Science.gov

Sample records for ground control

  1. Remotely Sensed Ground Control Points

    NASA Astrophysics Data System (ADS)

    Hummel, P.

    2016-06-01

    Accurate ground control is required to georeferenced airborne and spaceborne images. The production of ortho-photogrammetric data requires ground control that is traditionally provided as Ground Control Points (GCPs) by GNSS measurements in the field. However, it can be difficult to acquire accurate ground control points due to required turn-around time, high costs or impossible access. CompassData, Inc. a specialist in ground control, has expanded its service to deliver Remotely Sensed Ground Control Points (RSGCPs®). TerraSAR-X and TanDEM-X are two satellites with such high accuracy of their orbital positions and SAR data that RSGCPs® can be produced to a sub-meter quality depending on certain parameters and circumstances. The technology and required parameters are discussed in this paper as well as the resulting accuracies.

  2. Ground Control System Description Document

    SciTech Connect

    Eric Loros

    2001-07-31

    The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System

  3. Ground control for highwall mining

    SciTech Connect

    Zipf, R.K.; Mark, C.

    2007-09-15

    Perhaps the greatest risk to both equipment and personnel associated with highwall mining is from ground control. The two most significant ground control hazards are rock falls from highwall and equipment entrapment underground. In the central Appalachians, where the majority of highwall mining occurs in the USA, hillseams (or mountain cracks) are the most prominent structure that affects highwall stability. The article discusses measures to minimise the risk of failure associated with hillstreams. A 'stuck' or trapped highwall miner, and the ensuring retrieval or recovery operation, can be extremely disruptive to the highwall mining process. Most entrapment, are due to roof falls in the hole. The options for recovery are surface retrieval, surface excavation or underground recovery. Proper pillar design is essential to maintain highwall stability and prevent entrapments. NIOSH has developed the Analysis of Retreat Mining Pillar stability-Highwall Mining (ARMPS-HWM) computer program to help mine planners with this process. 10 figs.

  4. Ground Control for Emplacement Drifts for LA

    SciTech Connect

    Y. Sun

    2004-07-09

    The purpose of this calculation is to analyze the stability of repository emplacement drifts during the preclosure period, and to provide a final ground support method for emplacement drifts for the License Application (LA). The scope of the work includes determination of input parameter values and loads, selection of appropriate process and methods for the calculation, application of selected methods, such as empirical or analytical, to the calculation, development and execution of numerical models, and evaluation of results. Results from this calculation are limited to use for design of the emplacement drifts and the final ground support system installed in these drifts. The design of non-emplacement openings and their ground support systems is covered in the ''Ground Control for Non-Emplacement Drifts for LA'' (BSC 2004c).

  5. Ground test for vibration control demonstrator

    NASA Astrophysics Data System (ADS)

    Meyer, C.; Prodigue, J.; Broux, G.; Cantinaud, O.; Poussot-Vassal, C.

    2016-09-01

    In the objective of maximizing comfort in Falcon jets, Dassault Aviation is developing an innovative vibration control technology. Vibrations of the structure are measured at several locations and sent to a dedicated high performance vibration control computer. Control laws are implemented in this computer to analyse the vibrations in real time, and then elaborate orders sent to the existing control surfaces to counteract vibrations. After detailing the technology principles, this paper focuses on the vibration control ground demonstration that was performed by Dassault Aviation in May 2015 on Falcon 7X business jet. The goal of this test was to attenuate vibrations resulting from fixed forced excitation delivered by shakers. The ground test demonstrated the capability to implement an efficient closed-loop vibration control with a significant vibration level reduction and validated the vibration control law design methodology. This successful ground test was a prerequisite before the flight test demonstration that is now being prepared. This study has been partly supported by the JTI CleanSky SFWA-ITD.

  6. Intelligent resources for satellite ground control operations

    NASA Technical Reports Server (NTRS)

    Jones, Patricia M.

    1994-01-01

    This paper describes a cooperative approach to the design of intelligent automation and describes the Mission Operations Cooperative Assistant for NASA Goddard flight operations. The cooperative problem solving approach is being explored currently in the context of providing support for human operator teams and also in the definition of future advanced automation in ground control systems.

  7. Ground Control for Emplacement Drifts for SR

    SciTech Connect

    Y. Sun

    2000-04-07

    This analysis demonstrates that a satisfactory ground control system can be designed for the Yucca Mountain site, and provides the technical basis for the design of ground support systems to be used in repository emplacement and non-emplacement drifts. The repository ground support design was based on analytical methods using acquired computer codes, and focused on the final support systems. A literature review of case histories, including the lessons learned from the design and construction of the ESF, the studies on the seismic damages of underground openings, and the use of rock mass classification systems in the ground support design, was conducted (Sections 6.3.4 and 6.4). This review provided some basis for determining the inputs and methodologies used in this analysis. Stability of the supported and unsupported emplacement and non-emplacement drifts was evaluated in this analysis. The excavation effects (i.e., state of the stress change due to excavation), thermal effects (i.e., due to heat output from waste packages), and seismic effects (i.e., from potential earthquake events) were evaluated, and stress controlled modes of failure were examined for two in situ stress conditions (k_0=0.3 and 1.0) using rock properties representing rock mass categories of 1 and 5. Variation of rock mass units such as the non-lithophysal (Tptpmn) and lithophysal (Tptpll) was considered in the analysis. The focus was on the non-lithophysal unit because this unit appears to be relatively weaker and has much smaller joint spacing. Therefore, the drift stability and ground support needs were considered to be controlled by the design for this rock unit. The ground support systems for both emplacement and non-emplacement drifts were incorporated into the models to assess their performance under in situ, thermal, and seismic loading conditions. Both continuum and discontinuum modeling approaches were employed in the analyses of the rock mass behavior and in the evaluation of the

  8. Limits to ground control in autonomous spacecraft

    NASA Technical Reports Server (NTRS)

    Wan, Alfred D. M.; Braspenning, Peter J.; Vreeswijk, Gerrard A. W.

    1995-01-01

    In this paper the autonomy concept used by ESA and NASA is critically evaluated. Moreover, a more proper ground control/spacecraft organizational structure is proposed on the basis of a new, more elaborated concept of autonomy. In an extended theoretical discussion its definitional properties and functionalities are established. The rather basic property of adaptivity leads to the categorization of behaviour into the modes of satisfaction and avoidance behaviour. However, the autonomy property with the most profound consequences is goal-robustness. The mechanism that implements goal-robustness tests newly generated goals and externally received goals on consistency with high-level goals. If goals appear not to be good instantiations or more acceptable replacements of existing goals, they are rejected. This means that ground control has to cooperate with the spacecraft instead of (intermittently) commanding it.

  9. CLASSIFICATION OF MGR GROUND CONTROL SYSTEM

    SciTech Connect

    R.J. Garrett

    1999-08-31

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) ground control system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333PY ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998).

  10. Guidance and control for unmanned ground vehicles

    NASA Astrophysics Data System (ADS)

    Bateman, Peter J.

    1994-06-01

    Techniques for the guidance, control, and navigation of unmanned ground vehicles are described in terms of the communication bandwidth requirements for driving and control of a vehicle remote from the human operator. Modes of operation are conveniently classified as conventional teleoperation, supervisory control, and fully autonomous control. The fundamental problem of maintaining a robust non-line-of-sight communications link between the human controller and the remote vehicle is discussed, as this provides the impetus for greater autonomy in the control system and the greatest scope for innovation. While supervisory control still requires the man to be providing the primary navigational intelligence, fully autonomous operation requires that mission navigation is provided solely by on-board machine intelligence. Methods directed at achieving this performance are described using various active and passive sensing of the terrain for route navigation and obstacle detection. Emphasis is given to TV imagery and signal processing techniques for image understanding. Reference is made to the limitations of current microprocessor technology and suitable computer architectures. Some of the more recent control techniques involve the use of neural networks, fuzzy logic, and data fusion and these are discussed in the context of road following and cross country navigation. Examples of autonomous vehicle testbeds operated at various laboratories around the world are given.

  11. Coal mine ground control. 3rd ed.

    SciTech Connect

    Peng, S.S.

    2008-09-15

    The third edition not only completely revises and updates the original subject areas, but also is broadened to include a number of new topics such as high horizontal stresses, computer modeling, and highwall stability. The subject areas covered in this book define the current field of coal mine ground control, except for the recently emerging topic of mine seals and some conventional subjects such as coal/rock cutting and impoundment dams. It contains 1,134 references from all published sources, and archived since 1876.

  12. TACSAT ground control and data collection

    NASA Astrophysics Data System (ADS)

    Cochrane, C. G.

    1993-02-01

    This paper addresses the concept of a satellite based system serving the needs of tactical users for direct access to communications and various forms of surveillance. Such a system must take account of the most effective methods for deployment and maintenance during its intended period of operation. In terms of the mission needs, the Tactical Satellite System (TACSAT) is required to provide the services for tactical users over a relatively small region of maybe some 1000-2000 km diameter. Also, the concept is likely to involve relatively short periods of operation of about 3 to 6 months for a typical operation scenario. The paper, therefore, addresses a system concept in which the emphasis is placed on reducing the scale of the logistics involved in the deployment of TACSAT elements and simplifying the ground operations and facilities necessary for the users to gain access to the services provided. This paper addresses the following: (1) the need for 'launch on demand'; (2) the possibility of launches being directly under the control of the area commander; (3) operating concepts for TACSATs, comparing the approach of launch-via-residual-mass as part of a larger mission, not dedicated to the TACSAT mission with the approach of dedicated, launch-on-demand; (4) identification of information flow requirements for TACSAT integrity and status evaluation and for surveillance data recovery; (5) determination of technical and cost drivers influencing the form and cost of ground installation and logistic issues; (6) integration of TACSAT facilities and services with other communications and surveillance systems available to the Tactical Commander; and (7) investigation of techniques minimize the ground control and data collection overhead.

  13. Emissions control for ground power gas turbines

    NASA Technical Reports Server (NTRS)

    Rudney, R. A.; Priem, R. J.; Juhasz, A. J.; Anderson, D. N.; Mroz, T. S.; Mularz, E. J.

    1977-01-01

    The similarities and differences of emissions reduction technology for aircraft and ground power gas turbines is described. The capability of this technology to reduce ground power emissions to meet existing and proposed emissions standards is presented and discussed. Those areas where the developing aircraft gas turbine technology may have direct application to ground power and those areas where the needed technology may be unique to the ground power mission are pointed out. Emissions reduction technology varying from simple combustor modifications to the use of advanced combustor concepts, such as catalysis, is described and discussed.

  14. Proceedings, 25th international conference on ground control in mining

    SciTech Connect

    Peng, S.S.; Mark, C.; Finfinger, G.; Tadolini, S.; Wahab Khair, A.; Heasley, K.; Luo, Y.

    2006-07-01

    Topics covered include: computer and physical modelling; geology in ground control; geophysics in ground control; ground control; impoundments stability; longwall gateroad support design; longwall operations; longwall shields and standing supports; mine design; multiple-seam mining interactions; pillar and pillar extraction; roof bolting; roof bolting - resin; and subsidence. Most of the topics include a retrospective paper which summarises the progress of the subject field during the past 25 years.

  15. Onboard utilization of ground control points for image correction. Volume 3: Ground control point simulation software design

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The software developed to simulate the ground control point navigation system is described. The Ground Control Point Simulation Program (GCPSIM) is designed as an analysis tool to predict the performance of the navigation system. The system consists of two star trackers, a global positioning system receiver, a gyro package, and a landmark tracker.

  16. Frozen Ground Controls on Hydrological Processes

    NASA Astrophysics Data System (ADS)

    Hinzman, L. D.; Kane, D. L.; Woo, M. K.

    2015-12-01

    Frozen ground establishes a unique discipline of hydrologic science where the hydrologic regime is intimately coupled with the thermal regime to the extent that one may not be completely understood without correct characterization of the other. In permafrost regions, material properties may change drastically on a scale of centimeters to meters, particularly in the vertical dimension due to distinct changes in soil and thermal characteristics. Properties may vary just as dramatically in the horizontal dimension across the boundary of discontinuous permafrost. Although the spatial extent of permafrost changes on relatively slow time scales in response to disturbance or a changing climate, this too introduces an added level of complexity. Permafrost may nearly eliminate the interactions between near-surface and sub-permafrost aquifers, which in essence defines the hydrologic response of every watershed that is directly influenced by permafrost. Even though the principles governing water movement in permafrost areas are the same as those in more temperate regions, interactions of extremes in climate and the land surface characteristics render permafrost hydrology different from the hydrology of temperate latitudes. Ice-rich permafrost prevents deep percolation of rainfall or snowmelt water, often maintaining a moist to saturated active layer above the permafrost table. Most hydrologic activities are confined above-ground or in the thin active layer, which supplies summer moisture for baseflow and/or plant transpiration. Limited storage capacity of the thawed active layer does not support extended baseflow in a stream, though the proportion of baseflow increases as the percentage of permafrost extent decreases. In areas where permafrost is discontinuous or where it has thawed substantially near the surface, local hydrology may display a markedly different character as there are stronger exchanges between the surface water and the ground water system, or water may drain

  17. Ground test accelerator control system software

    SciTech Connect

    Burczyk, L.; Dalesio, R.; Dingler, R.; Hill, J.; Howell, J.A.; Kerstiens, D.; King, R.; Kozubal, A.; Little, C.; Martz, V.; Rothrock, R.; Sutton, J.

    1988-01-01

    The GTA control system provides an environment in which the automation of a state-of-the-art accelerator can be developed. It makes use of commercially available computers, workstations, computer networks, industrial I/O equipment, and software. This system has built-in supervisory control (like most accelerator control systems), tools to support continuous control (like the process control industry), and sequential control for automatic startup and fault recovery (like few other accelerator control systems). Several software tools support these levels of control: a real-time operating system (VxWorks) with a real-time kernel (VRTX), a configuration database, a sequencer, and a graphics editor. VxWorks supports multitasking, fast context-switching, and preemptive scheduling. VxWorks/VRTX is a network-based development environment specifically designed to work in partnership with the UNIX operating system. A database provides the interface to the accelerator components. It consists of a run time library and a database configuration and editing tool. A sequencer initiates and controls the operation of all sequence programs (expressed as state programs). A graphics editor gives the user the ability to create color graphic displays showing the state of the machine in either text or graphics form. 11 refs., 2 figs.

  18. Grounding cognitive control in associative learning.

    PubMed

    Abrahamse, Elger; Braem, Senne; Notebaert, Wim; Verguts, Tom

    2016-07-01

    Cognitive control covers a broad range of cognitive functions, but its research and theories typically remain tied to a single domain. Here we outline and review an associative learning perspective on cognitive control in which control emerges from associative networks containing perceptual, motor, and goal representations. Our review identifies 3 trending research themes that are shared between the domains of conflict adaptation, task switching, response inhibition, and attentional control: Cognitive control is context-specific, can operate in the absence of awareness, and is modulated by reward. As these research themes can be envisaged as key characteristics of learning, we propose that their joint emergence across domains is not coincidental but rather reflects a (latent) growth of interest in learning-based control. Associative learning has the potential for providing broad-scaled integration to cognitive control theory, and offers a promising avenue for understanding cognitive control as a self-regulating system without postulating an ill-defined set of homunculi. We discuss novel predictions, theoretical implications, and immediate challenges that accompany an associative learning perspective on cognitive control. (PsycINFO Database Record PMID:27148628

  19. Computer-assisted ground control management system. Information circular/1994

    SciTech Connect

    Conover, D.P.; McDonnell, J.P.; Hanna, K.

    1994-01-01

    The U.S. Bureau of Mines (USBM) has developed a computer-assisted Ground Control Management System (GCMS) for near real-time evaluation of underground coal mine ground conditions. The GCMS combines existing mine monitoring system and sensor technology with automated computer analysis techniques to enhance the acquisition, analysis, and display of geostructural data. The GCMS, which combines mine structure data with other information, such as geologic conditions and mine layout, has provided information on mining-induced stress transfer and pressure buildup associated with several ground control events. Real-time collection, processing, and analysis of mine structure and shield pressure information has proven to be an effective method for assessing near-face ground conditions while mining progresses. The GCMS provides the mine operator with information to rapidly identify and manage potentially hazardous ground conditions while mining is in progress.

  20. Ground adaptive standing controller for a powered transfemoral prosthesis.

    PubMed

    Lawson, Brian E; Varol, Huseyin Atakan; Goldfarb, Michael

    2011-01-01

    The scope of this work is the design and verification of a new standing controller for a powered knee and ankle prosthesis. The controller is based upon a finite-state impedance control approach previously developed by the authors. The controller provides a comprehensive standing behavior that incorporates ground adaptation for unlevel terrain. An amputee subject tested the controller with a powered prosthesis for a variety of standing conditions. Results indicate that the powered prosthesis can estimate the ground slope within ±1 degree over a range of ±15 degrees, and that it can provide appropriate joint impedances for standing on slopes within this range.

  1. A New Definition for Ground Control

    NASA Technical Reports Server (NTRS)

    2002-01-01

    LandForm(R) VisualFlight(R) blends the power of a geographic information system with the speed of a flight simulator to transform a user's desktop computer into a "virtual cockpit." The software product, which is fully compatible with all Microsoft(R) Windows(R) operating systems, provides distributed, real-time three-dimensional flight visualization over a host of networks. From a desktop, a user can immediately obtain a cockpit view, a chase-plane view, or an airborne tracker view. A customizable display also allows the user to overlay various flight parameters, including latitude, longitude, altitude, pitch, roll, and heading information. Rapid Imaging Software sought assistance from NASA, and the VisualFlight technology came to fruition under a Phase II SBIR contract with Johnson Space Center in 1998. Three years later, on December 13, 2001, Ken Ham successfully flew NASA's X-38 spacecraft from a remote, ground-based cockpit using LandForm VisualFlight as part of his primary situation awareness display in a flight test at Edwards Air Force Base, California.

  2. Assessing control strategies for ground level ozone

    NASA Astrophysics Data System (ADS)

    Sule, Neelesh Vijay

    2009-12-01

    Developing cost effective control strategies for ozone has been a challenge to air quality modelers. Conventionally, the control strategies are applied across-the board to the region. The main aim of this research was to develop a Decision-Making Framework (DMF) for evaluating and optimizing the selection of ozone control strategies. Conventional across-the-board reductions conduct emission reductions uniformly throughout the region and throughout the day. By contrast, this dissertation studied targeted reductions, in which emission sources of various types are reduced at various times and locations. The proposed DMF comprised of four phases: (1) Initialization, (2) Mining, (3) Metamodeling, and (4) Optimization. This DMF was tested on a DFW 2009 future case episode which was based on a 10-day episode from August 13-22, 1999. 612 emission variables were identified in three source categories viz. point, area (includes non-road) and line (on-road). The emission control regions and time periods along with ozone monitoring regions and time periods were defined. The control strategy emission reductions and costs were also identified in this stage. Initially a Latin hypercube experimental design was setup to organize 30 sets of emission reduction scenarios to be modeled using the photochemical model CAMx. Data mining reduced the number of variables to a maximum of 126. A second Latin hypercube was setup to organize another 30 emission reduction scenarios for the significant variables identified by data mining. Metamodels were developed for ozone from the 60 CAMx runs using linear regression models constructed with the stepwise model selection method. Stepwise regression further reduced the number of variables. The metamodels were implemented in optimization as a surrogate for time-intensive CAMx modeling. Appropriate constraints were calculated for each metamodel to ensure that it satisfied EPA's MAT. The optimization was formulated to find the most cost effective

  3. Active control landing gear for ground loads alleviation

    NASA Technical Reports Server (NTRS)

    Mcgehee, J. R.

    1985-01-01

    An active landing gear has been created by connecting the hydraulic piston in an oleo strut to a hydraulic supply. A controller modulates the pressure in the oleo to achieve the desired dynamic characteristics. Tests on ground rigs (documented by a film) have demonstrated the successful alleviation of induced structural ground loads and the next step will be a flight test using a fighter aircraft.

  4. Deposit control in ground water remediation equipment

    SciTech Connect

    Horn, B.; Soeder, K.

    1995-12-31

    Remedial actions at all types of hazardous waste sites require the implementation of various water treatment technologies. Though the many groundwater treatment technologies are constantly developing, some age-old problems associated with handling any water remains. These operating problems include deposition of naturally occurring inorganic solutes such as iron, manganese, calcium and fouling by indigenous micro-organisms. Fouling of air stripping towers is a common example of this phenomenon. Virtually all groundwater treatment systems experience some degree of operating impediment from this cause. Some systems may take years for deposits to become problems, but many systems become inoperable within weeks or months. Recently released studies by the American Petroleum Institute show that deposit control is the most common operation problem causing remediation system failure. Such failures result in greatly increased operation & maintenance costs and non compliance with regulatory mandates.

  5. Ground Control Station Development for the Dexterous Orbital Servicing System

    NASA Technical Reports Server (NTRS)

    Backes, P. G.; Tharp, G.; Bon, B.; Hayati, S.; Phan, L.

    1995-01-01

    The Dexterous Orbital Servicing System (DOSS) flight test program is being developed by NASA to verify the ability to utilize telerobotics for servicing Space Station Alpha. The development of a ground control station for Earth based control of DOSS is described. This flight test program provides a manipulator which is mounted on a multi-purpose experiment support structure in a Space Shuttle bay.

  6. Configurable technology development for reusable control and monitor ground systems

    NASA Technical Reports Server (NTRS)

    Uhrlaub, David R.

    1994-01-01

    The control monitor unit (CMU) uses configurable software technology for real-time mission command and control, telemetry processing, simulation, data acquisition, data archiving, and ground operations automation. The base technology is currently planned for the following control and monitor systems: portable Space Station checkout systems; ecological life support systems; Space Station logistics carrier system; and the ground system of the Delta Clipper (SX-2) in the Single-Stage Rocket Technology program. The CMU makes extensive use of commercial technology to increase capability and reduce development and life-cycle costs. The concepts and technology are being developed by McDonnell Douglas Space and Defense Systems for the Real-Time Systems Laboratory at NASA's Kennedy Space Center under the Payload Ground Operations Contract. A second function of the Real-Time Systems Laboratory is development and utilization of advanced software development practices.

  7. The ACTS NASA Ground Station/Master Control Station

    NASA Technical Reports Server (NTRS)

    Meadows, David N.

    1992-01-01

    Two of the major components of the ACTS Ground Segment are the NASA Ground Station (NGS) and the Master Control Station (MCS), colocated at the NASA Lewis Research Center. Essentially, the NGS provides the communications links by which the MCS performs its various network control and monitoring functions. The NGS also provides telecommunications links capable of transmission/reception of up to approximately 70 Mbit/s of digital telephonic traffic. Operating as a system, the entire complex of equipment is referred to as the NGS/MCS. This paper provides an 'as-built' description of the NGS/MCS as a system.

  8. Ground controlled robotic assembly operations for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Parrish, Joseph C.

    1991-01-01

    A number of dextrous robotic systems and associated positioning and transportation devices are available on Space Station Freedom (SSF) to perform assembly tasks that would otherwise need to be performed by extravehicular activity (EVA) crewmembers. The currently planned operating mode for these robotic systems during the assembly phase is teleoperation by intravehicular activity (IVA) crewmembers. While this operating mode is less hazardous and expensive than manned EVA operations, and has insignificant control loop time delays, the amount of IVA time available to support telerobotic operations is much less than the anticipated requirements. Some alternative is needed to allow the robotic systems to perform useful tasks without exhausting the available IVA resources; ground control is one such alternative. The issues associated with ground control of SSF robotic systems to alleviate onboard crew time availability constraints are investigated. Key technical issues include the effect of communication time delays, the need for safe, reliable execution of remote operations, and required modifications to the SSF ground and flight system architecture. Time delay compensation techniques such as predictive displays and world model-based force reflection are addressed and collision detection and avoidance strategies to ensure the safety of the on-orbit crew, Orbiter, and SSF are described. Although more time consuming and difficult than IVA controlled teleoperations or manned EVA, ground controlled telerobotic operations offer significant benefits during the SSF assembly phase, and should be considered in assembly planning activities.

  9. VIEW OF CONTROL PANEL (RIGHT) AT THE GROUND FLOOR LEVEL ...

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

    VIEW OF CONTROL PANEL (RIGHT) AT THE GROUND FLOOR LEVEL AND SIDE OF THE MISSILE TUBE (FOREGROUND). VIEW FACING EAST - U.S. Naval Base, Pearl Harbor, Ford Island Polaris Missile Lab & U.S. Fleet Ballistic Missile Submarine Training Center, Between Lexington Boulvevard and the sea plane ramps on the southwest side of Ford Island, Pearl City, Honolulu County, HI

  10. 24 CFR 3285.204 - Ground moisture control.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Ground moisture control. 3285.204 Section 3285.204 Housing and Urban Development Regulations Relating to Housing and Urban Development... URBAN DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Site Preparation § 3285.204...

  11. Ground vehicle control at NIST: From teleoperation to autonomy

    NASA Technical Reports Server (NTRS)

    Murphy, Karl N.; Juberts, Maris; Legowik, Steven A.; Nashman, Marilyn; Schneiderman, Henry; Scott, Harry A.; Szabo, Sandor

    1994-01-01

    NIST is applying their Real-time Control System (RCS) methodology for control of ground vehicles for both the U.S. Army Researh Lab, as part of the DOD's Unmanned Ground Vehicles program, and for the Department of Transportation's Intelligent Vehicle/Highway Systems (IVHS) program. The actuated vehicle, a military HMMWV, has motors for steering, brake, throttle, etc. and sensors for the dashboard gauges. For military operations, the vehicle has two modes of operation: a teleoperation mode--where an operator remotely controls the vehicle over an RF communications network; and a semi-autonomous mode called retro-traverse--where the control system uses an inertial navigation system to steer the vehicle along a prerecorded path. For the IVHS work, intelligent vision processing elements replace the human teleoperator to achieve autonomous, visually guided road following.

  12. 7th international conference on ground control in mining

    SciTech Connect

    Peng, S.S.

    1988-01-01

    These proceedings contain 38 papers describing strata control, rock mechanics, and ground subsidence, especially in longwall mining. Other mining methods discussed include room and pillar mining, retreat mining, caving mining, and auger underground mining. Design, performance, and mathematical models of support pillars and other types of strata support systems are described. Most of the studies were done in US coal mines, but several papers describing strata control in India, China, South Africa, and Taiwan are included. All papers have been indexed separately.

  13. Ground-water contamination and legal controls in Michigan

    USGS Publications Warehouse

    Deutsch, Morris

    1963-01-01

    The great importance of the fresh ground-water resources of Michigan is evident because 90 percent of the rural and about 70 percent of the total population of the State exclusive of the Detroit metropolitan area are supplied from underground sources. The water-supply and public-health problems that have been caused by some cases of ground-water contamination in the State illustrate the necessity of protecting this vital resource.Manmade and natural contaminants, including many types of chemical and organic matter, have entered many of the numerous aquifers of the State. Aquifers have been contaminated by waste-laden liquids percolating from the surface or from the zone of aeration and by direct injection to the aquifer itself. Industrial and domestic wastes, septic tanks, leaking sewers, flood waters or other poor quality surface waters, mine waters, solids stored or spread at the surface, and even airborne wastes all have been sources of ground-water contamination in Michigan. In addition, naturally occurring saline waters have been induced into other aquifers by overpumping or unrestricted flow from artesian wells, possibly by dewatering operations, and by the deepening of surface stream channels. Vertical migration of saline waters through open holes from formations underlying various important aquifers also has spoiled some of the fresh ground waters in the State. In spite of the contamination that has occurred, however, the total amount of ground water that has been spoiled is only a small part of the total resource. Neither is the contamination so widespread as that of the surface streams of Michigan.Overall legal authority to control most types of ground-water contamination in the State has been assigned by the Michigan Legislature to the Water Resources Commission, although the Department of Conservation and the Health Department also exercise important water-pollution control functions. The Michigan Supreme Court, in an important case upholding the power

  14. Active control landing gear for ground load alleviation

    NASA Technical Reports Server (NTRS)

    Mcgehee, J. R.; Morris, D. L.

    1985-01-01

    Results of analytical and experimental investigations of a series-hydraulic active control landing gear show that such a gear is feasible when using existing hardware and is very effective in reducing loads, relative to those generated by a conventional (passive year) gear, transmitted to the airframe during ground operations. Analytical results obtained from an active gear, flexible aircraft, take-off and landing analysis are in good agreement with experimental data and indicate that the analysis is a valid tool for study and initial design of series-hydraulic active control landing gears. An analytical study of a series-hydraulic active control main landing gear on an operational supersonic airplane shows that the active gear has the potential for improving the dynamic response of the aircraft and significantly reducing structural fatigue damage during ground operations.

  15. Coherent Control of Ground State NaK Molecules

    NASA Astrophysics Data System (ADS)

    Yan, Zoe; Park, Jee Woo; Loh, Huanqian; Will, Sebastian; Zwierlein, Martin

    2016-05-01

    Ultracold dipolar molecules exhibit anisotropic, tunable, long-range interactions, making them attractive for the study of novel states of matter and quantum information processing. We demonstrate the creation and control of 23 Na40 K molecules in their rovibronic and hyperfine ground state. By applying microwaves, we drive coherent Rabi oscillations of spin-polarized molecules between the rotational ground state (J=0) and J=1. The control afforded by microwave manipulation allows us to pursue engineered dipolar interactions via microwave dressing. By driving a two-photon transition, we are also able to observe Ramsey fringes between different J=0 hyperfine states, with coherence times as long as 0.5s. The realization of long coherence times between different molecular states is crucial for applications in quantum information processing. NSF, AFOSR- MURI, Alfred P. Sloan Foundation, DARPA-OLE

  16. Ground vibration test of the laminar flow control JStar airplane

    NASA Technical Reports Server (NTRS)

    Kehoe, M. W.; Cazier, F. W., Jr.; Ellison, J. F.

    1985-01-01

    A ground vibration test was conducted on a Lockheed JetStar airplane that had been modified for the purpose of conducting laminar flow control experiments. The test was performed prior to initial flight flutter tests. Both sine-dwell and single-point-random excitation methods were used. The data presented include frequency response functions and a comparison of mode frequencies and mode shapes from both methods.

  17. ALLY: An operator's associate for satellite ground control systems

    NASA Technical Reports Server (NTRS)

    Bushman, J. B.; Mitchell, Christine M.; Jones, P. M.; Rubin, K. S.

    1991-01-01

    The key characteristics of an intelligent advisory system is explored. A central feature is that human-machine cooperation should be based on a metaphor of human-to-human cooperation. ALLY, a computer-based operator's associate which is based on a preliminary theory of human-to-human cooperation, is discussed. ALLY assists the operator in carrying out the supervisory control functions for a simulated NASA ground control system. Experimental evaluation of ALLY indicates that operators using ALLY performed at least as well as they did when using a human associate and in some cases even better.

  18. Study to eliminate ground resonance using active controls

    NASA Technical Reports Server (NTRS)

    Straub, F. K.

    1984-01-01

    The effectiveness of active control blade feathering in increasing rotor body damping and the possibility to eliminate ground resonance instabilities were investigated. An analytical model representing rotor flapping and lead-lag degrees of freedom and body pitch, roll, longitudinal and lateral motion is developed. Active control blade feathering is implemented as state variable feedback through a conventional swashplate. The influence of various feedback states, feedback gain, and weighting between the cyclic controls is studied through stability and response analyses. It is shown that blade cyclic inplane motion, roll rate and roll acceleration feedback can add considerable damping to the system and eliminate ground resonance instabilities, which the feedback phase is also a powerful parameter, if chosen properly, it maximizes augmentation of the inherent regressing lag mode damping. It is shown that rotor configuration parameters, like blade root hinge offset, flapping stiffness, and precone considerably influence the control effectiveness. It is found that active control is particularly powerful for hingeless and bearingless rotor systems.

  19. Ground Operations Autonomous Control and Integrated Health Management

    NASA Technical Reports Server (NTRS)

    Daniels, James

    2014-01-01

    The Ground Operations Autonomous Control and Integrated Health Management plays a key role for future ground operations at NASA. The software that is integrated into this system is called G2 2011 Gensym. The purpose of this report is to describe the Ground Operations Autonomous Control and Integrated Health Management with the use of the G2 Gensym software and the G2 NASA toolkit for Integrated System Health Management (ISHM) which is a Computer Software Configuration Item (CSCI). The decision rationale for the use of the G2 platform is to develop a modular capability for ISHM and AC. Toolkit modules include knowledge bases that are generic and can be applied in any application domain module. That way, there's a maximization of reusability, maintainability, and systematic evolution, portability, and scalability. Engine modules are generic, while application modules represent the domain model of a specific application. Furthermore, the NASA toolkit, developed since 2006 (a set of modules), makes it possible to create application domain models quickly, using pre-defined objects that include sensors and components libraries for typical fluid, electrical, and mechanical systems.

  20. Factors controlling tungsten concentrations in ground water, Carson Desert, Nevada

    USGS Publications Warehouse

    Seiler, R.L.; Stollenwerk, K.G.; Garbarino, J.R.

    2005-01-01

    An investigation of a childhood leukemia cluster by US Centers for Disease Control and Prevention revealed that residents of the Carson Desert, Nevada, are exposed to high levels of W and this prompted an investigation of W in aquifers used as drinking water sources. Tungsten concentrations in 100 ground water samples from all aquifers used as drinking water sources in the area ranged from 0.27 to 742 ??g/l. Ground water in which W concentrations exceed 50 ??g/l principally occurs SE of Fallon in a geothermal area. The principal sources of W in ground water are natural and include erosion of W-bearing mineral deposits in the Carson River watershed upstream of Fallon, and, possibly, upwelling geothermal waters. Ground water in the Fallon area is strongly reducing and reductive dissolution of Fe and Mn oxyhydroxides may be releasing W; however, direct evidence that the metal oxides contain W is not available. Although W and Cl concentrations in the Carson River, a lake, and water from many wells, appear to be controlled by evaporative concentration, evaporation alone cannot explain the elevated W concentrations found in water from some of the wells. Concentrations of W exceeding 50 ??g/l are exclusively associated with Na-HCO3 and Na-Cl water types and pH > 8.0; in these waters, geochemical modeling indicates that W exhibits <10% adsorption. Tungsten concentrations are strongly and positively correlated with As, B, F, and P, indicating either common sources or common processes controlling their concentrations. Geochemical modeling indicates W concentrations are consistent with pH-controlled adsorption of W. The geochemical model PHREEQC was used to calculate IAP values, which were compared with published Ksp values for primary W minerals. FeWO4, MnWO4, Na2WO4, and MgWO4 were undersaturated and CaWO4 and SrWO 4 were approaching saturation. These conclusions are tentative because of uncertainty in the thermodynamic data. The similar behavior of As and W observed in

  1. SILEX ground segment control facilities and flight operations

    NASA Astrophysics Data System (ADS)

    Demelenne, Benoit; Tolker-Nielsen, Toni; Guillen, Jean-Claude

    1999-04-01

    The European Space Agency is going to conduct an inter orbit link experiment which will connect a low Earth orbiting satellite and a Geostationary satellite via optical terminals. This experiment has been called SILEX (Semiconductor Inter satellite Link Experiment). Two payloads have been built. One called PASTEL (PASsager de TELecommunication) has been embarked on the French Earth observation satellite SPOT4 which has been launched successfully in March 1998. The future European experimental data relay satellite ARTEMIS (Advanced Relay and TEchnology MISsion), which will route the data to ground, will carry the OPALE terminal (Optical Payload Experiment). The European Space Agency is responsible for the operation of both terminals. Due to the complexity and experimental character of this new optical technology, the development, preparation and validation of the ground segment control facilities required a long series of technical and operational qualification tests. This paper is presenting the operations concept and the early results of the PASTEL in orbit operations.

  2. Control of Asymmetric Cell Divisions during Root Ground Tissue Maturation.

    PubMed

    Choi, Ji Won; Lim, Jun

    2016-07-01

    Controlling the production of diverse cell/tissue types is essential for the development of multicellular organisms such as animals and plants. The Arabidopsis thaliana root, which contains distinct cells/tissues along longitudinal and radial axes, has served as an elegant model to investigate how genetic programs and environmental signals interact to produce different cell/tissue types. In the root, a series of asymmetric cell divisions (ACDs) give rise to three ground tissue layers at maturity (endodermis, middle cortex, and cortex). Because the middle cortex is formed by a periclinal (parallel to the axis) ACD of the endodermis around 7 to 14 days post-germination, middle cortex formation is used as a parameter to assess maturation of the root ground tissue. Molecular, genetic, and physiological studies have revealed that the control of the timing and extent of middle cortex formation during root maturation relies on the interaction of plant hormones and transcription factors. In particular, abscisic acid and gibberellin act synergistically to regulate the timing and extent of middle cortex formation, unlike their typical antagonism. The SHORT-ROOT, SCARECROW, SCARECROW-LIKE 3, and DELLA transcription factors, all of which belong to the plant-specific GRAS family, play key roles in the regulation of middle cortex formation. Recently, two additional transcription factors, SEUSS and GA- AND ABA-RESPONSIVE ZINC FINGER, have also been characterized during ground tissue maturation. In this review, we provide a detailed account of the regulatory networks that control the timing and extent of middle cortex formation during post-embryonic root development. PMID:27306644

  3. Control of Asymmetric Cell Divisions during Root Ground Tissue Maturation

    PubMed Central

    Choi, Ji Won; Lim, Jun

    2016-01-01

    Controlling the production of diverse cell/tissue types is essential for the development of multicellular organisms such as animals and plants. The Arabidopsis thaliana root, which contains distinct cells/tissues along longitudinal and radial axes, has served as an elegant model to investigate how genetic programs and environmental signals interact to produce different cell/tissue types. In the root, a series of asymmetric cell divisions (ACDs) give rise to three ground tissue layers at maturity (endodermis, middle cortex, and cortex). Because the middle cortex is formed by a periclinal (parallel to the axis) ACD of the endodermis around 7 to 14 days post-germination, middle cortex formation is used as a parameter to assess maturation of the root ground tissue. Molecular, genetic, and physiological studies have revealed that the control of the timing and extent of middle cortex formation during root maturation relies on the interaction of plant hormones and transcription factors. In particular, abscisic acid and gibberellin act synergistically to regulate the timing and extent of middle cortex formation, unlike their typical antagonism. The SHORT-ROOT, SCARECROW, SCARECROW-LIKE 3, and DELLA transcription factors, all of which belong to the plant-specific GRAS family, play key roles in the regulation of middle cortex formation. Recently, two additional transcription factors, SEUSS and GA- AND ABA-RESPONSIVE ZINC FINGER, have also been characterized during ground tissue maturation. In this review, we provide a detailed account of the regulatory networks that control the timing and extent of middle cortex formation during post-embryonic root development. PMID:27306644

  4. Automatic Scheduling and Planning (ASAP) in future ground control systems

    NASA Technical Reports Server (NTRS)

    Matlin, Sam

    1988-01-01

    This report describes two complementary approaches to the problem of space mission planning and scheduling. The first is an Expert System or Knowledge-Based System for automatically resolving most of the activity conflicts in a candidate plan. The second is an Interactive Graphics Decision Aid to assist the operator in manually resolving the residual conflicts which are beyond the scope of the Expert System. The two system designs are consistent with future ground control station activity requirements, support activity timing constraints, resource limits and activity priority guidelines.

  5. The 18th Annual Intelligent Ground Vehicle Competition: trends and influences for intelligent ground vehicle control

    NASA Astrophysics Data System (ADS)

    Theisen, Bernard L.; Frederick, Philip; Smuda, William

    2011-01-01

    The Intelligent Ground Vehicle Competition (IGVC) is one of four, unmanned systems, student competitions that were founded by the Association for Unmanned Vehicle Systems International (AUVSI). The IGVC is a multidisciplinary exercise in product realization that challenges college engineering student teams to integrate advanced control theory, machine vision, vehicular electronics and mobile platform fundamentals to design and build an unmanned system. Teams from around the world focus on developing a suite of dual-use technologies to equip ground vehicles of the future with intelligent driving capabilities. Over the past 18 years, the competition has challenged undergraduate, graduate and Ph.D. students with real world applications in intelligent transportation systems, the military and manufacturing automation. To date, teams from over 75 universities and colleges have participated. This paper describes some of the applications of the technologies required by this competition and discusses the educational benefits. The primary goal of the IGVC is to advance engineering education in intelligent vehicles and related technologies. The employment and professional networking opportunities created for students and industrial sponsors through a series of technical events over the four-day competition are highlighted. Finally, an assessment of the competition based on participation is presented.

  6. Semi-autonomous unmanned ground vehicle control system

    NASA Astrophysics Data System (ADS)

    Anderson, Jonathan; Lee, Dah-Jye; Schoenberger, Robert; Wei, Zhaoyi; Archibald, James

    2006-05-01

    Unmanned Ground Vehicles (UGVs) have advantages over people in a number of different applications, ranging from sentry duty, scouting hazardous areas, convoying goods and supplies over long distances, and exploring caves and tunnels. Despite recent advances in electronics, vision, artificial intelligence, and control technologies, fully autonomous UGVs are still far from being a reality. Currently, most UGVs are fielded using tele-operation with a human in the control loop. Using tele-operations, a user controls the UGV from the relative safety and comfort of a control station and sends commands to the UGV remotely. It is difficult for the user to issue higher level commands such as patrol this corridor or move to this position while avoiding obstacles. As computer vision algorithms are implemented in hardware, the UGV can easily become partially autonomous. As Field Programmable Gate Arrays (FPGAs) become larger and more powerful, vision algorithms can run at frame rate. With the rapid development of CMOS imagers for consumer electronics, frame rate can reach as high as 200 frames per second with a small size of the region of interest. This increase in the speed of vision algorithm processing allows the UGVs to become more autonomous, as they are able to recognize and avoid obstacles in their path, track targets, or move to a recognized area. The user is able to focus on giving broad supervisory commands and goals to the UGVs, allowing the user to control multiple UGVs at once while still maintaining the convenience of working from a central base station. In this paper, we will describe a novel control system for the control of semi-autonomous UGVs. This control system combines a user interface similar to a simple tele-operation station along with a control package, including the FPGA and multiple cameras. The control package interfaces with the UGV and provides the necessary control to guide the UGV.

  7. De-tabooing dying control - a grounded theory study

    PubMed Central

    2013-01-01

    Background Dying is inescapable yet remains a neglected issue in modern health care. The research question in this study was “what is going on in the field of dying today?” What emerged was to eventually present a grounded theory of control of dying focusing specifically on how people react in relation to issues about euthanasia and physician-assisted suicide (PAS). Methods Classic grounded theory was used to analyze interviews with 55 laypersons and health care professionals in North America and Europe, surveys on attitudes to PAS among physicians and the Swedish general public, and scientific literature, North American discussion forum websites, and news sites. Results Open awareness of the nature and timing of a patient’s death became common in health care during the 1960s in the Western world. Open dying awareness contexts can be seen as the start of a weakening of a taboo towards controlled dying called de-tabooing. The growth of the hospice movement and palliative care, but also the legalization of euthanasia and PAS in the Benelux countries, and PAS in Montana, Oregon and Washington further represents de-tabooing dying control. An attitude positioning between the taboo of dying control and a growing taboo against questioning patient autonomy and self-determination called de-paternalizing is another aspect of de-tabooing. When confronted with a taboo, people first react emotionally based on “gut feelings” - emotional positioning. This is followed by reasoning and label wrestling using euphemisms and dysphemisms - reflective positioning. Rarely is de-tabooing unconditional but enabled by stipulated positioning as in soft laws (palliative care guidelines) and hard laws (euthanasia/PAS legislation). From a global perspective three shapes of dying control emerge. First, suboptimal palliative care in closed awareness contexts seen in Asian, Islamic and Latin cultures, called closed dying. Second, palliative care and sedation therapy, but not euthanasia

  8. Feasibility of Automated Adaptive GCA (Ground Controlled Approach) Controller Training System.

    ERIC Educational Resources Information Center

    Feuge, Robert L.; And Others

    An analysis of the conceptual feasibility of using automatic speech recognition and understanding technology in the design of an advanced training system was conducted. The analysis specifically explored application to Ground Controlled Approach (GCA) controller training. A systems engineering approach was followed to determine the feasibility of…

  9. Next Generation GPS Ground Control Segment (OCX) Navigation Design

    NASA Technical Reports Server (NTRS)

    Bertiger, Willy; Bar-Sever, Yoaz; Harvey, Nate; Miller, Kevin; Romans, Larry; Weiss, Jan; Doyle, Larry; Solorzano, Tara; Petzinger, John; Stell, Al

    2010-01-01

    In February 2010, a Raytheon-led team was selected by The Air Force to develop, implement, and operate the next generation GPS ground control segment (OCX). To meet and exceed the demanding OCX navigation performance requirements, the Raytheon team partnered with ITT (Navigation lead) and JPL to adapt major elements of JPL's navigation technology, proven in the operations of the Global Differential GPS (GDGPS) System. Key design goals for the navigation subsystem include accurate ephemeris and clock accuracy (user range error), ease of model upgrades, and a smooth and safe transition from the legacy system to OCX.We will describe key elements of the innovative architecture of the OCX navigation subsystem,and demonstrate the anticipated performance of the system through high fidelity simulations withactual GPS measurements.

  10. Developing satellite ground control software through graphical models

    NASA Technical Reports Server (NTRS)

    Bailin, Sidney; Henderson, Scott; Paterra, Frank; Truszkowski, Walt

    1992-01-01

    This paper discusses a program of investigation into software development as graphical modeling. The goal of this work is a more efficient development and maintenance process for the ground-based software that controls unmanned scientific satellites launched by NASA. The main hypothesis of the program is that modeling of the spacecraft and its subsystems, and reasoning about such models, can--and should--form the key activities of software development; by using such models as inputs, the generation of code to perform various functions (such as simulation and diagnostics of spacecraft components) can be automated. Moreover, we contend that automation can provide significant support for reasoning about the software system at the diagram level.

  11. Path planning and Ground Control Station simulator for UAV

    NASA Astrophysics Data System (ADS)

    Ajami, A.; Balmat, J.; Gauthier, J.-P.; Maillot, T.

    In this paper we present a Universal and Interoperable Ground Control Station (UIGCS) simulator for fixed and rotary wing Unmanned Aerial Vehicles (UAVs), and all types of payloads. One of the major constraints is to operate and manage multiple legacy and future UAVs, taking into account the compliance with NATO Combined/Joint Services Operational Environment (STANAG 4586). Another purpose of the station is to assign the UAV a certain degree of autonomy, via autonomous planification/replanification strategies. The paper is organized as follows. In Section 2, we describe the non-linear models of the fixed and rotary wing UAVs that we use in the simulator. In Section 3, we describe the simulator architecture, which is based upon interacting modules programmed independently. This simulator is linked with an open source flight simulator, to simulate the video flow and the moving target in 3D. To conclude this part, we tackle briefly the problem of the Matlab/Simulink software connection (used to model the UAV's dynamic) with the simulation of the virtual environment. Section 5 deals with the control module of a flight path of the UAV. The control system is divided into four distinct hierarchical layers: flight path, navigation controller, autopilot and flight control surfaces controller. In the Section 6, we focus on the trajectory planification/replanification question for fixed wing UAV. Indeed, one of the goals of this work is to increase the autonomy of the UAV. We propose two types of algorithms, based upon 1) the methods of the tangent and 2) an original Lyapunov-type method. These algorithms allow either to join a fixed pattern or to track a moving target. Finally, Section 7 presents simulation results obtained on our simulator, concerning a rather complicated scenario of mission.

  12. Ground Operations Autonomous Control and Integrated Health Management

    NASA Technical Reports Server (NTRS)

    Figueroa, Fernando; Walker, Mark; Wilkins, Kim; Johnson, Robert; Sass, Jared; Youney, Justin

    2014-01-01

    An intelligent autonomous control capability has been developed and is currently being validated in ground cryogenic fluid management operations. The capability embodies a physical architecture consistent with typical launch infrastructure and control systems, augmented by a higher level autonomous control (AC) system enabled to make knowledge-based decisions. The AC system is supported by an integrated system health management (ISHM) capability that detects anomalies, diagnoses causes, determines effects, and could predict future anomalies. AC is implemented using the concept of programmed sequences that could be considered to be building blocks of more generic mission plans. A sequence is a series of steps, and each executes actions once conditions for the step are met (e.g. desired temperatures or fluid state are achieved). For autonomous capability, conditions must consider also health management outcomes, as they will determine whether or not an action is executed, or how an action may be executed, or if an alternative action is executed instead. Aside from health, higher level objectives can also drive how a mission is carried out. The capability was developed using the G2 software environment (www.gensym.com) augmented by a NASA Toolkit that significantly shortens time to deployment. G2 is a commercial product to develop intelligent applications. It is fully object oriented. The core of the capability is a Domain Model of the system where all elements of the system are represented as objects (sensors, instruments, components, pipes, etc.). Reasoning and decision making can be done with all elements in the domain model. The toolkit also enables implementation of failure modes and effects analysis (FMEA), which are represented as root cause trees. FMEA's are programmed graphically, they are reusable, as they address generic FMEA referring to classes of subsystems or objects and their functional relationships. User interfaces for integrated awareness by

  13. Active control of shocks and sonic boom ground signal

    NASA Astrophysics Data System (ADS)

    Yagiz, Bedri

    The manipulation of a flow field to obtain a desired change is a much heightened subject. Active flow control has been the subject of the major research areas in fluid mechanics for the past two decades. It offers new solutions for mitigation of shock strength, sonic boom alleviation, drag minimization, reducing blade-vortex interaction noise in helicopters, stall control and the performance maximization of existing designs to meet the increasing requirements of the aircraft industries. Despite the wide variety of the potential applications of active flow control, the majority of studies have been performed at subsonic speeds. The active flow control cases were investigated in transonic speed in this study. Although the active flow control provides significant improvements, the sensibility of aerodynamic performance to design parameters makes it a nontrivial and expensive problem, so the designer has to optimize a number of different parameters. For the purpose of gaining understanding of the active flow control concepts, an automated optimization cycle process was generated. Also, the optimization cycle reduces cost and turnaround time. The mass flow coefficient, location, width and angle were chosen as design parameters to maximize the aerodynamic performance of an aircraft. As the main contribution of this study, a detailed parametric study and optimization process were presented. The second step is to appraise the practicability of weakening the shock wave and thereby reducing the wave drag in transonic flight regime using flow control devices such as two dimensional contour bump, individual jet actuator, and also the hybrid control which includes both control devices together, thereby gaining the desired improvements in aerodynamic performance of the air-vehicle. After this study, to improve the aerodynamic performance, the flow control and shape parameters are optimized separately, combined, and in a serial combination. The remarkable part of all these

  14. Intelligent Command and Control Systems for Satellite Ground Operations

    NASA Technical Reports Server (NTRS)

    Mitchell, Christine M.

    1999-01-01

    This grant, Intelligent Command and Control Systems for Satellite Ground Operations, funded by NASA Goddard Space Flight Center, has spanned almost a decade. During this time, it has supported a broad range of research addressing the changing needs of NASA operations. It is important to note that many of NASA's evolving needs, for example, use of automation to drastically reduce (e.g., 70%) operations costs, are similar requirements in both government and private sectors. Initially the research addressed the appropriate use of emerging and inexpensive computational technologies, such as X Windows, graphics, and color, together with COTS (commercial-off-the-shelf) hardware and software such as standard Unix workstations to re-engineer satellite operations centers. The first phase of research supported by this grant explored the development of principled design methodologies to make effective use of emerging and inexpensive technologies. The ultimate performance measures for new designs were whether or not they increased system effectiveness while decreasing costs. GT-MOCA (The Georgia Tech Mission Operations Cooperative Associate) and GT-VITA (Georgia Tech Visual and Inspectable Tutor and Assistant), whose latter stages were supported by this research, explored model-based design of collaborative operations teams and the design of intelligent tutoring systems, respectively. Implemented in proof-of-concept form for satellite operations, empirical evaluations of both, using satellite operators for the former and personnel involved in satellite control operations for the latter, demonstrated unequivocally the feasibility and effectiveness of the proposed modeling and design strategy underlying both research efforts. The proof-of-concept implementation of GT-MOCA showed that the methodology could specify software requirements that enabled a human-computer operations team to perform without any significant performance differences from the standard two-person satellite

  15. Proceedings, 24th international conference on ground control in mining

    SciTech Connect

    Peng, S.S.; Mark, C.; Finfinger, G.; Tadolini, S.; Wahab Khair, A.; Heasley, K.

    2005-07-01

    Topics covered: longwall mining; multiple seam mining; pillar/pillar extraction; surface subsidence; roof falls; geology; high horizontal stresses; highwall mining/slope stability; mine/roof support design; roof bolting; and detection of ground conditions.

  16. Definition of ground test for Large Space Structure (LSS) control verification

    NASA Technical Reports Server (NTRS)

    Waites, H. B.; Doane, G. B., III; Tollison, D. K.

    1984-01-01

    An overview for the definition of a ground test for the verification of Large Space Structure (LSS) control is given. The definition contains information on the description of the LSS ground verification experiment, the project management scheme, the design, development, fabrication and checkout of the subsystems, the systems engineering and integration, the hardware subsystems, the software, and a summary which includes future LSS ground test plans. Upon completion of these items, NASA/Marshall Space Flight Center will have an LSS ground test facility which will provide sufficient data on dynamics and control verification of LSS so that LSS flight system operations can be reasonably ensured.

  17. System and method for transferring telemetry data between a ground station and a control center

    NASA Technical Reports Server (NTRS)

    Ray, Timothy J. (Inventor); Ly, Vuong T. (Inventor)

    2012-01-01

    Disclosed herein are systems, computer-implemented methods, and tangible computer-readable media for coordinating communications between a ground station, a control center, and a spacecraft. The method receives a call to a simple, unified application programmer interface implementing communications protocols related to outer space, when instruction relates to receiving a command at the control center for the ground station generate an abstract message by agreeing upon a format for each type of abstract message with the ground station and using a set of message definitions to configure the command in the agreed upon format, encode the abstract message to generate an encoded message, and transfer the encoded message to the ground station, and perform similar actions when the instruction relates to receiving a second command as a second encoded message at the ground station from the control center and when the determined instruction type relates to transmitting information to the control center.

  18. Control performance evaluation of railway vehicle MR suspension using fuzzy sky-ground hook control algorithm

    NASA Astrophysics Data System (ADS)

    Ha, S. H.; Choi, S. B.; Lee, G. S.; Yoo, W. H.

    2013-02-01

    This paper presents control performance evaluation of railway vehicle featured by semi-active suspension system using magnetorheological (MR) fluid damper. In order to achieve this goal, a nine degree of freedom of railway vehicle model, which includes car body and bogie, is established. The wheel-set data is loaded from measured value of railway vehicle. The MR damper system is incorporated with the governing equation of motion of the railway vehicle model which includes secondary suspension. To illustrate the effectiveness of the controlled MR dampers on suspension system of railway vehicle, the control law using the sky-ground hook controller is adopted. This controller takes into account for both vibration control of car body and increasing stability of bogie by adopting a weighting parameter between two performance requirements. The parameters appropriately determined by employing a fuzzy algorithm associated with two fuzzy variables: the lateral speed of the car body and the lateral performance of the bogie. Computer simulation results of control performances such as vibration control and stability analysis are presented in time and frequency domains.

  19. A controlled experiment in ground water flow model calibration

    USGS Publications Warehouse

    Hill, M.C.; Cooley, R.L.; Pollock, D.W.

    1998-01-01

    Nonlinear regression was introduced to ground water modeling in the 1970s, but has been used very little to calibrate numerical models of complicated ground water systems. Apparently, nonlinear regression is thought by many to be incapable of addressing such complex problems. With what we believe to be the most complicated synthetic test case used for such a study, this work investigates using nonlinear regression in ground water model calibration. Results of the study fall into two categories. First, the study demonstrates how systematic use of a well designed nonlinear regression method can indicate the importance of different types of data and can lead to successive improvement of models and their parameterizations. Our method differs from previous methods presented in the ground water literature in that (1) weighting is more closely related to expected data errors than is usually the case; (2) defined diagnostic statistics allow for more effective evaluation of the available data, the model, and their interaction; and (3) prior information is used more cautiously. Second, our results challenge some commonly held beliefs about model calibration. For the test case considered, we show that (1) field measured values of hydraulic conductivity are not as directly applicable to models as their use in some geostatistical methods imply; (2) a unique model does not necessarily need to be identified to obtain accurate predictions; and (3) in the absence of obvious model bias, model error was normally distributed. The complexity of the test case involved implies that the methods used and conclusions drawn are likely to be powerful in practice.Nonlinear regression was introduced to ground water modeling in the 1970s, but has been used very little to calibrate numerical models of complicated ground water systems. Apparently, nonlinear regression is thought by many to be incapable of addressing such complex problems. With what we believe to be the most complicated synthetic

  20. Eurobot Ground Prototype Control System Overview & Tests Results

    NASA Astrophysics Data System (ADS)

    Merlo, Andrea; Martelli, Andrea; Pensavalle, Emanuele; Ferraris, Simona; Didot, Frederic

    2010-08-01

    In the planned missions on Moon and Mars, robotics can play a key role, as robots can both assist astronauts and, above all, relieve them of dangerous or too difficult tasks. To this aim, both cooperative capabilities and a great level of autonomy are needed: the robotic crew assistant must be able to work on its own, without supervision by humans, and to help astronauts to accomplish tasks otherwise unfeasible for them. Within this context, a project named Eurobot Ground Prototype, conducted in conjunction with ESA and Thales Alenia Space, is presented. EGP is a dual-arm mobile manipulator and exploits both stereo cameras and force/torque sensors in order to rely on visual and force feedback. This paper provides an overview of the performed and on going activities within the Eurobot Ground Prototype project.

  1. Antenna testing for the Inmarsat 2 ground control system

    NASA Astrophysics Data System (ADS)

    Ashton, C.

    1992-02-01

    This article describes how the antennas of the Inmarsat 2 TT&C and IOT ground stations were tested and calibrated. It explains the main test methods used, giving the theory behind the tests and indicates some of the practical difficulties encountered during testing. Techniques described include the use of radio stars, boresight antennas and satellite verification testing using Intelsat and Inmarsat satellites. Parameters tested include gain, G/T (figure of merit), sidelobe patterns, cross polar discrimination and isolation.

  2. A Critique of the Capacity of Strauss Grounded Theory for Prediction, Change, and Control in Organisational Strategy via a Grounded Theorisation of Leisure and Cultural Strategy

    ERIC Educational Resources Information Center

    Bakir, Ali; Bakir, Vian

    2006-01-01

    In this paper we critique grounded theory's ability to fulfil its aim of offering a practical vehicle for prediction, change, and control as stipulated in grounded theory's original formulation by Glaser and Strauss, and later developed by Strauss. We do this through a case study approach, whereby we develop a grounded theory of leisure and…

  3. Temperature and Humidity Independent Control Research on Ground Source Heat Pump Air Conditioning System

    NASA Astrophysics Data System (ADS)

    Chen, G.; Wang, L. L.

    Taking green demonstration center building air conditioning system as an example, this paper presents the temperature and humidity independent control system combined with ground source heat pump system, emphasis on the design of dry terminal device system, fresh air system and ground source heat pump system.

  4. Load control system. [for space shuttle external tank ground tests

    NASA Technical Reports Server (NTRS)

    Grosse, J. C.

    1977-01-01

    The load control system developed for the shuttle external structural tests is described. The system consists of a load programming/display module, and a load control module along with the following hydraulic system components: servo valves, dump valves, hydraulic system components, and servo valve manifold blocks. One load programming/display subsystem can support multiple load control subsystem modules.

  5. Commercial off the Shelf Ground Control Supports Calibration and Conflation from Ground to Space Based Sensors

    NASA Astrophysics Data System (ADS)

    Danielová, M.; Hummel, P.

    2016-06-01

    The need for rapid deployment of aerial and satellite imagery in support of GIS and engineering integration projects require new sources of geodetic control to ensure the accuracy for geospatial projects. In the past, teams of surveyors would need to deploy to project areas to provide targeted or photo identifiable points that are used to provide data for orthorecificaion, QA/QC and calibration for multi-platform sensors. The challenge of integrating street view, UAS, airborne and Space based sensors to produce the common operational picture requires control to tie multiple sources together. Today commercial off the shelf delivery of existing photo identifiable control is increasing the speed of deployment of this data without having to revisit sites over and over again. The presentation will discuss the processes developed by CompassData to build a global library of 40,000 control points available today. International Organization for Standardization (ISO) based processes and initiatives ensure consistent quality of survey data, photo identifiable features selected and meta data to support photogrammetrist, engineers and GIS professionals to quickly deliver projects with better accuracy.

  6. Piloted simulation of a ground-based time-control concept for air traffic control

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Green, Steven M.

    1989-01-01

    A concept for aiding air traffic controllers in efficiently spacing traffic and meeting scheduled arrival times at a metering fix was developed and tested in a real time simulation. The automation aid, referred to as the ground based 4-D descent advisor (DA), is based on accurate models of aircraft performance and weather conditions. The DA generates suggested clearances, including both top-of-descent-point and speed-profile data, for one or more aircraft in order to achieve specific time or distance separation objectives. The DA algorithm is used by the air traffic controller to resolve conflicts and issue advisories to arrival aircraft. A joint simulation was conducted using a piloted simulator and an advanced concept air traffic control simulation to study the acceptability and accuracy of the DA automation aid from both the pilot's and the air traffic controller's perspectives. The results of the piloted simulation are examined. In the piloted simulation, airline crews executed controller issued descent advisories along standard curved path arrival routes, and were able to achieve an arrival time precision of + or - 20 sec at the metering fix. An analysis of errors generated in turns resulted in further enhancements of the algorithm to improve the predictive accuracy. Evaluations by pilots indicate general support for the concept and provide specific recommendations for improvement.

  7. Method of Controlling Steering of a Ground Vehicle

    NASA Technical Reports Server (NTRS)

    Dawson, Andrew D. (Inventor); Bluethmann, William J. (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Guo, Raymond (Inventor); Atluri, Venkata Prasad (Inventor)

    2016-01-01

    A method of controlling steering of a vehicle through setting wheel angles of a plurality of modular electronic corner assemblies (eModules) is provided. The method includes receiving a driving mode selected from a mode selection menu. A position of a steering input device is determined in a master controller. A velocity of the vehicle is determined, in the master controller, when the determined position of the steering input device is near center. A drive mode request corresponding to the selected driving mode to the plurality of steering controllers is transmitted to the master controller. A required steering angle of each of the plurality of eModules is determined, in the master controller, as a function of the determined position of the steering input device, the determined velocity of the vehicle, and the selected first driving mode. The eModules are set to the respective determined steering angles.

  8. Ground Control for Non-Emplacement Drifts for LA

    SciTech Connect

    D. Tang

    2004-02-26

    The purpose of this calculation is to analyze the stability of repository non-emplacement drifts during the preclosure period, and to provide a final ground support method for non-emplacement drifts for the License Application (LA). This calculation will provide input for the development of LA documents. The scope of this calculation is limited to the non-emplacement drifts including access mains, ramps, exhaust mains, turnouts, intersections between access mains and turnouts, and intersections between exhaust mains and emplacement drifts, portals, TBM launch chambers, observation drift and test alcove in the performance confirmation (PC) facilities, etc. The calculation is limited to the non-emplacement drifts subjected to a combined loading of in-situ stress, seismic stress, and/or thermal stress. Other effects such as hydrological and chemical effects are not considered in this analysis.

  9. Definition of ground test for Large Space Structure (LSS) control verification, appendix G

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A Large Space Structure (LSS) ground test facility was developed to help verify LSS passive and active control theories. The facility also perform: (1) subsystem and component testing; (2) remote sensing and control; (3) parameter estimation and model verification; and (4) evolutionary modeling and control. The program is examined as is and looks at the first experiment to be performed in the laboratory.

  10. Advanced Ground Systems Maintenance Cryogenics Test Lab Control System Upgrade Project

    NASA Technical Reports Server (NTRS)

    Harp, Janice Leshay

    2014-01-01

    This project will outfit the Simulated Propellant Loading System (SPLS) at KSC's Cryogenics Test Laboratory with a new programmable logic control system. The control system upgrade enables the Advanced Ground Systems Maintenace Element Integration Team and other users of the SPLS to conduct testing in a controls environment similar to that used at the launch pad.

  11. Tug fleet and ground operations schedules and controls. Volume 2: part 1

    NASA Technical Reports Server (NTRS)

    1975-01-01

    This Tug Fleet and Ground Operations Schedules and Controls Study addresses both ground operational data and technical requirements that span the Tug planning phase and operations phase. A similar study covering mission operations (by others) provides the complimentary flight operations details. The two studies provide the planning data requirements, resource allocation, and control milestones for supporting the requirements of the STS program. This Tug Fleet and Ground Operations Schedules and Controls Study incorporates the basic ground operations requirements and concepts provided by previous studies with the interrelationships of the planning, IUS transition, and Tug fleet operations phases. The interrelationships of these phases were studied as a system to optimize overall program benefits and minimize operational risk factors.

  12. Intelligent command and control systems for satellite ground operations

    NASA Technical Reports Server (NTRS)

    Mitchell, Christine M.

    1994-01-01

    The Georgia Tech portion of the Intelligent Control Center project includes several complementary activities. Two major activities entail thesis level research; the other activities are either support activities or preliminary explorations (e.g., task analyses) to support the research. The first research activity is the development of principles for the design of active interfaces to support monitoring during real-time supports. It is well known that as the operator's task becomes less active, i.e., more monitoring and less active control, there is concern that the operator will be less involved and less able to rapidly identify anomalous or failure situations. The research project to design active monitoring interfaces is an attempt to remediate this undesirable side-effect of increasingly automated control systems that still depend ultimately on operator supervision. The second research activity is the exploration of the use of case-based reasoning as a way to accumulate operator experience and make it available in computational form.

  13. Ground Control Setup of the (LIF) Large Isothermal Furnace

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Large Isothermal Furnace (LIF) was flown on a mission in cooperation with the National Space Development Agency (NASDA) of Japan. LIF is a vacuum-heating furnace designed to heat large samples uniformly. The furnace consists of a sample container and heating element surrounded by a vacuum chamber. A crewmemeber will insert a sample cartridge into the furnace. The furnace will be activated and operations will be controlled automatically by a computer in response to an experiment number entered on the control panel. At the end of operations, helium will be discharged into the furnace, allowing cooling to start. Cooling will occur through the use of a water jacket while rapid cooling of samples can be accomplished through a controlled flow of helium. Data from experiments will help scientists better understand this important process which is vital to the production of high-quality semiconductor crystals.

  14. Ground control requirements for precision processing of ERTS images

    USGS Publications Warehouse

    Burger, Thomas C.

    1972-01-01

    When the first Earth Resources Technology Satellite (ERTS-A) flies in 1972, NASA expects to receive and bulk-process 9,000 images a week. From this deluge of images, a few will be selected for precision processing; that is, about 5 percent will be further treated to improve the geometry of the scene, both in the relative and absolute sense. Control points are required for this processing. This paper describes the control requirements for relating ERTS images to a reference surface of the earth. Enough background on the ERTS-A satellite is included to make the requirements meaningful to the user.

  15. Ground control requirements for precision processing of ERTS images

    USGS Publications Warehouse

    Burger, Thomas C.

    1973-01-01

    With the successful flight of the ERTS-1 satellite, orbital height images are available for precision processing into products such as 1:1,000,000-scale photomaps and enlargements up to 1:250,000 scale. In order to maintain positional error below 100 meters, control points for the precision processing must be carefully selected, clearly definitive on photos in both X and Y. Coordinates of selected control points measured on existing ½ and 15-minute standard maps provide sufficient accuracy for any space imaging system thus far defined. This procedure references the points to accepted horizontal and vertical datums. Maps as small as 1:250,000 scale can be used as source material for coordinates, but to maintain the desired accuracy, maps of 1:100,000 and larger scale should be used when available.

  16. 1997 annual ground control operating plan for the Waste Isolation Pilot Plant

    SciTech Connect

    1997-02-01

    This plan presents background information and a working guide to assist Mine Operations and Engineering in developing strategies for addressing ground control issues at the Waste Isolation Pilot Plant (WIPP). With the anticipated receipt of waste in late 1997, this document provides additional detail to Panel 1 activities and options. The plan also serves as a foundation document for development and revision of the annual long-term ground control plan. Section 2.0 documents the current status of all underground excavations with respect to location, geology, geometry, age, ground support, operational use, projected life, and physical conditions. Section 3.0 presents the methods used to evaluate ground conditions, including visual observations of the roof, ribs, and floor, inspection of observation holes, and review of instrumentation data. Section 4.0 lists several ground support options and specific applications of each. Section 5.0 discusses remedial ground control measures that have been implemented to date. Section 6.0 presents projections and recommendations for ground control actions based on the information in Sections 2.0 through 5.0 of this plan and on a rating of the critical nature of each specific area. Section 7.0 presents a summary statement, and Section 8.0 includes references. Appendix A provides an overview and critique of ground control systems that have been, or may be, used at the site. Because of the dynamic nature of the underground openings and associated geotechnical activities, this plan will be revised as additional data are incorporated.

  17. Increasing the utilization of the ISS Mobile Servicing System through ground control

    NASA Astrophysics Data System (ADS)

    Rembala, Richard; Aziz, Sarmad

    2007-10-01

    On February 24th, 2005 the Mobile Servicing System (MSS) was maneuvred on the International Space Station (ISS) by an operator from the ground for the first time, marking a first in human space flight history. Allowing ground support teams the capability to move the MSS in a manner that satisfies human space flight safety requirements provides an invaluable tool in supporting more efficient utilization of both the MSS and the ISS. Ground control allows for the optimal separation of on-orbit crew and ground functions; thereby redirecting more on-orbit crew time towards other more scientifically rewarding ISS utilization activities. Apart from supporting routine ISS operations, significant benefits will also be gained from ground control to support engineering investigations. One of the "way-of-doing-business" adjustments that was required for the MSS on the ISS over the original robotic manipulator system developed for the Space Shuttle (the "SRMS"), was in the sustaining engineering support function. Many SRMS minor on-orbit anomalies are investigated in detail after the mission is completed and the arm has returned to earth. In the case of the MSS where it remains on-orbit, engineering investigations and performance characterization efforts are more challenging. However, contrary to initial expectations, the challenge in troubleshooting and characterizing the MSS was not because of lack of data or insight into the on-orbit system, but rather due to lack of on-orbit crew time for engineering investigations. This has led to some engineering support teams having to wait up to a year before even straightforward troubleshooting investigations could be scheduled and executed. Ground control affords a more efficient way of characterizing and maintaining the health of the MSS. This paper will describe the utilization challenges the MSS has faced in the past, provide an overview of the MSS ground control capability, and discuss the benefits that are expected to be gained

  18. BIOPACK: the ground controlled late access biological research facility.

    PubMed

    van Loon, Jack J W A

    2004-03-01

    Future Space Shuttle flights shall be characterized by activities necessary to further build the International Space Station, ISS. During these missions limited resources are available to conduct biological experiments in space. The Shuttles' Middeck is a very suitable place to conduct science during the ISS assembly missions or dedicated science missions. The BIOPACK, which flew its first mission during the STS-107, provides a versatile Middeck Locker based research tool for gravitational biology studies. The core facility occupies the space of only two Middeck Lockers. Experiment temperatures are controlled for bacteria, plant, invertebrate and mammalian cultures. Gravity levels and profiles can be set ranging from 0 to 2.0 x g on three independent centrifuges. This provides the experimenter with a 1.0 x g on-board reference and intermediate hypogravity and hypergravity data points to investigate e.g. threshold levels in biological responses. Temperature sensitive items can be stored in the facilities' -10 degrees C and +4 degrees C stowage areas. During STS-107 the facility also included a small glovebox (GBX) and passive temperature controlled units (PTCU). The GBX provides the experimenter with two extra levels of containment for safe sample handling. This biological research facility is a late access (L-10 hrs) laboratory, which, when reaching orbit, could automatically be starting up reducing important experiment lag-time and valuable crew time. The system is completely telecommanded when needed. During flight system parameters like temperatures, centrifuge speeds, experiment commanding or sensor readouts can be monitored and changed when needed. Although ISS provides a wide range of research facilities there is still need for an STS-based late access facility such as the BIOPACK providing experimenters with a very versatile research cabinet for biological experiments under microgravity and in-flight control conditions.

  19. Comparison ofdvanced turboprop interior noise control ground and flight test data

    NASA Technical Reports Server (NTRS)

    Simpson, Myles A.; Tran, Boi N.

    1992-01-01

    Interior noise ground tests conducted on a DC-9 aircraft test section are described. The objectives were to study ground test and analysis techniques for evaluating the effectiveness of interior noise control treatments for advanced turboprop aircraft, and to study the sensitivity of the ground test results to changes in various test conditions. Noise and vibration measurements were conducted under simulated advanced turboprop excitation, for two interior noise control treatment configurations. These ground measurement results were compared with results of earlier UHB (Ultra High Bypass) Demonstrator flight sts with comparable interior treatment configurations. The Demonstrator is an MD-80 test aircraft with the left JT8D engine replaced with a prototype UHB advanced turboprop engine.

  20. Pushing the Limits of Cubesat Attitude Control: A Ground Demonstration

    NASA Technical Reports Server (NTRS)

    Sanders, Devon S.; Heater, Daniel L.; Peeples, Steven R.; Sules. James K.; Huang, Po-Hao Adam

    2013-01-01

    A cubesat attitude control system (ACS) was designed at the NASA Marshall Space Flight Center (MSFC) to provide sub-degree pointing capabilities using low cost, COTS attitude sensors, COTS miniature reaction wheels, and a developmental micro-propulsion system. The ACS sensors and actuators were integrated onto a 3D-printed plastic 3U cubesat breadboard (10 cm x 10 cm x 30 cm) with a custom designed instrument board and typical cubesat COTS hardware for the electrical, power, and data handling and processing systems. In addition to the cubesat development, a low-cost air bearing was designed and 3D printed in order to float the cubesat in the test environment. Systems integration and verification were performed at the MSFC Small Projects Rapid Integration & Test Environment laboratory. Using a combination of both the miniature reaction wheels and the micro-propulsion system, the open and closed loop control capabilities of the ACS were tested in the Flight Robotics Laboratory. The testing demonstrated the desired sub-degree pointing capability of the ACS and also revealed the challenges of creating a relevant environment for development testin

  1. Ground and flight testing for aircraft guidance and control

    SciTech Connect

    Onken, R.; Rediess, H.A.

    1984-12-01

    A simple airborne flight management descent algorithm designed to define a flight profile subject to the constraints of using idle thrust, a clean airplane configuration (landing gear up, flaps zero, and speed brakes retracted), and fixed-time end conditions was developed and flight tested in the NASA TSRV B-737 research airplane. The research test flights, conducted in the Denver ARTCC automated time-based metering LFM/PD ATC environment, demonstrated that time guidance and control in the cockpit was acceptable to the pilots and ATC controllers and resulted in arrival of the airplane over the metering fix with standard deviations in airspeed error of 6.5 knots, in altitude error of 23.7 m (77.8 ft), and in arrival time accuracy of 12 sec. These accuracies indicated a good representation of airplane performance and wind modeling. Fuel savings will be obtained on a fleet-wide basis through a reduction of the time error dispersions at the metering fix and on a single-airplane basis by presenting the pilot with guidance for a fuel-efficient descent.

  2. Definition of ground test for verification of large space structure control

    NASA Technical Reports Server (NTRS)

    Doane, G. B., III; Glaese, J. R.; Tollison, D. K.; Howsman, T. G.; Curtis, S. (Editor); Banks, B.

    1984-01-01

    Control theory and design, dynamic system modelling, and simulation of test scenarios are the main ideas discussed. The overall effort is the achievement at Marshall Space Flight Center of a successful ground test experiment of a large space structure. A simplified planar model of ground test experiment of a large space structure. A simplified planar model of ground test verification was developed. The elimination from that model of the uncontrollable rigid body modes was also examined. Also studied was the hardware/software of computation speed.

  3. Factors controlling the regional distribution of vanadium in ground water

    USGS Publications Warehouse

    Wright, Michael T.; Belitz, Kenneth

    2010-01-01

    Although the ingestion of vanadium (V) in drinking water may have possible adverse health effects, there have been relatively few studies of V in groundwater. Given the importance of groundwater as a source of drinking water in many areas of the world, this study examines the potential sources and geochemical processes that control the distribution of V in groundwater on a regional scale. Potential sources of V to groundwater include dissolution of V rich rocks, and waste streams from industrial processes. Geochemical processes such as adsorption/desorption, precipitation/dissolution, and chemical transformations control V concentrations in groundwater. Based on thermodynamic data and laboratory studies, V concentrations are expected to be highest in samples collected from oxic and alkaline groundwater. However, the extent to which thermodynamic data and laboratory results apply to the actual distribution of V in groundwater is not well understood. More than 8400 groundwater samples collected in California were used in this study. Of these samples, high (> or = 50 μg/L) and moderate (25 to 49 μg/L) V concentrations were most frequently detected in regions where both source rock and favorable geochemical conditions occurred. The distribution of V concentrations in groundwater samples suggests that significant sources of V are mafic and andesitic rock. Anthropogenic activities do not appear to be a significant contributor of V to groundwater in this study. High V concentrations in groundwater samples analyzed in this study were almost always associated with oxic and alkaline groundwater conditions, which is consistent with predictions based on thermodynamic data.

  4. Open solutions to distributed control in ground tracking stations

    NASA Technical Reports Server (NTRS)

    Heuser, William Randy

    1994-01-01

    The advent of high speed local area networks has made it possible to interconnect small, powerful computers to function together as a single large computer. Today, distributed computer systems are the new paradigm for large scale computing systems. However, the communications provided by the local area network is only one part of the solution. The services and protocols used by the application programs to communicate across the network are as indispensable as the local area network. And the selection of services and protocols that do not match the system requirements will limit the capabilities, performance, and expansion of the system. Proprietary solutions are available but are usually limited to a select set of equipment. However, there are two solutions based on 'open' standards. The question that must be answered is 'which one is the best one for my job?' This paper examines a model for tracking stations and their requirements for interprocessor communications in the next century. The model and requirements are matched with the model and services provided by the five different software architectures and supporting protocol solutions. Several key services are examined in detail to determine which services and protocols most closely match the requirements for the tracking station environment. The study reveals that the protocols are tailored to the problem domains for which they were originally designed. Further, the study reveals that the process control model is the closest match to the tracking station model.

  5. Feed forward and feedback control for over-ground locomotion in anaesthetized cats

    NASA Astrophysics Data System (ADS)

    Mazurek, K. A.; Holinski, B. J.; Everaert, D. G.; Stein, R. B.; Etienne-Cummings, R.; Mushahwar, V. K.

    2012-04-01

    The biological central pattern generator (CPG) integrates open and closed loop control to produce over-ground walking. The goal of this study was to develop a physiologically based algorithm capable of mimicking the biological system to control multiple joints in the lower extremities for producing over-ground walking. The algorithm used state-based models of the step cycle each of which produced different stimulation patterns. Two configurations were implemented to restore over-ground walking in five adult anaesthetized cats using intramuscular stimulation (IMS) of the main hip, knee and ankle flexor and extensor muscles in the hind limbs. An open loop controller relied only on intrinsic timing while a hybrid-CPG controller added sensory feedback from force plates (representing limb loading), and accelerometers and gyroscopes (representing limb position). Stimulation applied to hind limb muscles caused extension or flexion in the hips, knees and ankles. A total of 113 walking trials were obtained across all experiments. Of these, 74 were successful in which the cats traversed 75% of the 3.5 m over-ground walkway. In these trials, the average peak step length decreased from 24.9 ± 8.4 to 21.8 ± 7.5 (normalized units) and the median number of steps per trial increased from 7 (Q1 = 6, Q3 = 9) to 9 (8, 11) with the hybrid-CPG controller. Moreover, within these trials, the hybrid-CPG controller produced more successful steps (step length ≤ 20 cm ground reaction force ≥ 12.5% body weight) than the open loop controller: 372 of 544 steps (68%) versus 65 of 134 steps (49%), respectively. This supports our previous preliminary findings, and affirms that physiologically based hybrid-CPG approaches produce more successful stepping than open loop controllers. The algorithm provides the foundation for a neural prosthetic controller and a framework to implement more detailed control of locomotion in the future.

  6. Feed forward and feedback control for over-ground locomotion in anaesthetized cats

    PubMed Central

    Mazurek, K A; Holinski, B J; Everaert, D G; Stein, R B; Etienne-Cummings, R; Mushahwar, V K

    2012-01-01

    The biological central pattern generator (CPG) integrates open and closed loop control to produce over-ground walking. The goal of this study was to develop a physiologically based algorithm capable of mimicking the biological system to control multiple joints in the lower extremities for producing over-ground walking. The algorithm used state-based models of the step cycle each of which produced different stimulation patterns. Two configurations were implemented to restore over-ground walking in five adult anaesthetized cats using intramuscular stimulation (IMS) of the main hip, knee and ankle flexor and extensor muscles in the hind limbs. An open loop controller relied only on intrinsic timing while a hybrid-CPG controller added sensory feedback from force plates (representing limb loading), and accelerometers and gyroscopes (representing limb position). Stimulation applied to hind limb muscles caused extension or flexion in the hips, knees and ankles. A total of 113 walking trials were obtained across all experiments. Of these, 74 were successful in which the cats traversed 75% of the 3.5 m over-ground walkway. In these trials, the average peak step length decreased from 24.9 ± 8.4 to 21.8 ± 7.5 (normalized units) and the median number of steps per trial increased from 7 (Q1=6, Q3 = 9) to 9 (8, 11) with the hybrid-CPG controller. Moreover, these trials, the hybrid-CPG controller produced more successful steps (step length ≤ 20 cm; ground reaction force ≥ 12.5% body weight) than the open loop controller: 372 of 544 steps (68%) versus 65 of 134 steps (49%), respectively. This supports our previous preliminary findings, and affirms that physiologically based hybrid-CPG approaches produce more successful stepping than open loop controllers. The algorithm provides the foundation for a neural prosthetic controller and a framework to implement more detailed control of locomotion in the future. PMID:22328615

  7. Height estimation and control of a rotorcraft in ground effect using multiple pressure probes

    NASA Astrophysics Data System (ADS)

    Hooi, Chin Gian

    This thesis describes a dynamic height estimator and controller for rotorcraft landing and hovering in ground effect based on flowfield sensing and modeling. The rotor downwash in ground effect is represented using a ring-source potential flow model selected for real-time use. Experimental verification of the flow model and an augmented flow model for tilt are presented. A nonlinear dynamic model of a compound pendulum heave test stand that reduces to the dynamics of a rotorcraft in ground effect is presented with open-loop analysis and closed-loop control simulation. Equations of motion and stability characterization of of a heaving rotor IGE are derived for external perturbations and it is shown that a uniform sideward wind does not cause instability and uniform axial wind from the top can cause instability. Flowfield velocity measurements are assimilated into a grid-based recursive Bayesian filter to estimate height above ground in both simulation and experiment. Height tracking in ground effect and landing using the estimated height are implemented with a dynamic linear controller in both simulation and experiment. Mean estimation and motion errors are found to be no greater than 5% and 9% respectively, demonstrating that height estimation and control is possible with only flow sensing and modeling.

  8. RCRA ground-water monitoring decision procedures viewed as quality control schemes.

    PubMed

    Starks, T H; Flatman, G T

    1991-01-01

    The problems of developing and comparing statistical procedures appropriate to the monitoring of ground water at hazardous waste sites are discussed. It is suggested that these decision procedures should be viewed as quality control schemes and compared in the same way that industrial quality control schemes are compared. The results of a Monte Carlo simulation study of run-length distribution of a combined Shewhart-CUSUM quality control scheme are reported.

  9. Maneuver Planning for Conjunction Risk Mitigation with Ground-track Control Requirements

    NASA Technical Reports Server (NTRS)

    McKinley, David

    2008-01-01

    The planning of conjunction Risk Mitigation Maneuvers (RMM) in the presence of ground-track control requirements is analyzed. Past RMM planning efforts on the Aqua, Aura, and Terra spacecraft have demonstrated that only small maneuvers are available when ground-track control requirements are maintained. Assuming small maneuvers, analytical expressions for the effect of a given maneuver on conjunction geometry are derived. The analytical expressions are used to generate a large trade space for initial RMM design. This trade space represents a significant improvement in initial maneuver planning over existing methods that employ high fidelity maneuver models and propagation.

  10. Subjective evaluation with FAA criteria: A multidimensional scaling approach. [ground track control management

    NASA Technical Reports Server (NTRS)

    Kreifeldt, J. G.; Parkin, L.; Wempe, T. E.; Huff, E. F.

    1975-01-01

    Perceived orderliness in the ground tracks of five A/C during their simulated flights was studied. Dynamically developing ground tracks for five A/C from 21 separate runs were reproduced from computer storage and displayed on CRTS to professional pilots and controllers for their evaluations and preferences under several criteria. The ground tracks were developed in 20 seconds as opposed to the 5 minutes of simulated flight using speedup techniques for display. Metric and nonmetric multidimensional scaling techniques are being used to analyze the subjective responses in an effort to: (1) determine the meaningfulness of basing decisions on such complex subjective criteria; (2) compare pilot/controller perceptual spaces; (3) determine the dimensionality of the subjects' perceptual spaces; and thereby (4) determine objective measures suitable for comparing alternative traffic management simulations.

  11. The Next Generation of Ground Operations Command and Control; Scripting in C no. and Visual Basic

    NASA Technical Reports Server (NTRS)

    Ritter, George; Pedoto, Ramon

    2010-01-01

    Scripting languages have become a common method for implementing command and control solutions in space ground operations. The Systems Test and Operations Language (STOL), the Huntsville Operations Support Center (HOSC) Scripting Language Processor (SLP), and the Spacecraft Control Language (SCL) offer script-commands that wrap tedious operations tasks into single calls. Since script-commands are interpreted, they also offer a certain amount of hands-on control that is highly valued in space ground operations. Although compiled programs seem to be unsuited for interactive user control and are more complex to develop, Marshall Space flight Center (MSFC) has developed a product called the Enhanced and Redesign Scripting (ERS) that makes use of the graphical and logical richness of a programming language while offering the hands-on and ease of control of a scripting language. ERS is currently used by the International Space Station (ISS) Payload Operations Integration Center (POIC) Cadre team members. ERS integrates spacecraft command mnemonics, telemetry measurements, and command and telemetry control procedures into a standard programming language, while making use of Microsoft's Visual Studio for developing Visual Basic (VB) or C# ground operations procedures. ERS also allows for script-style user control during procedure execution using a robust graphical user input and output feature. The availability of VB and C# programmers, and the richness of the languages and their development environment, has allowed ERS to lower our "script" development time and maintenance costs at the Marshall POIC.

  12. 30 CFR 77.1004 - Ground control; inspection and maintenance; general.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Ground control; inspection and maintenance; general. 77.1004 Section 77.1004 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK...

  13. 30 CFR 77.1004 - Ground control; inspection and maintenance; general.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Ground control; inspection and maintenance; general. 77.1004 Section 77.1004 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK...

  14. 30 CFR 77.1004 - Ground control; inspection and maintenance; general.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ground control; inspection and maintenance; general. 77.1004 Section 77.1004 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK...

  15. 30 CFR 77.1004 - Ground control; inspection and maintenance; general.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Ground control; inspection and maintenance; general. 77.1004 Section 77.1004 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK...

  16. 30 CFR 77.1004 - Ground control; inspection and maintenance; general.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Ground control; inspection and maintenance; general. 77.1004 Section 77.1004 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK...

  17. Mixed Waste Management Facility (MWMF) Old Burial Ground (OBG) source control technology and inventory study

    SciTech Connect

    Flach, G.P.; Rehder, T.E.; Kanzleiter, J.P.

    1996-10-02

    This report has been developed to support information needs for wastes buried in the Burial Ground Complex. Information discussed is presented in a total of four individual attachments. The general focus of this report is to collect information on estimated source inventories, leaching studies, source control technologies, and to provide information on modeling parameters and associated data deficiencies.

  18. First conference on ground control problems in the Illinois Coal Basin: proceedings

    SciTech Connect

    Chugh, Y. P.; Van Besien, A.

    1980-06-01

    The first conference on ground control problems in the Illinois Coal Basin was held at the Southern Illinois University at Carbondale, Illinois, August 22-24, 1979. Twenty-one papers from the proceedings have been entered individually into EDB; one had been entered previously from other sources. (LTN)

  19. The Ground Control Room as an Enabling Technology in the Unmanned Aerial System

    NASA Technical Reports Server (NTRS)

    Gear, Gary; Mace, Thomas

    2007-01-01

    This viewgraph presentation reviews the development of the ground control room as an required technology for the use of an Unmanned Aerial system. The Unmanned Aerial system is a strategic component of the Global Observing System, which will serve global science needs. The unmanned aerial system will use the same airspace as manned aircraft, therefore there will be unique telemetry needs.

  20. Proposed ground-based control of accelerometer on Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Delombard, Richard

    1993-01-01

    This paper describes the innovative control of an accelerometer to support the needs of the scientists operating science experiments that are on-board Space Station Freedom (SSF). Accelerometers in support of science experiments on the shuttle have typically been passive, record-only devices that present data only after the mission or that present limited data to the crew or ground operators during the mission. With the advent of science experiment operations on SSF, the principal investigators will need microgravity acceleration data during, as well as after, experiment operations. Because their data requirements may change during the experiment operations, the principal investigators will be allocated some control of accelerometer parameters. This paper summarizes the general-purpose Space Acceleration Measurement System (SAMS) operation that supports experiments on the shuttle and describes the control of the SAMS for Space Station Freedom. Emphasis is placed on the proposed ground-based control of the accelerometer by the principal investigators.

  1. The deep space network, volume 18. [Deep Space Instrumentation Facility, Ground Communication Facility, and Network Control System

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The objectives, functions, and organization of the Deep Space Network are summarized. The Deep Space Instrumentation Facility, the Ground Communications Facility, and the Network Control System are described.

  2. Walking or Waiting? Topologies of the Breeding Ground in Malaria Control

    PubMed Central

    Lezaun, Javier

    2013-01-01

    Few places bear as much historical and scientific significance as the breeding ground, the accumulation of stagnant water where disease-carrying insects lay their eggs. Since the turn of the twentieth century, when mosquitoes of the Anopheles genus were identified as the vector of malaria transmission, these aquatic habitats have been a key object of epidemiological research and public health intervention against the disease. Yet the breeding ground can be incorporated into a number of different topologies, each implying a different spatialization of malaria and a distinct imagination of what kind of mosquito control is ‘doable'. A contemporary example of malaria control in Dar es Salaam, Tanzania, illuminates an essential tension between what we characterize as territorial and bionomic approaches to the breeding ground—that is, between control strategies premised on treating all mosquito habitats within a given region, and those that prioritize certain sites on the basis of their position within ecological networks. Each topology localizes the breeding ground by reference to a distinct set of relations, and thus advances an idiosyncratic understanding of what sort of research is worthwhile conducting and what kinds of intervention are sustainable. The multiple ways in which the breeding ground can become an object of research and action clarifies the role of topology as an infra-logic of public health, and makes explicit the politics implicit in efforts to bring different orders of the local to scale. PMID:25937707

  3. Factors controlling As and U in shallow ground water, southern Carson Desert, Nevada

    USGS Publications Warehouse

    Welch, A.H.; Lico, M.S.

    1998-01-01

    Unusually high As and U concentrations (> 100 ??g/L) are widespread in shallow ground water beneath the southern Carson Desert. The high concentrations, which locally exceed 1000 ??g/L, are of concern from a human health standpoint because the shallow ground water is used for domestic supply. Possible affects on wildlife are also of concern because the ground water flows into shallow lakes and marshes within wildlife refuges. Arsenic and U concentrations in ground water of the southern Carson Desert appear to be affected by evaporative concentration, redox reactions, and adsorption. The relation of these elements with Cl suggest that most of the high concentrations can be attributed to evaporative concentration of Carson River water, the primary source of recharge. Some ground water contains higher As and U concentrations that cannot be explained by evaporative concentration alone. Oxidation-reduction reactions, involving metal oxides and sedimentary-organic matter, appear to contribute As, U, inorganic C, Fe and Mn to the ground water. Arsenic in Fe-oxide was confirmed by chemical extraction and is consistent with laboratory adsorption studies. Uranium in both sedimentary-organic C and Fe-oxide coatings has been confirmed by fission tracks and petrographic examination. Arsenic concentrations in the ground water and chemical extracts of aquifer sediments are broadly consistent with adsorption as a control on some dissolved As concentrations. An apparent loss of As from some ground water as evaporative concentration proceeds is consistent with adsorption as a control on As. However, evidence for adsorption should be viewed with caution, because the adsorption model used values for the adsorbent that have not been shown to be valid for the aquifer sediments throughout the southern Carson Desert. Hydrologic and geochemical conditions in the Carson Desert are similar to other areas with high As and U concentrations in ground water, including the Salton Sea basin and

  4. Vibrating barrier: a novel device for the passive control of structures under ground motion

    PubMed Central

    Cacciola, P.; Tombari, A.

    2015-01-01

    A novel device, called vibrating barrier (ViBa), that aims to reduce the vibrations of adjacent structures subjected to ground motion waves is proposed. The ViBa is a structure buried in the soil and detached from surrounding buildings that is able to absorb a significant portion of the dynamic energy arising from the ground motion. The working principle exploits the dynamic interaction among vibrating structures due to the propagation of waves through the soil, namely the structure–soil–structure interaction. The underlying theoretical aspects of the novel control strategy are scrutinized along with its numerical modelling. Closed-form solutions are also derived to design the ViBa in the case of harmonic excitation. Numerical and experimental analyses are performed in order to investigate the efficiency of the device in mitigating the effects of ground motion waves on the structural response. A significant reduction in the maximum structural acceleration of 87% has been achieved experimentally. PMID:26345731

  5. Mitigation of ground motion effects in linear accelerators via feed-forward control

    NASA Astrophysics Data System (ADS)

    Pfingstner, J.; Artoos, K.; Charrondiere, C.; Janssens, St.; Patecki, M.; Renier, Y.; Schulte, D.; Tomás, R.; Jeremie, A.; Kubo, K.; Kuroda, S.; Naito, T.; Okugi, T.; Tauchi, T.; Terunuma, N.

    2014-12-01

    Ground motion is a severe problem for many particle accelerators, since it excites beam oscillations, which decrease the beam quality and create beam-beam offset (at colliders). Orbit feedback systems can only compensate ground motion effects at frequencies significantly smaller than the beam repetition rate. In linear colliders, where the repetition rate is low, additional counter measures have to be put in place. For this reason, a ground motion mitigation method based on feed-forward control is presented in this paper. It has several advantages compared to other techniques (stabilization systems and intratrain feedback systems) such as cost reduction and potential performance improvement. An analytical model is presented that allows the derivation of hardware specification and performance estimates for a specific accelerator and ground motion model. At the Accelerator Test Facility (ATF2), ground motion sensors have been installed to verify the feasibility of important parts of the mitigation strategy. In experimental studies, it has been shown that beam excitations due to ground motion can be predicted from ground motion measurements on a pulse-to-pulse basis. Correlations of up to 80% between the estimated and measured orbit jitter have been observed. Additionally, an orbit jitter source was identified and has been removed, which halved the orbit jitter power at ATF2 and shows that the feed-forward scheme is also very useful for the detection of installation issues. We believe that the presented mitigation method has the potential to reduce costs and improve the performance of linear colliders and potentially other linear accelerators.

  6. Control and learning for intelligent mobility of unmanned ground vehicles in complex terrains

    NASA Astrophysics Data System (ADS)

    Trentini, M.; Beckman, B.; Digney, B.

    2005-05-01

    The Autonomous Intelligent Systems program at Defence R&D Canada-Suffield envisions autonomous systems contributing to decisive operations in the urban battle space. Creating effective intelligence for these systems demands advances in perception, world representation, navigation, and learning. In the land environment, these scientific areas have garnered much attention, while largely ignoring the problem of locomotion in complex terrain. This is a gap in robotics research, where sophisticated algorithms are needed to coordinate and control robotic locomotion in unknown, highly complex environments. Unlike traditional control problems, intuitive and systematic control tools for robotic locomotion do not readily exist thus limiting their practical application. This paper addresses the mobility problem for unmanned ground vehicles, defined here as the autonomous maneuverability of unmanned ground vehicles in unknown, highly complex environments. It discusses the progress and future direction of intelligent mobility research at Defence R&D Canada-Suffield and presents the research tools, topics and plans to address this critical research gap.

  7. Geological features that contribute to ground control problems in underground coal mines. Information circular/1993

    SciTech Connect

    Shea-Albin, V.R.

    1993-01-01

    A major portion of ground control problems encountered in underground coal mines can be attributed to geologic features in the strata surrounding the extracted coal seam. The U.S. Bureau of Mines has compiled information from several sources on the geological features that contribute to ground control problems in underground coal mines. The compilation includes sedimentary features such as paleochannels, crevasse splays, clastic dikes, mold and cast structures, concretions, lithologic factors, and structural features, such as folds, fractures, joints, cleat, and faults. The compiled information will aid in identifying the features, predicting their occurrence in advance of mining, and controlling or minimizing roof failure when these features are encountered in an underground coal mine.

  8. Fracture control of ground water flow and water chemistry in a rock aquitard

    USGS Publications Warehouse

    Eaton, T.T.; Anderson, M.P.; Bradbury, K.R.

    2007-01-01

    There are few studies on the hydrogeology of sedimentary rock aquitards although they are important controls in regional ground water flow systems. We formulate and test a three-dimensional (3D) conceptual model of ground water flow and hydrochemistry in a fractured sedimentary rock aquitard to show that flow dynamics within the aquitard are more complex than previously believed. Similar conceptual models, based on regional observations and recently emerging principles of mechanical stratigraphy in heterogeneous sedimentary rocks, have previously been applied only to aquifers, but we show that they are potentially applicable to aquitards. The major elements of this conceptual model, which is based on detailed information from two sites in the Maquoketa Formation in southeastern Wisconsin, include orders of magnitude contrast between hydraulic diffusivity (K/Ss) of fractured zones and relatively intact aquitard rock matrix, laterally extensive bedding-plane fracture zones extending over distances of over 10 km, very low vertical hydraulic conductivity of thick shale-rich intervals of the aquitard, and a vertical hydraulic head profile controlled by a lateral boundary at the aquitard subcrop, where numerous surface water bodies dominate the shallow aquifer system. Results from a 3D numerical flow model based on this conceptual model are consistent with field observations, which did not fit the typical conceptual model of strictly vertical flow through an aquitard. The 3D flow through an aquitard has implications for predicting ground water flow and for planning and protecting water supplies. ?? 2007 National Ground Water Association.

  9. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    PubMed

    Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M; Campos, Mercedes

    2015-01-01

    Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history), the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard), or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae) in 2,528 olive groves in Andalusia (Spain) from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention. PMID:25646778

  10. Is Ground Cover Vegetation an Effective Biological Control Enhancement Strategy against Olive Pests?

    PubMed Central

    Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M.; Campos, Mercedes

    2015-01-01

    Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history), the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard), or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae) in 2,528 olive groves in Andalusia (Spain) from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention. PMID:25646778

  11. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    PubMed

    Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M; Campos, Mercedes

    2015-01-01

    Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history), the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard), or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae) in 2,528 olive groves in Andalusia (Spain) from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  12. Processes controlling Sr in surface and ground waters of Tertiary tholeiitic flood basalts in Northern Iceland

    NASA Astrophysics Data System (ADS)

    Fridriksson, Thráinn; Arnórsson, Stefán; Bird, Dennis K.

    2009-11-01

    Strontium concentrations of 253 natural water samples from Skagafjördur, a Tertiary tholeiitic flood basalt region in northern Iceland range between 0.10 and 28 ppb. Surface environments (rivers, lakes, and peat soil waters) include the whole range of observed Sr concentrations whereas the Sr concentrations of ground waters are, in most cases, <3.5 ppb. Concentrations of Sr derived from basalt dissolution (i.e., rock-derived Sr) in waters of rivers and lakes exhibit a near linear correlation with the concentration of rock-derived Ca with a median molar Ca/Sr ratio of 1350. This systematic correlation suggests that Ca and Sr concentrations are controlled by weathering processes, i.e., the extent of dissolution of the basalt. The relative mobility of Sr during weathering in Skagafjördur is approximately half that of Ca, which is consistent with observed relative mobilities of these elements elsewhere in Iceland and in other basaltic regions. Peat soil waters commonly have lower concentrations of Sr and higher Ca concentrations than rivers and lakes, and molar ratios of rock-derived Ca to Sr in peat soil waters exhibit no systematic pattern. In several cases calculated concentrations of rock-derived Sr in peat soil waters yield negative values, suggesting a mineralogic sink for Sr in these waters. The low Sr concentrations in cold and thermal ground waters (<3.5 ppb) suggest mineralogic control over Sr in the ground water systems. Precipitation of secondary Sr minerals such as strontianite and celestite is ruled out as the ground waters are understaturated with respect to these minerals. Ground waters are characterized by high Ca/Sr molar ratios (˜5000 compared to bedrock Ca/Sr ratio of 730) suggesting that Sr is being preferentially incorporated (relative to Ca) into secondary minerals. The secondary minerals present in the bedrock in Skagafjördur that can preferentially incorporate Sr include zeolites, such as heulandite, chabazite, and thomsonite, and smectite

  13. Review of Ground Systems Development and Operations (GSDO) Tools for Verifying Command and Control Software

    NASA Technical Reports Server (NTRS)

    Aguilar, Michael L.; Bonanne, Kevin H.; Favretto, Jeffrey A.; Jackson, Maddalena M.; Jones, Stephanie L.; Mackey, Ryan M.; Sarrel, Marc A.; Simpson, Kimberly A.

    2014-01-01

    The Exploration Systems Development (ESD) Standing Review Board (SRB) requested the NASA Engineering and Safety Center (NESC) conduct an independent review of the plan developed by Ground Systems Development and Operations (GSDO) for identifying models and emulators to create a tool(s) to verify their command and control software. The NESC was requested to identify any issues or weaknesses in the GSDO plan. This document contains the outcome of the NESC review.

  14. Shuttle Payload Ground Command and Control: An Experiment Implementation Combustion Module-2 Software Development, STS-107

    NASA Technical Reports Server (NTRS)

    Carek, David Andrew

    2003-01-01

    This presentation covers the design of a command and control architecture developed by the author for the Combustion Module-2 microgravity experiment, which flew aboard the STS-107 Shuttle mission, The design was implemented to satisfy a hybrid network that utilized TCP/IP for both the onboard segment and ground segment, with an intermediary unreliable transport for the space to ground segment. With the infusion of Internet networking technologies into Space Shuttle, Space Station, and spacecraft avionics systems, comes the need for robust methodologies for ground command and control. Considerations of high bit error links, and unreliable transport over intermittent links must be considered in such systems. Internet protocols applied to these systems, coupled with the appropriate application layer protections, can provide adequate communication architectures for command and control. However, there are inherent limitations and additional complexities added by the use of Internet protocols that must be considered during the design. This presentation will discuss the rationale for the: framework and protocol algorithms developed by the author. A summary of design considerations, implantation issues, and learned lessons will be will be presented. A summary of mission results using this communications architecture will be presented. Additionally, areas of further needed investigation will be identified.

  15. Urea for SCR-based NOx Control Systems and Potential Impacts to Ground Water Resources

    SciTech Connect

    Layton, D.

    2002-01-03

    One of the key challenges facing manufacturers of diesel engines for light- and heavy-duty vehicles is the development of technologies for controlling emissions of nitrogen oxides, In this regard, selective catalytic reduction (SCR) systems represent control technology that can potentially achieve the NOx removal efficiencies required to meet new U.S. EPA standards. SCR systems rely on a bleed stream of urea solution into exhaust gases prior to catalytic reduction. While urea's role in this emission control technology is beneficial, in that it supports reduced NOx emissions, it can also be an environmental threat to ground water quality. This would occur if it is accidentally released to soils because once in that environmental medium, urea is subsequently converted to nitrate--which is regulated under the U.S. EPA's primary drinking water standards. Unfortunately, nitrate contamination of ground waters is already a significant problem across the U.S. Historically, the primary sources of nitrate in ground waters have been septic tanks and fertilizer applications. The basic concern over nitrate contamination is the potential health effects associated with drinking water containing elevated levels of nitrate. Specifically, consumption of nitrate-contaminated water can cause a blood disorder in infants known as methemoglobinemia.

  16. Tailoring NIST Security Controls for the Ground System: Selection and Implementation -- Recommendations for Information System Owners

    NASA Technical Reports Server (NTRS)

    Takamura, Eduardo; Mangum, Kevin

    2016-01-01

    The National Aeronautics and Space Administration (NASA) invests millions of dollars in spacecraft and ground system development, and in mission operations in the pursuit of scientific knowledge of the universe. In recent years, NASA sent a probe to Mars to study the Red Planet's upper atmosphere, obtained high resolution images of Pluto, and it is currently preparing to find new exoplanets, rendezvous with an asteroid, and bring a sample of the asteroid back to Earth for analysis. The success of these missions is enabled by mission assurance. In turn, mission assurance is backed by information assurance. The information systems supporting NASA missions must be reliable as well as secure. NASA - like every other U.S. Federal Government agency - is required to manage the security of its information systems according to federal mandates, the most prominent being the Federal Information Security Management Act (FISMA) of 2002 and the legislative updates that followed it. Like the management of enterprise information technology (IT), federal information security management takes a "one-size fits all" approach for protecting IT systems. While this approach works for most organizations, it does not effectively translate into security of highly specialized systems such as those supporting NASA missions. These systems include command and control (C&C) systems, spacecraft and instrument simulators, and other elements comprising the ground segment. They must be carefully configured, monitored and maintained, sometimes for several years past the missions' initially planned life expectancy, to ensure the ground system is protected and remains operational without any compromise of its confidentiality, integrity and availability. Enterprise policies, processes, procedures and products, if not effectively tailored to meet mission requirements, may not offer the needed security for protecting the information system, and they may even become disruptive to mission operations

  17. The Next Generation of Ground Operations Command and Control; Scripting in C Sharp and Visual Basic

    NASA Technical Reports Server (NTRS)

    Ritter, George; Pedoto, Ramon

    2010-01-01

    This slide presentation reviews the use of scripting languages in Ground Operations Command and Control. It describes the use of scripting languages in a historical context, the advantages and disadvantages of scripts. It describes the Enhanced and Redesigned Scripting (ERS) language, that was designed to combine the features of a scripting language and the graphical and IDE richness of a programming language with the utility of scripting languages. ERS uses the Microsoft Visual Studio programming environment and offers custom controls that enable an ERS developer to extend the Visual Basic and C sharp language interface with the Payload Operations Integration Center (POIC) telemetry and command system.

  18. Ultra-low-volume ground aerosols of technical malathion for the control of Aedes aegypti L

    PubMed Central

    Pant, C. P.; Mount, G. A.; Jatanasen, Sujarti; Mathis, H. L.

    1971-01-01

    The efficacy of malathion aerosols applied from the ground was evaluated for the control of Ae. aegypti. Several techniques for applying the aerosols to an inhabited locality were investigated, and it was found that excellent control of adult mosquitos could be obtained with a dosage of 438 ml/ha. Two treatments carried out 3 days apart enabled the adult mosquito population to be reduced by 99%, and it took about 2 weeks to regain its pretreatment level. Schedules of treatment and strategies to be applied during an epidemic are discussed. PMID:5317014

  19. Ground Control Point - Wireless System Network for UAV-based environmental monitoring applications

    NASA Astrophysics Data System (ADS)

    Mejia-Aguilar, Abraham

    2016-04-01

    In recent years, Unmanned Aerial Vehicles (UAV) have seen widespread civil applications including usage for survey and monitoring services in areas such as agriculture, construction and civil engineering, private surveillance and reconnaissance services and cultural heritage management. Most aerial monitoring services require the integration of information acquired during the flight (such as imagery) with ground-based information (such as GPS information or others) for improved ground truth validation. For example, to obtain an accurate 3D and Digital Elevation Model based on aerial imagery, it is necessary to include ground-based information of coordinate points, which are normally acquired with surveying methods based on Global Position Systems (GPS). However, GPS surveys are very time consuming and especially for longer time series of monitoring data repeated GPS surveys are necessary. In order to improve speed of data collection and integration, this work presents an autonomous system based on Waspmote technologies build on single nodes interlinked in a Wireless Sensor Network (WSN) star-topology for ground based information collection and later integration with surveying data obtained by UAV. Nodes are designed to be visible from the air, to resist extreme weather conditions with low-power consumption. Besides, nodes are equipped with GPS as well as Inertial Measurement Unit (IMU), accelerometer, temperature and soil moisture sensors and thus provide significant advantages in a broad range of applications for environmental monitoring. For our purpose, the WSN transmits the environmental data with 3G/GPRS to a database on a regular time basis. This project provides a detailed case study and implementation of a Ground Control Point System Network for UAV-based vegetation monitoring of dry mountain grassland in the Matsch valley, Italy.

  20. Fracture control of ground water flow and water chemistry in a rock aquitard.

    PubMed

    Eaton, Timothy T; Anderson, Mary P; Bradbury, Kenneth R

    2007-01-01

    There are few studies on the hydrogeology of sedimentary rock aquitards although they are important controls in regional ground water flow systems. We formulate and test a three-dimensional (3D) conceptual model of ground water flow and hydrochemistry in a fractured sedimentary rock aquitard to show that flow dynamics within the aquitard are more complex than previously believed. Similar conceptual models, based on regional observations and recently emerging principles of mechanical stratigraphy in heterogeneous sedimentary rocks, have previously been applied only to aquifers, but we show that they are potentially applicable to aquitards. The major elements of this conceptual model, which is based on detailed information from two sites in the Maquoketa Formation in southeastern Wisconsin, include orders of magnitude contrast between hydraulic diffusivity (K/S(s)) of fractured zones and relatively intact aquitard rock matrix, laterally extensive bedding-plane fracture zones extending over distances of over 10 km, very low vertical hydraulic conductivity of thick shale-rich intervals of the aquitard, and a vertical hydraulic head profile controlled by a lateral boundary at the aquitard subcrop, where numerous surface water bodies dominate the shallow aquifer system. Results from a 3D numerical flow model based on this conceptual model are consistent with field observations, which did not fit the typical conceptual model of strictly vertical flow through an aquitard. The 3D flow through an aquitard has implications for predicting ground water flow and for planning and protecting water supplies.

  1. Integrated Vehicle Ground Vibration Testing in Support of Launch Vehicle Loads and Controls Analysis

    NASA Technical Reports Server (NTRS)

    Askins, Bruce R.; Davis, Susan R.; Salyer, Blaine H.; Tuma, Margaret L.

    2008-01-01

    All structural systems possess a basic set of physical characteristics unique to that system. These unique physical characteristics include items such as mass distribution and damping. When specified, they allow engineers to understand and predict how a structural system behaves under given loading conditions and different methods of control. These physical properties of launch vehicles may be predicted by analysis or measured by certain types of tests. Generally, these properties are predicted by analysis during the design phase of a launch vehicle and then verified by testing before the vehicle becomes operational. A ground vibration test (GVT) is intended to measure by test the fundamental dynamic characteristics of launch vehicles during various phases of flight. During the series of tests, properties such as natural frequencies, mode shapes, and transfer functions are measured directly. These data will then be used to calibrate loads and control systems analysis models for verifying analyses of the launch vehicle. NASA manned launch vehicles have undergone ground vibration testing leading to the development of successful launch vehicles. A GVT was not performed on the inaugural launch of the unmanned Delta III which was lost during launch. Subsequent analyses indicated had a GVT been performed, it would have identified instability issues avoiding loss of the vehicle. This discussion will address GVT planning, set-up, execution and analyses, for the Saturn and Shuttle programs, and will also focus on the current and on-going planning for the Ares I and V Integrated Vehicle Ground Vibration Test (IVGVT).

  2. Scaled Composites' Doug Shane examines the screen of his ground control station during tests in New

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Scaled Composites' Doug Shane examines the screen of his ground control station during tests in New Mexico. Shane used this configuration as the ground control station to remotely pilot the Proteus aircraft during a NASA sponsored series of test flights. The unique Proteus aircraft served as a test bed for NASA-sponsored flight tests designed to validate collision-avoidance technologies proposed for uninhabited aircraft. The tests, flown over southern New Mexico in March, 2002, used the Proteus as a surrogate uninhabited aerial vehicle (UAV) while three other aircraft flew toward the Proteus from various angles on simulated collision courses. Radio-based 'detect, see and avoid' equipment on the Proteus successfully detected the other aircraft and relayed that information to a remote pilot on the ground at Las Cruces Airport. The pilot then transmitted commands to the Proteus to maneuver it away from the potential collisions. The flight demonstration, sponsored by NASA Dryden Flight Research Center, New Mexico State University, Scaled Composites, the U.S. Navy and Modern Technology Solutions, Inc., were intended to demonstrate that UAVs can be flown safely and compatibly in the same skies as piloted aircraft.

  3. Robust H∞ output-feedback control for path following of autonomous ground vehicles

    NASA Astrophysics Data System (ADS)

    Hu, Chuan; Jing, Hui; Wang, Rongrong; Yan, Fengjun; Chadli, Mohammed

    2016-03-01

    This paper presents a robust H∞ output-feedback control strategy for the path following of autonomous ground vehicles (AGVs). Considering the vehicle lateral velocity is usually hard to measure with low cost sensor, a robust H∞ static output-feedback controller based on the mixed genetic algorithms (GA)/linear matrix inequality (LMI) approach is proposed to realize the path following without the information of the lateral velocity. The proposed controller is robust to the parametric uncertainties and external disturbances, with the parameters including the tire cornering stiffness, vehicle longitudinal velocity, yaw rate and road curvature. Simulation results based on CarSim-Simulink joint platform using a high-fidelity and full-car model have verified the effectiveness of the proposed control approach.

  4. Tug fleet and ground operations schedules and controls. Volume 2: part 2, addenda

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The results of a study to assess the tug safing requirements at postlanding are presented. The study considered the normal (green light) conditions from orbiter landing to completion of preparations for the next launch. Normal tug ground turnaround operations include handling and transportation activities and the performance of inspections, tests, and checkout functions. These activities dictate that hazards to ground personnel, the tug, GSE, facilities, and ecology be reduced to the lowest practical level consistent with program objectives, cost, and schedules. During flight operations, the tug contains energy sources that constitute potential hazards but are required for mission accomplishment. These potential hazards have been reduced to an acceptable level for flight operation by design features and by providing for control of energy sources.

  5. Ground-based rodent control in a remote Hawaiian rainforest on Maui

    USGS Publications Warehouse

    Malcolm, T.R.; Swinnerton, K.J.; Groombridge, J.J.; Sparklin, B.D.; Brosius, C.N.; Vetter, J.P.; Foster, J.T.

    2008-01-01

    Effective control of introduced mammalian predators is essential to the recovery of native bird species in Hawai'i. Between August 1996 and December 2004, introduced rodents were controlled within three home ranges of the Po'ouli Melamprosops phaeosoma, a critically endangered Hawaiian honeycreeper. Rats were controlled using a combination of ground-based rodenticide (0.005% diphacinone) application and snap traps. Beginning in August 2001, we monitored the effectiveness of these rodent control efforts. Relative abundances of Black Rats Rattus rattus and Polynesian Rats R. exulans were measured in each of five snap-trapping grids seven times over a 35-month period. Rat populations decreased inside of the rodent control areas, but control effectiveness differed between rat species. During the first year of monitoring, target control levels for R. rattus were consistently achieved in only one of the rodent control areas. Control techniques were refined in areas failing to meet targets. Subsequently, we achieved target control levels for R. rattus more consistently in all three rodent control areas. However, relative abundances of R. exulans did not differ between rodent control and reference areas, indicating that our rodent control techniques were insufficient to reduce population levels of this species. These findings signify a need for further improvement of rodent control methods in Hawai'i, especially for Polynesian Rats, and demonstrate the critical importance of periodic monitoring of the response of rodent populations to management. In the future, managers may need to design rodent control operations targeting R. rattus and R. exulans independently to achieve best results.

  6. Optical Communication System for Remote Monitoring and Adaptive Control of Distributed Ground Sensors Exhibiting Collective Intelligence

    SciTech Connect

    Cameron, S.M.; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

    1998-11-01

    Comprehensive management of the battle-space has created new requirements in information management, communication, and interoperability as they effect surveillance and situational awareness. The objective of this proposal is to expand intelligent controls theory to produce a uniquely powerful implementation of distributed ground-based measurement incorporating both local collective behavior, and interoperative global optimization for sensor fusion and mission oversight. By using a layered hierarchal control architecture to orchestrate adaptive reconfiguration of autonomous robotic agents, we can improve overall robustness and functionality in dynamic tactical environments without information bottlenecks. In this concept, each sensor is equipped with a miniaturized optical reflectance modulator which is interactively monitored as a remote transponder using a covert laser communication protocol from a remote mothership or operative. Robot data-sharing at the ground level can be leveraged with global evaluation criteria, including terrain overlays and remote imaging data. Information sharing and distributed intelli- gence opens up a new class of remote-sensing applications in which small single-function autono- mous observers at the local level can collectively optimize and measure large scale ground-level signals. AS the need for coverage and the number of agents grows to improve spatial resolution, cooperative behavior orchestrated by a global situational awareness umbrella will be an essential ingredient to offset increasing bandwidth requirements within the net. A system of the type described in this proposal will be capable of sensitively detecting, tracking, and mapping spatial distributions of measurement signatures which are non-stationary or obscured by clutter and inter- fering obstacles by virtue of adaptive reconfiguration. This methodology could be used, for example, to field an adaptive ground-penetrating radar for detection of underground structures in

  7. Design and implementation of a microcomputer-based user interface controller for bursted data communications satellite ground terminals

    NASA Technical Reports Server (NTRS)

    Shalkhauser, Mary Jo W.

    1988-01-01

    The NASA Lewis Research Center is developing a laboratory-based satellite communications test bed for evaluation of state-of-the-art communications hardware and systems. Most of the digital components of the ground terminals are being constructed in-house at NASA Lewis. One of the ground terminal subsystems, the user interface controller, controls the connection and disconnection of all users to the communication network. The role of the user interface controller in the ground terminal is described and the design and implementation of the microcomputer-based subsystem is discussed.

  8. A tube-based robust nonlinear predictive control approach to semiautonomous ground vehicles

    NASA Astrophysics Data System (ADS)

    Gao, Yiqi; Gray, Andrew; Tseng, H. Eric; Borrelli, Francesco

    2014-06-01

    This paper proposes a robust control framework for lane-keeping and obstacle avoidance of semiautonomous ground vehicles. It presents a systematic way of enforcing robustness during the MPC design stage. A robust nonlinear model predictive controller (RNMPC) is used to help the driver navigating the vehicle in order to avoid obstacles and track the road centre line. A force-input nonlinear bicycle vehicle model is developed and used in the RNMPC control design. A robust invariant set is used in the RNMPC design to guarantee that state and input constraints are satisfied in the presence of disturbances and model error. Simulations and experiments on a vehicle show the effectiveness of the proposed framework.

  9. Controls on coral-ground development along the northern Mesoamerican Reef tract.

    PubMed

    Rodríguez-Martínez, Rosa E; Jordán-Garza, Adán G; Maldonado, Miguel A; Blanchon, Paul

    2011-01-01

    Coral-grounds are reef communities that colonize rocky substratum but do not form framework or three-dimensional reef structures. To investigate why, we used video transects and underwater photography to determine the composition, structure and status of a coral-ground community located on the edge of a rocky terrace in front of a tourist park, Xcaret, in the northern Mesoamerican Reef tract, Mexico. The community has a relatively low coral, gorgonian and sponge cover (<10%) and high algal cover (>40%). We recorded 23 species of Scleractinia, 14 species of Gorgonacea and 30 species of Porifera. The coral community is diverse but lacks large coral colonies, being dominated instead by small, sediment-tolerant, and brooding species. In these small colonies, the abundance of potentially lethal interactions and partial mortality is high but decreases when colonies are larger than 40 cm. Such characteristics are consistent with an environment control whereby storm waves periodically remove larger colonies and elevate sediment flux. The community only survives these storm conditions due to its slope-break location, which ensures lack of burial and continued local recruitment. A comparison with similar coral-ground communities in adjacent areas suggests that the narrow width of the rock terrace hinders sediment stabilization, thereby ensuring that communities cannot escape bottom effects and develop into three-dimensional reef structures on geological time scales. PMID:22194839

  10. Controls on Coral-Ground Development along the Northern Mesoamerican Reef Tract

    PubMed Central

    Rodríguez-Martínez, Rosa E.; Jordán-Garza, Adán G.; Maldonado, Miguel A.; Blanchon, Paul

    2011-01-01

    Coral-grounds are reef communities that colonize rocky substratum but do not form framework or three-dimensional reef structures. To investigate why, we used video transects and underwater photography to determine the composition, structure and status of a coral-ground community located on the edge of a rocky terrace in front of a tourist park, Xcaret, in the northern Mesoamerican Reef tract, Mexico. The community has a relatively low coral, gorgonian and sponge cover (<10%) and high algal cover (>40%). We recorded 23 species of Scleractinia, 14 species of Gorgonacea and 30 species of Porifera. The coral community is diverse but lacks large coral colonies, being dominated instead by small, sediment-tolerant, and brooding species. In these small colonies, the abundance of potentially lethal interactions and partial mortality is high but decreases when colonies are larger than 40 cm. Such characteristics are consistent with an environment control whereby storm waves periodically remove larger colonies and elevate sediment flux. The community only survives these storm conditions due to its slope-break location, which ensures lack of burial and continued local recruitment. A comparison with similar coral-ground communities in adjacent areas suggests that the narrow width of the rock terrace hinders sediment stabilization, thereby ensuring that communities cannot escape bottom effects and develop into three-dimensional reef structures on geological time scales. PMID:22194839

  11. Resetting transcription factor control circuitry toward ground-state pluripotency in human.

    PubMed

    Takashima, Yasuhiro; Guo, Ge; Loos, Remco; Nichols, Jennifer; Ficz, Gabriella; Krueger, Felix; Oxley, David; Santos, Fatima; Clarke, James; Mansfield, William; Reik, Wolf; Bertone, Paul; Smith, Austin

    2014-09-11

    Current human pluripotent stem cells lack the transcription factor circuitry that governs the ground state of mouse embryonic stem cells (ESC). Here, we report that short-term expression of two components, NANOG and KLF2, is sufficient to ignite other elements of the network and reset the human pluripotent state. Inhibition of ERK and protein kinase C sustains a transgene-independent rewired state. Reset cells self-renew continuously without ERK signaling, are phenotypically stable, and are karyotypically intact. They differentiate in vitro and form teratomas in vivo. Metabolism is reprogrammed with activation of mitochondrial respiration as in ESC. DNA methylation is dramatically reduced and transcriptome state is globally realigned across multiple cell lines. Depletion of ground-state transcription factors, TFCP2L1 or KLF4, has marginal impact on conventional human pluripotent stem cells but collapses the reset state. These findings demonstrate feasibility of installing and propagating functional control circuitry for ground-state pluripotency in human cells. PMID:25215486

  12. Resetting Transcription Factor Control Circuitry toward Ground-State Pluripotency in Human

    PubMed Central

    Takashima, Yasuhiro; Guo, Ge; Loos, Remco; Nichols, Jennifer; Ficz, Gabriella; Krueger, Felix; Oxley, David; Santos, Fatima; Clarke, James; Mansfield, William; Reik, Wolf; Bertone, Paul; Smith, Austin

    2014-01-01

    Summary Current human pluripotent stem cells lack the transcription factor circuitry that governs the ground state of mouse embryonic stem cells (ESC). Here, we report that short-term expression of two components, NANOG and KLF2, is sufficient to ignite other elements of the network and reset the human pluripotent state. Inhibition of ERK and protein kinase C sustains a transgene-independent rewired state. Reset cells self-renew continuously without ERK signaling, are phenotypically stable, and are karyotypically intact. They differentiate in vitro and form teratomas in vivo. Metabolism is reprogrammed with activation of mitochondrial respiration as in ESC. DNA methylation is dramatically reduced and transcriptome state is globally realigned across multiple cell lines. Depletion of ground-state transcription factors, TFCP2L1 or KLF4, has marginal impact on conventional human pluripotent stem cells but collapses the reset state. These findings demonstrate feasibility of installing and propagating functional control circuitry for ground-state pluripotency in human cells. PMID:25215486

  13. Hydrogeologic controls on ground-water and contaminant discharge to the Columbia River near the Hanford Townsite

    SciTech Connect

    Luttrell, S.P.; Newcomer, D.R.; Teel, S.S.; Vermeul, V.R.

    1992-11-01

    The purpose of this study is to quantify ground-water and contaminant discharge to the Columbia River in the Hanford Townsite vicinity. The primary objectives of the work are to: describe the hydrogeologic setting and controls on ground-water movement and contaminant discharge to the Columbia River; understand the river/aquifer relationship and its effects on contaminant discharge to the Columbia River; quantify the ground-water and contaminant mass discharge to the Columbia River; and provide data that may be useful for a three-dimensional model of ground-water flow and contaminant transport in the Hanford Townsite study area. The majority of ground-water contamination occurs within the unconfined aquifer; therefore, ground-water and contaminant discharge from the unconfined aquifer is the emphasis of this study. The period of study is primarily from June 1990 through March 1992.

  14. Entomopathogenic Nematodes for Control of Insect Pests Above and Below Ground with Comments on Commercial Production

    PubMed Central

    Lacey, Lawrence A.; Georgis, Ramon

    2012-01-01

    Entomopathogenic nematodes (EPNs) have been utilized in classical, conservation, and augmentative biological control programs. The vast majority of applied research has focused on their potential as inundatively applied augmentative biological control agents. Extensive research over the past three decades has demonstrated both their successes and failures for control of insect pests of crops, ornamental plants, trees and lawn and turf. In this paper we present highlights of their development for control of insect pests above and below ground. The target insects include those from foliar, soil surface, cryptic and subterranean habitats. Advances in mass-production and formulation technology of EPNs, the discovery of numerous efficacious isolates/strains, and the desirability of reducing pesticide usage have resulted in a surge of commercial use and development of EPNs. Commercially produced EPNs are currently in use for control of scarab larvae in lawns and turf, fungus gnats in mushroom production, invasive mole crickets in lawn and turf, black vine weevil in nursery plants, and Diaprepes root weevil in citrus in addition to other pest insects. However, demonstrated successful control of several other insects, often has not lead to capture of a significant share of the pesticide market for these pests. PMID:23482993

  15. Reconstructing 3D coastal cliffs from airborne oblique photographs without ground control points

    NASA Astrophysics Data System (ADS)

    Dewez, T. J. B.

    2014-05-01

    Coastal cliff collapse hazard assessment requires measuring cliff face topography at regular intervals. Terrestrial laser scanner techniques have proven useful so far but are expensive to use either through purchasing the equipment or through survey subcontracting. In addition, terrestrial laser surveys take time which is sometimes incompatible with the time during with the beach is accessible at low-tide. By comparison, structure from motion techniques (SFM) are much less costly to implement, and if airborne, acquisition of several kilometers of coastline can be done in a matter of minutes. In this paper, the potential of GPS-tagged oblique airborne photographs and SFM techniques is examined to reconstruct chalk cliff dense 3D point clouds without Ground Control Points (GCP). The focus is put on comparing the relative 3D point of views reconstructed by Visual SFM with their synchronous Solmeta Geotagger Pro2 GPS locations using robust estimators. With a set of 568 oblique photos, shot from the open door of an airplane with a triplet of synchronized Nikon D7000, GPS and SFM-determined view point coordinates converge to X: ±31.5 m; Y: ±39.7 m; Z: ±13.0 m (LE66). Uncertainty in GPS position affects the model scale, angular attitude of the reference frame (the shoreline ends up tilted by 2°) and absolute positioning. Ground Control Points cannot be avoided to orient such models.

  16. A ground track control algorithm for the Topographic Mapping Laser Altimeter (TMLA)

    NASA Technical Reports Server (NTRS)

    Blaes, V.; Mcintosh, R.; Roszman, L.; Cooley, J.

    1993-01-01

    The results of an analysis of an algorithm that will provide autonomous onboard orbit control using orbits determined with Global Positioning System (GPS) data. The algorithm uses the GPS data to (1) compute the ground track error relative to a fixed longitude grid, and (2) determine the altitude adjustment required to correct the longitude error. A program was written on a personal computer (PC) to test the concept for numerous altitudes and values of solar flux using a simplified orbit model including only the J sub 2 zonal harmonic and simple orbit decay computations. The algorithm was then implemented in a precision orbit propagation program having a full range of perturbations. The analysis showed that, even with all perturbations (including actual time histories of solar flux variation), the algorithm could effectively control the spacecraft ground track and yield more than 99 percent Earth coverage in the time required to complete one coverage cycle on the fixed grid (220 to 230 days depending on altitude and overlap allowance).

  17. Validation of space/ground antenna control algorithms using a computer-aided design tool

    NASA Technical Reports Server (NTRS)

    Gantenbein, Rex E.

    1995-01-01

    The validation of the algorithms for controlling the space-to-ground antenna subsystem for Space Station Alpha is an important step in assuring reliable communications. These algorithms have been developed and tested using a simulation environment based on a computer-aided design tool that can provide a time-based execution framework with variable environmental parameters. Our work this summer has involved the exploration of this environment and the documentation of the procedures used to validate these algorithms. We have installed a variety of tools in a laboratory of the Tracking and Communications division for reproducing the simulation experiments carried out on these algorithms to verify that they do meet their requirements for controlling the antenna systems. In this report, we describe the processes used in these simulations and our work in validating the tests used.

  18. Definition of ground test for verification of large space structure control

    NASA Technical Reports Server (NTRS)

    Glaese, John R.

    1994-01-01

    Under this contract, the Large Space Structure Ground Test Verification (LSSGTV) Facility at the George C. Marshall Space Flight Center (MSFC) was developed. Planning in coordination with NASA was finalized and implemented. The contract was modified and extended with several increments of funding to procure additional hardware and to continue support for the LSSGTV facility. Additional tasks were defined for the performance of studies in the dynamics, control and simulation of tethered satellites. When the LSSGTV facility development task was completed, support and enhancement activities were funded through a new competitive contract won by LCD. All work related to LSSGTV performed under NAS8-35835 has been completed and documented. No further discussion of these activities will appear in this report. This report summarizes the tether dynamics and control studies performed.

  19. Integrating care for neurodevelopmental disorders by unpacking control: A grounded theory study

    PubMed Central

    Waxegård, Gustaf; Thulesius, Hans

    2016-01-01

    Background To establish integrated healthcare pathways for patients with neurodevelopmental disorders (ND) such as autism spectrum disorder and attention-deficit hyperactivity disorder is challenging. This study sets out to investigate the main concerns for healthcare professionals when integrating ND care pathways and how they resolve these concerns. Methods Using classic grounded theory (Glaser), we analysed efforts to improve and integrate an ND care pathway for children and youth in a Swedish region over a period of 6 years. Data from 42 individual interviews with a range of ND professionals, nine group interviews with healthcare teams, participant observation, a 2-day dialogue conference, focus group meetings, regional media coverage, and reports from other Swedish regional ND projects were analysed. Results The main concern for participants was to deal with overwhelming ND complexity by unpacking control, which is control over strategies to define patients’ status and needs. Unpacking control is key to the professionals’ strivings to expand constructive life space for patients, to squeeze health care to reach available care goals, to promote professional ideologies, and to uphold workplace integrity. Control-seeking behaviour in relation to ND unpacking is ubiquitous and complicates integration of ND care pathways. Conclusions The Unpacking control theory expands central aspects of professions theory and may help to improve ND care development. PMID:27609793

  20. Age and gender differences in the control of vertical ground reaction force by the hip, knee and ankle joints.

    PubMed

    Toda, Haruki; Nagano, Akinori; Luo, Zhiwei

    2015-06-01

    [Purpose] This study examined the relationships between joint moment and the control of the vertical ground reaction force during walking in the elderly and young male and female individuals. [Subjects and Methods] Forty elderly people, 65 years old or older (20 males and 20 females), and 40 young people, 20 to 29 years old (20 males and 20 females), participated in this study. Joint moment and vertical ground reaction force during walking were obtained using a 3D motion analysis system and force plates. Stepwise linear regression analysis determined the joint moments that predict the amplitude of the vertical ground reaction force. [Results] Knee extension moment was related to the vertical ground reaction force in the young males and females. On the other hand, in the elderly females, hip, ankle, and knee joint moments were related to the first peak and second peak forces, and the minimum value of vertical ground reaction force, respectively. [Conclusion] Our results suggest that the young males and females make use of the knee joint moment to control of the vertical ground reaction force. There were differences between the elderly and the young females with regard to the joints used for the control of the vertical ground reaction force.

  1. Age and gender differences in the control of vertical ground reaction force by the hip, knee and ankle joints

    PubMed Central

    Toda, Haruki; Nagano, Akinori; Luo, Zhiwei

    2015-01-01

    [Purpose] This study examined the relationships between joint moment and the control of the vertical ground reaction force during walking in the elderly and young male and female individuals. [Subjects and Methods] Forty elderly people, 65 years old or older (20 males and 20 females), and 40 young people, 20 to 29 years old (20 males and 20 females), participated in this study. Joint moment and vertical ground reaction force during walking were obtained using a 3D motion analysis system and force plates. Stepwise linear regression analysis determined the joint moments that predict the amplitude of the vertical ground reaction force. [Results] Knee extension moment was related to the vertical ground reaction force in the young males and females. On the other hand, in the elderly females, hip, ankle, and knee joint moments were related to the first peak and second peak forces, and the minimum value of vertical ground reaction force, respectively. [Conclusion] Our results suggest that the young males and females make use of the knee joint moment to control of the vertical ground reaction force. There were differences between the elderly and the young females with regard to the joints used for the control of the vertical ground reaction force. PMID:26180331

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

    NASA Astrophysics Data System (ADS)

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

    2008-04-01

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

  3. A framework for the natural-language-perception-based creative control of unmanned ground vehicles

    NASA Astrophysics Data System (ADS)

    Ghaffari, Masoud; Liao, Xiaoqun; Hall, Ernest L.

    2004-09-01

    Mobile robots must often operate in an unstructured environment cluttered with obstacles and with many possible action paths. That is why mobile robotics problems are complex with many unanswered questions. To reach a high degree of autonomous operation, a new level of learning is required. On the one hand, promising learning theories such as the adaptive critic and creative control have been proposed, while on other hand the human brain"s processing ability has amazed and inspired researchers in the area of Unmanned Ground Vehicles but has been difficult to emulate in practice. A new direction in the fuzzy theory tries to develop a theory to deal with the perceptions conveyed by the natural language. This paper tries to combine these two fields and present a framework for autonomous robot navigation. The proposed creative controller like the adaptive critic controller has information stored in a dynamic database (DB), plus a dynamic task control center (TCC) that functions as a command center to decompose tasks into sub-tasks with different dynamic models and multi-criteria functions. The TCC module utilizes computational theory of perceptions to deal with the high levels of task planning. The authors are currently trying to implement the model on a real mobile robot and the preliminary results have been described in this paper.

  4. The development of an UAV borne direct georeferenced photogrammetric platform for Ground Control Point free applications.

    PubMed

    Chiang, Kai-Wei; Tsai, Meng-Lun; Chu, Chien-Hsun

    2012-01-01

    To facilitate applications such as environment detection or disaster monitoring, the development of rapid low cost systems for collecting near real time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. In this study, a fixed-wing Unmanned Aerial Vehicle (UAV)-based spatial information acquisition platform that can operate in Ground Control Point (GCP) free environments is developed and evaluated. The proposed UAV based photogrammetric platform has a Direct Georeferencing (DG) module that includes a low cost Micro Electro Mechanical Systems (MEMS) Inertial Navigation System (INS)/Global Positioning System (GPS) integrated system. The DG module is able to provide GPS single frequency carrier phase measurements for differential processing to obtain sufficient positioning accuracy. All necessary calibration procedures are implemented. Ultimately, a flight test is performed to verify the positioning accuracy in DG mode without using GCPs. The preliminary results of positioning accuracy in DG mode illustrate that horizontal positioning accuracies in the x and y axes are around 5 m at 300 m flight height above the ground. The positioning accuracy of the z axis is below 10 m. Therefore, the proposed platform is relatively safe and inexpensive for collecting critical spatial information for urgent response such as disaster relief and assessment applications where GCPs are not available.

  5. The development of an UAV borne direct georeferenced photogrammetric platform for Ground Control Point free applications.

    PubMed

    Chiang, Kai-Wei; Tsai, Meng-Lun; Chu, Chien-Hsun

    2012-01-01

    To facilitate applications such as environment detection or disaster monitoring, the development of rapid low cost systems for collecting near real time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. In this study, a fixed-wing Unmanned Aerial Vehicle (UAV)-based spatial information acquisition platform that can operate in Ground Control Point (GCP) free environments is developed and evaluated. The proposed UAV based photogrammetric platform has a Direct Georeferencing (DG) module that includes a low cost Micro Electro Mechanical Systems (MEMS) Inertial Navigation System (INS)/Global Positioning System (GPS) integrated system. The DG module is able to provide GPS single frequency carrier phase measurements for differential processing to obtain sufficient positioning accuracy. All necessary calibration procedures are implemented. Ultimately, a flight test is performed to verify the positioning accuracy in DG mode without using GCPs. The preliminary results of positioning accuracy in DG mode illustrate that horizontal positioning accuracies in the x and y axes are around 5 m at 300 m flight height above the ground. The positioning accuracy of the z axis is below 10 m. Therefore, the proposed platform is relatively safe and inexpensive for collecting critical spatial information for urgent response such as disaster relief and assessment applications where GCPs are not available. PMID:23012538

  6. The Development of an UAV Borne Direct Georeferenced Photogrammetric Platform for Ground Control Point Free Applications

    PubMed Central

    Chiang, Kai-Wei; Tsai, Meng-Lun; Chu, Chien-Hsun

    2012-01-01

    To facilitate applications such as environment detection or disaster monitoring, the development of rapid low cost systems for collecting near real time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. In this study, a fixed-wing Unmanned Aerial Vehicle (UAV)-based spatial information acquisition platform that can operate in Ground Control Point (GCP) free environments is developed and evaluated. The proposed UAV based photogrammetric platform has a Direct Georeferencing (DG) module that includes a low cost Micro Electro Mechanical Systems (MEMS) Inertial Navigation System (INS)/Global Positioning System (GPS) integrated system. The DG module is able to provide GPS single frequency carrier phase measurements for differential processing to obtain sufficient positioning accuracy. All necessary calibration procedures are implemented. Ultimately, a flight test is performed to verify the positioning accuracy in DG mode without using GCPs. The preliminary results of positioning accuracy in DG mode illustrate that horizontal positioning accuracies in the x and y axes are around 5 m at 300 m flight height above the ground. The positioning accuracy of the z axis is below 10 m. Therefore, the proposed platform is relatively safe and inexpensive for collecting critical spatial information for urgent response such as disaster relief and assessment applications where GCPs are not available. PMID:23012538

  7. Tug fleet and ground operations schedules and controls. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1975-01-01

    This study presents Tug Fleet and Ground Operations Schedules and Controls plan. This plan was developed and optimized out of a combination of individual Tug program phased subplans, special emphasis studies, contingency analyses and sensitivity analyses. The subplans cover the Tug program phases: (1) Tug operational, (2) Interim Upper Stage (IUS)/Tug fleet utilization, (3) and IUS/Tug payload integration, (4) Tug site activation, (5) IUS/Tug transition, (6) Tug acquisition. Resource requirements (facility, GSE, TSE, software, manpower, logistics) are provided in each subplan, as are appropriate Tug processing flows, active and total IUS and Tug fleet requirements, fleet management and Tug payload integration concepts, facility selection recommendations, site activation and IUS to Tug transition requirements. The impact of operational concepts on Tug acquisition is assessed and the impact of operating Tugs out of KSC and WTR is analyzed and presented showing WTR as a delta. Finally, cost estimates for fleet management and ground operations of the DDT&E and operational phases of the Tug program are given.

  8. A new approach for automatic matching of ground control points in urban areas from heterogeneous images

    NASA Astrophysics Data System (ADS)

    Cong, Chao; Liu, Dingsheng; Zhao, Lingjun

    2008-12-01

    This paper discusses a new method for the automatic matching of ground control points (GCPs) between satellite remote sensing Image and digital raster graphic (DRG) in urban areas. The key of this method is to automatically extract tie point pairs according to geographic characters from such heterogeneous images. Since there are big differences between such heterogeneous images respect to texture and corner features, more detail analyzations are performed to find similarities and differences between high resolution remote sensing Image and (DRG). Furthermore a new algorithms based on the fuzzy-c means (FCM) method is proposed to extract linear feature in remote sensing Image. Based on linear feature, crossings and corners extracted from these features are chosen as GCPs. On the other hand, similar method was used to find same features from DRGs. Finally, Hausdorff Distance was adopted to pick matching GCPs from above two GCP groups. Experiences shown the method can extract GCPs from such images with a reasonable RMS error.

  9. Interoperability of unattended ground sensors with an open architecture controller using SensorML

    NASA Astrophysics Data System (ADS)

    Chambers, Jon; Fairgrieve, Scott

    2010-04-01

    Unattended Ground Sensors (UGS) from a wide range of manufacturers have difficulty interoperating with each other and common control and dissemination points. Typically, sensor data is transmitted via RF or wired connections to a central location where the data can be fused together and transmitted further via satellite to a Processing, Exploitation and Dissemination (PED) system. These PED's are charged with analyzing the data to create real time actionable intelligence for the war fighter. However, when several disparate sensors from different manufacturers are used, interoperability problems arise. Therefore, a central UGS controller that accepts data from a wide range of sensors and helps them interoperate is essential. This paper addresses benefits derived from using the Open Geospatial Consortium's (OGC) Sensor Model Language (SensorML) sensor descriptions for an UGS controller. SensorML 1.0 is an approved OGC standard and is one of the major components within the OGC Sensor Web Enablement (SWE) suite of standards. SensorML provides standard models and an XML encoding for describing any process, including the process of measurement by sensors. By incorporating SensorML, an UGS controller can accept data from various sensors from different manufacturers, and interpret that data with the SensorML descriptions to allow the controller to take programmed actions and interoperate between sensors. Furthermore, SensorML can be used to translate the native sensor formats once the original data has been transmitted to the PED. Therefore, this makes a SensorML enabled UGS controller an extremely powerful tool that provides situational awareness by combining multiple sensors to form a single common operational picture (COP).

  10. Monitoring controlled graves representing common burial scenarios with ground penetrating radar

    NASA Astrophysics Data System (ADS)

    Schultz, John J.; Martin, Michael M.

    2012-08-01

    Implementing controlled geophysical research is imperative to understand the variables affecting detection of clandestine graves during real-life forensic searches. This study focused on monitoring two empty control graves (shallow and deep) and six burials containing a small pig carcass (Sus scrofa) representing different burial forensic scenarios: a shallow buried naked carcass, a deep buried naked carcass, a deep buried carcass covered by a layer of rocks, a deep buried carcass covered by a layer of lime, a deep buried carcass wrapped in an impermeable tarpaulin and a deep buried carcass wrapped in a cotton blanket. Multi-frequency, ground penetrating radar (GPR) data were collected monthly over a 12-month monitoring period. The research site was a cleared field within a wooded area in a humid subtropical environment, and the soil consisted of a Spodosol, a common soil type in Florida. This study compared 2D GPR reflection profiles and horizontal time slices obtained with both 250 and 500 MHz dominant frequency antennae to determine the utility of both antennae for grave detection in this environment over time. Overall, a combination of both antennae frequencies provided optimal detection of the targets. Better images were noted for deep graves, compared to shallow graves. The 250 MHz antenna provided better images for detecting deep graves, as less non-target anomalies were produced with lower radar frequencies. The 250 MHz antenna also provided better images detecting the disturbed ground. Conversely, the 500 MHz antenna provided better images when detecting the shallow pig grave. The graves that contained a pig carcass with associated grave items provided the best results, particularly the carcass covered with rocks and the carcass wrapped in a tarpaulin. Finally, during periods of increased soil moisture levels, there was increased detection of graves that was most likely related to conductive decompositional fluid from the carcasses.

  11. Sfm_georef: Automating image measurement of ground control points for SfM-based projects

    NASA Astrophysics Data System (ADS)

    James, Mike R.

    2016-04-01

    Deriving accurate DEM and orthomosaic image products from UAV surveys generally involves the use of multiple ground control points (GCPs). Here, we demonstrate the automated collection of GCP image measurements for SfM-MVS processed projects, using sfm_georef software (James & Robson, 2012; http://www.lancaster.ac.uk/staff/jamesm/software/sfm_georef.htm). Sfm_georef was originally written to provide geo-referencing procedures for SfM-MVS projects. It has now been upgraded with a 3-D patch-based matching routine suitable for automating GCP image measurement in both aerial and ground-based (oblique) projects, with the aim of reducing the time required for accurate geo-referencing. Sfm_georef is compatible with a range of SfM-MVS software and imports the relevant files that describe the image network, including camera models and tie points. 3-D survey measurements of ground control are then provided, either for natural features or artificial targets distributed over the project area. Automated GCP image measurement is manually initiated through identifying a GCP position in an image by mouse click; the GCP is then represented by a square planar patch in 3-D, textured from the image and oriented parallel to the local topographic surface (as defined by the 3-D positions of nearby tie points). Other images are then automatically examined by projecting the patch into the images (to account for differences in viewing geometry) and carrying out a sub-pixel normalised cross-correlation search in the local area. With two or more observations of a GCP, its 3-D co-ordinates are then derived by ray intersection. With the 3-D positions of three or more GCPs identified, an initial geo-referencing transform can be derived to relate the SfM-MVS co-ordinate system to that of the GCPs. Then, if GCPs are symmetric and identical, image texture from one representative GCP can be used to search automatically for all others throughout the image set. Finally, the GCP observations can be

  12. A ground based phase control system for the solar power satellite. Executive summary, volume 1, phase 3

    NASA Technical Reports Server (NTRS)

    Chie, C. M.

    1980-01-01

    The Solar Power Satellite (SPS) concept and the reference phase control system investigated in earlier efforts are reviewed. A summary overview of the analysis and selection of the pilot signal and power transponder design is presented along with the SOLARSIM program development and the simulated SPS phase control performance. Evaluations of the ground based phase control system as an alternate phase control concept are summarized.

  13. Prediction of forces and moments for flight vehicle control effectors. Part 2: An analysis of delta wing aerodynamic control effectiveness in ground effect

    NASA Technical Reports Server (NTRS)

    Maughmer, Mark D.; Ozoroski, L.; Ozoroski, T.; Straussfogel, D.

    1990-01-01

    Many types of hypersonic aircraft configurations are currently being studied for feasibility of future development. Since the control of the hypersonic configurations throughout the speed range has a major impact on acceptable designs, it must be considered in the conceptual design stage. Here, an investigation of the aerodynamic control effectiveness of highly swept delta planforms operating in ground effect is presented. A vortex-lattice computer program incorporating a free wake is developed as a tool to calculate aerodynamic stability and control derivatives. Data generated using this program are compared to experimental data and to data from other vortex-lattice programs. Results show that an elevon deflection produces greater increments in C sub L and C sub M in ground effect than the same deflection produces out of ground effect and that the free wake is indeed necessary for good predictions near the ground.

  14. Controlling laser beam irradiation area using an optical duplicate system to improve satellite–ground laser communications

    NASA Astrophysics Data System (ADS)

    Nakayama, Tomoko; Takayama, Yoshihisa; Fujikawa, Chiemi; Kodate, Kashiko

    2016-08-01

    To improve the quality of ground to satellite laser communications, we propose an optical duplicate system of the optical ground station. Our proposed approach can be used to control the beam irradiation area for a satellite position without changing the total power of the output beam and the mechanical drive unit; this is performed by controlling the input pattern of a liquid crystal filter inserted in the input plane of the optical duplicate system. Most of the power of the diffracted laser beam emitted from the ground is focused on the optical axis. By distributing the power to side lobes, it is possible to extend the coverage area for a satellite position. This system allows the laser beam irradiation area to be controlled by a sufficient degree by adjusting the threshold of the satellite reception level. We verify the efficacy of the system using wave optics numerical calculations.

  15. Controlling laser beam irradiation area using an optical duplicate system to improve satellite-ground laser communications

    NASA Astrophysics Data System (ADS)

    Nakayama, Tomoko; Takayama, Yoshihisa; Fujikawa, Chiemi; Kodate, Kashiko

    2016-08-01

    To improve the quality of ground to satellite laser communications, we propose an optical duplicate system of the optical ground station. Our proposed approach can be used to control the beam irradiation area for a satellite position without changing the total power of the output beam and the mechanical drive unit; this is performed by controlling the input pattern of a liquid crystal filter inserted in the input plane of the optical duplicate system. Most of the power of the diffracted laser beam emitted from the ground is focused on the optical axis. By distributing the power to side lobes, it is possible to extend the coverage area for a satellite position. This system allows the laser beam irradiation area to be controlled by a sufficient degree by adjusting the threshold of the satellite reception level. We verify the efficacy of the system using wave optics numerical calculations.

  16. Towards a common framework of grounded action cognition: Relating motor control, perception and cognition.

    PubMed

    Gentsch, Antje; Weber, Arne; Synofzik, Matthis; Vosgerau, Gottfried; Schütz-Bosbach, Simone

    2016-01-01

    The relation between motor control and action cognition - including action-related thoughts and action-related perception - has been subject to controversial discussions in the last three decades. During these decades, cognitive neuroscience has been increasingly confronted with a huge variety of different accounts trying to understand and explain the relation between these systems, their interdependencies and the mediating mechanisms by establishing notions such as "internal models", "simulation" or "shared representation". These accounts, however, include a large array of partly overlapping, partly contradictory theories using similar terms for different mechanisms and different terms for similar mechanisms. In the absence of a systematic work-up and comparison, this array of accounts and theories leads to confusion in the field, duplication of experimental work, and unconnected parallelism of theory formation within and between different disciplines. Here we provide a systematic comparison of current models and prospective theories that deal with the relation between cognition, perception and motor control mechanisms. In a second step, we propose "grounded action cognition" as a comprehensive metatheoretical framework which defines different hypothetical possibilities of the relations between these domains, offers systematic insights into current models and theories and last but not least may help to increase comparability of empirical research in the domain of action and action cognition.

  17. Ground Laboratory Soft X-Ray Durability Evaluation of Aluminized Teflon FEP Thermal Control Insulation. Revised

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; deGroh, Kim K.; Stueber, Thomas J.; Sechkar, Edward A.; Hall, Rachelle L.

    1998-01-01

    Metallized Teflon fluorinated ethylene propylene (FEP) thermal control insulation is mechanically degraded if exposed to a sufficient fluence of soft x-ray radiation. Soft x-ray photons (4-8 A in wavelength or 1.55 - 3.2 keV) emitted during solar flares have been proposed as a cause of mechanical properties degradation of aluminized Teflon FEP thermal control insulation on the Hubble Space Telescope (HST). Such degradation can be characterized by a reduction in elongation-to-failure of the Teflon FEP. Ground laboratory soft x-ray exposure tests of aluminized Teflon FEP were conducted to assess the degree of elongation degradation which would occur as a result of exposure to soft x-rays in the range of 3-10 keV. Tests results indicate that soft x-ray exposure in the 3-10 keV range, at mission fluence levels, does not alone cause the observed reduction in elongation of flight retrieved samples. The soft x-ray exposure facility design, mechanical properties degradation results and implications will be presented.

  18. Ground Laboratory Soft X-Ray Durability Evaluation of Aluminized Teflon FEP Thermal Control Insulation

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; deGroh, Kim K.; Stueber, Thomas J.; Sechkar, Edward A.

    1998-01-01

    Metallized Teflon fluorinated ethylene propylene (FEP) thermal control insulation is mechanically degraded if exposed to a sufficient fluence of soft x-ray radiation. Soft x-ray photons (4-8 A in wavelength or 1.55 - 3.2 keV) emitted during solar flares have been proposed as a cause of mechanical properties degradation of aluminized Teflon FEP thermal control insulation on the Hubble Space Telescope (HST). Such degradation can be characterized by a reduction in elongation-to-failure of the Teflon FER Ground laboratory soft x-ray exposure tests of aluminized Teflon FEP were conducted to assess the degree of elongation degradation which would occur as a result of exposure to soft x-rays in the range of 3-10 keV. Tests results indicate that soft x-ray exposure in the 3-10 keV range, at mission fluence levels, does not alone cause the observed reduction in elongation of flight retrieved samples. The soft x-ray exposure facility design, mechanical properties degradation results and implications will be presented.

  19. Standard Engineering Installation Package. Ground control approach radar systems and radome(S)

    NASA Astrophysics Data System (ADS)

    1983-01-01

    This standard engineering installation package (SEIP) is one in a series for upgrading air traffic control and navigational and landing aids at Army airfields and heliports worldwide. It provides the guidance involved in selecting, acquiring, and installing ground control approach radar systems. It gives a system description along with the technical aspects of the equipment and installation areas. It contains a list of applicable documents, describes a comprehensive checklist for site surveys, tells how to install equipment, the manpower required to do it and gives a bill of materials to accomplish it all. The SEIP describes quality assurance inspections and gives sample forms to ascertain areas of responsibility, checklists, and certification. One section gives a detailed test plan and checkout procedure while the system is in operation and suggests the form for a technical acceptance certificate. The SEIP also contains sample coordination documents of all agencies involved in the upgrading process and a completion certification that the project was met all of the test criteria.

  20. Use of remotely sensed imagery in investing ground control problems in an Alabama coal mine

    SciTech Connect

    Scarborough, J.A.; Kane, W.F.

    1989-03-01

    Lineaments, linear features which are expressions of fractures or discontinuities in the earth's surface, can be detected using Landsat imagery. A study using a composite of multispectral scanner (MSS) bands 4, 5, and 7 was performed in a mine within the Warrior coal basin of Alabama. Both surface and underground mapping were carried out to obtain fracture data. Positional control was established to relate locations of roof falls in the mine, surface and underground fractures, and lineaments. A data base was created, and statistical relationships concerning the direction and distance between these features were investigated. At the scale of the imagery, a lineament was found to be a zone of fractures whose general trend follows the regional trend but whose individual components may not have this tendency. These surface fractures within the lineament band tend to dip vertically and extend to the mine level. A statistical correlation was found between lineaments detected on remotely sensed imagery and ground control problems in the mine. Lineaments overlying the mine were related to roof falls; most roof falls occurred near a lineament. The lineament length was not an important factor, however, although the intersection of two lineaments was an element in roof fall frequency, the distance between a roof fall and an intersecting lineament was determined to be more significant. The results of this study represent a step toward the scientific use of satellite imagery for the layout and design of coal mines and other underground structures in the eastern US.

  1. A new method to obtain uniform distribution of ground control points based on regional statistical information

    NASA Astrophysics Data System (ADS)

    Ma, Chao; An, Wei; Deng, Xinpu

    2015-10-01

    The Ground Control Points (GCPs) is an important source of fundamental data in geometric correction for remote sensing imagery. The quantity, accuracy and distribution of GCPs are three factors which may affect the accuracy of geometric correction. It is generally required that the distribution of GCP should be uniform, so they can fully control the accuracy of mapping regions. In this paper, we establish an objective standard of evaluating the uniformity of the GCPs' distribution based on regional statistical information (RSI), and get an optimal distribution of GCPs. This sampling method is called RSIS for short in this work. The Amounts of GCPs in different regions by equally partitioning the image in regions in different manners are counted which forms a vector called RSI vector in this work. The uniformity of GCPs' distribution can be evaluated by a mathematical quantity of the RSI vector. An optimal distribution of GCPs is obtained by searching the RSI vector with the minimum mathematical quantity. In this paper, the simulation annealing is employed to search the optimal distribution of GCPs that have the minimum mathematical quantity of the RSI vector. Experiments are carried out to test the method proposed in this paper, and sampling designs compared are simple random sampling and universal kriging model-based sampling. The experiments indicate that this method is highly recommended as new GCPs sampling design method for geometric correction of remotely sensed imagery.

  2. Ground Simulator Studies of the Effects of Valve Friction, Stick Friction, Flexibility, and Backwash on Power Control System Quality

    NASA Technical Reports Server (NTRS)

    Brown, B Porter

    1958-01-01

    Report presents results of tests made on a power control system by means of a ground simulator to determine the effects of various combinations of valve friction and stick friction on the ability of the pilot to control the system. Various friction conditions were simulated with a rigid control system, a flexible system, and a rigid system having some backlash. For the tests, the period and damping of the simulated airplane were held constant.

  3. Technologies for low-bandwidth high-latency unmanned ground vehicle control

    NASA Astrophysics Data System (ADS)

    Pace, Teresa; Cogan, Ken; Hunt, Lee; Restine, Paul

    2014-05-01

    Automation technology has evolved at a rapid pace in recent years; however, many real-world problems require contextual understanding, problem solving, and other forms of higher-order thinking that extends beyond the capabilities of robots for the foreseeable future. This limits the complexity of automation which can be supplied to modern unmanned ground robots (UGV) and necessitates human-in-the-loop monitoring and control for some portions of missions. In order for the human operator to make decisions and provide tasking during key portions of the mission, existing solutions first derive significant information from a potentially dense reconstruction of the scene utilizing LIDAR, video, and other onboard sensors. A dense reconstruction contains too much data for real-time transmission over a modern wireless data link, so the robot electronics must first condense the scene representation prior to transmission. The control station receives this condensed scene representations and provides visual information to the human operator; the human operator then provides tele-operation commands in real-time to the robot. This paper discusses approaches to dense scene reduction of the data required to transmit to a human-in-the loop as well as the challenges associated with them. In addition, the complex and unstructured nature of real-world environments increases the need for tele-operation. Furthermore, many environments reduce the bandwidth and increase the latency of the link. Ultimately, worsening conditions will cause the tele-operation control process to break down, rendering the robot ineffective. In a worst-case scenario, extreme conditions causing a complete loss-of-communications could result in mission failure and loss of the vehicle.

  4. Kennedy Space Center Timing and Countdown Interface to Kennedy Ground Control Subsystem

    NASA Technical Reports Server (NTRS)

    Olsen, James C.

    2015-01-01

    Kennedy Ground Control System (KGCS) engineers at the National Aeronautics and Space Administration (NASA) Kennedy Space Center (KSC) are developing a time-tagging process to enable reconstruction of the events during a launch countdown. Such a process can be useful in the case of anomalies or other situations where it is necessary to know the exact time an event occurred. It is thus critical for the timing information to be accurate. KGCS will synchronize all items with Coordinated Universal Time (UTC) obtained from the Timing and Countdown (T&CD) organization. Network Time Protocol (NTP) is the protocol currently in place for synchronizing UTC. However, NTP has a peak error that is too high for today's standards. Precision Time Protocol (PTP) is a newer protocol with a much smaller peak error. The focus of this project has been to implement a PTP solution on the network to increase timing accuracy while introducing and configuring the implementation of a firewall between T&CD and the KGCS network.

  5. High-accuracy stereo matching based on adaptive ground control points.

    PubMed

    Chenbo Shi; Guijin Wang; Xuanwu Yin; Xiaokang Pei; Bei He; Xinggang Lin

    2015-04-01

    This paper proposes a novel high-accuracy stereo matching scheme based on adaptive ground control points (AdaptGCP). Different from traditional fixed GCP-based methods, we consider color dissimilarity, spatial relation, and the pixel-matching reliability to select GCP adaptively in each local support window. To minimize the global energy, we propose a practical solution, named as alternating updating scheme of disparity and confidence map, which can effectively eliminate the redundant and interfering information of unreliable pixels. The disparity values of those unreliable pixels are reassigned with the information provided by local plane model, which is fitted with GCPs. Then, the confidence map is updated according to the disparity reassignment and the left-right consistency. Finally, the disparity map is refined by multistep filers. Quantitative evaluations demonstrate the effectiveness of our AdaptGCP scheme for regularizing the ill-posed matching problem. The top ranks on Middlebury benchmark with different error thresholds show that our algorithm achieves the state-of-the-art performance among the latest stereo matching algorithms. This paper provides a new insight toward high-accuracy stereo matching. PMID:25608303

  6. Inactivation of foodborne pathogens in ground beef by cooking with highly controlled radio frequency energy.

    PubMed

    Schlisselberg, Dov B; Kler, Edna; Kalily, Emmanuel; Kisluk, Guy; Karniel, Ohad; Yaron, Sima

    2013-01-01

    The consumer demand for fresh tasting, high quality, low salt, preservative-free meals which require minimal preparation time magnifies the safety concern and emphasizes the need to use innovative technologies for food processing. A modern technique to uniformly heat and cook foods is based on a combination of convection and controlled radio frequency (RF) energy. However any advantage conferred on meat cooked by this method would be lost if application of the technology results in decreased safety. Our main goal was to study the inactivation efficacy of this method of cooking against pathogens in ground meat in comparison to standard convection cooking. Meat balls were artificially inoculated with GFP expressing Escherichia coli, Salmonella Typhimurium and Listeria monocytogenes as well as spores of Bacillus cereus and Bacillus thuringiensis and cooked by convection heating (220°C, 40 min), by using energy generated from frequencies in the RF bandwidth (RF cooking, 7.5 min) or by combined heating (5.5 min), until the center temperature of each sample reached 73°C. The mean reductions in total indigenous bacteria obtained by RF and convection were 2.8 and 2.5 log CFU/g, respectively. Cooking of meat balls with convection reduced the E. coli population (8 log CFU/g) by 5.5 log CFU/g, whilst treatment with RF reduced E. coli population to undetectable levels. The mean reductions of S. Typhimurium obtained by RF and convection were 5.7 and 6.5 log CFU/g, respectively. The combined treatment reduced the Salmonella population to undetectable levels. In contrast, L. monocytogenes was poorly affected by RF cooking. The mean reduction of L. monocytogenes obtained by RF energy was 0.4 log CFU/g, while convection cooking resulted in undetectable levels. Interestingly, the combined treatment also resulted with undetectable levels of Listeria although time of cooking was reduced by 86%. One-step cooking had negligible effects on the Bacillus spores and therefore a 2-step

  7. Instrument Display Visual Angles for Conventional Aircraft and the MQ-9 Ground Control Station

    NASA Technical Reports Server (NTRS)

    Bendrick, Gregg A.; Kamine, Tovy Haber

    2008-01-01

    Aircraft instrument panels should be designed such that primary displays are in optimal viewing location to minimize pilot perception and response time. Human Factors engineers define three zones (i.e. "cones") of visual location: 1) "Easy Eye Movement" (foveal vision); 2) "Maximum Eye Movement" (peripheral vision with saccades), and 3) "Head Movement" (head movement required). Instrument display visual angles were measured to determine how well conventional aircraft (T-34, T-38, F- 15B, F-16XL, F/A-18A, U-2D, ER-2, King Air, G-III, B-52H, DC-10, B747-SCA) and the MQ-9 ground control station (GCS) complied with these standards, and how they compared with each other. Methods: Selected instrument parameters included: attitude, pitch, bank, power, airspeed, altitude, vertical speed, heading, turn rate, slip/skid, AOA, flight path, latitude, longitude, course, bearing, range and time. Vertical and horizontal visual angles for each component were measured from the pilot s eye position in each system. Results: The vertical visual angles of displays in conventional aircraft lay within the cone of "Easy Eye Movement" for all but three of the parameters measured, and almost all of the horizontal visual angles fell within this range. All conventional vertical and horizontal visual angles lay within the cone of "Maximum Eye Movement". However, most instrument vertical visual angles of the MQ-9 GCS lay outside the cone of "Easy Eye Movement", though all were within the cone of "Maximum Eye Movement". All the horizontal visual angles for the MQ-9 GCS were within the cone of "Easy Eye Movement". Discussion: Most instrument displays in conventional aircraft lay within the cone of "Easy Eye Movement", though mission-critical instruments sometimes displaced less important instruments outside this area. Many of the MQ-9 GCS systems lay outside this area. Specific training for MQ-9 pilots may be needed to avoid increased response time and potential error during flight.

  8. Tools for automating spacecraft ground systems: The Intelligent Command and Control (ICC) approach

    NASA Technical Reports Server (NTRS)

    Stoffel, A. William; Mclean, David

    1996-01-01

    The practical application of scripting languages and World Wide Web tools to the support of spacecraft ground system automation, is reported on. The mission activities and the automation tools used at the Goddard Space Flight Center (MD) are reviewed. The use of the Tool Command Language (TCL) and the Practical Extraction and Report Language (PERL) scripting tools for automating mission operations is discussed together with the application of different tools for the Compton Gamma Ray Observatory ground system.

  9. Study on controlling measures of ground water resources and the effects on alleviating land subsidence in Shanghai, China

    NASA Astrophysics Data System (ADS)

    Ye, S.; Wu, J.; Xue, Y.

    2014-12-01

    Land subsidence in Shanghai caused by overly exploitation of ground water has been 93 years since 1921, with the largest cumulative land subsidence of 2.6m. Studies on controlling and alleviating land subsidence have been 53 years since 1961. Control on ground water exploitation, change in pumping aquifers, increase in artificial recharge have been used as the three measures to mitigate land subsidence. The amount of ground water exploitation decreased from 0.2 billion m3 in 1963 to 13 million m3, which meant the amount decreased by 93.5%. The amount of artificial recharge increased from 1.9 million m3 in 1963 to 18 million m3 in 2011, which meant it increased by 9.5 times. The amount of recharge was even 6 million m3 larger than the discharge. The main pumping aquifers were shift from the second and third confined aquifers to the fourth and fifth confined aquifers. With the application of the three measures, ground water levels in second and third confined aquifers increased from -20m in 1965 to -1m in 2011 and that in the fourth confined aquifer increased from -36m in 1998 to -9m in 2011. Some regional ground water drawdown cones disappeared. Land subsidence rate reduces from 38mm/year before 1965 to 7mm/year by now and some areas even rebound. The details of measures taken to control land subsidence between 1961 and 2011, and the responses in ground water flows and land subsidence characteristics are introduced. It concludes that decrease in ground water pumping is the most effective way to control land subsidence, increase in artificial recharge is a good assistant measure, and changing in pumping aquifers is not always show good results. Shanghai got increased land subsidence rate from 1990 to 2000 when changing pumping aquifers from the second and third to the fourth and fifth ones without properly evaluating the amount of exploitation in advance. It must be very careful when take the measure of changing pumping aquifers, and the proper amount of pumpage in

  10. Intelligent tutoring and aiding in satellite ground control. Ph.D. Thesis - Georgia Inst. of Tech., 1991

    NASA Technical Reports Server (NTRS)

    Chu, Rose W.; Mitchell, Christine M.

    1993-01-01

    In supervisory control systems such as satellite ground control, there is a need for human-centered automation where the focus is to understand and enhance the human-system interaction experience in the complex task environment. Operator support in the form of off-line intelligent tutoring and on-line intelligent aiding is one approach towards this effort. The tutor/aid paradigm is proposed here as a design approach that integrates the two aspects of operator support in one system for technically oriented adults in complex domains. This paper also presents GT-VITA, a proof-of-concept graphical, interactive, intelligent tutoring system that is a first attempt to illustrate the tutoring aspect of the tutor/aid paradigm in the domain of satellite ground control. Evaluation on GT-VITA is conducted with NASA personnel with very positive results. GT-VITA is presented being fielded as it is at Goddard Space Flight Center.

  11. The cost of developing and maintain the monitoring and control software of large ground-based telescopes

    NASA Astrophysics Data System (ADS)

    Guzman, Juan Carlos; Chiozzi, Gianluca; Bridger, Alan; Ibsen, Jorge

    2014-07-01

    There are several large ground-based telescopes currently under development such as the SKA and CCAT in radio as well as several 30m-class in the optical. A common challenge that all of these telescopes are facing is estimating the cost of design, construction and maintenance of their required software. This paper will present a cost breakdown of the monitoring and control software packages implemented for ASKAP including the effort spent to develop and maintain the in-house code and the effort saved by using third-party software, such as EPICS. The costing for ASKAP will be compared to those for the monitoring and control software of other large ground-based telescopes such as ALMA and VLT. This comparison will highlight trends and commonalities in the costing and provides a useful guide for costing future telescope control software builds or upgrades and the ongoing maintenance cost.

  12. Microtopographic and depth controls on active layer chemistry in Arctic polygonal ground

    SciTech Connect

    Newman, Brent D.; Throckmorton, Heather M.; Graham, David E.; Gu, Baohua; Hubbard, Susan S.; Liang, Liyuan; Wu, Yuxin; Heikoop, J. M.; Herndon, Elizabeth M.; Phelps, Tommy J.; Wilson, Cathy; Wullschleger, Stan D.

    2015-03-24

    Polygonal ground is a signature characteristic of Arctic lowlands, and carbon release from permafrost thaw can alter feedbacks to Arctic ecosystems and climate. This study describes the first comprehensive spatial examination of active layer biogeochemistry that extends across high- and low-centered, ice wedge polygons, their features, and with depth. Water chemistry measurements of 54 analytes were made on surface and active layer pore waters collected near Barrow, Alaska, USA. Significant differences were observed between high- and low-centered polygons suggesting that polygon types may be useful for landscape-scale geochemical classification. However, differences were found for polygon features (centers and troughs) for analytes that were not significant for polygon type, suggesting that finer-scale features affect biogeochemistry differently from polygon types. Depth variations were also significant, demonstrating important multidimensional aspects of polygonal ground biogeochemistry. These results have major implications for understanding how polygonal ground ecosystems function, and how they may respond to future change.

  13. Microtopographic and depth controls on active layer chemistry in Arctic polygonal ground

    NASA Astrophysics Data System (ADS)

    Newman, B. D.; Throckmorton, H. M.; Graham, D. E.; Gu, B.; Hubbard, S. S.; Liang, L.; Wu, Y.; Heikoop, J. M.; Herndon, E. M.; Phelps, T. J.; Wilson, C. J.; Wullschleger, S. D.

    2015-03-01

    Polygonal ground is a signature characteristic of Arctic lowlands, and carbon release from permafrost thaw can alter feedbacks to Arctic ecosystems and climate. This study describes the first comprehensive spatial examination of active layer biogeochemistry that extends across high- and low-centered, ice wedge polygons, their features, and with depth. Water chemistry measurements of 54 analytes were made on surface and active layer pore waters collected near Barrow, Alaska, USA. Significant differences were observed between high- and low-centered polygons suggesting that polygon types may be useful for landscape-scale geochemical classification. However, differences were found for polygon features (centers and troughs) for analytes that were not significant for polygon type, suggesting that finer-scale features affect biogeochemistry differently from polygon types. Depth variations were also significant, demonstrating important multidimensional aspects of polygonal ground biogeochemistry. These results have major implications for understanding how polygonal ground ecosystems function, and how they may respond to future change.

  14. Instrument Display Visual Angles for Conventional Aircraft and the MQ-9 Ground Control Station

    NASA Technical Reports Server (NTRS)

    Kamine, Tovy Haber; Bendrick, Gregg A.

    2008-01-01

    Aircraft instrument panels should be designed such that primary displays are in optimal viewing location to minimize pilot perception and response time. Human Factors engineers define three zones (i.e. cones ) of visual location: 1) "Easy Eye Movement" (foveal vision); 2) "Maximum Eye Movement" (peripheral vision with saccades), and 3) "Head Movement (head movement required). Instrument display visual angles were measured to determine how well conventional aircraft (T-34, T-38, F- 15B, F-16XL, F/A-18A, U-2D, ER-2, King Air, G-III, B-52H, DC-10, B747-SCA) and the MQ-9 ground control station (GCS) complied with these standards, and how they compared with each other. Selected instrument parameters included: attitude, pitch, bank, power, airspeed, altitude, vertical speed, heading, turn rate, slip/skid, AOA, flight path, latitude, longitude, course, bearing, range and time. Vertical and horizontal visual angles for each component were measured from the pilot s eye position in each system. The vertical visual angles of displays in conventional aircraft lay within the cone of "Easy Eye Movement" for all but three of the parameters measured, and almost all of the horizontal visual angles fell within this range. All conventional vertical and horizontal visual angles lay within the cone of Maximum Eye Movement. However, most instrument vertical visual angles of the MQ-9 GCS lay outside the cone of Easy Eye Movement, though all were within the cone of Maximum Eye Movement. All the horizontal visual angles for the MQ-9 GCS were within the cone of "Easy Eye Movement". Most instrument displays in conventional aircraft lay within the cone of Easy Eye Movement, though mission-critical instruments sometimes displaced less important instruments outside this area. Many of the MQ-9 GCS systems lay outside this area. Specific training for MQ-9 pilots may be needed to avoid increased response time and potential error during flight. The learning objectives include: 1) Know three

  15. Integrated optimal dynamics control of 4WD4WS electric ground vehicle with tire-road frictional coefficient estimation

    NASA Astrophysics Data System (ADS)

    Wang, Rongrong; Hu, Chuan; Wang, Zejiang; Yan, Fengjun; Chen, Nan

    2015-08-01

    This paper presents an integrated optimal dynamics control of four-wheel driving and four-wheel steering (4WD4WS) electric ground vehicles via hierarchical control methodology. In the higher-level design, an LQR controller is proposed to obtain the integrated lateral force and yaw moment, according to their respective reference values. The lower-level controller is designed to ensure all the tires work in the stable region while realizing the tracking control of the vehicle dynamics. The tire-road friction coefficient is estimated through the integrated longitudinal force and lateral force, respectively, using a brush tire model. To reduce the estimation error, a novel data fusion function is employed to generate the final estimation value. Finally, the effectiveness of the proposed control and estimation strategies is validated via CarSim-Simulink joint simulation.

  16. Effect of realistic grounds and atmospheric conditions on single-channel active control of outdoor sound propagation

    NASA Astrophysics Data System (ADS)

    Nakashima, Ann; Hodgson, Murray

    2005-03-01

    Engine run-up tests are a part of routine aircraft maintenance at the Vancouver International Airport. A source of noise complaints is the Dash-8 aircraft, which emits low-frequency, tonal noise. Active noise control is a potentially cost-effective alternative to passive noise-control methods, which are ineffective at controlling low-frequency noise. Since the run-up tests are performed outdoors, the effects of outdoor conditions on the performance of an active control system must be considered. In this paper, the results of a preliminary investigation of the effects of realistic meteorological conditions and ground impedance on the performance of a single-channel active-control system are presented. Computer simulations of single-channel active control of a monopole source were performed using the Green's-function parabolic-equation method. Different realistic atmospheric conditions, and reflective or soft ground, were used in the simulations. The results show that atmospheric refraction causes fluctuations in the noise attenuation achieved by a single-channel control system, and has the overall effect of decreasing its performance, making the system ineffective in some cases. .

  17. Estimation of vegetation parameters by inversion of radiative-transfer models from multispectral imagery supported by ground control measurements

    NASA Astrophysics Data System (ADS)

    Kurz, Franz; Hellwich, Olaf

    2001-09-01

    We propose a general framework to estimate vegetation parameters from multidimensional remote sensing data using physical models and a moderate amount of ground control data. This framework is exemplarily demonstrated for winter wheat fields imaged by the Daedalus multispectral scanner using physical radiative transfer models, like the SAIL and PROSPECT model, combined with a linear empirical model. Results show the invertibility of the model for leaf area index, chlorophyll content, dry matter, and water content. The attained accuracies of these parameters are compared to the amount of ground control data. The vegetation parameters estimated with help of the devised method are intended to be used to derive information about soil heterogeneities that are important for precision farming.

  18. Effects of urban storm-runoff control on ground-water recharge in Nassau County, New York

    USGS Publications Warehouse

    Ku, Henry; Hagelin, Nathan; Buxton, Herbert

    1992-01-01

    Before urban development, most ground-water recharge on Long Island, New York, occurred during the dormant season, when evapotranspiration is low. The use of recharge basins for collection and disposal of urban storm runoff in Nassau County has enabled ground-water recharge to occur also during the growing season. In contrast, the use of storm sewers to route storm runoff to streams and coastal waters has resulted in a decrease in ground-water recharge during the dormant season. The net result of these two forms of urban storm-runoff control has been an increase in annual recharge of about 12 percent in areas served by recharge basins and a decrease of about 10 percent in areas where storm runoff is routed to streams and tidewater. On a countywide basis, annual ground-water recharge has remained nearly the same as under predevelopment conditions, but its distribution pattern has changed. Redistribution resulted in increased recharge in the eastern and central parts of the county, and decreased recharge in the western and nearshore areas. Model simulation of recharge indicates that the water-table altitude has increased by as much as 5 ft above predevelopment levels in areas served by recharge basins and declined by as much as 3 feet in areas where stormwater is discharged to streams and tidewater.

  19. Dynamics and control of motion on the ground and in the air with application to biped robots

    NASA Astrophysics Data System (ADS)

    Hemami, H.; Zheng, Y.-F.

    The dynamics of a multi-linkage model of natural or man-made systems with arbitrary holonomic and non-holonomic constraints at the joints are formulated. The formulation is equally applicable to movements on the ground or in the air. Nonlinear control strategies for postural balance and rhythmic motion are presented. A predictive algorithm to compensate for computation or transmission delay is proposed. Digital computer simulations are presented to demonstrate the effectiveness of the control strategy for a five-link three-dimensional biped.

  20. Improved aircraft dynamic response and fatigue life during ground operations using an active control landing gear system

    NASA Technical Reports Server (NTRS)

    Mcgehee, J. R.; Carden, H. D.; Edson, R.

    1978-01-01

    A three-degree-of-freedom aircraft landing analysis incorporating a series-hydraulic active control main landing gear has been developed and verified using preliminary experimental data from drop tests of a modified main landing gear from a 2722 kg (6000 lbm) class of airplane. The verified analysis was also employed to predict the landing dynamics of a supersonic research airplane with an active control main landing gear system. The results of this investigation have shown that this type of active gear is feasible and indicate a potential for improving airplane dynamic response and reducing structural fatigue damage during ground operations by approximately 90% relative to that incurred with the passive gear.

  1. The SAX Italian scientific satellite. The on-board implemented automation as a support to the ground control capability

    NASA Technical Reports Server (NTRS)

    Martelli, Andrea

    1994-01-01

    This paper presents the capabilities implemented in the SAX system for an efficient operations management during its in-flight mission. SAX is an Italian scientific satellite for x-ray astronomy whose major mission objectives impose quite tight constraints on the implementation of both the space and ground segment. The most relevant mission characteristics require an operative lifetime of two years, performing scientific observations both in contact and in noncontact periods, with a low equatorial orbit supported by one ground station, so that only a few minutes of communications are available each orbit. This operational scenario determines the need to have a satellite capable of performing the scheduled mission automatically and reacting autonomously to contingency situations. The implementation approach of the on-board operations management, through which the necessary automation and autonomy are achieved, follows a hierarchical structure. This has been achieved adopting a distributed avionic architecture. Nine different on-board computers, in fact, constitute the on-board data management system. Each of them performs the local control and monitors its own functions while the system level control is performed at a higher level by the data handling applications software. The SAX on-board architecture provides the ground operators with different options of intervention by three classes of telecommands. The management of the scientific operations will be scheduled by the operation control center via dedicated operating plans. The SAX satellite flight mode is presently being integrated at Alenia Spazio premises in Turin for a launch scheduled for the end of 1995. Once in orbit, the SAX satellite will be subject to intensive check-out activities in order to verify the required mission performances. An overview of the envisaged procedure and of the necessary on-ground activities is therefore depicted as well.

  2. Controlling stress corrosion cracking in mechanism components of ground support equipment

    NASA Technical Reports Server (NTRS)

    Majid, W. A.

    1988-01-01

    The selection of materials for mechanism components used in ground support equipment so that failures resulting from stress corrosion cracking will be prevented is described. A general criteria to be used in designing for resistance to stress corrosion cracking is also provided. Stress corrosion can be defined as combined action of sustained tensile stress and corrosion to cause premature failure of materials. Various aluminum, steels, nickel, titanium and copper alloys, and tempers and corrosive environment are evaluated for stress corrosion cracking.

  3. Hydrologic and biogeochemical controls of river subsurface solutes under agriculturally enhanced ground water flow

    USGS Publications Warehouse

    Wildman, R.A.; Domagalski, J.L.; Hering, J.G.

    2009-01-01

    The relative influences of hydrologic processes and biogeochemistry on the transport and retention of minor solutes were compared in the riverbed of the lower Merced River (California, USA). The subsurface of this reach receives ground water discharge and surface water infiltration due to an altered hydraulic setting resulting from agricultural irrigation. Filtered ground water samples were collected from 30 drive point locations in March, June, and October 2004. Hydrologic processes, described previously, were verified by observations of bromine concentrations; manganese was used to indicate redox conditions. The separate responses of the minor solutes strontium, barium, uranium, and phosphorus to these influences were examined. Correlation and principal component analyses indicate that hydrologic processes dominate the distribution of trace elements in the ground water. Redox conditions appear to be independent of hydrologic processes and account for most of the remaining data variability. With some variability, major processes are consistent in two sampling transects separated by 100 m. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  4. What Controls Methane in Potable Ground Water in the Appalachian Basin?

    NASA Astrophysics Data System (ADS)

    Siegel, D. I.; Smith, B.; Perry, A. E.; Bothun, R.

    2014-12-01

    We present the results of baseline (pre-drilling) sampling for methane in 13,040 potable ground water samples in Northeastern Pennsylvania and 8,004 samples from a "Western Area" (southwest Pennsylvania, eastern Ohio, and north-central West Virginia) that were collected on behalf of Chesapeake Energy Corporation as part of its monitoring program prior to drilling unconventional oil and gas wells in the Marcellus and Utica Formations, as well as the results of a year-long study on temporal variability of methane in ground water at 12 locations in NE Pennsylvania We found dissolved methane common in potable ground water in the Appalachian Basin. In NE Pennsylvania, measureable dissolved methane occurred in 24% of our samples with 3.4% naturally exceeding the PADEP methane notification level of 7 mg/L. In the western area, dissolved methane occurred naturally in 36% of groundwater sampled and in Ohio, 4.1% of samples exceeded the Ohio dissolved methane action level of 10 mg/L. More methane is associated with hydrogeochemical facies trending towards Na-Cl and Na-HCO3 type waters in valleys and along hill flanks. We found no relationship occurs between the concentration of methane and proximity to pre-existing gas wells. Concentrations of methane in domestic wells can naturally vary by factors, depending on pumping regime and time of year.

  5. Microtopographic and depth controls on active layer chemistry in Arctic polygonal ground

    DOE PAGESBeta

    Newman, Brent D.; Throckmorton, Heather M.; Graham, David E.; Gu, Baohua; Hubbard, Susan S.; Liang, Liyuan; Wu, Yuxin; Heikoop, J. M.; Herndon, Elizabeth M.; Phelps, Tommy J.; et al

    2015-03-24

    Polygonal ground is a signature characteristic of Arctic lowlands, and carbon release from permafrost thaw can alter feedbacks to Arctic ecosystems and climate. This study describes the first comprehensive spatial examination of active layer biogeochemistry that extends across high- and low-centered, ice wedge polygons, their features, and with depth. Water chemistry measurements of 54 analytes were made on surface and active layer pore waters collected near Barrow, Alaska, USA. Significant differences were observed between high- and low-centered polygons suggesting that polygon types may be useful for landscape-scale geochemical classification. However, differences were found for polygon features (centers and troughs) formore » analytes that were not significant for polygon type, suggesting that finer-scale features affect biogeochemistry differently from polygon types. Depth variations were also significant, demonstrating important multidimensional aspects of polygonal ground biogeochemistry. These results have major implications for understanding how polygonal ground ecosystems function, and how they may respond to future change.« less

  6. Faulting arrested by control of ground-water withdrawal in Houston, Texas.

    USGS Publications Warehouse

    Holzer, T.; Gabrysch, R.K.; Verbeek, E.R.

    1983-01-01

    More than 86 historically active faults with an aggregate length of 150 miles have been identified within and adjacent to the Houston, Texas, metropolitan area. Although scarps of these faults grow gradually and without causing damaging earthquakes, historical fault offset has cost millions of dollars in damage to houses and other buildings, utilities, and highways that were built on or across the faults. The historical fault activity results from renewed movement along preexisting faults and appears to be caused principally by withdrawal of ground water for municipal, industrial, and agricultural uses in the Houston area. Approximately one-half of the area's water supply is obtained from local ground water. Monitoring by the US Geological Survey of heights of fault scarps indicates that many of the scarps have recently stopped increasing in height. The area where faulting has ceased coincides with the area where ground-water pumping was cut back in the mid-1970s to slow the damage caused by land subsidence along Galveston Bay and the Houston Ship Channel. Thus, it appears that efforts to halt land subsidence in the coastal area have provided the additional benefit of arresting damaging surface faulting. -from Authors

  7. Design and evaluation of an advanced air-ground data-link system for air traffic control

    NASA Technical Reports Server (NTRS)

    Denbraven, Wim

    1992-01-01

    The design and evaluation of the ground-based portion of an air-ground data-link system for air traffic control (ATC) are described. The system was developed to support the 4D Aircraft/ATC Integration Study, a joint simulation experiment conducted at NASA's Ames and Langley Research Centers. The experiment focused on airborne and ground-based procedures for handling aircraft equipped with a 4D-Flight Management System (FMS) and the system requirements needed to ensure conflict-free traffic flow. The Center/TRACON Automation System (CTAS) at Ames was used for the ATC part of the experiment, and the 4D-FMS-equipped aircraft was simulated by the Transport Systems Research Vehicle (TSRV) simulator at Langley. The data-link system supported not only conventional ATC communications, but also the communications needed to accommodate the 4D-FMS capabilities of advanced aircraft. Of great significance was the synergism gained from integrating the data link with CTAS. Information transmitted via the data link was used to improve the monitoring and analysis capability of CTAS without increasing controller input workload. Conversely, CTAS was used to anticipate and create prototype messages, thus reducing the workload associated with the manual creation of data-link messages.

  8. TDRSS data handling and management system study. Ground station systems for data handling and relay satellite control

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Results of a two-phase study of the (Data Handling and Management System DHMS) are presented. An original baseline DHMS is described. Its estimated costs are presented in detail. The DHMS automates the Tracking and Data Relay Satellite System (TDRSS) ground station's functions and handles both the forward and return link user and relay satellite data passing through the station. Direction of the DHMS is effected via a TDRSS Operations Control Central (OCC) that is remotely located. A composite ground station system, a modified DHMS (MDHMS), was conceptually developed. The MDHMS performs both the DHMS and OCC functions. Configurations and costs are presented for systems using minicomputers and midicomputers. It is concluded that a MDHMS should be configured with a combination of the two computer types. The midicomputers provide the system's organizational direction and computational power, and the minicomputers (or interface processors) perform repetitive data handling functions that relieve the midicomputers of these burdensome tasks.

  9. An approach to decision aid of boreal forest fire control using both of ground observation and remote sensing

    NASA Astrophysics Data System (ADS)

    Nakau, K.; Fukuda, M.; Hayasaka, H.; Kimura, K.; Kushida, K.; Matsuura, N.

    2004-12-01

    Burned area of boreal forest fires is increasing in these decades. Two thirds of forest fires are judged as man-made in Siberia. On the other hand, for boreal forest fire emits global warming gas due to combustion and to change of land coverage, forest fire may accelerate global warming. In 2003 summer, 17million hectares are burned in Siberia and CO2 emission is estimated as 3 hundred million tons. Thus, it is important to control forest fire. Toward this aim, we collected data of boreal forest fire in Alaska and east Siberia in summer fire seasons for two years. Data were acquired from each of ground observation, observation from aircraft and remotely sensed fire detection in June and July. Remotely detected fire using some algorisms were compared with observed data to evaluate the accuracy and earliness of automatic detection. Study areas are Alaska and East Siberia in this year and squares of 1000km centered on Yakutsk, Irkutsk and Krasnoyarsk for each in 2003. Daily NOAA and MODIS satellite images are corrected and used for fire detection. 750 ground observation reports are corrected from Russian agency including location, weather and fire front size and severity. 178 reports are corrected from JAL aircraft flying across Siberia including location and time. Comparison between ground truth data and satellite images was done for validation of automatic forest fire detection. Almost all location of ground and aircraft observation data of forest fires as large as 1 hectare were automatically detected at almost same time using satellite images where whether permitting. We are developing connection of fire detection algorithm and fire expansion simulation model to forecast the possible burned area. On the basis of fire expansion forecast, risk analysis of possible fire expansion for decision aid of fire-fighting activities will be analyzed.@@On the basis of these analyses, we will discuss some possible utilizations of remotely sensed forest fire to control them.

  10. Shale Failure Mechanics and Intervention Measures in Underground Coal Mines: Results From 50 Years of Ground Control Safety Research

    NASA Astrophysics Data System (ADS)

    Murphy, M. M.

    2016-02-01

    Ground control research in underground coal mines has been ongoing for over 50 years. One of the most problematic issues in underground coal mines is roof failures associated with weak shale. This paper will present a historical narrative on the research the National Institute for Occupational Safety and Health has conducted in relation to rock mechanics and shale. This paper begins by first discussing how shale is classified in relation to coal mining. Characterizing and planning for weak roof sequences is an important step in developing an engineering solution to prevent roof failures. Next, the failure mechanics associated with the weak characteristics of shale will be discussed. Understanding these failure mechanics also aids in applying the correct engineering solutions. The various solutions that have been implemented in the underground coal mining industry to control the different modes of failure will be summarized. Finally, a discussion on current and future research relating to rock mechanics and shale is presented. The overall goal of the paper is to share the collective ground control experience of controlling roof structures dominated by shale rock in underground coal mining.

  11. Shale Failure Mechanics and Intervention Measures in Underground Coal Mines: Results From 50 Years of Ground Control Safety Research

    PubMed Central

    2015-01-01

    Ground control research in underground coal mines has been ongoing for over 50 years. One of the most problematic issues in underground coal mines is roof failures associated with weak shale. This paper will present a historical narrative on the research the National Institute for Occupational Safety and Health has conducted in relation to rock mechanics and shale. This paper begins by first discussing how shale is classified in relation to coal mining. Characterizing and planning for weak roof sequences is an important step in developing an engineering solution to prevent roof failures. Next, the failure mechanics associated with the weak characteristics of shale will be discussed. Understanding these failure mechanics also aids in applying the correct engineering solutions. The various solutions that have been implemented in the underground coal mining industry to control the different modes of failure will be summarized. Finally, a discussion on current and future research relating to rock mechanics and shale is presented. The overall goal of the paper is to share the collective ground control experience of controlling roof structures dominated by shale rock in underground coal mining. PMID:26549926

  12. Tug fleet and ground operations schedules and controls. Volume 3: Program cost estimates

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Cost data for the tug DDT&E and operations phases are presented. Option 6 is the recommended option selected from seven options considered and was used as the basis for ground processing estimates. Option 6 provides for processing the tug in a factory clean environment in the low bay area of VAB with subsequent cleaning to visibly clean. The basis and results of the trade study to select Option 6 processing plan is included. Cost estimating methodology, a work breakdown structure, and a dictionary of WBS definitions is also provided.

  13. A Controller-in-the Loop Simulation of Ground-Based Automated Separation Assurance in a NextGen Environment

    NASA Technical Reports Server (NTRS)

    Homola, J.; Prevot, Thomas; Mercer, Joey S.; Brasil, Connie L.; Martin, Lynne Hazel; Cabrall, C.

    2010-01-01

    A controller-in-the-loop simulation was conducted in the Airspace Operations Laboratory (AOL) at the NASA Ames Research Center to investigate the functional allocation aspects associated with ground-based automated separation assurance in a far-term NextGen environment. In this concept, ground-based automation handled the detection and resolution of strategic and tactical conflicts and alerted the controller to deferred situations. The controller was responsible for monitoring the automation and managing situations by exception. This was done in conditions both with and without arrival time constraints across two levels of traffic density. Results showed that although workload increased with an increase in traffic density, it was still manageable in most situations. The number of conflicts increased similarly with a related increase in the issuance of resolution clearances. Although over 99% of conflicts were resolved, operational errors did occur but were tied to local sector complexities. Feedback from the participants revealed that they thought they maintained reasonable situation awareness in this environment, felt that operations were highly acceptable at the lower traffic density level but were less so as it increased, and felt overall that the concept as it was introduced here was a positive step forward to accommodating the more complex environment envisioned as part of NextGen.

  14. Low-Speed Stability-and-Control and Ground-Effects Measurements on the Industry Reference High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Kemmerly, Guy T.; Campbell, Bryan A.; Banks, Daniel W.; Yaros, Steven F.

    1999-01-01

    As a part of a national effort to develop an economically feasible High Speed Civil Transport (HSCT), a single configuration has been accepted as the testing baseline by the organizations working in the High Speed Research (HSR) program. The configuration is based on a design developed by the Boeing Company and is referred to as the Reference H (Ref H). The data contained in this report are low-speed stability-and-control and ground-effect measurements obtained on a 0.06 scale model of the Ref H in a subsonic tunnel.

  15. Summary of hydrogeologic controls on ground-water flow at the Nevada Test Site, Nye County, Nevada

    USGS Publications Warehouse

    Laczniak, R.J.; Cole, J.C.; Sawyer, D.A.; Trudeau, D.A.

    1996-01-01

    itself. This report summarizes what is known and inferred about ground-water flow throughout the NTS region. The report identifies and updates what is known about some of the major controls on ground-water flow, highlights some of the uncertainties in the current understanding, and prioritizes some of the technical needs as related to the Environmental Restoration Program. An apparent deficiency in the current understanding is a lack of knowledge about flow directions and rates away from major areas of testing. Efforts are necessary to delineate areas of downgradient flow and to identify factors that constrain and control flow within these areas. These efforts also should identify the areas most critical to gaining detailed understanding and to establishing long-term monitoring sites necessary for effective remediation.

  16. The use of oxygen scavengers to prevent the transient discolouration of ground beef packaged under controlled, oxygen-depleted atmospheres.

    PubMed

    Gill, C O; McGinnis, J C

    1995-01-01

    Rates of O(2) absorption from air were determined for a type of commercial O(2) scavenger that is formulated for rapid O(2) absorption at chiller temperatures. Rates of O(2) absorption from N(2) atmospheres containing 600 ppm O(2) were determined for trays that each contained 350 g of ground beef. Packs with controlled atmospheres of N(2) that contained ground beef and O(2) scavengers were prepared, to determine the conditions under which the scavengers could prevent the transient discolouration of the meat which arises from its reaction with the residual O(2) initially present in pack atmospheres. The rates of O(2) absorption by individual scavengers varied from the average by ±50%. The rate of O(2) absorption declined with decreasing oxygen concentration, from an average value per scavenger of about 12 ml h(-1) when O(2) concentrations were between 20 and 10%. At O(2) concentrations <1% (10,000 ppm) the rate of O(2) absorption was directly proportioned to the O(2) concentration so that the O(2) concentration in an atmosphere in a gas-impermeable pouch declined exponentially with time. The absorption of O(2) by ground beef was similarly dependent on the O(2) concentration. At 2 °C, the transient discolouration of beef in atmospheres initially containing about 50 ppm O(2) was prevented by the presence of 17.5 scavengers per l of atmosphere. At -15 °C, discolouration was prevented by 5 scavengers per l. The findings indicate that the O(2) concentration in pack atmospheres has to be reduced below 10 ppm within 30 min at 2 °C, or 2 h at -1.5 °C if ground beef is not to transiently discolour. It is unlikely that the required rates of O(2) absorption could be obtained economically with currently available, commercial O(2) scavengers.

  17. Summary of hydrogeologic controls on ground-water flow at the Nevada Test Site, Nye County, Nevada

    SciTech Connect

    Laczniak, R.J.; Cole, J.C.; Sawyer, D.A.; Trudeau, D.A.

    1996-07-01

    The underground testing of nuclear devices has generated substantial volumes of radioactive and other chemical contaminants below ground at the Nevada Test Site (NTS). Many of the more radioactive contaminants are highly toxic and are known to persist in the environment for thousands of years. In response to concerns about potential health hazards, the US Department of Energy, under its Environmental Restoration Program, has made NTS the subject of a long-term investigation. Efforts will assess whether byproducts of underground testing pose a potential hazard to the health and safety of the public and, if necessary, will evaluate and implement steps to remediate any of the identified dangers. Ground-water flow is the primary mechanism by which contaminants can be transported significant distances away from the initial point of injection. Flow paths between contaminant sources and potential receptors are separated by remote areas that span tens of miles. The diversity and structural complexity of the rocks along these flow paths complicates the hydrology of the region. Although the hydrology has been studied in some detail, much still remains uncertain about flow rates and directions through the fractured-rock aquifers that transmit water great distances across this arid region. Unique to the hydrology of NTS are the effects of underground testing, which severely alter local rock characteristics and affect hydrologic conditions throughout the region. This report summarizes what is known and inferred about ground-water flow throughout the NTS region. The report identifies and updates what is known about some of the major controls on ground-water flow, highlights some of the uncertainties in the current understanding, and prioritizes some of the technical needs as related to the Environmental Restoration Program. 113 refs.

  18. Spaceborne Autonomous and Ground Based Relative Orbit Control for the TerraSAR-X/TanDEM-X Formation

    NASA Technical Reports Server (NTRS)

    Ardaens, J. S.; D'Amico, S.; Kazeminejad, B.; Montenbruck, O.; Gill, E.

    2007-01-01

    . The goal of the ground segment is thus to regularly correct this configuration by performing small orbit correction maneuvers on TDX. The ground station contacts are limited due to the geographic position of the station and the costs for contact time. Only with a polar ground station a contact visibility is possible every orbit for LEO satellites. TSX and TDX use only the Weilheim ground station (in the southern part of Germany) during routine operations. This station allows two scheduled contact per day for the nominal orbit configuration, meaning that the satellite conditions can be checked with an interval of 12 hours. While this limitation is usually not critical for single satellite operations, the visibility constraints drive the achievable orbit control accuracy for a LEO formation if a ground based approach is chosen. Along-track position uncertainties and maneuver execution errors affect the relative motion and can be compensated only after a ground station contact.

  19. Spin-orbit coupling controlled ground state in Sr2ScOsO6

    NASA Astrophysics Data System (ADS)

    Taylor, A. E.; Morrow, R.; Fishman, R. S.; Calder, S.; Kolesnikov, A. I.; Lumsden, M. D.; Woodward, P. M.; Christianson, A. D.

    2016-06-01

    We report neutron scattering experiments which reveal a large spin gap in the magnetic excitation spectrum of weakly-monoclinic double perovskite Sr2ScOsO6 . The spin gap is demonstrative of appreciable spin-orbit-induced anisotropy, despite nominally orbitally-quenched 5 d3Os5 + ions. The system is successfully modeled including nearest neighbor interactions in a Heisenberg Hamiltonian with exchange anisotropy. We find that the presence of the spin-orbit-induced anisotropy is essential for the realization of the type I antiferromagnetic ground state. This demonstrates that physics beyond the LS or JJ coupling limits plays an active role in determining the collective properties of 4 d3 and 5 d3 systems and that theoretical treatments must include spin-orbit coupling.

  20. Spin-orbit coupling controlled ground state in Sr2ScOsO6

    DOE PAGESBeta

    Taylor, A. E.; Morrow, R.; Fishman, R. S.; Calder, S.; Kolesnikov, A. I.; Lumsden, M. D.; Woodward, P. M.; Christianson, A. D.

    2016-06-27

    In this paper, we report neutron scattering experiments which reveal a large spin gap in the magnetic excitation spectrum of weakly-monoclinic double perovskite Sr2ScOsO6. The spin gap is demonstrative of appreciable spin-orbit-induced anisotropy, despite nominally orbitally-quenched 5d3Os5+ ions. The system is successfully modeled including nearest neighbor interactions in a Heisenberg Hamiltonian with exchange anisotropy. We find that the presence of the spin-orbit-induced anisotropy is essential for the realization of the type I antiferromagnetic ground state. Finally, this demonstrates that physics beyond the LS or JJ coupling limits plays an active role in determining the collective properties of 4d3 and 5d3more » systems and that theoretical treatments must include spin-orbit coupling.« less

  1. NASA/MSFC ground experiment for large space structure control verification

    NASA Technical Reports Server (NTRS)

    Waites, H. B.; Seltzer, S. M.; Tollison, D. K.

    1984-01-01

    Marshall Space Flight Center has developed a facility in which closed loop control of Large Space Structures (LSS) can be demonstrated and verified. The main objective of the facility is to verify LSS control system techniques so that on orbit performance can be ensured. The facility consists of an LSS test article which is connected to a payload mounting system that provides control torque commands. It is attached to a base excitation system which will simulate disturbances most likely to occur for Orbiter and DOD payloads. A control computer will contain the calibration software, the reference system, the alignment procedures, the telemetry software, and the control algorithms. The total system will be suspended in such a fashion that LSS test article has the characteristics common to all LSS.

  2. Use of COTS in the Multimission Advanced Ground Intelligent Control (MAGIC) program

    SciTech Connect

    Crowley, N.L.

    1997-11-01

    This tutorial will discuss the experiences of the Space System Technologies Division of the USAF Phillips Laboratory (PL/VTS) in developing a COTS-based satellite control system. The system`s primary use is a testbed for new technologies that are intended for future integration into the operational satellite control system. As such, the control system architecture must be extremely open and flexible so we can integrate new components and functions easily and also provide our system to contractors for their component work. The system is based on commercial hardware, is based on Windows NT, and makes the maximum use of COTS components and industry standards.

  3. Pickup of visual information by the pilot during a ground control approach in a fighter aircraft simulator.

    PubMed

    Papin, J P; Naureils, P; Santucci, G

    1980-05-01

    Before providing the new single-seat fighter aircraft with selective visual information display systems, it is necessary to conduct new studies of the visual behavior of pilots flying these aircraft in order to determine the nature of information to be displayed. The authors describe a modified NAC Eye Mark recorder which can be used in tight spaces without any interfering light source and given an example of its use in an experiment conducted in a Mirage III R training simulator. The reported experiment was designed to analyse the visual behavior of 12 pilots of four different qualification levels who flew a ground control approach (GCA) test each day for five consecutive days. The results show that the pilot's visual behavior is stable, both on an intra- and inter-individual basis. In addition, it is possible to classify the control panel instruments as a function of the number of times and length of time they are checked.

  4. On shaky ground - A study of security vulnerabilities in control protocols

    SciTech Connect

    Byres, E. J.; Huffman, D.; Kube, N.

    2006-07-01

    The recent introduction of information technologies such as Ethernet R into nuclear industry control devices has resulted in significantly less isolation from the outside world. This raises the question of whether these systems could be attacked by malware, network hackers or professional criminals to cause disruption to critical operations in a manner similar to the impacts now felt in the business world. To help answer this question, a study was undertaken to test a representative control protocol to determine if it had vulnerabilities that could be exploited. A framework was created in which a test could express a large number of test cases in very compact formal language. This in turn, allowed for the economical automation of both the generation of selectively malformed protocol traffic and the measurement of device under test's (DUT) behavior in response to this traffic. Approximately 5000 protocol conformance tests were run against two major brands of industrial controller. More than 60 categories of errors were discovered, the majority of which were in the form of incorrect error responses to malformed traffic. Several malformed packets however, caused the device to respond or communicate in inappropriate ways. These would be relatively simple for an attacker to inject into a system and could result in the plant operator losing complete view or control of the control device. Based on this relatively small set of devices, we believe that the nuclear industry urgently needs to adopt better security robustness testing of control devices as standard practice. (authors)

  5. The role of unattended ground sensors (UGS) in regional confidence building and arms control

    SciTech Connect

    Vannoni, M.; Duggan, R.

    1997-03-01

    Although the Cold War has ended, the world has not become more peaceful. Without the stability provided by an international system dominated by two super-powers, local conflicts are more likely to escalate. Agreements to counter destabilizing pressures in regional conflicts can benefit from the use of cooperative monitoring. Cooperative monitoring is the collecting, analyzing, and sharing of information among parties to an agreement. Ground sensor technologies can contribute to the collection of relevant information. If implemented with consideration for local conditions, cooperative monitoring can build confidence, strengthen existing agreements, and set the stage for continued progress. This presentation describes two examples: the Israeli-Egyptian Sinai agreements of the 1970s and a conceptual example for the contemporary Korean Peninsula. The Sinai was a precedent for the successful use of UGS within the context of cooperative monitoring. The Korean Peninsula is the world`s largest military confrontation. Future confidence building measures that address the security needs of both countries could decrease the danger of conflict and help create an environment for a peace agreement.

  6. Migration strategies for service-enabling ground control stations for unmanned systems

    NASA Astrophysics Data System (ADS)

    Kroculick, Joseph B.

    2011-06-01

    Future unmanned systems will be integrated into the Global Information Grid (GIG) and support net-centric data sharing, where information in a domain is exposed to a wide variety of GIG stakeholders that can make use of the information provided. Adopting a Service-Oriented Architecture (SOA) approach to package reusable UAV control station functionality into common control services provides a number of benefits including enabling dynamic plug and play of components depending on changing mission requirements, supporting information sharing to the enterprise, and integrating information from authoritative sources such as mission planners with the UAV control stations data model. It also allows the wider enterprise community to use the services provided by unmanned systems and improve data quality to support more effective decision-making. We explore current challenges in migrating UAV control systems that manage multiple types of vehicles to a Service-Oriented Architecture (SOA). Service-oriented analysis involves reviewing legacy systems and determining which components can be made into a service. Existing UAV control stations provide audio/visual, navigation, and vehicle health and status information that are useful to C4I systems. However, many were designed to be closed systems with proprietary software and hardware implementations, message formats, and specific mission requirements. An architecture analysis can be performed that reviews legacy systems and determines which components can be made into a service. A phased SOA adoption approach can then be developed that improves system interoperability.

  7. Transportable Payload Operations Control Center reusable software: Building blocks for quality ground data systems

    NASA Technical Reports Server (NTRS)

    Mahmot, Ron; Koslosky, John T.; Beach, Edward; Schwarz, Barbara

    1994-01-01

    The Mission Operations Division (MOD) at Goddard Space Flight Center builds Mission Operations Centers which are used by Flight Operations Teams to monitor and control satellites. Reducing system life cycle costs through software reuse has always been a priority of the MOD. The MOD's Transportable Payload Operations Control Center development team established an extensive library of 14 subsystems with over 100,000 delivered source instructions of reusable, generic software components. Nine TPOCC-based control centers to date support 11 satellites and achieved an average software reuse level of more than 75 percent. This paper shares experiences of how the TPOCC building blocks were developed and how building block developer's, mission development teams, and users are all part of the process.

  8. Environmental Impact of Controlled-Source Explosions in Ethiopia (Project EAGLE): Surface Shaking, Ground Velocities, and Effects on Buildings

    NASA Astrophysics Data System (ADS)

    Les, A.; Klemperer, S. L.; Keranen, K.; Khan, A.; Maguire, P.

    2003-12-01

    In January 2003, as part of the Ethiopia-Afar Geoscientific Lithospheric Experiment (EAGLE) we conducted a refraction and wide-angle reflection survey of the Main Ethiopian Rift. 757 RefTek "Texan" seismographs with vertical geophones were deployed in 400 km-long axial and cross-rift lines, with another 231 in a central 3D array 100 km in diameter. An 80-instrument passive array of intermediate and broadband sensors was active during our experiment. We recorded 19 borehole shots loaded in nominal 50-meter boreholes, 2 quarry shots, and 2 lake shots. The shots ranged in size from 50-5750 kg, with the most common shot size being 1 tonne. Prior to loading each shot-hole, we measured distances between shots and the nearest structure, typically un-reinforced mud-and-wood houses, occasionally concrete irrigation ditches and aqueducts. We then used semi-empirical formulae derived by Oriard (Hendron and Oriard, 1972) to calculate expected maximum and minimum bounds on ground velocity at these structures, and selected an appropriate shot size to keep the predicted velocity below the "threshold for cosmetic damage", or 2 inches per second, at the most vulnerable structure. The Oriard formulae are derived from measurements associated with blasting for mining and civil engineering purposes and may not accurately predict the ground velocity from the source depths and explosive type used in the EAGLE and other controlled-source experiments. A detailed, trace-by-trace analysis of maximum ground velocities at our closest seismographs can provide data that will be useful in planning future large-scale seismic experiments. Preliminary results from traces within 20 km of our borehole shots suggest that maximum recorded ground velocities were within or below the maximum-minimum range predicted by Oriard, and hence that larger shot sizes could have been used with acceptable risks. A lake shot fired at the optimum depth (84 m for a 1 tonne shot) produced ground velocities that exceeded

  9. Preliminary estimates of range measurements to a spacecraft by means of ground digitally controlled oscillators

    NASA Technical Reports Server (NTRS)

    Liu, A.; Pease, G.

    1974-01-01

    Range measurements to the Pioneer 10 and Mariner 10 spacecraft were made, without the use of a ranging system per se, by using the Jet Propulsion Laboratory Deep Space Network's new digitally controlled oscillator (DCO) device. These measurements were accomplished by controlling the linear ramps of the transmitted carrier frequency with a recently installed DCO instrument at the Goldstone facility and analyzing the received linearly ramped Doppler data with a computer program. The accuracy of these range measurements is on the order of 1.5 km.

  10. The control system of the 12-m medium-size telescope prototype: a test-ground for the CTA array control

    NASA Astrophysics Data System (ADS)

    Oya, I.; Anguner, E. A.; Behera, B.; Birsin, E.; Fuessling, M.; Lindemann, R.; Melkumyan, D.; Schlenstedt, S.; Schmidt, T.; Schwanke, U.; Sternberger, R.; Wegner, P.; Wiesand, S.

    2014-07-01

    The Cherenkov Telescope Array (CTA) will be the next generation ground-based very-high energy -ray observatory. CTA will consist of two arrays: one in the Northern hemisphere composed of about 20 telescopes, and the other one in the Southern hemisphere composed of about 100 telescopes, both arrays containing telescopes of different sizes and types and in addition numerous auxiliary devices. In order to provide a test-ground for the CTA array control, the steering software of the 12-m medium size telescope (MST) prototype deployed in Berlin has been implemented using the tools and design concepts under consideration to be used for the control of the CTA array. The prototype control system is implemented based on the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) control middleware, with components implemented in Java, C++ and Python. The interfacing to the hardware is standardized via the Object Linking and Embedding for Process Control Unified Architecture (OPC UA). In order to access the OPC UA servers from the ACS framework in a common way, a library has been developed that allows to tie the OPC UA server nodes, methods and events to the equivalents in ACS components. The front-end of the archive system is able to identify the deployed components and to perform the sampling of the monitoring points of each component following time and value change triggers according to the selected configurations. The back-end of the archive system of the prototype is composed by two different databases: MySQL and MongoDB. MySQL has been selected as storage of the system configurations, while MongoDB is used to have an efficient storage of device monitoring data, CCD images, logging and alarm information. In this contribution, the details and conclusions on the implementation of the control software of the MST prototype are presented.

  11. The administration`s arms control agenda: Gaining ground under fire

    SciTech Connect

    Holum, J.D.

    1996-03-01

    Its perhaps too easy to forget that Russia is still one country that could inflict overwhelming nuclear devastation on the United States. Russia`s Dumas elections and presidential elections speaks of changes in Russia, but this transformation will take many years and requires our consistent engagement and steady support. The author examines the Clinton Administration`s arms control agenda.

  12. Ground Truthing the ‘Conventional Wisdom’ of Lead Corrosion Control Using Mineralogical Analysis

    EPA Science Inventory

    For drinking water distribution systems (DWDS) with lead-bearing plumbing materials some form of corrosion control is typically necessary, with the goal of mitigating lead release by forming adherent, stable corrosion scales composed of low-solubility mineral phases. Conventional...

  13. Ground Truthing the 'Conventional Wisdom' of Lead Corrosion Control Using Mineralogical Analysis

    EPA Science Inventory

    For drinking water distribution systems (DWDS) with lead-bearing plumbing materials some form of corrosion control is typically necessary, with the goal of mitigating lead release by forming adherent, stable corrosion scales composed of low-solubility mineral phases. Conventional...

  14. Investigating Hydrogeologic Controls on Sandhill Wetlands in Covered Karst with 2D Resistivity and Ground Penetrating Radar

    NASA Astrophysics Data System (ADS)

    Downs, C. M.; Nowicki, R. S.; Rains, M. C.; Kruse, S.

    2015-12-01

    In west-central Florida, wetland and lake distribution is strongly controlled by karst landforms. Sandhill wetlands and lakes are sand-filled upland basins whose water levels are groundwater driven. Lake dimensions only reach wetland edges during extreme precipitation events. Current wetland classification schemes are inappropriate for identifying sandhill wetlands due to their unique hydrologic regime and ecologic expression. As a result, it is difficult to determine whether or not a wetland is impacted by groundwater pumping, development, and climate change. A better understanding of subsurface structures and how they control the hydrologic regime is necessary for development of an identification and monitoring protocol. Long-term studies record vegetation diversity and distribution, shallow ground water levels and surface water levels. The overall goals are to determine the hydrologic controls (groundwater, seepage, surface water inputs). Most recently a series of geophysical surveys was conducted at select sites in Hernando and Pasco County, Florida. Electrical resistivity and ground penetrating radar were employed to image sand-filled basins and the top of the limestone bedrock and stratigraphy of wetland slopes, respectively. The deepest extent of these sand-filled basins is generally reflected in topography as shallow depressions. Resistivity along inundated wetlands suggests the pools are surface expressions of the surficial aquifer. However, possible breaches in confining clay layers beneath topographic highs between depressions are seen in resistivity profiles as conductive anomalies and in GPR as interruptions in otherwise continuous horizons. These data occur at sites where unconfined and confined water levels are in agreement, suggesting communication between shallow and deep groundwater. Wetland plants are observed outside the historic wetland boundary at many sites, GPR profiles show near-surface layers dipping towards the wetlands at a shallower

  15. Effect of spaceflight hardware on the skeletal properties of ground control mice

    NASA Astrophysics Data System (ADS)

    Bateman, Ted; Lloyd, Shane; Dunlap, Alex; Ferguson, Virginia; Simske, Steven; Stodieck, Louis; Livingston, Eric

    Introduction: Spaceflight experiments using mouse or rat models require habitats that are specifically designed for the microgravity environment. During spaceflight, rodents are housed in a specially designed stainless steel meshed cage with gravity-independent food and water delivery systems and constant airflow to push floating urine and feces towards a waste filter. Differences in the housing environment alone, not even considering the spaceflight environment itself, may lead to physiological changes in the animals contained within. It is important to characterize these cage differences so that results from spaceflight experiments can be more reliably compared to studies from other laboratories. Methods: For this study, we examined the effect of NASA's Animal Enclosure Module (AEM) spaceflight hardware on the skeletal properties of 8-week-old female C57BL/6J mice. This 13-day experiment, conducted on the ground, modeled the flight experiment profile of the CBTM-01 payload on STS-108, with standard vivarium-housed mice being compared to AEM-housed mice (n = 12/group). Functional differences were compared via mechanical testing, micro-hardness indentation, microcomputed tomography, and mineral/matrix composition. Cellular changes were examined by serum chemistry, histology, quantitative histomorphometry, and RT-PCR. A Student's t-test was utilized, with the level of Type I error set at 95 Results: There was no change in elastic, maximum, or fracture force mechanical properties at the femur mid-diaphysis, however, structural stiffness was -17.5 Conclusions: Housing mice in the AEM spaceflight hardware had minimal effects on femur cortical bone properties. However, trabecular bone at the proximal tibia in AEM mice experi-enced large increases in microarchitecture and mineral composition. Increases in bone density were accompanied by reductions in bone-forming osteoblasts and bone-resorbing osteoclasts, representing a general decline in bone turnover at this site

  16. World Model Based Remote Control and Teleperception for Space and Ground Servicing Applications

    NASA Astrophysics Data System (ADS)

    Jacobus, Charles J.; Gallarda, Harry S.; Walker, Michael W.; Conrad, David J.; Borenstein, Johann; Quek, Francis; Mitchell, Brian T.

    1990-03-01

    A World Modeling System for operating a remote robotic servicing system should provide an operator with the same degree of flexibility and feedback possible from teleoperators, but under a supervisory control constraint. Thus, a sophisticated software system must exist on both the remote servicer and the local platform. This system must provide simulations and offline programming of the remote servicer (and its environment) for the operator to compose new commands (and test them). It must provide communications to and from the remote platform (within bandwidth limitations). It must allow interaction at multiple levels of abstraction (for instance at the task level, the robotic path planning level, and the robot joint level), and it must provide sensors, sensor processing, and model matching capabilities required to direct remote autonomous operations (like tracking or grip point identification) and to keep the local simulated servicer environment up to date. This concept of a World Modeling System encompasses perception and control of robotic systems.

  17. IT Security Support for the Spaceport Command Control Systems Development Ground Support Development Operations

    NASA Technical Reports Server (NTRS)

    Branch, Drew A.

    2014-01-01

    Security is one of the most if not the most important areas today. After the several attacks on the United States, security everywhere has heightened from airports to the communication among the military branches legionnaires. With advanced persistent threats (APT's) on the rise following Stuxnet, government branches and agencies are required, more than ever, to follow several standards, policies and procedures to reduce the likelihood of a breach. Attack vectors today are very advanced and are going to continue to get more and more advanced as security controls advance. This creates a need for networks and systems to be in an updated and secured state in a launch control system environment. FISMA is a law that is mandated by the government to follow when government agencies secure networks and devices. My role on this project is to ensure network devices and systems are in compliance with NIST, as outlined in FISMA. I will achieve this by providing assistance with security plan documentation and collection, system hardware and software inventory, malicious code and malware scanning, and configuration of network devices i.e. routers and IDS's/IPS's. In addition, I will be completing security assessments on software and hardware, vulnerability assessments and reporting, and conducting patch management and risk assessments. A guideline that will help with compliance with NIST is the SANS Top 20 Critical Controls. SANS Top 20 Critical Controls as well as numerous security tools, security software and the conduction of research will be used to successfully complete the tasks given to me. This will ensure compliance with FISMA and NIST, secure systems and a secured network. By the end of this project, I hope to have carried out the tasks stated above as well as gain an immense knowledge about compliance, security tools, networks and network devices, as well as policies and procedures.

  18. IT Security Support for the Spaceport Command Control Systems Development Ground Support Development Operations

    NASA Technical Reports Server (NTRS)

    Branch, Drew

    2013-01-01

    Security is one of the most if not the most important areas today. After the several attacks on the United States, security everywhere was heightened from Airports to the communication among the military branches legionnaires. With advanced persistent threats (APTs) on the rise following Stuxnet, government branches and agencies are required, more than ever, to follow several standards, policies and procedures to reduce the likelihood of a breach. Attack vectors today are very advanced and are going to continue to get more and more advanced as security controls advance. This creates a need for networks and systems to be in an updated and secured state in a launch control system environment. FISMA is a law that is mandated by the government to follow when government agencies secure networks and devices. My role on this project is to ensure network devices and systems are in compliance with NIST, as outlined in FISMA. I will achieve this by providing assistance with security plan documentation and collection, system hardware and software inventory, malicious code and malware scanning and configuration of network devices i.e. routers and IDSsIPSs. In addition I will be completing security assessments on software and hardware, vulnerability assessments and reporting, conducting patch management and risk assessments. A guideline that will help with compliance with NIST is the SANS Top 20 Critical Controls. SANS Top 20 Critical Controls as well as numerous security tools, security software and the conduction of research will be used to successfully complete the tasks given to me. This will ensure compliance with FISMA and NIST, secure systems and a secured network. By the end of this project, I hope to have carried out stated above as well as gain an immense knowledge about compliance, security tools, networks and network devices, policies and procedures.

  19. Response of ground-water levels of flood control operations in three basins, south-eastern Florida

    USGS Publications Warehouse

    Pitt, William A.J.

    1974-01-01

    Three basins in southeastern Florida were investigated to determine the changes in ground-water levels and canal flows that occurred in response to operation of coastal water-control structures in each canal. All three basins are underlain by the Biscayne aquifer. They are, Snapper Creek Canal basin, where the Biscayne aquifer is of high permeability; the Snake Creek Canal basin, where the aquifer is of moderate permeability; and the Pompano-Cypress Canal basin, where the aquifer is of low permeability. In each basin, drainage is a function of permeability; thus, where the permeability of the aquifer is high, drainage is excellent. The coastal water-conrol structures are intended to afford flood protection in the three basins. In general the control operation criteria for flood control in newly developing areas in southeastern Florida do not provide adequate protection from flooding because of the time required for the aquifer to respond to changes in the controls. Adequate protection would require increasing the density of secondary drainage canals, but this could achieved only by reducing the quantity of water available for recharging those segments of the Biscayne aquifer adjacent to the canals. (Woodrad-USGS)

  20. Dried, ground banana plant leaves (Musa spp.) for the control of Haemonchus contortus and Trichostrongylus colubriformis infections in sheep.

    PubMed

    Gregory, L; Yoshihara, E; Ribeiro, B L M; Silva, L K F; Marques, E C; Meira, E B S; Rossi, R S; Sampaio, P H; Louvandini, H; Hasegawa, M Y

    2015-12-01

    To evaluate the anthelmintic effect of Musa spp. leaves, 12 animals were artificially infected with Haemonchus contortus, and another 12 animals were infected with Trichostrongylus colubriformis. Then, both treatment groups were offered 400 g of dried ground banana plant leaves, and the control animals were offered only 1000 g of coast cross hay. During the trials, the animals received weekly physical examinations. The methods used to evaluate the efficiency of this treatment were packed cell volume, total plasma protein and faecal egg counts, and egg hatchability tests were performed on days -2, +3, +6, +9, +13 and +15. Coproculture tests were performed on day -2 to confirm monospecific infections. In the FEC and EHT, a statistically significant difference (0.04, 0.005; p < 0.05) was noted for T. colubriformis. There were no statistically significant differences (p > 0.05) for Haemochus contortus group in all tests. Our results confirmed previous findings suggesting that dried ground banana plant leaves possess anthelmintic activity.

  1. Internet-based control for the intelligent unmanned ground vehicle: Bearcat Cub

    NASA Astrophysics Data System (ADS)

    Ghaffari, Masoud; Narayanan, Sugan; Sethuramasamyraja, Balaji; Hall, Ernest L.

    2003-10-01

    Secure remote access with inter-operatability for operating a robot can be successfully achieved using the web services provided in the .NET framework. The complete design of the machine discussed in this paper is made on the .NET framework. The server which operates the robot is configured to IIS. The algorithm for obstacle detection is coded on a different server using the .NET framework. By using web services, the robot can be accessed by other servers. These web services are consumed by the server on which the robot executes. A proxy is created on this server. The whole control is given in the form of a series of web pages which can be accessed by any web browser. However in order to input parameters and control the robot, authentication is required. The user provides authentication credentials which are matched with the existing information on the data base. After authentication, the user proceeds further to control the robot. The security and reliability of remote access is provided by the components that come with the web services namely, SOAP, WSDL and Proxy.

  2. Ergonomic problems regarding the interactive touch input via screens in onboard and ground-based flight control

    NASA Technical Reports Server (NTRS)

    Holzhausen, K. P.; Gaertner, K. P.

    1985-01-01

    A significant problem concerning the integration of display and switching functions is related to the fact that numerous informative data which have to be processed by man must be read from only a few display devices. A satisfactory ergonomic design of integrated display devices and keyboards is in many cases difficult, because not all functions which can be displayed and selected are simultaneously available. A technical solution which provides an integration of display and functional elements on the basis of the highest flexibility is obtained by using a cathode ray tube with a touch-sensitive screen. The employment of an integrated data input/output system is demonstrated for the cases of onboard and ground-based flight control. Ergonomic studies conducted to investigate the suitability of an employment of touch-sensitive screens are also discussed.

  3. Recent changes in particulate air pollution over China observed from space and the ground: effectiveness of emission control.

    PubMed

    Lin, Jintai; Nielsen, Chris P; Zhao, Yu; Lei, Yu; Liu, Yang; McElroy, Michael B

    2010-10-15

    The Chinese government has moved aggressively since 2005 to reduce emissions of a number of pollutants including primary particulate matter (PM) and sulfur dioxide (SO(2)), efforts inadvertently aided since late 2008 by economic recession. Satellite observations of aerosol optical depth (AOD) and column nitrogen dioxide (NO(2)) provide independent indicators of emission trends, clearly reflecting the sharp onset of the recession in the fall of 2008 and rebound of the economy in the latter half of 2009. Comparison of AOD with ground-based observations of PM over a longer period indicate that emission-control policies have not been successful in reducing concentrations of aerosol pollutants at smaller size range over industrialized regions of China. The lack of success is attributed to the increasing importance of anthropogenic secondary aerosols formed from precursor species including nitrogen oxides (NO(x)), non-methane volatile organic compounds (NMVOC), and ammonia (NH(3)).

  4. Effects of structural faults on ground control in selected coal mines in southwestern Virginia. Report of Investigations/1989

    SciTech Connect

    Molinda, G.M.; Ingram, D.K.

    1989-01-01

    Two faults related to the Pine Mountain overthrust sheet in Buchanan County, VA, were investigated by the Bureau of Mines to determine their effect on ground control and to develop recognition criteria for prediction. Five underground mines encountering these faults were visited and mapped for structural information. The information, along with surface mapping, indicated that the Pistol Gap and Keen Mountain Faults show right-lateral, strike-slip faulting and bedding planes slippage, which can be projected linearly and vertically. These fault zones are up to 200 ft wide, with coalbed offsets up to 18 ft vertically, coalbed swags (depressions) up to 15 ft, and roof falls up to 20 ft high. Recognition criteria include bedding plane slips, coalbed offsets, fault gouge, coalbed swag (depressions or synclines), and disturbed bedding.

  5. Experiences with a Requirements-Based Programming Approach to the Development of a NASA Autonomous Ground Control System

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.; Gracanin, Denis; Erickson, John

    2005-01-01

    Requirements-to-Design-to-Code (R2D2C) is an approach to the engineering of computer-based systems that embodies the idea of requirements-based programming in system development. It goes further; however, in that the approach offers not only an underlying formalism, but full formal development from requirements capture through to the automatic generation of provably-correct code. As such, the approach has direct application to the development of systems requiring autonomic properties. We describe a prototype tool to support the method, and illustrate its applicability to the development of LOGOS, a NASA autonomous ground control system, which exhibits autonomic behavior. Finally, we briefly discuss other areas where the approach and prototype tool are being considered for application.

  6. Optimising UAV topographic surveys processed with structure-from-motion: Ground control quality, quantity and bundle adjustment

    NASA Astrophysics Data System (ADS)

    James, Mike R.; Robson, Stuart; d'Oleire-Oltmanns, Sebastian; Niethammer, Uwe

    2016-04-01

    Structure-from-motion (SfM) algorithms are greatly facilitating the production of detailed topographic models based on images collected by unmanned aerial vehicles (UAVs). However, SfM-based software does not generally provide the rigorous photogrammetric analysis required to fully understand survey quality. Consequently, error related to problems in control point data or the distribution of control points can remain undiscovered. Even if these errors are not large in magnitude, they can be systematic, and thus have strong implications for the use of products such as digital elevation models (DEMs) and orthophotos. Here, we develop a Monte Carlo approach to (1) improve the accuracy of products when SfM-based processing is used and (2) reduce the associated field effort by identifying suitable lower density deployments of ground control points. The method highlights over-parameterisation during camera self-calibration and provides enhanced insight into control point performance when rigorous error metrics are not available. Processing was implemented using commonly-used SfM-based software (Agisoft PhotoScan), which we augment with semi-automated and automated GCPs image measurement. We apply the Monte Carlo method to two contrasting case studies - an erosion gully survey (Taurodont, Morocco) carried out with an fixed-wing UAV, and an active landslide survey (Super-Sauze, France), acquired using a manually controlled quadcopter. The results highlight the differences in the control requirements for the two sites, and we explore the implications for future surveys. We illustrate DEM sensitivity to critical processing parameters and show how the use of appropriate parameter values increases DEM repeatability and reduces the spatial variability of error due to processing artefacts.

  7. Ground-based LiDAR integration with avalanche control operations: target planning and assessment of control effectiveness

    NASA Astrophysics Data System (ADS)

    Deems, J. S.; LeWinter, A.; Gadomski, P. J.; Finnegan, D. C.

    2015-12-01

    The varying distribution of snow depth in avalanche starting zones exerts a strong influence on avalanche potential and character. Extreme depth changes over short distances are common, especially in wind-affected, above-treeline environments. Snow depth also affects the ease of avalanche triggering. Experience shows that avalanche reduction efforts are often more successful when targeting shallow trigger point areas near deeper slabs with explosives or ski cutting. We are exploring the use of high resolution snow depth and depth change maps from differential LiDAR scans to quantify loading patterns for use in both pre-control planning and in post-control assessment. We present results from our ongoing work at the Arapahoe Basin and Aspen Highlands ski areas in Colorado, USA, and from a new collaboration with the Colorado Department of Transportation. At Arapahoe Basin we have tested rapid snow depth product generation for use in planning placement of explosives for artificial avalanche triggering. At Aspen Highlands we have explored measurement of minimum disturbance depth from bootpacking. In a new application, we are assessing avalanche hazard reduction with new Gazex exploder arrays on Loveland and Berthoud Passes.

  8. A wind-tunnel investigation of parameters affecting helicopter directional control at low speeds in ground effect

    NASA Technical Reports Server (NTRS)

    Yeager, W. T., Jr.; Young, W. H., Jr.; Mantay, W. R.

    1974-01-01

    An investigation was conducted in the Langley full-scale tunnel to measure the performance of several helicopter tail-rotor/fin configurations with regard to directional control problems encountered at low speeds in ground effect. Tests were conducted at wind azimuths of 0 deg to 360 deg in increments of 30 deg and 60 deg and at wind speeds from 0 to 35 knots. The results indicate that at certain combinations of wind speed and wind azimuth, large increases in adverse fin force require correspondingly large increases in the tail-rotor thrust, collective pitch, and power required to maintain yaw trim. Changing the tail-rotor direction of rotation to top blade aft for either a pusher tail rotor (tail-rotor wake blowing away from fin) or a tractor tail rotor (tail-rotor wake blowing against fin) will alleviate this problem. For a pusher tail rotor at 180 deg wind azimuth, increases in the fin/tail-rotor gap were not found to have any significant influence on the overall vehicle directional control capability. Changing the tail rotor to a higher position was found to improve tail-rotor performance for a fin-off configuration at a wind azimuth of 180 deg. A V-tail configuration with a pusher tail rotor with top blade aft direction of rotation was found to be the best configuration with regard to overall directional control capability.

  9. Topographic control of the depth of ground thaw in a peat covered continuous permafrost site in the Canadian arctic tundra

    NASA Astrophysics Data System (ADS)

    Endrizzi, Stefano; Marsh, Philip; Quinton, William; Dall'Amico, Matteo

    2010-05-01

    Recent research has suggested an energy-based framework for delineating runoff contributing areas for permafrost dominated, tundra environments, where end of winter snow cover, and turbulent and radiant fluxes of energy and water are affected by topography, and control both snowmelt and the depth of ground thaw. The resulting spatially variable thaw depth, when combined with spatially variable water supply, spatially variable organic soil thickness, and depth variable hydraulic conductivity in organic soils, has a significant impact on the flow of water from uplands to the stream channel. In order to consider the effects of a spatially variable depth of thaw on runoff in a tundra basin, the hydrologic model GEOtop was applied to the Siksik Creek drainage basin located approximately 50 km north of Inuvik, NWT, Canada, characterized by a relatively gentle topography, with elevation ranging from 0 and 80 m a.s.l.. The small surface area of the basin (approximately 1 km2) allows the model to be run at a relatively high resolution. GEOtop is a grid based model with a complete surface energy balance scheme that accounts for variations in both the turbulent fluxes of sensible and latent heat, as well as for variations in radiant fluxes. The model also has a complete subsurface heat and water flux scheme that is able to route water and energy both vertically between a large number of soil layers, and horizontally between grids. Field data for model validation include meteorological data, depth of thaw, and runoff data for a 3 year period between 1992 and 1994, and high resolution DEM and vegetation height data obtained from airborne LiDAR in 2004. The purpose of this work is studying how topography controls the depth of thaw, and, therefore, the effects of a spatially variable snow cover are intentionally neglected. GEOtop was then run in a simple configuration, assuming an initial condition of uniform frost table at the ground surface at the end of snow melt, with snow

  10. Human-Automation Interaction Design for Adaptive Cruise Control Systems of Ground Vehicles.

    PubMed

    Eom, Hwisoo; Lee, Sang Hun

    2015-01-01

    A majority of recently developed advanced vehicles have been equipped with various automated driver assistance systems, such as adaptive cruise control (ACC) and lane keeping assistance systems. ACC systems have several operational modes, and drivers can be unaware of the mode in which they are operating. Because mode confusion is a significant human error factor that contributes to traffic accidents, it is necessary to develop user interfaces for ACC systems that can reduce mode confusion. To meet this requirement, this paper presents a new human-automation interaction design methodology in which the compatibility of the machine and interface models is determined using the proposed criteria, and if the models are incompatible, one or both of the models is/are modified to make them compatible. To investigate the effectiveness of our methodology, we designed two new interfaces by separately modifying the machine model and the interface model and then performed driver-in-the-loop experiments. The results showed that modifying the machine model provides a more compact, acceptable, effective, and safe interface than modifying the interface model. PMID:26076406

  11. Controls on ground-water chemistry in the Horse Heaven Hills, south-central Washington

    USGS Publications Warehouse

    Steinkampf, W.C.; Bortleson, Gilbert C.; Packard, F.A.

    1985-01-01

    Miocene basaltic aquifers are the source of domestic and municipal water, and about 20,000 acre-feet of irrigation water annually, in the Horse Heaven Hills in south-central Washington State. Groundwater chemical variations derive from the hydraulic characteristics is of the geohydrologic system, from groundwater basalt reactions, and from irrigation. Some dissolved species concentrations increase with residence time; others decrease. Recharge area groundwaters are calcium magnesium sodium bicarbonate waters with sodium-adsorption ratios (SAR's) less than 1.0. They evolve to sodium potassium bicarbonate waters with SAR 's as high as 17. Glassy and cryptocrystalline phases of the basalt are the main sources of dissolved sodium. They dissolve by silicate hydrolysis in carbon dioxide charged waters that recharge the aquifer system. Dissolved silicon, iron, and aluminum concentrations are controlled by the solubilities of amorphous secondary alteration products, which order to silica phases, oxyhydroxides, and smectite. Carbonate mineral precipitation is induced by increasing pH from the hydrolysis reaction. Sodium and potassium concentrations increase until clinoptilolite saturation is reached and precipitation begins. Deviations from the general variation patterns are due to localized geologic structures which distort the groundwater flow system, and to the irrigation use of Columbia River water. (USGS)

  12. Human-Automation Interaction Design for Adaptive Cruise Control Systems of Ground Vehicles.

    PubMed

    Eom, Hwisoo; Lee, Sang Hun

    2015-01-01

    A majority of recently developed advanced vehicles have been equipped with various automated driver assistance systems, such as adaptive cruise control (ACC) and lane keeping assistance systems. ACC systems have several operational modes, and drivers can be unaware of the mode in which they are operating. Because mode confusion is a significant human error factor that contributes to traffic accidents, it is necessary to develop user interfaces for ACC systems that can reduce mode confusion. To meet this requirement, this paper presents a new human-automation interaction design methodology in which the compatibility of the machine and interface models is determined using the proposed criteria, and if the models are incompatible, one or both of the models is/are modified to make them compatible. To investigate the effectiveness of our methodology, we designed two new interfaces by separately modifying the machine model and the interface model and then performed driver-in-the-loop experiments. The results showed that modifying the machine model provides a more compact, acceptable, effective, and safe interface than modifying the interface model.

  13. Human-Automation Interaction Design for Adaptive Cruise Control Systems of Ground Vehicles

    PubMed Central

    Eom, Hwisoo; Lee, Sang Hun

    2015-01-01

    A majority of recently developed advanced vehicles have been equipped with various automated driver assistance systems, such as adaptive cruise control (ACC) and lane keeping assistance systems. ACC systems have several operational modes, and drivers can be unaware of the mode in which they are operating. Because mode confusion is a significant human error factor that contributes to traffic accidents, it is necessary to develop user interfaces for ACC systems that can reduce mode confusion. To meet this requirement, this paper presents a new human-automation interaction design methodology in which the compatibility of the machine and interface models is determined using the proposed criteria, and if the models are incompatible, one or both of the models is/are modified to make them compatible. To investigate the effectiveness of our methodology, we designed two new interfaces by separately modifying the machine model and the interface model and then performed driver-in-the-loop experiments. The results showed that modifying the machine model provides a more compact, acceptable, effective, and safe interface than modifying the interface model. PMID:26076406

  14. Ground-Based Testing of Replacement Thermal Control Materials for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Townsend, Jacqueline A.; Hansen, Patricia A.; McClendon, Mark W.; deGroh, Kim K.; Banks, Bruce A.; Triolo, Jack J.

    1998-01-01

    The mechanical and optical properties of the metallized Teflon FEP thermal control materials on the Hubble Space Telescope (HST) have degraded over the nearly seven years the telescope has been in orbit. Given the damage to the outer layer of the multi-layer insulation (MLI) that was apparent during the second servicing mission (SM2), the decision was made to replace the outer layer during subsequent servicing missions. A Failure Review Board was established to investigate the damage to the MLI and identify a replacement material. The replacement material had to meet the stringent thermal requirements of the spacecraft and maintain mechanical integrity for at least ten years. Ten candidate materials were selected and exposed to ten-year HST-equivalent doses of simulated orbital environments. Samples of the candidates were exposed sequentially to low and high energy electrons and protons, atomic oxygen, x-ray radiation, ultraviolet radiation and thermal cycling. Following the exposures, the mechanical integrity and optical properties of the candidates were investigated using Optical Microscopy, Scanning Electron Microscopy (SEM), a Laboratory Portable Spectroreflectometer (LPSR) and a Lambda 9 Spectroreflectometer. Based on the results of these simulations and analyses, the Failure Review Board selected a replacement material and two alternates that showed the highest likelihood of providing the requisite thermal properties and surviving for ten years in orbit.

  15. Control of impact crater fracture systems on subsurface hydrology, ground subsidence, and collapse, Mars

    NASA Astrophysics Data System (ADS)

    Rodríguez, Jose Alexis Palmero; Sasaki, Sho; Dohm, James M.; Tanaka, Ken L.; Strom, Bob; Kargel, Jeff; Kuzmin, Ruslan; Miyamoto, Hideaki; Spray, John G.; Fairén, Alberto G.; Komatsu, Goro; Kurita, Kei; Baker, Victor

    2005-06-01

    Noachian layered materials are pervasively exposed throughout the highlands of Mars. The layered deposits, in places many kilometers thick, exhibit impact craters of diverse morphologic characteristics, ranging from highly degraded to pristine, most of which formed during the period of heavy bombardment. In addition, exhumed impact craters, ancient channels, and fluvial and alluvial fans are visible in the layered deposits through MOC imagery. These features are more abundant in Noachian terrains, which indicates relatively high erosion rates during ancient Mars that competed with heavy meteoritic bombardment. The Noachian layered materials are thus expected to contain numerous buried impact craters in various states of preservation. Here, we propose that impact craters (buried and exposed) and associated fracture systems dominate the basement structural fabric of the ancient highlands and that they have significantly influenced the hydrogeology. Diversity in the occurrence of high and low densities of impact craters and associated fracture systems controls the magnitude of the local effects of magmatic-driven hydrothermal activity. In and surrounding the Tharsis region, for example, the formation of chaotic terrains (the source regions of the circum-Chryse outflow channel system) and a large diversity of collapse structures, including impact crater moats and pit chains, appear to be the result of enhanced hydrothermal activity.

  16. Control of impact crater fracture systems on subsurface hydrology, ground subsidence, and collapse, Mars

    USGS Publications Warehouse

    Rodriguez, J.A.P.; Sasaki, S.; Dohm, J.M.; Tanaka, K.L.; Strom, B.; Kargel, J.; Kuzmin, R.; Miyamoto, H.; Spray, J.G.; Fairen, A.G.; Komatsu, G.; Kurita, K.; Baker, V.

    2005-01-01

    Noachian layered materials are pervasively exposed throughout the highlands of Mars. The layered deposits, in places many kilometers thick, exhibit impact craters of diverse morphologic characteristics, ranging from highly degraded to pristine, most of which formed during the period of heavy bombardment. In addition, exhumed impact craters, ancient channels, and fluvial and alluvial fans are visible in the layered deposits through MOC imagery. These features are more abundant in Noachian terrains, which indicates relatively high erosion rates during ancient Mars that competed with heavy meteoritic bombardment. The Noachian layered materials are thus expected to contain numerous buried impact craters in various states of preservation. Here, we propose that impact craters (buried and exposed) and associated fracture systems dominate the basement structural fabric of the ancient highlands and that they have significantly influenced the hydrogeology. Diversity in the occurrence of high and low densities of impact craters and associated fracture systems controls the magnitude of the local effects of magmatic-driven hydrothermal activity. In and surrounding the Tharsis region, for example, the formation of chaotic terrains (the source regions of the circum-Chryse outflow channel system) and a large diversity of collapse structures, including impact crater moats and pit chains, appear to be the result of enhanced hydrothermal activity. Copyright 2005 by the American Geophysical Union.

  17. An Ecological Approach to the Design of UAV Ground Control Station (GCS) Status Displays

    NASA Technical Reports Server (NTRS)

    Dowell, Susan; Morphew, Ephimia; Shively, Jay

    2003-01-01

    Use of UAVs in military and commercial applications will continue to increase. However, there has been limited research devoted to UAV GCS design. The current study employed an ecological approach to interfac e design. Ecological Interface Design (EID) can be characterized as r epresenting the properties of a system, such that an operator is enco uraged to use skill-based behavior when problem solving. When more ef fortful cognitive processes become necessary due to unfamiliar situations, the application of EID philosophy supports the application of kn owledge-based behavior. With advances toward multiple UAV command and control, operators need GCS interfaces designed to support understan ding of complex systems. We hypothesized that use of EID principles f or the display of UAV status information would result in better opera tor performance and situational awareness, while decreasing workload. Pilots flew a series of missions with three UAV GCS displays of statu s information (Alphanumeric, Ecological, and Hybrid display format). Measures of task performance, Situational Awareness, and workload dem onstrated the benefits of using an ecological approach to designing U AV GCS displays. The application of ecological principles to the design of UAV GCSs is a promising area for improving UAV operations.

  18. Below- and above-ground controls on tree water use in lowland tropical forests

    NASA Astrophysics Data System (ADS)

    Meinzer, F. C.; Woodruff, D.; McCulloh, K.; Domec, J.

    2012-12-01

    scaled uniformly with branch leaf-specific conductivity and with the branch leaf area to sapwood area ratio; a tree architecture-based proxy for leaf-specific conductivity. At the canopy-atmosphere interface, a combination of high stomatal conductance and relatively large leaf size enhanced the role of the boundary layer over stomata in controlling transpiration (increased decoupling coefficient; omega). Uniform scaling of tree water use characteristics with simple biophysical, hydraulic and architectural traits across species may facilitate predictions of changes in tropical forest water use with shifts in species composition associated with climate change and changing land-use.

  19. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, and Human Health and Safety

    NASA Technical Reports Server (NTRS)

    Atwell, William; Koontz, Steve; Normand, Eugene

    2012-01-01

    Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems. The effects of primary cosmic ray particles and secondary particle showers produced by nuclear reactions with the atmosphere, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth s surface, especially if the net target area of the sensitive electronic system components is large. Finally, accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO). In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as human health and the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based atmospheric flight, and space flight environments. Ground test methods applied to microelectronic components and systems are used in combinations with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport

  20. Structural controls on ground-water conditions and estimated aquifer properties near Bill Williams Mountain, Williams, Arizona

    USGS Publications Warehouse

    Pierce, Herbert A.

    2001-01-01

    As of 1999, surface water collected and stored in reservoirs is the sole source of municipal water for the city of Williams. During 1996 and 1999, reservoirs reached historically low levels. Understanding the ground-water flow system is critical to managing the ground-water resources in this part of the Coconino Plateau. The nearly 1,000-meter-deep regional aquifer in the Redwall and Muav Limestones, however, makes studying or utilizing the resource difficult. Near-vertical faults and complex geologic structures control the ground-water flow system on the southwest side of the Kaibab Uplift near Williams, Arizona. To address the hydrogeologic complexities in the study area, a suite of techniques, which included aeromagnetic, gravity, square-array resistivity, and audiomagnetotelluric surveys, were applied as part of a regional study near Bill Williams Mountain. Existing well data and interpreted geophysical data were compiled and used to estimate depths to the water table and to prepare a potentiometric map. Geologic characteristics, such as secondary porosity, coefficient of anisotropy, and fracture-strike direction, were calculated at several sites to examine how these characteristics change with depth. The 14-kilometer-wide, seismically active northwestward-trending Cataract Creek and the northeastward-trending Mesa Butte Fault systems intersect near Bill Williams Mountain. Several north-south-trending faults may provide additional block faulting north and west of Bill Williams Mountain. Because of the extensive block faulting and regional folding, the volcanic and sedimentary rocks are tilted toward one or more of these faults. These faults provide near-vertical flow paths to the regional water table. The nearly radial fractures allow water that reaches the regional aquifer to move away from the Bill Williams Mountain area. Depth to the regional aquifer is highly variable and depends on location and local structures. On the basis of interpreted

  1. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground Based Computation and Control Systems and Human Health and Safety

    NASA Technical Reports Server (NTRS)

    Atwell, William; Koontz, Steve; Normand, Eugene

    2012-01-01

    In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as on human health and safety, as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in earth surface, atmospheric flight, and space flight environments. Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools (e.g. ground based test methods as well as high energy particle transport and reaction codes) needed to design, test, and verify the safety and reliability of modern complex electronic systems as well as effects on human health and safety. The effects of primary cosmic ray particles, and secondary particle showers produced by nuclear reactions with spacecraft materials, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth's surface, especially if the net target area of the sensitive electronic system components is large. Accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO).

  2. Efficacy of Insecticide and Bioinsecticide Ground Sprays to Control Metisa plana Walker (Lepidoptera: Psychidae) in Oil Palm Plantations, Malaysia.

    PubMed

    Salim, Hasber; Rawi, Che Salmah Md; Ahmad, Abu Hassan; Al-Shami, Salman Abdo

    2015-12-01

    The effectiveness of the synthetic insecticides trichlorfon, lambda-cyhalothrin, cypermethrin emulsion concentrated (EC) and cypermethrin emulsion water based (EW) and a bio-insecticide, Bacillus thuringiensis subsp. kurstaki (Btk), was evaluated at 3, 7, 14 and 30 days after treatment (DAT) for the control of Metisa plana larvae in an oil palm (Elaeis guineensis) plantation in Malaysia. Although all synthetic insecticides effectively reduced the larval population of M. plana, trichlorfon, lambda-cyhalothrin and cypermethrin EC were the fastest-acting. The larval population dropped below the economic threshold level (ETL) 30 days after a single application of the synthetic insecticides. Application of Btk, however, gave poor results, with the larval population remaining above the ETL post treatment. In terms of operational productivity, ground spraying using power spray equipment was time-consuming and resulted in poor coverage. Power spraying may not be appropriate for controlling M. plana infestations in large fields. Using a power sprayer, one man could cover 2-3 ha per day. Hence, power spraying is recommended during outbreaks of infestation in areas smaller than 50 ha.

  3. Piloted simulation of an air-ground profile negotiation process in a time-based Air Traffic Control environment

    NASA Technical Reports Server (NTRS)

    Williams, David H.; Green, Steven M.

    1993-01-01

    Historically, development of airborne flight management systems (FMS) and ground-based air traffic control (ATC) systems has tended to focus on different objectives with little consideration for operational integration. A joint program, between NASA's Ames Research Center (Ames) and Langley Research Center (Langley), is underway to investigate the issues of, and develop systems for, the integration of ATC and airborne automation systems. A simulation study was conducted to evaluate a profile negotiation process (PNP) between the Center/TRACON Automation System (CTAS) and an aircraft equipped with a four-dimensional flight management system (4D FMS). Prototype procedures were developed to support the functional implementation of this process. The PNP was designed to provide an arrival trajectory solution which satisfies the separation requirements of ATC while remaining as close as possible to the aircraft's preferred trajectory. Results from the experiment indicate the potential for successful incorporation of aircraft-preferred arrival trajectories in the CTAS automation environment. Fuel savings on the order of 2 percent to 8 percent, compared to fuel required for the baseline CTAS arrival speed strategy, were achieved in the test scenarios. The data link procedures and clearances developed for this experiment, while providing the necessary functionality, were found to be operationally unacceptable to the pilots. In particular, additional pilot control and understanding of the proposed aircraft-preferred trajectory, and a simplified clearance procedure were cited as necessary for operational implementation of the concept.

  4. Application of Long-period Ground Motion Prediction using Earthquake Early Warning System to Elevator Emergency Operation Control System of a High-Rise Building

    NASA Astrophysics Data System (ADS)

    Kubo, Tomohiro; Hisada, Yoshiaki; Horiuchi, Shigeki; Yamamoto, Shunroku

    We propose the method of the elevator operation control for the long-period ground motion using Earthquake Early Warning System (EEWS) and apply this method to the elevator operation control system of the 29-story building of Kogakuin University in the downtown Tokyo, Shinjuku, Japan. First, we estimate the velocity of surface wave that travels through the crustal calculated by the theoretical method, and we estimate the long-period ground motion by Green's function and calculate the lumped mass model response by the estimated long-period ground motion. Next we develop the trigger condition stopping the elevator based on above results. When EEWS is received, we reference the trigger condition and stop the elevator. Next, we apply the elevator operation control for the long-period ground motion proposed method to Kogakuin University, which is high-rise building and located at the central of Tokyo. We compare the estimation the long-period ground motion by the wavenumber integration with the observation data. As a result, the estimated waves between 2 sec and 4 sec almost correspond the observed waves, but the estimated waves between 4 sec and 6 sec underestimate the observed waves because of the 3D effects of the Kanto sedimentary basin. Thus, we estimate the long-period ground motion to the estimation on the side of prudence given the assumption of the source model, because EEWS provides only the location and magnitude of an earthquake. We confirm that the proposed method is able to control the elevator for the long-period ground motion.

  5. Correlation of the Hubble Space Telescope (HST) Space Telescope Imaging Spectrometer (STIS) On-Orbit Data with Pre-launch Predictions and Ground Contamination Controls

    NASA Technical Reports Server (NTRS)

    Hansen, Patricia A.

    2003-01-01

    The Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) was deployed on-orbit in February 1997. The contamination program for STIS was stringently controlled as the five-year end-of-life deposition was set at 158, per optical element. Contamination was controlled through materials selection, extensive vacuum outgassing certifications, cleaning techniques, and environmental controls. In addition to ground contamination controls, on-orbit contamination controls were implemented for both the HST servicing mission activities and early post-servicing mission checkout. The extensive contamination control program will be discussed and the STIS on-orbit data will be correlated with the prelaunch analytical predictions.

  6. Detection of conduit-controlled ground-water flow in northwestern Puerto Rico using aerial photograph interpretation and geophysical methods

    USGS Publications Warehouse

    Rodríguez-Martínez, Jesús; Richards, Ronald T.

    2000-01-01

    The development potential of ground-water resources in the karst limestone of northwestern Puerto Rico, in an area extending from the Río Camuy to Aguadilla, is uncertain as a result of limited knowledge of the location of areas where a high density of cavities (interconnected fractures, conduits, and other dissolution features) might suggest the occurrence of high water yields. The presence in northwestern Puerto Rico of numerous coastal submarine springs, cavernous porosity in some of the wells, and rivers with entrenched and underground paths, indicate that it is probable that water-bearing, subterranean interconnected cavities occur in the area between the Río Camuy and Aguadilla. The number of exploratory wells needed to determine the location of these conduits or zones of enhanced secondary porosity could be substantially reduced if more information were available about the location of these subterranean features, greatly reducing the drilling costs associated with a trial-and-error exploratory process. A 3-year study was conducted by the U.S. Geological Survey, in cooperation with the Puerto Rico Aqueduct and Sewer Authority, to detect the presence of cavities that might suggest the occurrence of conduit-controlled groundwater flow. Aerial photographs, geologic and topographic maps, and field reconnaissance were used to identify such linear terrain features as ridges, entrenched canyons, and fracture traces. Natural potential and gravity geophysical methods were also used. The following sites were selected for the aerial photograph interpretation and geophysical testing: Caimital Bajo uplands and former Ramey Air Force Base in Aguadilla; Quebrada de los Cedros between Aguadilla and Isabela; the University of Puerto Rico Agricultural Experiment Station, Otilio dairy farm, and Pozo Brujo in Isabela; the Monte Encantado area in Moca and Isabela; and the Rio Camuy cave system in Hatillo and Camuy. In general, the degree of success varied with site and the

  7. Quality-control results for ground-water and surface-water data, Sacramento River Basin, California, National Water-Quality Assessment, 1996-1998

    USGS Publications Warehouse

    Munday, Cathy; Domagalski, Joseph L.

    2003-01-01

    Evaluating the extent that bias and variability affect the interpretation of ground- and surface-water data is necessary to meet the objectives of the National Water-Quality Assessment (NAWQA) Program. Quality-control samples used to evaluate the bias and variability include annual equipment blanks, field blanks, field matrix spikes, surrogates, and replicates. This report contains quality-control results for the constituents critical to the ground- and surface-water components of the Sacramento River Basin study unit of the NAWQA Program. A critical constituent is one that was detected frequently (more than 50 percent of the time in blank samples), was detected at amounts exceeding water-quality standards or goals, or was important for the interpretation of water-quality data. Quality-control samples were collected along with ground- and surface-water samples during the high intensity phase (cycle 1) of the Sacramento River Basin NAWQA beginning early in 1996 and ending in 1998. Ground-water field blanks indicated contamination of varying levels of significance when compared with concentrations detected in environmental ground-water samples for ammonia, dissolved organic carbon, aluminum, and copper. Concentrations of aluminum in surface-water field blanks were significant when compared with environmental samples. Field blank samples collected for pesticide and volatile organic compound analyses revealed no contamination in either ground- or surface-water samples that would effect the interpretation of environmental data, with the possible exception of the volatile organic compound trichloromethane (chloroform) in ground water. Replicate samples for ground water and surface water indicate that variability resulting from sample collection, processing, and analysis was generally low. Some of the larger maximum relative percentage differences calculated for replicate samples occurred between samples having lowest absolute concentration differences and(or) values near

  8. A study on model fidelity for model predictive control-based obstacle avoidance in high-speed autonomous ground vehicles

    NASA Astrophysics Data System (ADS)

    Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

    2016-11-01

    This paper investigates the level of model fidelity needed in order for a model predictive control (MPC)-based obstacle avoidance algorithm to be able to safely and quickly avoid obstacles even when the vehicle is close to its dynamic limits. The context of this work is large autonomous ground vehicles that manoeuvre at high speed within unknown, unstructured, flat environments and have significant vehicle dynamics-related constraints. Five different representations of vehicle dynamics models are considered: four variations of the two degrees-of-freedom (DoF) representation as lower fidelity models and a fourteen DoF representation with combined-slip Magic Formula tyre model as a higher fidelity model. It is concluded that the two DoF representation that accounts for tyre nonlinearities and longitudinal load transfer is necessary for the MPC-based obstacle avoidance algorithm in order to operate the vehicle at its limits within an environment that includes large obstacles. For less challenging environments, however, the two DoF representation with linear tyre model and constant axle loads is sufficient.

  9. Long-term sequential monitoring of controlled graves representing common burial scenarios with ground penetrating radar: Years 2 and 3

    NASA Astrophysics Data System (ADS)

    Schultz, John J.; Walter, Brittany S.; Healy, Carrie

    2016-09-01

    Geophysical techniques such as ground-penetrating radar (GPR) have been successfully used for forensic searches to locate clandestine graves and physical evidence. However, additional controlled research is needed to fully understand the applicability of this technology when searching for clandestine graves in various environments, soil types, and for longer periods of time post-burial. The purpose of this study was to determine the applicability of GPR for detecting controlled graves in a Spodosol representing multiple burial scenarios for Years 2 and 3 of a three-year monitoring period. Objectives included determining how different burial scenarios are factors in producing a distinctive anomalous response; determining how different GPR imagery options (2D reflection profiles and horizontal time slices) can provide increased visibility of the burials; and comparing GPR imagery between 500 MHz and 250 MHz dominant frequency antennae. The research site contained a grid with eight graves representing common forensic burial scenarios in a Spodosol, a common soil type of Florida, with six graves containing a pig carcass (Sus scrofa). Burial scenarios with grave items (a deep grave with a layer of rocks over the carcass and a carcass wrapped in a tarpaulin) produced a more distinctive response with clearer target reflections over the duration of the monitoring period compared to naked carcasses. Months with increased precipitation were also found to produce clearer target reflections than drier months, particularly during Year 3 when many grave scenarios that were not previously visible became visible after increased seasonal rainfall. Overall, the 250 MHz dominant frequency antenna imagery was more favorable than the 500 MHz. While detection of a simulated grave may be difficult to detect over time, long term detection of a grave in a Spodosol may be possible if the disturbed spodic horizon is detected. Furthermore, while grave visibility increased with the 2D

  10. International Space Station Sustaining Engineering: A Ground-Based Test Bed for Evaluating Integrated Environmental Control and Life Support System and Internal Thermal Control System Flight Performance

    NASA Technical Reports Server (NTRS)

    Ray, Charles D.; Perry, Jay L.; Callahan, David M.

    2000-01-01

    As the International Space Station's (ISS) various habitable modules are placed in service on orbit, the need to provide for sustaining engineering becomes increasingly important to ensure the proper function of critical onboard systems. Chief among these are the Environmental Control and Life Support System (ECLSS) and the Internal Thermal Control System (ITCS). Without either, life onboard the ISS would prove difficult or nearly impossible. For this reason, a ground-based ECLSS/ITCS hardware performance simulation capability has been developed at NASA's Marshall Space Flight Center. The ECLSS/ITCS Sustaining Engineering Test Bed will be used to assist the ISS Program in resolving hardware anomalies and performing periodic performance assessments. The ISS flight configuration being simulated by the test bed is described as well as ongoing activities related to its preparation for supporting ISS Mission 5A. Growth options for the test facility are presented whereby the current facility may be upgraded to enhance its capability for supporting future station operation well beyond Mission 5A. Test bed capabilities for demonstrating technology improvements of ECLSS hardware are also described.

  11. Questa baseline and pre-mining ground-water-quality investigation. 16. Quality assurance and quality control for water analyses

    USGS Publications Warehouse

    McCleskey, R. Blaine; Nordstrom, D. Kirk; Naus, Cheryl A.

    2004-01-01

    The Questa baseline and pre-mining ground-water quality investigation has the main objective of inferring the ground-water chemistry at an active mine site. Hence, existing ground-water chemistry and its quality assurance and quality control is of crucial importance to this study and a substantial effort was spent on this activity. Analyses of seventy-two blanks demonstrated that contamination from processing, handling, and analyses were minimal. Blanks collected using water deionized with anion and cation exchange resins contained elevated concentrations of boron (0.17 milligrams per liter (mg/L)) and silica (3.90 mg/L), whereas double-distilled water did not. Boron and silica were not completely retained by the resins because they can exist as uncharged species in water. Chloride was detected in ten blanks, the highest being 3.9 mg/L, probably as the result of washing bottles, filter apparatuses, and tubing with hydrochloric acid. Sulfate was detected in seven blanks; the highest value was 3.0 mg/L, most likely because of carryover from the high sulfate waters sampled. With only a few exceptions, the remaining blank analyses were near or below method detection limits. Analyses of standard reference water samples by cold-vapor atomic fluorescence spectrometry, ion chromatography, inductively coupled plasma-optical emission spectrometry, inductively coupled plasma-mass spectrometry, FerroZine, graphite furnace atomic absorption spectrometry, hydride generation atomic spectrometry, and titration provided an accuracy check. For constituents greater than 10 times the detection limit, 95 percent of the samples had a percent error of less than 8.5. For constituents within 10 percent of the detection limit, the percent error often increased as a result of measurement imprecision. Charge imbalance was calculated using WATEQ4F and 251 out of 257 samples had a charge imbalance less than 11.8 percent. The charge imbalance for all samples ranged from -16 to 16 percent. Spike

  12. Control of strong ground motion of mining-induced earthquakes by the strength of the seismogenic rock mass

    USGS Publications Warehouse

    McGarr, A.

    2002-01-01

    The shear stress ?? that can be sustained by the rock mass in the environs of a mining-induced earthquake controls the near-fault peak ground velocity v of that event according to v???0.25(??/G) ??, where ?? is the shear wave speed and G is the modulus of rigidity. To estimate ?? at mining depths, I review the results of four studies involving Witwatersrand tremors that relate to the bulk shear strength. The first and most general analysis uses the common assumptions that the seismogenic crust is pervasively faulted, has hydrostatic pore pressure before mining, and an extensional stress state that is close to failure. Mining operations reduce the pore pressure to zero within the mine and redistribute the stresses such that, in localized regions, the state of stress is again at the point of failure. Laboratory friction experiments can be used to estimate ?? in the zero-pore-pressure regime. Second, model calculations of states of stress in the vicinity of milling at about 3 km depth indicated the shear stress available to cause faulting near the centre of a distribution of induced earthquakes. Third, laboratory experiments combined with microscopic analyses of fault gouge from the rupture zone of a mining-induced event provided an estimate of the average shear stress acting on the fault to cause this earthquake at a depth of 2 km. Fourth, moment tensors determined for mining- induced earthquakes usually show substantial implosive components, from which it is straightforward to estimate ??. These four different analyses yield estimates of ?? that fall in the range 30 to 61 MPa which implies that near-fault particle velocities could he as high as about 1.5 m/s. To the extent that the causative fault ruptures previously intact rock, both ?? and v, in localized regions, could be several times higher than 61 MPa and 1.5 m/s.

  13. Biogeochemical and hydrological processes controlling the transport and fate of 1,2-dibromoethane (EDB) in soil and ground water, central Florida

    USGS Publications Warehouse

    Katz, Brian G.

    1993-01-01

    Widespread contamination of ground water in central Florida by 1,2-dibromoethane (EDB) has resulted because of its heavy usage as a soil fumigant during a 20-year period, its relatively high aqueous solubility, and the low sorption capacity of the highly permeable sandy soils lacking organic matter. Two models were used to improve understanding of biogeochemical and hydrological processes that control the transport and fate of EDB in soil and ground water. First, a mass-balance model was developed to estimate the max-imum concentration of EDB in ground water resulting from known application rates of EDB. Key processes that were quantified in the model included volatilization, diffusion of EDB vapor in soils, partitioning between aqueous and gaseous phases, sorption of EDB vapor on organic carbon and soil particles, chemical and biological degradation reactions, and nonreversible binding of EDB to soils. Model calculations using an EDB half-life of 0.65 year closely reproduced the maximum observed concentrations in ground water, 37 and 0.22 micrograms per liter, at downgradient sites in two study areas in central Florida. Maximum concentrations of EDB in ground water also were estimated in a second model that incorporated an analytical solution to the three-dimensional advection-dispersion equation for instantaneous point sources of EDB entering the flow systems in the two study areas. The model used an EDB half-life of 0.65 year (obtained from the mass-balance calculations), mean ground-water flow velocities of 0.6 to 1 meter per day, coefficients of longitudinal hydro-dynamic dispersion of 0.6 to 1.0 square meter per day, and coefficients of transverse hydrodynamic dispersion of 0.1 square meter per day. Peak concentrations of EDB in ground water calculated from the analytical model agreed closely with observed peak concentrations measured from 1983 through 1987.

  14. Grounded theory.

    PubMed

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  15. Examination about Influence for Precision of 3d Image Measurement from the Ground Control Point Measurement and Surface Matching

    NASA Astrophysics Data System (ADS)

    Anai, T.; Kochi, N.; Yamada, M.; Sasaki, T.; Otani, H.; Sasaki, D.; Nishimura, S.; Kimoto, K.; Yasui, N.

    2015-05-01

    As the 3D image measurement software is now widely used with the recent development of computer-vision technology, the 3D measurement from the image is now has acquired the application field from desktop objects as wide as the topography survey in large geographical areas. Especially, the orientation, which used to be a complicated process in the heretofore image measurement, can be now performed automatically by simply taking many pictures around the object. And in the case of fully textured object, the 3D measurement of surface features is now done all automatically from the orientated images, and greatly facilitated the acquisition of the dense 3D point cloud from images with high precision. With all this development in the background, in the case of small and the middle size objects, we are now furnishing the all-around 3D measurement by a single digital camera sold on the market. And we have also developed the technology of the topographical measurement with the air-borne images taken by a small UAV [1~5]. In this present study, in the case of the small size objects, we examine the accuracy of surface measurement (Matching) by the data of the experiments. And as to the topographic measurement, we examine the influence of GCP distribution on the accuracy by the data of the experiments. Besides, we examined the difference of the analytical results in each of the 3D image measurement software. This document reviews the processing flow of orientation and the 3D measurement of each software and explains the feature of the each software. And as to the verification of the precision of stereo-matching, we measured the test plane and the test sphere of the known form and assessed the result. As to the topography measurement, we used the air-borne image data photographed at the test field in Yadorigi of Matsuda City, Kanagawa Prefecture JAPAN. We have constructed Ground Control Point which measured by RTK-GPS and Total Station. And we show the results of analysis made

  16. Aquifer-scale controls on the distribution of nitrate and ammonium in ground water near La Pine, Oregon, USA

    NASA Astrophysics Data System (ADS)

    Hinkle, Stephen R.; Böhlke, J. K.; Duff, John H.; Morgan, David S.; Weick, Rodney J.

    2007-02-01

    SummaryGeochemical and isotopic tools were applied at aquifer, transect, and subtransect scales to provide a framework for understanding sources, transport, and fate of dissolved inorganic N in a sandy aquifer near La Pine, Oregon. NO 3 is a common contaminant in shallow ground water in this area, whereas high concentrations of NH 4-N (up to 39 mg/L) are present in deep ground water. N concentrations, N/Cl ratios, tracer-based apparent ground-water ages, N isotope data, and hydraulic gradients indicate that septic tank effluent is the primary source of NO 3. N isotope data, N/Cl and N/C relations, 3H data, and hydraulic considerations point to a natural, sedimentary organic matter source for the high concentrations of NH 4, and are inconsistent with an origin as septic tank N. Low recharge rates and flow velocities have largely restricted anthropogenic NO 3 to isolated plumes within several meters of the water table. A variety of geochemical and isotopic data indicate that denitrification also affects NO 3 gradients in the aquifer. Ground water in the La Pine aquifer evolves from oxic to increasingly reduced conditions. Suboxic conditions are achieved after about 15-30 y of transport below the water table. NO 3 is denitrified near the oxic/suboxic boundary. Denitrification in the La Pine aquifer is characterized well at the aquifer scale with a redox boundary approach that inherently captures spatial variability in the distribution of electron donors.

  17. Ground-water sampling methods and quality-control data for the Red River of the North basin, Minnesota, North Dakota, and South Dakota, 1993-95

    USGS Publications Warehouse

    Menheer, M.A.; Brigham, M.E.

    1997-01-01

    Quality-control data demonstrated that most constituents measured for this study yielded reproducible data, with low to undetectable contamination from the sampling and analytical procedures. Several constituents were occasionally or frequently detected in blank samples at levels similar to low-concentration ground-water-quality samples. For example, iron was detected in 75 percent of the blank samples, with a maximum concentration of 27 [ig/L, indicating that iron contamination may interfere with its determination at low levels in ground waters. Copper, aluminum, and dissolved organic carbon concentrations in blank samples overlap those determined in ground-waterquality samples, thereby precluding quantitative reporting of those constituents. Most pesticide data are reproducible, with minimal bias. Some pesticides had low but consistent recoveries; these data may be useful if spike and surrogate data are carefully considered. Data for some pesticides measured in this study should not be quantitatively reported or used, because they may underestimate the concentrations of those pesticides in ground waters.

  18. Mixing a grounded theory approach with a randomized controlled trial related to intimate partner violence: what challenges arise for mixed methods research?

    PubMed

    Catallo, Cristina; Jack, Susan M; Ciliska, Donna; Macmillan, Harriet L

    2013-01-01

    Little is known about how to systematically integrate complex qualitative studies within the context of randomized controlled trials. A two-phase sequential explanatory mixed methods study was conducted in Canada to understand how women decide to disclose intimate partner violence in emergency department settings. Mixing a RCT (with a subanalysis of data) with a grounded theory approach required methodological modifications to maintain the overall rigour of this mixed methods study. Modifications were made to the following areas of the grounded theory approach to support the overall integrity of the mixed methods study design: recruitment of participants, maximum variation and negative case sampling, data collection, and analysis methods. Recommendations for future studies include: (1) planning at the outset to incorporate a qualitative approach with a RCT and to determine logical points during the RCT to integrate the qualitative component and (2) consideration for the time needed to carry out a RCT and a grounded theory approach, especially to support recruitment, data collection, and analysis. Data mixing strategies should be considered during early stages of the study, so that appropriate measures can be developed and used in the RCT to support initial coding structures and data analysis needs of the grounded theory phase.

  19. Grounded cognition.

    PubMed

    Barsalou, Lawrence W

    2008-01-01

    Grounded cognition rejects traditional views that cognition is computation on amodal symbols in a modular system, independent of the brain's modal systems for perception, action, and introspection. Instead, grounded cognition proposes that modal simulations, bodily states, and situated action underlie cognition. Accumulating behavioral and neural evidence supporting this view is reviewed from research on perception, memory, knowledge, language, thought, social cognition, and development. Theories of grounded cognition are also reviewed, as are origins of the area and common misperceptions of it. Theoretical, empirical, and methodological issues are raised whose future treatment is likely to affect the growth and impact of grounded cognition.

  20. LONG-TERM STABILITY OF THE LOCAL GROUND CONTROL NETWORK AT THE CO-LOCATION SITE OF MEDICINA

    NASA Astrophysics Data System (ADS)

    Abbondanza, C.; Sarti, P.; Legrand, J.

    2009-12-01

    ITRF combinations rely on the availability of accurate tie vectors linking reference points of space geodetic techniques. Co-located instruments are assumed to move consistently and no local relative motion is taken into account. Instabilities may degrade the quality of the co-location itself and perturb the result of ITRF combinations. This work aims to determine the stability of the local ground control network at Medicina (Italy) with independent surveying methods. The observatory hosts a co-location between a VLBI telescope and two GPS antennas, MEDI and MSEL. It is located in the Po Plain where thick layers of clays are the prevalent soil characteristics. Hence, provision of long term stability of geodetic monuments is a challenge and monitoring their stability is an issue. MEDI and the VLBI station regularly contribute to the determination of ITRF, while MSEL is part of the EUREF network. A set of five tie vectors observations linking the VLBI and MEDI reference points was acquired between 2001 and 2007. It is our main tool for performing local deformation analysis. Additionally, the GPS time series of MEDI and MSEL were used to cross check and confirm the local instability detected by terrestrial methods. To achieve a rigorous and reliable investigation of the local stability, multi-epoch terrestrial observations were homogeneously processed according to common parameterizations in a consistent reference frame. Similarly, continuous GPS observations from MEDI and MSEL were analysed according to the new EPN reprocessing strategy in order to monitor the short baseline between MEDI and MSEL; to spotlight any change in its length. Both approaches confirm differential motions at the site which can be related to monument instabilities originated by the particularly unfavourable local geological setting and the inapt design of the monuments foundation. The monuments move non homogeneously at rates reaching up to 1.6 mm/year, this value being comparable to intra

  1. Practical applications of cosmic ray science: Spacecraft, aircraft, ground based computation and control systems, and human health and safety

    NASA Astrophysics Data System (ADS)

    Atwell, William; Koontz, Steve; Normand, Eugene

    2013-02-01

    In this paper we review cosmic ray effects on the performance and reliability of microelectronic systems and human health as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based, atmospheric flight, and space flight environments. Ground based test methods applied to microelectronic components and systems are used in combination with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport codes are an important tool for evaluating possible human health effects of cosmic ray. Finally, the limitations on human space operations beyond low-Earth orbit imposed by long term exposure to galactic cosmic rays are discussed.

  2. Aquifer-scale controls on the distribution of nitrate and ammonium in ground water near La Pine, Oregon, USA

    USGS Publications Warehouse

    Hinkle, S.R.; Böhlke, J.K.; Duff, J.H.; Morgan, D.S.; Weick, R.J.

    2007-01-01

    Geochemical and isotopic tools were applied at aquifer, transect, and subtransect scales to provide a framework for understanding sources, transport, and fate of dissolved inorganic N in a sandy aquifer near La Pine, Oregon. NO3 is a common contaminant in shallow ground water in this area, whereas high concentrations of NH4-N (up to 39 mg/L) are present in deep ground water. N concentrations, N/Cl ratios, tracer-based apparent ground-water ages, N isotope data, and hydraulic gradients indicate that septic tank effluent is the primary source of NO3. N isotope data, N/Cl and N/C relations, 3H data, and hydraulic considerations point to a natural, sedimentary organic matter source for the high concentrations of NH4, and are inconsistent with an origin as septic tank N. Low recharge rates and flow velocities have largely restricted anthropogenic NO3 to isolated plumes within several meters of the water table. A variety of geochemical and isotopic data indicate that denitrification also affects NO3 gradients in the aquifer. Ground water in the La Pine aquifer evolves from oxic to increasingly reduced conditions. Suboxic conditions are achieved after about 15-30 y of transport below the water table. NO3 is denitrified near the oxic/suboxic boundary. Denitrification in the La Pine aquifer is characterized well at the aquifer scale with a redox boundary approach that inherently captures spatial variability in the distribution of electron donors. ?? 2006 Elsevier B.V. All rights reserved.

  3. Ground-based simulation of telepresence for materials science experiments. [remote viewing and control of processes aboard Space Station

    NASA Technical Reports Server (NTRS)

    Johnston, James C.; Rosenthal, Bruce N.; Bonner, Mary JO; Hahn, Richard C.; Herbach, Bruce

    1989-01-01

    A series of ground-based telepresence experiments have been performed to determine the minimum video frame rate and resolution required for the successive performance of materials science experiments in space. The approach used is to simulate transmission between earth and space station with transmission between laboratories on earth. The experiments include isothermal dendrite growth, physical vapor transport, and glass melting. Modifications of existing apparatus, software developed, and the establishment of an inhouse network are reviewed.

  4. Control of the electronic ground state on an electron-transfer copper site by second-sphere perturbations.

    PubMed

    Morgada, Marcos N; Abriata, Luciano A; Zitare, Ulises; Alvarez-Paggi, Damian; Murgida, Daniel H; Vila, Alejandro J

    2014-06-10

    The Cu(A) center is a dinuclear copper site that serves as an optimized hub for long-range electron transfer in heme-copper terminal oxidases. Its electronic structure can be described in terms of a σ(u)* ground-state wavefunction with an alternative, less populated ground state of π(u) symmetry, which is thermally accessible. It is now shown that second-sphere mutations in the Cu(A) containing subunit of Thermus thermophilus ba3 oxidase perturb the electronic structure, which leads to a substantial increase in the population of the π(u) state, as shown by different spectroscopic methods. This perturbation does not affect the redox potential of the metal site, and despite an increase in the reorganization energy, it is not detrimental to the electron-transfer kinetics. The mutations were achieved by replacing the loops that are involved in protein-protein interactions with cytochrome c, suggesting that transient protein binding could also elicit ground-state switching in the oxidase, which enables alternative electron-transfer pathways.

  5. The U.S. Geological Survey Modular Ground-Water Model - PCGN: A Preconditioned Conjugate Gradient Solver with Improved Nonlinear Control

    USGS Publications Warehouse

    Naff, Richard L.; Banta, Edward R.

    2008-01-01

    The preconditioned conjugate gradient with improved nonlinear control (PCGN) package provides addi-tional means by which the solution of nonlinear ground-water flow problems can be controlled as compared to existing solver packages for MODFLOW. Picard iteration is used to solve nonlinear ground-water flow equations by iteratively solving a linear approximation of the nonlinear equations. The linear solution is provided by means of the preconditioned conjugate gradient algorithm where preconditioning is provided by the modi-fied incomplete Cholesky algorithm. The incomplete Cholesky scheme incorporates two levels of fill, 0 and 1, in which the pivots can be modified so that the row sums of the preconditioning matrix and the original matrix are approximately equal. A relaxation factor is used to implement the modified pivots, which determines the degree of modification allowed. The effects of fill level and degree of pivot modification are briefly explored by means of a synthetic, heterogeneous finite-difference matrix; results are reported in the final section of this report. The preconditioned conjugate gradient method is coupled with Picard iteration so as to efficiently solve the nonlinear equations associated with many ground-water flow problems. The description of this coupling of the linear solver with Picard iteration is a primary concern of this document.

  6. Techniques for enhancing durability and equivalence ratio control in a rich-lean, three-stage ground power gas turbine combustor

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.

    1982-01-01

    Rig tests of a can-type combustor were performed to demonstrate two advanced ground power engine combustor concepts: steam cooled rich-burn combustor primary zones for enhanced durability; and variable combustor geometry for three stage combustion equivalence ratio control. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This offers the potential of both long life and reduced use of strategic materials for liner fabrication. Three degrees of variable geometry were successfully implemented to control airflow distribution within the combustor. One was a variable blade angle axial flow air swirler to control primary airflow while the other two consisted of rotating bands to control secondary and tertiary or dilution air flow.

  7. Effect of ground-grid changes on control-cable voltages at Bruce NGS B. Report No. 90-141-K

    SciTech Connect

    Harvey, S.M.; Dick, E.P.

    1990-01-01

    On August 4th and October 15th, 1989, while thunderstorms were in progress, numerous electrical and instrumentation faults appeared on units 0 and 5 of Bruce Nuclear Generating Station B, resulting in the temporary unavailability of critical standby generators, unwarranted station service transfers, and fuse blowing on DC supply wiring. An investigation appeared to implicate the control and annunciation cables running between the powerhouse and standby generators SG5 and SG6 located between the intake and outflow channels at the south end of the station. It was hypothesized that the installation of additional, appropriately placed, bonding conductors to the station ground mat could alleviate the problem. This report describes some field tests performed to determine the effect of adding additional bonding conductors on the ground potential difference and on the voltages and currents appearing on a selected cable.

  8. Evaluation of ERTS multispectral signatures in relation to ground control signatures using a nested-sampling approach

    NASA Technical Reports Server (NTRS)

    Lyon, R. J. P. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. Ground measured spectral signatures of wavelength bands matching ERTS MSS were collected using a radiometer at several Californian and Nevadan sites, and directly compared with similar data from ERTS CCTs. The comparison was tested at the highest possible spatial resolution for ERTS, using deconvoluted MSS data, and contrasted with that of ground measured spectra, originally from 1 meter squares. In the mobile traverses of the grassland sites, these one meter fields of view were integrated into eighty meter transects along the five km track across four major rock/soil types. Suitable software was developed to read the MSS CCT tapes, to shadeprint individual bands with user-determined greyscale stretching. Four new algorithms for unsupervised and supervised, normalized and unnormalized clustering were developed, into a program termed STANSORT. Parallel software allowed the field data to be calibrated, and by using concurrently continuously collected, upward- and downward-viewing, 4 band radiometers, bidirectional reflectances could be calculated.

  9. A robust nonlinear skid-steering control design applied to the MULE (6x6) unmanned ground vehicle

    NASA Astrophysics Data System (ADS)

    Kaloust, Joseph

    2006-05-01

    The paper presents a robust nonlinear skid-steering control design concept. The control concept is based on the recursive/backstepping control design technique and is capable of compensating for uncertainties associated with sensor noise measurements and/or system dynamic state uncertainties. The objective of this control design is to demonstrate the performance of the nonlinear controller under uncertainty associate with road traction (rough off-road and on-road terrain). The MULE vehicle is used in the simulation modeling and results.

  10. Stochastic modeling and control system designs of the NASA/MSFC Ground Facility for large space structures: The maximum entropy/optimal projection approach

    NASA Technical Reports Server (NTRS)

    Hsia, Wei-Shen

    1986-01-01

    In the Control Systems Division of the Systems Dynamics Laboratory of the NASA/MSFC, a Ground Facility (GF), in which the dynamics and control system concepts being considered for Large Space Structures (LSS) applications can be verified, was designed and built. One of the important aspects of the GF is to design an analytical model which will be as close to experimental data as possible so that a feasible control law can be generated. Using Hyland's Maximum Entropy/Optimal Projection Approach, a procedure was developed in which the maximum entropy principle is used for stochastic modeling and the optimal projection technique is used for a reduced-order dynamic compensator design for a high-order plant.

  11. The Results of Ground-based and In-flight Testing of Charge-dissipative and Conducting EKOM Thermal Control Paints

    NASA Astrophysics Data System (ADS)

    Kleiman, J. I.; Iskanderova, Z.; Issoupov, V.; Grigorevskiy, A. V.; Kiseleva, L. V.; Finckenor, M.; Naumov, S. F.; Sokolova, S. P.; Kurilenok, A. O.

    2009-01-01

    An international program on comparative evaluation of space durability of thermal control paints from a number of countries was initiated a few years ago at ITL with coatings from Russia, France and USA being studied. This paper describes the results of the study on space durability of three types of charge-dissipative and conductive Russian advanced polymer-based EKOM thermal control paints. Extensive ground-based testing in fast atomic oxygen (FAO) beam facilities was used to test the space durability of these paints and the enhancement of their atomic oxygen erosion resistance by a surface modification technology, Photosil™. All pristine EKOM paints were also tested in a direct materials exposure experiment on Russian module "Zvezda" onboard the International Space Station. Space durability and change of the major physical properties were evaluated after these experiments using a number of analytical techniques. Both, the ground-based testing and the flight experiments indicated signs of surface erosion with some changes of thermal optical properties. Therefore, the paints were also modified by a surface treatment technology, Photosil™, to increase their erosion resistance to atomic oxygen, tested in the same ground-based FAO facilities up to high FAO fluencies and compared with testing results of pristine materials. The comparison indicated that the surface-modified paints exhibit reduced mass loss, full stabilization and no surface morphology changes, thus indicating at full protection from the high FAO fluencies. It was demonstrated that the developed surface modification treatment could be applied successfully to charge dissipative and conductive paints, to enhance the low Earth orbit (LEO) environment resistance of external thermal control coatings in long-term space missions.

  12. Observation of an Aligned Gas - Solid "Eutectic" during Controlled Directional Solidification Aboard the International Space Station - Comparison with Ground-based Studies

    NASA Technical Reports Server (NTRS)

    Grugel, R. N.; Anilkumar, A.

    2005-01-01

    Direct observation of the controlled melting and solidification of succinonitrile was conducted in the glovebox facility of the International Space Station (ISS). The experimental samples were prepared on ground by filling glass tubes, 1 cm ID and approximately 30 cm in length, with pure succinonitrile (SCN) in an atmosphere of nitrogen at 450 millibar pressure for eventual processing in the Pore Formation and Mobility Investigation (PFMI) apparatus in the glovebox facility (GBX) on board the ISS. Real time visualization during controlled directional melt back of the sample showed nitrogen bubbles emerging from the interface and moving through the liquid up the imposed temperature gradient. Over a period of time these bubbles disappear by dissolving into the melt. Translation is stopped after melting back of about 9 cm of the sample, with an equilibrium solid-liquid interface established. During controlled re-solidification, aligned tubes of gas were seen growing perpendicular to the planar solid/liquid interface, inferring that the nitrogen previously dissolved into the liquid SCN was now coming out at the solid/liquid interface and forming the little studied liquid = solid + gas eutectic-type reaction. The observed structure is evaluated in terms of spacing dimensions, interface undercooling, and mechanisms for spacing adjustments. Finally, the significance of processing in a microgravity environment is ascertained in view of ground-based results.

  13. Multispectral signatures in relation to ground control signature using nested sampling approach. [mineral detection in Nevada and California

    NASA Technical Reports Server (NTRS)

    Lyon, R. J. P.; Honey, F. R. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. In a cooperative study with USGS personnel, it has been possible to detect a 1.5 by 1 mile anomaly on ERTS CCT data, in the pine-covered mountains of western Nevada. This anomalous area is about 3-5 times larger than that of the known geobotanical anomaly which lies centrally within the area. The site has been studied on the ground and bi-directional reflectances, relative to BaS04 obtained for 40 trees, using both in-vivo techniques (similar to cherry picker operations) and field determinations of cut branches. The anomaly can be seen best by color transparencies made from 5/4, 6/4, 7/4 ratioed digital data, the 3 ratios each being coded by one of 3 colors (blue, green, and red).

  14. Hardware Development and Locomotion Control Strategy for an Over-Ground Gait Trainer: NaTUre-Gaits

    PubMed Central

    Low, Kin Huat; Qu, Xingda; Lim, Hup Boon; Hoon, Kay Hiang

    2014-01-01

    Therapist-assisted body weight supported (TABWS) gait rehabilitation was introduced two decades ago. The benefit of TABWS in functional recovery of walking in spinal cord injury and stroke patients has been demonstrated and reported. However, shortage of therapists, labor-intensiveness, and short duration of training are some limitations of this approach. To overcome these deficiencies, robotic-assisted gait rehabilitation systems have been suggested. These systems have gained attentions from researchers and clinical practitioner in recent years. To achieve the same objective, an over-ground gait rehabilitation system, NaTUre-gaits, was developed at the Nanyang Technological University. The design was based on a clinical approach to provide four main features, which are pelvic motion, body weight support, over-ground walking experience, and lower limb assistance. These features can be achieved by three main modules of NaTUre-gaits: 1) pelvic assistance mechanism, mobile platform, and robotic orthosis. Predefined gait patterns are required for a robotic assisted system to follow. In this paper, the gait pattern planning for NaTUre-gaits was accomplished by an individual-specific gait pattern prediction model. The model generates gait patterns that resemble natural gait patterns of the targeted subjects. The features of NaTUre-gaits have been demonstrated by walking trials with several subjects. The trials have been evaluated by therapists and doctors. The results show that 10-m walking trial with a reduction in manpower. The task-specific repetitive training approach and natural walking gait patterns were also successfully achieved. PMID:27170876

  15. Study of the Reactions Controlling the Mobility of Uranium in Ground and Surface Water Systems in Contact with Apatite

    SciTech Connect

    Taffet, M

    2004-04-22

    The objective of this project was to define the mechanisms, equilibria, kinetics, and extent of sorption of aqueous uranium onto hydroxyapatite (Ca{sub 5}(PO{sub 4}){sub 3}(OH)) for a range of pH, ionic strength, aqueous uranium concentration, dissolved carbon/air CO{sub 2}, and mineral surface area. We conducted chemical modeling, batch and flow-through experiments, chemical analysis, x-ray absorption and diffraction measurement, and electron microscopy. Our motivation was the need to immobilize U in water and soil to prevent it's entry into water supplies and ultimately, biological systems. Applying hydroxyapatite to in-situ treatment of uranium-bearing ground water could be an effective, low cost technology. We found that hydroxyapatite quickly, effectively, and reversibly sorbed uranium at a high capacity by inner-sphere complexation over a wide range of conditions. Our results indicate that at aqueous uranium concentrations below 10-20 ppb: (1) equilibrium sorption of uranium to hydroxyapatite occurs in hours, regardless of pH; (2) in ambient and CO{sub 2}-free atmospheres, over 98% of initial uranium is sorbed to hydroxyapatite, (3) in waters in equilibrium with higher air CO{sub 2} concentrations, sorption removed over 97% of aqueous uranium, except above pH 9, where aqueous uranium concentrations were reduced by less than 40%, and (4) at near-neutral pH, bicarbonate alkalinities in excess of 500 slightly retarded sorption of uranium to hydroxyapatite, relative to lower alkalinities. Uranium sorption and precipitation are reversible and are not appreciably affected by ionic strength. The reversibility of these reactions requires that in situ treatment be carefully monitored to avoid breakthrough and de-sorption of uranium unto ground water. At typical surface conditions, sorption is the only mode of uranium sequestration below 20-50 ppb U - above this range, precipitation of uranium phosphate minerals begins to dominate sequestration processes. We verified

  16. Bilateral symmetry of ground reaction force with a motor-controlled resistance exercise system using a mechanical advantage barbell for spaceflight.

    PubMed

    Paulus, David C; Settlage, Daniel M

    2012-01-01

    The reduced gravity experienced during spaceflight leads to muscle and bone atrophy, and resistance exercise has proven to be an effective countermeasure. Thus, a compact computer-controlled electric-motor resistance exercise system is being developed for NASA. In order to save power, space, and weight, the torque specifications of the motor were reduced by half because of a unique barbell design that employs a two-to-one mechanical advantage. Since the force-generating motor is on one side of the barbell, there is the potential for asymmetric barbell loading. Therefore, the purpose of this preliminary study is to compare the unilateral ground reaction forces (GRF) of the new barbell of the motor and ground sides. Multiple repetitions of fixed tempo deadlift exercise were performed with motor-controlled resistance using the new barbell. Unilateral GRF data was measured with a force plate under each foot, and the readings from each force plate are compared to each other. Results indicate the mechanical advantage barbell exercises have bilaterally asymmetric GRF compared to a theoretical 50-50 split, and the astronauts would need to alternate the left-right orientation to compensate for the asymmetry. PMID:22846303

  17. Behavior of aircraft antiskid breaking systems on dry and wet runway surfaces: A slip-ratio-controlled system with ground speed reference from unbraked nose wheel

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.; Stubbs, S. M.

    1977-01-01

    An experimental investigation was conducted at the Langley aircraft landing loads and traction facility to study the braking and cornering response of a slip ratio controlled aircraft antiskid braking system with ground speed reference derived from an unbraked nose wheel. The investigation, conducted on dry and wet runway surfaces, utilized one main gear wheel, brake, and tire assembly of a DC-9 series 10 airplane. During maximum braking, the average ratio of the drag force friction coefficient developed by the antiskid system to the maximum drag force friction coefficient available was higher on the dry surface than on damp and flooded surfaces, and was reduced with lighter vertical loads, higher yaw angles, and when new tire treads were replaced by worn treads. Similarly, the average ratio of side force friction coefficient developed by the tire under antiskid control to the maximum side force friction coefficient available to a freely rolling yawed tire decreased with increasing yaw angle, generally increased with ground speed, and decreased when tires with new treads were replaced by those with worn treads.

  18. Geochemical processes controlling selenium in ground water after mining, Powder River Basin, Wyoming, U.S.A.

    USGS Publications Warehouse

    Naftz, D.L.; Rice, J.A.

    1989-01-01

    Geochemical data for samples of overburden from three mines in the Powder River Basin indicate a statistically significant (0.01 confidence level) positive correlation (r = 0.74) between Se and organic C. Results of factor analysis with varimax rotation on the major and trace element data from the rock samples indicate large (>50) varimax loadings for Se in two of the three factors. In Factor 1, the association of Se with constituents common to detrital grains indicates that water transporting the detrital particles into the Powder River Basin also carried dissolved Se. The large (>50) varimax loadings of Se and organic C in Factor 2 probably are due to the organic affinities characteristic of Se. Dissolved Se concentrations in water samples collected at one coal mine are directly related to the dissolved organic C concentrations. Hydrophilic acid concentrations in the water samples from the mine ranged from 35 to 43% of the total dissolved organic C, and hydrophobic acid concentrations ranged from 40 to 49% of the total dissolved organic C. The largest dissolved organic C concentrations in water from the same mine (34-302 mg/l), coupled with the large proportion of acidic components, may saturate adsorption sites on geothite and similar minerals that comprise the aquifer material, thus decreasing the extent of selenite (SeO32-) adsorption as a sink for Se as the redox state of ground water decreases. ?? 1989.

  19. Characteristic investigation and control of a modular multilevel converter-based HVDC system under single-line-to-ground fault conditions

    DOE PAGESBeta

    Shi, Xiaojie; Wang, Zhiqiang; Liu, Bo; Liu, Yiqi; Tolbert, Leon M.; Wang, Fred

    2014-05-16

    This paper presents the analysis and control of a multilevel modular converter (MMC)-based HVDC transmission system under three possible single-line-to-ground fault conditions, with special focus on the investigation of their different fault characteristics. Considering positive-, negative-, and zero-sequence components in both arm voltages and currents, the generalized instantaneous power of a phase unit is derived theoretically according to the equivalent circuit model of the MMC under unbalanced conditions. Based on this model, a novel double-line frequency dc-voltage ripple suppression control is proposed. This controller, together with the negative-and zero-sequence current control, could enhance the overall fault-tolerant capability of the HVDCmore » system without additional cost. To further improve the fault-tolerant capability, the operation performance of the HVDC system with and without single-phase switching is discussed and compared in detail. Lastly, simulation results from a three-phase MMC-HVDC system generated with MATLAB/Simulink are provided to support the theoretical analysis and proposed control schemes.« less

  20. Characteristic investigation and control of a modular multilevel converter-based HVDC system under single-line-to-ground fault conditions

    SciTech Connect

    Shi, Xiaojie; Wang, Zhiqiang; Liu, Bo; Liu, Yiqi; Tolbert, Leon M.; Wang, Fred

    2014-05-16

    This paper presents the analysis and control of a multilevel modular converter (MMC)-based HVDC transmission system under three possible single-line-to-ground fault conditions, with special focus on the investigation of their different fault characteristics. Considering positive-, negative-, and zero-sequence components in both arm voltages and currents, the generalized instantaneous power of a phase unit is derived theoretically according to the equivalent circuit model of the MMC under unbalanced conditions. Based on this model, a novel double-line frequency dc-voltage ripple suppression control is proposed. This controller, together with the negative-and zero-sequence current control, could enhance the overall fault-tolerant capability of the HVDC system without additional cost. To further improve the fault-tolerant capability, the operation performance of the HVDC system with and without single-phase switching is discussed and compared in detail. Lastly, simulation results from a three-phase MMC-HVDC system generated with MATLAB/Simulink are provided to support the theoretical analysis and proposed control schemes.

  1. Managing the Paradox of Control: The Case of Ground-Up Implementation of Active Learning in Singapore's Primary Schools

    ERIC Educational Resources Information Center

    Lim-Ratnam, Christina; Atencio, Matthew; Lee, Christine Kim-Eng

    2016-01-01

    The Singaporean education system has recently shifted emphasis from being highly centralised and standardised towards one that aims to promote innovation and autonomy at the school level. Yet, the concomitant move towards a more decentralised and flexible curriculum enacted and controlled at the local level has not been straightforward.…

  2. Escape and evade control policies for ensuring the physical security of nonholonomic, ground-based, unattended mobile sensor nodes

    NASA Astrophysics Data System (ADS)

    Mascarenas, David; Stull, Christopher; Farrar, Charles

    2011-06-01

    In order to realize the wide-scale deployment of high-endurance, unattended mobile sensing technologies, it is vital to ensure the self-preservation of the sensing assets. Deployed mobile sensor nodes face a variety of physical security threats including theft, vandalism and physical damage. Unattended mobile sensor nodes must be able to respond to these threats with control policies that facilitate escape and evasion to a low-risk state. In this work the Precision Immobilization Technique (PIT) problem has been considered. The PIT maneuver is a technique that a pursuing, car-like vehicle can use to force a fleeing vehicle to abruptly turn ninety degrees to the direction of travel. The abrupt change in direction generally causes the fleeing driver to lose control and stop. The PIT maneuver was originally developed by law enforcement to end vehicular pursuits in a manner that minimizes damage to the persons and property involved. It is easy to imagine that unattended autonomous convoys could be targets of this type of action by adversarial agents. This effort focused on developing control policies unattended mobile sensor nodes could employ to escape, evade and recover from PIT-maneuver-like attacks. The development of these control policies involved both simulation as well as small-scale experimental testing. The goal of this work is to be a step toward ensuring the physical security of unattended sensor node assets.

  3. GEOMORPHIC CONTROLS ON MEADOW ECOSYSTEMS – INSIGHTS INTO LOCAL PROCESSES USING NEAR-SURFACE SEISMIC TECHNIQUES AND GROUND PENETRATING RADAR

    EPA Science Inventory

    Geomorphic controls on riparian meadows in the Central Great Basin of Nevada are an important aspect in determining the formation of and planning the management of these systems. The current hypothesis is that both alluvial fan sediment and faulted bedrock steps interact to cont...

  4. Evaluation of steam for Meloidogyne Arenaria control in production of in-ground floriculture crops in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Steam and soil solarization were investigated for control of the root-knot nematode Meloidogyne arenaria in two years of field trials on a commercial flower farm in Florida. The objective was to determine if pre-plant steam treatments in combination with solarization, or solarization alone effective...

  5. Impact of synoptic controls and boundary layer processes on ground-level ozone evolution at an urban site

    NASA Astrophysics Data System (ADS)

    Haman, Christine Lanier

    Houston, Texas frequently exceeds the standard for ground-level ozone during the spring and fall. The large commuting population and vast number of industrial sources provide the necessary ingredients for photochemical ozone production in the presence of favorable meteorological conditions. The lack of continuous boundary layer (BL) observations prevents a comprehensive understanding of its role in ozone evolution. In this study, almost two years of BL observations are utilized to investigate the impacts of synoptic and micrometeorological-scale forcings on ozone. Aerosol gradients derived from ceilometer backscatter retrievals are used to identify the BL and residual layers (RL). Overall agreement is found between ceilometer and sonde estimates of the RL and BL heights (BLH), but difficulty detecting the layers occurs during cloud periods or immediately following precipitation. Large monthly variability is present in the peak afternoon BLH (e.g. mean August and December peaks are ˜2000 and 1100 m, respectively). Monthly nocturnal BLHs display much smaller differences. The majority of ozone exceedances occur during large-scale subsidence and weak winds in a postfrontal environment. These conditions result in turbulent kinetic energy, mechanical mixing, and ventilation processes that are 2--3 times weaker on exceedance days, which inhibit morning BL growth by an average of ˜100 m·hr-1 compared to low ozone days. The spring has higher nocturnal ozone levels, which is likely attributable to longer day lengths (˜78 minutes), stronger winds (˜0.78 m·s -1), and higher background ozone (˜5 ppbv) compared to the fall. Boundary layer entrainment plays an important role in ozone evolution. Exceedance days show a characteristic early morning rapid rise of ozone. Vertical ozone profiles indicate the RL ozone peak is ˜60 ppbv on exceedance days, which is ˜25 ppbv (+/- 10 ppbv) greater than low ozone days. The Integrated Profile Mixing (IPM) and Photochemical Budget (PB

  6. Controlled Ecological Life Support System. Design, Development, and Use of a Ground-Based Plant Growth Module

    NASA Technical Reports Server (NTRS)

    Macelroy, Robert D.; Smernoff, David T.; Rummel, John D.

    1987-01-01

    Problems of food production by higher plants are addressed. Experimentation requirements and necessary equipment for designing an experimental Controlled Ecological Life Support System (CELSS) Plant Growth Module are defined. A framework is provided for the design of laboratory sized plant growth chambers. The rationale for the development of an informal collaborative effort between investigators from universities and industry and those at Ames is evaluated. Specific research problems appropriate for collaborative efforts are identified.

  7. Component testing of a ground based gas turbine steam cooled rich-burn primary zone combustor for emissions control of nitrogeneous fuels

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.

    1986-01-01

    This effort summarizes the work performed on a steam cooled, rich-burn primary zone, variable geometry combustor designed for combustion of nitrogeneous fuels such as heavy oils or synthetic crude oils. The steam cooling was employed to determine its feasibility and assess its usefulness as part of a ground based gas turbine bottoming cycle. Variable combustor geometry was employed to demonstrate its ability to control primary and secondary zone equivalence ratios and overall pressure drop. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This low temperature offers the potential of both long life and reduced use of strategic materials for liner fabrication. These degrees of variable geometry were successfully employed to control air flow distribution within the combustor. A variable blade angle axial flow air swirler was used to control primary zone air flow, while the secondary and tertiary zone air flows were controlled by rotating bands which regulated air flow to the secondary zone quench holes and the dilutions holes respectively.

  8. Component testing of a ground based gas turbine steam cooled rich-burn primary zone combustor for emissions control of nitrogeneous fuels

    NASA Astrophysics Data System (ADS)

    Schultz, D. F.

    This effort summarizes the work performed on a steam cooled, rich-burn primary zone, variable geometry combustor designed for combustion of nitrogeneous fuels such as heavy oils or synthetic crude oils. The steam cooling was employed to determine its feasibility and assess its usefulness as part of a ground based gas turbine bottoming cycle. Variable combustor geometry was employed to demonstrate its ability to control primary and secondary zone equivalence ratios and overall pressure drop. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This low temperature offers the potential of both long life and reduced use of strategic materials for liner fabrication. These degrees of variable geometry were successfully employed to control air flow distribution within the combustor. A variable blade angle axial flow air swirler was used to control primary zone air flow, while the secondary and tertiary zone air flows were controlled by rotating bands which regulated air flow to the secondary zone quench holes and the dilutions holes respectively.

  9. Mapping starting zone snow depth with a ground-based LiDAR to improve avalanche control and forecasting

    NASA Astrophysics Data System (ADS)

    Deems, J. S.; Gadomski, P. J.; Vellone, D.; Evanczyk, R.; LeWinter, A. L.; Birkeland, K.; Finnegan, D. C.

    2014-12-01

    The varying distribution of snow depth in avalanche starting zones exerts a strong influence on avalanche potential and character. Extreme depth changes over short distances are common, especially in wind-affected, above-treeline environments. Snow depth also affects the ease of avalanche triggering. Experience shows that avalanche reduction efforts are often more successful when targeting shallow trigger point areas near deeper slabs with explosives or ski cutting. Our pilot study explores the use of high resolution snow depth and depth change maps from differential LiDAR scans to quantify loading patterns for use in both pre-control planning and in post-control assessment. We present results from our initial work at the Arapahoe Basin Ski Area in Colorado, USA. A-Basin has a large number avalanche starting zones above treeline at elevations up to 4,000 m. The three study areas represent a range of institutional avalanche management history - the East Wall has been operated since 1970, Montezuma Bowl since 2008, and the Steep Gullies are under study for area expansion. Summer mapping produced a zero depth surface. Mapping multiple times during the snow season allowed us to produce time series maps of snow depth and snow depth change at high resolution to explore depth and slab thickness variations due to wind redistribution. We conducted surveys before and after loading events and control work, allowing the exploration of loading patterns, slab thickness, shot and ski cut locations, bed surfaces, entrainment, and avalanche characteristics. We also evaluate the state of terrestrial laser scanning for use in operational settings.

  10. Survivability enhancement study for C/sup 3/I/BM (communications, command, control and intelligence/battle management) ground segments: Final report

    SciTech Connect

    Not Available

    1986-10-30

    This study involves a concept developed by the Fairchild Space Company which is directly applicable to the Strategic Defense Initiative (SDI) Program as well as other national security programs requiring reliable, secure and survivable telecommunications systems. The overall objective of this study program was to determine the feasibility of combining and integrating long-lived, compact, autonomous isotope power sources with fiber optic and other types of ground segments of the SDI communications, command, control and intelligence/battle management (C/sup 3/I/BM) system in order to significantly enhance the survivability of those critical systems, especially against the potential threats of electromagnetic pulse(s) (EMP) resulting from high altitude nuclear weapon explosion(s). 28 figs., 2 tabs.

  11. A comparison of lower limb EMG and ground reaction forces between barefoot and shod gait in participants with diabetic neuropathic and healthy controls

    PubMed Central

    2010-01-01

    Background It is known that when barefoot, gait biomechanics of diabetic neuropathic patients differ from non-diabetic individuals. However, it is still unknown whether these biomechanical changes are also present during shod gait which is clinically advised for these patients. This study investigated the effect of the participants own shoes on gait biomechanics in diabetic neuropathic individuals compared to barefoot gait patterns and healthy controls. Methods Ground reaction forces and lower limb EMG activities were analyzed in 21 non-diabetic adults (50.9 ± 7.3 yr, 24.3 ± 2.6 kg/m2) and 24 diabetic neuropathic participants (55.2 ± 7.9 yr, 27.0 ± 4.4 kg/m2). EMG patterns of vastus lateralis, lateral gastrocnemius and tibialis anterior, along with the vertical and antero-posterior ground reaction forces were studied during shod and barefoot gait. Results Regardless of the disease, walking with shoes promoted an increase in the first peak vertical force and the peak horizontal propulsive force. Diabetic individuals had a delay in the lateral gastrocnemius EMG activity with no delay in the vastus lateralis. They also demonstrated a higher peak horizontal braking force walking with shoes compared to barefoot. Diabetic participants also had a smaller second peak vertical force in shod gait and a delay in the vastus lateralis EMG activity in barefoot gait compared to controls. Conclusions The change in plantar sensory information that occurs when wearing shoes revealed a different motor strategy in diabetic individuals. Walking with shoes did not attenuate vertical forces in either group. Though changes in motor strategy were apparent, the biomechanical did not support the argument that the use of shoes contributes to altered motor responses during gait. PMID:20128894

  12. Evaluation of Thermal Control Coatings and Polymeric Materials Exposed to Ground Simulated Atomic Oxygen and Vacuum Ultraviolet Radiation

    NASA Technical Reports Server (NTRS)

    Kamenetzky, R. R.; Vaughn, J. A.; Finckenor, M. M.; Linton, R. C.

    1995-01-01

    Numerous thermal control and polymeric samples with potential International Space Station applications were evaluated for atomic oxygen and vacuum ultraviolet radiation effects in the Princeton Plasma Physics Laboratory 5 eV Neutral Atomic Oxygen Facility and in the MSFC Atomic Oxygen Drift Tube System. Included in this study were samples of various anodized aluminum samples, ceramic paints, polymeric materials, and beta cloth, a Teflon-impregnated fiberglass cloth. Aluminum anodizations tested were black duranodic, chromic acid anodize, and sulfuric acid anodize. Paint samples consisted of an inorganic glassy black paint and Z-93 white paint made with the original PS7 binder and the new K2130 binder. Polymeric samples evaluated included bulk Halar, bulk PEEK, and silverized FEP Teflon. Aluminized and nonaluminized Chemfab 250 beta cloth were also exposed. Samples were evaluated for changes in mass, thickness, solar absorptance, and infrared emittance. In addition to material effects, an investigation was made comparing diffuse reflectance/solar absorptance measurements made using a Beckman DK2 spectroreflectometer and like measurements made using an AZ Technology-developed laboratory portable spectroreflectometer.

  13. Grounding of space structures

    NASA Technical Reports Server (NTRS)

    Bosela, P. A.; Fertis, D. G.; Shaker, F. J.

    1992-01-01

    Space structures, such as the Space Station solar arrays, must be extremely light-weight, flexible structures. Accurate prediction of the natural frequencies and mode shapes is essential for determining the structural adequacy of components, and designing a controls system. The tension pre-load in the 'blanket' of photovoltaic solar collectors, and the free/free boundary conditions of a structure in space, causes serious reservations on the use of standard finite element techniques of solution. In particular, a phenomenon known as 'grounding', or false stiffening, of the stiffness matrix occurs during rigid body rotation. This paper examines the grounding phenomenon in detail. Numerous stiffness matrices developed by others are examined for rigid body rotation capability, and found lacking. A force imbalance inherent in the formulations examined is the likely cause of the grounding problem, suggesting the need for a directed force formulation.

  14. Hydrogeologic controls on ground-water discharge to the Washington METRO subway tunnel near the Medical Center station and Crossover, Montgomery County, Maryland

    USGS Publications Warehouse

    Greene, Earl A.; Shapiro, Allen M.; LaMotte, Andrew E.

    2004-01-01

    Excessive water intrusion has been observed inside several of the Washington Metropolitan Area Transit Authority subway tunnels, with the worst leakage occurring along the Red Line tunnels and stations north of Dupont Circle in Washington, D.C. These tunnels were constructed in bedrock that contains permeable (water-bearing) joints and fractures. Excessive water leakage through the walls and water inside the underground facilities has damaged mechanical and electrical components in the tunnel, and has escalated the deterioration rate of the rail system. The U.S. Geological Survey and the Washington Metropolitan Area Transit Authority have worked cooperatively on a study from 200003 to describe and quantify the factors controlling ground-water flow into the Red Line subway tunnel near the Medical Center Station and Crossover in Montgomery County, Maryland. The Red Line near the Medical Center Station and Crossover passes through or beneath the gneissic Sykesville Formation and the biotite-hornblende tonalite member of the Georgetown Intrusive Suite, both of which contain numerous fractures. The mapped foliation and joints of the Sykesville Formation in the vicinity of the Medical Center Station and Crossover are generally orientated north-south. Fractures in the Sykesville Formation in outcrops appear to be poorly connected. In the biotite-hornblende tonalite member of the Georgetown Intrusive Suite, the general orientation of the mapped foliation and joints is east-west. In contrast to the fractures in the Sykesville Formation, the fractures in the Georgetown Intrusive Suite in outcrops appear to be more numerous and have a greater degree of connectivity. Fractures intersecting four bedrock wells near the Medical Center Station and Crossover that were drilled into the biotite-hornblende tonalite member of the Georgetown Intrusive Suite show an east-west orientation matching the foliation and joints shown on geologic maps. The excessive water intrusion at the

  15. Ground-based time-guidance algorithm for control of airplanes in a time-metered air traffic control environment: A piloted simulation study

    NASA Technical Reports Server (NTRS)

    Knox, C. E.; Imbert, N.

    1986-01-01

    The rapidly increasing costs of flight operations and the requirement for increased fuel conservation have made it necessary to develop more efficient ways to operate airplanes and to control air traffic for arrivals and departures to the terminal area. One concept of controlling arrival traffic through time metering has been jointly studied and evaluated by NASA and ONERA/CERT in piloted simulation tests. From time errors attained at checkpoints, airspeed and heading commands issued by air traffic control were computed by a time-guidance algorithm for the pilot to follow that would cause the airplane to cross a metering fix at a preassigned time. These tests resulted in the simulated airplane crossing a metering fix with a mean time error of 1.0 sec and a standard deviation of 16.7 sec when the time-metering algorithm was used. With mismodeled winds representing the unknown in wind-aloft forecasts and modeling form, the mean time error attained when crossing the metering fix was increased and the standard deviation remained approximately the same. The subject pilots reported that the airspeed and heading commands computed in the guidance concept were easy to follow and did not increase their work load above normal levels.

  16. Regional analysis of ground and above-ground climate

    SciTech Connect

    Not Available

    1981-12-01

    The regional suitability of underground construction as a climate control technique is discussed with reference to (1) a bioclimatic analysis of long-term weather data for 29 locations in the United States to determine appropriate above ground climate control techniques, (2) a data base of synthesized ground temperatures for the coterminous United States, and (3) monthly dew point ground temperature comparisons for identifying the relative likelihood of condensation from one region to another. It is concluded that the suitability of earth tempering as a practice and of specific earth-sheltered design stereotypes varies geographically; while the subsurface almost always provides a thermal advantage on its own terms when compared to above ground climatic data, it can, nonetheless, compromise the effectiveness of other, regionally more important climate control techniques. Also contained in the report are reviews of above and below ground climate mapping schemes related to human comfort and architectural design, and detailed description of a theoretical model of ground temperature, heat flow, and heat storage in the ground. Strategies of passive climate control are presented in a discussion of the building bioclimatic analysis procedure which has been applied in a computer analysis of 30 years of weather data for each of 29 locations in the United States.

  17. Ground Water

    USGS Publications Warehouse

    ,

    1986-01-01

    Some water underlies the Earth's surface almost everywhere, beneath hills, mountains,plains, and deserts. It's not always accessible, or fresh enough for use without treatment, and it's sometimes difficult to locate or to measure and descri be. This water may occur close to the land surface, as in a marsh, or it may lie many hundreds of feet below the surface, as in some arid areas of the West. Water at very shallow depths might be just a few hours old ; at moderate depth, it may be 100 years old; and at great depth or after having flowed long distances from places of entry, water may be several thousands of years old . Water under the Earth's surface is called ground water.

  18. Calibrating and adjusting expectations in life: A grounded theory on how elderly persons with somatic health problems maintain control and balance in life and optimize well-being

    PubMed Central

    Helvik, Anne-Sofie; Iversen, Valentina Cabral; Steiring, Randi; Hallberg, Lillemor R-M

    2011-01-01

    Aim This study aims at exploring the main concern for elderly individuals with somatic health problems and what they do to manage this. Method In total, 14 individuals (mean=74.2 years; range=68–86 years) of both gender including hospitalized and outpatient persons participated in the study. Open interviews were conducted and analyzed according to grounded theory, an inductive theory-generating method. Results The main concern for the elderly individuals with somatic health problems was identified as their striving to maintain control and balance in life. The analysis ended up in a substantive theory explaining how elderly individuals with somatic disease were calibrating and adjusting their expectations in life in order to adapt to their reduced energy level, health problems, and aging. By adjusting the expectations to their actual abilities, the elderly can maintain a sense of that they still have the control over their lives and create stability. The ongoing adjustment process is facilitated by different strategies and result despite lower expectations in subjective well-being. The facilitating strategies are utilizing the network of important others, enjoying cultural heritage, being occupied with interests, having a mission to fulfill, improving the situation by limiting boundaries and, finally, creating meaning in everyday life. Conclusion The main concern of the elderly with somatic health problems was to maintain control and balance in life. The emerging theory explains how elderly people with somatic health problems calibrate their expectations of life in order to adjust to reduced energy, health problems, and aging. This process is facilitated by different strategies and result despite lower expectation in subjective well-being. PMID:21468299

  19. Effectiveness of riparian buffers in controlling ground-water discharge of nitrate to streams in selected hydrogeologic settings of the North Carolina Coastal Plain

    USGS Publications Warehouse

    Spruill, T.B.

    2004-01-01

    Water-quality and hydrologic information were collected along ground-water flow paths from two well-drained and two poorly drained Coastal Plain settings in North Carolina to evaluate the relative effectiveness of riparian buffers in reducing discharge of nitrate to streams. At one well-drained site with a 100 m buffer, little or no effect was detected on surface-water quality by discharging ground water because extensive woody vegetation in the buffer was able to take up not only most nitrate, but also most ground water before discharging to the stream during the growing season (March-October). At the second well-drained site, ground water discharging to the stream from the side with a buffer contained about 2 mg/L of nitrate-nitrogen after passing through the bed of the stream compared to 6 mg/L in ground water discharging from the side with no buffer. In the poorly drained settings, nitrate in ground water decreased from about 6 mg/L in the recharge area to less than 0.02 mg/L downgradient from the riparian buffer. Ground water discharging from the side with no buffer contained 0.83 mg/L. Riparian buffers appear effective in reducing nitrate in ground water discharging to Coast Plain streams. ?? US Government 2004.

  20. Control of groundwater pH during bioremediation: Improvement and validation of a geochemical model to assess the buffering potential of ground silicate minerals

    NASA Astrophysics Data System (ADS)

    Lacroix, Elsa; Brovelli, Alessandro; Holliger, Christof; Barry, D. A.

    2014-05-01

    Accurate control of groundwater pH is of critical importance for in situ biological treatment of chlorinated solvents. The use of ground silicate minerals mixed with groundwater is an appealing buffering strategy as silicate minerals may act as long-term sources of alkalinity. In a previous study, we developed a geochemical model for evaluation of the pH buffering capacity of such minerals. The model included the main microbial processes driving groundwater acidification as well as mineral dissolution. In the present study, abiotic mineral dissolution experiments were conducted with five silicate minerals (andradite, diopside, fayalite, forsterite, nepheline). The goal of the study was to validate the model and to test the buffering capacity of the candidate minerals identified previously. These five minerals increased the pH from acidic to neutral and slightly basic values. The model was revised and improved to represent better the experimental observations. In particular, the experiments revealed the importance of secondary mineral precipitation on the buffering potential of silicates, a process not included in the original formulation. The main secondary phases likely to precipitate were identified through model calibration, as well as the degree of saturation at which they formed. The predictions of the revised geochemical model were in good agreement with the observations, with a correlation coefficient higher than 0.9 in most cases. This study confirmed the potential of silicates to act as pH control agents and showed the reliability of the geochemical model, which can be used as a design tool for field applications.

  1. Control of dynamic foot-ground interactions in male and female soccer athletes: Females exhibit reduced dexterity and higher limb stiffness during landing

    PubMed Central

    Lyle, Mark A.; Valero-Cuevas, Francisco J.; Gregor, Robert J.; Powers, Christopher M.

    2014-01-01

    Controlling dynamic interactions between the lower limb and ground is important for skilled locomotion and may influence injury risk in athletes. It is well known that female athletes sustain anterior cruciate ligament (ACL) tears at higher rates than male athletes, and exhibit lower extremity biomechanics thought to increase injury risk during sport maneuvers. The purpose of this study was to examine whether lower extremity dexterity (LED) – the ability to dynamically control endpoint force magnitude and direction as quantified by compressing an unstable spring with the lower limb at submaximal forces – is a potential contributing factor to the “at-risk” movement behavior exhibited by female athletes. We tested this hypothesis by comparing LED-test performance and single-limb drop jump biomechanics between 14 female and 14 male high school soccer players. We found that female athletes exhibited reduced LED-test performance (p=0.001) and higher limb stiffness during landing (p=0.008) calculated on average within 51 ms of foot contact. Females also exhibited higher coactivation at the ankle (p=0.001) and knee (p=0.02) before landing. No sex differences in sagittal plane joint angles and center of mass velocity at foot contact were observed. Collectively, our results raise the possibility that the higher leg stiffness observed in females during landing is an anticipatory behavior due in part to reduced lower extremity dexterity. The reduced lower extremity dexterity and compensatory stiffening strategy may contribute to the heightened risk of ACL injury in this population. PMID:24275440

  2. Ground water in Oklahoma

    USGS Publications Warehouse

    Leonard, A.R.

    1960-01-01

    One of the first requisites for the intelligent planning of utilization and control of water and for the administration of laws relating to its use is data on the quantity, quality, and mode of occurrence of the available supplies. The collection, evaluation and interpretation, and publication of such data are among the primary functions of the U.S. Geological Survey. Since 1895 the Congress has made appropriations to the Survey for investigation of the water resources of the Nation. In 1929 the Congress adopted the policy of dollar-for-dollar cooperation with the States and local governmental agencies in water-resources investigations of the U.S. Geological Survey. In 1937 a program of ground-water investigations was started in cooperation with the Oklahoma Geological Survey, and in 1949 this program was expanded to include cooperation with the Oklahoma Planning and Resources Board. In 1957 the State Legislature created the Oklahoma Water Resources Board as the principal State water agency and it became the principal local cooperator. The Ground Water Branch of the U.S. Geological Survey collects, analyzes, and evaluates basic information on ground-water resources and prepares interpretive reports based on those data. Cooperative ground-water work was first concentrated in the Panhandle counties. During World War II most work was related to problems of water supply for defense requirements. Since 1945 detailed investigations of ground-water availability have been made in 11 areas, chiefly in the western and central parts of the State. In addition, water levels in more than 300 wells are measured periodically, principally in the western half of the State. In Oklahoma current studies are directed toward determining the source, occurrence, and availability of ground water and toward estimating the quantity of water and rate of replenishment to specific areas and water-bearing formations. Ground water plays an important role in the economy of the State. It is

  3. Contamination Control and Evaluation for Manufacturing, Ground Tests, Flight Operation and Post-Retrieval Analyses of the TANPOPO Exposed Panels and Capture Panels

    NASA Astrophysics Data System (ADS)

    Yano, Hajime; Hashimoto, Hirofumi; Kawaguchi, Yuko; Yokobori, Shin-ichi; Uchihori, Yukio; Tabata, Makoto; Yamagishi, Akihiko; Sasaki, Satoshi; Imai, Eiichi

    The TANPOPO (“dandelion” in Japanese) is Japan’s first astrobiology space experiment to be exposed on and retrieved from the ISS-Kibo Exposed Facility from the 2014-5 timeframe. During its 1-3 years of continuous exposure operation in the low earth orbit (LEO) of the Earth, it aims to test key questions consisted of the “quasi-panspermia” hypothesis, a theory for exogenesis origin of life and their precursor transports among celestial bodies The TANPOPO experiment consists of following six sub-themes (ST): 1) the first intact capture of terrestrial microbial colonies in LEO, 2) survival test of terrestrial microbes long exposed in LEO, 3) alteration tests of artificially composed “astronomical organic analogs” long exposed in LEO, 4) intact capture of organic-bearing micrometeoroids with the lowest peak temperature ever in LEO, 5) space flight verification of the world’s lowest density aerogels for intact capture of microparticles, and 6) meteoroid and orbital debris flux assessment only capable to be measured in-situ in LEO. Each will utilize one or more Capture Panel(CP) and Exposure Panel (EP) samples from various pointing faces onboard the Kibo Exposed Facility, i.e., anti-Earth pointing face(Space), leading face (East) and anti-Pressurized Facility face (North), as the ISS is an Earth gravity gradient three-axis stabilized satellite. In order to both satisfy scientific values and planetary protection policy, contamination control and evaluation protocols are implemented for the whole process of manufacturing, ground tests, flight operation and post-retrieval initial analyses of both CPs and EPs. The CPs employ blocks of 0.01g/ccultra-low dense aerogels on its to intact capture impacting solid microparticles such as organic-bearing micrometeoroids, artificial orbital debris and possible terrestrial aerosols temporally reached to the LEO, for assessing the possibility of interplanetary transport of life and its precursors. By analyzing them

  4. Ultrafast laser control of vibrational dynamics for a two-dimensional model of HONO 2 in the ground electronic state: separation of conformers, control of the bond length, selective preparation of the discrete and the continuum states

    NASA Astrophysics Data System (ADS)

    Oppel, M.; Paramonov, G. K.

    1998-06-01

    Selective excitation of the vibrational bound and the continuum states, controlled by subpicosecond infrared (IR) laser pulses, is simulated within the Schrödinger wave function formalism for a two-dimensional model of the HONO 2 molecule in the ground electronic state. State-selective excitation of the OH bond is achieved by single optimal laser pulses, with the probability being 97% for the bound states and more than 91% for the resonances. Stable, long-living continuum states are prepared with more than 96% probability by two optimal laser pulses, with the expectation energy of the molecule being well above the dissociation threshold of the ON single bond, and its life-time being at least 100 ps. The length of the ON single bond can be controlled selectively: stretching and contraction by about 45% of its equilibrium length are demonstrated. Laser separation of spatial conformers of HONO 2 in inhomogeneous conditions occurring on an anisotropic surface or created by a direct current (DC) electric field is analysed. The relative yields of target conformers may be very high, ranging from 10 to 10 8, and the absolute yields of up to 40% and more are calculated.

  5. Hydrogeologic controls on the transport and fate of nitrate in ground water beneath riparian buffer zones: Results from thirteen studies across the United States

    USGS Publications Warehouse

    Puckett, L.J.

    2004-01-01

    During the last two decades there has been growing interest in the capacity of riparian buffer zones to remove nitrate from ground waters moving through them. Riparian zone sediments often contain organic carbon, which favors formation of reducing conditions that can lead to removal of nitrate through denitrification. Over the past decade the National Water Quality Assessment (NAWQA) Program has investigated the transport and fate of nitrate in ground and surface waters in study areas across the United States. In these studies riparian zone efficiency in removing nitrate varied widely as a result of variations in hydrogeologic factors. These factors include (1) denitrification in the up-gradient aquifer due to the presence of organic carbon or other electron donors, (2) long residence times (>50 years) along ground-water flow paths allowing even slow reactions to completely remove nitrate, (3) dilution of nitrate enriched waters with older water having little nitrate, (4) bypassing of riparian zones due to extensive use of drains and ditches, and (5) movement of ground water along deep flow paths below reducing zones. By developing a better understanding of the hydrogeologic settings in which riparian buffer zones are likely to be inefficient we can develop improved nutrient management plans. ?? US Government 2004.

  6. Hydrologic characterization of the Fry Canyon, Utah site prior to field demonstration of reactive chemical barriers to control radionuclide and trace-element contamination in ground water

    SciTech Connect

    Naftz, D.L.; Freethey, G.W.; Davis, J.A.

    1997-12-31

    The Fry Canyon Site in southeastern Utah has been selected as a long term demonstration site to assess the performance of selected reaction barrier technologies for the removal of uranium and other trace elements from ground water. Objectives include site characterization and evaluation of barrier technologies.

  7. Air Ground Integration Study

    NASA Technical Reports Server (NTRS)

    Lozito, Sandy; Mackintosh, Margaret-Anne; DiMeo, Karen; Kopardekar, Parimal

    2002-01-01

    A simulation was conducted to examine the effect of shared air/ground authority when each is equipped with enhanced traffic- and conflict-alerting systems. The potential benefits of an advanced air traffic management (ATM) concept referred to as "free flight" include improved safety through enhanced conflict detection and resolution capabilities, increased flight-operations management, and better decision-making tools for air traffic controllers and flight crews. One element of the free-flight concept suggests shifting aircraft separation responsibility from air traffic controllers to flight crews, thereby creating an environment with "shared-separation" authority. During FY00. NASA, the Federal Aviation Administration (FAA), and the Volpe National Transportation Systems Center completed the first integrated, high-fidelity, real-time, human-in-the-loop simulation.

  8. Strong ground motion generated by controlled blasting experiments and mining induced seismic events recorded underground at deep level mines in South Africa

    NASA Astrophysics Data System (ADS)

    Milev, A.; Selllers, E.; Skorpen, L.; Scheepers, L.; Murphy, S.; Spottiswoode, S. M.

    2011-12-01

    A number of simulated rockbursts were conducted underground at deep level gold mines in South Africa in order to estimate the rock mass response when subjected to strong ground motion. The rockbursts were simulated by means of large blasts detonated in solid rock close to the sidewall of a tunnel. The simulated rockbursts involved the design of the seismic source, seismic observations in the near and far field, high-speed video filming, a study of rock mass conditions such as fractures, joints, rock strength etc. Knowledge of the site conditions before and after the simulated rockbursts was also gained. The numerical models used in the design of the simulated rockbursts were calibrated by small blasts taking place at each experimental site. A dense array of shock type accelerometers was installed along the blasting wall to monitor the attenuation of the strong ground motion as a function of the distance from the source. The attenuation of peak particle velocities, was found to be proportional to R^-1.7. Special investigations were carried out to evaluate the mechanism and the magnitude of damage, as well as the support behaviour under excessive dynamic loading. The strong ground motion generated by mining induced seismic events was studied, as part of this work, not only to characterize the rock mass response, but also to estimate the site effect on the surface of the underground excavations. A stand-alone instrument especially designed for recording strong ground motions was used to create a large database of peak particle velocities measured on stope hangingwalls. A total number of 58 sites located in stopes where the Carbon Leader Reef, Ventersdorp Contact Reef, Vaal Reef and Basal Reef are mined, were monitored. The peak particle velocities were measured at the surface of the excavations to identify the effect of the free surface and the fractures surrounding the underground mining. Based on these measurements the generally accepted velocity criterion of 3 m

  9. Ground difference compensating system

    DOEpatents

    Johnson, Kris W.; Akasam, Sivaprasad

    2005-10-25

    A method of ground level compensation includes measuring a voltage of at least one signal with respect to a primary ground potential and measuring, with respect to the primary ground potential, a voltage level associated with a secondary ground potential. A difference between the voltage level associated with the secondary ground potential and an expected value is calculated. The measured voltage of the at least one signal is adjusted by an amount corresponding to the calculated difference.

  10. Ground water and energy

    SciTech Connect

    Not Available

    1980-11-01

    This national workshop on ground water and energy was conceived by the US Department of Energy's Office of Environmental Assessments. Generally, OEA needed to know what data are available on ground water, what information is still needed, and how DOE can best utilize what has already been learned. The workshop focussed on three areas: (1) ground water supply; (2) conflicts and barriers to ground water use; and (3) alternatives or solutions to the various issues relating to ground water. (ACR)

  11. 21 CFR 110.20 - Plant and grounds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Plant and grounds. 110.20 Section 110.20 Food and... Facilities § 110.20 Plant and grounds. (a) Grounds. The grounds about a food plant under the control of the... litter and waste, and cutting weeds or grass within the immediate vicinity of the plant buildings...

  12. Ground and flight test experience with a triple redundant digital fly by wire control system. [installed in F-8C aircraft

    NASA Technical Reports Server (NTRS)

    Jarvis, C. R.; Szalai, K. J.

    1981-01-01

    A triplex digital fly by wire flight control system was developed and installed in an F-8C aircraft to provide fail operative, full authority control. Hardware and software redundancy management techniques were designed to detect and identify failures in the system. Control functions typical of those projected for future actively controlled vehicles were implemented.

  13. Detachment of Tertiary Dendrite Arms during Controlled Directional Solidification in Aluminum - 7 wt Percent Silicon Alloys: Observations from Ground-based and Microgravity Processed Samples

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N.; Erdman, Robert; Van Hoose, James R.; Tewari, Surendra; Poirier, David

    2012-01-01

    Electron Back Scattered Diffraction results from cross-sections of directionally solidified aluminum 7wt% silicon alloys unexpectedly revealed tertiary dendrite arms that were detached and mis-oriented from their parent arm. More surprisingly, the same phenomenon was observed in a sample similarly processed in the quiescent microgravity environment aboard the International Space Station (ISS) in support of the joint US-European MICAST investigation. The work presented here includes a brief introduction to MICAST and the directional solidification facilities, and their capabilities, available aboard the ISS. Results from the ground-based and microgravity processed samples are compared and possible mechanisms for the observed tertiary arm detachment are suggested.

  14. Electrical Subsurface Grounding Analysis

    SciTech Connect

    J.M. Calle

    2000-11-01

    The purpose and objective of this analysis is to determine the present grounding requirements of the Exploratory Studies Facility (ESF) subsurface electrical system and to verify that the actual grounding system and devices satisfy the requirements.

  15. Ground Water Remediation Technologies

    EPA Science Inventory

    The USEPA's Ground Water and Ecosystems Restoration Division (GWERD) conducts research and provides technical assistance to support the development of strategies and technologies to protect and restore ground water, surface water, and ecosystems impacted by man-made and natural...

  16. GROUND WATER SAMPLING ISSUES

    EPA Science Inventory

    Obtaining representative ground water samples is important for site assessment and
    remedial performance monitoring objectives. Issues which must be considered prior to initiating a ground-water monitoring program include defining monitoring goals and objectives, sampling point...

  17. Measurement scheme for a ground-state parity non-conserving (PNC) measurement in a cesium atomic beam via two-pathway coherent control

    NASA Astrophysics Data System (ADS)

    Choi, Jungu; Elliott, Dan; Elliott's Lab Team

    2016-05-01

    We present a detailed analysis of an experimental setup for parity non-conserving (PNC) measurements in a cesium atomic beam. We employ a parallel-plate transmission line (PPTL) structure and highly reflective cylindrical mirrors to form a microwave cavity resonator to excite the PNC transitions in the cesium hyperfine ground states. In addition, a variable external dc field is applied to observe the Stark-induced transition, which would interfere with the PNC transition as the dc field amplitude changes. Finally, strong Raman lasers are used to excite the ground hyperfine transition. The Raman fields interfere with the weak transitions, and by varying the phase difference between the Raman fields and the microwave fields, we would infer the weak transition amplitudes from the signal modulation. The experimental setup requires maintaining coherent phase relations between all fields, well-characterized dc and rf field patterns, the two co-propagating Raman lasers, and suppression of the magnetic dipole contribution. Our analysis of the field modes supported by the PPTL structure indicates that with a moderate rf power and a few tens of seconds of data collection time, the PNC measurement of less than 3% uncertainty would be feasible.

  18. LISA Pathfinder ground testing

    NASA Astrophysics Data System (ADS)

    Guzman, Felipe; LISA Pathfinder Team

    2010-01-01

    The space-based gravitational wave observatory LISA is a joint NASA-ESA mission that requires challenging technology to ensure pure geodetic trajectories of test masses and the interferometric measurement of distance variations between them. The LISA Pathfinder mission is an ESA-launched technology demonstrator of key LISA subsystems such as spacecraft control with micronewton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of pre-flight hardware of the Gravitational Reference Sensor and Optical Metrology subsystems is currently ongoing. Studies have been carried out on very sensitive torsion pendulums that effectively reproduce a free-fall condition for the test mass within a horizontal plane in the lab, down to frequencies < 0.1 mHz. Thermal gradient induced effects, impact of gas molecules, noisy charging, surface charge patches, and other effects have been investigated and their physical models consolidated. A final upper limit on non-modeled disturbances has also been obtained within one order of magnitude of LISA requirements at 1 mHz. The interferometry system has also been extensively studied to identify noise sources and develop approaches to mitigate them. Engineering models of the optical bench, laser head and laser modulators have been interconnected and tested for functionality and noise level in closed-loop operation, demonstrating the required optical metrology sensitivity to test mass displacement. This poster presents the current status in the development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts.

  19. Ground water: a review.

    USGS Publications Warehouse

    Bredehoeft, J.D.

    1983-01-01

    There is growing documentation that a significant portion of the Nation's fresh ground water in the densely populated areas of the USA is contaminated. Because of the slow rates of ground-water movement, ground water once contaminated will remain so for decades, often longer. Cleanup of contaminated ground water is almost always expensive and often technically unfeasible; the expense is often prohibitive. -from Author

  20. Grounds Maintenance Evaluation.

    ERIC Educational Resources Information Center

    Chesapeake Public Schools, VA. Office of Program Evaluation.

    The Grounds Shop of the Chesapeake Public School Division (Virginia) Department of School Plants was evaluated in 1995-96. The goals of the grounds maintenance program are to provide safe and attractive grounds for students, parents, and staff of the school district. The evaluation examined the extent to which these goals are being met by using…

  1. 49 CFR 236.107 - Ground tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Rules and Instructions: All Systems Inspections and Tests; All Systems § 236.107 Ground tests. (a) Except as provided in paragraph (b) of this section, a test for grounds on each energy bus furnishing power to circuits,...

  2. Procedures for ground-water investigations

    SciTech Connect

    Not Available

    1992-12-01

    This manual was developed by the Pacific Northwest Laboratory (PNL) to document the procedures used to carry out and control the technical aspects of ground-water investigations at the PNL. Ground-water monitoring procedures are developed and used in accordance with the PNL Quality Assurance Program.

  3. 49 CFR 236.2 - Grounds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., single-break, signal control circuits using a grounded common, and alternating current power distribution... internal to microprocessor-based appliances; (4) Circuitry internal to semiconductor-based memory; or (5) Alternating current power distribution circuits that are grounded in the interest of safety....

  4. COMPILATION OF GROUND-WATER MODELS

    EPA Science Inventory

    Ground-water modeling is a computer-based methodology for mathematical analysis of the mechanisms and controls of ground-water systems for the evaluation of policies, action, and designs that may affect such systems. n addition to satisfying scientific interest in the workings of...

  5. Telerobotic ground-remote operations

    NASA Technical Reports Server (NTRS)

    Bon, Bruce; Zimmerman, Wayne

    1991-01-01

    The Telerobotic Ground-Remote Operations task consists of development of a demonstration local-site operator control station that includes a graphical user interface (GUI) for control of a remote robot, and development of operator-assisted perception algorithms and software that will provide flexible and accurate world modeling capabilities. The topics covered are presented in view graph form and include: (1) local site development configuration; (2) system design; (3) operator control station (local site) software block diagram; (4) operator-assisted perception; and (5) program status.

  6. Electrical Ground Support Equipment Fabrication, Specification for

    NASA Technical Reports Server (NTRS)

    Denson, Erik C.

    2014-01-01

    This document specifies parts, materials, and processes used in the fabrication, maintenance, repair, and procurement of electrical and electronic control and monitoring equipment associated with ground support equipment (GSE) at the Kennedy Space Center (KSC).

  7. Application of cranberry concentrate (Vaccinium macrocarpon) to control Escherichia coli O157:H7 in ground beef and its antimicrobial mechanism related to the downregulated slp, hdeA and cfa.

    PubMed

    Wu, Vivian C H; Qiu, Xujian; de los Reyes, Benildo G; Lin, Chih-Sheng; Pan, Yingjie

    2009-02-01

    The possible use of cranberry concentrate (CC) as a natural food preservative was studied by examining its antimicrobial effect on the growth of Escherichia coli O157:H7 inoculated in ground beef, its organoleptical effect on beef patties, and its antimicrobial mechanism on the gene regulation level. Inoculated ground beef was added with CC and stored at 4 degrees C for 5 days. Bacteria were detected on day 0, 1, 3, and 5. Cranberry concentrate (2.5%, 5%, and 7.5% w/w) reduced total aerobic bacteria 1.5 log, 2.1 log, and 2.7 log CFU/g and E. coli O157:H7 0.4 log, 0.7 log, and 2.4 log CFU/g, respectively, when compared to the control on day 5. Fifty panelists evaluated the burgers supplemented with CC. No differences in appearance, flavor, and taste were found among burgers with 0%, 2.5%, and 5% CC. The expression of E. coli O157:H7 cyclopropane fatty acyl phospholipid synthase (cfa), hypothetical protein (hdeA), outer membrane porin protein C (ompC), hyperosmotically inducible periplasmic protein (osmY), and outer membrane protein induced after carbon starvation (slp) genes with or without CC (2.5% v/v) treatment was investigated by quantitative real-time PCR. Compared to the control, slp, hdeA, and cfa were markedly downregulated, ompC was slightly downregulated, while osmY was slightly affected.

  8. Spin-orbit coupling control of anisotropy, ground state and frustration in 5d(2) Sr2MgOsO6.

    PubMed

    Morrow, Ryan; Taylor, Alice E; Singh, D J; Xiong, Jie; Rodan, Steven; Wolter, A U B; Wurmehl, Sabine; Büchner, Bernd; Stone, M B; Kolesnikov, A I; Aczel, Adam A; Christianson, A D; Woodward, Patrick M

    2016-01-01

    The influence of spin-orbit coupling (SOC) on the physical properties of the 5d(2) system Sr2MgOsO6 is probed via a combination of magnetometry, specific heat measurements, elastic and inelastic neutron scattering, and density functional theory calculations. Although a significant degree of frustration is expected, we find that Sr2MgOsO6 orders in a type I antiferromagnetic structure at the remarkably high temperature of 108 K. The measurements presented allow for the first accurate quantification of the size of the magnetic moment in a 5d(2) system of 0.60(2) μB -a significantly reduced moment from the expected value for such a system. Furthermore, significant anisotropy is identified via a spin excitation gap, and we confirm by first principles calculations that SOC not only provides the magnetocrystalline anisotropy, but also plays a crucial role in determining both the ground state magnetic order and the size of the local moment in this compound. Through comparison to Sr2ScOsO6, it is demonstrated that SOC-induced anisotropy has the ability to relieve frustration in 5d(2) systems relative to their 5d(3) counterparts, providing an explanation of the high TN found in Sr2MgOsO6. PMID:27571715

  9. Endogenous control of sexual size dimorphism: Gonadal androgens have neither direct nor indirect effect on male growth in a Madagascar ground gecko (Paroedura picta).

    PubMed

    Kubička, Lukáš; Starostová, Zuzana; Kratochvíl, Lukáš

    2015-12-01

    Changes in the effect of gonadal androgens on male growth are considered as a possible mechanism allowing shifts in magnitude and even direction of sexual size dimorphism in vertebrates, particularly squamate reptiles. Positive effects of gonadal androgens on male growth were found in several male-larger species of lizards. Contrastingly, we document that in the male-larger Madagascar ground gecko (Paroedura picta) gonadal androgens do not affect male growth under constant thermal conditions. However, the absence of a thermal gradient might prevent the potential indirect effect of gonadal androgens on growth via the influence of circulating hormones on an individual's thermoregulation and hence metabolic rate. In order to study this, we monitored the growth and body temperature of socially isolated sham-operated and castrated males of the same species in a thermal gradient. We also compared the oxygen consumption and activity between the treatment groups in the open field to test the effect of gonadal hormones on these traits potentially affecting growth. Even under a thermal gradient we found no effect of gonadal androgens on growth rate or final body dimensions. Castration also did not significantly affect oxygen consumption or activity in the open field test. Together with our previous findings, we can exclude both the direct effect of male gonadal androgens on the ontogeny of sexual size dimorphism via the influence on the growth axis, and the indirect influence of gonadal androgens acting on the ontogeny of SSD through the effect on thermoregulation, metabolic rate and activity. PMID:26431613

  10. Baseline data-collection and quality-control protocols and procedures for the Equus beds ground-water recharge demonstration project near Wichita, Kansas, 1995-96

    USGS Publications Warehouse

    Ziegler, A.C.; Combs, L.J.

    1997-01-01

    The Equus Beds Ground-Water Recharge Demonstration Project is being conducted from 1995 through 1999 as part of the High Plains States Groundwater Recharge Demonstration Program to determine if recharge of the Equus beds aquifer in south-central Kansas is a viable alternative in meeting the increased demands for water in this rapidly growing part of the State. As part of the demonstration project, protocols and procedures were developed for the collection of baseline hydrologic and water-quality data from September 1995 through September 1996 and are described in this report. During this initial phase of the demonstration project, 33 data-collection sites were identified and instrumented, and an aquifer test at one site was conducted to determine transmissivity, specific yield, hydraulic conductivity, and riverbed conductance of the Equus beds aquifer in the area northwest of Wichita, Kansas. Selected water-quality samples were analyzed for as many as 340 chemical constituents to determine the baseline or ambient concentrations of inorganic and orgainc constituents.

  11. Spin-orbit coupling control of anisotropy, ground state and frustration in 5d2 Sr2MgOsO6

    NASA Astrophysics Data System (ADS)

    Morrow, Ryan; Taylor, Alice E.; Singh, D. J.; Xiong, Jie; Rodan, Steven; Wolter, A. U. B.; Wurmehl, Sabine; Büchner, Bernd; Stone, M. B.; Kolesnikov, A. I.; Aczel, Adam A.; Christianson, A. D.; Woodward, Patrick M.

    2016-08-01

    The influence of spin-orbit coupling (SOC) on the physical properties of the 5d2 system Sr2MgOsO6 is probed via a combination of magnetometry, specific heat measurements, elastic and inelastic neutron scattering, and density functional theory calculations. Although a significant degree of frustration is expected, we find that Sr2MgOsO6 orders in a type I antiferromagnetic structure at the remarkably high temperature of 108 K. The measurements presented allow for the first accurate quantification of the size of the magnetic moment in a 5d2 system of 0.60(2) μB –a significantly reduced moment from the expected value for such a system. Furthermore, significant anisotropy is identified via a spin excitation gap, and we confirm by first principles calculations that SOC not only provides the magnetocrystalline anisotropy, but also plays a crucial role in determining both the ground state magnetic order and the size of the local moment in this compound. Through comparison to Sr2ScOsO6, it is demonstrated that SOC-induced anisotropy has the ability to relieve frustration in 5d2 systems relative to their 5d3 counterparts, providing an explanation of the high TN found in Sr2MgOsO6.

  12. Spin-orbit coupling control of anisotropy, ground state and frustration in 5d2 Sr2MgOsO6

    PubMed Central

    Morrow, Ryan; Taylor, Alice E.; Singh, D. J.; Xiong, Jie; Rodan, Steven; Wolter, A. U. B.; Wurmehl, Sabine; Büchner, Bernd; Stone, M. B.; Kolesnikov, A. I.; Aczel, Adam A.; Christianson, A. D.; Woodward, Patrick M.

    2016-01-01

    The influence of spin-orbit coupling (SOC) on the physical properties of the 5d2 system Sr2MgOsO6 is probed via a combination of magnetometry, specific heat measurements, elastic and inelastic neutron scattering, and density functional theory calculations. Although a significant degree of frustration is expected, we find that Sr2MgOsO6 orders in a type I antiferromagnetic structure at the remarkably high temperature of 108 K. The measurements presented allow for the first accurate quantification of the size of the magnetic moment in a 5d2 system of 0.60(2) μB –a significantly reduced moment from the expected value for such a system. Furthermore, significant anisotropy is identified via a spin excitation gap, and we confirm by first principles calculations that SOC not only provides the magnetocrystalline anisotropy, but also plays a crucial role in determining both the ground state magnetic order and the size of the local moment in this compound. Through comparison to Sr2ScOsO6, it is demonstrated that SOC-induced anisotropy has the ability to relieve frustration in 5d2 systems relative to their 5d3 counterparts, providing an explanation of the high TN found in Sr2MgOsO6. PMID:27571715

  13. Spin-orbit coupling control of anisotropy, ground state and frustration in 5d2Sr2MgOsO6

    DOE PAGESBeta

    Morrow, Ryan; Taylor, Alice E.; Singh, D. J.; Xiong, Jie; Rodan, Steven; Wolter, A. U. B.; Wurmehl, Sabine; Büchner, Bernd; Stone, M. B.; Kolesnikov, A. I.; et al

    2016-08-30

    The influence of spin-orbit coupling (SOC) on the physical properties of the 5d2 system Sr2MgOsO6 is probed via a combination of magnetometry, specific heat measurements, elastic and inelastic neutron scattering, and density functional theory calculations. Although a significant degree of frustration is expected, we find that Sr2MgOsO6 orders in a type I antiferromagnetic structure at the remarkably high temperature of 108 K. The measurements presented allow for the first accurate quantification of the size of the magnetic moment in a 5d2 system of 0.60(2) μB a significantly reduced moment from the expected value for such a system. Furthermore, significant anisotropymore » is identified via a spin excitation gap, and we confirm by first principles calculations that SOC not only provides the magnetocrystalline anisotropy, but also plays a crucial role in determining both the ground state magnetic order and the moment size in this compound. In conclusion, through comparison to Sr2ScOsO6, it is demonstrated that SOC-induced anisotropy has the ability to relieve frustration in 5d2 systems relative to their 5d3 counterparts, providing an explanation of the high TN found in Sr2MgOsO6.« less

  14. Endogenous control of sexual size dimorphism: Gonadal androgens have neither direct nor indirect effect on male growth in a Madagascar ground gecko (Paroedura picta).

    PubMed

    Kubička, Lukáš; Starostová, Zuzana; Kratochvíl, Lukáš

    2015-12-01

    Changes in the effect of gonadal androgens on male growth are considered as a possible mechanism allowing shifts in magnitude and even direction of sexual size dimorphism in vertebrates, particularly squamate reptiles. Positive effects of gonadal androgens on male growth were found in several male-larger species of lizards. Contrastingly, we document that in the male-larger Madagascar ground gecko (Paroedura picta) gonadal androgens do not affect male growth under constant thermal conditions. However, the absence of a thermal gradient might prevent the potential indirect effect of gonadal androgens on growth via the influence of circulating hormones on an individual's thermoregulation and hence metabolic rate. In order to study this, we monitored the growth and body temperature of socially isolated sham-operated and castrated males of the same species in a thermal gradient. We also compared the oxygen consumption and activity between the treatment groups in the open field to test the effect of gonadal hormones on these traits potentially affecting growth. Even under a thermal gradient we found no effect of gonadal androgens on growth rate or final body dimensions. Castration also did not significantly affect oxygen consumption or activity in the open field test. Together with our previous findings, we can exclude both the direct effect of male gonadal androgens on the ontogeny of sexual size dimorphism via the influence on the growth axis, and the indirect influence of gonadal androgens acting on the ontogeny of SSD through the effect on thermoregulation, metabolic rate and activity.

  15. [Introduction to grounded theory].

    PubMed

    Wang, Shou-Yu; Windsor, Carol; Yates, Patsy

    2012-02-01

    Grounded theory, first developed by Glaser and Strauss in the 1960s, was introduced into nursing education as a distinct research methodology in the 1970s. The theory is grounded in a critique of the dominant contemporary approach to social inquiry, which imposed "enduring" theoretical propositions onto study data. Rather than starting from a set theoretical framework, grounded theory relies on researchers distinguishing meaningful constructs from generated data and then identifying an appropriate theory. Grounded theory is thus particularly useful in investigating complex issues and behaviours not previously addressed and concepts and relationships in particular populations or places that are still undeveloped or weakly connected. Grounded theory data analysis processes include open, axial and selective coding levels. The purpose of this article was to explore the grounded theory research process and provide an initial understanding of this methodology.

  16. Electrical grounding prong socket

    DOEpatents

    Leong, Robert

    1991-01-01

    The invention is a socket for a grounding prong used in a three prong electrical plug and a receptacle for the three prong plug. The socket being sufficiently spacious to prevent the socket from significantly stretching when a larger, U-shaped grounding prong is inserted into the socket, and having a ridge to allow a snug fit when a smaller tubular shape grounding prong is inserted into the socket.

  17. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, Exploration, and Human Health and Safety

    NASA Technical Reports Server (NTRS)

    Koontz, Steve

    2015-01-01

    In this presentation a review of galactic cosmic ray (GCR) effects on microelectronic systems and human health and safety is given. The methods used to evaluate and mitigate unwanted cosmic ray effects in ground-based, atmospheric flight, and space flight environments are also reviewed. However not all GCR effects are undesirable. We will also briefly review how observation and analysis of GCR interactions with planetary atmospheres and surfaces and reveal important compositional and geophysical data on earth and elsewhere. About 1000 GCR particles enter every square meter of Earth’s upper atmosphere every second, roughly the same number striking every square meter of the International Space Station (ISS) and every other low- Earth orbit spacecraft. GCR particles are high energy ionized atomic nuclei (90% protons, 9% alpha particles, 1% heavier nuclei) traveling very close to the speed of light. The GCR particle flux is even higher in interplanetary space because the geomagnetic field provides some limited magnetic shielding. Collisions of GCR particles with atomic nuclei in planetary atmospheres and/or regolith as well as spacecraft materials produce nuclear reactions and energetic/highly penetrating secondary particle showers. Three twentieth century technology developments have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems and assess effects on human health and safety effects. The key technology developments are: 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems. Space and geophysical exploration needs drove the development of the instruments and analytical tools needed to recover compositional and structural data from GCR induced nuclear reactions and secondary particle showers. Finally, the

  18. Soil C:N stoichiometry controls carbon sink partitioning between above-ground tree productivity and soil organic matter in high fertility forests

    NASA Astrophysics Data System (ADS)

    Cotrufo, M.; Alberti, G.; Vicca, S.; Inglima, I.; Belelli-Marchesini, L.; Genesio, L.; Miglietta, F.; Marjanovic, H.; Martinez, C.; Matteucci, G.; Peressotti, A.; Petrella, L.; Rodeghiero, M.

    2013-12-01

    The release of organic compounds from roots is a key process influencing soil carbon (C) dynamics and nutrient availability in terrestrial ecosystems and is a process by which plants stimulate microbial activity and soil organic matter (SOM) mineralization thus releasing nitrogen (N) to sustain their gross and net primary production (GPP and NPP). Root inputs also contribute to soil organic matter (SOM) formation. In this study, we quantified the annual net root derived C input to soil (Net-Croot) across six high fertile forests using an in-growth core isotope technique. On the basis of Net-Croot, wood and coarse root biomass changes and eddy covariance data, we quantified net belowground C sequestration. This and GPP were inversely related to soil C:N, but not to climate or age. Because, at these high fertile sites, biomass growth did not change with soil C:N ratio, biomass growth-to-GPP ratio significantly increased with increasing soil C:N. This was true for both our six forest sites and for high fertile sites across a set of other 23 sites selected at global scale. We suggest that, at high fertile sites, the interaction between plant demand for nutrients, soil stoichiometry and microbial activity sustain higher ecosystem C-sink allocation to above ground tree biomass with increasing soil C:N ratio and that this clear and strong relationship can be used for modelling forest C sink partitioning between plant biomass and soil. When C:N is high, microbes have a low C use efficiency, respire more of the fresh C inputs by roots and prime SOM decomposition increasing N availability for tree uptake. Soil C sequestration would therefore decrease, whereas the extra N released during SOM decomposition can promote tree growth and ecosystem C sink allocation in aboveground biomass. Conversely, C is sequestered in soil when the low soil C:N promotes microbial C use efficiency and new SOM formation.

  19. Ground truth versus no ground truth

    NASA Technical Reports Server (NTRS)

    Torbert, G. B.

    1970-01-01

    The area of study was the southeastern Arizona test site and three areas within the site were studied in detail: Safford, Point of Pines, and Fort Apache-White River. These areas have terrain contrast ranging from flat arid regions to high alpine mountains. Data were obtained from the Apollo 9 photographic missions, high altitude aerial photography, and simulated ERTS-A data from high altitude aircraft. Various monoscopic and steroscopic devices were used to analyze the features, and film density variations were studied. No ground-based data were permitted. Thematic maps were prepared for geology, geomorphology, vegetation, hydrology, and soils. Interpreted boundaries were delineated, with no collaborative data used in the interpretation. Ground-based data were gathered during the overflight of high altitude aerial photography. A further study was made using the ground truth, and the data gathered on the ground were compared with original mapping. 80% to 85% of the interpretations in the areas checked were correct. It was proved that it is possible to monitor gross features of the vigor of crop lands and vegetative cover, to type soils and classify geologic features, and to determine hydrologic conditions.

  20. Spacelab Ground Processing

    NASA Astrophysics Data System (ADS)

    Scully, Edward J.; Gaskins, Roger B.

    1982-02-01

    Spacelab (SL) ground processing is active at the Kennedy Space Center (KSC). The palletized payload for the second Shuttle launch is staged and integrated with interface verification active. The SL Engineering Model is being assembled for subsequent test and checkout activities. After delivery of SL flight elements from Europe, prelaunch operations for the first SL flight start with receipt of the flight experiment packages and staging of the SL hardware. Experiment operations consist of integrating the various experiment elements into the SL racks, floors and pallets. Rack and floor assemblies with the experiments installed, are integrated into the flight module. Aft end-cone installation, pallet connections, and SL subsystems interface verifications are accomplished, and SL-Orbiter interfaces verified. The Spacelab cargo is then transferred to the Orbiter Processing Facility (OPF) in a controlled environment using a canister/transporter. After the SL is installed into the Orbiter payload bay, physical and functional integrity of all payload-to-Orbiter interfaces are verified and final close-out operations conducted. Spacelab payload activities at the launch pad are minimal with the payload bay doors remaining closed. Limited access is available to the module through the Spacelab Transfer Tunnel. After mission completion, the SL is removed from the Orbiter in the OPF and returned to the SL processing facility for experiment equipment removal and reconfiguration for the subsequent mission.

  1. Ground characterization for JAPE

    NASA Technical Reports Server (NTRS)

    Attenborough, Keith; Taherzadeh, Shahram

    1993-01-01

    Above-ground propagation modelling at the JAPE (Joint Acoustic Propagation Experiment) site requires a reasonably accurate model for the acoustical properties of the ground. Various models for the JAPE site are offered based on theoretical fits to short range data and to longer range data obtained with random noise and pure tones respectively from a loudspeaker under approximately quiescent isothermal conditions.

  2. Stochastic ground motion simulation

    USGS Publications Warehouse

    Rezaeian, Sanaz; Xiaodan, Sun; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan

    2014-01-01

    Strong earthquake ground motion records are fundamental in engineering applications. Ground motion time series are used in response-history dynamic analysis of structural or geotechnical systems. In such analysis, the validity of predicted responses depends on the validity of the input excitations. Ground motion records are also used to develop ground motion prediction equations(GMPEs) for intensity measures such as spectral accelerations that are used in response-spectrum dynamic analysis. Despite the thousands of available strong ground motion records, there remains a shortage of records for large-magnitude earthquakes at short distances or in specific regions, as well as records that sample specific combinations of source, path, and site characteristics.

  3. Communication, concepts and grounding.

    PubMed

    van der Velde, Frank

    2015-02-01

    This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain and communication between humans or between humans and machines. In the first form of communication, a concept is activated by sensory input. Due to grounding, the information provided by this communication is not just determined by the sensory input but also by the outgoing connection structure of the conceptual representation, which is based on previous experiences and actions. The second form of communication, that between humans or between humans and machines, is influenced by the first form. In particular, a more successful interpersonal communication might require forms of situated cognition and interaction in which the entire representations of grounded concepts are involved.

  4. Preventing and controlling land subsidence in Shanghai -towards more integrated and effective land use and ground water governance in the Yangtze Delta

    NASA Astrophysics Data System (ADS)

    Dai, Liping

    2016-04-01

    The Yangtze Delta, covers 210,700 square kilometers and with 156 million inhabitants (NRDC, 2010; The National Bureau of Statistics, 2011), is one of the areas most severely affected by land subsidence in China. Up to 2012, the area with cumulative subsidence above 200 mm in Yangtze Delta has been closed to 10,000 square kilometers. Shanghai, located at the estuary of the Yangtze River and with a population of 23 million, is the most densely populated city in Yangtze Delta (The National Bureau of Statistics, 2011). Since 1921, the recorded cumulative subsidence has been 200 to 300 mm in the central area of the city (Chai, Shen, Zhu, & Zhang, 2005). Excessive pumping of groundwater is considered to be the leading reason, accounts for nearly 70%, of the city's land subsidence, the weight of skyscrapers and global warming also play hefty roles (30%) (Springer, 2012). Research has shown that the main method to control land subsidence in Shanghai is to prevent groundwater from dropping (Chai, Shen, Zhu, & Zhang, 2005), the city has made great efforts in this regard since 1965 (the beginning of the so-called "control period"), for example, it has been recharging underground water through 121 wells with more than 60,000 tons every day since 2012 (Chinadaily, 2012). It is a huge burden considering the city has been suffering from a shortage of fresh water. In 2013, with the other two provinces of Jiangsu and Zhejiang in Yangtze Delta, Shanghai signed a delta cooperation agreement on the prevention and control of land subsidence and jointly issued a Prevention and Control Planning on Land Subsidence in Yangtze Delta (2014-2020), which aims to establish a long-effect mechanism in the delta scope. This research aims to analyze and assess the land and groundwater governance arrangements related to land subsidence in the Yangtze Delta in general and Shanghai in specific, in order to develop optimizing adaptation strategies and associated governance arrangements. It examines the

  5. Longevity of emplacement drift ground support materials

    SciTech Connect

    Tang, David

    2000-04-01

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. The Development Plan (DP) for this analysis is given in Longevity of Emplacement Drift Ground Support Materials (CRWMS M and O 1999a). The objective of this analysis is to update the previous analysis (CRWMS M and O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M and O 2000b), the Monitored Geologic Repository Project Description Document (CRWMS M and O 1999b), and in environmental conditions, and to provide updated information on candidate ground support materials.

  6. Area-Wide Ground Applications of Bacillus thuringiensis var. israelensis for the Control of Aedes albopictus in Residential Neighborhoods: From Optimization to Operation

    PubMed Central

    Williams, Gregory M.; Faraji, Ary; Unlu, Isik; Healy, Sean P.; Farooq, Muhammad; Gaugler, Randy; Hamilton, George; Fonseca, Dina M.

    2014-01-01

    The increasing range of Aedes albopictus, the Asian tiger mosquito, in the USA and the threat of chikungunya and dengue outbreaks vectored by this species have necessitated novel approaches to control this peridomestic mosquito. Conventional methods such as adulticiding provide temporary relief, but fail to manage this pest on a sustained basis. We explored the use of cold aerosol foggers and misting machines for area-wide applications of Bacillus thuringiensis var. israelensis (VectoBac WDG) as a larvicide targeting Aedes albopictus. During 2010–2013 we performed initially open field trials and then 19 operational area-wide applications in urban and suburban residential areas in northeastern USA to test three truck-mounted sprayers at two application rates. Area-wide applications of WDG in open field conditions at 400 and 800 g/ha killed on average 87% of tested larvae. Once techniques were optimized in residential areas, applications with a Buffalo Turbine Mist Sprayer at a rate of 800 g/ha, the best combination, consistently provided over 90% mortality. Importantly, there was no significant decrease in efficacy with distance from the spray line even in blocks of row homes with trees and bushes in the backyards. Under laboratory conditions Bti deposition in bioassay cups during the operational trials resulted in over 6 weeks of residual control. Our results demonstrate that area-wide truck mounted applications of WDG can effectively suppress Ae. albopictus larvae and should be used in integrated mosquito management approaches to control this nuisance pest and disease vector. PMID:25329314

  7. Measurement, characterization, and prediction of strong ground motion

    USGS Publications Warehouse

    Joyner, William; Boore, David M.

    1988-01-01

    A number of predictive relationships derived from regression analysis of strong-motion data are available for horizontal peak acceleration, velocity, and response spectral values. Theoretical prediction of ground motion calls for stochastic source models because source heterogeneities control the amplitude of ground motion at most, if not all, frequencies of engineering interest. Theoretical methods have been developed for estimation of ground-motion parameters and simulation of ground-motion time series. These methods are particularly helpful for regions such, as eastern North America where strong-motion data are sparse. The authors survey the field, first reviewing developments in ground-motion measurement and data processing. The authors then consider the choice of parameters for characterizing strong ground motion and describe the wave-types involved in strong ground motion and the factors affecting ground-motion amplitudes. They conclude by describing methods for predicting ground motion.

  8. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120.376 Grounded distribution systems (Neutral grounded). (a) If a grounded distribution system is provided, there must be only one connection to... 46 Shipping 4 2013-10-01 2013-10-01 false Grounded distribution systems (Neutral grounded)....

  9. METHOD OF LOCATING GROUNDS

    DOEpatents

    Macleish, K.G.

    1958-02-11

    ABS>This patent presents a method for locating a ground in a d-c circult having a number of parallel branches connected across a d-c source or generator. The complete method comprises the steps of locating the ground with reference to the mildpoint of the parallel branches by connecting a potentiometer across the terminals of the circuit and connecting the slider of the potentiometer to ground through a current indicating instrument, adjusting the slider to right or left of the mildpoint so as to cause the instrument to indicate zero, connecting the terminal of the network which is farthest from the ground as thus indicated by the potentiometer to ground through a condenser, impressing a ripple voltage on the circuit, and then measuring the ripple voltage at the midpoint of each parallel branch to find the branch in which is the lowest value of ripple voltage, and then measuring the distribution of the ripple voltage along this branch to determine the point at which the ripple voltage drops off to zero or substantially zero due to the existence of a ground. The invention has particular application where a circuit ground is present which will disappear if the normal circuit voltage is removed.

  10. Reducing stray ground currents

    SciTech Connect

    Harlow, H.W.

    1980-09-01

    Utility customers of Clark County, Washington reported that electric shocks from stray ground currents were interfering with cattle, businesses, and equipment. The Public Utility District (PUD) investigated each claim and explored several ways to lower shocks below 10 volts. Ground rods were installed as a low-cost option. The rods reduced ground voltages by 33 percent and motor starting peaks by 50 percent. Variations in earth composition, people, and animals require individualized solutions. A major part of the solution is based on cost and line location. (DCK)

  11. The Value of A Nuclear Ground Test

    SciTech Connect

    Blessing, David

    2006-07-01

    With limited budget for space exploration, it is important to look for ways to reduce the cost of the development of a space nuclear power system. One of the major contributors in cost estimates for such a development is the cost to conduct a nuclear ground test, which is an integrated test of the entire nuclear power system with the reactor providing nuclear power in a suitable test facility. Such a nuclear ground test would include the reactor, primary coolant system, shielding, power conversion, reactor instrumentation and control, power control electronics, and at least part of the flight heat rejection system. These components and systems will have been tested separately, but in the nuclear ground test they are tested together with heat supplied by the reactor for the first time. The unit tested would not be flown. This paper discusses the value of a nuclear ground test and identifies the specific test objectives that would be met in a nuclear ground test and the degree to which they could be met using an electrically heated integrated test. In the absence of a nuclear ground test, confidence in the system design can be increased by successful operation of units on the Moon or Mars. This paper comments on the ability of such operation to support validation of the design for manned missions. Finally this paper discusses features of a nuclear power system that would be particularly desirable to improve the chances that the flight unit will operate successfully if a nuclear ground test is not conducted. (author)

  12. Ground test experiment for large space structures

    NASA Technical Reports Server (NTRS)

    Tollison, D. K.; Waites, H. B.

    1985-01-01

    In recent years a new body of control theory has been developed for the design of control systems for Large Space Structures (LSS). The problems of testing this theory on LSS hardware are aggravated by the expense and risk of actual in orbit tests. Ground tests on large space structures can provide a proving ground for candidate control systems, but such tests require a unique facility for their execution. The current development of such a facility at the NASA Marshall Space Flight Center (MSFC) is the subject of this report.

  13. Ground potential rise monitor

    DOEpatents

    Allen, Zachery Warren; Zevenbergen, Gary Allen

    2012-07-17

    A device and method for detecting ground potential rise (GPR) comprising a first electrode, a second electrode, and a voltage attenuator. The first electrode and the second electrode are both electrically connected to the voltage attenuator. A means for determining the presence of a dangerous ground potential is connected to the voltage attenuator. The device and method further comprises a means for enabling one or more alarms upon the detection of the dangerous ground potential. Preferably, a first transmitter/receiver is connected to the means for enabling one or more alarms. Preferably, a second transmitter/receiver, comprising a button, is electromagnetically connected to the first transmitter/receiver. Preferably, the means for determining the presence of a dangerous ground potential comprises a means for determining the true RMS voltage at the output of the voltage attenuator, a transient detector connected to the output of the voltage attenuator, or a combination thereof.

  14. Ground-to-ground communications for mission support

    NASA Technical Reports Server (NTRS)

    Dickinson, W. B.

    1981-01-01

    The objective of the NASA Communications Division is to provide operational communications in support of NASA projects and mission activities. Nascom is a generic term referring collectively to a global system of circuits and switching and terminal facilities established and operated by NASA to provide longhaul operational communications support for all NASA projects. Aspects of network evolution are discussed, taking into account the integrated Nascom network. A description is presented of the present Nascom network, giving attention to the Spaceflight Tracking and Data Network (STDN), the Deep Space Network (DSN), the voice network, and the Teletypewriter (TTY) Network. Concepts and techniques for the 1980's are also considered. It is pointed out that the Nascom Network will extend the Tracking and Data Relay Satellite System (TDRSS) forward- and return-link services to users of the TDRSS by providing ground-to-ground data communications links between the NASA Ground Terminal at White Sands, New Mexico, and major user spacecraft control centers and data capture/data processing facilities.

  15. Ground Water in Hawaii

    USGS Publications Warehouse

    Gingerich, Stephen B.; Oki, Delwyn S.

    2000-01-01

    Ground water is one of Hawaii's most important natural resources. It is used for drinking water, irrigation, and domestic, commercial, and industrial needs. Ground water provides about 99 percent of Hawaii's domestic water and about 50 percent of all freshwater used in the State. Total ground water pumped in Hawaii was about 500 million gallons per day during 1995, which is less than 3 percent of the average total rainfall (about 21 billion gallons per day) in Hawaii. From this perspective, the ground-water resource appears ample; however, much of the rainfall runs off to the ocean in streams or returns to the atmosphere by evapotranspiration. Furthermore, ground-water resources can be limited because of water-quality, environmental, or economic concerns. Water beneath the ground surface occurs in two principal zones: the unsaturated zone and the saturated zone. In the unsaturated zone, the pore spaces in rocks contain both air and water, whereas in the saturated zone, the pore spaces are filled with water. The upper surface of the saturated zone is referred to as the water table. Water below the water table is referred to as ground water. Ground-water salinity can range from freshwater to that of seawater. Freshwater is commonly considered to be water with a chloride concentration less than 250 mg/L, and this concentration represents about 1.3 percent of the chloride concentration of seawater (19,500 mg/L). Brackish water has a chloride concentration between that of freshwater (250 mg/L) and saltwater (19,500 mg/L).

  16. Dynamic ground effects

    NASA Technical Reports Server (NTRS)

    Paulson, John W., Jr.; Kemmerly, Guy T.; Gilbert, William P.

    1990-01-01

    A research program is underway at the NASA Langley Research Center to study the effect of rate of descent on ground effects. A series of powered models were tested in the Vortex Research Facility under conditions with rate of descent and in the 14 x 22 Foot Subsonic Tunnel under identical conditions but without rate of descent. These results indicate that the rate of descent can have a significant impact on ground effects particularly if vectored or reversed thrust is used.

  17. Residual shear strength variability as a primary control on movement of landslides reactivated by earthquake-induced ground motion: Implications for coastal Oregon, U.S.

    USGS Publications Warehouse

    Schulz, William H.; Wang, Gonghui

    2014-01-01

    Most large seismogenic landslides are reactivations of preexisting landslides with basal shear zones in the residual strength condition. Residual shear strength often varies during rapid displacement, but the response of residual shear zones to seismic loading is largely unknown. We used a ring shear apparatus to perform simulated seismic loading tests, constant displacement rate tests, and tests during which shear stress was gradually varied on specimens from two landslides to improve understanding of coseismic landslide reactivation and to identify shear strength models valid for slow gravitational failure through rapid coseismic failure. The landslides we studied represent many along the Oregon, U.S., coast. Seismic loading tests resulted in (1) catastrophic failure involving unbounded displacement when stresses represented those for the existing landslides and (2) limited to unbounded displacement when stresses represented those for hypothetical dormant landslides, suggesting that coseismic landslide reactivation may be significant during future great earthquakes occurring near the Oregon Coast. Constant displacement rate tests indicated that shear strength decreased exponentially during the first few decimeters of displacement but increased logarithmically with increasing displacement rate when sheared at 0.001 cm s−1 or greater. Dynamic shear resistance estimated from shear strength models correlated well with stresses observed during seismic loading tests, indicating that displacement rate and amount primarily controlled failure characteristics. We developed a stress-based approach to estimate coseismic landslide displacement that utilizes the variable shear strength model. The approach produced results that compared favorably to observations made during seismic loading tests, indicating its utility for application to landslides.

  18. Quantitative Campylobacter spp., antibiotic resistance genes, and veterinary antibiotics in surface and ground water following manure application: Influence of tile drainage control.

    PubMed

    Frey, Steven K; Topp, Edward; Khan, Izhar U H; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Lapen, David R

    2015-11-01

    This work investigated chlortetracycline, tylosin, and tetracycline (plus transformation products), and DNA-based quantitative Campylobacter spp. and Campylobacter tetracycline antibiotic resistant genes (tet(O)) in tile drainage, groundwater, and soil before and following a liquid swine manure (LSM) application on clay loam plots under controlled (CD) and free (FD) tile drainage. Chlortetracycline/tetracycline was strongly bound to manure solids while tylosin dominated in the liquid portion of manure. The chlortetracycline transformation product isochlortetracycline was the most persistent analyte in water. Rhodamine WT (RWT) tracer was mixed with manure and monitored in tile and groundwater. RWT and veterinary antibiotic (VA) concentrations were strongly correlated in water which supported the use of RWT as a surrogate tracer. While CD reduced tile discharge and eliminated application-induced VA movement (via tile) to surface water, total VA mass loading to surface water was not affected by CD. At both CD and FD test plots, the biggest 'flush' of VA mass and highest VA concentrations occurred in response to precipitation received 2d after application, which strongly influenced the flow abatement capacity of CD on account of highly elevated water levels in field initiating overflow drainage for CD systems (when water level <0.3m below surface). VA concentrations in tile and groundwater became very low within 10d following application. Both Campylobacter spp. and Campylobacter tet(O) genes were present in groundwater and soil prior to application, and increased thereafter. Unlike the VA compounds, Campylobacter spp. and Campylobacter tet(O) gene loadings in tile drainage were reduced by CD, in relation to FD. PMID:26065824

  19. Quantitative Campylobacter spp., antibiotic resistance genes, and veterinary antibiotics in surface and ground water following manure application: Influence of tile drainage control.

    PubMed

    Frey, Steven K; Topp, Edward; Khan, Izhar U H; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Lapen, David R

    2015-11-01

    This work investigated chlortetracycline, tylosin, and tetracycline (plus transformation products), and DNA-based quantitative Campylobacter spp. and Campylobacter tetracycline antibiotic resistant genes (tet(O)) in tile drainage, groundwater, and soil before and following a liquid swine manure (LSM) application on clay loam plots under controlled (CD) and free (FD) tile drainage. Chlortetracycline/tetracycline was strongly bound to manure solids while tylosin dominated in the liquid portion of manure. The chlortetracycline transformation product isochlortetracycline was the most persistent analyte in water. Rhodamine WT (RWT) tracer was mixed with manure and monitored in tile and groundwater. RWT and veterinary antibiotic (VA) concentrations were strongly correlated in water which supported the use of RWT as a surrogate tracer. While CD reduced tile discharge and eliminated application-induced VA movement (via tile) to surface water, total VA mass loading to surface water was not affected by CD. At both CD and FD test plots, the biggest 'flush' of VA mass and highest VA concentrations occurred in response to precipitation received 2d after application, which strongly influenced the flow abatement capacity of CD on account of highly elevated water levels in field initiating overflow drainage for CD systems (when water level <0.3m below surface). VA concentrations in tile and groundwater became very low within 10d following application. Both Campylobacter spp. and Campylobacter tet(O) genes were present in groundwater and soil prior to application, and increased thereafter. Unlike the VA compounds, Campylobacter spp. and Campylobacter tet(O) gene loadings in tile drainage were reduced by CD, in relation to FD.

  20. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  1. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  2. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  3. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  4. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  5. Ground influence on airfoils

    NASA Technical Reports Server (NTRS)

    Raymond, Arthur E

    1921-01-01

    The question of ground influence on airplanes has recently attracted some attention in view of the claims made by certain designers that the landing speed of their airplanes is much decreased by an increase in lift coefficient due to the proximity of the ground in landing. The results of wind tunnel tests indicate that ground effect is not entirely beneficial. It decreases the landing speed and cushions the landing shock somewhat. However, it does so at the expense of an increased length of preliminary skimming over the ground. By decreasing the drag and increasing the lift, it lengthens the distance necessary for the airplane to travel before losing enough speed to land. On the other hand, its influence is helpful in taking off, especially in the case of flying boats with their low-lying wings. In the conventional tractor airplane, the height of the wings above the ground is determined largely by propeller clearance. However, a small low-speed airplane like the Pischoff and large low-speed commercial aircraft with engines between wings can utilize ground influence to good advantage.

  6. Robot locomotion on weak ground

    NASA Astrophysics Data System (ADS)

    Qian, Feifei; Li, Chen; Umbanhowar, Paul; Goldman, Daniel

    2012-11-01

    Natural substrates like sand, soil, and leaf litter vary widely in penetration resistance. Little is known about how animals (and increasingly robots) respond to this variation. To address this deficit, we built an air fluidized bed trackway, in which we control penetration resistance of 1mm granular substrates down to zero by increasing the upward flow rate, Q , to the fluidization transition. Using a 2 . 5 kg bio-inspired hexapedal robot as our model locomotor, we systematically study how locomotion performance (average forward speed, v) varies with penetration resistance, limb kinematics, and foot morphology. Average robot speed decreases with increasing Q, and decreases faster for robots with higher leg frequency or narrower leg width. A previously developed model, which captured the robot's performance on granular media with Q = 0 , also captures the observed performance for weakened states with Q > 0 . A single dimensionless control parameter from the model, which combines gait and ground parameters, determines v for all penetration resistances. Our ground control technique and modeling approach provide a way to probe and understand the limits of locomotor performance on yielding substrates.

  7. Block ground interaction of rockfalls

    NASA Astrophysics Data System (ADS)

    Volkwein, Axel; Gerber, Werner; Kummer, Peter

    2016-04-01

    During a rockfall the interaction of the falling block with the ground is one of the most important factors that define the evolution of a rockfall trajectory. It steers the rebound, the rotational movement, possibly brake effects, friction losses and damping effects. Therefore, if most reliable rockfall /trajectory simulation software is sought a good understanding of the block ground interaction is necessary. Today's rockfall codes enable the simulation of a fully 3D modelled block within a full 3D surface . However, the details during the contact, i.e. the contact duration, the penetration depth or the dimension of the marks in the ground are usually not part of the simulation. Recent field tests with rocks between 20 and 80 kg have been conducted on a grassy slope in 2014 [1]. A special rockfall sensor [2] within the blocks measured the rotational velocity and the acting accelerations during the tests. External video records and a so-called LocalPositioningSystem deliver information on the travel velocity. With these data not only the flight phases of the trajectories but also the contacts with the ground can be analysed. During the single jumps of a block the flight time, jump length, the velocity, and the rotation are known. During the single impacts their duration and the acting accelerations are visible. Further, the changes of rotational and translational velocity influence the next jump of the block. The change of the rotational velocity over the whole trajectory nicely visualizes the different phases of a rockfall regarding general acceleration and deceleration in respect to the inclination and the topography of the field. References: [1] Volkwein A, Krummenacher B, Gerber W, Lardon J, Gees F, Brügger L, Ott T (2015) Repeated controlled rockfall trajectory testing. [Abstract] Geophys. Res. Abstr. 17: EGU2015-9779. [2] Volkwein A, Klette J (2014) Semi-Automatic Determination of Rockfall Trajectories. Sensors 14: 18187-18210.

  8. MTX (Microwave Tokamak Experiment) facility and machine grounding plan

    SciTech Connect

    Bell, H.H.; Rice, B.W.; Petersen, D.E.; Herrera, C.H.

    1987-10-07

    A key issue in the design of fusion research experiments and their related facilities is the control of ground currents. Because of the large magnetic field, high voltages and high currents present in most of these installations, it is essential to avoid ground loops, and to control ground currents during both normal operations and fault conditions. This paper describes the grounding policy that was developed for MTX. The vault area was divided into zones, and each of the four walls was treated as a separate grounding area. Cable runs and magnet buss bars were run into the machine radially. The paper also describes the steps taken to isolate diagnostic signals and power for pumps and instruments. The paper outlines some of the field calculations used to predict problem areas, and to reveal voltage isolation levels that were required. The paper includes the active ground fault detection system used to insure the integrity of the ground system. 2 refs., 5 figs.

  9. Reinventing Grounded Theory: Some Questions about Theory, Ground and Discovery

    ERIC Educational Resources Information Center

    Thomas, Gary; James, David

    2006-01-01

    Grounded theory's popularity persists after three decades of broad-ranging critique. In this article three problematic notions are discussed--"theory," "ground" and "discovery"--which linger in the continuing use and development of grounded theory procedures. It is argued that far from providing the epistemic security promised by grounded theory,…

  10. Pollution of ground water in Europe

    PubMed Central

    Buchan, S.; Key, A.

    1956-01-01

    This paper discusses pollution of ground water in 20 countries of the European region, giving for each an account of the geology and hydrogeology, water supplies, the extent and nature of ground water pollution, and the legal, administrative, and technical means of controlling that pollution. For the countries not considered in the preceding article on surface water pollution, an account is also given of the superficial physical features, rainfall, population, and industries. A general discussion follows of such questions as the ways in which ground water pollution may occur, the factors mitigating or aggravating pollution, and ways of protection against pollution. The authors consider that the problem of ground water pollution in Europe may well be more serious than it would appear to be on the evidence so far obtained. PMID:13374533

  11. Space/ground systems as cooperating agents

    NASA Technical Reports Server (NTRS)

    Grant, T. J.

    1994-01-01

    Within NASA and the European Space Agency (ESA) it is agreed that autonomy is an important goal for the design of future spacecraft and that this requires on-board artificial intelligence. NASA emphasizes deep space and planetary rover missions, while ESA considers on-board autonomy as an enabling technology for missions that must cope with imperfect communications. ESA's attention is on the space/ground system. A major issue is the optimal distribution of intelligent functions within the space/ground system. This paper describes the multi-agent architecture for space/ground systems (MAASGS) which would enable this issue to be investigated. A MAASGS agent may model a complete spacecraft, a spacecraft subsystem or payload, a ground segment, a spacecraft control system, a human operator, or an environment. The MAASGS architecture has evolved through a series of prototypes. The paper recommends that the MAASGS architecture should be implemented in the operational Dutch Utilization Center.

  12. Benchmarking without ground truth

    NASA Astrophysics Data System (ADS)

    Santini, Simone

    2006-01-01

    Many evaluation techniques for content based image retrieval are based on the availability of a ground truth, that is on a "correct" categorization of images so that, say, if the query image is of category A, only the returned images in category A will be considered as "hits." Based on such a ground truth, standard information retrieval measures such as precision and recall and given and used to evaluate and compare retrieval algorithms. Coherently, the assemblers of benchmarking data bases go to a certain length to have their images categorized. The assumption of the existence of a ground truth is, in many respect, naive. It is well known that the categorization of the images depends on the a priori (from the point of view of such categorization) subdivision of the semantic field in which the images are placed (a trivial observation: a plant subdivision for a botanist is very different from that for a layperson). Even within a given semantic field, however, categorization by human subjects is subject to uncertainty, and it makes little statistical sense to consider the categorization given by one person as the unassailable ground truth. In this paper I propose two evaluation techniques that apply to the case in which the ground truth is subject to uncertainty. In this case, obviously, measures such as precision and recall as well will be subject to uncertainty. The paper will explore the relation between the uncertainty in the ground truth and that in the most commonly used evaluation measures, so that the measurements done on a given system can preserve statistical significance.

  13. Monitoring for pesticides in ground water in Nevada

    USGS Publications Warehouse

    Adams, Patricia A.; Moses, Charles W.; Bevans, Hugh E.

    1997-01-01

    Many pesticides designed to control weed encroachment, plant disease, and insect predation are used in agricultural and urban areas in the United States. Contamination of ground water by pesticides has increased over the last 20 years (U.S. Environmental Protection Agency, 1992). In 1985, the U.S. Environmental Protection Agency (USEPA) estimated the detection of at least 17 agricultural pesticides in the ground water of 23 states. By 1988, pesticides identified in ground water had increased to 46 in 26 states. To protect ground water from pesticide contamination, USEPA, through the Federal Fungicide Insecticide and Rodenticide Act (FIFRA), requires all states to institute a ground-water protection program.

  14. Remote Operations and Ground Control Centers

    NASA Technical Reports Server (NTRS)

    Bryant, Barry S.; Lankford, Kimberly; Pitts, R. Lee

    2004-01-01

    The Payload Operations Integration Center (POIC) at the Marshall Space Flight Center supports the International Space Station (ISS) through remote interfaces around the world. The POIC was originally designed as a gateway to space for remote facilities; ranging from an individual user to a full-scale multiuser environment. This achievement was accomplished while meeting program requirements and accommodating the injection of modern technology on an ongoing basis to ensure cost effective operations. This paper will discuss the open POIC architecture developed to support similar and dissimilar remote operations centers. It will include technologies, protocols, and compromises which on a day to day basis support ongoing operations. Additional areas covered include centralized management of shared resources and methods utilized to provide highly available and restricted resources to remote users. Finally, the effort of coordinating the actions of participants will be discussed.

  15. The grounding of temporal metaphors.

    PubMed

    Lai, Vicky T; Desai, Rutvik H

    2016-03-01

    Grounded cognition suggests that the processing of conceptual knowledge cued by language relies on the sensory-motor regions. Does temporal language similarly engage brain areas involved in time perception? Participants read sentences that describe the temporal extent of events with motion verbs (The hours crawled until the release of the news) and their static controls. Comparison conditions were fictive motion (The trail crawled until the end of the hills) and literal motion (The caterpillar crawled towards the top of the tree), along with their static controls. Several time sensitive locations, identified using a meta-analysis, showed activation specific to temporal metaphors, including in the left insula, right claustrum, and bilateral posterior superior temporal sulci. Fictive and literal motion contrasts did not show this difference. Fictive motion contrast showed activation in a conceptual motion sensitive area of the left posterior inferior temporal sulcus (ITS). These data suggest that language of time is at least partially grounded in experiential time. In addition, motion semantics has different consequences for events and objects: temporal events become animate, while static entities become motional. PMID:26854961

  16. Coding Issues in Grounded Theory

    ERIC Educational Resources Information Center

    Moghaddam, Alireza

    2006-01-01

    This paper discusses grounded theory as one of the qualitative research designs. It describes how grounded theory generates from data. Three phases of grounded theory--open coding, axial coding, and selective coding--are discussed, along with some of the issues which are the source of debate among grounded theorists, especially between its…

  17. Shadow of ground zero

    SciTech Connect

    Haaland, C.M.

    1984-01-01

    The history of the development of nuclear weapons starting with the detonation of the A-bombs on Japan is reviewed. An overview of nuclear weapon effects is presented. The effects of electromagnetic pulse (EMP), initial nuclear radiation, thermal radiation and blast are discussed with reference to how people outside can survive when ground zero is only a few miles away. 8 references. (ACR)

  18. Informed Grounded Theory

    ERIC Educational Resources Information Center

    Thornberg, Robert

    2012-01-01

    There is a widespread idea that in grounded theory (GT) research, the researcher has to delay the literature review until the end of the analysis to avoid contamination--a dictum that might turn educational researchers away from GT. Nevertheless, in this article the author (a) problematizes the dictum of delaying a literature review in classic…

  19. Echoes at Ground Zero

    ERIC Educational Resources Information Center

    Chronicle of Higher Education, 2006

    2006-01-01

    An excerpt from the opening piece in "Everything That Rises: A Book of Convergences" by Lawrence Weschler is presented where the author is talking with Joel Meyerowitz, the only photographer granted unimpeded access to the clean-up operations at ground zero after the terrorist attacks of September 11, 2001. The two discuss the parallels between…

  20. Korea's School Grounds Projects

    ERIC Educational Resources Information Center

    Park, Joohun

    2003-01-01

    This article describes two projects which Korea has undertaken to improve its school grounds: (1) the Green School Project; and (2) the School Forest Pilot Project. The Korean Ministry of Education and Human Resources Development (MOE&HRI) recently launched the Green School Project centred on existing urban schools with poor outdoor environments.…

  1. Four frequency ground scatterometer

    NASA Technical Reports Server (NTRS)

    Dickerson, E. T.

    1982-01-01

    The FM-CW Radar, used as a microwave scatterometer is described. Scatterometer system design, scatterometer system calibration, parameter calculation and correction for data acquisition, ground scatterometer data acquistion at Jornada Experimental Range, and Kansas radar cross-calibration test are discussed.

  2. Technology at Ground Zero.

    ERIC Educational Resources Information Center

    Techniques: Connecting Education and Careers, 2002

    2002-01-01

    Describes the robots used to aid in rescue and recovery at Ground Zero after the September 11, 2001 attack on the World Trade Center. The robots were developed as a result of national Science Foundation Quick Response Research Awards. Describes several awards that were made following the attack. (JOW)

  3. Horticulture: Grounds Maintenance Employee.

    ERIC Educational Resources Information Center

    Sims, James; And Others

    The unit of individualized learning activities is designed to provide training in grounds maintenance. The materials in the unit are divided into two sections. The developmental or preliminary phase (15 pages) is for use by the instructor and includes brief descriptions of the job and of the student population, along with listings of the specific…

  4. Grounding in Instant Messaging

    ERIC Educational Resources Information Center

    Fox Tree, Jean E.; Mayer, Sarah A.; Betts, Teresa E.

    2011-01-01

    In two experiments, we investigated predictions of the "collaborative theory of language use" (Clark, 1996) as applied to instant messaging (IM). This theory describes how the presence and absence of different grounding constraints causes people to interact differently across different communicative media (Clark & Brennan, 1991). In Study 1, we…

  5. Ground-coupled heat pump demonstration

    NASA Astrophysics Data System (ADS)

    Oconnell, T.

    1983-09-01

    The results of a field evaluation of an innovative ground-coupled heat pump system which features a unique collector design and system control strategy aimed at maximizing heat pump performance by minimizing ground temperature change is discussed. The collector design includes several short closed loops, each consisting of a pair of polyethylene pipes buried 12 to 18 inches apart in a horizontal trench approximately six feet below ground. A micropressor is used to control flow and optimize system operation. Extrapolation of the results of experiments conducted on a unit length (250 ft.) of collector field during the 1981-82 and 1982-83 heating seasons indicates that a system seasonal performance factor of 2.75 to 3.0 will be achievable in practice.

  6. Ground-coupled heat pump demonstration

    SciTech Connect

    O'Connell, T.

    1983-09-01

    This report presents the results of a field evaluation of an innovative ground-coupled heat pump system which features a unique collector design and system control strategy aimed at maximizing heat pump performance by minimizing ground temperature change. The collector design includes several short closed loops, each consisting of a pair of polyethylene pipes buried 12 to 18 inches apart in a horizontal trench approximately six feet below ground. A micropressor is used to control flow and optimize system operation. Extrapolation of the results of experiments conducted on a unit length (250 ft.) of collector field during the 1981-82 and 1982-83 heating seasons indicates that a system seasonal performance factor of 2.75 to 3.0 will be achievable in practice.

  7. Ground Energy Balance For Shallow Geothermal Systems

    NASA Astrophysics Data System (ADS)

    Bayer, P.; Rivera, J.

    2015-12-01

    Vertical borehole heat exchangers (BHE) represent the most common applications by far in the field of shallow geothermal energy. They are typically operated for decades for energy extraction from the top 400 m of the subsurface. During this lifetime, thermal anomalies are generated in the ground and surface-near aquifers. These anomalies often grow over the years and compromise the overall performance of the geothermal system. As a basis for prediction and control of the developing energy imbalance in the ground, the focus is often set on the ground temperatures. This is reflected, for instance, in regulative temperature thresholds. As an alternative to temperature, we examine the temporal and spatial variability of heat fluxes and power sources during geothermal heat pump operation. The underlying idea is that knowledge of the primary heat sources is fundamental for the control of ground temperature evolution. For analysis of heat fluxes, an analytical framework for BHE simulation based on Kelvin's line source is re-formulated. This is applied to a synthetic study and for modelling a long-term application in the field. Our results show that during early operation phase, energy is extracted mainly from the underground. Local depletion at the borehole enhances the vertical fluxes with the relative contribution from the bottom reaching a limit of 24 % of the total power demand. The relative contribution from the ground surface becomes dominant for Fourier numbers larger than 0.13. For the full life cycle, vertical heat flux from the ground surface dominates the basal heat flux towards the BHE and it provides about two thirds of the demanded power. Finally, we reveal that the time for ground energy recovery after BHE shutdown may be longer than what is expected from simulated temperature trends.

  8. Multimission unattended ground sensor

    NASA Astrophysics Data System (ADS)

    Prado, Gervasio; Succi, George P.; Fitzgerald, James; Clapp, Daniel; Gampert, Robert; Martel, Philip O.

    2002-08-01

    Technological advances in a number of fields have allowed SenTech to develop a highly capable Unattended Ground Sensor (UGS) able to perform a number of critical missions such as ground and air vehicle surveillance, personnel detection and tracking and sniper localization. These sensors have also been combined with electro-optic sensors to provide target images and improved tracking accuracy. Processing is done in a highly integrated processing module developed under DARPA's IUGS program. Acoustic sensors have been engineered to achieve a three-pound unit with a 15 day field life and long range VHF communications. These sensors will be delivered in early 2002 for testing during field exercises. Extensive testing of the algorithms and software has been conducted over the last few years at a variety of government-sponsored tests and demonstrations. A Gateway unit has been developed which can manage the operation of an eight-sensor field and perform two-dimensional sensor fusion.

  9. Effects of thrust reversing in ground proximity

    NASA Technical Reports Server (NTRS)

    Joshi, P. B.; Hughes, R. V.

    1987-01-01

    The changes in stability and control characteristics encountered by a thrust reversing aircraft during its final approach, landing, and ground roll are described. These changes include a strong pitch-up accompanied by the loss of horizontal tail and aileron control effectiveness. The magnitude of reverser induced changes in ground effect are much larger than corresponding changes in free air. Some unexpected unsteady motions exhibited in wind tunnel by an aircraft model with reversers operating in ground proximity are also described. The cause of this oscillatory behavior was determined to be an unsteady interaction between the wall jets formed by impingement of reverser jets on the ground and the on-coming free stream. Time histories of rolling moments measured by the wind tunnel balance or support system were removed and frequencies were scaled by Strouhal number to full scale. Corrected time series were used to simulate the motion of a fighter aircraft with thrust reversers in ground effect. The simulation predicted large roll angles and nose down attitude at touchdown. Some phenomena of jet attachment to solid surfaces are discussed and areas for future research are recommended.

  10. Longevity of Emplacement Drift Ground Support Materials

    SciTech Connect

    D. Tang

    2000-01-07

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for selection of materials for ground support that will function throughout the preclosure period. The Development Plan (DP) for this analysis is given in CRWMS M&O (Civilian Radioactive Waste Management System Management and Operating Contractor) (1999a). The candidate materials for ground support are steel (carbon steel, ductile cast iron, galvanized steel, and stainless steel, etc.) and cement. Steel will mainly be used for steel sets, lagging, channels, rock bolts, and wire mesh. Cement usage is only considered in the case of grouted rock bolts. The candidate materials for the invert structure are steel and crushed rock ballast. The materials shall be evaluated for the repository emplacement drift environment under a specific thermal loading condition based on the proposed License Application Design Selection (LADS) design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground control materials for use in emplacement drifts. (2) Review existing documents concerning behavior of candidate ground control materials during the preclosure period. The major criteria to be considered for steel are mechanical and thermal properties, and durability, of which corrosion is the most important concern. (3) Evaluate the available results and develop recommendations for material(s) to be used.

  11. Goddard Ground System Environment

    NASA Technical Reports Server (NTRS)

    Liu, Ben

    2009-01-01

    This slide presentation reviews the Goddard Mission Services Evolution Center's work in providing the Ground System Infrastructure to allow for standard interfaces, and allow for a mix of heritage and new components. This software has been used by NASA and other Government users. Telemetry and command services are also provided as are mission planning and scheduling systems. Other areas that the presentation covers are work on trending systems, and data management system.

  12. 50. Ground floor, looking northwest at former location of ground ...

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

    50. Ground floor, looking northwest at former location of ground floor (bottom) level of milk room - Sheffield Farms Milk Plant, 1075 Webster Avenue (southwest corner of 166th Street), Bronx, Bronx County, NY

  13. Loma Prieta damage largely attributed to enhanced ground shaking

    USGS Publications Warehouse

    Holzer, T.L.

    1994-01-01

    Approximately 98% of the $5.9 billion in property damage from the 1989 Loma Prieta earthquake was caused directly by ground shaking; enhanced ground shaking was directly responsible for approximately two-thirds, $4.1 billion, of the total property loss. These observations indicate that we must understand local controls of shaking and enhancement, not just local sources of shaking. Earthquake hazard reduction efforts in the United States would benefit from improved understanding of phenomena that enhance ground shaking. -from Author

  14. Chapter IV - Safety During Payload Ground Processing

    NASA Technical Reports Server (NTRS)

    Kirkpatrick, Paul; Dollberg, John; Trinchero, Jean-Pierre

    2012-01-01

    This chapter describes the typical hazards that can be expected to be encountered when processing payloads on the ground. Also described are some of the more common controls for these hazards. Many of these controls are based on hard requirements but they are also based on specific lessons learned. This chapter uses the term Flight Hardware (F/H) for all payloads regardless of size.

  15. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must be... 46 Shipping 4 2011-10-01 2011-10-01 false Grounded distribution systems (Neutral grounded)....

  16. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must be... 46 Shipping 4 2012-10-01 2012-10-01 false Grounded distribution systems (Neutral grounded)....

  17. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must be... 46 Shipping 4 2014-10-01 2014-10-01 false Grounded distribution systems (Neutral grounded)....

  18. Modular approach for satellite communication ground terminals

    NASA Astrophysics Data System (ADS)

    Gould, G. R.

    Attention is given to a novel approach to the design and construction of ground terminals which encompasses a programmable timing generation concept, a flexible memory unit design, and variable speed serial-parallel/parallel-serial converters that will meet the various ground terminal operational requirements. These requirements include coherent phase shift and trunking terminals, and may be expanded to incorporate Demand Assignment Multiple Access and Network Control. Other design approaches are examined which employ single function, fixed timing subassemblies dedicated to the execution of specific functions. The use of multifunction units is, however, more cost effective from the viewpoints of production and maintainability.

  19. Ground based automated telescope

    SciTech Connect

    Colgate, S.A.; Thompson, W.

    1980-01-01

    Recommendation that a ground-based automated telescope of the 2-meter class be built for remote multiuser use as a natural facility. Experience dictates that a primary consideration is a time shared multitasking operating system with virtual memory overlayed with a real time priority interrupt. The primary user facility is a remote terminal networked to the single computer. Many users must have simultaneous time shared access to the computer for program development. The telescope should be rapid slewing, and hence a light weight construction. Automation allows for the closed loop pointing error correction independent of extreme accuracy of the mount.

  20. GRC Ground Support Facilities

    NASA Technical Reports Server (NTRS)

    SaintOnge, Thomas H.

    2010-01-01

    The ISS Program is conducting an "ISS Research Academy' at JSC the first week of August 2010. This Academy will be a tutorial for new Users of the International Space Station, focused primarily on the new ISS National Laboratory and its members including Non-Profit Organizations, other government agencies and commercial users. Presentations on the on-orbit research facilities accommodations and capabilities will be made, as well as ground based hardware development, integration and test facilities and capabilities. This presentation describes the GRC Hardware development, test and laboratory facilities.

  1. Predicting Ground Illuminance

    NASA Astrophysics Data System (ADS)

    Lesniak, Michael V.; Tregoning, Brett D.; Hitchens, Alexandra E.

    2015-01-01

    Our Sun outputs 3.85 x 1026 W of radiation, of which roughly 37% is in the visible band. It is directly responsible for nearly all natural illuminance experienced on Earth's surface, either in the form of direct/refracted sunlight or in reflected light bouncing off the surfaces and/or atmospheres of our Moon and the visible planets. Ground illuminance, defined as the amount of visible light intercepting a unit area of surface (from all incident angles), varies over 7 orders of magnitude from day to night. It is highly dependent on well-modeled factors such as the relative positions of the Sun, Earth, and Moon. It is also dependent on less predictable factors such as local atmospheric conditions and weather.Several models have been proposed to predict ground illuminance, including Brown (1952) and Shapiro (1982, 1987). The Brown model is a set of empirical data collected from observation points around the world that has been reduced to a smooth fit of illuminance against a single variable, solar altitude. It provides limited applicability to the Moon and for cloudy conditions via multiplicative reduction factors. The Shapiro model is a theoretical model that treats the atmosphere as a three layer system of light reflectance and transmittance. It has different sets of reflectance and transmittance coefficients for various cloud types.In this paper we compare the models' predictions to ground illuminance data from an observing run at the White Sands missile range (data was obtained from the United Kingdom's Meteorology Office). Continuous illuminance readings were recorded under various cloud conditions, during both daytime and nighttime hours. We find that under clear skies, the Shapiro model tends to better fit the observations during daytime hours with typical discrepancies under 10%. Under cloudy skies, both models tend to poorly predict ground illuminance. However, the Shapiro model, with typical average daytime discrepancies of 25% or less in many cases

  2. 30 CFR 57.3401 - Examination of ground conditions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... warrant during the work shift. Underground haulageways and travelways and surface area highwalls and banks... Control Precautions-Surface and Underground § 57.3401 Examination of ground conditions. Persons... supervisors or other designated persons shall examine and, where applicable, test ground conditions in...

  3. 30 CFR 57.3401 - Examination of ground conditions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... warrant during the work shift. Underground haulageways and travelways and surface area highwalls and banks... Control Precautions-Surface and Underground § 57.3401 Examination of ground conditions. Persons... supervisors or other designated persons shall examine and, where applicable, test ground conditions in...

  4. 30 CFR 57.3401 - Examination of ground conditions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Examination of ground conditions. 57.3401 Section 57.3401 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ground Control Precautions-Surface and Underground §...

  5. Procedures for ground-water investigations. Revision 1

    SciTech Connect

    Not Available

    1992-12-01

    This manual was developed by the Pacific Northwest Laboratory (PNL) to document the procedures used to carry out and control the technical aspects of ground-water investigations at the PNL. Ground-water monitoring procedures are developed and used in accordance with the PNL Quality Assurance Program.

  6. 30 CFR 57.3360 - Ground support use.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ground support use. 57.3360 Section 57.3360 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ground Control...

  7. Ground based infrared astronomy

    NASA Technical Reports Server (NTRS)

    Jennings, D. E.

    1988-01-01

    Infrared spectroscopic instrumentation has been developed for ground-based measurements of astrophysical objects in the intermediate infrared. A conventional Michelson interferometer is limited for astronomical applications in the intermediate infrared by quantum noise fluctuations in the radiation form the source and/or background incident on the detector, and the multiplex advantage is no longer available. One feasible approach to recovering the multiplex advantage is post-dispersion. The infrared signal after passing through telescope and interferometer, is dispersed by a low resolution grating spectrometer onto an array of detectors. The feasibility of the post-dispersion system has been demonstrated with observations of astrophysical objects in the 5 and 10 micrometer atmospheric windows from ground-based telescopes. During FY87/88 the post-disperser was used at the Kitt Peak 4-meter telescope and McMath telescope with facility Fourier transform spectrometers. Jupiter, Saturn, Mars, and Venus were observed. On Jupiter, the resolution at 12 micrometer was 0.01/cm, considerably higher than had been acheived previously. The spectrum contains Jovian ethane and acetylene emission. Construction was begun on the large cryogenic grating spectrometer.

  8. A thermal ground cloak

    NASA Astrophysics Data System (ADS)

    Yang, Tianzhi; Wu, Qinghe; Xu, Weikai; Liu, Di; Huang, Lujun; Chen, Fei

    2016-02-01

    The thermal cloak has been a long-standing scientific dream of researchers and engineers. Recently thermal metamaterials with man-made micro-structure have been presented based on the principle of transformation optics (TO). This new concept has received considerable attention, which is a powerful tool for manipulating heat flux in thermal imaging systems. However, the inherent material singularity has long been a captivation of experimental realization. As an alternative method, the scattering-cancellation-based cloak (or bi-layer thermal cloak) has been presented to remove the singularity for achieving the same cloaking performance. Nevertheless, such strategy needs prerequisite knowledge (geometry and conductivity) of the object to be cloaked. In this paper, a new thermal ground cloak is presented to overcome the limitations. The device is designed, fabricated and measured to verify the thermal cloaking performance. We experimentally show that the remarkably low complexity of the device can fully and effectively be manipulated using realizable transformation thermal devices. More importantly, this thermal ground cloak is designed to exclude heat flux without knowing the information of the cloaked object.

  9. Death of american ground sloths.

    PubMed

    Long, A; Martin, P S

    1974-11-15

    Organic remains, especially dung, of extinct ground sloths provide ideal material for radiocarbon dating. Rampart Cave, Arizona, revealed periodic occupation at intervals by the Shasta ground sloth from before 40,000 years ago until 11,000 years ago. Dates from other caves in the arid Southwest indicate that the Shasta ground sloth disappeared at very soon after the time of Clovis big game hunters. Ground sloth remains in South America are slightly younger. The timing of ground sloth extinction is in accord with the model of explosive overkill.

  10. 40 CFR 144.87 - How does the identification of ground water protection areas and other sensitive ground water...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false How does the identification of ground water protection areas and other sensitive ground water areas affect me? 144.87 Section 144.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) UNDERGROUND INJECTION CONTROL PROGRAM Requirements...

  11. Land subsidence caused by ground water withdrawal in urban areas

    USGS Publications Warehouse

    Holzer, T.L.; Johnson, A.I.

    1985-01-01

    At least eight urban areas in the world have encountered significant economic impact from land subsidence caused by pumping of ground water from unconsolidated sediment. The areas, most of which are coastal, include Bangkok, Houston, Mexico City, Osaka, San Jose, Shanghai, Tokyo, and Venice. Flooding related to decreased ground elevation is the principal adverse effect of the subsidence. Lesser effects include regional tilting, well-casing failures, "rising" buildings, and ground failure or rupture. Subsidence of most of these urban areas began before the phenomenon was discovered and understood. Thus, the subsidence problems were unanticipated. Methods to arrest subsidence typically have included control of ground water pumping and development of surface water to offset the reductions of ground water pumping. Ground water recharge has also been practiced. Areas threatened by flooding have been protected by extensive networks of dikes and sea walls, locks, and pumping stations to remove storm runoff. ?? 1985 D. Reidel Publishing Company.

  12. Predicting Ground Illuminance

    NASA Astrophysics Data System (ADS)

    Lesniak, Michael V.

    2014-01-01

    Our Sun outputs 3.85 × 1026 W of radiation, of which ≈37% is in the visible band. It is directly responsible for nearly all natural illuminance experienced on Earth's surface, either in the form of direct/refracted sunlight or in reflected light bouncing off the surfaces and/or atmospheres of our Moon and the visible planets. Ground illuminance, defined as the amount of visible light intercepting a unit area of surface (from all incident angles), varies over 7 orders of magnitude from day to night. It is highly dependent on well-modeled factors such as the relative positions of the Sun, Earth, and Moon. It is also dependent on less predictable factors such as local atmospheric conditions and weather. Several models have been proposed to predict ground illuminance, including Brown (1952) and Shapiro (1982, 1987). The Brown model is a set of empirical data collected from observation points around the world that has been reduced to a smooth fit of illuminance against a single variable, solar altitude. It provides limited applicability to the Moon and for cloudy conditions via multiplicative reduction factors. The Shapiro model is a theoretical model that treats the atmosphere as a three layer system of light reflectance and transmittance. It has different sets of reflectance and transmittance coefficients for various cloud types. Ground illuminance data from an observing run at the White Sands missile range were obtained from the United Kingdom Meteorology Office. Based on available weather reports, five days of clear sky observations were selected. These data are compared to the predictions of the two models. We find that neither of the models provide an accurate treatment during twilight conditions when the Sun is at or a few degrees below the horizon. When the Sun is above the horizon, the Shapiro model straddles the observed data, ranging between 90% and 120% of the recorded illuminance. During the same times, the Brown model is between 70% and 90% of the

  13. Automated Ground Umbilical Systems (AGUS) Project

    NASA Technical Reports Server (NTRS)

    Gosselin, Armand M.

    2007-01-01

    All space vehicles require ground umbilical systems for servicing. Servicing requirements can include, but are not limited to, electrical power and control, propellant loading and venting, pneumatic system supply, hazard gas detection and purging as well as systems checkout capabilities. Of the various types of umbilicals, all require several common subsystems. These typically include an alignment system, mating and locking system, fluid connectors, electrical connectors and control !checkout systems. These systems have been designed to various levels of detail based on the needs for manual and/or automation requirements. The Automated Ground Umbilical Systems (AGUS) project is a multi-phase initiative to develop design performance requirements and concepts for launch system umbilicals. The automation aspect minimizes operational time and labor in ground umbilical processing while maintaining reliability. This current phase of the project reviews the design, development, testing and operations of ground umbilicals built for the Saturn, Shuttle, X-33 and Atlas V programs. Based on the design and operations lessons learned from these systems, umbilicals can be optimized for specific applications. The product of this study is a document containing details of existing systems and requirements for future automated umbilical systems with emphasis on design-for-operations (DFO).

  14. 30 CFR 57.3401 - Examination of ground conditions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... warrant during the work shift. Underground haulageways and travelways and surface area highwalls and banks... Control Precautions-Surface and Underground § 57.3401 Examination of ground conditions. Persons.... Precautions—Surface Only...

  15. 30 CFR 57.3401 - Examination of ground conditions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... warrant during the work shift. Underground haulageways and travelways and surface area highwalls and banks... Control Precautions-Surface and Underground § 57.3401 Examination of ground conditions. Persons.... Precautions—Surface Only...

  16. Ground potential rise monitor

    SciTech Connect

    Allen, Zachery W.; Zevenbergen, Gary A.

    2012-04-03

    A device and method for detecting ground potential rise (GPR) comprising positioning a first electrode and a second electrode at a distance from each other into the earth. The voltage of the first electrode and second electrode is attenuated by an attenuation factor creating an attenuated voltage. The true RMS voltage of the attenuated voltage is determined creating an attenuated true RMS voltage. The attenuated true RMS voltage is then multiplied by the attenuation factor creating a calculated true RMS voltage. If the calculated true RMS voltage is greater than a first predetermined voltage threshold, a first alarm is enabled at a local location. If user input is received at a remote location acknowledging the first alarm, a first alarm acknowledgment signal is transmitted. The first alarm acknowledgment signal is then received at which time the first alarm is disabled.

  17. Economical ground data delivery

    NASA Technical Reports Server (NTRS)

    Markley, Richard W.; Byrne, Russell H.; Bromberg, Daniel E.

    1994-01-01

    Data delivery in the Deep Space Network (DSN) involves transmission of a small amount of constant, high-priority traffic and a large amount of bursty, low priority data. The bursty traffic may be initially buffered and then metered back slowly as bandwidth becomes available. Today both types of data are transmitted over dedicated leased circuits. The authors investigated the potential of saving money by designing a hybrid communications architecture that uses leased circuits for high-priority network communications and dial-up circuits for low-priority traffic. Such an architecture may significantly reduce costs and provide an emergency backup. The architecture presented here may also be applied to any ground station-to-customer network within the range of a common carrier. The authors compare estimated costs for various scenarios and suggest security safeguards that should be considered.

  18. Multiscale ground aurora observations

    NASA Astrophysics Data System (ADS)

    Kozelov, Boris

    Aurora is the most impressive phenomenon that initially motivates people's interest in the study of near-Earth space. Now auroral observations provide unique information about the processes occurring in the magnetosphere-ionosphere plasma: this is the only type of observations that gives detailed two-dimensional spatial distribution with sufficient temporal resolution. Fractal power-law distributions that are typical for aurora indicate the passing transients in near-Earth plasma. Spatio-temporal dynamics of active auroral forms on the night side is showing signs of turbulence and self-organized criticality at huge range of scales. Pulsing auroral forms are usually associated with the wave-particle interaction. The report describes the current state of the ground-based optical observations of aurorae at different scales and methods of analysis of their results.

  19. Ground-penetrating rada

    NASA Astrophysics Data System (ADS)

    Thuma, W. R.

    The theory and applications of digital Ground-Penetrating Radar were discussed at a 5-day seminar held at the China University of Geosciences in Wuhan, People's Republic of China, in April. Cohosted by the Department of Applied Geophysics and Canada-China Geoscience, more than 60 senior geophysicists, engineers, technical specialists, university professors and researchers attended.Focus of the meeting was the expanded uses of the new deep-penetrating fully digital PulseEKKO, which is gaining wide acceptance around the world. Attendees showed intense interest in this new and unique technology. Applications covered were groundwater and mineral exploration; engineering, construction and toxic waste site surveying; tunnel and underground mine probing for potential geological hazards, blind ore zones, karst cavities and solution pathways; and locating buried objects such as petroleum storage tanks, unexploded bombs and archeological remains.

  20. 2011 Ground Testing Highlights Article

    NASA Technical Reports Server (NTRS)

    Ross, James C.; Buchholz, Steven J.

    2011-01-01

    Two tests supporting development of the launch abort system for the Orion MultiPurpose Crew Vehicle were run in the NASA Ames Unitary Plan wind tunnel last year. The first test used a fully metric model to examine the stability and controllability of the Launch Abort Vehicle during potential abort scenarios for Mach numbers ranging from 0.3 to 2.5. The aerodynamic effects of the Abort Motor and Attitude Control Motor plumes were simulated using high-pressure air flowing through independent paths. The aerodynamic effects of the proximity to the launch vehicle during the early moments of an abort were simulated with a remotely actuated Service Module that allowed the position relative to the Crew Module to be varied appropriately. The second test simulated the acoustic environment around the Launch Abort Vehicle caused by the plumes from the 400,000-pound thrust, solid-fueled Abort Motor. To obtain the proper acoustic characteristics of the hot rocket plumes for the flight vehicle, heated Helium was used. A custom Helium supply system was developed for the test consisting of 2 jumbo high-pressure Helium trailers, a twelve-tube accumulator, and a 13MW gas-fired heater borrowed from the Propulsion Simulation Laboratory at NASA Glenn Research Center. The test provided fluctuating surface pressure measurements at over 200 points on the vehicle surface that have now been used to define the ground-testing requirements for the Orion Launch Abort Vehicle.

  1. Features of the Deployed NPOESS Ground System

    NASA Astrophysics Data System (ADS)

    Smith, D.; Grant, K. D.; Route, G.; Heckmann, G.

    2009-12-01

    NOAA, DoD, and NASA are jointly acquiring the National Polar-orbiting Operational Environmental Satellite System (NPOESS) replacing the current NOAA Polar-orbiting Operational Environmental Satellites (POES) and the DoD's Defense Meteorological Satellite Program (DMSP). The NPOESS satellites will carry a suite of sensors to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere and space. The ground data processing segment is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence & Information Systems (IIS). The IDPS processes NPOESS satellite data to provide environmental data products (aka, Environmental Data Records or EDRs) to US NOAA and DoD processing centers. The IDPS will process EDRs beginning with the NPOESS Preparatory Project (NPP) and through the lifetime of the NPOESS system. The command and telemetry segment is the Command, Control and Communications Segment (C3S), also developed by Raytheon IIS. C3S is responsible for managing the overall NPOESS mission from control and status of the space and ground assets to ensuring delivery of timely, high quality data from the Space Segment (SS) to IDPS for processing. In addition, the C3S provides the globally distributed ground assets necessary to collect and transport mission, telemetry, and command data between the satellites and the processing locations. The C3S provides all functions required for day-to-day commanding and state-of-health monitoring of the NPP and NPOESS satellites, and delivery of SMD to each Central IDP for data products development and transfer to System subscribers. The C3S also monitors and reports system-wide health, status and data communications with external systems and between the NPOESS segments. The NPOESS C3S and IDPS ground segments have been delivered and transitioned to operations for NPP. C3S was transitioned to operations at the NOAA Satellite Operations Facility in Suitland MD in August

  2. Integrated Ground Operations Demonstration Units Testing Plans and Status

    NASA Technical Reports Server (NTRS)

    Johnson, Robert G.; Notardonato, William U.; Currin, Kelly M.; Orozco-Smith, Evelyn M.

    2012-01-01

    Cryogenic propellant loading operations with their associated flight and ground systems are some of the most complex, critical activities in launch operations. Consequently, these systems and operations account for a sizeable portion of the life cycle costs of any launch program. NASA operations for handling cryogens in ground support equipment have not changed substantially in 50 years, despite advances in cryogenics, system health management and command and control technologies. This project was developed to mature, integrate and demonstrate advancement in the current state of the art in these areas using two distinct integrated ground operations demonstration units (GODU): GODU Integrated Refrigeration and Storage (IRAS) and GODU Autonomous Control

  3. Burial Ground Expansion Hydrogeologic Characterization

    SciTech Connect

    Gaughan , T.F.

    1999-02-26

    Sirrine Environmental Consultants provided technical oversight of the installation of eighteen groundwater monitoring wells and six exploratory borings around the location of the Burial Ground Expansion.

  4. Earthquake ground motion: Chapter 3

    USGS Publications Warehouse

    Luco, Nicolas; Valley, Michael; Crouse, C.B.

    2012-01-01

    Most of the effort in seismic design of buildings and other structures is focused on structural design. This chapter addresses another key aspect of the design process—characterization of earthquake ground motion. Section 3.1 describes the basis of the earthquake ground motion maps in the Provisions and in ASCE 7. Section 3.2 has examples for the determination of ground motion parameters and spectra for use in design. Section 3.3 discusses and provides an example for the selection and scaling of ground motion records for use in response history analysis.

  5. 14 CFR 25.415 - Ground gust conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.415 Ground gust conditions. (a) The control system must be designed as follows for control surface loads due to... surface horns, must be designed for limit hinge moments H, in foot pounds, obtained from the formula,...

  6. 14 CFR 23.415 - Ground gust conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Control Surface... follows for control surface loads due to ground gusts and taxiing downwind: (1) If an investigation of the... from control surface horns through the nearest stops or gust locks and their supporting structures....

  7. 14 CFR 25.415 - Ground gust conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.415 Ground gust conditions. (a) The control system must be designed as follows for control surface loads due to... surface horns, must be designed for limit hinge moments H, in foot pounds, obtained from the formula,...

  8. 14 CFR 25.415 - Ground gust conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.415 Ground gust conditions. (a) The control system must be designed as follows for control surface loads due to... surface horns, must be designed for limit hinge moments H, in foot pounds, obtained from the formula,...

  9. SUPERFUND GROUND WATER ISSUE: GROUND WATER SAMPLING FOR METALS ANALYSES

    EPA Science Inventory

    Filtration of ground-water samples for metals analysis is an issue identified by the Forum as a concern of Superfund decision-makers. Inconsistency in EPA Syperfund cleanup pracices occurs where one EPA Region implements a remedial action based on unfiltered ground-water samples,...

  10. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.376... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... 46 Shipping 7 2013-10-01 2013-10-01 false Grounded distribution systems (neutral grounded)....

  11. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.376... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... 46 Shipping 7 2011-10-01 2011-10-01 false Grounded distribution systems (neutral grounded)....

  12. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... 46 Shipping 7 2014-10-01 2014-10-01 false Grounded distribution systems (neutral grounded). 183... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems §...

  13. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... 46 Shipping 7 2012-10-01 2012-10-01 false Grounded distribution systems (neutral grounded). 183... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems §...

  14. 46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 120.376 Grounded distribution systems... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each... generator is connected to the bus, except the neutral of an emergency power generation system must...

  15. Study of the deformation mechanism of the Gaoliying ground fissure

    NASA Astrophysics Data System (ADS)

    Cheng, G.; Wang, H.; Luo, Y.; Guo, H.

    2015-11-01

    The Gaoliying ground fissure in Beijing has caused building cracking and road damage, and has seriously influenced city construction. Based on investigations and trenching, the influences of the fault and the variation of groundwater levels on the formation mechanism of the Gaoliying ground fissure were investigated by using FLAC3D. The results indicated that (1) the surface location of Gaoliying fissure is controlled by the underlying normal fault activity, and over pumping further exacerbates development of the ground fissure; (2) when the groundwater level declines, obvious differential settlement occurs at both sides of the ground fissure, in which greater settlement occurs in the vicinity of the hanging wall, the greater the distance from the hanging wall, the smaller the ground subsidence, however smaller ground subsidence occurs in the vicinity of the footwall, the greater the distance from the footwall, the greater the ground subsidence; (3) the vertical velocity of the ground fissure triggered by the fault activity and groundwater decline ranges from 15.5 to 18.3 mm a-1, which is basically in line with the monitoring data. The fault activity contributes about 28-39 %, and the groundwater contributes about 61-72 % to the deformation of the ground fissure, respectively.

  16. Acoustic ground impedance meter

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J.

    1981-01-01

    A compact, portable instrument was developed to measure the acoustic impedance of the ground, or other surfaces, by direct pressure-volume velocity measurement. A Helmholz resonator, constructed of heavy-walled stainless steel but open at the bottom, is positioned over the surface having the unknown impedance. The sound source, a cam-driven piston of known stroke and thus known volume velocity, is located in the neck of the resonator. The cam speed is a variable up to a maximum 3600 rpm. The sound pressure at the test surface is measured by means of a microphone flush-mounted in the wall of the chamber. An optical monitor of the piston displacement permits measurement of the phase angle between the volume velocity and the sound pressure, from which the real and imaginary parts of the impedance can be evaluated. Measurements using a 5-lobed cam can be made up to 300 Hz. Detailed design criteria and results on a soil sample are presented.

  17. Getting grounded: using Glaserian grounded theory to conduct nursing research.

    PubMed

    Hernandez, Cheri Ann

    2010-03-01

    Glaserian grounded theory is a powerful research methodology for understanding client behaviour in a particular area. It is therefore especially relevant for nurse researchers. Nurse researchers use grounded theory more frequently than other qualitative analysis research methods because of its ability to provide insight into clients' experiences and to make a positive impact. However, there is much confusion about the use of grounded theory.The author delineates key components of grounded theory methodology, areas of concern, and the resulting implications for nursing knowledge development. Knowledge gained from Glaserian grounded theory research can be used to institute measures for enhancing client-nurse relationships, improving quality of care, and ultimately improving client quality of life. In addition, it can serve to expand disciplinary knowledge in nursing because the resulting substantive theory is a middle-range theory that can be subjected to later quantitative testing.

  18. Operational Considerations when Designing New Ground Systems

    NASA Technical Reports Server (NTRS)

    Walyus, Keith; Barbahenn, George; Crabb, William; Miebach, Manfred; Pataro, Peter

    2000-01-01

    The Hubble Space Telescope (HST) launched in April of 1991 with a nominal 15-year old mission. Since then, the HST mission life has been extended to 2010. As is true for all NASA missions, HST is being asked to decrease its operational costs for the remainder of its mission life. Various techniques are being incorporated for cost reductions, with one of the core means being the design of a new and more efficient ground system for HST operations. This new ground system, "Vision 2000", will reduce operational and maintenance costs and also provide the HST Project with added flexibility to react to future changes. Vision 2000 began supporting HST Operations in January of 1999 and will support the mission for the remainder of the mission life. Upgrading a satellite's ground system is a popular approach for reducing costs, but it is also inherently risky. Validating a new ground system can be a severe distraction to a flight team while operating a satellite. Mission data collection and health and safety requirements are rarely, if ever, relaxed during this validation period, forcing flight teams to undertake an additional task while operating the satellite. Additionally, flight teams must usually undergo extensive training to effectively utilize the new system. Once again, this training usually occurs as an additional task, in addition to the nominal satellite operations. While operating the spacecraft, the Flight Team typically assists in the design, validation, and verification of a new ground system. This is a distraction and strain on the Flight Team, but the benefit of using the Flight Team in all phases of ground system development far outweigh the negative aspects. Finally, above the cost of the new system, the integration into the facility with the current control center system are resources and costs not normally taken into account in the design phase of the new system. In addition to the standard issues faced by a Project when upgrading its ground system, the

  19. Hypersonic Inflatable Aerodynamic Decelerator Ground Test Development

    NASA Technical Reports Server (NTRS)

    Del Corso, Jospeh A.; Hughes, Stephen; Cheatwood, Neil; Johnson, Keith; Calomino, Anthony

    2015-01-01

    Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology readiness levels have been incrementally matured by NASA over the last thirteen years, with most recent support from NASA's Space Technology Mission Directorate (STMD) Game Changing Development Program (GCDP). Recently STMD GCDP has authorized funding and support through fiscal year 2015 (FY15) for continued HIAD ground developments which support a Mars Entry, Descent, and Landing (EDL) study. The Mars study will assess the viability of various EDL architectures to enable a Mars human architecture pathfinder mission planned for mid-2020. At its conclusion in November 2014, NASA's first HIAD ground development effort had demonstrated success with fabricating a 50 W/cm2 modular thermal protection system, a 400 C capable inflatable structure, a 10-meter scale aeroshell manufacturing capability, together with calibrated thermal and structural models. Despite the unquestionable success of the first HIAD ground development effort, it was recognized that additional investment was needed in order to realize the full potential of the HIAD technology capability to enable future flight opportunities. The second HIAD ground development effort will focus on extending performance capability in key technology areas that include thermal protection system, lifting-body structures, inflation systems, flight control, stage transitions, and 15-meter aeroshell scalability. This paper presents an overview of the accomplishments under the baseline HIAD development effort and current plans for a follow-on development effort focused on extending those critical technologies needed to enable a Mars Pathfinder mission.

  20. English for Airport Ground Staff

    ERIC Educational Resources Information Center

    Cutting, Joan

    2012-01-01

    This article describes part of a European Commission Leonardo project that aimed to design a multimedia course for English language learners seeking work as ground staff in European airports. The structural-functional analysis of the dialogues written from the course showed that, across the four trades explored (security guards, ground handlers,…

  1. Ground water at Towaoc, Colorado

    USGS Publications Warehouse

    Powell, William J.

    1954-01-01

    At the request of the U.S bureau of Indian Affairs, the Ground Water Branch of the U. S Geological Survey made a reconnaissance of ground-water conditions in part of the Southern Ute Indian Reservation in the vicinity of Towaoc School. The study was requested because the water supply for the school and settlement was inadequate. 

  2. Designing the Successful Grounds Organization

    ERIC Educational Resources Information Center

    Gratto, Fred

    2011-01-01

    The most important component of any service organization is people. This is especially true of grounds management, because effective maintenance is dependent on good supervision and knowledgeable people. The grounds management function, therefore, must have personnel who are competent and committed. They must fully understand the scope of their …

  3. Electrochemical stabilization of clayey ground

    USGS Publications Warehouse

    Rzhanitzin, B.A.; Sokoloff, V.P.

    1947-01-01

    Recently developed new methods of stabilization of weak grounds (e.g. the silicate treatment) are based on injection of chemical solutions into the ground. Such methods are applicable accordingly only to the kinds of ground that have the coefficient of filtration higher than 2 meters per 24 hours and permit penetration of the chemical solutions under pressure. This limit, however, as it is shown by our experience in construction, excludes a numerous and an important class of grounds, stabilization of which is indispensable in many instances. For example, digging of trenches and pits in clayey, silty, or sandy ground shows that all these types act like typical "floaters" (sluds? -S) in the presence of the ground water pressure. There were several instances in the canalization of the city of Moskow where the laying of trenches below the ground water level has led to extreme difficulties with clayey and silty ground. Similar examples could be cited in mining, engineering hydrology, and railroad construction. For these reasons, the development of methods of stabilizing such difficult types of ground has become an urgent problem of our day. In 1936, the author began his investigations, at the ground Stabilization Laboratory of VODGEO Institute, with direct electrical current as the means of stabilization of grounds. Experiments had shown that a large number of clayey types, following passage of direct electrical current, undergoes a transformation of its physico-chemical properties. It was established that the (apparent -S) density of the ground is substantially increased in consequence of the application of direct electrical current. The ground loses also its capacity to swell and to soften in water. Later, after a more detailed study of the physico-chemical mechanism of the electrical stabilization, it became possible to develop the method so as to make it applicable to sandy and silty as well as to clayey ground. By this time (1941, S.), the method has already been

  4. Snowpack ground-truth manual

    NASA Technical Reports Server (NTRS)

    Jones, E. B.

    1983-01-01

    As remote sensing increasingly becomes more of an operational tool in the field of snow management and snow hydrology, there is need for some degree of standardization of ""snowpack ground truth'' techniques. This manual provides a first step in standardizing these procedures and was prepared to meet the needs of remote sensing researchers in planning missions requiring ground truth as well as those providing the ground truth. Focus is on ground truth for remote sensors primarily operating in the microwave portion of the electromagnetic spectrum; nevertheless, the manual should be of value to other types of sensor programs. This first edition of ground truth procedures must be updated as new or modified techniques are developed.

  5. Ground water investigations in Oklahoma

    USGS Publications Warehouse

    Davis, Leon V.

    1955-01-01

    Prior to 1937, ground-water work in Oklahoma consisted of broad scale early-day reconnaissance and a few brief investigations of local areas. The reconnaissance is distinguished by C. N. Gould's "Geology and Water Resources of Oklahoma" (Water-Supply Paper 148, 1905), which covers about half of the present State of Oklahoma. Among the shorter reports are two by Schwennesen for areas near Enid and Oklahoma City, one by Renick for Enid, and one by Thompson on irrigation possibilities near Gage. These reports are now inadequate by modern standards. Cooperative ground-water work in Oklahoma by the United States Geological Survey began in 1937, with the Oklahoma Geological Survey as cooperating agency. With the passage of the new ground-water law by the State Legislature in 1949, the need for more information on available ground waters and the safe yield of the various aquifers became very pressing. Accordingly, the Division of Water Resources of the Oklahoma Planning and Resources Board, to which was delegated the responsibility of administering the Ground-Water Law, entered into a cooperative agreement with the U.S. Geological Survey, providing for an expansion of ground-water investigations. Both cooperators have consistently given full and enthusiastic cooperation, often beyond the requirements of the cooperative program. The first cooperative investigation was an evaluation of ground-water supplies available for irrigation in the Panhandle. In 1937 the Panhandle was still very much in the dust bowl, and it was hoped that irrigation would alleviate the drought. A bulletin on Texas County was published in 1939, and one on Cimarron County in 1943. Ground-water investigations during the World War II were restricted to the demands of Army and Navy installations, and to defense industries. Ground-water investigations since 1945 have included both country-wide and aquifer-type investigations. In Oklahoma it has been the policy for the State cooperator to publish the

  6. Movable Ground Based Recovery System for Reuseable Space Flight Hardware

    NASA Technical Reports Server (NTRS)

    Sarver, George L. (Inventor)

    2013-01-01

    A reusable space flight launch system is configured to eliminate complex descent and landing systems from the space flight hardware and move them to maneuverable ground based systems. Precision landing of the reusable space flight hardware is enabled using a simple, light weight aerodynamic device on board the flight hardware such as a parachute, and one or more translating ground based vehicles such as a hovercraft that include active speed, orientation and directional control. The ground based vehicle maneuvers itself into position beneath the descending flight hardware, matching its speed and direction and captures the flight hardware. The ground based vehicle will contain propulsion, command and GN&C functionality as well as space flight hardware landing cushioning and retaining hardware. The ground based vehicle propulsion system enables longitudinal and transverse maneuverability independent of its physical heading.

  7. 14 CFR 121.421 - Flight attendants: Initial and transition ground training.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION... equipment and the controls for cabin heat and ventilation. (b) Initial and transition ground training...

  8. Longevity of Emplacement Drift Ground Support Materials

    SciTech Connect

    Tang, David H.

    2001-05-30

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. REV 01 ICN 01 of this analysis is developed in accordance with AP-3.10Q, Analyses and Models, Revision 2, ICN 4, and prepared in accordance with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M&O 2001a). The objective of this analysis is to update the previous analysis (CRWMS M&O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M&O 2000b), the Monitored Geologic Repository Project Description Document, which is included in the Requirements and Criteria for Implementing a Repository Design that can be Operated Over a Range of Thermal Modes (BSC 2001), input information, and in environmental conditions, and to provide updated information on candidate ground support materials. Candidate materials for ground support are carbon steel and cement grout. Steel is mainly used for steel sets, lagging, channel, rock bolts, and wire mesh. Cement grout is only considered in the case of grouted rock bolts. Candidate materials for the emplacement drift invert are carbon steel and granular natural material. Materials are evaluated for the repository emplacement drift environment based on the updated thermal loading condition and waste package design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground support materials for use in emplacement drifts. (2) Review existing documents concerning the behavior of candidate ground support materials during the preclosure period. (3) Evaluate impacts of temperature and radiation effects on mechanical and thermal properties of steel. Assess corrosion potential of steel at emplacement drift environment. (4) Evaluate factors

  9. Procedures for ground-water investigations

    SciTech Connect

    Not Available

    1989-09-01

    This manual was developed by the Pacific Northwest Laboratory (PNL) to document the procedures used to carry out and control the technical aspects of ground-water investigations at the PNL. Ground-water investigations are carried out to fulfill the requirements for the US Department of Energy (DOE) to meet the requirements of DOE Orders. Investigations are also performed for various clients to meet the requirements of the Resource Conservation and Recovery Act of 1976 (RCRA) and the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA). National standards including procedures published by the American Society for Testing and Materials (ASTM) and the US Geological Survey were utilized in developing the procedures contained in this manual.

  10. Ground Effect - Theory and Practice

    NASA Technical Reports Server (NTRS)

    Pistolesi, E

    1937-01-01

    The conclusion of a previous article by Pistolesi is that the increment of lift due to ground effect is largely attributable to the effect of induction of the free vortices, and is practically equivalent to a virtual increase in aspect ratio. The ground clearance was of the order of magnitude comparable to the wing chord. New reports by Le Seur and Datwyler treat the case of minimum distance from the ground and is confined to the plane problem only. The author briefly reviews these reports and also one by Timotika. References to all the reviewed reports are in the attached bibliography.

  11. LANDSAT-D ground segment operations plan, revision A

    NASA Technical Reports Server (NTRS)

    Evans, B.

    1982-01-01

    The basic concept for the utilization of LANDSAT ground processing resources is described. Only the steady state activities that support normal ground processing are addressed. This ground segment operations plan covers all processing of the multispectral scanner and the processing of thematic mapper through data acquisition and payload correction data generation for the LANDSAT 4 mission. The capabilities embedded in the hardware and software elements are presented from an operations viewpoint. The personnel assignments associated with each functional process and the mechanisms available for controlling the overall data flow are identified.

  12. Lean and Agile Development of the AITS Ground Software System

    NASA Astrophysics Data System (ADS)

    Richters, Mark; Dutruel, Etienne; Mecredy, Nicolas

    2013-08-01

    We present the ongoing development of a new ground software system used for integrating, testing and operating spacecraft. The Advanced Integration and Test Services (AITS) project aims at providing a solution for electrical ground support equipment and mission control systems in future Astrium Space Transportation missions. Traditionally ESA ground or flight software development projects are conducted according to a waterfall-like process as specified in the ECSS-E-40 standard promoted by ESA in the European industry. In AITS a decision was taken to adopt an agile development process. This work could serve as a reference for future ESA software projects willing to apply agile concepts.

  13. 46 CFR 129.375 - System grounding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Power Sources and Distribution Systems § 129.375 System grounding. (a) If a grounded distribution system... nonmetallic vessel with a grounded distribution system, the common ground plate must have— (1) Only one... 46 Shipping 4 2013-10-01 2013-10-01 false System grounding. 129.375 Section 129.375 Shipping...

  14. 46 CFR 129.375 - System grounding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Power Sources and Distribution Systems § 129.375 System grounding. (a) If a grounded distribution system... nonmetallic vessel with a grounded distribution system, the common ground plate must have— (1) Only one... 46 Shipping 4 2010-10-01 2010-10-01 false System grounding. 129.375 Section 129.375 Shipping...

  15. 46 CFR 129.375 - System grounding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Power Sources and Distribution Systems § 129.375 System grounding. (a) If a grounded distribution system... nonmetallic vessel with a grounded distribution system, the common ground plate must have— (1) Only one... 46 Shipping 4 2011-10-01 2011-10-01 false System grounding. 129.375 Section 129.375 Shipping...

  16. 46 CFR 129.375 - System grounding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Power Sources and Distribution Systems § 129.375 System grounding. (a) If a grounded distribution system... nonmetallic vessel with a grounded distribution system, the common ground plate must have— (1) Only one... 46 Shipping 4 2014-10-01 2014-10-01 false System grounding. 129.375 Section 129.375 Shipping...

  17. 46 CFR 129.375 - System grounding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Power Sources and Distribution Systems § 129.375 System grounding. (a) If a grounded distribution system... nonmetallic vessel with a grounded distribution system, the common ground plate must have— (1) Only one... 46 Shipping 4 2012-10-01 2012-10-01 false System grounding. 129.375 Section 129.375 Shipping...

  18. Redundant Grounding Circuit For Arc Welding

    NASA Technical Reports Server (NTRS)

    Burley, Richard K.

    1988-01-01

    Arc burns at loose ground connections prevented. Protective grounding scheme for arc-welding power supply includes four ground leads to workpiece and circuit that automatically turns off welding current if one or two ground leads becomes disconnected. Prevents burns and inadvertent welding occuring where full welding current passes through single loose ground contact.

  19. Ground water and climate change

    USGS Publications Warehouse

    Taylor, Richard G.; Scanlon, Bridget; Döll, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F.P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J.-F.; Holman, Ian; Treidel, Holger

    2012-01-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  20. Ground Penetrating Radar, Barrow, Alaska

    DOE Data Explorer

    John Peterson

    2015-03-06

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  1. Ground Water and Climate Change

    NASA Technical Reports Server (NTRS)

    Taylor, Richard G.; Scanlon, Bridget; Doell, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; Konikow, Leonard; Green, Timothy R.; Chen, Jianyao; Taniguchi, Makoto; Bierkens, Marc F. P.; MacDonald, Alan; Fan, Ying; Maxwell, Reed M.; Yechieli, Yossi; Gurdak, Jason J.; Allen, Diana M.; Shamsudduha, Mohammad; Hiscock, Kevin; Yeh, Pat J. -F; Holman, Ian; Treidel, Holger

    2013-01-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  2. Metrology of the ground effect

    NASA Astrophysics Data System (ADS)

    Filippi, P.; Habault, D.; Corsain, G.

    The analytical representation of sound propagation above a plane surface is investigated. Ground-effect modeling is shown to involve three phases: development of a ground model, representation of the acoustic field above the model, and determination of the ground characteristics. Three field-representation schemes applicable to either a localized-reaction-surface model or a porous-homogeneous-isotropic-layer model are briefly characterized. An iterative numerical algorithm for the identification of ground parameters is presented and applied to field data in order to calculate the specific complex normal impedance of a grass-covered field for a localized-reaction surface model. Good agreement is found between the calculated and observed values, which are compared in a graph.

  3. Flexible propulsors in ground effect.

    PubMed

    Quinn, Daniel B; Lauder, George V; Smits, Alexander J

    2014-09-01

    We present experimental evidence for the hydrodynamic benefits of swimming 'in ground effect', that is, near a solid boundary. This situation is common to fish that swim near the substrate, especially those that are dorsoventrally compressed, such as batoids and flatfishes. To investigate flexible propulsors in ground effect, we conduct force measurements and particle image velocimetry on flexible rectangular panels actuated at their leading edge near the wall of a water channel. For a given actuation mode, the panels swim faster near the channel wall while maintaining the same propulsive economy. In conditions producing net thrust, panels produce more thrust near the ground. When operating in resonance, swimming near the ground can also increase propulsive efficiency. Finally, the ground can act to suppress three-dimensional modes, thereby increasing thrust and propulsive efficiency. The planform considered here is non-biological, but the hydrodynamic benefits are likely to apply to more complex geometries, especially those where broad flexible propulsors are involved such as fish bodies and fins. Such fish could produce more thrust by swimming near the ground, and in some cases do so more efficiently. PMID:24667542

  4. Flexible propulsors in ground effect.

    PubMed

    Quinn, Daniel B; Lauder, George V; Smits, Alexander J

    2014-09-01

    We present experimental evidence for the hydrodynamic benefits of swimming 'in ground effect', that is, near a solid boundary. This situation is common to fish that swim near the substrate, especially those that are dorsoventrally compressed, such as batoids and flatfishes. To investigate flexible propulsors in ground effect, we conduct force measurements and particle image velocimetry on flexible rectangular panels actuated at their leading edge near the wall of a water channel. For a given actuation mode, the panels swim faster near the channel wall while maintaining the same propulsive economy. In conditions producing net thrust, panels produce more thrust near the ground. When operating in resonance, swimming near the ground can also increase propulsive efficiency. Finally, the ground can act to suppress three-dimensional modes, thereby increasing thrust and propulsive efficiency. The planform considered here is non-biological, but the hydrodynamic benefits are likely to apply to more complex geometries, especially those where broad flexible propulsors are involved such as fish bodies and fins. Such fish could produce more thrust by swimming near the ground, and in some cases do so more efficiently.

  5. Advanced Ground Systems Maintenance Prognostics Project

    NASA Technical Reports Server (NTRS)

    Perotti, Jose M.

    2015-01-01

    The project implements prognostics capabilities to predict when a component system or subsystem will no longer meet desired functional or performance criteria, called the end of life. The capability also provides an assessment of the remaining useful life of a hardware component. The project enables the delivery of system health advisories to ground system operators. This project will use modeling techniques and algorithms to assess components' health andpredict remaining life for such components. The prognostics capability being developed will beused:during the design phase and during pre/post operations to conduct planning and analysis ofsystem design, maintenance & logistics plans, and system/mission operations plansduring real-time operations to monitor changes to components' health and assess their impacton operations.This capability will be interfaced to Ground Operations' command and control system as a part ofthe AGSM project to help assure system availability and mission success. The initial modelingeffort for this capability will be developed for Liquid Oxygen ground loading applications.

  6. Mathematical models for space shuttle ground systems

    NASA Technical Reports Server (NTRS)

    Tory, E. G.

    1985-01-01

    Math models are a series of algorithms, comprised of algebraic equations and Boolean Logic. At Kennedy Space Center, math models for the Space Shuttle Systems are performed utilizing the Honeywell 66/80 digital computers, Modcomp II/45 Minicomputers and special purpose hardware simulators (MicroComputers). The Shuttle Ground Operations Simulator operating system provides the language formats, subroutines, queueing schemes, execution modes and support software to write, maintain and execute the models. The ground systems presented consist primarily of the Liquid Oxygen and Liquid Hydrogen Cryogenic Propellant Systems, as well as liquid oxygen External Tank Gaseous Oxygen Vent Hood/Arm and the Vehicle Assembly Building (VAB) High Bay Cells. The purpose of math modeling is to simulate the ground hardware systems and to provide an environment for testing in a benign mode. This capability allows the engineers to check out application software for loading and launching the vehicle, and to verify the Checkout, Control, & Monitor Subsystem within the Launch Processing System. It is also used to train operators and to predict system response and status in various configurations (normal operations, emergency and contingent operations), including untried configurations or those too dangerous to try under real conditions, i.e., failure modes.

  7. Identification of technical guidance related to ground water monitoring

    SciTech Connect

    Vogelsberger, R.R.; Smith, E.D.; Broz, M.; Wright, J.C. Jr.

    1987-05-01

    Monitoring of ground water quality is a key element of ground water protection and is mandated by several federal and state laws concerned with water quality or waste management. Numerous regulatory guidance documents and technical reports discuss various aspects of ground water monitoring, but at present there is no single source of guidance on procedures and practices for ground water monitoring. This report is intended to assist US Department of Energy (DOE) officials and facility operating personnel in identifying sources of guidance for developing and implementing ground water monitoring programs that are technically sound and that comply with applicable regulations. Federal statutes and associated regulations were reviewed to identify requirements related to ground water monitoring, and over 160 documents on topics related to ground water monitoring were evaluated for their technical merit, their utility as guidance for regulatory compliance, and their relevance to DOE's needs. For each of 15 technical topics involved in ground water monitoring, the report presents (1) a review of federal regulatory requirements and representative state requirements, (2) brief descriptions of the contents and merits of available guidance documents and technical references, and (3) recommendations of the guidance documents or other technical resources that appear to be most appropriate for use in DOE's monitoring activities. The contents of the report are applicable to monitoring activities involving both radioactive and nonradioactive substances. The main sources of regulatory requirements considered in the report are the Atomic Energy Act (including the Uranium Mill Tailings Radiation Control Act), Resource Conservation and Recovery Act, Comprehensive Environmental Response, Compensation and Liability Act, Safe Drinking Water Act, Toxic Substances Control Act, and Federal Water Pollution Control Act.

  8. ANOPP/VMS HSCT ground contour system

    NASA Technical Reports Server (NTRS)

    Rawls, John, Jr.; Glaab, Lou

    1992-01-01

    This viewgraph shows the integration of the Visual Motion Simulator with ANOPP. ANOPP is an acronym for the Aircraft NOise Prediction Program. It is a computer code consisting of dedicated noise prediction modules for jet, propeller, and rotor powered aircraft along with flight support and noise propagation modules, all executed under the control of an executive system. The Visual Motion Simulator (VMS) is a ground based motion simulator with six degrees of freedom. The transport-type cockpit is equipped with conventional flight and engine-thrust controls and with flight instrument displays. Control forces on the wheel, column, and rudder pedals are provided by a hydraulic system coupled with an analog computer. The simulator provides variable-feel characteristics of stiffness, damping, coulomb friction, breakout forces, and inertia. The VMS provides a wide range of realistic flight trajectories necessary for computing accurate ground contours. The NASA VMS will be discussed in detail later in this presentation. An equally important part of the system for both ANOPP and VMS is the engine performance. This will also be discussed in the presentation.

  9. Unmanned ground vehicles for integrated force protection

    NASA Astrophysics Data System (ADS)

    Carroll, Daniel M.; Mikell, Kenneth; Denewiler, Thomas

    2004-09-01

    The combination of Command and Control (C2) systems with Unmanned Ground Vehicles (UGVs) provides Integrated Force Protection from the Robotic Operation Command Center. Autonomous UGVs are directed as Force Projection units. UGV payloads and fixed sensors provide situational awareness while unattended munitions provide a less-than-lethal response capability. Remote resources serve as automated interfaces to legacy physical devices such as manned response vehicles, barrier gates, fence openings, garage doors, and remote power on/off capability for unmanned systems. The Robotic Operations Command Center executes the Multiple Resource Host Architecture (MRHA) to simultaneously control heterogeneous unmanned systems. The MRHA graphically displays video, map, and status for each resource using wireless digital communications for integrated data, video, and audio. Events are prioritized and the user is prompted with audio alerts and text instructions for alarms and warnings. A control hierarchy of missions and duty rosters support autonomous operations. This paper provides an overview of the key technology enablers for Integrated Force Protection with details on a force-on-force scenario to test and demonstrate concept of operations using Unmanned Ground Vehicles. Special attention is given to development and applications for the Remote Detection Challenge and Response (REDCAR) initiative for Integrated Base Defense.

  10. Ground-water flow and the possible effects of remedial actions at J-Field, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Hughes, W.B.

    1995-01-01

    J-Field, located in the Edgewood Area of Aberdeen Proving Ground, Md, has been used since World War II to test and dispose of explosives, chemical warfare agents, and industrial chemicals resulting in ground-water, surface-water, and soil contami- nation. The U.S. Geological Survey finite-difference model was used to better understand ground-water flow at the site and to simulate the effects of remedial actions. A surficial aquifer and a confined aquifer were simulated with the model. A confining unit separates these units and is represented by leakance between the layers. The area modeled is 3.65 mi2; the model was constructed with a variably spaced 40 X 38 grid. The horizontal and lower boundaries of the model are all no-flow boundaries. Steady-state conditions were used. Ground water at the areas under investigation flows from disposal pit areas toward discharge areas in adjacent estuaries or wetlands. Simulations indicate that capping disposal areas with an impermeable cover effectively slows advective ground water flow by 0.7 to 0.5 times. Barriers to lateral ground-water flow were simulated and effectively prevented the movement of ground water toward discharge areas. Extraction wells were simulated as a way to contain ground-water contamination and to extract ground water for treatment. Two wells pumping 5 gallons per minute each at the toxic-materials disposal area and a single well pumping 2.5 gallons per minute at the riot-control-agent disposal area effectively contained contamination at these sites. A combi- nation of barriers to horizontal flow east and south of the toxic-materials disposal area, and a single extraction well pumping at 5 gallons per minute can extract contaminated ground water and prevent pumpage of marsh water.

  11. Beijing Basin's amplification effect on long-period ground motion

    NASA Astrophysics Data System (ADS)

    Fu, Changhua

    2016-04-01

    A lot of high-rise buildings are located in basins. Previous researches tell us that the intensity of long-period ground motion in the basin is usually larger than that in its vicinities when a strong earthquake occurs. This higher intensity will cause severe damage to high-rise buildings which have long self-vibrating periods. So, by studying the characteristics of ground motion in the basin and analyzing basin amplification effect on long-period ground motion, we can understand reasonable seismic fortification requirement of high-rise buildings in the basin, and provide scientific reference for city future planning, earthquake emergency and rescue. Taking Beijing Basin as an example, we set up several scenario earthquakes, then use Ground-Motion-Simulation method to study how different scenario earthquakes influence basin's amplification effect on long-period ground motion. The research demonstrates that the amplification effect on 3~10-second ground motion acceleration response spectrum is mainly controlled by thickness of sediment in basin, although different seismic sources may cause the uncertainty to a certain extent. Thus, the average basin's amplification factor on 3~10-second ground motion acceleration response spectrum is computed, and the correlation function, that between the average amplification factor and equivalent thickness of sediment in basin, is analyzed. Finally, according to the distribution of high-rise buildings in Beijing Basin, preliminary discussion on the relationship between risk level of seismic hazard of high-rise buildings and basin structure is made.

  12. Optical Ground Segment Performance Summary

    NASA Astrophysics Data System (ADS)

    Breidenthal, J.; Xie, H.; Clare, L.

    2016-05-01

    The performance of candidate optical communication systems for deep space that would use a single optical ground station in conjunction with various space terminals is reported here. We considered three potential diameters of ground receive terminals (4, 8, and 12 m) and three potential ground transmit powers (1, 5, and 10 kW). Combinations of ground receive terminals, ground transmit terminals, and spacecraft terminals were assessed for data rate and volume (both uplink and downlink), and for uplink irradiance needed to enable downlink pointing, in the context of a set of 12 design reference missions. Raw physical link performance was assessed assuming clear weather conditions with conservative desert daytime turbulence, using communication link parameters that were optimized according to previously reported methods using the Strategic Optical Link Tool (SOLT). Also, realistic bad weather conditions were considered, assuming a random process that could at any time make transitions between two states: a cloud-free state and a cloudy state that completely interrupts data transmission. We compared the link performance achievable under our assumptions to the anticipated requirements associated with the design reference missions to determine the degree of satisfaction possible with various optical segments. Nine potential operating concepts for an optical communication system were described, and two were evaluated in detail for the Mars 2022 mission opportunity: raw data delivery and automatic repeat request for complete data delivery.

  13. Modeled ground water age distributions

    USGS Publications Warehouse

    Woolfenden, Linda R.; Ginn, Timothy R.

    2009-01-01

    The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

  14. [Research on ground scenery spectral radiation source with tunable spectra].

    PubMed

    Xiang, Jin-rong; Ren, Jian-wei; Li, Bao-yong; Wan, Zhi; Liu, Ze-xun; Liu, Hong-xing; Li, Xian-sheng; Sun, Jing-xu

    2015-02-01

    A spectrum-tunable ground scenery spectrum radiation source, using LEDs and bromine tungsten lamp as luminescence media, was introduced. System structure and control of the spectrum radiation source was expounded in detail. In order to simulate various ground scenery spectrum distribution with different shapes, a ground scenery spectral database was established in the control system. An improved genetic algorithm was proposed, and a large number of ground scenery spectra were produced by the simulator. Spectral similarity and the average spectral matching error of several typical ground scenery spectra were further analyzed. Spectral similarity of red bands, green bands, blue bands and near-infrared spectral band also was discussed. When the radiance of the target was 50 W x (m2 x sr)(-1), the average spectral matching error was less than 10% and spectral similarity was greater than 0.9, up to 0.983. Spectral similarity of red band, green band, blue band and near-infrared band (especially green band and near-infrared band) was less than that of full-band. Compared with blue band and red band, spectral similarity of green band and near-infrared band low-amplitude maximum can rearch 50%. Ground scenery spectrum radiation source can be used as radiometric calibration source for optical remote sensor, and calibration error, which is caused by objectives and calibration sources spectral mismatch, can be effectively reduced. PMID:25970881

  15. Ground-water resources in the tri-state region adjacent to the Lower Delaware River

    USGS Publications Warehouse

    Barksdale, Henry C.; Greenman, David W.; Lang, Solomon Max; Hilton, George Stockbridge; Outlaw, Donald E.

    1958-01-01

    The maximum beneficial utilization of the ground-water resources cannot be accomplished in haphazard fashion. It must be planned and controlled on the basis of sound, current information about the hydrology of the various aquifers. Continued and, in some areas, intensified investigations of the ground-water resources of the region should form the basis for such planning and control.

  16. 77 FR 51827 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Ground...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-27

    ...; Ground Control Plans for Surface Coal Mines and Surface Work Areas of Underground Coal Mines ACTION... (MSHA) sponsored information collection request (ICR) titled, ``Ground Control Plans for Surface Coal Mines and Surface Work Areas of Underground Coal Mines,'' to the Office of Management and Budget...

  17. The value ground of nursing.

    PubMed

    Snellman, Ingrid; Gedda, Kersti M

    2012-11-01

    The aim of this literature study was to suggest a value ground for nursing anchored in two ethical principles: the principle of human value and the right to experience a meaningful life. Previous nursing research between the years 2000 and 2009 was analysed. Presented values suggested in this value ground are thus in line with the nursing context and science of today. Statements within ethical literature have been used in order to formulate arguments aimed at supporting the values that were found in the study. In the literature study six values were found: trust, nearness, sympathy, support, knowledge and responsibility. These values hold equal status and are not presented in hierarchical order. They vary due to the persons involved, nursing situations and cultural surroundings, but have the common requirement of being non-excluding. In order to implement the values within the value ground, two prerequisites are discussed and claimed as essential: ethical dialogue and a caring encounter between care provider and patients.

  18. Grounding & human health - a review

    NASA Astrophysics Data System (ADS)

    Jamieson, I. A.; Jamieson, S. S.; ApSimon, H. M.; Bell, J. N. B.

    2011-06-01

    Whilst grounding is often undertaken in industry as a matter of good practice in situations where the risk of excess charge exists, little thought is usually given to the biological effects that such measures may have, or possible benefits that may arise from the more widespread application of electrostatic and other 'electromagnetic hygiene' measures in hospitals and the general built environment. Research, which is still in its infancy, indicates that grounding the human body using suitable methodologies, particularly in low electromagnetic field environments, can significantly enhance biological functioning. It is proposed that there are often a number of electrostatic and 'electromagnetic hygiene' factors that need to be addressed before the beneficial effects of grounding the human body can be fully realised in many everyday environments.

  19. The automated ground network system

    NASA Technical Reports Server (NTRS)

    Smith, Miles T.; Militch, Peter N.

    1993-01-01

    The primary goal of the Automated Ground Network System (AGNS) project is to reduce Ground Network (GN) station life-cycle costs. To accomplish this goal, the AGNS project will employ an object-oriented approach to develop a new infrastructure that will permit continuous application of new technologies and methodologies to the Ground Network's class of problems. The AGNS project is a Total Quality (TQ) project. Through use of an open collaborative development environment, developers and users will have equal input into the end-to-end design and development process. This will permit direct user input and feedback and will enable rapid prototyping for requirements clarification. This paper describes the AGNS objectives, operations concept, and proposed design.

  20. Ground states of holographic superconductors

    SciTech Connect

    Gubser, Steven S.; Nellore, Abhinav

    2009-11-15

    We investigate the ground states of the Abelian Higgs model in AdS{sub 4} with various choices of parameters, and with no deformations in the ultraviolet other than a chemical potential for the electric charge under the Abelian gauge field. For W-shaped potentials with symmetry-breaking minima, an analysis of infrared asymptotics suggests that the ground state has emergent conformal symmetry in the infrared when the charge of the complex scalar is large enough. But when this charge is too small, the likeliest ground state has Lifshitz-like scaling in the infrared. For positive mass quadratic potentials, Lifshitz-like scaling is the only possible infrared behavior for constant nonzero values of the scalar. The approach to Lifshitz-like scaling is shown in many cases to be oscillatory.

  1. Deregulation, chemical waste, and ground water: a 1949 debate.

    PubMed

    Ross, Benjamin; Amter, Steven

    2002-03-01

    When did scientists, regulators, and industry first realize that industrial waste threatens the quality of ground-water? The conventional wisdom holds that widespread knowledge of this problem only dates back to the 1970s. In this view, what knowledge did exist earlier was confined to small circles of technical specialists and not generally known in industry. The passage of the Dickey Act, which established California's Water Quality Control Boards in 1949, provides documentation of events and ideas against which this hypothesis can be tested directly. A legislative committee, after lenghty public hearings, produced a detailed scientific report about ground-water and stream pollution. Bitter public controversy then erupted among politicians, industry, regulators and scientists about whether and how to protect ground-water supplies from contamination by industrial wastes. This controversy in the most populous region of the western United States demonstrates that many well-informed policy-makers knew that industrial wastes could pollute ground-water.

  2. 46 CFR 183.376 - Grounded distribution systems (neutral grounded).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... VESSELS (UNDER 100 GROSS TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.376... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... generator to ground before the generator is connected to the bus, except the neutral of an emergency...

  3. Pyrolysis of ground pine chip and ground pellet particles

    DOE PAGESBeta

    Rezaei, Hamid; Yazdanpanah, Fahimeh; Lim, C. Jim; Lau, Anthony; Sokhansanj, Shahab

    2016-08-04

    In addition to particle size, biomass density influences heat and mass transfer rates during the thermal treatment processes. In this research, thermal behaviour of ground pine chip particles and ground pine pellet particles in the range of 0.25–5 mm was investigated. A single particle from ground pellets was almost 3 to 4 times denser than a single particle from ground chips at a similar size and volume of particle. Temperature was ramped up from room temperature (~25 °C) to 600 °C with heating rates of 10, 20, 30, and 50 °C/min. Pellet particles took 25–88 % longer time to drymore » than the chip particles. Microscopic examination of 3 mm and larger chip particles showed cracks during drying. No cracks were observed for pellet particles. The mass loss due to treatment at temperatures higher than 200 °C was about 80% both for chip and pellet particles. It took 4 min for chip and pellet particles to lose roughly 63% of their dry mass at a heating rate of 50 °C/min. The SEM structural analysis showed enlarged pores and cracks in cell walls of the pyrolyzed wood chips. As a result, these pores were not observed in pyrolyzed pellet particles.« less

  4. Ground-truth measurement systems

    NASA Technical Reports Server (NTRS)

    Serafin, R.; Seliga, T. A.; Lhermitte, R. M.; Nystuen, J. A.; Cherry, S.; Bringi, V. N.; Blackmer, R.; Heymsfield, G. M.

    1981-01-01

    Ground-truth measurements of precipitation and related weather events are an essential component of any satellite system designed for monitoring rainfall from space. Such measurements are required for testing, evaluation, and operations; they provide detailed information on the actual weather events, which can then be compared with satellite observations intended to provide both quantitative and qualitative information about them. Also, very comprehensive ground-truth observations should lead to a better understanding of precipitation fields and their relationships to satellite data. This process serves two very important functions: (a) aiding in the development and interpretation of schemes of analyzing satellite data, and (b) providing a continuing method for verifying satellite measurements.

  5. Ecophysiology of juvenile flatfish in nursery grounds

    NASA Astrophysics Data System (ADS)

    Yamashita, Yoh; Tanaka, Masaru; Miller, John M.

    2001-06-01

    Relationships between biotic and abiotic factors and the ecological performance of late larval and juvenile flatfish in nursery grounds are examined from ecophysiological viewpoints. The first events in the nursery are metamorphosis and settlement. Development of organs, osmoregulation and behavioural changes during metamorphosis, and size at metamorphosis are regulated by environmental factors. Various hormones play critical roles in this regulation. Effects of environmental conditions on individual growth in the nursery grounds are described on the basis of Fry's five environmental factors: limiting, controlling, masking, directive and lethal factors. The main limiting factors are food and dissolved oxygen; controlling factors are temperature and body size; masking factors are salinity and pollutants; lethal factors are extreme environments; and directive factors are food, predators and dissolved oxygen. In addition to temperature, it has been indicated that dissolved oxygen seems to be relatively important for flatfish of the eastern US and northern European countries, while food abundance appears to be more critical for Japanese flounder. The feasibility is discussed of ecophysiological modelling to predict individual growth and subpopulation production based on the assessment of the role of environmental variability using the above classification, which organises and integrates environmental effects.

  6. 14 CFR 417.109 - Ground safety.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ground safety. 417.109 Section 417.109... TRANSPORTATION LICENSING LAUNCH SAFETY Launch Safety Responsibilities § 417.109 Ground safety. (a) Ground safety... 417.115(c), and subpart E of this part provide launch operator ground safety requirements....

  7. 14 CFR 417.109 - Ground safety.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Ground safety. 417.109 Section 417.109... TRANSPORTATION LICENSING LAUNCH SAFETY Launch Safety Responsibilities § 417.109 Ground safety. (a) Ground safety... 417.115(c), and subpart E of this part provide launch operator ground safety requirements....

  8. 14 CFR 417.109 - Ground safety.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Ground safety. 417.109 Section 417.109... TRANSPORTATION LICENSING LAUNCH SAFETY Launch Safety Responsibilities § 417.109 Ground safety. (a) Ground safety... 417.115(c), and subpart E of this part provide launch operator ground safety requirements....

  9. 14 CFR 417.109 - Ground safety.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Ground safety. 417.109 Section 417.109... TRANSPORTATION LICENSING LAUNCH SAFETY Launch Safety Responsibilities § 417.109 Ground safety. (a) Ground safety... 417.115(c), and subpart E of this part provide launch operator ground safety requirements....

  10. 14 CFR 417.109 - Ground safety.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Ground safety. 417.109 Section 417.109... TRANSPORTATION LICENSING LAUNCH SAFETY Launch Safety Responsibilities § 417.109 Ground safety. (a) Ground safety... 417.115(c), and subpart E of this part provide launch operator ground safety requirements....

  11. 30 CFR 77.801 - Grounding resistors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Grounding resistors. 77.801 Section 77.801...-Voltage Distribution § 77.801 Grounding resistors. The grounding resistor, where required, shall be of the proper ohmic value to limit the voltage drop in the grounding circuit external to the resistor to...

  12. 30 CFR 77.801 - Grounding resistors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Grounding resistors. 77.801 Section 77.801...-Voltage Distribution § 77.801 Grounding resistors. The grounding resistor, where required, shall be of the proper ohmic value to limit the voltage drop in the grounding circuit external to the resistor to...

  13. 30 CFR 77.801 - Grounding resistors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Grounding resistors. 77.801 Section 77.801...-Voltage Distribution § 77.801 Grounding resistors. The grounding resistor, where required, shall be of the proper ohmic value to limit the voltage drop in the grounding circuit external to the resistor to...

  14. 30 CFR 77.801 - Grounding resistors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Grounding resistors. 77.801 Section 77.801...-Voltage Distribution § 77.801 Grounding resistors. The grounding resistor, where required, shall be of the proper ohmic value to limit the voltage drop in the grounding circuit external to the resistor to...

  15. CHARACTERIZING EXTREME GROUND MOTIONS AT YUCCA MTN

    SciTech Connect

    W. Silva, I. Wong, J. Ake, R. Quittmeyer, and C. Costantino

    2006-02-27

    Characterization of the epistemic uncertainty and aleatory variability of ground motion, as part of the Yucca Mountain nuclear waste repository PSHA (Stepp et al., 2001), results in ground motion values that increase without bound as lower and lower annual probabilities of exceedance are considered. For probabilities of exceedance less than about 10{sup -6} (yr{sup -1}), use of these results as input to the site response model leads to ground motion values for the repository that most engineering seismologists feel are not credible. To provide a defensible technical basis to develop credible emplacement level motions for extreme events, the undeformed nature of the 12.8 million year old lithophysal tuff units at Yucca Mountain provide strong constraints on the level of strain (stress) not experienced by the site since deposition of the tuff. Uniaxial unconfined compressive tests (the only tests available to the project) of the lithophysal tuff indicate axial strains of about 0.3% at fracture, which converts to approximately 0.2% shear-strain. This shear-strain limit (fracture strain), which has not occurred, is used with standard equivalent-linear (and nonlinear) point-source site response analyses to develop corresponding response spectra assuming a controlling earthquake of M 6.5 at a distance of 5 km, based on the site PSHA. In addition to the uncertainty in fracture shear-strain resulting from unconfined uniaxial tests, the analyses demonstrate that the uncertainty in nonlinear dynamic material properties of the tuff result in a factor of two uncertainty in extreme response spectra, conditional on a value of 0.2% for the fracture strain. To reduce the large uncertainty in extreme spectra, a high pressure ({approx} 1,000 ft), large scale ({approx} 1 ft{sup 3}) test device is needed that simulates earthquake loading conditions (cyclic shear strain). The test device would give direct measures of shear fracture strain for the lithophysal tuffs as well as reliable

  16. COMPILATION OF GROUND WATER MODELS

    EPA Science Inventory

    The full report presents an overview of currently available computer-based simulation models for ground-water flow, solute and heat transport, and hydrogeochemistry in both porous media and fractured rock. Separate sections address multiphase flow and related chemical species tra...

  17. The Envisat-1 ground segment

    NASA Astrophysics Data System (ADS)

    Harris, Ray; Ashton, Martin

    1995-03-01

    The European Space Agency (ESA) Earth Remote Sensing Satellite (ERS-1 and ERS-2) missions will be followed by the Polar Orbit Earth Mission (POEM) program. The first of the POEM missions will be Envisat-1. ESA has completed the design phase of the ground segment. This paper presents the main elements of that design. The main part of this paper is an overview of the Payload Data Segment (PDS) which is the core of the Envisat-1 ground segment, followed by two further sections which describe in more detail the facilities to be offered by the PDS for archiving and for user servcies. A further section describes some future issues for ground segment development. Logica was the prime contractor of a team of 18 companies which undertook the ESA financed architectural design study of the Envisat-1 ground segment. The outputs of the study included detailed specifications of the components that will acquire, process, archive and disseminate the payload data, together with the functional designs of the flight operations and user data segments.

  18. GROUND WATER TECHNICAL SUPPORT CENTER

    EPA Science Inventory

    EPA's Office of Research and Development operates a Ground Water Technical Support Center (GWTSC). The Center provides support on issues regarding subsurface contamination, contaminant fluxes to other media (e.g., surface water or air), and ecosystem restoration. The GWTSC creat...

  19. GROUND WATER SAMPLING FOR VOCS

    EPA Science Inventory

    Sampling protocol should be dictated by the sampling objective(s). It is important to obtain representative ground water samples, regardless of the sampling objective(s). Low-flow (minimum draw-down) purging and sampling techniques are best in most instances, particularly for VOC...

  20. Common Ground: Expanding Our Horizons.

    ERIC Educational Resources Information Center

    McDevitt, Michele J.

    In "Common Ground: Dialogue, Understanding, and the Teaching of Composition," Kurt Spellmeyer seeks to familiarize students and teachers with the linguistic and cultural no-man's-land separating them. Reinstating the value of two writing conventions often used by traditional students--expressive and commonplaces--can help expand on the horizons of…