Science.gov

Sample records for additional control points

  1. Low-boiling-point solvent additives can also enable morphological control in polymer solar cells

    SciTech Connect

    Mahadevapuram, Rakesh C.; Carr, John A.; Chen, Yuqing; Bose, Sayantan; Nalwa, Kanwar S.; Petrich, Jacob W.; Chaudhary, Sumit

    2013-11-02

    Processing organic photovoltaic (OPV) blend solutions with high-boiling-point solvent additives has recently been used for morphological control in bulk-heterojunction OPV cells. Here we show that even low-boiling-point solvents can be effective additives. When P3HT:PCBM OPV cells were processed with a low-boiling-point solvent tetrahydrafuran as an additive in parent solvent o-dichlorobenzene, charge extraction increased leading to fill factors as high as 69.5%, without low work-function cathodes, electrode buffer layers or thermal treatment. This was attributed to PCBM demixing from P3HT domains and better vertical phase separation, as indicated by photoluminescence lifetimes, hole mobilities, and shunt leakage currents. Dependence on solvent parameters and applicability beyond P3HT system was also investigated. (C) 2013 Elsevier B.V. All rights reserved.

  2. Morphological control in polymer solar cells using low-boiling-point solvent additives

    NASA Astrophysics Data System (ADS)

    Mahadevapuram, Rakesh C.

    In the global search for clean, renewable energy sources, organic photovoltaics (OPVs) have recently been given much attention. Popular modern-day OPVs are made from solution-processible, carbon-based polymers (e.g. the model poly(3-hexylthiophene) that are intimately blended with fullerene derivatives (e.g. [6,6]-phenyl-C71-butyric acid methyl ester) to form what is known as the dispersed bulk-heterojunction (BHJ). This BHJ architecture has produced some of the most efficient OPVs to date, with reports closing in on 10% power conversion efficiency. To push efficiencies further into double digits, many groups have identified the BHJ nanomorphology---that is, the phase separations and grain sizes within the polymer: fullerene composite---as a key aspect in need of control and improvement. As a result, many methods, including thermal annealing, slow-drying (solvent) annealing, vapor annealing, and solvent additives, have been developed and studied to promote BHJ self-organization. Processing organic photovoltaic (OPV) blend solutions with high-boiling-point solvent additives has recently been used for morphological control in BHJ OPV cells. Here we show that even low-boiling-point solvents can be effective additives. When P3HT:PCBM OPV cells were processed with a low-boiling-point solvent tetrahydrafuran as an additive in parent solvent o-dichlorobenzene, charge extraction increased leading to fill factors as high as 69.5%, without low work-function cathodes, electrode buffer layers or thermal treatment. This was attributed to PCBM demixing from P3HT domains and better vertical phase separation, as indicated by photoluminescence lifetimes, hole mobilities, and shunt leakage currents. Dependence on solvent parameters and applicability beyond P3HT system was also investigated.

  3. Floating Point Control Library

    2007-08-02

    Floating Point Control is a Library that allows for the manipulation of floating point unit exception masking funtions control exceptions in both the Streaming "Single Instruction, Multiple Data" Extension 2 (SSE2) unit and the floating point unit simultaneously. FPC also provides macros to set floating point rounding and precision control.

  4. SPS antenna pointing control

    NASA Technical Reports Server (NTRS)

    Hung, J. C.

    1980-01-01

    The pointing control of a microwave antenna of the Satellite Power System was investigated emphasizing: (1) the SPS antenna pointing error sensing method; (2) a rigid body pointing control design; and (3) approaches for modeling the flexible body characteristics of the solar collector. Accuracy requirements for the antenna pointing control consist of a mechanical pointing control accuracy of three arc-minutes and an electronic phased array pointing accuracy of three arc-seconds. Results based on the factors considered in current analysis, show that the three arc-minute overall pointing control accuracy can be achieved in practice.

  5. Smog control fuel additives

    SciTech Connect

    Lundby, W.

    1993-06-29

    A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

  6. Pointing control for LDR

    NASA Technical Reports Server (NTRS)

    Yam, Y.; Briggs, C.

    1988-01-01

    One important aspect of the LDR control problem is the possible excitations of structural modes due to random disturbances, mirror chopping, and slewing maneuvers. An analysis was performed to yield a first order estimate of the effects of such dynamic excitations. The analysis involved a study of slewing jitters, chopping jitters, disturbance responses, and pointing errors, making use of a simplified planar LDR model which describes the LDR dynamics on a plane perpendicular to the primary reflector. Briefly, the results indicate that the command slewing profile plays an important role in minimizing the resultant jitter, even to a level acceptable without any control action. An optimal profile should therefore be studied.

  7. Improvements in floating point addition/subtraction operations

    DOEpatents

    Farmwald, P.M.

    1984-02-24

    Apparatus is described for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  8. 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.

  9. Remote temperature-set-point controller

    DOEpatents

    Burke, William F.; Winiecki, Alan L.

    1986-01-01

    An instrument for carrying out mechanical strain tests on metallic samples with the addition of an electrical system for varying the temperature with strain, the instrument including opposing arms and associated equipment for holding a sample and varying the mechanical strain on the sample through a plurality of cycles of increasing and decreasing strain within predetermined limits, circuitry for producing an output signal representative of the strain during the tests, apparatus including a set point and a coil about the sample for providing a controlled temperature in the sample, and circuitry interconnected between the strain output signal and set point for varying the temperature of the sample linearly with strain during the tests.

  10. Wavefront sensing, control, and pointing

    NASA Technical Reports Server (NTRS)

    Pitts, Thomas; Sevaston, George; Agronin, Michael; Bely, Pierre; Colavita, Mark; Clampin, Mark; Harvey, James; Idell, Paul; Sandler, Dave; Ulmer, Melville

    1992-01-01

    A majority of future NASA astrophysics missions from orbiting interferometers to 16-m telescopes on the Moon have, as a common requirement, the need to bring light from a large entrance aperture to the focal plane in a way that preserves the spatial coherence properties of the starlight. Only by preserving the phase of the incoming wavefront, can many scientific observations be made, observations that range from measuring the red shift of quasi-stellar objects (QSO's) to detecting the IR emission of a planet in orbit around another star. New technologies for wavefront sensing, control, and pointing hold the key to advancing our observatories of the future from those already launched or currently under development. As the size of the optical system increases, either to increase the sensitivity or angular resolution of the instrument, traditional technologies for maintaining optical wavefront accuracy become prohibitively expensive or completely impractical. For space-based instruments, the low mass requirement and the large temperature excursions further challenge existing technologies. The Hubble Space Telescope (HST) is probably the last large space telescope to rely on passive means to keep its primary optics stable and the optical system aligned. One needs only look to the significant developments in wavefront sensing, control, and pointing that have occurred over the past several years to appreciate the potential of this technology for transforming the capability of future space observatories. Future developments in space-borne telescopes will be based in part on developments in ground-based systems. Telescopes with rigid primary mirrors much larger than 5 m in diameter are impractical because of gravity loading. New technologies are now being introduced, such as active optics, that address the scale problem and that allow very large telescopes to be built. One approach is a segmented design such as that being pioneered by the W.M. Keck telescope now under

  11. New ESP additive controls particulates

    SciTech Connect

    Durham, M.D.; Baldrey, K.E.; Bustard, C.J.; Martin, C.E.; Dharmarajan, N.N.

    1997-06-01

    This article reports that a conditioning agent enhanced precipitator performance after plant switched to low-sulfur coal. Firing low-sulfur coal at a power plant designed for medium- or high-sulfur coal will impact the downstream particulate control device. Since the performance of an electro-static precipitator (ESP) is a strong function of the sulfur content in the coal, switching to a low-sulfur coal will severely impact collection efficiency. Particle resistivity is the dominant parameter affecting the performance of an ESP. When the resistivity is too high, the ESP must be increased in size by a factor of two to three, resulting in proportionally increased capital and operating costs. Fly ash from low-sulfur coal is known to have a typical resistivity one or two orders of magnitude above that for ideal collection efficiency in a well-designed ESP. Therefore, when a utility burning a medium- or high-sulfur coal switches to a low-sulfur coal, the increase in particle resistivity resulting from the reduced SO{sub 3} concentration will lead to severe problems in the ESP. There have been many instances where utilities have switched from a high- to a low-sulfur coal, and the problems caused by the increased resistivity have had such a devastating effect on the performance of the ESP that emissions have increased by a factor of 10.

  12. Satellite Power System (SPS) antenna pointing control

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Accuracy requirements for the SPS antenna pointing control consists of a mechanical pointing accuracy of three arc minutes and an electronic phased array pointing accuracy of three arc seconds. Results of this study, based on the factors considered in current analysis, show that the three arc minute overall pointing control accuracy can be achieved for the SPS in practice.

  13. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  14. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  15. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  16. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  17. 47 CFR 22.325 - Control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Control points. 22.325 Section 22.325... Operational and Technical Requirements Operational Requirements § 22.325 Control points. Each station in the Public Mobile Services must have at least one control point and a person on duty who is responsible...

  18. Pointing control for the International Comet Mission

    NASA Technical Reports Server (NTRS)

    Leblanc, D. R.; Schumacher, L. L.

    1980-01-01

    The design of the pointing control system for the proposed International Comet Mission, intended to fly by Comet Halley and rendezvous with Comet Tempel-2 is presented. Following a review of mission objectives and the spacecraft configuration, design constraints on the pointing control system controlling the two-axis gimballed scan platform supporting the science instruments are discussed in relation to the scientific requirements of the mission. The primary design options considered for the pointing control system design for the baseline spacecraft are summarized, and the design selected, which employs a target-referenced, inertially stabilized control system, is described in detail. The four basic modes of operation of the pointing control subsystem (target acquisition, inertial hold, target track and slew) are discussed as they relate to operations at Halley and Tempel-2. It is pointed that the pointing control system design represents a significant advance in the state of the art of pointing controls for planetary missions.

  19. Controlling superconductivity by tunable quantum critical points.

    PubMed

    Seo, S; Park, E; Bauer, E D; Ronning, F; Kim, J N; Shim, J-H; Thompson, J D; Park, Tuson

    2015-03-04

    The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5.

  20. Controlling superconductivity by tunable quantum critical points.

    PubMed

    Seo, S; Park, E; Bauer, E D; Ronning, F; Kim, J N; Shim, J-H; Thompson, J D; Park, Tuson

    2015-01-01

    The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5. PMID:25737108

  1. Remote temperature-set-point controller

    DOEpatents

    Burke, W.F.; Winiecki, A.L.

    1984-10-17

    An instrument is described for carrying out mechanical strain tests on metallic samples with the addition of means for varying the temperature with strain. The instrument includes opposing arms and associated equipment for holding a sample and varying the mechanical strain on the sample through a plurality of cycles of increasing and decreasing strain within predetermined limits, circuitry for producing an output signal representative of the strain during the tests, apparatus including a a set point and a coil about the sample for providing a controlled temperature in the sample, and circuitry interconnected between the strain output signal and set point for varying the temperature of the sample linearly with strain during the tests.

  2. Control of the Crystalline Morphology of Poly(l-lactide) by Addition of High-Melting-Point Poly(l-lactide) and Its Effect on the Distribution of Multiwalled Carbon Nanotubes.

    PubMed

    Zhang, Kai; Peng, Ji-Kun; Shi, Yu-Dong; Chen, Yi-Fu; Zeng, Jian-Bing; Wang, Ming

    2016-08-01

    The key to fabricating conductive polymer/carbon nanotube (CNT) nanocomposites is controlling the distribution of CNTs in the polymer matrix. Here, an effective and simple approach for controlling the distribution of multiwalled CNTs (MWCNTs) is reported to largely improve the electrical conductivity of biodegradable poly(l-lactide) (PLLA) through crystalline morphology development by addition of high-melting-point PLLA (hPLLA) crystallites. hPLLA crystallites are efficient nucleating agents, increasing the crystallinity and crystallization rate of PLLA/MWCNT nanocomposites. Furthermore, the diameter of spherulites decreases from 9.7 to 1.0 μm with an increase in the concentration of hPLLA from 0.03 to 3.0 wt %. The electrical conductivity of PLLA/MWCNT nanocomposites with 0.3 wt % MWCNTs greatly increases from 1.89 × 10(-15) to 1.56 × 10(-8) S/cm with an increase in the matrix crystallinity from 2.4 to 46.8% on introducing trace amounts of hPLLA (0.07 wt %). The percolation threshold of PLLA/MWCNT nanocomposites is reduced from 0.51 to 0.21 wt % on addition of 0.07 wt % hPLLA. The high electrical conductivity and low percolation threshold of PLLA/MWCNT nanocomposites incorporated with hPLLA are related to the high crystallinity and crystalline morphologies of the PLLA matrix. Big spherulites lock a lot of MWCNTs at the intervals in the spherulites, which is harmful to the electrical conductivity. Small spherulites, with large surface areas, also need more MWCNTs to form conductive networks in the amorphous regions. Most MWCNTs that are bundled together to form conductive paths are found in samples with mid-sized spherulites of ∼6.7 μm. More interestingly, the high crystallinity and reconstructed MWCNT network also enhanced the Young modulus, elongation at break, and elastic modulus at high temperature of PLLA/MWCNT nanocomposites with small amounts of hPLLA. PMID:27379385

  3. Control of the Crystalline Morphology of Poly(l-lactide) by Addition of High-Melting-Point Poly(l-lactide) and Its Effect on the Distribution of Multiwalled Carbon Nanotubes.

    PubMed

    Zhang, Kai; Peng, Ji-Kun; Shi, Yu-Dong; Chen, Yi-Fu; Zeng, Jian-Bing; Wang, Ming

    2016-08-01

    The key to fabricating conductive polymer/carbon nanotube (CNT) nanocomposites is controlling the distribution of CNTs in the polymer matrix. Here, an effective and simple approach for controlling the distribution of multiwalled CNTs (MWCNTs) is reported to largely improve the electrical conductivity of biodegradable poly(l-lactide) (PLLA) through crystalline morphology development by addition of high-melting-point PLLA (hPLLA) crystallites. hPLLA crystallites are efficient nucleating agents, increasing the crystallinity and crystallization rate of PLLA/MWCNT nanocomposites. Furthermore, the diameter of spherulites decreases from 9.7 to 1.0 μm with an increase in the concentration of hPLLA from 0.03 to 3.0 wt %. The electrical conductivity of PLLA/MWCNT nanocomposites with 0.3 wt % MWCNTs greatly increases from 1.89 × 10(-15) to 1.56 × 10(-8) S/cm with an increase in the matrix crystallinity from 2.4 to 46.8% on introducing trace amounts of hPLLA (0.07 wt %). The percolation threshold of PLLA/MWCNT nanocomposites is reduced from 0.51 to 0.21 wt % on addition of 0.07 wt % hPLLA. The high electrical conductivity and low percolation threshold of PLLA/MWCNT nanocomposites incorporated with hPLLA are related to the high crystallinity and crystalline morphologies of the PLLA matrix. Big spherulites lock a lot of MWCNTs at the intervals in the spherulites, which is harmful to the electrical conductivity. Small spherulites, with large surface areas, also need more MWCNTs to form conductive networks in the amorphous regions. Most MWCNTs that are bundled together to form conductive paths are found in samples with mid-sized spherulites of ∼6.7 μm. More interestingly, the high crystallinity and reconstructed MWCNT network also enhanced the Young modulus, elongation at break, and elastic modulus at high temperature of PLLA/MWCNT nanocomposites with small amounts of hPLLA.

  4. Learning the Critical Points for Addition in Matematika GASING

    ERIC Educational Resources Information Center

    Siregar, Johannes Hamonangan; Wiyanti, Wiwik; Wakhyuningsih, Nur Safitri; Godjali, Ali

    2014-01-01

    We propose learning Matematika GASING to help students better understand the addition material. Matematika GASING is a way of learning mathematics in an easy, fun and enjoyable fashion. GASING is short for GAmpang, aSyIk, and menyenaNGkan (Bahasa Indonesia for easy, fun and enjoyable). It was originally developed by Prof. Yohanes Surya at the…

  5. Micro-Precision Interferometer: Pointing Control System

    NASA Technical Reports Server (NTRS)

    O'Brien, John

    1995-01-01

    This paper describes the development of the wavefront tilt (pointing) control system for the JPL Micro-Precision Interferometer (MPI). This control system employs piezo-electric actuators and a digital imaging sensor with feedback compensation to reject errors in instrument pointing. Stringent performance goals require large feedback, however, several characteristics of the plant tend to restrict the available bandwidth. A robust 7th-order wavefront tilt control system was successfully implemented on the MPI instrument, providing sufficient disturbance rejection performance to satisfy the established interference fringe visibility.

  6. Point to Point Control of the Hydrogen Mixer

    NASA Technical Reports Server (NTRS)

    Barbieri, Enrique; Richter, Hanz; Figueroa, Fernando

    2003-01-01

    We continue to build on the theoretical modelling of a liquid hydrogen (LH2) and gas hydrogen (GH2) mixer subsystem. The mixer described in this work is responsible for combining high pressure LH2 and GH2 to produce a hydrogen flow that meets certain thermodynamic properties. The desired properties are maintained by precise control of the LH2 and GH2 flows. The mixer is modelled as a general multi-flow lumped volume for single constituent fluids using density and internal energy as states. The set of nonlinear differential equations is modelled in the SIMULINK environment including a table look-up feature of the fluid thermodynamic properties. A small signal (linear) model is developed based on the nonlinear model and simulated as well. Pulse disturbances are introduced to the valve positions and the quality of the linear model is ascertained by comparing its behavior against the nonlinear model simulations. Valve control strategies that simulate an operator-in-the-loop scenario are then explored demonstrating the need for automatic feedback control. Finally, optimal single-output and multi-output Proportional/Integral controllers are designed based on the linear model and applied to the nonlinear model with excellent results to track simultaneous, constant setpoint changes in desired exit flow, exit temperature, and mixer pressure, as well as to reject unmeasureable but bounded additive step perturbations in the valve positions.

  7. Laboratory tests of sludge-control additives

    SciTech Connect

    Tatnall, R.E.

    1996-07-01

    Laboratory {open_quotes}jar{close_quotes} tests compared eleven different fuel oil and diesel fuel sludge-control additives. Factors studied included (1) ability to disperse and prevent buildup of sludge deposits on surfaces, (2) ability to protect steel from corrosion, (3) ability to inhibit growth and proliferation of bacteria, and (4) ability to disperse water. Results varied greatly, and it was found that many commercial products do not do what they claim. It is concluded that fuel retailers should not believe manufacturers` claims for their additive products, but rather should test such products themselves to be sure that the benefits of treatment are real. A simplified form of the procedure used here is proposed as one way for dealers to do such testing.

  8. Emission control devices, fuel additive, and fuel composition changes.

    PubMed Central

    Piver, W T

    1977-01-01

    Emission control devices are installed to meet the exhaust standards of the Clean Air Act for carbon monoxide and hydrocarbons, and it is necessary to know, from a public health point of view, how exhaust emissions may be affected by changes in fuel additives and fuel composition. Since these topics are concerned with developing technologies, the available literature on exhaust emission characteristics and the limited information on health effects, is reviewed. PMID:71235

  9. Bifurcated method and apparatus for floating point addition with decreased latency time

    DOEpatents

    Farmwald, Paul M.

    1987-01-01

    Apparatus for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  10. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  11. A low cost LST pointing control system

    NASA Technical Reports Server (NTRS)

    Glaese, J. R.; Kennel, H. F.; Nurre, G. S.; Seltzer, S. M.; Shelton, H. L.

    1975-01-01

    Vigorous efforts to reduce costs, coupled with changes in LST guidelines, took place in the Fall of 1974. These events made a new design of the LST and its Pointing and Attitude Control System possible. The major design changes are summarized as: an annular Support Systems Module; removal of image motion compensation; reaction wheels instead of CMG's; a magnetic torquer system to also perform the emergency and backup functions, eliminating the previously required mass expulsion system. Preliminary analysis indicates the Low Cost LST concept can meet the newly defined requirements and results in a significantly reduced development cost.

  12. Algebraic grid generation with control points

    NASA Technical Reports Server (NTRS)

    Eiseman, Peter R.; Choo, Yung K.; Smith, Robert E.

    1992-01-01

    The control-point form (CPF) formulation is an algebraically defined class of coordinate transformations by means of which the interior form of the coordinates can be manipulated in the local fashion, and any boundary can be either specified or manipulated in a similar manner. Currently, the most intense activity involving CPF is with such graphic interactive codes as TurboI and TurboT, for which detailed illustrative examples are given; these have furnished experience on whose basis future interactive strategies can be developed.

  13. Iron-control additives improve acidizing

    SciTech Connect

    Walker, M.; Dill, W. ); Besler, M. )

    1989-07-24

    Iron sulfide and sulfur precipitation in sour wells can be controlled with iron-sequestering agents and sulfide modifiers. Oil production has been routinely increased in sour wells where precipitation of iron sulfide and elemental sulfur has been brought under control. Production increases have been especially noteworthy on wells that had a history of rapid production decline after acid stimulation. Twenty-fold production increases have been recorded. Key to the production increase has been to increase permeability with: Iron chelating agents that control precipitation of iron sulfide. A sulfide modifier that reduces precipitation of solids in the presence of excessive amounts of hydrogen sulfide and prevents precipitation of elemental sulfur.

  14. CONTROL ROD ALLOY CONTAINING NOBLE METAL ADDITIONS

    DOEpatents

    Anderson, W.K.; Ray, W.E.

    1960-05-01

    Silver-base alloys suitable for use in the fabrication of control rods for neutronic reactors are given. The alloy consists of from 0.5 wt.% to about 1.5 wt.% of a noble metal of platinum, ruthenium, rhodium, osmium, or palladium, up to 10 wt.% of cadmium, from 2 to 20 wt.% indium, the balance being silver.

  15. Modular control of pointing beyond arm's length.

    PubMed

    Berret, Bastien; Bonnetblanc, François; Papaxanthis, Charalambos; Pozzo, Thierry

    2009-01-01

    Hand reaching and bipedal equilibrium are two important functions of the human motor behavior. However, how the brain plans goal-oriented actions combining target reaching with equilibrium regulation is not yet clearly understood. An important question is whether postural control and reaching are integrated in one single module or controlled separately. Here, we show that postural control and reaching motor commands are processed by means of a modular and flexible organization. Principal component and correlation analyses between pairs of angles were used to extract global and local coupling during a whole-body pointing beyond arm's length. A low-dimensional organization of the redundant kinematic chain allowing simultaneous target reaching and regulation of the center of mass (CoM) displacement in extrinsic space emerged from the first analysis. In follow-up experiments, both the CoM and finger trajectories were constrained by asking participants to reach from a reduced base of support with or without knee flexion, or by moving the endpoint along a predefined trajectory (straight or semicircular trajectories). Whereas joint covaried during free conditions and under equilibrium restrictions, it was decomposed in two task-dependent and task-independent modules, corresponding to a dissociation of arm versus legs, trunk, and head coordination, respectively, under imposed finger path conditions. A numerical simulation supported the idea that both postural and focal subtasks are basically integrated into the same motor command and that the CNS is able to combine or to separate the movement into autonomous functional synergies according to the task requirements.

  16. Optimal periodic control for spacecraft pointing and attitude determination

    NASA Technical Reports Server (NTRS)

    Pittelkau, Mark E.

    1993-01-01

    A new approach to autonomous magnetic roll/yaw control of polar-orbiting, nadir-pointing momentum bias spacecraft is considered as the baseline attitude control system for the next Tiros series. It is shown that the roll/yaw dynamics with magnetic control are periodically time varying. An optimal periodic control law is then developed. The control design features a state estimator that estimates attitude, attitude rate, and environmental torque disturbances from Earth sensor and sun sensor measurements; no gyros are needed. The state estimator doubles as a dynamic attitude determination and prediction function. In addition to improved performance, the optimal controller allows a much smaller momentum bias than would otherwise be necessary. Simulation results are given.

  17. Microstructural Control of Additively Manufactured Metallic Materials

    NASA Astrophysics Data System (ADS)

    Collins, P. C.; Brice, D. A.; Samimi, P.; Ghamarian, I.; Fraser, H. L.

    2016-07-01

    In additively manufactured (AM) metallic materials, the fundamental interrelationships that exist between composition, processing, and microstructure govern these materials’ properties and potential improvements or reductions in performance. For example, by using AM, it is possible to achieve highly desirable microstructural features (e.g., highly refined precipitates) that could not otherwise be achieved by using conventional approaches. Simultaneously, opportunities exist to manage macro-level microstructural characteristics such as residual stress, porosity, and texture, the last of which might be desirable. To predictably realize optimal microstructures, it is necessary to establish a framework that integrates processing variables, alloy composition, and the resulting microstructure. Although such a framework is largely lacking for AM metallic materials, the basic scientific components of the framework exist in literature. This review considers these key components and presents them in a manner that highlights key interdependencies that would form an integrated framework to engineer microstructures using AM.

  18. Comparing Number Lines and Touch Points to Teach Addition Facts to Students with Autism

    ERIC Educational Resources Information Center

    Cihak, David F.; Foust, Jennifer L.

    2008-01-01

    Three elementary students with autism were taught single-digit addition problem-solving skills using number and touch-point strategies. Prior to the study, all students were unable to correctly calculate single-digit addition problems. An alternating-treatments design was used to compare the acquisition performance of single-digit addition…

  19. Spectrophotometric study of complexation equilibria with H-point standard addition and H-point curve isolation methods.

    PubMed

    Abdollahi, H; Zeinali, S

    2004-01-01

    The use of H-point curve isolation (HPCIM) and H-point standard addition methods (HPSAM) for spectrophotometric studies of complex formation equilibria are proposed. One step complex formation, two successive stepwise and mononuclear complex formation systems, and competitive complexation systems are studied successfully by the proposed methods. HPCIM is used for extracting the spectrum of complex or sum of complex species and HPSAM is used for calculation of equilibrium concentrations of ligand for each sample. The outputs of these procedures are complete concentration profiles of equilibrium system, spectral profile of intermediate components, and good estimation of conditional formation constants. The reliability of the method is evaluated using model data. Spectrophotometric studies of murexide-calcium, dithizone-nickel, methyl thymol blue (MTB)-copper, and competition of murexide and sulfate ions for complexation with zinc, are used as experimental model systems with different complexation stoichiometries and spectral overlapping of involved components.

  20. MSFC Skylab attitude and pointing control system mission evaluation

    NASA Technical Reports Server (NTRS)

    Chubb, W. B.

    1974-01-01

    The results of detailed performance analyses of the attitude and pointing control system in-orbit hardware and software on Skylab are reported. Performance is compared with requirements, test results, and prelaunch predictions. A brief history of the altitude and pointing control system evolution leading to the launch configuration is presented. The report states that the attitude and pointing system satisfied all requirements.

  1. Pointing control design for autonomous space vehicle applications

    SciTech Connect

    Young, K.D.

    1993-03-01

    This paper addresses the design of pointing control systems for autonomous space vehicles. The function of the pointing control system is to keep distant orbiting objects within the field-of-view of an on-board optical sensor. We outline the development of novel nonlinear control algorithms which exploit the availability of on- board sensors. Simulation results comparing the performance of the different pointing control implementations are presented.

  2. Validation of acid washes as critical control points in hazard analysis and critical control point systems.

    PubMed

    Dormedy, E S; Brashears, M M; Cutter, C N; Burson, D E

    2000-12-01

    A 2% lactic acid wash used in a large meat-processing facility was validated as an effective critical control point (CCP) in a hazard analysis and critical control point (HACCP) plan. We examined the microbial profiles of beef carcasses before the acid wash, beef carcasses immediately after the acid wash, beef carcasses 24 h after the acid wash, beef subprimal cuts from the acid-washed carcasses, and on ground beef made from acid-washed carcasses. Total mesophilic, psychrotrophic, coliforms, generic Escherichia coli, lactic acid bacteria, pseudomonads, and acid-tolerant microorganisms were enumerated on all samples. The presence of Salmonella spp. was also determined. Acid washing significantly reduced all counts except for pseudomonads that were present at very low numbers before acid washing. All other counts continued to stay significantly lower (P < 0.05) than those on pre-acid-washed carcasses throughout all processing steps. Total bacteria, coliforms, and generic E. coli enumerated on ground beef samples were more than 1 log cycle lower than those reported in the U.S. Department of Agriculture Baseline data. This study suggests that acid washes may be effective CCPs in HACCP plans and can significantly reduce the total number of microorganisms present on the carcass and during further processing. PMID:11131890

  3. Control points within the cell cycle

    SciTech Connect

    Van't Hof, J.

    1984-01-01

    Evidence of the temporal order of chromosomal DNA replication argues favorably for the view that the cell cycle is controlled by genes acting in sequence whose time of expression is determined by mitosis and the amount of nuclear DNA (2C vs 4C) in the cell. Gl and G2 appear to be carbohydrate dependent in that cells starved of either carbohydrate of phosphate fail to make these transitions. Cells deprived of nitrate, however, fail only at Gl to S transition indicating that the controls that operate in G1 differ from those that operate in G2. 46 references, 5 figures.

  4. Strike Point Control for the National Spherical Torus Experiment (NSTX)

    SciTech Connect

    Kolemen, E.; Gates, D. A.; Rowley, C. W.; Kasdin, N. J.; Kallman, J.; Gerhardt, S.; Soukhanovskii, V.; Mueller, D.

    2010-07-09

    This paper presents the first control algorithm for the inner and outer strike point position for a Spherical Torus (ST) fusion experiment and the performance analysis of the controller. A liquid lithium divertor (LLD) will be installed on NSTX which is believed to provide better pumping than lithium coatings on carbon PFCs. The shape of the plasma dictates the pumping rate of the lithium by channeling the plasma to LLD, where strike point location is the most important shape parameter. Simulations show that the density reduction depends on the proximity of strike point to LLD. Experiments were performed to study the dynamics of the strike point, design a new controller to change the location of the strike point to desired location and stabilize it. The most effective PF coils in changing inner and outer strike points were identified using equilibrium code. The PF coil inputs were changed in a step fashion between various set points and the step response of the strike point position was obtained. From the analysis of the step responses, PID controllers for the strike points were obtained and the controller was tuned experimentally for better performance. The strike controller was extended to include the outer-strike point on the inner plate to accommodate the desired low outer-strike points for the experiment with the aim of achieving "snowflake" divertor configuration in NSTX.

  5. Pointing Control System for a High Precision Flight Telescope

    SciTech Connect

    BENTLEY,ANTHONY E.; WILCOXEN,JEFFREY LEE

    2000-12-01

    A pointing control system is developed and tested for a flying gimbaled telescope. The two-axis pointing system is capable of sub-microradian pointing stability and high accuracy in the presence of large host vehicle jitter. The telescope also has high agility--it is capable of a 50-degree retarget (in both axes simultaneously) in less than 2 seconds. To achieve the design specifications, high-accuracy, high-resolution, two-speed resolvers were used, resulting in gimbal-angle measurements stable to 1.5 microradians. In addition, on-axis inertial angle displacement sensors were mounted on the telescope to provide host-vehicle jitter cancellation. The inertial angle sensors are accurate to about 100 nanoradians, but do not measure low frequency displacements below 2 Hz. The gimbal command signal includes host-vehicle attitude information, which is band-limited. This provides jitter data below 20 Hz, but includes a variable latency between 15 and 25 milliseconds. One of the most challenging aspects of this design was to combine the inertial-angle-sensor data with the less perfect information in the command signal to achieve maximum jitter reduction. The optimum blending of these two signals, along with the feedback compensation were designed using Quantitative Feedback Theory.

  6. 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.

  7. One of two rotodip feeders used to control addition of ...

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

    One of two rotodip feeders used to control addition of alum solution into the water - Division Avenue Pumping Station & Filtration Plant, West 45th Street and Division Avenue, Cleveland, Cuyahoga County, OH

  8. 78. SAC control center aboveground addition partial first floor plan, ...

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

    78. SAC control center aboveground addition partial first floor plan, drawing number AW30-02-09, dated 15 October, 1962 - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  9. A multiple pointing-mount control strategy for space platforms

    NASA Technical Reports Server (NTRS)

    Johnson, C. D.

    1992-01-01

    A new disturbance-adaptive control strategy for multiple pointing-mount space platforms is proposed and illustrated by consideration of a simplified 3-link dynamic model of a multiple pointing-mount space platform. Simulation results demonstrate the effectiveness of the new platform control strategy. The simulation results also reveal a system 'destabilization phenomena' that can occur if the set of individual platform-mounted experiment controllers are 'too responsive.'

  10. Point defect concentrations and solid solution hardening in NiAl with Fe additions

    SciTech Connect

    Pike, L.M.; Chang, Y.A.; Liu, C.T.

    1997-08-01

    The solid solution hardening behavior exhibited when Fe is added to NiAl is investigated. This is an interesting problem to consider since the ternary Fe additions may choose to occupy either the Ni or the Al sublattice, affecting the hardness at differing rates. Moreover, the addition of Fe may affect the concentrations of other point defects such as vacancies and Ni anti-sites. As a result, unusual effects ranging from rapid hardening to solid solution softening are observed. Alloys with varying amounts of Fe were prepared in Ni-rich (40 at. % Al) and stoichiometric (50 at. % Al) compositions. Vacancy concentrations were measured using lattice parameter and density measurements. The site occupancy of Fe was determined using ALCHEMI. Using these two techniques the site occupancies of all species could be uniquely determined. Significant differences in the defect concentrations as well as the hardening behavior were encountered between the Ni-rich and stoichiometric regimes.

  11. Control of pyrite addition in coal liquefaction process

    DOEpatents

    Schmid, Bruce K.; Junkin, James E.

    1982-12-21

    Pyrite addition to a coal liquefaction process (22, 26) is controlled (118) in inverse proportion to the calcium content of the feed coal to maximize the C.sub.5 --900.degree. F. (482.degree. C.) liquid yield per unit weight of pyrite added (110). The pyrite addition is controlled in this manner so as to minimize the amount of pyrite used and thus reduce pyrite contribution to the slurry pumping load and disposal problems connected with pyrite produced slag.

  12. Octopuses use a human-like strategy to control precise point-to-point arm movements.

    PubMed

    Sumbre, Germán; Fiorito, Graziano; Flash, Tamar; Hochner, Binyamin

    2006-04-18

    One of the key problems in motor control is mastering or reducing the number of degrees of freedom (DOFs) through coordination. This problem is especially prominent with hyper-redundant limbs such as the extremely flexible arm of the octopus. Several strategies for simplifying these control problems have been suggested for human point-to-point arm movements. Despite the evolutionary gap and morphological differences, humans and octopuses evolved similar strategies when fetching food to the mouth. To achieve this precise point-to-point-task, octopus arms generate a quasi-articulated structure based on three dynamic joints. A rotational movement around these joints brings the object to the mouth . Here, we describe a peripheral neural mechanism-two waves of muscle activation propagate toward each other, and their collision point sets the medial-joint location. This is a remarkably simple mechanism for adjusting the length of the segments according to where the object is grasped. Furthermore, similar to certain human arm movements, kinematic invariants were observed at the joint level rather than at the end-effector level, suggesting intrinsic control coordination. The evolutionary convergence to similar geometrical and kinematic features suggests that a kinematically constrained articulated limb controlled at the level of joint space is the optimal solution for precise point-to-point movements.

  13. A chronology of the on-orbit pointing control system changes on the Hubble Space Telescope and associated pointing improvements

    NASA Technical Reports Server (NTRS)

    Sharkey, J. P.; Nurre, G. S.; Beals, G. A.; Nelson, J. D.

    1992-01-01

    The pointing control system on the Hubble Space Telescope was designed to keep an image stable in the focal plane to 0.007 arc seconds (rms) for observations lasting from seconds to hours. Following the on-orbit deployment, this level of pointing performance was achieved only for short intervals during each orbit because of unexpected disturbances originating in the Solar Arrays. Since this problem was first recognized, several control system redesigns have been carried out and uplinked to the spacecraft with increasing degrees of success. This paper presents a chronology of those activities. In addition, sufficient background material is included regarding the pointing control system and the Solar Array disturbance so that the contents can be understood without reverting to the details in the reference material.

  14. A chronology of the on-orbit pointing control system changes on the Hubble Space Telescope and associated pointing improvements

    NASA Astrophysics Data System (ADS)

    Sharkey, J. P.; Nurre, G. S.; Beals, G. A.; Nelson, J. D.

    1992-08-01

    The pointing control system on the Hubble Space Telescope was designed to keep an image stable in the focal plane to 0.007 arc seconds (rms) for observations lasting from seconds to hours. Following the on-orbit deployment, this level of pointing performance was achieved only for short intervals during each orbit because of unexpected disturbances originating in the Solar Arrays. Since this problem was first recognized, several control system redesigns have been carried out and uplinked to the spacecraft with increasing degrees of success. This paper presents a chronology of those activities. In addition, sufficient background material is included regarding the pointing control system and the Solar Array disturbance so that the contents can be understood without reverting to the details in the reference material.

  15. Disparities and Menthol Marketing: Additional Evidence in Support of Point of Sale Policies

    PubMed Central

    Moreland-Russell, Sarah; Harris, Jenine; Snider, Doneisha; Walsh, Heidi; Cyr, Julianne; Barnoya, Joaquin

    2013-01-01

    This study examined factors associated with point-of-sale tobacco marketing in St. Louis, an urban city in the United States. Using spatial analysis, descriptive statistics, and multilevel modeling, we examined point-of-sale data and the proportion of mentholated cigarette and total cigarette marketing from 342 individual tobacco retail stores within St. Louis census tracts characterized by the percent of black adults and children. Menthol and total tobacco product marketing was highest in areas with the highest percentages of black residents. When examining menthol marketing to children, we did not find as strong of a relationship, however results of multilevel modeling indicate that as the proportion of black children in a census tract increased, the proportion of menthol marketing near candy also increased. These results indicate the need for communities globally to counter this targeted marketing by taking policy action specifically through the enactment of marketing restrictions provided by the 2009 Family Smoking Prevention and Tobacco Control Act and the Framework Convention of Tobacco Control. PMID:24071922

  16. Disparities and menthol marketing: additional evidence in support of point of sale policies.

    PubMed

    Moreland-Russell, Sarah; Harris, Jenine; Snider, Doneisha; Walsh, Heidi; Cyr, Julianne; Barnoya, Joaquin

    2013-09-25

    This study examined factors associated with point-of-sale tobacco marketing in St. Louis, an urban city in the United States. Using spatial analysis, descriptive statistics, and multilevel modeling, we examined point-of-sale data and the proportion of mentholated cigarette and total cigarette marketing from 342 individual tobacco retail stores within St. Louis census tracts characterized by the percent of black adults and children. Menthol and total tobacco product marketing was highest in areas with the highest percentages of black residents. When examining menthol marketing to children, we did not find as strong of a relationship, however results of multilevel modeling indicate that as the proportion of black children in a census tract increased, the proportion of menthol marketing near candy also increased. These results indicate the need for communities globally to counter this targeted marketing by taking policy action specifically through the enactment of marketing restrictions provided by the 2009 Family Smoking Prevention and Tobacco Control Act and the Framework Convention of Tobacco Control.

  17. Digital controller design: Analysis of the annular suspension pointing system

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The annular suspension and pointing system (ASPS) a payload auxiliary pointing device of the space shuttle is briefly described along with the function of the digital controller. The equations of motion of a simplified plan planar model of the ASPS are derived. Results of computer simulations are discussed.

  18. Improvement of the cloud point extraction of uranyl ions by the addition of ionic liquids.

    PubMed

    Gao, Song; Sun, Taoxiang; Chen, Qingde; Shen, Xinghai

    2013-12-15

    The cloud point extraction (CPE) of uranyl ions by different kinds of extractants in Triton X-114 (TX-114) micellar solution was investigated upon the addition of ionic liquids (ILs) with various anions, i.e., bromide (Br(-)), tetrafluoroborate (BF4(-)), hexafluorophosphate (PF6(-)) and bis[(trifluoromethyl)sulfonyl]imide (NTf2(-)). A significant increase of the extraction efficiency was found on the addition of NTf2(-) based ILs when using neutral extractant tri-octylphosphine oxide (TOPO), and the extraction efficiency kept high at both nearly neutral and high acidity. However, the CPE with acidic extractants, e.g., bis(2-ethylhexyl) phosphoric acid (HDEHP) and 8-hydroxyquinoline (8-HQ) which are only effective at nearly neutral condition, was not improved by ILs. The results of zeta potential and (19)F NMR measurements indicated that the anion NTf2(-) penetrated into the TX-114 micelles and was enriched in the surfactant-rich phase during the CPE process. Meanwhile, NTf2(-) may act as a counterion in the CPE of UO2(2+) by TOPO. Furthermore, the addition of IL increased the separation factor of UO2(2+) and La(3+), which implied that in the micelle TOPO, NTf2(-) and NO3(-) established a soft template for UO2(2+). Therefore, the combination of CPE and IL provided a supramolecular recognition to concentrate UO2(2+) efficiently and selectively.

  19. Controller design and performance of the Spacelab instrument pointing system

    NASA Astrophysics Data System (ADS)

    Woelker, A.

    The Spacelab instrument pointing system (IPS) is designed for high-precision pointing of space experiments. The IPS demonstrated its performance during the maiden flight on the Shuttle in July 1985. The control system provides three-axis pointing and stabilization in the arcsec range for a variety of experiments. The envisaged pointing accuracy as well as the structural flexibility of the plant and disturbances imposed challenging requirements on the controller design. The control system comprises a feedback loop with attenuation filters and PID control as well as feed-forward compensation of external disturbances. Based on optical sensor and gyro measurements the attitude is determined via a special version of the Kalman filter.

  20. Simultaneous kinetic determination of levodopa and carbidopa by H-point standard addition method.

    PubMed

    Safavi, Afsaneh; Tohidi, Maryam

    2007-05-01

    The kinetic H-point standard addition method (HPSAM) was applied to the simultaneous determination of levodopa and carbidopa. The method was based on the difference in the rate of oxidation of these compounds with Cu(II)-neocuproine system and formation of Cu(I)-neocuproine complex at pH 5.5. The absorbance of the Cu(I)-neocuproine complex was monitored at 453 nm. Experimental conditions such as pH, reagent concentrations, ionic strength and temperature were optimized. Simultaneous determination of levodopa and carbidopa was performed in the range of 0.8-4 and 0.2-1.5 microg ml(-1), respectively. The proposed method was applied to the simultaneous determination of levodopa and carbidopa in pharmaceutical samples, and satisfactory results were obtained.

  1. Flight performance of Skylab attitude and pointing control system

    NASA Technical Reports Server (NTRS)

    Chubb, W. B.; Kennel, H. F.; Rupp, C. C.; Seltzer, S. M.

    1975-01-01

    The Skylab attitude and pointing control system (APCS) requirements are briefly reviewed and the way in which they became altered during the prelaunch phase of development is noted. The actual flight mission (including mission alterations during flight) is described. The serious hardware failures that occurred, beginning during ascent through the atmosphere, also are described. The APCS's ability to overcome these failures and meet mission changes are presented. The large around-the-clock support effort on the ground is discussed. Salient design points and software flexibility that should afford pertinent experience for future spacecraft attitude and pointing control system designs are included.

  2. Annular suspension and pointing system with controlled DC electromagnets

    NASA Technical Reports Server (NTRS)

    Vu, Josephine Lynn; Tam, Kwok Hung

    1993-01-01

    The Annular Suspension and Pointing System (ASPS) developed by the Flight System division of Sperry Corporation is a six-degree of freedom payload pointing system designed for use with the space shuttle. This magnetic suspension and pointing system provides precise controlled pointing in six-degrees of freedom, isolation of payload-carrier disturbances, and end mount controlled pointing. Those are great advantages over the traditional mechanical joints for space applications. In this design, we first analyzed the assumed model of the single degree ASPS bearing actuator and obtained the plant dynamics equations. By linearizing the plant dynamics equations, we designed the cascade and feedback compensators such that a stable and satisfied result was obtained. The specified feedback compensator was computer simulated with the nonlinearized plant dynamics equations. The results indicated that an unstable output occurred. In other words, the designed feedback compensator failed. The failure of the design is due to the Taylor's series expansion not converging.

  3. Digital controller design: Analysis of the annular suspension pointing system

    NASA Technical Reports Server (NTRS)

    Kuo, B. C.

    1979-01-01

    The Annular Suspension and Pointing System (ASPS) is a payload auxiliary pointing device of the Space Shuttle. The ASPS is comprised of two major subassemblies, a vernier and a coarse pointing subsystem. The experiment is attached to a mounting plate/rim combination which is suspended on magnetic bearing/actuators (MBA) strategically located about the rim. Fine pointing is achieved by gimballing the plate/rim within the MBA gaps. Control about the experiment line-of-sight is obtained through the use of a non-contacting rim drive and positioning torquer. All sensors used to close the servo loops on the vernier system are noncontacting elements. Therefore, the experiment is a free-flyer constrained only by the magnetic forces generated by the control loops.

  4. Ultrafast amplifier additive timing jitter characterization and control.

    PubMed

    Casanova, Alexis; D'Acremont, Quentin; Santarelli, Giorgio; Dilhaire, Stefan; Courjaud, Antoine

    2016-03-01

    We report on the characterization and long-term compensation of additive timing jitter introduced by a femtosecond ytterbium regenerative amplifier with a 100 kHz repetition rate. A balanced optical cross-correlation technique is used to generate a jitter error signal. This approach is well suited to characterize the additive timing jitter of Yb amplifiers seeded by narrow spectrum Yb oscillators. The balanced optical cross-correlator is in a noncollinear configuration allowing a background free coindence detection. This setup enables the measurement of additive timing jitter from the amplifier, with a noise floor of 300 as integrated from 10 Hz to 10 kHz. The measured additive timing jitter level is about 5 fs, integrated from 0.1 Hz to 10 kHz. The amplifier timing drift characterization and control are performed for more than an hour. PMID:26974074

  5. Noise Control for a Moving Evaluation Point Using Neural Networks

    NASA Astrophysics Data System (ADS)

    Maeda, Toshiki; Shiraishi, Toshihiko

    2016-09-01

    This paper describes the noise control for a moving evaluation point using neural networks by making the best use of its learning ability. Noise control is a technology which is effective on low-frequency noise. Based on the principle of superposition, a primary sound wave can be cancelled at an evaluation point by emitting a secondary opposite sound wave. To obtain good control performance, it is important to precisely identify the characteristics of all the sound paths. One of the most popular algorithms of noise control is filtered-x LMS algorithm. This algorithm can deliver a good result while all the sound paths do not change. However, the control system becomes uncontrollable while the evaluation point is moving. To solve the problem, the characteristics of all the paths are must be identified at all time. In this paper, we applied neural networks with the learning ability to the noise control system to follow the time-varying paths and verified its control performance by numerical simulations. Then, dropout technique for the networks is also applied. Dropout is a technique that prevent the network from overfitting and enables better control performance. By applying dropout for noise control, it prevents the system from diverging.

  6. Kinks in subducted slabs: Petrological evidence points to additional hindrance to the exhumation of UHP rocks

    NASA Astrophysics Data System (ADS)

    John, T.; Klemd, R.; Scherer, E. E.; Rondenay, S.; Gao, J.

    2012-12-01

    Sudden changes in the dip of subducted oceanic plates have been resolved by seismic imaging [1, 2]. Such kinking often coincides with the seismic disappearance of the low-velocity subducted oceanic crust, i.e., at a depth where eclogitization (dehydration) of the upper oceanic crust is nearly complete and the oceanic crust becomes almost seismically indistinguishable from mantle peridotite. We present petrological evidence for this phenomenon derived from oceanic blueschist- and eclogite-facies rocks from the Chinese Tianshan. The peak-metamorphic conditions of the samples range between 330 and 580°C at 1.5 to 2.3 GPa. Such a wide range of peak conditions for intercalated high- and ultrahigh-pressure rocks has also been reported from other Tianshan localities. These observations suggest that the rocks were derived from different depths within the subduction zone and later juxtaposed during exhumation within the subduction channel. Multi-point Lu-Hf isochrons from four high-pressure rocks yield consistent garnet-growth ages of around ~315 Ma, confirming that the eclogite-facies metamorphism of the Tianshan high-pressure rocks resulted from a single subduction event in the Late Carboniferous. These ages, in conjunction with the ~311 Ma cluster of 40Ar-39Ar and Rb-Sr white mica ages from the same localities imply rapid exhumation. Previously reported peak P-T estimates from UHP metasediments and eclogites all lie on a lower geothermal gradient—and thus on a colder P-T path at the slab-wedge interface—than that defined by the HP eclogites and meta-volcaniclastic rocks studied here. This suggests that the slab-subduction angle steepened sharply at approximately 90 km depth, just between the depths at which the HP and UHP rocks equilibrated. The increase in subduction angle may result from a greater slab pull resulting from eclogitization densification. An additional factor may be an ephemeral weakening of the slab as it undergoes eclogitization reactions [3, 4]. We

  7. Digital pointing control. [for Space Shuttle Data Bus

    NASA Technical Reports Server (NTRS)

    Studer, P. A.; Brown, R. J.

    1978-01-01

    The digital pointing control system developed for the Space Shuttle Data Bus is discussed. The device, which interfaces with NASA standard sensor units, contains a front panel controller, a development system to load, inspect, print, and store the program and data, and a 'test jig' to provide closed-loop controller operation. The system is described with particular reference to the tracker-gyro interfaces, the control algorithms and compensation procedures, Kalman-estimation filtering, the proportional power output, and the discrete output capability. The results of simulation studies are presented and the development status is noted.

  8. Control implementation for the SPUR floating point coprocessor

    SciTech Connect

    Jensen, D.

    1987-01-01

    SPUR is a RISC-based multiprocessor workstation being designed to facilitate parallel-processing research. Typically, RISC architectures achieve low performance levels for floating-point intensive applications, as the multiple-cycle floating-point instructions are not implemented in the hardware. In an attempt to raise these performance levels, the SPUR system provides floating-point support through an extended instruction set and tightly-coupled floating-point coprocessor. This report documents the implementation of the control unit for this floating-point coprocessor; describing the coprocessor interface, control PLA definitions, the finite state machine, the dynamic cycle counter, the 4-stage load-store pipeline, and the random logic generated to drive the datapath modules. Implementation techniques and trade-offs are discussed; including design strategy, area and speed optimization, noise margin considerations, and delay balancing rf the datapath control signals for clock skew minimization. Finally, in an attempt to raise these performance levels, the SPUR system The chip is implemented in 2-layer-metal 2..mu..m CMOS technology, and uses a four-phase non-overlapping clock with a target cycle time of approximately 100ns - 140 ns.

  9. Internal quality control in point-of-care testing: where's the evidence?

    PubMed

    Holt, Helen; Freedman, Danielle B

    2016-03-01

    ISO 22870 standards require protocols for performance of internal quality control for all point-of-care testing devices and training of users in its theory and practice. However, the unique setting of point-of-care testing (i.e. processes conducted by non-scientific users) means that laboratory internal quality control programmes do not easily translate to point-of-care testing. In addition, while the evidence base for internal quality control within the laboratory has been increasing, the equivalent literature surrounding point-of-care testing is very limited. This has led to wide variation in what is considered acceptable practice for internal quality control at the point of care. Indeed, it has been demonstrated that internal quality control is an area of deficiency in point-of-care testing. Internal quality control protocols used at point-of-care testing should be defined based on risk management. The protocol will therefore be dependent on analyser complexity and availability of inbuilt system checks, the risk associated with release of an incorrect patient result as well as frequency of use. The emphasis should be on designing an effective internal quality control protocol as opposed to the inherent tendency of introducing high-frequency quality control. Typically a simple pass or fail criterion is used for internal quality control in point-of-care testing based on whether internal quality control results fall within assigned ranges. While simply taught, such criteria can require broad internal quality control ranges to decrease the probability of false rejection (also reducing the probability of error detection). Customized internal quality control ranges, two-tier acceptance systems and assay-specific internal quality control can be used to improve error detection rates.

  10. Internal quality control in point-of-care testing: where's the evidence?

    PubMed

    Holt, Helen; Freedman, Danielle B

    2016-03-01

    ISO 22870 standards require protocols for performance of internal quality control for all point-of-care testing devices and training of users in its theory and practice. However, the unique setting of point-of-care testing (i.e. processes conducted by non-scientific users) means that laboratory internal quality control programmes do not easily translate to point-of-care testing. In addition, while the evidence base for internal quality control within the laboratory has been increasing, the equivalent literature surrounding point-of-care testing is very limited. This has led to wide variation in what is considered acceptable practice for internal quality control at the point of care. Indeed, it has been demonstrated that internal quality control is an area of deficiency in point-of-care testing. Internal quality control protocols used at point-of-care testing should be defined based on risk management. The protocol will therefore be dependent on analyser complexity and availability of inbuilt system checks, the risk associated with release of an incorrect patient result as well as frequency of use. The emphasis should be on designing an effective internal quality control protocol as opposed to the inherent tendency of introducing high-frequency quality control. Typically a simple pass or fail criterion is used for internal quality control in point-of-care testing based on whether internal quality control results fall within assigned ranges. While simply taught, such criteria can require broad internal quality control ranges to decrease the probability of false rejection (also reducing the probability of error detection). Customized internal quality control ranges, two-tier acceptance systems and assay-specific internal quality control can be used to improve error detection rates. PMID:26486440

  11. Engineering to Control Noise, Loading, and Optimal Operating Points

    SciTech Connect

    Mitchell R. Swartz

    2000-11-12

    Successful engineering of low-energy nuclear systems requires control of noise, loading, and optimum operating point (OOP) manifolds. The latter result from the biphasic system response of low-energy nuclear reaction (LENR)/cold fusion systems, and their ash production rate, to input electrical power. Knowledge of the optimal operating point manifold can improve the reproducibility and efficacy of these systems in several ways. Improved control of noise, loading, and peak production rates is available through the study, and use, of OOP manifolds. Engineering of systems toward the OOP-manifold drive-point peak may, with inclusion of geometric factors, permit more accurate uniform determinations of the calibrated activity of these materials/systems.

  12. Method and apparatus for determining the presence or absence of a pour point depressant additive in hydrocarbon liquids

    SciTech Connect

    Rummel, J.D.

    1986-07-29

    A method is described of determining the presence or absence of a pour point depressant additive in a hydrocarbon liquid derived from petroleum, the liquid containing paraffin wax, comprising the steps of: (a) cooling a sample of the liquid at a predetermined cooling rate from a temperature substantially above the cloud point temperature to a temperature substantially below the cloud point temperature; (b) monitoring the slope of the cooling rate curve and noting the points at which a deflection in the curve begins and ends; (c) determining the time interval between the beginning and ending points of the deflection of the curve, and (d) comparing the determined time interval to a reference time interval, associated with the predetermined cooling rate, so as to establish whether the determined time interval is less than or greater than the reference time interval thereby establishing the presence or absence, respectively, of a pour point depressant additive.

  13. Effects of additional external weight on posture and movement adaptations to fatigue induced by a repetitive pointing task.

    PubMed

    Cantú, Hiram; Emery, Kim; Côté, Julie N

    2014-06-01

    Fatigue and additional weight are risk factors of injuries by falls. Posture and trunk movement changes occur with fatigue induced by a repetitive pointing task. These changes facilitate arm movement but they may also jeopardize postural stability. When equilibrium is challenged, e.g. with additional weight, strategies that represent less postural threat could develop with fatigue. Nineteen participants performed two sessions (without, with 20% body weight added load (Load)) of a repetitive pointing task until shoulder fatigue (8 on Borg CR-10). There was no difference in time to fatigue between the two sessions. Anterior deltoid, biceps and upper trapezius muscle activity significantly increased with fatigue. Peak medial-lateral center-of-pressure (CoP) velocity and the mean vertical position of the reaching shoulder were both significantly lower with fatigue, though these fatigue-induced decreases were smaller with the added load. Reach-to-reach variability in CoP displacement significantly increased with fatigue, and more so with the added load. With fatigue, significant contralateral shifts occurred at the reaching shoulder and elbow joints, and ranges of motion (RoM) significantly increased at most joints but not at the center-of-mass (CoM). Conversely, Load main effects were mostly seen in CoM dependent measures. Significantly increased variability in mean and range values was seen with fatigue and Load in most of our kinematic and CoP dependent measures, with the most notable effects on CoM dependent measures. Findings suggest that the postural control system adapts to combined perturbing factors of fatigue and added load, likely by using parallel control mechanisms.

  14. Two Axis Pointing System (TAPS) attitude acquisition, determination, and control

    NASA Technical Reports Server (NTRS)

    Azzolini, John D.; Mcglew, David E.

    1990-01-01

    The Two Axis Pointing System (TAPS) is a 2 axis gimbal system designed to provide fine pointing of Space Transportation System (STS) borne instruments. It features center-of-mass instrument mounting and will accommodate instruments of up to 1134 kg (2500 pounds) which fit within a 1.0 by 1.0 by 4.2 meter (40 by 40 by 166 inch) envelope. The TAPS system is controlled by a microcomputer based Control Electronics Assembly (CEA), a Power Distribution Unit (PDU), and a Servo Control Unit (SCU). A DRIRU-II inertial reference unit is used to provide incremental angles for attitude propagation. A Ball Brothers STRAP star tracker is used for attitude acquisition and update. The theory of the TAPS attitude determination and error computation for the Broad Band X-ray Telescope (BBXRT) are described. The attitude acquisition is based upon a 2 star geometric solution. The acquisition theory and quaternion algebra are presented. The attitude control combines classical position, integral and derivative (PID) control with techniques to compensate for coulomb friction (bias torque) and the cable harness crossing the gimbals (spring torque). Also presented is a technique for an adaptive bias torque compensation which adjusts to an ever changing frictional torque environment. The control stability margins are detailed, with the predicted pointing performance, based upon simulation studies. The TAPS user interface, which provides high level operations commands to facilitate science observations, is outlined.

  15. Galileo Spacecraft Scan Platform Celestial Pointing Cone Control Gain Redesign

    NASA Technical Reports Server (NTRS)

    In, C-H. C.; Hilbert, K. B.

    1994-01-01

    During September and October 1991, pictures of the Gaspra asteroid and neighboring stars were taken by the Galileo Optical Navigation (OPNAV) Team for the purpose of navigation the spacecraft for a successful Gaspra encounter. The star tracks in these pictures showed that the scan platform celestial pointing cone controller performed poorly in compensating for wobble-induced cone offsets.

  16. 47 CFR 90.473 - Operation of internal transmitter control systems through licensed fixed control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operation of internal transmitter control... Transmitter Control Internal Transmitter Control Systems § 90.473 Operation of internal transmitter control systems through licensed fixed control points. An internal transmitter control system may be...

  17. Accuracy analysis of pointing control system of solar power station

    NASA Technical Reports Server (NTRS)

    Hung, J. C.; Peebles, P. Z., Jr.

    1978-01-01

    The first-phase effort concentrated on defining the minimum basic functions that the retrodirective array must perform, identifying circuits that are capable of satisfying the basic functions, and looking at some of the error sources in the system and how they affect accuracy. The initial effort also examined three methods for generating torques for mechanical antenna control, performed a rough analysis of the flexible body characteristics of the solar collector, and defined a control system configuration for mechanical pointing control of the array.

  18. Additional Evaluation of the Point-of-Contact Circulating Cathodic Antigen Assay for Schistosoma mansoni Infection

    PubMed Central

    Mwinzi, Pauline N. M.; Kittur, Nupur; Ochola, Elizabeth; Cooper, Philip J.; Campbell, Carl H.; King, Charles H.; Colley, Daniel G.

    2015-01-01

    Studies of the urine-based point-of-contact cathodic circulating antigen test (POC-CCA) in Schistosoma mansoni-endemic settings in Africa indicate it has good sensitivity in detecting infections, but in areas of low prevalence, the POC-CCA can be positive for persons who are egg-negative by Kato-Katz stool assays. We examined the POC-CCA assay for: (a) batch-to-batch stability; (b) intra-reader and inter-reader variability; (c) day-to-day variability compared to Kato-Katz stool assays, and (d) to see if praziquantel (PZQ) treatment converted Kato-Katz-negative/POC-CCA positive individuals to POC-CCA negativity. We found essentially no batch-to-batch variation, negligible intra-reader variability (2%), and substantial agreement for inter-reader reliability. Some day-to-day variation was observed over 5 days of urine collection, but less than the variation in Kato-Katz stool assays over 3 days. To evaluate the effect of treatment on Kato-Katz(−)/POC-CCA(+) children, 149 children in an area of 10–15% prevalence who were Kato-Katz(−) based on 3 stool samples but POC-CCA(+) were enrolled. Seven days after treatment (PZQ 40 mg/kg) samples were again collected and tested. Almost half (47%) POC-CCA positive children turned negative. Those still POC-CCA positive received a second treatment, and 34% of them turned POC-CCA negative upon this second treatment. Most who remained POC-CCA positive shifted each time to a “lesser” POC-CCA “level of positivity.” The data suggest that most Kato-Katz-negative/POC-CCA positive individuals harbor low-intensity infections, and each treatment kills all or some of their adult worms. The data also suggest that when evaluated by a more sensitive assay, the effective cure rates for PZQ are significantly less than those inferred from fecal testing. These findings have public health significance for the mapping and monitoring of Schistosoma infections and in planning the transition from schistosomiasis morbidity control to

  19. A multi-resolution fractal additive scheme for blind watermarking of 3D point data

    NASA Astrophysics Data System (ADS)

    Rahmes, Mark; Wilder, Kathy; Fox, Kevin

    2013-05-01

    We present a fractal feature space for 3D point watermarking to make geospatial systems more secure. By exploiting the self similar nature of fractals, hidden information can be spatially embedded in point cloud data in an acceptable manner as described within this paper. Our method utilizes a blind scheme which provides automatic retrieval of the watermark payload without the need of the original cover data. Our method for locating similar patterns and encoding information in LiDAR point cloud data is accomplished through a look-up table or code book. The watermark is then merged into the point cloud data itself resulting in low distortion effects. With current advancements in computing technologies, such as GPGPUs, fractal processing is now applicable for processing of big data which is present in geospatial as well as other systems. This watermarking technique described within this paper can be important for systems where point data is handled by numerous aerial collectors including analysts use for systems such as a National LiDAR Data Layer.

  20. Single-layer and bilayer graphene superlattices: collimation, additional Dirac points and Dirac lines.

    PubMed

    Barbier, Michaël; Vasilopoulos, Panagiotis; Peeters, François M

    2010-12-13

    We review the energy spectrum and transport properties of several types of one-dimensional superlattices (SLs) on single-layer and bilayer graphene. In single-layer graphene, for certain SL parameters an electron beam incident on an SL is highly collimated. On the other hand, there are extra Dirac points generated for other SL parameters. Using rectangular barriers allows us to find analytical expressions for the location of new Dirac points in the spectrum and for the renormalization of the electron velocities. The influence of these extra Dirac points on the conductivity is investigated. In the limit of δ-function barriers, the transmission T through and conductance G of a finite number of barriers as well as the energy spectra of SLs are periodic functions of the dimensionless strength P of the barriers, Pδ(x) = V(x)/ħv(F), with v(F) the Fermi velocity. For a Kronig-Penney SL with alternating sign of the height of the barriers, the Dirac point becomes a Dirac line for P = π/2+nπ with n an integer. In bilayer graphene, with an appropriate bias applied to the barriers and wells, we show that several new types of SLs are produced and two of them are similar to type I and type II semiconductor SLs. Similar to single-layer graphene SLs, extra 'Dirac' points are found in bilayer graphene SLs. Non-ballistic transport is also considered. PMID:21041227

  1. Dynamics and control simulation of the Spacelab Experiment Pointing Mount

    NASA Technical Reports Server (NTRS)

    Marsh, E. L.; Ward, R. S.

    1977-01-01

    Computer simulations were developed to evaluate the performance of four Experiment Pointing Mounts (EPM) being considered for Spacelab experiments in the 1980-1990 time frame. The system modeled compromises a multibody system consisting of the shuttle, a mechanical isolation device, the EPM, celestial and inertial sensors, bearings, gimbal torque motors and associated nonlinearities, the experiment payload, and control and estimator algorithms. Each mount was subjected to a common disturbance (shuttle vernier thruster firing and man push off) and command (stellar pointing or solar raster scan) input. The fundamental limitation common to all mounts was found to be sensor noise. System dynamics and hardware nonlinearities have secondary effects on pointing performance for sufficiently high bandwidth.

  2. How polymer additives reduce the pour point of hydrocarbon solvents containing wax crystals.

    PubMed

    Binks, Bernard P; Fletcher, Paul D I; Roberts, Noel A; Dunkerley, John; Greenfield, Hannah; Mastrangelo, Antonio; Trickett, Kieran

    2015-02-14

    We have investigated how four different pour point depressant (PPD) polymers affect the pour point transition in mixtures of a single pure wax in a solvent. We used either n-eicosane (C20), CH3(CH2)18CH3, n-tetracosane (C24), CH3(CH2)22CH3 or n-hexatriacontane (C36), CH3(CH2)34CH3 as the wax component with either n-heptane or toluene as the solvent component. For all wax-solvent combinations, the measured variation of wax solubility with temperature is well predicted by ideal solution theory. The variation of pour point temperature as a function of the overall wax concentration is quantitatively modelled using the idea that, for each overall wax concentration, the pour point occurs at a temperature at which a critical volume fraction ϕ* of wax crystals has precipitated. Close to the pour point temperature, extraction and examination of the wax crystals show they consist of polydisperse, irregularly-shaped platelets with axial ratios (h/d, where h is the plate thickness and d is the plate long dimension) in the range 0.005-0.05. It is found that the measured ϕ* values corresponding to the pour point transitions are weakly correlated with the wax crystal axial ratios (h/d) for all wax-solvent-PPD polymer combinations. These results indicate that the pour point transition occurs at a volume fraction larger than the value at which the volumes of rotation of the platelet crystals overlap, i.e., 2.5(h/d) < ϕ* < 11(h/d). PPD polymers work, in part, by increasing the wax crystal axial ratio (h/d), thereby increasing ϕ* and reducing the pour point temperature. Since the PPD's ability to modify the wax crystal shape relies on its adsorption to the crystal-solution surface, it is anticipated and observed experimentally that optimum PPD efficacy is correlated with the difference between the wax and the polymer solubility boundary temperatures. This finding and the mechanistic insight gained here provide the basis for a simple and rapid screening test to identify candidate

  3. How polymer additives reduce the pour point of hydrocarbon solvents containing wax crystals.

    PubMed

    Binks, Bernard P; Fletcher, Paul D I; Roberts, Noel A; Dunkerley, John; Greenfield, Hannah; Mastrangelo, Antonio; Trickett, Kieran

    2015-02-14

    We have investigated how four different pour point depressant (PPD) polymers affect the pour point transition in mixtures of a single pure wax in a solvent. We used either n-eicosane (C20), CH3(CH2)18CH3, n-tetracosane (C24), CH3(CH2)22CH3 or n-hexatriacontane (C36), CH3(CH2)34CH3 as the wax component with either n-heptane or toluene as the solvent component. For all wax-solvent combinations, the measured variation of wax solubility with temperature is well predicted by ideal solution theory. The variation of pour point temperature as a function of the overall wax concentration is quantitatively modelled using the idea that, for each overall wax concentration, the pour point occurs at a temperature at which a critical volume fraction ϕ* of wax crystals has precipitated. Close to the pour point temperature, extraction and examination of the wax crystals show they consist of polydisperse, irregularly-shaped platelets with axial ratios (h/d, where h is the plate thickness and d is the plate long dimension) in the range 0.005-0.05. It is found that the measured ϕ* values corresponding to the pour point transitions are weakly correlated with the wax crystal axial ratios (h/d) for all wax-solvent-PPD polymer combinations. These results indicate that the pour point transition occurs at a volume fraction larger than the value at which the volumes of rotation of the platelet crystals overlap, i.e., 2.5(h/d) < ϕ* < 11(h/d). PPD polymers work, in part, by increasing the wax crystal axial ratio (h/d), thereby increasing ϕ* and reducing the pour point temperature. Since the PPD's ability to modify the wax crystal shape relies on its adsorption to the crystal-solution surface, it is anticipated and observed experimentally that optimum PPD efficacy is correlated with the difference between the wax and the polymer solubility boundary temperatures. This finding and the mechanistic insight gained here provide the basis for a simple and rapid screening test to identify candidate

  4. Change point detection in risk adjusted control charts.

    PubMed

    Assareh, Hassan; Smith, Ian; Mengersen, Kerrie

    2015-12-01

    Precise identification of the time when a change in a clinical process has occurred enables experts to identify a potential special cause more effectively. In this article, we develop change point estimation methods for a clinical dichotomous process in the presence of case mix. We apply Bayesian hierarchical models to formulate the change point where there exists a step change in the odds ratio and logit of risk of a Bernoulli process. Markov Chain Monte Carlo is used to obtain posterior distributions of the change point parameters including location and magnitude of changes and also corresponding probabilistic intervals and inferences. The performance of the Bayesian estimator is investigated through simulations and the result shows that precise estimates can be obtained when they are used in conjunction with the risk-adjusted CUSUM and EWMA control charts. In comparison with alternative EWMA and CUSUM estimators, more accurate and precise estimates are obtained by the Bayesian estimator. These superiorities enhance when probability quantification, flexibility and generaliability of the Bayesian change point detection model are also considered. The Deviance Information Criterion, as a model selection criterion in the Bayesian context, is applied to find the best change point model for a given dataset where there is no prior knowledge about the change type in the process.

  5. PowerPoint Presentations: A Creative Addition to the Research Process.

    ERIC Educational Resources Information Center

    Perry, Alan E.

    2003-01-01

    Contends that the requirement of a PowerPoint presentation as part of the research process would benefit students in the following ways: learning how to conduct research; starting their research project sooner; honing presentation and public speaking skills; improving cooperative and social skills; and enhancing technology skills. Outlines the…

  6. Precision pointing control for SPICA: risk mitigation phase study

    NASA Astrophysics Data System (ADS)

    Mitani, Shinji; Kawakatsu, Yasuhiro; Sakai, Shin-ichiro; Murakami, Naomi; Yamawaki, Toshihiko; Mizutani, Tadahito; Komatsu, Keiji; Kataza, Hirokazu; Enya, Keigo; Nakagawa, Takao

    2014-08-01

    SPICA (Space Infrared Telescope for Cosmology and Astrophysics) is an astronomical mission optimized for mid- and far-infrared astronomy with a 3-m class telescope which is cryogenically cooled to be less than 6 K. The SPICA mechanical cooling system is indispensable for the mission but, generates micro-vibrations which could affect to the pointing stability performances. Activities to be undertaken during a risk mitigation phase (RMP) include consolidation of micro-vibration control design for the satellite, as well as a number of breadboarding activities centered on technologies that are critical to the success of the mission. This paper presents the RMP activity results on the microvibration control design.

  7. Controlling systems that drift through a tipping point

    NASA Astrophysics Data System (ADS)

    Nishikawa, Takashi; Ott, Edward

    2014-09-01

    Slow parameter drift is common in many systems (e.g., the amount of greenhouse gases in the terrestrial atmosphere is increasing). In such situations, the attractor on which the system trajectory lies can be destroyed, and the trajectory will then go to another attractor of the system. We consider the case where there are more than one of these possible final attractors, and we ask whether we can control the outcome (i.e., the attractor that ultimately captures the trajectory) using only small controlling perturbations. Specifically, we consider the problem of controlling a noisy system whose parameter slowly drifts through a saddle-node bifurcation taking place on a fractal boundary between the basins of multiple attractors. We show that, when the noise level is low, a small perturbation of size comparable to the noise amplitude applied at a single point in time can ensure that the system will evolve toward a target attracting state with high probability. For a range of noise levels, we find that the minimum size of perturbation required for control is much smaller within a time period that starts some time after the bifurcation, providing a "window of opportunity" for driving the system toward a desirable state. We refer to this procedure as tipping point control.

  8. Controlling systems that drift through a tipping point

    SciTech Connect

    Nishikawa, Takashi; Ott, Edward

    2014-09-01

    Slow parameter drift is common in many systems (e.g., the amount of greenhouse gases in the terrestrial atmosphere is increasing). In such situations, the attractor on which the system trajectory lies can be destroyed, and the trajectory will then go to another attractor of the system. We consider the case where there are more than one of these possible final attractors, and we ask whether we can control the outcome (i.e., the attractor that ultimately captures the trajectory) using only small controlling perturbations. Specifically, we consider the problem of controlling a noisy system whose parameter slowly drifts through a saddle-node bifurcation taking place on a fractal boundary between the basins of multiple attractors. We show that, when the noise level is low, a small perturbation of size comparable to the noise amplitude applied at a single point in time can ensure that the system will evolve toward a target attracting state with high probability. For a range of noise levels, we find that the minimum size of perturbation required for control is much smaller within a time period that starts some time after the bifurcation, providing a “window of opportunity” for driving the system toward a desirable state. We refer to this procedure as tipping point control.

  9. [Safety of food additives from a German and European point of view].

    PubMed

    Gürtler, R

    2010-06-01

    There are about 300 food additives permitted in the EU for which a re-evaluation program was initiated recently. Occasionally, it is speculated that the use of single food additives might be of safety concern. First results of the re-evaluation could give an impression on how such concerns were taken into account by responsible authorities, such as the European Food Safety Authority (EFSA). For some of the food additives, the lowest dose resulting in adverse effects was lower in recent studies compared to previous studies. Thus, the acceptable daily intake (ADI) derived applying the common uncertainty factor was lower than the ADI derived using data from previous studies. Therefore, it has to be considered whether the conditions of use need to be modified for these food additives.

  10. A microfluidic abacus channel for controlling the addition of droplets.

    PubMed

    Um, Eujin; Park, Je-Kyun

    2009-01-21

    This paper reports the first use of the abacus-groove structure to handle droplets in a wide microchannel, with no external forces integrated to the system other than the pumps. Microfluidic abacus channels are demonstrated for the sequential addition of droplets at the desired location. A control channel which is analogous to biasing in electronics can also be used to precisely determine the number of added droplets, when all other experimental conditions are fixed including the size of the droplets and the frequency of droplet-generation. The device allows programmable and autonomous operations of complex two-phase microfluidics as well as new applications for the method of analysis and computations in lab-on-a-chip devices.

  11. [Critical of the additive model of the randomized controlled trial].

    PubMed

    Boussageon, Rémy; Gueyffier, François; Bejan-Angoulvant, Theodora; Felden-Dominiak, Géraldine

    2008-01-01

    Randomized, double-blind, placebo-controlled clinical trials are currently the best way to demonstrate the clinical effectiveness of drugs. Its methodology relies on the method of difference (John Stuart Mill), through which the observed difference between two groups (drug vs placebo) can be attributed to the pharmacological effect of the drug being tested. However, this additive model can be questioned in the event of statistical interactions between the pharmacological and the placebo effects. Evidence in different domains has shown that the placebo effect can influence the effect of the active principle. This article evaluates the methodological, clinical and epistemological consequences of this phenomenon. Topics treated include extrapolating results, accounting for heterogeneous results, demonstrating the existence of several factors in the placebo effect, the necessity to take these factors into account for given symptoms or pathologies, as well as the problem of the "specific" effect.

  12. Control of Microthrix parvicella by aluminium salts addition.

    PubMed

    Durban, N; Juzan, L; Krier, J; Gillot, S

    2016-01-01

    Aluminium and iron chloride were added to a biological nutrient removal pilot plant (1,500 population equivalent) treating urban wastewater to investigate the control of Microthrix parvicella bulking and foaming by metallic salts. Monitoring plant performance over two 6-month periods showed a slight impact on the removal efficiencies. Addition of metallic salts (Me; aluminium or aluminium + iron) at a concentration of 41 mmol Me(kg MLSS·d) (MLSS: mixed liquor suspended solids) over 70 days allowed a stabilization of the diluted sludge volume index (DSVI), whereas higher dosages (94 mmol Me(kg MLSS·d) over 35 days or 137 mmol Me(kg MLSS·d) over 14 days induced a significant improvement of the settling conditions. Microscopic observations showed a compaction of biological aggregates with an embedding of filamentous bacteria into the flocs that is not specific to M. parvicella as bacteria from phylum Chloroflexi are embedded too. The quantitative polymerase chain reaction targeting M. parvicella further indicated a possible growth limitation in addition to the flocculation impact at the high dosages of metallic salts investigated. DSVI appeared to be correlated with the relative abundance of M. parvicella.

  13. Control of Microthrix parvicella by aluminium salts addition.

    PubMed

    Durban, N; Juzan, L; Krier, J; Gillot, S

    2016-01-01

    Aluminium and iron chloride were added to a biological nutrient removal pilot plant (1,500 population equivalent) treating urban wastewater to investigate the control of Microthrix parvicella bulking and foaming by metallic salts. Monitoring plant performance over two 6-month periods showed a slight impact on the removal efficiencies. Addition of metallic salts (Me; aluminium or aluminium + iron) at a concentration of 41 mmol Me(kg MLSS·d) (MLSS: mixed liquor suspended solids) over 70 days allowed a stabilization of the diluted sludge volume index (DSVI), whereas higher dosages (94 mmol Me(kg MLSS·d) over 35 days or 137 mmol Me(kg MLSS·d) over 14 days induced a significant improvement of the settling conditions. Microscopic observations showed a compaction of biological aggregates with an embedding of filamentous bacteria into the flocs that is not specific to M. parvicella as bacteria from phylum Chloroflexi are embedded too. The quantitative polymerase chain reaction targeting M. parvicella further indicated a possible growth limitation in addition to the flocculation impact at the high dosages of metallic salts investigated. DSVI appeared to be correlated with the relative abundance of M. parvicella. PMID:26819398

  14. Control of asteroid retrieval trajectories to libration point orbits

    NASA Astrophysics Data System (ADS)

    Ceriotti, Matteo; Sanchez, Joan Pau

    2016-09-01

    The fascinating idea of shepherding asteroids for science and resource utilization is being considered as a credible concept in a not too distant future. Past studies identified asteroids which could be efficiently injected into manifolds which wind onto periodic orbits around collinear Lagrangian points of the Sun-Earth system. However, the trajectories are unstable, and errors in the capture maneuver would lead to complete mission failure, with potential danger of collision with the Earth, if uncontrolled. This paper investigates the controllability of some asteroids along the transfers and the periodic orbits, assuming the use of a solar-electric low-thrust system shepherding the asteroid. Firstly, an analytical approach is introduced to estimate the stability of the trajectories from a dynamical point of view; then, a numerical control scheme based on a linear quadratic regulator is proposed, where the gains are optimized for each trajectory through a genetic algorithm. A stochastic simulation with a Monte Carlo approach is used to account for different perturbed initial conditions and the epistemic uncertainty on the asteroid mass. Results show that only a small subset of the considered combinations of trajectories/asteroids are reliably controllable, and therefore controllability must be taken into account in the selection of potential targets.

  15. Method for controlling a laser additive process using intrinsic illumination

    NASA Astrophysics Data System (ADS)

    Tait, Robert; Cai, Guoshuang; Azer, Magdi; Chen, Xiaobin; Liu, Yong; Harding, Kevin

    2015-05-01

    One form of additive manufacturing is to use a laser to generate a melt pool from powdered metal that is sprayed from a nozzle. The laser net-shape machining system builds the part a layer at a time by following a predetermined path. However, because the path may need to take many turns, maintaining a constant melt pool may not be easy. A straight section may require one speed and power while a sharp bend would over melt the metal at the same settings. This paper describes a process monitoring method that uses the intrinsic IR radiation from the melt pool along with a process model configured to establish target values for the parameters associated with the manufacture or repair. This model is based upon known properties of the metal being used as well as the properties of the laser beam. An adaptive control technique is then employed to control process parameters of the machining system based upon the real-time weld pool measurement. Since the system uses the heat radiant from the melt pool, other previously deposited metal does not confuse the system as only the melted material is seen by the camera.

  16. New Ganymede control point network and global shape model

    NASA Astrophysics Data System (ADS)

    Zubarev, A.; Nadezhdina, I.; Oberst, J.; Hussmann, H.; Stark, A.

    2015-11-01

    We computed a 3D control point network for Ganymede using combinations of 126 Voyager-1 and -2 and 87 Galileo images, benefiting from reconstructed trajectory data for the three spacecraft and a more complete Galileo image data base than was available for earlier studies. Using more than 3000 control point coordinates, we determine global shape parameters, including mean radius, spheroid- and ellipsoidal axes, and make tests for various equilibrium shape models, constrained by the most recent estimates for gravity field parameters. We confirm that Ganymede has a pronounced ellipsoidal shape, approximately aligned with the Jupiter-direction, in agreement with Ganymede being in tidal equilibrium. The point heights, suffering from large individual errors, do not reveal any large-scale topography below our typical error levels (97% <5 km). By analysis of data residuals we search for, but cannot detect Ganymede longitudinal forced librations. We conclude that libration amplitudes cannot be larger than 0.1° (corresponding to a lateral displacement of 4.6 km at the equator).

  17. Fixed Point Transformations Based Iterative Control of a Polymerization Reaction

    NASA Astrophysics Data System (ADS)

    Tar, József K.; Rudas, Imre J.

    As a paradigm of strongly coupled non-linear multi-variable dynamic systems the mathematical model of the free-radical polymerization of methyl-metachrylate with azobis (isobutyro-nitrile) as an initiator and toluene as a solvent taking place in a jacketed Continuous Stirred Tank Reactor (CSTR) is considered. In the adaptive control of this system only a single input variable is used as the control signal (the process input, i.e. dimensionless volumetric flow rate of the initiator), and a single output variable is observed (the process output, i.e. the number-average molecular weight of the polymer). Simulation examples illustrate that on the basis of a very rough and primitive model consisting of two scalar variables various fixed-point transformations based convergent iterations result in a novel, sophisticated adaptive control.

  18. Guaranteeing Pointing Performance of the SDO Sun-Pointing Controllers in Light of Nonlinear Effects

    NASA Technical Reports Server (NTRS)

    Starin, Scott R.; Bourkland, Kristin L.

    2007-01-01

    The Solar Dynamics Observatory (SDO) mission is the first Space Weather Research Network mission, part of NASA s Living With a Star program.1 This program seeks to understand the changing Sun and its effects on the Solar System, life, and society. To this end, the SDO spacecraft will carry three Sun-observing instruments to geosynchronous orbit: Helioseismic and Magnetic Imager (HMI), led by Stanford University; Atmospheric Imaging Assembly (AIA), led by Lockheed Martin Space and Astrophysics Laboratory; and Extreme Ultraviolet Variability Experiment (EVE), led by the University of Colorado. Links describing the instruments in detail may be found through the SDO web site.2 The basic mission goals are to observe the Sun for a very high percentage of the 5-year mission (10-year goal) with long stretches of uninterrupted observations and with constant, high-data-rate transmission to a dedicated ground station. These goals guided the design of the spacecraft bus that will carry and service the three-instrument payload. At the time of this publication, the SDO spacecraft bus is well into the integration and testing phase at the NASA Goddard Space Flight Center (GSFC). A three-axis stabilized attitude control system (ACS) is needed both to point at the Sun accurately and to keep the roll about the Sun vector correctly positioned. The ACS has four reaction wheel modes and 2 thruster actuated modes. More details about the ACS in general and the control modes in particular can be found in Refs. [3-6]. All four of SDO s wheel-actuated control modes involve Sun-pointing controllers, as might be expected from such a mission. Science mode, during which most science data is collected, uses specialized guide telescopes to point accurately at the Sun. Inertial mode has two sub-modes, one tracks a Sun-referenced target orientation, and another maintains an absolute (star-referenced) target orientation, that both employ a Kalman filter to process data from a digital Sun sensor and

  19. Attitude control/momentum management and payload pointing in advanced space vehicles

    NASA Technical Reports Server (NTRS)

    Parlos, Alexander G.; Jayasuriya, Suhada

    1990-01-01

    The design and evaluation of an attitude control/momentum management system for highly asymmetric spacecraft configurations are presented. The preliminary development and application of a nonlinear control system design methodology for tracking control of uncertain systems, such as spacecraft payload pointing systems are also presented. Control issues relevant to both linear and nonlinear rigid-body spacecraft dynamics are addressed, whereas any structural flexibilities are not taken into consideration. Results from the first task indicate that certain commonly used simplifications in the equations of motions result in unstable attitude control systems, when used for highly asymmetric spacecraft configurations. An approach is suggested circumventing this problem. Additionally, even though preliminary results from the second task are encouraging, the proposed nonlinear control system design method requires further investigation prior to its application and use as an effective payload pointing system design technique.

  20. Floating-point system quantization errors in digital control systems

    NASA Technical Reports Server (NTRS)

    Phillips, C. L.

    1973-01-01

    The results are reported of research into the effects on system operation of signal quantization in a digital control system. The investigation considered digital controllers (filters) operating in floating-point arithmetic in either open-loop or closed-loop systems. An error analysis technique is developed, and is implemented by a digital computer program that is based on a digital simulation of the system. As an output the program gives the programing form required for minimum system quantization errors (either maximum of rms errors), and the maximum and rms errors that appear in the system output for a given bit configuration. The program can be integrated into existing digital simulations of a system.

  1. Accuracy assessment of minimum control points for UAV photography and georeferencing

    NASA Astrophysics Data System (ADS)

    Skarlatos, D.; Procopiou, E.; Stavrou, G.; Gregoriou, M.

    2013-08-01

    In recent years, Autonomous Unmanned Aerial Vehicles (AUAV) became popular among researchers across disciplines because they combine many advantages. One major application is monitoring and mapping. Their ability to fly beyond eye sight autonomously, collecting data over large areas whenever, wherever, makes them excellent platform for monitoring hazardous areas or disasters. In both cases rapid mapping is needed while human access isn't always a given. Indeed, current automatic processing of aerial photos using photogrammetry and computer vision algorithms allows for rapid orthophomap production and Digital Surface Model (DSM) generation, as tools for monitoring and damage assessment. In such cases, control point measurement using GPS is either impossible, or time consuming or costly. This work investigates accuracies that can be attained using few or none control points over areas of one square kilometer, in two test sites; a typical block and a corridor survey. On board GPS data logged during AUAV's flight are being used for direct georeferencing, while ground check points are being used for evaluation. In addition various control point layouts are being tested using bundle adjustment for accuracy evaluation. Results indicate that it is possible to use on board single frequency GPS for direct georeferencing in cases of disaster management or areas without easy access, or even over featureless areas. Due to large numbers of tie points in the bundle adjustment, horizontal accuracy can be fulfilled with a rather small number of control points, but vertical accuracy may not.

  2. Pointing Control System Architecture for the Eclipse Mission

    NASA Technical Reports Server (NTRS)

    Kia, Tooraj; Brugarolas, Paul B.; Alexander, James W.; Li, Diane G.

    2006-01-01

    This paper describes the high performance pointing control system used to point the Eclipse telescope. Eclipse is a new mission under study at Jet Propulsion Laboratory for a proposal as a discovery mission. Eclipse is a space telescope for high-contrast optical astronomy. It will be used to investigate the planetary bodies and environments. The main objective of the Eclipse mission is to study planets around nearby stars. Eclipse is designed to reveal planets or dust structures by reducing the scattered and diffracted light within a few arcseconds of a star to a level three orders of magnitude lower than any instrument on the Hubble Space Telescope (HST). Eclipse achieves this high contrast using a 1.8 meter diameter telescope, a coronagraphic system for control of diffracted light, and active wavefront correction using a Precision Deformable Mirror (DM) for the suppression of scattered light. The observatory will be launched into a Sun-synchronous 690 Km, 98.2(deg) Earth Orbit in 2012.

  3. Pointing and tracking control for freedom's Solar Dynamic modules and vibration control of freedom

    NASA Technical Reports Server (NTRS)

    Quinn, Roger D.; Chen, Jiunn-Liang

    1992-01-01

    A control strategy is presented for pointing particular modules of flexible multibody space structures while simultaneously attenuating structural vibrations. The application that is addressed is the planned Space Station Freedom in a growth configuration with Solar Dynamic (SD) module. A NASTRAN model of Freedom is used to demonstrate the control strategy. Two cases of SD concentrator fine-pointing controller bandwidths are studied with examples. The effect of limiting the controller motor torques to realistic baseline values is examined. SD pointing and station vibration control is accomplished during realistic disturbances due to aerodynamic drag, Shuttle docking, and Shuttle reaction control system plume impingement on SD. Gravity gradient induced torques on SD are relatively small and pseudo-steady.

  4. Combinatorial reshaping of a lipase structure for thermostability: additive role of surface stabilizing single point mutations.

    PubMed

    Kumar, Rakesh; Singh, Ranvir; Kaur, Jagdeep

    2014-05-16

    Thermostable lipases are of high priority for industrial applications. In the present study, targeted improvement of the thermostability of a lipase from metagenomic origin was examined by using a combinatorial protein engineering approach exploring additive effects of single amino acid substitutions. A variant (LipR5) was generated after combination of two thermostabilizing mutations (R214C & N355K). Thermostability of the variant enzyme was analyzed by half-life measurement and circular dichroism (CD). To assess whether catalytic properties were affected by mutation, the optimal reaction conditions were determined. The protein LipR5, displayed optimum activity at 50°C and pH 8.0. It showed two fold enhancement in thermostability (at 60°C) as compared to LipR3 (R214C) and nearly 168 fold enhancement as compared to parent enzyme (LipR1). Circular dichroism and fluorescence study suggest that the protein structure had become more rigid and stable to denaturation. Study of 3D model suggested that Lys355 was involved in formation of a Hydrogen bond with OE1 of Glu284. Lys355 was also making salt bridge with OE2 of Glu284. PMID:24751523

  5. Control-structure interaction in precision pointing servo loops

    NASA Technical Reports Server (NTRS)

    Spanos, John T.

    1989-01-01

    The control-structure interaction problem is addressed via stability analysis of a generic linear servo loop model. With the plant described by the rigid body mode and a single elastic mode, structural flexibility is categorized into one of three types: (1) appendage, (2) in-the-loop minimum phase, and (3) in-the-loop nonminimum phase. Closing the loop with proportional-derivative (PD) control action and introducing sensor roll-off dynamics in the feedback path, stability conditions are obtained. Trade studies are conducted with modal frequency, modal participation, modal damping, loop bandwidth, and sensor bandwidth treated as free parameters. Results indicate that appendage modes are most likely to produce instability if they are near the sensor rolloff, whereas in-the-loop modes are most dangerous near the loop bandwidth. The main goal of this paper is to provide a fundamental understanding of the control-structure interaction problem so that it may benefit the design of complex spacecraft and pointing system servo loops. In this framework, the JPL Pathfinder gimbal pointer is considered as an example.

  6. End point control of an actinide precipitation reactor

    SciTech Connect

    Muske, K.R.; Palmer, M.J.

    1997-10-01

    The actinide precipitation reactors in the nuclear materials processing facility at Los Alamos National Laboratory are used to remove actinides and other heavy metals from the effluent streams generated during the purification of plutonium. These effluent streams consist of hydrochloric acid solutions, ranging from one to five molar in concentration, in which actinides and other metals are dissolved. The actinides present are plutonium and americium. Typical actinide loadings range from one to five grams per liter. The most prevalent heavy metals are iron, chromium, and nickel that are due to stainless steel. Removal of these metals from solution is accomplished by hydroxide precipitation during the neutralization of the effluent. An end point control algorithm for the semi-batch actinide precipitation reactors at Los Alamos National Laboratory is described. The algorithm is based on an equilibrium solubility model of the chemical species in solution. This model is used to predict the amount of base hydroxide necessary to reach the end point of the actinide precipitation reaction. The model parameters are updated by on-line pH measurements.

  7. Developing control points for halal slaughtering of poultry.

    PubMed

    Shahdan, I A; Regenstein, J M; Shahabuddin, A S M; Rahman, M T

    2016-07-01

    Halal (permissible or lawful) poultry meat production must meet industry, economic, and production needs, and government health requirements without compromising the Islamic religious requirements derived from the Qur'an and the Hadiths (the actions and sayings of the Prophet Muhammad, peace and blessings be upon him). Halal certification authorities may vary in their interpretation of these teachings, which leads to differences in halal slaughter requirements. The current study proposes 6 control points (CP) for halal poultry meat production based on the most commonly used halal production systems. CP 1 describes what is allowed and prohibited, such as blood and animal manure, and feed ingredients for halal poultry meat production. CP 2 describes the requirements for humane handling during lairage. CP 3 describes different methods for immobilizing poultry, when immobilization is used, such as water bath stunning. CP 4 describes the importance of intention, details of the halal slaughter, and the equipment permitted. CP 5 and CP 6 describe the requirements after the neck cut has been made such as the time needed before the carcasses can enter the scalding tank, and the potential for meat adulteration with fecal residues and blood. It is important to note that the proposed halal CP program is presented as a starting point for any individual halal certifying body to improve its practices.

  8. Developing control points for halal slaughtering of poultry.

    PubMed

    Shahdan, I A; Regenstein, J M; Shahabuddin, A S M; Rahman, M T

    2016-07-01

    Halal (permissible or lawful) poultry meat production must meet industry, economic, and production needs, and government health requirements without compromising the Islamic religious requirements derived from the Qur'an and the Hadiths (the actions and sayings of the Prophet Muhammad, peace and blessings be upon him). Halal certification authorities may vary in their interpretation of these teachings, which leads to differences in halal slaughter requirements. The current study proposes 6 control points (CP) for halal poultry meat production based on the most commonly used halal production systems. CP 1 describes what is allowed and prohibited, such as blood and animal manure, and feed ingredients for halal poultry meat production. CP 2 describes the requirements for humane handling during lairage. CP 3 describes different methods for immobilizing poultry, when immobilization is used, such as water bath stunning. CP 4 describes the importance of intention, details of the halal slaughter, and the equipment permitted. CP 5 and CP 6 describe the requirements after the neck cut has been made such as the time needed before the carcasses can enter the scalding tank, and the potential for meat adulteration with fecal residues and blood. It is important to note that the proposed halal CP program is presented as a starting point for any individual halal certifying body to improve its practices. PMID:26994198

  9. Sliding mode control of magnetic suspensions for precision pointing and tracking applications

    NASA Technical Reports Server (NTRS)

    Misovec, Kathleen M.; Flynn, Frederick J.; Johnson, Bruce G.; Hedrick, J. Karl

    1991-01-01

    A recently developed nonlinear control method, sliding mode control, is examined as a means of advancing the achievable performance of space-based precision pointing and tracking systems that use nonlinear magnetic actuators. Analytic results indicate that sliding mode control improves performance compared to linear control approaches. In order to realize these performance improvements, precise knowledge of the plant is required. Additionally, the interaction of an estimating scheme and the sliding mode controller has not been fully examined in the literature. Estimation schemes were designed for use with this sliding mode controller that do not seriously degrade system performance. The authors designed and built a laboratory testbed to determine the feasibility of utilizing sliding mode control in these types of applications. Using this testbed, experimental verification of the authors' analyses is ongoing.

  10. Effect of inorganic salts and glucose additives on dose-response, melting point and mass density of genipin gel dosimeters.

    PubMed

    Al-jarrah, A M; Abdul Rahman, Azhar; Shahrim, Iskandar; Razak, Nik Noor Ashikin Nik Ab; Ababneh, Baker; Tousi, Ehsan Taghizadeh

    2016-01-01

    Genipin gel dosimeters are hydrogels infused with a radiation-sensitive material which yield dosimetric information in three dimensions (3D). The effect of inorganic salts and glucose on the visible absorption dose-response, melting points and mass density of genipin gel dosimeters has been experimentally evaluated using 6-MV LINAC photons. As a result, the addition of glucose with optimum concentration of 10% (w/w) was found to improve the thermal stability of the genipin gel and increase its melting point (Tm) by 6 °C accompanied by a slight decrease of dose-response. Furthermore, glucose helps to adjust the gel mass density to obtain the desired tissue-equivalent properties. A drop of Tm was observed when salts were used as additives. As the salt concentration increased, gel Tm decreased. The mass density and melting point of the genipin gel could be adjusted using different amounts of glucose that improved the genipin gel suitability for 3D dose measurements without introducing additional toxicity to the final gel.

  11. Performance of supercritical CO{sub 2} Brayton cycle with additive gases at varying critical points for SFR application

    SciTech Connect

    Jeong, W. S.; Jeong, Y. H.

    2012-07-01

    The supercritical carbon dioxide Brayton cycle (S-CO{sub 2} cycle) has received attention as alternative to the energy conversion system for a Sodium-cooled Fast Reactor (SFR). The high cycle efficiency of S-CO{sub 2} cycle is attributed to significantly reduced compressor work. This is because the compressor operates like a pump in the vicinity of CO{sub 2} critical point. To make use of this feature, the minimum cycle operating range of S-CO{sub 2} cycle, which is the main compressor inlet condition, should be located close to the critical point of CO{sub 2}. This translated into that the critical point of CO{sub 2} is the limitation of the lowest cycle condition of S-CO{sub 2} cycles. To increase the flexibility and broaden the applicability of the cycle, changing the critical point of CO{sub 2} by mixing additive gases could be adopted. An increase in the efficiency of the S-CO{sub 2} cycle could be achieved by decreasing critical point of CO{sub 2}. In addition, increasing critical point of CO{sub 2} could be utilized to obtain improved cycle performances at ascending heat sink temperature of hot arid areas. Due to the rapid fluctuations of thermo-physical properties of gas mixtures near the critical point, an in-house cycle analysis code coupled to NIST property database was developed. Several gases were selected as potential additives through the screening process for thermal stability and chemical interaction with sodium. By using the developed cycle code, optimized cycles of each gas mixture were compared with the reference case of S-CO{sub 2} cycle. For decreased critical temperatures, CO{sub 2}-Xe and CO{sub 2}-Kr showed an increase in the total cycle efficiency. At increasing critical temperatures, the performance of CO{sub 2}-H{sub 2}S and CO{sub 2}-cyclohexane is superior to S-CO{sub 2}cycle when the compressor inlet temperature is above the critical temperature of CO{sub 2}. (authors)

  12. Additives and method for controlling clathrate hydrates in fluid systems

    DOEpatents

    Sloan, E.D. Jr.; Christiansen, R.L.; Lederhos, J.P.; Long, J.P.; Panchalingam, V.; Du, Y.; Sum, A.K.W.

    1997-06-17

    Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hindrance and/or charge repulsion. Also, polymers having an amide on which a C{sub 1}-C{sub 4} group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.

  13. Additives and method for controlling clathrate hydrates in fluid systems

    DOEpatents

    Sloan, Jr., Earle Dendy; Christiansen, Richard Lee; Lederhos, Joseph P.; Long, Jin Ping; Panchalingam, Vaithilingam; Du, Yahe; Sum, Amadeu Kun Wan

    1997-01-01

    Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hinderance and/or charge repulsion. Also, polymers having an amide on which a C.sub.1 -C.sub.4 group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.

  14. Improving efficiency and color purity of poly(9,9-dioctylfluorene) through addition of a high boiling-point solvent of 1-chloronaphthalene

    NASA Astrophysics Data System (ADS)

    Liang, Junfei; Yu, Lei; Zhao, Sen; Ying, Lei; Liu, Feng; Yang, Wei; Peng, Junbiao; Cao, Yong

    2016-07-01

    In this work, the β-phase of poly(9,9-dioctylfluorene) (PFO) was used as a probe to study the effects of the addition of a high boiling-point solvent of 1-chloronaphthalene on the nanostructures and electroluminescence of PFO films. Both absorption and photoluminescence spectra showed that the content of the β-phase in PFO film was obviously enhanced as a result of the addition of a small amount of 1-chloronaphthalene into the processing solvent of p-xylenes. Apparently rougher morphology associated with the effectively enhanced ordering of polymer chains across the entire film was observed for films processed from p-xylene solutions consisting of a certain amount of 1-chloronaphthalene, as revealed by atomic force microscopy and grazing incidence x-ray diffraction measurements. In addition to the effects on the nanostructures of films, of particular interest is that the performance and color purity of polymer light-emitting devices can be noticeably enhanced upon the addition of 1-chloronaphthalene. These observations highlight the importance of controlling the nanostructures of the emissive layer, and demonstrate that the addition of a low volume ratio of high boiling-point additive can be a promising strategy to attain high-performance polymer light-emitting diodes.

  15. Improving efficiency and color purity of poly(9,9-dioctylfluorene) through addition of a high boiling-point solvent of 1-chloronaphthalene.

    PubMed

    Liang, Junfei; Yu, Lei; Sen Zhao; Ying, Lei; Liu, Feng; Yang, Wei; Peng, Junbiao; Cao, Yong

    2016-07-15

    In this work, the β-phase of poly(9,9-dioctylfluorene) (PFO) was used as a probe to study the effects of the addition of a high boiling-point solvent of 1-chloronaphthalene on the nanostructures and electroluminescence of PFO films. Both absorption and photoluminescence spectra showed that the content of the β-phase in PFO film was obviously enhanced as a result of the addition of a small amount of 1-chloronaphthalene into the processing solvent of p-xylenes. Apparently rougher morphology associated with the effectively enhanced ordering of polymer chains across the entire film was observed for films processed from p-xylene solutions consisting of a certain amount of 1-chloronaphthalene, as revealed by atomic force microscopy and grazing incidence x-ray diffraction measurements. In addition to the effects on the nanostructures of films, of particular interest is that the performance and color purity of polymer light-emitting devices can be noticeably enhanced upon the addition of 1-chloronaphthalene. These observations highlight the importance of controlling the nanostructures of the emissive layer, and demonstrate that the addition of a low volume ratio of high boiling-point additive can be a promising strategy to attain high-performance polymer light-emitting diodes.

  16. Improving efficiency and color purity of poly(9,9-dioctylfluorene) through addition of a high boiling-point solvent of 1-chloronaphthalene.

    PubMed

    Liang, Junfei; Yu, Lei; Sen Zhao; Ying, Lei; Liu, Feng; Yang, Wei; Peng, Junbiao; Cao, Yong

    2016-07-15

    In this work, the β-phase of poly(9,9-dioctylfluorene) (PFO) was used as a probe to study the effects of the addition of a high boiling-point solvent of 1-chloronaphthalene on the nanostructures and electroluminescence of PFO films. Both absorption and photoluminescence spectra showed that the content of the β-phase in PFO film was obviously enhanced as a result of the addition of a small amount of 1-chloronaphthalene into the processing solvent of p-xylenes. Apparently rougher morphology associated with the effectively enhanced ordering of polymer chains across the entire film was observed for films processed from p-xylene solutions consisting of a certain amount of 1-chloronaphthalene, as revealed by atomic force microscopy and grazing incidence x-ray diffraction measurements. In addition to the effects on the nanostructures of films, of particular interest is that the performance and color purity of polymer light-emitting devices can be noticeably enhanced upon the addition of 1-chloronaphthalene. These observations highlight the importance of controlling the nanostructures of the emissive layer, and demonstrate that the addition of a low volume ratio of high boiling-point additive can be a promising strategy to attain high-performance polymer light-emitting diodes. PMID:27250786

  17. Direct laser additive fabrication system with image feedback control

    DOEpatents

    Griffith, Michelle L.; Hofmeister, William H.; Knorovsky, Gerald A.; MacCallum, Danny O.; Schlienger, M. Eric; Smugeresky, John E.

    2002-01-01

    A closed-loop, feedback-controlled direct laser fabrication system is disclosed. The feedback refers to the actual growth conditions obtained by real-time analysis of thermal radiation images. The resulting system can fabricate components with severalfold improvement in dimensional tolerances and surface finish.

  18. Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control.

    PubMed

    Slotwinski, John A; Garboczi, Edward J; Hebenstreit, Keith M

    2014-01-01

    Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part's porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity are presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented.

  19. Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control.

    PubMed

    Slotwinski, John A; Garboczi, Edward J; Hebenstreit, Keith M

    2014-01-01

    Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part's porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity are presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented. PMID:26601041

  20. Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control

    PubMed Central

    Slotwinski, John A; Garboczi, Edward J; Hebenstreit, Keith M

    2014-01-01

    Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part’s porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity are presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented. PMID:26601041

  1. Part height control of laser metal additive manufacturing process

    NASA Astrophysics Data System (ADS)

    Pan, Yu-Herng

    Laser Metal Deposition (LMD) has been used to not only make but also repair damaged parts in a layer-by-layer fashion. Parts made in this manner may produce less waste than those made through conventional machining processes. However, a common issue of LMD involves controlling the deposition's layer thickness. Accuracy is important, and as it increases, both the time required to produce the part and the material wasted during the material removal process (e.g., milling, lathe) decrease. The deposition rate is affected by multiple parameters, such as the powder feed rate, laser input power, axis feed rate, material type, and part design, the values of each of which may change during the LMD process. Using a mathematical model to build a generic equation that predicts the deposition's layer thickness is difficult due to these complex parameters. In this thesis, we propose a simple method that utilizes a single device. This device uses a pyrometer to monitor the current build height, thereby allowing the layer thickness to be controlled during the LMD process. This method also helps the LMD system to build parts even with complex parameters and to increase material efficiency.

  2. 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.

  3. Regiodivergent Addition of Phenols to Allylic Oxides: Control of 1,2 and 1,4-Additions for Cyclitol Synthesis**

    PubMed Central

    Moschitto, Matthew J.; Vaccarello, David N.; Lewis, Chad A.

    2015-01-01

    Control of 1,2- and 1,4-addition of substituted phenols to allylic oxides is achieved by intercepting palladium π-allyl complexes. The interconversion of palladium complexes results in the total synthesis of MK7607, cyathiformine B type, streptol, and a new cyclitol. PMID:25533617

  4. Instrument Pointing Control System for the Stellar Interferometry Mission - Planet Quest

    NASA Technical Reports Server (NTRS)

    Brugarolas, Paul B.; Kang, Bryan

    2006-01-01

    This paper describes the high precision Instrument Pointing Control System (PCS) for the Stellar Interferometry Mission (SIM) - Planet Quest. The PCS system provides front-end pointing, compensation for spacecraft motion, and feedforward stabilization, which are needed for proper interference. Optical interferometric measurements require very precise pointing (0.03 as, 1-(sigma) radial) for maximizing the interference pattern visibility. This requirement is achieved by fine pointing control of articulating pointing mirrors with feedback from angle tracking cameras. The overall pointing system design concept is presentcd. Functional requirements and an acquisition concept are given. Guide and Science pointing control loops are discussed. Simulation analyses demonstrate the feasibility of the design.

  5. Effective variable switching point predictive current control for ac low-voltage drives

    NASA Astrophysics Data System (ADS)

    Stolze, Peter; Karamanakos, Petros; Kennel, Ralph; Manias, Stefanos; Endisch, Christian

    2015-07-01

    This paper presents an effective model predictive current control scheme for induction machines driven by a three-level neutral point clamped inverter, called variable switching point predictive current control. Despite the fact that direct, enumeration-based model predictive control (MPC) strategies are very popular in the field of power electronics due to their numerous advantages such as design simplicity and straightforward implementation procedure, they carry two major drawbacks. These are the increased computational effort and the high ripples on the controlled variables, resulting in a limited applicability of such methods. The high ripples occur because in direct MPC algorithms the actuating variable can only be changed at the beginning of a sampling interval. A possible remedy for this would be to change the applied control input within the sampling interval, and thus to apply it for a shorter time than one sample. However, since such a solution would lead to an additional overhead which is crucial especially for multilevel inverters, a heuristic preselection of the optimal control action is adopted to keep the computational complexity at bay. Experimental results are provided to verify the potential advantages of the proposed strategy.

  6. Expressed breast milk on a neonatal unit: a hazard analysis and critical control points approach.

    PubMed

    Cossey, Veerle; Jeurissen, Axel; Thelissen, Marie-José; Vanhole, Chris; Schuermans, Annette

    2011-12-01

    With the increasing use of human milk and growing evidence of the benefits of mother's milk for preterm and ill newborns, guidelines to ensure its quality and safety are an important part of daily practice in neonatal intensive care units. Operating procedures based on hazard analysis and critical control points can standardize the handling of mother's expressed milk, thereby improving nutrition and minimizing the risk of breast milk-induced infection in susceptible newborns. Because breast milk is not sterile, microorganisms can multiply when the milk is not handled properly. Additional exogenous contamination should be prevented. Strict hygiene and careful temperature and time control are important during the expression, collection, transport, storage, and feeding of maternal milk. In contrast to formula milk, no legal standards exist for the use of expressed maternal milk. The need for additional measures, such as bacteriological screening or heat treatment, remains unresolved.

  7. Loop Heat Pipe Operation Using Heat Source Temperature for Set Point Control

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly accomplished by cold biasing the reservoir and using electrical heaters to provide the required control power. Using this method, the loop operating temperature can be controlled within +/- 0.5K. However, because of the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP has been carried out to investigate the effects on the LHP operation when the control temperature sensor is placed on the heat source instead of the reservoir. In these tests, the LHP reservoir is cold-biased and is heated by a control heater. Tests results show that it is feasible to use the heat source temperature for feedback control of the LHP operation. Using this method, the heat source temperature can be maintained within a tight range for moderate and high powers. At low powers, however, temperature oscillations may occur due to interactions among the reservoir control heater power, the heat source mass, and the heat output from the heat source. In addition, the heat source temperature could temporarily deviate from its set point during fast thermal transients. The implication is that more sophisticated feedback control algorithms need to be implemented for LHP transient operation when the heat source temperature is used for feedback control.

  8. Formation Flying With Decentralized Control in Libration Point Orbits

    NASA Technical Reports Server (NTRS)

    Folta, David; Carpenter, J. Russell; Wagner, Christoph

    2000-01-01

    A decentralized control framework is investigated for applicability of formation flying control in libration orbits. The decentralized approach, being non-hierarchical, processes only direct measurement data, in parallel with the other spacecraft. Control is accomplished via linearization about a reference libration orbit with standard control using a Linear Quadratic Regulator (LQR) or the GSFC control algorithm. Both are linearized about the current state estimate as with the extended Kalman filter. Based on this preliminary work, the decentralized approach appears to be feasible for upcoming libration missions using distributed spacecraft.

  9. 21 CFR 123.6 - Hazard analysis and Hazard Analysis Critical Control Point (HACCP) plan.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... identified food safety hazards, including as appropriate: (i) Critical control points designed to control... control points designed to control food safety hazards introduced outside the processing plant environment... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Hazard analysis and Hazard Analysis...

  10. 49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-point frogs and derails shall be selected through circuit controller operated directly by switch points... switch, movable-point frog, and derail in the routes governed by such signal. Circuits shall be arranged... when each switch, movable-point frog, and derail in the route is in proper position....

  11. 49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-point frogs and derails shall be selected through circuit controller operated directly by switch points... switch, movable-point frog, and derail in the routes governed by such signal. Circuits shall be arranged... when each switch, movable-point frog, and derail in the route is in proper position....

  12. 49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...-point frogs and derails shall be selected through circuit controller operated directly by switch points... switch, movable-point frog, and derail in the routes governed by such signal. Circuits shall be arranged... when each switch, movable-point frog, and derail in the route is in proper position....

  13. 49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...-point frogs and derails shall be selected through circuit controller operated directly by switch points... switch, movable-point frog, and derail in the routes governed by such signal. Circuits shall be arranged... when each switch, movable-point frog, and derail in the route is in proper position....

  14. 49 CFR 236.303 - Control circuits for signals, selection through circuit controller operated by switch points or...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-point frogs and derails shall be selected through circuit controller operated directly by switch points... switch, movable-point frog, and derail in the routes governed by such signal. Circuits shall be arranged... when each switch, movable-point frog, and derail in the route is in proper position....

  15. Pointing and control system design study for the space infrared telescope facility (SIRTF)

    NASA Technical Reports Server (NTRS)

    Lorell, K. R.; Aubrun, J. N.; Sridhar, B.; Cochran, R. W.

    1984-01-01

    The design and performance of pointing and control systems for two space infrared telescope facility vehicles were examined. The need for active compensation of image jitter using the secondary mirror or other optical elements was determined. In addition, a control system to allow the telescope to perform small angle slews, and to accomplish large angle slews at the rate of 15 deg per minute was designed. Both the 98 deg and the 28 deg inclination orbits were examined, and spacecraft designs were developed for each. The results indicate that active optical compensation of line-of-sight errors is not necessary if the system is allowed to settle for roughly ten seconds after a slew maneuver. The results are contingent on the assumption of rigid body dynamics, and a single structural mode between spacecraft and telescope. Helium slosh for a half full 4000 liter tank was analyzed, and did not represent a major control problem.

  16. Application of Hazard Analysis Critical Control Points system to enteral tube feeding in hospital.

    PubMed

    Oliveira, M R; Batista, C R; Aidoo, K E

    2001-10-01

    An HACCP system was implemented for the quality assurance of preparation, storage and delivery of enteral feeds to patients in hospital. Routine methods of feed preparation, storage and delivery to patients were studied and a flow chart was initially made. After identifying hazards, an HACCP team was assembled, a flow chart was modified and critical control points were defined using a decision tree. Control measures for each step of the process and its monitoring and corrective measures to be applied were also defined. In addition, feed samples were analysed for microbiological quality and feed storage temperatures were also recorded, before and after the implementation of the HACCP system. When the control measures were applied and monitored, the hazard was reduced. Bacterial counts in feed were reduced from 105 cfu mL-1 to < 101 cfu mL-1. The results show that contamination of enteral feed may be reduced or eliminated if a systematic approach such as HACCP is applied effectively.

  17. Anatomy of an experimental two-link flexible manipulator under end-point control

    NASA Technical Reports Server (NTRS)

    Oakley, Celia M.; Cannon, Robert H., Jr.

    1990-01-01

    The design and experimental implementation of an end-point controller for two-link flexible manipulators are presented. The end-point controller is based on linear quadratic Gaussian (LQG) theory and is shown to exhibit significant improvements in trajectory tracking over a conventional controller design. To understand the behavior of the manipulator structure under end-point control, a strobe sequence illustrating the link deflections during a typical slew maneuver is included.

  18. Hierarchical random additive process and logarithmic scaling of generalized high order, two-point correlations in turbulent boundary layer flow

    NASA Astrophysics Data System (ADS)

    Yang, X. I. A.; Marusic, I.; Meneveau, C.

    2016-06-01

    Townsend [Townsend, The Structure of Turbulent Shear Flow (Cambridge University Press, Cambridge, UK, 1976)] hypothesized that the logarithmic region in high-Reynolds-number wall-bounded flows consists of space-filling, self-similar attached eddies. Invoking this hypothesis, we express streamwise velocity fluctuations in the inertial layer in high-Reynolds-number wall-bounded flows as a hierarchical random additive process (HRAP): uz+=∑i=1Nzai . Here u is the streamwise velocity fluctuation, + indicates normalization in wall units, z is the wall normal distance, and ai's are independently, identically distributed random additives, each of which is associated with an attached eddy in the wall-attached hierarchy. The number of random additives is Nz˜ln(δ /z ) where δ is the boundary layer thickness and ln is natural log. Due to its simplified structure, such a process leads to predictions of the scaling behaviors for various turbulence statistics in the logarithmic layer. Besides reproducing known logarithmic scaling of moments, structure functions, and correlation function [" close="]3/2 uz(x ) uz(x +r ) >, new logarithmic laws in two-point statistics such as uz4(x ) > 1 /2, 1/3, etc. can be derived using the HRAP formalism. Supporting empirical evidence for the logarithmic scaling in such statistics is found from the Melbourne High Reynolds Number Boundary Layer Wind Tunnel measurements. We also show that, at high Reynolds numbers, the above mentioned new logarithmic laws can be derived by assuming the arrival of an attached eddy at a generic point in the flow field to be a Poisson process [Woodcock and Marusic, Phys. Fluids 27, 015104 (2015), 10.1063/1.4905301]. Taken together, the results provide new evidence supporting the essential ingredients of the attached eddy hypothesis to describe streamwise velocity fluctuations of large, momentum transporting eddies in wall-bounded turbulence, while

  19. a Libration Model for Enceladus Based on Geodetic Control Point Network Analysis

    NASA Astrophysics Data System (ADS)

    Nadezhdina, I. E.; Zubarev, A. E.; Brusnikin, E. S.; Oberst, J.

    2016-06-01

    A new global control point network was derived for Enceladus, based on Cassini and Voyager-2 image data. Cassini images were taken from 2005 to 2014, for Voyager we have only one flyby in the middle of 1981. We have derived 3D Cartesian coordinates for 1128 control points as well as improved pointing data for 12 Voyager and 193 Cassini images in the Enceladus-fixed coordinate system. The point accuracies vary from 55 m to 2900 m (average point accuracy - 221 m). From tracking of the control points we detect a librational motion described by a model which includes 3 different periods and amplitudes (Rambaux et al., 2011). We determine the amplitudes for each term. Our new control point network has a higher number of point measurements and a higher accuracy than previous data (Giese et al., 2014).

  20. Stability analysis of fixed points via chaos control.

    PubMed

    Locher, M.; Johnson, G. A.; Hunt, E. R.

    1997-12-01

    This paper reviews recent advances in the application of chaos control techniques to the stability analysis of two-dimensional dynamical systems. We demonstrate how the system's response to one or multiple feedback controllers can be utilized to calculate the characteristic multipliers associated with an unstable periodic orbit. The experimental results, obtained for a single and two coupled diode resonators, agree well with the presented theory. (c) 1997 American Institute of Physics. PMID:12779684

  1. Analytical optimal controls for the state constrained addition and removal of cryoprotective agents

    PubMed Central

    Chicone, Carmen C.; Critser, John K.

    2014-01-01

    Cryobiology is a field with enormous scientific, financial and even cultural impact. Successful cryopreservation of cells and tissues depends on the equilibration of these materials with high concentrations of permeating chemicals (CPAs) such as glycerol or 1,2 propylene glycol. Because cells and tissues are exposed to highly anisosmotic conditions, the resulting gradients cause large volume fluctuations that have been shown to damage cells and tissues. On the other hand, there is evidence that toxicity to these high levels of chemicals is time dependent, and therefore it is ideal to minimize exposure time as well. Because solute and solvent flux is governed by a system of ordinary differential equations, CPA addition and removal from cells is an ideal context for the application of optimal control theory. Recently, we presented a mathematical synthesis of the optimal controls for the ODE system commonly used in cryobiology in the absence of state constraints and showed that controls defined by this synthesis were optimal. Here we define the appropriate model, analytically extend the previous theory to one encompassing state constraints, and as an example apply this to the critical and clinically important cell type of human oocytes, where current methodologies are either difficult to implement or have very limited success rates. We show that an enormous increase in equilibration efficiency can be achieved under the new protocols when compared to classic protocols, potentially allowing a greatly increased survival rate for human oocytes, and pointing to a direction for the cryopreservation of many other cell types. PMID:22527943

  2. Controlled-release fertilizer (CRF): a green fertilizer for controlling non-point contamination in agriculture.

    PubMed

    Mao, Xiao-yun; Sun, Ke-jun; Wang, De-han; Liao, Zong-wen

    2005-01-01

    Fertilizers contribute greatly to high yields but also result in environmental non-point contamination, including the emission of greenhouse gas (N2O) and eutrophication of water bodies. How to solve this problem has become a serious challenge, especially for China as its high ecological pressure. Controlled-release fertilizer(CRF) has been developed to minimize the contamination while keeping high yield and has become a green fertilizer for agriculture. Several CRFs made with special coating technology were used for testing the fertilizer effects in yield and environment through pot experiment and field trial. The result indicated that the CRFs had higher N use efficiency, thus reducing N loss through leaching and volatilization while keeping higher yields. Comparing with imported standard CRFs, the test on CRFs showed similar fertilizer effect but with much lower cost. CRFs application is becoming a new approach for minimizing non-point contamination in agriculture. PMID:16295884

  3. Controlled-release fertilizer (CRF): a green fertilizer for controlling non-point contamination in agriculture.

    PubMed

    Mao, Xiao-yun; Sun, Ke-jun; Wang, De-han; Liao, Zong-wen

    2005-01-01

    Fertilizers contribute greatly to high yields but also result in environmental non-point contamination, including the emission of greenhouse gas (N2O) and eutrophication of water bodies. How to solve this problem has become a serious challenge, especially for China as its high ecological pressure. Controlled-release fertilizer(CRF) has been developed to minimize the contamination while keeping high yield and has become a green fertilizer for agriculture. Several CRFs made with special coating technology were used for testing the fertilizer effects in yield and environment through pot experiment and field trial. The result indicated that the CRFs had higher N use efficiency, thus reducing N loss through leaching and volatilization while keeping higher yields. Comparing with imported standard CRFs, the test on CRFs showed similar fertilizer effect but with much lower cost. CRFs application is becoming a new approach for minimizing non-point contamination in agriculture.

  4. Decentralized Control of Centipede-like Multi-legged Robots with Passive Intersegment Joints Based on Follow-the-Contact-Point Gait Control

    NASA Astrophysics Data System (ADS)

    Inagaki, Shinkichi; Niwa, Tomoya; Suzuki, Tatsuya

    This paper proposes a novel locomotion control, called Follow-the-Contact-Point (FCP) gait control, for a centipede-like multi-legged robot. The centipede-like multi-legged robot is composed by connecting segments, which have a trunk and a pair of legs, via a passive joint. This control method is motivated from behavioral knowledge of a centipede that each leg always contacts on the point which the anterior leg contacted. The FCP gait control realizes the walking behavior of centipede via decentralized event-driven control structure. In addition, merely by planning and allocating the contact point of legs of a head segment adequately, the robot can change the moving direction and also climb over an obstacle. We clarify the feasibility of the FCP gait control by showing the result of physical simulation of a 20-legged robot.

  5. 21 CFR 120.8 - Hazard Analysis and Critical Control Point (HACCP) plan.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...: (i) Critical control points designed to control food hazards that are reasonably likely to occur and... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Hazard Analysis and Critical Control Point (HACCP) plan. 120.8 Section 120.8 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND...

  6. [Pharmacist education from the view point of infection control pharmacist].

    PubMed

    Kitahara, Takashi

    2012-01-01

    Anyone may get infectious diseases without depending on normal persons or patients. We have the probability of infection in hospital or in community. Pharmacists need to have knowledge of the infection control from the viewpoint to contribute to sanitary improvement and an increase, and to secure the healthy life of the nation. And it is necessary to participate in prevention of hospital infection and infectious disease treatment. However, Faculty of Pharmaceutical Sciences six years system education or postgraduate education is not enough for the education of infection control to pharmacists. Therefore, in Nagasaki University Hospital, three Board Certified Infection Control Pharmacy Specialists (BCICPS) play a starring role in educating about the infection control for pharmacists. They lecture on the basic idea of nosocomial infection control and antibacterial chemotherapy, and perform the instruction by the practical skill about the hand antisepsis. We enhance the education effect by carrying out courses on lectures and practical skills. In this symposium, I introduce educational activities in the Nagasaki University Hospital. PMID:23208038

  7. Automatic control-point selection for image registration using disparity fitting

    NASA Astrophysics Data System (ADS)

    Conover, Damon M.; Delaney, John K.; Ricciardi, Paola; Loew, Murray H.

    2012-02-01

    We present an algorithm for automatically selecting and matching control points for the purpose of registering images acquired using different imaging modalities. The modulus maxima of the wavelet transform were used to define a criterion for identifying control points. This criterion is capable of selecting points based on the size of features in the image. This technique can be tailored, by adjusting the scale of the filters in the modulus calculation, to the specific objects or structures known to occur in each image being registered. The control-point matching technique includes an iterative method for reducing the set of control-point pairs using the horizontal and vertical disparities between the matched pairs of points. Least-squares planes are fit to the horizontal and vertical disparity data, and control-point pairings are deleted based on their distances from those planes. The remaining points are used to recompute the planes. The process is iterated until the remaining points fall within a certain distance from the planes. Finally, a spatial transformation is performed on the template image to bring it into alignment with the reference image. The result of the control-point pair reduction is a more accurate alignment than what would have been produced using the initial control-point pairs. These techniques are applicable to medical images, but examples are given using images of paintings.

  8. Point of care and patient privacy: who is in control?

    PubMed

    Morgan, J D

    1994-05-01

    Public and patient access to medical records has been severely limited through policies limiting physical and timely access and intellectual understanding of content. New expectations of patient/public access and control have arisen accompanying the new paradigms of health care delivery and health information (computer-based patient records). Examples from these new paradigms are personalized and presented in information system contexts from bedside to community settings. Patient and family involvement in care delivery, education, assessment, and control of privacy are explored. A personalized confidentiality/security/privacy module of the computer-based patient record is suggested.

  9. Plasmon excitation in metal slab by fast point charge: The role of additional boundary conditions in quantum hydrodynamic model

    SciTech Connect

    Zhang, Ying-Ying; An, Sheng-Bai; Song, Yuan-Hong Wang, You-Nian; Kang, Naijing; Mišković, Z. L.

    2014-10-15

    We study the wake effect in the induced potential and the stopping power due to plasmon excitation in a metal slab by a point charge moving inside the slab. Nonlocal effects in the response of the electron gas in the metal are described by a quantum hydrodynamic model, where the equation of electronic motion contains both a quantum pressure term and a gradient correction from the Bohm quantum potential, resulting in a fourth-order differential equation for the perturbed electron density. Thus, besides using the condition that the normal component of the electron velocity should vanish at the impenetrable boundary of the metal, a consistent inclusion of the gradient correction is shown to introduce two possibilities for an additional boundary condition for the perturbed electron density. We show that using two different sets of boundary conditions only gives rise to differences in the wake potential at large distances behind the charged particle. On the other hand, the gradient correction in the quantum hydrodynamic model is seen to cause a reduction in the depth of the potential well closest to the particle, and a reduction of its stopping power. Even for a particle moving in the center of the slab, we observe nonlocal effects in the induced potential and the stopping power due to reduction of the slab thickness, which arise from the gradient correction in the quantum hydrodynamic model.

  10. Pointing and control system enabling technology for future automated space missions

    NASA Technical Reports Server (NTRS)

    Dahlgren, J. B.

    1978-01-01

    Future automated space missions present challenging opportunities in the pointing-and-control technology disciplines. The enabling pointing-and-control system technologies for missions from 1985 to the year 2000 were identified and assessed. A generic mission set including Earth orbiter, planetary, and other missions which predominantly drive the pointing-and-control requirements was selected for detailed evaluation. Technology candidates identified were prioritized as planning options for future NASA-OAST advanced development programs. The primary technology thrusts in each candidate program were cited, and advanced development programs in pointing-and-control were recommended for the FY 80 to FY 87 period, based on these technology thrusts.

  11. Ubiquitous Points of Control over Regulatory T cells

    PubMed Central

    Pan, Fan; Barbi, Joseph

    2014-01-01

    Posttranslational modification by ubiquitin tagging is crucial for regulating the stability, activity and cellular localization of many target proteins and processes including DNA repair, cell cycle progression, protein quality control and signal transduction. It has long been appreciated that ubiquitin-mediated events are important for certain signaling pathways leading to leukocyte activation and the stimulation of effector function. It is now clear that the activities of molecules and pathways central to immune regulation are also modified and regulated through ubiquitin. Among the mechanisms of immune control, regulatory T cells (or Tregs) are themselves particularly sensitive to such regulation. E3 ligases and deubiquitinases both influence Tregs through their effects on signaling pathways pertinent for these cells or through the direct, posttranslational regulation of Foxp3. In this review we will summarize and discuss several examples of ubiquitin-mediated control over multiple aspects of biology of Tregs including their generation, function and phenotypic fidelity. Fully explored and exploited, these potential opportunities for Treg modulation may lead to novel immunotherapies for both positive and negative fine-tuning of immune restraint. PMID:24777637

  12. Implementation of control point form of algebraic grid-generation technique

    NASA Technical Reports Server (NTRS)

    Choo, Yung K.; Miller, David P.; Reno, Charles J.

    1991-01-01

    The control point form (CPF) provides explicit control of physical grid shape and grid spacing through the movement of the control points. The control point array, called a control net, is a space grid type arrangement of locations in physical space with an index for each direction. As an algebraic method CPF is efficient and works well with interactive computer graphics. A family of menu-driven, interactive grid-generation computer codes (TURBO) is being developed by using CPF. Key features of TurboI (a TURBO member) are discussed and typical results are presented. TurboI runs on any IRIS 4D series workstation.

  13. Configuration trade-offs for the Space Infrared Telescope Facility pointing control system

    NASA Technical Reports Server (NTRS)

    Pue, A. J.; Strohbehn, K.; Hunt, J. W.

    1985-01-01

    Conceptual pointing control system designs for the Space Infrared Telescope Facility (SIRTF) are examined in terms of fine guidance pointing and large-angle slewing accuracies. In particular, basic trade-offs between body pointing only and body pointing plus image motion compensation (IMC) are considered using a steady-state linear covariance analysis to compute rms pointing errors. It is shown that body pointing can provide good performance during nominal fine pointing but limits the telescope capability to rapidly slew and acquire targets. Overall, body pointing plus IMC would offer superior performance but must be judged against the difficulties posed by the attitude sensor noise and the higher cost and complexity of IMC. It is recommended that improved sensor designs be pursued while slewing performance be enhanced by a combination of an appropriate command profile and control compensation.

  14. Uncertainty Analysis of non-point source pollution control facilities design techniques in Korea

    NASA Astrophysics Data System (ADS)

    Lee, J.; Okjeong, L.; Gyeong, C. B.; Park, M. W.; Kim, S.

    2015-12-01

    The design of non-point sources control facilities in Korea is divided largely by the stormwater capture ratio, the stormwater load capture ratio, and the pollutant reduction efficiency of the facility. The stormwater capture ratio is given by a design formula as a function of the water quality treatment capacity, the greater the capacity, the more the amount of stormwater intercepted by the facility. The stormwater load capture ratio is defined as the ratio of the load entering the facility of the total pollutant load generated in the target catchment, and is given as a design formula represented by a function of the stormwater capture ratio. In order to estimate the stormwater capture ratio and load capture ratio, a lot of quantitative analysis of hydrologic processes acted in pollutant emission is required, but these formulas have been applied without any verification. Since systematic monitoring programs were insufficient, verification of these formulas was fundamentally impossible. However, recently the Korean ministry of Environment has conducted an long-term systematic monitoring project, and thus the verification of the formulas became possible. In this presentation, the stormwater capture ratio and load capture ratio are re-estimated using actual TP data obtained from long-term monitoring program at Noksan industrial complex located in Busan, Korea. Through the re-estimated process, the uncertainty included in the design process that has been applied until now will be shown in a quantitative extent. In addition, each uncertainty included in the stormwater capture ratio estimation and in the stormwater load capture ratio estimation will be expressed to quantify the relative impact on the overall non-point pollutant control facilities design process. Finally, the SWMM-Matlab interlocking module for model parameters estimation will be introduced. Acknowledgement This subject is supported by Korea Ministry of Environment as "The Eco Innovation Project : Non-point

  15. Control of node crossing points in Saturnian gravity-assist tours

    NASA Technical Reports Server (NTRS)

    Strange, N.

    2003-01-01

    In the Saturnian system, the control of the node crossing point is important to avoid debris in Saturn's ring plane and to target flybys of moons other than Titan. This paper describes how to use Titan gravity assists to control the spacecraft's node crossing point.

  16. Parameter Space of Fixed Points of the Damped Driven Pendulum Susceptible to Control of Chaos Algorithms

    NASA Astrophysics Data System (ADS)

    Dittmore, Andrew; Trail, Collin; Olsen, Thomas; Wiener, Richard J.

    2003-11-01

    We have previously demonstrated the experimental control of chaos in a Modified Taylor-Couette system with hourglass geometry( Richard J. Wiener et al), Phys. Rev. Lett. 83, 2340 (1999).. Identifying fixed points susceptible to algorithms for the control of chaos is key. We seek to learn about this process in the accessible numerical model of the damped, driven pendulum. Following Baker(Gregory L. Baker, Am. J. Phys. 63), 832 (1995)., we seek points susceptible to the OGY(E. Ott, C. Grebogi, and J. A. Yorke, Phys. Rev. Lett. 64), 1196 (1990). algorithm. We automate the search for fixed points that are candidates for control. We present comparisons of the space of candidate fixed points with the bifurcation diagrams and Poincare sections of the system. We demonstrate control at fixed points which do not appear on the attractor. We also show that the control algorithm may be employed to shift the system between non-communicating branches of the attractor.

  17. Robust optimal sun-pointing control of a large solar power satellite

    NASA Astrophysics Data System (ADS)

    Wu, Shunan; Zhang, Kaiming; Peng, Haijun; Wu, Zhigang; Radice, Gianmarco

    2016-10-01

    The robust optimal sun-pointing control strategy for a large geostationary solar power satellite (SPS) is addressed in this paper. The SPS is considered as a huge rigid body, and the sun-pointing dynamics are firstly proposed in the state space representation. The perturbation effects caused by gravity gradient, solar radiation pressure and microwave reaction are investigated. To perform sun-pointing maneuvers, a periodically time-varying robust optimal LQR controller is designed to assess the pointing accuracy and the control inputs. It should be noted that, to reduce the pointing errors, the disturbance rejection technique is combined into the proposed LQR controller. A recursive algorithm is then proposed to solve the optimal LQR control gain. Simulation results are finally provided to illustrate the performance of the proposed closed-loop system.

  18. Quality Assurance and Quality Control in Point-of-Care Testing.

    PubMed

    Newman, Ashleigh W; Behling-Kelly, Erica

    2016-03-01

    With advancements in the standard of care in veterinary medicine and instrument technology, performing in-house laboratory work on a variety of point-of-care instruments, ranging from glucometers to benchtop chemistry analyzers, has become increasingly commonplace. However, the ability of an instrument to perform a test does not guarantee that those results are accurate. Ensuring that your in-clinic laboratory is providing reliable data requires a comprehensive plan that encompasses both common sense practices aimed at preventing errors at each stage of the testing process, as well as standard operating procedures to validate and monitor analyzer performance. These 2 arms of the plan are known as quality assurance and quality control. Although these concepts are typically out of the comfort zone for veterinarians, just as the thought of business management may deter some veterinarians from practice ownership, it is not beyond the capabilities of veterinarians to learn, understand, and incorporate them into their practice. The objectives of this article are to convey the importance of quality assurance and quality control, walk you through the American Society for Veterinary Clinical Pathology guidelines on this topic, and provide direction to additional resources for further education on this topic, all with the focus on point-of-care testing in the in-clinic laboratory. PMID:27451043

  19. Design of a new high-performance pointing controller for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Johnson, C. D.

    1993-01-01

    A new form of high-performance, disturbance-adaptive pointing controller for the Hubble Space Telescope (HST) is proposed. This new controller is all linear (constant gains) and can maintain accurate 'pointing' of the HST in the face of persistent randomly triggered uncertain, unmeasurable 'flapping' motions of the large attached solar array panels. Similar disturbances associated with antennas and other flexible appendages can also be accommodated. The effectiveness and practicality of the proposed new controller is demonstrated by a detailed design and simulation testing of one such controller for a planar-motion, fully nonlinear model of HST. The simulation results show a high degree of disturbance isolation and pointing stability.

  20. Control of large space structures and associated precision-pointed payloads

    NASA Technical Reports Server (NTRS)

    Joshi, S. M.; Goglia, G. L.

    1982-01-01

    Stability and robustness of a two-level control system for large space structures were investigated. In particular, the effects of actuator/sensor nonlinearities and dynamics on the closed-loop stability were studied and the problem of control-systems design for fine-pointing of several individually pointed payloads mounted on a large space platform was examined. A composite controller is proposed and is stable and robust.

  1. Pointing and figure control system for a space-based far-IR segmented telescope

    NASA Technical Reports Server (NTRS)

    Lau, Kenneth

    1993-01-01

    A pointing and figure control system for two space-based far-IR telescopes, the 10-20 m Large Deployable Reflector and the 3.6 m Submillimeter Intermediate Mission, is described. The figure maintenance control system is designed to counter the optical elements translational and rotational changes induced by long-term thermal drifts that the support structure may experience. The pointing system applies optical truss to telescope pointing; a laser metrology system is used to transfer pointing informaton from an external fine guidance sensor to the telescope optical boresight, defined by the primary mirror, secondary mirror, and focal plane assembly.

  2. Methodological demonstration of laser beam pointing control for space gravitational wave detection missions.

    PubMed

    Dong, Yu-Hui; Liu, He-Shan; Luo, Zi-Ren; Li, Yu-Qiong; Jin, Gang

    2014-07-01

    In space laser interferometer gravitational wave (G.W.) detection missions, the stability of the laser beam pointing direction has to be kept at 10 nrad/√Hz. Otherwise, the beam pointing jitter noise will dominate the noise budget and make the detection of G.W. impossible. Disturbed by the residue non-conservative forces, the fluctuation of the laser beam pointing direction could be a few μrad/√Hz at frequencies from 0.1 mHz to 10 Hz. Therefore, the laser beam pointing control system is an essential requirement for those space G.W. detection missions. An on-ground test of such beam pointing control system is performed, where the Differential Wave-front Sensing technique is used to sense the beams pointing jitter. An active controlled steering mirror is employed to adjust the beam pointing direction to compensate the jitter. The experimental result shows that the pointing control system can be used for very large dynamic range up to 5 μrad. At the interested frequencies of space G.W. detection missions, between 1 mHz and 1 Hz, beam pointing stability of 6 nrad/√Hz is achieved. PMID:25085155

  3. Methodological demonstration of laser beam pointing control for space gravitational wave detection missions

    SciTech Connect

    Dong, Yu-Hui; Liu, He-Shan; Luo, Zi-Ren; Li, Yu-Qiong; Jin, Gang

    2014-07-15

    In space laser interferometer gravitational wave (G.W.) detection missions, the stability of the laser beam pointing direction has to be kept at 10 nrad/√Hz. Otherwise, the beam pointing jitter noise will dominate the noise budget and make the detection of G.W. impossible. Disturbed by the residue non-conservative forces, the fluctuation of the laser beam pointing direction could be a few μrad/√Hz at frequencies from 0.1 mHz to 10 Hz. Therefore, the laser beam pointing control system is an essential requirement for those space G.W. detection missions. An on-ground test of such beam pointing control system is performed, where the Differential Wave-front Sensing technique is used to sense the beams pointing jitter. An active controlled steering mirror is employed to adjust the beam pointing direction to compensate the jitter. The experimental result shows that the pointing control system can be used for very large dynamic range up to 5 μrad. At the interested frequencies of space G.W. detection missions, between 1 mHz and 1 Hz, beam pointing stability of 6 nrad/√Hz is achieved.

  4. Wireless power charging using point of load controlled high frequency power converters

    DOEpatents

    Miller, John M.; Campbell, Steven L.; Chambon, Paul H.; Seiber, Larry E.; White, Clifford P.

    2015-10-13

    An apparatus for wirelessly charging a battery of an electric vehicle is provided with a point of load control. The apparatus includes a base unit for generating a direct current (DC) voltage. The base unit is regulated by a power level controller. One or more point of load converters can be connected to the base unit by a conductor, with each point of load converter comprising a control signal generator that transmits a signal to the power level controller. The output power level of the DC voltage provided by the base unit is controlled by power level controller such that the power level is sufficient to power all active load converters when commanded to do so by any of the active controllers, without generating excessive power that may be otherwise wasted.

  5. Conceptual design of pointing control systems for space station gimballed payloads

    NASA Technical Reports Server (NTRS)

    Hughes, Robert O.

    1986-01-01

    A conceptual design of the control system for Payload Pointing Systems (PPS) is developed using classic Proportional-Integral-Derivatives (PID) techniques. The major source of system pointing error is due to the disturbance-rich environment of the space station in the form of gimbal baseplate motions. These baseplate vibrations are characterized using Fast Fourier Transform (FFT) techniques. Both time domain and frequency domain dynamic models are developed to assess control system performance. Three basic methods exist for the improvement of PPS pointing performance: increase control system bandwidth, add Image Motion Compensation, and/or reduce (or change) the baseplate disturbance environment.

  6. Choosing the Optimal Number of B-spline Control Points (Part 1: Methodology and Approximation of Curves)

    NASA Astrophysics Data System (ADS)

    Harmening, Corinna; Neuner, Hans

    2016-09-01

    Due to the establishment of terrestrial laser scanner, the analysis strategies in engineering geodesy change from pointwise approaches to areal ones. These areal analysis strategies are commonly built on the modelling of the acquired point clouds. Freeform curves and surfaces like B-spline curves/surfaces are one possible approach to obtain space continuous information. A variety of parameters determines the B-spline's appearance; the B-spline's complexity is mostly determined by the number of control points. Usually, this number of control points is chosen quite arbitrarily by intuitive trial-and-error-procedures. In this paper, the Akaike Information Criterion and the Bayesian Information Criterion are investigated with regard to a justified and reproducible choice of the optimal number of control points of B-spline curves. Additionally, we develop a method which is based on the structural risk minimization of the statistical learning theory. Unlike the Akaike and the Bayesian Information Criteria this method doesn't use the number of parameters as complexity measure of the approximating functions but their Vapnik-Chervonenkis-dimension. Furthermore, it is also valid for non-linear models. Thus, the three methods differ in their target function to be minimized and consequently in their definition of optimality. The present paper will be continued by a second paper dealing with the choice of the optimal number of control points of B-spline surfaces.

  7. Proper use of sludge-control additives in residential heating oil systems

    SciTech Connect

    Tatnall, R.E.

    1995-04-01

    Discussed are various aspects of heating oil `sludge`: How it forms, typical problems it causes, how sludge-control additives work, what should be expected of them, and what happens in a contaminated system when such additives are used. Test results from laboratory and field experiments demonstrate that performance of commercially available additives varies greatly. The concept of `end-of-the-line` treatment is described and compared with bulk fuel treatment. A procedure is described whereby a retailer can test additives himself, and thus determine just what those additives will or will not do for his business. Finally, the economics of an effective treatment program are outlined.

  8. The Feasibility of the Disturbance Accommodating Controller for Precision Antenna Pointing

    NASA Technical Reports Server (NTRS)

    Gresham, L. L.; Lansing, F. L.; Guiar, C. N.

    1988-01-01

    The objective of this study is to investigate the feasibility of a pointing (position loop) controller for the NASA-JPL Deep Space Network (DSN) antennas using the Disturbance Accommodating Control (DAC) theory. A model that includes state dependent disturbances was developed, and an example demonstrating the noise estimator is presented as an initial phase in the controller design. The goal is to improve pointing accuracy by the removal of the systematic errors caused by the antenna misalignment as well as sensor noise and random wind and thermal disturbances. Preliminary simulation results show that the DAC technique is successful in both cancelling the imposed errors and maintaining an optimal control policy.

  9. The Use of Principal Components for Creating Improved Imagery for Geometric Control Point Selection

    NASA Technical Reports Server (NTRS)

    Imhoff, M. L.

    1982-01-01

    A directed principal component (PC) analysis and its transformation was applied to 7-channel thematic mapper simulator (TMS) data and 4-channel LANDSAT multispectral scanner system (MSS) data collected over the city of Lancaster, Pennsylvania, to create improved imagery for geometric control point selection for image to image registration. Nineteen temporally stable geometric control points, such as road interactions and bridges, were selected for a 236 sq km area. The control points were visible on both the TMS and MSS imagery. On the first attempt the corresponding image control points were selected on both data sets without using the principal components transformation. Many of the road intersection locations were visible but the actual road crossings could not be distinguished. As a result, mensuration errors using raw data exceeded the equivalent of two (79 x 79 m) pixels. The application of a guided principal components transformation yielded TMS and MSS single band images showing improved detail in the scene's urban and residential infrastructure. The PC transformed data sets were then utilized for the reselection of geometric control points. By shown greater detail, control points on both the TMS and MSS imagery could be located with greater precision using the PC transformed data.

  10. Characterization of the alpha-1,2-N-acetylglucosaminyltransferase of Neisseria gonorrhoeae, a key control point in lipooligosaccharide biosynthesis.

    PubMed

    Wakarchuk, Warren; Schur, Melissa J; St Michael, Frank; Li, Jinjuan; Eichler, Eva; Whitfield, Dennis

    2004-06-01

    The biosynthesis of the lipooligosaccharide (LOS) in Neisseria meningitidis has a control point that regulates the extension of the alpha-chain on heptose (I) of the LOS. The gene that encodes the protein responsible for this control had been identified elsewhere, but the enzyme encoded by the gene was not characterized. We have now shown that this same control mechanism operates in the related species, Neisseria gonorrhoeae, using a gene knockout and subsequent characterization of the LOS species produced. We also cloned and expressed the enzyme from both of these pathogens. Using a synthetic acceptor substrate, we have shown unequivocally that the enzyme is an alpha-1,2-N-acetylglucosaminyltransferase. Experiments with both the core oligosaccharide and the synthetic acceptors suggests that the addition of the alpha-1,2-N-acetylglucosamine moiety on the heptose (II) residue precedes the addition of the ethanolamine phosphate at the O3 position on this heptose (II), and that in the absence of the alpha-1,2-N-acetylglucosamine moiety leads to the addition of an extra ethanolamine phosphate on the heptose (II) residue. Our data do not support the hypothesis that ethanolamine phosphate at O3 of heptose (II) is added and is then required for the addition of the N-acetylglucosamine at O2 by the LgtK enzyme. This enzyme represents a control point in the biosynthesis of the LOS of this pathogen and is a potential target for therapeutic intervention. PMID:15044393

  11. Control of a pointing, acquisition, and tracking subsystem for intersatellite laser links ISL2

    NASA Astrophysics Data System (ADS)

    Kern, R.; Kuel, U.; Hettlage, E.

    1987-01-01

    It is shown that the dynamical requirements determined for a CO2 lasercom system can be met with the fine pointing assembly (FPA) and the coarse pointing assembly (CPA) described here. The implemented control loops and the corresponding control logic provide the PAT subsystem with a high bandwidth and a short transition time from the acquisition to the tracking mode. It is demonstrated that the maximum angular rate of the LOS in connection with the maximum slew rate of the CPA and the magnification factor of the telescope determine the area around the singular point which the FPA must be able to cover.

  12. Simulation of flexible appendage interactions with Mariner Venus/Mercury attitude control and science platform pointing

    NASA Technical Reports Server (NTRS)

    Fleischer, G. E.

    1973-01-01

    A new computer subroutine, which solves the attitude equations of motion for any vehicle idealized as a topological tree of hinge-connected rigid bodies, is used to simulate and analyze science instrument pointing control interaction with a flexible Mariner Venus/Mercury (MVM) spacecraft. The subroutine's user options include linearized or partially linearized hinge-connected models whose computational advantages are demonstrated for the MVM problem. Results of the pointing control/flexible vehicle interaction simulations, including imaging experiment pointing accuracy predictions and implications for MVM science sequence planning, are described in detail.

  13. Highly Diastereoselective Chelation-controlled Additions to α-Silyloxy Ketones

    PubMed Central

    Stanton, Gretchen R.; Koz, Gamze

    2011-01-01

    The polar Felkin-Anh, Cornforth, and Cram-chelation models predict that the addition of organometallic reagents to silyl–protected α–hydroxy ketones proceeds via a non-chelation pathway to give anti-diol addition products. This prediction has held true for the vast majority of additions reported in the literature and few methods for chelation-controlled additions of organometallic reagents to silyl–protected α–hydroxy ketones have been introduced. Herein, we present a general and highly diastereoselective method for the addition of dialkylzincs and (E)-di-, (E)-tri- and (Z)-disubstituted vinylzinc reagents to α-silyloxy ketones using alkyl zinc halide Lewis acids, RZnX, to give chelation-controlled products (dr ≥18:1). The compatibility of organozinc reagents with other functional groups makes this method potentially very useful in complex molecule synthesis. PMID:21534530

  14. Costs and water quality effects of controlling point and nonpoint pollution sources

    SciTech Connect

    Macal, C.M.; Broomfield, B.J.

    1980-01-01

    Costs and water quality effects of controlling point and nonpoint pollution sources are compared for the DuPage River basin in northern Illinois. Costs are estimated for effluent standards for municipal wastewater treatment plants and for the alternative, controlling runoff from nonpoint sources such as streets, agricultural lands, and forests. A dynamic water-quality/hydrology simulation model is used to determine water quality effects of various treatment plant standards and nonpoint-source controls. Costs and water quality data are combined, and the point-source and nonpoint-source plans are compared on a cost-effectiveness basis. Nonpoint-source controls are found to be more cost-effective than stricter control of pollutants from point sources.

  15. A concept for the examination of reference points stability in horizontal control networks

    NASA Astrophysics Data System (ADS)

    Malarski, Ryszard

    2016-06-01

    This paper presents a concept for the identification of stable reference points used in horizontal control networks, which is based on the lengths of apparent displacement vectors and their mean errors. These vectors and their mean errors are obtained during the process of calculating displacements with free adjustment conditions. It will be shown that the influence of the apparent displacement vectors has a significant effect on the calculation of results. The identification of stable points, using the proposed method, is an integral part of the adjustment process and allows for the interrogation the influence of individual point inclusion or deletion from the reference database, on the values of displacements of controlled points. A detailed process of stable reference points identification is presented using the example of a linear-angular network for a barrage.

  16. Effects of Heat and Momentum Addition Inside and Outside the Compound Sonic Point of the Solar Wind

    NASA Astrophysics Data System (ADS)

    Hu, Q.; Webb, G. M.; McKenzie, J. F.

    2014-12-01

    We consider the effect of heat and momentum addition to the solar wind for a model including the effects of Alfven waves and plasma pressure (proton plus electron pressure). The mass flux per unit area in 1D flow maximizes when the flow speed equals the compound sound speed, including the effects of the Alfven wave pressure. We discuss the analogue of the Laval nozzle for the solar wind flow, and the dependence of the effective nozzle area as a function of radial distance, and the relationship of the nozzle area to the momentum equation and the Mach number of the flow. An analysis is carried out of the effects of heat and momentum addition to the wind, using a thin slice approximation, which leads to Rankine Hugoniot relations for weak deflagrations and detonations (i.e. the combustion Hugoniot). The linearized Hugoniot is used to analyze the effects of small momentum and energy addition to the wind in the thin slice approximation. We obtain the fully nonlinear Rankine Hugoniot equation solutions. The analysis also holds in the presence of Alfven waves, in which the wave energy exchange equation yields the wave action flux conservation law when their contribution to the compound sound speed is taken into account. The effective polytropic index γgamma and flow speed relative to the compound flow speed ahead of the slice play crucial roles in determining whether local acceleration or deceleration results. Some results are at first sight unexpected since γgamma for Alfven waves ranges from -1/2 (in sub-Alfvenic flow) to 3/2 in super-Alfvenic flow.

  17. Performance improvement of PI controllers through dynamic set-point weighting.

    PubMed

    Mudi, Rajani K; Dey, Chanchal

    2011-04-01

    Responses of high-order systems under Ziegler-Nichols tuned PI controllers (ZNPIs) are characterized by excessive oscillation with a large overshoot. Although, a fixed set-point weighting based PI controller (FSWPI) may decrease the overshoot considerably, it fails to reduce the oscillation in the set-point response. Moreover, both FSWPI and ZNPI exhibit equally poor load regulation. Keeping in mind an overall improved performance, we propose an online dynamic set-point weighting technique for ZNPIs. The dynamic set-point weighting factor (β(d)) is heuristically derived from the instantaneous process trend. Performance of the proposed dynamic set-point weighting based PI controller (DSWPI) for various second- and third-order processes including a pH process shows a significant improvement during both the set-point and load disturbance responses over other methods. Stability and robustness of the proposed DSWPI are addressed. Effectiveness of the DSWPI is demonstrated through the real-time implementation on a practical DC position control system.

  18. Antagonistic control of a dual-input mammalian gene switch by food additives.

    PubMed

    Xie, Mingqi; Ye, Haifeng; Hamri, Ghislaine Charpin-El; Fussenegger, Martin

    2014-08-01

    Synthetic biology has significantly advanced the design of mammalian trigger-inducible transgene-control devices that are able to programme complex cellular behaviour. Fruit-based benzoate derivatives licensed as food additives, such as flavours (e.g. vanillate) and preservatives (e.g. benzoate), are a particularly attractive class of trigger compounds for orthogonal mammalian transgene control devices because of their innocuousness, physiological compatibility and simple oral administration. Capitalizing on the genetic componentry of the soil bacterium Comamonas testosteroni, which has evolved to catabolize a variety of aromatic compounds, we have designed different mammalian gene expression systems that could be induced and repressed by the food additives benzoate and vanillate. When implanting designer cells engineered for gene switch-driven expression of the human placental secreted alkaline phosphatase (SEAP) into mice, blood SEAP levels of treated animals directly correlated with a benzoate-enriched drinking programme. Additionally, the benzoate-/vanillate-responsive device was compatible with other transgene control systems and could be assembled into higher-order control networks providing expression dynamics reminiscent of a lap-timing stopwatch. Designer gene switches using licensed food additives as trigger compounds to achieve antagonistic dual-input expression profiles and provide novel control topologies and regulation dynamics may advance future gene- and cell-based therapies.

  19. Antagonistic control of a dual-input mammalian gene switch by food additives

    PubMed Central

    Xie, Mingqi; Ye, Haifeng; Hamri, Ghislaine Charpin-El; Fussenegger, Martin

    2014-01-01

    Synthetic biology has significantly advanced the design of mammalian trigger-inducible transgene-control devices that are able to programme complex cellular behaviour. Fruit-based benzoate derivatives licensed as food additives, such as flavours (e.g. vanillate) and preservatives (e.g. benzoate), are a particularly attractive class of trigger compounds for orthogonal mammalian transgene control devices because of their innocuousness, physiological compatibility and simple oral administration. Capitalizing on the genetic componentry of the soil bacterium Comamonas testosteroni, which has evolved to catabolize a variety of aromatic compounds, we have designed different mammalian gene expression systems that could be induced and repressed by the food additives benzoate and vanillate. When implanting designer cells engineered for gene switch-driven expression of the human placental secreted alkaline phosphatase (SEAP) into mice, blood SEAP levels of treated animals directly correlated with a benzoate-enriched drinking programme. Additionally, the benzoate-/vanillate-responsive device was compatible with other transgene control systems and could be assembled into higher-order control networks providing expression dynamics reminiscent of a lap-timing stopwatch. Designer gene switches using licensed food additives as trigger compounds to achieve antagonistic dual-input expression profiles and provide novel control topologies and regulation dynamics may advance future gene- and cell-based therapies. PMID:25030908

  20. CMG-induced LST dynamics. [application of control moment gyroscope to pointing and control systems of large space telescope

    NASA Technical Reports Server (NTRS)

    Seltzer, S. M.

    1974-01-01

    The application of control moment gyroscopes to the pointing and control system of the large space telescope is discussed. The parameter plane analysis technique is used to present the nonlinearity representing the control moment gyroscope gimbal bearing friction. The technique affords both analytic and graphic portrayal of the effects of variations is selected system parameters. Diagrams of the systems involved in the tests are presented.

  1. Control of terahertz emission in photoconductive antennas through an additional optical continuous wave.

    PubMed

    Bockelt, A; Palací, J; Vidal, B

    2013-08-15

    The manipulation of the operating conditions of photoconductive antennas by means of an additional continuous wave (CW) is reported. It is used to control a fiber-based terahertz (THz) time-domain-spectroscopy system at telecom wavelengths. The injection of an optical CW into the transmitter allows the control of the THz amplitude without causing major degradation to the system performance. This, for instance, can be exploited to perform modulation of the THz signal. PMID:24104665

  2. Rectification of single and multiple frames of satellite scanner imagery using points and edges as control

    NASA Technical Reports Server (NTRS)

    Paderes, F. C., Jr.; Mikhail, E. M.; Foerstner, W.

    1984-01-01

    Rectification of single and overlapping multiple scanner frames produced by such satellite-borne scanners as the LANDSAT MSS was carried out using a newly developed comprehensive parametric model. Tests with both simulated and real image data demonstrate conclusively that this model in general is superior to the widely used polynomial model, and that the simultaneous rectification of overlapping frames using least squares techniques yields a high accuracy than sngle frame rectification due to the inclusion of tie points between the image frames. Used to control, edges or lines, whic are much more likely to be found in images, can replace conventional control points and can easily be implemented into the least squares approach. An efficient algorithm for findng corresponding points in image paris was developed which can be used for determining tie points between image frames and thus increase the ecnomy of the whole rectification procedure.

  3. Preservicing mission, on-orbit modifications to Hubble Space Telescope pointing control system

    NASA Astrophysics Data System (ADS)

    Nurre, G. S.; Sharkey, J. P.; Nelson, J. D.; Bradley, A. J.

    1995-03-01

    Because of unexpected, thermally induced disturbances originating in the solar arrays (SAs), the Hubble Space Telescope was initially unable to meet its pointing error specifications of 0.007 arc-s (root mean square) for observations lasting from a few seconds to several hours. The effort to pinpoint the mechanism causing the problem and to redesign the onboard controller to accommodate the disturbance began shortly after deployment. After controller modifications, the pointing errors were well within the specification for all of the orbit except for short intervals during transitions in and out of Earth's shadow. This paper presents a chronology of the redesign process and flight data showing the achieved pointing performance. During the recent servicing mission (December 1993) the SAs were replaced with arrays of a modified mechanical design. A preliminary assessment of pointing performance since that time is presented.

  4. Reducing Pointing Errors During Cassini Reaction Control System Orbit Trim Maneuvers

    NASA Technical Reports Server (NTRS)

    Rizvi, Farheen

    2013-01-01

    The effect of altering a gain parameter in the Cassini reaction control system (RCS) delta-V controller on the maneuver execution errors during orbit trim maneuvers (OTMs) is explored. Cassini consists of two reaction control thruster branches (A & B) each with eight thrusters. Currently, the B-branch is operational while the A-branch serves as a back-up. The four Z-thrusters control the X and Y-axes, while the four Y-thrusters control the Z-axis. During an OTM, the Z-thrusters fire to maintain the X and Y-axes pointing within an attitude control dead-zone (-10 to 10 milliradians). The errors do not remain at zero due to pointing error sources such as spacecraft center of mass offset from the geometric center of the Z-facing thrusters, and variability in the thruster forces due to the thruster hardware differences. The delta-V reaction control system (RCS) controller ensures that the attitude error remains within this dead-zone. Gain parameters within the RCS delta-V controller affect the maneuver execution errors. Different parameter values are used to explore effect on these errors. It is found that pointing error decreases and magnitude error increases rapidly for gain parameters 10 times greater than the current parameter values used in the flight software.

  5. Dual-mode disturbance-accommodating pointing controller for Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Addington, Stewart I.; Johnson, C. D.

    1995-03-01

    Cyclic thermal expansions and mechanical stiction effects in the solar arrays on the Hubble Space Telescope (HST) are triggering repeated occurrences of damped, relaxation-type flex-body vibrations of the solar arrays. Those solar array vibrations are, in turn, causing unwanted deviations of the telescope from its specified pointing direction. In this paper we propose two strategies one can adopt in designing a telescope-pointing controller to cope with the aforementioned disturbances: 1) a total isolation (TI) control strategy whereby the HST controller torques are designed to adaptively counteract and cancel out the persistent disturbing torques that are causing the unwanted telescope motions and 2) an array damping (AD) control strategy whereby the HST controller torques are used to actively augment the natural dampening of the solar array vibrations and the attendant telescope motions, between triggerings of the stiction-related flex-body relaxation oscillations. Using the principles of disturbance accommodation control theory, a dual-mode controller for a generic, planar-motion (single-axis) model of the HST is proposed. This controller incorporates both the TI and AD modes of disturbance accommodation. Simulation studies of the closed-loop system using generic parameter values clearly indicate, qualitatively, the enhanced pointing performance such a controller can achieve.

  6. Maximum Power Point Tracking Controller for Thermoelectric Generators with Peak Gain Control of Boost DC-DC Converters

    NASA Astrophysics Data System (ADS)

    Park, Jungyong; Kim, Shiho

    2012-06-01

    An analog maximum power point tracking (MPPT) circuit for a thermoelectric generator (TEG) is proposed. We show that the peak point of the voltage conversion gain of a boost DC-DC converter with an input voltage source having an internal resistor is the maximum power point of the TEG. The key characteristic of the proposed MPPT controller is that the duty ratio of the input clock pulse to the boost DC-DC converter shifts toward the maximum power point of the TEG by seeking the peak gain point of the boost DC-DC converters. The proposed MPPT technique provides a simple and useful analog MPPT solution, without employing digital microcontroller units.

  7. Acquisition Tracking and Pointing Control of the Bifocal Relay Mirror Spacecraft

    NASA Astrophysics Data System (ADS)

    Romano, Marcello; Agrawal, Brij N.

    This spacecraft consists of two large gimbaled telescopes, that are optically coupled and used to redirect a laser beam from a ground-based or spacecraft based source to a distant point on the earth or in space. The attitude control system consists of reaction wheels, star trackers and gyros. The optical control system consists of two fast steering mirrors and two optical tracker sensors. The very tight pointing and jitter requirements, together with the multi-body nature of the spacecraft, make the acquisition, tracking and pointing control very challenging. The control techniques developed in this research can be applied to imaging spacecrafts and spacecrafts with optical communications. numerical simulations. The simulations were performed to analyze two different control approaches proposed for the tracking and pointing of the Bifocal Relay Mirror spacecraft during operational phase. In the first control option considered, feed forward and feedback control are used for the spacecraft attitude control, while independent feedback is used by the optical subsystem in order to compensate the pointing error of the spacecraft. In the second control approach, the spacecraft and optical control systems are integrated. In case of uncertainty in target position and use of realistic sensors, using star tracker and rate gyros with Kalman Filter, the integrated control provides better performance. dynamics and control simulator of the Spacecraft Research and Design Center of Naval Postgraduate School. The attitude of this spherical air bearing based test-bed was controlled by three reaction wheels, while its attitude and angular velocity were sensed by an optical attitude sensor and three rate gyros, respectively. The three axes simulator platform included as payload a fully functional model of the transmitter section of the Bifocal Relay Mirror Spacecraft, consisting in one telescope with fast steering mirror and one optical tracker sensor. Two preliminary experiments have

  8. The Hubble Space Telescope fine guidance system operating in the coarse track pointing control mode

    NASA Technical Reports Server (NTRS)

    Whittlesey, Richard

    1993-01-01

    The Hubble Space Telescope (HST) Fine Guidance System has set new standards in pointing control capability for earth orbiting spacecraft. Two precision pointing control modes are implemented in the Fine Guidance System; one being a Coarse Track Mode which employs a pseudo-quadrature detector approach and the second being a Fine Mode which uses a two axis interferometer implementation. The Coarse Track Mode was designed to maintain FGS pointing error to within 20 milli-arc seconds (rms) when guiding on a 14.5 Mv star. The Fine Mode was designed to maintain FGS pointing error to less than 3 milli-arc seconds (rms). This paper addresses the HST FGS operating in the Coarse Track Mode. An overview of the implementation, the operation, and both the predicted and observed on orbit performance is presented. The discussion includes a review of the Fine Guidance System hardware which uses two beam steering Star Selector servos, four photon counting photomultiplier tube detectors, as well as a 24 bit microprocessor, which executes the control system firmware. Unanticipated spacecraft operational characteristics are discussed as they impact pointing performance. These include the influence of spherically aberrated star images as well as the mechanical shocks induced in the spacecraft during and following orbital day/night terminator crossings. Computer modeling of the Coarse Track Mode verifies the observed on orbit performance trends in the presence of these optical and mechanical disturbances. It is concluded that the coarse track pointing control function is performing as designed and is providing a robust pointing control capability for the Hubble Space Telescope.

  9. Precision Pointing Control System (PPCS) system design and analysis. [for gimbaled experiment platforms

    NASA Technical Reports Server (NTRS)

    Frew, A. M.; Eisenhut, D. F.; Farrenkopf, R. L.; Gates, R. F.; Iwens, R. P.; Kirby, D. K.; Mann, R. J.; Spencer, D. J.; Tsou, H. S.; Zaremba, J. G.

    1972-01-01

    The precision pointing control system (PPCS) is an integrated system for precision attitude determination and orientation of gimbaled experiment platforms. The PPCS concept configures the system to perform orientation of up to six independent gimbaled experiment platforms to design goal accuracy of 0.001 degrees, and to operate in conjunction with a three-axis stabilized earth-oriented spacecraft in orbits ranging from low altitude (200-2500 n.m., sun synchronous) to 24 hour geosynchronous, with a design goal life of 3 to 5 years. The system comprises two complementary functions: (1) attitude determination where the attitude of a defined set of body-fixed reference axes is determined relative to a known set of reference axes fixed in inertial space; and (2) pointing control where gimbal orientation is controlled, open-loop (without use of payload error/feedback) with respect to a defined set of body-fixed reference axes to produce pointing to a desired target.

  10. Single supplier single retailer inventory model controlled by the reorder and shipping points with sharing information

    NASA Astrophysics Data System (ADS)

    Ho, Wen-Tsung; Hsiao, Yu-Cheng

    2012-04-01

    This study investigated the integrated stochastic inventory problem for a two-stage supply chain consisting of a single retailer and a single supplier. By using batch shipment policy, the expected total cost can be significantly reduced. An equally sized batch shipment model, controlled by both the reorder and shipping points, with sharing information by enterprise resource planning and radio frequency identification is constructed. The problem is solved optimally by the proposed algorithm that determines the economic lot size, the optimal batch sizes and number of batches. A numerical example is included to illustrate the algorithmic procedures and to prove that the model controlled both by the reorder and shipping points is superior to the classic model controlled only by the reorder point.

  11. ATS-6 - Spacecraft Attitude Precision Pointing and Slewing Adaptive Control Experiment

    NASA Technical Reports Server (NTRS)

    Isley, W. C.; Endres, D. L.

    1975-01-01

    The primary objective of the Spacecraft Attitude Precision Pointing and Slewing Adaptive Control (SAPPSAC) experiment is to establish feasibility and evaluate capabilities of a ground-based spacecraft attitude control system, wherein RF command and telemetry links, together with a ground station on-line minicomputer, perform closed loop attitude control of the Applications Technology Satellite-6 (ATS-6). The ground processor is described, including operational characteristics and the controller software. Attitude maneuvers include precision pointing to fixed targets, slewing between targets, and generation of prescribed ground tracks. Test results show high performance and reliability for over 30 hours of on-line control with no serious anomalies. Attitude stabilization relative to a prescribed target has been achieved to better than 0.007 deg in pitch and roll and 0.02 deg in yaw for a period of 43 min. Ground tracks were generated which had maximum latitude/longitude deviations less than 0.15 deg from reference.

  12. Torsional Control of Stereoselectivities in Electrophilic Additions and Cycloadditions to Alkenes

    PubMed Central

    Wang, Hao; Houk, K. N.

    2013-01-01

    Torsional effects control the π-facial stereoselectivities of a variety of synthetically important organic reactions. This review surveys theoretical calculations that have led to the understanding of the influence of the torsional effects on several types of stereoselective organic reactions, especially electrophilic additions and cycloadditions to alkenes. PMID:24409340

  13. Control of dynamical localization by an additional quantum degree of freedom

    NASA Astrophysics Data System (ADS)

    Riedel, K.; Törmä, P.; Savichev, V.; Schleich, W. P.

    1999-01-01

    We identify a parameter that controls the localization length in a driven quantum system. This parameter results from an additional quantum degree of freedom. The center-of-mass motion of a two-level ion stored in a Paul trap and interacting with a standing-wave laser field exhibits this phenomenon. We also discuss the influence of spontaneous emission.

  14. 74. SAC control center addition sect 9top three floors, first ...

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

    74. SAC control center addition sect 9-top three floors, first floor plan, drawing number AS-BLT.AW30-02-03, dated May, 1958 - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  15. 40 CFR 52.1163 - Additional control measures for East Boston.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Additional control measures for East Boston. 52.1163 Section 52.1163 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... spaces at Logan Airport and increased parking charges at remaining spaces; (5) Construction of...

  16. Chill water additive controls transfer of Salmonella and Campylobacter by improved chlorine efficacy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In earlier work, we showed that a proprietary additive (T-128) maintains chlorine activity in the presence of organic material such as broiler parts. T-128 improves the efficacy of chlorine to control transfer of Campylobacter and Salmonella from inoculated wings to un-inoculated wings during immer...

  17. Neuro Emotional Technique for the treatment of trigger point sensitivity in chronic neck pain sufferers: A controlled clinical trial

    PubMed Central

    Bablis, Peter; Pollard, Henry; Bonello, Rod

    2008-01-01

    Background Trigger points have been shown to be active in many myofascial pain syndromes. Treatment of trigger point pain and dysfunction may be explained through the mechanisms of central and peripheral paradigms. This study aimed to investigate whether the mind/body treatment of Neuro Emotional Technique (NET) could significantly relieve pain sensitivity of trigger points presenting in a cohort of chronic neck pain sufferers. Methods Sixty participants presenting to a private chiropractic clinic with chronic cervical pain as their primary complaint were sequentially allocated into treatment and control groups. Participants in the treatment group received a short course of Neuro Emotional Technique that consists of muscle testing, general semantics and Traditional Chinese Medicine. The control group received a sham NET protocol. Outcome measurements included pain assessment utilizing a visual analog scale and a pressure gauge algometer. Pain sensitivity was measured at four trigger point locations: suboccipital region (S); levator scapulae region (LS); sternocleidomastoid region (SCM) and temporomandibular region (TMJ). For each outcome measurement and each trigger point, we calculated the change in measurement between pre- and post- treatment. We then examined the relationships between these measurement changes and six independent variables (i.e. treatment group and the above five additional participant variables) using forward stepwise General Linear Model. Results The visual analog scale (0 to 10) had an improvement of 7.6 at S, 7.2 at LS, 7.5 at SCM and 7.1 at the TMJ in the treatment group compared with no improvement of at S, and an improvement of 0.04 at LS, 0.1 at SCM and 0.1 at the TMJ point in the control group, (P < 0.001). Conclusion After a short course of NET treatment, measurements of visual analog scale and pressure algometer recordings of four trigger point locations in a cohort of chronic neck pain sufferers were significantly improved when

  18. Linear-quadratic-regulator pointing control system design for a high-altitude balloon payload

    SciTech Connect

    White, J.E.; Etter, J.R.

    1987-11-01

    A pointing control system design for the science package of a NASA high-altitude research balloon is described. The balloon assembly consists of a single helium balloon connected to a payload recovery parachute, payload gondola, and ballast hopper. Pointing of the scientific payload is accomplished via an arrangement of drive motors and a flywheel. Linear quadratic regulator (LQR) synthesis techniques are employed to produce the azimuth and elevation controller designs. The use of LQR synthesis is motivated by the azimuthal dynamic coupling encountered between the balloon and gondola. Two control devices are employed in azimuth, one of which is a decoupler motor and the other a flywheel. The decoupler motor is intended to isolate the gondola from the balloon such that the flywheel can be accelerated or decelerated about a steady-state angular velocity to provide precise azimuthal pointing. The multiple-input/multiple-output nature of the azimuth pointing problem is best handled in a matrix synthesis procedure such as LQR. The controller design methodology is explained, and a combination of time responses and singular value analyses are used to analytically evaluate the performance of the control system. 11 refs., 17 figs.

  19. Optimal control problems with switching points. Ph.D. Thesis, 1990 Final Report

    NASA Technical Reports Server (NTRS)

    Seywald, Hans

    1991-01-01

    An overview is presented of the problems and difficulties that arise in solving optimal control problems with switching points. A brief discussion of existing optimality conditions is given and a numerical approach for solving the multipoint boundary value problems associated with the first-order necessary conditions of optimal control is presented. Two real-life aerospace optimization problems are treated explicitly. These are altitude maximization for a sounding rocket (Goddard Problem) in the presence of a dynamic pressure limit, and range maximization for a supersonic aircraft flying in the vertical, also in the presence of a dynamic pressure limit. In the second problem singular control appears along arcs with active dynamic pressure limit, which in the context of optimal control, represents a first-order state inequality constraint. An extension of the Generalized Legendre-Clebsch Condition to the case of singular control along state/control constrained arcs is presented and is applied to the aircraft range maximization problem stated above. A contribution to the field of Jacobi Necessary Conditions is made by giving a new proof for the non-optimality of conjugate paths in the Accessory Minimum Problem. Because of its simple and explicit character, the new proof may provide the basis for an extension of Jacobi's Necessary Condition to the case of the trajectories with interior point constraints. Finally, the result that touch points cannot occur for first-order state inequality constraints is extended to the case of vector valued control functions.

  20. Control of Spacecraft Formations Around the Libration Points Using Electric Motors with One Bit of Resolution

    NASA Astrophysics Data System (ADS)

    Serpelloni, Edoardo; Maggiore, Manfredi; Damaren, Christopher J.

    2015-02-01

    This paper investigates a formation control problem for two space vehicles in the vicinity of the L 2 libration point of the Sun-Earth/Moon system. The objective is to accurately regulate the relative position vector between the vehicles to a desired configuration, under tight tolerances. It is shown that the formation control problem is solvable using six constant thrust electric actuators requiring only one bit of resolution, and bounded switching frequency. The proposed control law is hybrid, and it coordinates the sequence of on-off switches of the thrusters so as to achieve the control objective and, at the same time, avoid high-frequency switching.

  1. A Simple and Inexpensive Device for Slow, Controlled Addition of a Solution to a Reaction Mixture

    NASA Astrophysics Data System (ADS)

    Osvath, Peter

    1995-07-01

    A number of reactions require the slow and controlled addition of a solution containing one reagent to another. Attempting to control the flow rate over a number of hours using a conventional constant pressure addition funnel is a frustrating exercise; commercially available constant volume addition funnels are expensive and must be adjusted by trial and error each time a reaction is carried out. The use of an (expensive) peristaltic pump or syringe pump overcomes these problems but can introduce other complications. We have recently had occasion to carry out the synthesis of thioether macrocycles and cages requiring the slow and controlled addition of DMF solutions of (offensively odoriferous) thiols or (air-sensitive) thiolates to a reactant solution under nitrogen(1), Although the use of a syringe pump was called for, there are obvious difficulties associated with purging the solution and assembling such an apparatus under nitrogen, and we report a simple and inexpensive solution. A Male Luer Lock tip (recovered from a broken syringe) was sweated onto the flattened tip of a pressure-equalizing addition funnel and a syringe needle was attached. Judicious selection of needle length, bore size, and reactant volume can be used to control the addition time simply and reproducibly. With a 250-mL funnel, the flow rate changes by <25% from the beginning to the end of the addition. (In fact, a reduction in the rate of addition may even be advantageous as the reaction proceeds, the reagent in the receiving flask is consumed, its concentration drops, and the rate of reaction will decrease). A piece of fine Teflon tubing of appropriate length attached to the needle can be used to reduce the flow rate even further, but this is only necessary for very slow rates of addition. For example, the time of addition of 200 mL, of an ethanolic solution could be varied from approximately 5 minutes (150mm/17 gauge) to approximately 5 h (200mm/22 gauge), and once the addition time for a

  2. Design and development of an acquisition, tracking, pointing, and fire control system

    NASA Astrophysics Data System (ADS)

    Johnson, Carey J.; VanAllen, Robert; Dimmler, W. Michael; Dillow, James D.

    1999-08-01

    The ABL Acquisition, Tracking, Pointing and Fire Control systems functions are described. The key to the design process is a detailed situation that models the controls, algorithms, engagement sequence, mode logic, passive track sensors, active track sensor, plume phenomenology, active return from the target, and the effects of atmosphere. The application of the simulation to the design process is described, including passive track, active track, and kill assessment. Two field tests used to validate the simulation are briefly described.

  3. Classical and adaptive control algorithms for the solar array pointing system of the Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Ianculescu, G. D.; Klop, J. J.

    1992-01-01

    Classical and adaptive control algorithms for the solar array pointing system of the Space Station Freedom are designed using a continuous rigid body model of the solar array gimbal assembly containing both linear and nonlinear dynamics due to various friction components. The robustness of the design solution is examined by performing a series of sensitivity analysis studies. Adaptive control strategies are examined in order to compensate for the unfavorable effect of static nonlinearities, such as dead-zone uncertainties.

  4. Design and Implementation of a Digital Controller for a Vibration Isolation and Vernier Pointing System

    NASA Technical Reports Server (NTRS)

    Neff, Daniel J.; Britcher, Colin P.

    1996-01-01

    This paper discusses the recommissioning of the Annular Suspension and Pointing System (ASPS), originally developed in the mid 1970's for pointing and vibration isolation of space experiments. The hardware was developed for NASA Langley Research Center by Sperry Flight Systems (now Honeywell Satellite Systems), was delivered to NASA in 1983. Recently, the hardware was loaned to Old Dominion University (ODU). The ASPS includes coarse gimbal assemblies and a Vernier Pointing Assembly (VPA) that utilize magnetic suspension to provide noncontacting vibration isolation and vernier pointing of the payload. The VPA is the main focus of this research. At ODU, the system has been modified such that it can now be operated in a l-g environment without a gravity offload. Suspension of the annular iron rotor in five degrees-of-freedom has been achieved with the use of modern switching power amplifiers and a digital controller implemented on a 486-class PC.

  5. Design Considerations for Miniaturized Control Moment Gyroscopes for Rapid Retargeting and Precision Pointing of Small Satellites

    NASA Technical Reports Server (NTRS)

    Patankar, Kunal; Fitz-Coy, Norman; Roithmayr, Carlos M.

    2014-01-01

    This paper presents the design as well as characterization of a practical control moment gyroscope (CMG) based attitude control system (ACS) for small satellites in the 15-20 kilogram mass range performing rapid retargeting and precision pointing maneuvers. The paper focuses on the approach taken in the design of miniaturized CMGs while considering the constraints imposed by the use of commercial off-the-shelf (COTS) components as well as the size of the satellite. It is shown that a hybrid mode is more suitable for COTS based moment exchange actuators; a mode that uses the torque amplification of CMGs for rapid retargeting and direct torque capabilities of the flywheel motors for precision pointing. A simulation is provided to demonstrate on-orbit slew and pointing performance.

  6. Acute Alcohol Consumption Impairs Controlled but Not Automatic Processes in a Psychophysical Pointing Paradigm

    PubMed Central

    Johnston, Kevin; Timney, Brian; Goodale, Melvyn A.

    2013-01-01

    Numerous studies have investigated the effects of alcohol consumption on controlled and automatic cognitive processes. Such studies have shown that alcohol impairs performance on tasks requiring conscious, intentional control, while leaving automatic performance relatively intact. Here, we sought to extend these findings to aspects of visuomotor control by investigating the effects of alcohol in a visuomotor pointing paradigm that allowed us to separate the influence of controlled and automatic processes. Six male participants were assigned to an experimental “correction” condition in which they were instructed to point at a visual target as quickly and accurately as possible. On a small percentage of trials, the target “jumped” to a new location. On these trials, the participants’ task was to amend their movement such that they pointed to the new target location. A second group of 6 participants were assigned to a “countermanding” condition, in which they were instructed to terminate their movements upon detection of target “jumps”. In both the correction and countermanding conditions, participants served as their own controls, taking part in alcohol and no-alcohol conditions on separate days. Alcohol had no effect on participants’ ability to correct movements “in flight”, but impaired the ability to withhold such automatic corrections. Our data support the notion that alcohol selectively impairs controlled processes in the visuomotor domain. PMID:23861934

  7. 47 CFR 90.471 - Points of operation in internal transmitter control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... transmitter control systems are not synonymous with dispatch points (See § 90.467) nor with telephone positions which are part of the public, switched telephone network; and the scheme of regulation is to be... the licensee. The fixed position may be part of a private telephone exchange or it may be any...

  8. Public Data Set: Control and Automation of the Pegasus Multi-point Thomson Scattering System

    DOE Data Explorer

    Bodner, Grant M. [University of Wisconsin-Madison] (ORCID:0000000324979172); Bongard, Michael W. [University of Wisconsin-Madison] (ORCID:0000000231609746); Fonck, Raymond J. [University of Wisconsin-Madison] (ORCID:0000000294386762); Reusch, Joshua A. [University of Wisconsin-Madison] (ORCID:0000000284249422); Rodriguez Sanchez, Cuauhtemoc [University of Wisconsin-Madison] (ORCID:0000000334712586); Schlossberg, David J. [University of Wisconsin-Madison] (ORCID:0000000287139448)

    2016-08-12

    This public data set contains openly-documented, machine readable digital research data corresponding to figures published in G.M. Bodner et al., 'Control and Automation of the Pegasus Multi-point Thomson Scattering System,' Rev. Sci. Instrum. 87, 11E523 (2016).

  9. 21 CFR 120.8 - Hazard Analysis and Critical Control Point (HACCP) plan.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) plan. 120.8 Section 120.8 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... General Provisions § 120.8 Hazard Analysis and Critical Control Point (HACCP) plan. (a) HACCP plan. Each processor shall have and implement a written HACCP plan whenever a hazard analysis reveals one or more...

  10. Controlling a toxic shock of pentachlorophenol (PCP) to anaerobic digestion using activated carbon addition.

    PubMed

    Xiao, Yeyuan; De Araujo, Cecilia; Sze, Chun Chau; Stuckey, David C

    2015-04-01

    Several powdered and granular activated carbons (PACs and GACs) were tested for adsorption of pentachlorophenol (PCP) in bench-scale anaerobic digestion reactors to control the toxicity of PCP to acetoclastic methanogenesis. Results showed that the adsorption capacities of PAC were reduced by 21-54%, depending on the PAC addition time, in the presence of the methanogenic sludge compared to the controls without sludge. As a preventive measure, PAC at a low dose of 20% (mass ratio to the VSS) added 24 h prior to, or simultaneously with, the addition of PCP could completely eliminate the toxic effects of PCP. At the same dose, PAC also enabled methanogenesis to recover immediately after the sludge had been exposed to PCP for 24h. GAC was not effective in enabling the recovery of methanogenesis due to its slow adsorption kinetics; however, at a dose of 80% it could partially ameliorate the toxic shock of PCP. PMID:25665874

  11. Hierarchical tailoring of strut architecture to control permeability of additive manufactured titanium implants.

    PubMed

    Zhang, Z; Jones, D; Yue, S; Lee, P D; Jones, J R; Sutcliffe, C J; Jones, E

    2013-10-01

    Porous titanium implants are a common choice for bone augmentation. Implants for spinal fusion and repair of non-union fractures must encourage blood flow after implantation so that there is sufficient cell migration, nutrient and growth factor transport to stimulate bone ingrowth. Additive manufacturing techniques allow a large number of pore network designs. This study investigates how the design factors offered by selective laser melting technique can be used to alter the implant architecture on multiple length scales to control and even tailor the flow. Permeability is a convenient parameter that characterises flow, correlating to structure openness (interconnectivity and pore window size), tortuosity and hence flow shear rates. Using experimentally validated computational simulations, we demonstrate how additive manufacturing can be used to tailor implant properties by controlling surface roughness at a microstructual level (microns), and by altering the strut ordering and density at a mesoscopic level (millimetre). PMID:23910314

  12. [Spatial heterogeneity and classified control of agricultural non-point source pollution in Huaihe River Basin].

    PubMed

    Zhou, Liang; Xu, Jian-Gang; Sun, Dong-Qi; Ni, Tian-Hua

    2013-02-01

    Agricultural non-point source pollution is of importance in river deterioration. Thus identifying and concentrated controlling the key source-areas are the most effective approaches for non-point source pollution control. This study adopts inventory method to analysis four kinds of pollution sources and their emissions intensity of the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in 173 counties (cities, districts) in Huaihe River Basin. The four pollution sources include livestock breeding, rural life, farmland cultivation, aquacultures. The paper mainly addresses identification of non-point polluted sensitivity areas, key pollution sources and its spatial distribution characteristics through cluster, sensitivity evaluation and spatial analysis. A geographic information system (GIS) and SPSS were used to carry out this study. The results show that: the COD, TN and TP emissions of agricultural non-point sources were 206.74 x 10(4) t, 66.49 x 10(4) t, 8.74 x 10(4) t separately in Huaihe River Basin in 2009; the emission intensity were 7.69, 2.47, 0.32 t.hm-2; the proportions of COD, TN, TP emissions were 73%, 24%, 3%. The paper achieves that: the major pollution source of COD, TN and TP was livestock breeding and rural life; the sensitivity areas and priority pollution control areas among the river basin of non-point source pollution are some sub-basins of the upper branches in Huaihe River, such as Shahe River, Yinghe River, Beiru River, Jialu River and Qingyi River; livestock breeding is the key pollution source in the priority pollution control areas. Finally, the paper concludes that pollution type of rural life has the highest pollution contribution rate, while comprehensive pollution is one type which is hard to control.

  13. Loop Heat Pipe Operation Using Heat Source Temperature for Set Point Control

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    Loop heat pipes (LHPs) have been used for thermal control of several NASA and commercial orbiting spacecraft. The LHP operating temperature is governed by the saturation temperature of its compensation chamber (CC). Most LHPs use the CC temperature for feedback control of its operating temperature. There exists a thermal resistance between the heat source to be cooled by the LHP and the LHP's CC. Even if the CC set point temperature is controlled precisely, the heat source temperature will still vary with its heat output. For most applications, controlling the heat source temperature is of most interest. A logical question to ask is: "Can the heat source temperature be used for feedback control of the LHP operation?" A test program has been implemented to answer the above question. Objective is to investigate the LHP performance using the CC temperature and the heat source temperature for feedback control

  14. Assessment of autonomic control and respiratory sinus arrhythmia using point process models of human heart beat dynamics.

    PubMed

    Chen, Zhe; Brown, Emery N; Barbieri, Riccardo

    2009-07-01

    Tracking the autonomic control and respiratory sinus arrhythmia (RSA) from electrocardiogram and respiratory measurements is an important problem in cardiovascular control. We propose a point process adaptive filter algorithm based on an inverse Gaussian model to track heart beat intervals that incorporates respiratory measurements as a covariate and provides an analytic form for computing a dynamic estimate of RSA gain. We use Kolmogorov-Smirnov tests and autocorrelation function analyses to assess model goodness-of-fit. We illustrate the properties of the new dynamic estimate of RSA in the analysis of simulated heart beat data and actual heart beat data recorded from subjects in a four-state postural study of heart beat dynamics: control, sympathetic blockade, parasympathetic blockade, and combined sympathetic and parasympathetic blockade. In addition to giving an accurate description of the heart beat data, our adaptive filter algorithm confirms established findings pointing at a vagally mediated RSA and provides a new dynamic RSA estimate that can be used to track cardiovascular control between and within a broad range of postural, pharmacological, and age conditions. Our paradigm suggests a possible framework for designing a device for ambulatory monitoring and assessment of autonomic control in both laboratory research and clinical practice.

  15. Assessment of Autonomic Control and Respiratory Sinus Arrhythmia Using Point Process Models of Human Heart Beat Dynamics

    PubMed Central

    Chen, Zhe; Brown, Emery N.; Barbieri, Riccardo

    2009-01-01

    Tracking the autonomic control and respiratory sinus arrhythmia (RSA) from electrocardiogram and respiratory measurements is an important problem in cardiovascular control. We propose a point process adaptive filter algorithm based on an inverse Gaussian model to track heart beat intervals that incorporates respiratory measurements as a covariate and provides an analytic form for computing a dynamic estimate of RSA gain. We use Kolmogorov-Smirnov tests and autocorrelation function analyses to assess model goodness-of-fit. We illustrate the properties of the new dynamic estimate of RSA in the analysis of simulated heart beat data and actual heart beat data recorded from subjects in a four-state postural study of heart beat dynamics: control, sympathetic blockade, parasympathetic blockade, and combined sympathetic and parasympathetic blockade. In addition to giving an accurate description of the heart beat data, our adaptive filter algorithm confirms established findings pointing at a vagally mediated RSA, and it provides a new dynamic RSA estimate that can be used to track cardiovascular control between and within a broad range of postural, pharmacological and age conditions. Our paradigm suggests a possible framework for designing a device for ambulatory monitoring and assessment of autonomic control in both laboratory research and clinical practice. PMID:19272971

  16. Hospital food hygiene: the application of Hazard Analysis Critical Control Points to conventional hospital catering.

    PubMed

    Richards, J; Parr, E; Riseborough, P

    1993-08-01

    The Hazard Analysis Critical Control Point (HACCP) concept is a preventive approach to quality control. It is based on a logical, structured exploration of potential hazard points in a food operation and the introduction of control and monitoring measures. HACCP studies have been extensively applied to manufacturing systems. It has been difficult to extend this detailed systematic analysis to conventional catering, partly due to the wide range of foods being processed. We describe here the application of HACCP methods to a hospital department that uses conventional catering methods. Basic principles, based on the work flow and the range of products are established. The guidelines produced can be applied to any kitchen using similar catering methods. Examples of log charts used for monitoring are provided.

  17. Evaluation of the leap motion controller as a new contact-free pointing device.

    PubMed

    Bachmann, Daniel; Weichert, Frank; Rinkenauer, Gerhard

    2014-12-24

    This paper presents a Fitts' law-based analysis of the user's performance in selection tasks with the Leap Motion Controller compared with a standard mouse device. The Leap Motion Controller (LMC) is a new contact-free input system for gesture-based human-computer interaction with declared sub-millimeter accuracy. Up to this point, there has hardly been any systematic evaluation of this new system available. With an error rate of 7.8% for the LMC and 2.8% for the mouse device, movement times twice as large as for a mouse device and high overall effort ratings, the Leap Motion Controller's performance as an input device for everyday generic computer pointing tasks is rather limited, at least with regard to the selection recognition provided by the LMC.

  18. Evaluation of the Leap Motion Controller as a New Contact-Free Pointing Device

    PubMed Central

    Bachmann, Daniel; Weichert, Frank; Rinkenauer, Gerhard

    2015-01-01

    This paper presents a Fitts' law-based analysis of the user's performance in selection tasks with the Leap Motion Controller compared with a standard mouse device. The Leap Motion Controller (LMC) is a new contact-free input system for gesture-based human-computer interaction with declared sub-millimeter accuracy. Up to this point, there has hardly been any systematic evaluation of this new system available. With an error rate of 7.8 % for the LMC and 2.8% for the mouse device, movement times twice as large as for a mouse device and high overall effort ratings, the Leap Motion Controller's performance as an input device for everyday generic computer pointing tasks is rather limited, at least with regard to the selection recognition provided by the LMC. PMID:25609043

  19. Application of Model Reference Adaptive Control System to Instrument Pointing System /IPS/

    NASA Technical Reports Server (NTRS)

    Waites, H. B.

    1979-01-01

    A Model Reference Adaptive Controller (MRAC) is derived for a Shuttle payload called the Instrument Pointing System (IPS). The unique features of this MRAC design are that total state feedback is not required, that the internal structure of the model is independent of the internal structure of the IPS, and that the model input is of bounded variation and not required a priori. An application of Liapunov's stability theorems is used to synthesize a control signal which assures MRAC asymptotic stability. Exponential observers are used to obtain the necessary state information to implement the control synthesis. Results are presented which show how effectively the MRAC can maneuver the IPS.

  20. Fuzzy logic based feedback control system for laser beam pointing stabilization.

    PubMed

    Singh, Ranjeet; Patel, Kiran; Govindarajan, J; Kumar, Ajai

    2010-09-20

    This paper reports a fuzzy logic based feedback control system for beam pointing stabilization of a high-power nanosecond Nd:YAG laser operating at 30 Hz. This is achieved by generating the correcting signal for each consequent pulse from the error in the pointing position of the previous laser pulse. We have successfully achieved a reduction of beam position fluctuation from ±60 to ±5.0 μrad without the focusing optics and ±0.9 μrad with focusing optics. PMID:20856289

  1. Using Fast-Steering Mirror Control to Reduce Instrument Pointing Errors Caused by Spacecraft Jitter

    NASA Technical Reports Server (NTRS)

    Antol, Jeffery; Holtz, Ted M.; Cuda, Vince; Johnson, Thomas A.

    1996-01-01

    The scope of this study was to investigate the benefit of using feedback control of a Fast Steering Mirror (FSM) to reduce instrument pointing errors. Initially, the study identified FSM control technologies and categorized them according to their use, range of applicability, and physical requirements. Candidate payloads were then evaluated according to their relevance in use of fast steering minor control technologies. This leads to the mission and instrument selection which served as the candidate mission for numerical modeling. A standard SmallSat was designed in order to accommodate the payload requirements (weight, size, power, etc.). This included sizing the SmallSat bus, sizing the solar array, choosing appropriate antennas, and identifying an attitude control system (ACS). A feedback control system for the FSM compensation was then designed, and the instrument pointing error and SmallSat jitter environment for open-loop and closed-loop FSM control were evaluated for typical SmallSat disturbances. The results were then compared to determine the effectiveness of the FSM feedback control system.

  2. A Globally Stable Lyapunov Pointing and Rate Controller for the Magnetospheric MultiScale Mission (MMS)

    NASA Technical Reports Server (NTRS)

    Shah, Neerav

    2011-01-01

    The Magnetospheric MultiScale Mission (MMS) is scheduled to launch in late 2014. Its primary goal is to discover the fundamental plasma physics processes of reconnection in the Earth's magnetosphere. Each of the four MMS spacecraft is spin-stabilized at a nominal rate of 3 RPM. Traditional spin-stabilized spacecraft have used a number of separate modes to control nutation, spin rate, and precession. To reduce the number of modes and simplify operations, the Delta-H control mode is designed to accomplish nutation control, spin rate control, and precession control simultaneously. A nonlinear design technique, Lyapunov's method, is used to design the Delta-H control mode. A global spin rate controller selected as the baseline controller for MMS, proved to be insufficient due to an ambiguity in the attitude. Lyapunov's design method was used to solve this ambiguity, resulting in a controller that meets the design goals. Simulation results show the advantage of the pointing and rate controller for maneuvers larger than 90 deg and provide insight into the performance of this controller.

  3. Initial experiments on the end-point control of a flexible one-link robot

    NASA Technical Reports Server (NTRS)

    Cannon, R. H., Jr.; Schmitz, E.

    1984-01-01

    The present investigation is concerned with initial experiments regarding a specific unsolved control problem which appeared to be central to advances in the art of robotics. This problem involves the control of a flexible member (one link of a robot system). The position of the end-effector, called the end point or tip, is controlled by measuring that position and using the measurement as a basis for applying control torque to the other end of the flexible member, as for instance, the robot's elbow joint. A description is presented of the features of the first experimental arm which has been made, and an outline is provided of the general strategy for controlling it using its tip sensor and shoulder torquer.

  4. Design of set-point weighting PIλ + Dμ controller for vertical magnetic flux controller in Damavand tokamak.

    PubMed

    Rasouli, H; Fatehi, A

    2014-12-01

    In this paper, a simple method is presented for tuning weighted PI(λ) + D(μ) controller parameters based on the pole placement controller of pseudo-second-order fractional systems. One of the advantages of this controller is capability of reducing the disturbance effects and improving response to input, simultaneously. In the following sections, the performance of this controller is evaluated experimentally to control the vertical magnetic flux in Damavand tokamak. For this work, at first a fractional order model is identified using output-error technique in time domain. For various practical experiments, having desired time responses for magnetic flux in Damavand tokamak, is vital. To approach this, at first the desired closed loop reference models are obtained based on generalized characteristic ratio assignment method in fractional order systems. After that, for the identified model, a set-point weighting PI(λ) + D(μ) controller is designed and simulated. Finally, this controller is implemented on digital signal processor control system of the plant to fast/slow control of magnetic flux. The practical results show appropriate performance of this controller.

  5. Hazard analysis and critical control point systems in the United States Department of Agriculture regulatory policy.

    PubMed

    Billy, T J; Wachsmuth, I K

    1997-08-01

    Recent outbreaks of foodborne illness and studies by expert groups have established the need for fundamental change in the United States meat and poultry inspection programme to reduce the risk of foodborne illness. The Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA) has embarked on a broad effort to bring about such change, with particular emphasis on the reduction of pathogenic micro-organisms in raw meat and poultry products. The publication on 25 July 1996 of the Final Rule on pathogen reduction and hazard analysis and critical control point (HACCP) systems was a major milestone in the FSIS strategy for change. The Final Rule provides a framework for change and clarifies the respective roles of industry and government in ensuring the safety of meat and poultry products. With the implementation of this Final Rule underway, the FSIS has been exploring ways in which slaughter inspection carried out under an HACCP-based system can be changed so that food safety risks are addressed more adequately and the allocation of inspection resources is improved further. In addition, the FSIS is broadening the focus of food safety activities to extend beyond slaughter and processing plants by working with industry, academia and other government agencies. Such co-operation should lead to the development of measures to improve food safety before animals reach the slaughter plant and after products leave the inspected establishment for distribution to the retail level. For the future, the FSIS believes that quantitative risk assessments will be at the core of food safety activities. Risk assessments provide the most effective means of identifying how specific pathogens and other hazards may be encountered throughout the farm-to-table chain and of measuring the potential impact of various interventions. In addition, these assessments will be used in the development and evaluation of HACCP systems. The FSIS is currently conducting a

  6. Galactosyltransferase 4 is a major control point for glycan branching in N-linked glycosylation

    PubMed Central

    McDonald, Andrew G.; Hayes, Jerrard M.; Bezak, Tania; Głuchowska, Sonia A.; Cosgrave, Eoin F. J.; Struwe, Weston B.; Stroop, Corné J. M.; Kok, Han; van de Laar, Teun; Rudd, Pauline M.; Tipton, Keith F.; Davey, Gavin P.

    2014-01-01

    ABSTRACT Protein N-glycosylation is a common post-translational modification that produces a complex array of branched glycan structures. The levels of branching, or antennarity, give rise to differential biological activities for single glycoproteins. However, the precise mechanism controlling the glycan branching and glycosylation network is unknown. Here, we constructed quantitative mathematical models of N-linked glycosylation that predicted new control points for glycan branching. Galactosyltransferase, which acts on N-acetylglucosamine residues, was unexpectedly found to control metabolic flux through the glycosylation pathway and the level of final antennarity of nascent protein produced in the Golgi network. To further investigate the biological consequences of glycan branching in nascent proteins, we glycoengineered a series of mammalian cells overexpressing human chorionic gonadotropin (hCG). We identified a mechanism in which galactosyltransferase 4 isoform regulated N-glycan branching on the nascent protein, subsequently controlling biological activity in an in vivo model of hCG activity. We found that galactosyltransferase 4 is a major control point for glycan branching decisions taken in the Golgi of the cell, which might ultimately control the biological activity of nascent glycoprotein. PMID:25271059

  7. Compliance and control characteristics of an additive manufactured-flexure stage

    NASA Astrophysics Data System (ADS)

    Lee, ChaBum; Tarbutton, Joshua A.

    2015-04-01

    This paper presents a compliance and positioning control characteristics of additive manufactured-nanopositioning system consisted of the flexure mechanism and voice coil motor (VCM). The double compound notch type flexure stage was designed to utilize the elastic deformation of two symmetrical four-bar mechanisms to provide a millimeter-level working range. Additive manufacturing (AM) process, stereolithography, was used to fabricate the flexure stage. The AM stage was inspected by using 3D X-ray computerized tomography scanner: air-voids and shape irregularity. The compliance, open-loop resonance peak, and damping ratio of the AM stage were measured 0.317 mm/N, 80 Hz, and 0.19, respectively. The AM stage was proportional-integral-derivative positioning feedback-controlled and the capacitive type sensor was used to measure the displacement. As a result, the AM flexure mechanism was successfully 25 nm positioning controlled within 500 μm range. The resonance peak was found approximately at 280 Hz in closed-loop. This research showed that the AM flexure mechanism and the VCM can provide millimeter range with high precision and can be a good alternative to an expensive metal-based flexure mechanism and piezoelectric transducer.

  8. Compliance and control characteristics of an additive manufactured-flexure stage

    SciTech Connect

    Lee, ChaBum; Tarbutton, Joshua A.

    2015-04-15

    This paper presents a compliance and positioning control characteristics of additive manufactured-nanopositioning system consisted of the flexure mechanism and voice coil motor (VCM). The double compound notch type flexure stage was designed to utilize the elastic deformation of two symmetrical four-bar mechanisms to provide a millimeter-level working range. Additive manufacturing (AM) process, stereolithography, was used to fabricate the flexure stage. The AM stage was inspected by using 3D X-ray computerized tomography scanner: air-voids and shape irregularity. The compliance, open-loop resonance peak, and damping ratio of the AM stage were measured 0.317 mm/N, 80 Hz, and 0.19, respectively. The AM stage was proportional-integral-derivative positioning feedback-controlled and the capacitive type sensor was used to measure the displacement. As a result, the AM flexure mechanism was successfully 25 nm positioning controlled within 500 μm range. The resonance peak was found approximately at 280 Hz in closed-loop. This research showed that the AM flexure mechanism and the VCM can provide millimeter range with high precision and can be a good alternative to an expensive metal-based flexure mechanism and piezoelectric transducer.

  9. Compliance and control characteristics of an additive manufactured-flexure stage.

    PubMed

    Lee, ChaBum; Tarbutton, Joshua A

    2015-04-01

    This paper presents a compliance and positioning control characteristics of additive manufactured-nanopositioning system consisted of the flexure mechanism and voice coil motor (VCM). The double compound notch type flexure stage was designed to utilize the elastic deformation of two symmetrical four-bar mechanisms to provide a millimeter-level working range. Additive manufacturing (AM) process, stereolithography, was used to fabricate the flexure stage. The AM stage was inspected by using 3D X-ray computerized tomography scanner: air-voids and shape irregularity. The compliance, open-loop resonance peak, and damping ratio of the AM stage were measured 0.317 mm/N, 80 Hz, and 0.19, respectively. The AM stage was proportional-integral-derivative positioning feedback-controlled and the capacitive type sensor was used to measure the displacement. As a result, the AM flexure mechanism was successfully 25 nm positioning controlled within 500 μm range. The resonance peak was found approximately at 280 Hz in closed-loop. This research showed that the AM flexure mechanism and the VCM can provide millimeter range with high precision and can be a good alternative to an expensive metal-based flexure mechanism and piezoelectric transducer. PMID:25933897

  10. "The real point is control": the reception of Barbara McClintock's controlling elements.

    PubMed

    Comfort, N C

    1999-01-01

    In the standard narrative of her life, Barbara McClintock discovered genetic transposition in the 1940s but no one believed her. She was ignored until molecular biologists of the 1970s "rediscovered" transposition and vindicated her heretical discovery. New archival documents, as well as interviews and close reading of published papers, belie this narrative. Transposition was accepted immediately by both maize and bacterial geneticists. Maize geneticists confirmed it repeatedly in the early 1950s and by the late 1950s it was considered a classic discovery. But for McClintock, movable elements were part of an elaborate system of genetic control that she hypothesized to explain development and differentiation. This theory was highly speculative and was not widely accepted, even by those who had discovered transposition independently. When Jacob and Monod presented their alternative model for gene regulation, the operon, her controller argument was discarded as incorrect. Transposition, however, was soon discovered in microorganisms and by the late 1970s was recognized as a phenomenon of biomedical importance. For McClintock, the award of the 1983 Nobel Prize to her for the discovery of movable genetic elements, long treated as a legitimation, may well have been bittersweet. This new look at McClintock's experiments and theory has implications for the intellectual history of biology, the social history of American genetics, and McClintock's role in the historiography of women in science. PMID:11623812

  11. "The real point is control": the reception of Barbara McClintock's controlling elements.

    PubMed

    Comfort, N C

    1999-01-01

    In the standard narrative of her life, Barbara McClintock discovered genetic transposition in the 1940s but no one believed her. She was ignored until molecular biologists of the 1970s "rediscovered" transposition and vindicated her heretical discovery. New archival documents, as well as interviews and close reading of published papers, belie this narrative. Transposition was accepted immediately by both maize and bacterial geneticists. Maize geneticists confirmed it repeatedly in the early 1950s and by the late 1950s it was considered a classic discovery. But for McClintock, movable elements were part of an elaborate system of genetic control that she hypothesized to explain development and differentiation. This theory was highly speculative and was not widely accepted, even by those who had discovered transposition independently. When Jacob and Monod presented their alternative model for gene regulation, the operon, her controller argument was discarded as incorrect. Transposition, however, was soon discovered in microorganisms and by the late 1970s was recognized as a phenomenon of biomedical importance. For McClintock, the award of the 1983 Nobel Prize to her for the discovery of movable genetic elements, long treated as a legitimation, may well have been bittersweet. This new look at McClintock's experiments and theory has implications for the intellectual history of biology, the social history of American genetics, and McClintock's role in the historiography of women in science.

  12. Multiplicative noise effects on electroconvection in controlling additive noise by a magnetic field

    NASA Astrophysics Data System (ADS)

    Huh, Jong-Hoon

    2015-12-01

    We report multiplicative noise-induced threshold shift of electroconvection (EC) in the presence of a magnetic field H . Controlling the thermal fluctuation (i.e., additive noise) of the rodlike molecules of nematic liquid crystals by H , the EC threshold is examined at various noise levels [characterized by their intensity and cutoff frequency (fc) ]. For a sufficiently strong H (i.e., ignorable additive noise), a modified noise sensitivity characterizing the shift problem is in good agreement with experimental results for colored as well as white noise (fc→∞ ) ; until now, there was a large deviation for (sufficiently) colored noises. The present study shows that H provides us with ideal conditions for studying the corresponding Carr-Helfrich theory considering pure multiplicative noise.

  13. Note: vibration reduction control of an atomic force microscope using an additional cantilever.

    PubMed

    Kim, Chulsoo; Jung, Jongkyu; Park, Kyihwan

    2011-11-01

    Since an atomic force microscope is used to measure sub-nanometer level precision, it is sensitive to external vibration. If the vibration can be measured by using an additional sensor, we can obtain the vibration-free signal by subtracting the vibration signal from the signal containing the vibration. To achieve a highly effective vibration rejection ratio, it is important to decide where to locate the additional sensor. This is because the vibration measured at the sensing position should have the same phase as that of the vibration in the signal. Vibration reduction control using this electrical sensing method is verified through time domain analysis and topology images of a standard grid sample.

  14. Critical control points of complementary food preparation and handling in eastern Nigeria.

    PubMed Central

    Ehiri, J. E.; Azubuike, M. C.; Ubbaonu, C. N.; Anyanwu, E. C.; Ibe, K. M.; Ogbonna, M. O.

    2001-01-01

    OBJECTIVE: To investigate microbial contamination and critical control points (CCPs) in the preparation and handling of complementary foods in 120 households in Imo state, Nigeria. METHODS: The Hazard Analysis Critical Control Point (HACCP) approach was used to investigate processes and procedures that contributed to microbial contamination, growth and survival, and to identify points where controls could be applied to prevent or eliminate these microbiological hazards or reduce them to acceptable levels. Food samples were collected and tested microbiologically at different stages of preparation and handling. FINDINGS: During cooking, all foods attained temperatures capable of destroying vegetative forms of food-borne pathogens. However, the risk of contamination increased by storage of food at ambient temperature, by using insufficiently high temperatures to reheat the food, and by adding contaminated ingredients such as dried ground crayfish and soybean powder at stages where no further heat treatment was applied. The purchasing of contaminated raw foodstuffs and ingredients, particularly raw akamu, from vendors in open markets is also a CCP. CONCLUSION: Although an unsafe environment poses many hazards for children's food, the hygienic quality of prepared food can be assured if basic food safety principles are observed. When many factors contribute to food contamination, identification of CCPs becomes particularly important and can facilitate appropriate targeting of resources and prevention efforts. PMID:11417038

  15. Testing of an End-Point Control Unit Designed to Enable Precision Control of Manipulator-Coupled Spacecraft

    NASA Technical Reports Server (NTRS)

    Montgomery, Raymond C.; Ghosh, Dave; Tobbe, Patrick A.; Weathers, John M.; Manouchehri, Davoud; Lindsay, Thomas S.

    1994-01-01

    This paper presents an end-point control concept designed to enable precision telerobotic control of manipulator-coupled spacecraft. The concept employs a hardware unit (end-point control unit EPCU) that is positioned between the end-effector of the Space Shuttle Remote Manipulator System and the payload. Features of the unit are active compliance (control of the displacement between the end-effector and the payload), to allow precision control of payload motions, and inertial load relief, to prevent the transmission of loads between the end-effector and the payload. This paper presents the concept and studies the active compliance feature using a simulation and hardware. Results of the simulation show the effectiveness of the EPCU in smoothing the motion of the payload. Results are presented from initial, limited tests of a laboratory hardware unit on a robotic arm testbed at the l Space Flight Center. Tracking performance of the arm in a constant speed automated retraction and extension maneuver of a heavy payload with and without the unit active is compared for the design speed and higher speeds. Simultaneous load reduction and tracking performance are demonstrated using the EPCU.

  16. Preparation of the pointing and control system of the SOFIA Airborne Telescope for early science missions

    NASA Astrophysics Data System (ADS)

    Lampater, Ulrich; Herter, Terry; Keas, Paul; Harms, Franziska; Engfer, Christian; Salewsky, Peter; Jakob, Holger; Roeser, Hans-Peter

    2010-07-01

    During observation flights the telescope structure of the Stratospheric Observatory for Infrared Astronomy (SOFIA) is subject to disturbance excitations over a wide frequency band. The sources can be separated into two groups: inertial excitation caused by vibration of the airborne platform, and aerodynamic excitation that acts on the telescope assembly (TA) through an open port cavity. These disturbance sources constitute a major difference of SOFIA to other ground based and space observatories and achieving the required pointing accuracy of 1 arcsecond cumulative rms or better below 70 Hz in this environment is driving the design of the TA pointing and control system. In the current design it consists of two parts, the rigid body attitude control system and a feed forward based compensator of flexible TA deformation. This paper discusses the characterization and control system tuning of the as-built system. It is a process that integrates the study of the structural dynamic behavior of the TA, the resulting image motion in the focal plane, and the design and implementation of active control systems. Ground tests, which are performed under controlled experimental conditions, and in-flight characterization tests, both leading up to the early science performance capabilities of the observatory, are addressed.

  17. Optimal control of a spinning double-pyramid Earth-pointing tethered formation

    NASA Astrophysics Data System (ADS)

    Williams, Paul

    2009-06-01

    The dynamics and control of a tethered satellite formation for Earth-pointing observation missions is considered. For most practical applications in Earth orbit, a tether formation must be spinning in order to maintain tension in the tethers. It is possible to obtain periodic spinning solutions for a triangular formation whose initial conditions are close to the orbit normal. However, these solutions contain significant deviations of the satellites on a sphere relative to the desired Earth-pointing configuration. To maintain a plane of satellites spinning normal to the orbit plane, it is necessary to utilize "anchors". Such a configuration resembles a double-pyramid. In this paper, control of a double-pyramid tethered formation is studied. The equations of motion are derived in a floating orbital coordinate system for the general case of an elliptic reference orbit. The motion of the satellites is derived assuming inelastic tethers that can vary in length in a controlled manner. Cartesian coordinates in a rotating reference frame attached to the desired spin frame provide a simple means of expressing the equations of motion, together with a set of constraint equations for the tether tensions. Periodic optimal control theory is applied to the system to determine sets of controlled periodic trajectories by varying the lengths of all interconnecting tethers (nine in total), as well as retrieval and simple reconfiguration trajectories. A modal analysis of the system is also performed using a lumped mass representation of the tethers.

  18. Dithering Digital Ripple Correlation Control for Photovoltaic Maximum Power Point Tracking

    SciTech Connect

    Barth, C; Pilawa-Podgurski, RCN

    2015-08-01

    This study demonstrates a new method for rapid and precise maximum power point tracking in photovoltaic (PV) applications using dithered PWM control. Constraints imposed by efficiency, cost, and component size limit the available PWM resolution of a power converter, and may in turn limit the MPP tracking efficiency of the PV system. In these scenarios, PWM dithering can be used to improve average PWM resolution. In this study, we present a control technique that uses ripple correlation control (RCC) on the dithering ripple, thereby achieving simultaneous fast tracking speed and high tracking accuracy. Moreover, the proposed method solves some of the practical challenges that have to date limited the effectiveness of RCC in solar PV applications. We present a theoretical derivation of the principles behind dithering digital ripple correlation control, as well as experimental results that show excellent tracking speed and accuracy with basic hardware requirements.

  19. Rapid torque-limited line-of-sight pointing of SCOLE (Spacecraft Control Laboratory Experiment) configuration

    NASA Technical Reports Server (NTRS)

    Lin, J. G.

    1986-01-01

    The design concept of a control for rapid torque-limited slewing of a rigid-mast version of the NASA SCOLE configuration is presented and demonstrated by means of numerical simulation. The time-optimal control problem for the system is decomposed into separate single-axis problems, expanding analytically the implicit nonlinear transcendental expression for the SCOLE line-of-sight error, and the final Euler attitude angles and slew angles are determined. The simulation results are presented in tables and graphs, and it is found that bang-bang or bang-pause-bang slew maneuvers with control moment applied to the Shuttle and control force applied to the reflector, and with a 5-deg/s slew-rate limit, produce the best pointing accuracy and the shortest slew times, although the specified line-of-sight error of 0.02 deg cannot be achieved using such open-loop single-axis maneuvers.

  20. Analysis And Control Of Copper Plating Bath Additives And By-Products

    NASA Astrophysics Data System (ADS)

    Newton, Beverly; Kaiser, Edward

    2003-09-01

    New copper plating bath chemisties are being developed to meet the emerging need of plating copper into submicron features on semiconductor wafers. These chemistries are designed to provide a fast, efficient, fill for even the most challenging wafer terrain. It has been found that maintaining the concentration of the additives in these plating baths at certain levels is critical to the performance of the bath. Plating technology for semiconductor applications requires rigid bath control and disciplined methodology. Establishing correlations between what is found in the plated film and bath chemistry control parameters is fundamental in producing interconnects that are consistent and reliable. To establish these correlations, it is important to have a clear understanding of the chemical composition of the bath. It is theorized that the "suppressor" bath components help moderate the deposition rate of the copper fill and the "leveler" additives improve the topology of the copper overfill. Too much or too little of these components in the bath can be detrimental to the quality of the copper deposition and may result in "fill failure" leading to a higher than necessary scrap rate for the wafers. Indirect bath measurements, such as Cyclic Voltammetric Stripping (CVS), tell an incomplete story as these techniques only measures the combined effect of the additives and by-products on the plating quality. High Performance Liquid (HPLC) and Ion Chromatography are analytical techniques which provide important information on the concentration, chemical balance and trend measurement of major constituents such as additives, brighteners, boosters, stabilizers, carriers, levelers, inhibitors, accelerators, transition metals, metal complexes and contaminants in the plating bath. This information provides for improved device quality, reduced scrap rate and reduced costs of bath maintenance. This, however, is not the end of the story. In addition to additives, copper plating baths

  1. Addition of Dexamethasone and Buprenorphine to Bupivacaine Sciatic Nerve Block: A Randomized, Controlled Trial

    PubMed Central

    YaDeau, Jacques T.; Paroli, Leonardo; Fields, Kara G.; Kahn, Richard L.; LaSala, Vincent R.; Jules-Elysee, Kethy M.; Kim, David H.; Haskins, Stephen C.; Hedden, Jacob; Goon, Amanda; Roberts, Matthew M.; Levine, David S.

    2015-01-01

    Background and Objectives Sciatic nerve block provides analgesia after foot and ankle surgery, but block duration may be insufficient. We hypothesized that perineural dexamethasone and buprenorphine would reduce pain scores at 24 hours. Methods Ninety patients received ultrasound-guided sciatic (25 mL 0.25% bupivacaine) and adductor canal (10 mL 0.25% bupivacaine) blockade, with random assignment into 3 groups (30 patients per group): control blocks + intravenous dexamethasone (4 mg) (control); control blocks + intravenous buprenorphine (150 mcg) + intravenous dexamethasone (intravenous buprenorphine); nerve blocks containing buprenorphine + dexamethasone (perineural). Patients received mepivacaine neuraxial anesthesia and postoperative oxycodone / acetaminophen, meloxicam, pregabalin, and ondansetron. Patients and assessors were blinded to group assignment. The primary outcome was pain with movement at 24 hours. Results There was no difference in pain with movement at 24 hours (median score 0). However, the perineural group had longer block duration vs control (45.6 vs 30.0 hr). Perineural patients had lower scores for “worst pain” vs control (median 0 vs 2). Both intravenous buprenorphine and perineural groups were less likely to use opioids on the day after surgery, vs control (28.6%, 28.6%, 60.7%, respectively). Nausea after intravenous buprenorphine (but not perineural buprenorphine) was severe, frequent, and bothersome. Conclusions Pain scores were very low at 24 hours after surgery in the context of multimodal analgesia and were not improved by additives. However, perineural buprenorphine and dexamethasone prolonged block duration, reduced the worst pain experienced, and reduced opioid use. Intravenous buprenorphine caused troubling nausea and vomiting. Future research is needed to confirm and extend these observations. PMID:25974277

  2. Point-and-Click Cursor Control With an Intracortical Neural Interface System by Humans With Tetraplegia

    PubMed Central

    Kim, Sung-Phil; Simeral, John D.; Hochberg, Leigh R.; Donoghue, John P.; Friehs, Gerhard M.; Black, Michael J.

    2012-01-01

    We present a point-and-click intracortical neural interface system (NIS) that enables humans with tetraplegia to volitionally move a 2-D computer cursor in any desired direction on a computer screen, hold it still, and click on the area of interest. This direct brain–computer interface extracts both discrete (click) and continuous (cursor velocity) signals from a single small population of neurons in human motor cortex. A key component of this system is a multi-state probabilistic decoding algorithm that simultaneously decodes neural spiking activity of a small population of neurons and outputs either a click signal or the velocity of the cursor. The algorithm combines a linear classifier, which determines whether the user is intending to click or move the cursor, with a Kalman filter that translates the neural population activity into cursor velocity. We present a paradigm for training the multi-state decoding algorithm using neural activity observed during imagined actions. Two human participants with tetraplegia (paralysis of the four limbs) performed a closed-loop radial target acquisition task using the point-and-click NIS over multiple sessions. We quantified point-and-click performance using various human-computer interaction measurements for pointing devices. We found that participants could control the cursor motion and click on specified targets with a small error rate (<3% in one participant). This study suggests that signals from a small ensemble of motor cortical neurons (~40) can be used for natural point-and-click 2-D cursor control of a personal computer. PMID:21278024

  3. H-point standard addition method applied to simultaneous kinetic determination of antimony(III) and antimony(V) by adsorptive linear sweep voltammetry.

    PubMed

    Zarei, K; Atabati, M; Karami, M

    2010-07-15

    In this work, the applicability of H-point standard addition method (HPSAM) to the kinetic voltammetry data is verified. For this purpose, a procedure is described for the determination of Sb(III) and Sb(V) by adsorptive linear sweep voltammetry using pyrogallol as a complexing agent. The method is based on the differences between the rate of complexation of pyrogallol with Sb(V) and Sb(III) at pH 1.2. The results show that the H-point standard addition method is suitable for the speciation of antimony. Sb(III) and Sb(V) can be determined in the ranges of 0.003-0.120 and 0.010-0.240 microg mL(-1), respectively. Moreover, the solution is analyzed for any possible effects of foreign ions. The obtained results show that the HPSAM in combination to electroanalytical techniques is a powerful method with high sensitivity and selectivity. The procedure is successfully applied to the speciation of antimony in water samples.

  4. Formulation and bioavailability of controlled release salbutamol sulphate tablets using natural additives.

    PubMed

    Nouh, A T; Abd El-Gawad, A H; Guda, T K

    2010-04-01

    Salbutamol sulphate granules and physical mixtures were prepared using mastic with various natural additives. The prepared granules and physical mixtures were examined using IR and DSC. The obtained results indicate that there is no interaction between salbutamol sulphate and the formulation ingredients used. The physical properties and release behavior of the formulated tablets prepared from granules and physical mixtures were evaluated and showed good physical properties. The rate of drug release from tablets prepared from granules was found to be lower than that prepared from physical mixtures at fixed mastic concentration and the same additive. The rate of drug release decreased with increased mastic concentration in formulated tablets. Pectin and sodium alginate allowed the best controlled release rate of the drug. On the basis of the results obtained from the controlled release studies, selected sulbutamol formulations were subjected to an in vivo comparison with commercial sulbutamol tablets. The pharmacokinetic parameters AUC(0-24), C(max), and T(max) of sulbutamol from the selected formulation were determined after administration of a single oral dose of 8 mg and compared statistically using an ANOVA test. There was no significant difference in the AUC(0-24). On the other hand, there was a significant difference in the C(max) and T(max) between the commercial and the formulated tablets. These results demonstrate that the formulated tablets extended the time of the drug effect.

  5. Low fluid leakoff cementing compositions and filtration control additive for cement

    SciTech Connect

    Forrest, G.T.

    1993-07-20

    A cementing composition is described, for cementing oil or gas wells penetrating subterranean formations, capable of forming a fluid slurry when mixed with water comprising: dry hydraulic cement; and a filtration control additive of from about 0.2 to 5.0 percent by weight, based upon dry hydraulic cement, of finely ground peanut hulls, wherein 10 percent or more of the finely ground peanut hulls is in the particle size range of less than 20 standard sieve mesh and greater than 500 standard sieve mesh. In a process for cementing a casing in an oil or gas well penetrating a subterranean formation wherein a cement slurry, formed by mixing water and hydraulic cement, is pumped down the well to flow upwardly between the casing and the subterranean formation, the improvement is described comprising: utilizing as a filtration control additive of from about 0.2 to 5.0 percent by weight, based upon dry hydraulic cement, of finely ground peanut hulls, and utilizing finely ground peanut hulls wherein 10 percent or more of the finely ground peanut hulls is in the particle size range of less than 20 standard sieve mesh and greater than 500 standard sieve mesh.

  6. Impact of the number of control points has on isodose distributions in a dynamic multileaf collimator intensity-modulated radiation therapy delivery

    SciTech Connect

    Goraj, Andrew; Boer, Steven F. de

    2012-01-01

    Intensity-modulated radiation therapy (IMRT) is a powerful technique in planning the delivery of dose. The most common IMRT delivery requires the use of moving multileaf collimators (MLCs) to deliver the requested fluence pattern. A dynamic delivery IMRT field file will contain several control points that are defined MLC shapes at a marked fraction of the delivered monitor units. The size of this file and the fidelity of the deliverable fluence are proportional to the number of control points defined. This study investigates the effect of reducing the number of control points has on the resultant dose distribution quality in complex IMRT in efforts to reduce transfer times, loading times, check sum times and file storage. Analysis was performed with 6 head and neck patients on an Eclipse version 8.5 treatment planning system (Varian, Palo Alto, CA). To ensure the quality of all treatments, Eclipse defines a minimum of 64 and a maximum of 320 control points per subfield (Eclipse Algorithms Reference guide). All 6 patients' plans were calculated with fixed 64, 166, and 320 control points using the sliding window technique. In addition, each plan was calculated in variable mode (Normal mode) in which the planning system determined the required number of control points. Each of the 4 plans for each patient was renormalized to provide the same mean planning target volume (PTV) 70 dose. Dose values for critical and target structures were examined for each patient. When examining the minimum, maximum, and mean doses to all target structures, it was noted that the greatest reduction in target dose coverage caused by reduced number of control points was 0.5%, which occurred for the minimum dose to the PTV56 structure in one plan.' Dose analysis for critical structures showed no clinically significant increase in dose when compared with the 320 control point plan.

  7. Control and automation of the Pegasus multi-point Thomson scattering system

    DOE PAGES

    Bodner, Grant M.; Bongard, Michael W.; Fonck, Raymond J.; Reusch, Joshua A.; Rodriguez Sanchez, C.; Schlossberg, David J.

    2016-08-12

    A new control system for the Pegasus Thomson scattering diagnostic has recently been deployed to automate the laser operation, data collection process, and interface with the system-wide Pegasus control code. Automation has been extended to areas outside of data collection, such as manipulation of beamline cameras and remotely controlled turning mirror actuators to enable intra-shot beam alignment. In addition, the system has been upgraded with a set of fast (~1 ms) mechanical shutters to mitigate contamination from background light. Modification and automation of the Thomson system have improved both data quality and diagnostic reliability.

  8. Control and automation of the Pegasus multi-point Thomson scattering system

    NASA Astrophysics Data System (ADS)

    Bodner, G. M.; Bongard, M. W.; Fonck, R. J.; Reusch, J. A.; Rodriguez Sanchez, C.; Schlossberg, D. J.

    2016-11-01

    A new control system for the Pegasus Thomson scattering diagnostic has recently been deployed to automate the laser operation, data collection process, and interface with the system-wide Pegasus control code. Automation has been extended to areas outside of data collection, such as manipulation of beamline cameras and remotely controlled turning mirror actuators to enable intra-shot beam alignment. Additionally, the system has been upgraded with a set of fast (˜1 ms) mechanical shutters to mitigate contamination from background light. Modification and automation of the Thomson system have improved both data quality and diagnostic reliability.

  9. Two-axis Beam Steering Mirror Control system for Precision Pointing and Tracking Applications

    SciTech Connect

    Ulander, Klaus

    2006-01-01

    Precision pointing and tracking of laser beams is critical in numerous military and industrial applications. This is particularly true for systems requiring atmospheric beam propagation. Such systems are plagued by environmental influences which cause the optical signal to break up and wander. Example applications include laser communications, precision targeting, active imaging, chemical remote sensing, and laser vibrometry. The goal of this project is to build a beam steering system using a two-axis mirror to maintain precise pointing control. Ultimately, position control to 0.08% accuracy (40 {micro}rad) with a bandwidth of 200 Hz is desired. The work described encompasses evaluation of the instrumentation system and the subsequent design and implementation of an analog electronic controller for a two-axis mirror used to steer the beam. The controller operates over a wide temperature range, through multiple mirror resonances, and is independent of specific mirrors. The design was built and successfully fielded in a Lawrence Livermore National Laboratory free-space optics experiment. All measurements and performance parameters are derived from measurements made on actual hardware that was built and field tested. In some cases, specific design details have been omitted that involve proprietary information pertaining to Lawrence Livermore National Laboratory patent positions and claims. These omissions in no way impact the general validity of the work or concepts presented in this thesis.

  10. Proteasome and thiol involvement in quality control of glycosylphosphatidylinositol anchor addition.

    PubMed Central

    Wilbourn, B; Nesbeth, D N; Wainwright, L J; Field, M C

    1998-01-01

    Improperly processed secretory proteins are degraded by a hydrolytic system that is associated with the endoplasmic reticulum (ER) and appears to involve re-export of lumenal proteins into the cytoplasm for ultimate degradation by the proteasome. The chimaeric protein hGHDAF28, which contains a crippled glycosylphosphatidylinositol (GPI) C-terminal signal peptide, is degraded by a pathway highly similar to that for other ER-retained proteins and is characterized by formation of disulphide-linked aggregates, failure to reach the Golgi complex and intracellular degradation with a half life of approximately 2 h. Here we show that N-acetyl-leucinal-leucinal-norleucinal, MG-132 and lactacystin, all inhibitors of the proteasome, protect hGHDAF28; hGHDAF28 is still proteolytically cleaved in the presence of lactacystin or MG-132, by the removal of approximately 2 kDa, but the truncated fragment is not processed further. We demonstrate that the ubiquitination system accelerates ER-degradation of hGHDAF28, but is not essential to the process. Overall, these findings indicate that GPI quality control is mediated by the cytoplasmic proteasome. We also show that the presence of a cysteine residue in the GPI signal of hGHDAF28 is required for retention and degradation, as mutation of this residue to serine results in secretion of the fusion protein, implicating thiol-mediated retention as a mechanism for quality control of some GPI signals. Removal of the cysteine also prevents inclusion of hGHDAF28 in disulphide-linked aggregates, indicating that aggregate formation is an additional retention mechanism for this class of protein. Therefore our data suggest that an unpaired terminal cysteine is the retention motif of the hGHDAF28 GPI-processing signal and that additional information may be required for efficient engagement of ER quality control systems by the majority of GPI signals which lack cysteine residues. PMID:9576858

  11. The dynamics and control of large flexible space structures, 2. Part A: Shape and orientation control using point actuators

    NASA Technical Reports Server (NTRS)

    Bainum, P. M.; Reddy, A. S. S. R.

    1979-01-01

    The equations of planar motion for a flexible beam in orbit which includes the effects of gravity gradient torques and control torques from point actuators located along the beam was developed. Two classes of theorems are applied to the linearized form of these equations to establish necessary conditions for controlability for preselected actuator configurations. The feedback gains are selected: (1) based on the decoupling of the original coordinates and to obtain proper damping, and (2) by applying the linear regulator problem to the individual model coordinates separately. The linear control laws obtained using both techniques were evaluated by numerical integration of the nonlinear system equations. Numerical examples considering pitch and various number of modes with different combination of actuator numbers and locations are presented. The independent model control concept used earlier with a discretized model of the thin beam in orbit was reviewed for the case where the number of actuators is less than the number of modes. Results indicate that although the system is controllable it is not stable about the nominal (local vertical) orientation when the control is based on modal decoupling. An alternate control law not based on modal decoupling ensures stability of all the modes.

  12. Comparison of controller design approaches from a vibration suppression point of view

    NASA Astrophysics Data System (ADS)

    Nestorovic Trajkov, Tamara; Koeppe, Heinz; Gabbert, Ulrich

    2003-07-01

    The paper is aimed at presenting, in the sense of analyzing and comparison, some aspects of modeling, simulation and control of piezoelectric flexible smart structures from the vibration suppression point of view. Taking into account the necessity of a good model development for the purpose of the structure simulation and model-based control design, two approaches are considered: finite element (FEM) method based methodology and system identification approach. The finite element analysis includes modal analysis of the structures with piezoelectric active elements (actuators and sensors) together with the active elements dynamics. Resulting dynamic model of the structure is represented in the form of equations of motion, which after appropriate transformations and modal reduction lead to a state-space model convenient for the controller design. As an alternative, the subspace based system identification is proposed, which in case of the real structure availability, provides a model of the structure from the input-output measured data. Controller design for the purpose of vibration suppression is model based. Optimal LQ tracking and direct model reference adaptive control laws are considered. Uncontrolled and controlled behavior of structures is investigated and the comparison of the proposed control laws and their efficiency verification is performed through the examples.

  13. Can Vitamin D Supplementation in Addition to Asthma Controllers Improve Clinical Outcomes in Patients With Asthma?

    PubMed Central

    Luo, Jian; Liu, Dan; Liu, Chun-Tao

    2015-01-01

    Abstract Effects of vitamin D on acute exacerbation, lung function, and fraction of exhaled nitric oxide (FeNO) in patients with asthma are controversial. We aim to further evaluate the roles of vitamin D supplementation in addition to asthma controllers in asthmatics. From 1946 to July 2015, we searched the PubMed, Embase, Medline, Cochrane Central Register of Controlled Trials, and ISI Web of Science using “Vitamin D,” “Vit D,” or “VitD” and “asthma,” and manually reviewed the references listed in the identified articles. Randomized controlled trials which reported rate of asthma exacerbations and adverse events, forced expiratory volume in 1 s (FEV1, % of predicted value), FeNO, asthma control test (ACT), and serum 25-hydroxyvitamin D levels were eligible. We conducted the heterogeneities test and sensitivity analysis of the enrolled studies, and random-effects or fixed-effects model was applied to calculate risk ratio (RR) and mean difference for dichotomous and continuous data, respectively. Cochrane systematic review software Review Manager (RevMan) was used to test the hypothesis by Mann–Whitney U test, which were displayed in Forest plots. Seven trials with a total of 903 patients with asthma were pooled in our final studies. Except for asthma exacerbations (I2 = 81%, χ2 = 10.28, P = 0.006), we did not find statistical heterogeneity in outcome measures. The pooled RR of asthma exacerbation was 0.66 (95% confidence interval: 0.32–1.37), but without significant difference (z = 1.12, P = 0.26), neither was in FEV1 (z = 0.30, P = 0.77), FeNO (z = 0.28, P = 0.78), or ACT (z = 0.92, P = 0.36), although serum 25-hydroxyvitamin D was significantly increased (z = 6.16, P < 0.001). Vitamin D supplementation in addition to asthma controllers cannot decrease asthma exacerbation and FeNO, nor improve lung function and asthma symptoms, although it can be safely applied to increase serum 25

  14. Integrated watershed approach in controlling point and non-point source pollution within Zelivka drinking water reservoir.

    PubMed

    Holas, J; Hrncir, M

    2002-01-01

    An agricultural watershed involves manipulation of soil, water and other natural resources and it has profound impacts on ecosystems. To manage these complex issues, we must understand causes and consequences and interactions-related transport of pollutants, quality of the environment, mitigation measures and policy measures. A ten year period of economic changes has been analysed with respect to sustainable development concerning Zelivka drinking water reservoir and its watershed, where agriculture and forestry are the main human activities. It is recommended that all land users within a catchment area should receive payments for their contribution to water cycle management. Setting up the prevention principles and best management practices financially subsidized by a local water company has been found very effective in both point and non-point source pollution abatement, and the newly prepared Clean Water Programme actively involves local municipal authorities as well. The first step based on systems analysis was to propose effective strategies and select alternative measures and ways for their financing. Long term monitoring of nutrient loads entering the reservoir and hazardous events statistics resulted in maps characterising the territory including vulnerable zones and risk factors. Financing involves providing annual payments to farmers, who undertake to manage specified areas of their land in a particular way and one-off payments to realise proposed issues ensuring soil conservation and watershed ecosystem benefits.

  15. A tuneable switch for controlling environmental degradation of bioplastics: addition of isothiazolinone to polyhydroxyalkanoates.

    PubMed

    Woolnough, Catherine Anne; Yee, Lachlan Hartley; Charlton, Timothy Stuart; Foster, Leslie John Ray

    2013-01-01

    Controlling the environmental degradation of polyhydroxybutyrate (PHB) and polyhydroxyvalerate (P(HB-co-HV)) bioplastics would expand the range of their potential applications. Combining PHB and P(HB-co-HV) films with the anti-fouling agent 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOI, <10% w/w) restricted microbial colonisation in soil, but did not significantly affect melting temperature or the tensile strength of films. DCOI films showed reduced biofouling and postponed the onset of weight loss by up to 100 days, a 10-fold increase compared to unmodified films where the microbial coverage was significant. In addition, the rate of PHA-DCOI weight loss, post-onset, reduced by about 150%; in contrast a recorded weight loss of only 0.05% per day for P(HB-co-HV) with a 10% DCOI loading was observed. This is in stark contrast to the unmodified PHB film, where a recorded weight loss of only 0.75% per day was made. The 'switch' that initiates film weight loss, and its subsequent reduced rate, depended on the DCOI loading to control biofouling. The control of biofouling and environmental degradation for these DCOI modified bioplastics increases their potential use in biodegradable applications.

  16. A tuneable switch for controlling environmental degradation of bioplastics: addition of isothiazolinone to polyhydroxyalkanoates.

    PubMed

    Woolnough, Catherine Anne; Yee, Lachlan Hartley; Charlton, Timothy Stuart; Foster, Leslie John Ray

    2013-01-01

    Controlling the environmental degradation of polyhydroxybutyrate (PHB) and polyhydroxyvalerate (P(HB-co-HV)) bioplastics would expand the range of their potential applications. Combining PHB and P(HB-co-HV) films with the anti-fouling agent 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOI, <10% w/w) restricted microbial colonisation in soil, but did not significantly affect melting temperature or the tensile strength of films. DCOI films showed reduced biofouling and postponed the onset of weight loss by up to 100 days, a 10-fold increase compared to unmodified films where the microbial coverage was significant. In addition, the rate of PHA-DCOI weight loss, post-onset, reduced by about 150%; in contrast a recorded weight loss of only 0.05% per day for P(HB-co-HV) with a 10% DCOI loading was observed. This is in stark contrast to the unmodified PHB film, where a recorded weight loss of only 0.75% per day was made. The 'switch' that initiates film weight loss, and its subsequent reduced rate, depended on the DCOI loading to control biofouling. The control of biofouling and environmental degradation for these DCOI modified bioplastics increases their potential use in biodegradable applications. PMID:24146779

  17. A Tuneable Switch for Controlling Environmental Degradation of Bioplastics: Addition of Isothiazolinone to Polyhydroxyalkanoates

    PubMed Central

    Woolnough, Catherine Anne; Yee, Lachlan Hartley; Charlton, Timothy Stuart; Foster, Leslie John Ray

    2013-01-01

    Controlling the environmental degradation of polyhydroxybutyrate (PHB) and polyhydroxyvalerate (P(HB-co-HV)) bioplastics would expand the range of their potential applications. Combining PHB and P(HB-co-HV) films with the anti-fouling agent 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOI, <10% w/w) restricted microbial colonisation in soil, but did not significantly affect melting temperature or the tensile strength of films. DCOI films showed reduced biofouling and postponed the onset of weight loss by up to 100 days, a 10-fold increase compared to unmodified films where the microbial coverage was significant. In addition, the rate of PHA-DCOI weight loss, post-onset, reduced by about 150%; in contrast a recorded weight loss of only 0.05% per day for P(HB-co-HV) with a 10% DCOI loading was observed. This is in stark contrast to the unmodified PHB film, where a recorded weight loss of only 0.75% per day was made. The ‘switch’ that initiates film weight loss, and its subsequent reduced rate, depended on the DCOI loading to control biofouling. The control of biofouling and environmental degradation for these DCOI modified bioplastics increases their potential use in biodegradable applications. PMID:24146779

  18. Interferometric adaptive optics testbed for laser pointing, wave-front control and phasing.

    PubMed

    Baker, K L; Homoelle, D; Utternback, E; Stappaerts, E A; Siders, C W; Barty, C P J

    2009-09-14

    Implementing the capability to perform fast ignition experiments, as well as, radiography experiments on the National Ignition Facility (NIF) places stringent requirements on the control of each of the beam's pointing, intra-beam phasing and overall wave-front quality. In this article experimental results are presented which were taken on an interferometric adaptive optics testbed that was designed and built to test the capabilities of such a system to control phasing, pointing and higher order beam aberrations. These measurements included quantification of the reduction in Strehl ratio incurred when using the MEMS device to correct for pointing errors in the system. The interferometric adaptive optics system achieved a Strehl ratio of 0.83 when correcting for a piston, tip/tilt error between two adjacent rectangular apertures, the geometry expected for the National ignition Facility. The interferometric adaptive optics system also achieved a Strehl ratio of 0.66 when used to correct for a phase plate aberration of similar magnitude as expected from simulations of the ARC beam line. All of these corrections included measuring both the upstream and downstream aberrations in the testbed and applying the sum of these two measurements in open-loop to the MEMS deformable mirror.

  19. Interferometric adaptive optics testbed for laser pointing, wave-front control and phasing.

    PubMed

    Baker, K L; Homoelle, D; Utternback, E; Stappaerts, E A; Siders, C W; Barty, C P J

    2009-09-14

    Implementing the capability to perform fast ignition experiments, as well as, radiography experiments on the National Ignition Facility (NIF) places stringent requirements on the control of each of the beam's pointing, intra-beam phasing and overall wave-front quality. In this article experimental results are presented which were taken on an interferometric adaptive optics testbed that was designed and built to test the capabilities of such a system to control phasing, pointing and higher order beam aberrations. These measurements included quantification of the reduction in Strehl ratio incurred when using the MEMS device to correct for pointing errors in the system. The interferometric adaptive optics system achieved a Strehl ratio of 0.83 when correcting for a piston, tip/tilt error between two adjacent rectangular apertures, the geometry expected for the National ignition Facility. The interferometric adaptive optics system also achieved a Strehl ratio of 0.66 when used to correct for a phase plate aberration of similar magnitude as expected from simulations of the ARC beam line. All of these corrections included measuring both the upstream and downstream aberrations in the testbed and applying the sum of these two measurements in open-loop to the MEMS deformable mirror. PMID:19770884

  20. Post-operative endophthalmitis: the application of hazard analysis critical control points (HACCP) to an infection control problem.

    PubMed

    Baird, D R; Henry, M; Liddell, K G; Mitchell, C M; Sneddon, J G

    2001-09-01

    Hazard analysis critical control points (HACCP) is a quality assurance system widely used in the food industry to ensure safety. We adopted the HACCP approach when conventional infection control measures had failed to solve an ongoing problem with an increased incidence of postoperative endophthalmitis, and our ophthalmology unit was threatened with permanent cessation of intraocular surgery. Although time-consuming, the result was an entirely new set of protocols for the care of patients undergoing intraocular surgery, the development of an integrated care pathway, and a comprehensive and robust audit programme, which enabled intraocular surgery to continue in a new spirit of confidence. HACCP methodology has so far been little used in healthcare, but it might be usefully applied to a variety of apparently intractable infection control problems.

  1. Point source modeling of matched case–control data with multiple disease subtypes

    PubMed Central

    Li, Shi; Mukherjee, Bhramar; Batterman, Stuart

    2015-01-01

    In this paper, we propose nonlinear distance-odds models investigating elevated odds around point sources of exposure, under a matched case-control design where there are subtypes within cases. We consider models analogous to the polychotomous logit models and adjacent-category logit models for categorical outcomes and extend them to the nonlinear distance-odds context. We consider multiple point sources as well as covariate adjustments. We evaluate maximum likelihood, profile likelihood, iteratively reweighted least squares, and a hierarchical Bayesian approach using Markov chain Monte Carlo techniques under these distance-odds models. We compare these methods using an extensive simulation study and show that with multiple parameters and a nonlinear model, Bayesian methods have advantages in terms of estimation stability, precision, and interpretation. We illustrate the methods by analyzing Medicaid claims data corresponding to the pediatric asthma population in Detroit, Michigan, from 2004 to 2006. PMID:22826092

  2. 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.

  3. Solar Sails as a Tool for Spacecraft Motion Control Near Solar-Terrestrial Libration Points.

    NASA Astrophysics Data System (ADS)

    Eismont, N. A.

    Two problems are considered connected with the use of solar sails on spacecraft (s/c) moving in the vicinity of solar-terrestrial libration points L1 and L2. First problem is related to the exploration of s/c trajectories modification under influence of solar radiation pressure in case with comparatively big solar sails are mounted on s/c. In this case trajectory is shifted further from the Earth and closer to the Sun along Sun-Earth line. The shift may reach one million km or more. Simultaneously its size and shape are also changed. The dependence of these variations upon the mass to area ratio is determined. Such trajectories are interesting for solar wind shock waves investigations because it allows earlier detection of these waves as compared with use of "usual" motion of the s/c in L1 proximity. The other problem explored in the paper is s/c motion control using variation of forces produced by solar radiation pressure. The following approach for this variation is supposed: the sails include liquid crystal films with controllable transparency. When electrical voltage is applied film becomes transparent and solar pressure is minimal, in opposite case it is opaque and pressure increases. The other version of transparency variation use is two layer film: one layer is liquid crystal film; the other one is aluminium foil. With transparent liquid crystal film we have approximately two times higher solar radiation pressure than with opaque one. It gives the possibilities to control as orbital motion of s/c as its attitude. It is shown in the paper that comparatively small solar sails not bigger than usual solar array panels may be used for orbital control of s/c in the vicinity Sun-Earth collinear libration points if above described technics is applied. The required sails area to s/c mass is determined for solving the task of keeping s/c in vicinity of libration point and for trajectory amplitude change maneuvers. Thus the paper shows rather good perspective for the

  4. Stereo- and Temporally Controlled Coordination Polymerization Triggered by Alternating Addition of a Lewis Acid and Base.

    PubMed

    Liu, Bo; Cui, Dongmei; Tang, Tao

    2016-09-19

    Significant progress has been made with regard to temporally controlled radical and ring-opening polymerizations, for example, by means of chemical reagents, light, and voltage, whereas quantitative switch coordination polymerization is still challenging. Herein, we report the temporally and stereocontrolled 3,4-polymerization of isoprene through allosterically regulating the active metal center by alternating addition of Lewis basic pyridine to "poison" the Lewis acidic active metal species through acid-base interactions and Lewis acidic Al(i) Bu3 to release the original active species through pyridine abstraction. This process is quick, quantitative, and can be repeated multiple times while maintaining high 3,4-selectivity. Moreover, this strategy is also effective for the switch copolymerization of isoprene and styrene with dual 3,4- and syndiotactic selectivity. Tuning the switch cycles and intervals enables the isolation of various copolymers with different distributions of 3,4-polyisoprene and syndiotactic polystyrene sequences. PMID:27539866

  5. Bingel-Hirsch addition on endohedral metallofullerenes: kinetic versus thermodynamic control.

    PubMed

    Alegret, Núria; Rodríguez-Fortea, Antonio; Poblet, Josep M

    2013-04-15

    An extensive theoretical study of the Bingel-Hirsch addition of bromomalonate on scandium nitride endohedral fullerenes has been carried out. The prototypical and highly symmetrical Sc3N@I(h)-C80, with a structure that satisfies the isolated pentagon rule (IPR), and the non-IPR Sc3N@D3(6140)-C68 fullerene show analogous reaction paths despite the distinct topology of the carbon networks and different rotation freedom of the internal nitride cluster. For the two metallofullerenes, our results predict that the reaction takes place under kinetic control yielding open-cage fulleroids on [6,6] bonds, which is in good agreement with experimental data. The theoretical studies also show that predicting the reactivity of endohedral metallofullerenes is not straightforward and often an accurate analysis of the potential energy surface is required.

  6. Catalytic enantioselective addition of organoboron reagents to fluoroketones controlled by electrostatic interactions

    NASA Astrophysics Data System (ADS)

    Lee, Kyunga; Silverio, Daniel L.; Torker, Sebastian; Robbins, Daniel W.; Haeffner, Fredrik; van der Mei, Farid W.; Hoveyda, Amir H.

    2016-08-01

    Organofluorine compounds are central to modern chemistry, and broadly applicable transformations that generate them efficiently and enantioselectively are in much demand. Here we introduce efficient catalytic methods for the addition of allyl and allenyl organoboron reagents to fluorine-substituted ketones. These reactions are facilitated by readily and inexpensively available catalysts and deliver versatile and otherwise difficult-to-access tertiary homoallylic alcohols in up to 98% yield and >99:1 enantiomeric ratio. Utility is highlighted by a concise enantioselective approach to the synthesis of the antiparasitic drug fluralaner (Bravecto, presently sold as the racemate). Different forms of ammonium–organofluorine interactions play a key role in the control of enantioselectivity. The greater understanding of various non-bonding interactions afforded by these studies should facilitate the future development of transformations that involve fluoroorganic entities.

  7. Catalytic enantioselective addition of organoboron reagents to fluoroketones controlled by electrostatic interactions.

    PubMed

    Lee, KyungA; Silverio, Daniel L; Torker, Sebastian; Robbins, Daniel W; Haeffner, Fredrik; van der Mei, Farid W; Hoveyda, Amir H

    2016-08-01

    Organofluorine compounds are central to modern chemistry, and broadly applicable transformations that generate them efficiently and enantioselectively are in much demand. Here we introduce efficient catalytic methods for the addition of allyl and allenyl organoboron reagents to fluorine-substituted ketones. These reactions are facilitated by readily and inexpensively available catalysts and deliver versatile and otherwise difficult-to-access tertiary homoallylic alcohols in up to 98% yield and >99:1 enantiomeric ratio. Utility is highlighted by a concise enantioselective approach to the synthesis of the antiparasitic drug fluralaner (Bravecto, presently sold as the racemate). Different forms of ammonium-organofluorine interactions play a key role in the control of enantioselectivity. The greater understanding of various non-bonding interactions afforded by these studies should facilitate the future development of transformations that involve fluoroorganic entities.

  8. Controlling the corrosion and cathodic activation of magnesium via microalloying additions of Ge

    NASA Astrophysics Data System (ADS)

    Liu, R. L.; Hurley, M. F.; Kvryan, A.; Williams, G.; Scully, J. R.; Birbilis, N.

    2016-06-01

    The evolution of corrosion morphology and kinetics for magnesium (Mg) have been demonstrated to be influenced by cathodic activation, which implies that the rate of the cathodic partial reaction is enhanced as a result of anodic dissolution. This phenomenon was recently demonstrated to be moderated by the use of arsenic (As) alloying as a poison for the cathodic reaction, leading to significantly improved corrosion resistance. The pursuit of alternatives to toxic As is important as a means to imparting a technologically safe and effective corrosion control method for Mg (and its alloys). In this work, Mg was microalloyed with germanium (Ge), with the aim of improving corrosion resistance by retarding cathodic activation. Based on a combined analysis herein, we report that Ge is potent in supressing the cathodic hydrogen evolution reaction (reduction of water) upon Mg, improving corrosion resistance. With the addition of Ge, cathodic activation of Mg subject to cyclic polarisation was also hindered, with beneficial implications for future Mg electrodes.

  9. Catalytic enantioselective addition of organoboron reagents to fluoroketones controlled by electrostatic interactions.

    PubMed

    Lee, KyungA; Silverio, Daniel L; Torker, Sebastian; Robbins, Daniel W; Haeffner, Fredrik; van der Mei, Farid W; Hoveyda, Amir H

    2016-08-01

    Organofluorine compounds are central to modern chemistry, and broadly applicable transformations that generate them efficiently and enantioselectively are in much demand. Here we introduce efficient catalytic methods for the addition of allyl and allenyl organoboron reagents to fluorine-substituted ketones. These reactions are facilitated by readily and inexpensively available catalysts and deliver versatile and otherwise difficult-to-access tertiary homoallylic alcohols in up to 98% yield and >99:1 enantiomeric ratio. Utility is highlighted by a concise enantioselective approach to the synthesis of the antiparasitic drug fluralaner (Bravecto, presently sold as the racemate). Different forms of ammonium-organofluorine interactions play a key role in the control of enantioselectivity. The greater understanding of various non-bonding interactions afforded by these studies should facilitate the future development of transformations that involve fluoroorganic entities. PMID:27442282

  10. Catalytic enantioselective addition of organoboron reagents to fluoroketones controlled by electrostatic interactions

    NASA Astrophysics Data System (ADS)

    Lee, Kyunga; Silverio, Daniel L.; Torker, Sebastian; Robbins, Daniel W.; Haeffner, Fredrik; van der Mei, Farid W.; Hoveyda, Amir H.

    2016-08-01

    Organofluorine compounds are central to modern chemistry, and broadly applicable transformations that generate them efficiently and enantioselectively are in much demand. Here we introduce efficient catalytic methods for the addition of allyl and allenyl organoboron reagents to fluorine-substituted ketones. These reactions are facilitated by readily and inexpensively available catalysts and deliver versatile and otherwise difficult-to-access tertiary homoallylic alcohols in up to 98% yield and >99:1 enantiomeric ratio. Utility is highlighted by a concise enantioselective approach to the synthesis of the antiparasitic drug fluralaner (Bravecto, presently sold as the racemate). Different forms of ammonium-organofluorine interactions play a key role in the control of enantioselectivity. The greater understanding of various non-bonding interactions afforded by these studies should facilitate the future development of transformations that involve fluoroorganic entities.

  11. Quality control of laser- and powder bed-based Additive Manufacturing (AM) technologies

    NASA Astrophysics Data System (ADS)

    Berumen, Sebastian; Bechmann, Florian; Lindner, Stefan; Kruth, Jean-Pierre; Craeghs, Tom

    The quality of metal components manufactured by laser- and powder bed-based additive manufacturing technologies has continuously been improved over the last years. However, to establish this production technology in industries with very high quality standards the accessibility of prevalent quality management methods to all steps of the process chain needs still to be enhanced. This publication describes which tools are and will be available to fulfil those requirements from the perspective of a laser machine manufacturer. Generally five aspects of the part building process are covered by separate Quality Management (QM) modules: the powder quality, the temperature management, the process gas atmosphere, the melt pool behaviour and the documentation module. This paper sets the focus on melt pool analysis and control.

  12. [The different point of view about the sanitary control of importation of psychotropic substances in Brazil].

    PubMed

    Sebastião, Patrícia Cristina Antunes; Lucchese, Geraldo

    2010-11-01

    The purpose of this work is to analyze the process of importation, that is a part of the sanitary control of psychotropic substances, made by Brazilian National Health Surveillance Agency's ports, airports and borders. For this work, psychotropic substances are defined as active pharmaceutical raw materials present in the list B1 of Portaria nº 344/98; which need Anvisa's permission to be imported. For this purpose we used semistructured interviews with key informers and participant observation. The information were collected and systematized through the content analysis, thematic modality. The results show a very complex control which involves an intense bureaucratic process. The main identified critical points of the process were: the information system precariousness; the absence of human resources; deficiency of laboratorial support and infra-structure at customs. Anvisa's web page and the specific law are strong points of the process, but still needing improvements. We understood that despite of the progress made, there are many things to do for giving the country an efficient health control system to the importation of these substances. PMID:21120327

  13. Synergies in the space of control variables within the equilibrium-point hypothesis.

    PubMed

    Ambike, S; Mattos, D; Zatsiorsky, V M; Latash, M L

    2016-02-19

    We use an approach rooted in the recent theory of synergies to analyze possible co-variation between two hypothetical control variables involved in finger force production based on the equilibrium-point (EP) hypothesis. These control variables are the referent coordinate (R) and apparent stiffness (C) of the finger. We tested a hypothesis that inter-trial co-variation in the {R; C} space during repeated, accurate force production trials stabilizes the fingertip force. This was expected to correspond to a relatively low amount of inter-trial variability affecting force and a high amount of variability keeping the force unchanged. We used the "inverse piano" apparatus to apply small and smooth positional perturbations to fingers during force production tasks. Across trials, R and C showed strong co-variation with the data points lying close to a hyperbolic curve. Hyperbolic regressions accounted for over 99% of the variance in the {R; C} space. Another analysis was conducted by randomizing the original {R; C} data sets and creating surrogate data sets that were then used to compute predicted force values. The surrogate sets always showed much higher force variance compared to the actual data, thus reinforcing the conclusion that finger force control was organized in the {R; C} space, as predicted by the EP hypothesis, and involved co-variation in that space stabilizing total force. PMID:26701299

  14. Synergies in the space of control variables within the equilibrium-point hypothesis.

    PubMed

    Ambike, S; Mattos, D; Zatsiorsky, V M; Latash, M L

    2016-02-19

    We use an approach rooted in the recent theory of synergies to analyze possible co-variation between two hypothetical control variables involved in finger force production based on the equilibrium-point (EP) hypothesis. These control variables are the referent coordinate (R) and apparent stiffness (C) of the finger. We tested a hypothesis that inter-trial co-variation in the {R; C} space during repeated, accurate force production trials stabilizes the fingertip force. This was expected to correspond to a relatively low amount of inter-trial variability affecting force and a high amount of variability keeping the force unchanged. We used the "inverse piano" apparatus to apply small and smooth positional perturbations to fingers during force production tasks. Across trials, R and C showed strong co-variation with the data points lying close to a hyperbolic curve. Hyperbolic regressions accounted for over 99% of the variance in the {R; C} space. Another analysis was conducted by randomizing the original {R; C} data sets and creating surrogate data sets that were then used to compute predicted force values. The surrogate sets always showed much higher force variance compared to the actual data, thus reinforcing the conclusion that finger force control was organized in the {R; C} space, as predicted by the EP hypothesis, and involved co-variation in that space stabilizing total force.

  15. Datum maintenance of the main Egyptian geodetic control networks by utilizing Precise Point Positioning "PPP" technique

    NASA Astrophysics Data System (ADS)

    Rabah, Mostafa; Elmewafey, Mahmoud; Farahan, Magda H.

    2016-06-01

    A geodetic control network is the wire-frame or the skeleton on which continuous and consistent mapping, Geographic Information Systems (GIS), and surveys are based. Traditionally, geodetic control points are established as permanent physical monuments placed in the ground and precisely marked, located, and documented. With the development of satellite surveying methods and their availability and high degree of accuracy, a geodetic control network could be established by using GNSS and referred to an international terrestrial reference frame used as a three-dimensional geocentric reference system for a country. Based on this concept, in 1992, the Egypt Survey Authority (ESA) established two networks, namely High Accuracy Reference Network (HARN) and the National Agricultural Cadastral Network (NACN). To transfer the International Terrestrial Reference Frame to the HARN, the HARN was connected with four IGS stations. The processing results were 1:10,000,000 (Order A) for HARN and 1:1,000,000 (Order B) for NACN relative network accuracy standard between stations defined in ITRF1994 Epoch1996. Since 1996, ESA did not perform any updating or maintaining works for these networks. To see how non-performing maintenance degrading the values of the HARN and NACN, the available HARN and NACN stations in the Nile Delta were observed. The Processing of the tested part was done by CSRS-PPP Service based on utilizing Precise Point Positioning "PPP" and Trimble Business Center "TBC". The study shows the feasibility of Precise Point Positioning in updating the absolute positioning of the HARN network and its role in updating the reference frame (ITRF). The study also confirmed the necessity of the absent role of datum maintenance of Egypt networks.

  16. Robust Brain-Machine Interface Design Using Optimal Feedback Control Modeling and Adaptive Point Process Filtering

    PubMed Central

    Carmena, Jose M.

    2016-01-01

    Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman filters and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon optimal feedback-control (OFC) model of the brain’s behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user’s motor intention during CLDA—a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to

  17. Robust Brain-Machine Interface Design Using Optimal Feedback Control Modeling and Adaptive Point Process Filtering.

    PubMed

    Shanechi, Maryam M; Orsborn, Amy L; Carmena, Jose M

    2016-04-01

    Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman filters and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon optimal feedback-control (OFC) model of the brain's behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user's motor intention during CLDA-a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to parameter

  18. The hazard analysis and critical control point system in food safety.

    PubMed

    Herrera, Anavella Gaitan

    2004-01-01

    The Hazard Analysis and Critical Control Point (HACCP) system is a preventive method of ensuring food safety. Its objectives are the identification of consumer safety hazards that can occur in the production line and the establishment of a control process to guarantee a safer product for the consumer; it is based on the identification of potential hazards to food safety and on measures aimed at preventing these hazards. HACCP is the system of choice in the management of food safety. The principles of HACCP are applicable to all phases of food production, including basic husbandry practices, food preparation and handling, food processing, food service, distribution systems, and consumer handling and use. The HACCP system is involved in every aspect of food safety production (according to the UN Food and Agriculture Organization [FAO] and the International Commission on Microbiological Specifications for Foods [ICMSF]). The most basic concept underlying the HACCP system is that of prevention rather than inspection. The control of processes and conditions comprises the critical control point (CCP) element. HACCP is simply a methodical, flexible, and systematic application of the appropriate science and technology for planning, controlling, and documenting the safe production of foods. The successful application of HACCP requires the full commitment and involvement of management and the workforce, using a multidisciplinary approach that should include, as appropriate, expertise in agronomy, veterinary health, microbiology, public health, food technology, environmental health, chemistry, engineering, and so on according to the particular situation. Application of the HACCP system is compatible with the implementation of total quality management (TQM) systems such as the ISO 9000 series. PMID:15156035

  19. The hazard analysis and critical control point system in food safety.

    PubMed

    Herrera, Anavella Gaitan

    2004-01-01

    The Hazard Analysis and Critical Control Point (HACCP) system is a preventive method of ensuring food safety. Its objectives are the identification of consumer safety hazards that can occur in the production line and the establishment of a control process to guarantee a safer product for the consumer; it is based on the identification of potential hazards to food safety and on measures aimed at preventing these hazards. HACCP is the system of choice in the management of food safety. The principles of HACCP are applicable to all phases of food production, including basic husbandry practices, food preparation and handling, food processing, food service, distribution systems, and consumer handling and use. The HACCP system is involved in every aspect of food safety production (according to the UN Food and Agriculture Organization [FAO] and the International Commission on Microbiological Specifications for Foods [ICMSF]). The most basic concept underlying the HACCP system is that of prevention rather than inspection. The control of processes and conditions comprises the critical control point (CCP) element. HACCP is simply a methodical, flexible, and systematic application of the appropriate science and technology for planning, controlling, and documenting the safe production of foods. The successful application of HACCP requires the full commitment and involvement of management and the workforce, using a multidisciplinary approach that should include, as appropriate, expertise in agronomy, veterinary health, microbiology, public health, food technology, environmental health, chemistry, engineering, and so on according to the particular situation. Application of the HACCP system is compatible with the implementation of total quality management (TQM) systems such as the ISO 9000 series.

  20. 41 CFR 101-26.606 - Supply support available from the inventory control points of the military departments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... from the inventory control points of the military departments. 101-26.606 Section 101-26.606 Public... § 101-26.606 Supply support available from the inventory control points of the military departments. Federal civil agencies may obtain items of supply which are procured and managed by the inventory...

  1. Knowledge-based monitoring of the pointing control system on the Hubble space telescope

    NASA Technical Reports Server (NTRS)

    Dunham, Larry L.; Laffey, Thomas J.; Kao, Simon M.; Schmidt, James L.; Read, Jackson Y.

    1987-01-01

    A knowledge-based system for the real time monitoring of telemetry data from the Pointing and Control System (PCS) of the Hubble Space Telescope (HST) that enables the retention of design expertise throughout the three decade project lifespan by means other than personnel and documentation is described. The system will monitor performance, vehicle status, success or failure of various maneuvers, and in some cases diagnose problems and recommend corrective actions using a knowledge base built using mission scenarios and the more than 4,500 telemetry monitors from the HST.

  2. [Incorporation of the Hazard Analysis and Critical Control Point system (HACCP) in food legislation].

    PubMed

    Castellanos Rey, Liliana C; Villamil Jiménez, Luis C; Romero Prada, Jaime R

    2004-01-01

    The Hazard Analysis and Critical Control Point system (HACCP), recommended by different international organizations as the Codex Alimentarius Commission, the World Trade Organization (WTO), the International Office of Epizootics (OIE) and the International Convention for Vegetables Protection (ICPV) amongst others, contributes to ensuring the innocuity of food along the agro-alimentary chain and requires of Good Manufacturing Practices (GMP) for its implementation, GMP's which are legislated in most countries. Since 1997, Colombia has set rules and legislation for application of HACCP system in agreement with international standards. This paper discusses the potential and difficulties of the legislation enforcement and suggests some policy implications towards food safety.

  3. Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis

    PubMed Central

    Latash, Mark L.

    2009-01-01

    This brief review analyzes the evolution of motor control theories along two lines that emphasize active (motor programs) and reactive (reflexes) features of voluntary movements. It suggests that the only contemporary hypothesis that integrates both approaches in a fruitful way is the equilibrium-point hypothesis. Physical, physiological, and behavioral foundations of the EP-hypothesis are considered as well as relations between the EP-hypothesis and the recent developments of the notion of motor synergies. The paper ends with a brief review of the criticisms of the EP-hypothesis and challenges that the hypothesis faces at this time. PMID:19823595

  4. School food safety program based on hazard analysis and critical control point principles. Final rule.

    PubMed

    2009-12-15

    This final rule implements a legislative provision which requires school food authorities participating in the National School Lunch Program (NSLP) or the School Breakfast Program (SBP) to develop a school food safety program for the preparation and service of school meals served to children. The school food safety program must be based on the hazard analysis and critical control point (HACCP) system established by the Secretary of Agriculture. The food safety program will enable schools to take systematic action to prevent or minimize the risk of foodborne illness among children participating in the NSLP and SBP. PMID:20169679

  5. The CERN antiproton source: Controls aspects of the additional collector ring and fast sampling devices

    NASA Astrophysics Data System (ADS)

    Chohan, V.

    1990-08-01

    The upgrade of the CERN antiproton source, meant to gain an order of magnitude in antiproton flux, required the construction of an additional ring to complement the existing antiproton accumulator (AA) and an entire rebuild of the target zone. The AA also needed major modifications to handle the increased flux and perform purely as an accumulator, preceded by collection in the collector ring (AC). The upgrade, known as the ACOL (antiproton collector) project, was approved under strict time and budgetary constraints and the existing AA control system, based on the Proton Synchrotron (PS) Divisional norms of CAMAC and Norsk-Data computers, had to be extended in the light of this. The limited (9 months) installation period for the whole upgrade meant that substantial preparatory and planning activities had to be carried out during the normal running of the AA. Advantage was taken of the upgrade to improve and consolidate the AA. Some aspects of the control system related to this upgrade are discussed together with the integration of new applications and instrumentation. The overall machine installation and running-in was carried out within the defined milestones and the project has now achieved the physics design goals.

  6. HACCP models for quality control of entrée production in hospital foodservice systems. I. Development of hazard analysis critical control point models.

    PubMed

    Bobeng, B J; David, B D

    1978-11-01

    HACCP models were developed as part of a research project for quality control of entrée production in three types of hospital foodservice systems: Conventional, cook/chill, and cook/freeze. Critical control points at process stages were identified. Time-temperature was a critical control point throughout entrée production in each model; time-temperature parameters were established for critical control points. Equipment sanitation and personnel sanitation are critical control points for which standards must be established by each foodservice system. Determination of the effectiveness of control measures included continuous monitoring of critical control points for time-temperature. Sanitation of equipment and personnel should be monitored using standards established by the foodservice system.

  7. Formation Flying Satellite Control Around the L2 Sun-Earth Libration Point

    NASA Astrophysics Data System (ADS)

    Hamilton, Nicholas H.

    2001-12-01

    A growing interest in formation flying satellites demands development and analysis of control and estimation algorithms for station-keeping and formation maneuvering. This thesis discusses the development of a discrete linear-quadratic- regulator control algorithm for formations in the vicinity of the L2 sun-earth libration point. The development of an appropriate Kalman filter is included as well. Simulations are created for the analysis of the station-keeping and various formation maneuvers of the Stellar Imager mission. The simulations provide tracking error, estimation error, and control effort results. From the control effort, useful design parameters such as AV and propellant mass are determined. For formation maneuvering, the drone spacecraft track to within 4 meters of their desired position and within 1.3 millimeters per second of their desired zero velocity. The filter, with few exceptions, keeps the estimation errors within their three-sigma values. Without noise, the controller performs extremely well, with the drones tracking to within several micrometers. Bach drone uses around 1 to 2 grams of propellant per maneuver, depending on the circumstances.

  8. A unified point process probabilistic framework to assess heartbeat dynamics and autonomic cardiovascular control.

    PubMed

    Chen, Zhe; Purdon, Patrick L; Brown, Emery N; Barbieri, Riccardo

    2012-01-01

    In recent years, time-varying inhomogeneous point process models have been introduced for assessment of instantaneous heartbeat dynamics as well as specific cardiovascular control mechanisms and hemodynamics. Assessment of the model's statistics is established through the Wiener-Volterra theory and a multivariate autoregressive (AR) structure. A variety of instantaneous cardiovascular metrics, such as heart rate (HR), heart rate variability (HRV), respiratory sinus arrhythmia (RSA), and baroreceptor-cardiac reflex (baroreflex) sensitivity (BRS), are derived within a parametric framework and instantaneously updated with adaptive and local maximum likelihood estimation algorithms. Inclusion of second-order non-linearities, with subsequent bispectral quantification in the frequency domain, further allows for definition of instantaneous metrics of non-linearity. We here present a comprehensive review of the devised methods as applied to experimental recordings from healthy subjects during propofol anesthesia. Collective results reveal interesting dynamic trends across the different pharmacological interventions operated within each anesthesia session, confirming the ability of the algorithm to track important changes in cardiorespiratory elicited interactions, and pointing at our mathematical approach as a promising monitoring tool for an accurate, non-invasive assessment in clinical practice. We also discuss the limitations and other alternative modeling strategies of our point process approach.

  9. Pinhole/coronograph pointing control system integration and noise reduction analysis

    NASA Technical Reports Server (NTRS)

    Greene, M.

    1981-01-01

    The Pinhole Occulter Facility (P/OF) is a Space Shuttle based experiment for the production of solar coronographics and hard X-ray images. The system is basically pinhole camera utilizing a deployable 50-m flexible boom for separating the pinholes and coronograph shields from the recording devices located in the Shuttle bay. At the distal end of the boom from the Shuttle is a 25 kg mask containing pinholes and coronograph shields. At the proximal end the detectors are located and mounted, along with the deployable boom, to the ASPS gimbal pointing system (AGS). The mask must be pointed at the Sun with a high degree of pointing stability and accuracy to align the axes of the detectors with the pinholes and shields. Failure to do so will result in a blurring of the images on the detectors and a loss of resolution. Being a Shuttle based experiment, the system will be subjected to the disturbances of the Shuttle. The worst of these is thruster firing for orbit correction; the Shuttle uses a bang-bang thruster control system to maintain orbit to within preset limits. Other disturbances include man motion, motion induced by other systems, and gravity gradient torques.

  10. Interferometric adaptive optics for high-power laser pointing, wavefront control, and phasing

    NASA Astrophysics Data System (ADS)

    Baker, K. L.; Stappaerts, E. A.; Homoelle, D. C.; Henesian, M. A.; Bliss, E. S.; Siders, C. W.; Barty, C. P. J.

    2009-02-01

    Implementing the capability to perform fast ignition experiments, as well as, radiography experiments on the National Ignition Facility (NIF) places stringent requirements on the control of each of the beam's pointing and overall wavefront quality. One quad of the NIF beams, 4 beam pairs, will be utilized for these experiments and hydrodynamic and particle-in-cell simulations indicate that for the fast ignition experiments, these beams will be required to deliver 50%(4.0 kJ) of their total energy(7.96 kJ) within a 40 μm diameter spot at the end of a fast ignition cone target. This requirement implies a stringent pointing and overall phase conjugation error budget on the adaptive optics system used to correct these beam lines. The overall encircled energy requirement is more readily met by phasing of the beams in pairs but still requires high Strehl ratios, Sr, and RMS tip/tilt errors of approximately one μrad. To accomplish this task we have designed an interferometric adaptive optics system capable of beam pointing, high Strehl ratio and beam phasing with a single pixilated MEMS deformable mirror and interferometric wave-front sensor. We present the design of a testbed used to evaluate the performance of this wave-front sensor below along with simulations of its expected performance level.

  11. Interferometric adaptive optics for high power laser pointing, wave-front control and phasing

    SciTech Connect

    Baker, K L; Stappaerts, E A; Homoelle, D C; Henesian, M A; Bliss, E S; Siders, C W; Barty, C J

    2009-01-21

    Implementing the capability to perform fast ignition experiments, as well as, radiography experiments on the National Ignition Facility (NIF) places stringent requirements on the control of each of the beam's pointing and overall wavefront quality. One quad of the NIF beams, 4 beam pairs, will be utilized for these experiments and hydrodynamic and particle-in-cell simulations indicate that for the fast ignition experiments, these beams will be required to deliver 50% (4.0 kJ) of their total energy (7.96 kJ) within a 40 {micro}m diameter spot at the end of a fast ignition cone target. This requirement implies a stringent pointing and overall phase conjugation error budget on the adaptive optics system used to correct these beam lines. The overall encircled energy requirement is more readily met by phasing of the beams in pairs but still requires high Strehl ratios, Sr, and rms tip/tilt errors of approximately one {micro}rad. To accomplish this task we have designed an interferometric adaptive optics system capable of beam pointing, high Strehl ratio and beam phasing with a single pixilated MEMS deformable mirror and interferometric wave-front sensor. We present the design of a testbed used to evaluate the performance of this wave-front sensor below along with simulations of its expected performance level.

  12. Critical Point Facility (CPE) Group in the Spacelab Payload Operations Control Center (SL POCC)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Critical Point Facility (CPE) group in the SL POCC during STS-42, IML-1 mission.

  13. Critical Point Facility (CPF) Team in the Spacelab Payload Operations Control Center (SL POCC)

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Critical Point Facility (CPF) team in the SL POCC during the IML-1 mission.

  14. Adaptive robust maximum power point tracking control for perturbed photovoltaic systems with output voltage estimation.

    PubMed

    Koofigar, Hamid Reza

    2016-01-01

    The problem of maximum power point tracking (MPPT) in photovoltaic (PV) systems, despite the model uncertainties and the variations in environmental circumstances, is addressed. Introducing a mathematical description, an adaptive sliding mode control (ASMC) algorithm is first developed. Unlike many previous investigations, the output voltage is not required to be sensed and the upper bound of system uncertainties and the variations of irradiance and temperature are not required to be known. Estimating the output voltage by an update law, an adaptive-based H∞ tracking algorithm is then developed for the case the perturbations are energy-bounded. The stability analysis is presented for the proposed tracking control schemes, based on the Lyapunov stability theorem. From a comparison viewpoint, some numerical and experimental studies are also presented and discussed. PMID:26606851

  15. Adaptive robust maximum power point tracking control for perturbed photovoltaic systems with output voltage estimation.

    PubMed

    Koofigar, Hamid Reza

    2016-01-01

    The problem of maximum power point tracking (MPPT) in photovoltaic (PV) systems, despite the model uncertainties and the variations in environmental circumstances, is addressed. Introducing a mathematical description, an adaptive sliding mode control (ASMC) algorithm is first developed. Unlike many previous investigations, the output voltage is not required to be sensed and the upper bound of system uncertainties and the variations of irradiance and temperature are not required to be known. Estimating the output voltage by an update law, an adaptive-based H∞ tracking algorithm is then developed for the case the perturbations are energy-bounded. The stability analysis is presented for the proposed tracking control schemes, based on the Lyapunov stability theorem. From a comparison viewpoint, some numerical and experimental studies are also presented and discussed.

  16. Selection and allocation of manual traffic control points and personnel during emergencies.

    PubMed

    Parr, Scott A; Wolshon, Brian; Dixit, Vinayak

    2015-01-01

    Manual traffic control is an intersection control strategy in which law enforcement officers allocate intersection right-of-way to turning movements. Many emergency traffic management plans call for manual traffic control in response to oversaturated roadway conditions. This is because it is thought to more effectively move traffic during temporary surges in demand. The goal of this research was to evaluate the current state-of-the-practice used by the Army Corps of Engineers (ACE) in selecting intersections for manual traffic control and allocating police personnel to them during emergencies. This research uses the emergency traffic management plans developed by the ACE for nine counties in the Maryland Eastern Shore region. This area encompassing 14,318 intersections of which 74 were selected for manual traffic control during emergencies. This work sought to quantify the correlations that exist between intersection attributes and the ACE' decision to allocate officers to control them. The research findings suggest that US routes, State routes, and emergency evacuation routes are statistically significant in determining the need for police control at intersections. Also significant are intersection on contraflow corridors and intersections near grade separated interchanges. The model also determined that intersections isolated from evacuation routes and county exits were more likely to be selected for manual control, indicating that rural areas may rely on manual traffic control in the absence of multilane highway and freeways. This research also found that intersections involving evacuation routes, contraflow corridors, and grade separated interchanges may warrant additional police personnel (two or more officers) for manual traffic control.

  17. Selection and allocation of manual traffic control points and personnel during emergencies.

    PubMed

    Parr, Scott A; Wolshon, Brian; Dixit, Vinayak

    2015-01-01

    Manual traffic control is an intersection control strategy in which law enforcement officers allocate intersection right-of-way to turning movements. Many emergency traffic management plans call for manual traffic control in response to oversaturated roadway conditions. This is because it is thought to more effectively move traffic during temporary surges in demand. The goal of this research was to evaluate the current state-of-the-practice used by the Army Corps of Engineers (ACE) in selecting intersections for manual traffic control and allocating police personnel to them during emergencies. This research uses the emergency traffic management plans developed by the ACE for nine counties in the Maryland Eastern Shore region. This area encompassing 14,318 intersections of which 74 were selected for manual traffic control during emergencies. This work sought to quantify the correlations that exist between intersection attributes and the ACE' decision to allocate officers to control them. The research findings suggest that US routes, State routes, and emergency evacuation routes are statistically significant in determining the need for police control at intersections. Also significant are intersection on contraflow corridors and intersections near grade separated interchanges. The model also determined that intersections isolated from evacuation routes and county exits were more likely to be selected for manual control, indicating that rural areas may rely on manual traffic control in the absence of multilane highway and freeways. This research also found that intersections involving evacuation routes, contraflow corridors, and grade separated interchanges may warrant additional police personnel (two or more officers) for manual traffic control. PMID:25902295

  18. Benefits of Aldosterone Receptor Antagonism in Chronic Kidney Disease (BARACK D) trial–a multi-centre, prospective, randomised, open, blinded end-point, 36-month study of 2,616 patients within primary care with stage 3b chronic kidney disease to compare the efficacy of spironolactone 25 mg once daily in addition to routine care on mortality and cardiovascular outcomes versus routine care alone: study protocol for a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Chronic kidney disease (CKD) is common and increasing in prevalence. Cardiovascular disease (CVD) is a major cause of morbidity and death in CKD, though of a different phenotype to the general CVD population. Few therapies have proved effective in modifying the increased CVD risk or rate of renal decline in CKD. There are accumulating data that aldosterone receptor antagonists (ARA) may offer cardio-protection and delay renal impairment in patients with the CV phenotype in CKD. The use of ARA in CKD has therefore been increasingly advocated. However, no large study of ARA with renal or CVD outcomes is underway. Methods The study is a prospective randomised open blinded endpoint (PROBE) trial set in primary care where patients will mainly be identified by their GPs or from existing CKD lists. They will be invited if they have been formally diagnosed with CKD stage 3b or there is evidence of stage 3b CKD from blood results (eGFR 30–44 mL/min/1.73 m2) and fulfil the other inclusion/exclusion criteria. Patients will be randomised to either spironolactone 25 mg once daily in addition to routine care or routine care alone and followed-up for 36 months. Discussion BARACK D is a PROBE trial to determine the effect of ARA on mortality and cardiovascular outcomes (onset or progression of CVD) in patients with stage 3b CKD. Trial registration EudraCT: 2012-002672-13 ISRTN: ISRCTN44522369 PMID:24886488

  19. Acupuncture point injection treatment of primary dysmenorrhoea: a randomised, double blind, controlled study

    PubMed Central

    Wade, C; Wang, L; Zhao, W J; Cardini, F; Kronenberg, F; Gui, S Q; Ying, Z; Zhao, N Q; Chao, M T; Yu, J

    2016-01-01

    Objective To determine if injection of vitamin K3 in an acupuncture point is optimal for the treatment of primary dysmenorrhoea, when compared with 2 other injection treatments. Setting A Menstrual Disorder Centre at a public hospital in Shanghai, China. Participants Chinese women aged 14–25 years with severe primary dysmenorrhoea for at least 6 months not relieved by any other treatment were recruited. Exclusion criteria were the use of oral contraceptives, intrauterine devices or anticoagulant drugs, pregnancy, history of abdominal surgery, participation in other therapies for pain and diagnosis of secondary dysmenorrhoea. Eighty patients with primary dysmenorrhoea, as defined on a 4-grade scale, completed the study. Two patients withdrew after randomisation. Interventions A double-blind, double-dummy, randomised controlled trial compared vitamin K3 acupuncture point injection to saline acupuncture point injection and vitamin K3 deep muscle injection. Patients in each group received 3 injections at a single treatment visit. Primary and secondary outcome measures The primary outcome was the difference in subjective perception of pain as measured by an 11 unit Numeric Rating Scale (NRS). Secondary measurements were Cox Pain Intensity and Duration scales and the consumption of analgesic tablets before and after treatment and during 6 following cycles. Results Patients in all 3 groups experienced pain relief from the injection treatments. Differences in NRS measured mean pain scores between the 2 active control groups were less than 1 unit (−0.71, CI −1.37 to −0.05) and not significant, but the differences in average scores between the treatment hypothesised to be optimal and both active control groups (1.11, CI 0.45 to 1.78) and (1.82, CI 1.45 to 2.49) were statistically significant in adjusted mixed-effects models. Menstrual distress and use of analgesics were diminished for 6 months post-treatment. Conclusions Acupuncture point injection of

  20. Method for pan-tilt camera calibration using single control point.

    PubMed

    Li, Yunting; Zhang, Jun; Hu, Wenwen; Tian, Jinwen

    2015-01-01

    The pan-tilt (PT) camera is widely used in video surveillance systems due to its rotatable property and low cost. The rough output of a PT camera may not satisfy the demand of practical applications; hence an accurate calibration method of a PT camera is desired. However, high-precision camera calibration methods usually require sufficient control points not guaranteed in some practical cases of a PT camera. In this paper, we present a novel method to online calibrate the rotation angles of a PT camera by using only one control point. This is achieved by assuming that the intrinsic parameters and position of the camera are known in advance. More specifically, we first build a nonlinear PT camera model with respect to two parameters Pan and Tilt. We then convert the nonlinear model into a linear model according to sine and cosine of Tilt, where each element in the augmented coefficient matrix is a function of the single variable Pan. A closed-form solution of Pan and Tilt can then be derived by solving a quadratic equation of tangent of Pan. Our method is noniterative and does not need features matching; thus its time efficiency is better. We evaluate our calibration method on various synthetic and real data. The quantitative results demonstrate that the proposed method outperforms other state-of-the-art methods if the intrinsic parameters and position of the camera are known in advance.

  1. Research on the modeling of the missile's disturbance motion and the initial control point optimization

    NASA Astrophysics Data System (ADS)

    Guo, Jie; Zhu, Dalin; Tang, Shengjing

    2012-11-01

    The initial trajectory design of the missile is an important part of the overall design, but often a tedious calculation and analysis process due to the large dimension nonlinear differential equations and the traditional statistical analysis methods. To improve the traditional design methods, a robust optimization concept and method are introduced in this paper to deal with the determination of the initial control point. First, the Gaussian Radial Basis Network is adopted to establish the approximate model of the missile's disturbance motion based on the disturbance motion and disturbance factors analysis. Then, a direct analytical relationship between the disturbance input and statistical results is deduced on the basis of Gaussian Radial Basis Network model. Subsequently, a robust optimization model is established aiming at the initial control point design problem and the niche Pareto genetic algorithm for multi-objective optimization is adopted to solve this optimization model. An integral design example is give at last and the simulation results have verified the validity of this method.

  2. Whole-lake nitrate addition for control of methylmercury in mercury-contaminated Onondaga Lake, NY.

    PubMed

    Matthews, David A; Babcock, David B; Nolan, John G; Prestigiacomo, Anthony R; Effler, Steven W; Driscoll, Charles T; Todorova, Svetoslava G; Kuhr, Kenneth M

    2013-08-01

    Methylmercury (MeHg) strongly bioaccumulates in aquatic food webs resulting in exposure to humans and wildlife through consumption of fish. Production of MeHg is promoted by anaerobic conditions and the supply of inorganic Hg (Hg(2+)), sulfate (SO4(2-)), and labile organic carbon. The anaerobic sediments of stratified lakes are particularly active zones for methylation of Hg(2+) and can be an important source of MeHg to the water column during summer anoxia and fall turnover. Nitrate (NO3(-)) addition has recently been proposed as a novel approach for the control of MeHg accumulation in the hypolimnia of Hg-contaminated lakes. In 2011, a whole-lake NO3(-) addition pilot test was conducted in Hg-contaminated Onondaga Lake, NY with the objective of limiting release of MeHg from the pelagic sediments to the hypolimnion through maintenance of NO3(-)-N concentrations >1mgN/L. A liquid calcium-nitrate solution was added to the hypolimnion as a neutrally buoyant plume approximately three times per week during the summer stratification interval. Maximum hypolimnetic concentrations of MeHg and soluble reactive phosphorus (SRP) decreased 94% and 95% from 2009 levels, suggesting increased sorption to Fe and Mn oxyhydroxides in surficial sediments as the regulating mechanism. Increased MeHg concentrations in the upper waters during fall turnover, which had been a generally recurring pattern, did not occur in 2011, resulting in decreased exposure of aquatic organisms to MeHg. Over the 1992-2011 interval, the hypolimnetic NO3(-) supply explained 85% and 95% of the interannual variations in hypolimnetic accumulations of SRP and MeHg, respectively.

  3. Analysis of Time to Event Outcomes in Randomized Controlled Trials by Generalized Additive Models

    PubMed Central

    Argyropoulos, Christos; Unruh, Mark L.

    2015-01-01

    Background Randomized Controlled Trials almost invariably utilize the hazard ratio calculated with a Cox proportional hazard model as a treatment efficacy measure. Despite the widespread adoption of HRs, these provide a limited understanding of the treatment effect and may even provide a biased estimate when the assumption of proportional hazards in the Cox model is not verified by the trial data. Additional treatment effect measures on the survival probability or the time scale may be used to supplement HRs but a framework for the simultaneous generation of these measures is lacking. Methods By splitting follow-up time at the nodes of a Gauss Lobatto numerical quadrature rule, techniques for Poisson Generalized Additive Models (PGAM) can be adopted for flexible hazard modeling. Straightforward simulation post-estimation transforms PGAM estimates for the log hazard into estimates of the survival function. These in turn were used to calculate relative and absolute risks or even differences in restricted mean survival time between treatment arms. We illustrate our approach with extensive simulations and in two trials: IPASS (in which the proportionality of hazards was violated) and HEMO a long duration study conducted under evolving standards of care on a heterogeneous patient population. Findings PGAM can generate estimates of the survival function and the hazard ratio that are essentially identical to those obtained by Kaplan Meier curve analysis and the Cox model. PGAMs can simultaneously provide multiple measures of treatment efficacy after a single data pass. Furthermore, supported unadjusted (overall treatment effect) but also subgroup and adjusted analyses, while incorporating multiple time scales and accounting for non-proportional hazards in survival data. Conclusions By augmenting the HR conventionally reported, PGAMs have the potential to support the inferential goals of multiple stakeholders involved in the evaluation and appraisal of clinical trial

  4. Additional follow-up telephone counselling and initial smoking relapse: a longitudinal, controlled study

    PubMed Central

    Wu, Lei; He, Yao; Jiang, Bin; Zuo, Fang; Liu, Qinghui; Zhang, Li; Zhou, Changxi

    2016-01-01

    Objectives Smoking cessation services can help smokers to quit; however, many smoking relapse cases occur over time. Initial relapse prevention should play an important role in achieving the goal of long-term smoking cessation. Several studies have focused on the effect of extended telephone support in relapse prevention, but the conclusions remain conflicting. Design and setting From October 2008 to August 2013, a longitudinal, controlled study was performed in a large general hospital of Beijing. Participants The smokers who sought treatment at our smoking cessation clinic were non-randomised and divided into 2 groups: face-to-face individual counselling group (FC group), and face-to-face individual counselling plus telephone follow-up counselling group (FCF group). No pharmacotherapy was offered. Outcomes The timing of initial smoking relapse was compared between FC and FCF groups. Predictors of initial relapse were investigated during the first 180 days, using the Cox proportional hazards model. Results Of 547 eligible male smokers who volunteered to participate, 457 participants (117 in FC group and 340 in FCF group) achieved at least 24 h abstinence. The majority of the lapse episodes occurred during the first 2 weeks after the quit date. Smokers who did not receive the follow-up telephone counselling (FC group) tended to relapse to smoking earlier than those smokers who received the additional follow-up telephone counselling (FCF group), and the log-rank test was statistically significant (p=0.003). A Cox regression model showed that, in the FCF group, being married, and having a lower Fagerström test score, normal body mass index and doctor-diagnosed tobacco-related chronic diseases, were significantly independent protective predictors of smoking relapse. Conclusions Within the limitations of this study, it can be concluded that additional follow-up telephone counselling might be an effective strategy in preventing relapse. Further research is still

  5. Goal-directed and transfer-cue-elicited drug-seeking are dissociated by pharmacotherapy: evidence for independent additive controllers.

    PubMed

    Hogarth, Lee

    2012-07-01

    According to contemporary learning theory, drug-seeking behavior reflects the summation of 2 dissociable controllers. Whereas goal-directed drug-seeking is determined by the expected current incentive value of the drug, stimulus-elicited drug-seeking is determined by the expected probability of the drug independently of its current incentive value, and these 2 controllers contribute additively to observed drug-seeking. One applied prediction of this model is that smoking cessation pharmacotherapies selectively attenuate tonic but not cue-elicited craving because they downgrade the expected incentive value of the drug but leave expected probability intact. To test this, the current study examined whether nicotine replacement therapy (NRT) nasal spray would modify goal-directed tobacco choice in a human outcome devaluation procedure, but leave cue-elicited tobacco choice in a Pavlovian to instrumental transfer (PIT) procedure intact. Smokers (N= 96) first underwent concurrent choice training in which 2 responses earned tobacco or chocolate points, respectively. Participants then ingested either NRT nasal spray (1 mg) or chocolate (147 g) to devalue 1 outcome. Concurrent choice was then tested again in extinction to measure goal-directed control of choice, and in a PIT test to measure the extent to which tobacco and chocolate stimuli enhanced choice of the same outcome. It was found that NRT modified tobacco choice in the extinction test but not the extent to which the tobacco stimulus enhanced choice of the tobacco outcome in the PIT test. This dissociation suggests that the propensity to engage in drug-seeking is determined independently by the expected value and probability of the drug, and that pharmacotherapy has partial efficacy because it selectively effects expected drug value.

  6. Goal-directed and transfer-cue-elicited drug-seeking are dissociated by pharmacotherapy: evidence for independent additive controllers.

    PubMed

    Hogarth, Lee

    2012-07-01

    According to contemporary learning theory, drug-seeking behavior reflects the summation of 2 dissociable controllers. Whereas goal-directed drug-seeking is determined by the expected current incentive value of the drug, stimulus-elicited drug-seeking is determined by the expected probability of the drug independently of its current incentive value, and these 2 controllers contribute additively to observed drug-seeking. One applied prediction of this model is that smoking cessation pharmacotherapies selectively attenuate tonic but not cue-elicited craving because they downgrade the expected incentive value of the drug but leave expected probability intact. To test this, the current study examined whether nicotine replacement therapy (NRT) nasal spray would modify goal-directed tobacco choice in a human outcome devaluation procedure, but leave cue-elicited tobacco choice in a Pavlovian to instrumental transfer (PIT) procedure intact. Smokers (N= 96) first underwent concurrent choice training in which 2 responses earned tobacco or chocolate points, respectively. Participants then ingested either NRT nasal spray (1 mg) or chocolate (147 g) to devalue 1 outcome. Concurrent choice was then tested again in extinction to measure goal-directed control of choice, and in a PIT test to measure the extent to which tobacco and chocolate stimuli enhanced choice of the same outcome. It was found that NRT modified tobacco choice in the extinction test but not the extent to which the tobacco stimulus enhanced choice of the tobacco outcome in the PIT test. This dissociation suggests that the propensity to engage in drug-seeking is determined independently by the expected value and probability of the drug, and that pharmacotherapy has partial efficacy because it selectively effects expected drug value. PMID:22823420

  7. Binocular and Monocular Depth Cues in Online Feedback Control of 3-D Pointing Movement

    PubMed Central

    Hu, Bo; Knill, David C.

    2012-01-01

    Previous work has shown that humans continuously use visual feedback of the hand to control goal-directed movements online. In most studies, visual error signals were predominantly in the image plane and thus were available in an observer’s retinal image. We investigate how humans use visual feedback about finger depth provided by binocular and monocular depth cues to control pointing movements. When binocularly viewing a scene in which the hand movement was made in free space, subjects were about 60 ms slower in responding to perturbations in depth than in the image plane. When monocularly viewing a scene designed to maximize the available monocular cues to finger depth (motion, changing size and cast shadows), subjects showed no response to perturbations in depth. Thus, binocular cues from the finger are critical to effective online control of hand movements in depth. An optimal feedback controller that takes into account of the low peripheral stereoacuity and inherent ambiguity in cast shadows can explain the difference in response time in the binocular conditions and lack of response in monocular conditions. PMID:21724567

  8. Additional Saturday rehabilitation improves functional independence and quality of life and reduces length of stay: a randomized controlled trial

    PubMed Central

    2013-01-01

    Background Many inpatients receive little or no rehabilitation on weekends. Our aim was to determine what effect providing additional Saturday rehabilitation during inpatient rehabilitation had on functional independence, quality of life and length of stay compared to 5 days per week of rehabilitation. Methods This was a multicenter, single-blind (assessors) randomized controlled trial with concealed allocation and 12-month follow-up conducted in two publically funded metropolitan inpatient rehabilitation facilities in Melbourne, Australia. Patients were eligible if they were adults (aged ≥18 years) admitted for rehabilitation for any orthopedic, neurological or other disabling conditions excluding those admitted for slow stream rehabilitation/geriatric evaluation and management. Participants were randomly allocated to usual care Monday to Friday rehabilitation (control) or to Monday to Saturday rehabilitation (intervention). The additional Saturday rehabilitation comprised physiotherapy and occupational therapy. The primary outcomes were functional independence (functional independence measure (FIM); measured on an 18 to 126 point scale), health-related quality of life (EQ-5D utility index; measured on a 0 to 1 scale, and EQ-5D visual analog scale; measured on a 0 to 100 scale), and patient length of stay. Outcome measures were assessed on admission, discharge (primary endpoint), and at 6 and 12 months post discharge. Results We randomly assigned 996 adults (mean (SD) age 74 (13) years) to Monday to Saturday rehabilitation (n = 496) or usual care Monday to Friday rehabilitation (n = 500). Relative to admission scores, intervention group participants had higher functional independence (mean difference (MD) 2.3, 95% confidence interval (CI) 0.5 to 4.1, P = 0.01) and health-related quality of life (MD 0.04, 95% CI 0.01 to 0.07, P = 0.009) on discharge and may have had a shorter length of stay by 2 days (95% CI 0 to 4, P = 0.1) when compared to

  9. Controlling the corrosion and cathodic activation of magnesium via microalloying additions of Ge

    PubMed Central

    Liu, R. L.; Hurley, M. F.; Kvryan, A.; Williams, G.; Scully, J. R.; Birbilis, N.

    2016-01-01

    The evolution of corrosion morphology and kinetics for magnesium (Mg) have been demonstrated to be influenced by cathodic activation, which implies that the rate of the cathodic partial reaction is enhanced as a result of anodic dissolution. This phenomenon was recently demonstrated to be moderated by the use of arsenic (As) alloying as a poison for the cathodic reaction, leading to significantly improved corrosion resistance. The pursuit of alternatives to toxic As is important as a means to imparting a technologically safe and effective corrosion control method for Mg (and its alloys). In this work, Mg was microalloyed with germanium (Ge), with the aim of improving corrosion resistance by retarding cathodic activation. Based on a combined analysis herein, we report that Ge is potent in supressing the cathodic hydrogen evolution reaction (reduction of water) upon Mg, improving corrosion resistance. With the addition of Ge, cathodic activation of Mg subject to cyclic polarisation was also hindered, with beneficial implications for future Mg electrodes. PMID:27350286

  10. Postural control in response to a perturbation: role of vision and additional support.

    PubMed

    Krishnan, Vennila; Vennila, Krishnan; Aruin, Alexander S

    2011-07-01

    The purpose of the study was to investigate the availability of vision and additional support on anticipatory (APA) and compensatory (CPA) postural adjustments and their interaction. Eight healthy adults were exposed to external perturbations induced at the shoulder level while standing with and without holding onto a walker in full vision and while blindfolded. Electrical activity of the trunk and leg muscles and center of pressure (COPAP) displacement were recorded and quantified within the time intervals typical of APA and CPA. The results showed that with full vision, there was no difference in both APA and CPA in standing with and without holding onto a walker. With subjects holding onto a walker, CPA in standing blindfolded were comparable to CPA in full vision; this was seen in changes in the electrical activity of most of the muscles at the individual muscle, joint, and the muscle group levels as well as in COPAP displacement. The findings suggest that (1) in conditions where vision is available, vision overrules simultaneously available proprioceptive information from the support, (2) while in conditions where vision is not available, proprioceptive information from the support or support itself could be substituted for vision. It is possible to suggest that using a non-stabilizing support could be a valuable strategy to improve postural control when visual information is not available or compromised.

  11. Animated sulfonated or sulformethylated lignins as cement fluid loss control additives

    SciTech Connect

    Schilling, P.

    1991-05-07

    This patent describes a method of cementing a zone in a well penetrating a subterranean formation comprising injecting down the well and positioning in the zone to be cemented a hydraulic aqueous cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and a fluid loss control additive comprising from about 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been aminated by reacting it with between about 2-5 moles of a polyamine and 2-5 moles of an aldehyde per 1,000g of the lignin, and 0.1 to 1.5 parts of a compound selected from the group consisting of sodium carbonate, sodium metasilicate, sodium phosphate, sodium sulfite and sodium naphthalene sulfonate and a combination thereof.

  12. The Use of Additives to Control the Morphology of Thin Films Synthesized Using Aerosol Assisted Chemical Vapour Deposition

    NASA Astrophysics Data System (ADS)

    Kaye, Karl; Turner, David; McKenna, David; Cackett, Adam; Hyett, Geoffrey

    This paper identifies and discusses the use of additives to control the morphology of nanoscale crystalline zinc oxide films, grown using AACVD, principally from a solution of zinc acetate in methanol. We will discuss the use of both positively charged additives such as tetramethylammonium bromide and cetyltrimethylammonium bromide as well as negatively charged additives like sodium dodecylsulphate. Additives such as these, combined with other experimental parameters such as deposition time, have allowed us to control the size of the particles (from 100 to 400 nm in diameter), their orientation, and the regularity of their shape, from rough edged plates to well defined hexagons. We will show that the additives can be used to control morphology consistently over a temperature range of 250-400 °C, and that this technique can be applied generally to a number of additives and solvents.

  13. Control Point Analysis comparison for 3 different treatment planning and delivery complexity levels using a commercial 3-dimensional diode array

    SciTech Connect

    Abdellatif, Ady; Gaede, Stewart

    2014-07-01

    To investigate the use of “Control Point Analysis” (Sun Nuclear Corporation, Melbourne, FL) to analyze and compare delivered volumetric-modulated arc therapy (VMAT) plans for 3 different treatment planning complexity levels. A total of 30 patients were chosen and fully anonymized for the purpose of this study. Overall, 10 lung stereotactic body radiotherapy (SBRT), 10 head-and-neck (H and N), and 10 prostate VMAT plans were generated on Pinnacle{sup 3} and delivered on a Varian linear accelerator (LINAC). The delivered dose was measured using ArcCHECK (Sun Nuclear Corporation, Melbourne, FL). Each plan was analyzed using “Sun Nuclear Corporation (SNC) Patient 6” and “Control Point Analysis.” Gamma passing percentage was used to assess the differences between the measured and planned dose distributions and to assess the role of various control point binning combinations. Of the different sites considered, the prostate cases reported the highest gamma passing percentages calculated with “SNC Patient 6” (97.5% to 99.2% for the 3%, 3 mm) and “Control Point Analysis” (95.4% to 98.3% for the 3%, 3 mm). The mean percentage of passing control point sectors for the prostate cases increased from 51.8 ± 7.8% for individual control points to 70.6 ± 10.5% for 5 control points binned together to 87.8 ± 11.0% for 10 control points binned together (2%, 2-mm passing criteria). Overall, there was an increasing trend in the percentage of sectors passing gamma analysis with an increase in the number of control points binned together in a sector for both the gamma passing criteria (2%, 2 mm and 3%, 3 mm). Although many plans passed the clinical quality assurance criteria, plans involving the delivery of high Monitor Unit (MU)/control point (SBRT) and plans involving high degree of modulation (H and N) showed less delivery accuracy per control point compared with plans with low MU/control point and low degree of modulation (prostate)

  14. e-VLBI Access Point (eAXP) - a centralized control and EGAE configuration / management application

    NASA Astrophysics Data System (ADS)

    Ruszczyk, Chester Whitney, Alan

    Setting up experiments to utilize Experiment Guided Adaptive Endpoint (EGAE) and e-VLBI is presently a complex and time intensive process requiring scientific, Mark5 and networking knowledge. There is no central access to point to configure and manage all of these aspects of an experiment. The e-VLBI Access Point (eAXP) is a centralized control plane management tool that offers a GUI interface to augment the command line interface presently being used to set up and conduct experiments. eAXP contains three major toolsets: one to set up and execute an experiment using real-time or non-real time modes; the second to configure and manage EGAE; and a third to view statistics of the experiments. Initially the overall system architecture for eAXP is presented, followed by details of the Experiment Profiler toolset including screen shots of the system presently being tested. This will be followed by how eAXP will support real-time modes interfacing to the Dynamic Resource Allocation over GMPLS Optical Network (DRAGON) resource management project.

  15. Thermoplastic fusion bonding using a pressure-assisted boiling point control system.

    PubMed

    Park, Taehyun; Song, In-Hyouk; Park, Daniel S; You, Byoung Hee; Murphy, Michael C

    2012-08-21

    A novel thermoplastic fusion bonding method using a pressure-assisted boiling point (PABP) control system was developed to apply precise temperatures and pressures during bonding. Hot embossed polymethyl methacrylate (PMMA) components containing microchannels were sealed using the PABP system. Very low aspect ratio structures (AR = 1/100, 10 μm in depth and 1000 μm in width) were successfully sealed without collapse or deformation. The integrity and strength of the bonds on the sealed PMMA devices were evaluated using leakage and rupture tests; no leaks were detected and failure during the rupture tests occurred at pressures greater than 496 kPa. The PABP system was used to seal 3D shaped flexible PMMA devices successfully.

  16. Controlled excitation of electromagnetic band-gap line and point defect modes at microwave frequencies

    NASA Astrophysics Data System (ADS)

    Schuster, M.; Klein, N.

    2003-03-01

    We report on the controlled excitation of line and point defect modes in a two-dimensional hexagonal electromagnetic band-gap structure made of rods of dielectric material (aluminium oxide). We compared simulation performed with a numerical field simulation software and experimental measurements at microwave frequencies with regard to coupling from external waveguides to line defects and subsequent coupling to resonant modes. We observed that for a line defect in the photonic crystal the impedance matching to a waveguide is strongly dependent on the defect width. We furthermore demonstrated that the coupling to a localized defect resonance can be strongly influenced by the variation of certain single lattice elements, affecting transmission behavior and quality factor of the resonant modes.

  17. Mesoscopic capacitor and zero-point energy: Poisson's distribution for virtual charges, pressure, and decoherence control

    NASA Astrophysics Data System (ADS)

    Flores, J. C.

    2014-08-01

    Mesoscopic capacitor theory, which includes intrinsic inductive effects from quantum tunneling, is applied to conducting spherical shells. The zero-point pressure and the number of virtual charged pairs are determined assuming a Poisson distribution. They are completely defined by a dimensionless mesoscopic parameter (χc) measuring the average number of virtual pairs per solid angle and carrying mesoscopic information. Fluctuations remain finite and well defined. Connections with usual quantum-field-theory limit enables us to evaluate χc 1.007110. Equivalently, for a mesoscopic parallel-plate capacitor, the shot noise distribution becomes operative with χc 0.94705 as well being related to the density of virtual pairs. Temperature decoherence and capacitor control are discussed by considering typical values of quantum dot devices and Coulomb blockade theory.

  18. Kinetic spectrophotometric H-point standard addition method for the simultaneous determination of diloxanide furoate and metronidazole in binary mixtures and biological fluids.

    PubMed

    Issa, Mahmoud Mohamed; Nejem, R'afat Mahmoud; Abu Shanab, Alaa Mohamed; Shaat, Nahed Talab

    2013-10-01

    Simple, reliable, and sensitive kinetic spectrophotometric method has been developed for the simultaneous determination of diloxanide furoate and metronidazole using H-point standard addition method (HPSAM). The method is based on the oxidation rate difference of diloxanide and metronidazole by potassium permanganate in basic medium. A green color has been developed and measured at 610 nm. Different experimental parameters were carefully optimized. The limiting logarithmic and the initial-rate methods were adopted for the construction of the calibration curve of each individual reaction with potassium permanganate. Under the optimum conditions, Beer's law was obeyed in the range of 1.0-20.0 and 5.0-25.0 μg ml(-1) for diloxanide furoate and metronidazole, respectively. The detection limits were 0.22 μg ml(-1) for diloxanide furoate and 0.83 μg ml(-1) for metronidazole. Correlation coefficients of the regression equations were greater than 0.9970 in all cases. The precision of the method was satisfactory; the maximum value of relative standard deviation did not exceed 1.06% (n=5). The accuracy, expressed as recovery was between 99.4% and 101.4% with relative error of 0.12 and 0.14 for diloxanide furoate and metronidazole, respectively. The proposed method was successfully applied for the simultaneous determination of both drugs in pharmaceutical dosage forms and human urine samples and compared with alternative HPLC method.

  19. Assessment of potential jaw-tracking advantage using control point sequences of VMAT planning.

    PubMed

    Kim, Jung-in; Park, Jong Min; Park, So-Yeon; Choi, Chang Heon; Wu, Hong-Gyun; Ye, Sung-Joon

    2014-03-06

    This study aims to evaluate the potential jaw-tracking advantage using control point sequences of volume volumetric modulated arc therapy (VMAT) planning. VMAT plans for patients with prostate and head and neck (H&N) cancers were converted into new static arc (SA) plans. The SA plan consisted of a series of static fields at each control point of the VMAT plan. All other machine parameters of the SA plan were perfectly identical to those of the original VMAT plan. The jaw-tracking static arc (JTSA) plans were generated with fields that closed the jaws of each SA field into the multileaf collimators (MLCs) aperture. The dosimetric advantages of JTSA over SA were evaluated in terms of a dose-volume histogram (DVH) of organ at risk (OAR) after renormalizing both plans to make the same target coverage. Both plans were delivered to the MatriXX-based COMPASS system for 3D volume dose verification. The average jaw size reduction of the JTSA along the X direction was 3.1 ± 0.9 cm for prostate patients and 6.9 ± 1.9 cm for H&N patients. For prostate patients, the organs far from the target showed larger sparing (3.7%-8.1% on average) in JTSA than the organs adjacent to the target (1.1%-1.5%). For the H&N plans, the mean dose reductions for all organs ranged from 4.3% to 11.9%. The dose reductions were more significant in the dose regions of D80, D90, and D95 than the dose regions of D5, D10, and D20 for all patients. Likewise, the deliverability and reproducibility of jaw-tracking plan were validated. The measured dosimetric advantage of JTSA over SA coincided with the calculated one above.

  20. 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

  1. Time optimal control of an additional food provided predator-prey system with applications to pest management and biological conservation.

    PubMed

    Srinivasu, P D N; Prasad, B S R V

    2010-04-01

    Use of additional food has been widely recognized by experimental scientists as one of the important tools for biological control such as species conservation and pest management. The quality and quantity of additional food supplied to the predators is known to play a vital role in the controllability of the system. The present study is continuation of a previous work that highlights the importance of quality and quantity of the additional food in the dynamics of a predator-prey system in the context of biological control. In this article the controllability of the predator-prey system is analyzed by considering inverse of quality of the additional food as the control variable. Control strategies are offered to steer the system from a given initial state to a required terminal state in a minimum time by formulating Mayer problem of optimal control. It is observed that an optimal strategy is a combination of bang-bang controls and could involve multiple switches. Properties of optimal paths are derived using necessary conditions for Mayer problem. In the light of the results evolved in this work it is possible to eradicate the prey from the eco-system in the minimum time by providing the predator with high quality additional food, which is relevant in the pest management. In the perspective of biological conservation this study highlights the possibilities to drive the state to an admissible interior equilibrium (irrespective of its stability nature) of the system in a minimum time.

  2. Steric Effects Compete with Aryne Distortion to Control Regioselectivities of Nucleophilic Additions to 3-Silylarynes

    PubMed Central

    Bronner, Sarah M.; Mackey, Joel L.

    2012-01-01

    We report an experimental and computational study of 3-silylarynes. The addition of nucleophiles yield ortho-substituted products as a result of aryne distortion, but meta-substituted products form predominately when the nucleophile is large. Computations correctly predict the preferred site of attack observed in both nucleophilic addition and cycloaddition experiments. Nucleophilic additions to 3-t-butylbenzyne, which is not significantly distorted, give meta-substituted products. PMID:22876797

  3. Early treatment revisions by addition or switch for type 2 diabetes: impact on glycemic control, diabetic complications, and healthcare costs

    PubMed Central

    Schwab, Phil; Saundankar, Vishal; Bouchard, Jonathan; Wintfeld, Neil; Suehs, Brandon; Moretz, Chad; Allen, Elsie; DeLuzio, Antonio

    2016-01-01

    Background The study examined the prevalence of early treatment revisions after glycosylated hemoglobin (HbA1c) ≥9.0% (75 mmol/mol) and estimated the impact of early treatment revisions on glycemic control, diabetic complications, and costs. Research design and methods A retrospective cohort study of administrative claims data of plan members with type 2 diabetes and HbA1c ≥9.0% (75 mmol/mol) was completed. Treatment revision was identified as treatment addition or switch. Glycemic control was measured as HbA1c during 6–12 months following the first qualifying HbA1c ≥9.0% (75 mmol/mol) laboratory result. Complications severity (via Diabetes Complication Severity Index (DCSI)) and costs were measured after 12, 24, and 36 months. Unadjusted comparisons and multivariable models were used to examine the relationship between early treatment revision (within 90 days of HbA1c) and outcomes after controlling for potentially confounding factors measured during a 12-month baseline period. Results 8463 participants were included with a mean baseline HbA1c of 10.2% (75 mmol/mol). Early treatment revision was associated with greater reduction in HbA1c at 6–12 months (−2.10% vs −1.87%; p<0.001). No significant relationship was observed between early treatment revision and DCSI at 12, 24, or 36 months (p=0.931, p=0.332, and p=0.418). Total costs, medical costs, and pharmacy costs at 12, 24, or 36 months were greater for the early treatment revision group compared with the delayed treatment revision group (all p<0.05). Conclusions The findings suggest that in patients with type 2 diabetes mellitus, treatment revision within 90 days of finding an HbA1c ≥9.0% is associated with a greater level of near-term glycemic control and higher cost. The impact on end points such as diabetic complications may not be realized over relatively short time frames. PMID:26925237

  4. A feasibility study regarding the addition of a fifth control to a rotorcraft in-flight simulator

    NASA Technical Reports Server (NTRS)

    Turner, Simon; Andrisani, Dominick, II

    1992-01-01

    The addition of a large movable horizontal tail surface to the control system of a rotorcraft in-flight simulator being developed from a Sikorsky UH-60A Black Hawk Helicopter is evaluated. The capabilities of the control surface as a trim control and as an active control are explored. The helicopter dynamics are modeled using the Generic Helicopter simulation program developed by Sikorsky Aircraft. The effect of the horizontal tail on the helicopter trim envelope is examined by plotting trim maps of the aircraft attitude and controls as a function of the flight speed and horizontal tail incidence. The control power of the tail surface relative to that of the other controls is examined by comparing control derivatives extracted from the simulation program over the flight speed envelope. The horizontal tail's contribution as an active control is evaluated using an explicit model following control synthesis involving a linear model of the helicopter in steady, level flight at a flight speed of eighty knots. The horizontal tail is found to provide additional control flexibility in the longitudinal axis. As a trim control, it provides effective control of the trim pitch attitude at mid to high forward speeds. As an active control, the horizontal tail provides useful pitching moment generating capabilities at mid to high forward speeds.

  5. Optical tools and techniques for aligning solar payloads with the SPARCS control system. [Solar Pointing Aerobee Rocket Control System

    NASA Technical Reports Server (NTRS)

    Thomas, N. L.; Chisel, D. M.

    1976-01-01

    The success of a rocket-borne experiment depends not only on the pointing of the attitude control system, but on the alignment of the attitude control system to the payload. To ensure proper alignment, special optical tools and alignment techniques are required. Those that were used in the SPARCS program are described and discussed herein. These tools include theodolites, autocollimators, a 38-cm diameter solar simulator, a high-performance 1-m heliostat to provide a stable solar source during the integration of the rocket payload, a portable 75-cm sun tracker for use at the launch site, and an innovation called the Solar Alignment Prism. Using the real sun as the primary reference under field conditions, the Solar Alignment Prism facilitates the coalignment of the attitude sun sensor with the payload. The alignment techniques were developed to ensure the precise alignment of the solar payloads to the SPARCS attitude sensors during payload integration and to verify the required alignment under field conditions just prior to launch.

  6. Review and evaluation of literature on testing of chemical additives for scale control in geothermal fluids. Final report

    SciTech Connect

    Crane, C.H.; Kenkeremath, D.C.

    1981-01-01

    A selected group of reported tests of chemical additives in actual geothermal fluids are reviewed and evaluated to summarize the status of chemical scale-control testing and identify information and testing needs. The task distinguishes between scale control in the cooling system of a flash plant and elsewhere in the utilization system due to the essentially different operating environments involved. Additives for non-cooling geothermal fluids are discussed by scale type: silica, carbonate, and sulfide.

  7. A study of attitude control concepts for precision-pointing non-rigid spacecraft

    NASA Technical Reports Server (NTRS)

    Likins, P. W.

    1975-01-01

    Attitude control concepts for use onboard structurally nonrigid spacecraft that must be pointed with great precision are examined. The task of determining the eigenproperties of a system of linear time-invariant equations (in terms of hybrid coordinates) representing the attitude motion of a flexible spacecraft is discussed. Literal characteristics are developed for the associated eigenvalues and eigenvectors of the system. A method is presented for determining the poles and zeros of the transfer function describing the attitude dynamics of a flexible spacecraft characterized by hybrid coordinate equations. Alterations are made to linear regulator and observer theory to accommodate modeling errors. The results show that a model error vector, which evolves from an error system, can be added to a reduced system model, estimated by an observer, and used by the control law to render the system less sensitive to uncertain magnitudes and phase relations of truncated modes and external disturbance effects. A hybrid coordinate formulation using the provided assumed mode shapes, rather than incorporating the usual finite element approach is provided.

  8. 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.

  9. Development and implementation of hazard analysis and critical control point plans by several U.S. feed manufacturers.

    PubMed

    Herrman, Timothy J; Langemeier, Michael R; Frederking, Matt

    2007-12-01

    The commitment to consumer food safety, global trade, and proposed new regulations by the U.S. Food and Drug Administration Center for Veterinary Medicine has led to increased adoption of hazard analysis and critical control point (HACCP) by the U.S. feed industry. A project supported by the U.S. Department of Agriculture Integrated Food Safety Initiate titled "Development and Implementation of a Voluntary HACCP Program for the US Feed Industry" enabled faculty from three land grant universities to assist individuals from 14 feed companies that collectively manufacture 15 million metric tons of feed in 100 facilities to develop HACCP plans. The process flow in these plans averaged 20 steps, and the most detailed plan included 60 process steps. Chemical hazards were more commonly identified in HACCP plans (average of four hazards per plan) than were biological hazards (average of one per plan). The most prevalent chemical hazards were cross-contamination of type A medicated articles and type B medicated feeds, aflatoxin, and wrong ingredient inclusion in feed. The most common biological hazard was mammalian protein contamination of feed ingredients and finished feed for cattle. An assessment of time and costs associated with developing HACCP plans revealed that approximately 29% of the companies needed additional personnel or additional equipment to implement a HACCP plan, and on average 268 additional person hours were needed to develop and implement a HACCP plan. Plan design, compliance monitoring, and record keeping were the three most time-consuming activities needed for developing and implementing a HACCP plan. The average cost of additional equipment needed to implement a HACCP plan was $250.

  10. [Powdered infant formulae preparation guide for hospitals based on Hazard Analysis and Critical Control Points (HACCP) principles].

    PubMed

    Vargas-Leguás, H; Rodríguez Garrido, V; Lorite Cuenca, R; Pérez-Portabella, C; Redecillas Ferreiro, S; Campins Martí, M

    2009-06-01

    This guide for the preparation of powdered infant formulae in hospital environments is a collaborative work between several hospital services and is based on national and European regulations, international experts meetings and the recommendations of scientific societies. This guide also uses the Hazard Analysis and Critical Control Point principles proposed by Codex Alimentarius and emphasises effective verifying measures, microbiological controls of the process and the corrective actions when monitoring indicates that a critical control point is not under control. It is a dynamic guide and specifies the evaluation procedures that allow it to be constantly adapted.

  11. Effects of changing gravity on anticipatory grip force control during point-to-point movements of a hand-held object.

    PubMed

    Nowak, D A; Hermsdörfer, J; Philipp, J; Marquardt, C; Glasauer, S; Mai, N

    2001-07-01

    We investigated the quality of predictive grip force control during gravity changes induced by parabolic flight maneuvers. During these maneuvers gravity varied: There were 2 periods of hypergravity, in which terrestrial gravity nearly doubled, and a 20-s period of microgravity, during which a manipulated object was virtually weightless. We determined grip and load forces during vertical point-to-point movements of an instrumented object. Point-to-point movements were a combination of static (stationary holding) and dynamic (continuous movements) task conditions, which were separately analyzed in our previous studies. Analysis of the produced grip forces revealed that grip adjustments were closely linked to load force fluctuations under each gravity condition. In particular, grip force maxima coincided closely in time with load force peaks, although these occurred at different phases of the movement depending on the gravity level. However, quantitative analysis of the ratio of maximum grip force to the corresponding load force peak revealed an increased force ratio during microgravity when compared to that during normal and hypergravity. We hypothesize that the impaired precision of force coupling with respect to force magnitude during microgravity results from reduced feedback information about the object's mass during the stationary holding of the object in between each movement. The results indicate that the temporal grip force regulation is highly automatized and stable, whereas economical planning of force magnitude is more flexible and might reflect changes of the external loading condition.

  12. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  13. 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.

  14. Is telephone counselling a useful addition to physician advice and nicotine replacement therapy in helping patients to stop smoking? A randomized controlled trial

    PubMed Central

    Reid, R D; Pipe, A; Dafoe, W A

    1999-01-01

    BACKGROUND: The authors evaluated the incremental efficacy of telephone counselling by a nurse in addition to physician advice and nicotine replacement therapy in helping patients to stop smoking. METHODS: The trial was conducted at the University of Ottawa Heart Institute. A total of 396 volunteers who smoked 15 or more cigarettes daily were randomly assigned to either of 2 groups: usual care (control group) and usual care plus telephone counselling (intervention group); the groups were stratified by sex and degree of nicotine dependence. Usual care involved the receipt of physician advice on 3 occasions, self-help materials and 12 weeks of nicotine replacement therapy. Telephone counselling was provided by a nurse at 2, 6 and 13 weeks after the target quit date. Point-prevalent quit rates were determined at 52 weeks after the target quit date. RESULTS: The point-prevalent quit rates at 52 weeks did not differ significantly between the control and intervention groups (24.1% v. 23.4% respectively). The quit rates did not differ significantly at the secondary measurement points of 4, 12 and 26 weeks. INTERPRETATION: Brief physician assistance, along with nicotine replacement therapy, can help well-motivated smokers to quit. Three additional sessions of telephone counselling by a nurse were ineffective in increasing quit rates. This form of assistance may be useful in the absence of physician advice or when self-selected by patients. PMID:10373999

  15. Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Pilot-Scale Test Results

    SciTech Connect

    Gary M. Blythe

    2006-03-01

    This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, ''Field Testing of a Wet FGD Additive.'' The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemissions of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate that the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project will conduct pilot and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosage requirements to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB co-fired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot and full-scale jet bubbling reactor (JBR) FGD systems to be tested. A third utility, to be named later, will provide the high-sulfur Eastern bituminous coal full-scale FGD test site. Degussa Corporation is providing the TMT-15 additive and technical support to the test program. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot Additive Testing in

  16. Optimization strategy integrity for watershed agricultural non-point source pollution control based on Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Gong, Y.; Yu, Y. J.; Zhang, W. Y.

    2016-08-01

    This study has established a set of methodological systems by simulating loads and analyzing optimization strategy integrity for the optimization of watershed non-point source pollution control. First, the source of watershed agricultural non-point source pollution is divided into four aspects, including agricultural land, natural land, livestock breeding, and rural residential land. Secondly, different pollution control measures at the source, midway and ending stages are chosen. Thirdly, the optimization effect of pollution load control in three stages are simulated, based on the Monte Carlo simulation. The method described above is applied to the Ashi River watershed in Heilongjiang Province of China. Case study results indicate that the combined three types of control measures can be implemented only if the government promotes the optimized plan and gradually improves implementation efficiency. This method for the optimization strategy integrity for watershed non-point source pollution control has significant reference value.

  17. Ligand- and base-free Pd(II)-catalyzed controlled switching between oxidative Heck and conjugate addition reactions.

    PubMed

    Walker, Sarah E; Boehnke, Julian; Glen, Pauline E; Levey, Steven; Patrick, Lisa; Jordan-Hore, James A; Lee, Ai-Lan

    2013-04-19

    A simple change of solvent allows controlled and efficient switching between oxidative Heck and conjugate addition reactions on cyclic Michael acceptor substrates, catalyzed by a cationic Pd(II) catalyst system. Both reactions are ligand- and base-free and tolerant of air and moisture, and the controlled switching sheds light on some of the factors which favor one reaction over the other.

  18. 78 FR 74218 - Imposition of Additional Sanctions on Syria Under the Chemical and Biological Weapons Control and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... Imposition of Additional Sanctions on Syria Under the Chemical and Biological Weapons Control and Warfare... chemical weapons in violation of international law or lethal chemical weapons against its own nationals... the Chemical and Biological Weapons Control and Warfare Elimination Act of 1991, 22 U.S.C. 5604(a)...

  19. [Mechanism of contour hedgerow's control for non-point pollution in the semiarid region in northwest Hebei Province].

    PubMed

    Tang, Z; Cai, Q; Xu, F; Li, S; Wang, Z

    2001-11-01

    Slope nutrient loss is an important type of non-point pollution. The mechanism of non-point pollution control by using plenty of natural observed data in Hilly Loess region in Northwest Hebei Province, as well as combating with the large-scale artificial simulation rainfall in the field slope was analyzed. The study results show that the critical slope length was 10-15 m on the condition of rainstorm, which led to the generation of rill and made the erosion amount went up obviously. The study show that the nutrient loss in sediment was the main type of non-point pollution, the contour hedgerow the process of non-point pollution by controlling the nutrient loss in sediment, then the study got the erosion control model of the contour hedgerow.

  20. Control of Escherichia coli O157:H7 in contaminated alfalfa silage: Effects of silage additives.

    PubMed

    Ogunade, I M; Kim, D H; Jiang, Y; Weinberg, Z G; Jeong, K C; Adesogan, A T

    2016-06-01

    This study was conducted to examine if adding microbial inoculants or propionic acid to alfalfa silages contaminated with Escherichia coli O157:H7 would inhibit the growth of the pathogen during or after ensiling. Alfalfa forage was harvested at the early bloom stage, wilted to a dry matter concentration of 54%, chopped to 19-mm lengths, and ensiled after treatment with one of the following: (1) distilled water (control); (2) 1×10(5) cfu/g of E. coli O157:H7 (EC); (3) EC and 1×10(6) cfu/g of Lactobacillus plantarum (EC+LP); (4) EC and 1×10(6) cfu/g of Lactobacillus buchneri (EC+LB); and (5) EC and 2.2g/kg of propionic acid (EC+PA). Each treatment was ensiled in quadruplicate in laboratory silos for 0, 3, 7, 16, and 100d and analyzed for EC counts, pH, and organic acids. In addition, samples from d 100 were analyzed for chemical composition, ammonia-N, counts of yeasts and molds, and aerobic stability. Escherichia coli O157:H7 was detected in all silages until d 7, but by d 16 it was not detected in those treated with EC+LB and EC+LP, though it was still detected in EC and EC+PA silages. However, by d 100, the pathogen was not detected in any silage. The rate of pH decrease to 5.0 was fastest for the EC+LP silage (7d), followed by the EC+LB silage (16d). Nevertheless, all silages had attained a pH of or less than 5.0 by d 100. The rapid decrease in pH in EC+LP and EC+LB silages was observed due to higher lactate and acetate concentrations, respectively, relative to the other silages during the early fermentation phase (d 3-16). Propionic acid was only detected in the EC+PA silage. Yeast counts were lowest in EC+LB and EC+PA silages. Subsamples of all d-100 silages were reinoculated with 1×10(5) cfu/g of EC immediately after silo opening. When the pathogen was subsequently enumerated after 168h of aerobic exposure, it was not detected in silages treated with EC+PA, EC+LB, or EC+LP, which all had pH values less than 5.0. Whereas the EC silage had a pH value of 5

  1. Control of Escherichia coli O157:H7 in contaminated alfalfa silage: Effects of silage additives.

    PubMed

    Ogunade, I M; Kim, D H; Jiang, Y; Weinberg, Z G; Jeong, K C; Adesogan, A T

    2016-06-01

    This study was conducted to examine if adding microbial inoculants or propionic acid to alfalfa silages contaminated with Escherichia coli O157:H7 would inhibit the growth of the pathogen during or after ensiling. Alfalfa forage was harvested at the early bloom stage, wilted to a dry matter concentration of 54%, chopped to 19-mm lengths, and ensiled after treatment with one of the following: (1) distilled water (control); (2) 1×10(5) cfu/g of E. coli O157:H7 (EC); (3) EC and 1×10(6) cfu/g of Lactobacillus plantarum (EC+LP); (4) EC and 1×10(6) cfu/g of Lactobacillus buchneri (EC+LB); and (5) EC and 2.2g/kg of propionic acid (EC+PA). Each treatment was ensiled in quadruplicate in laboratory silos for 0, 3, 7, 16, and 100d and analyzed for EC counts, pH, and organic acids. In addition, samples from d 100 were analyzed for chemical composition, ammonia-N, counts of yeasts and molds, and aerobic stability. Escherichia coli O157:H7 was detected in all silages until d 7, but by d 16 it was not detected in those treated with EC+LB and EC+LP, though it was still detected in EC and EC+PA silages. However, by d 100, the pathogen was not detected in any silage. The rate of pH decrease to 5.0 was fastest for the EC+LP silage (7d), followed by the EC+LB silage (16d). Nevertheless, all silages had attained a pH of or less than 5.0 by d 100. The rapid decrease in pH in EC+LP and EC+LB silages was observed due to higher lactate and acetate concentrations, respectively, relative to the other silages during the early fermentation phase (d 3-16). Propionic acid was only detected in the EC+PA silage. Yeast counts were lowest in EC+LB and EC+PA silages. Subsamples of all d-100 silages were reinoculated with 1×10(5) cfu/g of EC immediately after silo opening. When the pathogen was subsequently enumerated after 168h of aerobic exposure, it was not detected in silages treated with EC+PA, EC+LB, or EC+LP, which all had pH values less than 5.0. Whereas the EC silage had a pH value of 5

  2. Field Testing of a Wet FGD Additive for Enhanced Mercury Control

    SciTech Connect

    Gary Blythe; MariJon Owens

    2007-12-31

    This document is the final report for DOE-NETL Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project has been to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project was intended to demonstrate whether such additives can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project involved pilot- and full-scale tests of the additives in wet FGD absorbers. The tests were intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power provided the Texas lignite/PRB co-fired test site for pilot FGD tests and project cost sharing. Southern Company provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested, and project cost sharing. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation provided the TMT-15 additive, and the Nalco Company provided the Nalco 8034 additive. Both companies also supplied technical support to the test program as in-kind cost sharing. The project was conducted in six tasks. Of the six tasks, Task 1 involved project planning and Task 6 involved

  3. Efficacy and nontarget effects of Larvadex as a feed additive for controlling house flies in caged-layer poultry manure.

    PubMed

    Axtell, R C; Edwards, T D

    1983-12-01

    The insect growth regulator N-cyclopropyl-1,3,5-triazine-2,4,6 triamine (Larvadex, CGA 72662, cyromazine) was provided as a feed additive (.3% Premix per ton of feed) to caged laying hens under field conditions in high rise, wide span and narrow poultry houses. The chemical effectively controlled house flies (Musca domestica) and soldier flies (Hermetia illucens). The feed additive had no adverse effect on the populations of manure-inhabiting mites (Macrochelidae and Uropodidae) and histerid beetles (Carcínops pumulio), which prey on fly eggs and larvae. Satisfactory fly control was demonstrated by use of the additive 50% of the time when the interval without the additive in the feed was 4 days but not when the interval was 7 days. Use of a fly monitoring program to time the use of the feed additive is advocated.

  4. Effectiveness of iron-based fuel additives for diesel soot control

    SciTech Connect

    Zeller, H.W.; Westphal, T.E.

    1992-01-01

    The U.S. Bureau of Mines evaluated the effects of two iron-based fuel additives on diesel particulate matter (DPM) emissions. The 5.6-L, six-cylinder test engine is typical of engines used in underground mines. One additive, ferrous picrate, did not measurably affect exhaust emissions. This report is mainly about a ferrocene-based additive that reduced DPM between 4 and 45 pct, depending on engine operating conditions. The report concludes that the DPM reductions were caused by the catalytic oxidation properties of a ferric oxide coating that developed inside the engine's combustion chamber. The ferric oxide coating also decreased gas-phase hydrocarbons and O[sub 2], but it increased CO[sub 2] and NO[sub x]. The increase in NO[sub x], of about 12 pct, is considered the only adverse effect of the ferrocene-based fuel additive. The results suggest that the effectiveness of ferrocene was partially offset by increased sulfates because of the high-sulfur fuel used. Recommendations for continuing fuel additive research are presented.

  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.

  6. 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

  7. 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

  8. 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

  9. Occurrence of Listeria spp. in critical control points and the environment of Minas Frescal cheese processing.

    PubMed

    Silva, Isabella M M; Almeida, R C C; Alves, M A O; Almeida, P F

    2003-03-25

    Critical control points (CCPs) associated with Minas Frescal cheese (a Brazilian soft white cheese, eaten fresh) processing in two dairy factories were determined using flow diagrams and microbiological tests for detection of Listeria monocytogenes and other species of Listeria. A total of 218 samples were collected along the production line and environment. The CCPs identified were reception of raw milk, pasteurization, coagulation and storage. Thirteen samples were positive for Listeria; 9 samples were Listeria innocua, 2 were Listeria grayi and 2 were L. monocytogenes. In factory A, Listeria was found in 50% of raw milk samples, 33.3% of curd samples, 16.7% of pasteurized milk samples, 16.7% of cheese samples and 25% of rubber pipes used to transport the whey. The microorganism was not obtained from environmental samples in this plant. In factory B, Listeria was found in one sample of raw milk (16.7%) and in three samples of environment (17.6%) and L. monocytogenes was obtained from raw milk (16.7%) and the floor of the cheese refrigeration room (14.3%). Two serotypes, 4b and 1/2a, were observed among the strains of L. monocytogenes isolated, both which are frequently involved in outbreaks of food-borne listeriosis and sporadic cases of the disease all over the world.

  10. Heliocentric trajectory analysis of Sun-pointing smart dust with electrochromic control

    NASA Astrophysics Data System (ADS)

    Mengali, Giovanni; Quarta, Alessandro A.

    2016-02-01

    A smart dust is a micro spacecraft, with a characteristic side length on the order of a few millimeters, whose surface is coated with electrochromic material. Its orbital dynamics is controlled by exploiting the differential force due to the solar radiation pressure, which is obtained by modulating the reflectivity coefficient of the electrochromic material within a range of admissible values. A significant thrust level can be reached due to the high values of area-to-mass ratio of such a spacecraft configuration. Assuming that the smart dust is designed to achieve a passive Sun-pointing attitude, the propulsive acceleration due to the solar radiation pressure lies along the Sun-spacecraft direction. The aim of this paper is to study the smart dust heliocentric dynamics in order to find a closed form, analytical solution of its trajectory when the reflectivity coefficient of the electrochromic material can assume two values only. The problem is addressed by introducing a suitable transformation that regularizes the spacecraft motion and translates the smart-dust dynamics into that of a linear harmonic oscillator with unitary frequency, whose forcing input is a boxcar function. The solution is found using the Laplace transform method, and afterwards the problem is generalized by accounting for the degradation of the electrochromic material due to its exposition to the solar radiation. Three spacecraft configurations, corresponding to low, medium and high performance smart dusts, are finally used to quantify the potentialities of these advanced devices in an interplanetary mission scenario.

  11. A Non-Linear Approach to Spacecraft Formation Control in the Vicinity of a Collinear Libration Point

    NASA Technical Reports Server (NTRS)

    Luquette, Richard J.; Sanner, Robert M.; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    An expanding interest in mission design strategies that exploit libration point regions, demands the continued development of enhanced, efficient, control algorithms for station-keeping and formation maintenance. Linear control strategies have been developed for station-keeping. However, their region of stability is bounded by the assumptions required for linearizing the governing equations of motion. For example, reference [I] discusses the development of a linear control design for maintaining a halo orbit about the Earth-Moon L2 libration point. Trial runs indicated the trajectory was unstable for starting points exceeding 45,000 km from the L2 point. Also, there was significant growth in the control effort required to maintain the orbit as the nominal radius increased. This result is a consequence of the increased influence of the system non-linearities, as the trajectory deviated from the linearization point, L2. As an alternative, this paper presents the development of a non-linear control strategy, based on a Hamiltonian formulation of the equations of motion. The control strategy is applied to the problem of formation maintenance, rather than simple station

  12. High-dose inhaled corticosteroids or addition of theophylline in patients with poorly controlled asthma?

    PubMed

    Celis, Pilar; Rada, Gabriel

    2015-08-19

    There are several management strategies for patients with poorly controlled asthma despite usual treatment. Increasing doses of inhaled corticosteroids or adding theophylline are among the therapeutic alternatives. However, the latter is associated with important adverse effects. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified only one systematic review including four pertinent randomized controlled trials. We combined the evidence using meta-analysis and generated a summary of findings following the GRADE approach. We concluded it is not clear whether theophylline or high-dose inhaled corticosteroids constitute a better alternative for symptomatic control or reduction in exacerbations in poorly controlled asthmatic patients because the certainty of the evidence is very low.

  13. Control of Asymmetry in the Radical Addition Approach to Chiral Amine Synthesis

    PubMed Central

    Friestad, Gregory K.

    2014-01-01

    The state-of-the-science in asymmetric free radical additions to imino compounds is presented, beginning with an overview of methods involving stereocontrol by various chiral auxiliary approaches. Chiral N-acylhydrazones are discussed with respect to their use as radical acceptors for Mn-mediated intermolecular additions, from design to scope surveys to applications to biologically active targets. A variety of aldehydes and ketones serve as viable precursors for the chiral hydrazones, and a variety of alkyl iodides may be employed as radical precursors, as discussed in a critical review of the functional group compatibility of the reaction. Applications to amino acid and alkaloid synthesis are presented to illustrate the synthetic potential of these versatile stereocontrolled carbon–carbon bond construction reactions. Asymmetric catalysis is discussed, from seminal work on the stereocontrol of radical addition to imino compounds by non-covalent interactions with stoichiometric amounts of catalysts, to more recent examples demonstrating catalyst turnover. PMID:24085561

  14. LONG-TERM DEMONSTRATION OF SORBENT ENHANCEMENT ADDITIVE TECHNOLOGY FOR MERCURY CONTROL

    SciTech Connect

    Jason D. Laumb; Dennis L. Laudal; Grant E. Dunham; John P. Kay; Christopher L. Martin; Jeffrey S. Thompson; Nicholas B. Lentz; Alexander Azenkeng; Kevin C. Galbreath; Lucinda L. Hamre

    2011-05-27

    Long-term demonstration tests of advanced sorbent enhancement additive (SEA) technologies have been completed at five coal-fired power plants. The targeted removal rate was 90% from baseline conditions at all five stations. The plants included Hawthorn Unit 5, Mill Creek Unit 4, San Miguel Unit 1, Centralia Unit 2, and Hoot Lake Unit 2. The materials tested included powdered activated carbon, treated carbon, scrubber additives, and SEAs. In only one case (San Miguel) was >90% removal not attainable. The reemission of mercury from the scrubber at this facility prevented >90% capture.

  15. A Non-Linear Approach to Spacecraft Formation Control in the Vicinity of a Collinear Libration Point

    NASA Technical Reports Server (NTRS)

    Luquette, Richard J.; Sanner, Robert M.; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    An expanding interest in mission design strategies that exploit libration point regions demands the continued development of enhanced, efficient, control algorithms for station-keeping and formation maintenance. This paper discusses the development of a non-linear, formation maintenance, control algorithm for trajectories in the vicinity of a libration point. However, the formulation holds for any trajectory governed by the equations of motion for the restricted three body problem. The control law guarantees exponential convergence, based on a Lyaponov analysis. FreeFlyer and MATLAB provide the simulation environment for controller performance evaluation. The simulation, modeled after the MAXIM Pathfinder mission, maintains the relative position of a "follower" spacecraft with respect to a "leader" spacecraft, stationed near the L2 libration point in the Sun-Earth system. Evaluation metrics are fuel usage and tracking accuracy.

  16. Developmentally controlled telomere addition in wild-type and mutant paramecia.

    PubMed Central

    Forney, J D; Blackburn, E H

    1988-01-01

    We analyzed sites of macronuclear telomere addition at a single genetic locus in Paramecium tetraurelia. We showed that in homozygous wild-type cells, differential genomic processing during macronuclear development resulted in the A surface antigen gene being located 8, 13, or 26 kilobases upstream from a macronuclear telomere. We describe variable rearrangements that occurred at the telomere 8 kilobases from the A gene. A mutant (d48) that forms a telomere near the 5' end of the A gene was also analyzed. This mutant was shown to create simple terminal deletions; telomeric repeats were added directly to the truncated wild-type A gene sequence. In both the mutant and wild-type cells, the telomeric sequences (a mixture of C4A2 and C3A3 repeats) were added to various sequences within a specific 200- to 500-base-pair region rather than to a single site. No similarities were found in the primary sequences surrounding the telomere addition sites. The mutation in d48 changed the region of telomere addition at the A gene locus; this is the first example in ciliates of a mutation that affects the site of telomere addition. Images PMID:3336360

  17. Innovative point focus solar concentrator: Volume 5, Electronic controls and electrical interface; Phase 1 topical report

    SciTech Connect

    1986-03-07

    This report discusses the following electronic equipment for the solar collector: LEC-1700 electrical control system; LEC-1700 controller; hand-held remote control unit; communications interface controller; RS-232C to CIC interface card; audio interface card; communications interface controller backplane; wiring harness; and ac power controller.

  18. A vision-based end-point control for a two-link flexible manipulator. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Obergfell, Klaus

    1991-01-01

    The measurement and control of the end-effector position of a large two-link flexible manipulator are investigated. The system implementation is described and an initial algorithm for static end-point positioning is discussed. Most existing robots are controlled through independent joint controllers, while the end-effector position is estimated from the joint positions using a kinematic relation. End-point position feedback can be used to compensate for uncertainty and structural deflections. Such feedback is especially important for flexible robots. Computer vision is utilized to obtain end-point position measurements. A look-and-move control structure alleviates the disadvantages of the slow and variable computer vision sampling frequency. This control structure consists of an inner joint-based loop and an outer vision-based loop. A static positioning algorithm was implemented and experimentally verified. This algorithm utilizes the manipulator Jacobian to transform a tip position error to a joint error. The joint error is then used to give a new reference input to the joint controller. The convergence of the algorithm is demonstrated experimentally under payload variation. A Landmark Tracking System (Dickerson, et al 1990) is used for vision-based end-point measurements. This system was modified and tested. A real-time control system was implemented on a PC and interfaced with the vision system and the robot.

  19. Space infrared telescope pointing control system. Infrared telescope tracking in the presence of target motion

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Schneider, J. B.

    1986-01-01

    The use of charge-coupled-devices, or CCD's, has been documented by a number of sources as an effective means of providing a measurement of spacecraft attitude with respect to the stars. A method exists of defocussing and interpolation of the resulting shape of a star image over a small subsection of a large CCD array. This yields an increase in the accuracy of the device by better than an order of magnitude over the case when the star image is focussed upon a single CCD pixel. This research examines the effect that image motion has upon the overall precision of this star sensor when applied to an orbiting infrared observatory. While CCD's collect energy within the visible spectrum of light, the targets of scientific interest may well have no appreciable visible emissions. Image motion has the effect of smearing the image of the star in the direction of motion during a particular sampling interval. The presence of image motion is incorporated into a Kalman filter for the system, and it is shown that the addition of a gyro command term is adequate to compensate for the effect of image motion in the measurement. The updated gyro model is included in this analysis, but has natural frequencies faster than the projected star tracker sample rate for dim stars. The system state equations are reduced by modelling gyro drift as a white noise process. There exists a tradeoff in selected star tracker sample time between the CCD, which has improved noise characteristics as sample time increases, and the gyro, which will potentially drift further between long attitude updates. A sample time which minimizes pointing estimation error exists for the random drift gyro model as well as for a random walk gyro model.

  20. Controlled laboratory challenge demonstrates substantial additive genetic variation in resistance to Streptococcus iniae in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is an etiologic agent of streptococcal disease in tilapia and is one of several Streptococcus spp. that negatively impact worldwide tilapia production. Methods for the prevention and control of S. iniae include vaccines, management strategies, and antibiotics. An alternative and ...

  1. PCB bioavailability control in Lumbriculus variegatus through different modes of activated carbon addition to sediments

    SciTech Connect

    Xueli Sun; Upal Ghosh

    2007-07-01

    PCB bioavailability to a freshwater oligochaete (Lumbriculus variegatus) was studied using sediments from a PCB-impacted river that was treated with different modes of granular activated carbon (GAC) addition. The GAC used was bituminous coal-based type TOP. For sediment treated with 2.6% GAC and mixed for 2 min prior to L. variegatus addition, the reduction in total PCB biouptake was 70% for 75-300 {mu}m size carbon, and 92% for the 45-180 {mu}m size carbon. For the case where the GAC was placed as a thin layer on top of the sediments without mixing, the reduction in total PCB uptake was 70%. PCB biouptake kinetics study using treated and untreated sediment showed that the maximum PCB uptake in tissue was achieved at 28 days and decreased after that time. Although the absolute uptake of PCB changed over time, the percent reduction in total PCB uptake upon GAC amendment remained constant after the first few days. Our results indicated that PCB bioavailability was reduced upon the addition and little or no mixing of GAC into sediments. PCB aqueous equilibrium concentration and desorption rates were greatly reduced after GAC amendment, indicating reductions in the two primary mechanisms of PCB bioavailability in sediments: chemical activity and chemical accessibility. 29 refs., 5 figs., 1 tab.

  2. Additive manufacturing of scaffolds with dexamethasone controlled release for enhanced bone regeneration.

    PubMed

    Costa, Pedro F; Puga, Ana M; Díaz-Gomez, Luis; Concheiro, Angel; Busch, Dirk H; Alvarez-Lorenzo, Carmen

    2015-12-30

    The adoption of additive manufacturing in tissue engineering and regenerative medicine (TERM) strategies greatly relies on the development of novel 3D printable materials with advanced properties. In this work we have developed a material for bone TERM applications with tunable bioerosion rate and dexamethasone release profile which can be further employed in fused deposition modelling (the most common and accessible 3D printing technology in the market). The developed material consisted of a blend of poly-ϵ-caprolactone (PCL) and poloxamine (Tetronic®) and was processed into a ready-to-use filament form by means of a simplified melt-based methodology, therefore eliminating the utilization of solvents. 3D scaffolds composed of various blend formulations were additively manufactured and analyzed revealing blend ratio-specific degradation rates and dexamethasone release profiles. Furthermore, in vitro culture studies revealed a similar blend ratio-specific trend concerning the osteoinductive activity of the fabricated scaffolds when these were seeded and cultured with human mesenchymal stem cells. The developed material enables to specifically address different regenerative requirements found in various tissue defects. The versatility of such strategy is further increased by the ability of additive manufacturing to accurately fabricate implants matching any given defect geometry.

  3. Complement receptor immunoglobulin: a control point in infection and immunity, inflammation and cancer.

    PubMed

    Small, Annabelle Grace; Al-Baghdadi, Marwah; Quach, Alex; Hii, Charles; Ferrante, Antonio

    2016-01-01

    The B7 family-related protein, V-set and Ig domain (VSIG4) / Z39Ig / complement receptor immunoglobulin (CRIg), is a new player in the regulation of immunity to infection and inflammation. The unique features of this receptor as compared with classical complement receptors, CR3 and CR4, have heralded the emergence of new concepts in the regulation of innate and adaptive immunity. Its selective expression in tissue macrophages and dendritic cells has been considered of importance in host defence and in maintaining tolerance against self-antigens. Although a major receptor for phagocytosis of complement opsonised bacteria, its array of emerging functions which incorporates the immune suppressive and anti-inflammatory action of the receptor have now been realised. Accumulating evidence from mouse experimental models indicates a potential role for CRIg in protection against bacterial infection and inflammatory diseases, such as rheumatoid arthritis, type 1 diabetes and systemic lupus erythematosus, and also in promotion of tumour growth. CRIg expression can be considered as a control point in these diseases, through which inflammatory mediators, including cytokines, act. The ability of CRIg to suppress cytotoxic T cell proliferation and function may underlie its promotion of cancer growth. Thus, the unique properties of this receptor open up new avenues for understanding of the pathways that regulate inflammation during infection, autoimmunity and cancer with the potential for new drug targets to be identified. While some complement receptors may be differently expressed in mice and humans, as well as displaying different properties, mouse CRIg has a structure and function similar to the human receptor, suggesting that extrapolation to human diseases is appropriate. Furthermore, there is emerging evidence in human conditions that CRIg may be a valuable biomarker in infection and immunity, inflammatory conditions and cancer prognosis. PMID:27045607

  4. Tribotronic control of friction in oil-based lubricants with ionic liquid additives.

    PubMed

    Cooper, P K; Li, H; Rutland, M W; Webber, G B; Atkin, R

    2016-08-24

    Atomic force microscopy (AFM) reveals that tribotronic control of friction using an external potential applied to a gold surface is possible for ionic liquid (IL) concentrations as low as 5 mol% in hexadecane. The IL used is trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate, in which both the cation and anion have surfactant-like structures, and is miscible with hexadecane in all proportions. For IL concentrations less than 5 mol% friction does not vary with applied potential, but for 5 mol% and above changing the potential changes the composition of the IL boundary layer from cation-enriched (negative potentials) to anion-enriched (positive potentials). As the lubricities of the cation-rich and anion-rich boundary layers differ, this enables active control of friction in oil-based lubricants. PMID:27511143

  5. Mosquitocidal vaccines: a neglected addition to malaria and dengue control strategies.

    PubMed

    Billingsley, Peter F; Foy, Brian; Rasgon, Jason L

    2008-09-01

    The transmission of vector-borne diseases is dependent upon the ability of the vector to survive for longer than the period of development of the pathogen within the vector. One means of reducing mosquito lifespan, and thereby reducing their capacity to transmit diseases, is to target mosquitoes with vaccines. Here, the principle behind mosquitocidal vaccines is described, their potential impact in malaria and dengue control is modeled and the current research that could make these vaccines a reality is reviewed. Mosquito genome data, combined with modern molecular techniques, can be exploited to overcome the limited advances in this field. Given the large potential benefit to vector-borne disease control, research into the development of mosquitocidal vaccines deserves a high profile. PMID:18678529

  6. Application of Hazard Analysis Critical Control Point (HACCP) to the handling of expressed breast milk on a neonatal unit.

    PubMed

    Hunter, P R

    1991-02-01

    Hazard Analysis Critical Control Point (HACCP) is a powerful procedure for ensuring quality and safety and has gained widespread use in industry. This paper describes the basic method which is a four-stage process including process analysis, hazard identification, identification of critical control points and devising effective control options. Suggestions as to how the method can be adapted to the control of hospital infection are made. A HACCP analysis, on the supply of expressed human breast milk to babies on a Special Care Baby Unit, is presented. Although only the mother's own milk was given to babies on the unit, several potential hazards were identified and suggestions have been made for their control.

  7. Evidence for additive polygenic control of pupation height in Drosophila ananassae.

    PubMed

    Singh, B N; Pandey, M B

    1993-01-01

    In order to study the mode of inheritance of pupation height in Drosophila ananassae, two mass culture stocks derived from ecogeographically different localities in India, were used to make a complete set of 16 crosses, which include parentals, F1, backcrosses, and F2. Pupation height defined as the distance a larva pupates over the surface of culture medium was scored in all 16 crosses. The two parental lines showed significant difference in pupation height. The F1 larvae in both reciprocal crosses had intermediate pupation height and there was no difference between two reciprocal crosses as well as between F1 and mid parent value. However, there was greater variance in the F2 generation. These findings provide evidence that the inheritance of pupation height fits a classical additive polygenic model and suggested that there is substantial amount of additive genetic variation in natural populations of D. ananassae. Furthermore, the analysis of reciprocal backcrosses shows significant maternal effect. Progeny with low pupating mothers showed lower pupation height than those with low pupating fathers and progeny with high pupating mothers had higher pupation height than those with high pupating fathers. Since the maternal effect was found only in backcrosses but not in the F1, it is suggested that this maternal effect on pupation height follows the pattern of inheritance of a transient maternal effect.

  8. Integrated quality control: implementation and validation of instrument function checks and procedural controls for a cartridge-based point-of-care system for critical care analysis.

    PubMed

    D'Orazio, Paul; Mansouri, Sohrab

    2013-03-01

    In this article, the process used to develop and validate an integrated quality-control system for a cartridge-based, point-of-care system for critical care analysis is outlined. Application of risk management principles has resulted in a quality control system using a combination of statistical quality control with onboard reference solutions and failure pattern recognition used to flag common failure modes during the analytical phase of the testing process. A combination of traditional external quality control, integrated quality control to monitor ongoing instrument functionality, operator training, and other laboratory-implemented monitors is most effective in controlling known failure modes during the testing process.

  9. From lab to industrial: PZT nanoparticles synthesis and process control for application in additive manufacturing

    NASA Astrophysics Data System (ADS)

    Huang, Hsien-Lin

    Lead Zirconate Titanate (PZT) nanoparticles hold many promising current and future applications, such as PZT ink for 3-D printing or seeds for PZT thick films. One common method is hydrothermal growth, in which temperature, duration time, or mineralizer concentrations are optimized to produce PZT nanoparticles with desired morphology, controlled size and size distribution. A modified hydrothermal process is used to fabricate PZT nanoparticles. The novelty is to employ a high ramping rate (e.g., 20 deg C/min) to generate abrupt supersaturation so as to promote burst nucleation of PZT nanoparticles as well as a fast cooling rate (e.g., 5 deg C/min) with a controlled termination of crystal growth. As a result, PZT nanoparticles with a size distribution ranging from 200 nm to 800 nm are obtained with cubic morphology and good crystallinity. The identification of nanoparticles is confirmed through use of X-ray diffractometer (XRD). XRD patterns are used to compare sample variations in their microstructures such as lattice parameter. A cubic morphology and particle size are also examined via SEM images. The hydrothermal process is further modified with excess lead (from 20% wt. to 80% wt.) to significantly reduce amorphous phase and agglomeration of the PZT nanoparticles. With a modified process, the particle size still remains within the 200 nm to 800 nm. Also, the crystal structures (microstructure) of the samples show little variations. Finally, a semi-continuous hydrothermal manufacturing process was developed to substantially reduce the fabrication time and maintained the same high quality as the nanoparticles prepared in an earlier stage. In this semi-continuous process, a furnace is maintained at the process temperature (200 deg C), whereas autoclaves containing PZT sol are placed in and out of the furnace to control the ramp-up and cooling rates. This setup eliminates an extremely time-consuming step of cooling down the furnace, thus saving tremendous amount of

  10. Formalin treatments pass new tests. Additional notes on the control of ecto-parasitic protozoa

    USGS Publications Warehouse

    1940-01-01

    After the completion of the eхреriments reported recently, in which the efficacy of formalin in controlling infections of Gostia mecatrix was demonstrated, the author was afforded an opportunity to test the value of formalin solutions in combatting established mixed infections of (Gyrodactylus, Tricbodina, Cyclochaeta) and a stalked protozoan on rainbow trout fingerlings. This opportunity was provided through the courtesy and cooperation of Clarence F. Pautzke, Chief Biologist for the Washington State Game Department, and Lee Walters, Superintendent of the Washington State Hatchery at Seward Park, Seattle.

  11. Sodium Bicarbonate Prevents Contrast-Induced Nephropathy in Addition to Theophylline: A Randomized Controlled Trial.

    PubMed

    Huber, Wolfgang; Huber, Toni; Baum, Stephan; Franzen, Michael; Schmidt, Christian; Stadlbauer, Thomas; Beitz, Analena; Schmid, Roland M; Schmid, Sebastian

    2016-05-01

    In this study, we investigated whether hydration with sodium bicarbonate is superior to hydration with saline in addition to theophylline (both groups) in the prophylaxis of contrast-induced nephropathy (CIN). It was a prospective, randomized, double-blinded study in a university hospital on 2 general intensive care units (63% of investigations) and normal wards.After approval of the local ethics committee and informed consent 152 patients with screening serum creatinine ≥1.1 mg/dL and/or at least 1 additional risk factor for CIN undergoing intravascular contrast media (CM) exposure were randomized to receive a total of 9 mL/kg bicarbonate 154 mmol/L (group B; n = 74) or saline 0.9% (group S; n = 78) hydration within 7 h in addition to intravenous application of 200 mg theophylline. Serum creatinine was determined immediately before, 24 and 48 h after CM exposure. As primary endpoint we investigated the incidence of CIN (increase of serum creatinine ≥0.5 mg/dL and/or ≥25% within 48 h of CM).Both groups were comparable regarding baseline characteristics. Incidence of CIN was significantly less frequent with bicarbonate compared to sodium hydration (1/74 [1.4%] vs 7/78 [9.0%]; P = 0.035). Time course of serum creatinine was more favorable in group B with decreases in serum creatinine after 24 h (-0.084 mg/dL [95% confidence interval: -0.035 to -0.133 mg/dL]; P = 0.008) and 48 h (-0.093 mg/dL (-0.025 to -0.161 mg/dL); P = 0.007) compared to baseline which were not observed in group S.In patients at increased risk of CIN receiving prophylactic theophylline, hydration with sodium bicarbonate reduces contrast-induced renal impairment compared to hydration with saline. PMID:27227933

  12. Dipeptidyl peptidase-4 inhibitors and the ischemic heart: Additional benefits beyond glycemic control.

    PubMed

    Chattipakorn, Nipon; Apaijai, Nattayaporn; Chattipakorn, Siriporn C

    2016-01-01

    Obese-insulin resistance and type 2 diabetes mellitus (T2DM) have become global health problems, and they are both associated with a higher risk of ischemic heart disease. Although reperfusion therapy is the treatment to increase blood supply to the ischemic myocardium, this intervention potentially causes cardiac tissue damage and instigates arrhythmias, processes known as reperfusion injury. Dipeptidyl peptidase 4 (DPP-4) inhibitors are glycemic control drugs commonly used in T2DM patients. Growing evidence from basic and clinical studies demonstrates that a DPP-4 inhibitor could exert cardioprotection and improve left ventricular function by reducing oxidative stress, apoptosis, and increasing reperfusion injury salvage kinase (RISK) activity. However, recent reports also showed potentially adverse cardiac events due to the use of a DPP-4 inhibitor. To investigate this disparity, future large clinical trials are essential in verifying whether DPP-4 inhibitors are beneficial beyond their glycemic control particularly for the ischemic heart in obese-insulin resistant subjects and T2DM patients.

  13. 77 FR 29307 - Control of Alcohol and Drug Use: Addition of Post-Accident Toxicological Testing for Non...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-17

    ... substances under the Controlled Substances Act (CSA), Title II of the Comprehensive Drug Abuse Prevention... substances by safety- sensitive employees, may be too narrow to cover the use of prescription and OTC drugs... additional costs to employers would be minimal and indirect, such as the cost of responding to an......

  14. Neuromuscular control of the point to point and oscillatory movements of a sagittal arm with the actor-critic reinforcement learning method.

    PubMed

    Golkhou, Vahid; Parnianpour, Mohamad; Lucas, Caro

    2005-04-01

    In this study, we have used a single link system with a pair of muscles that are excited with alpha and gamma signals to achieve both point to point and oscillatory movements with variable amplitude and frequency.The system is highly nonlinear in all its physical and physiological attributes. The major physiological characteristics of this system are simultaneous activation of a pair of nonlinear muscle-like-actuators for control purposes, existence of nonlinear spindle-like sensors and Golgi tendon organ-like sensor, actions of gravity and external loading. Transmission delays are included in the afferent and efferent neural paths to account for a more accurate representation of the reflex loops.A reinforcement learning method with an actor-critic (AC) architecture instead of middle and low level of central nervous system (CNS), is used to track a desired trajectory. The actor in this structure is a two layer feedforward neural network and the critic is a model of the cerebellum. The critic is trained by state-action-reward-state-action (SARSA) method. The critic will train the actor by supervisory learning based on the prior experiences. Simulation studies of oscillatory movements based on the proposed algorithm demonstrate excellent tracking capability and after 280 epochs the RMS error for position and velocity profiles were 0.02, 0.04 rad and rad/s, respectively. PMID:16154874

  15. The coarse pointing assembly for SILEX program or how to achieve outstanding pointing accuracy with simple hardware associated with consistent control laws

    NASA Astrophysics Data System (ADS)

    Buvat, Daniel; Muller, Gerard; Peyrot, Patrick

    1991-06-01

    Attention is given to the coarse pointing assembly (CPA) for the SILEX program, designed on the basis of 10 years of MATRA experience in very accurate drive mechanisms successfully conducted by the SPOT 1 and 2 flights as well as EURECA IOC. The basic key design feature of the mechanism is a 1200-step stepper motor driven in microstepping with harmonic defects compensation. This allows very low torque noise associated with a high accuracy (0.01 deg). The direct drive principle avoids backlash and permits a linear control of the output shaft of each drive. The only parts susceptible to possible wear are the ball bearings, which have a design margin of greater than 1000 for 10 yr of service life. In order to meet the dynamic performances required by SILEX, a closed loop active damping system is added to each drive unit. Two accelerometers used in a differential way sense the hinge microvibrations and an active damping loop reduces their Q factor down to a few dB. All CPA electrical parts (including motor, optical encoder, and accelerometer) are redundant to avoid single point of failure.

  16. Summary of Previous Chamber or Controlled Anthrax Studies and Recommendations for Possible Additional Studies

    SciTech Connect

    Piepel, Gregory F.; Amidan, Brett G.; Morrow, Jayne B.

    2010-12-29

    This report and an associated Excel file(a) summarizes the investigations and results of previous chamber and controlled studies(b) to characterize the performance of methods for collecting, storing and/or transporting, extracting, and analyzing samples from surfaces contaminated by Bacillus anthracis (BA) or related simulants. This report and the Excel are the joint work of the Pacific Northwest National Laboratory (PNNL) and the National Institute of Standards and Technology (NIST) for the Department of Homeland Security, Science and Technology Directorate. The report was originally released as PNNL-SA-69338, Rev. 0 in November 2009 with limited distribution, but was subsequently cleared for release with unlimited distribution in this Rev. 1. Only minor changes were made to Rev. 0 to yield Rev. 1. A more substantial update (including summarizing data from other studies and more condensed summary tables of data) is underway

  17. Powder Layer Preparation Using Vibration-controlled Capillary Steel Nozzles for Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Stichel, Thomas; Laumer, Tobias; Baumüller, Tobias; Amend, Philipp; Roth, Stephan

    In this report, the dry delivery of polyamide 12 powders by vibrating capillary steel nozzles is investigated and discussed regarding its potential for powder layer preparation in Laser Beam Melting. Therefore, a setup including a steel nozzle assembled on a piezoelectric actuator is presented, which enables the precise control over very small powder quantities by vibration excitation. An analysis reveals that the mass flow through the nozzle can be adjusted by the vibration modes in a certain range depending on the nozzle's specifications, whereas the vibration modes themselves show a complicated behaviour. Using a positioning system in combination with the vibrating nozzle, single-layer patterns consisting of polyamide 12 are produced and characterized regarding surface homogeneity and selectivity using a laser stripe sensor.

  18. Foreword: Additive Manufacturing: Interrelationships of Fabrication, Constitutive Relationships Targeting Performance, and Feedback to Process Control

    DOE PAGES

    Carpenter, John S.; Beese, Allison M.; Bourell, David L.; Hamilton, Reginald F.; Mishra, Rajiv; Sears, James

    2015-06-26

    Additive manufacturing (AM) offers distinct advantages over conventional manufacturing processes including the capability to both build and repair complex part shapes; to integrate and consolidate parts and thus overcome joining concerns; and to locally tailor material compositions as well as properties. Moreover, a variety of fields such as aerospace, military, automotive, and biomedical are employing this manufacturing technique as a way to decrease costs, increase manufacturing agility, and explore novel geometry/functionalities. In order to increase acceptance of AM as a viable processing method, pathways for qualifying both the material and the process need to be developed and, perhaps, standardized. Thismore » symposium was designed to serve as a venue for the international AM community—including government, academia, and industry—to define the fundamental interrelationships between feedstock, processing, microstructure, shape, mechanical behavior/materials properties, and function/performance. Eventually, insight into the connections between processing, microstructure, property, and performance will be achieved through experimental observations, theoretical advances, and computational modeling of physical processes. Finally, once this insight matures, AM will be able to move from the realm of making parts to making qualified materials that are certified for use with minimal need for post-fabrication characterization.« less

  19. Foreword: Additive Manufacturing: Interrelationships of Fabrication, Constitutive Relationships Targeting Performance, and Feedback to Process Control

    SciTech Connect

    Carpenter, John S.; Beese, Allison M.; Bourell, David L.; Hamilton, Reginald F.; Mishra, Rajiv; Sears, James

    2015-06-26

    Additive manufacturing (AM) offers distinct advantages over conventional manufacturing processes including the capability to both build and repair complex part shapes; to integrate and consolidate parts and thus overcome joining concerns; and to locally tailor material compositions as well as properties. Moreover, a variety of fields such as aerospace, military, automotive, and biomedical are employing this manufacturing technique as a way to decrease costs, increase manufacturing agility, and explore novel geometry/functionalities. In order to increase acceptance of AM as a viable processing method, pathways for qualifying both the material and the process need to be developed and, perhaps, standardized. This symposium was designed to serve as a venue for the international AM community—including government, academia, and industry—to define the fundamental interrelationships between feedstock, processing, microstructure, shape, mechanical behavior/materials properties, and function/performance. Eventually, insight into the connections between processing, microstructure, property, and performance will be achieved through experimental observations, theoretical advances, and computational modeling of physical processes. Finally, once this insight matures, AM will be able to move from the realm of making parts to making qualified materials that are certified for use with minimal need for post-fabrication characterization.

  20. Seagrass metabolism across a productivity gradient using the eddy covariance, Eulerian control volume, and biomass addition techniques

    NASA Astrophysics Data System (ADS)

    Long, Matthew H.; Berg, Peter; Falter, James L.

    2015-05-01

    The net ecosystem metabolism of the seagrass Thalassia testudinum was studied across a nutrient and productivity gradient in Florida Bay, Florida, using the Eulerian control volume, eddy covariance, and biomass addition techniques. In situ oxygen fluxes were determined by a triangular Eulerian control volume with sides 250 m long and by eddy covariance instrumentation at its center. The biomass addition technique evaluated the aboveground seagrass productivity through the net biomass added. The spatial and temporal resolutions, accuracies, and applicability of each method were compared. The eddy covariance technique better resolved the short-term flux rates and the productivity gradient across the bay, which was consistent with the long-term measurements from the biomass addition technique. The net primary production rates from the biomass addition technique, which were expected to show greater autotrophy due to the exclusion of sediment metabolism and belowground production, were 71, 53, and 30 mmol carbon m-2 d-1 at 3 sites across the bay. The net ecosystem metabolism was 35, 25, and 11 mmol oxygen m-2 d-1 from the eddy covariance technique and 10, -103, and 14 mmol oxygen m-2 d-1 from the Eulerian control volume across the same sites, respectively. The low-flow conditions in the shallow bays allowed for periodic stratification and long residence times within the Eulerian control volume that likely reduced its precision. Overall, the eddy covariance technique had the highest temporal resolution while producing accurate long-term flux rates that surpassed the capabilities of the biomass addition and Eulerian control volume techniques in these shallow coastal bays.

  1. Controlling Phase Separation of Interpenetrating Polymer Networks by Addition of Block Copolymers

    NASA Astrophysics Data System (ADS)

    Rohde, Brian; Krishnamoorti, Ramanan; Robertson, Megan

    2015-03-01

    Interpenetrating polymer networks (IPNs) offer a unique way to produce mechanically superior thermoset blends relative to the neat components. In this study, IPNs were prepared consisting of polydicyclopentadiene (polyDCPD), contributing high fracture toughness, and an epoxy resin (the diglycidyl ether of bisphenol A cured with nadic methyl anhydride), contributing high tensile strength and modulus. In the absence of compatibilization, the simultaneous curing of the networks leads to a macroscopically phase separated blend that exhibits poor mechanical behavior. To control phase separation and drive the system towards more mechanically robust nanostructured IPNs, block copolymers were designed to compatibilize this system, where one block possesses affinity to polyDCPD (polynorbornene in this study) and the other block possesses affinity to DGEBA (poly(ɛ-caprolactone) in this study). The influence of the block copolymer composition on the degree of phase separation and interfacial adhesion in the IPN was studied using a combination of small-angle scattering and imaging techniques. The resultant mechanical properties were explored and structure-property relationships were developed in this blend system.

  2. Controlling Phase Separation of Tough Interpenetrating Polymer Networks via Addition of Amphiphilic Block Copolymers

    NASA Astrophysics Data System (ADS)

    Rohde, Brian; Krishnamoorti, Ramanan; Robertson, Megan

    Interpenetrating polymer networks (IPNs) offer a unique way to combine the mechanical properties of two thermoset systems. Often used to create a material that possesses both high toughness and tensile properties, here we use polydicyclopentadiene, cured via ring opening metathesis polymerization, to contribute high toughness and diglycidyl ether of bisphenol A cured via anhydride chemistry to contribute high tensile strength and modulus. As the uncompatibilized system reacts in the presence of one another, mesoscopic phase separation occurs and dictates the overall efficacy of combining mechanical properties. To control phase separation and drive the system towards more mechanically robust nanostructed IPNs, amphiphilic block copolymers of polybutadiene- b-polyethylene oxide, where one block possesses strong affinity to polyDCPD and the other the DGEBA, were added to the system. Here we present a systematic study of the influence of block copolymer composition in the overall blend on degree of phase separation and morphology using a combination of small-angle x-ray scattering (SAXS) and scanning electron microscopy (SEM) techniques. The resultant mechanical properties are then explored in an effort to link mechanical properties to blend morphology.

  3. Angle-of-Attack-Modulated Terminal Point Control for Neptune Aerocapture

    NASA Technical Reports Server (NTRS)

    Queen, Eric M.

    2004-01-01

    An aerocapture guidance algorithm based on a calculus of variations approach is developed, using angle of attack as the primary control variable. Bank angle is used as a secondary control to alleviate angle of attack extremes and to control inclination. The guidance equations are derived in detail. The controller has very small onboard computational requirements and is robust to atmospheric and aerodynamic dispersions. The algorithm is applied to aerocapture at Neptune. Three versions of the controller are considered with varying angle of attack authority. The three versions of the controller are evaluated using Monte Carlo simulations with expected dispersions.

  4. Precise control of polymer coated nanopores by nanoparticle additives: Insights from computational modeling

    NASA Astrophysics Data System (ADS)

    Eskandari Nasrabad, Afshin; Jasnow, David; Zilman, Anton; Coalson, Rob D.

    2016-08-01

    Polymer-nanoparticle composites are a promising new class of materials for creation of controllable nano-patterned surfaces and nanopores. We use coarse-grained molecular dynamics simulations augmented with analytical theory to study the structural transitions of surface grafted polymer layers (brushes) induced by infiltration of nanoparticles that are attracted to the polymers in the layer. We systematically compare two different polymer brush geometries: one where the polymer chains are grafted to a planar surface and the other where the chains are grafted to the inside of a cylindrical nanochannel. We perform a comprehensive study of the effects of the material parameters such as the polymer chain length, chain grafting density, nanoparticle size, strength of attraction between nanoparticles and polymer monomers, and, in the case of the cylindrically grafted brush, the radius of the cylinder. We find a very general behavioral motif for all geometries and parameter values: the height of the polymer brush is non-monotonic in the nanoparticle concentration in solution. As the nanoparticle concentration increases, the brush height first decreases and after passing through a minimum value begins to increase, resulting in the swelling of the nanoparticle infused brush. These morphological features may be useful for devising tunable "smart" nano-devices whose effective dimensions can be reversibly and precisely adjusted by changing the nanoparticle concentration in solution. The results of approximate Self-Consistent Field Theory (SCFT) calculations, applicable in the regime of strong brush stretching, are compared to the simulation results. The SCFT calculations are found to be qualitatively, even semi-quantitatively, accurate when applied within their intended regime of validity, and provide a useful and efficient tool for modeling such materials.

  5. Addition of lidocaine injection immediately before physiotherapy for frozen shoulder: a randomized controlled trial.

    PubMed

    Hsu, Wei-Chun; Wang, Tao-Liang; Lin, Yi-Jia; Hsieh, Lin-Fen; Tsai, Chun-Mei; Huang, Kuang-Hui

    2015-01-01

    The intraarticular injection of lidocaine immediately before a physiotherapy session may relieve pain during the stretching and mobilization of the affected joint in patients with a frozen shoulder, thus enhancing the treatment effect. To compare the effects of intraarticular injection of lidocaine plus physiotherapy to that of physiotherapy alone in the treatment of a frozen shoulder, a prospective randomized controlled trial was conducted in the rehabilitation department of a private teaching hospital. Patients with a frozen shoulder were randomized into the physiotherapy group or the lidocaine injection plus physiotherapy (INJPT) group. The subjects in the INJPT group underwent injection of 3 ml of 1% lidocaine into the affected shoulder 10 to 20 minutes before each physiotherapy session. In each group, the treatment lasted 3 months. The primary outcome measures were the active and passive range of motion of the affected shoulder. The secondary outcome measures were the results of the Shoulder Disability Questionnaire, the Shoulder Pain and Disability Index, and the 36-item Short-Form Health Survey (SF-36). The outcome measures were evaluated before treatment and 1, 2, 3, 4, and 6 months after the start of treatment. The group comparisons showed significantly greater improvement in the INJPT group, mainly in active and passive shoulder range of motion in flexion and external rotation and improvements in pain and disability (P < 0.05); however, no significant group difference was seen in the SF-36 results. The intraarticular injection of lidocaine immediately before a physiotherapy session might be superior to physiotherapy alone in the treatment of a frozen shoulder. Trial registration: ClinicalTrials.gov NCT01817348.

  6. Control over hygroscopic growth of saline aqueous aerosol using Pluronic polymer additives.

    PubMed

    Haddrell, Allen E; Hargreaves, Graham; Davies, James F; Reid, Jonathan P

    2013-02-25

    difference in diameter is RH dependent, and may be much greater at higher humidities. These findings suggest that the addition of μM concentrations of larger Pluronic polymers to nebulizer formulations may greatly reduce the size of aerosols produced. PMID:23333755

  7. Ring Walking/Oxidative Addition Reactions for the Controlled Synthesis of Conjugated Polymers

    SciTech Connect

    Bazan, Guillermo C

    2012-04-03

    Power conversion efficiencies of plastic solar cells depend strongly on the molecular weight characteristics of the semiconducting polymers used for their fabrication. The synthesis of these materials typically relies on transition metal mediated catalytic reactions. In many instances, the ideal structures cannot be attained because of deficiencies in these reactions, particularly when it comes to being able to achieve high number average molecular weights and narrow molecular weight distributions. Another important conjugated polymer structure of interest is one in which a single functional group is attached at the end group of the chain. Such systems would be ideal for modifying surface properties at interfaces and for labeling biomolecular probes used in fluorescent biosensors. To respond to the challenges above, our efforts have centered on the design of homogenous transition metal complexes that are easy to prepare and effective in carrying out living, or quasi-living, condensative chain polymerization reactions. The key mechanistic challenge for the success of this reaction is to force the insertion of one monomer unit at a time via a process that involves migration of the transition metal-containing fragment to one terminus of the polymer chain. Chain growth characteristics are therefore favored when the metal does not dissociate from the newly formed reductive elimination product. We have proposed that dissociation is disfavored by the formation of a -complex, in which the metal can sample various locations of the electronically delocalized framework, a process that we term ring-walking , and find the functionality where oxidative addition takes place. Success has been achieved in the nickel-mediated cross coupling reaction of Grignard reagents with aromatic halides by using bromo[1,2-bis(diphenylphosphino)ethane]phenylnickel. This reagent can yield poly(thiophene)s (one of the most widely used type of polymer in plastic solar cells) with excellent

  8. Recommendations for dealing with waste contaminated with Ebola virus: a Hazard Analysis of Critical Control Points approach

    PubMed Central

    Edmunds, Kelly L; Elrahman, Samira Abd; Bell, Diana J; Brainard, Julii; Dervisevic, Samir; Fedha, Tsimbiri P; Few, Roger; Howard, Guy; Lake, Iain; Maes, Peter; Matofari, Joseph; Minnigh, Harvey; Mohamedani, Ahmed A; Montgomery, Maggie; Morter, Sarah; Muchiri, Edward; Mudau, Lutendo S; Mutua, Benedict M; Ndambuki, Julius M; Pond, Katherine; Sobsey, Mark D; van der Es, Mike; Zeitoun, Mark

    2016-01-01

    Abstract Objective To assess, within communities experiencing Ebola virus outbreaks, the risks associated with the disposal of human waste and to generate recommendations for mitigating such risks. Methods A team with expertise in the Hazard Analysis of Critical Control Points framework identified waste products from the care of individuals with Ebola virus disease and constructed, tested and confirmed flow diagrams showing the creation of such products. After listing potential hazards associated with each step in each flow diagram, the team conducted a hazard analysis, determined critical control points and made recommendations to mitigate the transmission risks at each control point. Findings The collection, transportation, cleaning and shared use of blood-soiled fomites and the shared use of latrines contaminated with blood or bloodied faeces appeared to be associated with particularly high levels of risk of Ebola virus transmission. More moderate levels of risk were associated with the collection and transportation of material contaminated with bodily fluids other than blood, shared use of latrines soiled with such fluids, the cleaning and shared use of fomites soiled with such fluids, and the contamination of the environment during the collection and transportation of blood-contaminated waste. Conclusion The risk of the waste-related transmission of Ebola virus could be reduced by the use of full personal protective equipment, appropriate hand hygiene and an appropriate disinfectant after careful cleaning. Use of the Hazard Analysis of Critical Control Points framework could facilitate rapid responses to outbreaks of emerging infectious disease. PMID:27274594

  9. Nonlinear control design techniques for precision formation flying at Lagrange points

    NASA Astrophysics Data System (ADS)

    Luquette, Richard J.

    Precision spacecraft formation flying is an enabling technology for a variety of proposed space-based observatories, such as NASA's Terrestrial Planet Finder (TPF), the Micro-Arcsecond X-Ray Imaging Mission (MAXIM), and Stellar Imager (SI). This research specifically examines the precision formation flying control architecture, characterizing the relative performance of linear and nonlinear controllers. Controller design is based on a 6DOF control architecture, characteristic of precision formation flying control. In an effort to minimize the influence of design parameters in the comparison, analysis employs "equivalent" controller gains, and incorporates an integrator in the linear control design. Controller performance is evaluated through various simulations designed to reflect a realistic space environment. The simulation architecture includes a full gravitational model and solar pressure effects. Spacecraft model properties are based on realistic mission design parameters. Control actuators are modeled as a fixed set of thrusters for both translation and attitude control. Analysis includes impact on controller performance due to omitted dynamics in the model (gravitational sources and solar pressure) and model uncertainty (mass properties, thruster placement and thruster alignment). Linearized equations of relative motion are derived for spacecraft operating in the context of the Restricted Three Body Problem. Linearization is performed with respect to a reference spacecraft within the formation. Analysis demonstrates robust stability for the Linear Quadratic Regulator controller design based on the linearized dynamics. Nonlinear controllers are developed based on Lyapunov analysis, including both non-adaptive and adaptive designs. While the linear controller demonstrates greater robustness to model uncertainty, both nonlinear controllers exhibit superior performance. The adaptive controller provides the best performance. As a key feature, the adaptive

  10. SU-E-T-199: How Number of Control Points Influences the Dynamic IMRT Plan Quality and Deliverability

    SciTech Connect

    Sharma, S; Manigandan, D; Chander, S; Subramani, V; Julka, P; Rath, G

    2014-06-01

    Purpose: To study the influence of number of control points on plan quality and deliverability. Methods: Five previously treated patients of carcinoma of rectum were selected. Planning target volume (PTV) and organs at risk (OARs) i.e. bladder and bowel were contoured. Dynamic IMRT plans (6MV, 7-fields, 45Gy/25 fractions and prescribed at 95% isodose) were created in Eclipse (Varian medical system, Palo Alto, CA) treatment planning system (TPS) for Varian CL2300C/D linear-accelerator. Base plan was calculated with 166 control points, variable mode (Eclipse Default). For generating other plans, all parameters were kept constant, only number of control points (Fixed mode) was varied as follows: 100, 166 and 200. Then, plan quality was analyzed in terms of maximum and mean dose received by the PTV and OARs. For plan deliverability, TPS calculated fluence was verified with I’matriXX (IBA Dosimetry, Germany) array and compared with TPS dose-plane using gamma index criteria of 3% dose difference and 3mm distance to agreement (DTA). Total number of monitor units (MU) required to deliver a plan was also noted. Results: The maximum variation for the PTV maximum with respect to eclipse default control point (166) was 0.28% (0.14Gy). Similarly, PTV mean varied only up to 0.22 %( 0.11Gy). Bladder maximum and bladder mean varied up to 0.51% (0.24Gy) and 0.16% (0.06Gy). The variation for the bowel maximum and bowel mean was also only 0.39% (0.19Gy) and 0.33% (0.04Gy). Total MU was within 0.32 % (4MU). Average gamma pass rate using different control points for five patients are 98.75±0.33%, 99.37±0.09%, 99.29±0.12%, 98.14±0.13% and 99.25±0.14% respectively. Conclusion: Slight variation (<1%) in PTV and OARs maximum and mean doses was observed with varying number of control points. Monitor unit was also not varied much. Reducing number of control points did not showed any comprise in plan deliverability in terms of gamma index pass rate.

  11. [Spatial discharge characteristics and total load control of non-point source pollutants based on the catchment scale].

    PubMed

    Wang, Xia-Hui; Lu, Jun; Zhang, Qing-Zhong; Wang, Bo; Yao, Rui-Hua; Zhang, Hui-Yuan; Huang, Feng

    2011-09-01

    Agricultural non-point source pollution is one of the major causes of water quality deterioration. Based on the analysis of the spatial discharge characteristics and intensity of major pollutants from the agricultural pollution source, the establishment of spatial management subzones for controlling agricultural non-point pollution and a design of a plan for total load control of pollutants from each subzone is an important way to improve the efficiency of control measures. In this paper the Four Lake basin in Hubei Province is adopted as the research case region and a systematic research of the control countermeasures of agricultural non-point pollution based on the catchment scale is carried out. The results shows that in the Four Lake basin, the COD, total nitrogen, total phosphorus and ammonia nitrogen load of the water environment are mainly caused by agricultural non-point pollution. These four kinds of non-point source pollutants respectively account for 67.6%, 82.2%, 84.7% and 50.9% of the total pollutant discharge amount in the basin. The analysis of the spatial discharge characteristics of non-point source pollutants in the Four Lake basin shows that the major contributor source regions of non-point source pollutant in the basin are the four counties, including Honghu, Jianli, Qianjiang and Shayang where the aquatic and livestock production are relatively developed. According to the spatial discharge characteristics of the pollutants and the evaluation of the discharge intensity of pollutants, the Four Lake basin is divided into three agricultural non-point pollution management subzones, which including Changhu upstream aquatic and livestock production pollution control subzone, Four-lake trunk canal rural non-point source pollution control subzone and Honghu aquatic production pollution control subzone. Specific pollution control measures are put forward for each subzone. With a comprehensive consideration of the water quality amelioration and the

  12. [Spatial discharge characteristics and total load control of non-point source pollutants based on the catchment scale].

    PubMed

    Wang, Xia-Hui; Lu, Jun; Zhang, Qing-Zhong; Wang, Bo; Yao, Rui-Hua; Zhang, Hui-Yuan; Huang, Feng

    2011-09-01

    Agricultural non-point source pollution is one of the major causes of water quality deterioration. Based on the analysis of the spatial discharge characteristics and intensity of major pollutants from the agricultural pollution source, the establishment of spatial management subzones for controlling agricultural non-point pollution and a design of a plan for total load control of pollutants from each subzone is an important way to improve the efficiency of control measures. In this paper the Four Lake basin in Hubei Province is adopted as the research case region and a systematic research of the control countermeasures of agricultural non-point pollution based on the catchment scale is carried out. The results shows that in the Four Lake basin, the COD, total nitrogen, total phosphorus and ammonia nitrogen load of the water environment are mainly caused by agricultural non-point pollution. These four kinds of non-point source pollutants respectively account for 67.6%, 82.2%, 84.7% and 50.9% of the total pollutant discharge amount in the basin. The analysis of the spatial discharge characteristics of non-point source pollutants in the Four Lake basin shows that the major contributor source regions of non-point source pollutant in the basin are the four counties, including Honghu, Jianli, Qianjiang and Shayang where the aquatic and livestock production are relatively developed. According to the spatial discharge characteristics of the pollutants and the evaluation of the discharge intensity of pollutants, the Four Lake basin is divided into three agricultural non-point pollution management subzones, which including Changhu upstream aquatic and livestock production pollution control subzone, Four-lake trunk canal rural non-point source pollution control subzone and Honghu aquatic production pollution control subzone. Specific pollution control measures are put forward for each subzone. With a comprehensive consideration of the water quality amelioration and the

  13. Design and evaluation of an optical fine-pointing control system for telescopes utilizing a digital star sensor

    NASA Technical Reports Server (NTRS)

    Ostroff, A. J.; Romanczyk, K. C.

    1973-01-01

    One of the most significant problems associated with the development of large orbiting astronomical telescopes is that of maintaining the very precise pointing accuracy required. A proposed solution to this problem utilizes dual-level pointing control. The primary control system maintains the telescope structure attitude stabilized within the field of view to the desired accuracy. In order to demonstrate the feasibility of optically stabilizing the star images to the desired accuracy a regulating system has been designed and evaluated. The control system utilizes a digital star sensor and an optical star image motion compensator, both of which have been developed for this application. These components have been analyzed mathematically, analytical models have been developed, and hardware has been built and tested.

  14. Cement cake properties in static filtration--On the role of fluid loss control additives on the cake porosity

    SciTech Connect

    Desbrieres, J. )

    1993-11-01

    The mechanism of the action of fluid loss control additives in cementing oilwell operations is principally the reduction of permeability of the cement filter cake. From filtration equations physical characteristics as porosity of the cement filter cake were investigated and compared with experimental data. A good correlation is observed when no adsorption is involved. The smallest pore diameter for obtaining an efficient control of fluid loss is shown to be of the same order of magnitude as the gyration radius of used macromolecular chains.

  15. Detection of interleukin-2 in addition to interferon-gamma discriminates active tuberculosis patients, latently infected individuals, and controls.

    PubMed

    Biselli, R; Mariotti, S; Sargentini, V; Sauzullo, I; Lastilla, M; Mengoni, F; Vanini, V; Girardi, E; Goletti, D; D' Amelio, R; Nisini, R

    2010-08-01

    Effective control of tuberculosis (TB) includes discrimination of subjects with active TB from individuals with latent TB infection (LTBI). As distinct interferon (IFN)-gamma and interleukin (IL)-2 profiles of antigen-specific T-cells have been associated with different clinical stages and antigen loads in several viral and bacterial diseases, we analysed these cytokines in TB using a modified QuantiFERON-TB Gold In Tube test. Detection of IL-2 in addition to IFN-gamma distinguishes not only Mycobacterium tuberculosis-infected subjects from healthy controls, but also individuals with LTBI from active TB patients. This may help to improve diagnostic tests for TB.

  16. Maximum Principle of Optimal Control of the Primitive Equations of the Ocean with Two Point Boundary State Constraint

    SciTech Connect

    Tachim Medjo, Theodore

    2010-08-15

    We study in this article the Pontryagin's maximum principle for a class of control problems associated with the primitive equations (PEs) of the ocean with two point boundary state constraint. These optimal problems involve a two point boundary state constraint similar to that considered in Wang, Nonlinear Anal. 51, 509-536, 2002 for the three-dimensional Navier-Stokes (NS) equations. The main difference between this work and Wang, Nonlinear Anal. 51, 509-536, 2002 is that the nonlinearity in the PEs is stronger than in the three-dimensional NS systems.

  17. Effect of kaolin addition on the performance of controlled low-strength material using industrial waste incineration bottom ash.

    PubMed

    Naganathan, Sivakumar; Razak, Hashim Abdul; Hamid, Siti Nadzriah Abdul

    2010-09-01

    Incineration of industrial waste produces large quantities of bottom ash which are normally sent to secured landfill, but is not a sustainable solution. Use of bottom ash in engineering applications will contribute to sustainability and generate revenue. One way of using the industrial waste incineration bottom ash is in controlled low-strength material (CLSM). Use of bottom ash in CLSM has problems related to bleeding and excessive strength development and so an additive has to be used to control bleeding and strength development. The main objective of this research is to study the effect of kaolin addition on the performance of CLSM made using industrial waste incineration bottom ash. CLSM mixes were made with bottom ash, cement, and refined kaolin. Various tests were performed on the CLSM in fresh and hardened states including compressive strength, water absorption, California bearing ratio (CBR) and the tests for concentration of leachable substances on the bleed and leachate. The compressive strength of CLSM tested ranged from 0.11 to 9.86 MPa. CBR values ranged from 6 to 46, and water absorption values from 12 to 36%. It was shown that the addition of kaolin delayed the initial setting time of CLSM mixtures, reduced bleeding, lowered the compressive strength, and increased the values of water absorption, sorption, and initial surface absorption. The CLSM tested did not have corrosivity. It was shown that the hardened CLSM was non hazardous, and the addition of kaolin increased the concentration of heavy metals and salts in the bleed and leachate.

  18. Design of robust line-of-sight pointing control system for the SCOLE configuration

    NASA Technical Reports Server (NTRS)

    Joshi, S. M.; Armstrong, E. S.

    1987-01-01

    Robust compensator design for attitude control of the Spacecraft Control Laboratory Experiment (SCOLE) configuration is considered. A loop-shaping procedure similar to that used in the LQG/LTR method is used to iteratively design the compensator. A satisfactory compensator is obtained by including the rigid modes and three elastic modes in the design model.

  19. Control over structure-specific flexibility improves anatomical accuracy for point-based deformable registration in bladder cancer radiotherapy

    SciTech Connect

    Wognum, S.; Chai, X.; Hulshof, M. C. C. M.; Bel, A.; Bondar, L.; Zolnay, A. G.; Hoogeman, M. S.

    2013-02-15

    Purpose: Future developments in image guided adaptive radiotherapy (IGART) for bladder cancer require accurate deformable image registration techniques for the precise assessment of tumor and bladder motion and deformation that occur as a result of large bladder volume changes during the course of radiotherapy treatment. The aim was to employ an extended version of a point-based deformable registration algorithm that allows control over tissue-specific flexibility in combination with the authors' unique patient dataset, in order to overcome two major challenges of bladder cancer registration, i.e., the difficulty in accounting for the difference in flexibility between the bladder wall and tumor and the lack of visible anatomical landmarks for validation. Methods: The registration algorithm used in the current study is an extension of the symmetric-thin plate splines-robust point matching (S-TPS-RPM) algorithm, a symmetric feature-based registration method. The S-TPS-RPM algorithm has been previously extended to allow control over the degree of flexibility of different structures via a weight parameter. The extended weighted S-TPS-RPM algorithm was tested and validated on CT data (planning- and four to five repeat-CTs) of five urinary bladder cancer patients who received lipiodol injections before radiotherapy. The performance of the weighted S-TPS-RPM method, applied to bladder and tumor structures simultaneously, was compared with a previous version of the S-TPS-RPM algorithm applied to bladder wall structure alone and with a simultaneous nonweighted S-TPS-RPM registration of the bladder and tumor structures. Performance was assessed in terms of anatomical and geometric accuracy. The anatomical accuracy was calculated as the residual distance error (RDE) of the lipiodol markers and the geometric accuracy was determined by the surface distance, surface coverage, and inverse consistency errors. Optimal parameter values for the flexibility and bladder weight

  20. Hardware description ADSP-21020 40-bit floating point DSP as designed in a remotely controlled digital CW Doppler radar

    SciTech Connect

    Morrison, R.E.; Robinson, S.H.

    1991-01-01

    A continuous wave Doppler radar system has been designed which is portable, easily deployed, and remotely controlled. The heart of this system is a DSP/control board using Analog Devices ADSP-21020 40-bit floating point digital signal processor (DSP) microprocessor. Two 18-bit audio A/D converters provide digital input to the DSP/controller board for near real time target detection. Program memory for the DSP is dual ported with an Intel 87C51 microcontroller allowing DSP code to be up-loaded or down-loaded from a central controlling computer. The 87C51 provides overall system control for the remote radar and includes a time-of-day/day-of-year real time clock, system identification (ID) switches, and input/output (I/O) expansion by an Intel 82C55 I/O expander. 5 refs., 8 figs., 2 tabs.

  1. Control-volume distributed multi-point flux approximation coupled with a lower-dimensional fracture model

    NASA Astrophysics Data System (ADS)

    Ahmed, R.; Edwards, M. G.; Lamine, S.; Huisman, B. A. H.; Pal, M.

    2015-03-01

    A cell-centered control-volume distributed multi-point flux approximation (CVD-MPFA) finite-volume formulation is presented for discrete fracture-matrix simulations. The grid is aligned with the fractures and barriers which are then modeled as lower-dimensional interfaces located between the matrix cells in the physical domain. The nD pressure equation is solved in the matrix domain coupled with an (n - 1)D pressure equation solved in the fractures. The CVD-MPFA formulation naturally handles fractures with anisotropic permeabilities on unstructured grids. Matrix-fracture fluxes are expressed in terms of matrix and fracture pressures, and must be added to the lower-dimensional flow equation (called the transfer function). An additional transmission condition is used between matrix cells adjacent to low permeable fractures to link the velocity and pressure jump across the fractures. Numerical tests serve to assess the convergence and accuracy of the lower-dimensional fracture model for highly anisotropic fractures having different apertures and permeability tensors. A transport equation for tracer flow is coupled via the Darcy flux for single and intersecting fractures. The lower-dimensional approach for intersecting fractures avoids the more restrictive CFL condition corresponding to the equi-dimensional approximation with explicit time discretization. Lower-dimensional fracture model results are compared with hybrid-grid and equi-dimensional model results. Fractures and barriers are efficiently modeled by lower-dimensional interfaces which yield comparable results to those of the equi-dimensional model. Highly conductive fractures are modeled as lower-dimensional entities without the use of locally refined grids that are required by the equi-dimensional model, while pressure continuity across fractures is built into the model, without depending on the extra degrees of freedom which must be added locally by the hybrid-grid method. The lower-dimensional fracture

  2. Multi-Scale Matching for the Automatic Location of Control Points in Large Scale Aerial Images Using Terrestrial Scenes

    NASA Astrophysics Data System (ADS)

    Berveglieri, A.; Tommaselli, A. M. G.

    2014-03-01

    A technique to automatically locate Ground Control Points (GCPs) in large aerial images is presented considering the availability of low accuracy direct georeferencing data. The approach is based on image chips of GCPs extracted from vertical terrestrial images. A strategy combining image matching techniques was implemented to select correct matches. These matches were used to define a 2D transformation with which the GCP is projected close to its correct position, reducing the search space in the aerial image. Area-based matching with some refinements is used to locate GCPs with sub-pixel precision. Experiments were performed with multi-scale images and assessed with a bundle block adjustment simulating an indirect sensor orientation. The accuracy analysis was accomplished based on discrepancies obtained from GCPs and check points. The results were better than interactive measurements and a planimetric accuracy of 1/5 of the Ground Sample Distance (GSD) for the check points was achieved.

  3. Hazard Analysis and Critical Control Points among Chinese Food Business Operators

    PubMed Central

    Amadei, Paolo; Masotti, Gianfranco; Condoleo, Roberto; Guidi, Alessandra

    2014-01-01

    The purpose of the present paper is to highlight some critical situations emerged during the implementation of long-term projects locally managed by Prevention Services, to control some manufacturing companies in Rome and Prato, Central Italy. In particular, some critical issues on the application of self-control in marketing and catering held by Chinese operators are underlined. The study showed serious flaws in preparing and controlling of manuals for good hygiene practice, participating of the consultants among food business operators (FBOs) to the control of the procedures. Only after regular actions by the Prevention Services, there have been satisfying results. This confirms the need to have qualified and expert partners able to promptly act among FBOs and to give adequate support to authorities in charge in order to guarantee food safety. PMID:27800356

  4. Paleogeographic controls of coal accumulation, Cretaceous Blackhawk Formation and Star Point Sandstone, Wasatch Plateau, Utah.

    USGS Publications Warehouse

    Flores, R.M.; Blanchard, L.F.; Sanchez, J.D.; Marley, W.E.; Muldoon, W.J.

    1984-01-01

    Considers the paleogeographic controls affecting the accumulation of coals in delta-barrier-island complexes. Progradation, lateral shifting, and abandonment of these complexes created four major landward-thinning tongues.-from Authors

  5. Neuroscience education in addition to trigger point dry needling for the management of patients with mechanical chronic low back pain: A preliminary clinical trial.

    PubMed

    Téllez-García, Mario; de-la-Llave-Rincón, Ana I; Salom-Moreno, Jaime; Palacios-Ceña, Maria; Ortega-Santiago, Ricardo; Fernández-de-Las-Peñas, César

    2015-07-01

    The objective of the current study was to determine the short-term effects of trigger point dry needling (TrP-DN) alone or combined with neuroscience education on pain, disability, kinesiophobia and widespread pressure sensitivity in patients with mechanical low back pain (LBP). Twelve patients with LBP were randomly assigned to receive either TrP-DN (TrP-DN) or TrP-DN plus neuroscience education (TrP-DN + EDU). Pain intensity (Numerical Pain Rating Scale, 0-10), disability (Roland-Morris Disability Questionnaire-RMQ-, Oswestry Low Back Pain Disability Index-ODI), kinesiophobia (Tampa Scale of Kinesiophobia-TSK), and pressure pain thresholds (PPT) over the C5-C6 zygapophyseal joint, transverse process of L3 vertebra, second metacarpal, and tibialis anterior muscle were collected at baseline and 1-week after the intervention. Patients treated with TrP-DN + EDU experienced a significantly greater reduction of kinesiophobia (P = 0.008) and greater increases in PPT over the transverse process of L3 (P = 0.049) than those patients treated only with TrP-DN. Both groups experienced similar decreases in pain, ODI and RMQ, and similar increases in PPT over the C5/C6 joint, second metacarpal, and tibialis anterior after the intervention (all, P > 0.05). The results suggest that TrP-DN was effective for improving pain, disability, kinesiophobia and widespread pressure sensitivity in patients with mechanical LBP at short-term. The inclusion of a neuroscience educational program resulted in a greater improvement in kinesiophobia. PMID:26118519

  6. Neuroscience education in addition to trigger point dry needling for the management of patients with mechanical chronic low back pain: A preliminary clinical trial.

    PubMed

    Téllez-García, Mario; de-la-Llave-Rincón, Ana I; Salom-Moreno, Jaime; Palacios-Ceña, Maria; Ortega-Santiago, Ricardo; Fernández-de-Las-Peñas, César

    2015-07-01

    The objective of the current study was to determine the short-term effects of trigger point dry needling (TrP-DN) alone or combined with neuroscience education on pain, disability, kinesiophobia and widespread pressure sensitivity in patients with mechanical low back pain (LBP). Twelve patients with LBP were randomly assigned to receive either TrP-DN (TrP-DN) or TrP-DN plus neuroscience education (TrP-DN + EDU). Pain intensity (Numerical Pain Rating Scale, 0-10), disability (Roland-Morris Disability Questionnaire-RMQ-, Oswestry Low Back Pain Disability Index-ODI), kinesiophobia (Tampa Scale of Kinesiophobia-TSK), and pressure pain thresholds (PPT) over the C5-C6 zygapophyseal joint, transverse process of L3 vertebra, second metacarpal, and tibialis anterior muscle were collected at baseline and 1-week after the intervention. Patients treated with TrP-DN + EDU experienced a significantly greater reduction of kinesiophobia (P = 0.008) and greater increases in PPT over the transverse process of L3 (P = 0.049) than those patients treated only with TrP-DN. Both groups experienced similar decreases in pain, ODI and RMQ, and similar increases in PPT over the C5/C6 joint, second metacarpal, and tibialis anterior after the intervention (all, P > 0.05). The results suggest that TrP-DN was effective for improving pain, disability, kinesiophobia and widespread pressure sensitivity in patients with mechanical LBP at short-term. The inclusion of a neuroscience educational program resulted in a greater improvement in kinesiophobia.

  7. Active control on high-order coherence and statistic characterization on random phase fluctuation of two classical point sources.

    PubMed

    Hong, Peilong; Li, Liming; Liu, Jianji; Zhang, Guoquan

    2016-01-01

    Young's double-slit or two-beam interference is of fundamental importance to understand various interference effects, in which the stationary phase difference between two beams plays the key role in the first-order coherence. Different from the case of first-order coherence, in the high-order optical coherence the statistic behavior of the optical phase will play the key role. In this article, by employing a fundamental interfering configuration with two classical point sources, we showed that the high- order optical coherence between two classical point sources can be actively designed by controlling the statistic behavior of the relative phase difference between two point sources. Synchronous position Nth-order subwavelength interference with an effective wavelength of λ/M was demonstrated, in which λ is the wavelength of point sources and M is an integer not larger than N. Interestingly, we found that the synchronous position Nth-order interference fringe fingerprints the statistic trace of random phase fluctuation of two classical point sources, therefore, it provides an effective way to characterize the statistic properties of phase fluctuation for incoherent light sources.

  8. Active control on high-order coherence and statistic characterization on random phase fluctuation of two classical point sources

    PubMed Central

    Hong, Peilong; Li, Liming; Liu, Jianji; Zhang, Guoquan

    2016-01-01

    Young’s double-slit or two-beam interference is of fundamental importance to understand various interference effects, in which the stationary phase difference between two beams plays the key role in the first-order coherence. Different from the case of first-order coherence, in the high-order optical coherence the statistic behavior of the optical phase will play the key role. In this article, by employing a fundamental interfering configuration with two classical point sources, we showed that the high- order optical coherence between two classical point sources can be actively designed by controlling the statistic behavior of the relative phase difference between two point sources. Synchronous position Nth-order subwavelength interference with an effective wavelength of λ/M was demonstrated, in which λ is the wavelength of point sources and M is an integer not larger than N. Interestingly, we found that the synchronous position Nth-order interference fringe fingerprints the statistic trace of random phase fluctuation of two classical point sources, therefore, it provides an effective way to characterize the statistic properties of phase fluctuation for incoherent light sources. PMID:27021589

  9. A double-loop structure in the adaptive generalized predictive control algorithm for control of robot end-point contact force.

    PubMed

    Wen, Shuhuan; Zhu, Jinghai; Li, Xiaoli; Chen, Shengyong

    2014-09-01

    Robot force control is an essential issue in robotic intelligence. There is much high uncertainty when robot end-effector contacts with the environment. Because of the environment stiffness effects on the system of the robot end-effector contact with environment, the adaptive generalized predictive control algorithm based on quantitative feedback theory is designed for robot end-point contact force system. The controller of the internal loop is designed on the foundation of QFT to control the uncertainty of the system. An adaptive GPC algorithm is used to design external loop controller to improve the performance and the robustness of the system. Two closed loops used in the design approach realize the system׳s performance and improve the robustness. The simulation results show that the algorithm of the robot end-effector contacting force control system is effective. PMID:24973336

  10. A double-loop structure in the adaptive generalized predictive control algorithm for control of robot end-point contact force.

    PubMed

    Wen, Shuhuan; Zhu, Jinghai; Li, Xiaoli; Chen, Shengyong

    2014-09-01

    Robot force control is an essential issue in robotic intelligence. There is much high uncertainty when robot end-effector contacts with the environment. Because of the environment stiffness effects on the system of the robot end-effector contact with environment, the adaptive generalized predictive control algorithm based on quantitative feedback theory is designed for robot end-point contact force system. The controller of the internal loop is designed on the foundation of QFT to control the uncertainty of the system. An adaptive GPC algorithm is used to design external loop controller to improve the performance and the robustness of the system. Two closed loops used in the design approach realize the system׳s performance and improve the robustness. The simulation results show that the algorithm of the robot end-effector contacting force control system is effective.

  11. Design of state-feedback controllers including sensitivity reduction, with applications to precision pointing

    NASA Technical Reports Server (NTRS)

    Hadass, Z.

    1974-01-01

    The design procedure of feedback controllers was described and the considerations for the selection of the design parameters were given. The frequency domain properties of single-input single-output systems using state feedback controllers are analyzed, and desirable phase and gain margin properties are demonstrated. Special consideration is given to the design of controllers for tracking systems, especially those designed to track polynomial commands. As an example, a controller was designed for a tracking telescope with a polynomial tracking requirement and some special features such as actuator saturation and multiple measurements, one of which is sampled. The resulting system has a tracking performance comparing favorably with a much more complicated digital aided tracker. The parameter sensitivity reduction was treated by considering the variable parameters as random variables. A performance index is defined as a weighted sum of the state and control convariances that sum from both the random system disturbances and the parameter uncertainties, and is minimized numerically by adjusting a set of free parameters.

  12. The differential characteristics of control rods of VVER-1000 core simulator at a low number of axial mesh points

    NASA Astrophysics Data System (ADS)

    Bolsunov, A. A.; Karpov, S. A.

    2013-12-01

    An algorithm for refining the differential characteristics of the control rods (CRs) of the control and protection system (CPS) for a neutronics model of the VVER-1000 simulator at a low number of axial mesh points of the core is described. The problem of determining the constants for a cell with a partially inserted CR is solved. The cell constants obtained using the proposed approach ensure smoothing of the differential characteristics of an absorbing rod. The algorithm was used in the VVER-1000 simulators (Bushehr NPP, unit no. 1; Rostov NPP, unit no. 1; and Balakovo NPP, unit no. 4).

  13. Kinesio Taping Does Not Provide Additional Benefits in Patients With Chronic Low Back Pain Who Receive Exercise and Manual Therapy: A Randomized Controlled Trial.

    PubMed

    Added, Marco Aurélio Nemitalla; Costa, Leonardo Oliveira Pena; de Freitas, Diego Galace; Fukuda, Thiago Yukio; Monteiro, Renan Lima; Salomão, Evelyn Cassia; de Medeiros, Flávia Cordeiro; Costa, Lucíola da Cunha Menezes

    2016-07-01

    Study Design Randomized controlled trial. Background Many clinical practice guidelines endorse both manual therapy and exercise as effective treatment options for patients with low back pain. To optimize the effects of the treatments recommended by the guidelines, a new intervention known as Kinesio Taping is being widely used in these patients. Objectives To determine the effectiveness of Kinesio Taping in patients with chronic nonspecific low back pain when added to a physical therapy program consisting of exercise and manual therapy. Methods One hundred forty-eight patients with chronic nonspecific low back pain were randomly allocated to receive 10 (twice weekly) sessions of physical therapy, consisting of exercise and manual therapy, or the same treatment with the addition of Kinesio Taping applied to the lower back. The primary outcomes were pain intensity and disability (5 weeks after randomization) and the secondary outcomes were pain intensity, disability (3 months and 6 months after randomization), global perceived effect, and satisfaction with care (5 weeks after treatment). Data were collected by a blinded assessor. Results No between-group differences were observed in the primary outcomes of pain intensity (mean difference, -0.01 points; 95% confidence interval [CI]: -0.88, 0.85) or disability (mean difference, 1.14 points; 95% CI: -0.85, 3.13) at 5 weeks' follow-up. In addition, no between-group differences were observed for any of the other outcomes evaluated, except for disability 6 months after randomization (mean difference, 2.01 points; 95% CI: 0.03, 4.00) in favor of the control group. Conclusion Patients who received a physical therapy program consisting of exercise and manual therapy did not get additional benefit from the use of Kinesio Taping. Level of Evidence Therapy, level 1b. Prospectively registered May 28, 2013 at www.ClinicalTrials.gov (NCT01866332). J Orthop Sports Phys Ther 2016;46(7):506-513. Epub 6 Jun 2016. doi:10.2519/jospt.2016.6590.

  14. Kinesio Taping Does Not Provide Additional Benefits in Patients With Chronic Low Back Pain Who Receive Exercise and Manual Therapy: A Randomized Controlled Trial.

    PubMed

    Added, Marco Aurélio Nemitalla; Costa, Leonardo Oliveira Pena; de Freitas, Diego Galace; Fukuda, Thiago Yukio; Monteiro, Renan Lima; Salomão, Evelyn Cassia; de Medeiros, Flávia Cordeiro; Costa, Lucíola da Cunha Menezes

    2016-07-01

    Study Design Randomized controlled trial. Background Many clinical practice guidelines endorse both manual therapy and exercise as effective treatment options for patients with low back pain. To optimize the effects of the treatments recommended by the guidelines, a new intervention known as Kinesio Taping is being widely used in these patients. Objectives To determine the effectiveness of Kinesio Taping in patients with chronic nonspecific low back pain when added to a physical therapy program consisting of exercise and manual therapy. Methods One hundred forty-eight patients with chronic nonspecific low back pain were randomly allocated to receive 10 (twice weekly) sessions of physical therapy, consisting of exercise and manual therapy, or the same treatment with the addition of Kinesio Taping applied to the lower back. The primary outcomes were pain intensity and disability (5 weeks after randomization) and the secondary outcomes were pain intensity, disability (3 months and 6 months after randomization), global perceived effect, and satisfaction with care (5 weeks after treatment). Data were collected by a blinded assessor. Results No between-group differences were observed in the primary outcomes of pain intensity (mean difference, -0.01 points; 95% confidence interval [CI]: -0.88, 0.85) or disability (mean difference, 1.14 points; 95% CI: -0.85, 3.13) at 5 weeks' follow-up. In addition, no between-group differences were observed for any of the other outcomes evaluated, except for disability 6 months after randomization (mean difference, 2.01 points; 95% CI: 0.03, 4.00) in favor of the control group. Conclusion Patients who received a physical therapy program consisting of exercise and manual therapy did not get additional benefit from the use of Kinesio Taping. Level of Evidence Therapy, level 1b. Prospectively registered May 28, 2013 at www.ClinicalTrials.gov (NCT01866332). J Orthop Sports Phys Ther 2016;46(7):506-513. Epub 6 Jun 2016. doi:10.2519/jospt.2016

  15. Chandra X-Ray Observatory Pointing Control System Performance During Transfer Orbit and Initial On-Orbit Operations

    NASA Technical Reports Server (NTRS)

    Quast, Peter; Tung, Frank; West, Mark; Wider, John

    2000-01-01

    The Chandra X-ray Observatory (CXO, formerly AXAF) is the third of the four NASA great observatories. It was launched from Kennedy Space Flight Center on 23 July 1999 aboard the Space Shuttle Columbia and was successfully inserted in a 330 x 72,000 km orbit by the Inertial Upper Stage (IUS). Through a series of five Integral Propulsion System burns, CXO was placed in a 10,000 x 139,000 km orbit. After initial on-orbit checkout, Chandra's first light images were unveiled to the public on 26 August, 1999. The CXO Pointing Control and Aspect Determination (PCAD) subsystem is designed to perform attitude control and determination functions in support of transfer orbit operations and on-orbit science mission. After a brief description of the PCAD subsystem, the paper highlights the PCAD activities during the transfer orbit and initial on-orbit operations. These activities include: CXO/IUS separation, attitude and gyro bias estimation with earth sensor and sun sensor, attitude control and disturbance torque estimation for delta-v burns, momentum build-up due to gravity gradient and solar pressure, momentum unloading with thrusters, attitude initialization with star measurements, gyro alignment calibration, maneuvering and transition to normal pointing, and PCAD pointing and stability performance.

  16. Initial performance improvements due to design modifications for the Pointing Control System on the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Nurre, G. S.; Sharkey, J. P.; Waites, H. B.

    Shortly after Hubble Space Telescope was deployed on orbit it became apparent that the Pointing Control System was experiencing unexpectedly large disturbances during certain portions of the orbit. While these disturbances were most pronounced during transitions of the Earth's shadow, significant disruptions to the pointing occurred at other times in the orbit. Careful analysis of the flight data has lead to the conclusion that the disturbances are caused by a combination of rapid thermal deformations of the Solar Arrays together with striction-friction mechanisms within the array that randomly release stored thermal/mechanical energy. This paper describes the baseline pointing control system design and the flight data that characterized the effects of the extraneous disturbances. The paper goes on to describe the procedure for modifying the onboard controller to attenuate the disturbances to levels consistent with the science operations. Flight data demonstrating the improved performance are shown and are tabulated to compare performance prior to and after phase I of the redesign.

  17. Precision Pointing Control to and Accurate Target Estimation of a Non-Cooperative Vehicle

    NASA Technical Reports Server (NTRS)

    VanEepoel, John; Thienel, Julie; Sanner, Robert M.

    2006-01-01

    In 2004, NASA began investigating a robotic servicing mission for the Hubble Space Telescope (HST). Such a mission would not only require estimates of the HST attitude and rates in order to achieve capture by the proposed Hubble Robotic Vehicle (HRV), but also precision control to achieve the desired rate and maintain the orientation to successfully dock with HST. To generalize the situation, HST is the target vehicle and HRV is the chaser. This work presents a nonlinear approach for estimating the body rates of a non-cooperative target vehicle, and coupling this estimation to a control scheme. Non-cooperative in this context relates to the target vehicle no longer having the ability to maintain attitude control or transmit attitude knowledge.

  18. Improvement of a geodetic triangulation through control points established by means of satellite or precision traversing

    NASA Technical Reports Server (NTRS)

    Saxena, N. K.

    1972-01-01

    Whether any significant increment to accuracy could be transferred from a super-control continental net (continental satellite net or super-transcontinental traverse) to the fundamental geodetic net (first-order triangulation) is discussed. This objective was accomplished by evaluating the positional accuracy improvement for a triangulation station, which is near the middle of the investigated geodetic triangulation net, by using various station constraints over its geodetic position. This investigation on a 1858 kilometer long triangulation chain shows that the super-control net can provide a useful constraint to the investigated geodetic triangulation net, and thus can improve it only when the accuracy of super-control net is at least 1 part in 500,000.

  19. Method for controlling boiling point distribution of coal liquefaction oil product

    DOEpatents

    Anderson, Raymond P.; Schmalzer, David K.; Wright, Charles H.

    1982-12-21

    The relative ratio of heavy distillate to light distillate produced in a coal liquefaction process is continuously controlled by automatically and continuously controlling the ratio of heavy distillate to light distillate in a liquid solvent used to form the feed slurry to the coal liquefaction zone, and varying the weight ratio of heavy distillate to light distillate in the liquid solvent inversely with respect to the desired weight ratio of heavy distillate to light distillate in the distillate fuel oil product. The concentration of light distillate and heavy distillate in the liquid solvent is controlled by recycling predetermined amounts of light distillate and heavy distillate for admixture with feed coal to the process in accordance with the foregoing relationships.

  20. Method for controlling boiling point distribution of coal liquefaction oil product

    DOEpatents

    Anderson, R.P.; Schmalzer, D.K.; Wright, C.H.

    1982-12-21

    The relative ratio of heavy distillate to light distillate produced in a coal liquefaction process is continuously controlled by automatically and continuously controlling the ratio of heavy distillate to light distillate in a liquid solvent used to form the feed slurry to the coal liquefaction zone, and varying the weight ratio of heavy distillate to light distillate in the liquid solvent inversely with respect to the desired weight ratio of heavy distillate to light distillate in the distillate fuel oil product. The concentration of light distillate and heavy distillate in the liquid solvent is controlled by recycling predetermined amounts of light distillate and heavy distillate for admixture with feed coal to the process in accordance with the foregoing relationships. 3 figs.

  1. Design and Integration of an All-Magnetic Attitude Control System for FASTSAT-HSV01's Multiple Pointing Objectives

    NASA Technical Reports Server (NTRS)

    DeKock, Brandon; Sanders, Devon; Vanzwieten, Tannen; Capo-Lugo, Pedro

    2011-01-01

    The FASTSAT-HSV01 spacecraft is a microsatellite with magnetic torque rods as it sole attitude control actuator. FASTSAT s multiple payloads and mission functions require the Attitude Control System (ACS) to maintain Local Vertical Local Horizontal (LVLH)-referenced attitudes without spin-stabilization, while the pointing errors for some attitudes be significantly smaller than the previous best-demonstrated for this type of control system. The mission requires the ACS to hold multiple stable, unstable, and non-equilibrium attitudes, as well as eject a 3U CubeSat from an onboard P-POD and recover from the ensuing tumble. This paper describes the Attitude Control System, the reasons for design choices, how the ACS integrates with the rest of the spacecraft, and gives recommendations for potential future applications of the work.

  2. Assessment Of ASTER GDEM And SRTM Performance By Comparing With Survey Control Points And Icesat/GLAS Data

    NASA Astrophysics Data System (ADS)

    Jarihani, A. A.; Callow, J. N.

    2011-12-01

    Topographic data plays a critical role in water resources modeling with determining watershed hydrologic characteristics from raster-based digital elevation models (DEM). Raster-based DEMs have been widely used to derive topographic attributes used in hydraulic and hydrologic modeling such as slope, stream network, basins boundary and area. Accurate models of floodplain topography are essential for having accurate output of hydrologic models. The Shuttle Radar Topography Mission (SRTM) provides near-global topographic coverage of the Earth's surface with unprecedented consistency and accuracy with the resolution of 1-3 arc sec. A new Global Digital Elevation Model (GDEM) from optical stereo data acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) was recently released with the resolution of 1 arc sec. This study the performance of the ASTER GDEM and SRTM DEMs is assessed by comparing with ground-based survey control points and point data from ICESat/GLAS (Ice, Cloud, and land Elevation Satellite/Geoscience Laser Altimeter System) for a 7x7degree area in Queensland Australia. This area contains large and remote river basins, where these datasets provide an invaluable resource from which river floodplain inundation can be measured and modelled. Our study focuses on both data and datum issues, which are required to provide a realistic assessment of the achievable relative and absolute ground topographic accuracies. We assessed ground-based survey control points' with ICESat satellite altimetry points and in turn assessed accuracy of the ASTER GDEM and SRTM DEMs over the study area. ICESat provides globally-distributed elevation data of high accuracy (2.47.3 m horizontal error and 0.040.13 m (per degree of incidence angle) vertical error)We applied the GLA14 elevation products (Land/Canopy elevations) for the Laser 3a observation period and Release 31 to compare with 5000 ground survey control points in study area.Our ICESat-control

  3. Optical Data Links For Point-Of-Sale (POS) Electronic Terminals, Communications And Control

    NASA Astrophysics Data System (ADS)

    Cheng, Charles C. K.; Parikh, Bipin D.

    1980-09-01

    This paper describes an optical data link designed to meet high performance, reliability, and cost requirements at 1.25 and 10 Mb/s. Several new technologies are embodied in this design. This link utilizes a fast, broad-area, low-brightness light-emitting diode (LED) optical source, a low-loss optical fiber having a large core and high numerical aperture (N.A.), and a PIN photodiode detector. Rather simple circuitry is used to drive the LED and to regenerate the received optical signal at the PIN. The optical interfacing hardware is designed to provide simultaneous transmission of the optical and electrical signals, making the optical data link compatible with mainframe hardware and providing relocatability and reduced installation costs. The data link has met the various performance specifications for point-of-sale (POS) terminals in the laboratory, and it is presently being evaluated more extensively.

  4. Survey on advances in orbital dynamics and control for libration point orbits

    NASA Astrophysics Data System (ADS)

    Xu, Ming; Liang, Yuying; Ren, Kewei

    2016-04-01

    Libration point orbits (LPOs) have drawn a lot of interest because of their great significance in deep space exploration. This paper summarizes the past developments and then presents the current state-of-art of LPOs including the dynamical structure of phase space, the transfer trajectories and homoclinic/heterclinic connections of LPOs, the station-keeping strategies, and some constellation deployments employing LPOs. Subsequently addressed are the applications of the LPO theory into the fields of lunar transfers, solar sail equilibria and formation flying. Finally, future research directions on LPOs are described from the aspects of the existence proof of Halo orbits, orbital design for the potential missions motivated by LPOs, and so on.

  5. Evaluation of Control Points in Youngstock and Adult Dairy Cow Management to Control Transmission of Mycobacterium avium subsp. paratuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Goal Complete a series of controlled on-farm trials to critically evaluate the efficacy and cost-benefit of commonly recommended management practices for reducing the transmission of Mycobacterium avium subsp. paratuberculosis (Map) in infected herds. Objective 1. Evaluate the effect of maternity...

  6. The influence of deposit control additives on nitrogen oxides emissions from spark ignition engines (case study: Tehran).

    PubMed

    Bidhendi, Gholamreza Nabi; Zand, Ali Daryabeigi; Tabrizi, Alireza Mikaeili; Pezeshk, Hamid; Baghvand, Akbar

    2007-04-15

    In the present research, the influence of a deposit control additive on NOx emissions from two types of gasoline engine vehicles i.e., Peykan (base on Hillman) and Pride (South Korea Kia motors) was studied. Exhaust NOx emissions were measured in to stages, before decarbonization process and after that. Statistical analysis was conducted on the measurement results. Results showed that NOx emissions from Peykans increased 0.28% and NOx emissions from Pride automobiles decreased 6.18% on average, due to the elimination of engine deposits. The observed variations were not statistically and practically significant. The results indicated that making use of detergent additives is not an effective way to reduce the exhaust NOx emissions from gasoline engine vehicles. PMID:19069943

  7. Stability of ZnO quantum dots tuned by controlled addition of ethylene glycol during their growth

    NASA Astrophysics Data System (ADS)

    Zimmermann, Lizandra M.; Baldissera, Paulo V.; Bechtold, Ivan H.

    2016-07-01

    ZnO quantum dots were prepared via a sol–gel route from zinc acetate and sodium hydroxide. The influence of ethylene glycol addition during the first stages of reaction (1–5 min) as a stabilizer, as well as the influence of its concentration in 2-propanol were investigated. The optimization led to particles with enough stability and homogeneity around 3.7 nm of diameter to allow for quantum confinement effect. Spectroscopic UV–vis absorption measurements allowed to explore the underlying mechanism of nucleation and growth and to have the control of it. The emission of the ZnO nanoparticles was explored under experimental perturbations with addition of small amounts of water to investigate the interplay between surface defects and the excitonic effect. The results suggest that the water interferes directly on the defects first and later on the excitonic recombination. Their morphology was determined with transmission electron microscopy.

  8. Stability of ZnO quantum dots tuned by controlled addition of ethylene glycol during their growth

    NASA Astrophysics Data System (ADS)

    Zimmermann, Lizandra M.; Baldissera, Paulo V.; Bechtold, Ivan H.

    2016-07-01

    ZnO quantum dots were prepared via a sol-gel route from zinc acetate and sodium hydroxide. The influence of ethylene glycol addition during the first stages of reaction (1-5 min) as a stabilizer, as well as the influence of its concentration in 2-propanol were investigated. The optimization led to particles with enough stability and homogeneity around 3.7 nm of diameter to allow for quantum confinement effect. Spectroscopic UV-vis absorption measurements allowed to explore the underlying mechanism of nucleation and growth and to have the control of it. The emission of the ZnO nanoparticles was explored under experimental perturbations with addition of small amounts of water to investigate the interplay between surface defects and the excitonic effect. The results suggest that the water interferes directly on the defects first and later on the excitonic recombination. Their morphology was determined with transmission electron microscopy.

  9. Development of a New Hypersonic Shock Tunnel Facility to Investigate Electromagnetic Energy Addition for Flow Control and Basic Supersonic Combustion

    NASA Astrophysics Data System (ADS)

    Toro, P. G. P.; Minucci, M. A. S.; Chanes, J. B.; Pereira, A. L.; Nagamatsu, H. T.

    2006-05-01

    A new 0.6-m. diameter Hypersonic Shock Tunnel is been designed, fabricated and will be installed at the Laboratory of Aerothermodynamics and Hypersonics IEAv-CTA, Brazil. The brand new hypersonic facility, designated as T3, is primarily intended to be used as an important tool in the investigation of supersonic combustion management and of electromagnetic energy addition for flow control. The design of the runnel enables relatively long test times, 2-10 milliseconds, suitable for basic supersonic combustion and energy addition by laser experiments. Free stream Mach numbers ranging from 6 to 25 can be produced and stagnation pressures and temperatures of 200 atm. and 5,500 K, respectively, can be generated. Shadowgraph and schlieren optical techniques will be used for flow visualization and the new facility is expected to be commissioned by the end of 2006.

  10. New Research on Multitasking Points to Role of Self-Control

    ERIC Educational Resources Information Center

    Sparks, Sarah D.

    2012-01-01

    For a generation of children immersed in technology, emerging research suggests that while the temptation to multitask may be pervasive, the ability to control it could be the real bellwether of academic success. The pervasiveness of technology and social media, coupled with a fear of missing out on something important, has led students to pay…

  11. 21 CFR 123.6 - Hazard analysis and Hazard Analysis Critical Control Point (HACCP) plan.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... establish controls because experience, illness data, scientific reports, or other information provide a... kinds of fish and fishery products together, or group kinds of production methods together, if the food... all production methods so grouped. (c) The contents of the HACCP plan. The HACCP plan shall, at...

  12. Effect of kaolin addition on the performance of controlled low-strength material using industrial waste incineration bottom ash.

    PubMed

    Naganathan, Sivakumar; Razak, Hashim Abdul; Hamid, Siti Nadzriah Abdul

    2010-09-01

    Incineration of industrial waste produces large quantities of bottom ash which are normally sent to secured landfill, but is not a sustainable solution. Use of bottom ash in engineering applications will contribute to sustainability and generate revenue. One way of using the industrial waste incineration bottom ash is in controlled low-strength material (CLSM). Use of bottom ash in CLSM has problems related to bleeding and excessive strength development and so an additive has to be used to control bleeding and strength development. The main objective of this research is to study the effect of kaolin addition on the performance of CLSM made using industrial waste incineration bottom ash. CLSM mixes were made with bottom ash, cement, and refined kaolin. Various tests were performed on the CLSM in fresh and hardened states including compressive strength, water absorption, California bearing ratio (CBR) and the tests for concentration of leachable substances on the bleed and leachate. The compressive strength of CLSM tested ranged from 0.11 to 9.86 MPa. CBR values ranged from 6 to 46, and water absorption values from 12 to 36%. It was shown that the addition of kaolin delayed the initial setting time of CLSM mixtures, reduced bleeding, lowered the compressive strength, and increased the values of water absorption, sorption, and initial surface absorption. The CLSM tested did not have corrosivity. It was shown that the hardened CLSM was non hazardous, and the addition of kaolin increased the concentration of heavy metals and salts in the bleed and leachate. PMID:20852000

  13. The effectiveness of the McKenzie method in addition to first-line care for acute low back pain: a randomized controlled trial

    PubMed Central

    2010-01-01

    Background Low back pain is a highly prevalent and disabling condition worldwide. Clinical guidelines for the management of patients with acute low back pain recommend first-line treatment consisting of advice, reassurance and simple analgesics. Exercise is also commonly prescribed to these patients. The primary aim of this study was to evaluate the short-term effect of adding the McKenzie method to the first-line care of patients with acute low back pain. Methods A multi-centre randomized controlled trial with a 3-month follow-up was conducted between September 2005 and June 2008. Patients seeking care for acute non-specific low back pain from primary care medical practices were screened. Eligible participants were assigned to receive a treatment programme based on the McKenzie method and first-line care (advice, reassurance and time-contingent acetaminophen) or first-line care alone, for 3 weeks. Primary outcome measures included pain (0-10 Numeric Rating Scale) over the first seven days, pain at 1 week, pain at 3 weeks and global perceived effect (-5 to 5 scale) at 3 weeks. Treatment effects were estimated using linear mixed models. Results One hundred and forty-eight participants were randomized into study groups, of whom 138 (93%) completed the last follow-up. The addition of the McKenzie method to first-line care produced statistically significant but small reductions in pain when compared to first-line care alone: mean of -0.4 points (95% confidence interval, -0.8 to -0.1) at 1 week, -0.7 points (95% confidence interval, -1.2 to -0.1) at 3 weeks, and -0.3 points (95% confidence interval, -0.5 to -0.0) over the first 7 days. Patients receiving the McKenzie method did not show additional effects on global perceived effect, disability, function or on the risk of persistent symptoms. These patients sought less additional health care than those receiving only first-line care (P = 0.002). Conclusions When added to the currently recommended first-line care of acute

  14. Tipping Points

    NASA Astrophysics Data System (ADS)

    Hansen, J.

    2007-12-01

    A climate tipping point, at least as I have used the phrase, refers to a situation in which a changing climate forcing has reached a point such that little additional forcing (or global temperature change) is needed to cause large, relatively rapid, climate change. Present examples include potential loss of all Arctic sea ice and instability of the West Antarctic and Greenland ice sheets. Tipping points are characterized by ready feedbacks that amplify the effect of forcings. The notion that these may be runaway feedbacks is a misconception. However, present "unrealized" global warming, due to the climate system's thermal inertia, exacerbates the difficulty of avoiding global warming tipping points. I argue that prompt efforts to slow CO2 emissions and absolutely reduce non-CO2 forcings are both essential if we are to avoid tipping points that would be disastrous for humanity and creation, the planet as civilization knows it.

  15. Use of Antimicrobial Food Additives as Potential Dipping Solutions to Control Pseudomonas spp. Contamination in the Frankfurters and Ham

    PubMed Central

    Oh, Mi-Hwa; Park, Beom-Young; Choi, Kyoung-Hee

    2014-01-01

    This study evaluated the effect of sodium diacetate and sodium lactate solutions for reducing the cell count of Pseudomonas spp. in frankfurters and hams. A mixture of Pseudomonas aeruginosa (NCCP10338, NCCP10250, and NCCP11229), and Pseudomonas fluorescens (KACC10323 and KACC10326) was inoculated on cooked frankfurters and ham. The inoculated samples were immersed into control (sterile distilled water), sodium diacetate (5 and 10%), sodium lactate (5 and 10%), 5% sodium diacetate + 5% sodium lactate, and 10% sodium diacetate + 10% sodium lactate for 0-10 min. Inoculated frankfurters and ham were also immersed into acidified (pH 3.0) solutions such as acidified sodium diacetate (5 and 10%), and acidified sodium lactate (5 and 10%) in addition to control (acidified distilled water) for 0-10 min. Total aerobic plate counts for Pseudomonas spp. were enumerated on Cetrimide agar. Significant reductions (ca. 2 Log CFU/g) in Pseudomonas spp. cells on frankfurters and ham were observed only for a combination treatment of 10% sodium lactate + 10% sodium diacetate. When the solutions were acidified to pH 3.0, the total reductions of Pseudomonas spp. were 1.5-4.0 Log CFU/g. The order of reduction amounts of Pseudomonas spp. cell counts was 10% sodium lactate > 5% sodium lactate ≥ 10% sodium diacetate > 5% sodium diacetate > control for frankfurters, and 10% sodium lactate > 5% sodium lactate > 10% sodium diacetate > 5% sodium diacetate > control for ham. The results suggest that using acidified food additive antimicrobials, as dipping solutions, should be useful in reducing Pseudomonas spp. on frankfurters and ham. PMID:26761492

  16. Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized using polyol method

    NASA Astrophysics Data System (ADS)

    Junaidi, Yunus, Muhammad; Triyana, Kuwat; Harsojo, Suharyadi, Edi

    2016-04-01

    We report our investigation on the effect of chloride ions on controlling the shapes and properties of silver nanorods (AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as a salt precursor and performed at the oil bath temperature of 140°C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorods were characterized using SEM and XRD. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline of silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorods decreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

  17. Statistical process control in the hybrid microelectronics manufacturing industry: A Navy view point

    NASA Astrophysics Data System (ADS)

    Azu, Charles C., Jr.

    1993-04-01

    The U.S. Navy is concerned with receiving high quality hybrid microelectronic circuits. The Navy recognizes that in order to obtain high quality circuits a manufacturer must have an effective statistical process control (SPC) program implemented. The implementation of effective SPC programs is an objective of the military hybrid microelectronics industry. Often the smaller sized manufacturers in the industry have little SPC implementation, while the larger manufacturers have practices originally developed for the control of other product lines outside the hybrid technology area. The industry recognizes that SPC programs will result in high quality hybrid microcircuits which the U.S. Navy requires. In the past, the goal of the industry had not been to put in effective process control methods, but to merely meet the government military standards on the quality of the hybrids they produce. This practice, at best, resulted in a 'hit or miss' situation when it comes to hybrid microcircuit assemblies meeting military standards. The U.S. Navy through its MicroCIM program has been challenging and working with the industry in the area of SPC practice methods. The major limitations so far have been a lack of available sensors for the real-time collection of effective SPC data on the factory floor. This paper will discuss the Navy's efforts in bringing about effective SPC programs in the military hybrid manufacturing industry.

  18. Minimum stiffness location of point support for control of fundamental natural frequency of rectangular plate by Rayleigh-Ritz method

    NASA Astrophysics Data System (ADS)

    Wang, D.; Yang, Z. C.; Yu, Z. G.

    2010-07-01

    The Rayleigh-Ritz method is employed to determine the minimum stiffness location of the elastic point support for raising the fundamental natural frequency of a rectangular plate to the second frequency of the unsupported plate, which usually is the upper limit of the first frequency for a single support. Based on the optimal design of the support position, the minimum stiffness can be obtained numerically by solving a characteristic eigenvalue sub-problem. In the Rayleigh-Ritz procedure the boundary characteristic orthogonal polynomials are used for the admissible functions. Several typical examples of plate structures with the additional point supports are analyzed in detail, and the results prove that the proposed method is very effective in the solution to the optimal design of the supports. It will be shown that elastic supports can be designed like rigid ones for the purpose of increasing the fundamental natural frequency of a rectangular plate.

  19. Design of set-point weighting PI{sup λ} + D{sup μ} controller for vertical magnetic flux controller in Damavand tokamak

    SciTech Connect

    Rasouli, H.; Fatehi, A.

    2014-12-15

    In this paper, a simple method is presented for tuning weighted PI{sup λ} + D{sup μ} controller parameters based on the pole placement controller of pseudo-second-order fractional systems. One of the advantages of this controller is capability of reducing the disturbance effects and improving response to input, simultaneously. In the following sections, the performance of this controller is evaluated experimentally to control the vertical magnetic flux in Damavand tokamak. For this work, at first a fractional order model is identified using output-error technique in time domain. For various practical experiments, having desired time responses for magnetic flux in Damavand tokamak, is vital. To approach this, at first the desired closed loop reference models are obtained based on generalized characteristic ratio assignment method in fractional order systems. After that, for the identified model, a set-point weighting PI{sup λ} + D{sup μ} controller is designed and simulated. Finally, this controller is implemented on digital signal processor control system of the plant to fast/slow control of magnetic flux. The practical results show appropriate performance of this controller.

  20. Public Support for Family Smoking Prevention and Tobacco Control Act Point-of-Sale Provisions: Results of a National Study

    PubMed Central

    Emery, Sherry L.; Ennett, Susan; McNaughton Reyes, Heath Luz; Scott, John C.; Ribisl, Kurt M.

    2015-01-01

    Objectives. We assessed public and smoker support for enacted and potential point-of-sale (POS) tobacco-control policies under the Family Smoking Prevention and Tobacco Control Act. Methods. We surveyed a US nationally representative sample of 17 507 respondents (6595 smokers) in January through February 2013, and used linear regression to calculate weighted point estimates and identify factors associated with support for POS policies among adults and smokers. Results. Overall, nonsmokers were more supportive than were smokers. Regardless of smoking status, African Americans, Hispanics, women, and those of older ages were more supportive than White, male, and younger respondents, respectively. Policy support varied by provision. More than 80% of respondents supported minors’ access restrictions and more than 45% supported graphic warnings. Support was lowest for plain packaging (23%), black-and-white advertising (26%), and a ban on menthol cigarettes (36%). Conclusions. Public support for marketing and POS provisions is low relative to other areas of tobacco control. Tobacco-control advocates and the Food and Drug Administration should build on existing levels of public support to promote and maintain evidence-based, but controversial, policy changes in the retail environment. PMID:26270303

  1. Working-point control technique for the homodyne interferometry in hydrophone calibration

    NASA Astrophysics Data System (ADS)

    Yang, Ping; Xing, Guangzhen

    2015-02-01

    The stabilization of a homodyne type Michelson interferometer for calibrating the high frequency hydrophone is presented in this article. For the detection of the ultrasonic field, a 5 um thickness pellicle was inserted in water moving in sympathy with the ultrasonic wave. To ensure high signal to noise ratio at high frequencies, a 5 MHz focusing transducer was driven by high voltage and harmonics of the shocked ultrasonic field could be activated. Nevertheless, the homodyne interferometer suffered from the drawback of signal fading caused by the low frequency noise in environment, including acoustic noise and water surface agitation. Direct Current Phase Tracking was utilized to maintain the quadrature working point for the interferometer. Most of environmental noises could be effectively compensated while stabilization was maintained. A piezoelectric actuator supporting the reference mirror was utilized as the stabilizing element whose output was frequency independent over the low frequency disturbances, usually below 200 Hz. The ultrasonic signal fading caused by environmental disturbances could be solved while the negative electric feedback loop was operating. The displacement and voltage output of the hydrophone under test were then processed by DFT to derive the fundamental and harmonic components. Under plane wave conditions, the ultrasonic pressure could be derived by the detected displacement with a stabilized homodyne interferometer, and the hydrophone could then be calibrated. Measurement results indicated that the hydrophone calibration system based on the active stabilization of homodyne interferometry was sound in theory and feasible in practice.

  2. Optimal Control of Shock Tube Flow via Water Addition with Application to Ignition Overpressure Mitigation in Launch Vehicles

    NASA Astrophysics Data System (ADS)

    Moshman, Nathan

    2009-11-01

    Ignition Overpressure (IOP) in launch vehicles occurs at the start of ignition when a steep rise in pressure propagates outward from the rocket nozzle. It is crucial to minimize the overpressure so as to decrease risk of damage to the rocket body. Currently, CFD studies exist on this situation but there are no optimization studies of the water addition as a means to suppress the IOP. The proposed dissertation will use a numerical method to compute an approximate solution for an optimal control problem constrained by the one-dimensional Euler PDEs of fluid dynamics as well as volume fraction conservation. A model for inter-phase transport of mass momentum and energy and fluid interface quantities will be given. The control will be water addition from external nozzles. The adjoint system of equations will be derived and discretized. Necessary optimal conditions will be derived. An SQP method will solve an optimal situation. Predictions will be validated against shock tube experiments at the NPS rocket lab.

  3. Robust control chart for change point detection of process variance in the presence of disturbances

    NASA Astrophysics Data System (ADS)

    Huat, Ng Kooi; Midi, Habshah

    2015-02-01

    A conventional control chart for detecting shifts in variance of a process is typically developed where in most circumstances the nominal value of variance is unknown and based upon one of the essential assumptions that the underlying distribution of the quality characteristic is normal. However, this is not always the case as it is fairly evident that the statistical estimates used for these charts are very sensitive to the occurrence of occasional outliers. This is for the reason that the robust control charts are put forward when the underlying normality assumption is not met, and served as a remedial measure to the problem of contamination in process data. Realizing that the existing approach, namely Biweight A pooled residuals method, appears to be resistance to localized disturbances but lack of efficiency when there are diffuse disturbances. To be concrete, diffuse disturbances are those that have equal change of being perturbed by any observation, while a localized disturbance will have effect on every member of a certain subsample or subsamples. Since the efficiency of estimators in the presence of disturbances can rely heavily upon whether the disturbances are distributed throughout the observations or concentrated in a few subsamples. Hence, to this end, in this paper we proposed a new robust MBAS control chart by means of subsample-based robust Modified Biweight A scale estimator in estimating the process standard deviation. It has strong resistance to both localized and diffuse disturbances as well as high efficiency when no disturbances are present. The performance of the proposed robust chart was evaluated based on some decision criteria through Monte Carlo simulation study.

  4. Distribution of controlled substances in the U.S. supply chain: where does the compass point?

    PubMed

    Ruble, James H

    2012-09-01

    Recent administrative actions taken by the Drug Enforcement Administration (DEA) in Florida have prompted an articulate and detailed discussion of the pharmaceutical supply chain for controlled substances. Current practices in commercial distribution systems may have a partial nexus to the proliferation of opioid prescription drug abuse in Florida. No single factor or entity is responsible for this abuse proliferation, and there is no intent to harm consumers; however, distribution practices are adding risk to public health. This commentary extends a discussion on supply chain practices that seem misaligned in the promotion of legitimate business objectives and advancing public health.

  5. Loop Heat Pipe Transient Behavior Using Heat Source Temperature for Set Point Control with Thermoelectric Converter on Reservoir

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly done by cold biasing the reservoir and using electrical heaters to provide the required control power. With this method, the loop operating temperature can be controlled within 0.5K or better. However, because the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if the LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP was carried out to investigate the effects on the LHP operation when the control temperature sensor was placed on the heat source instead of the reservoir. In these tests, the LHP reservoir was cold-biased and was heated by a control heater. Test results show that it was feasible to use the heat source temperature for feedback control of the LHP operation. In particular, when a thermoelectric converter was used as the reservoir control heater, the heat source temperature could be maintained within a tight range using a proportional-integral-derivative or on/off control algorithm. Moreover, because the TEC could provide both heating and cooling to the reservoir, temperature oscillations during fast transients such as loop startup could be eliminated or substantially reduced when compared to using an electrical heater as the control heater.

  6. Vertical Field of View Reference Point Study for Flight Path Control and Hazard Avoidance

    NASA Technical Reports Server (NTRS)

    Comstock, J. Raymond, Jr.; Rudisill, Marianne; Kramer, Lynda J.; Busquets, Anthony M.

    2002-01-01

    Researchers within the eXternal Visibility System (XVS) element of the High-Speed Research (HSR) program developed and evaluated display concepts that will provide the flight crew of the proposed High-Speed Civil Transport (HSCT) with integrated imagery and symbology to permit path control and hazard avoidance functions while maintaining required situation awareness. The challenge of the XVS program is to develop concepts that would permit a no-nose-droop configuration of an HSCT and expanded low visibility HSCT operational capabilities. This study was one of a series of experiments exploring the 'design space' restrictions for physical placement of an XVS display. The primary experimental issues here was 'conformality' of the forward display vertical position with respect to the side window in simulated flight. 'Conformality' refers to the case such that the horizon and objects appear in the same relative positions when viewed through the forward windows or display and the side windows. This study quantified the effects of visual conformality on pilot flight path control and hazard avoidance performance. Here, conformality related to the positioning and relationship of the artificial horizon line and associated symbology presented on the forward display and the horizon and associated ground, horizon, and sky textures as they would appear in the real view through a window presented in the side window display. No significant performance consequences were found for the non-conformal conditions.

  7. Chemical additive to enhance antimicrobial efficacy of chlorine and control cross-contamination during immersion chill of broiler carcasses.

    PubMed

    Schambach, B T; Berrang, M E; Harrison, M A; Meinersmann, R J

    2014-09-01

    Immersion chilling of broiler carcasses can be a site for cross-contamination between the occasional highly contaminated carcass and those that are co-chilled. Chlorine is often used as an antimicrobial but can be overcome by organic material. A proprietary chlorine stabilizer (T-128) based on phosphoric acid-propylene glycol was tested as a chill tank additive in experiments simulating commercial broiler chilling. In bench-scale experiments, 0.5% T-128 was compared with plain water (control), 50 ppm of chlorine, and the combination of 0.5% T-128 with 50 ppm of chlorine to control transfer of Salmonella and Campylobacter from inoculated wing drummettes to co-chilled uninoculated drummettes. Both chlorine and T-128 lessened cross-contamination with Salmonella (P < 0.05); T-128 and T-128 with chlorine were significantly more effective (P < 0.05) than the control or plain chlorine for control of Campylobacter. T-128 treatments were noted to have a pH of less than 4.0; an additional experiment demonstrated that the antimicrobial effect of T-128 was not due merely to a lower pH. In commercial broiler chilling, a pH close to 6.0 is preferred to maximize chlorine effectiveness, while maintaining water-holding capacity of the meat. In a set of pilot-scale experiments with T-128, a near-ideal pH of 6.3 was achieved by using tap water instead of the distilled water used in bench-scale experiments. Pilot-scale chill tanks were used to compare the combination of 0.5% T-128 and 50 ppm of chlorine with 50 ppm of plain chlorine for control of cross-contamination between whole carcasses inoculated with Salmonella and Campylobacter and co-chilled uninoculated carcasses. The T-128 treatment resulted in significantly less crosscontamination by either direct contact or water transfer with both organisms compared with plain chlorine treatment. T-128 may have use in commercial broiler processing to enhance the effectiveness of chlorine in processing water. PMID:25198851

  8. Chemical additive to enhance antimicrobial efficacy of chlorine and control cross-contamination during immersion chill of broiler carcasses.

    PubMed

    Schambach, B T; Berrang, M E; Harrison, M A; Meinersmann, R J

    2014-09-01

    Immersion chilling of broiler carcasses can be a site for cross-contamination between the occasional highly contaminated carcass and those that are co-chilled. Chlorine is often used as an antimicrobial but can be overcome by organic material. A proprietary chlorine stabilizer (T-128) based on phosphoric acid-propylene glycol was tested as a chill tank additive in experiments simulating commercial broiler chilling. In bench-scale experiments, 0.5% T-128 was compared with plain water (control), 50 ppm of chlorine, and the combination of 0.5% T-128 with 50 ppm of chlorine to control transfer of Salmonella and Campylobacter from inoculated wing drummettes to co-chilled uninoculated drummettes. Both chlorine and T-128 lessened cross-contamination with Salmonella (P < 0.05); T-128 and T-128 with chlorine were significantly more effective (P < 0.05) than the control or plain chlorine for control of Campylobacter. T-128 treatments were noted to have a pH of less than 4.0; an additional experiment demonstrated that the antimicrobial effect of T-128 was not due merely to a lower pH. In commercial broiler chilling, a pH close to 6.0 is preferred to maximize chlorine effectiveness, while maintaining water-holding capacity of the meat. In a set of pilot-scale experiments with T-128, a near-ideal pH of 6.3 was achieved by using tap water instead of the distilled water used in bench-scale experiments. Pilot-scale chill tanks were used to compare the combination of 0.5% T-128 and 50 ppm of chlorine with 50 ppm of plain chlorine for control of cross-contamination between whole carcasses inoculated with Salmonella and Campylobacter and co-chilled uninoculated carcasses. The T-128 treatment resulted in significantly less crosscontamination by either direct contact or water transfer with both organisms compared with plain chlorine treatment. T-128 may have use in commercial broiler processing to enhance the effectiveness of chlorine in processing water.

  9. Impact of phosphorus control measures on in-river phosphorus retention associated with point source pollution

    NASA Astrophysics Data System (ADS)

    Demars, B. O. L.; Harper, D. M.; Pitt, J.-A.; Slaughter, R.

    2005-06-01

    In-river phosphorus retention alters the quantity and timings of phosphorus delivery to downstream aquatic systems. Many intensive studies of in-river phosphorus retention have been carried out but generally on a short time scale (2-4 years). In this paper, monthly water quality data, collected by the Environment Agency of England and Wales over 12 years (1990-2001), were used to model daily phosphorus fluxes and monthly in-river phosphorus retention in the lowland calcareous River Wensum, Norfolk, UK. The calibrated model explained 79% and 89% of the observed variance before and after phosphorus control, respectively. A split test revealed that predicted TP loads were in good agreement with observed TP loads (r2=0.85), although TP loads were underestimated under high flow conditions. During relatively dry years, there was no net export of phosphorus from the catchment. High retention of phosphorus occurred, particularly during the summer months, which was not compensated for, by subsequent higher flow events. This was despite a relatively modest critical discharge (Q) above which net remobilisation occur. Phosphorus removal from the effluent at two major STWs (Sewage Treatment Works) reduced phosphorus retention but not the remobilisation. This may indicate that the presence of impoundments and weirs, or overbank flows may have more control on the phosphorus dynamics under high flow conditions. Further phosphorus remedial strategies will be necessary to prevent downstream risks of eutrophication occurring independently of the unpredictable variability in weather conditions. More research is also needed to quantify the impact of the weir and overbank flows on phosphorus dynamics.

  10. Pilot study on the additive effects of berberine and oral type 2 diabetes agents for patients with suboptimal glycemic control

    PubMed Central

    Di Pierro, Francesco; Villanova, Nicola; Agostini, Federica; Marzocchi, Rebecca; Soverini, Valentina; Marchesini, Giulio

    2012-01-01

    Background Suboptimal glycemic control is a common situation in diabetes, regardless of the wide range of drugs available to reach glycemic targets. Basic research in diabetes is endeavoring to identify new actives working as insulin savers, use of which could delay the introduction of injectable insulin or reduce the insulin dose needed. Commonly available as a nutraceutical, berberine is a potential candidate. Methods and results Because its low oral bioavailability can be overcome by P-glycoprotein inhibitors like herbal polyphenols, we have tested the nutraceutical combination of Berberis aristata extract and Silybum marianum extract (Berberol®) in type 2 diabetes in terms of its additive effect when combined with a conventional oral regimen for patients with suboptimal glycemic control. After 90 days of treatment, the nutraceutical association had a positive effect on glycemic and lipid parameters, significantly reducing glycosylated hemoglobin, basal insulin, homeostatic model assessment of insulin resistance, total and low-density lipoprotein cholesterol, and triglycerides. A relevant effect was also observed in terms of liver function by measuring aspartate transaminase and alanine transaminase. The product had a good safety profile, with distinctive gastrointestinal side effects likely due to its acarbose-like action. Conclusion Although further studies should be carried out to confirm our data, Berberol could be considered a good candidate as an adjunctive treatment option in diabetes, especially in patients with suboptimal glycemic control. PMID:22924000

  11. Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized by polyol method

    NASA Astrophysics Data System (ADS)

    Junaidi, Triyana, Kuwat; Harsojo, Suharyadi, Edi

    2016-04-01

    We report our investigation on the effect of chloride ions oncontrolling the shapes and properties of silver nanorods(AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as asalt precursor and performed at the oilbath temperature of 140 °C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorodswere characterized using UV-VIS, XRD, SEM and TEM. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorodsdecreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

  12. A dynamic in vitro lipolysis model. I. Controlling the rate of lipolysis by continuous addition of calcium.

    PubMed

    Zangenberg, N H; Müllertz, A; Kristensen, H G; Hovgaard, L

    2001-09-01

    Lipolysis by pancreatic lipase was investigated with the aim to establish an in vitro lipolysis model, which can be used to investigate the dissolution of poorly soluble lipophilic drug substances at controlled hydrolysis rates. The effects of three experimental parameters -- the concentrations of bile salts and Ca(2+) and the lipase activity -- were investigated. The effect on the rate of hydrolysis of emulsified soybean oil was investigated in experiments in a pH-stat at pH 6.5 and 37 degrees C. The free fatty acids produced by the hydrolysis were titrated at pH 6.5. It was shown that all three investigated parameters influence the initial rate of hydrolysis, whereas only the lipase activity and the concentration of Ca(2+) affect the subsequent stages. It was also shown that the rate of lipolysis can be controlled by the rate of adding Ca(2+). Thus, it is possible to design an in vitro model using readily available and inexpensive materials in which the hydrolysis rate can be controlled by the continuous addition of Ca(2+).

  13. Experimental and computational models of neurite extension at a choice point in response to controlled diffusive gradients

    NASA Astrophysics Data System (ADS)

    Catig, G. C.; Figueroa, S.; Moore, M. J.

    2015-08-01

    Ojective. Axons are guided toward desired targets through a series of choice points that they navigate by sensing cues in the cellular environment. A better understanding of how microenvironmental factors influence neurite growth during development can inform strategies to address nerve injury. Therefore, there is a need for biomimetic models to systematically investigate the influence of guidance cues at such choice points. Approach. We ran an adapted in silico biased turning axon growth model under the influence of nerve growth factor (NGF) and compared the results to corresponding in vitro experiments. We examined if growth simulations were predictive of neurite population behavior at a choice point. We used a biphasic micropatterned hydrogel system consisting of an outer cell restrictive mold that enclosed a bifurcated cell permissive region and placed a well near a bifurcating end to allow proteins to diffuse and form a gradient. Experimental diffusion profiles in these constructs were used to validate a diffusion computational model that utilized experimentally measured diffusion coefficients in hydrogels. The computational diffusion model was then used to establish defined soluble gradients within the permissive region of the hydrogels and maintain the profiles in physiological ranges for an extended period of time. Computational diffusion profiles informed the neurite growth model, which was compared with neurite growth experiments in the bifurcating hydrogel constructs. Main results. Results indicated that when applied to the constrained choice point geometry, the biased turning model predicted experimental behavior closely. Results for both simulated and in vitro neurite growth studies showed a significant chemoattractive response toward the bifurcated end containing an NGF gradient compared to the control, though some neurites were found in the end with no NGF gradient. Significance. The integrated model of neurite growth we describe will allow

  14. Empowering Parents of Obese Children (EPOC): A randomized controlled trial on additional long-term weight effects of parent training.

    PubMed

    Warschburger, Petra; Kroeller, Katja; Haerting, Johannes; Unverzagt, Susanne; van Egmond-Fröhlich, Andreas

    2016-08-01

    Although inpatient lifestyle treatment for obese children and adolescents can be highly effective in the short term, long-term results are unconvincing. One possible explanation might be that the treatment takes place far from parents' homes, limiting the possibility to incorporate the parents, who play a major role in establishing and maintaining a healthy lifestyle in childhood and adolescence. The main goal was to develop a brief behaviorally oriented parent training program that enhances 'obesity-specific' parenting skills in order to prevent relapse. We hypothesized that the inclusion of additional parent training would lead to an improved long-term weight course of obese children. Parents of obese children (n = 686; 7-13 years old) either participated in complementary cognitive-behavioral group sessions (n = 336) or received written information only (n = 350) during the inpatient stay. Children of both groups attended multidisciplinary inpatient rehabilitation. BMI-SDS as a primary outcome was evaluated at baseline, post-intervention and at 6- and 12-month follow-up. Intention-to-treat (ITT) as well as per-protocol analyses (PPA) were performed. A significant within-group decrease of 0.24 (95% CI 0.18 to 0.30) BMI-SDS points from the beginning of the inpatient stay through the first year was found, but no group difference at the one-year follow-up (mean difference 0.02; 95% CI -0.04 to 0.07). We also observed an increase in quality of life scores, intake of healthy food and exercise for both groups, without differences between groups (ITT and PPA). Thus, while the inpatient treatment proved highly effective, additional parent training did not lead to better results in long-term weight maintenance or to better psychosocial well-being compared to written psycho-educational material. Further research should focus on subgroups to answer the question of differential treatment effects.

  15. Hazard analysis of critical control points assessment as a tool to respond to emerging infectious disease outbreaks.

    PubMed

    Edmunds, Kelly L; Hunter, Paul R; Few, Roger; Bell, Diana J

    2013-01-01

    Highly pathogenic avian influenza virus (HPAI) strain H5N1 has had direct and indirect economic impacts arising from direct mortality and control programmes in over 50 countries reporting poultry outbreaks. HPAI H5N1 is now reported as the most widespread and expensive zoonotic disease recorded and continues to pose a global health threat. The aim of this research was to assess the potential of utilising Hazard Analysis of Critical Control Points (HACCP) assessments in providing a framework for a rapid response to emerging infectious disease outbreaks. This novel approach applies a scientific process, widely used in food production systems, to assess risks related to a specific emerging health threat within a known zoonotic disease hotspot. We conducted a HACCP assessment for HPAI viruses within Vietnam's domestic poultry trade and relate our findings to the existing literature. Our HACCP assessment identified poultry flock isolation, transportation, slaughter, preparation and consumption as critical control points for Vietnam's domestic poultry trade. Introduction of the preventative measures highlighted through this HACCP evaluation would reduce the risks posed by HPAI viruses and pressure on the national economy. We conclude that this HACCP assessment provides compelling evidence for the future potential that HACCP analyses could play in initiating a rapid response to emerging infectious diseases. PMID:23967294

  16. Application of hazard analysis critical control point (HACCP) as a possible control measure for Opisthorchis viverrini infection in cultured carp (Puntius gonionotus).

    PubMed

    Khamboonruang, C; Keawvichit, R; Wongworapat, K; Suwanrangsi, S; Hongpromyart, M; Sukhawat, K; Tonguthai, K; Lima dos Santos, C A

    1997-01-01

    Opisthorchiasis due to Opisthorchis viverrini and transmitted through infected freshwater cyprinoid fish (carps) affects more than 8 million people in Thailand, People's Democratic Republic of Lao, and Vietnam. The Hazard Analysis Critical Control Point (HACCP)-concept has been recommended by FAO and WHO to be included in programs to control foodborne trematode infections (FBT). HACCP is a multifactorial approach to control food hazards through surveillance of diseases, foods, and operations and education. This study describes the first attempt to apply HACCP to the prevention and control of Opisthorchis viverrini in pond culture carp (Puntius gonionotus). The experiment was designed and carried out by a multidisciplinary "HACCP team" including experts in the field of public health, parasitology, epidemiology, aquaculture, fisheries extension and fish inspection. The investigation was performed in two fish ponds in the District of Sun Pa Tong, Chiang Mai, Thailand. In the experimental pond, fish was cultured according to HACCP principles and compared with the control pond, which followed conventional aquaculture practices. Water supply to the pond, fish fry, fish feed and pond conditions during the growing period were identified as critical control points (CCPs). Hazards were identified and analyzed, as well as control measures, critical limits, monitoring procedures, corrective actions, and record keeping developed for each one of the above CCPs. Complete pond preparation, particularly aiming to eliminate contamination of pond water with O. viverrini eggs, fish infected with parasite meacercariae and the first intermediate host (Bithynia spp), was conducted. After the pond was filled with water, O. viverrini metacercaria-free fry were released into the pond. The preliminary results obtained indicate that HACCP-based principles applied to carp pond culture could be used as a strategy to prevent and control O. viverrini. Further studies should be undertaken aiming

  17. Point and counterpoint: patient control of access to data in their electronic health records.

    PubMed

    Caine, Kelly; Tierney, William M

    2015-01-01

    Information collection, storage, and management is central to the practice of health care. For centuries, patients' and providers' expectations kept medical records confidential between providers and patients. With the advent of electronic health records, patient health information has become more widely available to providers and health care managers and has broadened its potential use beyond individual patient care. Adhering to the principles of Fair Information Practice, including giving patients control over the availability and use of their individual health records, would improve care by fostering the sharing of sensitive information between patients and providers. However, adherence to such principles could put patients at risk for unsafe care as a result of both missed opportunities for providing needed care as well as provision of contraindicated care, as it would prevent health care providers from having full access to health information. Patients' expectations for the highest possible quality and safety of care, therefore, may be at odds with their desire to limit provider access to their health records. Conversely, provider expectations that patients would willingly seek care for embarrassing conditions and disclose sensitive information may be at odds with patients' information privacy rights. An open dialogue between patients and providers will be necessary to balance respect for patient rights with provider need for patient information.

  18. Point and counterpoint: patient control of access to data in their electronic health records.

    PubMed

    Caine, Kelly; Tierney, William M

    2015-01-01

    Information collection, storage, and management is central to the practice of health care. For centuries, patients' and providers' expectations kept medical records confidential between providers and patients. With the advent of electronic health records, patient health information has become more widely available to providers and health care managers and has broadened its potential use beyond individual patient care. Adhering to the principles of Fair Information Practice, including giving patients control over the availability and use of their individual health records, would improve care by fostering the sharing of sensitive information between patients and providers. However, adherence to such principles could put patients at risk for unsafe care as a result of both missed opportunities for providing needed care as well as provision of contraindicated care, as it would prevent health care providers from having full access to health information. Patients' expectations for the highest possible quality and safety of care, therefore, may be at odds with their desire to limit provider access to their health records. Conversely, provider expectations that patients would willingly seek care for embarrassing conditions and disclose sensitive information may be at odds with patients' information privacy rights. An open dialogue between patients and providers will be necessary to balance respect for patient rights with provider need for patient information. PMID:25480723

  19. Impact of phosphorus control measures on in-river phosphorus retention associated with point source pollution

    NASA Astrophysics Data System (ADS)

    Demars, B. O. L.; Harper, D. M.; Pitt, J.-A.; Slaughter, R.

    2005-01-01

    In-river phosphorus retention alters the quantity and timings of phosphorus delivery to downstream aquatic systems. Many intensive studies of in-river phosphorus retention have been carried out but generally on a short time scale (2-4 years). In this paper, monthly water quality data, collected by the Environment Agency of England and Wales over 12 years (1990-2001), were used to model daily phosphorus fluxes and monthly in-river phosphorus retention in the lowland calcareous River Wensum, Norfolk, UK. The effectiveness of phosphorus stripping at two major sewage treatment works was quantified over different hydrological conditions. The model explained 78% and 88% of the observed variance before and after phosphorus control, respectively. During relatively dry years, there was no net export of phosphorus from the catchment. High retention of phosphorus occurred, particularly during the summer months, which was not compensated for, by subsequent higher flow events. The critical discharge (Q) above which net remobilisation would occur, was only reached during few, high flow events Q25-Q13. Phosphorus removal from the effluent at two major STWs (Sewage Treatment Works) reduced the phosphorus catchment mass balance variability by 20-24% under the Q99-Q1. range of flow conditions. Although the absorbing capacity of the catchment against human impact was remarkable, further phosphorus remedial strategies will be necessary to prevent downstream risks of eutrophication occuring independently of the unpredictable variability in weather conditions.

  20. Populating a Control Point Database: A cooperative effort between the USGS, Grand Canyon Monitoring and Research Center and the Grand Canyon Youth Organization

    NASA Astrophysics Data System (ADS)

    Brown, K. M.; Fritzinger, C.; Wharton, E.

    2004-12-01

    The Grand Canyon Monitoring and Research Center measures the effects of Glen Canyon Dam operations on the resources along the Colorado River from Glen Canyon Dam to Lake Mead in support of the Grand Canyon Adaptive Management Program. Control points are integral for geo-referencing the myriad of data collected in the Grand Canyon including aerial photography, topographic and bathymetric data used for classification and change-detection analysis of physical, biologic and cultural resources. The survey department has compiled a list of 870 control points installed by various organizations needing to establish a consistent reference for data collected at field sites along the 240 mile stretch of Colorado River in the Grand Canyon. This list is the foundation for the Control Point Database established primarily for researchers, to locate control points and independently geo-reference collected field data. The database has the potential to be a valuable mapping tool for assisting researchers to easily locate a control point and reduce the occurrance of unknowingly installing new control points within close proximity of an existing control point. The database is missing photographs and accurate site description information. Current site descriptions do not accurately define the location of the point but refer to the project that used the point, or some other interesting fact associated with the point. The Grand Canyon Monitoring and Research Center (GCMRC) resolved this problem by turning the data collection effort into an educational exercise for the participants of the Grand Canyon Youth organization. Grand Canyon Youth is a non-profit organization providing experiential education for middle and high school aged youth. GCMRC and the Grand Canyon Youth formed a partnership where GCMRC provided the logistical support, equipment, and training to conduct the field work, and the Grand Canyon Youth provided the time and personnel to complete the field work. Two data

  1. a New Control Points Based Geometric Correction Algorithm for Airborne Push Broom Scanner Images Without On-Board Data

    NASA Astrophysics Data System (ADS)

    Strakhov, P.; Badasen, E.; Shurygin, B.; Kondranin, T.

    2016-06-01

    Push broom scanners, such as video spectrometers (also called hyperspectral sensors), are widely used in the present. Usage of scanned images requires accurate geometric correction, which becomes complicated when imaging platform is airborne. This work contains detailed description of a new algorithm developed for processing of such images. The algorithm requires only user provided control points and is able to correct distortions caused by yaw, flight speed and height changes. It was tested on two series of airborne images and yielded RMS error values on the order of 7 meters (3-6 source image pixels) as compared to 13 meters for polynomial-based correction.

  2. Lissajous Orbit Control for the Deep Space Climate Observatory Sun-Earth L1 Libration Point Mission

    NASA Technical Reports Server (NTRS)

    Roberts, Craig; Case, Sarah; Reagoso, John

    2015-01-01

    DSCOVR Lissajous Orbit sized such that orbit track never extends beyond 15 degrees from Earth-Sun line (as seen from Earth). Requiring delta-V maneuvers, control orbit to obey a Solar Exclusion Zone (SEZ) cone of half-angle 4 degrees about the Earth-Sun line. Spacecraft should never be less than 4 degrees from solar center as seen from Earth. Following Lissajous Orbit Insertion (LOI), DSCOVR should be in an opening phase that just skirts the 4-degree SEZ. Maximizes time to the point where a closing Lissajous will require avoidance maneuvers to keep it out of the SEZ. Station keeping maneuvers should take no more than 15 minutes.

  3. Application of Hazard Analysis Critical Control Point in the local manufacture of ready-to-use therapeutic foods (RUTFs).

    PubMed

    Henry, C Jeya K; Xin, Janice Lim Wen

    2014-06-01

    The local manufacture of ready-to-use therapeutic foods (RUTFs) is increasing, and there is a need to develop methods to ensure their safe production. We propose the application of Hazard Analysis Critical Control Point (HACCP) principles to achieve this goal. The basic principles of HACCP in the production of RUTFs are outlined. It is concluded that the implementation of an HACCP system in the manufacture of RUTFs is not only feasible but also attainable. The introduction of good manufacturing practices, coupled with an effective HACCP system, will ensure that RUTFs are produced in a cost-effective, safe, and hygienic manner. PMID:25069295

  4. Controlling the drying and film formation processes of polymer solution droplets with addition of small amount of surfactants.

    PubMed

    Kajiya, Tadashi; Kobayashi, Wataru; Okuzono, Tohru; Doi, Masao

    2009-11-26

    We studied how the addition of surfactants alters the drying and film formation processes of polymer solution droplets with contact lines strongly fixed by bank structures. We found that even if the amount of surfactant is quite small, it drastically changes the final profile of the polymer film from a ringlike profile to a flat profile. This property is observed commonly, irrespective of the polymer concentration, droplet volume, and type of solvent. We conjecture that the inhomogeneous distribution of the surfactant caused by the outward capillary flow induces the Marangoni flow directed toward the center of the droplet, which suppresses the outward flow. The present phenomenon implies an effective method for controlling the profile of the polymer film in inkjet printing technologies.

  5. Probiotics in addition to antibiotics for the treatment of acute tonsillitis: a randomized, placebo-controlled study.

    PubMed

    Gilbey, P; Livshits, L; Sharabi-Nov, A; Avraham, Y; Miron, D

    2015-05-01

    Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. The probiotic Streptococcus salivarius has been shown to be effective in reducing the frequency of recurrent pharyngeal infections in children and adult populations. However, probiotics have not yet been evaluated in the treatment of acute pharyngotonsillitis in adults. We aimed to examine whether the addition of S. salivarius probiotics to the routine therapy of acute pharyngotonsillitis in adult patients may shorten disease duration and reduce symptom severity. This study was a prospective, randomized, placebo-controlled, double-blinded study comparing treatment with probiotics to placebo in addition to antibiotics in patients who were hospitalized with severe pharyngotonsillitis. Laboratory results, pain levels, body temperature, and daily volume of fluids consumed were recorded for both groups. Sixty participants were recruited, 30 for each group. No statistically significant differences between the two groups were observed regarding any of the major clinical and laboratory parameters examined. Supplement probiotic treatment with S. salivarius in patients with acute pharyngotonsillitis treated with penicillin is ineffective in relation to the parameters examined in this study and we cannot, therefore, recommend the use of S. salivarius during active pharyngotonsillar infection treated with penicillin.

  6. Experimental investigations of the swirling flow in the conical diffuser using flow-feedback control technique with additional energy source

    NASA Astrophysics Data System (ADS)

    Tǎnasǎ, C.; Bosioc, A. I.; Susan-Resiga, R. F.; Muntean, S.

    2012-11-01

    The previous experimental and numerical investigations of decelerated swirling flows in conical diffusers have demonstrated that water injection along to the axis mitigates the pressure fluctuations associated to the precessing vortex rope [1]. However, for swirling flows similar to Francis turbines operated at partial discharge, the water jet becomes effective when the jet discharge is larger than 10% from the turbine discharge, leading to large volumetric losses when the jet is supplied from upstream the runner. As a result, it was introduced a new approach for supplying the jet by using a fraction of the discharge collected downstream the conical diffuser [2]. This is called flow-feedback control technique (FFCT) and it was investigated experimentally in order to assess its capability [3]. The FFCT approach not requires additional energy to supply the jet. Consequently, the turbine efficiency is not diminished due to the volumetric losses injected even if around 10% of the main flow is used. However, the equivalent amplitude of the pressure pulsations associated to the vortex rope decreases with 30% if 10% jet discharge is applied [3]. Using 12% water jet discharge from upstream then the equivalent amplitude of the pressure pulsations is mitigated with 70% according to Bosioc et al. [4]. In our case, an extra 2% jet discharge is required in order to obtain similar results with FFCT. This extra discharge is provided using an additional energy source. Therefore, the paper presents experimental investigation performed with FFCT with additional energy source. The experimental results obtained with this technique are compared against FFCT and the swirling flow with vortex rope, respectively.

  7. Can the Hazard Assessment and Critical Control Points (HACCP) system be used to design process-based hygiene concepts?

    PubMed Central

    Hübner, N.-O.; Fleßa, S.; Haak, J.; Wilke, F.; Hübner, C.; Dahms, C.; Hoffmann, W.; Kramer, A.

    2011-01-01

    Recently, the HACCP (Hazard Analysis and Critical Control Points) concept was proposed as possible way to implement process-based hygiene concepts in clinical practice, but the extent to which this food safety concept can be transferred into the health care setting is unclear. We therefore discuss possible ways for a translation of the principles of the HACCP for health care settings. While a direct implementation of food processing concepts into health care is not very likely to be feasible and will probably not readily yield the intended results, the underlying principles of process-orientation, in-process safety control and hazard analysis based counter measures are transferable to clinical settings. In model projects the proposed concepts should be implemented, monitored, and evaluated under real world conditions. PMID:22242105

  8. An Set-Free, All Digital Controlled Point-of-Load Regulator for Next Generation Power Systems: ADC-POL

    NASA Technical Reports Server (NTRS)

    Adell, Philippe C.; Liu, Tao; Vermeire, Bert; Bakkaloglu, Bertan; Aveline, David

    2011-01-01

    This paper presents a digitally controlled programmable point-of-load regulator for next-generation power systems. A novel digital control scheme was designed to minimize single-event effect (SEE)-induced transient effects. By effectively programming the loop transmission, the POL can trade off transient response time with SET robustness. The IC works with 1 to 5.5 V input voltage, 1-4.5V regulated output voltage, high efficiency (peak efficiency at 94%) and power of up to 5 W. The design was fabricated in the AMI i2t100 0.7 mu m complimentary, metal-oxide semiconductor (CMOS) process and characterized with the Jet Propulsion Laboratory (JPL) pulsed laser system.

  9. Intraflagellar transport particle size scales inversely with flagellar length: revisiting the balance-point length control model

    PubMed Central

    Engel, Benjamin D.; Ludington, William B.

    2009-01-01

    The assembly and maintenance of eukaryotic flagella are regulated by intraflagellar transport (IFT), the bidirectional traffic of IFT particles (recently renamed IFT trains) within the flagellum. We previously proposed the balance-point length control model, which predicted that the frequency of train transport should decrease as a function of flagellar length, thus modulating the length-dependent flagellar assembly rate. However, this model was challenged by the differential interference contrast microscopy observation that IFT frequency is length independent. Using total internal reflection fluorescence microscopy to quantify protein traffic during the regeneration of Chlamydomonas reinhardtii flagella, we determined that anterograde IFT trains in short flagella are composed of more kinesin-associated protein and IFT27 proteins than trains in long flagella. This length-dependent remodeling of train size is consistent with the kinetics of flagellar regeneration and supports a revised balance-point model of flagellar length control in which the size of anterograde IFT trains tunes the rate of flagellar assembly. PMID:19805630

  10. Exploration and classification of chromatographic fingerprints as additional tool for identification and quality control of several Artemisia species.

    PubMed

    Alaerts, Goedele; Pieters, Sigrid; Logie, Hans; Van Erps, Jürgen; Merino-Arévalo, Maria; Dejaegher, Bieke; Smeyers-Verbeke, Johanna; Vander Heyden, Yvan

    2014-07-01

    The World Health Organization accepts chromatographic fingerprints as a tool for identification and quality control of herbal medicines. This is the first study in which the distinction, identification and quality control of four different Artemisia species, i.e. Artemisia vulgaris, A. absinthium, A. annua and A. capillaris samples, is performed based on the evaluation of entire chromatographic fingerprint profiles developed with identical experimental conditions. High-Performance Liquid Chromatography (HPLC) with Diode Array Detection (DAD) was used to develop the fingerprints. Application of factorial designs leads to methanol/water (80:20 (v/v)) as the best extraction solvent for the pulverised plant material and to a shaking bath for 30 min as extraction method. Further, so-called screening, optimisation and fine-tuning phases were performed during fingerprint development. Most information about the different Artemisia species, i.e. the highest number of separated peaks in the fingerprint, was acquired on four coupled Chromolith columns (100 mm × 4.6 mm I.D.). Trifluoroacetic acid 0.05% (v/v) was used as mobile-phase additive in a stepwise linear methanol/water gradient, i.e. 5, 34, 41, 72 and 95% (v/v) methanol at 0, 9, 30, 44 and 51 min, where the last mobile phase composition was kept isocratic till 60 min. One detection wavelength was selected to perform data analysis. The lowest similarity between the fingerprints of the four species was present at 214 nm. The HPLC/DAD method was applied on 199 herbal samples of the four Artemisia species, resulting in 357 fingerprints. The within- and between-day variation of the entire method, as well as the quality control fingerprints obtained during routine analysis, were found acceptable. The distinction of these Artemisia species was evaluated based on the entire chromatographic profiles, developed by a shared method, and visualised in score plots by means of the Principal Component Analysis (PCA) exploratory data

  11. Empowering Parents of Obese Children (EPOC): A randomized controlled trial on additional long-term weight effects of parent training.

    PubMed

    Warschburger, Petra; Kroeller, Katja; Haerting, Johannes; Unverzagt, Susanne; van Egmond-Fröhlich, Andreas

    2016-08-01

    Although inpatient lifestyle treatment for obese children and adolescents can be highly effective in the short term, long-term results are unconvincing. One possible explanation might be that the treatment takes place far from parents' homes, limiting the possibility to incorporate the parents, who play a major role in establishing and maintaining a healthy lifestyle in childhood and adolescence. The main goal was to develop a brief behaviorally oriented parent training program that enhances 'obesity-specific' parenting skills in order to prevent relapse. We hypothesized that the inclusion of additional parent training would lead to an improved long-term weight course of obese children. Parents of obese children (n = 686; 7-13 years old) either participated in complementary cognitive-behavioral group sessions (n = 336) or received written information only (n = 350) during the inpatient stay. Children of both groups attended multidisciplinary inpatient rehabilitation. BMI-SDS as a primary outcome was evaluated at baseline, post-intervention and at 6- and 12-month follow-up. Intention-to-treat (ITT) as well as per-protocol analyses (PPA) were performed. A significant within-group decrease of 0.24 (95% CI 0.18 to 0.30) BMI-SDS points from the beginning of the inpatient stay through the first year was found, but no group difference at the one-year follow-up (mean difference 0.02; 95% CI -0.04 to 0.07). We also observed an increase in quality of life scores, intake of healthy food and exercise for both groups, without differences between groups (ITT and PPA). Thus, while the inpatient treatment proved highly effective, additional parent training did not lead to better results in long-term weight maintenance or to better psychosocial well-being compared to written psycho-educational material. Further research should focus on subgroups to answer the question of differential treatment effects. PMID:27074374

  12. Spacecraft Formation Flying near Sun-Earth L2 Lagrange Point: Trajectory Generation and Adaptive Full-State Feedback Control

    NASA Technical Reports Server (NTRS)

    Wong, Hong; Kapila, Vikram

    2004-01-01

    In this paper, we present a method for trajectory generation and adaptive full-state feedback control to facilitate spacecraft formation flying near the Sun-Earth L2 Lagrange point. Specifically, the dynamics of a spacecraft in the neighborhood of a Halo orbit reveals that there exist quasi-periodic orbits surrounding the Halo orbit. Thus, a spacecraft formation is created by placing a leader spacecraft on a desired Halo orbit and placing follower spacecraft on desired quasi-periodic orbits. To produce a formation maintenance controller, we first develop the nonlinear dynamics of a follower spacecraft relative to the leader spacecraft. We assume that the leader spacecraft is on a desired Halo orbit trajectory and the follower spacecraft is to track a desired quasi-periodic orbit surrounding the Halo orbit. Then, we design an adaptive, full-state feedback position tracking controller for the follower spacecraft providing an adaptive compensation for the unknown mass of the follower spacecraft. The proposed control law is simulated for the case of the leader and follower spacecraft pair and is shown to yield global, asymptotic convergence of the relative position tracking errors.

  13. Control of hydrogen sulfide production in oil fields by managing microbial communities through nitrate or nitrite addition

    NASA Astrophysics Data System (ADS)

    Hubert, Casey R. J.

    Nitrate or nitrite injection into oil reservoirs during water flooding has the potential to control biological souring, the production of hydrogen sulfide (H2S) by sulfate-reducing bacteria (SRB). Souring control is essential because sulfide is toxic, sulfide precipitates can plug reservoir formations, souring lowers crude oil value, and SRB induce corrosion. Nitrate and nitrite can stimulate heterotrophic nitrate- or nitrite-reducing bacteria (hNRB) and nitrate- or nitrite-reducing, sulfide oxidizing bacteria (NRSOB). Nitrite also inhibits SRB activity by blocking the sulfate reduction pathway. Continuous up-flow packed-bed bioreactors were inoculated with produced water from the Coleville oil field to establish sulfide-producing biofilms similar to those found in sour reservoirs. Nitrate or nitrite addition to bioreactors indicated that the dose required for hNRB or NR-SOB to control souring depended on the concentration of oil organics. Either mechanism mediates the net removal of oil organics (lactate) with nitrate or nitrite, with lower doses of nitrate required due to its greater oxidative power. Microbial community analysis by reverse sample genome probing (RSGP) revealed that NR-SOB mediated sulfide removal at low nitrate or nitrite concentrations when lactate was still available to SRB and the redox potential was low. At high nitrate doses hNRB oxidized lactate directly, produced nitrite and maintained a high redox potential, thus excluding SRB activity. Facultatively chemolithotrophic Campylobacter sp. strains were isolated from the bioreactors and incorporated into RSGP analyses, revealing their dominance in both NR-SOB- and hNRB-containing communities. The metabolic flexibility of these strains may confer a competitive advantage over obligate chemolithotrophs like Thiomicrospira sp. strain CVO or hNRB that do not have NR-SOB activity like newly isolated Thauera sp. and Rhodobacter sp. strains. A single high dose of nitrite resulted in immediate

  14. Screening Mosquito House Entry Points as a Potential Method for Integrated Control of Endophagic Filariasis, Arbovirus and Malaria Vectors

    PubMed Central

    Ogoma, Sheila B.; Lweitoijera, Dickson W.; Ngonyani, Hassan; Furer, Benjamin; Russell, Tanya L.; Mukabana, Wolfgang R.; Killeen, Gerry F.; Moore, Sarah J.

    2010-01-01

    Background Partial mosquito-proofing of houses with screens and ceilings has the potential to reduce indoor densities of malaria mosquitoes. We wish to measure whether it will also reduce indoor densities of vectors of neglected tropical diseases. Methodology The main house entry points preferred by anopheline and culicine vectors were determined through controlled experiments using specially designed experimental huts and village houses in Lupiro village, southern Tanzania. The benefit of screening different entry points (eaves, windows and doors) using PVC-coated fibre glass netting material in terms of reduced indoor densities of mosquitoes was evaluated compared to the control. Findings 23,027 mosquitoes were caught with CDC light traps; 77.9% (17,929) were Anopheles gambiae sensu lato, of which 66.2% were An. arabiensis and 33.8% An. gambiae sensu stricto. The remainder comprised 0.2% (50) An. funestus, 10.2% (2359) Culex spp. and 11.6% (2664) Mansonia spp. Screening eaves reduced densities of Anopheles gambiae s. l. (Relative ratio (RR)  = 0.91; 95% CI = 0.84, 0.98; P = 0.01); Mansonia africana (RR = 0.43; 95% CI = 0.26, 0.76; P<0.001) and Mansonia uniformis (RR = 0.37; 95% CI = 0.25, 0.56; P<0.001) but not Culex quinquefasciatus, Cx. univittatus or Cx. theileri. Numbers of these species were reduced by screening windows and doors but this was not significant. Significance This study confirms that across Africa, screening eaves protects households against important mosquito vectors of filariasis, Rift Valley Fever and O'Nyong nyong as well as malaria. While full house screening is required to exclude Culex species mosquitoes, screening of eaves alone or fitting ceilings has considerable potential for integrated control of other vectors of filariasis, arbovirus and malaria. PMID:20689815

  15. Equilibrium point control of a monkey arm simulator by a fast learning tree structured artificial neural network.

    PubMed

    Dornay, M; Sanger, T D

    1993-01-01

    A planar 17 muscle model of the monkey's arm based on realistic biomechanical measurements was simulated on a Symbolics Lisp Machine. The simulator implements the equilibrium point hypothesis for the control of arm movements. Given initial and final desired positions, it generates a minimum-jerk desired trajectory of the hand and uses the backdriving algorithm to determine an appropriate sequence of motor commands to the muscles (Flash 1987; Mussa-Ivaldi et al. 1991; Dornay 1991b). These motor commands specify a temporal sequence of stable (attractive) equilibrium positions which lead to the desired hand movement. A strong disadvantage of the simulator is that it has no memory of previous computations. Determining the desired trajectory using the minimum-jerk model is instantaneous, but the laborious backdriving algorithm is slow, and can take up to one hour for some trajectories. The complexity of the required computations makes it a poor model for biological motor control. We propose a computationally simpler and more biologically plausible method for control which achieves the benefits of the backdriving algorithm. A fast learning, tree-structured network (Sanger 1991c) was trained to remember the knowledge obtained by the backdriving algorithm. The neural network learned the nonlinear mapping from a 2-dimensional cartesian planar hand position (x,y) to a 17-dimensional motor command space (u1, . . ., u17). Learning 20 training trajectories, each composed of 26 sample points [[x,y], [u1, . . ., u17] took only 20 min on a Sun-4 Sparc workstation. After the learning stage, new, untrained test trajectories as well as the original trajectories of the hand were given to the neural network as input. The network calculated the required motor commands for these movements. The resulting movements were close to the desired ones for both the training and test cases. PMID:8324058

  16. The additional value of a night splint to eccentric exercises in chronic midportion Achilles tendinopathy: a randomised controlled trial

    PubMed Central

    de Vos, R J; Weir, A; Visser, R J A; de Winter, ThC; Tol, J L

    2007-01-01

    Aim To assess whether the use of a night splint is of added benefit on functional outcome in treating chronic midportion Achilles tendinopathy. Methods This was a single‐blind, prospective, single centre, randomised controlled trial set in the Sports Medical Department, The Hague Medical Centre, The Netherlands. Inclusion criteria were: age 18–70 years, active participation in sports, and tendon pain localised at 2–7 cm from distal insertion. Exclusion criteria were: insertional disorders, partial or complete ruptures, or systemic illness. 70 tendons were included and randomised into one of two treatment groups: eccentric exercises with a night splint (night splint group, n = 36) or eccentric exercises only (eccentric group, n = 34). Interventions Both groups completed a 12‐week heavy‐load eccentric training programme. One group received a night splint in addition to eccentric exercises. At baseline and follow‐up at 12 weeks, patient satisfaction, Victorian Institute of Sport Assessment–Achilles questionnaire (VISA‐A) score and reported compliance were recorded by a single‐blind trained researcher who was blinded to the treatment. Results After 12 weeks, patient satisfaction in the eccentric group was 63% compared with 48% in the night splint group. The VISA‐A score significantly improved in both groups; in the eccentric group from 50.1 to 68.8 (p = 0.001) and in the night splint group from 49.4 to 67.0 (p<0.001). There was no significant difference between the two groups in VISA‐A score (p = 0.815) and patient satisfaction (p = 0.261). Conclusion A night splint is not beneficial in addition to eccentric exercises in the treatment of chronic midportion Achilles tendinopathy. PMID:17178774

  17. Neural Correlates of Task Cost for Stance Control with an Additional Motor Task: Phase-Locked Electroencephalogram Responses

    PubMed Central

    Hwang, Ing-Shiou; Huang, Cheng-Ya

    2016-01-01

    With appropriate reallocation of central resources, the ability to maintain an erect posture is not necessarily degraded by a concurrent motor task. This study investigated the neural control of a particular postural-suprapostural procedure involving brain mechanisms to solve crosstalk between posture and motor subtasks. Participants completed a single posture task and a dual-task while concurrently conducting force-matching and maintaining a tilted stabilometer stance at a target angle. Stabilometer movements and event-related potentials (ERPs) were recorded. The added force-matching task increased the irregularity of postural response rather than the size of postural response prior to force-matching. In addition, the added force-matching task during stabilometer stance led to marked topographic ERP modulation, with greater P2 positivity in the frontal and sensorimotor-parietal areas of the N1-P2 transitional phase and in the sensorimotor-parietal area of the late P2 phase. The time-frequency distribution of the ERP primary principal component revealed that the dual-task condition manifested more pronounced delta (1–4 Hz) and beta (13–35 Hz) synchronizations but suppressed theta activity (4–8 Hz) before force-matching. The dual-task condition also manifested coherent fronto-parietal delta activity in the P2 period. In addition to a decrease in postural regularity, this study reveals spatio-temporal and temporal-spectral reorganizations of ERPs in the fronto-sensorimotor-parietal network due to the added suprapostural motor task. For a particular set of postural-suprapostural task, the behavior and neural data suggest a facilitatory role of autonomous postural response and central resource expansion with increasing interregional interactions for task-shift and planning the motor-suprapostural task. PMID:27010634

  18. A Serious Videogame as an Additional Therapy Tool for Training Emotional Regulation and Impulsivity Control in Severe Gambling Disorder

    PubMed Central

    Tárrega, Salomé; Castro-Carreras, Laia; Fernández-Aranda, Fernando; Granero, Roser; Giner-Bartolomé, Cristina; Aymamí, Neus; Gómez-Peña, Mónica; Santamaría, Juan J.; Forcano, Laura; Steward, Trevor; Menchón, José M.; Jiménez-Murcia, Susana

    2015-01-01

    Background: Gambling disorder (GD) is characterized by a significant lack of self-control and is associated with impulsivity-related personality traits. It is also linked to deficits in emotional regulation and frequently co-occurs with anxiety and depression symptoms. There is also evidence that emotional dysregulation may play a mediatory role between GD and psychopathological symptomatology. Few studies have reported the outcomes of psychological interventions that specifically address these underlying processes. Objectives: To assess the utility of the Playmancer platform, a serious video game, as an additional therapy tool in a CBT intervention for GD, and to estimate pre-post changes in measures of impulsivity, anger expression and psychopathological symptomatology. Method: The sample comprised a single group of 16 male treatment-seeking individuals with severe GD diagnosis. Therapy intervention consisted of 16 group weekly CBT sessions and, concurrently, 10 additional weekly sessions of a serious video game. Pre-post treatment scores on South Oaks Gambling Screen (SOGS), Barratt Impulsiveness Scale (BIS-11), I7 Impulsiveness Questionnaire (I7), State-Trait Anger Expression Inventory 2 (STAXI-2), Symptom Checklist-Revised (SCL-90-R), State-Trait Anxiety Inventory (STAI-S-T), and Novelty Seeking from the Temperament and Character Inventory-Revised (TCI-R) were compared. Results: After the intervention, significant changes were observed in several measures of impulsivity, anger expression and other psychopathological symptoms. Dropout and relapse rates during treatment were similar to those described in the literature for CBT. Conclusion: Complementing CBT interventions for GD with a specific therapy approach like a serious video game might be helpful in addressing certain underlying factors which are usually difficult to change, including impulsivity and anger expression. PMID:26617550

  19. Engineering of an MBR supernatant fouling layer by fine particles addition: a possible way to control cake compressibility.

    PubMed

    Teychene, Benoît; Guigui, Christelle; Cabassud, Corinne

    2011-02-01

    For membrane bioreactors (MBR) applied to wastewater treatment membrane fouling is still the prevalent issue. The main limiting phenomena related to fouling is a sudden jump of the transmembrane pressure (TMP) often attributed to the collapse of the fouling layer. Among existing techniques to avoid or to delay this collapse, the addition of active particles membrane fouling reducers (polymer, resins, powdered activated carbon (PAC), zeolithe...) showed promising results. Thus the main objective of this work is to determine if fouling can be reduced by inclusion of inert particles (500 nm and inert compared to other fouling reducers) and which is the impact on filtration performances of the structuring of the fouling. Those particles were chosen for their different surface properties and their capability to form well structured layer. Results, obtained at constant pressure in dead end mode, show that the presence of particles changes foulant deposition and induces non-compressible fouling (in the range of 0.5-1 bar) and higher rejection values compared to filtration done on supernatant alone. Indeed dead end filtration tests show that whatever interactions between biofluid and particles, the addition of particles leads to better filtration performances (in terms of rejection, and fouling layer compressibility). Moreover results confirm the important role played by macromolecular compounds, during supernatant filtration, creating highly compressible and reversible fouling. In conclusion, this study done at lab-scale suggests the potential benefit to engineer fouling structure to control or to delay the collapse of the fouling layer. Finally this study offers the opportunities to enlarge the choice of membrane fouling reducers by taking into consideration their ability to form more consistent fouling (i.e. rigid, structured fouling). PMID:21232780

  20. Short-chain fatty acids and L-lactate as feed additives to control Campylobacter jejuni infections in broilers.

    PubMed

    Van Deun, Kim; Haesebrouck, Freddy; Van Immerseel, Filip; Ducatelle, Richard; Pasmans, Frank

    2008-08-01

    The usefulness of butyrate, acetate, propionate and l-lactate for the control of Campylobacter jejuni infections in broilers was assessed. For this purpose, the effect of these acids on the growth of C. jejuni in broth and intestinal mucous was determined, as well as their influence on the invasiveness of C. jejuni in intestinal epithelial cells. From these in vitro obtained results, one acid was retained for use as a feed additive in an in vivo trial. Butyrate was the most successful of the short-chain fatty acids, with 12.5 mM being bactericidal for C. jejuni at pH 6.0. Propionate and acetate had a bacteriostatic effect at 50 mM. None of the short-chain fatty acids had a bactericidal effect at pH 7.5 at a maximum concentration of 50 mM. Mucous increased the minimum bactericidal concentration of butyrate, but not the bacteriostatic concentrations of propionate or acetate. When C. jejuni was incubated in growth subinhibitory concentrations of butyrate, acetate or propionate or 25 mM L-lactate, no alteration in the invasive capabilities of C. jejuni in Caco-2 cells was observed. The addition of butyrate-coated micro-beads to the feed was unsuccessful to reduce C. jejuni caecal colonization in a seeder model using 2-week-old broilers. In conclusion, despite the marked bactericidal effect of butyrate towards C. jejuni in vitro, butyrate-coated micro-beads do not protect broilers from caecal colonization with C. jejuni in the applied test conditions. This might be partially ascribed to the protective effect of mucous and the rapid absorption of butyrate by the enterocytes. PMID:18622853

  1. Effect of Latent Myofascial Trigger Points on Strength Measurements of the Upper Trapezius: A Case-Controlled Trial

    PubMed Central

    Anshul

    2011-01-01

    ABSTRACT Purpose: The purpose of this article was to determine whether strength is altered in the upper trapezius in the presence of latent myofascial trigger points (MTrP). Methods: This study was case controlled and used convenience sampling. The sample recruited was homogeneous with respect to age, sex, height, and body mass. Participants were assessed for the presence of latent MTrP in the upper trapezius and placed into two groups: an experimental group that had latent MTrP in the upper trapezius and a control group that did not. Eighteen women (mean age 21.4 y, SD 1.89; mean height 156.9 cm, SD 4.03; and mean body mass 51.7 kg, SD 5.84) made up the experimental group, and 19 women (mean age 20.3 y, SD 1.86; mean height 158.6 cm, SD 3.14; and mean body mass 53.2 kg, SD 5.17) made up the control group. We obtained strength measurements of the non-dominant arm using a handheld dynamometer and compared them between the two groups. Results: The difference in the strength measurements between the two groups was not statistically significant (p=0.59). Conclusions: The presence of latent MTrPs may not affect the strength of the upper trapezius. PMID:22942517

  2. Nausea control by needling at acupuncture point Neiguan (PC6) during an intraoral impression-taking procedure.

    PubMed

    Zotelli, Vera Lucia Rasera; Grillo, Cássia Maria; de Sousa, Maria da Luz Rosário

    2014-12-01

    The objective of this study was to evaluate the effectiveness of acupuncture point PC6 (Neiguan) in controlling nausea during intraoral impression taking. This study was conducted in Piracicaba, São Paulo, Brazil. The sample consisted of 33 adult volunteers with nausea, who were randomly divided into control and study groups, and treated with nonpenetrating sham acupuncture and real acupuncture, respectively, at acupoint PC6. The two groups had two maxillary impressions taken, one prior to acupuncture and the other after acupuncture. The nausea assessment was made using the visual analog scale, Gagging Severity Index (GSI), and Gagging Prevention Index. Volunteers' expectation that nausea would be reduced through acupuncture was also assessed. For statistical analysis, we used the t test and the Spearman correlation (p < 0.05). When assessed by Gagging Severity Index/Gagging Prevention Index, nausea was reduced in the real acupuncture group (p < 0.01). In the visual analog scale assessment, similar reductions of nausea were noted in both groups (p > 0.05). No correlation existed between the expected and the actual reductions in nausea. Our results indicate that acupoint PC6 was effective for controlling nausea during the maxillary impression-taking procedure. Patients' expectation did not influence the results.

  3. Hazard analysis critical control point (HACCP) in public catering services: a modified method, combined to bacteriologic assay.

    PubMed

    Ferrari, P

    1992-01-01

    During 1990 and 1991 the Veterinary and Public Health Services of USL 35 of Ravenna carried out a research programme aimed at the control of food-borne diseases in the sector of public catering services, in collaboration with the Public Health Laboratory (Presidio Multizonale di Prevenzione). The objectives were: obtaining sure information about health hazards in public catering services; checking structural characteristics and equipment of workrooms in restaurants, hotels and refectories; verifying food preparation and preservation methods; promoting health education to increase employees' awareness of hygiene-related problems. The first objective, evaluation of the level of the control of the workrooms exerted on the food contamination hazard by pathogenic or potentially pathogenic organisms, was carried out by allotting specific scores to several characteristics of laboratories or workers' habits, as suggested by the "Hazard Analysis Critical Control Point" (HACCP) method for butcher's shops and fish markets. Five hundred ninety-eight public catering service units have been inspected in restaurants, hotels, school-refectories, factories, hospitals and social houses; 2,097 bacteriological examinations by agar-contact plates and swabs were carried out; 118 preserved-food temperatures were measured, especially in deep-frozen and cooked food; 70 food specimens were tested to search for Salmonella spp. and Staphylococcus aureus and measure Total Aerobic Mesophilic Weight. The presence of Enterobacteriaceae and Escherichia coli was also tested.

  4. Control of a Vanadium Redox Battery and supercapacitor using a Three-Level Neutral Point Clamped converter

    NASA Astrophysics Data System (ADS)

    Etxeberria, A.; Vechiu, I.; Baudoin, S.; Camblong, H.; Kreckelbergh, S.

    2014-02-01

    The increasing use of distributed generators, which are mainly based on renewable sources, can create several issues in the operation of the electric grid. The microgrid is being analysed as a solution to the integration in the grid of the renewable sources at a high penetration level in a controlled way. The storage systems play a vital role in order to keep the energy and power balance of the microgrid. Due to the technical limitations of the currently available storage systems, it is necessary to use more than one storage technology to satisfy the requirements of the microgrid application. This work validates in simulations and experimentally the use of a Three-Level Neutral Point Clamped converter to control the power flow of a hybrid storage system formed by a SuperCapacitor and a Vanadium Redox Battery. The operation of the system is validated in two case studies in the experimental platform installed in ESTIA. The experimental results prove the validity of the proposed system as well as the designed control algorithm. The good agreement among experimental and simulation results also validates the simulation model, that can therefore be used to analyse the operation of the system in different case studies.

  5. Single-Amino Acid Modifications Reveal Additional Controls on the Proton Pathway of [FeFe]-Hydrogenase.

    PubMed

    Cornish, Adam J; Ginovska, Bojana; Thelen, Adam; da Silva, Julio C S; Soares, Thereza A; Raugei, Simone; Dupuis, Michel; Shaw, Wendy J; Hegg, Eric L

    2016-06-01

    The proton pathway of [FeFe]-hydrogenase is essential for enzymatic H2 production and oxidation and is composed of four residues and a water molecule. A computational analysis of this pathway in the [FeFe]-hydrogenase from Clostridium pasteurianum revealed that the solvent-exposed residue of the pathway (Glu282) forms hydrogen bonds to two residues outside of the pathway (Arg286 and Ser320), implying that these residues could function in regulating proton transfer. In this study, we show that substituting Arg286 with leucine eliminates hydrogen bonding with Glu282 and results in an ∼3-fold enhancement of H2 production activity when methyl viologen is used as an electron donor, suggesting that Arg286 may help control the rate of proton delivery. In contrast, substitution of Ser320 with alanine reduces the rate ∼5-fold, implying that it either acts as a member of the pathway or influences Glu282 to permit proton transfer. Interestingly, quantum mechanics/molecular mechanics and molecular dynamics calculations indicate that Ser320 does not play a structural role or indirectly influence the barrier for proton movement at the entrance of the channel. Rather, it may act as an additional proton acceptor for the pathway or serve in a regulatory role. While further studies are needed to elucidate the role of Ser320, collectively these data provide insights into the complex proton transport process. PMID:27186945

  6. The pyruvate-tricarboxylic acid cycle node: a focal point of virulence control in the enteric pathogen Yersinia pseudotuberculosis.

    PubMed

    Bücker, René; Heroven, Ann Kathrin; Becker, Judith; Dersch, Petra; Wittmann, Christoph

    2014-10-24

    Despite our increasing knowledge of the specific pathogenicity factors in bacteria, the contribution of metabolic processes to virulence is largely unknown. Here, we elucidate a tight connection between pathogenicity and core metabolism in the enteric pathogen Yersinia pseudotuberculosis by integrated transcriptome and [(13)C]fluxome analysis of the wild type and virulence-regulator mutants. During aerobic growth on glucose, Y. pseudotuberculosis reveals an unusual flux distribution with a high level of secreted pyruvate. The absence of the transcriptional and post-transcriptional regulators RovA, CsrA, and Crp strongly perturbs the fluxes of carbon core metabolism at the level of pyruvate metabolism and the tricarboxylic acid (TCA) cycle, and these perturbations are accompanied by transcriptional changes in the corresponding enzymes. Knock-outs of regulators of this metabolic branch point and of its central enzyme, pyruvate kinase (ΔpykF), result in mutants with significantly reduced virulence in an oral mouse infection model. In summary, our work identifies the pyruvate-TCA cycle node as a focal point for controlling the host colonization and virulence of Yersinia.

  7. Mitochondrial Development during Life Cycle Differentiation of African Trypanosomes: Evidence for a Kinetoplast-dependent Differentiation Control Point

    PubMed Central

    Timms, Mark W.; van Deursen, Frederick J.; Hendriks, Edward F.; Matthews, Keith R.

    2002-01-01

    Life cycle differentiation of African trypanosomes entails developmental regulation of mitochondrial activity. This requires regulation of the nuclear genome and the kinetoplast, the trypanosome's unusual mitochondrial genome. To investigate the potential cross talk between the nuclear and mitochondrial genome during the events of differentiation, we have 1) disrupted expression of a nuclear-encoded component of the cytochrome oxidase (COX) complex; and 2) generated dyskinetoplastid cells, which lack a mitochondrial genome. Using RNA interference (RNAi) and by disrupting the nuclear COX VI gene, we demonstrate independent regulation of COX component mRNAs encoded in the nucleus and kinetoplast. However, two independent approaches (acriflavine treatment and RNA interference ablation of mitochondrial topoisomerase II) failed to establish clonal lines of dyskinetoplastid bloodstream forms. Nevertheless, dyskinetoplastid forms generated in vivo could undergo two life cycle differentiation events: transition from bloodstream slender to stumpy forms and the initiation of transformation to procyclic forms. However, they subsequently arrested at a specific point in this developmental program before cell cycle reentry. These results provide strong evidence for a requirement for kinetoplast DNA in the bloodstream and for a kinetoplast-dependent control point during differentiation to procyclic forms. PMID:12388771

  8. 40 CFR 63.1586 - What are the emission points and control requirements for a non-industrial POTW treatment plant?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for closed-vent systems and control devices in § 63.693 of subpart DD of this part, except you may... control requirements for a non-industrial POTW treatment plant? 63.1586 Section 63.1586 Protection of... are the emission points and control requirements for a non-industrial POTW treatment plant? There...

  9. Control of Cr6+ emissions from gas metal arc welding using a silica precursor as a shielding gas additive.

    PubMed

    Topham, Nathan; Wang, Jun; Kalivoda, Mark; Huang, Joyce; Yu, Kuei-Min; Hsu, Yu-Mei; Wu, Chang-Yu; Oh, Sewon; Cho, Kuk; Paulson, Kathleen

    2012-03-01

    Hexavalent chromium (Cr(6+)) emitted from welding poses serious health risks to workers exposed to welding fumes. In this study, tetramethylsilane (TMS) was added to shielding gas to control hazardous air pollutants produced during stainless steel welding. The silica precursor acted as an oxidation inhibitor when it decomposed in the high-temperature welding arc, limiting Cr(6+) formation. Additionally, a film of amorphous SiO(2) was deposited on fume particles to insulate them from oxidation. Experiments were conducted following the American Welding Society (AWS) method for fume generation and sampling in an AWS fume hood. The results showed that total shielding gas flow rate impacted the effectiveness of the TMS process. Increasing shielding gas flow rate led to increased reductions in Cr(6+) concentration when TMS was used. When 4.2% of a 30-lpm shielding gas flow was used as TMS carrier gas, Cr(6+) concentration in gas metal arc welding (GMAW) fumes was reduced to below the 2006 Occupational Safety and Health Administration standard (5 μg m(-3)) and the efficiency was >90%. The process also increased fume particle size from a mode size of 20 nm under baseline conditions to 180-300 nm when TMS was added in all shielding gas flow rates tested. SiO(2) particles formed in the process scavenged nanosized fume particles through intercoagulation. Transmission electron microscopy imagery provided visual evidence of an amorphous film of SiO(2) on some fume particles along with the presence of amorphous SiO(2) agglomerates. These results demonstrate the ability of vapor phase silica precursors to increase welding fume particle size and minimize chromium oxidation, thereby preventing the formation of hexavalent chromium. PMID:22104317

  10. Control of Cr6+ emissions from gas metal arc welding using a silica precursor as a shielding gas additive.

    PubMed

    Topham, Nathan; Wang, Jun; Kalivoda, Mark; Huang, Joyce; Yu, Kuei-Min; Hsu, Yu-Mei; Wu, Chang-Yu; Oh, Sewon; Cho, Kuk; Paulson, Kathleen

    2012-03-01

    Hexavalent chromium (Cr(6+)) emitted from welding poses serious health risks to workers exposed to welding fumes. In this study, tetramethylsilane (TMS) was added to shielding gas to control hazardous air pollutants produced during stainless steel welding. The silica precursor acted as an oxidation inhibitor when it decomposed in the high-temperature welding arc, limiting Cr(6+) formation. Additionally, a film of amorphous SiO(2) was deposited on fume particles to insulate them from oxidation. Experiments were conducted following the American Welding Society (AWS) method for fume generation and sampling in an AWS fume hood. The results showed that total shielding gas flow rate impacted the effectiveness of the TMS process. Increasing shielding gas flow rate led to increased reductions in Cr(6+) concentration when TMS was used. When 4.2% of a 30-lpm shielding gas flow was used as TMS carrier gas, Cr(6+) concentration in gas metal arc welding (GMAW) fumes was reduced to below the 2006 Occupational Safety and Health Administration standard (5 μg m(-3)) and the efficiency was >90%. The process also increased fume particle size from a mode size of 20 nm under baseline conditions to 180-300 nm when TMS was added in all shielding gas flow rates tested. SiO(2) particles formed in the process scavenged nanosized fume particles through intercoagulation. Transmission electron microscopy imagery provided visual evidence of an amorphous film of SiO(2) on some fume particles along with the presence of amorphous SiO(2) agglomerates. These results demonstrate the ability of vapor phase silica precursors to increase welding fume particle size and minimize chromium oxidation, thereby preventing the formation of hexavalent chromium.

  11. Mechanisms of Evolutionary Innovation Point to Genetic Control Logic as the Key Difference Between Prokaryotes and Eukaryotes.

    PubMed

    Bains, William; Schulze-Makuch, Dirk

    2015-08-01

    The evolution of life from the simplest, original form to complex, intelligent animal life occurred through a number of key innovations. Here we present a new tool to analyze these key innovations by proposing that the process of evolutionary innovation may follow one of three underlying processes, namely a Random Walk, a Critical Path, or a Many Paths process, and in some instances may also constitute a "Pull-up the Ladder" event. Our analysis is based on the occurrence of function in modern biology, rather than specific structure or mechanism. A function in modern biology may be classified in this way either on the basis of its evolution or the basis of its modern mechanism. Characterizing key innovations in this way helps identify the likelihood that an innovation could arise. In this paper, we describe the classification, and methods to classify functional features of modern organisms into these three classes based on the analysis of how a function is implemented in modern biology. We present the application of our categorization to the evolution of eukaryotic gene control. We use this approach to support the argument that there are few, and possibly no basic chemical differences between the functional constituents of the machinery of gene control between eukaryotes, bacteria and archaea. This suggests that the difference between eukaryotes and prokaryotes that allows the former to develop the complex genetic architecture seen in animals and plants is something other than their chemistry. We tentatively identify the difference as a difference in control logic, that prokaryotic genes are by default 'on' and eukaryotic genes are by default 'off.' The Many Paths evolutionary process suggests that, from a 'default off' starting point, the evolution of the genetic complexity of higher eukaryotes is a high probability event.

  12. Role of quantity of additional food to predators as a control in predator-prey systems with relevance to pest management and biological conservation.

    PubMed

    Srinivasu, P D N; Prasad, B S R V

    2011-10-01

    Necessity to understand the role of additional food as a tool in biological control programs is being increasingly felt, particularly due to its eco-friendly nature. A thorough mathematical analysis in this direction revealed the vital role of quality and quantity of the additional food in the controllability of the predator-prey systems. In this article controllability of the additional food--provided predator-prey system is studied from perspectives of pest eradication and biological conservation. Time optimal paths have been constructed to drive the state of the system to a desired terminal state by choosing quantity of the additional food as control variable. The theory developed in this article has been illustrated by solving problems related to pest eradication and biological conservation.

  13. Control of optical and electrical properties of nanosheets by the chemical structure of the turning point in a foldable polymer

    NASA Astrophysics Data System (ADS)

    Ikeda, Taichi; Tamura, Hiroyuki; Sakurai, Tsuneaki; Seki, Shu

    2016-07-01

    Oligomers of tetra(ethylene glycol)-disubstituted phenyl-capped bithiophene (Ph2TPh) linked by catechol and resorcinol were prepared. Catechol and resorcinol link the monomers via the ortho- and meta-positions of the benzene ring, respectively, and function as turning points in the folding process of the polymer. It was confirmed that the ortho-linked 8mer (o-8mer) and meta-linked 8mer (m-8mer) could form nanosheets through the self-assembly of folded polymers in o-dichlorobenzene. We confirmed that the arrangement of thiophene units inside the nanosheets was controllable by changing the chemical structure of the turning point. The different arrangements of the Ph2TPh units led to changes in other physical properties such as UV-Vis absorption, nanosheet thickness and charge carrier transport. The absorption spectrum of the o-8mer nanosheets suggested that the Ph2TPh units are arranged vertical to the lateral direction of the nanosheets. On the other hand, the Ph2TPh units in the m-8mer nanosheets were considered to have a tilted orientation. The change in the Ph2TPh tilt angle inside the nanosheets was supported by the different thicknesses of the o-8mer and m-8mer nanosheets. The relationship between the absorption spectrum and Ph2TPh unit arrangement was discussed based on the DFT calculation. Intrinsic charge carrier transport properties were evaluated by a noncontact microwave-based method. The o-8mer nanosheets showed higher conductivity than the m-8mer and triazole-linked-8mer nanosheets. The lifetime of charge carriers in the nanosheet was longer than that in the lamellar structure of the drop-cast film.Oligomers of tetra(ethylene glycol)-disubstituted phenyl-capped bithiophene (Ph2TPh) linked by catechol and resorcinol were prepared. Catechol and resorcinol link the monomers via the ortho- and meta-positions of the benzene ring, respectively, and function as turning points in the folding process of the polymer. It was confirmed that the ortho-linked 8mer (o

  14. Monoamines and protein intake: are control mechanisms designed to monitor a threshold intake or a set point?

    PubMed

    Fernstrom, J D; Fernstrom, M H

    2001-08-01

    The concentration of TYR in brain changes directly with dietary protein content in the 0-10% PE range, but not higher. The effect is large: TYR concentrations rise as much as two- to threefold between 0% and 10% dietary protein content. This increase produces a clear stimulation of the rate of catecholamine synthesis, observed both for DA and NE, and notably in the hypothalamus, a brain area involved in appetite regulation. A similar relationship to chronic dietary protein intake may also exist for tryptophan and its neurotransmitter product, 5HT. Because the natural diet of rats, the animal model most commonly used in such studies, typically contains between 6% and 14% protein, and may contain less under unfavorable environmental circumstances, rats in the wild may frequently operate on the portion of the protein intake curve producing maximal changes in brain TYR (and perhaps TRP) concentrations. If so, then the production of catecholamines and 5HT may be similarly affected. By such a scenario, the brain might receive information regarding the animal's success in acquiring adequate amounts of protein in its diet. A similar argument can also be made for monkeys in the wild, based on their dietary habits, and thus possibly for humans. From this perspective, animals are hypothesized to monitor/regulate their intake of protein based on a threshold, rather than a set-point model. This notion is not new or unique to amino acids. For example, one current notion of leptin action is that it serves as a signal for energy intake important during periods of deficiency, but not excess. More generally, given the primacy in nature of the need to acquire adequate amounts of food in order to survive and reproduce, and the difficulty in achieving this nutritional goal, it may be that appetite control mechanisms have evolved in nature to center more on attaining and exceeding adequacy than on maintaining intake around a set-point well in excess of adequacy.

  15. Colloid Microthruster Feed System Development for Fine Pointing and Drag-Free Control of Multi-Year Astronomical Observatories

    NASA Astrophysics Data System (ADS)

    Ziemer, John; Mueller, J.; Spence, D.; Hruby, V.

    2014-01-01

    A new Colloid Microthruster feed system, including a propellant tank and redundant Microvalves, is being developed for fine pointing and drag-free operations of multi-year astronomical observatories under the PCOS SAT program. Almost all Gravitational Wave Observatory (GWO) concepts require microthrusters to maintain a drag-free environment for the inertial sensor instrument to meet the mission science objectives. The current state-of-the-art microthruster in the US is the Busek Colloid Micro-Newton Thruster (CMNT) originally developed under the New Millennium Program for the Space Technology 7 (ST7) and ESA's LISA Pathfinder (LPF) technology demonstration mission. The ST7 CMNT design includes a bellows propellant storage tank that is sized to provide up to 90 days of maximum thrust (30 µN). The new propellant tank is based on a blow-down, metal-diaphragm spherical tank design with enough capacity for a 5-year GWO mission. The new feed system will also include the third generation of Busek’s Microvalve, currently being developed under a NASA Phase II SBIR. The Microvalve is responsible for the picoliter per second control of the propellant from the tank to the thruster head, demanding parts with micron-level tolerances, critical alignments, and challenging acceptance test protocols. This microthruster system could also be considered for replacement of reaction wheels for slewing and fine pointing of other astronomical observatories, including Exo-Planet Observatory concepts. The goal of the PCOS SAT effort is to raise the new system to TRL 5 with performance and environmental testing within the next two years.

  16. Adaptation to elastic loads and BMI robot controls during rat locomotion examined with point-process GLMs.

    PubMed

    Song, Weiguo; Cajigas, Iahn; Brown, Emery N; Giszter, Simon F

    2015-01-01

    Currently little is known about how a mechanically coupled BMI system's actions are integrated into ongoing body dynamics. We tested a locomotor task augmented with a BMI system driving a robot mechanically interacting with a rat under three conditions: control locomotion (BL), "simple elastic load" (E) and "BMI with elastic load" (BMI/E). The effect of the BMI was to allow compensation of the elastic load as a function of the neural drive. Neurons recorded here were close to one another in cortex, all within a 200 micron diameter horizontal distance of one another. The interactions of these close assemblies of neurons may differ from those among neurons at longer distances in BMI tasks and thus are important to explore. A point process generalized linear model (GLM), was used to examine connectivity at two different binning timescales (1 ms vs. 10 ms). We used GLM models to fit non-Poisson neural dynamics solely using other neurons' prior neural activity as covariates. Models at different timescales were compared based on Kolmogorov-Smirnov (KS) goodness-of-fit and parsimony. About 15% of cells with non-Poisson firing were well fitted with the neuron-to-neuron models alone. More such cells were fitted at the 1 ms binning than 10 ms. Positive connection parameters ("excitation" ~70%) exceeded negative parameters ("inhibition" ~30%). Significant connectivity changes in the GLM determined networks of well-fitted neurons occurred between the conditions. However, a common core of connections comprising at least ~15% of connections persisted between any two of the three conditions. Significantly almost twice as many connections were in common between the two load conditions (~27%), compared to between either load condition and the baseline. This local point process GLM identified neural correlation structure and the changes seen across task conditions in the rats in this neural subset may be intrinsic to cortex or due to feedback and input reorganization in adaptation.

  17. A simulation-based interval two-stage stochastic model for agricultural non-point source pollution control through land retirement.

    PubMed

    Luo, B; Li, J B; Huang, G H; Li, H L

    2006-05-15

    This study presents a simulation-based interval two-stage stochastic programming (SITSP) model for agricultural non-point source (NPS) pollution control through land retirement under uncertain conditions. The modeling framework was established by the development of an interval two-stage stochastic program, with its random parameters being provided by the statistical analysis of the simulation outcomes of a distributed water quality approach. The developed model can deal with the tradeoff between agricultural revenue and "off-site" water quality concern under random effluent discharge for a land retirement scheme through minimizing the expected value of long-term total economic and environmental cost. In addition, the uncertainties presented as interval numbers in the agriculture-water system can be effectively quantified with the interval programming. By subdividing the whole agricultural watershed into different zones, the most pollution-related sensitive cropland can be identified and an optimal land retirement scheme can be obtained through the modeling approach. The developed method was applied to the Swift Current Creek watershed in Canada for soil erosion control through land retirement. The Hydrological Simulation Program-FORTRAN (HSPF) was used to simulate the sediment information for this case study. Obtained results indicate that the total economic and environmental cost of the entire agriculture-water system can be limited within an interval value for the optimal land retirement schemes. Meanwhile, a best and worst land retirement scheme was obtained for the study watershed under various uncertainties.

  18. Treatment of myofascial trigger-points with ultrasound combined with massage and exercise--a randomised controlled trial.

    PubMed

    Gam, A N; Warming, S; Larsen, L H; Jensen, B; Høydalsmo, O; Allon, I; Andersen, B; Gøtzsche, N E; Petersen, M; Mathiesen, B

    1998-07-01

    The effect of treatment with ultrasound, massage and exercises on myofascial trigger-points (MTrP) in the neck and shoulder was assessed in a randomised controlled trial. The outcome measures were pain at rest and on daily function (Visual Analogue Scale, VAS), analgesic usage, global preference and index of MTrP. Long-term effect for treatment and control groups was assessed after 6 months using a questionnaire. The patients were randomised to three groups. The first group was treated with ultrasound, massage and exercise (A), the second group with sham-ultrasound, massage and exercise (B), while the third group was a control group (C). The duration of the study was 6 weeks. Treatment was given twice a week from the second to the fifth week. The number and index of MTrPs were recorded at each treatment session in groups A and B but only at entry as well as end of study in group C. VAS and analgesic usage was recorded in all three groups throughout the study period. Six months after the last treatment session a questionnaire was send to the patients. A total of 67 patients were included. Nine patients dropped-out during the study, which left 58 patients that could be included in the final analysis. Twenty patients were randomised to group A, 18 to group B and 18 to group C. A significant reduction in index were found between treatment groups (A and B) and control group (C), but no difference between group A and B. VAS scores, analgesic usage or global preference showed no difference between group A, B or C. The patients in the group C were offered treatment (ultrasound, massage, exercise) after the 6 weeks treatment period. At the questionnaire after 6 month 44 (87%) of the 52 patients from all three groups who had treatment responded. Sixty-four percent answered that they had had good or some effects, 68 percent were still doing the exercise programme and 17 percent had received other forms of therapy after they had completed the study. No difference between

  19. Theory of point-defects, non-stoichiometry, and solute additions in SmCo{sub 5+x}-Sm{sub 2}Co{sub 17{minus}y} and related compounds

    SciTech Connect

    Welch, D.O.

    1998-08-01

    There is considerable interest in the possibility of producing Sm-Co-based nanocomposite magnets by rapid solidification and other far-from-equilibrium processing methods. Thermodynamic and kinetic models are quite valuable in understanding and optimizing such methods. This paper describes a method of estimation, utilizing tight-binding-based bond-order interatomic interaction potentials, of the thermodynamic properties of point defects such as vacancies, interstitials, antisite defects, and solute additions in the SmCo{sub 5+x} and Sm{sub 2}Co{sub 17{minus}y} phases and related rare-earth-transition metal compounds. Illustrative calculations for point defects in SmCo{sub 5} will be presented. The results suggest a unified model of the thermodynamic properties of the SmCo{sub 5+x}-Sm{sub 2}Co{sub 17{minus}y} region of the phase diagram, based on the 1-5 structure and the replacement of Sm by interacting dumb-bell interstitials to form the 2-17 structure; the model is similar in nature to theories of the thermodynamics of metal hydrides.

  20. Theory of point-defects, non-stoichiometry, and solute additions in SmCo{sub 5+x}-Sm{sub 2}Co{sub 17{minus}y} and related compounds

    SciTech Connect

    WELCH,D.O.

    1998-09-03

    There is considerable interest in the possibility of producing Sm-Co-based nanocomposite magnets by rapid solidification and other far-from-equilibrium processing methods. Thermodynamic and kinetic models are quite valuable in understanding and optimizing such methods. This paper describes a method of estimation, utilizing tight-binding-based bond-order interatomic interaction potentials, of the thermodynamic properties of point defects such as vacancies, interstitials, antisite defects, and solute additions in the SmCo{sub 5+x} and Sm{sub 2}Co {sub 17}-y phases and related rare-earth-transition metal compounds. Illustrative calculations for point defects in SmCo{sub 5} will be presented. The results suggest a unified model of the thermodynamic properties of the SmCo{sub 5+x} -- Sm{sub 2} Co{sub 17{minus}y} region of the phase diagram, based on the 1-5 structure and the replacement of Sm by interacting dumb-bell interstitials to form the 2-17 structure; the model is similar in nature to theories of the thermodynamics of metal hydrides.