire with a diameter of 0.014 inch. Elevator 012 could detach the goat maxillary sinus mucosa in the mesial or distal direction for 12.1±4.3 mm, while in the buccal or palatal direction for 12.5±6.7 mm. The elevator 014 could detach the goat maxillary sinus mucosa for 23.0±4.9 mm in the mesial or distal direction, and for 19.0±8.1 mm in the buccal or palatal direction. An average space volume of 1.7936±0.2079 ml was created after detaching the goat maxillay sinus mucosa in both mesial/distal direction and buccal/palatal direction using elevator 012; while the average space volume created using elevator 014 was 1.8764±0.2366 ml. Both two newly invented tube elevators could effectively detach the maxillary sinus mucosa on the goat ex vivo sinus models. Moreover, elevator 014 has advantages over the elevator 012 for the capability to detach sinus mucosa. © 2016 The Author(s) Published by S. Karger AG, Basel.

  18. 5. VIEW OF SECOND ELEVATOR WITH WOODFRAME HEADHOUSE AND ASPHALTIC ...

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

    5. VIEW OF SECOND ELEVATOR WITH WOOD-FRAME HEADHOUSE AND ASPHALTIC SIDING, LOOKING WEST. - Lockport DuPage Farmer's Elevator Company Grain Elevator, South of Romeoville Road, Lockport, Will County, IL

  19. Mean Cancer Mortality Rates in Low Versus High Elevation Counties in Texas

    PubMed Central

    Hart, John

    2010-01-01

    There is controversy as to whether low levels of radiation (i.e., < 5 rem) pose a health risk. This brief inquiry compares archived cancer mortality data in counties having relatively low (0–250 feet above sea level), medium (500–1000 feet above sea level), and high (3000+ feet above sea level) elevations also having corresponding greater natural background levels of radiation respectively. Cancer mortality was found to be lowest in the high elevation counties (mean = 58.2) followed by low elevation counties (67.5) and then medium elevation counties (70.4). Statistically significant differences were found between low –high elevations (p = 0.003), and medium – high elevations (p = 0.010), but not between low and medium elevations (p = 0.5). More rigorous research, with an accounting of confounding variables, is indicated. PMID:21191484

  20. Impact of a century of climate change on small-mammal communities in Yosemite National Park, USA.

    PubMed

    Moritz, Craig; Patton, James L; Conroy, Chris J; Parra, Juan L; White, Gary C; Beissinger, Steven R

    2008-10-10

    We provide a century-scale view of small-mammal responses to global warming, without confounding effects of land-use change, by repeating Grinnell's early-20th century survey across a 3000-meter-elevation gradient that spans Yosemite National Park, California, USA. Using occupancy modeling to control for variation in detectability, we show substantial ( approximately 500 meters on average) upward changes in elevational limits for half of 28 species monitored, consistent with the observed approximately 3 degrees C increase in minimum temperatures. Formerly low-elevation species expanded their ranges and high-elevation species contracted theirs, leading to changed community composition at mid- and high elevations. Elevational replacement among congeners changed because species' responses were idiosyncratic. Though some high-elevation species are threatened, protection of elevation gradients allows other species to respond via migration.

  1. A Double-Deck Elevator Group Supervisory Control System with Destination Floor Guidance System Using Genetic Network Programming

    NASA Astrophysics Data System (ADS)

    Yu, Lu; Zhou, Jin; Mabu, Shingo; Hirasawa, Kotaro; Hu, Jinglu; Markon, Sandor

    The Elevator Group Supervisory Control Systems (EGSCS) are the control systems that systematically manage three or more elevators in order to efficiently transport the passengers in buildings. Double-deck elevators, where two elevators are connected with each other, serve passengers at two consecutive floors simultaneously. Double-deck Elevator systems (DDES) become more complex in their behavior than conventional single-deck elevator systems (SDES). Recently, Artificial Intelligence (AI) technology has been used in such complex systems. Genetic Network Programming (GNP), a graph-based evolutionary method, has been applied to EGSCS and its advantages are shown in some papers. GNP can obtain the strategy of a new hall call assignment to the optimal elevator when it performs crossover and mutation operations to judgment nodes and processing nodes. Meanwhile, Destination Floor Guidance System (DFGS) is installed in DDES, so that passengers can also input their destinations at elevator halls. In this paper, we have applied GNP to DDES and compared DFGS with normal systems. The waiting time and traveling time of DFGS are all improved because of getting more information from DFGS. The simulations showed the effectiveness of the double-deck elevators with DFGS in different building traffics.

  2. Scots pine responses to elevated temperature and carbon dioxide concentration: growth and wood properties.

    PubMed

    Kilpeläinen, Antti; Peltola, Heli; Ryyppö, Aija; Kellomäki, Seppo

    2005-01-01

    Growth and wood properties of 20-year-old Scots pine (Pinus sylvestris L.) trees were studied for 6 years in 16 closed chambers providing a factorial combination of two temperature regimes (ambient and elevated) and two carbon dioxide concentrations ([CO2]) (ambient and twice ambient). The elevation of temperature corresponded to the predicted effect at the site of a doubling in atmospheric [CO2]. Annual height and radial growth and wood properties were analyzed during 1997-2002. Physical wood properties analyzed included early- and latewood widths and their proportions, intra-ring wood densities, early- and latewood density and mean fiber length. Chemical wood properties analyzed included concentrations of acetone-soluble extractives, lignin, cellulose and hemicellulose. There were no significant treatment effects on height growth during the 6-year study. Elevated [CO2] increased ring width by 66 and 47% at ambient and elevated temperatures, respectively. At ambient [CO2], elevated temperature increased ring width by 19%. Increased ring width in response to elevated [CO2] resulted from increases in both early- and latewood width; however, there was no effect of the treatments on early- and latewood proportions. Mean wood density, earlywood density and fiber length increased in response to elevated temperature. The chemical composition of wood was affected by elevated [CO2], which reduced the cellulose concentration, and by elevated temperature, which reduced the concentration of acetone-soluble extractives. Thus, over the 6-year period, radial growth was significantly increased by elevated [CO2], and some wood properties were significantly affected by elevated temperature or elevated [CO2], or both, indicating that climate change may affect the material properties of wood.

  3. Heat shock response and mammal adaptation to high elevation (hypoxia).

    PubMed

    Wang, Xiaolin; Xu, Cunshuan; Wang, Xiujie; Wang, Dongjie; Wang, Qingshang; Zhang, Baochen

    2006-10-01

    The mammal's high elevation (hypoxia) adaptation was studied by using the immunological and the molecular biological methods to understand the significance of Hsp (hypoxia) adaptation in the organic high elevation, through the mammal heat shock response. (1) From high elevation to low elevation (natural hypoxia): Western blot and conventional RT-PCR and real-time fluorescence quota PCR were adopted. Expression difference of heat shock protein of 70 (Hsp70) and natural expression of brain tissue of Hsp70 gene was determined in the cardiac muscle tissue among the different elevation mammals (yak). (2) From low elevation to high elevation (hypoxia induction): The mammals (domestic rabbits) from the low elevation were sent directly to the areas with different high elevations like 2300, 3300 and 5000 m above sea level to be raised for a period of 3 weeks before being slaughtered and the genetic inductive expression of the brain tissue of Hsp70 was determined with RT-PCR. The result indicated that all of the mammals at different elevations possessed their heat shock response gene. Hsp70 of the high elevation mammal rose abruptly under stress and might be induced to come into being by high elevation (hypoxia). The speedy synthesis of Hsp70 in the process of heat shock response is suitable to maintain the cells' normal physiological functions under stress. The Hsp70 has its threshold value. The altitude of 5000 m above sea level is the best condition for the heat shock response, and it starts to reduce when the altitude is over 6000 m above sea level. The Hsp70 production quantity and the cell hypoxia bearing capacity have their direct ratio.

  4. Differential in surface elevation change across mangrove forests in the intertidal zone

    NASA Astrophysics Data System (ADS)

    Fu, Haifeng; Wang, Wenqing; Ma, Wei; Wang, Mao

    2018-07-01

    A better understanding of surface elevation changes in different mangrove forests would improve our predictions of sea-level rise impacts, not only upon mangrove species distributions in the intertidal zone, but also on the functioning of these wetlands. Here, a two-year (2015-2017) dataset derived from 18 RSET-MH (rod surface elevation table-marker horizon) stations at Dongzhaigang Bay, Hainan, China, was analyzed to investigate how surface elevation changes differed across mangrove species zones. The current SET data indicated a rather high rate (9.6 mm y-1, on average) of surface elevation gain that was mostly consistent with that (8.1 mm y-1, on average) inferred from either the 137Cs or 210Pb dating of sediment cores. In addition, these surface elevation changes were sensitive to elevation in the intertidal zone and differed significantly between the two study sites (Sanjiang and Houpai). Mangrove species inhabiting the lower intertidal zone tended to experience greater surface elevation change at Sanjiang, which agrees with the general view that sedimentation and elevation gains are driven by elevation in the intertidal zone (i.e., greater when positioned lower in the intertidal profile). However, at Houpai, both surface elevation change and surface accretion showed the opposite trend (i.e., greater when positioned higher in the intertidal profile). This study's results indicate that the pattern of surface elevation changes across the intertidal profile maybe inconsistent due to intricate biophysical controls. Therefore, instead of using a constant rate, models should presume a topography that evolves at differing rates of surface elevation change in different species zones across the intertidal profile when predicting the impacts of sea-level rise on mangrove distributions.

  5. Elevated Liver Enzymes

    MedlinePlus

    Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

  6. ST segment elevation in lead aVR: what to expect from this orphan?

    PubMed

    Iskandar, Said B; Fahrig, Stephen A

    2008-12-01

    Standard 12-lead electrocardiography is used to diagnose acute myocardial infarctions in patient presenting with ST elevation. The specificity of ST segment elevation for the corresponding area is more than 90 percent. It has been suggested that ST-segment elevation in lead aVR may indicate left main disease. We will present a patient who had an ST segment elevation in this lead. We will review the current data about this finding, as well as the significance of ST segment elevation in other leads.

  7. 1. COMPARISON OF PLANS, SHOWING KONGENSGADE 6 (see photograph VI50 ...

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

    1. COMPARISON OF PLANS, SHOWING KONGENSGADE 6 (see photograph VI-50 50-2 for elevation), KONGENSGADE 8 (see photograph VI-50-3 for elevation), KONGENSGADE 9 (see photograph VI-50-3 for elevation), KONGENSGADE 17 (see photograph VI-50-5 for elevation), KONGENSGADE 56 (see photograph VI-50-8 for elevation), & KONGENSGADE 57 (see photograph VI-50-9 for elevation) - King Street Area Study, Kongensgade 5-18, 36, 37B, 51-58 (Houses), 5-18, 36-37B, 51-58 King Street, Frederiksted, St. Croix, VI

  8. Geographic variability in elevation and topographic constraints on the distribution of native and nonnative trout in the Great Basin

    USGS Publications Warehouse

    Warren, Dana R.; Dunham, Jason B.; Hockman-Wert, David

    2014-01-01

    Understanding local and geographic factors influencing species distributions is a prerequisite for conservation planning. Our objective in this study was to model local and geographic variability in elevations occupied by native and nonnative trout in the northwestern Great Basin, USA. To this end, we analyzed a large existing data set of trout presence (5,156 observations) to evaluate two fundamental factors influencing occupied elevations: climate-related gradients in geography and local constraints imposed by topography. We applied quantile regression to model upstream and downstream distribution elevation limits for each trout species commonly found in the region (two native and two nonnative species). With these models in hand, we simulated an upstream shift in elevation limits of trout distributions to evaluate potential consequences of habitat loss. Downstream elevation limits were inversely associated with latitude, reflecting regional gradients in temperature. Upstream limits were positively related to maximum stream elevation as expected. Downstream elevation limits were constrained topographically by valley bottom elevations in northern streams but not in southern streams, where limits began well above valley bottoms. Elevation limits were similar among species. Upstream shifts in elevation limits for trout would lead to more habitat loss in the north than in the south, a result attributable to differences in topography. Because downstream distributions of trout in the north extend into valley bottoms with reduced topographic relief, trout in more northerly latitudes are more likely to experience habitat loss associated with an upstream shift in lower elevation limits. By applying quantile regression to relatively simple information (species presence, elevation, geography, topography), we were able to identify elevation limits for trout in the Great Basin and explore the effects of potential shifts in these limits that could occur in response to changing climate conditions that alter streams directly (e.g., through changes in temperature and precipitation) or indirectly (e.g., through changing water use).

  9. Soils characterisation along ecological forest zones in the Eastern Himalayas

    NASA Astrophysics Data System (ADS)

    Simon, Alois; Dhendup, Kuenzang; Bahadur Rai, Prem; Gratzer, Georg

    2017-04-01

    Elevational gradients are commonly used to characterise vegetation patterns and, to a lesser extent, also to describe soil development. Furthermore, interactions between vegetation cover and soil characteristics are repeatedly observed. Combining information on soil development and easily to distinguish forest zones along elevational gradients, creates an added value for forest management decisions especially in less studied mountain regions. For this purpose, soil profiles along elevational gradients in the temperate conifer forests of Western and Central Bhutan, ranging from 2600-4000m asl were investigated. Thereby, 82 soil profiles were recorded and classified according to the World Reference Base for Soil Resources. Based on 19 representative profiles, genetic horizons were sampled and analysed. We aim to provide fundamental information on forest soil characteristics along these elevational transects. The results are presented with regard to ecological forest zones. The elevational distribution of the reference soil groups showed distinct distribution ranges for most of the soils. Cambisols were the most frequently recorded reference soil group with 58% of the sampled profiles, followed by Podzols in higher elevations, and Stagnosols, at intermediate elevations. Fluvisols occurred only at the lower end of the elevational transects and Phaeozems only at drier site conditions in the cool conifer dry forest zone. The humus layer thickness differs between forest zones and show a shift towards increased organic layer (O-layer) with increasing elevation. The reduced biomass productivity with increasing elevation and subsequently lower litter input compensates for the slow decomposition rates. The increasing O-layer thickness is an indicator of restrained intermixing of organic and mineral components by soil organisms at higher elevation. Overall, the soil types and soil characteristics along the elevational gradient showed a continuous and consistent change, instead of abrupt changes. We interpret these as manifestations of changes of temperature and precipitation with elevation which also drives forest zonation in these least anthropogenically influenced forest ecosystems. The elevational distribution of forest zones is correlated with the distribution of soil types and thus also reflects soil characteristics.

  10. The effects of elevated CO2 and eutrophication on surface elevation gain in a European salt marsh.

    PubMed

    Reef, Ruth; Spencer, Tom; Mӧller, Iris; Lovelock, Catherine E; Christie, Elizabeth K; McIvor, Anna L; Evans, Ben R; Tempest, James A

    2017-02-01

    Salt marshes can play a vital role in mitigating the effects of global environmental change by dissipating incident storm wave energy and, through accretion, tracking increasing water depths consequent upon sea level rise. Atmospheric CO 2 concentrations and nutrient availability are two key variables that can affect the biological processes that contribute to marsh surface elevation gain. We measured the effects of CO 2 concentrations and nutrient availability on surface elevation change in intact mixed-species blocks of UK salt marsh using six open-top chambers receiving CO 2 -enriched (800 ppm) or ambient (400 ppm) air. We found more rapid surface elevation gain in elevated CO 2 conditions: an average increase of 3.4 mm over the growing season relative to ambient CO 2 . Boosted regression analysis to determine the relative influence of different parameters on elevation change identified that a 10% reduction in microbial activity in elevated CO 2 -grown blocks had a positive influence on elevation. The biomass of Puccinellia maritima also had a positive influence on elevation, while other salt marsh species (e.g. Suaeda maritima) had no influence or a negative impact on elevation. Reduced rates of water use by the vegetation in the high CO 2 treatment could be contributing to elevation gain, either directly through reduced soil shrinkage or indirectly by decreasing microbial respiration rates due to lower redox levels in the soil. Eutrophication did not influence elevation change in either CO 2 treatment despite doubling aboveground biomass. The role of belowground processes (transpiration, root growth and decomposition) in the vertical adjustment of European salt marshes, which are primarily minerogenic in composition, could increase as atmospheric CO 2 concentrations rise and should be considered in future wetland models for the region. Elevated CO 2 conditions could enhance resilience in vulnerable systems such as those with low mineral sediment supply or where migration upwards within the tidal frame is constrained. © 2016 John Wiley & Sons Ltd.

  11. Elevation of Morning Blood Pressure in Sodium Resistant Subjects by High Sodium Diet

    PubMed Central

    Lim, Chi-Yeon; Shin, Sung-Joon; Oh, Sang-Woo; Park, Yong-Soon; Kim, Jong-Wook; Park, Hye-Kyoung; Kim, Cho-il; Park, Cheol-Young; Kim, Sun-Woong

    2013-01-01

    The present study evaluated the response of blood pressure (BP) by dietary sodium in sodium resistant (SR) subjects. One hundred one subjects (mean age, 46.0 yr; 31 hypertensives) were admitted and given low sodium-dietary approaches to stop hypertension (DASH) diet (LSD, 100 mM NaCl/day) for 7 days and high sodium-DASH diet (HSD, 300 mM NaCl/day) for the following 7 days. On the last day of each diet, 24 hr ambulatory BP was measured. Morning systolic BP (SBP) and diastolic BP (DBP) were elevated after HSD in all subjects (P < 0.01), but daytime SBP and DBP were not changed (P > 0.05). In hypertensive subjects, morning DBP elevation was greater than daytime DBP elevation (P = 0.036), although both DBPs were significantly elevated after HSD. The augmented elevation of morning DBP in hypertensive subjects was contributed by the absolute elevation of morning DBP (P = 0.032) and relative elevation to daytime DBP (P = 0.005) in sodium resistant (SR) subjects, but not by sodium sensitive subjects. Although there was no absolute elevation, SR subjects with normotension showed a relative elevation of morning SBP compared to daytime SBP change after HSD (P = 0.009). The present study demonstrates an absolute and relative elevation of morning BP in SR subjects by HSD. PMID:23580363

  12. 2. View of Mainline elevated structure, parallel to Washington Street, ...

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

    2. View of Mainline elevated structure, parallel to Washington Street, crossing over the Massachusetts Turnpike and the B&A R.R. tracks - looking North. - Boston Elevated Railway, Elevated Mainline, Washington Street, Boston, Suffolk County, MA

  13. Is moral elevation an approach-oriented emotion?

    PubMed Central

    Van de Vyver, Julie; Abrams, Dominic

    2017-01-01

    Abstract Two studies were designed to test whether moral elevation should be conceptualized as an approach-oriented emotion. The studies examined the relationship between moral elevation and the behavioral activation and inhibition systems. Study 1 (N = 80) showed that individual differences in moral elevation were associated with individual differences in behavioral activation but not inhibition. Study 2 (N = 78) showed that an elevation-inducing video promoted equally high levels of approach orientation as an anger-inducing video and significantly higher levels of approach orientation than a control video. Furthermore, the elevation-inducing stimulus (vs. the control condition) significantly promoted prosocial motivation and this effect was sequentially mediated by feelings of moral elevation followed by an approach-oriented state. Overall the results show unambiguous support for the proposal that moral elevation is an approach-oriented emotion. Applied and theoretical implications are discussed. PMID:28191027

  14. Comparing trapezius muscle activity in the different planes of shoulder elevation

    PubMed Central

    Ishigaki, Tomonobu; Ishida, Tomoya; Samukawa, Mina; Saito, Hiroshi; Hirokawa, Motoki; Ezawa, Yuya; Sugawara, Makoto; Tohyama, Harukazu; Yamanaka, Masanori

    2015-01-01

    [Purpose] The purpose of this study was to compare the upper, middle, and lower trapezius muscles’ activity in the different planes of shoulder elevation. [Subjects] Twenty male subjects volunteered for this study. [Methods] Surface electromyographic (EMG) activity for each of the three regions of the trapezius muscles in the three different planes of elevation were collected while the participants maintained 30, 60, and 90 degrees of elevation in each plane. The EMG data were normalized with maximum voluntary isometric contraction (%MVIC), and compared among the planes at each angle of elevation. [Results] There were significantly different muscle activities among the elevation planes at each angle. [Conclusion] This study found that the three regions of the trapezius muscles changed their activity depending on the planes of shoulder elevation. These changes in the trapezius muscles could induce appropriate scapular motion to face the glenoid cavity in the correct directions in different planes of shoulder elevation. PMID:26157248

  15. Comparing trapezius muscle activity in the different planes of shoulder elevation.

    PubMed

    Ishigaki, Tomonobu; Ishida, Tomoya; Samukawa, Mina; Saito, Hiroshi; Hirokawa, Motoki; Ezawa, Yuya; Sugawara, Makoto; Tohyama, Harukazu; Yamanaka, Masanori

    2015-05-01

    [Purpose] The purpose of this study was to compare the upper, middle, and lower trapezius muscles' activity in the different planes of shoulder elevation. [Subjects] Twenty male subjects volunteered for this study. [Methods] Surface electromyographic (EMG) activity for each of the three regions of the trapezius muscles in the three different planes of elevation were collected while the participants maintained 30, 60, and 90 degrees of elevation in each plane. The EMG data were normalized with maximum voluntary isometric contraction (%MVIC), and compared among the planes at each angle of elevation. [Results] There were significantly different muscle activities among the elevation planes at each angle. [Conclusion] This study found that the three regions of the trapezius muscles changed their activity depending on the planes of shoulder elevation. These changes in the trapezius muscles could induce appropriate scapular motion to face the glenoid cavity in the correct directions in different planes of shoulder elevation.

  16. Plant and microbial responses to nitrogen and phosphorus addition across an elevational gradient in subarctic tundra.

    PubMed

    Sundqvist, Maja K; Liu, Zhanfeng; Giesler, Reiner; Wardle, David A

    2014-07-01

    Temperature and nutrients are major limiting factors in subarctic tundra. Experimental manipulation of nutrient availability along elevational gradients (and thus temperature) can improve our understanding of ecological responses to climate change. However, no study to date has explored impacts of nutrient addition along a tundra elevational gradient, or across contrasting vegetation types along any elevational gradient. We set up a full factorial nitrogen (N) and phosphorus (P) fertilization experiment in each of two vegetation types (heath and meadow) at 500 m, 800 m, and 1000 m elevation in northern Swedish tundra. We predicted that plant and microbial communities in heath or at lower elevations would be more responsive to N addition while communities in meadow or at higher elevations would be more responsive to P addition, and that fertilizer effects would vary more with elevation for the heath than for the meadow. Although our results provided little support for these predictions, the relationship between nutrient limitation and elevation differed between vegetation types. Most plant and microbial properties were responsive to N and/or P fertilization, but responses often varied with elevation and/or vegetation type. For instance, vegetation density significantly increased with N + P fertilization relative to the other fertilizer treatments, and this increase was greatest at the lowest elevation for the heath but at the highest elevation for the meadow. Arbuscular mycorrhizae decreased with P fertilization at 500 m for the meadow, but with all fertilizer treatments in both vegetation types at 800 m. Fungal to bacterial ratios were enhanced by N+ P fertilization for the two highest elevations in the meadow only. Additionally, microbial responses to fertilization were primarily direct rather than indirect via plant responses, pointing to a decoupled response of plant and microbial communities to nutrient addition and elevation. Because our study shows how two community types differ in their responses to fertilization and elevation, and because the temperature range across this gradient is approximately 3 degrees C, our study is informative about how nutrient limitation in tundra may be influenced by temperature shifts that are comparable to those expected under climate change during this century.

  17. Patterns of reptile and amphibian species richness along elevational gradients in Mt. Kenya

    PubMed Central

    MALONZA, Patrick Kinyatta

    2015-01-01

    Faunal species richness is traditionally assumed to decrease with increasing elevation and decreasing primary productivity. Species richness is reported to peak at mid-elevation. This survey examines the herpetofaunal diversity and distribution in Mt. Kenya (central Kenya) by testing the hypothesis that changes in species richness with elevation relate to elevation-dependent changes in climate. Sampling along transects from an elevation of approximately 1 700 m in Chogoria forest block (wind-ward side) and approximately 2 600 m in Sirimon block (rain shadow zone) upwards in March 2009. This starts from the forest to montane alpine zones. Sampling of reptiles and amphibians uses pitfall traps associated with drift fences, time-limited searches and visual encounter surveys. The results show that herpetofaunal richness differs among three vegetation zones along the elevation gradient. Chogoria has higher biodiversity than Sirimon. More species occur at low and middle elevations and few exist at high elevations. The trends are consistent with expected optimum water and energy variables. The lower alpine montane zone has high species richness but low diversity due to dominance of some high elevations species. Unambiguous data do not support a mid-domain effect (mid-elevation peak) because the observed trend better fits a model in which climatic variables (rainfall and temperature) control species richness, which indirectly measures productivity. It is important to continue protection of all indigenous forests, especially at low to mid elevations. These areas are vulnerable to human destruction yet are home to some endemic species. Firebreaks can limit the spread of the perennial wildfires, especially on the moorlands. PMID:26646571

  18. Google Earth elevation data extraction and accuracy assessment for transportation applications

    PubMed Central

    Wang, Yinsong; Zou, Yajie; Henrickson, Kristian; Wang, Yinhai; Tang, Jinjun; Park, Byung-Jung

    2017-01-01

    Roadway elevation data is critical for a variety of transportation analyses. However, it has been challenging to obtain such data and most roadway GIS databases do not have them. This paper intends to address this need by proposing a method to extract roadway elevation data from Google Earth (GE) for transportation applications. A comprehensive accuracy assessment of the GE-extracted elevation data is conducted for the area of conterminous USA. The GE elevation data was compared with the ground truth data from nationwide GPS benchmarks and roadway monuments from six states in the conterminous USA. This study also compares the GE elevation data with the elevation raster data from the U.S. Geological Survey National Elevation Dataset (USGS NED), which is a widely used data source for extracting roadway elevation. Mean absolute error (MAE) and root mean squared error (RMSE) are used to assess the accuracy and the test results show MAE, RMSE and standard deviation of GE roadway elevation error are 1.32 meters, 2.27 meters and 2.27 meters, respectively. Finally, the proposed extraction method was implemented and validated for the following three scenarios: (1) extracting roadway elevation differentiating by directions, (2) multi-layered roadway recognition in freeway segment and (3) slope segmentation and grade calculation in freeway segment. The methodology validation results indicate that the proposed extraction method can locate the extracting route accurately, recognize multi-layered roadway section, and segment the extracted route by grade automatically. Overall, it is found that the high accuracy elevation data available from GE provide a reliable data source for various transportation applications. PMID:28445480

  19. Google Earth elevation data extraction and accuracy assessment for transportation applications.

    PubMed

    Wang, Yinsong; Zou, Yajie; Henrickson, Kristian; Wang, Yinhai; Tang, Jinjun; Park, Byung-Jung

    2017-01-01

    Roadway elevation data is critical for a variety of transportation analyses. However, it has been challenging to obtain such data and most roadway GIS databases do not have them. This paper intends to address this need by proposing a method to extract roadway elevation data from Google Earth (GE) for transportation applications. A comprehensive accuracy assessment of the GE-extracted elevation data is conducted for the area of conterminous USA. The GE elevation data was compared with the ground truth data from nationwide GPS benchmarks and roadway monuments from six states in the conterminous USA. This study also compares the GE elevation data with the elevation raster data from the U.S. Geological Survey National Elevation Dataset (USGS NED), which is a widely used data source for extracting roadway elevation. Mean absolute error (MAE) and root mean squared error (RMSE) are used to assess the accuracy and the test results show MAE, RMSE and standard deviation of GE roadway elevation error are 1.32 meters, 2.27 meters and 2.27 meters, respectively. Finally, the proposed extraction method was implemented and validated for the following three scenarios: (1) extracting roadway elevation differentiating by directions, (2) multi-layered roadway recognition in freeway segment and (3) slope segmentation and grade calculation in freeway segment. The methodology validation results indicate that the proposed extraction method can locate the extracting route accurately, recognize multi-layered roadway section, and segment the extracted route by grade automatically. Overall, it is found that the high accuracy elevation data available from GE provide a reliable data source for various transportation applications.

  20. Thermoregulation in the lizard Psammodromus algirus along a 2200-m elevational gradient in Sierra Nevada (Spain)

    NASA Astrophysics Data System (ADS)

    Zamora-Camacho, Francisco Javier; Reguera, Senda; Moreno-Rueda, Gregorio

    2016-05-01

    Achieving optimal body temperature maximizes animal fitness. Since ambient temperature may limit ectotherm thermal performance, it can be constrained in too cold or hot environments. In this sense, elevational gradients encompass contrasting thermal environments. In thermally pauperized elevations, ectotherms may either show adaptations or suboptimal body temperatures. Also, reproductive condition may affect thermal needs. Herein, we examined different thermal ecology and physiology capabilities of the lizard Psammodromus algirus along a 2200-m elevational gradient. We measured field (Tb) and laboratory-preferred (Tpref) body temperatures of lizards with different reproductive conditions, as well as ambient (Ta) and copper-model operative temperature (Te), which we used to determine thermal quality of the habitat (de), accuracy (db), and effectiveness of thermoregulation (de-db) indexes. We detected no Tb trend in elevation, while Ta constrained Tb only at high elevations. Moreover, while Ta decreased more than 7 °C with elevation, Tpref dropped only 0.6 °C, although significantly. Notably, low-elevation lizards faced excess temperature (Te > Tpref). Notably, de was best at middle elevations, followed by high elevations, and poorest at low elevations. Nonetheless, regarding microhabitat, high-elevation de was more suitable in sun-exposed microhabitats, which may increase exposition to predators, and at midday, which may limit daily activity. As for gender, db and de-db were better in females than in males. In conclusion, P. algirus seems capable to face a wide thermal range, which probably contributes to its extensive corology and makes it adaptable to climate changes.

  1. Surface topography of the Greenland Ice Sheet from satellite radar altimetry

    NASA Technical Reports Server (NTRS)

    Bindschadler, Robert A.; Zwally, H. Jay; Major, Judith A.; Brenner, Anita C.

    1989-01-01

    Surface elevation maps of the southern half of the Greenland subcontinent are produced from radar altimeter data acquired by the Seasat satellite. A summary of the processing procedure and examples of return waveform data are given. The elevation data are used to generate a regular grid which is then computer contoured to provide an elevation contour map. Ancillary maps show the statistical quality of the elevation data and various characteristics of the surface. The elevation map is used to define ice flow directions and delineate the major drainage basins. Regular maps of the Jakobshavns Glacier drainage basin and the ice divide in the vicinity of Crete Station are presented. Altimeter derived elevations are compared with elevations measured both by satellite geoceivers and optical surveying.

  2. SouthWest Elevation, Plan Showing Deck Framing, Deck Plan, Plan of ...

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

    South-West Elevation, Plan Showing Deck Framing, Deck Plan, Plan of Collar Beams, Etc., Typical Framing Details, End Elevations, Elevation of Scarf Top Chord, Joint Details - Perrine's Bridge, Spanning Wallkill River, Rifton, Ulster County, NY

  3. 33. Coal Fuel Elevator (diagonal in foreground), Fuel Elevator (left), ...

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

    33. Coal Fuel Elevator (diagonal in foreground), Fuel Elevator (left), Fuel Storage Bins (center), and Power Plant (right) Photographs taken by Joseph E.B. Elliot - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  4. 4th floor sacking deck looking east from 1945 elevator to ...

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

    4th floor sacking deck looking east from 1945 elevator to 1913 elevator indicating spout used to load bulk grain into rail cars - Stewart Company Grain Elevator, 16 West Carson Street, Pittsburgh, Allegheny County, PA

  5. Retrieving improved multi-temporal CryoSat elevations over ice caps and glaciers - a case study of Barnes ice cap

    NASA Astrophysics Data System (ADS)

    Nilsson, Johan; Burgess, David

    2014-05-01

    The CryoSat mission was launched in 2010 to observe the Earth's cryosphere. In contrast to previous satellite radar altimeters, this mission is expected to monitor the elevation of small ice caps and glaciers, which according to the IPCC will be the largest contributor to 21st century sea level rise. To date the ESA CryoSat SARiN level-2 (L2) elevation product is not yet fully optimized for use over these types of glaciated regions, as its processed with a more universal algorithm. Thus the aim of this study is to demonstrate that with the use of improved processing CryoSat SARiN data can be used for more accurate topography mapping and elevation change detection for ice caps and glaciers. To demonstrate this, elevations and elevation changes over Barnes ice cap, located on Baffin Island in the Canadian Arctic, have been estimated from available data from the years 2010-2013. ESA's CryoSat level-1b (L1b) SARiN baseline "B" data product was used and processed in-house to estimate surface elevations. The resulting product is referred to as DTU-L2. The processing focused on improving the retracker, reducing phase noise and correcting phase ambiguities. The accuracy of the DTU-L2 and the ESA-L2 product was determined by comparing the measured elevations against NASA's IceBridge Airborne Topographic Mapper (ATM) elevations from May 2011. The resulting difference in accuracy was determined by comparing their associated errors. From the multi-temporal measurements spanning the period 2010-2013, elevation changes where estimated and compared to ICESat derived changes from 2003-2009. The result of the study shows good agreement between the NASA measured ATM elevations and the DTU-L2 data. It also shows that the pattern of elevation change is similar to that derived from ICESat data. The accuracy of the DTU-L2 estimated elevations is on average several factors higher compared to the ESA-L2 elevation product. These preliminary results demonstrates that CryoSat elevation data, using improved processing, can be used for accurate topographic mapping and elevation change detection on ice caps and glaciers. Future work would entail extending this processing to other regions of this type to support these results.

  6. Changes in host-parasitoid food web structure with elevation.

    PubMed

    Maunsell, Sarah C; Kitching, Roger L; Burwell, Chris J; Morris, Rebecca J

    2015-03-01

    Gradients in elevation are increasingly used to investigate how species respond to changes in local climatic conditions. Whilst many studies have shown elevational patterns in species richness and turnover, little is known about how food web structure is affected by elevation. Contrasting responses of predator and prey species to elevation may lead to changes in food web structure. We investigated how the quantitative structure of a herbivore-parasitoid food web changes with elevation in an Australian subtropical rain forest. On four occasions, spread over 1 year, we hand-collected leaf miners at twelve sites, along three elevational gradients (between 493 m and 1159 m a.s.l). A total of 5030 insects, including 603 parasitoids, were reared, and summary food webs were created for each site. We also carried out a replicated manipulative experiment by translocating an abundant leaf-mining weevil Platynotocis sp., which largely escaped parasitism at high elevations (≥ 900 m a.s.l.), to lower, warmer elevations, to test if it would experience higher parasitism pressure. We found strong evidence that the environmental change that occurs with increasing elevation affects food web structure. Quantitative measures of generality, vulnerability and interaction evenness decreased significantly with increasing elevation (and decreasing temperature), whilst elevation did not have a significant effect on connectance. Mined plant composition also had a significant effect on generality and vulnerability, but not on interaction evenness. Several relatively abundant species of leaf miner appeared to escape parasitism at higher elevations, but contrary to our prediction, Platynotocis sp. did not experience greater levels of parasitism when translocated to lower elevations. Our study indicates that leaf-mining herbivores and their parasitoids respond differently to environmental conditions imposed by elevation, thus producing structural changes in their food webs. Increasing temperatures and changes in vegetation communities that are likely to result from climate change may have a restructuring effect on host-parasitoid food webs. Our translocation experiment, however, indicated that leaf miners currently escaping parasitism at high elevations may not automatically experience higher parasitism under warmer conditions and future changes in food web structure may depend on the ability of parasitoids to adapt to novel hosts. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

  7. Effect of elevation on distribution of female bats in the Black Hills, South Dakota

    USGS Publications Warehouse

    Cryan, P.M.; Bogan, M.A.; Altenbach, J.S.

    2000-01-01

    Presumably, reproductive female bats are more constrained by thermoregulatory and energy needs than are males and nonreproductive females. Constraints imposed on reproductive females may limit their geographic distribution relative to other bats. Such constraints likely increase with latitude and elevation. Males of 11 bat species that inhabit the Black Hills were captured more frequently than females, and reproductive females typically were encountered at low-elevational sites. To investigate the relationship between female distribution and elevation, we fitted a logistic regression model to evaluate the probability of reproductive-female capture as a function of elevation. Mist-net data from 1,197 captures of 7 species revealed that 75% of all captures were males. We found a significant inverse relationship between elevation and relative abundance of reproductive females. Relative abundance of reproductive females decreased as elevation increased. Reproductive females may be constrained from roosting and foraging in high-elevational habitats that impose thermoregulatory costs and decrease foraging efficiency. Failure to account for sex differences in distributional patterns along elevational gradients may significantly bias estimates of population size.

  8. A new sternum elevator reduces severe complications during minimally invasive repair of the pectus excavatum.

    PubMed

    Takagi, Satoshi; Oyama, Takuto; Tomokazu, Nishihira; Kinoshita, Koji; Makino, Taro; Ohjimi, Hiroyuki

    2012-06-01

    Although the Nuss procedure for pectus excavatum is widely employed, a variety of complications have been reported with relatively high frequency; those that involve cardiac and pericardial injuries can be life threatening. To reduce such dangers, we present here a newly developed sternal elevator. The elevator is horseshoe shaped. Its elevator side has the same curvature as a Nuss introducer, so that interference between devices is minimal and no extra skin incision is needed for the elevator insertion. The elevator holds the sternum forward and enlarges the retrosternal space for safer passage of thoracoscopically guided introducer. The authors have used the elevator for 61 pectus excavatum cases between March 2004 and December 2009 without any major complications. The entire process of substernal tunneling was endoscopically observed, which eliminated any blunt and blind dissection, even in a significantly depressed funnel chest case. With the device, the sternum was effectively elevated again for the placement of the second plate in 30 cases. Our newly developed sternum elevator makes the Nuss procedure safer and more affordable without introducing any extra scarring.

  9. Accuracy assessment of the U.S. Geological Survey National Elevation Dataset, and comparison with other large-area elevation datasets: SRTM and ASTER

    USGS Publications Warehouse

    Gesch, Dean B.; Oimoen, Michael J.; Evans, Gayla A.

    2014-01-01

    The National Elevation Dataset (NED) is the primary elevation data product produced and distributed by the U.S. Geological Survey. The NED provides seamless raster elevation data of the conterminous United States, Alaska, Hawaii, U.S. island territories, Mexico, and Canada. The NED is derived from diverse source datasets that are processed to a specification with consistent resolutions, coordinate system, elevation units, and horizontal and vertical datums. The NED serves as the elevation layer of The National Map, and it provides basic elevation information for earth science studies and mapping applications in the United States and most of North America. An important part of supporting scientific and operational use of the NED is provision of thorough dataset documentation including data quality and accuracy metrics. The focus of this report is on the vertical accuracy of the NED and on comparison of the NED with other similar large-area elevation datasets, namely data from the Shuttle Radar Topography Mission (SRTM) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER).

  10. Background-Source Cosmic-Photon Elevation Scaling and Cosmic-Neutron/Photon Date Scaling in MCNP6

    DOE PAGES

    Tutt, James Robert; Anderson, Casey Alan; McKinney, Gregg Walter

    2017-10-26

    Here, cosmic neutron and photon fluxes are known to scale exponentially with elevation. Consequently, cosmic neutron elevation scaling was implemented for use with the background-source option shortly after its introduction into MCNP6, whereby the neutron flux weight factor was adjusted by the elevation scaling factor when the user-specified elevation differed from the selected background.dat grid-point elevation. At the same time, an elevation scaling factor was suggested for the cosmic photon flux, however, cosmic photon elevation scaling is complicated by the fact that the photon background consists of two components: cosmic and terrestrial. Previous versions of the background.dat file did notmore » provide any way to separate these components. With Rel. 4 of this file in 2015, two new columns were added that provide the energy grid and differential cosmic photon flux separately from the total photon flux. Here we show that the cosmic photon flux component can now be scaled independently and combined with the terrestrial component to form the total photon flux at a user-specified elevation in MCNP6.« less

  11. Background-Source Cosmic-Photon Elevation Scaling and Cosmic-Neutron/Photon Date Scaling in MCNP6

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tutt, James Robert; Anderson, Casey Alan; McKinney, Gregg Walter

    Here, cosmic neutron and photon fluxes are known to scale exponentially with elevation. Consequently, cosmic neutron elevation scaling was implemented for use with the background-source option shortly after its introduction into MCNP6, whereby the neutron flux weight factor was adjusted by the elevation scaling factor when the user-specified elevation differed from the selected background.dat grid-point elevation. At the same time, an elevation scaling factor was suggested for the cosmic photon flux, however, cosmic photon elevation scaling is complicated by the fact that the photon background consists of two components: cosmic and terrestrial. Previous versions of the background.dat file did notmore » provide any way to separate these components. With Rel. 4 of this file in 2015, two new columns were added that provide the energy grid and differential cosmic photon flux separately from the total photon flux. Here we show that the cosmic photon flux component can now be scaled independently and combined with the terrestrial component to form the total photon flux at a user-specified elevation in MCNP6.« less

  12. Elevated atmospheric CO₂ mitigated photoinhibition in a tropical tree species, Gmelina arborea.

    PubMed

    Rasineni, Girish Kumar; Guha, Anirban; Reddy, Attipalli Ramachandra

    2011-05-03

    Effects of elevated CO₂ on photosynthetic CO₂ assimilation, PSII photochemistry and photoinhibition were investigated in the leaves of a fast growing tropical tree species, Gmelina arborea (Verbenaceae) during summer days of peak growth season under natural light. Elevated CO₂ had a significant effect on CO₂ assimilation rates and maximal efficiency of PSII photochemistry. Chlorophyll a fluorescence induction kinetics were measured to determine the influence of elevated CO₂ on PSII efficiency. During midday, elevated CO₂-grown Gmelina showed significantly higher net photosynthesis (p<0.001) and greater F(V)/F(M) (p<0.001) than those grown under ambient CO₂. The impact of elevated CO₂ on photosynthetic rates and Chl a fluorescence were more pronounced during midday depression where the impact of high irradiance decreased in plants grown under elevated CO₂ compared to ambient CO₂-grown plants. Our results clearly demonstrate that decreased susceptibility to photoinhibition in elevated CO₂ grown plants was associated with increased accumulation of active PSII reaction centers and efficient photochemical quenching. We conclude that elevated CO₂ treatment resulted in easy diminution of midday photosynthetic depression. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Changes in wetland sediment elevation following major storms: implications for estimating trends in relative sea-level rise

    USGS Publications Warehouse

    Cahoon, D.R.

    2003-01-01

    Hurricanes can be important agents of geomorphic change in coastal marshes and mangrove forests. Hurricanes can cause large-scale redistribution of sediments within the coastal environment resulting in sedimentation, erosion, disruption of vegetated substrates, or some combination of these processes in coastal wetlands. It has been proposed that such sediment pulsing events are important at maintaining wetland sediment elevations in sediment-poor settings with high rates of relative sea-level rise, such as the Mississippi River Delta. But do these pulsing events result in a net gain in sediment elevation even when substantial amounts of sediment are deposited? Clearly sediment erosion and scour would result in a loss of elevation. But will a substantial sediment deposit on poorly consolidated sediments always result in a net gain in elevation? If the wetland vegetation is killed by wind, tidal surge, or the introduction of saline water, will there be a collapse of sediment elevation in the absence of root production and ongoing decomposition of root matter? During the past decade several wetlands where my colleagues and I have monitored sedimentation and elevation change have been struck by one to several hurricanes. This paper describes the range of sediment elevation responses to hurricane strikes, the suggested mechanisms driving those responses, the implications for estimating long-term trends in relative sea-level rise, and future research needs for improving our understanding of the role that major storms play in wetland sediment elevation dynamics. For many wetlands the change in sediment elevation was directly proportional to the amount of sediment deposited by the storm. But surprisingly, there was a loss of elevation in some wetlands with substantial sediment deposits. In these wetlands, the impact of the storm was either direct (sedimentation and compaction) or indirect (vegetation death), and the effect on sediment elevation was either permanent or temporary. For example, 2 cm of sediment deposited by Hurricane Andrew on a healthy salt marsh in south Louisiana had a direct and positive effect on sediment elevation. But in a deteriorated salt marsh a 3 cm thick sediment deposit was associated with a permanent loss in elevation (we have monitored this site for 10 years). The apparent mechanism driving elevation loss was compaction of the weakened substrate by the weight of the sediment deposit, the storm surge waters, or both. Clearly, storm-related sediment pulses are not going to save this marsh from becoming submerged by rising sea level. A temporary loss in elevation, as much as 2 cm, was observed in a North Carolina salt marsh with a highly organic substrate after each of 3 successive hurricanes even when sediment was deposited. The loss in elevation was apparently related to degassing of the chronically flooded substrate while the rebound in elevation was apparently related to a temporary drawdown of marsh water levels. Interestingly, sediment elevation increased after Hurricane Dennis in 1999, although the increase was less than the thickness of the sediment deposit. Further research is required to determine the mechanisms driving storm-related elevation change (i.e., compaction and expansion) in this marsh. There were two marshes where the gain in sediment elevation was greater than the thickness of the sediment deposit, but the effect was short-lived. In a high salt marsh in southern California, we hypothesize that the temporary spike in elevation was related to the flushing of salts from the hypersaline soils, which enhanced root growth that led to an increase in elevation. In a marsh with a highly organic substrate in north Florida, temporary increases in elevation (as much as 2 cm) greater than the thickness of the sediment deposit were apparently related to groundwater fluxes, which may have been influenced by enhanced runoff from storm rainfall. Lastly, Hurricane Mitch

  14. Geomorphic controls on elevational gradients of species richness.

    PubMed

    Bertuzzo, Enrico; Carrara, Francesco; Mari, Lorenzo; Altermatt, Florian; Rodriguez-Iturbe, Ignacio; Rinaldo, Andrea

    2016-02-16

    Elevational gradients of biodiversity have been widely investigated, and yet a clear interpretation of the biotic and abiotic factors that determine how species richness varies with elevation is still elusive. In mountainous landscapes, habitats at different elevations are characterized by different areal extent and connectivity properties, key drivers of biodiversity, as predicted by metacommunity theory. However, most previous studies directly correlated species richness to elevational gradients of potential drivers, thus neglecting the interplay between such gradients and the environmental matrix. Here, we investigate the role of geomorphology in shaping patterns of species richness. We develop a spatially explicit zero-sum metacommunity model where species have an elevation-dependent fitness and otherwise neutral traits. Results show that ecological dynamics over complex terrains lead to the null expectation of a hump-shaped elevational gradient of species richness, a pattern widely observed empirically. Local species richness is found to be related to the landscape elevational connectivity, as quantified by a newly proposed metric that applies tools of complex network theory to measure the closeness of a site to others with similar habitat. Our theoretical results suggest clear geomorphic controls on elevational gradients of species richness and support the use of the landscape elevational connectivity as a null model for the analysis of the distribution of biodiversity.

  15. [Risk factors for elevated serum total bile acid in preterm infants].

    PubMed

    Song, Yan-Ting; Wang, Yong-Qin; Zhao, Yue-Hua; Zhu, Hai-Ling; Liu, Qian; Zhang, Xiao; Gao, Yi-Wen; Zhang, Wei-Ye; Sang, Yu-Tong

    2018-03-01

    To study the risk factors for elevated serum total bile acid (TBA) in preterm infants. A retrospective analysis was performed for the clinical data of 216 preterm infants who were admitted to the neonatal intensive care unit. According to the presence or absence of elevated TBA (TBA >24.8 μmol/L), the preterm infants were divided into elevated TBA group with 53 infants and non-elevated TBA group with 163 infants. A univariate analysis and an unconditional multivariate logistic regression analysis were used to investigate the risk factors for elevated TBA. The univariate analysis showed that there were significant differences between the elevated TBA group and the non-elevated TBA group in gestational age at birth, birth weight, proportion of small-for-gestational-age infants, proportion of infants undergoing ventilator-assisted ventilation, fasting time, parenteral nutrition time, and incidence of neonatal respiratory failure and sepsis (P<0.05). The unconditional multivariate logistic regression analysis showed that low birth weight (OR=3.84, 95%CI: 1.53-9.64) and neonatal sepsis (OR=2.56, 95%CI: 1.01-6.47) were independent risk factors for elevated TBA in preterm infants. Low birth weight and neonatal sepsis may lead to elevated TBA in preterm infants.

  16. The Landcover Impact on the Aspect/Slope Accuracy Dependence of the SRTM-1 Elevation Data for the Humboldt Range.

    PubMed

    Miliaresis, George C

    2008-05-15

    The U.S. National Landcover Dataset (NLCD) and the U.S National Elevation Dataset (NED) (bare earth elevations) were used in an attempt to assess to what extent the directional and slope dependency of the Shuttle Radar Topography Mission (SRTM) finished digital elevation model is affected by landcover. Four landcover classes: forest, shrubs, grass and snow cover, were included in the study area (Humboldt Range in NW portion of Nevada, USA). Statistics, rose diagrams, and frequency distributions of the elevation differences (NED-SRTM) per landcover class per geographic direction were used. The decomposition of elevation differences on the basis of aspect and slope terrain classes identifies a) over-estimation of elevation by the SRTM instrument along E, NE and N directions (negative elevation difference that decreases linearly with slope) while b) underestimation is evident towards W, SW and S directions (positive elevation difference increasing with slope). The aspect/slope/landcover elevation differences modelling overcome the systematic errors evident in the SRTM dataset and revealed vegetation height information and the snow penetration capability of the SRTM instrument. The linear regression lines per landcover class might provide means of correcting the systematic error (aspect/slope dependency) evident in SRTM dataset.

  17. The Landcover Impact on the Aspect/Slope Accuracy Dependence of the SRTM-1 Elevation Data for the Humboldt Range

    PubMed Central

    Miliaresis, George C.

    2008-01-01

    The U.S. National Landcover Dataset (NLCD) and the U.S National Elevation Dataset (NED) (bare earth elevations) were used in an attempt to assess to what extent the directional and slope dependency of the Shuttle Radar Topography Mission (SRTM) finished digital elevation model is affected by landcover. Four landcover classes: forest, shrubs, grass and snow cover, were included in the study area (Humboldt Range in NW portion of Nevada, USA). Statistics, rose diagrams, and frequency distributions of the elevation differences (NED-SRTM) per landcover class per geographic direction were used. The decomposition of elevation differences on the basis of aspect and slope terrain classes identifies a) over-estimation of elevation by the SRTM instrument along E, NE and N directions (negative elevation difference that decreases linearly with slope) while b) underestimation is evident towards W, SW and S directions (positive elevation difference increasing with slope). The aspect/slope/landcover elevation differences modelling overcome the systematic errors evident in the SRTM dataset and revealed vegetation height information and the snow penetration capability of the SRTM instrument. The linear regression lines per landcover class might provide means of correcting the systematic error (aspect/slope dependency) evident in SRTM dataset. PMID:27879870

  18. Geomorphic controls on elevational gradients of species richness

    PubMed Central

    Bertuzzo, Enrico; Carrara, Francesco; Mari, Lorenzo; Altermatt, Florian; Rodriguez-Iturbe, Ignacio; Rinaldo, Andrea

    2016-01-01

    Elevational gradients of biodiversity have been widely investigated, and yet a clear interpretation of the biotic and abiotic factors that determine how species richness varies with elevation is still elusive. In mountainous landscapes, habitats at different elevations are characterized by different areal extent and connectivity properties, key drivers of biodiversity, as predicted by metacommunity theory. However, most previous studies directly correlated species richness to elevational gradients of potential drivers, thus neglecting the interplay between such gradients and the environmental matrix. Here, we investigate the role of geomorphology in shaping patterns of species richness. We develop a spatially explicit zero-sum metacommunity model where species have an elevation-dependent fitness and otherwise neutral traits. Results show that ecological dynamics over complex terrains lead to the null expectation of a hump-shaped elevational gradient of species richness, a pattern widely observed empirically. Local species richness is found to be related to the landscape elevational connectivity, as quantified by a newly proposed metric that applies tools of complex network theory to measure the closeness of a site to others with similar habitat. Our theoretical results suggest clear geomorphic controls on elevational gradients of species richness and support the use of the landscape elevational connectivity as a null model for the analysis of the distribution of biodiversity. PMID:26831107

  19. Surface elevation dynamics in a regenerating mangrove forest at Homebush Bay, Australia

    USGS Publications Warehouse

    Rogers, K.; Saintilan, N.; Cahoon, D.

    2005-01-01

    Following the dieback of an interior portion of a mangrove forest at Homebush Bay, Australia, surface elevation tables and feldspar marker horizons were installed in the impacted, intermediate and control forest to measure vertical accretion, elevation change, and shallow subsidence. The objectives of the study were to determine current vertical accretion and elevation change rates as a guide to understanding mangrove dieback, ascertain the factors controlling surface elevation change, and investigate the sustainability of the mangrove forest under estimated sea-level rise conditions. The study demonstrates that the influences on surface dynamics are more complex than soil accretion and soil autocompaction alone. During strong vegetative regrowth in the impacted forest, surface elevation increase exceeded vertical accretion apparently as a result of belowground biomass production. In addition, surface elevation in all forest zones was correlated with total monthly rainfall during a severe El Ni?o event, highlighting the importance of rainfall to groundwater recharge and surface elevation. Surface elevation increase for all zones exceeded the 85-year sea level trend for Sydney Harbour. Since mean sea-level also decreased during the El Ni?o event, the decrease in surface elevation did not translate to an increase in inundation frequency or influence the sustainability of the mangrove forest. These findings indicate that subsurface soil processes such as organic matter accumulation and groundwater flux can significantly influence mangrove surface elevation, and contribute to the long-term sustainability of mangrove systems under a scenario of rising sea levels.

  20. Effect of high altitude on blood glucose meter performance.

    PubMed

    Fink, Kenneth S; Christensen, Dale B; Ellsworth, Allan

    2002-01-01

    Participation in high-altitude wilderness activities may expose persons to extreme environmental conditions, and for those with diabetes mellitus, euglycemia is important to ensure safe travel. We conducted a field assessment of the precision and accuracy of seven commonly used blood glucose meters while mountaineering on Mount Rainier, located in Washington State (elevation 14,410 ft). At various elevations each climber-subject used the randomly assigned device to measure the glucose level of capillary blood and three different concentrations of standardized control solutions, and a venous sample was also collected for later glucose analysis. Ordinary least squares regression was used to assess the effect of elevation and of other environmental potential covariates on the precision and accuracy of blood glucose meters. Elevation affects glucometer precision (p = 0.08), but becomes less significant (p = 0.21) when adjusted for temperature and relative humidity. The overall effect of elevation was to underestimate glucose levels by approximately 1-2% (unadjusted) for each 1,000 ft gain in elevation. Blood glucose meter accuracy was affected by elevation (p = 0.03), temperature (p < 0.01), and relative humidity (p = 0.04) after adjustment for the other variables. The interaction between elevation and relative humidity had a meaningful but not statistically significant effect on accuracy (p = 0.07). Thus, elevation, temperature, and relative humidity affect blood glucose meter performance, and elevated glucose levels are more greatly underestimated at higher elevations. Further research will help to identify which blood glucose meters are best suited for specific environments.

  1. 35. Coal Fuel Elevator (diagonal in center), Fuel Elevator (left), ...

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

    35. Coal Fuel Elevator (diagonal in center), Fuel Elevator (left), Fuel Storage Bins (center), and Power Plant (far center), and Retail Coal Storage Bins (right) Photograph taken by George Harven - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  2. 34. Coal Fuel Elevator (diagonal in foreground), Fuel Elevator (left), ...

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

    34. Coal Fuel Elevator (diagonal in foreground), Fuel Elevator (left), Fuel Storage Bins (center), and Power Plant (far center), and Retail Coal Storage Bins (right) Photograph taken by George Harven - Huber Coal Breaker, 101 South Main Street, Ashley, Luzerne County, PA

  3. 69. View underneath elevated Mainline structure (Section F5) looking ...

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

    69. View underneath elevated Mainline structure (Section F-5) - looking North - along Washington Street near the corner of the former Lotus Place. Arborway Yards and garage are at the right. - Boston Elevated Railway, Elevated Mainline, Washington Street, Boston, Suffolk County, MA

  4. 44 CFR 67.4 - Proposed flood elevation determination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Proposed flood elevation..., DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program APPEALS FROM PROPOSED FLOOD ELEVATION DETERMINATIONS § 67.4 Proposed flood elevation determination. The Federal...

  5. 76 FR 73534 - Proposed Flood Elevation Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-29

    ...-2011-0002; Internal Agency Docket No. FEMA-B-1230] Proposed Flood Elevation Determinations AGENCY... proposed Base (1% annual-chance) Flood Elevations (BFEs) and proposed BFE modifications for the communities... regarding the proposed regulatory flood elevations for the reach described by the downstream and upstream...

  6. 44 CFR 67.4 - Proposed flood elevation determination.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program APPEALS FROM PROPOSED FLOOD ELEVATION DETERMINATIONS § 67.4 Proposed flood elevation determination. The Federal... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Proposed flood elevation...

  7. 44 CFR 67.4 - Proposed flood elevation determination.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program APPEALS FROM PROPOSED FLOOD ELEVATION DETERMINATIONS § 67.4 Proposed flood elevation determination. The Federal... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Proposed flood elevation...

  8. Elevated seawater temperature, not pCO2, negatively affects post-spawning adult mussels (Mytilus edulis) under food limitation.

    PubMed

    Clements, Jeff C; Hicks, Carla; Tremblay, Réjan; Comeau, Luc A

    2018-01-01

    Pre-spawning blue mussels ( Mytilus edulis ) appear sensitive to elevated temperature and robust to elevated p CO 2 ; however, the effects of these stressors soon after investing energy into spawning remain unknown. Furthermore, while studies suggest that elevated p CO 2 affects the byssal attachment strength of Mytilus trossulus from southern latitudes, p CO 2 and temperature impacts on the byssus strength of other species at higher latitudes remain undocumented. In a 90 day laboratory experiment, we exposed post-spawning adult blue mussels ( M. edulis ) from Atlantic Canada to three p CO 2 levels ( p CO 2 ~625, 1295 and 2440 μatm) at two different temperatures (16°C and 22°C) and assessed energetic reserves on Day 90, byssal attachment strength on Days 30 and 60, and condition index and mortality on Days 30, 60 and 90. Results indicated that glycogen content was negatively affected under elevated temperature, but protein, lipid, and overall energy content were unaffected. Reduced glycogen content under elevated temperature was associated with reduced condition index, reduced byssal thread attachment strength, and increased mortality; elevated p CO 2 had no effects. Overall, these results suggest that the glycogen reserves of post-spawning adult M. edulis are sensitive to elevated temperature, and can result in reduced health and byssal attachment strength, leading to increased mortality. These results are similar to those reported for pre-spawning mussels and suggest that post-spawning blue mussels are tolerant to elevated p CO 2 and sensitive to elevated temperature. In contrast to previous studies, however, elevated pCO 2 did not affect byssus strength, suggesting that negative effects of elevated p CO 2 on byssus strength are not universal.

  9. Spring leaf flush in aspen (Populus tremuloides) clones is altered by long-term growth at elevated carbon dioxide and elevated ozone concentration.

    PubMed

    McGrath, Justin M; Karnosky, David F; Ainsworth, Elizabeth A

    2010-04-01

    Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO(2)]) and elevated ozone concentration ([O(3)]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO(2)] and [O(3)] predicted for approximately 2050. The responses of two clones were compared during the first month of spring leaf out when CO(2) fumigation had begun, but O(3) fumigation had not. Trees in elevated [CO(2)] plots showed a stimulation of leaf area index (36%), while trees in elevated [O(3)] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO(2)], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO(2)]; however, the two clones responded differently to long-term growth at elevated [O(3)]. The O(3)-sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O(3)] (-32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O(3)] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O(3)], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions. Published by Elsevier Ltd.

  10. Thermoregulation in the lizard Psammodromus algirus along a 2200-m elevational gradient in Sierra Nevada (Spain).

    PubMed

    Zamora-Camacho, Francisco Javier; Reguera, Senda; Moreno-Rueda, Gregorio

    2016-05-01

    Achieving optimal body temperature maximizes animal fitness. Since ambient temperature may limit ectotherm thermal performance, it can be constrained in too cold or hot environments. In this sense, elevational gradients encompass contrasting thermal environments. In thermally pauperized elevations, ectotherms may either show adaptations or suboptimal body temperatures. Also, reproductive condition may affect thermal needs. Herein, we examined different thermal ecology and physiology capabilities of the lizard Psammodromus algirus along a 2200-m elevational gradient. We measured field (T(b)) and laboratory-preferred (T(pref)) body temperatures of lizards with different reproductive conditions, as well as ambient (T(a)) and copper-model operative temperature (T(e)), which we used to determine thermal quality of the habitat (d(e)), accuracy (d(b)), and effectiveness of thermoregulation (de-db) indexes. We detected no Tb trend in elevation, while T(a) constrained T(b) only at high elevations. Moreover, while Ta decreased more than 7 °C with elevation, T(pref) dropped only 0.6 °C, although significantly. Notably, low-elevation lizards faced excess temperature (T(e) > T(pref)). Notably, de was best at middle elevations, followed by high elevations, and poorest at low elevations. Nonetheless, regarding microhabitat, high-elevation de was more suitable in sun-exposed microhabitats, which may increase exposition to predators, and at midday, which may limit daily activity. As for gender, d(b) and d(e)-d(b) were better in females than in males. In conclusion, P. algirus seems capable to face a wide thermal range, which probably contributes to its extensive corology and makes it adaptable to climate changes.

  11. Carbon gain and bud physiology in Populus tremuloides and Betula papyrifera grown under long-term exposure to elevated concentrations of CO2 and O3.

    PubMed

    Riikonen, Johanna; Kets, Katre; Darbah, Joseph; Oksanen, Elina; Sober, Anu; Vapaavuori, Elina; Kubiske, Mark E; Nelson, Neil; Karnosky, David F

    2008-02-01

    Paper birch (Betula papyrifera Marsh.) and three trembling aspen clones (Populus tremuloides Michx.) were studied to determine if alterations in carbon gain in response to an elevated concentration of CO(2) ([CO(2)]) or O(3) ([O(3)]) or a combination of both affected bud size and carbohydrate composition in autumn, and early leaf development in the following spring. The trees were measured for gas exchange, leaf size, date of leaf abscission, size and biochemical characteristics of the overwintering buds and early leaf development during the 8th-9th year of free-air CO(2) and O(3) exposure at the Aspen FACE site located near Rhinelander, WI. Net photosynthesis was enhanced 49-73% by elevated [CO(2)], and decreased 13-30% by elevated [O(3)]. Elevated [CO(2)] delayed, and elevated [O(3)] tended to accelerate, leaf abscission in autumn. Elevated [CO(2)] increased the ratio of monosaccharides to di- and oligosaccharides in aspen buds, which may indicate a lag in cold acclimation. The total carbon concentration in overwintering buds was unaffected by the treatments, although elevated [O(3)] decreased the amount of starch by 16% in birch buds, and reduced the size of aspen buds, which may be related to the delayed leaf development in aspen during the spring. Elevated [CO(2)] generally ameliorated the effects of elevated [O(3)]. Our results show that both elevated [CO(2)] and elevated [O(3)] have the potential to alter carbon metabolism of overwintering buds. These changes may cause carry-over effects during the next growing season.

  12. Biogeographical Interpretation of Elevational Patterns of Genus Diversity of Seed Plants in Nepal

    PubMed Central

    Li, Miao; Feng, Jianmeng

    2015-01-01

    This study tests if the biogeographical affinities of genera are relevant for explaining elevational plant diversity patterns in Nepal. We used simultaneous autoregressive (SAR) models to investigate the explanatory power of several predictors in explaining the diversity-elevation relationships shown in genera with different biogeographical affinities. Delta akaike information criterion (ΔAIC) was used for multi-model inferences and selections. Our results showed that both the total and tropical genus diversity peaked below the mid-point of the elevational gradient, whereas that of temperate genera had a nearly symmetrical, unimodal relationship with elevation. The proportion of temperate genera increased markedly with elevation, while that of tropical genera declined. Compared to tropical genera, temperate genera had wider elevational ranges and were observed at higher elevations. Water-related variables, rather than mid-domain effects (MDE), were the most significant predictors of elevational patterns of tropical genus diversity. The temperate genus diversity was influenced by energy availability, but only in quadratic terms of the models. Though climatic factors and mid-domain effects jointly explained most of the variation in the diversity of temperate genera with elevation, the former played stronger roles. Total genus diversity was most strongly influenced by climate and the floristic overlap of tropical and temperate floras, while the influences of mid-domain effects were relatively weak. The influences of water-related and energy-related variables may vary with biogeographical affinities. The elevational patterns may be most closely related to climatic factors, while MDE may somewhat modify the patterns. Caution is needed when investigating the causal factors underlying diversity patterns for large taxonomic groups composed of taxa of different biogeographical affinities. Right-skewed diversity-elevation patterns may be produced by the differential response of taxa with varying biogeographical affinities to climatic factors and MDE. PMID:26488164

  13. Biogeographical Interpretation of Elevational Patterns of Genus Diversity of Seed Plants in Nepal.

    PubMed

    Li, Miao; Feng, Jianmeng

    2015-01-01

    This study tests if the biogeographical affinities of genera are relevant for explaining elevational plant diversity patterns in Nepal. We used simultaneous autoregressive (SAR) models to investigate the explanatory power of several predictors in explaining the diversity-elevation relationships shown in genera with different biogeographical affinities. Delta akaike information criterion (ΔAIC) was used for multi-model inferences and selections. Our results showed that both the total and tropical genus diversity peaked below the mid-point of the elevational gradient, whereas that of temperate genera had a nearly symmetrical, unimodal relationship with elevation. The proportion of temperate genera increased markedly with elevation, while that of tropical genera declined. Compared to tropical genera, temperate genera had wider elevational ranges and were observed at higher elevations. Water-related variables, rather than mid-domain effects (MDE), were the most significant predictors of elevational patterns of tropical genus diversity. The temperate genus diversity was influenced by energy availability, but only in quadratic terms of the models. Though climatic factors and mid-domain effects jointly explained most of the variation in the diversity of temperate genera with elevation, the former played stronger roles. Total genus diversity was most strongly influenced by climate and the floristic overlap of tropical and temperate floras, while the influences of mid-domain effects were relatively weak. The influences of water-related and energy-related variables may vary with biogeographical affinities. The elevational patterns may be most closely related to climatic factors, while MDE may somewhat modify the patterns. Caution is needed when investigating the causal factors underlying diversity patterns for large taxonomic groups composed of taxa of different biogeographical affinities. Right-skewed diversity-elevation patterns may be produced by the differential response of taxa with varying biogeographical affinities to climatic factors and MDE.

  14. The National Map - Elevation

    USGS Publications Warehouse

    Gesch, Dean; Evans, Gayla; Mauck, James; Hutchinson, John; Carswell, William J.

    2009-01-01

    The National Elevation Dataset (NED) is the primary elevation data product produced and distributed by the USGS. The NED provides seamless raster elevation data of the conterminous United States, Alaska, Hawaii, and the island territories. The NED is derived from diverse source data sets that are processed to a specification with a consistent resolution, coordinate system, elevation units, and horizontal and vertical datums. The NED is the logical result of the maturation of the long-standing USGS elevation program, which for many years concentrated on production of topographic map quadrangle-based digital elevation models. The NED serves as the elevation layer of The National Map, and provides basic elevation information for earth science studies and mapping applications in the United States. The NED is a multi-resolution dataset that is updated bimonthly to integrate newly available, improved elevation source data. NED data are available nationally at grid spacings of 1 arc-second (approximately 30 meters) for the conterminous United States, and at 1/3 and 1/9 arc-seconds (approximately 10 and 3 meters, respectively) for parts of the United States. Most of the NED for Alaska is available at 2-arc-second (about 60 meters) grid spacing, where only lower resolution source data exist. Part of Alaska is available at the 1/3-arc-second resolution, and plans are in development for a significant upgrade in elevation data coverage of the State over the next 5 years. Specifications for the NED include the following: *Coordinate system: Geographic (decimal degrees of latitude and longitude), *Horizontal datum: North American Datum of 1983 (NAD 83), *Vertical datum: North American Vertical Datum of 1988 (NAVD 88) over the conterminous United States and varies in other areas, and *Elevation units: Decimal meters.

  15. Factors Determining Forest Diversity and Biomass on a Tropical Volcano, Mt. Rinjani, Lombok, Indonesia

    PubMed Central

    Dossa, Gbadamassi G. O.; Paudel, Ekananda; Fujinuma, Junichi; Yu, Haiying; Chutipong, Wanlop; Zhang, Yuan; Paz, Sherryl; Harrison, Rhett D.

    2013-01-01

    Tropical volcanoes are an important but understudied ecosystem, and the relationships between plant species diversity and compositional change and elevation may differ from mountains created by uplift, because of their younger and more homogeneous soils. We sampled vegetation over an altitudinal gradient on Mt. Rinjani, Lombok, Indonesia. We modeled alpha- (plot) and beta- (among plot) diversity (Fisher's alpha), compositional change, and biomass against elevation and selected covariates. We also examined community phylogenetic structure across the elevational gradient. We recorded 902 trees and shrubs among 92 species, and 67 species of ground-cover plants. For understorey, subcanopy and canopy plants, an increase in elevation was associated with a decline in alpha-diversity, whereas data for ground-cover plants suggested a hump-shaped pattern. Elevation was consistently the most important factor in determining alpha-diversity for all components. The alpha-diversity of ground-cover vegetation was also negatively correlated with leaf area index, which suggests low light conditions in the understorey may limit diversity at lower elevations. Beta-diversity increased with elevation for ground-cover plants and declined at higher elevations for other components of the vegetation. However, statistical power was low and we could not resolve the relative importance to beta-diversity of different factors. Multivariate GLMs of variation in community composition among plots explained 67.05%, 27.63%, 18.24%, and 19.80% of the variation (deviance) for ground-cover, understorey, subcanopy and canopy plants, respectively, and demonstrated that elevation was a consistently important factor in determining community composition. Above-ground biomass showed no significant pattern with elevation and was also not significantly associated with alpha-diversity. At lower elevations communities had a random phylogenetic structure, but from 1600 m communities were phylogenetically clustered. This suggests a greater role of environmental filtering at higher elevations, and thus provides a possible explanation for the observed decline in diversity with elevation. PMID:23935842

  16. Single-Frame Terrain Mapping Software for Robotic Vehicles

    NASA Technical Reports Server (NTRS)

    Rankin, Arturo L.

    2011-01-01

    This software is a component in an unmanned ground vehicle (UGV) perception system that builds compact, single-frame terrain maps for distribution to other systems, such as a world model or an operator control unit, over a local area network (LAN). Each cell in the map encodes an elevation value, terrain classification, object classification, terrain traversability, terrain roughness, and a confidence value into four bytes of memory. The input to this software component is a range image (from a lidar or stereo vision system), and optionally a terrain classification image and an object classification image, both registered to the range image. The single-frame terrain map generates estimates of the support surface elevation, ground cover elevation, and minimum canopy elevation; generates terrain traversability cost; detects low overhangs and high-density obstacles; and can perform geometry-based terrain classification (ground, ground cover, unknown). A new origin is automatically selected for each single-frame terrain map in global coordinates such that it coincides with the corner of a world map cell. That way, single-frame terrain maps correctly line up with the world map, facilitating the merging of map data into the world map. Instead of using 32 bits to store the floating-point elevation for a map cell, the vehicle elevation is assigned to the map origin elevation and reports the change in elevation (from the origin elevation) in terms of the number of discrete steps. The single-frame terrain map elevation resolution is 2 cm. At that resolution, terrain elevation from 20.5 to 20.5 m (with respect to the vehicle's elevation) is encoded into 11 bits. For each four-byte map cell, bits are assigned to encode elevation, terrain roughness, terrain classification, object classification, terrain traversability cost, and a confidence value. The vehicle s current position and orientation, the map origin, and the map cell resolution are all included in a header for each map. The map is compressed into a vector prior to delivery to another system.

  17. [Liver enzymes elevation: etiologic study and efficiency of a single-act office visit].

    PubMed

    Bendezú García, Rogger Álvaro; Casado Martín, Marta; Lázaro Sáez, Marta; Patrón Román, Gustavo Óliver; Gálvez Miras, Alejandra; Rodríguez Laiz, Gonzalo P; González Sánchez, Mercedes; Vega Sáenz, José Luis

    2013-01-01

    Liver enzyme (LE) elevation is a common finding in routine blood analysis. There is very little information on the most prevalent causes of these alterations in our population. In addition, a number of tests and several visits to the specialist are required to reach a diagnosis. For these reasons, we designed a protocol to streamline the evaluation of patients with LE elevations in a single-act office visit. From March 2008 until June 2010, we studied all patients with incidental LE elevation (isolated transaminase elevation, combined elevation of alkaline phosphatase [FA] and gamma-glutamyl transpeptidase [GGT], or isolated elevation of GGT) who were referred by their primary care physicians. At the time of referral, a complete biochemistry analysis was performed (LE, viral serology, autoantibodies, ceruloplasmin, iron metabolism, alpha-1-antitrypsin and thyroid hormones) and the patients underwent an abdominal ultrasound scan on the day of the office evaluation by the hepatologist. A total of 427 patients were included in our study. The most common cause of transaminase elevation was non-alcoholic fatty liver disease (NAFLD) (40%), followed by alcohol intake (17%), and hepatitis C virus infection (13%). Elevated GGT levels were most commonly related to NAFLD (30%), closely followed by alcohol intake (27%), and hepatotoxicity (8%). Combined elevation of GGT and FA was associated with NAFLD (21%), alcohol (17%), and hepatotoxicity (11%). Self-limited elevation was seen in 9% of the patients and we could not identify a definite cause in 11%. A definitive diagnosis was reached in 79% of the patients. The single-act office visit has proven to be efficient, yielding a diagnosis in most of the patients. The most common cause of elevated LE was NAFLD. Transaminase elevation must be confirmed before a more thorough work-up is started. Copyright © 2013 Elsevier España, S.L. and AEEH y AEG. All rights reserved.

  18. 77 FR 6980 - Final Flood Elevation Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-10

    ... feet above ground [caret] Elevation in meters (MSL) Modified Unincorporated Areas of Nowata County... Sea Level, rounded to the nearest 0.1 meter. ADDRESSES Unincorporated Areas of Nowata County Maps are... Communities affected elevation above ground [caret] Elevation in meters (MSL) Modified St. Lucie County...

  19. 77 FR 3625 - Final Flood Elevation Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ... feet above ground [caret] Elevation in meters (MSL) Modified City of Baltimore, Maryland Docket No... Sea Level, rounded to the nearest 0.1 meter. ADDRESSES City of Baltimore Maps are available for... Depth in feet Communities affected elevation above ground [caret] Elevation in meters (MSL) Modified...

  20. 78 FR 32579 - Airworthiness Directives; Bombardier, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ... elevator control system. Investigation revealed that, the increase in the elevator breakout force induced by the introduction of a new elevator centering mechanism, in combination with the existing [[Page... behaviors of the elevator control system. This proposed AD would require repetitive replacement of the...

  1. Global variation in elevational diversity patterns

    Treesearch

    Qinfeng Guo; Douglas A. Kelt; Zhongyu Sun; Hongxiao Liu; Liangjun Hu; Hai Ren; Jun We

    2013-01-01

    While horizontal gradients of biodiversity have been examined extensively in the past, vertical diversity gradients (elevation, water depth) are attracting increasing attention. We compiled data from 443 elevational gradients involving diverse organisms worldwide to investigate how elevational diversity patterns may vary between the Northern and Southern hemispheres...

  2. 10. Cartway from Collom Street looking south showing west elevation ...

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

    10. Cartway from Collom Street looking south showing west elevation of Building L (on left), north elevation of Building J, and east elevation of Building M (on right). - Daniel F. Waters Germantown Dye Works, 37-55 East Wister Street, Philadelphia, Philadelphia County, PA

  3. Reduced plant nutrition under elevated CO2 depresses the immunocompetence of cotton bollworm against its endoparasite

    NASA Astrophysics Data System (ADS)

    Yin, Jin; Sun, Yucheng; Ge, Feng

    2014-04-01

    Estimating the immunocompetence of herbivore insects under elevated CO2 is an important step in understanding the effects of elevated CO2 on crop-herbivore-natural enemy interactions. Current study determined the effect of elevated CO2 on the immune response of Helicoverpa armigera against its parasitoid Microplitis mediator. H. armigera were reared in growth chambers with ambient or elevated CO2, and fed wheat grown in the concentration of CO2 corresponding to their treatment levels. Our results showed that elevated CO2 decreases the nutritional quality of wheat, and reduces the total hemocyte counts and impairs the capacity of hemocyte spreading of hemolymph of cotton bollworm larvae, fed wheat grown in the elevated CO2, against its parasitoid; however, this effect was insufficient to change the development and parasitism traits of M. mediator. Our results suggested that lower plant nutritional quality under elevated CO2 could decrease the immune response of herbivorous insects against their parasitoid natural enemies.

  4. The Dengue Virus Mosquito Vector Aedes aegypti at High Elevation in México

    PubMed Central

    Lozano-Fuentes, Saul; Hayden, Mary H.; Welsh-Rodriguez, Carlos; Ochoa-Martinez, Carolina; Tapia-Santos, Berenice; Kobylinski, Kevin C.; Uejio, Christopher K.; Zielinski-Gutierrez, Emily; Monache, Luca Delle; Monaghan, Andrew J.; Steinhoff, Daniel F.; Eisen, Lars

    2012-01-01

    México has cities (e.g., México City and Puebla City) located at elevations > 2,000 m and above the elevation ceiling below which local climates allow the dengue virus mosquito vector Aedes aegypti to proliferate. Climate warming could raise this ceiling and place high-elevation cities at risk for dengue virus transmission. To assess the elevation ceiling for Ae. aegypti and determine the potential for using weather/climate parameters to predict mosquito abundance, we surveyed 12 communities along an elevation/climate gradient from Veracruz City (sea level) to Puebla City (∼2,100 m). Ae. aegypti was commonly encountered up to 1,700 m and present but rare from 1,700 to 2,130 m. This finding extends the known elevation range in México by > 300 m. Mosquito abundance was correlated with weather parameters, including temperature indices. Potential larval development sites were abundant in Puebla City and other high-elevation communities, suggesting that Ae. aegypti could proliferate should the climate become warmer. PMID:22987656

  5. [The expression of p53, MDM2 and Ref1 gene in cultured retina neurons of SD rats treated with vitamin B1 and/or elevated pressure].

    PubMed

    Yang, Zhikuan; Ge, Jian; Yin, Wei; Shen, Huangxuan; Liu, Haiquan; Guo, Yan

    2004-12-01

    To investigate the expression of p53, MDM2 and Ref1 gene in cultured retina neurons of SD rats treated with Vitamin B1 and (or) elevated pressure. The retinal neuron of postnatal SD rats were cultured in vivo, the elevated pressure was produced after 7 days, and the total RNA was extracted after another 2 days, expression of p53, MDM2 and Ref1 gene were analyzed with RT-PCR. The expression level of p53 and MDM2 gene were increased in elevated pressure group, normal with Ref1 gene expression. But the expression of p53 and MDM2 gene were decreased significantly in elevated pressure group treated with vitamine B1 compare to the elevated group. Apoptosis seem to be a mechanism of cell death in retinal neurons of SD rats with elevated pressure.Vitamine B1 have protect effects against elevated pressure.

  6. elevatr: Access Elevation Data from Various APIs | Science ...

    EPA Pesticide Factsheets

    Several web services are available that provide access to elevation data. This package provides access to several of those services and returns elevation data either as a SpatialPointsDataFrame from point elevation services or as a raster object from raster elevation services. Currently, the package supports access to the Mapzen Elevation Service, Mapzen Terrain Service, and the USGS Elevation Point Query Service. The R language for statistical computing is increasingly used for spatial data analysis . This R package, elevatr, is in response to this and provides access to elevation data from various sources directly in R. The impact of `elevatr` is that it will 1) facilitate spatial analysis in R by providing access to foundational dataset for many types of analyses (e.g. hydrology, limnology) 2) open up a new set of users and uses for APIs widely used outside of R, and 3) provide an excellent example federal open source development as promoted by the Federal Source Code Policy (https://sourcecode.cio.gov/).

  7. Effects of elevated CO2 and temperature on phytoplankton community biomass, species composition and photosynthesis during an experimentally induced autumn bloom in the western English Channel

    NASA Astrophysics Data System (ADS)

    Keys, Matthew; Tilstone, Gavin; Findlay, Helen S.; Widdicombe, Claire E.; Lawson, Tracy

    2018-05-01

    The combined effects of elevated pCO2 and temperature were investigated during an experimentally induced autumn phytoplankton bloom in vitro sampled from the western English Channel (WEC). A full factorial 36-day microcosm experiment was conducted under year 2100 predicted temperature (+4.5 °C) and pCO2 levels (800 µatm). Over the experimental period total phytoplankton biomass was significantly influenced by elevated pCO2. At the end of the experiment, biomass increased 6.5-fold under elevated pCO2 and 4.6-fold under elevated temperature relative to the ambient control. By contrast, the combined influence of elevated pCO2 and temperature had little effect on biomass relative to the control. Throughout the experiment in all treatments and in the control, the phytoplankton community structure shifted from dinoflagellates to nanophytoplankton . At the end of the experiment, under elevated pCO2 nanophytoplankton contributed 90 % of community biomass and was dominated by Phaeocystis spp. Under elevated temperature, nanophytoplankton comprised 85 % of the community biomass and was dominated by smaller nanoflagellates. In the control, larger nanoflagellates dominated whilst the smallest nanophytoplankton contribution was observed under combined elevated pCO2 and temperature ( ˜ 40 %). Under elevated pCO2, temperature and in the control there was a significant decrease in dinoflagellate biomass. Under the combined effects of elevated pCO2 and temperature, dinoflagellate biomass increased and was dominated by the harmful algal bloom (HAB) species, Prorocentrum cordatum. At the end of the experiment, chlorophyll a (Chl a) normalised maximum photosynthetic rates (PBm) increased > 6-fold under elevated pCO2 and > 3-fold under elevated temperature while no effect on PBm was observed when pCO2 and temperature were elevated simultaneously. The results suggest that future increases in temperature and pCO2 simultaneously do not appear to influence coastal phytoplankton productivity but significantly influence community composition during autumn in the WEC.

  8. Differences in symptoms, first medical contact and pre-hospital delay times between patients with ST- and non-ST-elevation myocardial infarction.

    PubMed

    Ängerud, Karin H; Sederholm Lawesson, Sofia; Isaksson, Rose-Marie; Thylén, Ingela; Swahn, Eva

    2017-11-01

    In ST-elevation myocardial infarction, time to reperfusion is crucial for the prognosis. Symptom presentation in myocardial infarction influences pre-hospital delay times but studies about differences in symptoms between patients with ST-elevation myocardial infarction and non-ST-elevation myocardial infarction are sparse and inconclusive. The aim was to compare symptoms, first medical contact and pre-hospital delay times in patients with ST-elevation myocardial infarction and non-ST-elevation myocardial infarction. This multicentre, observational study included 694 myocardial infarction patients from five hospitals. The patients filled in a questionnaire about their pre-hospital experiences within 24 h of hospital admittance. Chest pain was the most common symptom in ST-elevation myocardial infarction and non-ST-elevation myocardial infarction (88.7 vs 87.0%, p=0.56). Patients with cold sweat (odds ratio 3.61, 95% confidence interval 2.29-5.70), jaw pain (odds ratio 2.41, 95% confidence interval 1.04-5.58), and nausea (odds ratio 1.70, 95% confidence interval 1.01-2.87) were more likely to present with ST-elevation myocardial infarction, whereas the opposite was true for symptoms that come and go (odds ratio 0.58, 95% confidence interval 0.38-0.90) or anxiety (odds ratio 0.52, 95% confidence interval 0.29-0.92). Use of emergency medical services was higher among patients admitted with ST-elevation myocardial infarction. The pre-hospital delay time from symptom onset to first medical contact was significantly longer in non-ST-elevation myocardial infarction (2:05 h vs 1:10 h, p=0.001). Patients with ST-elevation myocardial infarction differed from those with non-ST-elevation myocardial infarction regarding symptom presentation, ambulance utilisation and pre-hospital delay times. This knowledge is important to be aware of for all healthcare personnel and the general public especially in order to recognise symptoms suggestive of ST-elevation myocardial infarction and when to decide if there is a need for an ambulance.

  9. ECG Criteria to Differentiate Between Takotsubo (Stress) Cardiomyopathy and Myocardial Infarction.

    PubMed

    Frangieh, Antonio H; Obeid, Slayman; Ghadri, Jelena-Rima; Imori, Yoichi; D'Ascenzo, Fabrizio; Kovac, Marc; Ruschitzka, Frank; Lüscher, Thomas F; Duru, Firat; Templin, Christian

    2016-06-13

    ECG criteria differentiating Takotsubo cardiomyopathy (TTC) from mainly anterior myocardial infarction (MI) have been suggested; however, this was in small patient populations. Twelve-lead admission ECGs of consecutive 200 TTC and 200 MI patients were compared in dichotomized groups based on the presence or absence of ST-elevation MI (STEMI versus STE-TTC and non-ST elevation MI versus non ST-elevation-TTC). When comparing STEMI and STE-TTC, ST-elevation in -aVR was characteristic of STE-TTC with a sensitivity/specificity of 43% and 95%, positive predictive value (PPV) 91%, and a negative predictive value (NPV) 62% (P<0.001); when ST-elevation in -aVR is accompanied by ST-elevation in inferior leads, sensitivity/specificity were 14% and 98% (PPV was 89% and NPV 52%) (P=0.001), and 12% and 100% when associated with ST-elevation in anteroseptal leads (PPV 100%, NPV 52%) (P<0.001). On the other hand, STEMI was characterized by ST-elevation in aVR (sensitivity/specificity of 31% and 95% P<0.001, PPV 85% and NPV 59%) and ST-depression in V2-V3-V4 (sensitivity/specificity of 24% and 100% P<0.001, PPV 100% and NPV 76%). When comparing non-ST elevation MI and non ST-elevation-TTC, T-inversion in leads I-aVL-V5-V6 had a sensitivity/specificity of 17% and 97% for non ST-elevation-TTC (PPV 83% and NPV 55%) (P<0.001), and ST-elevation in -aVR with T-inversion in any lead was also specific for non ST-elevation-TTC (sensitivity/specificity of 8% and 100%, PPV 100% and NPV 53%) (P=0.006). In non-ST elevation MI patients, the presence of ST-depression in V2-V3 was specific (sensitivity/specificity of 11% and 99%, PPV 91% and NPV 51%) (P=0.01). ECG on admission can differentiate between TTC and acute MI, with high specificity and positive predictive value. URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01947621. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  10. Experimental and analytical transonic flutter characteristics of a geared-elevator configuration

    NASA Technical Reports Server (NTRS)

    Ruhlin, C. L.; Doggett, R. V., Jr.; Gregory, R. A.

    1980-01-01

    The flutter model represented the aft fuselage and empennage of a proposed supersonic transport airplane and had an all movable horizontal tail with a geared elevator. It was tested mounted from a sting in the transonic dynamics tunnel. Symmetric flutter boundaries were determined experimentally at Mach numbers from 0.7 to 1.14 for a geared elevator configuration (gear ratio of 2.8 to 1.0) and an ungeared elevator configuration (gear ratio of 1.0 to 1.0). Gearing the elevator increased the experimental flutter dynamic pressures about 20 percent. Flutter calculations were made for the geared elevator configuration by using two analytical methods based on subsonic lifting surface theory. Both methods analyzed the stabilizer and elevator as a single, deforming surface, but one method also allowed the elevator to be analyzed as hinged from the stabilizer. All analyses predicted lower flutter dynamic pressures than experiment with best agreement (within 12 percent) for the hinged elevator method. Considering the model as mounted from a flexible rather than rigid sting in the analyses, had only a slight effect on the flutter results but was significant in that a sting related vibration mode was identified as a potentially flutter critical mode.

  11. Critical Technologies for the Development of Future Space Elevator Systems

    NASA Technical Reports Server (NTRS)

    Smitherman, David V., Jr.

    2005-01-01

    A space elevator is a tether structure extending through geosynchronous earth orbit (GEO) to the surface of the earth. Its center of mass is in GEO such that it orbits the earth in sync with the earth s rotation. In 2004 and 2005, the NASA Marshall Space Flight Center and the Institute for Scientific Research, Inc. worked under a cooperative agreement to research the feasibility of space elevator systems, and to advance the critical technologies required for the future development of space elevators for earth to orbit transportation. The discovery of carbon nanotubes in the early 1990's was the first indication that it might be possible to develop materials strong enough to make space elevator construction feasible. This report presents an overview of some of the latest NASA sponsored research on space elevator design, and the systems and materials that will be required to make space elevator construction possible. In conclusion, the most critical technology for earth-based space elevators is the successful development of ultra high strength carbon nanotube reinforced composites for ribbon construction in the 1OOGPa range. In addition, many intermediate technology goals and demonstration missions for the space elevator can provide significant advancements to other spaceflight and terrestrial applications.

  12. 2. Building 22 south elevation oblique. Ghost of Building 22A ...

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

    2. Building 22 south elevation oblique. Ghost of Building 22A visible on south elevation. South elevation of Building 22A in foreground. View looking NW. - John & James Dobson Carpet Mill (West Parcel), Building No. 22, 4041-4055 Ridge Avenue, Philadelphia, Philadelphia County, PA

  13. 49 CFR 172.325 - Elevated temperature materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Elevated temperature materials. 172.325 Section... REQUIREMENTS, AND SECURITY PLANS Marking § 172.325 Elevated temperature materials. (a) Except as provided in paragraph (b) of this section, a bulk packaging containing an elevated temperature material must be marked...

  14. 49 CFR 172.325 - Elevated temperature materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Elevated temperature materials. 172.325 Section... REQUIREMENTS, AND SECURITY PLANS Marking § 172.325 Elevated temperature materials. (a) Except as provided in paragraph (b) of this section, a bulk packaging containing an elevated temperature material must be marked...

  15. The oscillating wing with aerodynamically balanced elevator

    NASA Technical Reports Server (NTRS)

    Kussner, H G; Schwartz, I

    1941-01-01

    The two-dimensional problem of the oscillating wing with aerodynamically balanced elevator is treated in the manner that the wing is replaced by a plate with bends and stages and the airfoil section by a mean line consisting of one or more straights. The computed formulas and tables permit, on these premises, the prediction of the pressure distribution and of the aerodynamic reactions of oscillating elevators and tabs with any position of elevator hinge in respect to elevator leading edge.

  16. Navy Shipboard Cargo and Weapons Elevator Controller and Sensor Subsystem Problem Analysis.

    DTIC Science & Technology

    1981-12-24

    safe operation, and standardization. The conclusion of the review was that elevator manufact - urers in general have motives in design and construction...controller. Two days are spent on the elevator theory and the rest in hands-on training and trouble-shooting bad cards. There is also a 26-week...was spent on the two computer con- trolled elevators than on all of the remaining 20 freight, food , and weapons elevators on the ship. Phoenix

  17. Pre-hibernation energy reserves in a temperate anuran, Rana chensinensis, along a relatively fine elevational gradient

    USGS Publications Warehouse

    Lu, X.; Li, B.; Li, Y.; Ma, X.; Fellers, G.M.

    2008-01-01

    Temperate anurans have energy substrates in the liver, fat bodies, carcass and gonads; these stores provide support for metabolism and egg production during hibernation, and for breeding activities in spring. This paper compares the energy budget shortly before hibernation among Rana chensinensis populations at elevations of 1400, 1700 and 2000 m along a river in northern China. The larger frogs, regardless of elevation, had relatively heavy storage organs and the masses of nearly all these organs were positively correlated with each other. After controlling for the effect of body size, we found no significant difference in energetic organ mass among different age classes for each of the three populations. There were sexual differences in energy strategy. Males in all populations accumulated greater reserves in liver, fat bodies and carcass than did females. In contrast, females put more energy into their ovaries and oviducts. Frogs from higher elevations tended to have heavier organs than those from lower elevations; however, the pattern did not vary systematically along fine environmental gradients. Mid-elevation R. chensinensis built up significantly more reserves than low-elevation individuals, but were similar to their highland conspecifics. Males from higher elevations tended to have heavier liver and fat bodies; females were similar in liver and ovary mass across all elevations, but formed heavier fat bodies, oviducts and somatic tissue at higher elevation sites.

  18. Dissociative phenomena in congenital monocular elevation deficiency.

    PubMed

    Olson, R J; Scott, W E

    1998-04-01

    Monocular elevation deficiency is characterized by unilateral limitation of elevation in both adduction and abduction and is usually present at birth. Dissociative phenomena such as dissociated vertical deviation are well recognized in association with conditions such as congenital esotropia but much less so in association with conditions such as congenital monocular elevation deficiency. All 129 patients given the diagnosis of monocular elevation deficiency or double elevator palsy in the Pediatric Ophthalmology and Strabismus Clinic at the University of Iowa Hospitals and Clinics between 1971 and 1995 were reviewed. After those with history of trauma, myasthenia gravis, thyroid eye disease, orbital lesions, Brown syndrome, or monocular elevation deficiency with acquired onset were excluded, 31 patients with congenital monocular elevation deficiency remained for retrospective study. First diagnosed at median age 2.6 years (although all were noted by parents at less than 6 months of age) with mean follow-up of 5.0 years (up to 15.5 years), 9 of 31 (29%) developed dissociated vertical deviation in the eye with monocular elevation deficiency, all of whom had undergone strabismus surgery 0 to 9.7 years previously (mean 3.5 years). Those who developed dissociated vertical deviation were generally younger, were followed up longer, and had more accompanying horizontal strabismus than did those who did not develop dissociated vertical deviation. The results did not reach significance. The current study demonstrates that dissociated vertical deviation occurs in association with monocular elevation deficiency.

  19. Physiological Limits along an Elevational Gradient in a Radiation of Montane Ground Beetles

    PubMed Central

    Slatyer, Rachel A.; Schoville, Sean D.

    2016-01-01

    A central challenge in ecology and biogeography is to determine the extent to which physiological constraints govern the geographic ranges of species along environmental gradients. This study tests the hypothesis that temperature and desiccation tolerance are associated with the elevational ranges of 12 ground beetle species (genus Nebria) occurring on Mt. Rainier, Washington, U.S.A. Species from higher elevations did not have greater cold tolerance limits than lower-elevation species (all species ranged from -3.5 to -4.1°C), despite a steep decline in minimum temperature with elevation. Although heat tolerance limits varied among species (from 32.0 to 37.0°C), this variation was not generally associated with the relative elevational range of a species. Temperature gradients and acute thermal tolerance do not support the hypothesis that physiological constraints drive species turnover with elevation. Measurements of intraspecific variation in thermal tolerance limits were not significant for individuals taken at different elevations on Mt. Rainier, or from other mountains in Washington and Oregon. Desiccation resistance was also not associated with a species’ elevational distribution. Our combined results contrast with previously-detected latitudinal gradients in acute physiological limits among insects and suggest that other processes such as chronic thermal stress or biotic interactions might be more important in constraining elevational distributions in this system. PMID:27043311

  20. Warming and pCO2 effects on Florida stone crab larvae

    NASA Astrophysics Data System (ADS)

    Gravinese, Philip M.; Enochs, Ian C.; Manzello, Derek P.; van Woesik, Robert

    2018-05-01

    Greenhouse gas emissions are increasing ocean temperatures and the partial pressure of CO2 (pCO2), resulting in more acidic waters. It is presently unknown how elevated temperature and pCO2 will influence the early life history stages of the majority of marine coastal species. We investigated the combined effect of elevated temperature (30 °C control and 32 °C treatment) and elevated pCO2 (450 μatm control and 1100 μatm treatment) on the (i) growth, (ii) survival, (iii) condition, and (iv) morphology of larvae of the commercially important Florida stone crab, Menippe mercenaria. At elevated temperature, larvae exhibited a significantly shorter molt stage, and elevated pCO2 caused stage-V larvae to delay metamorphosis to post-larvae. On average, elevated pCO2 resulted in a 37% decrease in survivorship relative to the control; however the effect of elevated temperature reduced larval survivorship by 71%. Exposure to both elevated temperature and pCO2 reduced larval survivorship by 80% relative to the control. Despite this, no significant differences were detected in the condition or morphology of stone crab larvae when subjected to elevated temperature and pCO2 treatments. Although elevated pCO2 could result in a reduction in larval supply, future increases in seawater temperatures are even more likely to threaten the future sustainability of the stone-crab fishery.

  1. Mortality associated with bilirubin levels in insurance applicants.

    PubMed

    Fulks, Michael; Stout, Robert L; Dolan, Vera F

    2009-01-01

    Determine the relationship between bilirubin levels with and without other liver function test (LFT) elevations and relative mortality in life insurance applicants. By use of the Social Security Death Master File mortality was determined in 1,905,664 insurance applicants for whom blood samples were submitted to the Clinical Reference Laboratory. There were 50,174 deaths observed in this study population. Results were stratified by 3 age/sex groups: females, age <60; males, age <60; and all, age 60+. The median follow-up was 12 years. Relative mortality increased as bilirubin decreased below bilirubin levels seen for the middle 50% of the population. The known association of smoking with lower bilirubin values explained only part of the additional elevated risk at low bilirubin levels. In the absence of other LFT elevations, relative mortality remained unchanged as bilirubin increased beyond levels seen for the middle 50% of the population. When a bilirubin elevation was combined with other LFT elevations, mortality further increased only at the highest elevations of other LFTs, seen only in <2.5% of applicants. Isolated elevations of bilirubin in this healthy screening population were not associated with excess mortality but values below the midpoint were. Other investigations have suggested a cardiovascular cause may underlie the excess mortality associated with low bilirubin. In association with other LFT elevations, bilirubin elevation further increases the mortality risk only at the highest elevations of other LFTs.

  2. Topogrid Derived 10 Meter Resolution Digital Elevation Model of Charleston, and Parts of Berkeley, Colleton, Dorchester and Georgetown Counties, South Carolina

    USGS Publications Warehouse

    Chirico, Peter G.

    2005-01-01

    EXPLANATION The purpose of developing a new 10m resolution digital elevation model (DEM) of the Charleston Region was to more accurately depict geologic structure, surfical geology, and landforms of the Charleston County Region. Previously, many areas northeast and southwest of Charleston were originally mapped with a 20 foot contour interval. As a result, large areas within the National Elevation Dataset (NED) depict flat terraced topography where there was a lack of higher resolution elevation data. To overcome these data voids, the new DEM is supplemented with additional elevation data and break-lines derived from aerial photography and topographic maps. The resultant DEM is stored as a raster grid at uniform 10m horizontal resolution. The elevation model contained in this publication was prodcued utilizing the ANUDEM algorthim. ANUDEM allows for the inclusion of contours, streams, rivers, lake and water body polygons as well as spot height data to control the development of the elevation model. A preliminary statistical analysis using over 788 vertical elevation check points, primarily located in the northeastern part of the study area, derived from USGS 7.5 Minute Topographic maps reveals that the final DEM, has a vertical accuracy of ?3.27 meters. A table listing the elevation comparison between the elevation check points and the final DEM is provided.

  3. Distribution pattern of reptiles along an eastern Himalayan elevation gradient, India

    NASA Astrophysics Data System (ADS)

    Chettri, Basundhara; Bhupathy, Subramanian; Acharya, Bhoj Kumar

    2010-01-01

    We examined the spatial distribution pattern of reptiles in an eastern Himalayan elevation gradient. The factors governing the distribution have been assessed with emphasis on the mid-domain effect. We surveyed reptiles along the elevation gradient (300-4800 m) of the Teesta valley in Sikkim, Eastern Himalaya, India using time constrained visual encounter survey. A total of 42 species of reptiles were observed during the study, and the species richness peaked at 500-1000 m with no species beyond 3000 m. The observed pattern was consistent with estimated richness, both showing significant negative relation with elevation. Lizards showed a linear decline with elevation, whereas snakes followed a non-linear relation with peak at 500-1000 m. Observed species richness deviated significantly from that predicted by a mid-domain null model. The regression between empirical and simulated richness was not significant for total reptiles as well as lizards and snakes separately. Most species distributed in the high elevation extended towards lower elevation, but low elevation species (around 50%) were restricted below 1000 m. Deviation of empirical from predicted richness indicates that the distributions of reptile species were least governed by geographic hard boundaries. Climatic factors especially temperature explained much variation of reptiles along the Himalayan elevation gradient. Most reptiles were narrowly distributed, especially those found in low elevation indicating the importance of tropical low-land forests in the conservation of reptiles in Eastern Himalayas.

  4. Elevated [CO2] does not ameliorate the negative effects of elevated temperature on drought-induced mortality in Eucalyptus radiata seedlings.

    PubMed

    Duan, Honglang; Duursma, Remko A; Huang, Guomin; Smith, Renee A; Choat, Brendan; O'Grady, Anthony P; Tissue, David T

    2014-07-01

    It has been reported that elevated temperature accelerates the time-to-mortality in plants exposed to prolonged drought, while elevated [CO(2)] acts as a mitigating factor because it can reduce stomatal conductance and thereby reduce water loss. We examined the interactive effects of elevated [CO(2)] and temperature on the inter-dependent carbon and hydraulic characteristics associated with drought-induced mortality in Eucalyptus radiata seedlings grown in two [CO(2)] (400 and 640 μL L(-1)) and two temperature (ambient and ambient +4 °C) treatments. Seedlings were exposed to two controlled drying and rewatering cycles, and then water was withheld until plants died. The extent of xylem cavitation was assessed as loss of stem hydraulic conductivity. Elevated temperature triggered more rapid mortality than ambient temperature through hydraulic failure, and was associated with larger water use, increased drought sensitivities of gas exchange traits and earlier occurrence of xylem cavitation. Elevated [CO(2)] had a negligible effect on seedling response to drought, and did not ameliorate the negative effects of elevated temperature on drought. Our findings suggest that elevated temperature and consequent higher vapour pressure deficit, but not elevated [CO(2)], may be the primary contributors to drought-induced seedling mortality under future climates. © 2013 John Wiley & Sons Ltd.

  5. Elevational Ranges of Montane Birds and Deforestation in the Western Andes of Colombia.

    PubMed

    Ocampo-Peñuela, Natalia; Pimm, Stuart L

    2015-01-01

    Deforestation causes habitat loss, fragmentation, degradation, and can ultimately cause extinction of the remnant species. Tropical montane birds face these threats with the added natural vulnerability of narrower elevational ranges and higher specialization than lowland species. Recent studies assess the impact of present and future global climate change on species' ranges, but only a few of these evaluate the potentially confounding effect of lowland deforestation on species elevational distributions. In the Western Andes of Colombia, an important biodiversity hotspot, we evaluated the effects of deforestation on the elevational ranges of montane birds along altitudinal transects. Using point counts and mist-nets, we surveyed six altitudinal transects spanning 2200 to 2800 m. Three transects were forested from 2200 to 2800 m, and three were partially deforested with forest cover only above 2400 m. We compared abundance-weighted mean elevation, minimum elevation, and elevational range width. In addition to analysing the effect of deforestation on 134 species, we tested its impact within trophic guilds and habitat preference groups. Abundance-weighted mean and minimum elevations were not significantly different between forested and partially deforested transects. Range width was marginally different: as expected, ranges were larger in forested transects. Species in different trophic guilds and habitat preference categories showed different trends. These results suggest that deforestation may affect species' elevational ranges, even within the forest that remains. Climate change will likely exacerbate harmful impacts of deforestation on species' elevational distributions. Future conservation strategies need to account for this by protecting connected forest tracts across a wide range of elevations.

  6. Elevational Ranges of Montane Birds and Deforestation in the Western Andes of Colombia

    PubMed Central

    2015-01-01

    Deforestation causes habitat loss, fragmentation, degradation, and can ultimately cause extinction of the remnant species. Tropical montane birds face these threats with the added natural vulnerability of narrower elevational ranges and higher specialization than lowland species. Recent studies assess the impact of present and future global climate change on species’ ranges, but only a few of these evaluate the potentially confounding effect of lowland deforestation on species elevational distributions. In the Western Andes of Colombia, an important biodiversity hotspot, we evaluated the effects of deforestation on the elevational ranges of montane birds along altitudinal transects. Using point counts and mist-nets, we surveyed six altitudinal transects spanning 2200 to 2800m. Three transects were forested from 2200 to 2800m, and three were partially deforested with forest cover only above 2400m. We compared abundance-weighted mean elevation, minimum elevation, and elevational range width. In addition to analysing the effect of deforestation on 134 species, we tested its impact within trophic guilds and habitat preference groups. Abundance-weighted mean and minimum elevations were not significantly different between forested and partially deforested transects. Range width was marginally different: as expected, ranges were larger in forested transects. Species in different trophic guilds and habitat preference categories showed different trends. These results suggest that deforestation may affect species’ elevational ranges, even within the forest that remains. Climate change will likely exacerbate harmful impacts of deforestation on species’ elevational distributions. Future conservation strategies need to account for this by protecting connected forest tracts across a wide range of elevations. PMID:26641477

  7. Short-Term Moderately Elevated Intraocular Pressure Is Associated With Elevated Scotopic Electroretinogram Responses

    PubMed Central

    Choh, Vivian; Gurdita, Akshay; Tan, Bingyao; Prasad, Ratna C.; Bizheva, Kostadinka; Joos, Karen M.

    2016-01-01

    Purpose Moderately elevated intraocular pressure (IOP) is a risk factor for open-angle glaucoma. Some patients suffer glaucoma despite clinically measured normal IOPs. Fluctuations in IOP may have a significant role since IOPs are higher during sleep and inversion activities. Controlled transient elevations of IOPs in rats over time lead to optic nerve structural changes that are similar to the early changes observed in constant chronic models of glaucoma. Because early intervention decreases glaucoma progression, this study was done to determine if early physiological changes to the retina could be detected with noninvasive electrophysiological and optical imaging tests during moderately elevated IOP. Methods Intraocular pressures were raised to moderately high levels (35 mm Hg) in one eye of Sprague-Dawley rats while the other (control) eye was untreated. One group of rats underwent scotopic threshold response (STR) and electroretinogram (ERG) testing, while another 3 groups underwent optical coherence tomography (OCT) imaging, Western blot, or histologic evaluation. Results The amplitudes of the STR and ERG responses in eyes with moderately elevated IOPs were enhanced compared to the values before IOP elevation, and compared to untreated contralateral eyes. Structural changes to the optic nerve also occurred during IOP elevation. Conclusions Although ischemic IOP elevations are well-known to globally reduce components of the scotopic ERG, acute elevation in rats to levels often observed in untreated glaucoma patients caused an increase in these parameters. Further exploration of these phenomena may be helpful in better understanding the mechanisms mediating early retinal changes during fluctuating or chronically elevated IOP. PMID:27100161

  8. Wetland Accretion Rate Model of Ecosystem Resilience (WARMER) and its application to habitat sustainability for endangered species in the San Francisco Estuary

    USGS Publications Warehouse

    Swanson, Kathleen M.; Drexler, Judith Z.; Schoellhamer, David H.; Thorne, Karen M.; Casazza, Michael L.; Overton, Cory T.; Callaway, John C.; Takekawa, John Y.

    2014-01-01

    Salt marsh faunas are constrained by specific habitat requirements for marsh elevation relative to sea level and tidal range. As sea level rises, changes in relative elevation of the marsh plain will have differing impacts on the availability of habitat for marsh obligate species. The Wetland Accretion Rate Model for Ecosystem Resilience (WARMER) is a 1-D model of elevation that incorporates both biological and physical processes of vertical marsh accretion. Here, we use WARMER to evaluate changes in marsh surface elevation and the impact of these elevation changes on marsh habitat for specific species of concern. Model results were compared to elevation-based habitat criteria developed for marsh vegetation, the endangered California clapper rail (Rallus longirostris obsoletus), and the endangered salt marsh harvest mouse (Reithrodontomys raviventris) to determine the response of marsh habitat for each species to predicted >1-m sea-level rise by 2100. Feedback between vertical accretion mechanisms and elevation reduced the effect of initial elevation in the modeled scenarios. Elevation decreased nonlinearly with larger changes in elevation during the latter half of the century when the rate of sea-level rise increased. Model scenarios indicated that changes in elevation will degrade habitat quality within salt marshes in the San Francisco Estuary, and degradation will accelerate in the latter half of the century as the rate of sea-level rise accelerates. A sensitivity analysis of the model results showed that inorganic sediment accumulation and the rate of sea-level rise had the greatest influence over salt marsh sustainability.

  9. Hydrologic connectivity: Quantitative assessments of hydrologic-enforced drainage structures in an elevation model

    USGS Publications Warehouse

    Poppenga, Sandra K.; Worstell, Bruce B.

    2016-01-01

    Elevation data derived from light detection and ranging present challenges for hydrologic modeling as the elevation surface includes bridge decks and elevated road features overlaying culvert drainage structures. In reality, water is carried through these structures; however, in the elevation surface these features impede modeled overland surface flow. Thus, a hydrologically-enforced elevation surface is needed for hydrodynamic modeling. In the Delaware River Basin, hydrologic-enforcement techniques were used to modify elevations to simulate how constructed drainage structures allow overland surface flow. By calculating residuals between unfilled and filled elevation surfaces, artificially pooled depressions that formed upstream of constructed drainage structure features were defined, and elevation values were adjusted by generating transects at the location of the drainage structures. An assessment of each hydrologically-enforced drainage structure was conducted using field-surveyed culvert and bridge coordinates obtained from numerous public agencies, but it was discovered the disparate drainage structure datasets were not comprehensive enough to assess all remotely located depressions in need of hydrologic-enforcement. Alternatively, orthoimagery was interpreted to define drainage structures near each depression, and these locations were used as reference points for a quantitative hydrologic-enforcement assessment. The orthoimagery-interpreted reference points resulted in a larger corresponding sample size than the assessment between hydrologic-enforced transects and field-surveyed data. This assessment demonstrates the viability of rules-based hydrologic-enforcement that is needed to achieve hydrologic connectivity, which is valuable for hydrodynamic models in sensitive coastal regions. Hydrologic-enforced elevation data are also essential for merging with topographic/bathymetric elevation data that extend over vulnerable urbanized areas and dynamic coastal regions.

  10. Seasonal Dynamics of Mobile Carbon Supply in Quercus aquifolioides at the Upper Elevational Limit

    PubMed Central

    Zhu, Wan-Ze; Cao, Min; Wang, San-Gen; Xiao, Wen-Fan; Li, Mai-He

    2012-01-01

    Many studies have tried to explain the physiological mechanisms of the alpine treeline phenomenon, but the debate on the alpine treeline formation remains controversial due to opposite results from different studies. The present study explored the carbon-physiology of an alpine shrub species (Quercus aquifolioides) grown at its upper elevational limit compared to lower elevations, to test whether the elevational limit of alpine shrubs (<3 m in height) are determined by carbon limitation or growth limitation. We studied the seasonal variations in non-structural carbohydrate (NSC) and its pool size in Q. aquifolioides grown at 3000 m, 3500 m, and at its elevational limit of 3950 m above sea level (a.s.l.) on Zheduo Mt., SW China. The tissue NSC concentrations along the elevational gradient varied significantly with season, reflecting the season-dependent carbon balance. The NSC levels in tissues were lowest at the beginning of the growing season, indicating that plants used the winter reserve storage for re-growth in the early spring. During the growing season, plants grown at the elevational limit did not show lower NSC concentrations compared to plants at lower elevations, but during the winter season, storage tissues, especially roots, had significantly lower NSC concentrations in plants at the elevational limit compared to lower elevations. The present results suggest the significance of winter reserve in storage tissues, which may determine the winter survival and early-spring re-growth of Q. aquifolioides shrubs at high elevation, leading to the formation of the uppermost distribution limit. This result is consistent with a recent hypothesis for the alpine treeline formation. PMID:22479567

  11. Elevated post-void residual volume in a geriatric post-hip fracture assessment in women-associated factors and risk of mortality.

    PubMed

    Nuotio, Maria S; Luukkaala, Tiina; Tammela, Teuvo

    2018-04-09

    Multiple factors contribute to elevated post-void residual urine volumes (PVR), but they may indicate detrusor underactivity (DU), especially in older women. The aim here was to examine factors associated with and prognostic significance of elevated PVR in a geriatric post-hip fracture assessment in a female population. Consecutive female hip fracture patients (n = 409) aged 65 years and older were included. PVR was measured by bladder scanner. PVR of 160 ml or more was deemed elevated. Age-adjusted univariate logistic regression analyses were conducted to examine the association of the domains of the comprehensive geriatric assessment (CGA) with elevated PVR. Cox proportional hazards model was used to determine the age-adjusted association of an elevated PVR with 1-year mortality. Of the patients, 64 (15.6%) had elevated PVR. Having urinary or fecal incontinence, difficulties in physical activities of daily living, malnutrition, poor performance on Timed Up and Go and Elderly Mobility Scale were significantly associated with elevated PVR. Difficulties in instrumental activities of daily living, renal dysfunction, constipation, polypharmacy, nocturia, cognitive impairment and depressive mood were not associated with elevated PVR. Elevated PVR significantly increased the risk of mortality 1 year post hip fracture. Elevated PVR is relatively common in older female hip fracture patients and associated with physical functioning, malnutrition and risk of mortality. Even though a causal relationship cannot be confirmed, the findings may suggest a relationship between DU and physical frailty. PVR deserves to be included in the CGA of frail older patients including women.

  12. 14 CFR 23.155 - Elevator control force in maneuvers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...

  13. 14 CFR 23.155 - Elevator control force in maneuvers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...

  14. 14 CFR 23.155 - Elevator control force in maneuvers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...

  15. 14 CFR 23.155 - Elevator control force in maneuvers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...

  16. 14 CFR 23.155 - Elevator control force in maneuvers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Elevator control force in maneuvers. 23.155 Section 23.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Controllability and Maneuverability § 23.155 Elevator control force in maneuvers. (a) The elevator control force...

  17. 78 FR 56174 - In-Core Thermocouples at Different Elevations and Radial Positions in Reactor Core

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-12

    ...-core thermocouples at different elevations and radial positions throughout the reactor core to enable... different elevations and radial positions throughout the reactor core to enable NPP operators to accurately... NPPs with in-core thermocouples at different elevations and radial positions throughout the reactor...

  18. 3. N elevation, E wing; 3/4 view of W wing ...

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

    3. N elevation, E wing; 3/4 view of W wing showing E and N elevations; N elevation of Building 69, Plating and Tinning Shop; looking SW. (Ceronie) - Rock Island Arsenal, Building No. 66, Rodman Avenue between Third & Fourth Streets, Rock Island, Rock Island County, IL

  19. Contrasting Decadal-Scale Changes in Elevation and Vegetation in Two Long Island Sound Salt Marshes

    EPA Science Inventory

    Northeastern US salt marshes face multiple co-stressors, including accelerating rates of relative sea level rise (RSLR), elevated nutrient inputs, and low sediment supplies. In order to evaluate how marsh surface elevations respond to such factors, we used surface elevation table...

  20. 29 CFR 1918.87 - Ship's cargo elevators.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Ship's cargo elevators. 1918.87 Section 1918.87 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Handling Cargo § 1918.87 Ship's cargo elevators. (a) Safe working load. The safe working loads of ship's cargo elevators shall be determined and followed...

  1. 29 CFR 1918.87 - Ship's cargo elevators.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Ship's cargo elevators. 1918.87 Section 1918.87 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Handling Cargo § 1918.87 Ship's cargo elevators. (a) Safe working load. The safe working loads of ship's cargo elevators shall be determined and followed...

  2. 29 CFR 1918.87 - Ship's cargo elevators.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Ship's cargo elevators. 1918.87 Section 1918.87 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Handling Cargo § 1918.87 Ship's cargo elevators. (a) Safe working load. The safe working loads of ship's cargo elevators shall be determined and followed...

  3. 29 CFR 1918.87 - Ship's cargo elevators.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Ship's cargo elevators. 1918.87 Section 1918.87 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Handling Cargo § 1918.87 Ship's cargo elevators. (a) Safe working load. The safe working loads of ship's cargo elevators shall be determined and followed...

  4. Parenting and Early Adolescent Internalizing: The Importance of Teasing Apart Anxiety and Depressive Symptoms

    ERIC Educational Resources Information Center

    Johnson, Lesley E.; Greenberg, Mark T.

    2013-01-01

    This community-based study examined differences in parenting quality and parent symptoms for youth in four categories: anxious (elevated anxiety symptoms), depressed (elevated depressive symptoms), comorbid (elevated anxiety and depressive symptoms), and nonelevated (elevations of neither type). Respondents were 976 young adolescents (mean age =…

  5. ELEVATED CO2 AND ELEVATED TEMPERATURE HAVE NO EFFECT ON DOUGLAS-FIR FINE-ROOT DYNAMICS IN NITROGEN-POOR SOIL

    EPA Science Inventory

    Here, we investigate fine-root production, mortality and standing crop of Douglas-fir (Pseudotsuga menziesii) seedlings exposed to elevated atmospheric CO2 and elevated air temperature. We hypothesized that these treatments would increase fine-root production, but that mortality ...

  6. 77 FR 45513 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-01

    ... prompted by a report of elevator vibration and bearing swage failures. This proposed AD would require, for... aft attach lugs for the elevator tab control mechanism, and replacement if necessary, and for other... elevator tab control mechanism, which could result in elevator and tab vibration. Consequent structural...

  7. 44 CFR 67.3 - Establishment and maintenance of a flood elevation determination docket (FEDD).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MITIGATION National Flood Insurance Program APPEALS FROM PROPOSED FLOOD ELEVATION DETERMINATIONS § 67.3 Establishment and maintenance of a flood elevation determination docket (FEDD). The Federal Insurance... of a flood elevation determination docket (FEDD). 67.3 Section 67.3 Emergency Management and...

  8. 44 CFR 67.3 - Establishment and maintenance of a flood elevation determination docket (FEDD).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... MITIGATION National Flood Insurance Program APPEALS FROM PROPOSED FLOOD ELEVATION DETERMINATIONS § 67.3 Establishment and maintenance of a flood elevation determination docket (FEDD). The Federal Insurance... of a flood elevation determination docket (FEDD). 67.3 Section 67.3 Emergency Management and...

  9. 77 FR 46940 - Airworthiness Directives; Glasflugel Gliders

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-07

    ... condition as corrosion damage to the elevator control rod that could lead to failure of the elevator control... into the elevator control rod through a control bore hole and resulted in corrosion damage. The investigation concluded as well that the corrosion cannot be detected from outside the elevator control rod...

  10. 29 CFR 780.707 - Establishments “commonly recognized” as country elevators.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...” (107 Cong. Rec. (daily ed.) p. 5883). It is also appropriate to consider the characteristics and... distinctions which have been recognized between country elevators and other types of establishments. For... mill elevators, non-elevator-type bulk grain storing establishments, and “flat warehouses” in which...

  11. Elevation-relief ratio, hypsometric integral, and geomorphic area-altitude analysis.

    NASA Technical Reports Server (NTRS)

    Pike, R. J.; Wilson, S. E.

    1971-01-01

    Mathematical proof establishes identity of hypsometric integral and elevation-relief ratio, two quantitative topographic descriptors developed independently of one another for entirely different purposes. Operationally, values of both measures are in excellent agreement for arbitrarily bounded topographic samples, as well as for low-order fluvial watersheds. By using a point-sampling technique rather than planimetry, elevation-relief ratio (defined as mean elevation minus minimum elevation divided by relief) is calculated manually in about a third of the time required for the hypsometric integral.

  12. Radio frequency elevator for a pulsed positron beam

    NASA Astrophysics Data System (ADS)

    Dickmann, Marcel; Mitteneder, Johannes; Kögel, Gottfried; Egger, Werner; Sperr, Peter; Ackermann, Ulrich; Piochacz, Christian; Dollinger, Günther

    2016-06-01

    An elevator increases the potential energy of a particle beam with respect to ground potential without any alteration of kinetic energy and other beam parameters. This elevator is necessary for the implementation of the Munich Scanning Positron Microscope (SPM) at the intense positron source NEPOMUC at the research reactor FRM II in Munich. The principles of the rf elevator for pure electrostatically guided positrons are described. Measurements of beam quality behind the elevator are reported, which confirm that after the implementation of elevator and SPM at NEPOMUC the SPM can be operated at a considerably improved resolution (~ 0.3 μm) and event rate (~3.7 kHz) compared to the laboratory based β+-source.

  13. An assessment of maintainability of elevator system to improve facilities management knowledge-base

    NASA Astrophysics Data System (ADS)

    Siti, N. A.; Asmone, A. S.; Chew, M. Y. L.

    2018-02-01

    Elevator system is a highly specialized machinery that requires technicians that have a wider array of knowledge in maintaining the system to be safe and reliable. While attaining reliable data of elevator malfunction become challenges, this study has filled the gap by gathering the management-maintenance issues and operational defects of elevator system. Forty-three types of operation defects were found and the consequence defects and their possible causes of occurrences were discussed. To respond to the prime challenges of maintaining elevator system provided by the industry players’ perspective, a theoretical framework is established as a recommendation to improve knowledge base of defects in elevator system which comprises good practices, and solutions to rectify each defects found. Hence, this research paper has theoretically improved the knowledge base of maintainability of elevator system and provide meaningful guidelines in practical senses to the industry professionals.

  14. Effects of decadal exposure to interacting elevated CO2 and/or O3 on paper birch (Betula papyrifera) reproduction.

    PubMed

    Darbah, Joseph N T; Kubiske, Mark E; Nelson, Neil; Oksanen, Elina; Vapaavuori, Elina; Karnosky, David F

    2008-10-01

    We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO(2) and/or O(3) on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO(2) increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O(3) also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO(2)+O(3)) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO(2) may have a largely positive impact on forest tree reproduction and regeneration while elevated O(3) will likely have a negative impact.

  15. Clutch size declines with elevation in tropical birds

    USGS Publications Warehouse

    Boyce, A.J.; Freeman, Benjamin G.; Mitchell, Adam E.; Martin, Thomas E.

    2015-01-01

    Clutch size commonly decreases with increasing elevation among temperate-zone and subtropical songbird species. Tropical songbirds typically lay small clutches, thus the ability to evolve even smaller clutch sizes at higher elevations is unclear and untested. We conducted a comparative phylogenetic analysis using data gathered from the literature to test whether clutch size varied with elevation among forest passerines from three tropical biogeographic regions—the Venezuelan Andes and adjacent lowlands, Malaysian Borneo, and New Guinea. We found a significant negative effect of elevation on variation in clutch size among species. We found the same pattern using field data sampled across elevational gradients in Venezuela and Malaysian Borneo. Field data were not available for New Guinea. Both sets of results demonstrate that tropical montane species across disparate biogeographic realms lay smaller clutches than closely related low-elevation species. The environmental sources of selection underlying this pattern remain uncertain and merit further investigation.

  16. Responses of growth, photosynthesis and VOC emissions of Pinus tabulaeformis Carr. Exposure to elevated CO2 and/or elevated O3 in an urban area.

    PubMed

    Xu, Sheng; Chen, Wei; Huang, Yanqing; He, Xingyuan

    2012-03-01

    Responses of growth, photosynthesis and emission of volatile organic compounds of Pinus tabulaeformis exposed to elevated CO(2) (700 ppm) and O(3) (80 ppb) were studied in open top chambers. Elevated CO(2) increased growth, but it did not significantly (p > 0.05) affect net photosynthetic rate, stomatal conductance, chlorophyll content, the maximum quantum yield of photosystem II, or the effective quantum yield of photosystem II electron transport after 90 d of gas exposure. Elevated O(3) decreased growth (by 42.2% in needle weight and 25.8% in plant height), net photosynthetic rate and stomatal conductance after 90 d of exposure, but its negative effects were alleviated by elevated CO(2). Elevated O(3) significantly (p < 0.05) increased the emission rate of volatile organic compounds, which may be a helpful response to protect photosynthetic apparatus against O(3) damage.

  17. Elevated-CO2 Response of Stomata and Its Dependence on Environmental Factors

    PubMed Central

    Xu, Zhenzhu; Jiang, Yanling; Jia, Bingrui; Zhou, Guangsheng

    2016-01-01

    Stomata control the flow of gases between plants and the atmosphere. This review is centered on stomatal responses to elevated CO2 concentration and considers other key environmental factors and underlying mechanisms at multiple levels. First, an outline of general responses in stomatal conductance under elevated CO2 is presented. Second, stomatal density response, its development, and the trade-off with leaf growth under elevated CO2 conditions are depicted. Third, the molecular mechanism regulating guard cell movement at elevated CO2 is suggested. Finally, the interactive effects of elevated CO2 with other factors critical to stomatal behavior are reviewed. It may be useful to better understand how stomata respond to elevated CO2 levels while considering other key environmental factors and mechanisms, including molecular mechanism, biochemical processes, and ecophysiological regulation. This understanding may provide profound new insights into how plants cope with climate change. PMID:27242858

  18. Antarctic surface elevation and slope from multi-mission lidar mapping

    NASA Astrophysics Data System (ADS)

    Sutterley, T. C.; Velicogna, I.; Neumann, T.; Markus, T.

    2017-12-01

    We present integrated estimates of surface elevation change and slope for the Antarctic Ice Sheet from a combination of measurements from the Airborne Topographic Mapper (ATM), the Land, Vegetation and Ice Sensor (LVIS) and the Ice Cloud and land Elevation Satellite (ICESat-1). This technique is a data-driven approach that calculates elevation differentials on a shot-by-shot basis. Our method extends the records of each instrument, increases the overall spatial coverage compared to a single instrument and produces high-quality, integrated maps of surface elevation, surface elevation change and slope. We use our estimates of elevation change to assess the current state of major outlet glaciers in the Bellinghausen Sea, Amundsen Sea and Getz regions of West Antarctica (WAIS). In the Amundsen Sea, we find that thinning rates of Pine Island Glacier have decreased after 2011 while thinning rates of Smith and Kohler glaciers have increased unabated.

  19. Differential response of Aspen and Birch trees to heat stress under elevated carbon dioxide

    Treesearch

    Joseph N.T. Darbah; Thomas D. Sharkey; Carlo Calfapietra; David F. Karnosky

    2010-01-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO2 and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO2 protected photosynthesis of both species against moderate heat stress. Elevated CO...

  20. 5. View West. West side and rear elevations of c. ...

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

    5. View West. West side and rear elevations of c. 1890 first rear addition; partial north rear elevation of c. 1900 side ell addition; and north rear and west side elevation of final rear addition of c. 1940. - Vaughn Chevrolet Building, 101-109 East Main Street, Monongahela, Washington County, PA

  1. Use of elevator instruments when luxating and extracting teeth in dentistry: clinical techniques

    PubMed Central

    2017-01-01

    In dentistry, elevator instruments are used to luxate teeth, and this technique imparts forces to tooth particles that sever the periodontal ligament around tooth roots inside the socket and expand alveolar bone around tooth particles. These effects can result in extraction of the tooth particles or facilitate systematic forceps extraction of the tooth particles. This article presents basic oral surgery techniques for applying elevators to luxate teeth. Determination of the optimal luxation technique requires understanding of the functions of the straight elevator and the Cryer elevator, the concept of purchase points, how the design elements of elevator working ends and tips influence the functionality of an elevator, application of forces to tooth particles, sectioning teeth at furcations, and bone removal to facilitate luxation. The effectiveness of tooth particle luxation is influenced by elevator tip shape and size, the magnitude and the vectors of forces applied to the tooth particle by the tip, and sectioning and bone removal within the operating field. Controlled extraction procedures are facilitated by a dental operating microscope or the magnification of binocular surgical loupes telescopes, combined with co-axial illumination. PMID:28770164

  2. Echolocation with bat buzz emissions: model and biomimetic sonar for elevation estimation.

    PubMed

    Kuc, Roman

    2012-01-01

    Just prior to capture the Buzz II emissions of some mouth-emitting bats, such as Eptesicus fuscus, are observed to exhibit spectra having multiple peaks. This paper proposes an echolocation strategy that uses such spectra with energy concentrated in specific frequency bands for determining target elevation. A biomimetic sonar was implemented to produce a tri-modal spectrum by driving a speaker with a signal rich in harmonics. The emission magnitudes at these harmonic frequencies measured as a function of elevation in the zero-azimuth plane form distinct beams. A template was formed from the ratio of the first harmonic and fundamental magnitudes to determine elevation. The elevation estimator exhibited a sub-degree accuracy (SD = 0.4° over a 20° interval centered at the elevation at which these two beams intersect in the zero-azimuth plane. Spectral cues from -40° to +10° elevation allow a qualitative non-linear control of sonar orientation to drive the target to the beam-intersection point where quantitative elevation estimates are available. © 2012 Acoustical Society of America.

  3. Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration.

    PubMed

    Reis, Gustavo Msm; Grigg, John; Chua, Brian; Lee, Anne; Lim, Ridia; Higgins, Ralph; Martins, Alessandra; Goldberg, Ivan; Clement, Colin I

    2017-01-01

    The aim of this article is to evaluate the rate of patients developing sustained elevated intraocular pressure (IOP) after ranibizumab (Lucentis) intravitreal (IVT) injections. This is a retrospective study. Charts of 192 consecutive patients receiving Lucentis for age-related macular degeneration (AMD) were retrospectively reviewed. We enrolled patients with at least two IOP measurements between injections. Elevated IOP was defined as >21 mm Hg with an increase of at least 20% from baseline. Noninjected contralateral eyes of the same patient cohort were used as control. Primary outcome was defined as elevated IOP. Secondary outcomes were presence and type of glaucoma, number of injections, and time to IOP elevation. Elevated IOP occurred at a significantly higher rate in eyes receiving IVT ranibizumab (7.47%; n = 9) compared with control (0.93%; n = 1). Patients with preexisting glaucoma or ocular hypertension (OHT) were more likely to develop elevated IOP after IVT ranibizumab injection. Intravitreal ranibizumab injections are associated with sustained IOP elevation in some eyes. Reis GMSM, Grigg J, Chua B, Lee A, Lim R, Higgins R, Martins A, Goldberg I, Clement CI. The Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration. J Curr Glaucoma Pract 2017;11(1):3-7.

  4. Growth and wood/bark properties of Abies faxoniana seedlings as affected by elevated CO2.

    PubMed

    Qiao, Yun-Zhou; Zhang, Yuan-Bin; Wang, Kai-Yun; Wang, Qian; Tian, Qi-Zhuo

    2008-03-01

    Growth and wood and bark properties of Abies faxoniana seedlings after one year's exposure to elevated CO2 concentration (ambient + 350 (+/- 25) micromol/mol) under two planting densities (28 or 84 plants/m(2)) were investigated in closed-top chambers. Tree height, stem diameter and cross-sectional area, and total biomass were enhanced under elevated CO2 concentration, and reduced under high planting density. Most traits of stem bark were improved under elevated CO2 concentration and reduced under high planting density. Stem wood production was significantly increased in volume under elevated CO2 concentration under both densities, and the stem wood density decreased under elevated CO2 concentration and increased under high planting density. These results suggest that the response of stem wood and bark to elevated CO2 concentration is density dependent. This may be of great importance in a future CO2 enriched world in natural forests where plant density varies considerably. The results also show that the bark/wood ratio in diameter, stem cross-sectional area and dry weight are not proportionally affected by elevated CO2 concentration under the two contrasting planting densities. This indicates that the response magnitude of stem bark and stem wood to elevated CO2 concentration are different but their response directions are the same.

  5. Does a decade of elevated [CO2] affect a desert perennial plant community?

    PubMed

    Newingham, Beth A; Vanier, Cheryl H; Kelly, Lauren J; Charlet, Therese N; Smith, Stanley D

    2014-01-01

    Understanding the effects of elevated [CO2 ] on plant community structure is crucial to predicting ecosystem responses to global change. Early predictions suggested that productivity in deserts would increase via enhanced water-use efficiency under elevated [CO2], but the response of intact arid plant communities to elevated [CO2 ] is largely unknown. We measured changes in perennial plant community characteristics (cover, species richness and diversity) after 10 yr of elevated [CO2] exposure in an intact Mojave Desert community at the Nevada Desert Free-Air CO2 Enrichment (FACE) Facility. Contrary to expectations, total cover, species richness, and diversity were not affected by elevated [CO2]. Over the course of the experiment, elevated [CO2] had no effect on changes in cover of the evergreen C3 shrub, Larrea tridentata; alleviated decreases in cover of the C4 bunchgrass, Pleuraphis rigida; and slightly reduced the cover of C3 drought-deciduous shrubs. Thus, we generally found no effect of elevated [CO2] on plant communities in this arid ecosystem. Extended drought, slow plant growth rates, and highly episodic germination and recruitment of new individuals explain the lack of strong perennial plant community shifts after a decade of elevated [CO2]. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  6. Resting metabolic expenditure as a potential source of variation in growth rates of the sagebrush lizard.

    PubMed

    Sears, Michael W

    2005-02-01

    Along an elevational gradient on SW Utah, sagebrush lizards (Sceloporus graciosus) exhibit an unexpected pattern of growth. Lizards from a high elevation population grow faster than lizards from two populations at lower elevations despite shorter daily and seasonal activity. Results from a common environment study of growth suggest that the differences in growth are not due to adaptation to local environmental conditions. In this study, I test the hypothesis that higher growth rates in lizards from high elevation may be attributable to reduced resting metabolic expenditure compared to that of lizards from populations at two lower elevations. Resting metabolic rates were measured for individuals from each of the study populations across different times of day and over a broad range of temperatures. Under the same laboratory conditions, field-caught lizards from the high elevation population exhibited lower metabolic rates when compared to lizards from lower elevations. Daily resting metabolic expenditures were calculated using the observed metabolic rates coupled with estimates of daily activity. Daily resting metabolic expenditure was 50% greater for individuals from the two lower elevation populations, which could result in 12.5% more energy that could be potentially allocated to growth for lizards from high elevation. Such energetic savings may be able to explain differences in the patterns of growth observed in nature.

  7. Patterns of oribatid mite species diversity: testing the effects of elevation, area and sampling effort.

    PubMed

    Mumladze, Levan; Murvanidze, Maka; Maraun, Mark

    2017-07-01

    Elevational gradients in species diversity and species area relationships are two well established patterns that are not mutually exclusive in space and time. Elevation and area are both considered as good proxies to detect and characterize the patterns of species diversity distribution. However, such studies are hampered by the incomplete biodiversity data available for ecologists, which may affect the pattern perceptions. Using the large dataset of oribatid mite communities sampled in Georgia, we tested the effects of altitude and area on species distribution using various approaches, while explicitly considering the biases from sampling effort. Our results showed that elevation and area are strongly correlated (with increasing absolute elevation, land area decreases) and both have strong linear effects on species diversity distribution when studied separately. Approaches based on multiple regression and direct removal of co-varied factors, indicated that the effect of area can actually override the effect of elevation in describing the oribatid species diversity distribution along with elevation. On the other hand, the bias of sampling proved significant in perception of elevational species richness pattern with less effect on elevational species area relationship. We suggest that the sampling alone may be responsible for patterns observed and thus should be considered in ecological studies when eligible.

  8. Use of prototype two-channel endoscope with elevator enables larger lift-and-snare endoscopic mucosal resection in a porcine model

    PubMed Central

    Atkinson, Matthew; Chukwumah, Chike; Marks, Jeffrey; Chak, Amitabh

    2014-01-01

    Background: Flat and depressed lesions are becoming increasingly recognized in the esophagus, stomach, and colon. Various techniques have been described for endoscopic mucosal resection (EMR) of these lesions. Aims: To evaluate the efficacy of lift-grasp-cut EMR using a prototype dual-channel forward-viewing endoscope with an instrument elevator in one accessory channel (dual-channel elevator scope) as compared to standard dual-channel endoscopes. Methods: EMR was performed using a lift-grasp-cut technique on normal flat rectosigmoid or gastric mucosa in live porcine models after submucosal injection of 4 mL of saline using a dual-channel elevator scope or a standard dual-channel endoscope. With the dual-channel elevator scope, the elevator was used to attain further lifting of the mucosa. The primary endpoint was size of the EMR specimen and the secondary endpoint was number of complications. Results: Twelve experiments were performed (six gastric and six colonic). Mean specimen diameter was 2.27 cm with the dual-channel elevator scope and 1.34 cm with the dual-channel endoscope (P = 0.018). Two colonic perforations occurred with the dual-channel endoscope, vs no complications with the dual-channel elevator scope. Conclusions: The increased lift of the mucosal epithelium, through use of the dual-channel elevator scope, allows for larger EMR when using a lift-grasp-cut technique. Noting the thin nature of the porcine colonic wall, use of the elevator may also make this technique safer. PMID:24760237

  9. [Correlation of medial compartmental joint line elevation with femorotibial angle correction and clinical function after unicompartmental arthroplasty].

    PubMed

    Zhang, Zhan-Feng; Wang, Dan; Min, Ji-Kang

    2017-04-25

    To study the correlation of postoperative femorotibial angle with medial compartmental joint line elevation after unicompartmental arthroplasty(UKA), as well as the correlation of joint line elevation with the clinical function by measuring radiological joint line. A retrospective study of 56 patients from July 2012 to August 2015 was performed. The mean body mass index (BMI) was 23.5 (ranged, 18.3 to 30.1). The standing anteroposterior radiographs of these patients were assessed both pre-and post-operatively, and the knee function was evaluated according to HSS grading. The correlation between postoperative femorotibial angle(FTA) and joint line elevation was analyzed as well as the correlation between joint line elevation and the clinical function. The mean medial joint line elevation was (2.2±2.0) mm(ranged, -3.3 to 7.0 mm), and the mean FTA correction was (2.3±3.0)°(ranged, -4.5° to 9.6°). The mean follow-up period was 12.2 months. There was a significant correlation between in joint line elevation and FTA correction( P <0.05), while there was no significant correlation between joint line elevation and the clinical function( P >0.05). There was a significant correlation between medial compartmental joint line elevation and FTA correction after UKA, and the proximal tibial osteotomy was critical during the procedure. There was no significant correlation between joint line elevation and the clinical function, which may be related to the design of UKA prosthesis.

  10. Microbes on mountainsides: Contrasting elevational patterns of bacterial and plant diversity

    PubMed Central

    Bryant, Jessica A.; Lamanna, Christine; Morlon, Hélène; Kerkhoff, Andrew J.; Enquist, Brian J.; Green, Jessica L.

    2008-01-01

    The study of elevational diversity gradients dates back to the foundation of biogeography. Although elevational patterns of plant and animal diversity have been studied for centuries, such patterns have not been reported for microorganisms and remain poorly understood. Here, in an effort to assess the generality of elevational diversity patterns, we examined soil bacterial and plant diversity along an elevation gradient. To gain insight into the forces that structure these patterns, we adopted a multifaceted approach to incorporate information about the structure, diversity, and spatial turnover of montane communities in a phylogenetic context. We found that observed patterns of plant and bacterial diversity were fundamentally different. While bacterial taxon richness and phylogenetic diversity decreased monotonically from the lowest to highest elevations, plants followed a unimodal pattern, with a peak in richness and phylogenetic diversity at mid-elevations. At all elevations bacterial communities had a tendency to be phylogenetically clustered, containing closely related taxa. In contrast, plant communities did not exhibit a uniform phylogenetic structure across the gradient: they became more overdispersed with increasing elevation, containing distantly related taxa. Finally, a metric of phylogenetic beta-diversity showed that bacterial lineages were not randomly distributed, but rather exhibited significant spatial structure across the gradient, whereas plant lineages did not exhibit a significant phylogenetic signal. Quantifying the influence of sample scale in intertaxonomic comparisons remains a challenge. Nevertheless, our findings suggest that the forces structuring microorganism and macroorganism communities along elevational gradients differ. PMID:18695215

  11. Combination treatment of elevated UVB radiation, CO2 and temperature has little effect on silver birch (Betula pendula) growth and phytochemistry.

    PubMed

    Lavola, Anu; Nybakken, Line; Rousi, Matti; Pusenius, Jyrki; Petrelius, Mari; Kellomäki, Seppo; Julkunen-Tiitto, Riitta

    2013-12-01

    Elevations of carbon dioxide, temperature and ultraviolet-B (UBV) radiation in the growth environment may have a high impact on the accumulation of carbon in plants, and the different factors may work in opposite directions or induce additive effects. To detect the changes in the growth and phytochemistry of silver birch (Betula pendula) seedlings, six genotypes were exposed to combinations of ambient or elevated levels of CO2 , temperature and UVB radiation in top-closed chambers for 7 weeks. The genotypes were relatively similar in their responses, and no significant interactive effects of three-level climate factors on the measured parameters were observed. Elevated UVB had no effect on growth, nor did it alter plant responses to CO2 and/or temperature in combined treatments. Growth in all plant parts increased under elevated CO2 , and height and stem biomass increased under elevated temperature. Increased carbon distribution to biomass did not reduce its allocation to phytochemicals: condensed tannins, most flavonols and phenolic acids accumulated under elevated CO2 and elevated UVB, but this effect disappeared under elevated temperature. Leaf nitrogen content decreased under elevated CO2 . We conclude that, as a result of high genetic variability in phytochemicals, B. pendula seedlings have potential to adapt to the tested environmental changes. The induction in protective flavonoids under UVB radiation together with the positive impact of elevated CO2 and temperature mitigates possible UVB stress effects, and thus atmospheric CO2 concentration and temperature are the climate change factors that will dictate the establishment and success of birch at higher altitudes in the future. © 2013 Scandinavian Plant Physiology Society.

  12. Association of CA 15-3 and CEA with clinicopathological parameters in patients with metastatic breast cancer.

    PubMed

    Geng, Biao; Liang, Man-Man; Ye, Xiao-Bing; Zhao, Wen-Ying

    2015-01-01

    The objective of this study was to investigate the association of serum cancer antigen 15-3 (CA 15-3) and carcinoembryonic antigen (CEA) levels with clinicopathological parameters in patients diagnosed with metastatic breast cancer (MBC). We retrospectively evaluated the medical records of 284 patients diagnosed with MBC between January, 2007 and December, 2012 who fulfilled the specified criteria and the association between the levels of the two tumor marker and clinicopathological parameters was analyzed. Of the 284 patients, elevated CA 15-3 and CEA levels at initial diagnosis of recurrence were identified in 163 (57.4%) and 97 (34.2%) patients, respectively. Elevated CA 15-3 and CEA levels were significantly associated with breast cancer molecular subtypes (P<0.001 and P=0.032, respectively). Cases with luminal subtypes exhibited a higher percentage of elevated CA 15-3 and CEA levels compared to non-luminal subtypes. Elevated CA 15-3 level was correlated with bone metastasis (P=0.017). However, elevation of CEA was observed regardless of the site of metastasis. Elevation of CA 15-3 was significantly more common in MBC with multiple metastatic sites compared to MBC with a single metastasis (P=0.001). However, the incidence of elevated CEA levels did not differ between patients with a single and those with multiple metastatic sites. In conclusion, elevated CA 15-3 and CEA levels at initial diagnosis of recurrence were found to be associated with breast cancer molecular subtypes, whereas an elevated CA 15-3 level was significantly correlated with bone metastasis and an elevated CEA level was observed regardless of metastatic site. The proportion of MBC cases with elevated CA 15-3 levels differed according to the number of metastatic sites.

  13. Influence of elevation on bark beetle (Coleoptera: Curculionidae, Scolytinae) community structure and flight periodicity in ponderosa pine forests of Arizona.

    PubMed

    Williams, Kelly K; McMillin, Joel D; DeGomez, Tom E; Clancy, Karen M; Miller, Andy

    2008-02-01

    We examined abundance and flight periodicity of five Ips and six Dendroctonus species (Coleoptera: Curculionidae, Scolytinae) among three different elevation bands in ponderosa pine (Pinus ponderosa Douglas ex. Lawson) forests of northcentral Arizona. Bark beetle populations were monitored at 10 sites in each of three elevation bands (low: 1,600-1,736 m; middle: 2,058-2,230 m; high: 2,505-2,651 m) for 3 yr (2004-2006) using pheromone-baited Lindgren funnel traps. Trap contents were collected weekly from March to December. We also studied temperature differences among the elevation bands and what role this may play in beetle flight behavior. Bark beetles, regardless of species, showed no consistent elevational trend in abundance among the three bands. The higher abundances of Ips lecontei Swaine, I. calligraphus ponderosae Swaine, Dendroctonus frontalis Zimmerman, and D. brevicomis LeConte at low and middle elevations offset the greater abundance of I. knausi Swaine, D. adjunctus Blandford, D. approximatus Dietz, and D. valens LeConte at high elevations. I. pini (Say) and I. latidens LeConte were found in similar numbers across the three bands. Flight periodicity of several species varied among elevation bands. In general, the flight period shortened as elevation increased; flight initiated later and terminated earlier in the year. The timing, number, and magnitude of peaks in flight activity also varied among the elevation bands. These results suggest that abundance and flight seasonality of several bark beetles are related to elevation and the associated temperature differences. The implications of these results are discussed in relation to bark beetle management and population dynamics.

  14. Changes in carbohydrate content and membrane stability of two ecotypes of Calamagrostis arundinacea growing at different elevations in the drawdown zone of the Three Gorges Reservoir.

    PubMed

    Lei, Shutong; Zeng, Bo; Yuan, Zhi; Su, Xiaolei

    2014-01-01

    The Three Gorges project has caused many ecosystem problems. Ecological restoration using readily-available plants is an effective way of mitigating environmental impacts. Two perennial submergence-tolerant ecotypes of Calamagrostis arundinacea were planted in an experimental field in the drawdown zone. Responses of the two plant ecotypes to flooding stress in the drawdown zone were unknown. Carbohydrate content and membrane stability, two key factors for survival of plants under flooding stress, of two ecotypes (designated "dwarf" and "green") of C. arundinacea growing at different elevations of the drawdown zone were investigated. Live stems (LS) and dead stems (DS) of the two plant ecotypes at eight elevations (175, 170, 162, 160, 158, 155, 152 m and 149 m) were sampled. Contents of soluble sugar, starch and malondialdehyde (MDA), as well as plasma membrane permeability of live stems were measured. The lowest elevations for survival of dwarf and green C. arundinacea were 160 m and 158 m, respectively. Soluble sugar content of live stems of both ecotypes decreased with elevation, with amounts from an elevation of 170 m being lower than from an elevation of 175 m. MDA content and plasma membrane permeability in live stems of green C. arundinacea did not increase with the decrease in elevation, while these measures in dwarf C. arundinacea from an elevation of 162 m were significantly higher than from an elevation of 175 m. Carbohydrate content, especially soluble sugar content, in both ecotypes was more sensitive to flooding stress than membrane stability. Green C. arundinacea had a higher tolerance to submergence than dwarf C. arundinacea, and thus green C. arundinacea can be planted at lower elevations than dwarf C. arundinacea.

  15. Combined effects of Lanthanum(III) and elevated Ultraviolet-B radiation on root nitrogen nutrient in soybean seedlings.

    PubMed

    Huang, Guangrong; Wang, Lihong; Sun, Zhaoguo; Li, Xiaodong; Zhou, Qing; Huang, Xiaohua

    2015-02-01

    Rare earth element pollution and elevated ultraviolet-B (UV-B) radiation occur simultaneously in some regions, but the combined effects of these two factors on plants have not attracted enough attention. Nitrogen nutrient is vital to plant growth. In this study, the combined effects of lanthanum(III) and elevated UV-B radiation on nitrate reduction and ammonia assimilation in soybean (Glycine max L.) roots were investigated. Treatment with 0.08 mmol L(-1) La(III) did not change the effects of elevated UV-B radiation on nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthase (GOGAT), glutamate dehydrogenase (GDH), nitrate, ammonium, amino acids, or soluble protein in the roots. Treatment with 0.24 mmol L(-1) La(III) and elevated UV-B radiation synergistically decreased the NR, NiR, GS, and GOGAT activities as well as the nitrate, amino acid, and soluble protein levels, except for the GDH activity and ammonium content. Combined treatment with 1.20 mmol L(-1) La(III) and elevated UV-B radiation produced severely deleterious effects on all test indices, and these effects were stronger than those induced by La(III) or elevated UV-B radiation treatment alone. Following the withdrawal of La(III) and elevated UV-B radiation, all test indices for the combined treatments with 0.08/0.24 mmol L(-1) La(III) and elevated UV-B radiation recovered to a certain extent, but they could not recover for treatments with 1.20 mmol L(-1) La(III) and elevated UV-B radiation. In summary, combined treatment with La(III) and elevated UV-B radiation seriously affected nitrogen nutrition in soybean roots through the inhibition of nitrate reduction and ammonia assimilation.

  16. Effects of elevated O₃ on microbes in the rhizosphere of mycorrhizal snap bean with different O₃ sensitivity.

    PubMed

    Wang, Shuguang; Wang, Fei; Diao, Xiaojun; He, Liansheng

    2014-02-01

    Elevated ozone (O₃) generally affects microbial biomass and community structure in rhizosphere, but these effects are unclear in mycorrhizal plants because arbuscular mycorrhizal (AM) fungi often benefit microbial growth in the rhizosphere. Here, we investigate the effects of elevated O₃ on microbial biomass and community structure in the rhizosphere of mycorrhizal snap bean (Phaseolus vulgaris L.) with different O₃ sensitivity (R123: O₃-tolerant plant; S156: O₃-sensitive plant) based on the phospholipid fatty acids (PLFAs) method. Compared with ambient O₃, elevated O₃ significantly decreased mycorrhizal colonization rates in the 2 genotypes, especially in S156 plants. The wet masses of shoot and root were decreased by elevated O₃ in the 2 genotypes independent of AM inoculation, but they were higher in the mycorrhizal plant than in the nonmycorrhizal plant independent of O₃ concentration. Elevated O₃ significantly decreased the relative proportion of specific fungal PLFAs in the nonmycorrhizal plant, but this effect disappeared in the mycorrhizal plant. The relative proportions of specific PLFAs of other microbial groups (Gram-positive, Gram-negative, and actinomycete) in the rhizosphere and all specific PLFAs in the hyphosphere were not affected by elevated O₃ independent of AM inoculation. In the rhizosphere of the 2 genotypes, microbial community structure was changed by AM inoculation and elevated O₃ as well as by their interaction; in the hyphosphere, however, microbial community structure was changed by elevated O₃ only in R123 plants. It is concluded that AM inoculation can offset negative effect of elevated O₃ on fungal biomass but seems to enhance shift of microbial community structure in rhizosphere under elevated O₃.

  17. CO 2 elevation improves photosynthetic performance in progressive warming environment in white birch seedlings.

    PubMed

    Zhang, Shouren; Dang, Qing-Lai

    2013-01-01

    White birch (Betula paperifera Mash) seedlings were exposed to progressively warming in greenhouses under ambient and elevated CO 2 concentrations for 5 months to explore boreal tree species' potential capacity to acclimate to global climate warming and CO 2 elevation. In situ foliar gas exchange, in vivo carboxylation characteristics and chlorophyll fluorescence were measured at temperatures of 26 (o)C and 37 (o)C. Elevated CO 2 significantly increased net photosynthetic rate (Pn) at both measurement temperatures, and Pn at 37 (o)C was higher than that at 26 (o)C under elevated CO 2. Stomatal conductance (gs) was lower at 37 (o)C than at 26 (o)C, while transpiration rate (E) was higher at 37 (o)C than that at 26 (o)C. Elevated CO 2 significantly increased instantaneous water-use efficiency (WUE) at both 26 (o)C and 37 (o)C, but WUE was markedly enhanced at 37 (o)C under elevated CO 2. The effect of temperature on maximal carboxylation rate (Vcmax), PAR-saturated electron transport rate (Jmax) and triose phosphate utilization (TPU) varied with CO 2, and the Vcmax and Jmax were significantly higher at 37 (o)C than at 26 (o)C under elevated CO 2. However, there were no significant interactive effects of CO 2 and temperature on TPU. The actual photochemical efficiency of PSII (DF/ Fm'), total photosynthetic linear electron transport rate through PSII (JT) and the partitioning of JT to carboxylation (Jc) were higher at 37 (o)C than at 26 (o)C under elevated CO 2. Elevated CO 2 significantly suppressed the partitioning of JT to oxygenation (Jo/JT). The data suggest that the CO 2 elevation and progressive warming greatly enhanced photosynthesis in white birch seedlings in an interactive fashion.

  18. The outcome of ecosystem manipulation by elevating atmospheric CO2 is influenced by tree identity and mixture

    NASA Astrophysics Data System (ADS)

    Godbold, Douglas; Smith, Andrew; Lukac, Martin

    2013-04-01

    Free Air Carbon dioxide Enrichment (FACE) has often been used predict the response of forest ecosystems to a future high CO2 world. Many of these investigations have been restricted to exposure of single species or genotypes to elevated CO2. To investigate the interaction between tree mixture and elevated CO2, Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of single species and a three species polyculture in a free-air CO2 enrichment study (BangorFACE). The trees were exposed to ambient or elevated CO2 for 4 years. Aboveground woody biomass was increased in polyculture under both ambient and elevated CO2, but the response to elevated CO2 was smaller in polyculture than in the monocultures. In some years, a longer leaf retention was shown under high CO2, and is an indication that environmental factors may moderate tree response to high CO2. Fine and coarse root biomass, together with fine root turnover and fine root morphological characteristics were also measured. Fine root biomass and morphology responded differentially to the elevated CO2 at different soil depths in the three species when grown in monocultures. In polyculture, a greater response to elevated CO2 was observed in coarse roots, and fine root area index. Total fine root biomass was positively affected by elevated CO2 at the end of the experiment, but not by species diversity. Our results show that the aboveground and belowground response to elevated CO2 is significantly affected by intra- and inter-specific competition, and that elevated CO2 response may be reduced in forest communities comprised of tree species with contrasting functional traits but also that other environmental factors may induce previously unseen effects.

  19. The effect of elevated temperatures on the life history and insecticide resistance phenotype of the major malaria vector Anopheles arabiensis (Diptera: Culicidae).

    PubMed

    Oliver, Shüné V; Brooke, Basil D

    2017-02-14

    Temperature plays a crucial role in the life history of insects. Recent climate change research has highlighted the importance of elevated temperature on malaria vector distribution. This study aims to examine the role of elevated temperatures on epidemiologically important life-history traits in the major malaria vector, Anopheles arabiensis. Specifically, the differential effects of temperature on insecticide-resistant and susceptible strains were examined. Two laboratory strains of A. arabiensis, the insecticide-susceptible SENN and the insecticide-resistant SENN DDT strains, were used to examine the effect of elevated temperatures on larval development and adult longevity. The effects of various elevated temperatures on insecticide resistance phenotypes were also examined and the biochemical basis of the changes in insecticide resistance phenotype was assessed. SENN and SENN DDT larvae developed at similar rates at elevated temperatures. SENN DDT adult survivorship did not vary between control and elevated temperatures, while the longevity of SENN adults at constantly elevated temperatures was significantly reduced. SENN DDT adults lived significantly longer than SENN at constantly elevated temperatures. Elevated rearing temperatures, as well as a short-term exposure to 37 and 39 °C as adults, augmented pyrethroid resistance in adult SENN DDT, and increased pyrethroid tolerance in SENN. Detoxification enzyme activity was not implicated in this phenotypic effect. Quercertin-induced synergism of inducible heat shock proteins negated this temperature-mediated augmentation of pyrethroid resistance. Insecticide-resistant A. arabiensis live longer than their susceptible counterparts at elevated temperatures. Exposure to heat shock augments pyrethroid resistance in both resistant and susceptible strains. This response is potentially mediated by inducible heat shock proteins.

  20. Water relations and gas exchange in poplar and willow under water stress and elevated atmospheric CO2.

    PubMed

    Johnson, Jon D; Tognetti, Roberto; Paris, Piero

    2002-05-01

    Predictions of shifts in rainfall patterns as atmospheric [CO2] increases could impact the growth of fast growing trees such as Populus spp. and Salix spp. and the interaction between elevated CO2 and water stress in these species is unknown. The objectives of this study were to characterize the responses to elevated CO2 and water stress in these two species, and to determine if elevated CO2 mitigated drought stress effects. Gas exchange, water potential components, whole plant transpiration and growth response to soil drying and recovery were assessed in hybrid poplar (clone 53-246) and willow (Salix sagitta) rooted cuttings growing in either ambient (350 &mgr;mol mol-1) or elevated (700 &mgr;mol mol-1) atmospheric CO2 concentration ([CO2]). Predawn water potential decreased with increasing water stress while midday water potentials remained unchanged (isohydric response). Turgor potentials at both predawn and midday increased in elevated [CO2], indicative of osmotic adjustment. Gas exchange was reduced by water stress while elevated [CO2] increased photosynthetic rates, reduced leaf conductance and nearly doubled instantaneous transpiration efficiency in both species. Dark respiration decreased in elevated [CO2] and water stress reduced Rd in the trees growing in ambient [CO2]. Willow had 56% lower whole plant hydraulic conductivity than poplar, and showed a 14% increase in elevated [CO2] while poplar was unresponsive. The physiological responses exhibited by poplar and willow to elevated [CO2] and water stress, singly, suggest that these species respond like other tree species. The interaction of [CO2] and water stress suggests that elevated [CO2] did mitigate the effects of water stress in willow, but not in poplar.

  1. The Encoding of Sound Source Elevation in the Human Auditory Cortex.

    PubMed

    Trapeau, Régis; Schönwiesner, Marc

    2018-03-28

    Spatial hearing is a crucial capacity of the auditory system. While the encoding of horizontal sound direction has been extensively studied, very little is known about the representation of vertical sound direction in the auditory cortex. Using high-resolution fMRI, we measured voxelwise sound elevation tuning curves in human auditory cortex and show that sound elevation is represented by broad tuning functions preferring lower elevations as well as secondary narrow tuning functions preferring individual elevation directions. We changed the ear shape of participants (male and female) with silicone molds for several days. This manipulation reduced or abolished the ability to discriminate sound elevation and flattened cortical tuning curves. Tuning curves recovered their original shape as participants adapted to the modified ears and regained elevation perception over time. These findings suggest that the elevation tuning observed in low-level auditory cortex did not arise from the physical features of the stimuli but is contingent on experience with spectral cues and covaries with the change in perception. One explanation for this observation may be that the tuning in low-level auditory cortex underlies the subjective perception of sound elevation. SIGNIFICANCE STATEMENT This study addresses two fundamental questions about the brain representation of sensory stimuli: how the vertical spatial axis of auditory space is represented in the auditory cortex and whether low-level sensory cortex represents physical stimulus features or subjective perceptual attributes. Using high-resolution fMRI, we show that vertical sound direction is represented by broad tuning functions preferring lower elevations as well as secondary narrow tuning functions preferring individual elevation directions. In addition, we demonstrate that the shape of these tuning functions is contingent on experience with spectral cues and covaries with the change in perception, which may indicate that the tuning functions in low-level auditory cortex underlie the perceived elevation of a sound source. Copyright © 2018 the authors 0270-6474/18/383252-13$15.00/0.

  2. Dispersal limitation does not control high elevational distribution of alien plant species in the southern Sierra Nevada, California

    USGS Publications Warehouse

    Rundel, Philip W.; Keeley, Jon E.

    2016-01-01

    Patterns of elevational distribution of alien plant species in the southern Sierra Nevada of California were used to test the hypothesis that alien plant species invading high elevations around the world are typically climate generalists capable of growing across a wide elevational range. The Sierra Nevada has been heavily impacted for more than a century and a half, first by heavy grazing up into high elevation meadows, followed by major logging, and finally, by impacts associated with recreational use. The comparative elevational patterns of distribution and growth form were compared for native and alien plant species in the four families (Asteraceae, Brassicaceae, Fabaceae, and Poaceae) that contribute the majority of naturalized aliens in the study area. The distribution of realized climatic niche breadth, as measured by elevational range of occurrence, was virtually identical for alien and native species, with both groups showing a roughly Gaussian distribution peaking with species whose range covers a span of 1500–1999 m. In contrast to alien species, which only rarely occurred at higher elevations, native species showed a distribution of upper elevation limits peaking at 3000–3499 m, an elevation that corresponds to the zone of upper montane and subalpine forests. Consistent with a hypothesis of abiotic limitations, only a few alien species have been ecologically successful invaders at subalpine and alpine elevations above 2500 m. The low diversity of aliens able to become established in these habitats is unlikely due to dispersal limitations, given the long history of heavy grazing pressure at high elevations across this region. Instead, this low diversity is hypothesized to be a function of life history traits and multiple abiotic stresses that include extremes of cold air and soil temperature, heavy snowfall, short growing seasons, and low resource availability. These findings have significant implications for resource managers.

  3. Does joint line elevation after revision knee arthroplasty affect tibio-femoral kinematics, contact pressure or collateral ligament lengths? An in vitro analysis

    PubMed Central

    Kowalczewski, Jacek B.; Chevalier, Yan; Okon, Tomasz; Innocenti, Bernardo; Bellemans, Johan

    2015-01-01

    Introduction Correct restoration of the joint line is generally considered as crucial when performing total knee arthroplasty (TKA). During revision knee arthroplasty however, elevation of the joint line occurs frequently. The general belief is that this negatively affects the clinical outcome, but the reasons are still not well understood. Material and methods In this cadaveric in vitro study the biomechanical consequences of joint line elevation were investigated using a previously validated cadaver model simulating active deep knee squats and passive flexion-extension cycles. Knee specimens were sequentially tested after total knee arthroplasty with joint line restoration and after 4 mm joint line elevation. Results The tibia rotated internally with increasing knee flexion during both passive and squatting motion (range: 17° and 7° respectively). Joint line elevation of 4 mm did not make a statistically significant difference. During passive motion, the tibia tended to become slightly more adducted with increasing knee flexion (range: 2°), while it went into slighlty less adduction during squatting (range: –2°). Neither of both trends was influenced by joint line elevation. Also anteroposterior translation of the femoral condyle centres was not affected by joint line elevation, although there was a tendency for a small posterior shift (of about 3 mm) during squatting after joint line elevation. In terms of kinetics, ligaments lengths and length changes, tibiofemoral contact pressures and quadriceps forces all showed the same patterns before and joint line elevation. No statistically significant changes could be detected. Conclusions Our study suggests that joint line elevation by 4 mm in revision total knee arthroplasty does not cause significant kinematic and kinetic differences during passive flexion/extension movement and squatting in the tibio-femoral joint, nor does it affect the elongation patterns of collateral ligaments. Therefore, clinical problems after joint line elevation are probably situated in the patello-femoral joint or caused by joint line elevation of more than 4 mm. PMID:25995746

  4. National requirements for improved elevation data

    USGS Publications Warehouse

    Snyder, Gregory I.; Sugarbaker, Larry J.; Jason, Allyson L.; Maune, David F.

    2014-01-01

    This report presents the results of surveys, structured interviews, and workshops conducted to identify key national requirements for improved elevation data for the United States and its territories, including coastlines. Organizations also identified and reported the expected economic benefits that would be realized if their requirements for improved elevation were met (appendixes 1–3). This report describes the data collection methodology and summarizes the findings. Participating organizations included 34 Federal agencies, 50 States and two territories, and a sampling of local governments, tribes, and nongovernmental orgnizations. The nongovernmental organizations included The Nature Conservancy and a sampling of private sector businesses. These data were collected in 2010-2011 as part of the National Enhanced Elevation Assessment (NEEA), a study to identify program alternatives for better meeting the Nation’s elevation data needs. NEEA tasks included the collection of national elevation requirements; analysis of the benefits and costs of meeting these requirements; assessment of emerging elevation technologies, lifecycle data management needs, and costs for managing and distributing a national-scale dataset and derived products; and candidate national elevation program alternatives that balance costs and benefits in meeting the Nation’s elevation requirements. The NEEA was sponsored by the National Digital Elevation Program (NDEP), a government coordination body with the U.S. Geological Survey (USGS) as managing partner that includes the National Geospatial-Intelligence Agency (NGA), the Federal Emergency Management Agency (FEMA), the Natural Resources Conservation Service (NRCS), the U.S. Army Corps of Engineers (USACE), and the National Oceanic and Atmospheric Administration (NOAA), among the more than a dozen agencies and organizations. The term enhanced elevation data as used in this report refers broadly to three-dimensional measurements of land or submerged topography, built features, vegetation structure, and other landscape detail. Additional information about NEEA and its later use in the development of a 3D Elevation Program (3DEP) can be found at http://nationalmap.gov/3DEP/index.html.

  5. Changes in Respiratory Mitochondrial Machinery and Cytochrome and Alternative Pathway Activities in Response to Energy Demand Underlie the Acclimation of Respiration to Elevated CO2 in the Invasive Opuntia ficus-indica1[OA

    PubMed Central

    Gomez-Casanovas, Nuria; Blanc-Betes, Elena; Gonzalez-Meler, Miquel A.; Azcon-Bieto, Joaquim

    2007-01-01

    Studies on long-term effects of plants grown at elevated CO2 are scarce and mechanisms of such responses are largely unknown. To gain mechanistic understanding on respiratory acclimation to elevated CO2, the Crassulacean acid metabolism Mediterranean invasive Opuntia ficus-indica Miller was grown at various CO2 concentrations. Respiration rates, maximum activity of cytochrome c oxidase, and active mitochondrial number consistently decreased in plants grown at elevated CO2 during the 9 months of the study when compared to ambient plants. Plant growth at elevated CO2 also reduced cytochrome pathway activity, but increased the activity of the alternative pathway. Despite all these effects seen in plants grown at high CO2, the specific oxygen uptake rate per unit of active mitochondria was the same for plants grown at ambient and elevated CO2. Although decreases in photorespiration activity have been pointed out as a factor contributing to the long-term acclimation of plant respiration to growth at elevated CO2, the homeostatic maintenance of specific respiratory rate per unit of mitochondria in response to high CO2 suggests that photorespiratory activity may play a small role on the long-term acclimation of respiration to elevated CO2. However, despite growth enhancement and as a result of the inhibition in cytochrome pathway activity by elevated CO2, total mitochondrial ATP production was decreased by plant growth at elevated CO2 when compared to ambient-grown plants. Because plant growth at elevated CO2 increased biomass but reduced respiratory machinery, activity, and ATP yields while maintaining O2 consumption rates per unit of mitochondria, we suggest that acclimation to elevated CO2 results from physiological adjustment of respiration to tissue ATP demand, which may not be entirely driven by nitrogen metabolism as previously suggested. PMID:17660349

  6. Humic Acid Composition and Characteristics of Soil Organic Matter in Relation to the Elevation Gradient of Moso Bamboo Plantations.

    PubMed

    Wang, Hsueh-Ching; Chou, Chiao-Ying; Chiou, Chyi-Rong; Tian, Guanglong; Chiu, Chih-Yu

    2016-01-01

    Studying the influence of climatic and/or site-specific factors on soil organic matter (SOM) along an elevation gradient is important for understanding the response of SOM to global warming. We evaluated the composition of SOM and structure of humic acids along an altitudinal gradient from 600 to 1400 m in moso bamboo (Phyllostachys edulis) plantations in central Taiwan using NMR spectroscopy and photometric analysis. Total organic C and total nitrogen (N) content increased with increasing elevation. Aromaticity decreased and ΔlogK (the logarithm of the absorbance ratio of humic acids at 400 and 600 nm) increased with increasing elevation, which suggests that SOM humification decreased with increasing elevation. High temperature at low elevations seemed to enhance the decomposition (less accumulation of total organic C and N) and humification (high aromaticity and low ΔlogK). The alkyl-C/O-alkyl-C (A/O-A) ratio of humic acids increased with increasing elevation, which suggests that SOM humification increased with increasing elevation; this finding was contrary to the trend observed for ΔlogK and aromaticity. Such a discrepancy might be due to the relatively greater remaining of SOM derived from high alkyl-C broadleaf litter of previous forest at high elevations. The ratio of recalcitrant C to total organic C was low at low elevations, possibly because of enhanced decomposition of recalcitrant SOM from the previous broadleaf forest during long-term intensive cultivation and high temperature. Overall, the change in SOM pools and in the rate of humification with elevation was primarily affected by changes in climatic conditions along the elevation gradient in these bamboo plantations. However, when the composition of SOM, as assessed by NMR spectroscopy and photometric analysis was considered, site-specific factors such as residual SOM from previous forest and intensive cultivation history could also have an important effect on the humic acid composition and humification of SOM.

  7. Humic Acid Composition and Characteristics of Soil Organic Matter in Relation to the Elevation Gradient of Moso Bamboo Plantations

    PubMed Central

    Wang, Hsueh-Ching; Chou, Chiao-Ying; Chiou, Chyi-Rong; Tian, Guanglong

    2016-01-01

    Studying the influence of climatic and/or site-specific factors on soil organic matter (SOM) along an elevation gradient is important for understanding the response of SOM to global warming. We evaluated the composition of SOM and structure of humic acids along an altitudinal gradient from 600 to 1400 m in moso bamboo (Phyllostachys edulis) plantations in central Taiwan using NMR spectroscopy and photometric analysis. Total organic C and total nitrogen (N) content increased with increasing elevation. Aromaticity decreased and ΔlogK (the logarithm of the absorbance ratio of humic acids at 400 and 600 nm) increased with increasing elevation, which suggests that SOM humification decreased with increasing elevation. High temperature at low elevations seemed to enhance the decomposition (less accumulation of total organic C and N) and humification (high aromaticity and low ΔlogK). The alkyl-C/O-alkyl-C (A/O-A) ratio of humic acids increased with increasing elevation, which suggests that SOM humification increased with increasing elevation; this finding was contrary to the trend observed for ΔlogK and aromaticity. Such a discrepancy might be due to the relatively greater remaining of SOM derived from high alkyl-C broadleaf litter of previous forest at high elevations. The ratio of recalcitrant C to total organic C was low at low elevations, possibly because of enhanced decomposition of recalcitrant SOM from the previous broadleaf forest during long-term intensive cultivation and high temperature. Overall, the change in SOM pools and in the rate of humification with elevation was primarily affected by changes in climatic conditions along the elevation gradient in these bamboo plantations. However, when the composition of SOM, as assessed by NMR spectroscopy and photometric analysis was considered, site-specific factors such as residual SOM from previous forest and intensive cultivation history could also have an important effect on the humic acid composition and humification of SOM. PMID:27583451

  8. Functional role of long-lived flowers in preventing pollen limitation in a high elevation outcrossing species

    PubMed Central

    Pacheco, Diego Andrés; Dudley, Leah S

    2017-01-01

    Abstract Low pollinator visitation in harsh environments may lead to pollen limitation which can threaten population persistence. Consequently, avoidance of pollen limitation is expected in outcrossing species subjected to habitually low pollinator service. The elevational decline in visitation rates on many high mountains provides an outstanding opportunity for addressing this question. According to a recent meta-analysis, levels of pollen limitation in alpine and lowland species do not differ. If parallel trends are manifested among populations of alpine species with wide elevational ranges, how do their uppermost populations contend with lower visitation? We investigated visitation rates and pollen limitation in high Andean Rhodolirium montanum. We test the hypothesis that lower visitation rates at high elevations are compensated for by the possession of long-lived flowers. Visitation rates decreased markedly over elevation as temperature decreased. Pollen limitation was absent at the low elevation site but did occur at the high elevation site. While initiation of stigmatic pollen deposition at high elevations was not delayed, rates of pollen arrival were lower, and cessation of pollination, as reflected by realized flower longevity, occurred later in the flower lifespan. Comparison of the elevational visitation decline and levels of pollen limitation indicates that flower longevity partially compensates for the lower visitation rates at high elevation. The functional role of flower longevity, however, was strongly masked by qualitative pollen limitation arising from higher abortion levels attributable to transference of genetically low-quality pollen in large clones. Stronger clonal growth at high elevations could counterbalance the negative fitness consequences of residual pollen limitation due to low visitation rates and/or difficult establishment under colder conditions. Visitation rates on the lower part of the elevational range greatly exceeded community rates recorded several decades ago when the planet was cooler. Current pollen limitation for some species in some habitats might underestimate historical levels. PMID:29225762

  9. Elevated temperature and CO(2) concentration effects on xylem anatomy of Scots pine.

    PubMed

    Kilpeläinen, Antti; Gerendiain, Ane Zubizarreta; Luostarinen, Katri; Peltola, Heli; Kellomäki, Seppo

    2007-09-01

    We studied the effects of elevated temperature and carbon dioxide concentration ([CO(2)]) alone and together on wood anatomy of 20-year-old Scots pine (Pinus sylvestris L.) trees. The study was conducted in 16 closed chambers, providing a factorial combination of two temperature regimes and two CO(2) concentrations (ambient and elevated), with four trees in each treatment. The climate scenario included a doubling of [CO(2)] and a corresponding increase of 2-6 degrees C in temperature at the site depending on the season. Anatomical characteristics analyzed were annual earlywood, latewood and ring widths, intra-ring wood densities (earlywood, latewood and mean wood density), tracheid width, length, wall thickness, lumen diameter, wall thickness:lumen diameter ratio and mass per unit length (coarseness), and numbers of rays, resin canals and tracheids per xylem cross-sectional area. Elevated [CO(2)] increased ring width in four of six treatment years; earlywood width increased in the first two years and latewood width in the third year. Tracheid walls in both the earlywood and latewood tended to become thicker over the 6-year treatment period when temperature or [CO(2)] was elevated alone, whereas in the combined treatment they tended to become thinner relative to the tracheids of trees grown under ambient conditions. Latewood tracheid lumen diameters were larger in all the treatments relative to ambient conditions over the 6-year period, whereas lumen diameters in earlywood increased only in response to elevated [CO(2)] and were 3-6% smaller in the treatments with elevated temperature than in ambient conditions. Tracheid width, length and coarseness were greater in trees grown in elevated than in ambient temperature. The number of resin canals per mm(2) decreased in the elevated [CO(2)] treatment and increased in the elevated temperature treatments relative to ambient conditions. The treatments decreased the number of rays and tracheids per mm(2) of cross-sectional area, the greatest decrease occurring in the elevated [CO(2)] treatment. It seemed that xylem anatomy was affected more by elevated temperature than by elevated [CO(2)] and that the effects of temperature were confined to the earlywood.

  10. Prevalence of abnormal serum liver enzymes in patients with type 2 diabetes mellitus: a cross-sectional study from China.

    PubMed

    Chen, Shuang; Guo, Xiaofan; Chen, Yintao; Dong, Siyuan; Sun, Yingxian

    2016-11-01

    This cross-sectional study aimed to determine the prevalence of elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in Chinese type 2 diabetic patients and identify contributing risk factors. This cross-sectional study was conducted in rural areas of China, and 1,198 type 2 diabetic patients with complete data were recruited. Elevated ALT and AST levels were defined as >40 U/L. Prevalence of abnormal liver enzymes was analyzed and multivariable analysis was used to identify independent risk factors. 10.3% and 6.1% diabetic patients had elevated ALT and elevated AST, respectively. The prevalence of elevated liver enzymes was gender-related; it was 13.8% in men and 7.5% in women for elevated ALT, and 7.4% in men and 3.1% in women for elevated AST. High triglyceride was positively associated with both elevated ALT (OR 1.80, 95% CI 1.08-3.01, p = 0.024) and elevated AST (OR 2.24, 95%CI 1.08-4.65, p = 0.031), while taking anti-diabetes medicine was inversely related to both elevated ALT (OR 0.48, 95% CI 0.29-0.80, p = 0.005) and elevated AST (OR 0.37, 95% CI 0.17-0.82, p = 0.014). The risk of elevated ALT in diabetic patients increased with the presence of obesity (OR 2.54, 95% CI 1.07-6.01, p = 0.034), and was lower in women (OR 0.37, 95% CI 0.19-0.72, p = 0.003). Hypertension (OR 4.33, 95% CI 1.41-13.30, p = 0.011), current drinking status (OR 2.90, 95% CI 1.21-6.96, p = 0.017) and national minority (OR 3.26, 95%CI 1.31-8.12, p = 0.011) were risk factors for elevated AST. A relatively high prevalence of abnormal serum liver enzymes in diabetic patients was demonstrated in China, especially in males. More attention should be paid to preventing liver injuries in diabetic patients.

  11. Using Selective Drainage Methods to Extract Continuous Surface Flow from 1-Meter Lidar-Derived Digital Elevation Data

    USGS Publications Warehouse

    Poppenga, Sandra K.; Worstell, Bruce B.; Stoker, Jason M.; Greenlee, Susan K.

    2010-01-01

    Digital elevation data commonly are used to extract surface flow features. One source for high-resolution elevation data is light detection and ranging (lidar). Lidar can capture a vast amount of topographic detail because of its fine-scale ability to digitally capture the surface of the earth. Because elevation is a key factor in extracting surface flow features, high-resolution lidar-derived digital elevation models (DEMs) provide the detail needed to consistently integrate hydrography with elevation, land cover, structures, and other geospatial features. The U.S. Geological Survey has developed selective drainage methods to extract continuous surface flow from high-resolution lidar-derived digital elevation data. The lidar-derived continuous surface flow network contains valuable information for water resource management involving flood hazard mapping, flood inundation, and coastal erosion. DEMs used in hydrologic applications typically are processed to remove depressions by filling them. High-resolution DEMs derived from lidar can capture much more detail of the land surface than courser elevation data. Therefore, high-resolution DEMs contain more depressions because of obstructions such as roads, railroads, and other elevated structures. The filling of these depressions can significantly affect the DEM-derived surface flow routing and terrain characteristics in an adverse way. In this report, selective draining methods that modify the elevation surface to drain a depression through an obstruction are presented. If such obstructions are not removed from the elevation data, the filling of depressions to create continuous surface flow can cause the flow to spill over an obstruction in the wrong location. Using this modified elevation surface improves the quality of derived surface flow and retains more of the true surface characteristics by correcting large filled depressions. A reliable flow surface is necessary for deriving a consistently connected drainage network, which is important in understanding surface water movement and developing applications for surface water runoff, flood inundation, and erosion. Improved methods are needed to extract continuous surface flow features from high-resolution elevation data based on lidar.

  12. Selenium and mercury have a synergistic negative effect on fish reproduction.

    PubMed

    Penglase, S; Hamre, K; Ellingsen, S

    2014-04-01

    Selenium (Se) can reduce the negative impacts of mercury (Hg) toxicity on growth and survival, but little is known about how these two elements interact in reproduction. In the following study we explored the effects of organic Hg and Se on the growth, survival and reproduction of female zebrafish (Danio rerio). Fish were fed one of four diets from 73 until 226 dpf in a 2 × 2 factorial design, using selenomethionine (SeMet) and methylmercury (MeHg) as the Se and Hg sources, respectively. Each diet contained Se at either requirement (0.7 mg Se/kg DM) or elevated levels (10 mg Se/kgDM), and Hg at either low (0.05 mg Hg/kg DM) or elevated (12 mg Hg/kg DM) levels. Between 151 and 206 dpf the female fish were pairwise crossed against untreated male fish and the mating success, fecundity, embryo survival, and subsequent overall reproductive success were measured. Elevated dietary Se reduced Hg levels in both the adult fish and their eggs. Elevated dietary Hg and Se increased egg Se levels to a greater extent than when dietary Se was elevated alone. At elevated maternal intake levels, egg concentrations of Se and Hg reflected the maternal dietary levels and not the body burdens of the adult fish. Elevated dietary Hg reduced the growth and survival of female fish, but these effects were largely prevented with elevated dietary Se. Elevated dietary Se alone did not affect fish growth or survival. Compared to other treatments, elevated dietary Hg alone increased both mating and overall reproductive success with <100 days of exposure, but decreased these parameters with >100 days exposure. Elevated dietary Se decreased fecundity, embryo survival, and overall reproductive success. The combination of elevated Se and Hg had a synergistic negative effect on all aspects of fish reproduction compared to those groups fed elevated levels of either Se or Hg. Overall the data demonstrate that while increased dietary Se may reduce adverse effects of Hg on the growth and survival in adult fish, it can negatively affect fish reproductive potential, and the effect on reproduction is enhanced in the presence of elevated Hg. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Comparison of AltiKa and CryoSat-2 Elevation and Elevation Rates over the Amundsen Sea Sector

    NASA Astrophysics Data System (ADS)

    Otosaka, I.; Shepherd, A.; Hogg, A.

    2017-12-01

    Altimeters have been successfully used for more than two decades to observe changes in the ice sheet surface and to estimate the contribution of ice sheets to sea level rise. The Satellite for Argos and AltiKa (SARAL) was launched in February 2013 as a joint mission between the French space agency (CNES) and the Indian Space Research Organisation (ISRO). While the altimeters previously launched into space are operating at Ku-band (13.6 GHz), the altimeter on board SARAL, AltiKa, is the first instrument to operate at Ka-band (36.8 GHz). The higher frequency of AltiKa is expected to lead to reduced penetration of the radar signal into the snowpack, compared to Ku-band. A comparison of ice sheet elevation measurements recorded at the two frequencies may therefore provide useful information on surface and its scattering properties. In this study, we compare elevation and elevation rates recorded by AltiKa and CryoSat-2 between March 2013 and April 2017 over the Amundsen Sea Sector (ASS), one of the most rapidly changing sectors of West Antarctica. Elevation and elevation rates are computed within 5 km grid cells using a plane fit method, taking into account the contributions of topography and fluctuations in elevation and backscatter. The drifting orbit and imaging modes of CryoSat-2 result in 78,7 % sampling of the study area, whereas AltiKa samples 39,7 % due to its sparser orbit pattern and due to loss of signal in steeply sloping coastal margins. Over the study period, the root mean square difference between elevation and elevation change recorded at Ka-band and Ku-band were 40.3 m and 0.54 m/yr, respectively. While the broad spatial pattern of elevation change is well resolved by both satellites, data gaps along the Getz coastline may be partly responsible for the lower elevation change rate observed at Ka-band. We also compared CryoSat-2 and AltiKa to coincident airborne data from NASA's Operation IceBridge (OIB). The mean difference of elevation rate between space borne data and IceBridge data are respectively -0.09 m/yr and -0.08 m/yr at Ka and Ku band, highlighting the good capability of both CryoSat-2 and AltiKa to accurately map ice sheet elevation change.

  14. The Use of Sun Elevation Angle for Stereogrammetric Boreal Forest Height in Open Canopies

    NASA Technical Reports Server (NTRS)

    Montesano, Paul M.; Neigh, Christopher; Sun, Guoqing; Duncanson, Laura Innice; Van Den Hoek, Jamon; Ranson, Kenneth Jon

    2017-01-01

    Stereogrammetry applied to globally available high resolution spaceborne imagery (HRSI; less than 5 m spatial resolution) yields fine-scaled digital surface models (DSMs) of elevation. These DSMs may represent elevations that range from the ground to the vegetation canopy surface, are produced from stereoscopic image pairs (stereo pairs) that have a variety of acquisition characteristics, and have been coupled with lidar data of forest structure and ground surface elevation to examine forest height. This work explores surface elevations from HRSI DSMs derived from two types of acquisitions in open canopy forests. We (1) apply an automated mass-production stereogrammetry workflow to along-track HRSI stereo pairs, (2) identify multiple spatially coincident DSMs whose stereo pairs were acquired under different solar geometry, (3) vertically co-register these DSMs using coincident spaceborne lidar footprints (from ICESat-GLAS) as reference, and(4) examine differences in surface elevations between the reference lidar and the co-registered HRSI DSMs associated with two general types of acquisitions (DSM types) from different sun elevation angles. We find that these DSM types, distinguished by sun elevation angle at the time of stereo pair acquisition, are associated with different surface elevations estimated from automated stereogrammetry in open canopy forests. For DSM values with corresponding reference ground surface elevation from spaceborne lidar footprints in open canopy northern Siberian Larix forests with slopes less than10, our results show that HRSI DSM acquired with sun elevation angles greater than 35deg and less than 25deg (during snow-free conditions) produced characteristic and consistently distinct distributions of elevation differences from reference lidar. The former include DSMs of near-ground surfaces with root mean square errors less than 0.68 m relative to lidar. The latter, particularly those with angles less than 10deg, show distributions with larger differences from lidar that are associated with open canopy forests whose vegetation surface elevations are captured. Terrain aspect did not have a strong effect on the distribution of vegetation surfaces. Using the two DSM types together, the distribution of DSM-differenced heights in forests (6.0 m, sigma = 1.4 m) was consistent with the distribution of plot-level mean tree heights (6.5m, sigma = 1.2 m). We conclude that the variation in sun elevation angle at time of stereo pair acquisition can create illumination conditions conducive for capturing elevations of surfaces either near the ground or associated with vegetation canopy. Knowledge of HRSI acquisition solar geometry and snow cover can be used to understand and combine stereogrammetric surface elevation estimates to co-register rand difference overlapping DSMs, providing a means to map forest height at fine scales, resolving the vertical structure of groups of trees from spaceborne platforms in open canopy forests.

  15. Availability of food resources, distribution of invasive species, and conservation of a Hawaiian bird along a gradient of elevation

    USGS Publications Warehouse

    Banko, P.C.; Oboyski, P.T.; Slotterback, J.W.; Dougill, Steve J.; Goltz, Dan M.; Johnson, L.; Laut, M.E.; Murray, T.C.

    2002-01-01

    Aim: We evaluated how an elevation gradient affects: (1) the availability of food required by a specialist seed-eater, Loxioides bailleui Oustalet (Drepanidinae), or pallia, and hence the distribution of this endangered Hawaiian bird, and (2) the distribution of alien threats to Loxioides populations, their primary foods, and their dry-forest habitat, and hence strategies for their conservation. Location: We worked throughout the subalpine forest that encircles Mauna Kea Volcano, Hawai'i Island, but we focused our studies mainly on the western slope between 2000 and 3000 m elevation, where the gradient of elevation was greatest and palila were most abundant. Methods: We determined phenology and productivity patterns of the endemic dry-forest tree species, Sophora chrysophylla (Salisb.) Seem. (Fabaceae), or ma??mane, which provides Loxioides with most of their food, and another common endemic tree, Myoporum sandwicense A. Gray (Myoporaceae), or naio, which provides some resources, along a 786-m elevation gradient at monthly intervals for 10 years (Sophora only). We also determined the availability each month of moth larvae (Lepidoptera) for that were important in the diet of nestling and adult palila. In addition, we documented the incidence of parasitism on moth larvae by several wasp (Hymenoptera) and fly (Diptera) species, and we determined the distribution of predatory wasps and ants (Hymenoptera), which potentially threaten insect prey of birds. Percentage cover of alien grass species that pose fire threats in palila habitat and other weeds were assessed during one survey. Small mammal abundance and distribution were determined by trapping during three (rodent) or five (carnivore) surveys. Results: Sophora flower and seed (pod) availability varied predictably along the elevation gradient, with about 4 months separating peaks in reproduction at high and low elevations. This, together with highly variable production of flowers and pods within elevation strata, resulted in Sophora resources being available to Loxioides throughout the year on the western slope of Mauna Kea. Sophora produced flowers and pods more seasonally where gradients of elevation were short; thus, resources were available less consistently. In contrast, Myoporum produced flowers and fruits with little variation with respect to season or elevation. The availability of important insect prey of Loxioides was also related to elevation, in part because threats to Lepidoptera larvae from parasitic wasps were generally less at higher elevations. Threats to insect prey from predatory ants was also less at higher elevations but the abundance of predatory wasps was not related to elevation. Several weeds that pose the most serious threats to Loxioides habitat were more abundant at mid and low elevations, and alien grass cover was somewhat greater at mid elevation, thereby increasing fire risks in the centre of Loxioides habitat. Predatory mammals, in particular Felis catus Linnaeus, were common throughout the subalpine forest of Mauna Kea. However, Rattus rattus Linnaeus was rare, especially at higher elevations, whereas Mus musculus Linnaeus was more abundant at lower elevations. Main conclusions: Loxioides are concentrated in habitat that is distributed along a substantial gradient of elevation at least in part because food is available throughout the year and threats to food resources are less concentrated. To recover Loxioides elsewhere in its former range, habitats must be restored and alien threats reduced along extensive elevation gradients. Conservation along environmental gradients will likely benefit other Hawaiian birds that track the availability of food across landscapes or that have been stranded in the higher portions of their original ranges because of the greater impacts of alien diseases, predators, food competitors, and habitat stressors at lower elevations.

  16. Forest vegetation related to elevation in the White Mountains of New Hampshire

    Treesearch

    William B. Leak; Raymond E. Graber

    1974-01-01

    Maximum tree size and species composition are related to elevation on Mount Washington (disturbed by logging) and Mount Whiteface (uncut) in the White Mountains of New Hampshire. Species migrational trends and differences between the two mountains in species elevational limits indicate that both hardwoods and softwoods will move to higher elevations in areas where...

  17. ELEVATED CO2 AND ELEVATED TEMPERATURE AFFECT CARBON AND NITROGEN CONCENTRATIONS BUT NOT ACCUMULATION IN PSEUDOTSUGA MENZIESII SEEDLINGS

    EPA Science Inventory

    To determine the impact of climate change on concentrations and accumulation of C and N in trees, we grew Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) seedlings treated with ambient or elevated (+180 mol mol-1) CO2, and with ambient or elevated (+3.5 C) temperature for f...

  18. 29 CFR 780.711 - Exemption of mixed business applies only to country elevators.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Exemption of mixed business applies only to country elevators. 780.711 Section 780.711 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION... Elevator § 780.711 Exemption of mixed business applies only to country elevators. The language of section...

  19. 29 CFR 780.711 - Exemption of mixed business applies only to country elevators.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Exemption of mixed business applies only to country elevators. 780.711 Section 780.711 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION... Elevator § 780.711 Exemption of mixed business applies only to country elevators. The language of section...

  20. 29 CFR 780.711 - Exemption of mixed business applies only to country elevators.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Exemption of mixed business applies only to country elevators. 780.711 Section 780.711 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION... Elevator § 780.711 Exemption of mixed business applies only to country elevators. The language of section...

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