Science.gov

Sample records for slow control system

  1. Slow Control System for the NIFFTE High Precision TPC

    NASA Astrophysics Data System (ADS)

    Thornton, Remington

    2010-11-01

    The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) has designed a Time Projection Chamber (TPC) to measure neutron induced fission cross-section measurements of the major actinides to sub-1% precision over a wide incident neutron energy range. These measurements are necessary to design the next generation of nuclear power plants. In order to achieve our high precision goals, an accurate and efficient slow control system must be implemented. Custom software has been created to control the hardware through Maximum Integration Data Acquisition System (MIDAS). This includes reading room and device temperature, setting the high voltage power supplies, and reading voltages. From hardware to software, an efficient design has been implemented and tested. This poster will present the setup and data from this slow control system.

  2. Slow control systems of the Reactor Experiment for Neutrino Oscillation

    NASA Astrophysics Data System (ADS)

    Choi, J. H.; Jang, H. I.; Choi, W. Q.; Choi, Y.; Jang, J. S.; Jeon, E. J.; Joo, K. K.; Kim, B. R.; Kim, H. S.; Kim, J. Y.; Kim, S. B.; Kim, S. Y.; Kim, W.; Kim, Y. D.; Ko, Y. J.; Lee, J. K.; Lim, I. T.; Pac, M. Y.; Park, I. G.; Park, J. S.; Park, R. G.; Seo, H. K.; Seo, S. H.; Shin, C. D.; Siyeon, K.; Yeo, I. S.; Yu, I.

    2016-02-01

    The RENO experiment has been in operation since August 2011 to measure reactor antineutrino disappearance using identical near and far detectors. For accurate measurements of neutrino mixing parameters and efficient data taking, it is crucial to monitor and control the detector in real time. Environmental conditions also need to be monitored for stable operation of detectors as well as for safety reasons. In this paper, we report the design, hardware, operation, and performance of the slow control system.

  3. Slow Control System for the NIFFTE Collaboration TPC

    NASA Astrophysics Data System (ADS)

    Ringle, Erik; Niffte Collaboration Collaboration

    2011-10-01

    As world energy concerns continue to dominate public policy in the 21st century, the need for cleaner and more efficient nuclear power is necessary. In order to effectively design and implement plans for generation IV nuclear reactors, more accurate fission cross-section measurements are necessary. The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration, in an effort to meet this need, has constructed a Time Projection Chamber (TPC) which aims to reduce the uncertainty of the fission cross-section to less than 1%. Using the Maximum Integration Data Acquisition System (MIDAS) framework, slow control measurements are integrated into a single interface to facilitate off-site monitoring. The Hart Scientific 1560 Black Stack will be used with two 2564 Thermistor Scanner Modules to monitor internal temperature of the TPC. A Prologix GPIB to Ethernet controller will be used to interface the hardware with MIDAS. This presentation will detail the design and implementation of the slow control system for the TPC. This work was supported by the U.S. Department of Energy Division of Energy Research.

  4. Optimal Control Modification for Robust Adaptation of Singularly Perturbed Systems with Slow Actuators

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.; Ishihara, Abraham; Stepanyan, Vahram; Boskovic, Jovan

    2009-01-01

    Recently a new optimal control modification has been introduced that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. This modification is based on an optimal control formulation to minimize the L2 norm of the tracking error. The optimal control modification adaptive law results in a stable adaptation in the presence of a large adaptive gain. This study examines the optimal control modification adaptive law in the context of a system with a time scale separation resulting from a fast plant with a slow actuator. A singular perturbation analysis is performed to derive a modification to the adaptive law by transforming the original system into a reduced-order system in slow time. The model matching conditions in the transformed time coordinate results in increase in the feedback gain and modification of the adaptive law.

  5. The Slow Controls System of the New Muon g-2 Experiment at Fermilab

    NASA Astrophysics Data System (ADS)

    Eads, Michael; New Muon g-2 Collaboration

    2015-04-01

    The goal of the new muon g-2 experiment (E-989), currently under construction at Fermi National Accelerator Laboratory, is to measure the anomalous gyromagnetic ratio of the muon with unprecedented precision. The uncertainty goal of the experiment, 0.14ppm, represents a four-fold improvement over the current best measurement of this value and has the potential to increase the current three standard deviation disagreement with the predicted standard model value to five standard deviations. Measuring the operating conditions of the experiment will be essential to achieving these uncertainty goals. This talk will describe the design and the current status of E-989's slow controls system. This system, based on the MIDAS Slow Control Bus, will be used to measure and record currents, voltages, temperatures, humidities, pressures, flows, and other data which is collected asynchronously with the injection of the muon beam. The system consists of a variety of sensors and front-end electronics which interface to back-end data acquisition, data storage, and data monitoring systems. Parts of the system are all already operational and the full system will be completed before beam commissioning begins in 2017.

  6. A versatile and light-weight slow control system for small-scale applications

    NASA Astrophysics Data System (ADS)

    Zappa, P.; Bütikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; von Sivers, M.

    2016-09-01

    We present an open source slow control system for small and medium scale projects. Thanks to its modular and flexible design, where the various instruments are read and controlled by independent plugins, Doberman (Detector OBsERving and Monitoring ApplicatioN) can be quickly adapted for many applications, also making use of existing code or proprietary components. The system uses a SQL database to store the data from the instruments and provides an online application to display and browse through the data. It allows the modification of device settings while the program is running and features a protocol to handle exceptions, including the automated distribution of alarm messages. We present two case studies from astroparticle physics, on which Doberman is successfully deployed: a low-background screening facility installed in a remote underground laboratory and a detector R&D platform using cryogenic liquid xenon.

  7. Is groundwater age the main control for slow turnover of nitrate in a fractured groundwater system?

    NASA Astrophysics Data System (ADS)

    Osenbrück, Karsten; Schwientek, Marc; Rügner, Hermann; Grathwohl, Peter

    2015-04-01

    Slow transformation processes are known to control the chemical, isotopic, and redox evolution of large-scale aquifers (Edmunds et al., 1982; Katz et al., 1995). However, at the field scale some of the crucial biogeochemical processes governing pollutant turnover and their interrelations with hydrology are poorly understood. Particularly, only little is known about denitrification in fractured rock aquifers. Therefore, the main objective of the presented study is to assess where and how slow turnover of nitrate ans other pollutants in the deeper subsurface take place. The studied fractured and partly karstified aquifer consisting of Triassic black limestones and dolomites is located in the catchment of the Ammer river (ca. 350 km²) close to Tübingen in southern Germany. Near the recharge area, the aquifer is covered by loess allowing intensive agriculture. Further downgradient, the cover consist of a series of mudstones and sandstones of variable permeability. The aquifer is used for drinking water purposes by regional water suppliers. Land-use is dominated by agriculture with arable land covering nearly 50% of the catchment. Over the last years a variety of groundwater samples have been collected from the groundwater system including 6 water supply wells, 4 karstic springs, and 9 monitoring wells in the recharge area. This allowed to identify spatial and temporal patterns of water quality including concentrations of major ions, dissolved organic carbon (DOC), organic pollutants (e.g., pesticides), and environmental isotopes. Groundwater age distributions at most of these locations were derived from tritium, 3He, CFCs and SF6. Groundwaters in the recharge area show high concentrations of nutrients (e.g. 20-51 mg/L of nitrate and 0.2 to 0.05 µg/L of phosphate). Of special concern are disparate nitrate concentrations ranging from below 0.4 to 20 mg/L in water supply wells although screen depths of the production wells are similar. Concentrations of dissolved

  8. Double Chooz Slow Monitoring System

    NASA Astrophysics Data System (ADS)

    Chang, Pi-Jung; Horton-Smith, Glenn; McKee, David; Shrestha, Deepak; Winslow, Lindley; Conrad, Janet

    2010-02-01

    The Double Chooz experiment aims to measure neutrino flux from two nearly identical detectors with an uncertainty less than 0.6%. The Double Chooz slow monitoring system records conditions of the experiment's environment which can impact the experiment's goals. The slow monitoring system includes temperatures and voltages in electronics, experimental hall environmental conditions, line voltages, liquid temperatures, PMT's magnetic field, radon concentrations, and photo-tube high voltages. This system scans all channels automatically, stores data in a common database, and warns of changes in the two detectors' physical environments. Most functions in this system can be accomplished by 1-Wire products from Dallas Semiconductor. We can use a single master for several functions' controls and operations and the power is derived from a signal bus. Every device has a unique unalterable ID. The sensors monitoring the liquid system, such as liquid thermal meters, are covered by epoxy in order to isolate in the liquid. Their radioactivity can be ignored and will not affect the uncertainty in the system. )

  9. Electronic Control Of Slow Rotations

    NASA Technical Reports Server (NTRS)

    Howard, David E.; Smith, Dennis A.

    1992-01-01

    Digital/analog circuit controls both angular position and speed of rotation of motor shaft with high precision. Locks angular position of motor to phase of rotation-command clock signal at binary submultiple of master clock signal. Circuit or modified version used to control precisely position and velocity of robotic manipulator, to control translation mechanism of crystal-growing furnace, to position hands of mechanical clock, or to control angular position and rate of rotation in any of large variety of rotating mechanisms.

  10. TANGO standard software to control the Nuclotron beam slow extraction

    NASA Astrophysics Data System (ADS)

    Andreev, V. A.; Volkov, V. I.; Gorbachev, E. V.; Isadov, V. A.; Kirichenko, A. E.; Romanov, S. V.; Sedykh, G. S.

    2016-09-01

    TANGO Controls is a basis of the NICA control system. The report describes the software which integrates the Nuclotron beam slow extraction subsystem into the TANGO system of NICA. Objects of control are power supplies for resonance lenses. The software consists of the subsystem device server, remote client and web-module for viewing the subsystem data.

  11. Slow-Release Sachets of Neoseiulus cucumeris Predatory Mites Reduce Intraguild Predation by Dalotia coriaria in Greenhouse Biological Control Systems

    PubMed Central

    Pochubay, Emily; Tourtois, Joseph; Himmelein, Jeanne; Grieshop, Matthew

    2015-01-01

    Intraguild predation of Neoseiulus cucumeris Oudemans (Phytoseiidae) by soil-dwelling predators, Dalotia coriaria Kraatz (Staphylinidae) may limit the utility of open rearing systems in greenhouse thrips management programs. We determined the rate of D. coriaria invasion of N. cucumeris breeder material presented in piles or sachets, bran piles (without mites), and sawdust piles. We also observed mite dispersal from breeder piles and sachets when D. coriaria were not present. Dalotia coriaria invaded breeder and bran piles at higher rates than sawdust piles and sachets. Furthermore, proportions of N. cucumeris in sachets were six- to eight-fold higher compared with breeder piles. When D. coriaria were absent, N. cucumeris dispersed from breeder piles and sachets for up to seven weeks. In earlier weeks, more N. cucumeris dispersed from breeder piles compared with sachets, and in later weeks more N. cucumeris dispersed from sachets compared with breeder piles. Sachets protected N. cucumeris from intraguild predation by D. coriaria resulting in higher populations of mites. Therefore, sachets should be used in greenhouse biocontrol programs that also release D. coriaria. Furthermore, breeder piles that provide “quick-releases” or sachets that provide “slow-releases” of mites should be considered when incorporating N. cucumeris into greenhouse thrips management programs. PMID:26463199

  12. Slow-Release Sachets of Neoseiulus cucumeris Predatory Mites Reduce Intraguild Predation by Dalotia coriaria in Greenhouse Biological Control Systems.

    PubMed

    Pochubay, Emily; Tourtois, Joseph; Himmelein, Jeanne; Grieshop, Matthew

    2015-06-01

    Intraguild predation of Neoseiulus cucumeris Oudemans (Phytoseiidae) by soil-dwelling predators, Dalotia coriaria Kraatz (Staphylinidae) may limit the utility of open rearing systems in greenhouse thrips management programs. We determined the rate of D. coriaria invasion of N. cucumeris breeder material presented in piles or sachets, bran piles (without mites), and sawdust piles. We also observed mite dispersal from breeder piles and sachets when D. coriaria were not present. Dalotia coriaria invaded breeder and bran piles at higher rates than sawdust piles and sachets. Furthermore, proportions of N. cucumeris in sachets were six- to eight-fold higher compared with breeder piles. When D. coriaria were absent, N. cucumeris dispersed from breeder piles and sachets for up to seven weeks. In earlier weeks, more N. cucumeris dispersed from breeder piles compared with sachets, and in later weeks more N. cucumeris dispersed from sachets compared with breeder piles. Sachets protected N. cucumeris from intraguild predation by D. coriaria resulting in higher populations of mites. Therefore, sachets should be used in greenhouse biocontrol programs that also release D. coriaria. Furthermore, breeder piles that provide "quick-releases" or sachets that provide "slow-releases" of mites should be considered when incorporating N. cucumeris into greenhouse thrips management programs.

  13. Large Deviations in Fast-Slow Systems

    NASA Astrophysics Data System (ADS)

    Bouchet, Freddy; Grafke, Tobias; Tangarife, Tomás; Vanden-Eijnden, Eric

    2016-02-01

    The incidence of rare events in fast-slow systems is investigated via analysis of the large deviation principle (LDP) that characterizes the likelihood and pathway of large fluctuations of the slow variables away from their mean behavior—such fluctuations are rare on short time-scales but become ubiquitous eventually. Classical results prove that this LDP involves an Hamilton-Jacobi equation whose Hamiltonian is related to the leading eigenvalue of the generator of the fast process, and is typically non-quadratic in the momenta—in other words, the LDP for the slow variables in fast-slow systems is different in general from that of any stochastic differential equation (SDE) one would write for the slow variables alone. It is shown here that the eigenvalue problem for the Hamiltonian can be reduced to a simpler algebraic equation for this Hamiltonian for a specific class of systems in which the fast variables satisfy a linear equation whose coefficients depend nonlinearly on the slow variables, and the fast variables enter quadratically the equation for the slow variables. These results are illustrated via examples, inspired by kinetic theories of turbulent flows and plasma, in which the quasipotential characterizing the long time behavior of the system is calculated and shown again to be different from that of an SDE.

  14. Slow-scan television system.

    PubMed

    Hunten, D M; Nelson, B E; Stump, C J

    1976-09-01

    An unconventional, highly sensitive camera system is described, suitable for silicon or amplified silicon (SIT or EBS) vidicons. Features are a variable field size and sweep rate and a low-noise video amplifier. Used on a 91-cm telescope, it can detect 15th magnitude stars with the silicon vidicon. With an SIT tube, the limit is 17 on the 91-cm and 20.5 on the 4-m telescope. The system is briefly compared with an I-SIT camera.

  15. Slow-scan television system.

    PubMed

    Hunten, D M; Nelson, B E; Stump, C J

    1976-09-01

    An unconventional, highly sensitive camera system is described, suitable for silicon or amplified silicon (SIT or EBS) vidicons. Features are a variable field size and sweep rate and a low-noise video amplifier. Used on a 91-cm telescope, it can detect 15th magnitude stars with the silicon vidicon. With an SIT tube, the limit is 17 on the 91-cm and 20.5 on the 4-m telescope. The system is briefly compared with an I-SIT camera. PMID:20165372

  16. Slow motions in systems with fast modulated excitation

    NASA Astrophysics Data System (ADS)

    Kremer, E.

    2016-11-01

    It is well known that high-frequency excitation can modify the behavior of systems with respect to slow motions. The goal of this study is consideration of these effects in a rather general case of analytical systems with modulated sinusoidal excitation. The method of direct separation of motions proposed by I.I. Blekhman was applied in a modified form with the explicit introduction of a small parameter. Equations for the slow motions are obtained and an analysis of how they depend on the structure of the original equations is performed. Five basic effects corresponding to different possible dependencies of the modulation amplitude on position, velocity, and slow time are selected (some of them for the first time). These effects offer a possibility for designing a high-frequency control of the slow motions with specified properties. For example, high-frequency excitation in a system with a nonlinear friction can essentially increase the effective damping. The results are also of significance for system identification and diagnostics. Analysis of a hydraulic valve is given as an example of application.

  17. Rapidly reconfigurable slow-light system based on off-resonant Raman absorption

    NASA Astrophysics Data System (ADS)

    Vudyasetu, Praveen K.; Camacho, Ryan M.; Howell, John C.

    2010-11-01

    We present a slow-light system based on dual Raman absorption resonances in warm rubidium vapor. Each Raman absorption resonance is produced by a control beam in an off-resonant Λ system. This system combines all optical control of the Raman absorption and the low-dispersion broadening properties of the double Lorentzian absorption slow light. The bandwidth, group delay, and central frequency of the slow-light system can all be tuned dynamically by changing the properties of the control beam. We demonstrate multiple pulse delays with low distortion and show that such a system has fast switching dynamics and thus fast reconfiguration rates.

  18. Slow dynamics perspectives on the Embodied-Brain Systems Science.

    PubMed

    Yano, Shiro; Maeda, Takaki; Kondo, Toshiyuki

    2016-03-01

    Recent researches point out the importance of the fast-slow cognitive process and learning process of self-body. Bayesian perspectives on the cognitive system also attract research attentions. The view of fast-slow dynamical system has long attracted wide range of attentions from physics to the neurobiology. In many research fields, there is a vast well-organized and coherent behavior in the multi degrees-of-freedom. This behavior matches the mathematical fact that fast-slow system is essentially described with a few variables. In this paper, we review the mathematical basis for understanding the fast-slow dynamical systems. Additionally, we review the basis of Bayesian statistics and provide a fast-slow perspective on the Bayesian inference.

  19. Learned control of slow potential interhemispheric asymmetry in schizophrenia.

    PubMed

    Gruzelier, J; Hardman, E; Wild, J; Zaman, R

    1999-12-01

    We report on the feasibility of teaching 16 (DSM-IV) schizophrenic patients, subdivided by syndrome, self-regulation of interhemispheric asymmetry having demonstrated efficient learning of interhemispheric control in normal subjects. Reversal of asymmetry may be important to treatment and recovery in schizophrenia for following improvement on neuroleptic drugs functional hemispheric asymmetries have reversed, with directions of reversal and pre-existing asymmetry dependent on syndrome. Asymmetry reversal in animals, manifested by spatial turning tendencies, has been used as a marker of neuroleptic action and involves striatal dopamine under reciprocal hemispheric control. We gave as feedback the left right asymmetry in slow potential negativity recorded from the sensory motor strip (C3,4). Feedback took the form of a rocket on a screen which rose or fell with leftward or rightward shifts in negativity. Patients were able to learn control (P < 0.01). In those patients with lesser ability this was due to inability to sustain concentration throughout the session rather than slow initial learning. Active syndrome patients were better able to shift negativity rightward and withdrawn patients leftward, directions associated with drug reversal of functional asymmetry and symptom recovery for each syndrome. Accordingly our demonstration that many symptomatic schizophrenic patients are capable of learning control opens the door to electrocortical operant conditioning training in schizophrenia with therapeutic regimens.

  20. Slow Relaxation in Anderson Critical Systems

    NASA Astrophysics Data System (ADS)

    Choi, Soonwon; Yao, Norman; Choi, Joonhee; Kucsko, Georg; Lukin, Mikhail

    2016-05-01

    We study the single particle dynamics in disordered systems with long range hopping, focusing on the critical cases, i.e., the hopping amplitude decays as 1 /rd in d-dimension. We show that with strong on-site potential disorder, the return probability of the particle decays as power-law in time. As on-site potential disorder decreases, the temporal profile smoothly changes from a simple power-law to the sum of multiple power-laws with exponents ranged from 0 to νmax. We analytically compute the decay exponents using a simple resonance counting argument, which quantitatively agrees with exact numerical results. Our result implies that the dynamics in Anderson Critical systems are dominated by resonances. Harvard-MIT CUA, Kwanjeong Educational Fellowship, AFOSR MURI, Samsung Scholarship.

  1. Fast-slow analysis for parametrically and externally excited systems with two slow rationally related excitation frequencies.

    PubMed

    Han, Xiujing; Bi, Qinsheng; Ji, Peng; Kurths, Jürgen

    2015-07-01

    We present a general method for analyzing mixed-mode oscillations (MMOs) in parametrically and externally excited systems with two low excitation frequencies (PEESTLEFs) for the case of arbitrary m:n relation between the slow frequencies of excitations. The validity of the approach has been demonstrated using the equations of Duffing and van der Pol, separately. Our study shows that, by introducing a slow variable and finding the relation between the slow variable and the slow excitations, PEESTLEFs can be transformed into a fast-slow form with a single slow variable and therefore MMOs observed in PEESTLEFs can be understood by the classical machinery of fast subsystem analysis of the transformed fast-slow system. PMID:26274251

  2. Controls on the seasonal deformation of slow-moving landslides

    NASA Astrophysics Data System (ADS)

    Handwerger, Alexander L.; Roering, Joshua J.; Schmidt, David A.

    2013-09-01

    Precipitation drives seasonal velocity changes in slow-moving landslides by increasing pore-water pressure and reducing the effective normal stress along basal shear zones. This pressure change is often modeled as a pore-water pressure wave that diffuses through the landslide body, such that the minimum time required for landslides to respond to rainfall should vary as the square of landslide depth (which often approximates the saturated thickness) and inversely with hydraulic diffusivity. Here, we assess this model with new observations from the landslide-prone Eel River catchment, Northern California. Using satellite radar interferometry (InSAR) time series, precipitation data, and high-resolution topographic data from airborne lidar, we quantify the seasonal dynamics of 10 slow-moving landslides, which share the same lithologic, tectonic, and Mediterranean climate conditions. These slope failures have areas ranging from 0.16 to 3.1 km2, depths that vary from 8 to 40 m, and average downslope velocities of 0.2 to 1.2 m/yr. Each slide exhibits well-defined seasonal velocity changes with a periodicity of ˜1 yr and responds (i.e., accelerates) within 40 days following the onset of rainfall. Despite a five-fold variation in landslide depth, we do not detect systematic differences in response time within the resolution of our observations. Our results could imply that: 1) slides in our study area are sensitive to subtle hydrologic perturbations, 2) the 'effective' diffusivity governing slide behavior is much higher than field-derived values because pore pressure transmission and slide dynamics are facilitated by preferential flow paths, particularly cracks related to deformation and seasonal shrink-swell cycles, or 3) a simple one-dimensional linear diffusion model may fail to capture the three-dimensional time-dependent hydrologic changes inherent in an evolving mechanical-hydrologic system, such as a slow-moving landslide.

  3. [Effects of slow/controlled release fertilizers on the growth and nutrient use efficiency of pepper].

    PubMed

    Tang, Shuan-Hu; Zhang, Fa-Bao; Huang, Xu; Chen, Jian-Sheng; Xu, Pei-Zhi

    2008-05-01

    Pot trails were conducted from 2003 to 2005 to study the effects of slow/controlled release fertilizers on the growth and nutrient use efficiency of pepper. The results indicated that in comparison with conventional splitting fertilization (T1), basal application of polymer-coated controlled release fertilizer (T2) enhanced the single fruit mass and vitamin C concentration, improved the root activity, and increased the fruit yield by 8.4%, but no significant effect was observed on the dissoluble sugar concentration in fruit. NH4MgPO4-coated controlled release fertilizer (T3) increased the dissoluble sugar concentration by 5.67%, but had less effect on single fruit mass and vitamin C concentration. Under the application of T3, the root system had a vigorous growth at early stages but became infirm at later stages, resulting in a lower yield. Comparing with T1, the application of 3 slow release fertilizers increased the dissoluble sugar concentration in fruit, enhanced the root activity, but had less effect on the yield. All test slow/controlled release fertilizers increased the use efficiency of N, P, and K significantly, with an exception for T2 which increased the use efficiency of N and K but decreased that of P. It was demonstrated that an appropriate application of slow/controlled release fertilizers could enhance pepper' s root activity and improve nutrient use efficiency. PMID:18655582

  4. [Effects of slow/controlled release fertilizers on the growth and nutrient use efficiency of pepper].

    PubMed

    Tang, Shuan-Hu; Zhang, Fa-Bao; Huang, Xu; Chen, Jian-Sheng; Xu, Pei-Zhi

    2008-05-01

    Pot trails were conducted from 2003 to 2005 to study the effects of slow/controlled release fertilizers on the growth and nutrient use efficiency of pepper. The results indicated that in comparison with conventional splitting fertilization (T1), basal application of polymer-coated controlled release fertilizer (T2) enhanced the single fruit mass and vitamin C concentration, improved the root activity, and increased the fruit yield by 8.4%, but no significant effect was observed on the dissoluble sugar concentration in fruit. NH4MgPO4-coated controlled release fertilizer (T3) increased the dissoluble sugar concentration by 5.67%, but had less effect on single fruit mass and vitamin C concentration. Under the application of T3, the root system had a vigorous growth at early stages but became infirm at later stages, resulting in a lower yield. Comparing with T1, the application of 3 slow release fertilizers increased the dissoluble sugar concentration in fruit, enhanced the root activity, but had less effect on the yield. All test slow/controlled release fertilizers increased the use efficiency of N, P, and K significantly, with an exception for T2 which increased the use efficiency of N and K but decreased that of P. It was demonstrated that an appropriate application of slow/controlled release fertilizers could enhance pepper' s root activity and improve nutrient use efficiency.

  5. Diversity of Hydrothermal Systems on Slow Spreading Ocean Ridges

    NASA Astrophysics Data System (ADS)

    Rona, Peter A.; Devey, Colin W.; Dyment, Jérôme; Murton, Bramley J.

    Diversity of Hydrothermal Systems on Slow Spreading Ocean Ridges presents a multidisciplinary overview of the remarkable emerging diversity of hydrothermal systems on slow spreading ocean ridges in the Atlantic, Indian, and Arctic oceans. When hydrothermal systems were first found on the East Pacific Rise and other Pacific Ocean ridges beginning in the late 1970s, the community consensus held that the magma delivery rate of intermediate to fast spreading was necessary to support black smoker-type high-temperature systems and associated chemosynthetic ecosystems and polymetallic sulfide deposits. Contrary to that consensus, hydrothermal systems not only occur on slow spreading ocean ridges but, as reported in this volume, are generally larger, exhibit different chemosynthetic ecosystems, produce larger mineral deposits, and occur in a much greater diversity of geologic settings than those systems in the Pacific. The full diversity of hydrothermal systems on slow spreading ocean ridges, reflected in the contributions to this volume, is only now emerging and opens an exciting new frontier for ocean ridge exploration, including • Processes of heat and chemical transfer from the Earth's mantle and crust via slow spreading ocean ridges to the oceans • The major role of detachment faulting linking crust and mantle in hydrothermal circulation • Chemical reaction products of mantle involvement including serpentinization, natural hydrogen, abiotic methane, and hydrocarbon synthesis • Generation of large polymetallic sulfide deposits hosted in ocean crust and mantle • Chemosynthetic vent communities hosted in the diverse settings The readership for this volume will include schools, universities, government laboratories, and scientific societies in developed and developing nations, including over 150 nations that have ratified the United Nations Convention on the Law of the Sea.

  6. Slow wave activity and slow oscillations in sleepwalkers and controls: effects of 38 h of sleep deprivation.

    PubMed

    Perrault, Rosemarie; Carrier, Julie; Desautels, Alex; Montplaisir, Jacques; Zadra, Antonio

    2013-08-01

    Sleepwalkers have been shown to have an unusually high number of arousals from slow wave sleep and lower slow wave activity (SWA) power during the night than controls. Because sleep deprivation increases the frequency of slow wave sleep (SWS) arousals in sleepwalkers, it may also affect the expression of the homeostatic process to a greater extent than shown previously. We thus investigated SWA power as well as slow wave oscillation (SWO) density in 10 sleepwalkers and nine controls at baseline and following 38 h of sleep deprivation. There was a significant increase in SWA during participants' recovery sleep, especially during their second non-rapid eye movement (NREM) period. SWO density was similarly increased during recovery sleep's first two NREM periods. A fronto-central gradient in SWA and SWO was also present on both nights. However, no group differences were noted on any of the 2 nights on SWA or SWO. This unexpected result may be related to the heterogeneity of sleepwalkers as a population, as well as our small sample size. SWA pressure after extended sleep deprivation may also result in a ceiling effect in both sleepwalkers and controls. PMID:23398262

  7. Slow wave activity and slow oscillations in sleepwalkers and controls: effects of 38 h of sleep deprivation.

    PubMed

    Perrault, Rosemarie; Carrier, Julie; Desautels, Alex; Montplaisir, Jacques; Zadra, Antonio

    2013-08-01

    Sleepwalkers have been shown to have an unusually high number of arousals from slow wave sleep and lower slow wave activity (SWA) power during the night than controls. Because sleep deprivation increases the frequency of slow wave sleep (SWS) arousals in sleepwalkers, it may also affect the expression of the homeostatic process to a greater extent than shown previously. We thus investigated SWA power as well as slow wave oscillation (SWO) density in 10 sleepwalkers and nine controls at baseline and following 38 h of sleep deprivation. There was a significant increase in SWA during participants' recovery sleep, especially during their second non-rapid eye movement (NREM) period. SWO density was similarly increased during recovery sleep's first two NREM periods. A fronto-central gradient in SWA and SWO was also present on both nights. However, no group differences were noted on any of the 2 nights on SWA or SWO. This unexpected result may be related to the heterogeneity of sleepwalkers as a population, as well as our small sample size. SWA pressure after extended sleep deprivation may also result in a ceiling effect in both sleepwalkers and controls.

  8. Voltage-controlled slow light in asymmetry double quantum dots

    NASA Astrophysics Data System (ADS)

    Yuan, Chun-Hua; Zhu, Ka-Di

    2006-07-01

    The authors demonstrate theoretically that there exists electromagnetically induced transparency in an asymmetric double quantum dot system using tunneling instead of pump laser. The group velocity slowdown factor is theoretically analyzed as a function of electron tunneling at different broadened linewidths. With feasible parameters for applications to a 100Gbits/s optical network, numerical calculation infers group velocity as low as 300m/s. The scheme is expected to be useful in constructing a variable semiconductor optical buffer based on electromagnetically induced transparency in an asymmetric double quantum dot controlled by voltage.

  9. Density evolution in systems with slow approach to equilibrium

    NASA Astrophysics Data System (ADS)

    Nelson, Kevin Taylor

    This dissertation investigates the evolution of probability densities under the Frobenius-Perron operator U in chaotic iterated-map systems that are slow to reach equilibrium. It first concentrates on one-dimensional maps that are slow to reach equilibrium because they feature intermittent chaos due to the presence of a marginal fixed point. Using the method of shift states and coherent states under U, certain results are obtained concerning the spectrum of U in various functional spaces, using as the main example the cusp map f( x) = 1 - ∣1-2x . Those results are applied to obtain corrections to the well-known leading 1/t form of the x-x autocorrelation function C(t). The symbolic dynamics of one-dimensional maps are then investigated, with particular emphasis on the implications of the existence of intermittent chaos and with applications to topological conjugation. Next, the statistics of extreme values in one-dimensional maps are investigated. Fn(x) is defined as the probability that a point chosen from an initial probability distribution and its first n - 1 iterates under a particular map are all less than x; the properties of F n(x) are derived analytically for a wide variety of one-dimensional maps, and the conclusions are confirmed numerically. Finally, higher-dimensional area-preserving maps are investigated. The technique of local spectral decomposition for U, in which approximate right and left eigenstates for U are constructed localized on unstable periodic points, is used to study density evolution and correlation of observables over time.

  10. Global intracellular slow-wave dynamics of the thalamocortical system.

    PubMed

    Sheroziya, Maxim; Timofeev, Igor

    2014-06-25

    It is widely accepted that corticothalamic neurons recruit the thalamus in slow oscillation, but global slow-wave thalamocortical dynamics have never been experimentally shown. We analyzed intracellular activities of neurons either from different cortical areas or from a variety of specific and nonspecific thalamic nuclei in relation to the phase of global EEG signal in ketamine-xylazine anesthetized mice. We found that, on average, slow-wave active states started off within frontal cortical areas as well as higher-order and intralaminar thalamus (posterior and parafascicular nuclei) simultaneously. Then, the leading edge of active states propagated in the anteroposterior/lateral direction over the cortex at ∼40 mm/s. The latest structure we recorded within the slow-wave cycle was the anterior thalamus, which followed active states of the retrosplenial cortex. Active states from different cortical areas tended to terminate simultaneously. Sensory thalamic ventral posterior medial and lateral geniculate nuclei followed cortical active states with major inhibitory and weak tonic-like "modulator" EPSPs. In these nuclei, sharp-rising, large-amplitude EPSPs ("drivers") were not modulated by cortical slow waves, suggesting their origin in ascending pathways. The thalamic active states in other investigated nuclei were composed of depolarization: some revealing "driver"- and "modulator"-like EPSPs, others showing "modulator"-like EPSPs only. We conclude that sensory thalamic nuclei follow the propagating cortical waves, whereas neurons from higher-order thalamic nuclei display "hub dynamics" and thus may contribute to the generation of cortical slow waves.

  11. CONTROL SYSTEM FOR NEUTRONIC REACTORS

    DOEpatents

    Crever, F.E.

    1962-05-01

    BS>A slow-acting shim rod for control of major variations in reactor neutron flux and a fast-acting control rod to correct minor flux variations are employed to provide a sensitive, accurate control system. The fast-acting rod is responsive to an error signal which is produced by changes in the neutron flux from a predetermined optimum level. When the fast rod is thus actuated in a given direction, means is provided to actuate the slow-moving rod in that direction to return the fast rod to a position near the midpoint of its control range. (AEC)

  12. CONTROL SYSTEM

    DOEpatents

    Shannon, R.H.; Williamson, H.E.

    1962-10-30

    A boiling water type nuclear reactor power system having improved means of control is described. These means include provisions for either heating the coolant-moderator prior to entry into the reactor or shunting the coolantmoderator around the heating means in response to the demand from the heat engine. These provisions are in addition to means for withdrawing the control rods from the reactor. (AEC)

  13. Hydrothermal activity at slow-spreading ridges: variability and importance of magmatic controls

    NASA Astrophysics Data System (ADS)

    Escartin, Javier

    2016-04-01

    Hydrothermal activity along mid-ocean ridge axes is ubiquitous, associated with mass, chemical, and heat exchanges between the deep lithosphere and the overlying envelopes, and sustaining chemiosynthetic ecosystems at the seafloor. Compared with hydrothermal fields at fast-spreading ridges, those at slow spreading ones show a large variability as their location and nature is controlled or influenced by several parameters that are inter-related: a) tectonic setting, ranging from 'volcanic systems' (along the rift valley floor, volcanic ridges, seamounts), to 'tectonic' ones (rift-bounding faults, oceanic detachment faults); b) the nature of the host rock, owing to compositional heterogeneity of slow-spreading lithosphere (basalt, gabbro, peridotite); c) the type of heat source (magmatic bodies at depth, hot lithosphere, serpentinization reactions); d) and the associated temperature of outflow fluids (high- vs.- low temperature venting and their relative proportion). A systematic review of the distribution and characteristics of hydrothermal fields along the slow-spreading Mid-Atlantic Ridge suggests that long-lived hydrothermal activity is concentrated either at oceanic detachment faults, or along volcanic segments with evidence of robust magma supply to the axis. A detailed study of the magmatically robust Lucky Strike segment suggests that all present and past hydrothermal activity is found at the center of the segment. The association of these fields to central volcanos, and the absence of indicators of hydrothermal activity along the remaining of the ridge segment, suggests that long-lived hydrothermal activity in these volcanic systems is maintained by the enhanced melt supply and the associated magma chamber(s) required to build these volcanic edifices. In this setting, hydrothermal outflow zones at the seafloor are systematically controlled by faults, indicating that hydrothermal fluids in the shallow crust exploit permeable fault zones to circulate. While

  14. The manual control of vehicles undergoing slow transitions in dynamic characteristics

    NASA Technical Reports Server (NTRS)

    Moriarty, T. E.

    1974-01-01

    The manual control was studied of a vehicle with slowly time-varying dynamics to develop analytic and computer techniques necessary for the study of time-varying systems. The human operator is considered as he controls a time-varying plant in which the changes are neither abrupt nor so slow that the time variations are unimportant. An experiment in which pilots controlled the longitudinal mode of a simulated time-varying aircraft is described. The vehicle changed from a pure double integrator to a damped second order system, either instantaneously or smoothly over time intervals of 30, 75, or 120 seconds. The regulator task consisted of trying to null the error term resulting from injected random disturbances with bandwidths of 0.8, 1.4, and 2.0 radians per second. Each of the twelve experimental conditons was replicated ten times. It is shown that the pilot's performance in the time-varying task is essentially equivalent to his performance in stationary tasks which correspond to various points in the transition. A rudimentary model for the pilot-vehicle-regulator is presented.

  15. 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

    particular needle length/bore is determined, the tap on the addition funnel is turned fully on, so no adjustment is necessary. When needles with a particularly fine bore are used, a small plug of glass wool should be inserted in the constriction above the tap, to filter the solution and prevent blockage of the needle. An inert atmosphere is readily maintained throughout the system. The elimination of atmospheric contamination, containment of odors and controlled slow addition have led to improved yields and less complaints from fellow inhabitants of the laboratory! Literature Cited 1. Osvath, P.; Sargeson, A. M.; Skelton, B. W.; White, A. H. J. Chem. Soc., Chem. Commun. 1991, 1036. Osvath. P.; Sargeson, A. J. Chem. Soc., Chem. Commun. 1993, 40.

  16. Neodymium 1D systems: targeting new sources for field-induced slow magnetization relaxation.

    PubMed

    Jassal, Amanpreet Kaur; Aliaga-Alcalde, Núria; Corbella, Montserrat; Aravena, Daniel; Ruiz, Eliseo; Hundal, Geeta

    2015-09-28

    Two non-isostructural homometallic 1D neodymium species displaying field-induced slow magnetization relaxations are presented together with theoretical studies. It is established that both systems are better described as organized 1D single molecule magnets (SMMs). Studies show great potential of Nd(III) ions to provide homometallic chains with slow magnetic relaxation.

  17. Deflection of slow light by magneto-optically controlled atomic media

    SciTech Connect

    Zhou, D. L.; Wang, R. Q.; Zhou, Lan; Yi, S.; Sun, C. P.

    2007-11-15

    We present a semiclassical theory for light deflection by a coherent {lambda}-type three-level atomic medium in an inhomogeneous magnetic field or an inhomogeneous control laser. When the atomic energy levels (or the Rabi coupling by the control laser) are position-dependent due to the Zeeman effect caused by the inhomogeneous magnetic field (or due to inhomogeneity of the control field profile), the spatial dependence of the refraction index of the atomic medium will result in an observable deflection of slow signal light when the electromagnetically induced transparency cancels medium absorption. Our theoretical approach based on Fermat's principle in geometrical optics not only provides a consistent explanation for the most recent experiment in a straightforward way, but also predicts the two-photon detuning dependent behaviors and larger deflection angles by three orders of magnitude for the slow signal light deflection by the atomic media in an inhomogeneous off-resonant control laser field.

  18. Controlling slow and fast light and dynamic pulse-splitting with tunable optical gain in a whispering-gallery-mode microcavity

    NASA Astrophysics Data System (ADS)

    Asano, M.; Özdemir, Ş. K.; Chen, W.; Ikuta, R.; Yang, L.; Imoto, N.; Yamamoto, T.

    2016-05-01

    We report controllable manipulation of slow and fast light in a whispering-gallery-mode microtoroid resonator fabricated from Erbium (Er3+) doped silica. We observe continuous transition of the coupling between the fiber-taper waveguide and the microresonator from undercoupling to critical coupling and then to overcoupling regimes by increasing the pump power even though the spatial distance between the resonator and the waveguide was kept fixed. This, in turn, enables switching from fast to slow light and vice versa just by increasing the optical gain. An enhancement of delay of two-fold over the passive silica resonator (no optical gain) was observed in the slow light regime. Moreover, we show dynamic pulse splitting and its control in slow/fast light systems using optical gain.

  19. Exponentially Slow Heating in Periodically Driven Many-Body Systems.

    PubMed

    Abanin, Dmitry A; De Roeck, Wojciech; Huveneers, François

    2015-12-18

    We derive general bounds on the linear response energy absorption rates of periodically driven many-body systems of spins or fermions on a lattice. We show that, for systems with local interactions, the energy absorption rate decays exponentially as a function of driving frequency in any number of spatial dimensions. These results imply that topological many-body states in periodically driven systems, although generally metastable, can have very long lifetimes. We discuss applications to other problems, including the decay of highly energetic excitations in cold atomic and solid-state systems. PMID:26722939

  20. Large Deviations and Importance Sampling for Systems of Slow-Fast Motion

    SciTech Connect

    Spiliopoulos, Konstantinos

    2013-02-15

    In this paper we develop the large deviations principle and a rigorous mathematical framework for asymptotically efficient importance sampling schemes for general, fully dependent systems of stochastic differential equations of slow and fast motion with small noise in the slow component. We assume periodicity with respect to the fast component. Depending on the interaction of the fast scale with the smallness of the noise, we get different behavior. We examine how one range of interaction differs from the other one both for the large deviations and for the importance sampling. We use the large deviations results to identify asymptotically optimal importance sampling schemes in each case. Standard Monte Carlo schemes perform poorly in the small noise limit. In the presence of multiscale aspects one faces additional difficulties and straightforward adaptation of importance sampling schemes for standard small noise diffusions will not produce efficient schemes. It turns out that one has to consider the so called cell problem from the homogenization theory for Hamilton-Jacobi-Bellman equations in order to guarantee asymptotic optimality. We use stochastic control arguments.

  1. SNMP-SI: A Network Management Tool Based on Slow Intelligence System Approach

    NASA Astrophysics Data System (ADS)

    Colace, Francesco; de Santo, Massimo; Ferrandino, Salvatore

    The last decade has witnessed an intense spread of computer networks that has been further accelerated with the introduction of wireless networks. Simultaneously with, this growth has increased significantly the problems of network management. Especially in small companies, where there is no provision of personnel assigned to these tasks, the management of such networks is often complex and malfunctions can have significant impacts on their businesses. A possible solution is the adoption of Simple Network Management Protocol. Simple Network Management Protocol (SNMP) is a standard protocol used to exchange network management information. It is part of the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite. SNMP provides a tool for network administrators to manage network performance, find and solve network problems, and plan for network growth. SNMP has a big disadvantage: its simple design means that the information it deals with is neither detailed nor well organized enough to deal with the expanding modern networking requirements. Over the past years much efforts has been given to improve the lack of Simple Network Management Protocol and new frameworks has been developed: A promising approach involves the use of Ontology. This is the starting point of this paper where a novel approach to the network management based on the use of the Slow Intelligence System methodologies and Ontology based techniques is proposed. Slow Intelligence Systems is a general-purpose systems characterized by being able to improve performance over time through a process involving enumeration, propagation, adaptation, elimination and concentration. Therefore, the proposed approach aims to develop a system able to acquire, according to an SNMP standard, information from the various hosts that are in the managed networks and apply solutions in order to solve problems. To check the feasibility of this model first experimental results in a real scenario are showed.

  2. Boundary-equilibrium bifurcations in piecewise-smooth slow-fast systems.

    PubMed

    Kowalczyk, P; Glendinning, P

    2011-06-01

    In this paper we study the qualitative dynamics of piecewise-smooth slow-fast systems (singularly perturbed systems) which are everywhere continuous. We consider phase space topology of systems with one-dimensional slow dynamics and one-dimensional fast dynamics. The slow manifold of the reduced system is formed by a piecewise-continuous curve, and the differentiability is lost across the switching surface. In the full system the slow manifold is no longer continuous, and there is an O(ɛ) discontinuity across the switching manifold, but the discontinuity cannot qualitatively alter system dynamics. Revealed phase space topology is used to unfold qualitative dynamics of planar slow-fast systems with an equilibrium point on the switching surface. In this case the local dynamics corresponds to so-called boundary-equilibrium bifurcations, and four qualitative phase portraits are uncovered. Our results are then used to investigate the dynamics of a box model of a thermohaline circulation, and the presence of a boundary-equilibrium bifurcation of a fold type is shown.

  3. Boundary-equilibrium bifurcations in piecewise-smooth slow-fast systems.

    PubMed

    Kowalczyk, P; Glendinning, P

    2011-06-01

    In this paper we study the qualitative dynamics of piecewise-smooth slow-fast systems (singularly perturbed systems) which are everywhere continuous. We consider phase space topology of systems with one-dimensional slow dynamics and one-dimensional fast dynamics. The slow manifold of the reduced system is formed by a piecewise-continuous curve, and the differentiability is lost across the switching surface. In the full system the slow manifold is no longer continuous, and there is an O(ɛ) discontinuity across the switching manifold, but the discontinuity cannot qualitatively alter system dynamics. Revealed phase space topology is used to unfold qualitative dynamics of planar slow-fast systems with an equilibrium point on the switching surface. In this case the local dynamics corresponds to so-called boundary-equilibrium bifurcations, and four qualitative phase portraits are uncovered. Our results are then used to investigate the dynamics of a box model of a thermohaline circulation, and the presence of a boundary-equilibrium bifurcation of a fold type is shown. PMID:21721768

  4. Slow cryopreservation is not superior to vitrification in human spermatozoa; an experimental controlled study

    PubMed Central

    Ali Mohamed, Mohamed Shehata

    2015-01-01

    Background: Spermatozoa cryopreservation is used for the management of infertility and some other medical conditions. The routinely applied cryopreservation technique depends on permeating cryoprotectants, whose toxic effects have raised the attention towards permeating cryoprotectants-free vitrification technique. Objective: To compare between the application of slow cryopreservation and vitrification on human spermatozoa. Materials and Methods: This was an experimental controlled study involving 33 human semen samples, where each sample was divided into three equal parts; fresh control, conventional slow freezing, and permeating cryoprotectants-free vitrification. Viability and mitochondrial membrane potential (MMP) of control and post-thawing spermatozoa were assessed with the sperm viability kit and the JC-1 kit, respectively, using fluorescence-activated cell sorting analysis. Results: Significant reduction of the progressive motility, viability and MMP was observed by the procedure of freezing and thawing, while there was not any significant difference between both cryopreservation techniques. Cryopreservation resulted in 48% reduction of the percentage of viable spermatozoa and 54.5% rise in the percentage of dead spermatozoa. In addition, high MMP was reduced by 24% and low MMP was increased by 34.75% in response to freezing and thawing. Progressive motility of spermatozoa was correlated significantly positive with high MMP and significantly negative with low MMP in control as well as post-thawing specimens (r=0.8881/ -0.8412, 0.7461/ -0.7510 and 0.7603/ -0.7839 for control, slow and vitrification respectively, p=0.0001). Conclusion: Although both cryopreservation techniques have similar results, vitrification is faster, easier and associated with less toxicity and costs. Thus, vitrification is recommended for the clinical application. PMID:26644792

  5. Slow and fast light in a phase sensitive system

    NASA Astrophysics Data System (ADS)

    Shen, Shuo; Xu, Xiwei; Xiao, Yanhong

    2013-03-01

    Using atomic motion to coherently spread light information stored in atoms provides a novel means to manipulate atom-light interactions. We demonstrate light splitting with moving atoms in a paraffin coated vapor cell, by using phase sensitive degenerate four wave mixing, or self-rotation. This scheme amplifies the beam splitter signal, and in the meantime maintains the phase coherence between the beam splitter channels. Light storage efficiency in the beam-splitting channel can be also enhanced. Such an amplified beam splitter should have applications in optical memory, optical routers and atomic coherence control.

  6. Slow-light Airy wave packets and their active control via electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Hang, Chao; Huang, Guoxiang

    2013-07-01

    We propose a scheme to generate (3+1)-dimensional slow-light Airy wave packets in a resonant Λ-type three-level atomic gas via electromagnetically induced transparency. We show that in the absence of dispersion the Airy wave packets formed by a probe field consist of two Airy wave packets accelerated in transverse directions and a longitudinal Gaussian pulse with a constant propagating velocity lowered to 10-5c (c is the light speed in vacuum). We also show that in the presence of dispersion it is possible to generate another type of slow-light Airy wave packet consisting of two Airy beams in transverse directions and an Airy wave packet in the longitudinal direction. In this case, the longitudinal velocity of the Airy wave packet can be further reduced during propagation. Additionally, we further show that the transverse accelerations (or bending) of the both types of slow-light Airy wave packets can be completely eliminated and the motional trajectories of them can be actively manipulated and controlled by using a Stern-Gerlach gradient magnetic field.

  7. Numerical continuation of canard orbits in slow-fast dynamical systems

    NASA Astrophysics Data System (ADS)

    Desroches, M.; Krauskopf, B.; Osinga, H. M.

    2010-03-01

    A trajectory of a system with two clearly separated time scales generally consists of fast segments (or jumps) followed by slow segments where the trajectory follows an attracting part of a slow manifold. The switch back to fast dynamics typically occurs when the trajectory passes a fold with respect to a fast direction. A special role is played by trajectories known as canard orbits, which do not jump at a fold but, instead, follow a repelling slow manifold for some time. We concentrate here on the case of a slow-fast system with two slow and one fast variable, where canard orbits arise geometrically as intersection curves of two-dimensional attracting and repelling slow manifolds. Canard orbits are intimately related to the dynamics near special points known as folded singularities, which in turn have been shown to explain small-amplitude oscillations that can be found as part of so-called mixed-mode oscillations. In this paper we present a numerical method to detect and then follow branches of canard orbits in a system parameter. More specifically, we define well-posed two-point boundary value problems (BVPs) that represent orbit segments on the slow manifolds, and we continue their solution families with the package AUTO. In this way, we are able to deal effectively with the numerical challenge of strong attraction to and strong repulsion from the slow manifolds. Canard orbits are detected as the transverse intersection points of the curves along which attracting and repelling slow manifolds intersect a suitable section (near a folded node). These intersection points correspond to a unique pair of orbits segments, one on the attracting and one on the repelling slow manifold. After concatenation of the respective pairs of orbit segments, all detected canard orbits are represented as solutions of a single BVP, which allows us to continue them in system parameters. We demonstrate with two examples—the self-coupled FitzHugh-Nagumo system and a three

  8. RISK FACTORS FOR SLOW GAIT SPEED: A NESTED CASE-CONTROL SECONDARY ANALYSIS OF THE MEXICAN HEALTH AND AGING STUDY

    PubMed Central

    Pérez-Zepeda, M.U.; González-Chavero, J.G.; Salinas-Martinez, R.; Gutiérrez-Robledo, L.M.

    2016-01-01

    Background Physical performance tests play a major role in the geriatric assessment. In particular, gait speed has shown to be useful for predicting adverse outcomes. However, risk factors for slow gait speed (slowness) are not clearly described. Objectives To determine risk factors associated with slowness in Mexican older adults. Design A two-step process was adopted for exploring the antecedent risk factors of slow gait speed. First, the cut-off values for gait speed were determined in a representative sample of Mexican older adults. Then, antecedent risk factors of slow gait speed (defined using the identified cut-points) were explored in a nested, cohort case-control study. Setting, participants One representative sample of a cross-sectional survey for the first step and the Mexican Health and Aging Study (a cohort characterized by a 10-year follow-up). Measurements A 4-meter usual gait speed test was conducted. Lowest gender and height-stratified groups were considered as defining slow gait speed. Sociodemographic characteristics, comorbidities, psychological and health-care related variables were explored to find those associated with the subsequent development of slow gait speed. Unadjusted and adjusted logistic regression models were performed. Results In the final model, age, diabetes, hypertension, and history of fractures were associated with the development of slow gait speed. Conclusions Early identification of subjects at risk of developing slow gait speed may halt the path to disability due to the robust association of this physical performance test with functional decline. PMID:26889463

  9. Cooperative dynamics in coupled systems of fast and slow phase oscillators.

    PubMed

    Sakaguchi, Hidetsugu; Okita, Takayuki

    2016-02-01

    We propose a coupled system of fast and slow phase oscillators. We observe two-step transitions to quasiperiodic motions by direct numerical simulations of this coupled oscillator system. A low-dimensional equation for order parameters is derived using the Ott-Antonsen ansatz. The applicability of the ansatz is checked by the comparison of numerical results of the coupled oscillator system and the reduced low-dimensional equation. We investigate further several interesting phenomena in which mutual interactions between the fast and slow oscillators play an essential role. Fast oscillations appear intermittently as a result of excitatory interactions with slow oscillators in a certain parameter range. Slow oscillators experience an oscillator-death phenomenon owing to their interaction with fast oscillators. This oscillator death is explained as a result of saddle-node bifurcation in a simple phase equation obtained using the temporal average of the fast oscillations. Finally, we show macroscopic synchronization of the order 1:m between the slow and fast oscillators.

  10. Physical limits to broadening compensation in a linear slow light system.

    PubMed

    Gonzalez-Herraez, Miguel; Thévenaz, Luc

    2009-03-16

    The dispersion experienced by a signal in a slow light system leads to a significant pulse broadening and sets a limit to the maximum delay actually achievable by the system. To overcome this limitation, a substantial research effort is currently being carried out, and successful strategies to reduce distortion in linear slow light systems have already been demonstrated. Recent theoretical and experimental works have even claimed the achievement of zero-broadening of pulses in these systems. In this work we obtain some physical limits to broadening compensation in linear slow light systems based on simple Fourier analysis. We show that gain and dispersion broadening can never compensate in such a system. Additionally, it is simply proven that all the linear slow light systems that introduce a low-pass filtering of the signal (a reduction in the signal root-mean- square spectral width), will always cause pulse broadening. These demonstrations are done using a rigorous shape-independent definition of pulse width (the root-mean-square temporal width) and arguments borrowed from time-frequency analysis. PMID:19293903

  11. [Soil biological activities at maize seedling stage under application of slow/controlled release nitrogen fertilizers].

    PubMed

    Li, Dongpo; Wu, Zhijie; Chen, Lijun; Liang, Chenghua; Zhang, Lili; Wang, Weicheng; Yang, Defu

    2006-06-01

    With pot experiment and simulating field ecological environment, this paper studied the effects of different slow/ controlled release N fertilizers on the soil nitrate - reductase and urease activities and microbial biomass C and N at maize seedling stage. The results showed that granular urea amended with dicyandiamide (DCD) and N-(n-bultyl) thiophosphoric triamide (NBPT) induced the highest soil nitrate-reductase activity, granular urea brought about the highest soil urease activity and microbial biomass C and N, while starch acetate (SA)-coated granular urea, SA-coated granular urea amended with DCD, methyl methacrylate (MMA) -coated granular urea amended with DCD, and no N fertilization gave a higher soil urease activity. Soil microbial C and N had a similar variation trend after applying various kinds of test slow/controlled release N fertilizers, and were the lowest after applying SA-coated granular urea amended with DCD and NBPT. Coated granular urea amended with inhibitors had a stronger effect on soil biological activities than coated granular urea, and MMA-coating had a better effect than SA-coating. PMID:16964940

  12. [Soil biological activities at maize seedling stage under application of slow/controlled release nitrogen fertilizers].

    PubMed

    Li, Dongpo; Wu, Zhijie; Chen, Lijun; Liang, Chenghua; Zhang, Lili; Wang, Weicheng; Yang, Defu

    2006-06-01

    With pot experiment and simulating field ecological environment, this paper studied the effects of different slow/ controlled release N fertilizers on the soil nitrate - reductase and urease activities and microbial biomass C and N at maize seedling stage. The results showed that granular urea amended with dicyandiamide (DCD) and N-(n-bultyl) thiophosphoric triamide (NBPT) induced the highest soil nitrate-reductase activity, granular urea brought about the highest soil urease activity and microbial biomass C and N, while starch acetate (SA)-coated granular urea, SA-coated granular urea amended with DCD, methyl methacrylate (MMA) -coated granular urea amended with DCD, and no N fertilization gave a higher soil urease activity. Soil microbial C and N had a similar variation trend after applying various kinds of test slow/controlled release N fertilizers, and were the lowest after applying SA-coated granular urea amended with DCD and NBPT. Coated granular urea amended with inhibitors had a stronger effect on soil biological activities than coated granular urea, and MMA-coating had a better effect than SA-coating.

  13. Effects of pregnancy on slow cortical potentials in migraine patients and healthy controls.

    PubMed

    Darabaneanu, S; Kropp, P; Niederberger, U; Strenge, H; Gerber, W-D

    2008-10-01

    Increased negative amplitudes and lack of habituation of contingent negative variation (CNV) in migraine are well established and are supposed to reflect an altered cortical excitability level. Migraine attacks occur less during pregnancy but often relapse after delivery. We investigated the effect of pregnancy on slow cortical potentials and reaction time in migraine patients and healthy controls. Four groups were examined: 14 pregnant migraine patients, 12 non-pregnant migraine patients, 15 pregnant healthy women and 16 non-pregnant healthy women aged 19-38 years. Two recordings were performed in the pregnant subjects: in the 36th week of gestation and 4 weeks after delivery. The non-pregnant subjects were recorded at the same time interval of 8 weeks. Pregnant migraine patients showed significantly fewer migraine days during the third trimester of pregnancy and returned to nearly the former level 4 weeks post delivery. Non-pregnant migraine patients demonstrated a significant reduction of migraine days at the second measurement. There was no effect of pregnancy on CNV amplitudes, but there was an effect of pregnancy on the habituation coefficient and reaction time of migraine patients. Faster habituation from a higher preactivation level was found. As an explanation for the changed habituation level we favour the model of correlation between preactivation level and habituation level, the so-called law of initial value. We found a correlation between preactivation level and habituation. Our study confirms a specific effect of pregnancy on slow cortical potentials in migraine patients. PMID:18624798

  14. The calcineurin-NFAT pathway controls activity-dependent circadian gene expression in slow skeletal muscle

    PubMed Central

    Dyar, Kenneth A.; Ciciliot, Stefano; Tagliazucchi, Guidantonio Malagoli; Pallafacchina, Giorgia; Tothova, Jana; Argentini, Carla; Agatea, Lisa; Abraham, Reimar; Ahdesmäki, Miika; Forcato, Mattia; Bicciato, Silvio; Schiaffino, Stefano; Blaauw, Bert

    2015-01-01

    Objective Physical activity and circadian rhythms are well-established determinants of human health and disease, but the relationship between muscle activity and the circadian regulation of muscle genes is a relatively new area of research. It is unknown whether muscle activity and muscle clock rhythms are coupled together, nor whether activity rhythms can drive circadian gene expression in skeletal muscle. Methods We compared the circadian transcriptomes of two mouse hindlimb muscles with vastly different circadian activity patterns, the continuously active slow soleus and the sporadically active fast tibialis anterior, in the presence or absence of a functional skeletal muscle clock (skeletal muscle-specific Bmal1 KO). In addition, we compared the effect of denervation on muscle circadian gene expression. Results We found that different skeletal muscles exhibit major differences in their circadian transcriptomes, yet core clock gene oscillations were essentially identical in fast and slow muscles. Furthermore, denervation caused relatively minor changes in circadian expression of most core clock genes, yet major differences in expression level, phase and amplitude of many muscle circadian genes. Conclusions We report that activity controls the oscillation of around 15% of skeletal muscle circadian genes independently of the core muscle clock, and we have identified the Ca2+-dependent calcineurin-NFAT pathway as an important mediator of activity-dependent circadian gene expression, showing that circadian locomotor activity rhythms drive circadian rhythms of NFAT nuclear translocation and target gene expression. PMID:26629406

  15. Mixed-mode oscillations and slow manifolds in the self-coupled FitzHugh-Nagumo system

    NASA Astrophysics Data System (ADS)

    Desroches, Mathieu; Krauskopf, Bernd; Osinga, Hinke M.

    2008-03-01

    We investigate the organization of mixed-mode oscillations in the self-coupled FitzHugh-Nagumo system. These types of oscillations can be explained as a combination of relaxation oscillations and small-amplitude oscillations controlled by canard solutions that are associated with a folded singularity on a critical manifold. The self-coupled FitzHugh-Nagumo system has a cubic critical manifold for a range of parameters, and an associated folded singularity of node-type. Hence, there exist corresponding attracting and repelling slow manifolds that intersect in canard solutions. We present a general technique for the computation of two-dimensional slow manifolds (smooth surfaces). It is based on a boundary value problem approach where the manifolds are computed as one-parameter families of orbit segments. Visualization of the computed surfaces gives unprecedented insight into the geometry of the system. In particular, our techniques allow us to find and visualize canard solutions as the intersection curves of the attracting and repelling slow manifolds.

  16. QUANTUM CONTROL OF LIGHT: From Slow Light and FAST CARS to Nuclear γ-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Scully, Marlan

    2007-06-01

    In recent work we have demonstrated strong coherent backward wave oscillation using forward propagating fields only. This surprising result is achieved by applying laser fields to an ultra-dispersive medium with proper chosen detunings to excite a molecular vibrational coherence that corresponds to a backward propagating wave [PRL, 97, 113001 (2006)]. The physics then has much in common with propagation of ultra-slow light. Applications of coherent scattering and remote sensing to the detection of bio and chemical pathogens (e.g., anthrax) via Coherent Anti-Raman Scattering together with Femtosecond Adaptive Spectroscopic Techniques (FAST CARS [Opt. Comm., 244, 423 (2005)]) will be discussed. Furthermore, the interplay between quantum optics (Dicke super and sub-radiant states) and nuclear physics (forward scattering of γ radiation) provides interesting problems and insights into the quantum control of scattered light [PRL, 96, 010501 (2005)].

  17. [Nutrient release characteristics and use efficiency of slow- and controlled release fertilizers].

    PubMed

    Duan, Lu-Lu; Zhang, Min; Liu, Gang; Shang, Zhao-Cong; Yang, Yi

    2009-05-01

    Water extraction method and soil incubation method were used to study the nutrient release characteristics of four slow- and controlled release fertilizers (CRF1, CRF2, SCU, and IBDU), and pot experiment was conducted to assess the effects of the release characteristics on the nutrient requirements of canola (Brassica napus L.). The nutrient release curves of test fertilizers in water were S pattern for CRF1 and CRF2, burst pattern for SCU, and reverse L pattern for IBDU. The nutrient release characteristics of the four fertilizers in water and in soil all fitted binomial equations, suggesting that there existed some similarities in the nutrient release in the two media. The nutrient uptake and biomass of canola plants treated with CRF1 and CRF2 were significantly higher than those treated with SCU and IBDU, and CRF2 had the greatest effect. The nutrient release curves of CRF1 and CRF2 accorded more closely with the nutrient requirements of canola.

  18. EDITORIAL: Slow light Slow light

    NASA Astrophysics Data System (ADS)

    Boyd, Robert; Hess, Ortwin; Denz, Cornelia; Paspalakis, Emmanuel

    2010-10-01

    Research into slow light began theoretically in 1880 with the paper [1] of H A Lorentz, who is best known for his work on relativity and the speed of light. Experimental work started some 60 years later with the work of S L McCall and E L Hahn [2] who explored non-linear self-induced transparency in ruby. This field of research has burgeoned in the last 10 years, starting with the work of L Vestergaard Hau and coworkers on slow light via electromagnetically induced transparency in a Bose-Einstein condensate [3]. Many groups are now able to slow light down to a few metres per second or even stop the motion of light entirely [4]. Today, slow light - or more often `slow and fast light' - has become its own vibrant field with a strongly increasing number of publications. In broad scope, slow light research can be categorized in terms of the sort of physical mechanism used to slow down the light. One sort of slow light makes use of material dispersion. This dispersion can be the natural dispersion of the ordinary refractive index or can be the frequency dependence of some nonlinear optical process, such as electromagnetically induced transparency, coherent population oscillations, stimulated light scattering, or four-wave mixing processes. The second sort of slow light makes use of the wavelength dependence of artificially structured materials, such as photonic crystals, optical waveguides, and collections of microresonators. Material systems in which slow light has been observed include metal vapours, rare-earth-doped materials, Raman and Brillioun gain media, photonic crystals, microresonators and, more recently, metamaterials. A common feature of all of these schemes is the presence of a sharp single resonance or multiple resonances produced by an atomic transition, a resonance in a photonic structure, or in a nonlinear optical process. Current applications of slow light include a series of attractive topics in optical information processing, such as optical data

  19. Possible petrological controls on the location and time scale of slow slip in SW Japan

    NASA Astrophysics Data System (ADS)

    Wallis, S.; Mizukami, T.; Yokoyama, H.; Hiramatsu, Y.; Arai, S.; Kawahara, H.; Nagaya, T.

    2014-12-01

    To examine the possibility that there was a petrological control on the location and nature of episodic tremor and slip (ETS), we compared the petrological characteristics of wedge mantle material to the results of recent geophysical observations in the Shikoku area, southwest Japan. This study revealed a close relationship between predicted mineral assemblages in the mantle wedge and the characteristics of slow slip behaviour recorded in the Shikoku area: Short-term ETSs take place in the antigorite +olivine stability field and silent long-term slow slip events (SSEs) take place in the antigorite+brucite stability field. The petrology of the mantle wedge may be an important control on the fluid pressure along the subduction interface and influence the time scales of SSEs. The Cretaceous Sanbagawa oceanic subduction complex of SW Japan preserves fragments of the former mantle wedge in contact with subducted slab units. P-T paths and peak P-T conditions show this belt formed as the result of subduction of a young slab under relatively warm conditions. These characteristics make the Sanbagawa belt a good analogue to modern warm subduction zones such as the Philippine Sea subduction zone beneath SW Japan and offer the possibility of directly examining the former plate boundary. Mantle wedge units derived from shallow depths show evidence for widely developed primary brucite and antigorite. In contrast, units derived from greater depths and higher peak temeratures consist dominantly of antigorite and olivine. Observations of the natural serpentinites suggest that the shallow serpentinite with brucite shows higher absorbency of water and provides fluid pathways that can reduce the fluid pore pressure on the subduction boundary.

  20. Optimal control of charge transfer for slow H+ + D collisions with shaped laser pulses.

    PubMed

    Zhang, Wei; Shu, Chuan-Cun; Ho, Tak-San; Rabitz, Herschel; Cong, Shu-Lin

    2014-03-01

    We show that optimally shaped laser pulses can beneficially influence charge transfer in slow H(+)+D collisions. Time-dependent wave packet optimal control simulations are performed based on a two-state adiabatic Hamiltonian. Optimal control is performed using either an adaptive or a fixed target to obtain the desired laser control field. In the adaptive target scheme, the target state is updated according to the renormalized fragmentary yield in the exit channel throughout the optimization process. In the fixed target scheme, the target state in the exit channel is a normalized outgoing Gaussian wave packet located at a large internuclear separation. Both approaches produced excellent optimal outcomes, far exceeding that achieved in the field-free collisional charge transfer. The adaptive target scheme proves to be more efficient, and often with complex final wave packet. In contrast, the fixed target scheme, although more slowly convergent, is found to produce high fidelity for the desired target wave packet. The control mechanism in both cases utilizes bound vibrational states of the transient HD(+) complex.

  1. Optimal control of charge transfer for slow H+ + D collisions with shaped laser pulses

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Shu, Chuan-Cun; Ho, Tak-San; Rabitz, Herschel; Cong, Shu-Lin

    2014-03-01

    We show that optimally shaped laser pulses can beneficially influence charge transfer in slow H++D collisions. Time-dependent wave packet optimal control simulations are performed based on a two-state adiabatic Hamiltonian. Optimal control is performed using either an adaptive or a fixed target to obtain the desired laser control field. In the adaptive target scheme, the target state is updated according to the renormalized fragmentary yield in the exit channel throughout the optimization process. In the fixed target scheme, the target state in the exit channel is a normalized outgoing Gaussian wave packet located at a large internuclear separation. Both approaches produced excellent optimal outcomes, far exceeding that achieved in the field-free collisional charge transfer. The adaptive target scheme proves to be more efficient, and often with complex final wave packet. In contrast, the fixed target scheme, although more slowly convergent, is found to produce high fidelity for the desired target wave packet. The control mechanism in both cases utilizes bound vibrational states of the transient HD+ complex.

  2. A miniature bidirectional telemetry system for in-vivo gastric slow wave recordings

    PubMed Central

    Farajidavar, Aydin; O’Grady, Gregory; Rao, Smitha M.N.; Cheng, Leo K; Abell, Thomas; Chiao, J.-C.

    2012-01-01

    Stomach contractions are initiated and coordinated by an underlying electrical activity (slow waves), and electrical dysrhythmias accompany motility diseases. Electrical recordings taken directly from the stomach provide the most valuable data, but face technical constraints. Serosal or mucosal electrodes have cables that traverse the abdominal wall, or a natural orifice, causing discomfort and possible infection, and restricting mobility. These problems motivated the development of a wireless system. The bidirectional telemetric system constitutes a front-end transponder, a back-end receiver and a graphical user interface. The front-end module conditions the analog signals, then digitizes and loads the data into a radio for transmission. Data receipt at the back-end is acknowledged via a transceiver function. The system was validated in a bench-top study, then validated in-vivo using serosal electrodes connected simultaneously to a commercial wired system. The front-end module was 35×35×27 mm3 and weighed 20 g. Bench-top tests demonstrated reliable communication within a distance range of 30 m, power consumption of 13.5 mW, and 124-hour operation when utilizing a 560-mAh, 3-V battery. In-vivo, slow wave frequencies were recorded identically with the wireless and wired reference systems (2.4 cycles/min), automated activation time detection was modestly better for the wireless system (5% vs 14% false positive rate), and signal amplitudes were modestly higher via the wireless system (462 vs 386 μV; p<0.001). This telemetric system for slow wave acquisition is reliable, power efficient, readily portable and potentially implantable. The device will enable chronic monitoring and evaluation of slow wave patterns in animals and patients. PMID:22635054

  3. A miniature bidirectional telemetry system for in vivo gastric slow wave recordings.

    PubMed

    Farajidavar, Aydin; O'Grady, Gregory; Rao, Smitha M N; Cheng, Leo K; Abell, Thomas; Chiao, J-C

    2012-06-01

    Stomach contractions are initiated and coordinated by an underlying electrical activity (slow waves), and electrical dysrhythmias accompany motility diseases. Electrical recordings taken directly from the stomach provide the most valuable data, but face technical constraints. Serosal or mucosal electrodes have cables that traverse the abdominal wall, or a natural orifice, causing discomfort and possible infection, and restricting mobility. These problems motivated the development of a wireless system. The bidirectional telemetric system constitutes a front-end transponder, a back-end receiver and a graphical userinter face. The front-end module conditions the analogue signals, then digitizes and loads the data into a radio for transmission. Data receipt at the backend is acknowledged via a transceiver function. The system was validated in a bench-top study, then validated in vivo using serosal electrodes connected simultaneously to a commercial wired system. The front-end module was 35 × 35 × 27 mm3 and weighed 20 g. Bench-top tests demonstrated reliable communication within a distance range of 30 m, power consumption of 13.5 mW, and 124 h operation when utilizing a 560 mAh, 3 V battery. In vivo,slow wave frequencies were recorded identically with the wireless and wired reference systems (2.4 cycles min−1), automated activation time detection was modestly better for the wireless system (5% versus 14% FP rate), and signal amplitudes were modestly higher via the wireless system (462 versus 3 86μV; p<0.001). This telemetric system for slow wave acquisition is reliable,power efficient, readily portable and potentially implantable. The device will enable chronic monitoring and evaluation of slow wave patterns in animals and patients.0967-3334/ PMID:22635054

  4. Ca2+ controls slow NAD(P)H oscillations in glucose-stimulated mouse pancreatic islets

    PubMed Central

    Luciani, Dan S; Misler, Stanley; Polonsky, Kenneth S

    2006-01-01

    Exposure of pancreatic islets of Langerhans to physiological concentrations of glucose leads to secretion of insulin in an oscillatory pattern. The oscillations in insulin secretion are associated with oscillations in cytosolic Ca2+ concentration ([Ca2+]c). Evidence suggests that the oscillations in [Ca2+]c and secretion are driven by oscillations in metabolism, but it is unclear whether metabolic oscillations are intrinsic to metabolism or require Ca2+ feedback. To address this question we explored the interaction of Ca2+ concentration and islet metabolism using simultaneous recordings of NAD(P)H autofluorescence and [Ca2+]c, in parallel with measurements of mitochondrial membrane potential (ΔΨm). All three parameters responded to 10 mm glucose with multiphasic dynamics culminating in slow oscillations with a period of ∼5 min. This was observed in ∼90% of islets examined from various mouse strains. NAD(P)H oscillations preceded those of [Ca2+]c, but their upstroke was often accelerated during the increase in [Ca2+]c, and Ca2+ influx was a prerequisite for their generation. Prolonged elevations of [Ca2+]c augmented NAD(P)H autofluorescence of islets in the presence of 3 mm glucose, but often lowered NAD(P)H autofluorescence of islets exposed to 10 mm glucose. Comparable rises in [Ca2+]c depolarized ΔΨm. The NAD(P)H lowering effect of an elevation of [Ca2+]c was reversed during inhibition of mitochondrial electron transport. These findings reveal the existence of slow oscillations in NAD(P)H autofluorescence in intact pancreatic islets, and suggest that they are shaped by Ca2+ concentration in a dynamic balance between activation of NADH-generating mitochondrial dehydrogenases and a Ca2+-induced decrease in NADH. We propose that a component of the latter reflects mitochondrial depolarization by Ca2+, which reduces respiratory control and consequently accelerates oxidation of NADH. PMID:16455690

  5. Two types of antigorite serpentinite controlling heterogeneous slow-slip behaviours of slab-mantle interface

    NASA Astrophysics Data System (ADS)

    Mizukami, Tomoyuki; Yokoyama, Hironori; Hiramatsu, Yoshihiro; Arai, Shoji; Kawahara, Hirokazu; Nagaya, Takayoshi; Wallis, Simon R.

    2014-09-01

    It is known that plate boundaries in subduction zones show heterogeneous slip nature with strongly coupled seismogenic zones and various types of episodic tremor and slip (ETS) zones. In order to examine the petrological controls on the large-scale structure, we compared recent geophysical observations in the Shikoku area, southwest Japan with petrological models of the hanging wall mantle wedge. As a result, we found a close relationship between mineral assemblages in the mantle wedge and the characteristics of slow slip behaviour recorded in the Shikoku area: Short-term ETSs take place in the antigorite + olivine stability field and silent long-term slow slip events (SSEs) take place in the antigorite + brucite stability field. Based on observations of natural antigorite serpentinites, we propose a model that the dominant serpentinization reaction in the mantle wedge changes with increasing depth resulting in variable extents of pore fluid pressures along slip planes. The serpentinization reaction in the antigorite + brucite stability field (olivine + H2O → antigorite + brucite) proceeds at the expense of water. This is consistent with moderately elevated pore pressures inferred for long-term SSEs. The existence of weak brucite enhances the development of shear zones oblique to the main foliation. The resultant anastomosing network provides fluid pathways that may help reduce pore pressures on slip planes. In contrast, progress of the serpentinization reaction in the antigorite + olivine stability field (olivine + H2O + SiO2 → antigorite) results in a large amount of residual water that contributes to further increase pore fluid pressures on slip planes of short-term SSEs. Our results imply that understanding of serpentinization reactions and their contributions to fluid networks in mantle wedge is important in constructing quantitative 3-D models for strain evolutions along plate boundaries.

  6. A 4-way wavelength demultiplexer based on the plasmonic broadband slow wave system.

    PubMed

    Zhou, Yong Jin; Yang, Bao Jia

    2014-09-01

    We propose a broadband slow wave system based on the thin metal-insulator-metal (MIM) graded grating structure composed of two corrugated metal strips with periodic array of grooves on a thin dielectric substrate. The guided spoof surface plasmon polaritons (SSPPs) at different frequencies can be localized at different positions along the ultrathin MIM grating. By introducing specially designed non-corrugated MIM branches with specific lengths at the locations where the EM waves are trapped, the trapped EM waves can be released and propagate along these branches. A 4-way wavelength demultiplexer based on such plasmonic broadband slow wave system is then demonstrated and fabricated. To improve the isolations between different branches at lower frequencies, band-reject filters are inserted at the front of some MIM branches. The measurements and the simulation results have shown very good agreements, which validate the feasibility of the 4-way wavelength demultiplexer.

  7. How gravity and muscle action control mediolateral center of mass excursion during slow walking: a simulation study.

    PubMed

    Jansen, Karen; De Groote, Friedl; Duysens, Jacques; Jonkers, Ilse

    2014-01-01

    Maintaining mediolateral (ML) balance is very important to prevent falling during walking, especially at very slow speeds. The effect of walking speed on support and propulsion of the center of mass (COM) has been focus of previous studies. However, the influence of speed on ML COM control and the associated coupling with sagittal plane control remains unclear. Simulations of walking at very slow and normal speeds were generated for twelve healthy subjects. Our results show that gluteus medius (GMED) contributions to ML stability decrease, while its contributions to sagittal plane accelerations increase during very slow compared to normal walking. Simultaneously the destabilizing influence of gravity increases in ML direction at a very slow walking speed. This emphasizes the need for a tight balance between gravity and gluteus medius action to ensure ML stability. When walking speed increases, GMED has a unique role in controlling ML acceleration and therefore stabilizing ML COM excursion. Contributions of other muscles decrease in all directions during very slow speed. Increased contributions of these muscles are therefore required to provide for both stability and propulsion when walking speed increases.

  8. Control system design method

    DOEpatents

    Wilson, David G.; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  9. Control of sleep-to-wake transitions via fast aminoacid and slow neuropeptide transmission

    PubMed Central

    Mosqueiro, Thiago; de Lecea, Luis; Huerta, Ramon

    2014-01-01

    The Locus Coeruleus (LC) modulates cortical, subcortical, cerebellar, brainstem and spinal cord circuits and it expresses receptors for neuromodulators that operate in a time scale of several seconds. Evidences from anatomical, electrophysiological and optogenetic experiments have shown that LC neurons receive input from a group of neurons called Hypocretins (HCRTs) that release a neuropeptide called hypocretin. It is less known how these two groups of neurons can be coregulated using GABAergic neurons. Since the time scales of GABAA inhibition is several orders of magnitude faster than the hypocretin neuropeptide effect, we investigate the limits of circuit activity regulation using a realistic model of neurons. Our investigation shows that GABAA inhibition is insufficient to control the activity levels of the LCs. Despite slower forms of GABAA can in principle work, there is not much plausibility due to the low probability of the presence of slow GABAA and lack of robust stability at the maximum firing frequencies. The best possible control mechanism predicted by our modeling analysis is the presence of inhibitory neuropeptides that exert effects in a similar time scale as the hypocretin/orexin. Although the nature of these inhibitory neuropeptides has not been identified yet, it provides the most efficient mechanism in the modeling analysis. Finally, we present a reduced mean-field model that perfectly captures the dynamics and the phenomena generated by this circuit. This investigation shows that brain communication involving multiple time scales can be better controlled by employing orthogonal mechanisms of neural transmission to decrease interference between cognitive processes and hypothalamic functions. PMID:25598695

  10. Multistage slow relaxation in a Hamiltonian system: The Fermi-Pasta-Ulam model

    NASA Astrophysics Data System (ADS)

    Matsuyama, Hironori J.; Konishi, Tetsuro

    2015-08-01

    The relaxation process toward equipartition of energy among normal modes in a Hamiltonian system with many degrees of freedom, the Fermi-Pasta-Ulam (FPU) model is investigated numerically. We introduce a general indicator of relaxation σ which denotes the distance from equipartition state. In the time evolution of σ , some long-time interferences with relaxation, named "plateaus," are observed. In order to examine the details of the plateaus, relaxation time of σ and excitation time for each normal mode are measured as a function of the energy density ɛ0=E0/N . As a result, multistage relaxation is detected in the finite-size system. Moreover, by an analysis of the Lyapunov spectrum, the spectrum of mode energy occupancy, and the power spectrum of mode energy, we characterize the multistage slow relaxation, and some dynamical phases are extracted: quasiperiodic motion, stagnant motion (escaping from quasiperiodic motion), local chaos, and stronger chaos with nonthermal noise. We emphasize that the plateaus are robust against the arranging microscopic state. In other words, we can often observe plateaus and multistage slow relaxation in the FPU phase space. Slow relaxation is expected to remain or vanish in the thermodynamic limit depending on indicators.

  11. Fast and Slow Responses of the South Asian Monsoon System to Anthropogenic Aerosols

    SciTech Connect

    Ganguly, Dilip; Rasch, Philip J.; Wang, Hailong; Yoon, Jin-Ho

    2012-09-25

    Using a global climate model with fully predictive aerosol life cycle, we investigate the fast and slow responses of the South Asian monsoon system to anthropogenic aerosol forcing. Our results show that the feedbacks associated with sea surface temperature (SST) change caused by aerosols play a more important role than the aerosol's direct impact on radiation, clouds and land surface (rapid adjustments) in shaping the total equilibrium climate response of the monsoon system to aerosol forcing. Inhomogeneous SST cooling caused by anthropogenic aerosols eventually reduces the meridional tropospheric temperature gradient and the easterly shear of zonal winds over the region, slowing down the local Hadley cell circulation, decreasing the northward moisture transport, and causing a reduction in precipitation over South Asia. Although total responses in precipitation are closer to the slow responses in general, the fast component dominates over land areas north of 25°N. Our results also show an east-west asymmetry in the fast responses to anthropogenic aerosols causing increases in precipitation west of 80°E but decreases east of it.

  12. Multistage slow relaxation in a Hamiltonian system: The Fermi-Pasta-Ulam model.

    PubMed

    Matsuyama, Hironori J; Konishi, Tetsuro

    2015-08-01

    The relaxation process toward equipartition of energy among normal modes in a Hamiltonian system with many degrees of freedom, the Fermi-Pasta-Ulam (FPU) model is investigated numerically. We introduce a general indicator of relaxation σ which denotes the distance from equipartition state. In the time evolution of σ, some long-time interferences with relaxation, named "plateaus," are observed. In order to examine the details of the plateaus, relaxation time of σ and excitation time for each normal mode are measured as a function of the energy density ε0=E0/N. As a result, multistage relaxation is detected in the finite-size system. Moreover, by an analysis of the Lyapunov spectrum, the spectrum of mode energy occupancy, and the power spectrum of mode energy, we characterize the multistage slow relaxation, and some dynamical phases are extracted: quasiperiodic motion, stagnant motion (escaping from quasiperiodic motion), local chaos, and stronger chaos with nonthermal noise. We emphasize that the plateaus are robust against the arranging microscopic state. In other words, we can often observe plateaus and multistage slow relaxation in the FPU phase space. Slow relaxation is expected to remain or vanish in the thermodynamic limit depending on indicators. PMID:26382486

  13. An intrinsic value system for developing multiple invariant representations with incremental slowness learning

    PubMed Central

    Luciw, Matthew; Kompella, Varun; Kazerounian, Sohrob; Schmidhuber, Juergen

    2013-01-01

    Curiosity Driven Modular Incremental Slow Feature Analysis (CD-MISFA;) is a recently introduced model of intrinsically-motivated invariance learning. Artificial curiosity enables the orderly formation of multiple stable sensory representations to simplify the agent's complex sensory input. We discuss computational properties of the CD-MISFA model itself as well as neurophysiological analogs fulfilling similar functional roles. CD-MISFA combines 1. unsupervised representation learning through the slowness principle, 2. generation of an intrinsic reward signal through learning progress of the developing features, and 3. balancing of exploration and exploitation to maximize learning progress and quickly learn multiple feature sets for perceptual simplification. Experimental results on synthetic observations and on the iCub robot show that the intrinsic value system is essential for representation learning. Representations are typically explored and learned in order from least to most costly, as predicted by the theory of curiosity. PMID:23755011

  14. Plasmonic-dielectric systems for high-order dispersionless slow or stopped subwavelength light.

    PubMed

    Karalis, Aristeidis; Joannopoulos, J D; Soljacić, Marin

    2009-07-24

    A material platform of multilayered surface-plasmon-dielectric-polariton systems is introduced, along with a new physical mechanism enabling simultaneous cancellation of group-velocity and attenuation dispersion to extremely high orders for subwavelength light of any small positive, negative, or zero group velocity. These dispersion-free systems could have significant impact on the development of nanophotonics, e.g., in the design of efficient and very compact delay lines and active devices. The same dispersion-manipulation mechanism can be employed to tailor at will exotic slow-light dispersion relations.

  15. Coexisting attractors and chaotic canard explosions in a slow-fast optomechanical system

    NASA Astrophysics Data System (ADS)

    Marino, Francesco; Marin, Francesco

    2013-05-01

    The multiple time scale dynamics induced by radiation pressure and photothermal effects in a high-finesse optomechanical resonator is experimentally studied. At difference with two-dimensional slow-fast systems, the transition from the quasiharmonic to the relaxational regime occurs via chaotic canard explosions, where large-amplitude relaxation spikes are separated by an irregular number of subthreshold oscillations. We also show that this regime coexists with other periodic attractors, on which the trajectories evolve on a substantially faster time scale. The experimental results are reproduced and analyzed by means of a detailed physical model of our system.

  16. Coexisting attractors and chaotic canard explosions in a slow-fast optomechanical system.

    PubMed

    Marino, Francesco; Marin, Francesco

    2013-05-01

    The multiple time scale dynamics induced by radiation pressure and photothermal effects in a high-finesse optomechanical resonator is experimentally studied. At difference with two-dimensional slow-fast systems, the transition from the quasiharmonic to the relaxational regime occurs via chaotic canard explosions, where large-amplitude relaxation spikes are separated by an irregular number of subthreshold oscillations. We also show that this regime coexists with other periodic attractors, on which the trajectories evolve on a substantially faster time scale. The experimental results are reproduced and analyzed by means of a detailed physical model of our system. PMID:23767597

  17. Critical slowing down, phase relations, and dissipation in driven oscillatory systems

    SciTech Connect

    Tsarouhas, G.E.; Ross, J. )

    1989-04-06

    Three dynamical properties of forced nonlinear systems are discussed with approximate analytic solutions obtained from the dynamic equations for oscillatory systems, near a supercritical Hopf bifurcation, driven by periodic perturbations of small amplitude. With these solutions we first obtain the phase difference between the response of the system and the periodic perturbation and its dependence on the parameters, and hence the mechanism, of the system. Second, we derive expressions for critical slowing down near edges of entrainment bands, with consideration of possible variation of both the radius and phase of the perturbed limit cycle with the amplitude of perturbation. Third, we show by analysis the previously numerically calculated variation of the dissipation within entrainment bands, which depends on the square of the amplitude of the response of the perturbed system.

  18. ISABELLE control system

    SciTech Connect

    Humphrey, J W; Frankel, R S; Niederer, J A

    1980-01-01

    Design principles for the Brookhaven ISABELLE control intersecting storage ring accelerator are described. Principal features include a locally networked console and control computer complex, a system wide process data highway, and intelligent local device controllers. Progress to date is summarized.

  19. Control System Damps Vibrations

    NASA Technical Reports Server (NTRS)

    Kopf, E. H., Jr.; Brown, T. K.; Marsh, E. L.

    1983-01-01

    New control system damps vibrations in rotating equipment with help of phase-locked-loop techniques. Vibrational modes are controlled by applying suitable currents to drive motor. Control signals are derived from sensors mounted on equipment.

  20. Jefferson Lab Data Acquisition Run Control System

    SciTech Connect

    Vardan Gyurjyan; Carl Timmer; David Abbott; William Heyes; Edward Jastrzembski; David Lawrence; Elliott Wolin

    2004-10-01

    A general overview of the Jefferson Lab data acquisition run control system is presented. This run control system is designed to operate the configuration, control, and monitoring of all Jefferson Lab experiments. It controls data-taking activities by coordinating the operation of DAQ sub-systems, online software components and third-party software such as external slow control systems. The main, unique feature which sets this system apart from conventional systems is its incorporation of intelligent agent concepts. Intelligent agents are autonomous programs which interact with each other through certain protocols on a peer-to-peer level. In this case, the protocols and standards used come from the domain-independent Foundation for Intelligent Physical Agents (FIPA), and the implementation used is the Java Agent Development Framework (JADE). A lightweight, XML/RDF-based language was developed to standardize the description of the run control system for configuration purposes.

  1. Slow Antihydrogen

    SciTech Connect

    Gabrielse, G.; Speck, A.; Storry, C.H.; Le Sage, D.; Guise, N.; Larochelle, P.C.; Grzonka, D.; Oelert, W.; Schepers, G.; Sefzick, T.; Pittner, H.; Herrmann, M.; Walz, J.; Haensch, T.W.

    2004-10-20

    Slow antihydrogen is now produced by two different production methods. In Method I, large numbers of H atoms are produced during positron-cooling of antiprotons within a nested Penning trap. In a just-demonstrated Method II, lasers control the production of antihydrogen atoms via charge exchange collisions. Field ionization detection makes it possible to probe the internal structure of the antihydrogen atoms being produced - most recently revealing atoms that are too tightly bound to be well described by the guiding center atom approximation. The speed of antihydrogen atoms has recently been measured for the first time. After the requested overview, the recent developments are surveyed.

  2. Modeling of nonlinear physiological systems with fast and slow dynamics. II. Application to cerebral autoregulation.

    PubMed

    Mitsis, G D; Zhang, R; Levine, B D; Marmarelis, V Z

    2002-04-01

    Dynamic autoregulation of cerebral hemodynamics in healthy humans is studied using the novel methodology of the Laguerre-Volterra network for systems with fast and slow dynamics (Mitsis, G. D., and V. Z. Marmarelis, Ann. Biomed. Eng. 30:272-281, 2002). Since cerebral autoregulation is mediated by various physiological mechanisms with significantly different time constants, it is used to demonstrate the efficacy of the new method. Results are presented in the time and frequency domains and reveal that cerebral autoregulation is a nonlinear and dynamic (frequency-dependent) system with considerable nonstationarities. Quantification of the latter reveals greater variability in specific frequency bands for each subject in the low and middle frequency range (below 0.1 Hz). The nonlinear dynamics are prominent also in the low and middle frequency ranges, where the frequency response of the system exhibits reduced gain. PMID:12086006

  3. PDX diagnostic control system

    SciTech Connect

    Mika, R.

    1981-01-01

    This paper describes a computer-base diagnostic control system operating on the PDX Tokamak. The prime function of the system is to control mechanical positioning devices associated with various diagnostics including Thomson Scattering, X-Ray Pulse Height Analyzer, Rotating Scanning Monochromator, Fast Ion Detection Experiment, Bolometers and Plasma Limiters. The diagnostic control system consists of a PDP-11/34 computer, a CAMAC system partitioned between the PDX control room and the PDX machine area, and special electronic control modules developed at PPL. The special modules include a digital closed loop motor controller and user interface control panel for control and status display. A standard control panel was developed for interfacing each system user with the PDP-11/34 computer, through specially developed CAMAC modules.

  4. Simplified greywater treatment systems: Slow filters of sand and slate waste followed by granular activated carbon.

    PubMed

    Zipf, Mariah Siebert; Pinheiro, Ivone Gohr; Conegero, Mariana Garcia

    2016-07-01

    One of the main actions of sustainability that is applicable to residential, commercial, and public buildings is the rational use of water that contemplates the reuse of greywater as one of the main options for reducing the consumption of drinking water. Therefore, this research aimed to study the efficiencies of simplified treatments for greywater reuse using slow sand and slow slate waste filtration, both followed by granular activated carbon filters. The system monitoring was conducted over 28 weeks, using analyses of the following parameters: pH, turbidity, apparent color, biochemical oxygen demand (BOD), chemical oxygen demand (COD), surfactants, total coliforms, and thermotolerant coliforms. The system was run at two different filtration rates: 6 and 2 m(3)/m(2)/day. Statistical analyses showed no significant differences in the majority of the results when filtration rate changed from 6 to 2 m(3)/m(2)/day. The average removal efficiencies with regard to the turbidity, apparent color, COD and BOD were 61, 54, 56, and 56%, respectively, for the sand filter, and 66, 61, 60, and 51%, respectively, for the slate waste filter. Both systems showed good efficiencies in removing surfactants, around 70%, while the pH reached values of around 7.80. The average removal efficiencies of the total and thermotolerant coliforms were of 61 and 90%, respectively, for the sand filter, and 67 and 80%, respectively, for the slate waste filter. The statistical analysis found no significant differences between the responses of the two systems, which attest to the fact that the slate waste can be a substitute for sand. The maximum levels of efficiency were high, indicating the potential of the systems, and suggesting their optimization in order to achieve much higher average efficiencies.

  5. Boiler control systems engineering

    SciTech Connect

    Gilman, J.

    2005-07-01

    The book provides in-depth coverage on how to safely and reliably control the firing of a boiler. Regardless of the capacity or fuel, certain fundamental control systems are required for boiler control. Large utility systems are more complex due to the number of burners and the overall capacity and equipment. This book covers engineering details on control systems and provides specific examples of boiler control including configuration and tuning. References to requirements are based on the 2004 NFPA 85 along with other ISA standards. Detailed chapters cover: Boiler fundamentals including piping and instrument diagrams (P&IDs) and a design basis checklist; Control of boilers, from strategies and bumpless transfer to interlock circuitry and final control elements; Furnace draft; Feedwater; Coal-fired boilers; Fuel and air control; Steam temperature; Burner management systems; Environment; and Control valve sizing. 2 apps.

  6. Segment alignment control system

    NASA Technical Reports Server (NTRS)

    Aubrun, JEAN-N.; Lorell, Ken R.

    1988-01-01

    The segmented primary mirror for the LDR will require a special segment alignment control system to precisely control the orientation of each of the segments so that the resulting composite reflector behaves like a monolith. The W.M. Keck Ten Meter Telescope will utilize a primary mirror made up of 36 actively controlled segments. Thus the primary mirror and its segment alignment control system are directly analogous to the LDR. The problems of controlling the segments in the face of disturbances and control/structures interaction, as analyzed for the TMT, are virtually identical to those for the LDR. The two systems are briefly compared.

  7. Intelligent flight control systems

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.

    1993-01-01

    The capabilities of flight control systems can be enhanced by designing them to emulate functions of natural intelligence. Intelligent control functions fall in three categories. Declarative actions involve decision-making, providing models for system monitoring, goal planning, and system/scenario identification. Procedural actions concern skilled behavior and have parallels in guidance, navigation, and adaptation. Reflexive actions are spontaneous, inner-loop responses for control and estimation. Intelligent flight control systems learn knowledge of the aircraft and its mission and adapt to changes in the flight environment. Cognitive models form an efficient basis for integrating 'outer-loop/inner-loop' control functions and for developing robust parallel-processing algorithms.

  8. An alien divalent ion reveals a major role for Ca²⁺ buffering in controlling slow transmitter release.

    PubMed

    Babai, Norbert; Kochubey, Olexiy; Keller, Daniel; Schneggenburger, Ralf

    2014-09-17

    Ca(2+)-dependent transmitter release occurs in a fast and in a slow phase, but the differential roles of Ca(2+) buffers and Ca(2+) sensors in shaping release kinetics are still controversial. Replacing extracellular Ca(2+) by Sr(2+) causes decreased fast release but enhanced slow release at many synapses. Here, we established presynaptic Sr(2+) uncaging and made quantitative Sr(2+)- and Ca(2+)-imaging experiments at the mouse calyx of Held synapse, to reveal the interplay between Ca(2+) sensors and Ca(2+) buffers in the control of fast and slow release. We show that Sr(2+) activates the fast, Synaptotagmin-2 (Syt2) sensor for vesicle fusion with sixfold lower affinity but unchanged high cooperativity. Surprisingly, Sr(2+) also activates the slow sensor that remains in Syt2 knock-out synapses with a lower efficiency, and Sr(2+) was less efficient than Ca(2+) in the limit of low concentrations in wild-type synapses. Quantitative imaging experiments show that the buffering capacity of the nerve terminal is markedly lower for Sr(2+) than for Ca(2+) (~5-fold). This, together with an enhanced Sr(2+) permeation through presynaptic Ca(2+) channels (~2-fold), admits a drastically higher spatially averaged Sr(2+) transient compared with Ca(2+). Together, despite the lower affinity of Sr(2+) at the fast and slow sensors, the massively higher amplitudes of spatially averaged Sr(2+) transients explain the enhanced late release. This also allows us to conclude that Ca(2+) buffering normally controls late release and prevents the activation of the fast release sensor by residual Ca(2+).

  9. Intermittent Control Systems

    ERIC Educational Resources Information Center

    Montgomery, Thomas L.; And Others

    1975-01-01

    The technique of intermittent control systems for air quality control as developed and used by the Tennessee Valley Authority is investigated. Although controversial, all Tennessee Valley Authority sulfur dioxide elimination programs are scheduled to be operational this year. Existing or anticipated intermittent control systems are identified. (BT)

  10. Automated Serials Control System.

    ERIC Educational Resources Information Center

    Pan, Elizabeth

    In 1967, the New York State Library at Albany (NYSL) developed a tape-oriented, off-line serials control system for 10,000 active titles. The system would perform all the serials control functions: bibliographic control, check-in of current receipts, claiming for gaps in receipts and late issues, binding notification for completed sets,…

  11. Hybrid stochastic simulation of reaction-diffusion systems with slow and fast dynamics

    SciTech Connect

    Strehl, Robert; Ilie, Silvana

    2015-12-21

    In this paper, we present a novel hybrid method to simulate discrete stochastic reaction-diffusion models arising in biochemical signaling pathways. We study moderately stiff systems, for which we can partition each reaction or diffusion channel into either a slow or fast subset, based on its propensity. Numerical approaches missing this distinction are often limited with respect to computational run time or approximation quality. We design an approximate scheme that remedies these pitfalls by using a new blending strategy of the well-established inhomogeneous stochastic simulation algorithm and the tau-leaping simulation method. The advantages of our hybrid simulation algorithm are demonstrated on three benchmarking systems, with special focus on approximation accuracy and efficiency.

  12. A slow-release system of bacterial cellulose gel and nanoparticles for hydrophobic active ingredients.

    PubMed

    Numata, Yukari; Mazzarino, Leticia; Borsali, Redouane

    2015-01-01

    A combination of bacterial cellulose (BC) gel and amphiphilic block copolymer nanoparticles was investigated as a drug delivery system (DDS) for hydrophobic active ingredients. Poly(ethylene oxide)-b-poly(caprolactone) (PEO-b-PCL) and retinol were used as the block copolymer and hydrophobic active ingredient, respectively. The BC gel was capable of incorporating copolymer nanoparticles and releasing them in an acetic acid-sodium acetate buffer solution (pH 5.2) at 37 °C. The percentage of released copolymer reached a maximum value of approximately 60% after 6h and remained constant after 24h. The percentage of retinol released from the copolymer-containing BC gel reached a maximum value at 4h. These results show that the combination of BC gel and nanoparticles is a slow-release system that may be useful in the cosmetic and biomedical fields for skin treatment and preparation. PMID:25840273

  13. A slow-release system of bacterial cellulose gel and nanoparticles for hydrophobic active ingredients.

    PubMed

    Numata, Yukari; Mazzarino, Leticia; Borsali, Redouane

    2015-01-01

    A combination of bacterial cellulose (BC) gel and amphiphilic block copolymer nanoparticles was investigated as a drug delivery system (DDS) for hydrophobic active ingredients. Poly(ethylene oxide)-b-poly(caprolactone) (PEO-b-PCL) and retinol were used as the block copolymer and hydrophobic active ingredient, respectively. The BC gel was capable of incorporating copolymer nanoparticles and releasing them in an acetic acid-sodium acetate buffer solution (pH 5.2) at 37 °C. The percentage of released copolymer reached a maximum value of approximately 60% after 6h and remained constant after 24h. The percentage of retinol released from the copolymer-containing BC gel reached a maximum value at 4h. These results show that the combination of BC gel and nanoparticles is a slow-release system that may be useful in the cosmetic and biomedical fields for skin treatment and preparation.

  14. Lithospheric Controls on the Rifting of Continents at Slow Rates of Extension

    NASA Astrophysics Data System (ADS)

    Armitage, J. J.; Henstock, T. J.; Minshull, T. A.; Hopper, J. R.

    2004-12-01

    The North Atlantic Igneous Province (NAIP) has escaped a simple explanation for its vast size and thickness. The region has a complicated history with many sedimentary basins that may or may not contain oceanic lithosphere and that pre-date the NAIP by between 20 and 100 Ma. Should these regions of pre-thinned lithosphere be ignored however in models that hope to explain the presence of the NAIP? We use the major and rare earth composition of melts generated within our dynamic model of extension of the lithosphere to predict seismic velocities within the emplaced igneous material. Previous models of the North Atlantic make the case clear for the presence of an exhaustible thermal anomaly that lay under the lithosphere. We test models with a 200 m°C, 50 km thick thermal anomaly beneath 125 km thick lithosphere to the sensitivity to regions of pre-thinning. The mantle potential temperature is 1325 m°C. The aim is to assess the importance of such failed rift basins. Extensional events that have stretching factors more than 3 to 4; pre-date the rift by 20 to 40 Myrs; and are less than 150 km from the centre of extension of a successful rift, have the effect of reducing the viscosity of the upper lithosphere, creating a region where the flow of mantle material can reach shallower depths. For an exhaustible thermal anomaly to have an affect, it must be advected above the solidus before it loses significant amounts of heat to the surroundings. There are two ways to achieve this, have a fast rate of rifting or introduce a pre-thinned region. We suggest that for enhanced melting leading to the formation of the NAIP, on or off axis pre-thinning is likely requirement, given the half rates of extension are slow. We suggest that the pre- thinning caused by the formation of the Hatton-Rockall Trough is enough, when combined with a 200 m °C thermal anomaly, to explain the magmatism of the Southeast Greenland Hatton Bank conjugate system. Such pre-thinning leads to asymmetric

  15. Lithospheric Controls on the Rifting of Continents at Slow Rates of Extension

    NASA Astrophysics Data System (ADS)

    Armitage, J. J.; Henstock, T. J.; Minshull, T. A.; Hopper, J. R.

    2007-12-01

    The North Atlantic Igneous Province (NAIP) has escaped a simple explanation for its vast size and thickness. The region has a complicated history with many sedimentary basins that may or may not contain oceanic lithosphere and that pre-date the NAIP by between 20 and 100 Ma. Should these regions of pre-thinned lithosphere be ignored however in models that hope to explain the presence of the NAIP? We use the major and rare earth composition of melts generated within our dynamic model of extension of the lithosphere to predict seismic velocities within the emplaced igneous material. Previous models of the North Atlantic make the case clear for the presence of an exhaustible thermal anomaly that lay under the lithosphere. We test models with a 200 m°C, 50 km thick thermal anomaly beneath 125 km thick lithosphere to the sensitivity to regions of pre-thinning. The mantle potential temperature is 1325 m°C. The aim is to assess the importance of such failed rift basins. Extensional events that have stretching factors more than 3 to 4; pre-date the rift by 20 to 40 Myrs; and are less than 150 km from the centre of extension of a successful rift, have the effect of reducing the viscosity of the upper lithosphere, creating a region where the flow of mantle material can reach shallower depths. For an exhaustible thermal anomaly to have an affect, it must be advected above the solidus before it loses significant amounts of heat to the surroundings. There are two ways to achieve this, have a fast rate of rifting or introduce a pre-thinned region. We suggest that for enhanced melting leading to the formation of the NAIP, on or off axis pre-thinning is likely requirement, given the half rates of extension are slow. We suggest that the pre- thinning caused by the formation of the Hatton-Rockall Trough is enough, when combined with a 200 m °C thermal anomaly, to explain the magmatism of the Southeast Greenland Hatton Bank conjugate system. Such pre-thinning leads to asymmetric

  16. Fast-Scale and Slow-Scale Subharmonic Oscillation of Valley Current-Mode Controlled Buck Converter

    NASA Astrophysics Data System (ADS)

    Zhou, Guo-Hua; Xu, Jian-Ping; Bao, Bo-Cheng; Zhang, Fei; Liu, Xue-Shan

    2010-09-01

    A valley current-mode (VCM) controlled buck converter with current source load (CSI) has complex phenomena of fast-scale and slow-scale subharmonic oscillations. The piecewise smooth switching model of the VCM controlled buck converter with CSI is established. It is found that attractive regions of fast-scale and slow-scale subharmonic oscillations exist in the bifurcation diagram, and two tori exist in the corresponding Poincaré mapping. The research results by time-domain simulation indicate that U-type subharmonic oscillation (SO) constituted by SO and frequency-reduced subharmonic oscillation (FSO) exists in inductor current, and sine-type SO constituted by fast scale and low scale exists in output voltage respectively. Experimental results are given to verify the analysis and simulation results.

  17. A data-driven prediction method for fast-slow systems

    NASA Astrophysics Data System (ADS)

    Groth, Andreas; Chekroun, Mickael; Kondrashov, Dmitri; Ghil, Michael

    2016-04-01

    In this work, we present a prediction method for processes that exhibit a mixture of variability on low and fast scales. The method relies on combining empirical model reduction (EMR) with singular spectrum analysis (SSA). EMR is a data-driven methodology for constructing stochastic low-dimensional models that account for nonlinearity and serial correlation in the estimated noise, while SSA provides a decomposition of the complex dynamics into low-order components that capture spatio-temporal behavior on different time scales. Our study focuses on the data-driven modeling of partial observations from dynamical systems that exhibit power spectra with broad peaks. The main result in this talk is that the combination of SSA pre-filtering with EMR modeling improves, under certain circumstances, the modeling and prediction skill of such a system, as compared to a standard EMR prediction based on raw data. Specifically, it is the separation into "fast" and "slow" temporal scales by the SSA pre-filtering that achieves the improvement. We show, in particular that the resulting EMR-SSA emulators help predict intermittent behavior such as rapid transitions between specific regions of the system's phase space. This capability of the EMR-SSA prediction will be demonstrated on two low-dimensional models: the Rössler system and a Lotka-Volterra model for interspecies competition. In either case, the chaotic dynamics is produced through a Shilnikov-type mechanism and we argue that the latter seems to be an important ingredient for the good prediction skills of EMR-SSA emulators. Shilnikov-type behavior has been shown to arise in various complex geophysical fluid models, such as baroclinic quasi-geostrophic flows in the mid-latitude atmosphere and wind-driven double-gyre ocean circulation models. This pervasiveness of the Shilnikow mechanism of fast-slow transition opens interesting perspectives for the extension of the proposed EMR-SSA approach to more realistic situations.

  18. JT-60 Control System

    SciTech Connect

    Yonekawa, I.; Kawamata, Y.; Totsuka, T.; Akasaka, H.; Sueoka, M.; Kurihara, K.; Kimura, T.

    2002-09-15

    The present status of the JT-60U control system is reported including its original design concept, the progress of the system, and various modifications since the JT-60 upgrade. This control system has features of a functionally distributed and hierarchical structure, using CAMAC interfaces initially, which have been replaced by versatile module Europe (VME)-bus interfaces, and a protective interlock system composed of both software and hard-wired interlock logics. Plant monitoring and control are performed by efficient data communication through CAMAC highways and Ethernet with TCP/IP protocols. Sequential control of plasma discharges is executed by a combination of a remodeled VME-bus system and a timing system. A real-time plasma control system and a human interface system have been continuously modified corresponding to the progress of JT-60U experiments.

  19. Control and optimization system

    DOEpatents

    Xinsheng, Lou

    2013-02-12

    A system for optimizing a power plant includes a chemical loop having an input for receiving an input parameter (270) and an output for outputting an output parameter (280), a control system operably connected to the chemical loop and having a multiple controller part (230) comprising a model-free controller. The control system receives the output parameter (280), optimizes the input parameter (270) based on the received output parameter (280), and outputs an optimized input parameter (270) to the input of the chemical loop to control a process of the chemical loop in an optimized manner.

  20. Intelligent Control Systems Research

    NASA Technical Reports Server (NTRS)

    Loparo, Kenneth A.

    1994-01-01

    Results of a three phase research program into intelligent control systems are presented. The first phase looked at implementing the lowest or direct level of a hierarchical control scheme using a reinforcement learning approach assuming no a priori information about the system under control. The second phase involved the design of an adaptive/optimizing level of the hierarchy and its interaction with the direct control level. The third and final phase of the research was aimed at combining the results of the previous phases with some a priori information about the controlled system.

  1. The ILC control system.

    SciTech Connect

    Carwardine, J.; Saunders, C.; Arnold, N.; Lenkszus, F.; Rehlich, K.; Simrock, S.; Banerjee, b.; Chase, B.; Gottschalk, E.; Joireman, P.; Kasley, P.; Lackey, S.; McBride, P.; Pavlicek, V.; Patrick, J.; Votava, M.; Wolbers, S.; Furukawa, K.; Michizono, S.; Larson, R.S.; Downing, R.; DESY; FNAL; SLAC

    2007-01-01

    Since the last ICALEPCS, a small multi-region team has developed a reference design model for a control system for the International Linear Collider as part of the ILC Global Design Effort. The scale and performance parameters of the ILC accelerator require new thinking in regards to control system design. Technical challenges include the large number of accelerator systems to be controlled, the large scale of the accelerator facility, the high degree of automation needed during accelerator operations, and control system equipment requiring 'Five Nines' availability. The R&D path for high availability touches the control system hardware, software, and overall architecture, and extends beyond traditional interfaces into the technical systems. Software considerations for HA include fault detection through exhaustive out-of-band monitoring and automatic state migration to redundant systems, while the telecom industry's emerging ATCA standard - conceived, specified, and designed for High Availability - is being evaluated for suitability for ILC front-end electronics.

  2. Overcoming the slow recovery of MOX gas sensors through a system modeling approach.

    PubMed

    Monroy, Javier G; González-Jiménez, Javier; Blanco, Jose Luis

    2012-01-01

    Metal Oxide Semiconductor (MOX) gas transducers are one of the preferable technologies to build electronic noses because of their high sensitivity and low price. In this paper we present an approach to overcome to a certain extent one of their major disadvantages: their slow recovery time (tens of seconds), which limits their suitability to applications where the sensor is exposed to rapid changes of the gas concentration. Our proposal consists of exploiting a double first-order model of the MOX-based sensor from which a steady-state output is anticipated in real time given measurements of the transient state signal. This approach assumes that the nature of the volatile is known and requires a precalibration of the system time constants for each substance, an issue that is also described in the paper. The applicability of the proposed approach is validated with several experiments in real, uncontrolled scenarios with a mobile robot bearing an e-nose. PMID:23202015

  3. The Patuki intrusive suite: closed-system fractionation beneath a slow-spreading ridge

    NASA Astrophysics Data System (ADS)

    Sivell, W. J.; Waterhouse, J. B.

    A wide range of mafic and ultramafic rock types, together with cogenetic silicic plagiogranites, form a structurally coherent intrusive sequence within the Patuki Volcanics at south D'Urville Island, New Zealand. In addition, gabbroic rocks comprise abundant tectonic inclusions in highly-sheared, concordant serpentinite bands which intrude the Patuki suite. Chemical evidence suggests many of the gabbros, including those in which recrystallization has obliterated original textures, represent magmatic cumulates and indicates extensive closed-system fractionation analogous to that known to occur beneath slow-spreading mid-oceanic ridges. Dyke intrusion occurred throughout the generation of the suite. An early stage of spreading is suggested by the anomalously low thickness of the sequence, the non-sheeted nature of the dyke suite and chemical characteristics of the lavas which comprise the extrusive component of the ophiolite.

  4. Overcoming the Slow Recovery of MOX Gas Sensors through a System Modeling Approach

    PubMed Central

    Monroy, Javier G.; González-Jiménez, Javier; Blanco, Jose Luis

    2012-01-01

    Metal Oxide Semiconductor (MOX) gas transducers are one of the preferable technologies to build electronic noses because of their high sensitivity and low price. In this paper we present an approach to overcome to a certain extent one of their major disadvantages: their slow recovery time (tens of seconds), which limits their suitability to applications where the sensor is exposed to rapid changes of the gas concentration. Our proposal consists of exploiting a double first-order model of the MOX-based sensor from which a steady-state output is anticipated in real time given measurements of the transient state signal. This approach assumes that the nature of the volatile is known and requires a precalibration of the system time constants for each substance, an issue that is also described in the paper. The applicability of the proposed approach is validated with several experiments in real, uncontrolled scenarios with a mobile robot bearing an e-nose. PMID:23202015

  5. Slow manifold structure in explosive kinetics. 2. Extension to higher dimensional systems.

    PubMed

    Giona, M; Adrover, A; Creta, F; Valorani, M

    2006-12-21

    This Article extends the geometric analysis of slow invariant manifolds in explosive kinetics developed by Creta et al. to three-dimensional and higher systems. Invariant manifolds can be characterized by different families of Lyapunov-type numbers, based either on the relative growth of normal to tangential perturbations or on the deformation of m-dimensional volume elements (if the manifold is m-dimensional) and of the complementary (n - m)-elements in the normal orthogonal complement. The latter approach, based on elementary concepts of exterior algebra, is particularly simple because the evolution of the relevant volume elements can be related to suitable local stretching rates, and local analysis can be performed directly from the knowledge of the Jacobian matrix of the vector field. Several examples of bifurcations of the points-at-infinity, which modify the manifold structure, are discussed for 3-D models of exothermic reactions.

  6. Control system design guide

    SciTech Connect

    Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

    2003-05-01

    The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

  7. Novel microsatellite control system

    SciTech Connect

    Moore, K.R.; Frigo, J.R.; Tilden, M.W.

    1996-12-31

    The authors are developing extremely simple yet quite capable analog pulse-coded neural networks for smaller-faster-cheaper spacecraft attitude and control systems. They will demonstrate a prototype microsatellite that uses the novel control system to autonomously stabilize itself in the ambient magnetic field and point itself at the brightest available light source.

  8. Stochastic switching in slow-fast systems: a large-fluctuation approach.

    PubMed

    Heckman, Christoffer R; Schwartz, Ira B

    2014-02-01

    In this paper we develop a perturbation method to predict the rate of occurrence of rare events for singularly perturbed stochastic systems using a probability density function approach. In contrast to a stochastic normal form approach, we model rare event occurrences due to large fluctuations probabilistically and employ a WKB ansatz to approximate their rate of occurrence. This results in the generation of a two-point boundary value problem that models the interaction of the state variables and the most likely noise force required to induce a rare event. The resulting equations of motion of describing the phenomenon are shown to be singularly perturbed. Vastly different time scales among the variables are leveraged to reduce the dimension and predict the dynamics on the slow manifold in a deterministic setting. The resulting constrained equations of motion may be used to directly compute an exponent that determines the probability of rare events. To verify the theory, a stochastic damped Duffing oscillator with three equilibrium points (two sinks separated by a saddle) is analyzed. The predicted switching time between states is computed using the optimal path that resides in an expanded phase space. We show that the exponential scaling of the switching rate as a function of system parameters agrees well with numerical simulations. Moreover, the dynamics of the original system and the reduced system via center manifolds are shown to agree in an exponentially scaling sense. PMID:25353557

  9. Evaluation of a low-dose/slow-rotating SPECT-CT system

    NASA Astrophysics Data System (ADS)

    Hamann, M.; Aldridge, M.; Dickson, J.; Endozo, R.; Lozhkin, K.; Hutton, B. F.

    2008-05-01

    The 4-slice CT that forms part of the GE Infinia Hawkeye-4 SPECT-CT scanner (Hawkeye) is evaluated against the diagnostic 16-slice CT that is incorporated in the GE Discovery ST PET-CT system (DST). The x-ray tube of the slow-rotating Hawkeye system (23 s/rotation) operates at approximately a third of the dose of diagnostic systems as used for conventional diagnostic imaging. Image reconstruction is optimized for low noise. High-contrast spatial resolution significantly falls behind diagnostic figures: the average of MTF50 and MTF10 (resolution where the MTF has fallen to 50% and 10%) is 2.8 ± 0.1 cm-1 for Hawkeye and 5.3 ± 0.1 cm-1 for the DST (standard reconstruction filters). Resolution in the direction of the couch movement (z coordinate) is governed by the fixed Hawkeye slice width of 5 mm. Reconstruction accuracy is found to be increased by reducing the default z increment from 4.4 mm to 2.2 mm. Low-contrast object detectability is superior compared with diagnostic systems operating in the Hawkeye dose range. In the diagnostic dose regime, however, small low-contrast details remain visible in DST that are not detectable with Hawkeye. Although not of diagnostic quality, the low-dose Hawkeye provides appropriate data for SPECT attenuation correction and anatomical localization capability. For more information on this article, see medicalphysicsweb.org

  10. Control system retrofit guidelines

    SciTech Connect

    Stoddard, L.E.; Gil, L.F. )

    1992-07-01

    This report has been prepared by Black Veatch for the Electric Power Research Institute under Contract RP2710-16. This project has been a part of an EPRI program to enhance computer and control technology applications for the utility industry. It is estimated that the utility industry will spend 500 million dollars in the next two years for control system enhancement projects. The need for such enhancement results from a combination of the age and obsolescence of the control systems in existing fossil-fired plants, the decision by utilities to extend the lifetime of those plants, the changes in operating strategies, and the continued development of control systems with expanded capabilities. Opportunities for control system retrofits are myriad; therefore, utilities are faced with complex decisions as to how best to use the limited financial resources available for such projects. To assist utilities in making these decisions, the Electric Power Research Institute (EPRI) has retained Black Veatch and Sargent Lundy to develop a set of control system retrofit guideline documents. The guidelines are in a three-volume format. Volume I--Control System Retrofit Project Methodology; Volume II--Control System Technical Assessment; and Volume III--Utility Case Studies. Volume II (this document) gives guidance in the technical assessment for a retrofit, and has been prepared by Black Veatch under EPRI RP2710-16. The combination of these guideline documents gives utilities the necessary guidance to perform a retrofit project in a straightforward, cost-effective manner.

  11. Common Control System Vulnerability

    SciTech Connect

    Trent Nelson

    2005-12-01

    The Control Systems Security Program and other programs within the Idaho National Laboratory have discovered a vulnerability common to control systems in all sectors that allows an attacker to penetrate most control systems, spoof the operator, and gain full control of targeted system elements. This vulnerability has been identified on several systems that have been evaluated at INL, and in each case a 100% success rate of completing the attack paths that lead to full system compromise was observed. Since these systems are employed in multiple critical infrastructure sectors, this vulnerability is deemed common to control systems in all sectors. Modern control systems architectures can be considered analogous to today's information networks, and as such are usually approached by attackers using a common attack methodology to penetrate deeper and deeper into the network. This approach often is composed of several phases, including gaining access to the control network, reconnaissance, profiling of vulnerabilities, launching attacks, escalating privilege, maintaining access, and obscuring or removing information that indicates that an intruder was on the system. With irrefutable proof that an external attack can lead to a compromise of a computing resource on the organization's business local area network (LAN), access to the control network is usually considered the first phase in the attack plan. Once the attacker gains access to the control network through direct connections and/or the business LAN, the second phase of reconnaissance begins with traffic analysis within the control domain. Thus, the communications between the workstations and the field device controllers can be monitored and evaluated, allowing an attacker to capture, analyze, and evaluate the commands sent among the control equipment. Through manipulation of the communication protocols of control systems (a process generally referred to as ''reverse engineering''), an attacker can then map out the

  12. Drone Control System

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Drones, subscale vehicles like the Firebees, and full scale retired military aircraft are used to test air defense missile systems. The DFCS (Drone Formation Control System) computer, developed by IBM (International Business Machines) Federal Systems Division, can track ten drones at once. A program called ORACLS is used to generate software to track and control Drones. It was originally developed by Langley and supplied by COSMIC (Computer Software Management and Information Center). The program saved the company both time and money.

  13. PRESSURE SYSTEM CONTROL

    DOEpatents

    Esselman, W.H.; Kaplan, G.M.

    1961-06-20

    The control of pressure in pressurized liquid systems, especially a pressurized liquid reactor system, may be achieved by providing a bias circuit or loop across a closed loop having a flow restriction means in the form of an orifice, a storage tank, and a pump connected in series. The subject invention is advantageously utilized where control of a reactor can be achieved by response to the temperature and pressure of the primary cooling system.

  14. Model Predictions of Chemically Controlled Slow Crack Growth with Application to Mechanical Effects in Geothermal Environments

    SciTech Connect

    Viani, B E

    2001-04-11

    Representative, simplified geothermal rock-fluid systems are investigated with a modeling approach to estimate how rock water interactions affect coupled properties related to mechanical stability and permeability improvement through fracturing. First, geochemical modeling is used to determine the evolution of fluid chemistry at temperatures up to 300 C when fluids are in contact with representative rocks of continental origin. Then, a kinetic crack growth model for quartz is used to predict growth rate for subcritical cracks in acidic and basic environments. The predicted growth rate is highly sensitive to temperature and pH in the ranges tested. At present, the model is limited to situations in which quartz controls the mechanical process of interest, such as well bore stability in silica cemented rocks and the opening of quartz filled veins to enhance permeability.

  15. Mooring systems design based on analytical expressions of catastrophes of slow motion dynamics

    SciTech Connect

    Bernitsas, M.M.; Garza-Rios, L.O.

    1996-12-31

    Analytical expressions of the necessary and sufficient conditions for stability of mooring systems representing bifurcation boundaries, and expressions defining the morphogeneses occurring across boundaries are presented. These expressions provide means for evaluating the stability of a mooring system around an equilibrium position and constructing catastrophe sets in any parametric design space. These expressions allow the designer to select appropriate values for the mooring parameters without resorting to trial and error. A number of realistic applications are provided for barge and tanker mooring systems which exhibit qualitatively different nonlinear dynamics. The mathematical model consists of the nonlinear, third order maneuvering equations of the horizontal plane slow motion dynamics of a vessel moored to one or more terminals. Mooring lines are modeled by synthetic nylon ropes, chains, or steel cables. External excitation consists of time independent current, wind, and mean wave drift forces. The analytical expressions presented in this paper apply to nylon ropes and current excitation. Expressions for other combinations of lines and excitation can be derived.

  16. Differentiation at the single cell level: slow, noisy, and out of control

    NASA Astrophysics Data System (ADS)

    Suel, Gurol

    2006-03-01

    Transient differentiation allows genetically identical cells to generate dynamical phenotypic diversity in a homogeneous environment. In Bacillus subtilis, competence is a transient state associated with the capability for DNA uptake from the environment. Individual genes and proteins underlying differentiation into the competent state have been elucidated, but it is unclear how these genes interact dynamically in individual cells to control both entry into competence and return to vegetative growth. Here we show that transient differentiation can be understood in terms of excitable behavior of the underlying genetic circuit. Using quantitative fluorescence time-lapse microscopy, we directly observed the activities of multiple circuit components simultaneously in individual cells. We analyzed the resulting data in terms of a mathematical model. A core module containing positive and negative feedback loops controls both entry into, and exit from, the competent state. Reengineering the competence network to bypass the negative feedback loop specifically blocks exit from competence converting the excitable system into a bistable one. These results show that a simple genetic circuit combines stochastic and deterministic elements to support transient differentiation through excitability.

  17. Digital flight control systems

    NASA Technical Reports Server (NTRS)

    Caglayan, A. K.; Vanlandingham, H. F.

    1977-01-01

    The design of stable feedback control laws for sampled-data systems with variable rate sampling was investigated. These types of sampled-data systems arise naturally in digital flight control systems which use digital actuators where it is desirable to decrease the number of control computer output commands in order to save wear and tear of the associated equipment. The design of aircraft control systems which are optimally tolerant of sensor and actuator failures was also studied. Detection of the failed sensor or actuator must be resolved and if the estimate of the state is used in the control law, then it is also desirable to have an estimator which will give the optimal state estimate even under the failed conditions.

  18. Power Systems Control Architecture

    SciTech Connect

    James Davidson

    2005-01-01

    A diagram provided in the report depicts the complexity of the power systems control architecture used by the national power structure. It shows the structural hierarchy and the relationship of the each system to those other systems interconnected to it. Each of these levels provides a different focus for vulnerability testing and has its own weaknesses. In evaluating each level, of prime concern is what vulnerabilities exist that provide a path into the system, either to cause the system to malfunction or to take control of a field device. An additional vulnerability to consider is can the system be compromised in such a manner that the attacker can obtain critical information about the system and the portion of the national power structure that it controls.

  19. IGISOL control system modernization

    NASA Astrophysics Data System (ADS)

    Koponen, J.; Hakala, J.

    2016-06-01

    Since 2010, the IGISOL research facility at the Accelerator laboratory of the University of Jyväskylä has gone through major changes. Comparing the new IGISOL4 facility to the former IGISOL3 setup, the size of the facility has more than doubled, the length of the ion transport line has grown to about 50 m with several measurement setups and extension capabilities, and the accelerated ions can be fed to the facility from two different cyclotrons. The facility has evolved to a system comprising hundreds of manual, pneumatic and electronic devices. These changes have prompted the need to modernize also the facility control system taking care of monitoring and transporting the ion beams. In addition, the control system is also used for some scientific data acquisition tasks. Basic guidelines for the IGISOL control system update have been remote control, safety, usability, reliability and maintainability. Legacy components have had a major significance in the control system hardware and for the renewed control system software the Experimental Physics and Industrial Control System (EPICS) has been chosen as the architectural backbone.

  20. Load Control System Reliability

    SciTech Connect

    Trudnowski, Daniel

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  1. Optimal Control Modification for Time-Scale Separated Systems

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2012-01-01

    Recently a new optimal control modification has been introduced that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. This modification is based on an optimal control formulation to minimize the L2 norm of the tracking error. The optimal control modification adaptive law results in a stable adaptation in the presence of a large adaptive gain. This study examines the optimal control modification adaptive law in the context of a system with a time scale separation resulting from a fast plant with a slow actuator. A singular perturbation analysis is performed to derive a modification to the adaptive law by transforming the original system into a reduced-order system in slow time. A model matching conditions in the transformed time coordinate results in an increase in the actuator command that effectively compensate for the slow actuator dynamics. Simulations demonstrate effectiveness of the method.

  2. What is system control?

    SciTech Connect

    Hirst, E.; Kirby, B.

    1999-11-01

    Just as the aviation industry needs air-traffic controllers to manage the movement of airplanes for safety and commerce, so too, the electricity industry requires system operators. The electrical-system-control functions encompass a range of activities that support commercial transactions and maintain bulk-power reliability. As part of a project for the Edison Electric Institute, the authors examined the functions and costs of system control and the issues that need to be resolved in a restructured electricity industry (Hirst and Kirby 1998).

  3. Two semantic systems in the brain for rapid and slow differentiation of abstract and concrete words.

    PubMed

    Il'yuchenok, I R; Sysoeva, O V; Ivanitskii, A M

    2008-11-01

    Most studies of semantic processing address changes in the late (300-800 msec) components of evoked potentials. However, recent years have seen the appearance of data showing that humans can perceive the sense of stimuli presented to them in significantly shorter periods of time. We report here studies of the mechanism of semantic analysis of written abstract and concrete words in four series of experiments: 1) reading of words on a monitor screen; 2) simple classification of all presented words into the categories "abstract" and "concrete;" 3) complex, i.e., selective classification of words written only in a specified color with a prompt as to which color would be used for the word; 4) complex classification of words of only a specified color without a prior prompt. Early (40-100 msec) differences in evoked brain potentials were seen on comparison of responses to abstract and concrete words, predominantly in the frontal areas in the case of simple reading of words and in the more dorsal areas in the case of tasks with simple classification. All cases of explicit classification of words were characterized by differences in late (450-700 msec) components in the left frontal zone. The results indicate the existence of two semantic systems: a rapid, implicit system associated with activation of the right frontal area, and a slow, explicit system of word classification which is predominantly associated with activity in the left frontal area. The relationship between the two systems is to a certain extent reciprocal: the rapid system can by inhibited by introduction of a word classification task.

  4. Investigating the potential for a self-sustaining slow pyrolysis system under varying operating conditions.

    PubMed

    Crombie, Kyle; Mašek, Ondřej

    2014-06-01

    This work aimed to investigate the impact of highest treatment temperature (HTT), heating rate, carrier gas flow rate and feedstock on the composition and energy content of pyrolysis gas to assess whether a self-sustained system could be achieved through the combustion of the gas fraction alone, leaving other co-products available for alternative high-value uses. Calculations based on gas composition showed that the pyrolysis process could be sustained by the energy contained within the pyrolysis gases alone. The lower energy limit (6% biomass higher heating value (HHV)) was surpassed by pyrolysis at ⩾450°C while only a HTT of 650°C consistently met the upper energy limit (15% biomass HHV). These findings fill an important gap in literature related to the energy balance of the pyrolysis systems for biochar production, and show that, at least from an energy balance perspective; self-sustained slow pyrolysis for co-production of biochar and liquid products is feasible.

  5. Velocity estimation of slow moving targets in AT-InSAR systems

    NASA Astrophysics Data System (ADS)

    Budillon, A.; Pascazio, V.; Schirinzi, G.

    2007-10-01

    Along Track Interferometric Synthetic Aperture Radar (AT-InSAR) systems use more than one SAR antennas (typically two), mounted on the same platform and displaced along the platform moving direction, to detect slow ground moving targets. The phase of the ATI signal is related to the target motion parameters and may thus be used to estimate the radial velocity. In this paper we approach the velocity estimation problem using statistical techniques based on the statistical distribution of the measured interferometric phases. We analyze the radial velocity estimation with respect to ATI system parameters, such as velocity values, the signal to clutter ratio (SCR), the clutter to noise ratio (CNR), considering a deterministic target whose velocity is estimated using a Gaussian model. This model allows to take into account the lack of knowledge of the target radar cross section (RCS) values and provides an analytical form for the interferometric phase probability density function. Simulations results show that the adoption of Maximum Likelihood (ML) techniques, to perform a joint estimation of velocity and SCR, and multi-channel configurations, to overcome ambiguities problems, provide very good velocity estimation accuracy.

  6. Investigating the potential for a self-sustaining slow pyrolysis system under varying operating conditions.

    PubMed

    Crombie, Kyle; Mašek, Ondřej

    2014-06-01

    This work aimed to investigate the impact of highest treatment temperature (HTT), heating rate, carrier gas flow rate and feedstock on the composition and energy content of pyrolysis gas to assess whether a self-sustained system could be achieved through the combustion of the gas fraction alone, leaving other co-products available for alternative high-value uses. Calculations based on gas composition showed that the pyrolysis process could be sustained by the energy contained within the pyrolysis gases alone. The lower energy limit (6% biomass higher heating value (HHV)) was surpassed by pyrolysis at ⩾450°C while only a HTT of 650°C consistently met the upper energy limit (15% biomass HHV). These findings fill an important gap in literature related to the energy balance of the pyrolysis systems for biochar production, and show that, at least from an energy balance perspective; self-sustained slow pyrolysis for co-production of biochar and liquid products is feasible. PMID:24747394

  7. Evaluation of symptomatic slow-acting drugs in osteoarthritis using the GRADE system

    PubMed Central

    Bruyère, Olivier; Burlet, Nansa; Delmas, Pierre D; Rizzoli, René; Cooper, Cyrus; Reginster, Jean-Yves

    2008-01-01

    Background Symptomatic slow-acting drugs (SYSADOA) have been largely studied over the last decade. The objective of this study is to prepare a document providing recommendations for the use of SYSADOA in osteoarthritis (OA). Methods The following interventions were taken into consideration: avocado/soybean unsaponifiables, chondroitin sulfate, diacereine, glucosamine sulfate, hyaluronic acid, oral calcitonin, risedronate, strontium ranelate. Recommendations were based on the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. The GRADE system is based on a sequential assessment of the quality of evidence, followed by assessment of the balance between benefits versus downsides and subsequent judgment about the strength of recommendations. Results Chondroitin sulfate, diacereine, glucosamine sulfate, avocado/soybean unsaponifiables and hyaluronic acid have demonstrated pain reduction and physical function improvement with very low toxicity, with moderate to high quality evidence. Even if pre-clinical data and some preliminary in vivo studies have suggested that oral calcitonin and strontium ranelate could be of potential interest in OA, additional well-designed studies are needed. Conclusion In the benefit/risk ratio, the use of chondroitin sulfate, diacereine, glucosamine sulfate, avocado/soybean unsaponifiables and hyaluronic acid could be of potential interest for the symptomatic management of OA. PMID:19087296

  8. Control of fossil-fuel particulate black carbon and organic matter, possibly the most effective method of slowing global warming

    NASA Astrophysics Data System (ADS)

    Jacobson, Mark Z.

    2002-10-01

    Under the 1997 Kyoto Protocol, no control of black carbon (BC) was considered. Here, it is found, through simulations in which 12 identifiable effects of aerosol particles on climate are treated, that any emission reduction of fossil-fuel (f.f.) particulate BC plus associated organic matter (OM) may slow global warming more than may any emission reduction of CO2 or CH4 for a specific period. When all f.f. BC + OM and anthropogenic CO2 and CH4 emissions are eliminated together, the period is 25-100 years. It is also estimated that historical net global warming can be attributed roughly to greenhouse gas plus f.f. BC + OM warming minus substantial cooling by other particles. Eliminating all f.f. BC + OM could eliminate 20-45% of net warming (8-18% of total warming before cooling is subtracted out) within 3-5 years if no other change occurred. Reducing CO2 emissions by a third would have the same effect, but after 50-200 years. Finally, diesel cars emitting continuously under the most recent U.S. and E.U. particulate standards (0.08 g/mi; 0.05 g/km) may warm climate per distance driven over the next 100+ years more than equivalent gasoline cars. Thus, fuel and carbon tax laws that favor diesel appear to promote global warming. Toughening vehicle particulate emission standards by a factor of 8 (0.01 g/mi; 0.006 g/km) does not change this conclusion, although it shortens the period over which diesel cars warm to 13-54 years. Although control of BC + OM can slow warming, control of greenhouse gases is necessary to stop warming. Reducing BC + OM will not only slow global warming but also improve human health.

  9. Flight control actuation system

    NASA Technical Reports Server (NTRS)

    Wingett, Paul T. (Inventor); Gaines, Louie T. (Inventor); Evans, Paul S. (Inventor); Kern, James I. (Inventor)

    2004-01-01

    A flight control actuation system comprises a controller, electromechanical actuator and a pneumatic actuator. During normal operation, only the electromechanical actuator is needed to operate a flight control surface. When the electromechanical actuator load level exceeds 40 amps positive, the controller activates the pneumatic actuator to offset electromechanical actuator loads to assist the manipulation of flight control surfaces. The assistance from the pneumatic load assist actuator enables the use of an electromechanical actuator that is smaller in size and mass, requires less power, needs less cooling processes, achieves high output forces and adapts to electrical current variations. The flight control actuation system is adapted for aircraft, spacecraft, missiles, and other flight vehicles, especially flight vehicles that are large in size and travel at high velocities.

  10. Flight control actuation system

    NASA Technical Reports Server (NTRS)

    Wingett, Paul T. (Inventor); Gaines, Louie T. (Inventor); Evans, Paul S. (Inventor); Kern, James I. (Inventor)

    2006-01-01

    A flight control actuation system comprises a controller, electromechanical actuator and a pneumatic actuator. During normal operation, only the electromechanical actuator is needed to operate a flight control surface. When the electromechanical actuator load level exceeds 40 amps positive, the controller activates the pneumatic actuator to offset electromechanical actuator loads to assist the manipulation of flight control surfaces. The assistance from the pneumatic load assist actuator enables the use of an electromechanical actuator that is smaller in size and mass, requires less power, needs less cooling processes, achieves high output forces and adapts to electrical current variations. The flight control actuation system is adapted for aircraft, spacecraft, missiles, and other flight vehicles, especially flight vehicles that are large in size and travel at high velocities.

  11. NUCLEAR REACTOR CONTROL SYSTEM

    DOEpatents

    Epler, E.P.; Hanauer, S.H.; Oakes, L.C.

    1959-11-01

    A control system is described for a nuclear reactor using enriched uranium fuel of the type of the swimming pool and other heterogeneous nuclear reactors. Circuits are included for automatically removing and inserting the control rods during the course of normal operation. Appropriate safety circuits close down the nuclear reactor in the event of emergency.

  12. Determination of birefringence and slow axis distribution using an interferometric measurement system with liquid crystal phase shifter.

    PubMed

    Nose, Toshiaki; Kamata, Keisuke; Takeuchi, Toru; Okano, Keiju; Fujita, Naoko; Muraguchi, Hajime; Ozaki, Noriaki; Honma, Michinori; Ito, Ryouta

    2014-11-01

    It is known that liquid crystal (LC) cells are useful as compact and easy-to-handle phase shifters that are readily coupled into the optics of standard microscope systems. Here, a uniformly aligned molecular LC phase shifter is introduced into a polarization microscope to attain a birefringence imaging system, using the phase-shift interferometric technique. Since the birefringence can be determined accurately only when the optical axis of the sample is parallel or perpendicular to the slow axis (variable axis) of the LC phase shifter, an improved data analysis method is proposed for determining the birefringence independently of the direction; a simple method of determining the slow axis distribution is also demonstrated. Measurements of the birefringence and slow axis distribution properties of a potato starch particle are demonstrated to confirm the novel determination method. PMID:25402881

  13. A Multirate Control Strategy to the Slow Sensors Problem: An Interactive Simulation Tool for Controller Assisted Design

    PubMed Central

    Salt, Julián; Cuenca, Ángel; Palau, Francisco; Dormido, Sebastián

    2014-01-01

    In many control applications, the sensor technology used for the measurement of the variable to be controlled is not able to maintain a restricted sampling period. In this context, the assumption of regular and uniform sampling pattern is questionable. Moreover, if the control action updating can be faster than the output measurement frequency in order to fulfill the proposed closed loop behavior, the solution is usually a multirate controller. There are some known aspects to be careful of when a multirate system (MR) is going to be designed. The proper multiplicity between input-output sampling periods, the proper controller structure, the existence of ripples and others issues need to be considered. A useful way to save time and achieve good results is to have an assisted computer design tool. An interactive simulation tool to deal with MR seems to be the right solution. In this paper this kind of simulation application is presented. It allows an easy understanding of the performance degrading or improvement when changing the multirate sampling pattern parameters. The tool was developed using Sysquake, a Matlab-like language with fast execution and powerful graphic facilities. It can be delivered as an executable. In the paper a detailed explanation of MR treatment is also included and the design of four different MR controllers with flexible structure to be adapted to different schemes will also be presented. The Smith's predictor in these MR schemes is also explained, justified and used when time delays appear. Finally some interesting observations achieved using this interactive tool are included. PMID:24583971

  14. A multirate control strategy to the slow sensors problem: an interactive simulation tool for controller assisted design.

    PubMed

    Salt, Julián; Cuenca, Ángel; Palau, Francisco; Dormido, Sebastián

    2014-01-01

    In many control applications, the sensor technology used for the measurement of the variable to be controlled is not able to maintain a restricted sampling period. In this context, the assumption of regular and uniform sampling pattern is questionable. Moreover, if the control action updating can be faster than the output measurement frequency in order to fulfill the proposed closed loop behavior, the solution is usually a multirate controller. There are some known aspects to be careful of when a multirate system (MR) is going to be designed. The proper multiplicity between input-output sampling periods, the proper controller structure, the existence of ripples and others issues need to be considered. A useful way to save time and achieve good results is to have an assisted computer design tool. An interactive simulation tool to deal with MR seems to be the right solution. In this paper this kind of simulation application is presented. It allows an easy understanding of the performance degrading or improvement when changing the multirate sampling pattern parameters. The tool was developed using Sysquake, a Matlab-like language with fast execution and powerful graphic facilities. It can be delivered as an executable. In the paper a detailed explanation of MR treatment is also included and the design of four different MR controllers with flexible structure to be adapted to different schemes will also be presented. The Smith's predictor in these MR schemes is also explained, justified and used when time delays appear. Finally some interesting observations achieved using this interactive tool are included. PMID:24583971

  15. A multirate control strategy to the slow sensors problem: an interactive simulation tool for controller assisted design.

    PubMed

    Salt, Julián; Cuenca, Ángel; Palau, Francisco; Dormido, Sebastián

    2014-01-01

    In many control applications, the sensor technology used for the measurement of the variable to be controlled is not able to maintain a restricted sampling period. In this context, the assumption of regular and uniform sampling pattern is questionable. Moreover, if the control action updating can be faster than the output measurement frequency in order to fulfill the proposed closed loop behavior, the solution is usually a multirate controller. There are some known aspects to be careful of when a multirate system (MR) is going to be designed. The proper multiplicity between input-output sampling periods, the proper controller structure, the existence of ripples and others issues need to be considered. A useful way to save time and achieve good results is to have an assisted computer design tool. An interactive simulation tool to deal with MR seems to be the right solution. In this paper this kind of simulation application is presented. It allows an easy understanding of the performance degrading or improvement when changing the multirate sampling pattern parameters. The tool was developed using Sysquake, a Matlab-like language with fast execution and powerful graphic facilities. It can be delivered as an executable. In the paper a detailed explanation of MR treatment is also included and the design of four different MR controllers with flexible structure to be adapted to different schemes will also be presented. The Smith's predictor in these MR schemes is also explained, justified and used when time delays appear. Finally some interesting observations achieved using this interactive tool are included.

  16. Rapid slowing of maximal finger movement rate: fatigue of central motor control?

    PubMed

    Rodrigues, Julian P; Mastaglia, Frank L; Thickbroom, Gary W

    2009-07-01

    Exploring the limits of the motor system can provide insights into the mechanisms underlying performance deterioration, such as force loss during fatiguing isometric muscle contraction, which has been shown to be due to both peripheral and central factors. However, the role of central factors in performance deterioration during dynamic tasks has received little attention. We studied index finger flexion/extension movement performed at maximum voluntary rate (MVR) in ten healthy subjects, measuring movement rate and amplitude over time, and performed measures of peripheral fatigue. During 20 s finger movements at MVR, there was a decline in movement rate beginning at 7-9 s and continuing until the end of the task, reaching 73% of baseline (P < 0.001), while amplitude remained unchanged. Isometric maximum voluntary contraction force and speed of single ballistic flexion and extension finger movements remained unchanged after the task, indicating a lack of peripheral fatigue. The timing of finger flexor and extensor EMG burst activity changed during the task from an alternating flexion/extension pattern to a less effective co-contraction pattern. Overall, these findings suggest a breakdown of motor control rather than failure of muscle force generation during an MVR task, and therefore that the mechanisms underlying the early decline in movement rate are central in origin. PMID:19526228

  17. Phantom hand and wrist movements in upper limb amputees are slow but naturally controlled movements.

    PubMed

    De Graaf, J B; Jarrassé, N; Nicol, C; Touillet, A; Coyle, T; Maynard, L; Martinet, N; Paysant, J

    2016-01-15

    After limb amputation, patients often wake up with a vivid perception of the presence of the missing limb, called "phantom limb". Phantom limbs have mostly been studied with respect to pain sensation. But patients can experience many other phantom sensations, including voluntary movements. The goal of the present study was to quantify phantom movement kinematics and relate these to intact limb kinematics and to the time elapsed since amputation. Six upper arm and two forearm amputees with various delays since amputation (6months to 32years) performed phantom finger, hand and wrist movements at self-chosen comfortable velocities. The kinematics of the phantom movements was indirectly obtained via the intact limb that synchronously mimicked the phantom limb movements, using a Cyberglove® for measuring finger movements and an inertial measurement unit for wrist movements. Results show that the execution of phantom movements is perceived as "natural" but effortful. The types of phantom movements that can be performed are variable between the patients but they could all perform thumb flexion/extension and global hand opening/closure. Finger extension movements appeared to be 24% faster than finger flexion movements. Neither the number of types of phantom movements that can be executed nor the kinematic characteristics were related to the elapsed time since amputation, highlighting the persistence of post-amputation neural adaptation. We hypothesize that the perceived slowness of phantom movements is related to altered proprioceptive feedback that cannot be recalibrated by lack of visual feedback during phantom movement execution.

  18. Turbocharger control system

    SciTech Connect

    Yogo, K.; Nomura, I.

    1987-04-21

    A turbocharger control system is described utilizing a carburetor system. This system includes a carburetor having an air-fuel induction passage, a fuel supply passage for supplying fuel to the air-fuel induction passage, and a turbocharger compressor impeller disposed upstream of a throttle valve and compressing an air-fuel mixture flow delivered to an engine intake manifold. The turbocharger control system comprises: a surge tank provided in the intake manifold; an air control valve including means for controlling an air bleeding amount supplied to the air induction passage in response to changes in pressure of the surge tank. The air control valve further comprises a valve housing having an end wall and including a first, second and third chamber formed therein. A diaphragm has a valve member for controlling communication between the second chamber and the third chamber in response to a pressure existing in the first chamber, a spring biasing the diaphragm in a direction such that the valve member is maintained in a closed position against the pressure in the first chamber. A valve seat plate is in contact with the valve member. The first chamber is connected with the surge tank and the second chamber is connected with the fuel supply passage, and the third chamber is connected with atmosphere. The first chamber is defined by a valve housing of the air control valve, the end wall and the diaphragm and the valve member has a tapered form.

  19. Computer controlled antenna system

    NASA Technical Reports Server (NTRS)

    Raumann, N. A.

    1972-01-01

    The application of small computers using digital techniques for operating the servo and control system of large antennas is discussed. The advantages of the system are described. The techniques were evaluated with a forty foot antenna and the Sigma V computer. Programs have been completed which drive the antenna directly without the need for a servo amplifier, antenna position programmer or a scan generator.

  20. MFTF supervisory control system

    NASA Astrophysics Data System (ADS)

    1980-12-01

    A computerized supervisory control system is being developed for the Mirror Fusion Test Facility. The system includes nine Perkin-Elmer 7/32 and 8/32 computers connected by a block of common core memory (128 kilobytes). The network is a disk designed for reliability and redundancy. If one computer goes down, the local-control micro-processors that it controls are switched to another computer in a matter of seconds. The control consoles permit operators to open and close valves, start or stop pumps, and adjust operating levels. The experiment is controlled by two superconsoles and five satellite consoles. The software, written in PASCAL, contains such subsystems as organizing the computers into a network, operating the consoles and accessing the data base.

  1. Analysis of slow- and fast-α band asymmetry during performance of a saccadic eye movement task: dissociation between memory- and attention-driven systems.

    PubMed

    Sanfim, Antonio; Velasques, Bruna; Machado, Sergio; Arias-Carrión, Oscar; Paes, Flávia; Teixeira, Silmar; Santos, Joana Luz; Bittencourt, Juliana; Basile, Luis F; Cagy, Mauricio; Piedade, Roberto; Sack, Alexander T; Nardi, Antonio Egídio; Ribeiro, Pedro

    2012-01-15

    This study aimed at analyzing the relationship between slow- and fast-alpha asymmetry within frontal cortex and the planning, execution and voluntary control of saccadic eye movements (SEM), and quantitative electroencephalography (qEEG) was recorded using a 20-channel EEG system in 12 healthy participants performing a fixed (i.e., memory-driven) and a random SEM (i.e., stimulus-driven) condition. We find main effects for SEM condition in slow- and fast-alpha asymmetry at electrodes F3-F4, which are located over premotor cortex, specifically a negative asymmetry between conditions. When analyzing electrodes F7-F8, which are located over prefrontal cortex, we found a main effect for condition in slow-alpha asymmetry, particularly a positive asymmetry between conditions. In conclusion, the present approach supports the association of slow- and fast-alpha bands with the planning and preparation of SEM, and the specific role of these sub-bands for both, the attention network and the coordination and integration of sensory information with a (oculo)-motor response.

  2. CNEOST Control Software System

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Zhao, Hai-bin; Xia, Yan; Lu, Hao; Li, Bin

    2016-01-01

    In 2013, CNEOST (China Near Earth Object Survey Telescope) adapted its hardware system for the new CCD camera. Based on the new system architecture, the control software is re-designed and implemented. The software system adopts the messaging mechanism based on the WebSocket protocol, and possesses good flexibility and expansibility. The user interface based on the responsive web design has realized the remote observations under both desktop and mobile devices. The stable operation of the software system has greatly enhanced the operation efficiency while reducing the complexity, and has also made a successful attempt for the future system design of telescope and telescope cloud.

  3. CNEOST Control Software System

    NASA Astrophysics Data System (ADS)

    Wang, X.; Zhao, H. B.; Xia, Y.; Lu, H.; Li, B.

    2015-03-01

    In 2013, CNEOST (China Near Earth Object Survey Telescope) adapted its hardware system for the new CCD camera. Based on the new system architecture, the control software is re-designed and implemented. The software system adopts the message passing mechanism via WebSocket protocol, and improves its flexibility, expansibility, and scalability. The user interface with responsive web design realizes the remote operating under both desktop and mobile devices. The stable operating of software system has greatly enhanced the operation efficiency while reducing the complexity, and has also made a successful attempt for the future system design of telescope and telescope cloud.

  4. Composite fuzzy sliding mode control of nonlinear singularly perturbed systems.

    PubMed

    Nagarale, Ravindrakumar M; Patre, B M

    2014-05-01

    This paper deals with the robust asymptotic stabilization for a class of nonlinear singularly perturbed systems using the fuzzy sliding mode control technique. In the proposed approach the original system is decomposed into two subsystems as slow and fast models by the singularly perturbed method. The composite fuzzy sliding mode controller is designed for stabilizing the full order system by combining separately designed slow and fast fuzzy sliding mode controllers. The two-time scale design approach minimizes the effect of boundary layer system on the full order system. A stability analysis allows us to provide sufficient conditions for the asymptotic stability of the full order closed-loop system. The simulation results show improved system performance of the proposed controller as compared to existing methods. The experimentation results validate the effectiveness of the proposed controller.

  5. Vertical-angle control system in the LLMC

    NASA Astrophysics Data System (ADS)

    Li, Binhua; Yang, Lei; Tie, Qiongxian; Mao, Wei

    2000-10-01

    A control system of the vertical angle transmission used in the Lower Latitude Meridian Circle (LLMC) is described in this paper. The transmission system can change the zenith distance of the tube quickly and precisely. It works in three modes: fast motion, slow motion and lock mode. The fast motion mode and the slow motion mode are that the tube of the instrument is driven by a fast motion stepper motor and a slow motion one separately. The lock mode is running for lock mechanism that is driven by a lock stepper motor. These three motors are controlled together by a single chip microcontroller, which is controlled in turn by a host personal computer. The slow motion mechanism and its rotational step angle are fully discussed because the mechanism is not used before. Then the hardware structure of this control system based on a microcontroller is described. Control process of the system is introduced during a normal observation, which is divided into eleven steps. All the steps are programmed in our control software in C++ and/or in ASM. The C++ control program is set up in the host PC, while the ASM control program is in the microcontroller system. Structures and functions of these rprograms are presented. Some details and skills for programming are discussed in the paper too.

  6. A Neuro-Mechanical Model of a Single Leg Joint Highlighting the Basic Physiological Role of Fast and Slow Muscle Fibres of an Insect Muscle System

    PubMed Central

    Toth, Tibor Istvan; Schmidt, Joachim; Büschges, Ansgar; Daun-Gruhn, Silvia

    2013-01-01

    In legged animals, the muscle system has a dual function: to produce forces and torques necessary to move the limbs in a systematic way, and to maintain the body in a static position. These two functions are performed by the contribution of specialized motor units, i.e. motoneurons driving sets of specialized muscle fibres. With reference to their overall contraction and metabolic properties they are called fast and slow muscle fibres and can be found ubiquitously in skeletal muscles. Both fibre types are active during stepping, but only the slow ones maintain the posture of the body. From these findings, the general hypothesis on a functional segregation between both fibre types and their neuronal control has arisen. Earlier muscle models did not fully take this aspect into account. They either focused on certain aspects of muscular function or were developed to describe specific behaviours only. By contrast, our neuro-mechanical model is more general as it allows functionally to differentiate between static and dynamic aspects of movement control. It does so by including both muscle fibre types and separate motoneuron drives. Our model helps to gain a deeper insight into how the nervous system might combine neuronal control of locomotion and posture. It predicts that (1) positioning the leg at a specific retraction angle in steady state is most likely due to the extent of recruitment of slow muscle fibres and not to the force developed in the individual fibres of the antagonistic muscles; (2) the fast muscle fibres of antagonistic muscles contract alternately during stepping, while co-contraction of the slow muscle fibres takes place during steady state; (3) there are several possible ways of transition between movement and steady state of the leg achieved by varying the time course of recruitment of the fibres in the participating muscles. PMID:24244298

  7. A neuro-mechanical model of a single leg joint highlighting the basic physiological role of fast and slow muscle fibres of an insect muscle system.

    PubMed

    Toth, Tibor Istvan; Schmidt, Joachim; Büschges, Ansgar; Daun-Gruhn, Silvia

    2013-01-01

    In legged animals, the muscle system has a dual function: to produce forces and torques necessary to move the limbs in a systematic way, and to maintain the body in a static position. These two functions are performed by the contribution of specialized motor units, i.e. motoneurons driving sets of specialized muscle fibres. With reference to their overall contraction and metabolic properties they are called fast and slow muscle fibres and can be found ubiquitously in skeletal muscles. Both fibre types are active during stepping, but only the slow ones maintain the posture of the body. From these findings, the general hypothesis on a functional segregation between both fibre types and their neuronal control has arisen. Earlier muscle models did not fully take this aspect into account. They either focused on certain aspects of muscular function or were developed to describe specific behaviours only. By contrast, our neuro-mechanical model is more general as it allows functionally to differentiate between static and dynamic aspects of movement control. It does so by including both muscle fibre types and separate motoneuron drives. Our model helps to gain a deeper insight into how the nervous system might combine neuronal control of locomotion and posture. It predicts that (1) positioning the leg at a specific retraction angle in steady state is most likely due to the extent of recruitment of slow muscle fibres and not to the force developed in the individual fibres of the antagonistic muscles; (2) the fast muscle fibres of antagonistic muscles contract alternately during stepping, while co-contraction of the slow muscle fibres takes place during steady state; (3) there are several possible ways of transition between movement and steady state of the leg achieved by varying the time course of recruitment of the fibres in the participating muscles.

  8. A computational physiology approach to personalized treatment models: the beneficial effects of slow breathing on the human cardiovascular system.

    PubMed

    Fonoberova, Maria; Mezić, Igor; Buckman, Jennifer F; Fonoberov, Vladimir A; Mezić, Adriana; Vaschillo, Evgeny G; Mun, Eun-Young; Vaschillo, Bronya; Bates, Marsha E

    2014-10-01

    Heart rate variability biofeedback intervention involves slow breathing at a rate of ∼6 breaths/min (resonance breathing) to maximize respiratory and baroreflex effects on heart period oscillations. This intervention has wide-ranging clinical benefits and is gaining empirical support as an adjunct therapy for biobehavioral disorders, including asthma and depression. Yet, little is known about the system-level cardiovascular changes that occur during resonance breathing or the extent to which individuals differ in cardiovascular benefit. This study used a computational physiology approach to dynamically model the human cardiovascular system at rest and during resonance breathing. Noninvasive measurements of heart period, beat-to-beat systolic and diastolic blood pressure, and respiration period were obtained from 24 healthy young men and women. A model with respiration as input was parameterized to better understand how the cardiovascular processes that control variability in heart period and blood pressure change from rest to resonance breathing. The cost function used in model calibration corresponded to the difference between the experimental data and model outputs. A good match was observed between the data and model outputs (heart period, blood pressure, and corresponding power spectral densities). Significant improvements in several modeled cardiovascular functions (e.g., blood flow to internal organs, sensitivity of the sympathetic component of the baroreflex, ventricular elastance) were observed during resonance breathing. Individual differences in the magnitude and nature of these dynamic responses suggest that computational physiology may be clinically useful for tailoring heart rate variability biofeedback interventions for the needs of individual patients.

  9. Neural Flight Control System

    NASA Technical Reports Server (NTRS)

    Gundy-Burlet, Karen

    2003-01-01

    The Neural Flight Control System (NFCS) was developed to address the need for control systems that can be produced and tested at lower cost, easily adapted to prototype vehicles and for flight systems that can accommodate damaged control surfaces or changes to aircraft stability and control characteristics resulting from failures or accidents. NFCS utilizes on a neural network-based flight control algorithm which automatically compensates for a broad spectrum of unanticipated damage or failures of an aircraft in flight. Pilot stick and rudder pedal inputs are fed into a reference model which produces pitch, roll and yaw rate commands. The reference model frequencies and gains can be set to provide handling quality characteristics suitable for the aircraft of interest. The rate commands are used in conjunction with estimates of the aircraft s stability and control (S&C) derivatives by a simplified Dynamic Inverse controller to produce virtual elevator, aileron and rudder commands. These virtual surface deflection commands are optimally distributed across the aircraft s available control surfaces using linear programming theory. Sensor data is compared with the reference model rate commands to produce an error signal. A Proportional/Integral (PI) error controller "winds up" on the error signal and adds an augmented command to the reference model output with the effect of zeroing the error signal. In order to provide more consistent handling qualities for the pilot, neural networks learn the behavior of the error controller and add in the augmented command before the integrator winds up. In the case of damage sufficient to affect the handling qualities of the aircraft, an Adaptive Critic is utilized to reduce the reference model frequencies and gains to stay within a flyable envelope of the aircraft.

  10. Well valve control system

    SciTech Connect

    Schwendemann, K.L.; McCracken, O.W.; Mondon, C.G.; Wortham, L.C.

    1987-01-13

    A system is described for controlling well testing through an upper and lower test string with a subsea test tree connected therebetween and latch means to release the upper test string from the subsea test tree comprising: a. first and second selectively programmable microprocessor means; b. means for storing system operating limits in each microprocessor means; c. means for changing the operating limits in response to changes in well conditions; d. means for communicating operating fluid pressure to the subsurface test tree and the latch means; e. solenoid pilot valves controlling the flow of the operating fluid pressure to the subsea test tree and the latch means; f. the first microprocessor means located at a central control console; g. the second microprocessor means located near the solenoid valves; h. means for transmitting signals between the first and second microprocessor means and validating the accuracy of the signals; and i. electronic circuits to control operation of the solenoid valves in response to validated signals.

  11. SERVOMOTOR CONTROL SYSTEM

    DOEpatents

    MacNeille, S.M.

    1958-12-01

    Control systems for automatic positioning of an electric motor operated vapor valve are described which is operable under the severe conditions existing in apparatus for electro-magnetlcally separating isotopes. In general, the system includes a rotor for turning the valve comprising two colls mounted mutually perpendicular to each other and also perpendicular to the magnetic field of the isotope separating apparatus. The coils are furnished with both a-c and d- c current by assoclate control circuitry and a position control is provided for varying the ratlo of the a-c currents in the coils and at the same time, but in an inverse manner, the ratio between the d-c currents in the coils is varied. With the present system the magnitude of the motor torque is constant for all valves of the rotor orientatlon angle.

  12. Lack of Critical Slowing Down Suggests that Financial Meltdowns Are Not Critical Transitions, yet Rising Variability Could Signal Systemic Risk

    PubMed Central

    Hoarau, Quentin

    2016-01-01

    Complex systems inspired analysis suggests a hypothesis that financial meltdowns are abrupt critical transitions that occur when the system reaches a tipping point. Theoretical and empirical studies on climatic and ecological dynamical systems have shown that approach to tipping points is preceded by a generic phenomenon called critical slowing down, i.e. an increasingly slow response of the system to perturbations. Therefore, it has been suggested that critical slowing down may be used as an early warning signal of imminent critical transitions. Whether financial markets exhibit critical slowing down prior to meltdowns remains unclear. Here, our analysis reveals that three major US (Dow Jones Index, S&P 500 and NASDAQ) and two European markets (DAX and FTSE) did not exhibit critical slowing down prior to major financial crashes over the last century. However, all markets showed strong trends of rising variability, quantified by time series variance and spectral function at low frequencies, prior to crashes. These results suggest that financial crashes are not critical transitions that occur in the vicinity of a tipping point. Using a simple model, we argue that financial crashes are likely to be stochastic transitions which can occur even when the system is far away from the tipping point. Specifically, we show that a gradually increasing strength of stochastic perturbations may have caused to abrupt transitions in the financial markets. Broadly, our results highlight the importance of stochastically driven abrupt transitions in real world scenarios. Our study offers rising variability as a precursor of financial meltdowns albeit with a limitation that they may signal false alarms. PMID:26761792

  13. Lack of Critical Slowing Down Suggests that Financial Meltdowns Are Not Critical Transitions, yet Rising Variability Could Signal Systemic Risk.

    PubMed

    Guttal, Vishwesha; Raghavendra, Srinivas; Goel, Nikunj; Hoarau, Quentin

    2016-01-01

    Complex systems inspired analysis suggests a hypothesis that financial meltdowns are abrupt critical transitions that occur when the system reaches a tipping point. Theoretical and empirical studies on climatic and ecological dynamical systems have shown that approach to tipping points is preceded by a generic phenomenon called critical slowing down, i.e. an increasingly slow response of the system to perturbations. Therefore, it has been suggested that critical slowing down may be used as an early warning signal of imminent critical transitions. Whether financial markets exhibit critical slowing down prior to meltdowns remains unclear. Here, our analysis reveals that three major US (Dow Jones Index, S&P 500 and NASDAQ) and two European markets (DAX and FTSE) did not exhibit critical slowing down prior to major financial crashes over the last century. However, all markets showed strong trends of rising variability, quantified by time series variance and spectral function at low frequencies, prior to crashes. These results suggest that financial crashes are not critical transitions that occur in the vicinity of a tipping point. Using a simple model, we argue that financial crashes are likely to be stochastic transitions which can occur even when the system is far away from the tipping point. Specifically, we show that a gradually increasing strength of stochastic perturbations may have caused to abrupt transitions in the financial markets. Broadly, our results highlight the importance of stochastically driven abrupt transitions in real world scenarios. Our study offers rising variability as a precursor of financial meltdowns albeit with a limitation that they may signal false alarms.

  14. Lack of Critical Slowing Down Suggests that Financial Meltdowns Are Not Critical Transitions, yet Rising Variability Could Signal Systemic Risk.

    PubMed

    Guttal, Vishwesha; Raghavendra, Srinivas; Goel, Nikunj; Hoarau, Quentin

    2016-01-01

    Complex systems inspired analysis suggests a hypothesis that financial meltdowns are abrupt critical transitions that occur when the system reaches a tipping point. Theoretical and empirical studies on climatic and ecological dynamical systems have shown that approach to tipping points is preceded by a generic phenomenon called critical slowing down, i.e. an increasingly slow response of the system to perturbations. Therefore, it has been suggested that critical slowing down may be used as an early warning signal of imminent critical transitions. Whether financial markets exhibit critical slowing down prior to meltdowns remains unclear. Here, our analysis reveals that three major US (Dow Jones Index, S&P 500 and NASDAQ) and two European markets (DAX and FTSE) did not exhibit critical slowing down prior to major financial crashes over the last century. However, all markets showed strong trends of rising variability, quantified by time series variance and spectral function at low frequencies, prior to crashes. These results suggest that financial crashes are not critical transitions that occur in the vicinity of a tipping point. Using a simple model, we argue that financial crashes are likely to be stochastic transitions which can occur even when the system is far away from the tipping point. Specifically, we show that a gradually increasing strength of stochastic perturbations may have caused to abrupt transitions in the financial markets. Broadly, our results highlight the importance of stochastically driven abrupt transitions in real world scenarios. Our study offers rising variability as a precursor of financial meltdowns albeit with a limitation that they may signal false alarms. PMID:26761792

  15. Magnetic and gravity anomalies of the slow-spreading system in the Gulf of Aden

    NASA Astrophysics Data System (ADS)

    Nakanishi, M.; Fujimoto, H.; Tamaki, K.; Okino, K.

    2002-12-01

    The spreading system in the Gulf of Aden between Somalia, NE Africa, and Arabia has an ENE-WSW trend and its half spreading rate is about 1.0 cm/yr (e.g., Jestin et al., 1994). Previous studies (e.g., Tamsett and Searle, 1988) provided the general morphology of the spreading system. To reveal detailed morphology and tectonics of the spreading system in the Gulf of Aden, geophysical investigation was conducted along the spreading system between 45°30OE and 50°20OE by the R/V Hakuho-maru from December 2000 to January 2001. Bathymetric data were collected using an echo sounder SEA BEAM 2120 aboard R/V Hakuho-maru. Magnetic and gravity data were collected by towed proton magnetometer and shipboard gravimeter, respectively. The strike of the spreading centers east of 46°30OE is N65°W. The topographic expression of the spreading centers east of N46°30OE is an axial rift valley offset by transform faults siilar to that observed at slow spreading centers in other areas. The bathymetric feature of the spreading centers between 45°50OE and 46°30OE with a strike N80°E is N65°W trending en-echelon basins. The spreading center west of 45°50OE with a strike E-W is bouned by linear ridges and its bathymetric expression is N65°W trending en-echelon ridges. The axial rift valley west of N46°30OE is not offset by any prominent transform faults. Negative magnetic anomaly is dominant over the axial valleys. Its amplitude is about 500 nT and the wavelength is about 30 km. Prominent linear negative magnetic anomaly, which is more than 1000 nT, exists west of N46°30OE. The strike of the linear magnetic anomaly correlates with that of axial valleys west of N46°30OE. Mantle Bouguer gravity anomaly of the spreading centers increases eastward. This trend correlates with the eastward deepening of spreading centers.

  16. Sulfur rate control system

    SciTech Connect

    Bell, T.A.; Mullendore, M.G.; Kleinfeldt, T.E.; Walker, H.G. Jr.

    1993-07-20

    A sulfur rate control system is described for substantially optimizing particulate removal performance of an electrostatic precipitator in fluid communication with a flue carrying combustion products of a fossil fuel, comprising: an electrostatic precipitator having an inlet for receiving a flue gas: means for injecting sulfur trioxide into a flue for mixing with said flue gas at a location preceding entry of said flue gas into said electrostatic precipitator, said injection of sulfur trioxide being varied responsive to a proportional control signal; and, control means coupled to both said flue and said sulfur trioxide injection means for generating said proportional control signal, said control means including (1) means for measuring a sulfur dioxide concentration quantity in said flue gas at a location preceding said sulfur trioxide injection means, (2) means for measuring a flow rate of particulates in said flue gas at a location preceding said sulfur trioxide injection means, and (3) a controller for calculating a ratio between said sulfur dioxide concentration quantity and said flow rate of particulates, said ratio calculating controller having a first input coupled to said sulfur dioxide measuring means and a second input coupled to said particulate flow rate measuring means for generating said proportional control signal in proportion to a difference between a predetermined value and said ratio between said sulfur dioxide concentration quantity and said flow rate of particulates, said ratio controller having an output coupled to said sulfur trioxide injection means for maximizing particulate removal efficiency of said electrostatic precipitator.

  17. Modern tandem control systems

    NASA Astrophysics Data System (ADS)

    Lutz, J. R.; Marsaudon, J. C.

    1993-04-01

    Nowadays, tandem electrostatic accelerators can benefit greatly from the growing possibilities provided by modern control facilities. Controlling an electrostatic accelerator first requires the solution of technological problems raised by the necessity of fitting inside the tank equipment which is highly stressed by the physical environment. Then, these controls can take advantage of new techniques which appear on the market. Present computer technology provides cheap powerful workstations for efficient operator interfacing, and new modular and distributed control concepts have been developed for general use in experimental physics, in data acquisition and in control systems. The general trend towards standardization is now accepted for both hardware and software and this brings benefits to the designer and the user.

  18. Spacelab environmental control system

    NASA Technical Reports Server (NTRS)

    Mitchell, K. L.; Sessions, B. W.; Turner, L. D.

    1976-01-01

    This paper describes the NASA/MSFC thermal control activities performed in support of the European design and development of the Spacelab environmental control system (ECS) and the integration of the ECS with experiments and with the Shuttle Orbiter. Thermal interfaces with the Orbiter are reviewed, including payload bay temperature profiles for the long module and pallet Spacelab configuration for the on-orbit mission phase. Thermal designs and predicted thermal performance are also reviewed for the module air cooling systems and specific experiment interfaces, such as the experiment dedicated heat exchanger and rack cooling.

  19. REACTOR CONTROL SYSTEM

    DOEpatents

    MacNeill, J.H.; Estabrook, J.Y.

    1960-05-10

    A reactor control system including a continuous tape passing through a first coolant passageway, over idler rollers, back through another parallel passageway, and over motor-driven rollers is described. Discrete portions of fuel or poison are carried on two opposed active sections of the tape. Driving the tape in forward or reverse directions causes both active sections to be simultaneously inserted or withdrawn uniformly, tending to maintain a more uniform flux within the reactor. The system is particularly useful in mobile reactors, where reduced inertial resistance to control rod movement is important.

  20. Controlling cogeneration systems

    SciTech Connect

    Petro, J.

    1985-03-01

    The interest in cogeneration and peakshaving systems has grown rapidly as the cost of energy has driven large users to look to other means to supply their electrical demand more economically. Likewise, utilities faced with rising fuel costs and plants operating at near-full capacities are turning to cogenerators to reduce their peak demand loads. The federal government, through the Federal Energy Regulatory Commission, has promoted this situation by enacting rules that encourage cogeneration and remove obstacles that are deterring its use. It appears that in the 1980s, a larger percentage of onsite power installations are being decided on for economic reasons, rather than solely for the need for standby power. A review of recent cogeneration installations verifies this opinion, since they are being installed in places where standby power is not required nor would be considered in normal circumstances. Integral with the basic cogeneration and peak-shaving systems are the switchgear and its associated controls. Controls can range from the relatively basic ones for a manually-operated system to complex ones for a highlyautomated, highly-monitored system. No cookbook solution can determine the exact controls required for either of these types of applications. It remains the responsibility of the system designer to specify controls that are adequate.

  1. Electric turbocompound control system

    DOEpatents

    Algrain, Marcelo C.

    2007-02-13

    Turbocompound systems can be used to affect engine operation using the energy in exhaust gas that is driving the available turbocharger. A first electrical device acts as a generator in response to turbocharger rotation. A second electrical device acts as a motor to put mechanical power into the engine, typically at the crankshaft. Apparatus, systems, steps, and methods are described to control the generator and motor operations to control the amount of power being recovered. This can control engine operation closer to desirable parameters for given engine-related operating conditions compared to actual. The electrical devices can also operate in "reverse," going between motor and generator functions. This permits the electrical device associated with the crankshaft to drive the electrical device associated with the turbocharger as a motor, overcoming deficient engine operating conditions such as associated with turbocharger lag.

  2. Timing control system

    NASA Technical Reports Server (NTRS)

    Wiker, Gordon A. (Inventor); Wells, Jr., George H. (Inventor)

    1989-01-01

    A timing control system is disclosed which is particularly useful in connection with simulated mortar shells. Special circuitry is provided to assure that the shell does not overshoot, but rather detonates early in case of an improper condition; this ensures that ground personnel will not be harmed by a delayed detonation. The system responds to an externally applied frequency control code which is configured to avoid any confusion between different control modes. A premature detonation routine is entered in case an improper time-setting signal is entered, or if the shell is launched before completion of the time-setting sequence. Special provisions are also made for very early launch situations and improper detonator connections. An alternate abort mode is provided to discharge the internal power supply without a detonation in a manner that can be externally monitored, thereby providing a mechanism for non-destructive testing. The abort mode also accelerates the timing function for rapid testing.

  3. Timing Control System

    NASA Technical Reports Server (NTRS)

    Wiker, Gordon A. (Inventor); Wells, George H., Jr. (Inventor)

    1987-01-01

    A timing control system is disclosed which is particularly useful in connection with simulated mortar shells. Special circuitry is provided to assure that the shell does not over shoot, but rather detonates early in case of an improper condition; this ensures that ground personnel will not be harmed by a delayed detonation. The system responds to an externally applied frequency control code which is configured to avoid any confusion between different control modes. A premature detonation routine is entered in case an improper time-setting signal is entered, or if the shell is launched before completion of the time-setting sequence. Special provisions are also made for very early launch situations and improper detonator connections. An alternate abort mode is provided to discharge the internal power supply without a detonation in a manner that can be externally monitored, thereby providing a mechanism for non-destructive testing. The abort mode also accelerates the timing function for rapid testing.

  4. Cryogenic Control System

    SciTech Connect

    Goloborod'ko, S.; /Fermilab

    1989-02-27

    The control system (CS) for the cryogenic arrangement of the DO Liquid Argon Calorimeter consists of a Texas instruments 560/565 Programmable Logical Controller (PLC), two remote bases with Remote Base Controllers and a corresponding set of input/output (I/O) modules, and a PC AST Premium 286 (IBM AT Compatible). The PLC scans a set of inputs and provides a set of outputs based on a ladder logic program and PID control loops. The inputs are logic or analog (current, voltage) signals from equipment status switches or transducers. The outputs are logic or analog (current or voltage) signals for switching solenoids and positioning pneumatic actuators. Programming of the PLC is preformed by using the TISOFT2/560/565 package, which is installed in the PC. The PC communicates to the PLC through a serial RS232 port and provides operator interface to the cryogenic process using Xpresslink software.

  5. Telerobot control system

    NASA Technical Reports Server (NTRS)

    Backes, Paul G. (Inventor); Tso, Kam S. (Inventor)

    1993-01-01

    This invention relates to an operator interface for controlling a telerobot to perform tasks in a poorly modeled environment and/or within unplanned scenarios. The telerobot control system includes a remote robot manipulator linked to an operator interface. The operator interface includes a setup terminal, simulation terminal, and execution terminal for the control of the graphics simulator and local robot actuator as well as the remote robot actuator. These terminals may be combined in a single terminal. Complex tasks are developed from sequential combinations of parameterized task primitives and recorded teleoperations, and are tested by execution on a graphics simulator and/or local robot actuator, together with adjustable time delays. The novel features of this invention include the shared and supervisory control of the remote robot manipulator via operator interface by pretested complex tasks sequences based on sequences of parameterized task primitives combined with further teleoperation and run-time binding of parameters based on task context.

  6. Photovoltaic system controller

    SciTech Connect

    Gerken, K.F.; Sullivan, R.A.

    1989-12-19

    This patent describes a photovoltaic system controller for utilization with a photovoltaic power system including at least a photovoltaic array, a system battery adapted to be charged by the array and a load adapted to be powered by the battery. The controller comprising a microprocessor having an erasable programmable memory. The microprocessor having means to receive input data from the array, the battery and the load. The microprocessor having means to evaluate the input data in relation to at least one predetermined setpoint, the microprocessor in response to the evaluation being adapted to disconnect the battery from the array or to disconnect the load from the battery. The setpoint being adapted to be adjusted to a second setpoint by adjustment means, and the erasable programmable memory being adapted to be changed whereby the evaluation performed by the microprocessor is also changed.

  7. Use of Slow-Scan Television Systems in Telemedicine, Distance Education, Government, and Industrial Applications.

    ERIC Educational Resources Information Center

    Southworth, Glen

    Reducing the costs of teaching by television through slow-scan methods is discussed. Conventional television is costly to use, largely because the wide-band communications circuits required are in limited supply. One technical answer is bandwidth compression to fit an image into less spectrum space. A simpler and far less costly answer is to…

  8. A special pair of phytohormones controls excitability, slow closure, and external stomach formation in the Venus flytrap.

    PubMed

    Escalante-Pérez, María; Krol, Elzbieta; Stange, Annette; Geiger, Dietmar; Al-Rasheid, Khaled A S; Hause, Bettina; Neher, Erwin; Hedrich, Rainer

    2011-09-13

    Venus flytrap's leaves can catch an insect in a fraction of a second. Since the time of Charles Darwin, scientists have struggled to understand the sensory biology and biomechanics of this plant, Dionaea muscipula. Here we show that insect-capture of Dionaea traps is modulated by the phytohormone abscisic acid (ABA) and jasmonates. Water-stressed Dionaea, as well as those exposed to the drought-stress hormone ABA, are less sensitive to mechanical stimulation. In contrast, application of 12-oxo-phytodienoic acid (OPDA), a precursor of the phytohormone jasmonic acid (JA), the methyl ester of JA (Me-JA), and coronatine (COR), the molecular mimic of the isoleucine conjugate of JA (JA-Ile), triggers secretion of digestive enzymes without any preceding mechanical stimulus. Such secretion is accompanied by slow trap closure. Under physiological conditions, insect-capture is associated with Ca(2+) signaling and a rise in OPDA, Apparently, jasmonates bypass hapto-electric processes associated with trap closure. However, ABA does not affect OPDA-dependent gland activity. Therefore, signals for trap movement and secretion seem to involve separate pathways. Jasmonates are systemically active because application to a single trap induces secretion and slow closure not only in the given trap but also in all others. Furthermore, formerly touch-insensitive trap sectors are converted into mechanosensitive ones. These findings demonstrate that prey-catching Dionaea combines plant-specific signaling pathways, involving OPDA and ABA with a rapidly acting trigger, which uses ion channels, action potentials, and Ca(2+) signals.

  9. Use and disuse and the control of acetylcholinesterase activity in fast and slow twitch muscle of rat

    NASA Technical Reports Server (NTRS)

    Dettbarn, W. D.; Groswald, D.; Gupta, R. C.; Misulis, K. E.

    1985-01-01

    The role of acetylcholinesterase (AChE) in neuromuscular transmission is relatively well established, little is known, however, of the mechanisms that regulate its synthesis and control its specific distribution in fast and slow muscle. Innervation plays an important role in the regulation of AChE and elimination of the influence of the nerve by surgical denervation results in a loss of AChE. The influences of the nerve and how they are mediated was investigated. It is suggested that muscle usage and other factors such as materials carried by axonal transport may participate in the regulation of this enzyme. The mechanisms that regulate AChE and its molecular forms in two functionally different forms are studied.

  10. Dynamitron control systems

    NASA Astrophysics Data System (ADS)

    Lisanti, Thomas F.

    2005-12-01

    The Dynamitron control system utilizes the latest personal computer technology in control circuitry and components. Both the DPC-2000 and newer Millennium series of control systems make use of their modular architecture in both software and hardware to keep up with customer and engineering demands. This also allows the main structure of the software to remain constant for the user while software drivers are easily changed as hardware demands are modified and improved. The system is presented as four units; the Remote I/O (Input/Output), Local Analog and Digital I/O, Operator Interface and the Main Computer. The operator is provided with a selection of many informative screen displays. The control program handles all graphic screen displays and the updating of these screens directly; it does not communicate to a display terminal. This adds to the quick response and excellent operator feedback received while operating the accelerator. The CPU also has the ability to store and record all process variable setpoints for each product that will be treated. All process parameters are printed to a report at regular intervals during a process run for record keeping.

  11. Management control system description

    SciTech Connect

    Bence, P. J.

    1990-10-01

    This Management Control System (MCS) description describes the processes used to manage the cost and schedule of work performed by Westinghouse Hanford Company (Westinghouse Hanford) for the US Department of Energy, Richland Operations Office (DOE-RL), Richland, Washington. Westinghouse Hanford will maintain and use formal cost and schedule management control systems, as presented in this document, in performing work for the DOE-RL. This MCS description is a controlled document and will be modified or updated as required. This document must be approved by the DOE-RL; thereafter, any significant change will require DOE-RL concurrence. Westinghouse Hanford is the DOE-RL operations and engineering contractor at the Hanford Site. Activities associated with this contract (DE-AC06-87RL10930) include operating existing plant facilities, managing defined projects and programs, and planning future enhancements. This document is designed to comply with Section I-13 of the contract by providing a description of Westinghouse Hanford's cost and schedule control systems used in managing the above activities. 5 refs., 22 figs., 1 tab.

  12. Use of slow-release plant infochemicals to control aphids: a first investigation in a Belgian wheat field

    PubMed Central

    Zhou, Haibo; Chen, Longsheng; Liu, Yong; Chen, Julian; Francis, Frédéric

    2016-01-01

    Using infochemicals to develop a push–pull strategy in pest control is a potential way to promote sustainable crop production. Infochemicals from plant essential oils were mixed with paraffin oil for slow release in field experiments on wheat to control the population density of cereal aphids and to enhance their natural enemies. (Z)-3-Hexenol (Z3H) attracted Metopolophum dirhodum and Sitobion avenae, the predominant species on wheat in Belgium, and may be a useful infochemical for aphid control by attracting aphids away from field plots. Release of (E)-β-farnesene (EBF) or a garlic extract (GE) led to a significant decrease in the abundance of wheat aphids. The main natural enemies of cereal aphids found were lacewings (47.8%), hoverflies (39.4%), and ladybirds (12.8%). Ladybird abundance varied little before the end of the wheat-growing season. Our results suggest that these chemicals can form the basis of a “push–pull” strategy for aphid biological control, with GE and EBF acting as a pest- and beneficial-pulling stimulus and Z3H for aphid pulling. PMID:27530318

  13. Use of slow-release plant infochemicals to control aphids: a first investigation in a Belgian wheat field.

    PubMed

    Zhou, Haibo; Chen, Longsheng; Liu, Yong; Chen, Julian; Francis, Frédéric

    2016-01-01

    Using infochemicals to develop a push-pull strategy in pest control is a potential way to promote sustainable crop production. Infochemicals from plant essential oils were mixed with paraffin oil for slow release in field experiments on wheat to control the population density of cereal aphids and to enhance their natural enemies. (Z)-3-Hexenol (Z3H) attracted Metopolophum dirhodum and Sitobion avenae, the predominant species on wheat in Belgium, and may be a useful infochemical for aphid control by attracting aphids away from field plots. Release of (E)-β-farnesene (EBF) or a garlic extract (GE) led to a significant decrease in the abundance of wheat aphids. The main natural enemies of cereal aphids found were lacewings (47.8%), hoverflies (39.4%), and ladybirds (12.8%). Ladybird abundance varied little before the end of the wheat-growing season. Our results suggest that these chemicals can form the basis of a "push-pull" strategy for aphid biological control, with GE and EBF acting as a pest- and beneficial-pulling stimulus and Z3H for aphid pulling. PMID:27530318

  14. Use of slow-release plant infochemicals to control aphids: a first investigation in a Belgian wheat field.

    PubMed

    Zhou, Haibo; Chen, Longsheng; Liu, Yong; Chen, Julian; Francis, Frédéric

    2016-08-17

    Using infochemicals to develop a push-pull strategy in pest control is a potential way to promote sustainable crop production. Infochemicals from plant essential oils were mixed with paraffin oil for slow release in field experiments on wheat to control the population density of cereal aphids and to enhance their natural enemies. (Z)-3-Hexenol (Z3H) attracted Metopolophum dirhodum and Sitobion avenae, the predominant species on wheat in Belgium, and may be a useful infochemical for aphid control by attracting aphids away from field plots. Release of (E)-β-farnesene (EBF) or a garlic extract (GE) led to a significant decrease in the abundance of wheat aphids. The main natural enemies of cereal aphids found were lacewings (47.8%), hoverflies (39.4%), and ladybirds (12.8%). Ladybird abundance varied little before the end of the wheat-growing season. Our results suggest that these chemicals can form the basis of a "push-pull" strategy for aphid biological control, with GE and EBF acting as a pest- and beneficial-pulling stimulus and Z3H for aphid pulling.

  15. Slow Movements of Bio-Inspired Limbs

    NASA Astrophysics Data System (ADS)

    Babikian, Sarine; Valero-Cuevas, Francisco J.; Kanso, Eva

    2016-10-01

    Slow and accurate finger and limb movements are essential to daily activities, but the underlying mechanics is relatively unexplored. Here, we develop a mathematical framework to examine slow movements of tendon-driven limbs that are produced by modulating the tendons' stiffness parameters. Slow limb movements are driftless in the sense that movement stops when actuations stop. We demonstrate, in the context of a planar tendon-driven system representing a finger, that the control of stiffness suffices to produce stable and accurate limb postures and quasi-static (slow) transitions among them. We prove, however, that stable postures are achievable only when tendons are pretensioned, i.e., they cannot become slack. Our results further indicate that a non-smoothness in slow movements arises because the precision with which individual stiffnesses need to be altered changes substantially throughout the limb's motion.

  16. Slowed muscle force production and sensory organization deficits contribute to altered postural control strategies in children with developmental coordination disorder.

    PubMed

    Fong, Shirley S M; Ng, Shamay S M; Yiu, Beverley P H L

    2013-09-01

    This study aimed to (1) compare the postural control strategies, sensory organization of balance control, and lower limb muscle performance of children with and without developmental coordination disorder (DCD) and (2) determine the association between postural control strategies, sensory organization parameters and knee muscle performance indices among children with DCD. Fifty-eight DCD-affected children and 46 typically developing children participated in the study. Postural control strategies and sensory organization were evaluated with the sensory organization test (SOT). Knee muscle strength and time to produce maximum muscle torque (at 180°/s) were assessed using an isokinetic machine. Analysis of variance was used to compare the outcome variables between groups, and multiple regression analysis was used to examine the relationships between postural control strategies, sensory organization parameters, and isokinetic indices in children with DCD. The DCD group had significantly lower strategy scores (SOT conditions 5 and 6), lower visual and vestibular ratios, and took a longer time to reach peak torque in the knee flexor muscles than the control group (p>0.05). After accounting for age, sex, and body mass index, the vestibular ratio explained 35.8% of the variance in the strategy score of SOT condition 5 (p<0.05). Moreover, the visual ratio, vestibular ratio, and time to peak torque of the knee flexors were all significant predictors (p<0.05) of the strategy score during SOT condition 6, accounting for 14, 19.7, and 19.8% of its variance, respectively. The children with DCD demonstrated deficits in postural control strategy, sensory organization and prolonged duration of muscle force development. Slowed knee muscle force production combined with poor visual and vestibular functioning may result in greater use of hip strategy by children with DCD in sensory challenging environments.

  17. The UMC control system

    SciTech Connect

    Dallard, K.E.; Adams, R.J.

    1983-05-01

    The control system for the Central Cormorant Underwater Manifold Centre (UMC) is an important step forward in developing the technology of subsea production. It provides reliable, fast operation of over 250 UMC valves and sensors at a distance of 7 kilometres. Included in the paper is an overview of the complete control system with selected components described in more detail. Principal guidelines which shaped the final design configuration are also discussed and problems encountered during design and manufacture are highlighted. The paper stresses the thorough testing that was an essential requirement prior to installation. Finally, general conclusions are drawn about the approach taken which would be of benefit to similar projects in the future.

  18. Vehicle speed control system

    SciTech Connect

    Yoshida, D.; Tanno, T.; Fukunaga, T.

    1987-06-16

    This patent describes a vehicle speed control system for performing vehicle speed control by controlling the displacement of at least one of a hydraulic pump and a hydraulic motor of a hydraulic transmission through an electric servo device, comprising: vehicle speed setting means for generating a voltage signal corresponding to a vehicle speed to be set; compensating means interposed between the vehicle speed setting means and the electric servo device, the compensating means comprising a first delay element; and second delay element having a response characteristic slower than that of the first delay element. A selecting means for judging as to whether a voltage signal changed by the operation of the vehicle speed setting means represents an acceleration command or a deceleration command and for selecting the first delay element when the voltage signal represents an acceleration command and for selecting the second delay element when the voltage signal represents a deceleration command.

  19. Incoherent control of locally controllable quantum systems

    SciTech Connect

    Dong Daoyi; Zhang Chenbin; Rabitz, Herschel; Pechen, Alexander; Tarn, T.-J.

    2008-10-21

    An incoherent control scheme for state control of locally controllable quantum systems is proposed. This scheme includes three steps: (1) amplitude amplification of the initial state by a suitable unitary transformation, (2) projective measurement of the amplified state, and (3) final optimization by a unitary controlled transformation. The first step increases the amplitudes of some desired eigenstates and the corresponding probability of observing these eigenstates, the second step projects, with high probability, the amplified state into a desired eigenstate, and the last step steers this eigenstate into the target state. Within this scheme, two control algorithms are presented for two classes of quantum systems. As an example, the incoherent control scheme is applied to the control of a hydrogen atom by an external field. The results support the suggestion that projective measurements can serve as an effective control and local controllability information can be used to design control laws for quantum systems. Thus, this scheme establishes a subtle connection between control design and controllability analysis of quantum systems and provides an effective engineering approach in controlling quantum systems with partial controllability information.

  20. Turbocharger control system

    SciTech Connect

    Fujawa, C.S.; Masteller, S.B.

    1986-06-10

    A turbocharger control system is described for an engine having a turbocharger with a variable output compressor driven by a variable input turbine, the compressor boosting the pressure of an input manifold of the engine and the turbine being run from the exhaust gases of the engine. The control system consists of: a computing circuit including input circuit means for receiving input signals representative of operational parameters of the engine, programmable memory means for storing predetermined tabular data and sequential and computational instructions, processor means responsive to the memory means for receiving the input signals and generating output signals as a function of the input signals, tabular data, and instructions, and output circuit means for outputing the plurality of output signals, sensor means connected to the engine and the computing circuit for sensing the pressure in the manifold, the temperature of the exhaust gases, the speed of the engine, and position of the throttle, compressor and turbine actuators of the engine and generating signals representative thereof; and actuator means connected to the output circuit means for controlling the position of the actuators in response to predetermined ones of the output signals, respectively; the computing circuit, sensor means, and actuator means defining a turbine control loop for regulating the input of the exhaust gasses to the turbine as a function of the error difference between an optimum manifold pressure of the engine and the actual manifold pressure of the engine; and a compressor control loop for regulating the output of air flow from the compressor as a function of the speed and acceleration of the engine.

  1. A Model for Systemic Control

    NASA Astrophysics Data System (ADS)

    Schwaninger, Markus; Ambroz, Kristjan; Olaya, Camilo

    2006-06-01

    Where should one begin with a design for the self-control of social systems? That is the question addressed by this paper. The traditional concepts of control rest on the feedback loop; control is essential to the attainment of goals. However, the simple feedback loop is insufficient for the modeling of a control system for an organization or other social system. For those systems, which search for multiple goals, it is necessary to design multilevel control systems incorporating the notion of pre-control. This eminently anticipatory function has hardly been considered by past research. Pre-control as understood here is a higher-order control that takes place between different logical levels of a control system. The Model of Systemic Control (MSC), a framework for multilevel control with pre-control relationships, is expounded and illustrated by means of a System Dynamics model.

  2. MIRADAS control system

    NASA Astrophysics Data System (ADS)

    Rosich Minguell, Josefina; Garzón Lopez, Francisco

    2012-09-01

    The Mid-resolution InfRAreD Astronomical Spectrograph (MIRADAS, a near-infrared multi-object echelle spectrograph operating at spectral resolution R=20,000 over the 1-2.5μm bandpass) was selected in 2010 by the Gran Telescopio Canarias (GTC) partnership as the next-generation near-infrared spectrograph for the world's largest optical/infrared telescope, and is being developed by an international consortium. The MIRADAS consortium includes the University of Florida, Universidad de Barcelona, Universidad Complutense de Madrid, Instituto de Astrofísica de Canarias, Institut de Física d'Altes Energies, Institut d'Estudis Espacials de Catalunya and Universidad Nacional Autónoma de México. This paper shows an overview of the MIRADAS control software, which follows the standards defined by the telescope to permit the integration of this software on the GTC Control System (GCS). The MIRADAS Control System is based on a distributed architecture according to a component model where every subsystem is selfcontained. The GCS is a distributed environment written in object oriented C++, which runs components in different computers, using CORBA middleware for communications. Each MIRADAS observing mode, including engineering, monitoring and calibration modes, will have its own predefined sequence, which are executed in the GCS Sequencer. These sequences will have the ability of communicating with other telescope subsystems.

  3. Crawling the Control System

    SciTech Connect

    Theodore Larrieu

    2009-10-01

    Information about accelerator operations and the control system resides in various formats in a variety of places on the lab network. There are operating procedures, technical notes, engineering drawings, and other formal controlled documents. There are programmer references and API documentation generated by tools such as doxygen and javadoc. There are the thousands of electronic records generated by and stored in databases and applications such as electronic logbooks, training materials, wikis, and bulletin boards and the contents of text-based configuration files and log files that can also be valuable sources of information. The obvious way to aggregate all these sources is to index them with a search engine that users can then query from a web browser. Toward this end, the Google "mini" search appliance was selected and implemented because of its low cost and its simple web-based configuration and management. In addition to crawling and indexing electronic documents, the appliance provides an API that has been used to supplement search results with live control system data such as current values of EPICS process variables and graphs of recent data from the archiver.

  4. A special pair of phytohormones controls excitability, slow closure, and external stomach formation in the Venus flytrap

    PubMed Central

    Escalante-Pérez, María; Krol, Elzbieta; Stange, Annette; Geiger, Dietmar; Al-Rasheid, Khaled A. S.; Hause, Bettina; Neher, Erwin; Hedrich, Rainer

    2011-01-01

    Venus flytrap's leaves can catch an insect in a fraction of a second. Since the time of Charles Darwin, scientists have struggled to understand the sensory biology and biomechanics of this plant, Dionaea muscipula. Here we show that insect-capture of Dionaea traps is modulated by the phytohormone abscisic acid (ABA) and jasmonates. Water-stressed Dionaea, as well as those exposed to the drought-stress hormone ABA, are less sensitive to mechanical stimulation. In contrast, application of 12-oxo-phytodienoic acid (OPDA), a precursor of the phytohormone jasmonic acid (JA), the methyl ester of JA (Me-JA), and coronatine (COR), the molecular mimic of the isoleucine conjugate of JA (JA-Ile), triggers secretion of digestive enzymes without any preceding mechanical stimulus. Such secretion is accompanied by slow trap closure. Under physiological conditions, insect-capture is associated with Ca2+ signaling and a rise in OPDA, Apparently, jasmonates bypass hapto-electric processes associated with trap closure. However, ABA does not affect OPDA-dependent gland activity. Therefore, signals for trap movement and secretion seem to involve separate pathways. Jasmonates are systemically active because application to a single trap induces secretion and slow closure not only in the given trap but also in all others. Furthermore, formerly touch-insensitive trap sectors are converted into mechanosensitive ones. These findings demonstrate that prey-catching Dionaea combines plant-specific signaling pathways, involving OPDA and ABA with a rapidly acting trigger, which uses ion channels, action potentials, and Ca2+ signals. PMID:21896747

  5. CONTROL ROOM WITH SPRINKLER SYSTEM CONTROLS, INCLUDING MANUAL CONTROL BOXES ...

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

    CONTROL ROOM WITH SPRINKLER SYSTEM CONTROLS, INCLUDING MANUAL CONTROL BOXES FOR THE VENTILATION SYSTEM AND A PLC SWITCH FOR AUTOMATIC CO (CARBON MONOXIDE) SYSTEM. THE AIR TESTING SYSTEM IS FREE STANDING AND THE FANS ARE COMPUTER-OPERATED. - Alaskan Way Viaduct and Battery Street Tunnel, Seattle, King County, WA

  6. About the stability of phase shifts between slow oscillations around 0.1 Hz in cardiovascular and cerebral systems.

    PubMed

    Pfurtscheller, Gert; Klobassa, Daniela S; Altstätter, Christof; Bauernfeind, Günther; Neuper, Christa

    2011-07-01

    One important feature of the baroreflex loop is its strong preference for oscillations around 0.1 Hz. In this study, we investigated heart rate intervals, arterial blood pressure (BP), and prefrontal oxyhemoglobin changes during 5 min rest and during brisk finger movements in 19 healthy subjects. We analyzed the phase coupling around 0.1 Hz between cardiovascular and (de)oxyhemoglobin oscillations, using the cross-spectral method. The analyses revealed phase shifts for slow oscillations in BP and heart rate intervals between -10° and -118° (BP always leading). These phase shifts increased significantly (p<0.01) in the movement session. The coupling between cardiovascular and oxyhemoglobin oscillations was less clear. Only 12 subjects demonstrated a phase coupling (COH(2) ≥ 0.5) between oxyhemoglobin and BP oscillations. This may be explained by an overwhelming proportion of nonlinearity in cardiovascular and hemodynamic systems. The phase shifts between slow cardiovascular and hemodynamic oscillations are relatively stable subject-specific biometric features and could be of interest for person identification in addition to other biometric data. Slow BP-coupled oscillations in prefrontal oxyhemoglobin changes can seriously impair the detection of mentally induced hemodynamic changes in an optical brain-computer interface, a novel nonmuscular communication system. PMID:21693389

  7. BLTC control system software

    SciTech Connect

    Logan, J.B., Fluor Daniel Hanford

    1997-02-10

    This is a direct revision to Rev. 0 of the BLTC Control System Software. The entire document is being revised and released as HNF-SD-FF-CSWD-025, Rev 1. The changes incorporated by this revision include addition of a feature to automate the sodium drain when removing assemblies from sodium wetted facilities. Other changes eliminate locked in alarms during cold operation and improve the function of the Oxygen Analyzer. See FCN-620498 for further details regarding these changes. Note the change in the document number prefix, in accordance with HNF-MD-003.

  8. Smog control system

    SciTech Connect

    Eichhorn, C.D.

    1992-01-01

    A smog control system is designed comprised of fans or blowers which are located to introduce air into a smog particle destruction chamber operated with laser energy. The smog particles are broken down and the air is passed into a filtering chamber which may adopt the form of a liquid charcoal chamber. The air may be bubbled through the liquid charcoal and the effluent may then be passed into a freshening agent chamber. The air may then pass as an effluent from the freshening agent chamber. A liquid charcoal supply may be connected to the liquid charcoal chamber and the recovered liquid charcoal which has been spent may be reused for other purposes.

  9. Tethered Satellite System control system design

    NASA Technical Reports Server (NTRS)

    Tomlin, Donald D.; Mowery, David K.; Bodley, Carl S.

    1989-01-01

    This paper discusses the control aspects of the Tethered Satellite System mission. The deployer controls system uses length-error and tension-error feedback to control in-plane libration, length, and length rate. The satellite's reaction control system is used to augment tether tension, control rates and attitude about the tether axis, and to damp in-plane and out-of-plane libration. The orbiter's reaction control system is also used to control in-plane and out-of-plane libration. Results of simulations are presented for the flight portion of the Tethered Satellite System mission.

  10. Airflow control system

    DOEpatents

    Motszko, Sean Ronald; McEnaney, Ryan Patrick; Brush, Jeffrey Alan; Zimmermann, Daniel E.

    2007-03-13

    A dual airflow control system for an environment having a first air zone and a second air zone. The system includes a first input device operable to generate a first input signal indicative of a desired airflow to the first zone and a second input device operable to generate a second input signal indicative of a desired airflow to the second zone. First and second flow regulators are configured to regulate airflow to the first and second zones, respectively, such that the first and second regulators selectively provide the airflow to each of the first and second zones based on the first and second input signals. A single actuator is associated with the first and second flow regulators. The actuator is operable to simultaneously actuate the first and second flow regulators based on an input from the first and second input devices to allow the desired airflows to the first and the second zones.

  11. Cathepsin activities and membrane integrity of zebrafish (Danio rerio) oocytes after freezing to -196 degrees C using controlled slow cooling.

    PubMed

    Zhang, T; Rawson, D M; Tosti, L; Carnevali, O

    2008-04-01

    This study investigated enzymatic activity of cathepsins and the membrane integrity of zebrafish (Danio rerio) oocytes after freezing to -196 degrees C using controlled slow cooling. Stage III oocytes (>0.5mm), obtained through dissection of anaesthetised female fish and desegregation of ovarian cumulus, were exposed to 2M methanol or 2M DMSO (both prepared in Hank's medium) for 30min at 22 degrees C before being loaded into 0.5ml plastic straws and placed into a programmable cooler. After controlled slow freezing, samples were plunged into liquid nitrogen (LN) and held for at least 10min, and thawed by immersing straws into a 27 degrees C water bath for 10s. Thawed oocytes were washed twice in Hank's medium. Cathepsin activity and membrane integrity of oocytes were assessed both after cryoprotectant treatment at 22 degrees C and after freezing in LN. Cathepsin B and L colorimetric analyses were performed using substrates Z-Arg-ArgNNap and Z-Phe-Arg-4MbetaNA-HCl, respectively, and 2-naphthylamine and 4-methoxy-2-naphthylamine were used as standards. Cathepsin D activity was performed by analysing the level of hydrolytic action on haemoglobin. Oocytes membrane integrity was assessed using 0.2% Trypan blue staining for 5min. Analysis of cathepsin activities showed that whilst the activity of cathepsin B and D was not affected by 2M DMSO treatment, their activity was lowered when treated with 2M methanol. Following freezing to -196 degrees C, the activity of all cathepsins (B, D and L) was significantly decreased in both 2M DMSO and 2M methanol. Trypan blue staining showed that 63.0+/-11.3% and 72.7+/-5.2% oocytes membrane stayed intact after DMSO and methanol treatment for 30min at 22 degrees C, respectively, whilst 14.9+/-2.6% and 1.4+/-0.8% stayed intact after freezing in DMSO and methanol to -196 degrees C. The results indicate that cryoprotectant treatment and freezing modified the activities of lysosomal enzymes involved in oocyte maturation and yolk

  12. Slow growth of the Rayleigh-Plateau instability in aqueous two phase systems

    PubMed Central

    Geschiere, Sam D.; Ziemecka, Iwona; van Steijn, Volkert; Koper, Ger J. M.; Esch, Jan H. van; Kreutzer, Michiel T.

    2012-01-01

    This paper studies the Rayleigh-Plateau instability for co-flowing immiscible aqueous polymer solutions in a microfluidic channel. Careful vibration-free experiments with controlled actuation of the flow allowed direct measurement of the growth rate of this instability. Experiments for the well-known aqueous two phase system (ATPS, or aqueous biphasic systems) of dextran and polyethylene glycol solutions exhibited a growth rate of 1 s−1, which was more than an order of magnitude slower than an analogous experiment with two immiscible Newtonian fluids with viscosities and interfacial tension that closely matched the ATPS experiment. Viscoelastic effects and adhesion to the walls were ruled out as explanations for the observed behavior. The results are remarkable because all current theory suggests that such dilute polymer solutions should break up faster, not slower, than the analogous Newtonian case. Microfluidic uses of aqueous two phase systems include separation of labile biomolecules but have hitherto be limited because of the difficulty in making droplets. The results of this work teach how to design devices for biological microfluidic ATPS platforms. PMID:22536307

  13. Slow slip and the transition from fast to slow fronts in the rupture of frictional interfaces.

    PubMed

    Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Scheibert, Julien; Thøgersen, Kjetil; Amundsen, David Skålid; Malthe-Sørenssen, Anders

    2014-06-17

    The failure of the population of microjunctions forming the frictional interface between two solids is central to fields ranging from biomechanics to seismology. This failure is mediated by the propagation along the interface of various types of rupture fronts, covering a wide range of velocities. Among them are the so-called slow fronts, which are recently discovered fronts much slower than the materials' sound speeds. Despite intense modeling activity, the mechanisms underlying slow fronts remain elusive. Here, we introduce a multiscale model capable of reproducing both the transition from fast to slow fronts in a single rupture event and the short-time slip dynamics observed in recent experiments. We identify slow slip immediately following the arrest of a fast front as a phenomenon sufficient for the front to propagate further at a much slower pace. Whether slow fronts are actually observed is controlled both by the interfacial stresses and by the width of the local distribution of forces among microjunctions. Our results show that slow fronts are qualitatively different from faster fronts. Because the transition from fast to slow fronts is potentially as generic as slow slip, we anticipate that it might occur in the wide range of systems in which slow slip has been reported, including seismic faults. PMID:24889640

  14. Slow Scan Telemedicine

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Originally developed under contract for NASA by Ball Bros. Research Corporation for acquiring visual information from lunar and planetary spacecraft, system uses standard closed circuit camera connected to a device called a scan converter, which slows the stream of images to match an audio circuit, such as a telephone line. Transmitted to its destination, the image is reconverted by another scan converter and displayed on a monitor. In addition to assist scans, technique allows transmission of x-rays, nuclear scans, ultrasonic imagery, thermograms, electrocardiograms or live views of patient. Also allows conferencing and consultation among medical centers, general practitioners, specialists and disease control centers. Commercialized by Colorado Video, Inc., major employment is in business and industry for teleconferencing, cable TV news, transmission of scientific/engineering data, security, information retrieval, insurance claim adjustment, instructional programs, and remote viewing of advertising layouts, real estate, construction sites or products.

  15. KEK-IMSS Slow Positron Facility

    NASA Astrophysics Data System (ADS)

    Hyodo, T.; Wada, K.; Yagishita, A.; Kosuge, T.; Saito, Y.; Kurihara, T.; Kikuchi, T.; Shirakawa, A.; Sanami, T.; Ikeda, M.; Ohsawa, S.; Kakihara, K.; Shidara, T.

    2011-12-01

    The Slow Positron Facility at the Institute of Material Structure Science (IMSS) of High Energy Accelerator Research Organization (KEK) is a user dedicated facility with an energy tunable (0.1 - 35 keV) slow positron beam produced by a dedicated 55MeV linac. The present beam line branches have been used for the positronium time-of-flight (Ps-TOF) measurements, the transmission positron microscope (TPM) and the photo-detachment of Ps negative ions (Ps-). During the year 2010, a reflection high-energy positron diffraction (RHEPD) measurement station is going to be installed. The slow positron generator (converter/ moderator) system will be modified to get a higher slow positron intensity, and a new user-friendly beam line power-supply control and vacuum monitoring system is being developed. Another plan for this year is the transfer of a 22Na-based slow positron beam from RIKEN. This machine will be used for the continuous slow positron beam applications and for the orientation training of those who are interested in beginning researches with a slow positron beam.

  16. Cooperative Voltage Control Method by Power Factor Control of PV Systems and LRT

    NASA Astrophysics Data System (ADS)

    Kawasaki, Shoji; Kanemoto, Noriaki; Taoka, Hisao; Matsuki, Junya; Hayashi, Yasuhiro

    Recently, the number of system interconnection of the renewable energy sources (RES) such as the photovoltaic generation (PV) and wind power generation is increasing drastically, and there is in danger of changing the voltages in a distribution system by the precipitous output variation of RESs. In this study, the authors propose one voltage control method of the distribution system by the power factor control of plural PV systems in consideration of cooperation with the load ratio control transformer (LRT) of laggard control response installed beforehand in the distribution system. In the proposed method, the slow voltage variation is controlled by LRT, and the steep voltage variation uncontrollable by LRT is controlled by plural PV systems, as a result, all the node voltages are controllable within the proper limits. In order to verify the validity of the proposed method, the numerical calculations are carried out by using an analytical model of distribution system which interconnected PV systems.

  17. Control of Fossil-Fuel Particulate Black Carbon and Organic Matter, the Most Effective Method of Slowing Global Warming

    NASA Astrophysics Data System (ADS)

    Jacobson, M. Z.

    2001-12-01

    Under the 1997 Kyoto Protocol, no control of black carbon (BC) was considered. Here, it is found, through simulations in which seven new particles feedbacks to climate are identified, that any emission reduction of fossil-fuel (f.f.) particulate BC plus associated organic matter (OM) will slow global warming more than will any emission reduction of CO2 or CH4 for a definite time period. When all f.f. BC+OM and anthropogenic CO2 and CH4 emissions are eliminated together, that period is 20-90 years. It is also found that historical net global warming can be attributed roughly to greenhouse-gas plus f.f. BC+OM warming minus anthropogenic sulfate cooling. Eliminating all f.f. BC+OM could eliminate more than 40 percent of such net warming within three years if no other changes occurred. Reducing CO2 emissions by a third would have the same effect, but after 50-200 years. Finally, diesel cars warm climate more than do equivalent gasoline cars; thus, fuel- and carbon-tax laws that favor diesel promote global warming.

  18. Slow Pseudotachylites

    NASA Astrophysics Data System (ADS)

    Pec, M.; Stunitz, H.; Heilbronner, R.

    2011-12-01

    Tectonic pseudotachylites as solidified, friction induced melts are believed to be the only unequivocal evidence for paleo-earthquakes. Earthquakes occur when fast slip (1 - 3 m/s) propagates on a localized failure plane and are always related with stress drops. The mechanical work expended, together with the rock composition and the efficiency of thermal dissipation, controls whether the temperature increase on a localized slip plane will be sufficient to induce fusion. We report the formation of pseudotachylites during steady-state plastic flow at slow bulk shear strain rates (~10^-3 to ~10^-5 /s corresponding to slip rates of ~10^-6 to ~10^-8 m/s) in experiments performed at high confining pressures (500 MPa) and temperatures (300°C) corresponding to a depth of ~15 km. Crushed granitioid rock (Verzasca gneiss), grain size ≤ 200 μm, with 0.2 wt% water added was placed between alumina forcing blocks pre-cut at 45°, weld-sealed in platinum jackets and deformed with a constant displacement rate in a solid medium deformation apparatus (modified Griggs rig). Microstructural observations show the development of a S-C-C' fabric with C' slip zones being the dominant feature. Strain hardening in the beginning of the experiment is accompanied with compaction which is achieved by closely spaced R1 shears pervasively cutting the whole gouge zone and containing fine-grained material (d < 100 nm). The peak strength is achieved at γ ~ 2 at shear stress levels of 1350-1450 MPa when compaction ceases. During further deformation, large local displacements (γ > 10) are localized in less densely spaced, ~10 μm thick C'-C slip zones which develop predominantly in feldspars and often contain micas. In TEM, they appear to have no porosity consisting of partly amorphous material and small crystalline fragments with the average grain size of 20 nm. After the peak strength, the samples weaken by ~20 MPa and continue deforming up to γ ~ 4 without any stress drops. Strain

  19. Optically controlled welding system

    NASA Technical Reports Server (NTRS)

    Gordon, Stephen S. (Inventor)

    1988-01-01

    An optically controlled welding system wherein a welding torch having through-the-torch viewing capabilities is provided with an optical beam splitter to create a transmitted view and a reflective view of a welding operation. These views are converted to digital signals which are then processed and utilized by a computerized robotic welder to make the welding torch responsive thereto. Other features include an actively cooled electrode holder which minimizes a blocked portion of the view by virtue of being constructed of a single spoke or arm, and a weld pool contour detector comprising a laser beam directed onto the weld pool with the position of specular radiation reflected therefrom, being characteristic of a penetrated or unpenetrated condition of the weld pool.

  20. Optically controlled welding system

    NASA Technical Reports Server (NTRS)

    Gordon, Stephen S. (Inventor)

    1989-01-01

    An optically controlled welding system (10) wherein a welding torch (12) having through-the-torch viewing capabilities is provided with an optical beam splitter (56) to create a transmitted view and a reflective view of a welding operation. These views are converted to digital signals which are then processed and utilized by a computerized robotic welder (15) to make the welding torch responsive thereto. Other features includes an actively cooled electrode holder (26) which minimizes a blocked portion of the view by virtue of being constructed of a single spoke or arm (28) and a weld pool contour detector (14) comprising a laser beam directed onto the weld pool with the position of specular radiation reflected therefrom being characteristic of a penetrated or unpenetrated condition of the weld pool.

  1. Pollution control system

    SciTech Connect

    Voliva, B.H.; Bernstein, I.B.

    1984-09-25

    A pollution control system is disclosed wherein condensable pollutants are removed from a high-temperature gas stream by counterflow contact in a vertical tower with downwardly flowing, relatively cool absorbent oil. The absorbent is at a sufficiently low temperature so as to rapidly condense a portion of the pollutants in order to form a fog of fine droplets of pollutant entrained by the gas stream, which fog is incapable of being absorbed by the absorbent. The remainder of the condensable pollutants is removed by downwardly flowing absorbent oil, and the gas and entrained fog are directed from the tower to gas/droplet separation means, such as an electrostatic precipitator. The fog is thereby separated from the gas and substantially pollutant-free gas is discharged to the atmosphere.

  2. Generic device controller for accelerator control systems

    SciTech Connect

    Mariotti, R.; Buxton, W.; Frankel, R.; Hoff, L.

    1987-01-01

    A new distributed intelligence control system has become operational at the AGS for transport, injection, and acceleration of heavy ions. A brief description of the functionality of the physical devices making up the system is given. An attempt has been made to integrate the devices for accelerator specific interfacing into a standard microprocessor system, namely, the Universal Device Controller (UDC). The main goals for such a generic device controller are to provide: local computing power; flexibility to configure; and real time event handling. The UDC assemblies and software are described. (LEW)

  3. On Restructurable Control System Theory

    NASA Technical Reports Server (NTRS)

    Athans, M.

    1983-01-01

    The state of stochastic system and control theory as it impacts restructurable control issues is addressed. The multivariable characteristics of the control problem are addressed. The failure detection/identification problem is discussed as a multi-hypothesis testing problem. Control strategy reconfiguration, static multivariable controls, static failure hypothesis testing, dynamic multivariable controls, fault-tolerant control theory, dynamic hypothesis testing, generalized likelihood ratio (GLR) methods, and adaptive control are discussed.

  4. Turbocharger control system

    SciTech Connect

    Kawabata, Y.

    1987-02-17

    This patent describes a turbocharger control system utilized in an internal combustion engine having a turbocharger turbine with a downstream passage, a combustion chamber, an exhaust treatment device, an actuator, a link mechanism connected to the actuator, a compressor, and a throttle valve. The engine also has an engine intake manifold, air flow passage means leading from the compressor to the throttle valve and an exhaust passage leading from the combustion chamber. The system comprises: bypass passage means connecting the exhaust passage leading from the combustion chamber to the turbocharger turbine with the downstream passage of the turbine so as to connect the combustion chamber directly to the exhaust treatment device around the turbine; a waste gate valve connected to the actuator by means of the link mechanism so as to close the bypass passage wherein the actuator comprises a first chamber continuously communicating with atmospheric pressure, a second chamber connected to the air flow passage means leading from the compressor to the throttle valve, and a third chamber connected to the engine intake manifold; first spring means interposed in the first chamber for biasing the waste gate valve toward a closed position; and second spring means interposed in the third chamber and having a stronger spring load characteristic than the first spring means for biasing the waste gate valve towards an opened position.

  5. Division 1137 property control system

    SciTech Connect

    Pastor, D.J.

    1982-01-01

    An automated data processing property control system was developed by Mobile and Remote Range Division 1137. This report describes the operation of the system and examines ways of using it in operational planning and control.

  6. Environment control system

    DOEpatents

    Sammarone, Dino G.

    1978-01-01

    A system for controlling the environment of an enclosed area in nuclear reactor installations. The system permits the changing of the environment from nitrogen to air, or from air to nitrogen, without the release of any radioactivity or process gas to the outside atmosphere. In changing from a nitrogen to an air environment, oxygen is inserted into the enclosed area at the same rate which the nitrogen-oxygen gas mixture is removed from the enclosed area. The nitrogen-oxygen gas mixture removed from the enclosed area is mixed with hydrogen, the hydrogen recombining with the oxygen present in the gas to form water. The water is then removed from the system and, if it contains any radioactive products, can be utilized to form concrete, which can then be transferred to a licensed burial site. The process gas is purified further by stripping it of carbon dioxide and then distilling it to remove any xenon, krypton, and other fission or non-condensable gases. The pure nitrogen is stored as either a cryogenic liquid or a gas. In changing from an air to nitrogen environment, the gas is removed from the enclosed area, mixed with hydrogen to remove the oxygen present, dried, passed through adsorption beds to remove any fission gases, and reinserted into the enclosed area. Additionally, the nitrogen stored during the nitrogen to air change, is inserted into the enclosed area, the nitrogen from both sources being inserted into the enclosed area at the same rate as the removal of the gas from the containment area. As designed, the amount of nitrogen stored during the nitrogen to air change substantially equals that required to replace oxygen removed during an air to nitrogen change.

  7. NSLS control system upgrade status

    SciTech Connect

    Smith, J.; Ramamoorthy, S.; Tang, Y.; Flannigan, J.; Sathe, S.; Keane, J.; Krinsky, S.

    1993-07-01

    The NSLS control system initially installed in 1978 has undergone several modifications but the basic system architecture remained relatively unchanged. The need for faster response, increased reliability and better diagnostics made the control system upgrade a priority. Since the NSLS runs continuously, major changes to the control system are difficult. The upgrade plan had to allow continuous incremental changes to the control system without having any detrimental effect on operations. The plan had to provide for immediate improvement in a few key areas, such as data access rates, and be complete in a short time. At present, most accelerator operations utilize the upgraded control system.

  8. Environmental control system

    SciTech Connect

    Foley, P. N.; Turbard, A. M.

    1985-05-21

    An environmental control system for controlling the environmental conditions in a swimming pool hall 1 comprises a heat pump having a multi-section evaporator 8, compressors 23a and 23b and a multi-section condensor 18. In the day-time, the dry bulb temperature in the pool hall is maintained by circulating space air through a duct 3 to the evaporator 8 where the latent heat is recovered from the moisture laden air. This heat is rejected via the condensor 18 either to the now drier recirculated air or fresh air from an inlet 13 or a mixture of air from the two sources. In a night mode of operation, circulation of space air through the duct 3 is prevented and instead it is recirculated via a direct recirculation duct 53 and is heated by the condensor 18, the heat used to do this being recovered from outside air inducted into the evaporator 8 via an inlet 50. In order to prevent frosting of the evaporator when the outside air temperature is too low, a damper 52 may be opened to allow some space air to pass through the evaporator 8 and raise its temperature. In order to increase the heat recovery capability of the compressor, storage tank 56 is used to collect waste water from showers etc. and also from backwash through the pool water filter and when this tank is full, its water is chilled by means of a water chiller 15 in parallel with the evaporator and the heat so recovered is rejected to the re-circulating space air by means of the condensor 18.

  9. Antibacterial Surgical Silk Sutures Using a High-Performance Slow-Release Carrier Coating System.

    PubMed

    Chen, Xiaojie; Hou, Dandan; Wang, Lu; Zhang, Qian; Zou, Jiahan; Sun, Gang

    2015-10-14

    Sutures are a vital part for surgical operation, and suture-associated surgical site infections are an important issue of postoperative care. Antibacterial sutures have been proved to reduce challenging complications caused by bacterial infections. In recent decades, triclosan-free sutures have been on their way to commercialization. Alternative antibacterial substances are becoming relevant to processing surgical suture materials. Most of the antibacterial substances are loaded directly on sutures by dipping or coating methods. The aim of this study was to optimize novel antibacterial braided silk sutures based on levofloxacin hydrochloride and poly(ε-caprolactone) by two different processing sequences, to achieve suture materials with slow-release antibacterial efficacy and ideal physical and handling properties. Silk strands were processed into sutures on a circular braiding machine, and antibacterial treatment was introduced alternatively before or after braiding by two-dipping-two-rolling method (M1 group and M2 group). The antibacterial activity and durability against Staphylococcus aureus and Escherichia coli were tested. Drug release profiles were measured in phosphate buffer with different pH values, and release kinetics model was built to analyze the sustained drug release mechanism between the interface of biomaterials and the in vitro aqueous environment. Knot-pull tensile strength, thread-to-thread friction, and bending stiffness were determined to evaluate physical and handling properties of sutures. All coated sutures showed continuous antibacterial efficacy and slow drug release features for more than 5 days. Besides, treated sutures fulfilled U.S. Pharmacopoeia required knot-pull tensile strength. The thread-to-thread friction and bending stiffness for the M1 group changed slightly when compared with those of uncoated ones. However, physical and handling characteristics of the M2 group tend to approach those of monofilament ones. The novel suture

  10. Antibacterial Surgical Silk Sutures Using a High-Performance Slow-Release Carrier Coating System.

    PubMed

    Chen, Xiaojie; Hou, Dandan; Wang, Lu; Zhang, Qian; Zou, Jiahan; Sun, Gang

    2015-10-14

    Sutures are a vital part for surgical operation, and suture-associated surgical site infections are an important issue of postoperative care. Antibacterial sutures have been proved to reduce challenging complications caused by bacterial infections. In recent decades, triclosan-free sutures have been on their way to commercialization. Alternative antibacterial substances are becoming relevant to processing surgical suture materials. Most of the antibacterial substances are loaded directly on sutures by dipping or coating methods. The aim of this study was to optimize novel antibacterial braided silk sutures based on levofloxacin hydrochloride and poly(ε-caprolactone) by two different processing sequences, to achieve suture materials with slow-release antibacterial efficacy and ideal physical and handling properties. Silk strands were processed into sutures on a circular braiding machine, and antibacterial treatment was introduced alternatively before or after braiding by two-dipping-two-rolling method (M1 group and M2 group). The antibacterial activity and durability against Staphylococcus aureus and Escherichia coli were tested. Drug release profiles were measured in phosphate buffer with different pH values, and release kinetics model was built to analyze the sustained drug release mechanism between the interface of biomaterials and the in vitro aqueous environment. Knot-pull tensile strength, thread-to-thread friction, and bending stiffness were determined to evaluate physical and handling properties of sutures. All coated sutures showed continuous antibacterial efficacy and slow drug release features for more than 5 days. Besides, treated sutures fulfilled U.S. Pharmacopoeia required knot-pull tensile strength. The thread-to-thread friction and bending stiffness for the M1 group changed slightly when compared with those of uncoated ones. However, physical and handling characteristics of the M2 group tend to approach those of monofilament ones. The novel suture

  11. Different neural manifestations of two slow frequency bands in resting functional magnetic resonance imaging: a systemic survey at regional, interregional, and network levels.

    PubMed

    Xue, Shao-Wei; Li, Da; Weng, Xu-Chu; Northoff, Georg; Li, Dian-Wen

    2014-05-01

    Temporal and spectral perspectives are two fundamental facets in deciphering fluctuating signals. In resting state, the dynamics of blood oxygen level-dependent (BOLD) signals recorded by functional magnetic resonance imaging (fMRI) have been proven to be strikingly informative (0.01-0.1 Hz). The distinction between slow-4 (0.027-0.073 Hz) and slow-5 (0.01-0.027 Hz) has been described, but the pertinent data have never been systematically investigated. This study used fMRI to measure spontaneous brain activity and to explore the different spectral characteristics of slow-4 and slow-5 at regional, interregional, and network levels, respectively assessed by regional homogeneity (ReHo) and mean amplitude of low-frequency fluctuation (mALFF), functional connectivity (FC) patterns, and graph theory. Results of paired t-tests supported/replicated recent research dividing low-frequency BOLD fluctuation into slow-4 and slow-5 for ReHo and mALFF. Interregional analyses showed that for brain regions reaching statistical significance, FC strengths at slow-4 were always weaker than those at slow-5. Community detection algorithm was applied to FC data and unveiled two modules sensitive to frequency effects: one comprised sensorimotor structure, and the other encompassed limbic/paralimbic system. Graph theoretical analysis verified that slow-4 and slow-5 differed in local segregation measures. Although the manifestation of frequency differences seemed complicated, the associated brain regions can be grossly categorized into limbic/paralimbic, midline, and sensorimotor systems. Our results suggest that future resting fMRI research addressing the three above systems either from neuropsychiatric or psychological perspectives may consider using spectrum-specific analytical strategies. PMID:24456196

  12. Aircraft control system

    NASA Technical Reports Server (NTRS)

    Kendall, Greg T. (Inventor); Morgan, Walter R. (Inventor)

    2010-01-01

    A span-loaded, highly flexible flying wing, having horizontal control surfaces mounted aft of the wing on extended beams to form local pitch-control devices. Each of five spanwise wing segments of the wing has one or more motors and photovoltaic arrays, and produces its own lift independent of the other wing segments, to minimize inter-segment loads. Wing dihedral is controlled by separately controlling the local pitch-control devices consisting of a control surface on a boom, such that inboard and outboard wing segment pitch changes relative to each other, and thus relative inboard and outboard lift is varied.

  13. High morphological variation of vestibular system accompanies slow and infrequent locomotion in three-toed sloths.

    PubMed

    Billet, Guillaume; Hautier, Lionel; Asher, Robert J; Schwarz, Cathrin; Crumpton, Nick; Martin, Thomas; Ruf, Irina

    2012-10-01

    The semicircular canals (SCs), part of the vestibular apparatus of the inner ear, are directly involved in the detection of angular motion of the head for maintaining balance, and exhibit adaptive patterns for locomotor behaviour. Consequently, they are generally believed to show low levels of intraspecific morphological variation, but few studies have investigated this assumption. On the basis of high-resolution computed tomography, we present here, to our knowledge, the first comprehensive study of the pattern of variation of the inner ear with a focus on Xenarthra. Our study demonstrates that extant three-toed sloths show a high level of morphological variation of the bony labyrinth of the inner ear. Especially, the variation in shape, relative size and angles of their SCs greatly differ from those of other, faster-moving taxa within Xenarthra and Placentalia in general. The unique pattern of variation in three-toed sloths suggests that a release of selection and/or constraints on their organ of balance is associated with the observed wide range of phenotypes. This release is coincident with their slow and infrequent locomotion and may be related, among other possible factors, to a reduced functional demand for a precise sensitivity to movement.

  14. High morphological variation of vestibular system accompanies slow and infrequent locomotion in three-toed sloths.

    PubMed

    Billet, Guillaume; Hautier, Lionel; Asher, Robert J; Schwarz, Cathrin; Crumpton, Nick; Martin, Thomas; Ruf, Irina

    2012-10-01

    The semicircular canals (SCs), part of the vestibular apparatus of the inner ear, are directly involved in the detection of angular motion of the head for maintaining balance, and exhibit adaptive patterns for locomotor behaviour. Consequently, they are generally believed to show low levels of intraspecific morphological variation, but few studies have investigated this assumption. On the basis of high-resolution computed tomography, we present here, to our knowledge, the first comprehensive study of the pattern of variation of the inner ear with a focus on Xenarthra. Our study demonstrates that extant three-toed sloths show a high level of morphological variation of the bony labyrinth of the inner ear. Especially, the variation in shape, relative size and angles of their SCs greatly differ from those of other, faster-moving taxa within Xenarthra and Placentalia in general. The unique pattern of variation in three-toed sloths suggests that a release of selection and/or constraints on their organ of balance is associated with the observed wide range of phenotypes. This release is coincident with their slow and infrequent locomotion and may be related, among other possible factors, to a reduced functional demand for a precise sensitivity to movement. PMID:22859594

  15. Evaluation of a soil incubation method to characterize nitrogen release patterns of slow- and controlled-release fertilizers.

    PubMed

    Medina, L Carolina; Sartain, Jerry B; Obreza, Thomas A; Hall, William L; Thiex, Nancy J

    2014-01-01

    Several technologies have been proposed to characterize the nutrient release patterns of slow-release fertilizers (SRF) and controlled-release fertilizers (CRF) during the last few decades. These technologies have been developed mainly by manufacturers, and are product-specific, based on the regulation and analysis of each SRF and CRF product. Despite previous efforts to characterize SRF and CRF materials, no standardized, validated method exists to assess their nutrient release patterns. However, the increased production and distribution of these materials in specialty and nonspecialty markets requires an appropriate method to verify product claims and material performance. A soil incubation column leaching procedure was evaluated to determine its suitability as a standard method to estimate nitrogen (N) release patterns of SRFs and CRFs during 180 days. The influence of three soil/sand ratios, three incubation temperatures, and four soils on method behavior was assessed using five SRFs and three CRFs. In general, the highest soil/sand ratio increased the N release rate of all materials, but this effect was more marked for the SRFs. Temperature had the greatest influence on N release rates. For CRFs, the initial N release rates and the percentage N released/day increased as temperature increased. For SRFs, raising the temperature from 25 to 35 degreesC increased initial N release rate and the total cumulative N released, and almost doubled the percentage released/day. The percentage N released/day from all products generally increased as the texture of the soil changed from sandy to loamy (lowa>California>Pennsylvania>Florida). The soil incubation technique was demonstrated to be robust and reliable for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and variations in soil/sand ratio, temperature, and soil had little effect on the results. PMID:25051610

  16. Evaluation of a soil incubation method to characterize nitrogen release patterns of slow- and controlled-release fertilizers.

    PubMed

    Medina, L Carolina; Sartain, Jerry B; Obreza, Thomas A; Hall, William L; Thiex, Nancy J

    2014-01-01

    Several technologies have been proposed to characterize the nutrient release patterns of slow-release fertilizers (SRF) and controlled-release fertilizers (CRF) during the last few decades. These technologies have been developed mainly by manufacturers, and are product-specific, based on the regulation and analysis of each SRF and CRF product. Despite previous efforts to characterize SRF and CRF materials, no standardized, validated method exists to assess their nutrient release patterns. However, the increased production and distribution of these materials in specialty and nonspecialty markets requires an appropriate method to verify product claims and material performance. A soil incubation column leaching procedure was evaluated to determine its suitability as a standard method to estimate nitrogen (N) release patterns of SRFs and CRFs during 180 days. The influence of three soil/sand ratios, three incubation temperatures, and four soils on method behavior was assessed using five SRFs and three CRFs. In general, the highest soil/sand ratio increased the N release rate of all materials, but this effect was more marked for the SRFs. Temperature had the greatest influence on N release rates. For CRFs, the initial N release rates and the percentage N released/day increased as temperature increased. For SRFs, raising the temperature from 25 to 35 degreesC increased initial N release rate and the total cumulative N released, and almost doubled the percentage released/day. The percentage N released/day from all products generally increased as the texture of the soil changed from sandy to loamy (lowa>California>Pennsylvania>Florida). The soil incubation technique was demonstrated to be robust and reliable for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and variations in soil/sand ratio, temperature, and soil had little effect on the results.

  17. System for controlling apnea

    SciTech Connect

    Holzrichter, John F

    2015-05-05

    An implanted stimulation device or air control device are activated by an external radar-like sensor for controlling apnea. The radar-like sensor senses the closure of the air flow cavity, and associated control circuitry signals (1) a stimulator to cause muscles to open the air passage way that is closing or closed or (2) an air control device to open the air passage way that is closing or closed.

  18. Networked control of microgrid system of systems

    NASA Astrophysics Data System (ADS)

    Mahmoud, Magdi S.; Rahman, Mohamed Saif Ur; AL-Sunni, Fouad M.

    2016-08-01

    The microgrid has made its mark in distributed generation and has attracted widespread research. However, microgrid is a complex system which needs to be viewed from an intelligent system of systems perspective. In this paper, a network control system of systems is designed for the islanded microgrid system consisting of three distributed generation units as three subsystems supplying a load. The controller stabilises the microgrid system in the presence of communication infractions such as packet dropouts and delays. Simulation results are included to elucidate the effectiveness of the proposed control strategy.

  19. Distributed systems status and control

    NASA Technical Reports Server (NTRS)

    Kreidler, David; Vickers, David

    1990-01-01

    Concepts are investigated for an automated status and control system for a distributed processing environment. System characteristics, data requirements for health assessment, data acquisition methods, system diagnosis methods and control methods were investigated in an attempt to determine the high-level requirements for a system which can be used to assess the health of a distributed processing system and implement control procedures to maintain an accepted level of health for the system. A potential concept for automated status and control includes the use of expert system techniques to assess the health of the system, detect and diagnose faults, and initiate or recommend actions to correct the faults. Therefore, this research included the investigation of methods by which expert systems were developed for real-time environments and distributed systems. The focus is on the features required by real-time expert systems and the tools available to develop real-time expert systems.

  20. SPring-8 beamline control system.

    PubMed

    Ohata, T; Konishi, H; Kimura, H; Furukawa, Y; Tamasaku, K; Nakatani, T; Tanabe, T; Matsumoto, N; Ishii, M; Ishikawa, T

    1998-05-01

    The SPring-8 beamline control system is now taking part in the control of the insertion device (ID), front end, beam transportation channel and all interlock systems of the beamline: it will supply a highly standardized environment of apparatus control for collaborative researchers. In particular, ID operation is very important in a third-generation synchrotron light source facility. It is also very important to consider the security system because the ID is part of the storage ring and is therefore governed by the synchrotron ring control system. The progress of computer networking systems and the technology of security control require the development of a highly flexible control system. An interlock system that is independent of the control system has increased the reliability. For the beamline control system the so-called standard model concept has been adopted. VME-bus (VME) is used as the front-end control system and a UNIX workstation as the operator console. CPU boards of the VME-bus are RISC processor-based board computers operated by a LynxOS-based HP-RT real-time operating system. The workstation and the VME are linked to each other by a network, and form the distributed system. The HP 9000/700 series with HP-UX and the HP 9000/743rt series with HP-RT are used. All the controllable apparatus may be operated from any workstation. PMID:15263588

  1. Factors Affecting the Design of Slow Release Formulations of Herbicides Based on Clay-Surfactant Systems. A Methodological Approach

    PubMed Central

    Galán-Jiménez, María del Carmen; Mishael, Yael-Golda; Nir, Shlomo; Morillo, Esmeralda; Undabeytia, Tomás

    2013-01-01

    A search for clay-surfactant based formulations with high percentage of the active ingredient, which can yield slow release of active molecules is described. The active ingredients were the herbicides metribuzin (MZ), mesotrione (MS) and flurtamone (FL), whose solubilities were examined in the presence of four commercial surfactants; (i) neutral: two berols (B048, B266) and an alkylpolyglucoside (AG6202); (ii) cationic: an ethoxylated amine (ET/15). Significant percent of active ingredient (a.i.) in the clay/surfactant/herbicide formulations could be achieved only when most of the surfactant was added as micelles. MZ and FL were well solubilized by berols, whereas MS by ET/15. Sorption of surfactants on the clay mineral sepiolite occurred mostly by sorption of micelles, and the loadings exceeded the CEC. Higher loadings were determined for B266 and ET/15. The sorption of surfactants was modeled by using the Langmuir-Scatchard equation which permitted the determination of binding coefficients that could be used for further predictions of the sorbed amounts of surfactants under a wide range of clay/surfactant ratios. A possibility was tested of designing clay-surfactant based formulations of certain herbicides by assuming the same ratio between herbicides and surfactants in the formulations as for herbicides incorporated in micelles in solution. Calculations indicated that satisfactory FL formulations could not be synthesized. The experimental fractions of herbicides in the formulations were in agreement with the predicted ones for MS and MZ. The validity of this approach was confirmed in in vitro release tests that showed a slowing down of the release of a.i. from the designed formulations relative to the technical products. Soil dissipation studies with MS formulations also showed improved bioactivity of the clay-surfactant formulation relative to the commercial one. This methodological approach can be extended to other clay-surfactant systems for encapsulation and

  2. Factors affecting the design of slow release formulations of herbicides based on clay-surfactant systems. A methodological approach.

    PubMed

    Galán-Jiménez, María Del Carmen; Mishael, Yael-Golda; Nir, Shlomo; Morillo, Esmeralda; Undabeytia, Tomás

    2013-01-01

    A search for clay-surfactant based formulations with high percentage of the active ingredient, which can yield slow release of active molecules is described. The active ingredients were the herbicides metribuzin (MZ), mesotrione (MS) and flurtamone (FL), whose solubilities were examined in the presence of four commercial surfactants; (i) neutral: two berols (B048, B266) and an alkylpolyglucoside (AG6202); (ii) cationic: an ethoxylated amine (ET/15). Significant percent of active ingredient (a.i.) in the clay/surfactant/herbicide formulations could be achieved only when most of the surfactant was added as micelles. MZ and FL were well solubilized by berols, whereas MS by ET/15. Sorption of surfactants on the clay mineral sepiolite occurred mostly by sorption of micelles, and the loadings exceeded the CEC. Higher loadings were determined for B266 and ET/15. The sorption of surfactants was modeled by using the Langmuir-Scatchard equation which permitted the determination of binding coefficients that could be used for further predictions of the sorbed amounts of surfactants under a wide range of clay/surfactant ratios. A possibility was tested of designing clay-surfactant based formulations of certain herbicides by assuming the same ratio between herbicides and surfactants in the formulations as for herbicides incorporated in micelles in solution. Calculations indicated that satisfactory FL formulations could not be synthesized. The experimental fractions of herbicides in the formulations were in agreement with the predicted ones for MS and MZ. The validity of this approach was confirmed in in vitro release tests that showed a slowing down of the release of a.i. from the designed formulations relative to the technical products. Soil dissipation studies with MS formulations also showed improved bioactivity of the clay-surfactant formulation relative to the commercial one. This methodological approach can be extended to other clay-surfactant systems for encapsulation and

  3. Supervisory control systems

    NASA Technical Reports Server (NTRS)

    Sheridan, T. B.

    1974-01-01

    The various functions of a computer are considered that serve in connecting the man, with his displays and controls, to an external environment, manipulator activators and the interoceptors that are in the actuators, and to the interosensors and the motors or the actuators to drive the sensors. Projected is an improved exoskeleton mechanism with computer control and some supervisory control that may give a quadriplegic the ability to walk and run around.

  4. Nanoscale control designs for systems.

    PubMed

    Chen, Yung-Yue

    2014-02-01

    Nanoscale control is the science of the control of objects at dimensions with 100 nm or less and the manipulation of them at this level of precision. The desired attributes of systems under nanoscale control design are extreme high resolution, accuracy, stability, and fast response. An important perspective of investigation in nanoscale control design includes system modeling and precision control devices and materials at a nanoscale dimension, i.e., design of nanopositioners. Nanopositioners are mechatronic systems with an ultraprecise resolution down to a fraction of an atomic diameter and developed to move objects over a small range in nanoscale dimension. After reviewing a lot of existing literatures for nanoscale control designs, the way to successful nanoscale control is accurate position sensing and feedback control of the motion. An overview of nanoscale identification, linear, and nonlinear control technologies, and devices that are playing a key role in improving precision, accuracy, and response of operation of these systems are introduced in this research.

  5. Controls of maglev suspension systems

    SciTech Connect

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

    1993-06-01

    This study investigates alternative control designs of maglev vehicle suspension systems. Active and semi-active control law designs are introduced into primary and secondary suspensions of maglev vehicles. A one-dimensional vehicle with two degrees of freedom, to simulate the German Transrapid Maglev System, is used for suspension control designs. The transient and frequency responses of suspension systems and PSDs of vehicle accelerations are calculated to evaluate different control designs. The results show that active and semi-active control designs indeed improve the response of vehicle and provide an acceptable ride comfort for maglev systems.

  6. Fluid delivery control system

    DOEpatents

    Hoff, Brian D.; Johnson, Kris William; Algrain, Marcelo C.; Akasam, Sivaprasad

    2006-06-06

    A method of controlling the delivery of fluid to an engine includes receiving a fuel flow rate signal. An electric pump is arranged to deliver fluid to the engine. The speed of the electric pump is controlled based on the fuel flow rate signal.

  7. The ATLAS Detector Control System

    NASA Astrophysics Data System (ADS)

    Lantzsch, K.; Arfaoui, S.; Franz, S.; Gutzwiller, O.; Schlenker, S.; Tsarouchas, C. A.; Mindur, B.; Hartert, J.; Zimmermann, S.; Talyshev, A.; Oliveira Damazio, D.; Poblaguev, A.; Braun, H.; Hirschbuehl, D.; Kersten, S.; Martin, T.; Thompson, P. D.; Caforio, D.; Sbarra, C.; Hoffmann, D.; Nemecek, S.; Robichaud-Veronneau, A.; Wynne, B.; Banas, E.; Hajduk, Z.; Olszowska, J.; Stanecka, E.; Bindi, M.; Polini, A.; Deliyergiyev, M.; Mandic, I.; Ertel, E.; Marques Vinagre, F.; Ribeiro, G.; Santos, H. F.; Barillari, T.; Habring, J.; Huber, J.; Arabidze, G.; Boterenbrood, H.; Hart, R.; Iakovidis, G.; Karakostas, K.; Leontsinis, S.; Mountricha, E.; Ntekas, K.; Filimonov, V.; Khomutnikov, V.; Kovalenko, S.; Grassi, V.; Mitrevski, J.; Phillips, P.; Chekulaev, S.; D'Auria, S.; Nagai, K.; Tartarelli, G. F.; Aielli, G.; Marchese, F.; Lafarguette, P.; Brenner, R.

    2012-12-01

    The ATLAS experiment is one of the multi-purpose experiments at the Large Hadron Collider (LHC) at CERN, constructed to study elementary particle interactions in collisions of high-energy proton beams. Twelve different sub detectors as well as the common experimental infrastructure are controlled and monitored by the Detector Control System (DCS) using a highly distributed system of 140 server machines running the industrial SCADA product PVSS. Higher level control system layers allow for automatic control procedures, efficient error recognition and handling, manage the communication with external systems such as the LHC controls, and provide a synchronization mechanism with the ATLAS data acquisition system. Different databases are used to store the online parameters of the experiment, replicate a subset used for physics reconstruction, and store the configuration parameters of the systems. This contribution describes the computing architecture and software tools to handle this complex and highly interconnected control system.

  8. Autorotation flight control system

    NASA Technical Reports Server (NTRS)

    Bachelder, Edward N. (Inventor); Lee, Dong-Chan (Inventor); Aponso, Bimal L. (Inventor)

    2011-01-01

    The present invention provides computer implemented methodology that permits the safe landing and recovery of rotorcraft following engine failure. With this invention successful autorotations may be performed from well within the unsafe operating area of the height-velocity profile of a helicopter by employing the fast and robust real-time trajectory optimization algorithm that commands control motion through an intuitive pilot display, or directly in the case of autonomous rotorcraft. The algorithm generates optimal trajectories and control commands via the direct-collocation optimization method, solved using a nonlinear programming problem solver. The control inputs computed are collective pitch and aircraft pitch, which are easily tracked and manipulated by the pilot or converted to control actuator commands for automated operation during autorotation in the case of an autonomous rotorcraft. The formulation of the optimal control problem has been carefully tailored so the solutions resemble those of an expert pilot, accounting for the performance limitations of the rotorcraft and safety concerns.

  9. Moving Object Control System

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor)

    2001-01-01

    A method is provided for controlling two objects relatively moveable with respect to each other. A plurality of receivers are provided for detecting a distinctive microwave signal from each of the objects and measuring the phase thereof with respect to a reference signal. The measured phase signal is used to determine a distance between each of the objects and each of the plurality of receivers. Control signals produced in response to the relative distances are used to control the position of the two objects.

  10. D0 Cryo System Control System Autodialer

    SciTech Connect

    Urbin, J.; /Fermilab

    1990-04-17

    The DO cryogenic system is controlled by a TI565-PLC based control system. This allows the system to be unmanned when in steady state operation. System experts will need to be contacted when system parameters exceed normal operating points and reach alarm setpoints. The labwide FIRUS system provides one alarm monitor and communication link. An autodialer provides a second and more flexible alarm monitor and communication link. The autodialer monitors contact points in the control system and after receiving indication of an alarm accesses a list of experts which it calls until it receives an acknowledgement. There are several manufacturers and distributors of autodialer systems. This EN explains the search process the DO cryo group used to fmd an autodialer system that fit the cryo system's needs and includes information and specs for the unit we chose.

  11. Comparison of Carcass Characteristics, Meat Quality, and Blood Parameters of Slow and Fast Grown Female Broiler Chickens Raised in Organic or Conventional Production System

    PubMed Central

    Cömert, Muazzez; Şayan, Yılmaz; Kırkpınar, Figen; Bayraktar, Ö. Hakan; Mert, Selim

    2016-01-01

    The objective of the study was to compare the carcass characteristics, meat quality, and blood parameters of slow and fast grown female broiler chickens fed in organic or conventional production system. The two genotypes tested were medium slow-growing chickens (SG, Hubbard Red JA) and commercial fast-growing chickens (FG, Ross 308). Both genotypes (each represented by 400 chickens) were divided into two sub-groups fed either organic (O) or conventional (C) systems. Chickens of each genotype and system were raised in a semi environmentally controlled poultry house until 21 d of age and were assigned to 5 pens of 40 chickens each. Then, O system chickens were transferred into an open-side poultry house with an outdoor run. At 81 d of age, 10 female chickens from each genotype and from each production system (n = 40) were randomly chosen to provide material for analysis, and were weighed and brought to the slaughterhouse to assess carcass characteristics and meat quality. The blood parameters were determined by using 5 female chickens from each genotype and from each production system (n = 20). FG had the higher live weight, along with carcass, breast, and thigh-drumstick weights compared to SG (p<0.05). FG had the higher breast yield, whereas SG had the higher thigh-drumstick yield (p<0.05). The O system resulted in a higher amount of abdominal fat (p<0.05). In addition, the O system values were higher for dry matter, crude ash, crude protein, and pH15 values in breast meat, and for crude ash, crude protein, and pH15 values in drumstick meat (p<0.05). In addition, total saturated fatty acids, total mono-unsaturated fatty acids, and total omega 3 were significantly higher in the O system than in the C system. Thus, the O system showed a positive advantage compared to the C system regarding female chicken meat quality, primarily within the ash, protein, and total omega 3 fatty acid profiles. In conclusion, the present study indicated that the main factor affecting the

  12. Comparison of Carcass Characteristics, Meat Quality, and Blood Parameters of Slow and Fast Grown Female Broiler Chickens Raised in Organic or Conventional Production System.

    PubMed

    Cömert, Muazzez; Şayan, Yılmaz; Kırkpınar, Figen; Bayraktar, Ö Hakan; Mert, Selim

    2016-07-01

    The objective of the study was to compare the carcass characteristics, meat quality, and blood parameters of slow and fast grown female broiler chickens fed in organic or conventional production system. The two genotypes tested were medium slow-growing chickens (SG, Hubbard Red JA) and commercial fast-growing chickens (FG, Ross 308). Both genotypes (each represented by 400 chickens) were divided into two sub-groups fed either organic (O) or conventional (C) systems. Chickens of each genotype and system were raised in a semi environmentally controlled poultry house until 21 d of age and were assigned to 5 pens of 40 chickens each. Then, O system chickens were transferred into an open-side poultry house with an outdoor run. At 81 d of age, 10 female chickens from each genotype and from each production system (n = 40) were randomly chosen to provide material for analysis, and were weighed and brought to the slaughterhouse to assess carcass characteristics and meat quality. The blood parameters were determined by using 5 female chickens from each genotype and from each production system (n = 20). FG had the higher live weight, along with carcass, breast, and thigh-drumstick weights compared to SG (p<0.05). FG had the higher breast yield, whereas SG had the higher thigh-drumstick yield (p<0.05). The O system resulted in a higher amount of abdominal fat (p<0.05). In addition, the O system values were higher for dry matter, crude ash, crude protein, and pH(15) values in breast meat, and for crude ash, crude protein, and pH(15) values in drumstick meat (p<0.05). In addition, total saturated fatty acids, total mono-unsaturated fatty acids, and total omega 3 were significantly higher in the O system than in the C system. Thus, the O system showed a positive advantage compared to the C system regarding female chicken meat quality, primarily within the ash, protein, and total omega 3 fatty acid profiles. In conclusion, the present study indicated that the main factor affecting

  13. A telerobotic digital controller system

    NASA Technical Reports Server (NTRS)

    Brown, Richard J.

    1992-01-01

    This system is a network of joint mounted dual axes digital servo-controllers (DDSC), providing control of various joints and end effectors of different robotic systems. This report provides description of and user required information for the Digital Controller System Network (DSCN) and, in particular, the DDSC, Model DDSC-2, developed to perform the controller functions. The DDSC can control 3 phase brushless or brush type DC motors, requiring up to 8 amps. Only four wires, two for power and 2 for serial communication, are required, except for local sensor and motor connections. This highly capable, very flexible, programmable servo-controller, contained on a single, compact printed circuit board measuring only 4.5 x 5.1 inches, is applicable to control systems of all types from sub-arc second precision pointing to control of robotic joints and end effectors. This document concentrates on the robotic applications for the DDSC.

  14. Neurofeedback of slow cortical potentials: neural mechanisms and feasibility of a placebo-controlled design in healthy adults

    PubMed Central

    Gevensleben, Holger; Albrecht, Björn; Lütcke, Henry; Auer, Tibor; Dewiputri, Wan Ilma; Schweizer, Renate; Moll, Gunther; Heinrich, Hartmut; Rothenberger, Aribert

    2014-01-01

    To elucidate basic mechanisms underlying neurofeedback we investigated neural mechanisms of training of slow cortical potentials (SCPs) by considering EEG- and fMRI. Additionally, we analyzed the feasibility of a double-blind, placebo-controlled design in NF research based on regulation performance during treatment sessions and self-assessment of the participants. Twenty healthy adults participated in 16 sessions of SCPs training: 9 participants received regular SCP training, 11 participants received sham feedback. At three time points (pre, intermediate, post) fMRI and EEG/ERP-measurements were conducted during a continuous performance test (CPT). Performance-data during the sessions (regulation performance) in the treatment group and the placebo group were analyzed. Analysis of EEG-activity revealed in the SCP group a strong enhancement of the CNV (electrode Cz) at the intermediate assessment, followed by a decrease back to baseline at the post-treatment assessment. In contrast, in the placebo group a continuous but smaller increase of the CNV could be obtained from pre to post assessment. The increase of the CNV in the SCP group at intermediate testing was superior to the enhancement in the placebo group. The changes of the CNV were accompanied by a continuous improvement in the test performance of the CPT from pre to intermediate to post assessment comparable in both groups. The change of the CNV in the SCP group is interpreted as an indicator of neural plasticity and efficiency while an increase of the CNV in the placebo group might reflect learning and improved timing due to the frequent task repetition. In the fMRI analysis evidence was obtained for neuronal plasticity. After regular SCP neurofeedback activation in the posterior parietal cortex decreased from the pre- to the intermediate measurement and increased again in the post measurement, inversely following the U-shaped increase and decrease of the tCNV EEG amplitude in the SCP-trained group

  15. Neurofeedback of slow cortical potentials: neural mechanisms and feasibility of a placebo-controlled design in healthy adults.

    PubMed

    Gevensleben, Holger; Albrecht, Björn; Lütcke, Henry; Auer, Tibor; Dewiputri, Wan Ilma; Schweizer, Renate; Moll, Gunther; Heinrich, Hartmut; Rothenberger, Aribert

    2014-01-01

    To elucidate basic mechanisms underlying neurofeedback we investigated neural mechanisms of training of slow cortical potentials (SCPs) by considering EEG- and fMRI. Additionally, we analyzed the feasibility of a double-blind, placebo-controlled design in NF research based on regulation performance during treatment sessions and self-assessment of the participants. Twenty healthy adults participated in 16 sessions of SCPs training: 9 participants received regular SCP training, 11 participants received sham feedback. At three time points (pre, intermediate, post) fMRI and EEG/ERP-measurements were conducted during a continuous performance test (CPT). Performance-data during the sessions (regulation performance) in the treatment group and the placebo group were analyzed. Analysis of EEG-activity revealed in the SCP group a strong enhancement of the CNV (electrode Cz) at the intermediate assessment, followed by a decrease back to baseline at the post-treatment assessment. In contrast, in the placebo group a continuous but smaller increase of the CNV could be obtained from pre to post assessment. The increase of the CNV in the SCP group at intermediate testing was superior to the enhancement in the placebo group. The changes of the CNV were accompanied by a continuous improvement in the test performance of the CPT from pre to intermediate to post assessment comparable in both groups. The change of the CNV in the SCP group is interpreted as an indicator of neural plasticity and efficiency while an increase of the CNV in the placebo group might reflect learning and improved timing due to the frequent task repetition. In the fMRI analysis evidence was obtained for neuronal plasticity. After regular SCP neurofeedback activation in the posterior parietal cortex decreased from the pre- to the intermediate measurement and increased again in the post measurement, inversely following the U-shaped increase and decrease of the tCNV EEG amplitude in the SCP-trained group

  16. Suppression of dynamics and frequency synchronization in coupled slow and fast dynamical systems

    NASA Astrophysics Data System (ADS)

    Gupta, Kajari; Ambika, G.

    2016-06-01

    We present our study on the emergent states of two interacting nonlinear systems with differing dynamical time scales. We find that the inability of the interacting systems to fall in step leads to difference in phase as well as change in amplitude. If the mismatch is small, the systems settle to a frequency synchronized state with constant phase difference. But as mismatch in time scale increases, the systems have to compromise to a state of no oscillations. We illustrate this for standard nonlinear systems and identify the regions of quenched dynamics in the parameter plane. The transition curves to this state are studied analytically and confirmed by direct numerical simulations. As an important special case, we revisit the well-known model of coupled ocean-atmosphere system used in climate studies for the interactive dynamics of a fast oscillating atmosphere and slowly changing ocean. Our study in this context indicates occurrence of multi stable periodic states and steady states of convection coexisting in the system, with a complex basin structure.

  17. Highly oriented nanoplates of layered double hydroxides as an ultra slow release system.

    PubMed

    Lee, Jong Hyeon; Jung, Duk-Young

    2012-06-01

    A novel controlled molecular release based on highly oriented nanoplates of layered double hydroxide was fabricated on indium tin oxide substrates by electrophoretic deposition of exfoliated LDH nanosheets. The LDH particle coating exhibited a superior release performance of the order of hours. PMID:22531710

  18. Tests Of Helicopter Control System

    NASA Technical Reports Server (NTRS)

    Hilbert, Kathryn B.; Lebacqz, J. Victor; Hindson, William S.

    1988-01-01

    Advanced control systems being developed for rotorcraft. Report discusses aspects of development of multivariable, explicit-model-following control system for CH-47B fly-by-wire helicopter. Project part of recent trend toward use of highly-augmented, high-gain flight-control systems to assist pilots of military helicopters in performance of demanding tasks and to improve handling qualities of aircraft.

  19. Generic Observatory Control System

    NASA Astrophysics Data System (ADS)

    Pearson, M.; Ritchie, I.

    2013-09-01

    EOS has developed systems over many years to support research into Space Situational Awareness (SSA) and Satellite Laser Ranging (SLR). These systems are based upon a software architecture that simplifies systems development with the goals of supporting multiple missions at low-cost. To date the software architecture has supported local, remote and international operation of the Space Research Centre facilities at Mt. Stromlo, Australia in both manual and automatic modes. The design objectives of this software architecture are discussed in the context of future development paths aimed at lowering systems integration costs even further, and enabling participation in international SSA networks.

  20. Prolonged mild therapeutic hypothermia versus fever control with tight hemodynamic monitoring and slow rewarming in patients with severe traumatic brain injury: a randomized controlled trial.

    PubMed

    Maekawa, Tsuyoshi; Yamashita, Susumu; Nagao, Seigo; Hayashi, Nariyuki; Ohashi, Yasuo

    2015-04-01

    Although mild therapeutic hypothermia is an effective neuroprotective strategy for cardiac arrest/resuscitated patients, and asphyxic newborns, recent randomized controlled trials (RCTs) have equally shown good neurological outcome between targeted temperature management at 33 °C versus 36 °C, and have not shown consistent benefits in patients with traumatic brain injury (TBI). We aimed to determine the effect of therapeutic hypothermia, while avoiding some limitations of earlier studies, which included patient selection based on Glasgow coma scale (GCS), delayed initiation of cooling, short duration of cooling, inter-center variation in patient care, and relatively rapid rewarming. We conducted a multicenter RCT in patients with severe TBI (GCS 4-8). Patients were randomly assigned (2:1 allocation ratio) to either therapeutic hypothermia (32-34 °C, n = 98) or fever control (35.5-37 °C, n = 50). Patients with therapeutic hypothermia were cooled as soon as possible for ≥ 72 h and rewarmed at a rate of <1 °C/day. All patients received tight hemodynamic monitoring under intensive neurological care. The Glasgow Outcome Scale was assessed at 6 months by physicians who were blinded to the treatment allocation. The overall rates of poor neurological outcomes were 53% and 48% in the therapeutic hypothermia and fever control groups, respectively. There were no significant differences in the likelihood of poor neurological outcome (relative risk [RR] 1.24, 95% confidence interval [CI] 0.62-2.48, p = 0.597) or mortality (RR 1.82, 95% CI 0.82-4.03, p = 0.180) between the two groups. We concluded that tight hemodynamic management and slow rewarming, together with prolonged therapeutic hypothermia (32-34 °C) for severe TBI, did not improve the neurological outcomes or risk of mortality compared with strict temperature control (35.5-37 °C). PMID:25099730

  1. Prolonged mild therapeutic hypothermia versus fever control with tight hemodynamic monitoring and slow rewarming in patients with severe traumatic brain injury: a randomized controlled trial.

    PubMed

    Maekawa, Tsuyoshi; Yamashita, Susumu; Nagao, Seigo; Hayashi, Nariyuki; Ohashi, Yasuo

    2015-04-01

    Although mild therapeutic hypothermia is an effective neuroprotective strategy for cardiac arrest/resuscitated patients, and asphyxic newborns, recent randomized controlled trials (RCTs) have equally shown good neurological outcome between targeted temperature management at 33 °C versus 36 °C, and have not shown consistent benefits in patients with traumatic brain injury (TBI). We aimed to determine the effect of therapeutic hypothermia, while avoiding some limitations of earlier studies, which included patient selection based on Glasgow coma scale (GCS), delayed initiation of cooling, short duration of cooling, inter-center variation in patient care, and relatively rapid rewarming. We conducted a multicenter RCT in patients with severe TBI (GCS 4-8). Patients were randomly assigned (2:1 allocation ratio) to either therapeutic hypothermia (32-34 °C, n = 98) or fever control (35.5-37 °C, n = 50). Patients with therapeutic hypothermia were cooled as soon as possible for ≥ 72 h and rewarmed at a rate of <1 °C/day. All patients received tight hemodynamic monitoring under intensive neurological care. The Glasgow Outcome Scale was assessed at 6 months by physicians who were blinded to the treatment allocation. The overall rates of poor neurological outcomes were 53% and 48% in the therapeutic hypothermia and fever control groups, respectively. There were no significant differences in the likelihood of poor neurological outcome (relative risk [RR] 1.24, 95% confidence interval [CI] 0.62-2.48, p = 0.597) or mortality (RR 1.82, 95% CI 0.82-4.03, p = 0.180) between the two groups. We concluded that tight hemodynamic management and slow rewarming, together with prolonged therapeutic hypothermia (32-34 °C) for severe TBI, did not improve the neurological outcomes or risk of mortality compared with strict temperature control (35.5-37 °C).

  2. NUCLEAR REACTOR CONTROL SYSTEM

    DOEpatents

    Howard, D.F.; Motta, E.E.

    1961-06-27

    A method for controlling the excess reactivity in a nuclear reactor throughout the core life while maintaining the neutron flux distribution at the desired level is described. The control unit embodies a container having two electrodes of different surface area immersed in an electrolytic solution of a good neutron sbsorbing metal ion such as boron, gadolinium, or cadmium. Initially, the neutron absorber is plated on the larger electrode to control the greater neutron flux of a freshly refueled core. As the fuel burns up, the excess reactivity decreases and the neutron absorber is then plated onto the smaller electrode so that the number of neutrons absorbed also decreases. The excess reactivity in the core may thus be maintained without the introduction of serious perturbations in the neutron flux distributibn.

  3. AUTOMATIC FREQUENCY CONTROL SYSTEM

    DOEpatents

    Hansen, C.F.; Salisbury, J.D.

    1961-01-10

    A control is described for automatically matching the frequency of a resonant cavity to that of a driving oscillator. The driving oscillator is disconnected from the cavity and a secondary oscillator is actuated in which the cavity is the frequency determining element. A low frequency is mixed with the output of the driving oscillator and the resultant lower and upper sidebands are separately derived. The frequencies of the sidebands are compared with the secondary oscillator frequency. deriving a servo control signal to adjust a tuning element in the cavity and matching the cavity frequency to that of the driving oscillator. The driving oscillator may then be connected to the cavity.

  4. Ground Control System Description Document

    SciTech Connect

    Eric Loros

    2001-07-31

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

  5. The CARMA Control System

    NASA Astrophysics Data System (ADS)

    Gwon, C.; Beard, A. D.; Daniel, P.; Hobbs, R.; Scott, S. L.; Kraybill, J. C.; Leitch, E.; Mehringer, D. M.; Plante, R.; Amarnath, N. S.; Pound, M. W.; Rauch, K. P.; Teuben, P. J.

    2004-07-01

    The Combined Array for Research in Millimeter-wave Astronomy (CARMA) will be the combination of the BIMA, OVRO, and SZA millimeter arrays. With first light scheduled for 2005, CARMA will be the first heterogeneous millimeter array, combining antennas varying from 3.5 m to 10.4 m in diameter. The controls for CARMA involve creating a uniform interface for all antennas. The antennas are grouped into five independently-controlled sub-arrays, which will be used for scientific observations, engineering, or maintenance. The sub-arrays are controlled by two components: the Sub-array Command Processor (SCP) and the Sub-array Tracker (SAT). While each sub-array has a dedicated SCP for handling command processing, a single SAT computes and distributes slowly varying parameters to the necessary sub-arrays. The sub-array interface uses CORBA distributed objects to physically separate the user interface from the array. This allows for stability in the core engine controlling the array while enabling flexibility in the user interface implementation.

  6. The APS control system network

    SciTech Connect

    Sidorowicz, K.V.; McDowell, W.P.

    1995-12-31

    The APS accelerator control system is a distributed system consisting of operator interfaces, a network, and computer-controlled interfaces to hardware. This implementation of a control system has come to be called the {open_quotes}Standard Model.{close_quotes} The operator interface is a UNDC-based workstation with an X-windows graphical user interface. The workstation may be located at any point on the facility network and maintain full functionality. The function of the network is to provide a generalized communication path between the host computers, operator workstations, input/output crates, and other hardware that comprise the control system. The crate or input/output controller (IOC) provides direct control and input/output interfaces for each accelerator subsystem. The network is an integral part of all modem control systems and network performance will determine many characteristics of a control system. This paper will describe the overall APS network and examine the APS control system network in detail. Metrics are provided on the performance of the system under various conditions.

  7. Slow strain rate fracture of high-strength steel at controlled electrochemical potentials in ammonium chloride, potassium chloride, and ammonium nitrate solutions

    SciTech Connect

    Nguyen, D.T.; Nichols, D.E.; Daniels, R.D.

    1992-08-15

    Slow strain rate testing has been undertaken to determine the effects of individual chemical species on the fracture process of high-strength 4340 steel. Test environments included potassium chloride, ammonium nitrate, and ammonium chloride at concentrations from 0.001 to 1.0 mole por liter at ambient temperature. Tests were performed at cathodic and anodic controlled potentials, as well as at the open-circuit potential, to delineate the stress corrosion cracking range.

  8. Advanced flight control system study

    NASA Technical Reports Server (NTRS)

    Mcgough, J.; Moses, K.; Klafin, J. F.

    1982-01-01

    The architecture, requirements, and system elements of an ultrareliable, advanced flight control system are described. The basic criteria are functional reliability of 10 to the minus 10 power/hour of flight and only 6 month scheduled maintenance. A distributed system architecture is described, including a multiplexed communication system, reliable bus controller, the use of skewed sensor arrays, and actuator interfaces. Test bed and flight evaluation program are proposed.

  9. Griffiths effects and slow dynamics in nearly many-body localized systems

    NASA Astrophysics Data System (ADS)

    Gopalakrishnan, Sarang; Agarwal, Kartiek; Demler, Eugene A.; Huse, David A.; Knap, Michael

    2016-04-01

    The low-frequency response of systems near a many-body localization transition can be dominated by rare regions that are locally critical or "in the other phase." It is known that in one dimension, these rare regions can cause the dc conductivity and diffusion constant to vanish even inside the delocalized thermal phase. Here, we present a general analysis of such Griffiths effects in the thermal phase near the many-body localization transition: we consider both one-dimensional and higher-dimensional systems, subject to quenched randomness, and discuss both linear response (including the frequency- and wave-vector-dependent conductivity) and more general dynamics. In all the regimes we consider, we identify observables that are dominated by rare-region effects. In some cases (one-dimensional systems and Floquet systems with no extensive conserved quantities), essentially all long-time local observables are dominated by rare-region effects; in others, generic observables are instead dominated by hydrodynamic long-time tails throughout the thermal phase, and one must look at specific probes, such as spin echo, to see Griffiths behavior.

  10. Controlling pulse delay by light and low magnetic fields: slow light in emerald induced by transient spectral hole-burning.

    PubMed

    Rajan, Rajitha Papukutty; Riesen, Hans; Rebane, Aleksander

    2013-11-15

    Slow light based on transient spectral hole-burning is reported for emerald, Be(3)Al(2)Si(6)O(18):Cr(3+). Experiments were conducted in π polarization on the R(1)(± 3/2) line (E2 ← A(2)4) at 2.2 K in zero field and low magnetic fields B||c. The hole width was strongly dependent on B||c, and this allowed us to smoothly tune the pulse delay from 40 to 154 ns between zero field and B||c = 15.2 mT. The latter corresponds to a group velocity of 16 km/s. Slow light in conjunction with a linear filter theory can be used as a powerful and accurate technique in time-resolved spectroscopy, e.g., to determine spectral hole-widths as a function of time. PMID:24322070

  11. Dual pressure displacement control system

    SciTech Connect

    Louis, J.E.; Klocke, C.C.

    1988-02-02

    This patent describes a dual pressure servo control system for a variable displacement hydraulic unit having displacement setting means positioned by a hydraulic servo mechanism. The hydraulic unit is provided with main loop lines at least one of which is capable of being subjected to high main loop pressure during operation of the hydraulic unit, a control line including a displacement control valve providing a controlled flow of fluid under pressure to the servo mechanism, and a source of fluid under pressure for the control line comprising a low pressure source connected to the control line through a check valve and high pressure source comprising of a high pressure control line connected to the control line downstream of the check valve. The high pressure control line includes a flow restriction limiting flow to the control line means and generating a significant flow induced pressure drop in the high pressure control line once movement in the servo mechanism is initiated.

  12. Singular perturbations and time scales in the design of digital flight control systems

    NASA Technical Reports Server (NTRS)

    Naidu, Desineni S.; Price, Douglas B.

    1988-01-01

    The results are presented of application of the methodology of Singular Perturbations and Time Scales (SPATS) to the control of digital flight systems. A block diagonalization method is described to decouple a full order, two time (slow and fast) scale, discrete control system into reduced order slow and fast subsystems. Basic properties and numerical aspects of the method are discussed. A composite, closed-loop, suboptimal control system is constructed as the sum of the slow and fast optimal feedback controls. The application of this technique to an aircraft model shows close agreement between the exact solutions and the decoupled (or composite) solutions. The main advantage of the method is the considerable reduction in the overall computational requirements for the evaluation of optimal guidance and control laws. The significance of the results is that it can be used for real time, onboard simulation. A brief survey is also presented of digital flight systems.

  13. The Principle for Artificial Molecular Machine and Noise: Slow Stochastic Dynamics in Complex Systems

    NASA Astrophysics Data System (ADS)

    Matsuura, H.; Nakano, M.; Nemoto, T.

    2004-04-01

    A novel Nano-Molecular Machine Model (DS-NMM) was proposed in order to further the understanding of the movement of the actin-myosin system in muscle. DS-NMM is comprised of numerous inclined rods extending from a central body in a manner similar to myosin; furthermore, its movement is forward in one direction upon independent vibration of these rods. DS-NMM can convert thermal noise to unidirectional motion employing stochastic resonance and inclined rods in random open fields. Concrete estimates were obtained of the physical characteristics of DS-NMM as a conceptual model of the actin-myosin system. When DS-NMM displays radius of 5 nm and mass of 10-21 kg, which are characteristic of a myosin molecule, the estimated frequency of stochastic resonance closely approaches phonon frequency, 1011 rad/s. The amplitude of stochastic resonance is 2×10-11 m. Moreover, physical work of this machine is approximately 10-18 joules, which is nearly equal to the energy output generated upon hydrolysis of one ATP molecule (10-10N/head). We concluded that the actin-myosin system in muscle derives its movement from the random motion of water molecules.

  14. Dynamically controlled crystal growth system

    NASA Technical Reports Server (NTRS)

    Bray, Terry L. (Inventor); Kim, Larry J. (Inventor); Harrington, Michael (Inventor); DeLucas, Lawrence J. (Inventor)

    2002-01-01

    Crystal growth can be initiated and controlled by dynamically controlled vapor diffusion or temperature change. In one aspect, the present invention uses a precisely controlled vapor diffusion approach to monitor and control protein crystal growth. The system utilizes a humidity sensor and various interfaces under computer control to effect virtually any evaporation rate from a number of different growth solutions simultaneously by means of an evaporative gas flow. A static laser light scattering sensor can be used to detect aggregation events and trigger a change in the evaporation rate for a growth solution. A control/follower configuration can be used to actively monitor one chamber and accurately control replicate chambers relative to the control chamber. In a second aspect, the invention exploits the varying solubility of proteins versus temperature to control the growth of protein crystals. This system contains miniature thermoelectric devices under microcomputer control that change temperature as needed to grow crystals of a given protein. Complex temperature ramps are possible using this approach. A static laser light scattering probe also can be used in this system as a non-invasive probe for detection of aggregation events. The automated dynamic control system provides systematic and predictable responses with regard to crystal size. These systems can be used for microgravity crystallization projects, for example in a space shuttle, and for crystallization work under terrestial conditions. The present invention is particularly useful for macromolecular crystallization, e.g. for proteins, polypeptides, nucleic acids, viruses and virus particles.

  15. Control systems on Lie groups.

    NASA Technical Reports Server (NTRS)

    Jurdjevic, V.; Sussmann, H. J.

    1972-01-01

    The controllability properties of systems which are described by an evolution equation in a Lie group are studied. The revelant Lie algebras induced by a right invariant system are singled out, and the basic properties of attainable sets are derived. The homogeneous case and the general case are studied, and results are interpreted in terms of controllability. Five examples are given.

  16. Virtual Control Systems Environment (VCSE)

    ScienceCinema

    Atkins, Will

    2016-07-12

    Will Atkins, a Sandia National Laboratories computer engineer discusses cybersecurity research work for process control systems. Will explains his work on the Virtual Control Systems Environment project to develop a modeling and simulation framework of the U.S. electric grid in order to study and mitigate possible cyberattacks on infrastructure.

  17. Virtual Control Systems Environment (VCSE)

    SciTech Connect

    Atkins, Will

    2012-10-08

    Will Atkins, a Sandia National Laboratories computer engineer discusses cybersecurity research work for process control systems. Will explains his work on the Virtual Control Systems Environment project to develop a modeling and simulation framework of the U.S. electric grid in order to study and mitigate possible cyberattacks on infrastructure.

  18. D-Factor: A Quantitative Model of Application Slow-Down in Multi-Resource Shared Systems

    SciTech Connect

    Lim, Seung-Hwan; Huh, Jae-Seok; Kim, Youngjae; Shipman, Galen M; Das, Chita

    2012-01-01

    Scheduling multiple jobs onto a platform enhances system utilization by sharing resources. The benefits from higher resource utilization include reduced cost to construct, operate, and maintain a system, which often include energy consumption. Maximizing these benefits comes at a price - resource contention among jobs increases job completion time. In this paper, we analyze slow-downs of jobs due to contention for multiple resources in a system; referred to as dilation factor. We observe that multiple-resource contention creates non-linear dilation factors of jobs. From this observation, we establish a general quantitative model for dilation factors of jobs in multi-resource systems. A job is characterized by a vector-valued loading statistics and dilation factors of a job set are given by a quadratic function of their loading vectors. We demonstrate how to systematically characterize a job, maintain the data structure to calculate the dilation factor (loading matrix), and calculate the dilation factor of each job. We validate the accuracy of the model with multiple processes running on a native Linux server, virtualized servers, and with multiple MapReduce workloads co-scheduled in a cluster. Evaluation with measured data shows that the D-factor model has an error margin of less than 16%. We also show that the model can be integrated with an existing on-line scheduler to minimize the makespan of workloads.

  19. Development of biotechnology control systems.

    PubMed

    Romeu, F J

    1995-03-01

    Advances in genetic engineering have generated great interest in biotechnology systems. Modern fermentation processes have a more scientific basis and can be optimized more quickly by utilizing instrumentation and control technology that permits increasing yield and product quality. The automation technology, to a large extent, can determine the degree of success of growing microorganisms. The automation system in modern biotechnology facilities includes a number of leading technologies such as sensors, indicators, data acquisition, distributed control, programmable control, communications, data base management, on-line data analysis techniques and application software. Modern computer systems have made fermentation processes easier and more accurate by performing tasks such as on-line analysis, statistical process control and supervisory control, while microprocessor-based distributed process controllers perform direct digital control, batch and sequencing control. This paper addresses technical issues related to the development of instrumentation and control systems that integrate these technologies through methodologies that permit the timely generation of the documentation and drawings that specify the control system for procurement, installation, commissioning, validation and operation.

  20. Control principles of complex systems

    NASA Astrophysics Data System (ADS)

    Liu, Yang-Yu; Barabási, Albert-László

    2016-07-01

    A reflection of our ultimate understanding of a complex system is our ability to control its behavior. Typically, control has multiple prerequisites: it requires an accurate map of the network that governs the interactions between the system's components, a quantitative description of the dynamical laws that govern the temporal behavior of each component, and an ability to influence the state and temporal behavior of a selected subset of the components. With deep roots in dynamical systems and control theory, notions of control and controllability have taken a new life recently in the study of complex networks, inspiring several fundamental questions: What are the control principles of complex systems? How do networks organize themselves to balance control with functionality? To address these questions here recent advances on the controllability and the control of complex networks are reviewed, exploring the intricate interplay between the network topology and dynamical laws. The pertinent mathematical results are matched with empirical findings and applications. Uncovering the control principles of complex systems can help us explore and ultimately understand the fundamental laws that govern their behavior.

  1. On the Slow Diffusion of Point-of-Care Systems in Therapeutic Drug Monitoring

    PubMed Central

    Sanavio, Barbara; Krol, Silke

    2015-01-01

    Recent advancements in point-of-care (PoC) technologies show great transformative promises for personalized preventative and predictive medicine. However, fields like therapeutic drug monitoring (TDM), that first allowed for personalized treatment of patients’ disease, still lag behind in the widespread application of PoC devices for monitoring of patients. Surprisingly, very few applications in commonly monitored drugs, such as anti-epileptics, are paving the way for a PoC approach to patient therapy monitoring compared to other fields like intensive care cardiac markers monitoring, glycemic controls in diabetes, or bench-top hematological parameters analysis at the local drug store. Such delay in the development of portable fast clinically effective drug monitoring devices is in our opinion due more to an inertial drag on the pervasiveness of these new devices into the clinical field than a lack of technical capability. At the same time, some very promising technologies failed in the clinical practice for inadequate understanding of the outcome parameters necessary for a relevant technological breakthrough that has superior clinical performance. We hope, by over-viewing both TDM practice and its yet unmet needs and latest advancement in micro- and nanotechnology applications to PoC clinical devices, to help bridging the two communities, the one exploiting analytical technologies and the one mastering the most advanced techniques, into translating existing and forthcoming technologies in effective devices. PMID:25767794

  2. Aircraft control system

    NASA Technical Reports Server (NTRS)

    Lisoski, Derek L. (Inventor); Kendall, Greg T. (Inventor)

    2007-01-01

    A solar rechargeable, long-duration, span-loaded flying wing, having no fuselage or rudder. Having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn, pitch and yaw. The wing is configured to deform under flight loads to position the propellers such that the control can be achieved. Each of five segments of the wing has one or more motors and photovoltaic arrays, and produces its own lift independent of the other segments, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface.

  3. Microprocessor control of photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Millner, A. R.; Kaufman, D. L.

    1984-01-01

    The present low power CMOS microprocessor controller for photovoltaic power systems possesses three programs, which are respectively intended for (1) conventional battery-charging systems with state-of-charge estimation and sequential shedding of subarrays and loads, (2) maximum power-controlled battery-charging systems, and (3) variable speed dc motor drives. Attention is presently given to the development of this terrestrial equipment for spacecraft use.

  4. Emission control system

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2008-01-01

    Methods and apparatus utilizing hydrogen peroxide are useful to reduce NOx, SOx and mercury (or other heavy metal) emissions from combustion flue gas streams. Continuous concentration of hydrogen peroxide to levels approaching or exceeding propellant-grade hydrogen peroxide facilitates increased system efficiency. In this manner, combustion flue gas streams can be treated for the removal of NOx, SOx and heavy metals, while isolating useful by-products streams of sulfuric acid and nitric acid as well as solids for the recovery of the heavy metals.

  5. Development of modified-release tablets of zolpidem tartrate by biphasic quick/slow delivery system.

    PubMed

    Mahapatra, Anjan Kumar; Sameeraja, N H; Murthy, P N

    2015-06-01

    Zolpidem tartrate is a non-benzodiazepine analogue of imidazopyridine of sedative and hypnotic category. It has a short half-life with usual dosage regimen being 5 mg, two times a day, or 10 mg, once daily. The duration of action is considered too short in certain circumstances. Thus, it is desirable to lengthen the duration of action. The formulation design was implemented by preparing extended-release tablets of zolpidem tartrate using the biphasic delivery system technology, where sodium starch glycolate acts as a superdisintegrant in immediate-release part and hydroxypropyl methyl cellulose as a release retarding agent in extended-release core. Tablets were prepared by direct compression. Both the core and the coat contained the drug. The pre-compression blends were evaluated for angle of repose, bulk density, and compressibility index. The tablets were evaluated for thickness, hardness, weight variation test, friability, and in vitro release studies. No interaction was observed between zolpidem tartrate and excipients from the Fourier transform infrared spectroscopy and differential scanning calorimetry analysis. The results of all the formulations prepared were compared with reference product Stilnoct®. Optimized formulations showed release patterns that match the United States Pharmacopeia (USP) guidelines for zolpidem tartrate extended-release tablets. The mechanism of drug release was studied using different mathematical models, and the optimized formulation has shown Fickian diffusion. Accelerated stability studies were performed on the optimized formulation.

  6. Macitentan slows down the dermal fibrotic process in systemic sclerosis: in vitro findings.

    PubMed

    Corallo, C; Pecetti, G; Iglarz, M; Volpi, N; Franci, D; Montella, A; D' Onofrio, F; Nuti, R; Giordano, N

    2013-01-01

    Systemic sclerosis (or scleroderma) is an autoimmune disease characterized by skin and internal organ fibrosis, caused by microvascular dysfunction. The microvascular damage seems to be a consequence of an endothelial autoimmune response, followed by activation of the inflammatory cascade and massive deposition of collagen. Endothelin-1 (ET-1) contributes to the inflammatory and fibrotic processes by increasing the concentration of pro-inflammatory and pro-fibrotic cytokines, and it is considered one of the most relevant mediators of vascular damage in scleroderma. It is indeed found in very high concentration in serum of sclerodermic patients. Moreover, in these pathological conditions there is an increased expression of ET-1 receptors (ETA and ETB), which mediate the detrimental action of ET-1, and often a change of ETA/ETB ratio. The aim of the present study is to evaluate the in vitro effect of macitentan, an orally active tissue-targeting dual endothelin receptor antagonist, and its major metabolite (ACT-132577) on alpha smooth muscle actin (alphaSMA) expression, evaluated on dermal fibroblasts from healthy subjects and on dermal fibroblasts from lesional and non-lesional skin from sclerodermic patients. The combination of macitentan and its major metabolite reduced the levels of αSMA after 48 h in sclerodermic fibroblasts from lesional skin. No relevant changes in αSMA levels were found in fibroblasts from non-lesional skin, whose behavior is similar to that of dermal fibroblasts from healthy patients.

  7. An inducible expression system for high-level expression of recombinant proteins in slow growing mycobacteria.

    PubMed

    Leotta, Lisa; Spratt, Joanne M; Kong, Carlyn U; Triccas, James A

    2015-09-01

    A novel protein expression vector utilising the inducible hspX promoter of Mycobacterium tuberculosis was constructed and evaluated in this study. High-level induction of three mycobacterial antigens, comprising up to 9% of bacterial sonicate, was demonstrated in recombinant Mycobacterium bovis BCG when grown under low-oxygen tension, which serves to enhance hspX promoter activity. Recombinant proteins were efficiently purified from bacterial lysates in a soluble form by virtue of a C-terminal 6-histidine tag. Purification of the immunodominant M. tuberculosis Ag85B antigen using this system resulted in a recombinant protein that stimulated significant IFN-γ release from Ag85B-reactive T cells generated after vaccination of mice with an Ag85B-expressing vaccine. Further, the M. tuberculosis L-alanine dehydrogenase (Ald) protein purified from recombinant BCG displayed strong enzymatic activity in recombinant form. This study demonstrated that high levels of native-like recombinant mycobacterial proteins can be produced in mycobacterial hosts, and this may aid the analysis of mycobacterial protein function and the development of new treatments. PMID:26021569

  8. System xC- is a mediator of microglial function and its deletion slows symptoms in amyotrophic lateral sclerosis mice.

    PubMed

    Mesci, Pinar; Zaïdi, Sakina; Lobsiger, Christian S; Millecamps, Stéphanie; Escartin, Carole; Seilhean, Danielle; Sato, Hideyo; Mallat, Michel; Boillée, Séverine

    2015-01-01

    Amyotrophic lateral sclerosis is the most common adult-onset motor neuron disease and evidence from mice expressing amyotrophic lateral sclerosis-causing SOD1 mutations suggest that neurodegeneration is a non-cell autonomous process where microglial cells influence disease progression. However, microglial-derived neurotoxic factors still remain largely unidentified in amyotrophic lateral sclerosis. With excitotoxicity being a major mechanism proposed to cause motor neuron death in amyotrophic lateral sclerosis, our hypothesis was that excessive glutamate release by activated microglia through their system [Formula: see text] (a cystine/glutamate antiporter with the specific subunit xCT/Slc7a11) could contribute to neurodegeneration. Here we show that xCT expression is enriched in microglia compared to total mouse spinal cord and absent from motor neurons. Activated microglia induced xCT expression and during disease, xCT levels were increased in both spinal cord and isolated microglia from mutant SOD1 amyotrophic lateral sclerosis mice. Expression of xCT was also detectable in spinal cord post-mortem tissues of patients with amyotrophic lateral sclerosis and correlated with increased inflammation. Genetic deletion of xCT in mice demonstrated that activated microglia released glutamate mainly through system [Formula: see text]. Interestingly, xCT deletion also led to decreased production of specific microglial pro-inflammatory/neurotoxic factors including nitric oxide, TNFa and IL6, whereas expression of anti-inflammatory/neuroprotective markers such as Ym1/Chil3 were increased, indicating that xCT regulates microglial functions. In amyotrophic lateral sclerosis mice, xCT deletion surprisingly led to earlier symptom onset but, importantly, this was followed by a significantly slowed progressive disease phase, which resulted in more surviving motor neurons. These results are consistent with a deleterious contribution of microglial-derived glutamate during symptomatic

  9. Effects of different rearing systems on muscle and meat quality traits of slow- and medium-growing male chickens.

    PubMed

    Almasi, A; Andrassyne, B G; Milisits, G; Kustosne, P O; Suto, Z

    2015-01-01

    1. This experiment was conducted to evaluate the effect of production system on the meat quality of slow- and medium-growing chickens. A total of 1075 1-d-old male chicks were equally divided into 6 experimental groups, represented by three strains (SG: TETRA-H, MG1: TETRA HB Color, MG2: Shaver Farm) and were reared in a poultry house in floor pens (12 males/m(2)). 2. On d 49, 150 healthy birds (50/genotype) were placed in a free-range family farm while the rest of the birds remained indoors. All birds were fed ad libitum and consumed the same diet. On d 70, 20 birds of each experimental group were slaughtered and muscle samples were taken from the left breast and thigh muscles. 3. Thigh muscle of SG males kept on free range was darker (L* = 75.12 vs. 78.33) with lower frying loss (45.9% vs. 55.9%) compared with the indoor group. Similar results were obtained from the MG1 group. Free-range MG2 males had lighter thigh meat (L* = 50.7 vs. 57.8) and lower frying loss compared to the indoor group. 4. In general, the indoor treatment had a lower impact on breast meat than the outdoor system. Regardless of the rearing system, genotypic differences were more pronounced in thigh than in breast muscle.

  10. Adaptable state based control system

    NASA Technical Reports Server (NTRS)

    Rasmussen, Robert D. (Inventor); Dvorak, Daniel L. (Inventor); Gostelow, Kim P. (Inventor); Starbird, Thomas W. (Inventor); Gat, Erann (Inventor); Chien, Steve Ankuo (Inventor); Keller, Robert M. (Inventor)

    2004-01-01

    An autonomous controller, comprised of a state knowledge manager, a control executor, hardware proxies and a statistical estimator collaborates with a goal elaborator, with which it shares common models of the behavior of the system and the controller. The elaborator uses the common models to generate from temporally indeterminate sets of goals, executable goals to be executed by the controller. The controller may be updated to operate in a different system or environment than that for which it was originally designed by the replacement of shared statistical models and by the instantiation of a new set of state variable objects derived from a state variable class. The adaptation of the controller does not require substantial modification of the goal elaborator for its application to the new system or environment.

  11. Integrated Aeropropulsion Control System Design

    NASA Technical Reports Server (NTRS)

    Lin, C. -F.; Hurley, Francis X.; Huang, Jie; Hadaegh, F. Y.

    1996-01-01

    %T Integrated Aeropropulsion Control System Design%A C-F. Lin%A Francis X. Hurley%A Jie Huang%A F. Y. Hadaegh%J International Conference on Control and Information(psi)995%C Hong Kong%D June 1995%K aeropropulsion, control, system%U http://jpltrs.jpl.nasa.gov/1995/95-0658.pdfAn integrated intelligent control approach is proposed to design a high performance control system for aeropropulsion systems based on advanced sensor processing, nonlinear control and neural fuzzy control integration. Our approach features the following innovations:??e complexity and uncertainty issues are addressed via the distributed parallel processing, learning, and online reoptimization properties of neural networks.??e nonlinear dynamics and the severe coupling can be naturally incorporated into the design framework.??e knowledge base and decision making logic furnished by fuzzy systems leads to a human intelligence enhanced control scheme.In addition, fault tolerance, health monitoring and reconfigurable control strategies will be accommodated by this approach to ensure stability, graceful degradation and reoptimization in the case of failures, malfunctions and damage.!.

  12. Control theory for random systems

    NASA Technical Reports Server (NTRS)

    Bryson, A. E., Jr.

    1972-01-01

    A survey is presented of the current knowledge available for designing and predicting the effectiveness of controllers for dynamic systems which can be modeled by ordinary differential equations. A short discussion of feedback control is followed by a description of deterministic controller design and the concept of system state. The need for more realistic disturbance models led to the use of stochastic process concepts, in particular the Gauss-Markov process. A compensator controlled system, with random forcing functions, random errors in the measurements, and random initial conditions, is treated as constituting a Gauss-Markov random process; hence the mean-square behavior of the controlled system is readily predicted. As an example, a compensator is designed for a helicopter to maintain it in hover in a gusty wind over a point on the ground.

  13. Deposition System Controller

    2005-10-01

    This software is a complete thin film deposition controller. The software takes as its input a script file that dictates enablinig/disabling of sputtering power supplies, pause times, velocities and distances to move a substrate. An emulator has been created and built into the software package that can debug in advance any deposition script and decide if there is an overrun condition, accidental infinite look, and can estimate a time for completion. All necessary process variablesmore » are data logged and recorded for later inspection. This emulator currently interfaces to a Parker-Compumotor SX6 stepper moror indexer, but the software is written in such a way that it is easily modifiable for interface to othe brand and models of motor drivers. Other process I/O variables may be easily added. The software uses any multifunction DAQ card from National Instruments via their free NIDAQ API package, but again, the software is written such that othe brand DAQ cards may be used.« less

  14. Emission control system

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor); Chung, J. Landy (Inventor)

    2009-01-01

    Methods and apparatus utilizing hydrogen peroxide are useful to reduce SOx and mercury (or other heavy metal) emissions from combustion flue gas streams. The methods and apparatus may further be modified to reduce NOx emissions. Continuous concentration of hydrogen peroxide to levels approaching or exceeding propellant-grade hydrogen peroxide facilitates increased system efficiency. In this manner, combustion flue gas streams can be treated for the removal of SOx and heavy metals, while isolating useful by-products streams of sulfuric acid as well as solids for the recovery of the heavy metals. Where removal of NOx emissions is included, nitric acid may also be isolated for use in fertilizer or other industrial applications.

  15. Manual control of unstable systems

    NASA Technical Reports Server (NTRS)

    Allen, R. W.; Hogue, J. R.; Parseghian, Z.

    1986-01-01

    Under certain operational regimes and failure modes, air and ground vehicles can present the human operator with a dynamically unstable or divergent control task. Research conducted over the last two decades has explored the ability of the human operator to control unstable systems under a variety of circumstances. Past research is reviewed and human operator control capabilities are summarized. A current example of automobile directional control under rear brake lockup conditions is also reviewed. A control system model analysis of the driver's steering control task is summarized, based on a generic driver/vehicle model presented at last year's Annual Manual. Results from closed course braking tests are presented that confirm the difficulty the average driver has in controlling the unstable directional dynamics arising from rear wheel lockup.

  16. Optimal Control Modification Adaptive Law for Time-Scale Separated Systems

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2010-01-01

    Recently a new optimal control modification has been introduced that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. This modification is based on an optimal control formulation to minimize the L2 norm of the tracking error. The optimal control modification adaptive law results in a stable adaptation in the presence of a large adaptive gain. This study examines the optimal control modification adaptive law in the context of a system with a time scale separation resulting from a fast plant with a slow actuator. A singular perturbation analysis is performed to derive a modification to the adaptive law by transforming the original system into a reduced-order system in slow time. A model matching conditions in the transformed time coordinate results in an increase in the actuator command that effectively compensate for the slow actuator dynamics. Simulations demonstrate effectiveness of the method.

  17. Shaping the role of 'fast' and 'slow' drivers of change in forest-shrubland socio-ecological systems.

    PubMed

    Ferrara, Agostino; Kelly, Claire; Wilson, Geoff A; Nolè, Angelo; Mancino, Giuseppe; Bajocco, Sofia; Salvati, Luca

    2016-03-15

    The temporal speeds and spatial scales at which ecosystem processes operate are often at odds with the scale and speed at which natural resources such as soil, water and vegetation are managed those. Scale mismatches often occur as a result of the time-lag between policy development, implementation and observable changes in natural capital in particular. In this study, we analyse some of the transformations that can occur in complex forest-shrubland socio-ecological systems undergoing biophysical and socioeconomic change. We use a Multiway Factor Analysis (MFA) applied to a representative set of variables to assess changes in components of natural, economic and social capitals over time. Our results indicate similarities among variables and spatial units (i.e. municipalities) which allows us to rank the variables used to describe the SES according to their rapidity of change. The novelty of the proposed framework lies in the fact that the assessment of rapidity-to-change, based on the MFA, takes into account the multivariate relationships among the system's variables, identifying the net rate of change for the whole system, and the relative impact that individual variables exert on the system itself. The aim of this study was to assess the influence of fast and slow variables on the evolution of socio-economic systems based on simplified multivariate procedures applicable to vastly different socio-economic contexts and conditions. This study also contributes to quantitative analysis methods for long-established socio-ecological systems, which may help in designing more effective, and sustainable land management strategies in environmentally sensitive areas.

  18. Shaping the role of 'fast' and 'slow' drivers of change in forest-shrubland socio-ecological systems.

    PubMed

    Ferrara, Agostino; Kelly, Claire; Wilson, Geoff A; Nolè, Angelo; Mancino, Giuseppe; Bajocco, Sofia; Salvati, Luca

    2016-03-15

    The temporal speeds and spatial scales at which ecosystem processes operate are often at odds with the scale and speed at which natural resources such as soil, water and vegetation are managed those. Scale mismatches often occur as a result of the time-lag between policy development, implementation and observable changes in natural capital in particular. In this study, we analyse some of the transformations that can occur in complex forest-shrubland socio-ecological systems undergoing biophysical and socioeconomic change. We use a Multiway Factor Analysis (MFA) applied to a representative set of variables to assess changes in components of natural, economic and social capitals over time. Our results indicate similarities among variables and spatial units (i.e. municipalities) which allows us to rank the variables used to describe the SES according to their rapidity of change. The novelty of the proposed framework lies in the fact that the assessment of rapidity-to-change, based on the MFA, takes into account the multivariate relationships among the system's variables, identifying the net rate of change for the whole system, and the relative impact that individual variables exert on the system itself. The aim of this study was to assess the influence of fast and slow variables on the evolution of socio-economic systems based on simplified multivariate procedures applicable to vastly different socio-economic contexts and conditions. This study also contributes to quantitative analysis methods for long-established socio-ecological systems, which may help in designing more effective, and sustainable land management strategies in environmentally sensitive areas. PMID:26741563

  19. The AMSC network control system

    NASA Technical Reports Server (NTRS)

    Garner, William B.

    1990-01-01

    The American Mobile Satellite Corporation (AMSC) is going to construct, launch, and operate a satellite system in order to provide mobile satellite services to the United States. AMSC is going to build, own, and operate a Network Control System (NCS) for managing the communications usage of the satellites, and to control circuit switched access between mobile earth terminals and feeder-link earth stations. An overview of the major NCS functional and performance requirements, the control system physical architecture, and the logical architecture is provided.

  20. The AMSC network control system

    NASA Astrophysics Data System (ADS)

    Garner, William B.

    The American Mobile Satellite Corporation (AMSC) is going to construct, launch, and operate a satellite system in order to provide mobile satellite services to the United States. AMSC is going to build, own, and operate a Network Control System (NCS) for managing the communications usage of the satellites, and to control circuit switched access between mobile earth terminals and feeder-link earth stations. An overview of the major NCS functional and performance requirements, the control system physical architecture, and the logical architecture is provided.

  1. Position feedback control system

    DOEpatents

    Bieg, Lothar F.; Jokiel, Jr., Bernhard; Ensz, Mark T.; Watson, Robert D.

    2003-01-01

    Disclosed is a system and method for independently evaluating the spatial positional performance of a machine having a movable member, comprising an articulated coordinate measuring machine comprising: a first revolute joint; a probe arm, having a proximal end rigidly attached to the first joint, and having a distal end with a probe tip attached thereto, wherein the probe tip is pivotally mounted to the movable machine member; a second revolute joint; a first support arm serially connecting the first joint to the second joint; and coordinate processing means, operatively connected to the first and second revolute joints, for calculating the spatial coordinates of the probe tip; means for kinematically constraining the articulated coordinate measuring machine to a working surface; and comparator means, in operative association with the coordinate processing means and with the movable machine, for comparing the true position of the movable machine member, as measured by the true position of the probe tip, with the desired position of the movable machine member.

  2. The Microwave Anisotropy Probe (MAP) Attitude Control System

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Andrews, Stephen F.; ODonnell, James R., Jr.; Ward, David K.; Ericsson, Aprille J.; Bauer, Frank H. (Technical Monitor)

    2002-01-01

    The Microwave Anisotropy Probe mission is designed to produce a map of the cosmic microwave background radiation over the entire celestial sphere by executing a fast spin and a slow precession of its spin axis about the Sun line to obtain a highly interconnected set of measurements. The spacecraft attitude is sensed and controlled using an Inertial Reference Unit, two Autonomous Star Trackers, a Digital Sun Sensor, twelve Coarse Sun Sensors, three Reaction Wheel Assemblies, and a propulsion system. This paper describes the design of the attitude control system that carries out this mission and presents some early flight experience.

  3. MULTIPLE ECH LAUNCHER CONTROL SYSTEM

    SciTech Connect

    GREEN,M.T; PONCE,D; GRUNLOH,H.J; ELLIS,R.A; GROSNICKLE,W.H; HUMPHREY,R.L

    2003-10-01

    OAK-B135 The addition of new, high power gyrotrons to the heating and current drive arsenal at DIII-D, required a system upgrade for control of fully steerable ECH Launchers. Each launcher contains two pointing mirrors with two degrees of mechanical freedom. The two flavors of motion are called facet and tilt. Therefore up to four channels of motion per launcher need to be controlled. The system utilizes absolute encoders to indicate mirror position and therefore direction of the microwave beam. The launcher movement is primarily controlled by PLC, but future iterations of design, may require this control to be accomplished by a CPU on fast bus such as Compact PCI. This will be necessary to accomplish real time position control. Safety of equipment and personnel is of primary importance when controlling a system of moving parts. Therefore multiple interlocks and fault status enunciators have been implemented. This paper addresses the design of a Multiple ECH Launcher Control System, and characterizes the flexibility needed to upgrade to a real time position control system in the future.

  4. Weld analysis and control system

    NASA Technical Reports Server (NTRS)

    Kennedy, Larry Z. (Inventor); Rodgers, Michael H. (Inventor); Powell, Bradley W. (Inventor); Burroughs, Ivan A. (Inventor); Goode, K. Wayne (Inventor)

    1994-01-01

    The invention is a Weld Analysis and Control System developed for active weld system control through real time weld data acquisition. Closed-loop control is based on analysis of weld system parameters and weld geometry. The system is adapted for use with automated welding apparatus having a weld controller which is capable of active electronic control of all aspects of a welding operation. Enhanced graphics and data displays are provided for post-weld analysis. The system provides parameter acquisition, including seam location which is acquired for active torch cross-seam positioning. Torch stand-off is also monitored for control. Weld bead and parent surface geometrical parameters are acquired as an indication of weld quality. These parameters include mismatch, peaking, undercut, underfill, crown height, weld width, puddle diameter, and other measurable information about the weld puddle regions, such as puddle symmetry, etc. These parameters provide a basis for active control as well as post-weld quality analysis and verification. Weld system parameters, such as voltage, current and wire feed rate, are also monitored and archived for correlation with quality parameters.

  5. Comparison of automatic control systems

    NASA Technical Reports Server (NTRS)

    Oppelt, W

    1941-01-01

    This report deals with a reciprocal comparison of an automatic pressure control, an automatic rpm control, an automatic temperature control, and an automatic directional control. It shows the difference between the "faultproof" regulator and the actual regulator which is subject to faults, and develops this difference as far as possible in a parallel manner with regard to the control systems under consideration. Such as analysis affords, particularly in its extension to the faults of the actual regulator, a deep insight into the mechanism of the regulator process.

  6. The AGS Booster control system

    SciTech Connect

    Frankel, R.; Auerbach, E.; Culwick, B.; Clifford, T.; Mandell, S.; Mariotti, R.; Salwen, C.; Schumburg, N.

    1988-01-01

    Although moderate in size, the Booster construction project requires a comprehensive control system. There are three operational modes: as a high intensity proton injector for the AGS, as a heavy ion accelerator and injector supporting a wide range of ions and as a polarized proton storage injector. These requirements are met using a workstation based extension of the existing AGS control system. Since the Booster is joining a complex of existing accelerators, the new system will be capable of supporting multiuser operational scenarios. A short discussion of this system is discussed in this paper.

  7. Integrated control system and method

    SciTech Connect

    Wang, Paul Sai Keat; Baldwin, Darryl; Kim, Myoungjin

    2013-10-29

    An integrated control system for use with an engine connected to a generator providing electrical power to a switchgear is disclosed. The engine receives gas produced by a gasifier. The control system includes an electronic controller associated with the gasifier, engine, generator, and switchgear. A gas flow sensor monitors a gas flow from the gasifier to the engine through an engine gas control valve and provides a gas flow signal to the electronic controller. A gas oversupply sensor monitors a gas oversupply from the gasifier and provides an oversupply signal indicative of gas not provided to the engine. A power output sensor monitors a power output of the switchgear and provide a power output signal. The electronic controller changes gas production of the gasifier and the power output rating of the switchgear based on the gas flow signal, the oversupply signal, and the power output signal.

  8. The ILC global control system.

    SciTech Connect

    Carwardine, J.; Arnold, N.; Lenkszus, F.; Saunders, C.; Rehlich, K.; Simrock, S.; Banerjee, B.; Chase, B.; Gottschalk, E.; Joireman, P.; Kasley, P.; Lackey, S.; McBride, P.; Pavlicek, V.; Patrick, J.; Votava, M.; Wolbers, S.; Furukawa, K.; Michizono, S.; Larsen , R .S.; Downing, R.; FNAL; DESY; KEK; SLAC

    2008-01-01

    The scale and performance parameters of the ILC require new thinking in regards to control system design. This design work has begun quite early in comparison to most accelerator projects, with the goal of uniquely high overall accelerator availability. Among the design challenges are high control system availability, precision timing and rf phase reference distribution, standardizing of interfaces, operability, and maintainability. We present the current state of the design and take a prospective look at ongoing research and development projects.

  9. Pump control system for windmills

    SciTech Connect

    Avery, D.E.

    1983-07-12

    A windmill control system is disclosed having lever means, for varying length of stroke of the pump piston, and a control means, responsive to the velocity of the wind to operate the lever means to vary the length of stroke and hence the effective displacement of the pump in accordance with available wind energy, with the control means having a sensing member separate from the windmill disposed in the wind and displaceable thereby in accordance with wind velocity.

  10. Pump control system for windmills

    DOEpatents

    Avery, Don E.

    1983-01-01

    A windmill control system having lever means, for varying length of stroke of the pump piston, and a control means, responsive to the velocity of the wind to operate the lever means to vary the length of stroke and hence the effective displacement of the pump in accordance with available wind energy, with the control means having a sensing member separate from the windmill disposed in the wind and displaceable thereby in accordance with wind velocity.

  11. A novel microsatellite control system

    SciTech Connect

    Moore, K.R.; Frigo, J.R.; Tilden, M.W.

    1998-02-01

    The authors are researching extremely simple yet quite capable analog pulse-coded neural networks for ``smaller-faster-cheaper`` spacecraft attitude and control systems. The will demonstrate a prototype microsatellite that uses their novel control method to autonomously stabilize itself in the ambient magnetic field and point itself at the brightest available light source. Though still in design infancy, the ``Nervous Net`` controllers described could allow for space missions not currently possible given conventional satellite hardware. Result, prospects and details are presented.

  12. 3. EAGLE ROCK CONTROL CENTER, OPERATIONS CONTROL. AS SYSTEM BECOMES ...

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

    3. EAGLE ROCK CONTROL CENTER, OPERATIONS CONTROL. AS SYSTEM BECOMES INCREASINGLY AUTOMATED, EAGLE ROCK WILL BECOME MORE AND MORE THE CENTRAL CONTROL SYSTEM OF THE METROPOLITAN WATER DISTRICT. - Eagle Rock Operations Control Center, Pasadena, Los Angeles County, CA

  13. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1982-01-01

    A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

  14. Reliable timing systems for computer controlled accelerators

    NASA Astrophysics Data System (ADS)

    Knott, Jürgen; Nettleton, Robert

    1986-06-01

    Over the past decade the use of computers has set new standards for control systems of accelerators with ever increasing complexity coupled with stringent reliability criteria. In fact, with very slow cycling machines or storage rings any erratic operation or timing pulse will cause the loss of precious particles and waste hours of time and effort of preparation. Thus, for the CERN linac and LEAR (Low Energy Antiproton Ring) timing system reliability becomes a crucial factor in the sense that all components must operate practically without fault for very long periods compared to the effective machine cycle. This has been achieved by careful selection of components and design well below thermal and electrical limits, using error detection and correction where possible, as well as developing "safe" decoding techniques for serial data trains. Further, consistent structuring had to be applied in order to obtain simple and flexible modular configurations with very few components on critical paths and to minimize the exchange of information to synchronize accelerators. In addition, this structuring allows the development of efficient strategies for on-line and off-line fault diagnostics. As a result, the timing system for Linac 2 has, so far, been operating without fault for three years, the one for LEAR more than one year since its final debugging.

  15. Inhibition of Astrocytic Glutamine Synthetase by Lead is Associated with a Slowed Clearance of Hydrogen Peroxide by the Glutathione System

    PubMed Central

    Robinson, Stephen R.; Lee, Alan; Bishop, Glenda M.; Czerwinska, Hania; Dringen, Ralf

    2015-01-01

    Lead intoxication in humans is characterized by cognitive impairments, particularly in the domain of memory, where evidence indicates that glutamatergic neurotransmission may be impacted. Animal and cell culture studies have shown that lead decreases the expression and activity of glutamine synthetase (GS) in astrocytes, yet the basis of this effect is uncertain. To investigate the mechanism responsible, the present study exposed primary astrocyte cultures to a range of concentrations of lead acetate (0–330 μM) for up to 24 h. GS activity was significantly reduced in cells following 24 h incubation with 100 or 330 μM lead acetate. However, no reduction in GS activity was detected when astrocytic lysates were co-incubated with lead acetate, suggesting that the mechanism is not due to a direct interaction and involves intact cells. Since GS is highly sensitive to oxidative stress, the capacity of lead to inhibit the clearance of hydrogen peroxide (H2O2) was investigated. It was found that exposure to lead significantly diminished the capacity of astrocytes to degrade H2O2, and that this was due to a reduction in the effectiveness of the glutathione system, rather than to catalase. These results suggest that the inhibition of GS activity in lead poisoning is a consequence of slowed H2O2 clearance, and supports the glutathione pathway as a primary therapeutic target. PMID:26696846

  16. Nova laser alignment control system

    SciTech Connect

    Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L.; Shelton, R.T.

    1984-03-29

    Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently with the computer system. Automatic alignment is accomplished by using image analysis techniques to determine beam references points from video images acquired along the laser chain. A major goal of the design is to contribute substantially to rapid experimental turnaround and consistent alignment results. This paper describes the computer-based control structure and the software methods developed for aligning this large laser system.

  17. Electromechanical propellant control system actuator

    NASA Technical Reports Server (NTRS)

    Myers, W. Neill; Weir, Rae Ann

    1990-01-01

    New control mechanism technologies are currently being sought to provide alternatives to hydraulic actuation systems. The Propulsion Laboratory at Marshall Space Flight Center (MSFC) is involved in the development of electromechanical actuators (EMA's) for this purpose. Through this effort, an in-house designed electromechanical propellant valve actuator has been assembled and is presently being evaluated. This evaluation will allow performance comparisons between EMA and hydraulics systems. The in-house design consists of the following hardware: a three-phase brushless motor, a harmonic drive, and an output spline which will mate with current Space Shuttle Main Engine (SSME) propellant control valves. A resolver and associated electronics supply position feedback for the EMA. System control is provided by a solid-state electronic controller and power supply. Frequency response testing has been performed with further testing planned as hardware and test facilities become available.

  18. Space construction base control system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Aspects of an attitude control system were studied and developed for a large space base that is structurally flexible and whose mass properties change rather dramatically during its orbital lifetime. Topics of discussion include the following: (1) space base orbital pointing and maneuvering; (2) angular momentum sizing of actuators; (3) momentum desaturation selection and sizing; (4) multilevel control technique applied to configuration one; (5) one-dimensional model simulation; (6) N-body discrete coordinate simulation; (7) structural analysis math model formulation; and (8) discussion of control problems and control methods.

  19. Expert system for train control

    NASA Astrophysics Data System (ADS)

    Drish, William F., Jr.

    1995-08-01

    The train energy model (TEM), a general train simulator developed at the Association of American Railroads, is widely used in the railroad industry. Recently, a new train controller, the general automatic train-controller (GAT), has been developed for TEM. In the GAT, the 'intelligence' or 'expertise' is a set of 'if-then' train-handling rules in an external file. The expert system for train control presented in this paper is a slightly simplified version of the GAT. The main thesis of this paper is: simple, unchained rules are adequate for complex train control. Thus, an 'inference engine' using forward chaining is not required.

  20. Balanced bridge feedback control system

    NASA Technical Reports Server (NTRS)

    Lurie, Boris J. (Inventor)

    1990-01-01

    In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus has a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.

  1. Electrically driven environmental control system

    SciTech Connect

    Mcnamara, J.E.

    1984-05-01

    An environmental control system (ECS) being developed under the title of energy efficient environmental control system is described. The ECS is a closed-loop, electrically driven, vapor cycle system. The vapor cycle will have a compressor driven by a variable speed, high-voltage dc motor. The reasons for selecting this type of system are discussed here. Breadboard testing of a variable speed compressor to demonstrate the feasibility of such an approach has been completed. The testing results were used to develop a preliminary design of a prototype compressor. In future phases of the program, the prototype compressor will be developed a prototype system will be constructed and laboratory tested and finally the prototype system will be flight demonstrated.

  2. Advanced flight control system study

    NASA Technical Reports Server (NTRS)

    Hartmann, G. L.; Wall, J. E., Jr.; Rang, E. R.; Lee, H. P.; Schulte, R. W.; Ng, W. K.

    1982-01-01

    A fly by wire flight control system architecture designed for high reliability includes spare sensor and computer elements to permit safe dispatch with failed elements, thereby reducing unscheduled maintenance. A methodology capable of demonstrating that the architecture does achieve the predicted performance characteristics consists of a hierarchy of activities ranging from analytical calculations of system reliability and formal methods of software verification to iron bird testing followed by flight evaluation. Interfacing this architecture to the Lockheed S-3A aircraft for flight test is discussed. This testbed vehicle can be expanded to support flight experiments in advanced aerodynamics, electromechanical actuators, secondary power systems, flight management, new displays, and air traffic control concepts.

  3. Control system health test system and method

    DOEpatents

    Hoff, Brian D.; Johnson, Kris W.; Akasam, Sivaprasad; Baker, Thomas M.

    2006-08-15

    A method is provided for testing multiple elements of a work machine, including a control system, a component, a sub-component that is influenced by operations of the component, and a sensor that monitors a characteristic of the sub-component. In one embodiment, the method is performed by the control system and includes sending a command to the component to adjust a first parameter associated with an operation of the component. Also, the method includes detecting a sensor signal from the sensor reflecting a second parameter associated with a characteristic of the sub-component and determining whether the second parameter is acceptable based on the command. The control system may diagnose at least one of the elements of the work machine when the second parameter of the sub-component is not acceptable.

  4. Learning fuzzy logic control system

    NASA Technical Reports Server (NTRS)

    Lung, Leung Kam

    1994-01-01

    The performance of the Learning Fuzzy Logic Control System (LFLCS), developed in this thesis, has been evaluated. The Learning Fuzzy Logic Controller (LFLC) learns to control the motor by learning the set of teaching values that are generated by a classical PI controller. It is assumed that the classical PI controller is tuned to minimize the error of a position control system of the D.C. motor. The Learning Fuzzy Logic Controller developed in this thesis is a multi-input single-output network. Training of the Learning Fuzzy Logic Controller is implemented off-line. Upon completion of the training process (using Supervised Learning, and Unsupervised Learning), the LFLC replaces the classical PI controller. In this thesis, a closed loop position control system of a D.C. motor using the LFLC is implemented. The primary focus is on the learning capabilities of the Learning Fuzzy Logic Controller. The learning includes symbolic representation of the Input Linguistic Nodes set and Output Linguistic Notes set. In addition, we investigate the knowledge-based representation for the network. As part of the design process, we implement a digital computer simulation of the LFLCS. The computer simulation program is written in 'C' computer language, and it is implemented in DOS platform. The LFLCS, designed in this thesis, has been developed on a IBM compatible 486-DX2 66 computer. First, the performance of the Learning Fuzzy Logic Controller is evaluated by comparing the angular shaft position of the D.C. motor controlled by a conventional PI controller and that controlled by the LFLC. Second, the symbolic representation of the LFLC and the knowledge-based representation for the network are investigated by observing the parameters of the Fuzzy Logic membership functions and the links at each layer of the LFLC. While there are some limitations of application with this approach, the result of the simulation shows that the LFLC is able to control the angular shaft position of the

  5. Control system for thermoelectric refrigerator

    NASA Technical Reports Server (NTRS)

    Nelson, John L. (Inventor); Criscuolo, Lance (Inventor); Gilley, Michael D. (Inventor); Park, Brian V. (Inventor)

    1996-01-01

    Apparatus including a power supply (202) and control system is provided for maintaining the temperature within an enclosed structure (40) using thermoelectric devices (92). The apparatus may be particularly beneficial for use with a refrigerator (20) having superinsulation materials (46) and phase change materials (112) which cooperate with the thermoelectric device (92) to substantially enhance the overall operating efficiency of the refrigerator (20). The electrical power supply (202) and control system allows increasing the maximum power capability of the thermoelectric device (92) in response to increased heat loads within the refrigerator (20). The electrical power supply (202) and control system may also be used to monitor the performance of the cooling system (70) associated with the refrigerator (20).

  6. Marine loading vapor control systems

    SciTech Connect

    Babet, F.H.

    1996-09-01

    The EPA and State air quality control boards have mandated the collection and destruction or recovery of vapors generated by the loading of some hydrocarbons and chemicals into marine vessels. This is a brief overview of the main US Coast Guard requirements for marine vapor control systems. As with most regulations, they are open to interpretation. In an attempt to more clearly define the intent of the regulations, the US Coast Guard has issued guidelines to assist the certifying entities in ensuring compliance with intended regulations. If a company is contemplating the installation of a marine loading vapor control system, the authors strongly recommend that one engage the services of a certifying entity, either as the designer, or an advisor and ultimately the certifier of the system. This should be done well up front in the design of the system to avoid costly mistakes which can occur as a result of lack of knowledge or misinterpretation of the regulations and guidelines.

  7. New Main Ring control system

    SciTech Connect

    Seino, K.; Anderson, L.; Ducar, R.; Franck, A.; Gomilar, J.; Hendricks, B.; Smedinghoff, J.

    1990-03-01

    The Fermilab Main Ring control system has been operational for over sixteen years. Aging and obsolescence of the equipment make the maintenance difficult. Since the advent of the Tevatron, considerable upgrades have been made to the controls of all the Fermilab accelerators except the Main Ring. Modernization of the equipment and standardization of the hardware and software have thus become inevitable. The Tevatron CAMAC serial system has been chosen as a basic foundation in order to make the Main Ring control system compatible with the rest of the accelerator complex. New hardware pieces including intelligent CAMAC modules have been designed to satisfy unique requirements. Fiber optic cable and repeaters have been installed in order to accommodate new channel requirements onto the already saturated communication medium system. 8 refs., 2 figs.

  8. Movement - uncontrolled or slow

    MedlinePlus

    Dystonia; Involuntary slow and twisting movements; Choreoathetosis; Leg and arm movements - uncontrollable; Arm and leg movements - uncontrollable; Slow involuntary movements of large muscle groups; Athetoid movements

  9. Component Control System for a Vehicle

    NASA Technical Reports Server (NTRS)

    Fraser-Chanpong, Nathan (Inventor); Spain, Ivan (Inventor); Dawson, Andrew D. (Inventor); Bluethmann, William J. (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Guo, Raymond (Inventor); Waligora, Thomas M. (Inventor); Akinyode, Akinjide Akinniyi (Inventor); Reed, Ryan M. (Inventor)

    2016-01-01

    A vehicle includes a chassis, a modular component, and a central operating system. The modular component is supported by the chassis. The central operating system includes a component control system, a primary master controller, and a secondary master controller. The component control system is configured for controlling the modular component. The primary and secondary master controllers are in operative communication with the component control system. The primary and secondary master controllers are configured to simultaneously transmit commands to the component control system. The component control system is configured to accept commands from the secondary master controller only when a fault occurs in the primary master controller.

  10. CHARA Array Enclosure Control System

    NASA Astrophysics Data System (ADS)

    Hines, Braden E.; ten Brummelaar, Theo A.

    2002-12-01

    The CHARA Array at Mt. Wilson consists of six telescopes spread over hundreds of meters of rugged territory. Making efficient use of such a large physical instrument requires automation and tele-operation of the distributed resources. One system which is key to making daily operations routine is the enclosure control system, which is used to open and close the walls of the enclosure in order to enable quick equilibration of the telescope with its environment in order to minimize ground seeing effects on observations. This paper describes this enclosure control system, which is a distributed hardware/software system consisting of software running on a central control station in the operations room, together with software and hardware installed on six remote computers. The system must be robust in the presence of absent or intermittent nodes or network connections, must provide for both manual or remote control of the enclosures, and must provide for hardware and personnel safety. Remote operation of the system from Atlanta, Georgia has been demonstrated, and the system has proven extremely robust in regular use to date.

  11. Development of a slow non-viral DNA release system from PDLLA scaffolds fabricated using a supercritical CO2 technique.

    PubMed

    Heyde, Mieke; Partridge, Kris A; Howdle, Steven M; Oreffo, Richard O C; Garnett, Martin C; Shakesheff, Kevin M

    2007-10-15

    Polyamidoamine polymers (PAA) comprising methylene-bisacrylamide/dimethylethylene-diamine monomers were synthesized, complexed with DNA and incorporated into porous P(DL)LA scaffolds by using a supercritical CO(2) (scCO(2)) technique. Scaffolds were made in a dry state consequently there was a need to lyophilize the complexes. A statistically significant reduction of the transfection efficiency was observed in the absence of trehalose when compared to the original complex after freeze-drying. Increasing concentrations (0-10% w/v) of trehalose were added to the complex prior to freeze-drying. Structure dependent differences in DNA binding were evaluated by gel electrophoresis and thermal transition analysis. TEM and PCS showed aggregate formation after freeze-drying without trehalose. Scaffolds were characterized by pore sizes of 173 +/- 73 microm and a porosity of 71%. The transfection potential of the released DNA was investigated by seeding scaffolds with A549 cells and following firefly luciferase as a marker gene after 48 h exposure. Low but continuous levels of transfection were observed for PAA complexes during a 60-day study. Complexes made with Lipofectaminetrade mark gave initially higher levels of DNA release but no further expression was seen after 40 days. Uncomplexed DNA showed background levels of transfection. Culturing cells on 3D scaffolds showed a benefit in retention of transfection activity with time compared to 2D controls. Transfection levels could be increased when cells were grown in OptiMEM. This study demonstrated that PAA/DNA complexes incorporated into a P(DL)LA scaffold made by using scCO(2) processing exhibited a slow release and extended gene expression profile. PMID:17405179

  12. A new ovitrap made of slow release natural materials containing pyriproxyfen for Aedes aegypti (Diptera:Culicidae) control.

    PubMed

    Juan, Laura; Seccacini, Emilia; Zerba, Eduardo; Licastro, Susana

    2013-07-01

    ABSTRACT This initial study is aimed to measure the performance of incorporating pyriproxyfen in natural materials with low environmental impact to obtain slow release formulations that can be used as larvicidal or autocidal ovitraps avoiding hatched Aedes aegypti (L.) eggs to emerge as adults. Hollow candles made of beeswax or paraffin:stearin 1:1 mixture containing pyriproxyfen 0.01 and 0.05% were prepared and used as holding water containers for larval bioassay. Pyriproxyfen was released quickly into the larvae-breeding water. Ae. aegypti larvae were introduced immediately after the addition of tap water to the hollow candles (t = 1 min) or after 1, 4, and 8 h. More than 40% of the larvae did not emerge as adults for t = 1 min, reaching 80-100% when the larvae were added after 1 or 4 h, respectively. The hollow candles were kept at room temperature, and water was replaced every 15 d. Bioassays performed every 30 d showed that the residual activity obtained for both matrices and both concentrations of pyriproxyfen was higher than 360 d, with 100% inhibition of adult emergence. PMID:23926792

  13. Advanced Light Source control system

    SciTech Connect

    Magyary, S.; Chin, M.; Cork, C.; Fahmie, M.; Lancaster, H.; Molinari, P.; Ritchie, A.; Robb, A.; Timossi, C.

    1989-03-01

    The Advanced Light Source (ALS) is a third generation 1--2 GeV synchrotron radiation source designed to provide ports for 60 beamlines. It uses a 50 MeV electron linac and 1.5 GeV, 1 Hz, booster synchrotron for injection into a 1--2 GeV storage ring. Interesting control problems are created because of the need for dynamic closed beam orbit control to eliminate interaction between the ring tuning requirements and to minimize orbit shifts due to ground vibrations. The extremely signal sensitive nature of the experiments requires special attention to the sources of electrical noise. These requirements have led to a control system design which emphasizes connectivity at the accelerator equipment end and a large I/O bandwidth for closed loop system response. Not overlooked are user friendliness, operator response time, modeling, and expert system provisions. Portable consoles are used for local operation of machine equipment. Our solution is a massively parallel system with >120 Mbits/sec I/O bandwidth and >1500 Mips computing power. At the equipment level connections are made using over 600 powerful Intelligent Local Controllers (ILC-s) mounted in 3U size Eurocard slots using fiber-optic cables between rack locations. In the control room, personal computers control and display all machine variables at a 10 Hz rate including the scope signals which are collected though the control system. Commercially available software and industry standards are used extensively. Particular attention is paid to reliability, maintainability and upgradeability. 10 refs., 11 figs.

  14. Skylab thruster attitude control system

    NASA Technical Reports Server (NTRS)

    Wilmer, G. E., Jr.

    1974-01-01

    Preflight activities and the Skylab mission support effort for the thruster attitude control system (TACS) are documented. The preflight activities include a description of problems and their solutions encountered in the development, qualification, and flight checkout test programs. Mission support effort is presented as it relates to system performance assessment, real-time problem solving, flight anomalies, and the daily system evaluation. Finally, the detailed flight evaluation is presented for each phase of the mission using system telemetry data. Data assert that the TACS met or exceeded design requirements and fulfilled its assigned mission objectives.

  15. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-06-25

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  16. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A.; Beloussov, Alexandre V.; Bakir, Julide; Armon, Deganit; Olsen, Howard B.; Salem, Dana

    2008-07-08

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  17. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A.; Beloussov, Alexandre V.; Bakir, Julide; Armon, Deganit; Olsen, Howard B.; Salem, Dana

    2010-09-21

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  18. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-12-03

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  19. Antenna surface contour control system

    NASA Astrophysics Data System (ADS)

    Ahl, Elvin L.; Miller, James B.

    1989-03-01

    The invention is a system for automatically controlling the surface contour of a deployable and restowable antenna having a mesh reflector surface supported by a circular, folding hoop affixed to a central, telescoping column. The antenna, when deployed, forms a quad-aperture reflector with each quadrant of the mesh surface shaped to provide an offset parabolic radio frequency (RF) reflector. The hoop is supported and positioned by quartz support cords attached to the top of a column and by lower graphite hoop control cords that extend between the hoop and base of the column. The antenna, an RF reflective surface, is a gold plated molybdenum wire mesh supported on a graphite cord truss structure that includes the hoop control cords and a plurality of surface control cords attached at selected points on the surface and to the base of the column. The contour of the three-dimensional surface of the antenna is controlled by selectively adjusting the lengths of the surface control cords and the graphite hoop control cords by means of novel actuator assemblies that automatically sense and change the lengths of the lower hoop control cords and surface control cords.

  20. Antenna surface contour control system

    NASA Technical Reports Server (NTRS)

    Ahl, Elvin L. (Inventor); Miller, James B. (Inventor)

    1989-01-01

    The invention is a system for automatically controlling the surface contour of a deployable and restowable antenna having a mesh reflector surface supported by a circular, folding hoop affixed to a central, telescoping column. The antenna, when deployed, forms a quad-aperture reflector with each quadrant of the mesh surface shaped to provide an offset parabolic radio frequency (RF) reflector. The hoop is supported and positioned by quartz support cords attached to the top of a column and by lower graphite hoop control cords that extend between the hoop and base of the column. The antenna, an RF reflective surface, is a gold plated molybdenum wire mesh supported on a graphite cord truss structure that includes the hoop control cords and a plurality of surface control cords attached at selected points on the surface and to the base of the column. The contour of the three-dimensional surface of the antenna is controlled by selectively adjusting the lengths of the surface control cords and the graphite hoop control cords by means of novel actuator assemblies that automatically sense and change the lengths of the lower hoop control cords and surface control cords.

  1. Preventing Integrator Windup In A Control System

    NASA Technical Reports Server (NTRS)

    Kaminer, Isaac

    1992-01-01

    Design concept for control system addresses how to prevent control inputs to plant from exceeding electrical limits imposed by mechanical limits of control actuators in plant, and prevent windup in integrators in control system. Concept consists of two parts. First, to rearrange terms of control equation to move integrators into output path of control system. Second, involves limiting inputs to integrators when one control input of plant reaches its limit. Concept applicable to control systems typical of aircraft autopilot systems.

  2. Reactor control rod timing system

    DOEpatents

    Wu, Peter T. K.

    1982-01-01

    A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.

  3. Reactor control rod timing system

    SciTech Connect

    Wu, P.T.

    1982-02-09

    A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (Above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.

  4. Space construction base control system

    NASA Technical Reports Server (NTRS)

    Kaczynski, R. F.

    1979-01-01

    Several approaches for an attitude control system are studied and developed for a large space construction base that is structurally flexible. Digital simulations were obtained using the following techniques: (1) the multivariable Nyquist array method combined with closed loop pole allocation, (2) the linear quadratic regulator method. Equations for the three-axis simulation using the multilevel control method were generated and are presented. Several alternate control approaches are also described. A technique is demonstrated for obtaining the dynamic structural properties of a vehicle which is constructed of two or more submodules of known dynamic characteristics.

  5. ITER Plasma Control System Development

    NASA Astrophysics Data System (ADS)

    Snipes, Joseph; ITER PCS Design Team

    2015-11-01

    The development of the ITER Plasma Control System (PCS) continues with the preliminary design phase for 1st plasma and early plasma operation in H/He up to Ip = 15 MA in L-mode. The design is being developed through a contract between the ITER Organization and a consortium of plasma control experts from EU and US fusion laboratories, which is expected to be completed in time for a design review at the end of 2016. This design phase concentrates on breakdown including early ECH power and magnetic control of the poloidal field null, plasma current, shape, and position. Basic kinetic control of the heating (ECH, ICH, NBI) and fueling systems is also included. Disruption prediction, mitigation, and maintaining stable operation are also included because of the high magnetic and kinetic stored energy present already for early plasma operation. Support functions for error field topology and equilibrium reconstruction are also required. All of the control functions also must be integrated into an architecture that will be capable of the required complexity of all ITER scenarios. A database is also being developed to collect and manage PCS functional requirements from operational scenarios that were defined in the Conceptual Design with links to proposed event handling strategies and control algorithms for initial basic control functions. A brief status of the PCS development will be presented together with a proposed schedule for design phases up to DT operation.

  6. The MICE Run Control System

    NASA Astrophysics Data System (ADS)

    Hanlet, Pierrick; Mice Collaboration

    2014-06-01

    The Muon Ionization Cooling Experiment (MICE) is a demonstration experiment to prove the feasibility of cooling a beam of muons for use in a Neutrino Factory and/or Muon Collider. The MICE cooling channel is a section of a modified Study II cooling channel which will provide a 10% reduction in beam emittance. In order to ensure a reliable measurement, MICE will measure the beam emittance before and after the cooling channel at the level of 1%, or a relative measurement of 0.001. This renders MICE a precision experiment which requires strict controls and monitoring of all experimental parameters in order to control systematic errors. The MICE Controls and Monitoring system is based on EPICS and integrates with the DAQ, Data monitoring systems, and a configuration database. The new MICE Run Control has been developed to ensure proper sequencing of equipment and use of system resources to protect data quality. A description of this system, its implementation, and performance during recent muon beam data collection will be discussed.

  7. Cockpit control system conceptual design

    NASA Technical Reports Server (NTRS)

    Meholic, Greg; Brown, Rhonda; Hall, Melissa; Harvey, Robert; Singer, Michael; Tella, Gustavo

    1993-01-01

    The purpose of this project was to provide a means for operating the ailerons, elevator, elevator trim, rudder, nosewheel steering, and brakes in the Triton primary flight trainer. The main design goals under consideration were to illustrate system and subsystem integration, control function ability, and producibility. Weight and maintenance goals were addressed.

  8. GTC control system: an overview

    NASA Astrophysics Data System (ADS)

    Filgueira, Jose M.; Rodriguez, Daniel

    1998-05-01

    The GTC project is in charge of the construction of an optical/IR 10-meter class telescope at the Observatorio del Roque de los Muchachos in Canary Islands. The GTC control system (GCS) will be responsible for the management and operation of the telescope, including its instrumentation. Its conceptual design has been completed in summer 1997. The continuous and rapid development of hardware, software and communications technology has permitted a greater complexity in control systems. In their turn, the development of active and adaptive optics, the new methods of optimizing available observing time and the continuous development programs to maintain telescope competitiveness present new challenges in the design of control systems. During its life-cycles, the GCS will be subject to continuous changes brought about by different factors, such as the advent of new technologies, the evolution of the requirements, the development of new instruments and fault correction. These factors must be taken on board with the minimum possible impact, not only on the project but also on the availability of the GTC once it enters into operation. This will only be possible through the selection and planning of an adequate technological framework that enables these changes to be assimilated throughout the life-cycle of the telescope. In this presentation the fundamental aspects of this framework along the current status of the control system design are outlined.

  9. Propulsive Reaction Control System Model

    NASA Technical Reports Server (NTRS)

    Brugarolas, Paul; Phan, Linh H.; Serricchio, Frederick; San Martin, Alejandro M.

    2011-01-01

    This software models a propulsive reaction control system (RCS) for guidance, navigation, and control simulation purposes. The model includes the drive electronics, the electromechanical valve dynamics, the combustion dynamics, and thrust. This innovation follows the Mars Science Laboratory entry reaction control system design, and has been created to meet the Mars Science Laboratory (MSL) entry, descent, and landing simulation needs. It has been built to be plug-and-play on multiple MSL testbeds [analysis, Monte Carlo, flight software development, hardware-in-the-loop, and ATLO (assembly, test and launch operations) testbeds]. This RCS model is a C language program. It contains two main functions: the RCS electronics model function that models the RCS FPGA (field-programmable-gate-array) processing and commanding of the RCS valve, and the RCS dynamic model function that models the valve and combustion dynamics. In addition, this software provides support functions to initialize the model states, set parameters, access model telemetry, and access calculated thruster forces.

  10. Fiber optic control system integration

    NASA Technical Reports Server (NTRS)

    Poppel, G. L.; Glasheen, W. M.; Russell, J. C.

    1987-01-01

    A total fiber optic, integrated propulsion/flight control system concept for advanced fighter aircraft is presented. Fiber optic technology pertaining to this system is identified and evaluated for application readiness. A fiber optic sensor vendor survey was completed, and the results are reported. The advantages of centralized/direct architecture are reviewed, and the concept of the protocol branch is explained. Preliminary protocol branch selections are made based on the F-18/F404 application. Concepts for new optical tools are described. Development plans for the optical technology and the described system are included.

  11. The ALMA Telescope Control System

    NASA Astrophysics Data System (ADS)

    Farris, A.; Marson, Ralph; Kern, Jeff

    2005-10-01

    The Atacama Large Millimeter Array (ALMA) is a joint project between North America, Europe and Japan. ALMA is an aperture synthesis radio telescope consisting of 50 12-meter antennas located at an elevation of 5,000 meters in Llano de Chajnantor, Chile. These antennas will operate at frequencies ranging from 31.3 GHz to 950 GHz. The antennas can be moved and placed in different configurations, with baselines between the antennas varying from 150 meters to 20 km. The 50 antennas are supplemented by sixteen additional ones, known as the ALMA Compact Array (ACA): 12 7-meter antennas and 4 12-meter antennas. The ALMA control system will consist of over 70 computers separated by distances of over 20 km. Two aspects of the system are apparent: its distributed nature and its need to accurately synchronize events across many computers separated by large distances. In this paper we describe key features of the architecture of the ALMA Control System, focusing on its properties as a distributed system and on the mechanisms employed to achieve its time synchronization goals. This control system is a distributed system that uses the ALMA Common Software (ACS) as a middleware system layered on top of CORBA. The architecture of the control system extensively employs the component/container model in ACS. In addition, the use of CORBA allows us to employ Java in the higher levels of the control system, leaving C++ to the lower time-critical levels. Python as a scripting language is used by astronomers, to craft standard observing programs, and engineers, in a testing and debugging mode. Key to the concept of an aperture synthesis telescope is a special purpose hardware system known as a correlator, responsible for making various delay model corrections and correlating the signals from the antennas. There are two correlators in ALMA, one for the array of 50 antennas and one for the ACA. This entire system operates under a control system that must synchronize events across the

  12. Fiberoptics for propulsion control system

    NASA Technical Reports Server (NTRS)

    Baumbick, R. J.

    1984-01-01

    In aircraft systems with digital controls, fiberoptics has advantages over wire systems because of its inherent immunity to electromagnetic noise (EMI) and electromagnetic pulses (EMP). It also offers a weight benefit when metallic conductors are replaced by optical fibers. To take full advantage of the benefits of optical waveguides, passive optical sensors are also being developed to eliminate the need for electrical power to the sensor. Fiberoptics may also be used for controlling actuators on engine and airframe. In this application, the optical fibers, connectors, etc. will be subjected to high temperature and vibrations. This paper discussed the use of fiberoptics in aircraft propulsion systems together with the optical sensors and optically controlled actuators being developed to take full advantage of the benefits which fiberoptics offers. The requirements for sensors and actuators in advanced propulsion systems are identified. The benefits of using fiberoptics in place of conventional wire systems are discussed as well as the environmental conditions under which the optical components must operate.

  13. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1981-01-01

    A commutated automatic gain control system (AGC) was designed and constructed for the prototype Loran C receiver. The AGC is designed to improve the signal-to-signal ratio of the received Loran signals. The AGC design does not require any analog to digital conversion and it utilizes commonly available components. The AGC consists of: (1) a circuit which samples the peak of the envelope of the Loran signal to obtain an AGC voltage for each of three Loran stations, (2) a dc gain circuit to control the overall gain of the AGC system, and (3) an AGC amplification of the input RF signal. The performance of the AGC system was observed in bench and flight tests; it has improved the overall accuracy of the receiver. Improvements in the accuracy of the time difference calculations to within approx. + or - 1.5 microseconds of the observed time differnces for a given position are reported.

  14. Slowing the Spread of Grapevine Leafroll-Associated Viruses in Commercial Vineyards With Insecticide Control of the Vector, Pseudococcus maritimus (Hemiptera: Pseudococcidae).

    PubMed

    Wallingford, A K; Fuchs, M F; Martinson, T; Hesler, S; Loeb, G M

    2015-01-01

    Vineyards were surveyed for grapevine leafroll-associated viruses and their insect vectors in New York State's Finger Lakes region in 2006-2008. Grape mealybug, Pseudococcus maritimus (Erhorn) (Hemiptera: Pseudococcidae), European Fruit Lecanium, Parthenolecanium corni (Bouche), and Cottony Maple Scale, Pulvinaria acericola (Walsh and Riley) (Hemiptera: Coccidae) were identified as vector species in this region. An increase in the incidence of Grapevine leafroll-associated virus 1 (GLRaV-1) and GLRaV-3 was observed in 8 of the 20 vineyards surveyed, which implies transmission by these insect vectors. Two of the vineyards for which a temporal increase in disease incidence was documented were then used to evaluate the efficacy of foliar applications of horticultural oil and two classes of insecticides for control of P. maritimus and for slowing virus spread over 2 years of vine protection. Delayed dormant applications of horticultural oil contributed to control of early season crawlers; however, this was not the case for control of summer populations. Applications of acetamiprid and spirotetramat achieved control in summer populations; however, spirotetramat outperformed acetamiprid in percent reduction of treated compared with control vines and in a side-by-side trial. Vines treated with spirotetramat had a lower percentage of new vines testing positive for GLRaV-1 than control vines after 2 years, while no other spray program altered the increase in incidence of GLRaV-1 or -3.

  15. Slowing the Spread of Grapevine Leafroll-Associated Viruses in Commercial Vineyards With Insecticide Control of the Vector, Pseudococcus maritimus (Hemiptera: Pseudococcidae).

    PubMed

    Wallingford, A K; Fuchs, M F; Martinson, T; Hesler, S; Loeb, G M

    2015-01-01

    Vineyards were surveyed for grapevine leafroll-associated viruses and their insect vectors in New York State's Finger Lakes region in 2006-2008. Grape mealybug, Pseudococcus maritimus (Erhorn) (Hemiptera: Pseudococcidae), European Fruit Lecanium, Parthenolecanium corni (Bouche), and Cottony Maple Scale, Pulvinaria acericola (Walsh and Riley) (Hemiptera: Coccidae) were identified as vector species in this region. An increase in the incidence of Grapevine leafroll-associated virus 1 (GLRaV-1) and GLRaV-3 was observed in 8 of the 20 vineyards surveyed, which implies transmission by these insect vectors. Two of the vineyards for which a temporal increase in disease incidence was documented were then used to evaluate the efficacy of foliar applications of horticultural oil and two classes of insecticides for control of P. maritimus and for slowing virus spread over 2 years of vine protection. Delayed dormant applications of horticultural oil contributed to control of early season crawlers; however, this was not the case for control of summer populations. Applications of acetamiprid and spirotetramat achieved control in summer populations; however, spirotetramat outperformed acetamiprid in percent reduction of treated compared with control vines and in a side-by-side trial. Vines treated with spirotetramat had a lower percentage of new vines testing positive for GLRaV-1 than control vines after 2 years, while no other spray program altered the increase in incidence of GLRaV-1 or -3. PMID:26223949

  16. Slowing the Spread of Grapevine Leafroll-Associated Viruses in Commercial Vineyards With Insecticide Control of the Vector, Pseudococcus maritimus (Hemiptera: Pseudococcidae)

    PubMed Central

    Fuchs, M. F.; Martinson, T.; Hesler, S.; Loeb, G. M.

    2015-01-01

    Vineyards were surveyed for grapevine leafroll-associated viruses and their insect vectors in New York State’s Finger Lakes region in 2006–2008. Grape mealybug, Pseudococcus maritimus (Erhorn) (Hemiptera: Pseudococcidae), European Fruit Lecanium, Parthenolecanium corni (Bouche), and Cottony Maple Scale, Pulvinaria acericola (Walsh and Riley) (Hemiptera: Coccidae) were identified as vector species in this region. An increase in the incidence of Grapevine leafroll-associated virus 1 (GLRaV-1) and GLRaV-3 was observed in 8 of the 20 vineyards surveyed, which implies transmission by these insect vectors. Two of the vineyards for which a temporal increase in disease incidence was documented were then used to evaluate the efficacy of foliar applications of horticultural oil and two classes of insecticides for control of P. maritimus and for slowing virus spread over 2 years of vine protection. Delayed dormant applications of horticultural oil contributed to control of early season crawlers; however, this was not the case for control of summer populations. Applications of acetamiprid and spirotetramat achieved control in summer populations; however, spirotetramat outperformed acetamiprid in percent reduction of treated compared with control vines and in a side-by-side trial. Vines treated with spirotetramat had a lower percentage of new vines testing positive for GLRaV-1 than control vines after 2 years, while no other spray program altered the increase in incidence of GLRaV-1 or -3. PMID:26223949

  17. Welding arc length control system

    NASA Technical Reports Server (NTRS)

    Iceland, William F. (Inventor)

    1993-01-01

    The present invention is a welding arc length control system. The system includes, in its broadest aspects, a power source for providing welding current, a power amplification system, a motorized welding torch assembly connected to the power amplification system, a computer, and current pick up means. The computer is connected to the power amplification system for storing and processing arc weld current parameters and non-linear voltage-ampere characteristics. The current pick up means is connected to the power source and to the welding torch assembly for providing weld current data to the computer. Thus, the desired arc length is maintained as the welding current is varied during operation, maintaining consistent weld penetration.

  18. Cyber Incidents Involving Control Systems

    SciTech Connect

    Robert J. Turk

    2005-10-01

    The Analysis Function of the US-CERT Control Systems Security Center (CSSC) at the Idaho National Laboratory (INL) has prepared this report to document cyber security incidents for use by the CSSC. The description and analysis of incidents reported herein support three CSSC tasks: establishing a business case; increasing security awareness and private and corporate participation related to enhanced cyber security of control systems; and providing informational material to support model development and prioritize activities for CSSC. The stated mission of CSSC is to reduce vulnerability of critical infrastructure to cyber attack on control systems. As stated in the Incident Management Tool Requirements (August 2005) ''Vulnerability reduction is promoted by risk analysis that tracks actual risk, emphasizes high risk, determines risk reduction as a function of countermeasures, tracks increase of risk due to external influence, and measures success of the vulnerability reduction program''. Process control and Supervisory Control and Data Acquisition (SCADA) systems, with their reliance on proprietary networks and hardware, have long been considered immune to the network attacks that have wreaked so much havoc on corporate information systems. New research indicates this confidence is misplaced--the move to open standards such as Ethernet, Transmission Control Protocol/Internet Protocol, and Web technologies is allowing hackers to take advantage of the control industry's unawareness. Much of the available information about cyber incidents represents a characterization as opposed to an analysis of events. The lack of good analyses reflects an overall weakness in reporting requirements as well as the fact that to date there have been very few serious cyber attacks on control systems. Most companies prefer not to share cyber attack incident data because of potential financial repercussions. Uniform reporting requirements will do much to make this information available to

  19. LANSCE personnel access control system

    SciTech Connect

    Sturrock, J.C.; Gallegos, F.R.; Hall, M.J.

    1997-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. The Personnel Access Control System (PACS) is a component of the RSS that is designed to prevent personnel access to areas where prompt radiation is a hazard. PACS was designed to replace several older personnel safety systems (PSS) with a single modem unified design. Lessons learned from the operation over the last 20 years were incorporated into a redundant sensor, single-point failure safe, fault tolerant, and tamper-resistant system that prevents access to the beam areas by controlling the access keys and beam stoppers. PACS uses a layered philosophy to the physical and electronic design. The most critical assemblies are battery backed up, relay logic circuits; less critical devices use Programmable Logic Controllers (PLCs) for timing functions and communications. Outside reviewers have reviewed the operational safety of the design. The design philosophy, lessons learned, hardware design, software design, operation, and limitations of the device are described.

  20. Epidemiological evaluations of the efficacy of slow-released praziquantel-medicated bars for dogs in the prevention and control of cystic echinococcosis in man and animals.

    PubMed

    Wei, Jiao; Cheng, Fu; Qun, Qu; Nurbek; Xu, Shi-Dong; Sun, Li-Feng; Han, Xin-Kui; Muhan; Han, Ling-Ling; Irixiati; Jie, Peng; Zhang, Ke-Jiu; Islayin; Chai, Jun-jie

    2005-12-01

    To assess the epidemiological efficacy of type SRP III slow-released praziquantel-medicated bars for dogs in the prevention and control of cystic echinococcosis in man and livestock, praziquantel-medicated bars were implanted subcutaneously in over 90% of dogs in villages in north Xinjiang, China, where cystic echinococcosis is highly endemic. After implantation, infection rate of Echinococcus granulosus in dogs, specific antibodies in children and prevalence of echinococcosis in one-year-old lambs were observed for 3 years. Coproantigen of E. granulosus was positive in 41.2% of the dogs at the start of experiment. In the second and third year after medicated-bar implantation, coproantigen was undetectable in any dogs examined, while 3.0% of dogs were positive at the end of the fourth year. The antibody positive rate in 7-year-old pupils, that was 41.2% before the experiment, declined gradually and it was 5.4% in the fourth year, while children in the non-intervention control area showed 30.6% seropositivity. The prevalence of hydatid disease in children aged 7-16 years also declined significantly. The prevalence of hydatidosis in lambs one year of age was 44.8% in the first year, dropping to 10.7% in the fourth year, while in the non-intervention control area the level of infection was 46.4%. These results demonstrated not only that the slow released praziquantel-medicated bars efficiently blocked reinfection in dogs at least for 2 years, but also the measure was effective in preventing transmission of cystic echinococcosis to both man and livestock.

  1. Anomalously slow spin dynamics and short-range correlations in the quantum spin ice systems Yb2Ti2O7 and Yb2Sn2O7

    NASA Astrophysics Data System (ADS)

    Maisuradze, A.; Dalmas de Réotier, P.; Yaouanc, A.; Forget, A.; Baines, C.; King, P. J. C.

    2015-09-01

    We report a positive muon spin relaxation and rotation (μ SR ) study of the quantum spin ice materials Yb2Ti2O7 and Yb2Sn2O7 focusing on the low field response. In agreement with earlier reports, data recorded in small longitudinal fields evidence anomalously slow spin dynamics in the microsecond range below the temperature Tc at which the specific heat displays an intense peak, namely Tc=0.24 K and 0.15 K, respectively, for the two systems. We found that slow dynamics extends above Tc up to at least 0.7 K for both compounds. The conventional dynamical Gaussian Kubo-Toyabe model describes the μ SR spectra recorded above Tc. At lower temperatures a published analytical extension of the Gaussian Kubo-Toyabe model provides a good description, consistent with the existence of short-range magnetic correlations. While the physical response of the two systems is qualitatively the same, Yb2Ti2O7 exhibits a much larger local magnetic susceptibility than Yb2Sn2O7 below Tc. Considering previously reported ac susceptibility, neutron scattering, and μ SR results, we suggest the existence of anomalously slow spin dynamics to be a common physical property of pyrochlore magnetic materials. The possibility of molecular spin substructures to be associated to the slow dynamics and therefore the short-range correlations is mentioned. The slow spin dynamics observed under field does not exclude the presence of much faster dynamics detected in extremely low or zero field.

  2. Pallet loading dust control system

    SciTech Connect

    Cecala, A.B.; Covelli, A.

    1987-01-01

    This paper presents a pallet loading dust control system designed to lower the dust exposure of workers during the bag stacking process at mineral processing facilities. The system makes bag stacking much easier because the pallet height remains constant throughout the entire bag stacking cycle through the use of a hydraulic lift table. The system uses a push-pull ventilation technique to capture the dust generated during bag stacking. A low-volume, high-velocity blower system operating at approximately 150 cfm blows a stream of air over the top layer of bags on the pallet. The blower system is composed of two 3-in air jets (approximately 1,200-ft/min velocity) directed toward an exhaust system on the opposite side of the pallet. As these air jets travel across the pallet, they entrain the dust generated during bag stacking. The exhaust ventilation system pulls approximately 2,500 cfm of air and dust through the exhaust hood. This exhaust air can then be dumped into a bag-house ventilation system, or filtered before being discharged outside the mill.

  3. Microprocessor controlled portable TLD system

    NASA Technical Reports Server (NTRS)

    Apathy, I.; Deme, S.; Feher, I.

    1996-01-01

    An up-to-date microprocessor controlled thermoluminescence dosemeter (TLD) system for environmental and space dose measurements has been developed. The earlier version of the portable TLD system, Pille, was successfully used on Soviet orbital stations as well as on the US Space Shuttle, and for environmental monitoring. The new portable TLD system, Pille'95, consists of a reader and TL bulb dosemeters, and each dosemeter is provided with an EEPROM chip for automatic identification. The glow curve data are digitised and analysed by the program of the reader. The measured data and the identification number appear on the LED display of the reader. Up to several thousand measured data together with the glow curves can be stored on a removable flash memory card. The whole system is supplied either from built-in rechargeable batteries or from the mains of the space station.

  4. Controlled Ecological Life Support System

    NASA Technical Reports Server (NTRS)

    Averner, Maurice M.

    1989-01-01

    The NASA CELLS program is based upon the integration of biological and physiochemical processes in order to produce a system that will produce food, a breathable atmosphere, and potable water from metabolic and other wastes. The CELSS concept is described and a schematic system diagram is provided. Central to the CELSS concept is the Plant Growth Chamber, where green plant photosynthesis produces food, and aids in the production of oxygen and water. Progress to date at the Breadboard Facility at the Kennedy Space Center is summarized. The Breadboard Facility will implement the basic techniques and processes required for a CELSS based on photosynthetic plant growth in a ground-based system of practical size and results will be extrapolated to predict the performance of a full-sized system. Current available technology and near-future forecasts for plant growth techniques (focusing on maximum productivity), food sources (to select optimal CELSS plants), and waste management and contaminant control are discussed.

  5. Controlling storage/retrieval system

    SciTech Connect

    Conrad, S.J.

    1984-11-15

    This article discusses the combination of a vertical carousel storage and retrieval system and computerized material requirements planning and inventory control which has resulted in a material handling system that is saving money and increasing productivity for Hewlett-Packard. The combination is also proving to be very versatile, with different plants opting for various levels of automation to suit their particular needs. This article reviews what Hewlett-Packard is doing and discusses why the company decided to purchase high-density vertical carousels. Three company divisions' needs and operations are outlined.

  6. Heat engine generator control system

    DOEpatents

    Rajashekara, K.; Gorti, B.V.; McMullen, S.R.; Raibert, R.J.

    1998-05-12

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power. 8 figs.

  7. Heat engine generator control system

    DOEpatents

    Rajashekara, Kaushik; Gorti, Bhanuprasad Venkata; McMullen, Steven Robert; Raibert, Robert Joseph

    1998-01-01

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power.

  8. Autonomous grain combine control system

    DOEpatents

    Hoskinson, Reed L.; Kenney, Kevin L.; Lucas, James R.; Prickel, Marvin A.

    2013-06-25

    A system for controlling a grain combine having a rotor/cylinder, a sieve, a fan, a concave, a feeder, a header, an engine, and a control system. The feeder of the grain combine is engaged and the header is lowered. A separator loss target, engine load target, and a sieve loss target are selected. Grain is harvested with the lowered header passing the grain through the engaged feeder. Separator loss, sieve loss, engine load and ground speed of the grain combine are continuously monitored during the harvesting. If the monitored separator loss exceeds the selected separator loss target, the speed of the rotor/cylinder, the concave setting, the engine load target, or a combination thereof is adjusted. If the monitored sieve loss exceeds the selected sieve loss target, the speed of the fan, the size of the sieve openings, or the engine load target is adjusted.

  9. Experimental research control software system

    NASA Astrophysics Data System (ADS)

    Cohn, I. A.; Kovalenko, A. G.; Vystavkin, A. N.

    2014-05-01

    A software system, intended for automation of a small scale research, has been developed. The software allows one to control equipment, acquire and process data by means of simple scripts. The main purpose of that development is to increase experiment automation easiness, thus significantly reducing experimental setup automation efforts. In particular, minimal programming skills are required and supervisors have no reviewing troubles. Interactions between scripts and equipment are managed automatically, thus allowing to run multiple scripts simultaneously. Unlike well-known data acquisition commercial software systems, the control is performed by an imperative scripting language. This approach eases complex control and data acquisition algorithms implementation. A modular interface library performs interaction with external interfaces. While most widely used interfaces are already implemented, a simple framework is developed for fast implementations of new software and hardware interfaces. While the software is in continuous development with new features being implemented, it is already used in our laboratory for automation of a helium-3 cryostat control and data acquisition. The software is open source and distributed under Gnu Public License.

  10. Lyapunov Control of Quantum Systems with Impulsive Control Fields

    PubMed Central

    Yang, Wei; Sun, Jitao

    2013-01-01

    We investigate the Lyapunov control of finite-dimensional quantum systems with impulsive control fields, where the studied quantum systems are governed by the Schrödinger equation. By three different Lyapunov functions and the invariant principle of impulsive systems, we study the convergence of quantum systems with impulsive control fields and propose new results for the mentioned quantum systems in the form of sufficient conditions. Two numerical simulations are presented to illustrate the effectiveness of the proposed control method. PMID:23766712

  11. HTGR Resilient Control System Strategy

    SciTech Connect

    Lynne M. Stevens

    2010-09-01

    A preeminent objective for corporate and government organizations is the protection of major investments, which is attained by achieving state awareness, a comprehensive understanding of security and safety, for critical infrastructures. Given the dependence of critical infrastructure on control systems for automation, the integrity of these systems and their ability to provide owner/operators a high degree of state awareness is essential in attaining a high degree of investment protection and public acceptance. Operators as well as government are therefore burdened to ensure they have a timely understanding of the status of their plant or all plants, respectively, to ensure efficient operations and investment and public protection. “This characterization is a significant objective that must consider many aspects of instrumentation, control, and intelligent systems in order to achieve the required result. These aspects include sensory, communication, analysis, decision, and human system interfaces necessary to achieve fusion of data and presentation of results that will provide an understanding of what issues are important and why.

  12. Noise-controlled slow-fast oscillations in predator-prey models with the Beddington functional response

    NASA Astrophysics Data System (ADS)

    Mankin, R.; Laas, T.; Soika, E.; Ainsaar, A.

    2007-09-01

    The influence of environmental fluctuations (modeled as a multiplicative dichotomous noise) on predator-prey interaction is studied using a metapopulation model with N prey-subpopulations. Investigating the role that predator interference plays in the dynamics of such trophic systems, the Beddington functional response is considered. In case the growth rates of prey and predator are widely different, we obtain analytic results by a dynamical mean-field approximation. In some regions of the system parameters, variations of noise amplitude or correlation time can cause transitions of the mean field from a globally stable equilibrium to the stable limit cycle as well as in the opposite direction. The conditions for the occurrence of such a phenomenon are found and illustrated by phase diagrams. Implications of the results on the colored-noise-induced extinction of a predator population are also discussed.

  13. Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Lattime, Scott B.; Taylor, Shawn; DeCastro, Jonathan A.; Oswald, Jay; Melcher, Kevin J.

    2005-01-01

    Reducing blade tip clearances through active tip clearance control in the high pressure turbine can lead to significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life. Current engines employ scheduled cooling of the outer case flanges to reduce high pressure turbine tip clearances during cruise conditions. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, reburst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). In an effort to improve upon current thermal methods, a first generation mechanically-actuated active clearance control (ACC) system has been designed and fabricated. The system utilizes independent actuators, a segmented shroud structure, and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. Ambient temperature performance tests of this first generation ACC system assessed individual seal component leakage rates and both static and dynamic overall system leakage rates. The ability of the nine electric stepper motors to control the position of the seal carriers in both open- and closed-loop control modes for single and multiple cycles was investigated. The ability of the system to follow simulated engine clearance transients in closed-loop mode showed the system was able to track clearances to within a tight tolerance ( 0.001 in. error).

  14. Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Lattime, Scott B.; DeCastro, Jonathan A.; Oswald, Jay; Melcher, Kevin J.

    2005-01-01

    Reducing blade tip clearances through active tip clearance control in the high pressure turbine can lead to significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life. Current engines employ scheduled cooling of the outer case flanges to reduce high pressure turbine tip clearances during cruise conditions. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, reburst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). In an effort to improve upon current thermal methods, a first generation mechanically-actuated active clearance control (ACC) system has been designed and fabricated. The system utilizes independent actuators, a segmented shroud structure, and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. Ambient temperature performance tests of this first generation ACC system assessed individual seal component leakage rates and both static and dynamic overall system leakage rates. The ability of the nine electric stepper motors to control the position of the seal carriers in both open- and closed-loop control modes for single and multiple cycles was investigated. The ability of the system to follow simulated engine clearance transients in closed-loop mode showed the system was able to track clearances to within a tight tolerance (0.001 in. error).

  15. 14 CFR 25.395 - Control system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Control system. 25.395 Section 25.395... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.395 Control system. (a) Longitudinal, lateral, directional, and drag control system and their supporting structures...

  16. 49 CFR 193.2619 - Control systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Control systems. 193.2619 Section 193.2619...: FEDERAL SAFETY STANDARDS Maintenance § 193.2619 Control systems. (a) Each control system must be properly adjusted to operate within design limits. (b) If a control system is out of service for 30 days or more,...

  17. 14 CFR 25.395 - Control system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control system. 25.395 Section 25.395... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.395 Control system. (a) Longitudinal, lateral, directional, and drag control system and their supporting structures...

  18. 49 CFR 193.2619 - Control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Control systems. 193.2619 Section 193.2619...: FEDERAL SAFETY STANDARDS Maintenance § 193.2619 Control systems. (a) Each control system must be properly adjusted to operate within design limits. (b) If a control system is out of service for 30 days or more,...

  19. 14 CFR 25.395 - Control system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Control system. 25.395 Section 25.395... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.395 Control system. (a) Longitudinal, lateral, directional, and drag control system and their supporting structures...

  20. Nonlinear systems identification and control via dynamic multitime scales neural networks.

    PubMed

    Fu, Zhi-Jun; Xie, Wen-Fang; Han, Xuan; Luo, Wei-Dong

    2013-11-01

    This paper deals with the adaptive nonlinear identification and trajectory tracking via dynamic multilayer neural network (NN) with different timescales. Two NN identifiers are proposed for nonlinear systems identification via dynamic NNs with different timescales including both fast and slow phenomenon. The first NN identifier uses the output signals from the actual system for the system identification. In the second NN identifier, all the output signals from nonlinear system are replaced with the state variables of the NNs. The online identification algorithms for both NN identifier parameters are proposed using Lyapunov function and singularly perturbed techniques. With the identified NN models, two indirect adaptive NN controllers for the nonlinear systems containing slow and fast dynamic processes are developed. For both developed adaptive NN controllers, the trajectory errors are analyzed and the stability of the systems is proved. Simulation results show that the controller based on the second identifier has better performance than that of the first identifier.

  1. Thermal control system corrosion study

    NASA Technical Reports Server (NTRS)

    Yee, Robert; Folsom, Rolfe A.; Mucha, Phillip E.

    1990-01-01

    During the development of an expert system for autonomous control of the Space Station Thermal Control System (TCS), the thermal performance of the Brassboard TCS began to gradually degrade. This degradation was due to filter clogging by metallic residue. A study was initiated to determine the source of the residue and the basic cause of the corrosion. The investigation focused on the TCS design, materials compatibility, Ames operating and maintenance procedures, and chemical analysis of the residue and of the anhydrous ammonia used as the principal refrigerant. It was concluded that the corrosion mechanisms involved two processes: the reaction of water alone with large, untreated aluminum parts in a high pH environment and the presence of chlorides and chloride salts. These salts will attack the aluminum oxide layer and may enable galvanic corrosion between the aluminum and the more noble stainless steel and other metallic elements present. Recommendations are made for modifications to the system design, the materials used, and the operating and maintenance procedures, which should largely prevent the recurrence of these corrosion mechanisms.

  2. Thermal control system corrosion study

    NASA Astrophysics Data System (ADS)

    Yee, Robert; Folsom, Rolfe A.; Mucha, Phillip E.

    1990-02-01

    During the development of an expert system for autonomous control of the Space Station Thermal Control System (TCS), the thermal performance of the Brassboard TCS began to gradually degrade. This degradation was due to filter clogging by metallic residue. A study was initiated to determine the source of the residue and the basic cause of the corrosion. The investigation focused on the TCS design, materials compatibility, Ames operating and maintenance procedures, and chemical analysis of the residue and of the anhydrous ammonia used as the principal refrigerant. It was concluded that the corrosion mechanisms involved two processes: the reaction of water alone with large, untreated aluminum parts in a high pH environment and the presence of chlorides and chloride salts. These salts will attack the aluminum oxide layer and may enable galvanic corrosion between the aluminum and the more noble stainless steel and other metallic elements present. Recommendations are made for modifications to the system design, the materials used, and the operating and maintenance procedures, which should largely prevent the recurrence of these corrosion mechanisms.

  3. Internal combustion engine control system

    SciTech Connect

    Lambert, J.E.

    1989-12-12

    This patent describes an internal combustion engine control system apparatus. It comprises: carburetor venturi means flowing basic combustion air and having a induced fuel flow in the basic combustion air; carburetor by pass throttle valve means having a biased open position and causing and trimming the flow of supplementary combustion air parallel to and then into the basic combustion air for mixing; engine throttle valve means regulating the flow of a mixture of the supplementary combustion air and the basic combustion air with induced fuel flow for engine combustion; Separate electrical step motor means connected to the carburetor by-pass throttle valve means and to the engine throttle valve means; and pre-programmed microprocessor means connected to each of the electrical stepmotor means. The microprocessor means controlling one of the electrical stepmotor means and the trim positioning of the carburetor by-pass throttle valve means in response to sensed engine speed and sensed engine manifold pressure or throttle position conditions.

  4. Instrumentation, Control, and Intelligent Systems

    SciTech Connect

    Not Available

    2005-09-01

    Abundant and affordable energy is required for U.S. economic stability and national security. Advanced nuclear power plants offer the best near-term potential to generate abundant, affordable, and sustainable electricity and hydrogen without appreciable generation of greenhouse gases. To that end, Idaho National Laboratory (INL) has been charged with leading the revitalization of nuclear power in the U.S. The INL vision is to become the preeminent nuclear energy laboratory with synergistic, world-class, multi-program capabilities and partnerships by 2015. The vision focuses on four essential destinations: (1) Be the preeminent internationally-recognized nuclear energy research, development, and demonstration laboratory; (2) Be a major center for national security technology development and demonstration; (3) Be a multi-program national laboratory with world-class capabilities; (4) Foster academic, industry, government, and international collaborations to produce the needed investment, programs, and expertise. Crucial to that effort is the inclusion of research in advanced instrumentation, control, and intelligent systems (ICIS) for use in current and advanced power and energy security systems to enable increased performance, reliability, security, and safety. For nuclear energy plants, ICIS will extend the lifetime of power plant systems, increase performance and power output, and ensure reliable operation within the system's safety margin; for national security applications, ICIS will enable increased protection of our nation's critical infrastructure. In general, ICIS will cost-effectively increase performance for all energy security systems.

  5. Utilizing expert systems for satellite monitoring and control

    NASA Technical Reports Server (NTRS)

    Hughes, Peter M.

    1991-01-01

    Spacecraft analysts in the spacecraft control center for the Cosmic Background Explorer (COBE) satellite are currently utilizing a fault-isolation expert system developed to assist in the isolation and correction of faults in the communications link. This system, the communication link expert assistance resource (CLEAR), monitors real time spacecraft and ground systems performance parameters in search of configuration discrepancies and communications link problems. If such a discrepancy or problem is isolated, CLEAR alerts the analyst and provides advice on how to resolve the problem swiftly and effectively. The CLEAR system is the first real time expert system to be used in the operational environment of a satellite control center at the NASA Goddard Space Flight Center. Clear has not only demonstrated the utility and potential of an expert system in the demanding environment of a satellite control center, but also has revealed many of the pitfalls and deficiencies of development of expert systems. One of the lessons learned from this and other initial expert system projects is that prototypes can often be developed quite rapidly, but operational expert systems require considerable effort. Development is generally a slow, tedious process that typically requires the special skills of trained programmers. Due to the success of CLEAR and several other systems in the control center domain, a large number of expert systems will certainly be developed to support control center operations during the early 1990's. To facilitate the development of these systems, a project was initiated to develop an integrated, domain-specific tool, the generic spacecraft analyst assistent (GenSAA), that alows the spacecraft analysts to rapidly create simple expert systems themselves. By providing a highly graphical point-and-select method of system development, GenSAA allows the analyst to utilize and/or modify previously developed rule bases and system components; thus, facilitating

  6. Researches of the Electrotechnical Laboratory. No. 51: Study of formation and sustainment of reversed field pinch by slow control of magnetic field

    NASA Astrophysics Data System (ADS)

    Hirano, Yoichi

    1993-07-01

    Experimental results of controlled thermonuclear fusion research on Reversed Field Pinch (RFP) machines, TPE-1RM and TPE-1RM15, are presented. The main experimental results of TPE-1RM, such as RFP configuration formation conditions, insensitivity of RFP configuration to the initial conditions, its dependency on the instantaneous boundary condition, very high temperature measured by Thomson scattering of ruby laser, the ion temperature measured by Doppler broadening of C(4+) line, proportionality of the electron temperature and density to the plasma current, and the linear increase of the ion temperature with the plasma current are outlined. The main experiment results of TPE-1RM15 are as follows: (1) the RFP configuration can be formed by magnetic field control much slower than that in TPE-1RM; (2) the RFP configuration can be sustained by maintaining the plasma current and the reversal of toroidal field; (3) the electron temperature and density are kept nearly constant by sustaining the configuration; (4) the equilibrium position control by the quasi-DC (Direct Current) vertical field is essential for reducing the toroidal loop voltage; (5) the confinement property in the large current region is greatly improved by using purified molybdenum limiters; and (6) the electron density and temperature are roughly proportional to the plasma current. It is demonstrated that the theoretically predicted relaxation towards the RFP configuration exists and the RFP configuration can be formed with the slow formation whose current rise time is in the range of milli-second.

  7. Hydrothermal activity along the slow-spreading Lucky Strike ridge segment (Mid-Atlantic Ridge): Distribution, heatflux, and geological controls

    NASA Astrophysics Data System (ADS)

    Escartin, J.; Barreyre, T.; Cannat, M.; Garcia, R.; Gracias, N.; Deschamps, A.; Salocchi, A.; Sarradin, P. M.; Ballu, V.

    2015-12-01

    We have reviewed available visual information from the seafloor, and recently acquired microbathymetry for several traverses across the Lucky Strike segment to evaluate the distribution of hydrothermal activity. The Lucky Strike segment hosts three active hydrothermal fields: Capelinhos, Ewan, and the known Main Lucky Strike Hydrothermal Field (MLSHF). Capelinhos is located 1.3 km E of the axis and the MLSHF, and consists of a ~20 m sulfide mound with black smoker vents. Ewan is located ~1.8 km south from the MLSHF along the axial graben, and displays only diffuse flow along and around scarps of collapse structures associated with fault scarps. At the MLSHF we have identified an inactive site, thus broadening the extent of this field. Heat flux estimates from these new sites are relatively low and correspond to ~10% of the heat flux estimated for the Main field, with an integrated heatflux of 200-1200 MW. Overall, most of the flux (up to 80-90%) is associated with diffuse outflow, with the Ewan site showing solely diffuse flow and Capelinhos mostly focused flow. Microbathymetry also reveals a large, off-axis (~2.4 km) hydrothermal field, similar to the TAG mound in size, on the flanks of a rifted volcano. The association of these fields to a central volcano, and the absence of indicators of hydrothermal activity along the ridge segment, suggest that sustained hydrothermal activity is maintained by the enhanced melt supply and the associated magma chamber(s) required to build central volcanoes. Hydrothermal outflow zones at the seafloor are systematically controlled by faults, indicating that hydrothermal circulation in the shallow crust exploits permeable fault zones. Central volcanoes are thus associated with long-lived hydrothermal activity, and these sites may play a major role in the distribution and biogeography of vent communities.

  8. 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.

  9. 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.

  10. Anthropogenic control on geomorphic process rates: can we slow down the erosion rates? (Geomorphology Outstanding Young Scientist Award & Penck Lecture)

    NASA Astrophysics Data System (ADS)

    Vanacker, V.

    2012-04-01

    The surface of the Earth is changing rapidly, largely in response to anthropogenic perturbation. Direct anthropogenic disturbance of natural environments may be much larger in many places than the (projected) indirect effects of climate change. There is now large evidence that humans have significantly altered geomorphic process rates, mainly through changes in vegetation composition, density and cover. While much attention has been given to the impact of vegetation degradation on geomorphic process rates, I suggest that the pathway of restoration is equally important to investigate. First, vegetation recovery after crop abandonment has a rapid and drastic impact on geomorphic process rates. Our data from degraded catchments in the tropical Andes show that erosion rates can be reduced by up to 100 times when increasing the protective vegetation cover. During vegetation restoration, the combined effects of the reduction in surface runoff, sediment production and hydrological connectivity are stronger than the individual effects together. Therefore, changes in erosion and sedimentation during restoration are not simply the reverse of those observed during degradation. Second, anthropogenic perturbation causes a profound but often temporary change in geomorphic process rates. Reconstruction of soil erosion rates in Spain shows us that modern erosion rates in well-vegetated areas are similar to long-term rates, despite evidence of strong pulses in historical erosion rates after vegetation clearance and agriculture. The soil vegetation system might be resilient to short pulses of accelerated erosion (and deposition), as there might exist a dynamic coupling between soil erosion and production also in degraded environments.

  11. Nuclear electric propulsion reactor control systems status

    NASA Technical Reports Server (NTRS)

    Ferg, D. A.

    1973-01-01

    The thermionic reactor control system design studies conducted over the past several years for a nuclear electric propulsion system are described and summarized. The relevant reactor control system studies are discussed in qualitative terms, pointing out the significant advantages and disadvantages including the impact that the various control systems would have on the nuclear electric propulsion system design. A recommendation for the reference control system is made, and a program for future work leading to an engineering model is described.

  12. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2004-08-31

    The deep hard rock drilling environment induces severe vibrations into the drillstring, which can cause reduced rates of penetration (ROP) and premature failure of the equipment. The only current means of controlling vibration under varying conditions is to change either the rotary speed or the weight-on-bit (WOB). These changes often reduce drilling efficiency. Conventional shock subs are useful in some situations, but often exacerbate the problems. The objective of this project is development of a unique system to monitor and control drilling vibrations in a ''smart'' drilling system. This system has two primary elements: (1) The first is an active vibration damper (AVD) to minimize harmful axial, lateral and torsional vibrations. The hardness of this damper will be continuously adjusted using a robust, fast-acting and reliable unique technology. (2) The second is a real-time system to monitor drillstring vibration, and related parameters. This monitor adjusts the damper according to local conditions. In some configurations, it may also send diagnostic information to the surface via real-time telemetry. The AVD is implemented in a configuration using magnetorheological (MR) fluid. By applying a current to the magnetic coils in the damper, the viscosity of the fluid can be changed rapidly, thereby altering the damping coefficient in response to the measured motion of the tool. Phase I of this program entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype. Phase I of the project was completed by the revised end date of May 31, 2004. The objectives of this phase were met, and all prerequisites for Phase II have been completed.

  13. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2004-10-13

    The deep hard rock drilling environment induces severe vibrations into the drillstring, which can cause reduced rates of penetration (ROP) and premature failure of the equipment. The only current means of controlling vibration under varying conditions is to change either the rotary speed or the weight-on-bit (WOB). These changes often reduce drilling efficiency. Conventional shock subs are useful in some situations, but often exacerbate the problems. The objective of this project is development of a unique system to monitor and control drilling vibrations in a ''smart'' drilling system. This system has two primary elements: (1) The first is an active vibration damper (AVD) to minimize harmful axial, lateral and torsional vibrations. The hardness of this damper will be continuously adjusted using a robust, fast-acting and reliable unique technology. (2) The second is a real-time system to monitor drillstring vibration, and related parameters. This monitor adjusts the damper according to local conditions. In some configurations, it may also send diagnostic information to the surface via real-time telemetry. The AVD is implemented in a configuration using magnetorheological (MR) fluid. By applying a current to the magnetic coils in the damper, the viscosity of the fluid can be changed rapidly, thereby altering the damping coefficient in response to the measured motion of the tool. Phase I of this program entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype. Phase I of the project was completed by the revised end date of May 31, 2004. The objectives of this phase were met, and all prerequisites for Phase II have been completed. The month of June, 2004 was primarily occupied with the writing of the Phase I Final Report, the sole deliverable of Phase I, which will be submitted in the next quarter. Redesign of the laboratory prototype and design of the downhole (Phase II) prototype was begun.

  14. Generic NOx Control Intelligent System

    1997-03-24

    GNOCIS is a system of programs designed to perform on-line closed-loop optimization of utility boilers. The major components of the system include: GNREAD A program which resides on the host digital control system (DCS) that retrieves data from the DCS and then transmits the collected data to the GNOCIS host system. GNWRITE A program which resides on the host DCS that receives data from the GNOCIS host platform and then sends this information to themore » DCS. GNARCH A program which resides on the GNOCIS host platform that receives data from GNREAD or GNCTL and then archives this data on a periodic basis. GNCTL A program which resides on the GNOCIS host platform that receives data from GNREAD and then executes the optimizer/combustion model. GNDCS Configuration changes to the DCS which allows automatic implementation of the GNOCIS recommendations and closed-loop operation. Substantial safeguards and constraints are imbedded in this component to prevent adverse impact on unit operation.« less

  15. Generic NOx Control Intelligent System

    SciTech Connect

    Sorge, John

    1997-03-24

    GNOCIS is a system of programs designed to perform on-line closed-loop optimization of utility boilers. The major components of the system include: GNREAD A program which resides on the host digital control system (DCS) that retrieves data from the DCS and then transmits the collected data to the GNOCIS host system. GNWRITE A program which resides on the host DCS that receives data from the GNOCIS host platform and then sends this information to the DCS. GNARCH A program which resides on the GNOCIS host platform that receives data from GNREAD or GNCTL and then archives this data on a periodic basis. GNCTL A program which resides on the GNOCIS host platform that receives data from GNREAD and then executes the optimizer/combustion model. GNDCS Configuration changes to the DCS which allows automatic implementation of the GNOCIS recommendations and closed-loop operation. Substantial safeguards and constraints are imbedded in this component to prevent adverse impact on unit operation.

  16. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2005-10-31

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. The principal objectives of Phase II are: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in drilling laboratories and test wells. Work during this quarter centered on the rebuilding of the prototype using the improved valve design described in the Jan-March report1. Most of the components have been received and assembly was nearly complete at the end of the period. Testing started in October and results will be submitted in the next report. The field testing component of this Phase has been rethought. The current plan is to adapt the laboratory prototype for use in a drilling laboratory and run a series of controlled drilling tests with and without the DVMCS. This should give a more quantitative evaluation of its value, which will help us sign a commercialization partner. While this testing is underway, we will order and begin machining parts for full field prototypes to be use in Phase III. A modification application is being submitted in October to reflect these changes.

  17. Autonomous intelligent cruise control system

    NASA Astrophysics Data System (ADS)

    Baret, Marc; Bomer, Thierry T.; Calesse, C.; Dudych, L.; L'Hoist, P.

    1995-01-01

    Autonomous intelligent cruise control (AICC) systems are not only controlling vehicles' speed but acting on the throttle and eventually on the brakes they could automatically maintain the relative speed and distance between two vehicles in the same lane. And more than just for comfort it appears that these new systems should improve the safety on highways. By applying a technique issued from the space research carried out by MATRA, a sensor based on a charge coupled device (CCD) was designed to acquire the reflected light on standard-mounted car reflectors of pulsed laser diodes emission. The CCD is working in a unique mode called flash during transfer (FDT) which allows identification of target patterns in severe optical environments. It provides high accuracy for distance and angular position of targets. The absence of moving mechanical parts ensures high reliability for this sensor. The large field of view and the high measurement rate give a global situation assessment and a short reaction time. Then, tracking and filtering algorithms have been developed in order to select the target, on which the equipped vehicle determines its safety distance and speed, taking into account its maneuvering and the behaviors of other vehicles.

  18. Ethylene monitoring and control system

    NASA Technical Reports Server (NTRS)

    Nelson, Bruce N. (Inventor); Richard, II, Roy V. (Inventor); Kane, James A. (Inventor)

    2001-01-01

    A system that can accurately monitor and control low concentrations of ethylene gas includes a test chamber configured to receive sample gas potentially containing an ethylene concentration and ozone, a detector configured to receive light produced during a reaction between the ethylene and ozone and to produce signals related thereto, and a computer connected to the detector to process the signals to determine therefrom a value of the concentration of ethylene in the sample gas. The supply for the system can include a four way valve configured to receive pressurized gas at one input and a test chamber. A piston is journaled in the test chamber with a drive end disposed in a drive chamber and a reaction end defining with walls of the test chamber a variable volume reaction chamber. The drive end of the piston is pneumatically connected to two ports of the four way valve to provide motive force to the piston. A manifold is connected to the variable volume reaction chamber, and is configured to receive sample gasses from at least one of a plurality of ports connectable to degreening rooms and to supply the sample gas to the reactive chamber for reaction with ozone. The apparatus can be used to monitor and control the ethylene concentration in multiple degreening rooms.

  19. Ethylene monitoring and control system

    NASA Technical Reports Server (NTRS)

    Nelson, Bruce N. (Inventor); Richard, II, Roy V. (Inventor); Kanc, James A. (Inventor)

    2000-01-01

    A system that can accurately monitor and control low concentrations of ethylene gas includes a test chamber configured to receive sample gas potentially containing an ethylene concentration and ozone, a detector configured to receive light produced during a reaction between the ethylene and ozone and to produce signals related thereto, and a computer connected to the detector to process the signals to determine therefrom a value of the concentration of ethylene in the sample gas. The supply for the system can include a four way valve configured to receive pressurized gas at one input and a test chamber. A piston is journaled in the test chamber with a drive end disposed in a drive chamber and a reaction end defining with walls of the test chamber a variable volume reaction chamber. The drive end of the piston is pneumatically connected to two ports of the four way valve to provide motive force to the piston. A manifold is connected to the variable volume reaction chamber, and is configured to receive sample gasses from at least one of a plurality of ports connectable to degreening rooms and to supply the sample gas to the reactive chamber for reaction with ozone. The apparatus can be used to monitor and control the ethylene concentration in multiple degreening rooms.

  20. Control rod drive hydraulic system

    DOEpatents

    Ose, Richard A.

    1992-01-01

    A hydraulic system for a control rod drive (CRD) includes a variable output-pressure CR pump operable in a charging mode for providing pressurized fluid at a charging pressure, and in a normal mode for providing the pressurized fluid at a purge pressure, less than the charging pressure. Charging and purge lines are disposed in parallel flow between the CRD pump and the CRD. A hydraulic control unit is disposed in flow communication in the charging line and includes a scram accumulator. An isolation valve is provided in the charging line between the CRD pump and the scram accumulator. A controller is operatively connected to the CRD pump and the isolation valve and is effective for opening the isolation valve and operating the CRD pump in a charging mode for charging the scram accumulator, and closing the isolation valve and operating the CRD pump in a normal mode for providing to the CRD through the purge line the pressurized fluid at a purge pressure lower than the charging pressure.

  1. Exhaust gas recirculation control system

    SciTech Connect

    Yamada, K.

    1981-02-03

    An E.G.R. control system includes a pressure modulator operative to modulate the magnitude of the port vacuum as applied to a diaphragm type actuator of an E.G.R. valve. The modulator comprises a housing and a diaphragm assembly disposed in the housing and consisting of a pair of diaphragms and a member connecting the diaphragms so that they are deformed simultaneously. The diaphragm assembly divides the interior of the housing into first, second and third chambers which are communicated with the engine carburetor venturi, vented to the atmosphere and communicated with the E.G.R. passage between the E.G.R. valve and a fixed restriction in the E.G.R. passage upstream of the E.G.R. valve, respectively, so that the diaphragm assembly is moved in response to variation in the venturi vacuum and also in response to variation in the exhaust gas pressure in the E.G.R. passage between the restriction and the E.G.R. valve. A valve member is mounted on the diaphragm assembly for movement therewith to control the flow of the atmospheric air from the second chamber into the E.G.R. valve actuator so that the port vacuum as applied to the E.G.R. valve actuator is modulated. The controlled flow of the recirculated exhaust gases through the E.G.R. passage from the exhaust pipe into the intake pipe is in proportion to the intake air flow.

  2. Control System for Prosthetic Devices

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J. (Inventor)

    1996-01-01

    A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that of movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part through the full-shrg position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.

  3. 14 CFR 31.49 - Control systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: MANNED FREE BALLOONS Design Construction § 31.49 Control systems. (a) Each control must operate... and subsequent inadvertent operation. (b) Each control system and operating device must be designed... elements of the control system must have design features or must be distinctly and permanently marked...

  4. Stochastic dynamics on slow manifolds

    NASA Astrophysics Data System (ADS)

    Constable, George W. A.; McKane, Alan J.; Rogers, Tim

    2013-07-01

    The theory of slow manifolds is an important tool in the study of deterministic dynamical systems, giving a practical method by which to reduce the number of relevant degrees of freedom in a model, thereby often resulting in a considerable simplification. In this paper we demonstrate how the same basic methodology may also be applied to stochastic dynamical systems, by examining the behaviour of trajectories conditioned on the event that they do not depart the slow manifold. We apply the method to two models: one from ecology and one from epidemiology, achieving a reduction in model dimension and illustrating the high quality of the analytical approximations.

  5. EVA Systems Flight Controller Talks With Students

    NASA Video Gallery

    From NASA's International Space Station Mission Control Center, EVA Systems Flight Controller Sandy Fletcher participates in a Digital Learning Network (DLN) event with students from Northtowne Ele...

  6. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  7. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  8. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  9. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  10. 14 CFR 27.395 - Control system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... service use, including consideration of fatigue, jamming, ground gusts, control inertia, and friction... jamming, ground gusts, control inertia, or friction, the system must withstand the limit pilot...

  11. Hydraulically powered dissimilar teleoperated system controller design

    SciTech Connect

    Jansen, J.F.; Kress, R.L.

    1996-04-01

    This paper will address two issues associated with the implementation of a hydraulically powered dissimilar master-slave teleoperated system. These issues are the overall system control architecture and the design of robust hydraulic servo controllers for the position control problem. Finally, a discussion of overall system performance on an actual teleoperated system will be presented.

  12. Control systems development, research and development

    NASA Astrophysics Data System (ADS)

    Bailey, L. R.

    1986-07-01

    This report describes design and implementation of several computerized control systems. These implementations include: an ultrasonic weld tester, an automated vacuum oven, a differential pressure gaging system, a die casting control system, a lathe crash prevention and monitoring system, an electric eddy current weld scanner, a bar code scanner, a gage controller, and thermocouple tester.

  13. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2005-07-27

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. The principal objectives of Phase II are: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in drilling laboratories and test wells. Work during this quarter centered on the rebuilding of the prototype using the improved valve design described in the last report. Most of the components have been received and assembly has begun. Testing is expected to resume in August. In April, a paper was presented at the American Association of Drilling Engineers National Technical Conference in Houston. The paper was well received, and several oilfield service and supply companies sent inquiries regarding commercial distribution of the system. These are currently being pursued, but none have yet been finalized.

  14. Active thermal control system evolution

    NASA Technical Reports Server (NTRS)

    Petete, Patricia A.; Ames, Brian E.

    1991-01-01

    The 'restructured' baseline of the Space Station Freedom (SSF) has eliminated many of the growth options for the Active Thermal Control System (ATCS). Modular addition of baseline technology to increase heat rejection will be extremely difficult. The system design and the available real estate no longer accommodate this type of growth. As the station matures during its thirty years of operation, a demand of up to 165 kW of heat rejection can be expected. The baseline configuration will be able to provide 82.5 kW at Eight Manned Crew Capability (EMCC). The growth paths necessary to reach 165 kW have been identified. Doubling the heat rejection capability of SSF will require either the modification of existing radiator wings or the attachment of growth structure to the baseline truss for growth radiator wing placement. Radiator performance can be improved by enlarging the surface area or by boosting the operating temperature with a heat pump. The optimal solution will require both modifications. The addition of growth structure would permit the addition of a parallel ATCS using baseline technology. This growth system would simplify integration. The feasibility of incorporating these growth options to improve the heat rejection capacity of SSF is under evaluation.

  15. Environmental Control and Life Support Systems and Power Systems ...

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

    Environmental Control and Life Support Systems and Power Systems - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  16. Microscopic image analysis of slow crack growth in vitreous materials

    SciTech Connect

    Smith, W.L.

    1986-04-01

    Automated computer control, advanced video techniques, and digital image processing have been integrated into a servo-hydraulic testing system to produce a state-of-the-art testing environment. This system, in combination with an ultra high vacuum controlled environmental chamber, is used to produce high accuracy, subcritical slow crack growth data in vitreous materials. This video presentation is a review of the technologies used to extract data from the double cleavage drilled compression (DCDC) sample geometry.

  17. Digital flight control actuation system study

    NASA Technical Reports Server (NTRS)

    Rossing, R.; Hupp, R.

    1974-01-01

    Flight control actuators and feedback sensors suitable for use in a redundant digital flight control system were examined. The most appropriate design approach for an advanced digital flight control actuation system for development and use in a fly-by-wire system was selected. The concept which was selected consisted of a PM torque motor direct drive. The selected system is compatible with concurrent and independent development efforts on the computer system and the control law mechanizations.

  18. Air control system providing healthful enclosed environment

    SciTech Connect

    Rhodes, J.A.

    1991-08-27

    This patent describes an environmentally controlled building. It comprises an outer wall defining an outer building perimeter and having at least one fenestration therethrough for passage of personnel; a roof supported by and cooperating with the outer wall to define a building exterior and interior; and an environmental control system for controlling the environment within the building interior, the environmental control system including a heating and air conditioning unit, having an air inlet, for controlling the temperature of air drawing into the air control system; a humidity control unit, having an inlet connected to the heating and air conditioning unit, for controlling the humidity of air within the air control system; an air blower for forcing air from the environmental control system into the building interior; and an air filtering system having an inlet connected to the humidity control unit and an outlet connected to the blower.

  19. Critical Slowing Down Governs the Transition to Neuron Spiking

    PubMed Central

    Meisel, Christian; Klaus, Andreas; Kuehn, Christian; Plenz, Dietmar

    2015-01-01

    Many complex systems have been found to exhibit critical transitions, or so-called tipping points, which are sudden changes to a qualitatively different system state. These changes can profoundly impact the functioning of a system ranging from controlled state switching to a catastrophic break-down; signals that predict critical transitions are therefore highly desirable. To this end, research efforts have focused on utilizing qualitative changes in markers related to a system’s tendency to recover more slowly from a perturbation the closer it gets to the transition—a phenomenon called critical slowing down. The recently studied scaling of critical slowing down offers a refined path to understand critical transitions: to identify the transition mechanism and improve transition prediction using scaling laws. Here, we outline and apply this strategy for the first time in a real-world system by studying the transition to spiking in neurons of the mammalian cortex. The dynamical system approach has identified two robust mechanisms for the transition from subthreshold activity to spiking, saddle-node and Hopf bifurcation. Although theory provides precise predictions on signatures of critical slowing down near the bifurcation to spiking, quantitative experimental evidence has been lacking. Using whole-cell patch-clamp recordings from pyramidal neurons and fast-spiking interneurons, we show that 1) the transition to spiking dynamically corresponds to a critical transition exhibiting slowing down, 2) the scaling laws suggest a saddle-node bifurcation governing slowing down, and 3) these precise scaling laws can be used to predict the bifurcation point from a limited window of observation. To our knowledge this is the first report of scaling laws of critical slowing down in an experiment. They present a missing link for a broad class of neuroscience modeling and suggest improved estimation of tipping points by incorporating scaling laws of critical slowing down as a

  20. Birth control - slow release methods

    MedlinePlus

    ... ovaries from releasing an egg. Releasing egg during menstrual cycle is called ovulation. They do this by changing ... implants are likely to get pregnant. Your regular menstrual cycles should return within 3 to 4 weeks after ...

  1. Effect of a free-range raising system on growth performance, carcass yield, and meat quality of slow-growing chicken.

    PubMed

    Wang, K H; Shi, S R; Dou, T C; Sun, H J

    2009-10-01

    Experiments were conducted to evaluate the effect of free-range raising systems on growth performance, carcass yield, and meat quality of slow-growing chickens. Slow-growing female chickens, Gushi chickens, were selected as the experimental birds. Two hundred 1-d-old female chicks were raised in a pen for 35 d. On d 36, ninety healthy birds, with similar BW (353.7+/-32.1g), were selected and randomly assigned to 2 treatments (indoor treatment and free-range treatment, P>0.05). Each treatment was represented by 3 groups containing 15 birds (45 birds per treatment). During the indoor treatment, the chickens were raised in floor pens in a conventional poultry research house (7 birds/m2). In the free-range treatment, the chickens were housed in a similar indoor house (7 birds/m2); in addition, they also had a free-range grass paddock (1 bird/m2). All birds were provided with the same starter and finisher diets and were raised for 112 d. Results showed that the BW and weight gain of the chickens in the free-range treatment were much lower than that of the chickens in the indoor floor treatments (P<0.05). There was no effect of the free-range raising system on eviscerated carcass, breast, thigh, and wing yield (P>0.05). However, the abdominal fat yield and tibia strength (P<0.05) significantly declined. The nutrient composition (water, protein, and fat), water-holding capacity, shear force, and pH of the muscle were largely unaffected (P>0.05) by the free-range raising system. The data indicated that the free-range raising system could significantly reduce growth performance, abdominal fat, and tibia strength, but with no effect on carcass traits and meat quality in slow-growing chickens.

  2. Evolving Systems and Adaptive Key Component Control

    NASA Technical Reports Server (NTRS)

    Frost, Susan A.; Balas, Mark J.

    2009-01-01

    We propose a new framework called Evolving Systems to describe the self-assembly, or autonomous assembly, of actively controlled dynamical subsystems into an Evolved System with a higher purpose. An introduction to Evolving Systems and exploration of the essential topics of the control and stability properties of Evolving Systems is provided. This chapter defines a framework for Evolving Systems, develops theory and control solutions for fundamental characteristics of Evolving Systems, and provides illustrative examples of Evolving Systems and their control with adaptive key component controllers.

  3. Novel fatty acid gentamicin salts as slow-release drug carrier systems for anti-infective protection of vascular biomaterials.

    PubMed

    Obermeier, A; Matl, F D; Schwabe, J; Zimmermann, A; Kühn, K D; Lakemeier, S; von Eisenhart-Rothe, R; Stemberger, A; Burgkart, R

    2012-07-01

    Infections of vascular prostheses are still a major risk in surgery. The current work presents an in vitro evaluation of novel slow release antibiotic coatings based on new gentamicin fatty acid salts for polytetrafluoroethylene grafts. These grafts were coated with gentamicin sodium dodecyl sulfate, gentamicin laurate and gentamicin palmitate. Drug release kinetics, anti-infective characteristics, biocompatibility and haemocompatibility of developed coatings were compared to commercially available gelatin sealed PTFE grafts (SEALPTFE™) and knitted silver coated Dacron(®) grafts (InterGard(®)). Each gentamicin fatty acid coating showed a continuous drug release in the first eight hours followed by a low continuous release. Grafts coated with gentamicin fatty acids reduced bacterial growth even beyond pathologically relevant high concentrations. Cytotoxicity levels depending on drug formulation bringing up gentamicin palmitate as the most promising biocompatible coating. Thrombelastography studies, ELISA assays and an amidolytic substrate assay confirmed haemocompatibility of developed gentamicin fatty acid coatings comparable to commercially available grafts. PMID:22476651

  4. Automatic oscillator frequency control system

    NASA Technical Reports Server (NTRS)

    Smith, S. F. (Inventor)

    1985-01-01

    A frequency control system makes an initial correction of the frequency of its own timing circuit after comparison against a frequency of known accuracy and then sequentially checks and corrects the frequencies of several voltage controlled local oscillator circuits. The timing circuit initiates the machine cycles of a central processing unit which applies a frequency index to an input register in a modulo-sum frequency divider stage and enables a multiplexer to clock an accumulator register in the divider stage with a cyclical signal derived from the oscillator circuit being checked. Upon expiration of the interval, the processing unit compares the remainder held as the contents of the accumulator against a stored zero error constant and applies an appropriate correction word to a correction stage to shift the frequency of the oscillator being checked. A signal from the accumulator register may be used to drive a phase plane ROM and, with periodic shifts in the applied frequency index, to provide frequency shift keying of the resultant output signal. Interposition of a phase adder between the accumulator register and phase plane ROM permits phase shift keying of the output signal by periodic variation in the value of a phase index applied to one input of the phase adder.

  5. Novel high efficient coatings for anti-microbial surgical sutures using chlorhexidine in fatty acid slow-release carrier systems.

    PubMed

    Obermeier, Andreas; Schneider, Jochen; Wehner, Steffen; Matl, Florian Dominik; Schieker, Matthias; von Eisenhart-Rothe, Rüdiger; Stemberger, Axel; Burgkart, Rainer

    2014-01-01

    Sutures can cause challenging surgical site infections, due to capillary effects resulting in bacteria permeating wounds. Anti-microbial sutures may avoid these complications by inhibiting bacterial pathogens. Recently, first triclosan-resistances were reported and therefore alternative substances are becoming clinically relevant. As triclosan alternative chlorhexidine, the "gold standard" in oral antiseptics was used. The aim of the study was to optimize novel slow release chlorhexidine coatings based on fatty acids in surgical sutures, to reach a high anti-microbial efficacy and simultaneously high biocompatibility. Sutures were coated with chlorhexidine laurate and chlorhexidine palmitate solutions leading to 11, 22 or 33 µg/cm drug concentration per length. Drug release profiles were determined in aqueous elutions. Antibacterial efficacy against Staphylococcus aureus was assessed in agar diffusion tests. Biocompatibility was evaluated via established cytotoxicity assay (WST-1). A commercially triclosan-containing suture (Vicryl Plus), was used as anti-microbial reference. All coated sutures fulfilled European Pharmacopoeia required tensile strength and proved continuous slow drug release over 96 hours without complete wash out of the coated drug. High anti-microbial efficacy for up to 5 days was observed. Regarding biocompatibility, sutures using 11 µg/cm drug content displayed acceptable cytotoxic levels according to ISO 10993-5. The highest potential for human application were shown by the 11 µg/cm chlorhexidine coated sutures with palmitic acid. These novel coated sutures might be alternatives to already established anti-microbial sutures such as Vicryl Plus in case of triclosan-resistance. Chlorhexidine is already an established oral antiseptic, safety and efficacy should be proven for clinical applications in anti-microbial sutures. PMID:24983633

  6. [Supra-molecular assembly and magnetic targeted slow-release effect of "dextran-magnetic layered double hydroxide-fluorouracil" drug delivery system].

    PubMed

    Gou, Guo-jing; Liu, Yan-hong; Sun, Yue; Huang, Je; Xue, Bing; Dong, Li-e

    2011-11-01

    The drug-loading system of DMF (dextran - magnetic layered double hydroxide - fluorouracil) was synthesized by "co-precipitation intercalated assembly - dextran composite in situ - solvent conversion" technology. The crystal-phase characteristic and slow-release performance of DMF were investigated through X-ray diffraction (XRD), infrared spectrum (IR), transmission electron microscopy (TEM), thermogravimetry (TG) and in vitro release experiment. The targeted transshipment and slow-release effect of DMF system were evaluated by in vivo animal experiment. It was showed that the XRD of DMF matched with R-sixtetragonum type layered double hydroxide and Fd-3m cubic type ferrite. IR test demonstrated that the DMF system was a supra-molecular complex consisted of Dextran (DET), magnetic layered double hydroxide (MLDH) and fluorouracil (FU) components. The two-level supra-molecular MLDH-FU presented six-edge lozenge TEM morphology, with layered characteristics. DET on the surface of DMF was capable of protecting the layered structure of MLDH-FU, improving particle dispersion properties, and strengthening the slow-release performance of the drug delivery system. The drug release model of DMF at pH 7.35 of PBS in vitro fit to the zero-order kinetics equation C = 1.1716 x 10(-5) + 4.4626 x 10(-7) t. The drug delivery system DMF could transport drugs principally to in vivo target organs with a local effect, targeted specificity, and excellent circulation transshipment performance. The pharmacokinetic process of DMF presented multi-peak phenomenon with peak attenuation and cyclic growth. The peaks appeared at 0.25, 1, 3, 5 and 9 d separately after dosing intervention. The first peak process of DMF accorded with a pharmacokinetic equation of C(FU) = 14.34 e(-0.530t) + 36.04 e(-0.321t) + 24.18 e(-0.96t), and presented the characteristic of slow absorption and fast elimination. As for subsequent peak processes, half-life increased, bioavailability increased, and plasma clearance

  7. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2006-01-17

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. The principal objectives of Phase II are: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in drilling laboratories and test wells. Work during this quarter centered on the testing of the rebuilt laboratory prototype and its conversion into a version that will be operable in the drilling tests at TerraTek Laboratories. In addition, formations for use in these tests were designed and constructed, and a test protocol was developed. The change in scope and no-cost extension of Phase II to January, 2006, described in our last report, were approved. The tests are scheduled to be run during the week of January 23, and should be completed before the end of the month.

  8. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2006-09-30

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. The principal objectives of Phase II were: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in drilling laboratories and test wells. Phase II concluded on January 31, 2006, and the final report was issued. Work on Phase III of the project began during the previous quarter. Efforts this quarter have focused on the manufacture of the prototype and precommercial parts, field test planning and commercialization. The current extreme lead times quoted by oilfield machine shops for collar components, will delay the deployment of the field prototypes. The delivery date for five critical parts from one supplier has slipped to late November, which will preclude deployment for a field test before late December or early January. We are exploring whether we can take the partially made parts and complete them earlier in our own shop.

  9. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2005-01-28

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. The principal objectives of Phase II are: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in drilling laboratories and test wells. The redesign and upgrade of the laboratory prototype was completed on schedule and it was assembled during the last period. Testing was begin during the first week of October. Initial results indicated that the dynamic range of the damping was less than predicted and that the maximum damping was also less than required. A number of possible explanations for these results were posited, and test equipment was acquired to evaluate the various hypotheses. Testing was just underway at the end of this period.

  10. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2004-10-29

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. Phase II began on June 1, and the first month's effort were reported in the seventh quarterly report on the project.1 The principal objectives of Phase II are: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in drilling laboratories and test wells. The redesign and upgrade of the laboratory prototype was completed on schedule during this period, and assembly was complete at the end of this period. Testing will begin during the first week of October. This aspect of the project is thus approximately six weeks behind schedule. Design of the field prototype is progressing per schedule.

  11. Orbiter active thermal control system description

    NASA Technical Reports Server (NTRS)

    Laubach, G. E.

    1975-01-01

    A brief description of the Orbiter Active Thermal Control System (ATCS) including (1) major functional requirements of heat load, temperature control and heat sink utilization, (2) the overall system arrangement, and (3) detailed description of the elements of the ATCS.

  12. 49 CFR 193.2619 - Control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... adjusted to operate within design limits. (b) If a control system is out of service for 30 days or more, it... each season. (2) Control systems that are intended for fire protection must be inspected and tested...

  13. Downhole Vibration Monitoring & Control System

    SciTech Connect

    Martin E. Cobern

    2007-03-31

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. The principal objectives of Phase II were: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in a drilling laboratory. Phase II concluded on January 31, 2006, and the Phase II final report was issued. Work on Phase III of the project began during the first quarter, 2006. Efforts the current quarter have continued to focus on the manufacture of the prototype and precommercial parts, field test planning and commercialization. The continued extreme lead times quoted by oilfield machine shops for collar components significantly delayed the deployment of the prototype and precommercial units. All parts have now been received for two units, and all but one for the third. Mechanical assembly of the first two systems is complete and the electronics installation and laboratory testing will be finished in April. We have entered into a Memorandum of Understanding with a major US oilfield equipment supplier, which calls for their assisting with our field tests, in cash and in kind. We are close to signing a definitive agreement which includes the purchase of the three precommercial units. We had also signed a CRADA with the Rocky Mountain Oilfield Test Center (RMOTC), and scheduled a test at their site, The RMOTC drilling schedule continues to slip, and the test cannot begin until the first week of May. Based on these factors, we have requested a no-cost extension to July 31, 2007.

  14. Design of feedback control systems for unstable plants with saturating actuators

    NASA Technical Reports Server (NTRS)

    Kapasouris, Petros; Athans, Michael; Stein, Gunter

    1988-01-01

    A new control design methodology is introduced for multi-input/multi-output systems with unstable open loop plants and saturating actuators. A control system is designed using well known linear control theory techniques and then a reference prefilter is introduced so that when the references are sufficiently small, the control system operates linearly as designated. For signals large enough to cause saturations, the control law is modified in such a way to ensure stability and to preserve, to the extent possible, the behavior of the linear control design. Key benefits of this methodology are: the modified feedback system never produces saturating control signals, integrators and/or slow dynamics in the compensator never windup, the directionaL properties of the controls are maintained, and the closed loop system has certain guaranteed stability properties. The advantages of the new design methodology are illustrated in the simulation of an approximation of the AFTI-16 (Advanced Fighter Technology Integration) aircraft multivariable longitudinal dynamics.

  15. AGS slow extracted beam improvement

    SciTech Connect

    Marneris, I.; Danowski, G.; Sandberg, J.; Soukas, A.

    1997-07-01

    The Brookhaven AGS is a strong focusing accelerator which is used to accelerate protons and various heavy ion species to an equivalent proton energy of 29 GeV. Since the late 1960`s it has been serving high energy physics (HEP - proton beam) users of both slow and fast extracted beams. The AGS fixed target program presently uses primary proton and heavy ion beams (HIP) in slowly extracted fashion over spill lengths of 1.5 to 4.0 seconds. Extraction is accomplished by flattoping the main and extraction magnets and exciting a third integer resonance in the AGS. Over the long spill times, control of the subharmonic amplitude components up to a frequency of 1 kilohertz is very crucial. One of the most critical contributions to spill modulation is due to the AGS MMPS. An active filter was developed to reduce these frequencies and it`s operation is described in a previous paper. However there are still frequency components in the 60-720 Hz sub-harmonic ripple range, modulating the spill structure due to extraction power supplies and any remaining structures on the AGS MMPS. A recent scheme is being developed to use the existing tune-trim control horizontal quadrupole magnets and power supply to further reduce these troublesome noise sources. Feedback from an external beam sensor and overcoming the limitations of the quadrupole system by lead/lag compensation techniques will be described.

  16. Noise and Controllability: Suppression of Controllability in Large Quantum Systems

    SciTech Connect

    Khasin, M.; Kosloff, R.

    2011-03-25

    A closed quantum system is defined as completely controllable if an arbitrary unitary transformation can be executed using the available controls. In practice, control fields are a source of unavoidable noise. Can one design control fields such that the effect of noise is negligible on the timescale of the transformation? Complete controllability in practice requires that the effect of noise can be suppressed for an arbitrary transformation. The present study considers a paradigm of control, where the Lie-algebraic structure of the control Hamiltonian is fixed, while the size of the system increases, determined by the dimension of the Hilbert space representation of the algebra. We show that for large quantum systems, generic noise in the controls dominates for a typical class of target transformation; i.e., complete controllability is destroyed by the noise.

  17. Determination of Nitrogen, Phosphorus, and Potassium Release Rates of Slow- and Controlled-Release Fertilizers: Single-Laboratory Validation, First Action 2015.15.

    PubMed

    Thiex, Nancy

    2016-01-01

    A previously validated method for the determination of nitrogen release patterns of slow- and controlled-release fertilizers (SRFs and CRFs, respectively) was submitted to the Expert Review Panel (ERP) for Fertilizers for consideration of First Action Official Method(SM) status. The ERP evaluated the single-laboratory validation results and recommended the method for First Action Official Method status and provided recommendations for achieving Final Action. The 180 day soil incubation-column leaching technique was demonstrated to be a robust and reliable method for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and the results were only slightly affected by variations in environmental factors such as microbial activity, soil moisture, temperature, and texture. The release of P and K were also studied, but at fewer replications than for N. Optimization experiments on the accelerated 74 h extraction method indicated that temperature was the only factor found to substantially influence nutrient-release rates from the materials studied, and an optimized extraction profile was established as follows: 2 h at 25°C, 2 h at 50°C, 20 h at 55°C, and 50 h at 60°C. PMID:26987312

  18. Statistical correlation of the soil incubation and the accelerated laboratory extraction methods to estimate nitrogen release rates of slow- and controlled-release fertilizers.

    PubMed

    Medina, L Carolina; Sartain, Jerry; Obreza, Thomas; Hall, William L; Thiex, Nancy J

    2014-01-01

    Several technologies have been proposed to characterize the nutrient release patterns of enhanced-efficiency fertilizers (EEFs) during the last few decades. These technologies have been developed mainly by manufacturers and are product-specific based on the regulation and analysis of each EEF product. Despite previous efforts to characterize nutrient release of slow-release fertilizer (SRF) and controlled-release fertilizer (CRF) materials, no official method exists to assess their nutrient release patterns. However, the increased production and distribution of EEFs in specialty and nonspecialty markets requires an appropriate method to verify nutrient claims and material performance. Nonlinear regression was used to establish a correlation between the data generated from a 180-day soil incubation-column leaching procedure and 74 h accelerated lab extraction method, and to develop a model that can predict the 180-day nitrogen (N) release curve for a specific SRF and CRF product based on the data from the accelerated laboratory extraction method. Based on the R2 > 0.90 obtained for most materials, results indicated that the data generated from the 74 h accelerated lab extraction method could be used to predict N release from the selected materials during 180 days, including those fertilizers that require biological activity for N release. PMID:25051612

  19. Technical note: use of slow-release estradiol and prostaglandin F2alpha to induce pseudopregnancy and control estrus in gilts.

    PubMed

    Cushman, R A; Davis, P E; Boonyaprakob, U; Hedgpeth, V S; Burns, P J; Britt, J H

    1999-11-01

    We determined whether a single injection of slow-release estradiol-17beta (SRE2) would induce pseudopregnancy in gilts and whether PGF2alpha would regress the corpora lutea (CL) of pseudopregnancy. Crossbred gilts (n = 40) were induced to ovulate by treatment with 400 IU of hCG + 200 IU of eCG (PG600, Intervet, Millsboro, DE) given at 180 d of age (d = 0). On d 14, gilts were injected i.m. with one of five doses (n = 8 gilts/dose) of SRE2 (0, 12.5, 25, 50, or 100 mg). Blood samples were collected before SRE2 and twice weekly until d 73 to monitor serum progesterone (P4) and estradiol (E2). On d 59, gilts received (i.m.) 10 mg of PGF2alpha (Lutalyse, Pharmacia Upjohn, Kalamazoo, MI) and were checked for estrus for 7 d. On d 62, mammary development was scored (0 = no development; 1 = some development; 2 = teat and gland development) by a neutral observer. Treatment with SRE2 increased (P < .05) peak E2 concentrations, duration of luteal function, and mammary gland score. There were no differences (chi-square, P > .05) among doses of SRE2 in the percentage of pseudopregnant gilts that showed luteolysis after PGF2alpha. We conclude that a single injection of SRE2 can induce pseudopregnancy and that the CL can be regressed with PGF2alpha, providing a simple method for controlling estrus in gilts.

  20. Optimization and validation of an accelerated laboratory extraction method to estimate nitrogen release patterns of slow- and controlled-release fertilizers.

    PubMed

    Medina, L Carolina; Sartain, Jerry B; Obreza, Thomas A; Hall, William L; Thiex, Nancy J

    2014-01-01

    Several technologies have been proposed to characterize the nutrient release and availability patterns of enhanced-efficiency fertilizers (EEFs), especially slow-release fertilizers (SRFs) and controlled-release fertilizers (CRFs) during the last few decades. These technologies have been developed mainly by manufacturers and are product-specific based on the regulation and analysis of each EEF product. Despite previous efforts to characterize EEF materials, no validated method exists to assess their nutrient release patterns. However, the increased use of EEFs in specialty and nonspecialty markets requires an appropriate method to verify nutrient claims and material performance. A series of experiments were conducted to evaluate the effect of temperature, fertilizer test portion size, and extraction time on the performance of a 74 h accelerated laboratory extraction method to measure SRF and CRF nutrient release profiles. Temperature was the only factor that influenced nutrient release rate, with a highly marked effect for phosphorus and to a lesser extent for nitrogen (N) and potassium. Based on the results, the optimal extraction temperature set was: Extraction No. 1-2:00 h at 25 degrees C; Extraction No. 2-2:00 h at 50 degrees C; Extraction No. 3-20:00 h at 55 degrees C; and Extraction No. 4-50:00 h at 60 degrees C. Ruggedness of the method was tested by evaluating the effect of small changes in seven selected factors on method behavior using a fractional multifactorial design. Overall, the method showed ruggedness for measuring N release rates of coated CRFs.

  1. Statistical correlation of the soil incubation and the accelerated laboratory extraction methods to estimate nitrogen release rates of slow- and controlled-release fertilizers.

    PubMed

    Medina, L Carolina; Sartain, Jerry; Obreza, Thomas; Hall, William L; Thiex, Nancy J

    2014-01-01

    Several technologies have been proposed to characterize the nutrient release patterns of enhanced-efficiency fertilizers (EEFs) during the last few decades. These technologies have been developed mainly by manufacturers and are product-specific based on the regulation and analysis of each EEF product. Despite previous efforts to characterize nutrient release of slow-release fertilizer (SRF) and controlled-release fertilizer (CRF) materials, no official method exists to assess their nutrient release patterns. However, the increased production and distribution of EEFs in specialty and nonspecialty markets requires an appropriate method to verify nutrient claims and material performance. Nonlinear regression was used to establish a correlation between the data generated from a 180-day soil incubation-column leaching procedure and 74 h accelerated lab extraction method, and to develop a model that can predict the 180-day nitrogen (N) release curve for a specific SRF and CRF product based on the data from the accelerated laboratory extraction method. Based on the R2 > 0.90 obtained for most materials, results indicated that the data generated from the 74 h accelerated lab extraction method could be used to predict N release from the selected materials during 180 days, including those fertilizers that require biological activity for N release.

  2. Determination of Nitrogen, Phosphorus, and Potassium Release Rates of Slow- and Controlled-Release Fertilizers: Single-Laboratory Validation, First Action 2015.15.

    PubMed

    Thiex, Nancy

    2016-01-01

    A previously validated method for the determination of nitrogen release patterns of slow- and controlled-release fertilizers (SRFs and CRFs, respectively) was submitted to the Expert Review Panel (ERP) for Fertilizers for consideration of First Action Official Method(SM) status. The ERP evaluated the single-laboratory validation results and recommended the method for First Action Official Method status and provided recommendations for achieving Final Action. The 180 day soil incubation-column leaching technique was demonstrated to be a robust and reliable method for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and the results were only slightly affected by variations in environmental factors such as microbial activity, soil moisture, temperature, and texture. The release of P and K were also studied, but at fewer replications than for N. Optimization experiments on the accelerated 74 h extraction method indicated that temperature was the only factor found to substantially influence nutrient-release rates from the materials studied, and an optimized extraction profile was established as follows: 2 h at 25°C, 2 h at 50°C, 20 h at 55°C, and 50 h at 60°C.

  3. Computer controlled thermal fatigue test system

    SciTech Connect

    Schmale, D.T.; Jones, W.B.

    1986-01-01

    A servo-controlled hydraulic mechanical test system has been configured to conduct computer-controlled thermal fatigue tests. The system uses induction heating, a digital temperature controller, infrared pyrometry, forced air cooling, and quartz rod extensometry. In addition, a digital computer controls the tests and allows precise data analysis and interpretation.

  4. 50 CFR 600.420 - Control system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Control system. 600.420 Section 600.420..., DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Confidentiality of Statistics § 600.420 Control system. (a) The Assistant Administrator maintains a control system to protect the identity of submitters...

  5. A multistrategy control system for field controllers of astronomical instruments

    NASA Astrophysics Data System (ADS)

    Zhu, Dan; Zhu, Yuhua

    2010-07-01

    As well-known, system on a programmable chip (SOPC) is widely used in a variety of field control systems , due to their flexible configurations and intelligent stand-alone characteristics. They are also increasingly used in astronomical instrument control nowadays. For those complex and diverse systems, a number of different control strategies are stored in FLASH, but the controller of on-chip determines which one to load. At the same time, it can be switched intelligently and remotely to form a multi-strategy control system, so as to extend the control functions and achieve system on-line reconfiguration quickly. In this paper we describe a design concept and realization method of a multistrategy control system on the basis of FPGA-based system on a chip. Its hardware core is Altera's Cyclone series EP3C25 chip .In SOPC BUILDER development environment ,a control system is constructed, which consists of NIOS II soft core as CPU ,REMOTE_UPDATE IP core and control algorithms as well. The concept and design has been verified in the field controllers for various astronomical applications. Satisfactory results have been obtained.

  6. Slow rupture of frictional interfaces

    NASA Astrophysics Data System (ADS)

    Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

    2012-02-01

    The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

  7. Optimization for efficient structure-control systems

    NASA Technical Reports Server (NTRS)

    Oz, Hayrani; Khot, Narendra S.

    1993-01-01

    The efficiency of a structure-control system is a nondimensional parameter which indicates the fraction of the total control power expended usefully in controlling a finite-dimensional system. The balance of control power is wasted on the truncated dynamics serving no useful purpose towards the control objectives. Recently, it has been demonstrated that the concept of efficiency can be used to address a number of control issues encountered in the control of dynamic systems such as the spillover effects, selection of a good input configuration and obtaining reduced order control models. Reference (1) introduced the concept and presented analyses of several Linear Quadratic Regulator designs on the basis of their efficiencies. Encouraged by the results of Ref. (1), Ref. (2) introduces an efficiency modal analysis of a structure-control system which gives an internal characterization of the controller design and establishes the link between the control design and the initial disturbances to affect efficient structure-control system designs. The efficiency modal analysis leads to identification of principal controller directions (or controller modes) distinct from the structural natural modes. Thus ultimately, many issues of the structure-control system revolve around the idea of insuring compatibility of the structural modes and the controller modes with each other, the better the match the higher the efficiency. A key feature in controlling a reduced order model of a high dimensional (or infinity-dimensional distributed parameter system) structural dynamic system must be to achieve high efficiency of the control system while satisfying the control objectives and/or constraints. Formally, this can be achieved by designing the control system and structural parameters simultaneously within an optimization framework. The subject of this paper is to present such a design procedure.

  8. Food control systems in Canada.

    PubMed

    Smith, T M; Jukes, D J

    1997-04-01

    This paper provides an overview of the responsibilities and jurisdictional boundaries of Health Canada (HC) and Agriculture and Agri-Food Canada (AAFC) with regard to food regulation in Canada. It examines their interagency coordination within the federal structure and with other levels of government, industry, and the consumer. The international developments are considered with the North American Free Trade Agreement (NAFTA) and the Canada, United States Trade Agreement (CUSTA) being regarded as likely to have a significant future impact. The federal food safety and quality system is complex and fragmented. Federal food regulation comes under the jurisdiction of four federal departments: HC, AAFC, Industry Canada (IC), and Fisheries and Oceans Canada (FOC). All four departments are involved with inspection, surveillance, and the analysis of food sold in Canada. In addition, Canada's ten provincial and two territorial governments have provincial-, regional-, municipal-, and local-level governments that also have jurisdiction over food safety and quality. Consideration is first given to the main legislative provision covering food--the Federal Food and Drugs Act. This Act is administered by several of the Federal Government departments. The role of these departments is examined individually along with additional, more specific legal provisions for which responsibility is not divided (in particular, the Canada Agricultural Products [CAP] Act administered by AAFC, and the Consumer Packaging and Labeling Act [CPLA] administered by IC). The various reviews that have taken place in the recent past and those still in progress are considered, and the final part of this paper looks at the international developments that are likely to have a major impact on the future development of the Canadian food control system.

  9. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2006-05-01

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. The principal objectives of Phase II were: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in drilling laboratories and test wells. Phase II concluded on January 31, 2006. The month of January was devoted to the final preparations for, and conducting of testing of the DVMCS at TerraTek laboratories in Salt Lake City. This testing was concluded on January 27, 2006. Much of the effort in this period was then devoted to the analysis of the data and the preparation of the Phase II final report. The report was issued after the close of the period. Work on Phase III of the project began during this quarter. It has consisted of making some modifications in the prototype design to make it more suitable for field testing an more practical for commercial use. This work is continuing. The redesign effort, coupled with the current extreme lead times quoted by oilfield machine shops for collar components, will delay the deployment of the field prototypes. The precommercial prototypes are being developed in parallel, so the project should be completed per the current schedule.

  10. DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

    SciTech Connect

    Martin E. Cobern

    2005-04-27

    The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. The principal objectives of Phase II are: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in drilling laboratories and test wells. As a result of the lower than expected performance of the MR damper noted last quarter, several additional tests were conducted. These dealt with possible causes of the lack of dynamic range observed in the testing: additional damping from the oil in the Belleville springs; changes in properties of the MR fluid; and, residual magnetization of the valve components. Of these, only the last was found to be significant. By using a laboratory demagnetization apparatus between runs, a dynamic range of 10:1 was achieved for the damper, more than adequate to produce the needed improvements in drilling. Additional modeling was also performed to identify a method of increasing the magnetic field in the damper. As a result of the above, several changes were made in the design. Additional circuitry was added to demagnetize the valve as the field is lowered. The valve was located to above the Belleville springs to reduce the load placed upon it and offer a greater range of materials for its construction. In addition, to further increase the field strength, the coils were relocated from the mandrel to the outer housing. At the end of the quarter, the redesign was complete and new parts were on order. The project is approximately three months behind schedule at this time.

  11. Spacecraft attitude control using a smart control system

    NASA Technical Reports Server (NTRS)

    Buckley, Brian; Wheatcraft, Louis

    1992-01-01

    Traditionally, spacecraft attitude control has been implemented using control loops written in native code for a space hardened processor. The Naval Research Lab has taken this approach during the development of the Attitude Control Electronics (ACE) package. After the system was developed and delivered, NRL decided to explore alternate technologies to accomplish this same task more efficiently. The approach taken by NRL was to implement the ACE control loops using systems technologies. The purpose of this effort was to: (1) research capabilities required of an expert system in processing a classic closed-loop control algorithm; (2) research the development environment required to design and test an embedded expert systems environment; (3) research the complexity of design and development of expert systems versus a conventional approach; and (4) test the resulting systems against the flight acceptance test software for both response and accuracy. Two expert systems were selected to implement the control loops. Criteria used for the selection of the expert systems included that they had to run in both embedded systems and ground based environments. Using two different expert systems allowed a comparison of the real-time capabilities, inferencing capabilities, and the ground-based development environment. The two expert systems chosen for the evaluation were Spacecraft Command Language (SCL), and NEXTPERT Object. SCL is a smart control system produced for the NRL by Interface and Control Systems (ICS). SCL was developed to be used for real-time command, control, and monitoring of a new generation of spacecraft. NEXPERT Object is a commercially available product developed by Neuron Data. Results of the effort were evaluated using the ACE test bed. The ACE test bed had been developed and used to test the original flight hardware and software using simulators and flight-like interfaces. The test bed was used for testing the expert systems in a 'near-flight' environment

  12. Fuzzy logic control and optimization system

    DOEpatents

    Lou, Xinsheng

    2012-04-17

    A control system (300) for optimizing a power plant includes a chemical loop having an input for receiving an input signal (369) and an output for outputting an output signal (367), and a hierarchical fuzzy control system (400) operably connected to the chemical loop. The hierarchical fuzzy control system (400) includes a plurality of fuzzy controllers (330). The hierarchical fuzzy control system (400) receives the output signal (367), optimizes the input signal (369) based on the received output signal (367), and outputs an optimized input signal (369) to the input of the chemical loop to control a process of the chemical loop in an optimized manner.

  13. Avionics GPB Control System Analysis

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Gravity Probe B is a Satellite being developed by Lockheed Martin under NASA contract through MSFC and managed by Stanford University. The goal of the satellite experiment is to test the accuracy of drift predictions made using Einstein s General Theory of Relativity. The drift in the direction of the spin axes of 4 highly precise quartz spherical gyroscopes induced by motion in the earth s gravitational field will be measured over a year s duration with the known, non-relativistic effects removed. The expected angles of drift for a one year period are approximately 6.6 arcsec for drift in the orbit plane called geodetic drift and 0.033 arcsec of drift normal to the orbit plane called frame dragging. The aerodynamic drag force on the GPB Satellite is compensated by a translation control system. It is pointed at a guide star and maintained in spin at a rate to be selected in the range 0.1 - 1 rpm. The purpose of our task is to update the TREETOPS GPB spacecraft simulation and to assist MSFC in assessing the affect of Helium slosh dynamics on spacecraft pointing performance.

  14. Essential Roles of GABA Transporter-1 in Controlling Rapid Eye Movement Sleep and in Increased Slow Wave Activity after Sleep Deprivation

    PubMed Central

    Xu, Xin-Hong; Qu, Wei-Min; Bian, Min-Juan; Huang, Fang; Fei, Jian; Urade, Yoshihiro; Huang, Zhi-Li

    2013-01-01

    GABA is the major inhibitory neurotransmitter in the mammalian central nervous system that has been strongly implicated in the regulation of sleep. GABA transporter subtype 1 (GAT1) constructs high affinity reuptake sites for GABA and regulates GABAergic transmission in the brain. However, the role of GAT1 in sleep-wake regulation remains elusive. In the current study, we characterized the spontaneous sleep-wake cycle and responses to sleep deprivation in GAT1 knock-out (KO) mice. GAT1 KO mice exhibited dominant theta-activity and a remarkable reduction of EEG power in low frequencies across all vigilance stages. Under baseline conditions, spontaneous rapid eye movement (REM) sleep of KO mice was elevated both during the light and dark periods, and non-REM (NREM) sleep was reduced during the light period only. KO mice also showed more state transitions from NREM to REM sleep and from REM sleep to wakefulness, as well as more number of REM and NREM sleep bouts than WT mice. During the dark period, KO mice exhibited more REM sleep bouts only. Six hours of sleep deprivation induced rebound increases in NREM and REM sleep in both genotypes. However, slow wave activity, the intensity component of NREM sleep was briefly elevated in WT mice but remained completely unchanged in KO mice, compared with their respective baselines. These results indicate that GAT1 plays a critical role in the regulation of REM sleep and homeostasis of NREM sleep. PMID:24155871

  15. Essential roles of GABA transporter-1 in controlling rapid eye movement sleep and in increased slow wave activity after sleep deprivation.

    PubMed

    Xu, Xin-Hong; Qu, Wei-Min; Bian, Min-Juan; Huang, Fang; Fei, Jian; Urade, Yoshihiro; Huang, Zhi-Li

    2013-01-01

    GABA is the major inhibitory neurotransmitter in the mammalian central nervous system that has been strongly implicated in the regulation of sleep. GABA transporter subtype 1 (GAT1) constructs high affinity reuptake sites for GABA and regulates GABAergic transmission in the brain. However, the role of GAT1 in sleep-wake regulation remains elusive. In the current study, we characterized the spontaneous sleep-wake cycle and responses to sleep deprivation in GAT1 knock-out (KO) mice. GAT1 KO mice exhibited dominant theta-activity and a remarkable reduction of EEG power in low frequencies across all vigilance stages. Under baseline conditions, spontaneous rapid eye movement (REM) sleep of KO mice was elevated both during the light and dark periods, and non-REM (NREM) sleep was reduced during the light period only. KO mice also showed more state transitions from NREM to REM sleep and from REM sleep to wakefulness, as well as more number of REM and NREM sleep bouts than WT mice. During the dark period, KO mice exhibited more REM sleep bouts only. Six hours of sleep deprivation induced rebound increases in NREM and REM sleep in both genotypes. However, slow wave activity, the intensity component of NREM sleep was briefly elevated in WT mice but remained completely unchanged in KO mice, compared with their respective baselines. These results indicate that GAT1 plays a critical role in the regulation of REM sleep and homeostasis of NREM sleep.

  16. Spacecraft command and control using expert systems

    NASA Technical Reports Server (NTRS)

    Norcross, Scott; Grieser, William H.

    1994-01-01

    This paper describes a product called the Intelligent Mission Toolkit (IMT), which was created to meet the changing demands of the spacecraft command and control market. IMT is a command and control system built upon an expert system. Its primary functions are to send commands to the spacecraft and process telemetry data received from the spacecraft. It also controls the ground equipment used to support the system, such as encryption gear, and telemetry front-end equipment. Add-on modules allow IMT to control antennas and antenna interface equipment. The design philosophy for IMT is to utilize available commercial products wherever possible. IMT utilizes Gensym's G2 Real-time Expert System as the core of the system. G2 is responsible for overall system control, spacecraft commanding control, and spacecraft telemetry analysis and display. Other commercial products incorporated into IMT include the SYBASE relational database management system and Loral Test and Integration Systems' System 500 for telemetry front-end processing.

  17. REACTOR CONTROL ROD OPERATING SYSTEM

    DOEpatents

    Miller, G.

    1961-12-12

    A nuclear reactor control rod mechanism is designed which mechanically moves the control rods into and out of the core under normal conditions but rapidly forces the control rods into the core by catapultic action in the event of an emergency. (AEC)

  18. An expert system for restructurable control

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan

    1988-01-01

    Work in progress on an expert system which restructures and tunes control systems on-line is presented. The expert system coordinates the different methods for redesigning and implementing the control strategies due to system changes. The research is directed toward aircraft and jet engine applications. The implementation is written in LISP and is currently running on a special purpose LISP machine.

  19. The cryogenic control system of BEPCII

    NASA Astrophysics Data System (ADS)

    Li, Gang; Wang, Ke-Xiang; Zhao, Ji-Jiu; Yue, Ke-Juan; Dai, Ming-Hui; Huang, Yi-Ling; Jiang, Bo

    2008-04-01

    A superconducting cryogenic system has been designed and deployed in the Beijing Electron- Positron Collider Upgrade Project (BEPCII). The system consists of a Siemens PLC (S7-PLC, Programmable Logic Controller) for the compressor control, an Allen Bradley (AB) PLC for the cryogenic equipments, and the Experimental Physics and Industrial Control System (EPICS) that integrates the PLCs. The system fully automates the superconducting cryogenic control with process control, PID (Proportional-Integral-Differential) control loops, real-time data access and data storage, alarm handler and human machine interface. It is capable of automatic recovery as well. This paper describes the BEPCII cryogenic control system, data communication between S7-PLC and EPICS Input/Output Controllers (IOCs), and the integration of the flow control, the low level interlock, the AB-PLC, and EPICS.

  20. Identification and Control of Mechanical Systems

    NASA Astrophysics Data System (ADS)

    Juang, Jer-Nan; Phan, Minh Q.

    2001-08-01

    The control of vibrating systems is a significant issue in the design of aircraft, spacecraft, bridges, and high-rise buildings. This book discusses the control of vibrating systems, integrating structural dynamics, vibration analysis, modern control, and system identification. By integrating these subjects engineers will need only one book, rather than several texts or courses, to solve vibration control problems. The authors cover key developments in aerospace control and identification theory, including virtual passive control, observer and state-space identification, and data-based controller synthesis. They address many practical issues and applications, and show examples of how various methods are applied to real systems. Some methods show the close integration of system identification and control theory from the state-space perspective, rather than from the traditional input-output model perspective of adaptive control. This text will be useful for advanced undergraduate and beginning graduate students in aerospace, mechanical, and civil engineering, as well as for practicing engineers.

  1. SAFETY SYSTEM FOR CONTROL ROD

    DOEpatents

    Paget, J.A.

    1963-05-14

    A structure for monitoring the structural continuity of a control rod foi a neutron reactor is presented. A electric conductor readily breakable under mechanical stress is fastened along the length of the control rod at a plurality of positions and forms a closed circuit with remote electrical components responsive to an open circuit. A portion of the conductor between the control rod and said components is helically wound to allow free and normally unrestricted movement of the segment of conductor secured to the control rod relative to the remote components. Any break in the circuit is indicative of control rod breakage. (AEC)

  2. Monitoring local configuration and anomalously slow relaxation of a nonergodic system of interacting liquid nanoclusters in a disordered confinement of a random porous medium

    NASA Astrophysics Data System (ADS)

    Borman, V. D.; Belogorlov, A. A.; Bortnikova, S. A.; Tronin, V. N.

    2016-09-01

    The relaxation of a confined nonwetting liquid dispersed in a disordered nanoporous medium has been experimentally studied in the system consisting of water and the L23 hydrophobized silica gel. Discovered that the relaxation of these states to study the system occurs as a result of the relaxation of local metastable configurations of filled and empty pores of the porous medium. Such relaxation occurs abnormally slowly back to the power law with the exponent α < 0.16. The observed anomalously slow relaxation of such a system and comparison with the time dependence of the volume of the confined liquid obtained in confirm the correctness of the description of disordered media on the basis of the notion of local metastable structures.

  3. Long life reliability thermal control systems study

    NASA Technical Reports Server (NTRS)

    Scollon, T. R., Jr.; Killen, R. E.

    1972-01-01

    The results of a program undertaken to conceptually design and evaluate a passive, high reliability, long life thermal control system for space station application are presented. The program consisted of four steps: (1) investigate and select potential thermal system elements; (2) conceive, evaluate and select a thermal control system using these elements; (3) conduct a verification test of a prototype segment of the selected system; and (4) evaluate the utilization of waste heat from the power supply. The result of this project is a conceptual thermal control system design which employs heat pipes as primary components, both for heat transport and temperature control. The system, its evaluation, and the test results are described.

  4. EBT data acquisition system control facilities

    SciTech Connect

    Burris, R.D.

    1982-01-01

    A multicomputer, multitask data acquisition and analysis system has been implemented for the Elmo Bumpy Torus (EBT) experiment in controlled fusion. This document describes the control features of the computer system, including the provision of time and date to all computers, the control of data file names, the maintenance of critical data bases, and the control of various tasks. The physical control of the experiment itself, through the provision of voltages or the sensing of conditions, is not described in this document.

  5. Slow-scan operation of long linear CCD arrays

    NASA Technical Reports Server (NTRS)

    Vicars-Harris, M.

    1975-01-01

    Linear CCD arrays used singly or in optically butted assemblies permit practical implementation of long line array systems with 6000 or more picture elements per line with readout rates in excess of 5 MHz. Display and tape recording of slow scan imagery with over 1000 picture elements per line also presents unique challenges. This paper discusses performance results and the operation of 1728-element CCD arrays for generation of high resolution slow scan imagery and some approaches for recording and display of the imagery. The implication of dark current and its control are discussed.

  6. Spacecraft component heater control system

    NASA Technical Reports Server (NTRS)

    Bachtel, Frederick D. (Inventor); Owen, James W. (Inventor)

    1989-01-01

    A heater control circuit is disclosed as being constructed in a single integrated circuit, with the integrated circuit conveniently mounted proximate to a spacecraft component requiring temperature control. Redundant heater controllers control power applied to strip heaters disposed to provide heat to a component responsive to sensed temperature from temperature sensors. Signals from these sensors are digitized and compared with a dead band temperature and set point temperature stored in memory to generate an error signal if the sensed temperature is outside the parameter stored in the memory. This error signal is utilized by a microprocessor to selectively instruct the heater controllers to apply power to the strip heaters. If necessary, the spacecraft central processor may access or interrogate the microprocessor in order to alter the set point temperature and dead band temperature range to obtain operational data relating to the operation of an integrated circuit for relaying to the ground control, or to switch off faulty components.

  7. Common Badging and Access Control System (CBACS)

    NASA Technical Reports Server (NTRS)

    Dischinger, Portia

    2005-01-01

    This slide presentation presents NASA's Common Badging and Access Control System. NASA began a Smart Card implementation in January 2004. Following site surveys, it was determined that NASA's badging and access control systems required upgrades to common infrastructure in order to provide flexibly, usability, and return on investment prior to a smart card implantation. Common Badging and Access Control System (CBACS) provides the common infrastructure from which FIPS-201 compliant processes, systems, and credentials can be developed and used.

  8. Refurbishment program of HANARO control computer system

    SciTech Connect

    Kim, H. K.; Choe, Y. S.; Lee, M. W.; Doo, S. K.; Jung, H. S.

    2012-07-01

    HANARO, an open-tank-in-pool type research reactor with 30 MW thermal power, achieved its first criticality in 1995. The programmable controller system MLC (Multi Loop Controller) manufactured by MOORE has been used to control and regulate HANARO since 1995. We made a plan to replace the control computer because the system supplier no longer provided technical support and thus no spare parts were available. Aged and obsolete equipment and the shortage of spare parts supply could have caused great problems. The first consideration for a replacement of the control computer dates back to 2007. The supplier did not produce the components of MLC so that this system would no longer be guaranteed. We established the upgrade and refurbishment program in 2009 so as to keep HANARO up to date in terms of safety. We designed the new control computer system that would replace MLC. The new computer system is HCCS (HANARO Control Computer System). The refurbishing activity is in progress and will finish in 2013. The goal of the refurbishment program is a functional replacement of the reactor control system in consideration of suitable interfaces, compliance with no special outage for installation and commissioning, and no change of the well-proved operation philosophy. HCCS is a DCS (Discrete Control System) using PLC manufactured by RTP. To enhance the reliability, we adapt a triple processor system, double I/O system and hot swapping function. This paper describes the refurbishment program of the HANARO control system including the design requirements of HCCS. (authors)

  9. Upgrade of the linac control system

    SciTech Connect

    Munson, F.; Tieman, B.; Kramer, S.

    1995-08-01

    The new ATLAS control system, based on the commercial product {open_quotes}VISTA{close_quotes}, continues to be developed and to absorb more of the facility control work load. Cryogenic temperature is now monitored by the new system and the old temperature monitoring system was retired. Resonator and solenoid control can now be handled by the new system. With this step, all components of the accelerator can now be operated from the new system. Many of the {open_quotes}high-level{close_quotes} programs remain to be ported to the new system, but we believe that all features available from the old system will be available on the new system by October 1995. The enhanced features of the new system, distributed control, and user-friendly interfaces make the new system the one of choice. So as new capabilities are made available, they are quickly adopted as the system-of-choice by the operators.

  10. Robust tuning of robot control systems

    NASA Technical Reports Server (NTRS)

    Minis, I.; Uebel, M.

    1992-01-01

    The computed torque control problem is examined for a robot arm with flexible, geared, joint drive systems which are typical in many industrial robots. The standard computed torque algorithm is not directly applicable to this class of manipulators because of the dynamics introduced by the joint drive system. The proposed approach to computed torque control combines a computed torque algorithm with torque controller at each joint. Three such control schemes are proposed. The first scheme uses the joint torque control system currently implemented on the robot arm and a novel form of the computed torque algorithm. The other two use the standard computed torque algorithm and a novel model following torque control system based on model following techniques. Standard tasks and performance indices are used to evaluate the performance of the controllers. Both numerical simulations and experiments are used in evaluation. The study shows that all three proposed systems lead to improved tracking performance over a conventional PD controller.

  11. Data-Driven H∞ Control for Nonlinear Distributed Parameter Systems.

    PubMed

    Luo, Biao; Huang, Tingwen; Wu, Huai-Ning; Yang, Xiong

    2015-11-01

    The data-driven H∞ control problem of nonlinear distributed parameter systems is considered in this paper. An off-policy learning method is developed to learn the H∞ control policy from real system data rather than the mathematical model. First, Karhunen-Loève decomposition is used to compute the empirical eigenfunctions, which are then employed to derive a reduced-order model (ROM) of slow subsystem based on the singular perturbation theory. The H∞ control problem is reformulated based on the ROM, which can be transformed to solve the Hamilton-Jacobi-Isaacs (HJI) equation, theoretically. To learn the solution of the HJI equation from real system data, a data-driven off-policy learning approach is proposed based on the simultaneous policy update algorithm and its convergence is proved. For implementation purpose, a neural network (NN)- based action-critic structure is developed, where a critic NN and two action NNs are employed to approximate the value function, control, and disturbance policies, respectively. Subsequently, a least-square NN weight-tuning rule is derived with the method of weighted residuals. Finally, the developed data-driven off-policy learning approach is applied to a nonlinear diffusion-reaction process, and the obtained results demonstrate its effectiveness. PMID:26277007

  12. An intelligent control system for failure detection and controller reconfiguration

    NASA Technical Reports Server (NTRS)

    Biswas, Saroj K.

    1994-01-01

    We present an architecture of an intelligent restructurable control system to automatically detect failure of system components, assess its impact on system performance and safety, and reconfigure the controller for performance recovery. Fault detection is based on neural network associative memories and pattern classifiers, and is implemented using a multilayer feedforward network. Details of the fault detection network along with simulation results on health monitoring of a dc motor have been presented. Conceptual developments for fault assessment using an expert system and controller reconfiguration using a neural network are outlined.

  13. Control technology for future aircraft propulsion systems

    NASA Technical Reports Server (NTRS)

    Zeller, J. R.; Szuch, J. R.; Merrill, W. C.; Lehtinen, B.; Soeder, J. F.

    1984-01-01

    The need for a more sophisticated engine control system is discussed. The improvements in better thrust-to-weight ratios demand the manipulation of more control inputs. New technological solutions to the engine control problem are practiced. The digital electronic engine control (DEEC) system is a step in the evolution to digital electronic engine control. Technology issues are addressed to ensure a growth in confidence in sophisticated electronic controls for aircraft turbine engines. The need of a control system architecture which permits propulsion controls to be functionally integrated with other aircraft systems is established. Areas of technology studied include: (1) control design methodology; (2) improved modeling and simulation methods; and (3) implementation technologies. Objectives, results and future thrusts are summarized.

  14. THE SNS RESONANCE CONTROL COOLING SYSTEM CONTROL VALVE UPGRADE PERFORMANCE

    SciTech Connect

    Williams, Derrick C; Schubert, James Phillip; Tang, Johnny Y

    2008-01-01

    The normal-conducting linac of the Spallation Neutron Source (SNS) uses 10 separate Resonance Control Cooling System (RCCS) water skids to control the resonance of 6 Drift Tube Linac (DTL) and 4 Coupled Cavity Linac (CCL) accelerating structures. The RCCS water skids use 2 control valves; one to regulate the chilled water flow and the other to bypass water to a chilled water heat exchanger. These valves have hydraulic actuators that provide position and feedback to the control system. Frequency oscillations occur using these hydraulic actuators due to their coarse movement and control of the valves. New pneumatic actuator and control positioners have been installed on the DTL3 RCCS water skid to give finer control and regulation of DTL3 cavity temperature. This paper shows a comparison of resonance control performance for the two valve configurations.

  15. On controllability of nonlinear stochastic systems

    NASA Astrophysics Data System (ADS)

    Sakthivel, R.; Kim, J.-H.; Mahmudov, N. I.

    2006-12-01

    In this paper, complete controllability for nonlinear stochastic systems is studied. First this paper addresses the problem of complete controllability of nonlinear stochastic systems with standard Brownian motion. Then this result is extended to establish complete controllability criterion for stochastic systems with fractional Brownian motion. A fixed point approach is employed for achieving the required result. The solutions are given by a variation of constants formula which allows us to study the complete controllability for nonlinear stochastic systems. In this paper, we prove the complete controllability of nonlinear stochastic system under the natural assumption that the associated linear control system is completely controllable. Finally, an illustrative example is provided to show the usefulness of the proposed technique.

  16. Seasat-A attitude control system

    NASA Technical Reports Server (NTRS)

    Weiss, R.; Rodden, J. J.; Hendricks, R. J.

    1977-01-01

    The Seasat-A attitude control system controls the attitude of the satellite system during injection into final circular orbit after Atlas boost, during orbit adjust and trim phases, and throughout the 3-year mission. Ascent and injection guidance and attitude control are provided by the Agena spacecraft with a gyrocompassed mass expulsion system. On-orbit attitude control functions are performed by a system that has its functional roots in the gravity-gradient momentum bias technology. The paper discusses hardware, control laws, and simulation results.

  17. A Programmable System for Motion Control

    NASA Technical Reports Server (NTRS)

    Nowlin, Brent C.

    2003-01-01

    The need for improved flow measurements in the flow path of aeronautics testing facilities has led the NASA Glenn Research Center to develop a new motion control system. The new system is programmable, offering a flexibility unheard of in previous systems. The motion control system is PLC-based, which leads to highly accurate positioning ability, as well as reliability. The user interface is a software-based HMI package, which also adds flexibility to the overall system. The system also has the ability to create and execute motion profiles. This paper discusses the system's operation, control implementation, and experiences.

  18. The front-end electronics and slow control of large area SiPM for the SST-1M camera developed for the CTA experiment

    NASA Astrophysics Data System (ADS)

    Aguilar, J. A.; Bilnik, W.; Borkowski, J.; Cadoux, F.; Christov, A.; della Volpe, D.; Favre, Y.; Heller, M.; Kasperek, J.; Lyard, E.; Marszałek, A.; Moderski, R.; Montaruli, T.; Porcelli, A.; Prandini, E.; Rajda, P.; Rameez, M.; Schioppa, E.; Troyano Pujadas, I.; Ziȩtara, K.; Błocki, J.; Bogacz, L.; Bulik, T.; Curyło, M.; Dyrda, M.; Frankowski, A.; Grudniki, Ł.; Grudzińska, M.; Idźkowski, B.; Jamrozy, M.; Janiak, M.; Lalik, K.; Mach, E.; Mandat, D.; Michałowski, J.; Neronov, A.; Niemiec, J.; Ostrowski, M.; Paśsko, P.; Pech, M.; Schovanek, P.; Seweryn, K.; Skowron, K.; Sliusar, V.; Sowiński, M.; Stawarz, Ł.; Stodulska, M.; Stodulski, M.; Toscano, S.; Walter, R.; Wiȩcek, M.; Zagdański, A.; Żychowski, P.

    2016-09-01

    The single mirror Small Size Telescope (SST-1M) is one of the proposed designs for the smallest type of telescopes, SSTs that will compose the Cherenkov Telescope Array (CTA). The SST-1M camera will use Silicon PhotoMultipliers (SiPM) which are nowadays commonly used in High Energy Physics experiments and many imaging applications. However the unique pixel shape and size have required a dedicated development by the University of Geneva and Hamamatsu. The resulting sensor has a surface of ∼94 mm2 and a total capacitance of ∼3.4 nF. These unique characteristics, combined with the stringent requirements of the CTA project on timing and charge resolution have led the University of Geneva to develop custom front-end electronics. The preamplifier stage has been tailored in order to optimize the signal shape using measurement campaigns and electronic simulation of the sensor. A dedicated trans-impedance pre-amplifier topology is used resulting in a power consumption of 400 mW per pixel and a pulse width < 30 ns. The measurements that have led to the choice of the different components and the resulting performance are detailed in this paper. The slow control electronics was designed to provide the bias voltage with 6.7 mV precision and to correct for temperature variation with a forward feedback compensation with 0.17 °C resolution. It is fully configurable and can be monitored using CANbus interface. The architecture and the characterization of the various elements are presented.

  19. Optimization and validation of an accelerated laboratory extraction method to estimate nitrogen release patterns of slow- and controlled-release fertilizers.

    PubMed

    Medina, L Carolina; Sartain, Jerry B; Obreza, Thomas A; Hall, William L; Thiex, Nancy J

    2014-01-01

    Several technologies have been proposed to characterize the nutrient release and availability patterns of enhanced-efficiency fertilizers (EEFs), especially slow-release fertilizers (SRFs) and controlled-release fertilizers (CRFs) during the last few decades. These technologies have been developed mainly by manufacturers and are product-specific based on the regulation and analysis of each EEF product. Despite previous efforts to characterize EEF materials, no validated method exists to assess their nutrient release patterns. However, the increased use of EEFs in specialty and nonspecialty markets requires an appropriate method to verify nutrient claims and material performance. A series of experiments were conducted to evaluate the effect of temperature, fertilizer test portion size, and extraction time on the performance of a 74 h accelerated laboratory extraction method to measure SRF and CRF nutrient release profiles. Temperature was the only factor that influenced nutrient release rate, with a highly marked effect for phosphorus and to a lesser extent for nitrogen (N) and potassium. Based on the results, the optimal extraction temperature set was: Extraction No. 1-2:00 h at 25 degrees C; Extraction No. 2-2:00 h at 50 degrees C; Extraction No. 3-20:00 h at 55 degrees C; and Extraction No. 4-50:00 h at 60 degrees C. Ruggedness of the method was tested by evaluating the effect of small changes in seven selected factors on method behavior using a fractional multifactorial design. Overall, the method showed ruggedness for measuring N release rates of coated CRFs. PMID:25051611

  20. Name Authority Control in a Communication System.

    ERIC Educational Resources Information Center

    Elias, Cathy Ann; Fair, C. James

    1983-01-01

    Examines use of Electronic Office System by Corporate Media Relations, a division of Communication Services, Standard Oil Company, focusing on the problem of name authority control. The media query file, variant entry problems, problems resulting from ineffective name authority control, and developing a control system are covered. Four sources are…

  1. 50 CFR 600.420 - Control system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... statistics required by an FMP. The control system: (1) Identifies those persons who have access to the... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Control system. 600.420 Section 600.420..., DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Confidentiality of Statistics § 600.420 Control...

  2. F-15 IFCS: Intelligent Flight Control System

    NASA Technical Reports Server (NTRS)

    Bosworth, John

    2007-01-01

    This viewgraph presentation describes the F-15 Intelligent Flight Control System (IFCS). The goals of this project include: 1) Demonstrate revolutionary control approaches that can efficiently optimize aircraft performance in both normal and failure conditions; and 2) Demonstrate advance neural network-based flight control technology for new aerospace systems designs.

  3. Control system for glassing hot presses

    SciTech Connect

    Howell, J.F.

    1984-06-13

    A software programmable control system has been developed that automates the glass fusing process used in the production of semiconductor thermopile elements. The new control system replaces an older, mostly manual, electromechanical design. This report describes the new control design and its functional features.

  4. SPS flexible system control assessment analysis

    NASA Technical Reports Server (NTRS)

    Balas, M. J.

    1981-01-01

    Active control of the Satellite Power System (SPS0, a large mechanically flexible aerospace structure is addressed. The control algorithm is the principle component in the feedback link from sensors to actuators. An analysis of the interaction of the SPS structure and its active control system is presented.

  5. Research study: Space vehicle control systems

    NASA Technical Reports Server (NTRS)

    Likins, P. W.; Longman, R. W.

    1979-01-01

    From the control point of view, spacecraft are classified into two main groups: those for which the spacecraft is fully defined before the control system is designed; and those for which the control system must be specified before certain interchangeable parts of a multi-purpose spacecraft are selected for future missions. Consideration is given to both classes of problems.

  6. Slow launch for HGH.

    PubMed

    Gilden, D

    1995-05-01

    The human growth hormone (HGH) expanded access program for people with AIDS wasting syndrome is now in its fourth month. Enrollment has been slow, largely due to cost. Since HGH falls under the Food and Drug Administration's (FDA) Treatment Investigational New Drug (TIND) regulations, patients are required to pay for the drug--at a cost of about $150 per day, or more than $1,000 per week. Few insurance companies will compensate for the cost of HGH, and no state Medicaid or AIDS Drug Assistance Programs have agreed to cover the compound. Serono Laboratories, the manufacturer, is operating an indigent program that provides free or discount HGH for individuals who cannot purchase the drug any other way. There are only 25 slots available in this program. Lack of available data on how and when to use the drug creates obstacles for physicians. Most of the public data available comes from a single, twelve-week, placebo-controlled study involving 178 participants. However, there are alternative treatments for wasting syndrome. A regimen of testosterone and synthetic anabolic steroids, given to men, has provided positive results on an anecdotal basis. Wasting syndrome comes from a metabolic change which occurs with chronic HIV infection. Rather than first using stores of fat, the body breaks down protein to meet its energy requirements.

  7. FIPA agent based network distributed control system

    SciTech Connect

    D. Abbott; V. Gyurjyan; G. Heyes; E. Jastrzembski; C. Timmer; E. Wolin

    2003-03-01

    A control system with the capabilities to combine heterogeneous control systems or processes into a uniform homogeneous environment is discussed. This dynamically extensible system is an example of the software system at the agent level of abstraction. This level of abstraction considers agents as atomic entities that communicate to implement the functionality of the control system. Agents' engineering aspects are addressed by adopting the domain independent software standard, formulated by FIPA. Jade core Java classes are used as a FIPA specification implementation. A special, lightweight, XML RDFS based, control oriented, ontology markup language is developed to standardize the description of the arbitrary control system data processor. Control processes, described in this language, are integrated into the global system at runtime, without actual programming. Fault tolerance and recovery issues are also addressed.

  8. SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

    SciTech Connect

    C.J. Fernado

    1998-09-17

    The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I&C) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I&C and will typically be integrated over a data communication network. The subsurface I&C systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures that

  9. Microprocessor systems for industrial process control

    NASA Technical Reports Server (NTRS)

    Lesh, F. H.

    1980-01-01

    Six computers operate synchronously and are interconnected by three independent data buses. Processors control one subsystem. Some can control buses to transfer data at 1 megabit per second. Every 2.5 msec each processor examines list of things to do during next interval. This spacecraft control system could be adapted for controlling complex industrial processes.

  10. Intelligent Engine Systems: Adaptive Control

    NASA Technical Reports Server (NTRS)

    Gibson, Nathan

    2008-01-01

    We have studied the application of the baseline Model Predictive Control (MPC) algorithm to the control of main fuel flow rate (WF36), variable bleed valve (AE24) and variable stator vane (STP25) control of a simulated high-bypass turbofan engine. Using reference trajectories for thrust and turbine inlet temperature (T41) generated by a simulated new engine, we have examined MPC for tracking these two reference outputs while controlling a deteriorated engine. We have examined the results of MPC control for six different transients: two idle-to-takeoff transients at sea level static (SLS) conditions, one takeoff-to-idle transient at SLS, a Bode power command and reverse Bode power command at 20,000 ft/Mach 0.5, and a reverse Bode transient at 35,000 ft/Mach 0.84. For all cases, our primary focus was on the computational effort required by MPC for varying MPC update rates, control horizons, and prediction horizons. We have also considered the effects of these MPC parameters on the performance of the control, with special emphasis on the thrust tracking error, the peak T41, and the sizes of violations of the constraints on the problem, primarily the booster stall margin limit, which for most cases is the lone constraint that is violated with any frequency.

  11. Indirect learning control for nonlinear dynamical systems

    NASA Technical Reports Server (NTRS)

    Ryu, Yeong Soon; Longman, Richard W.

    1993-01-01

    In a previous paper, learning control algorithms were developed based on adaptive control ideas for linear time variant systems. The learning control methods were shown to have certain advantages over their adaptive control counterparts, such as the ability to produce zero tracking error in time varying systems, and the ability to eliminate repetitive disturbances. In recent years, certain adaptive control algorithms have been developed for multi-body dynamic systems such as robots, with global guaranteed convergence to zero tracking error for the nonlinear system euations. In this paper we study the relationship between such adaptive control methods designed for this specific class of nonlinear systems, and the learning control problem for such systems, seeking to converge to zero tracking error in following a specific command repeatedly, starting from the same initial conditions each time. The extension of these methods from the adaptive control problem to the learning control problem is seen to be trivial. The advantages and disadvantages of using learning control based on such adaptive control concepts for nonlinear systems, and the use of other currently available learning control algorithms are discussed.

  12. 76 FR 63899 - Positive Train Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ... regulations requiring certain railroads to implement PTC systems. See 76 FR 52918 (Aug. 24, 2011). Interested... Federal Railroad Administration 49 CFR Part 236 RIN 2130-AC27 Positive Train Control Systems AGENCY... meet certain risk-based criteria in order to avoid positive train control (PTC) system...

  13. Control concepts for tillage systems. [Commander

    SciTech Connect

    Schafer, R.L.; Young, S.C.; Hendrick, J.G.; Johnson, C.E.

    1981-01-01

    Prescribed tillage to meet aronomic needs will be important to future goals of productivity, energy efficiency, and resource conservation. Control systems will be an important feature of the tillage systems that are developed to implement prescribed tillage. A control concept for tillage systems is described. 6 refs.

  14. Serials Control System Procedures and Policies.

    ERIC Educational Resources Information Center

    Schlembach, Mary C.

    This document includes procedures and policies for a networked serials control system originally developed at the Grainger Engineering Library Information Center at the University of Illinois at Urbana-Champaign (UIUC). The serials control systems encompass serials processing, public service, and end-user functions. The system employs a…

  15. Covariance control of discrete stochastic bilinear systems

    NASA Technical Reports Server (NTRS)

    Skelton, R. E.; Kherat, S. M.; Yaz, E.

    1991-01-01

    The covariances that certain bilinear stochastic discrete time systems may possess are characterized. An explicit parameterization of all controllers that assign such covariances is given. The state feedback assignability and robustness of the system are discussed from a deterministic point of view. This work extends the theory of covariance control for continuous time bilinear systems to a discrete time setting.

  16. A System for Information Documentation and Control

    ERIC Educational Resources Information Center

    Klinger, Dennis M.; Taggart, William M. Jr.

    1974-01-01

    Southeast Regional Data Center (SERDAC) has an operational Information Documentation and Control System that provides the documentation and control necessary for SERDAC to implement an organizational data base to support its many applications. (Author)

  17. Adding PCs to SLC Control System

    SciTech Connect

    Lahey, T.; Levitt, S.; MacKenzie, R.; Spencer, N.; Underwood, K.

    1993-05-01

    The SLAC Controls Department has interfaced IBM-Compatible PCs to the SLC Control System, for use by the Final Focus Test Beam (FFTB) experimenters, who are building new accelerator equipment and developing and testing it at their home institutions. They will bring the equipment to SLAC and integrate it into the control system using a new software package. The machine physicists and operators will use the existing SLC control system applications and database device types to control and monitor the equipment. The PCs support a limited control environment: they run DOS and exchange messages with the existing control system via TCP/IP over ethernet, using the new SLC Area Message Service. This mechanism will also allow SLC to implement other commercial device controllers that can communicate over ethernet and run the same software interface code.

  18. Automated Cryocooler Monitor and Control System Software

    NASA Technical Reports Server (NTRS)

    Britchcliffe, Michael J.; Conroy, Bruce L.; Anderson, Paul E.; Wilson, Ahmad

    2011-01-01

    This software is used in an automated cryogenic control system developed to monitor and control the operation of small-scale cryocoolers. The system was designed to automate the cryogenically cooled low-noise amplifier system described in "Automated Cryocooler Monitor and Control System" (NPO-47246), NASA Tech Briefs, Vol. 35, No. 5 (May 2011), page 7a. The software contains algorithms necessary to convert non-linear output voltages from the cryogenic diode-type thermometers and vacuum pressure and helium pressure sensors, to temperature and pressure units. The control function algorithms use the monitor data to control the cooler power, vacuum solenoid, vacuum pump, and electrical warm-up heaters. The control algorithms are based on a rule-based system that activates the required device based on the operating mode. The external interface is Web-based. It acts as a Web server, providing pages for monitor, control, and configuration. No client software from the external user is required.

  19. Portable, remote environmental control system

    SciTech Connect

    Cherry, R.L.; Maes, R.P.; Pfeiffer, G.F.

    1984-02-28

    A portable thermostat is coupled to the control unit of a heating or cooling device through a radio link. The RF signal transmitted by the thermostat is encoded and then decoded by the control unit in order to prevent interference with other similar devices. In order to maximize the life of a battery powering the thermostat, the thermostat calls for the energization of a heating or cooling device by transmitting the RF signal at widely spaced intervals. The heating or cooling device is energized by shunting a pair of terminals, thereby completing an AC control loop. The unit applies the terminals to a storage copacitor during a small portion of each EC cycle to power the control unit while shunting the terminals during the remaining part of the cycle.

  20. Fire control system for mobile vehicles using fuzzy controllers

    NASA Astrophysics Data System (ADS)

    Krishna Moorty, J. A. R.; Marathe, Rajeev; Srivastava, Hari Babu

    2005-12-01

    Inertial stabilization of electro-optical sighting systems and weapon slaving control loops are essential constituents of modern fire control systems for mobile combat vehicles. These systems are used for surveillance, target tracking and engaging the targets under dynamic conditions. Firing accuracy of such systems largely depends on stabilization and weapon slaving accuracies. Accuracy requirements become stringent as the operating range increases. Several other issues such as bore sighting offsets, ballistic offsets and mounting error compensation etc. are also to be considered. Fuzzy knowledge based controller (FKBC) offers an alternative method to the conventional control synthesis methodologies using root locus, Bode plots or pole placement. Fuzzy control loops are particularly useful when the plant consists of substantial non-linearity due to actuator saturation, stiction, Coulomb friction, digitization etc. Since, the control surface obtained through this method is non-linear, generally it provides greater flexibility to designer to achieve better damping, lesser control energy even in presence of various constraints. This work presents the design of weapon slaving loop using a fuzzy controller. The weapon is slaved to a gimbaled electro-optical sight, which has a stabilized line of sight along two axes. The system under consideration is designed for naval platforms. A two-input (error and rate of change of error) and single output (incremental control) fuzzy controller has been designed to position the weapon at desired position. Implementation of controller has been done using digitized inputs. Simulations have been carried out to evaluate the performance of the integrated fire control system under the presence of various non-linearities, sensor inaccuracies and other exogenous inputs like host platform generated disturbances and measurement noise. Stringent requirements of disturbance attenuation, tracking and command following have been met.

  1. Designing control system information models

    NASA Technical Reports Server (NTRS)

    Panin, K. I.; Zinchenko, V. P.

    1973-01-01

    Problems encountered in modeling information models are discussed, Data cover condition, functioning of the object of control, and the environment involved in the control. Other parameters needed for the model include: (1) information for forming an image of the real situation, (2) data for analyzing and evaluating an evolving situation, (3) planning actions, and (4) data for observing and evaluating the results of model realization.

  2. Slow cortical potential neurofeedback and self-management training in outpatient care for children with ADHD: study protocol and first preliminary results of a randomized controlled trial

    PubMed Central

    Christiansen, Hanna; Reh, Verena; Schmidt, Martin H.; Rief, Winfried

    2014-01-01

    Background: Treatment for children with attention deficit/hyperactivity disorder (ADHD) today is predominantly pharmacological. While it is the most common treatment, it might not always be the most appropriate one. Moreover, long term effects remain unclear. Behavior therapy (BT) and non-pharmacological treatments such as neurofeedback (NF) are promising alternatives, though there are no routine outpatient care/effectiveness studies yet that have included children with medication or changes in medication. Methods/design: This paper presents the protocol of a randomized controlled trial to compare the effectiveness of a Slow Cortical Potential (SCP) NF protocol with self-management (SM) in a high frequent outpatient care setting. Both groups (NF/SM) receive a total of 30 high frequent therapy sessions. Additionally, 6 sessions are reserved for comorbid problems. The primary outcome measure is the reduction of ADHD core symptoms according to parent and teacher ratings. Preliminary Results: Untill now 58 children were included in the study (48 males), with a mean age of 8.42 (1.34) years, and a mean IQ of 110 (13.37). Conners-3 parent and teacher ratings were used to estimate core symptom change. Since the study is still ongoing, and children are in different study stages, pre-post and follow-up results are not yet available for all children included. Preliminary results suggest overall good pre-post effects, though. For parent and teacher ratings an ANOVA with repeated measures yielded overall satisfying pre-post effects (η2 0.175–0.513). Differences between groups (NF vs. SM) could not yet be established (p = 0.81). Discussion: This is the first randomized controlled trial to test the effectiveness of a NF protocol in a high frequent outpatient care setting that does not exclude children on or with changes in medication. First preliminary results show positive effects. The rationale for the trial, the design, and the strengths and limitations of the study are

  3. Combined air and water pollution control system

    NASA Technical Reports Server (NTRS)

    Wolverton, Billy C. (Inventor); Jarrell, Lamont (Inventor)

    1990-01-01

    A bioaquatic air pollution control system for controlling both water and atmospheric pollution is disclosed. The pollution control system includes an exhaust for directing polluted gases out of a furnace and a fluid circulating system which circulates fluid, such as waste water, from a source, past the furnace where the fluid flow entrains the pollutants from the furnace. The combined fluid and pollutants are then directed through a rock/plant/microbial filtering system. A suction pump pumps the treated waste water from the filter system past the exhaust to again entrain more pollutants from the furnace where they are combined with the fluid (waste water) and directed to the filter system.

  4. Electron Cyclotron Resonance Heating (ECRH) Control System

    SciTech Connect

    Heefner, J.W.; Williams, C.W.; Lauze, R.R.; Karsner, P.G.

    1985-11-11

    The ECRH Control System was installed on the Tandem Mirror Experiment-Upgrade (TMX-U) in 1980. The system provides approximately 1 MW of 28 GHz microwave power to the TMX-U plasma. The subsystems of ECRH that must be controlled include high-voltage charging supplies, series pass tubes, and magnet supplies. In addition to the devices that must be controlled, many interlocks must be continuously monitored. The previous control system used relay logic and analog controls to operate the system. This approach has many drawbacks such as lack of system flexibility and maintainability. In order to address these problems, it was decided to go with a CAMAC and Modicon based system that uses a Hewlett-Packard 9836C personal computer to replace the previous analog controls. 2 figs.

  5. Electronic system for optical shutter control

    NASA Technical Reports Server (NTRS)

    Viljoen, H. C.; Gaylord, T. K.

    1976-01-01

    The paper describes a precise and versatile electronic system for shutter control in light beam experiments. Digital and analog circuitry is used to provide automatic timing, exposure control, manual operation, and remote programmability. A block diagram of the system is presented and the individual circuits - the timer control circuit, the clock control circuit, the comparator circuit, the exposure (integrator) circuit, and the shutter drive circuit are discussed in detail and diagrams are provided.

  6. Can ageing be slowed?

    PubMed Central

    Gaman, L; Stoian, I; Atanasiu, V

    2011-01-01

    Redox metabolism has long been considered to play important roles in aging and the development of age-related diseases. Both dietary and pharmacological manipulations of redox metabolism have been associated with the extension of lifespan. Increasing new evidence s also suggests that the process of aging may derive from imperfect clearance of oxidatively damaged material. The accumulation of this molecular “garbage”, relatively indigestible, further hinders cellular functions, induces progressive failure of maintenance and repair and increases the probability of death. One important trend in anti–aging strategy is, therefore, to prevent or even revert the accumulation of these oxidatively altered molecules by stimulating the maintenance and repair systems through hormesis. A promising approach for slowing down ageing and achieving a healthy senescence is represented by repeated exposure to various mild stresses (caloric restriction, moderate exercise, nutritional or pharmacological hormetins). This article reviews the potential therapeutic tools available to date for increasing longevity and obtaining and successful ageing from the redox and hormetic perspective. PMID:22514565

  7. Aid For Simulating Digital Flight Control Systems

    NASA Technical Reports Server (NTRS)

    Hartman, Richard M.

    1991-01-01

    DIVERS translator is computer program to convert descriptions of digital flight-control systems (DFCS) into computer program. Language developed to represent design charts of DFCS. Translator converts DIVERS source code into easily transportable language, while minimizing probability that results are affected by interpretation of programmer. Final translated program used as standard of comparison to verify operation of actual flight-control systems. Applicable to simulation of other control systems; for example, electrical circuits and logic processes. Written in C.

  8. New User Interface Capabilities for Control Systems

    SciTech Connect

    Kasemir, Kay

    2009-01-01

    Latest technologies promise new control system User Interface (UI) features and greater interoperability of applications. New developments using Java and Eclipse aim to unify diverse control systems and make communication between applications seamless. Web based user interfaces can improve portability and remote access. Modern programming tools improve efficiency, support testing and facilitate shared code. This paper will discuss new developments aimed at improving control system interfaces and their development environment.

  9. Resilient Control Systems: Next Generation Design Research

    SciTech Connect

    Craig Rieger

    2009-05-01

    Since digital control systems were introduced to the market more than 30 years ago, the operational efficiency and stability gained through their use have fueled our migration and ultimate dependence on them for the monitoring and control of critical infrastructure. While these systems have been designed for functionality and reliability, a hostile cyber environment and uncertainties in complex networks and human interactions have placed additional parameters on the design expectations for control systems.

  10. An advanced intelligent control system framework

    NASA Technical Reports Server (NTRS)

    Nemeth, ED; Anderson, Ronald R.; Maram, Jon; Norman, Arnie; Merrill, Walt

    1992-01-01

    A reusable rocket-engine intelligent control system (RREICS) framework was developed to a define a control framework for rocket-engine systems that reduces the required engine maintenance, extends the useful operating life, and maximizes the probability of mission success. The RREICS framework defines a controller that handles a rocket engine cluster as a single system rather than as a collection of individual engines. This enables the controller to alter individual engine operations in response to engine performance or integrity degradations while maintaining the propulsion subsystem external parameters at the levels required for mission success. A simplified model of a three engine cluster and the associated propulsion subsystem controller is also described.

  11. The integration of two control systems

    SciTech Connect

    Bickley, M.; White, K.

    1995-12-31

    During the past year the Continuous Electron Beam Accelerator Facility (CEBAF) has installed a new machine control system, based on the Experimental Physics and Industrial Control System (EPICS). The migration from CEBAF`s old control system, Thaumaturgic Automated Control Logic (TACL), had to be done concurrently with commissioning of the CEBAF accelerator. The smooth transition to EPICS was made possible by the similarity of the control systems` topological design and network communication protocol. Both systems have operator display computer nodes which are decoupled from the data acquisition and control nodes. The communication between display and control nodes of both control systems is based on making named requests for data, with data being passed on change of value. Due to TACL`s use of a central communications process, it was possible to integrate both control systems` network communications in that process. This in turn meant that CEBAF did not require changes to any other software in order to support network communication between TACL and EPICS. CEBAF implemented the machine`s control under EPICS in an evolutionary, controlled manner. 4 refs., 3 figs.

  12. The integration of two control systems

    SciTech Connect

    Bickley, M; White, K

    1995-01-01

    During the past year the Continuous Electron Beam Accelerator Facility (CEBAF) has installed a new machine control system, based on the Experimental Physics and Industrial Control System (EPICS). The migration from CEBAF`s old control system, Thaumaturgic Automated Control Logic (TACL), had to be done concurrently with commissioning of the CEBAF accelerator. The smooth transition to EPICS was made possible by the similarity of the control systems` topological design and network communication protocol. Both systems have operator display computer nodes which are decoupled from the data acquisition and control nodes. The communication between display and control nodes of both control systems is based on making named requests for data, with data being passed on change of value. Due to TACL`s use of a central communications process, it was possible to integrate both control systems` network communications in that process. This in turn meant that CEBAF did not require changes to any other software in order to support network communication between TACL and EPICS. CEBAF implemented the machine`s control under EPICS in an evolutionary, controlled manner. 4 refs., 3 figs.

  13. Noise screen for attitude control system

    NASA Technical Reports Server (NTRS)

    Rodden, John J. (Inventor); Stevens, Homer D. (Inventor); Hong, David P. (Inventor); Hirschberg, Philip C. (Inventor)

    2002-01-01

    An attitude control system comprising a controller and a noise screen device coupled to the controller. The controller is adapted to control an attitude of a vehicle carrying an actuator system that is adapted to pulse in metered bursts in order to generate a control torque to control the attitude of the vehicle in response to a control pulse. The noise screen device is adapted to generate a noise screen signal in response to the control pulse that is generated when an input attitude error signal exceeds a predetermined deadband attitude level. The noise screen signal comprises a decaying offset signal that when combined with the attitude error input signal results in a net attitude error input signal away from the predetermined deadband level to reduce further control pulse generation.

  14. Engines-only flight control system

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W. (Inventor); Gilyard, Glenn B (Inventor); Conley, Joseph L. (Inventor); Stewart, James F. (Inventor); Fullerton, Charles G. (Inventor)

    1994-01-01

    A backup flight control system for controlling the flightpath of a multi-engine airplane using the main drive engines is introduced. The backup flight control system comprises an input device for generating a control command indicative of a desired flightpath, a feedback sensor for generating a feedback signal indicative of at least one of pitch rate, pitch attitude, roll rate and roll attitude, and a control device for changing the output power of at least one of the main drive engines on each side of the airplane in response to the control command and the feedback signal.

  15. Towards a new Mercator Observatory Control System

    NASA Astrophysics Data System (ADS)

    Pessemier, W.; Raskin, G.; Prins, S.; Saey, P.; Merges, F.; Padilla, J. P.; Van Winckel, H.; Waelkens, C.

    2010-07-01

    A new control system is currently being developed for the 1.2-meter Mercator Telescope at the Roque de Los Muchachos Observatory (La Palma, Spain). Formerly based on transputers, the new Mercator Observatory Control System (MOCS) consists of a small network of Linux computers complemented by a central industrial controller and an industrial real-time data communication network. Python is chosen as the high-level language to develop flexible yet powerful supervisory control and data acquisition (SCADA) software for the Linux computers. Specialized applications such as detector control, auto-guiding and middleware management are also integrated in the same Python software package. The industrial controller, on the other hand, is connected to the majority of the field devices and is targeted to run various control loops, some of which are real-time critical. Independently of the Linux distributed control system (DCS), this controller makes sure that high priority tasks such as the telescope motion, mirror support and hydrostatic bearing control are carried out in a reliable and safe way. A comparison is made between different controller technologies including a LabVIEW embedded system, a PROFINET Programmable Logic Controller (PLC) and motion controller, and an EtherCAT embedded PC (soft-PLC). As the latter is chosen as the primary platform for the lower level control, a substantial part of the software is being ported to the IEC 61131-3 standard programming languages. Additionally, obsolete hardware is gradually being replaced by standard industrial alternatives with fast EtherCAT communication. The use of Python as a scripting language allows a smooth migration to the final MOCS: finished parts of the new control system can readily be commissioned to replace the corresponding transputer units of the old control system with minimal downtime. In this contribution, we give an overview of the systems design, implementation details and the current status of the project.

  16. Adaptive control applied to Space Station attitude control system

    NASA Technical Reports Server (NTRS)

    Lam, Quang M.; Chipman, Richard; Hu, Tsay-Hsin G.; Holmes, Eric B.; Sunkel, John

    1992-01-01

    This paper presents an adaptive control approach to enhance the performance of current attitude control system used by the Space Station Freedom. The proposed control law was developed based on the direct adaptive control or model reference adaptive control scheme. Performance comparisons, subject to inertia variation, of the adaptive controller and the fixed-gain linear quadratic regulator currently implemented for the Space Station are conducted. Both the fixed-gain and the adaptive gain controllers are able to maintain the Station stability for inertia variations of up to 35 percent. However, when a 50 percent inertia variation is applied to the Station, only the adaptive controller is able to maintain the Station attitude.

  17. Control system for fluid heated steam generator

    DOEpatents

    Boland, J.F.; Koenig, J.F.

    1984-05-29

    A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

  18. Control system for fluid heated steam generator

    DOEpatents

    Boland, James F.; Koenig, John F.

    1985-01-01

    A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

  19. Controlled transitions between cupolets of chaotic systems

    NASA Astrophysics Data System (ADS)

    Morena, Matthew A.; Short, Kevin M.; Cooke, Erica E.

    2014-03-01

    We present an efficient control scheme that stabilizes the unstable periodic orbits of a chaotic system. The resulting orbits are known as cupolets and collectively provide an important skeleton for the dynamical system. Cupolets exhibit the interesting property that a given sequence of controls will uniquely identify a cupolet, regardless of the system's initial state. This makes it possible to transition between cupolets, and thus unstable periodic orbits, simply by switching control sequences. We demonstrate that although these transitions require minimal controls, they may also involve significant chaotic transients unless carefully controlled. As a result, we present an effective technique that relies on Dijkstra's shortest path algorithm from algebraic graph theory to minimize the transients and also to induce certainty into the control of nonlinear systems, effectively providing an efficient algorithm for the steering and targeting of chaotic systems.

  20. Controlled transitions between cupolets of chaotic systems.

    PubMed

    Morena, Matthew A; Short, Kevin M; Cooke, Erica E

    2014-03-01

    We present an efficient control scheme that stabilizes the unstable periodic orbits of a chaotic system. The resulting orbits are known as cupolets and collectively provide an important skeleton for the dynamical system. Cupolets exhibit the interesting property that a given sequence of controls will uniquely identify a cupolet, regardless of the system's initial state. This makes it possible to transition between cupolets, and thus unstable periodic orbits, simply by switching control sequences. We demonstrate that although these transitions require minimal controls, they may also involve significant chaotic transients unless carefully controlled. As a result, we present an effective technique that relies on Dijkstra's shortest path algorithm from algebraic graph theory to minimize the transients and also to induce certainty into the control of nonlinear systems, effectively providing an efficient algorithm for the steering and targeting of chaotic systems.