WorldWideScience

Sample records for controlled hydrogen mobility

  1. Integrated mobile robot control

    Science.gov (United States)

    Amidi, Omead; Thorpe, Chuck E.

    1991-03-01

    This paper describes the strucwre implementation and operation of a real-time mobile robot controller which integrates capabilities such as: position estimation path specification and hacking human interfaces fast communication and multiple client support The benefits of such high-level capabilities in a low-level controller was shown by its implementation for the Naviab autonomous vehicle. In addition performance results from positioning and tracking systems are reported and analyzed.

  2. Hydrogen concentration control utilizing a hydrogen permeable membrane

    International Nuclear Information System (INIS)

    Keating, S.J. Jr.

    1976-01-01

    The concentration of hydrogen in a fluid mixture is controlled to a desired concentration by flowing the fluid through one chamber of a diffusion cell separated into two chambers by a hydrogen permeable membrane. A gradient of hydrogen partial pressure is maintained across the membrane to cause diffusion of hydrogen through the membrane to maintain the concentration of hydrogen in the fluid mixture at the predetermined level. The invention has particular utility for the purpose of injecting into and/or separating hydrogen from the reactor coolant of a nuclear reactor system

  3. Mobile gene silencing in Arabidopsis is regulated by hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Dacheng Liang

    2014-12-01

    Full Text Available In plants and nematodes, RNAi can spread from cells from which it is initiated to other cells in the organism. The underlying mechanism controlling the mobility of RNAi signals is not known, especially in the case of plants. A genetic screen designed to recover plants impaired in the movement but not the production or effectiveness of the RNAi signal identified RCI3, which encodes a hydrogen peroxide (H2O2-producing type III peroxidase, as a key regulator of silencing mobility in Arabidopsis thaliana. Silencing initiated in the roots of rci3 plants failed to spread into leaf tissue or floral tissue. Application of exogenous H2O2 reinstated the spread in rci3 plants and accelerated it in wild-type plants. The addition of catalase or MnO2, which breaks down H2O2, slowed the spread of silencing in wild-type plants. We propose that endogenous H2O2, under the control of peroxidases, regulates the spread of gene silencing by altering plasmodesmata permeability through remodelling of local cell wall structure, and may play a role in regulating systemic viral defence.

  4. Controlling Hydrogenation of Graphene on Ir(111)

    DEFF Research Database (Denmark)

    Balog, Richard; Andersen, Mie; Jørgensen, Bjarke

    2013-01-01

    Combined fast X-ray photoelectron spectroscopy and density functional theory calculations reveal the presence of two types of hydrogen adsorbate structures at the graphene/ Ir(111) interface, namely, graphane-like islands and hydrogen dimer structures. While the former give rise to a periodic...... pattern, dimers tend to destroy the periodicity. Our data reveal distinctive growth rates and stability of both types of structures, thereby allowing one to obtain well-defined patterns of hydrogen clusters. The ability to control and manipulate the formation and size of hydrogen structures on graphene...

  5. Project Profile: Hydrogen Fuel Cell Mobile Lighting Tower (HFCML)

    Science.gov (United States)

    McLaughlin, Russell

    2013-01-01

    NASA is committed to finding innovative solutions that improve the operational performance of ground support equipment while providing environment and cost benefits, as well. Through the Hydrogen Fuel Cell Mobile Lighting Tower (HFCML) project, NASA gained operational exposure to a novel application of high efficiency technologies. Traditionally, outdoor lighting and auxiliary power at security gates, launch viewing sites, fallback areas, outage support, and special events is provided by diesel generators with metal halide lights. Diesel generators inherently contribute to C02, NOx, particulate emissions, and are very noisy. In 2010, engineers from NASA's Technology Evaluation for Environmental Risk Mitigation Principal Center (TEERM) introduced KSC operations to a novel technology for outdoor lighting needs. Developed by a team led by Sandia National Laboratory (SNL), the technology pairs a 5kW hydrogen fuel cell with robust high efficiency plasma lights in a towable trailer. Increased efficiency, in both the fuel cell power source and lighting load, yields longer run times between fueling operations while providing greater auxiliary power. Because of the unit's quiet operation and no exhaust fumes, it is capable of being used indoors and in emergency situations, and meets the needs of all other operational roles for metal halide/diesel generators. The only discharge is some water and warm air. Environmental benefits include elimination of diesel particulate emissions and estimated 73% greenhouse gas emissions savings when the hydrogen source is natural gas (per GREET model). As the technology matures the costs could become competitive for the fuel cell units which are approximately 5 times diesel units. Initial operational . concerns included the hydrogen storage tanks and valves, lightning safety/grounding, and required operating and refueling procedures. TEERM facilitated technical information exchange (design drawings, technical standards, and operations

  6. Infrared intensities and charge mobility in hydrogen bonded complexes

    Energy Technology Data Exchange (ETDEWEB)

    Galimberti, Daria; Milani, Alberto; Castiglioni, Chiara [Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta,” Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2013-08-21

    The analytical model for the study of charge mobility in the molecules presented by Galimberti et al.[J. Chem. Phys. 138, 164115 (2013)] is applied to hydrogen bonded planar dimers. Atomic charges and charge fluxes are obtained from density functional theory computed atomic polar tensors and related first derivatives, thus providing an interpretation of the IR intensity enhancement of the X–H stretching band observed upon aggregation. Our results show that both principal and non-principal charge fluxes have an important role for the rationalization of the spectral behavior; moreover, they demonstrate that the modulation of the charge distribution during vibrational motions of the –XH⋯Y– fragment is not localized exclusively on the atoms directly involved in hydrogen bonding. With these premises we made some correlations between IR intensities, interaction energies, and charge fluxes. The model was tested on small dimers and subsequently to the bigger one cytosine-guanine. Thus, the model can be applied to complex systems.

  7. Laser controlled magnetism in hydrogenated fullerene films

    International Nuclear Information System (INIS)

    Makarova, Tatiana L.; Shelankov, Andrei L.; Kvyatkovskii, Oleg E.; Zakharova, Irina B.; Buga, Sergei G.; Volkov, Aleksandr P.

    2011-01-01

    Room temperature ferromagnetic-like behavior in fullerene photopolymerized films treated with monatomic hydrogen is reported. The hydrogen treatment controllably varies the paramagnetic spin concentration and laser induced polymerization transforms the paramagnetic phase to a ferromagnetic-like one. Excess laser irradiation destroys magnetic ordering, presumably due to structural changes, which was continuously monitored by Raman spectroscopy. We suggest an interpretation of the data based on first-principles density-functional spin-unrestricted calculations which show that the excess spin from mono-atomic hydrogen is delocalized within the host fullerene and the laser-induced polymerization promotes spin exchange interaction and spin alignment in the polymerized phase.

  8. Modelling and Control of a Mobile Robot

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg

    1998-01-01

    In order to control a mobile robot, kinematic odels as well as dynamic models are required. This parer describes these basic models for an experimental mobile robot under construction at the Department of Control and Engineering Design. A description of a set of trajectory control rules is given...

  9. Information needs and instrumentation for hydrogen control and management

    International Nuclear Information System (INIS)

    Park, Gun Chul; Suh, Kune Y.; Lee, Seung Dong; Lee, Jin Yong; Jae, Moo Sung

    2000-03-01

    In this study we examined instrument information, which is related to the severe accident management, guidance. We also examined the hydrogen control and management strategy. Hydrogen control occupies and important part in severe accident management and adequate hydrogen control strategy i needed to maintain the plant integrity. Reducing containment hydrogen during a severe accident will mitigate a potential containment failure mechanism. One of the hydrogen control strategies os intentional burning by the hydrogen igniter. Though intentional hydrogen burn strategy may cause pressure and temperature spikes, which are adverse effects, it si the fastest way of reducing the containment hydrogen concentration. From the Ulchin 3 and 4 plant information we developed a simple hydrogen ignition decision tree. And from the information of decision tree, hydrogen ignition decision can be determined in Containment Event Tree (CET). The end branch values in the CET are hydrogen concentrations, which will be used to assess the accident management measure

  10. Information needs and instrumentation for hydrogen control and management

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gun Chul; Suh, Kune Y.; Lee, Seung Dong; Lee, Jin Yong [Seoul National Univ., Seoul (Korea, Republic of); Jae, Moo Sung [Hanyang Univ., Seoul (Korea, Republic of)

    2000-03-15

    In this study we examined instrument information, which is related to the severe accident management, guidance. We also examined the hydrogen control and management strategy. Hydrogen control occupies and important part in severe accident management and adequate hydrogen control strategy i needed to maintain the plant integrity. Reducing containment hydrogen during a severe accident will mitigate a potential containment failure mechanism. One of the hydrogen control strategies os intentional burning by the hydrogen igniter. Though intentional hydrogen burn strategy may cause pressure and temperature spikes, which are adverse effects, it si the fastest way of reducing the containment hydrogen concentration. From the Ulchin 3 and 4 plant information we developed a simple hydrogen ignition decision tree. And from the information of decision tree, hydrogen ignition decision can be determined in Containment Event Tree (CET). The end branch values in the CET are hydrogen concentrations, which will be used to assess the accident management measure.

  11. Improved hydrogen monitoring helps control corrosion

    International Nuclear Information System (INIS)

    Strauss, S.D.

    1985-01-01

    Hydrogen analyzers have long been used for corrosion monitoring in both fossil-fired boilers and nuclear steam generators. The most recent stimulus for hydrogen monitoring has been provided by cracking of recirculation piping in water reactors. This paper examines the Hydran 202N, which represents an adaption of one instrument that has been used to monitor the degradation of transformer oils and fiberoptic cables. The sensing probe consists of a flow-through cell, an isolating membrane, and a miniature hydrogen/air fuel cell. The use of Hydran 202N at several fossil-fired and nuclear plants is described and the fossilplant application related to the effectiveness of water-chemistry control for a 400 psig oil-fired boiler is examined at a refinery

  12. Configuration and mobility of hydrogen implanted in aluminium

    International Nuclear Information System (INIS)

    Bugeat, J.P.; Chami, A.C.; Ligeon, E.

    1976-01-01

    Localization methods through channeling and nuclear reaction analysis using low energy ion beam were applied to the study of deuterium and hydrogen implanted in aluminium single crystals. It was shown that implanted hydrogen occupies a tetrahedral site in the lattice as far as the implantation temperature is lower than 175K. This fact is interpreted by considering an interaction between hydrogen and monovacancies created during the implantation [fr

  13. Post-accident hydrogen control in GKT-containment

    International Nuclear Information System (INIS)

    Komurka, M.

    1983-06-01

    The maximum possible temperature and pressure rise is analysed by assuming hydrogen deflagration with no heat loss to the vessel walls for hydrogen concentrations up to 10 Vol%. Alternative hydrogen control system to inerting, air dilution and recombiners based on controlled venting by passing the vented gas through the delay line of the gas treatment system is recommended. The combination of hydrogen control with control of noble gas radioactivity is though to have a positive effect on safety. (Author) [de

  14. Interaction control of a redundant mobile manipulator

    International Nuclear Information System (INIS)

    Chung, J.H.; Velinsky, S.A.; Hess, R.A.

    1998-01-01

    This paper discusses the modeling and control of a spatial mobile manipulator that consists of a robotic manipulator mounted on a wheeled mobile platform. The Lagrange-d'Alembert formulation is used to obtain a concise description of the dynamics of the system, which is subject to nonholonomic constraints. The complexity of the model is increased by introducing kinematic redundancy, which is created when a multilinked manipulator is used. The kinematic redundancy is resolved by decomposing the mobile manipulator into two subsystems: the mobile platform and the manipulator. The redundancy resolution scheme employs a nonlinear interaction-control algorithm, which is developed and applied to coordinate the two subsystems' controllers. The subsystem controllers are independently designed, based on each subsystem's dynamic characteristics. Simulation results show the promise of the developed algorithm

  15. Multiscale study on hydrogen mobility in metallic fusion divertor material

    International Nuclear Information System (INIS)

    Heinola, K.

    2010-01-01

    For achieving efficient fusion energy production, the plasma-facing wall materials of the fusion reactor should ensure long time operation. In the next step fusion device, ITER, the first wall region facing the highest heat and particle load, i.e. the divertor area, will mainly consist of tiles based on tungsten. During the reactor operation, the tungsten material is slowly but inevitably saturated with tritium. Tritium is the relatively short-lived hydrogen isotope used in the fusion reaction. The amount of tritium retained in the wall materials should be minimized and its recycling back to the plasma must be unrestrained, otherwise it cannot be used for fueling the plasma. A very expensive and thus economically not viable solution is to replace the first walls quite often. A better solution is to heat the walls to temperatures where tritium is released. Unfortunately, the exact mechanisms of hydrogen release in tungsten are not known. In this thesis both experimental and computational methods have been used for studying the release and retention of hydrogen in tungsten. The experimental work consists of hydrogen implantations into pure polycrystalline tungsten, the determination of the hydrogen concentrations using ion beam analyses (IBA) and monitoring the out-diffused hydrogen gas with thermodesorption spectrometry (TDS) as the tungsten samples are heated at elevated temperatures. Combining IBA methods with TDS, the retained amount of hydrogen is obtained as well as the temperatures needed for the hydrogen release. With computational methods the hydrogen-defect interactions and implantation-induced irradiation damage can be examined at the atomic level. The method of multiscale modelling combines the results obtained from computational methodologies applicable at different length and time scales. Electron density functional theory calculations were used for determining the energetics of the elementary processes of hydrogen in tungsten, such as diffusivity and

  16. Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project

    Energy Technology Data Exchange (ETDEWEB)

    Stottler, Gary

    2012-02-08

    General Motors, LLC and energy partner Shell Hydrogen, LLC, deployed a system of hydrogen fuel cell electric vehicles integrated with a hydrogen fueling station infrastructure to operate under real world conditions as part of the U.S. Department of Energy's Controlled Hydrogen Fleet and Infrastructure Validation and Demonstration Project. This technical report documents the performance and describes the learnings from progressive generations of vehicle fuel cell system technology and multiple approaches to hydrogen generation and delivery for vehicle fueling.

  17. Renewable energy for hydrogen production and sustainable urban mobility

    International Nuclear Information System (INIS)

    Briguglio, N.; Andaloro, L.; Ferraro, M.; Di Blasi, A.; Dispenza, G.; Antonucci, V.; Matteucci, F.; Breedveld, L.

    2010-01-01

    In recent years, the number of power plants based on renewable energy (RWE) has been increasing and hydrogen as an energy carrier has become a suitable medium-to-long term storage solution as well as a ''fuel'' for FCEV's because of its CO 2 -free potential. In this context, the aim of the present study is to carry out both an economic and environmental analysis of a start-up RWE plant using a simulation code developed in previous work and a Life Cycle Assessment (LCA). The plant will be located in the South of Italy (Puglia) and will consist of different RWE sources (Wind Power, Photovoltaic, Biomass). RWE will be used to produce hydrogen from an electrolyzer, which will feed a fleet of buses using different fuels (methane, hydrogen, or a mixture of these). In particular, a wind turbine of 850 kW will feed a hydrogen production plant and a biomass plant will produce methane. Preliminary studies have shown that it is possible to obtain hydrogen at a competitive cost (DOE target) and that components (wind turbine, electrolyzer, vessel, etc.) influence the final price. In addition, LCA results have permitted a comparison of different minibuses using either fossil fuels or renewable energy sources. (author)

  18. Renewable energy for hydrogen production and sustainable urban mobility

    Energy Technology Data Exchange (ETDEWEB)

    Briguglio, N.; Andaloro, L.; Ferraro, M.; Di Blasi, A.; Dispenza, G.; Antonucci, V. [Istituto di Tecnologie avanzate per l' Energia ' ' Nicola Giordano' ' Salita S, Lucia sopra Contesse, 5, 98126 Messina (Italy); Matteucci, F. [TRE SpA Tozzi Renewable Energy, Via Zuccherificio, 10, 48100 Mezzano (RA) (Italy); Breedveld, L. [2B Via della Chiesa Campocroce, 4, 31021 Mogliano Veneto (TV) (Italy)

    2010-09-15

    In recent years, the number of power plants based on renewable energy (RWE) has been increasing and hydrogen as an energy carrier has become a suitable medium-to-long term storage solution as well as a ''fuel'' for FCEV's because of its CO{sub 2}-free potential. In this context, the aim of the present study is to carry out both an economic and environmental analysis of a start-up RWE plant using a simulation code developed in previous work and a Life Cycle Assessment (LCA). The plant will be located in the South of Italy (Puglia) and will consist of different RWE sources (Wind Power, Photovoltaic, Biomass). RWE will be used to produce hydrogen from an electrolyzer, which will feed a fleet of buses using different fuels (methane, hydrogen, or a mixture of these). In particular, a wind turbine of 850 kW will feed a hydrogen production plant and a biomass plant will produce methane. Preliminary studies have shown that it is possible to obtain hydrogen at a competitive cost (DOE target) and that components (wind turbine, electrolyzer, vessel, etc.) influence the final price. In addition, LCA results have permitted a comparison of different minibuses using either fossil fuels or renewable energy sources. (author)

  19. Catalytic production of hydrogen from methanol for mobile, stationary and portable fuel-cell power plants

    International Nuclear Information System (INIS)

    Lukyanov, Boris N

    2008-01-01

    Main catalytic processes for hydrogen production from methanol are considered. Various schemes of fuel processors for hydrogen production in stationary, mobile and portable power plants based on fuel cells are analysed. The attention is focussed on the design of catalytic reactors of fuel processors and on the state-of-the-art in the design of catalysts for methanol conversion, carbon monoxide steam conversion and carbon monoxide selective oxidation. Prospects for the use of methanol in on-board fuel processors are discussed.

  20. Information needs and instrumentation availability for hydrogen control and management

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hong [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of); Park, Gun Chul; Suh, Kune Y.; Lee, Seung Dong; Lee, Jin Yong [Seoul National Univ., Seoul (Korea, Republic of); Jae, Moo Sung [Hansung Univ., Seoul (Korea, Republic of)

    1999-03-15

    This study is concerned with development of comprehensive hydrogen management strategies based on identification of a severe accident condition and formulation of hydrogen models. Reducing containment hydrogen during a severe accident will mitigate a potential containment failure mechanism. One of the hydrogen control strategies is intentional burning by the hydrogen igniter. Though intentional hydrogen burn strategy will cause pressure and temperature spikes, it is the fastest way of reducing the containment hydrogen concentration. Based on the Westinghouse owners group Severe Accident Management Guidance (SAMG) hydrogen ignition decision tree was developed. From the information of decision tree, hydrogen ignition decision can be determined in Containment Event Tree (CET). We have examined previous hydrogen generation related models in fuel coolant interaction (FCI) and developed transient model for it. Using this model, we have simulated the Argonne National Laboratory (ANL) tests which are single droplet experiments, and Fully Instrumented Test Site (FITS) tests which contain dynamic fragmentation.

  1. Hydrogen-water vapor mixtures: Control of hydrothermal atmospheres by hydrogen osmosis

    Science.gov (United States)

    Shaw, H.R.

    1963-01-01

    Experiments at 700??C and 800 bars total pressure demonstrate positive deviations from ideality for mixtures of hydrogen and H2O gases. The deviations are greater than predicted with Stockmayer's method. The composition of the mixture and the fugacity of hydrogen are controlled by diffusing hydrogen through metallic membranes. The results give the fugacities of both H 2O and oxygen.

  2. Hydrogen mobility is moving forward; Wasserstoff-Mobilitaet kommt voran

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Duran, Andres [Air Liquide Deutschland GmbH, Duesseldorf (Germany)

    2013-06-15

    The European Union (EU) declared aim is to cover at least 20 percent of energy needs from alternative sources until 2020. EU as well as federal and state governments promote various projects, to establish hydrogen as an energy carrier. Air Liquide participates by setting up a hydrogen infrastructure in this future project. [German] Erklaertes Ziel der Europaeischen Union (EU) ist es, bis 2020 mindestens 20 Prozent des Energiebedarfs aus alternativen Quellen zu decken. Dazu foerdern EU sowie Bund und Laender verschiedene Projekte, die Wasserstoff als Energietraeger etablieren sollen. Air Liquide beteiligt sich durch Mitarbeit am Aufbau einer Wasserstoff-Infrastruktur an diesem Zukunftsvorhaben.

  3. Catalytic on-board hydrogen production from methanol and ammonia for mobile application

    Energy Technology Data Exchange (ETDEWEB)

    Soerijanto, H.

    2008-08-15

    This PhD thesis deals with the catalytic hydrogen production for mobile application, for example for the use in fuel cells for electric cars. Electric powered buses with fuel cells as driving system are well known, but the secure hydrogen storage in adequate amounts for long distance drive is still a topic of discussion. Methanol is an excellent hydrogen carrier. First of all it has a high H:C ratio and therefore a high energy density. Secondly the operating temperature of steam reforming of methanol is comparatively low (250 C) and there is no risk of coking since methanol has no C-C bond. Thirdly methanol is a liquid, which means that the present gasoline infrastructure can be used. For the further development of catalysts and for the construction of a reformer it is very important to characterize the catalysts very well. For the dimensioning and the control of an on-board production of hydrogen it is essential to draw accurately on the thermodynamic, chemical and kinetic data of the reaction. At the first part of this work the mesoporous Cu/ZrO{sub 2}/CeO{sub 2}-catalysts with various copper contents were characterized and their long-term stability and selectivity were investigated, and the kinetic data were determined. Carbon monoxide is generated by reforming of carbon containing material. This process is undesired since CO poisons the Pt electrode of the fuel cell. The separation of hydrogen by metal membranes is technically feasible and a high purity of hydrogen can be obtained. However, due to their high density this procedure is not favourable because of its energy loss. In this study a concept is presented, which enables an autothermal mode by application of ceramic membrane and simultaneously could help to deal with the CO problem. The search for an absolutely selective catalyst is uncertain. The production of CO can be neither chemically nor thermodynamically excluded, if carbon is present in the hydrogen carrier. Since enrichment or separation are

  4. Catalytic on-board hydrogen production from methanol and ammonia for mobile application

    Energy Technology Data Exchange (ETDEWEB)

    Soerijanto, H

    2008-08-15

    This PhD thesis deals with the catalytic hydrogen production for mobile application, for example for the use in fuel cells for electric cars. Electric powered buses with fuel cells as driving system are well known, but the secure hydrogen storage in adequate amounts for long distance drive is still a topic of discussion. Methanol is an excellent hydrogen carrier. First of all it has a high H:C ratio and therefore a high energy density. Secondly the operating temperature of steam reforming of methanol is comparatively low (250 C) and there is no risk of coking since methanol has no C-C bond. Thirdly methanol is a liquid, which means that the present gasoline infrastructure can be used. For the further development of catalysts and for the construction of a reformer it is very important to characterize the catalysts very well. For the dimensioning and the control of an on-board production of hydrogen it is essential to draw accurately on the thermodynamic, chemical and kinetic data of the reaction. At the first part of this work the mesoporous Cu/ZrO{sub 2}/CeO{sub 2}-catalysts with various copper contents were characterized and their long-term stability and selectivity were investigated, and the kinetic data were determined. Carbon monoxide is generated by reforming of carbon containing material. This process is undesired since CO poisons the Pt electrode of the fuel cell. The separation of hydrogen by metal membranes is technically feasible and a high purity of hydrogen can be obtained. However, due to their high density this procedure is not favourable because of its energy loss. In this study a concept is presented, which enables an autothermal mode by application of ceramic membrane and simultaneously could help to deal with the CO problem. The search for an absolutely selective catalyst is uncertain. The production of CO can be neither chemically nor thermodynamically excluded, if carbon is present in the hydrogen carrier. Since enrichment or separation are

  5. Control synchronization of differential mobile robots

    NARCIS (Netherlands)

    Nijmeijer, H.; Rodriguez Angeles, A.; Allgoewer, F.

    2004-01-01

    In this paper a synchronization controller for differential mobile robots is proposed. The synchronization goal is to control the angular position of each wheel to a desired trajectory and at the same time the differential (or synchronization) error between the angular positions of the two wheels.

  6. Hydrogen Storage Materials for Mobile and Stationary Applications: Current State of the Art.

    Science.gov (United States)

    Lai, Qiwen; Paskevicius, Mark; Sheppard, Drew A; Buckley, Craig E; Thornton, Aaron W; Hill, Matthew R; Gu, Qinfen; Mao, Jianfeng; Huang, Zhenguo; Liu, Hua Kun; Guo, Zaiping; Banerjee, Amitava; Chakraborty, Sudip; Ahuja, Rajeev; Aguey-Zinsou, Kondo-Francois

    2015-09-07

    One of the limitations to the widespread use of hydrogen as an energy carrier is its storage in a safe and compact form. Herein, recent developments in effective high-capacity hydrogen storage materials are reviewed, with a special emphasis on light compounds, including those based on organic porous structures, boron, nitrogen, and aluminum. These elements and their related compounds hold the promise of high, reversible, and practical hydrogen storage capacity for mobile applications, including vehicles and portable power equipment, but also for the large scale and distributed storage of energy for stationary applications. Current understanding of the fundamental principles that govern the interaction of hydrogen with these light compounds is summarized, as well as basic strategies to meet practical targets of hydrogen uptake and release. The limitation of these strategies and current understanding is also discussed and new directions proposed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. AMC’s Hydrogen Future: Sustainable Air Mobility

    Science.gov (United States)

    2009-06-01

    levels, acidification of the oceans , desertification and the increased intensity of hurricanes. Since the United States is the leading consumer of...and steel to Carbon Fiber Reinforced Plastics (CFRP). The Institute of Space and Astronautical Science (ISAS) designed a liquid hydrogen composite...shell interior with a carbon fiber reinforced plastic outer shell with insulation and water proof tape cover (see Figure 35). The tank ended up

  8. Robot motion control in mobile environment

    Institute of Scientific and Technical Information of China (English)

    Iliya V Miroshnik; HUANG Xian-lin(黄显林); HE Jie(贺杰)

    2003-01-01

    With the problem of robot motion control in dynamic environment represented by mobile obstacles,working pieces and external mechanisms considered, a relevant control actions design procedure has been pro-posed to provide coordination of robot motions with respect to the moving external objects so that an extension ofrobot spatial motion techniques and active robotic strategies based on approaches of nonlinear control theory canbe achieved.

  9. Atomic layer deposition of high-mobility hydrogen-doped zinc oxide

    NARCIS (Netherlands)

    Macco, B.; Knoops, H.C.M.; Verheijen, M.A.; Beyer, W.; Creatore, M.; Kessels, W.M.M.

    2017-01-01

    In this work, atomic layer deposition (ALD) has been employed to prepare high-mobility H-doped zinc oxide (ZnO:H) films. Hydrogen doping was achieved by interleaving the ZnO ALD cycles with H2 plasma treatments. It has been shown that doping with H2 plasma offers key advantages over traditional

  10. High Charge Mobility of a Perylene Bisimide Dye with Hydrogen-bond Formation Group

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A perylene bisimide dye covalently bonded with a hydrogen-bond formation group of 1,3, 5-triazine-2, 4-diamine has been synthesized. Its casting films show a charge carrier mobility over 10-3 cm2/Vs, which is in the range of the highest values found for other promising charge transport materials suitable for solution processable technique.

  11. Hydrogen isotopes mobility and trapping in V-Cr-Ti alloys

    International Nuclear Information System (INIS)

    Budylkin, N.; Voloschin, L.; Mironova, E.; Riazantseva, N.; Tebus, V.

    1996-01-01

    In the last years the V-Ti-Cr alloys were considered as candidate materials for different structures of fusion reactors (blanket, first wall, divertor and so on) due to their advantages over other structure materials. Mobility and trapping parameters of hydrogen are essential characteristics for an assessment of using the V-Ti-Cr alloys in FR. In this paper: hydrogen problems for V-Ti-Cr alloys are formulated; V-H system data base is analyzed; study results of the hydrogen mobility and trapping in V-4Ti-4Cr and V-10Ti-5Cr alloys are given; the classification of V-alloys as radioactive waste according to the Russian Federation waste management rules is developed taking into account the residual amount of tritium ('inventory'). (orig.)

  12. Training for power plant personnel on hydrogen production and control

    International Nuclear Information System (INIS)

    Dickelman, G.J.

    1982-01-01

    It is the purpose of this paper to address the issue of training for power plant personnel in the area of hydrogen control. The authors experience in the training business indicates that most of the operations and engineering personnel have a very limited awareness of this phenomenon. Topics discussed in this paper include: 1) theory of hydrogen combustion kinetics; 2) incidents involving hydrogen combustion events; 3) normal operations interfacing with hydrogen; 4) accident conditions; and 5) mitigation schemes

  13. Model predictive Controller for Mobile Robot

    OpenAIRE

    Alireza Rezaee

    2017-01-01

    This paper proposes a Model Predictive Controller (MPC) for control of a P2AT mobile robot. MPC refers to a group of controllers that employ a distinctly identical model of process to predict its future behavior over an extended prediction horizon. The design of a MPC is formulated as an optimal control problem. Then this problem is considered as linear quadratic equation (LQR) and is solved by making use of Ricatti equation. To show the effectiveness of the proposed method this controller is...

  14. Controller Design Of Unicycle Mobile Robot

    Directory of Open Access Journals (Sweden)

    Mohd Zamzuri Abd Rashid

    2012-10-01

    Full Text Available ABSTRACT: The ability of unicycle mobile robot to stand and move around using one wheel has attracted a lot of researchers to conduct studies about the system, particularly in the design of the system mechanisms and the control strategies. This paper reports the investigation done on the design of the controller of the unicycle mobile robot system to maintain its stability in both longitudinal and lateral directions. The controller proposed is a Linear Quadratic Controller (LQR type which is based on the linearized model of the system. A thorough simulation studies have been carried out to find out the performance of the LQR controller. The best controller gain, K acquired through the simulation is selected to be implemented and tested in the experimental hardware. Finally, the results obtained from the experimental study are compared to the simulation results to study the controller efficacy. The analysis reveals that the proposed controller design is able to stabilize the unicycle mobile robot.ABSTRAK: Kemampuan robot satu roda untuk berdiri dan bergerak di sekitar telah menarik minat ramai penyelidik untuk mengkaji sistem robot terutamanya didalam bidang rangka mekanikal dan strategi kawalan robot. Kertas kajian ini melaporkan hasil penyelidikan ke atas strategi kawalan robot bagi memastikan sistem robot satu roda dapat distabilkan dari arah sisi dan hadapan. Strategi kawalan yang dicadang, menggunakan teknik kawalan kuadratik sejajar (Linear Quadratic Control yang berdasarkan model robot yang telah dipermudahkan. Kajian simulasi secara terperinci telah dijalankan bagi mengkaji prestasi strategi kawalan yang dicadangkan. Dari kajian simulasi sistem robot, pemilihan faktor konstan, K yang sesuai di dalam strategi kawalan telah dibuat, agar dapat dilaksanakan ke atas sistem robot yang dibangunkan. Keputusan dari kajian simulasi dan tindak balas oleh sistem robot yang dibangunkan akhirnya dibandingkan bagi melihat kesesuaian faktor kostan, K

  15. Hydrogen control in the System 80+TM ALWR design

    International Nuclear Information System (INIS)

    Schneider, R.E.; Jacob, M.C.; Carpentino, F.L.; Wachowiak, R.M.

    2004-01-01

    This paper provides an assessment of the features built into the System 80 +TM Advanced Light Water Reactor (ALWR) design for controlling hydrogen concentration during a hypothetical severe accident. Although the significantly larger System 80 + containment volume serves to passively maintain the global average below detonable limits, the design incorporates a Hydrogen Mitigation System (HMS) to further reduce the local hydrogen concentration. The HMS consists of a large number of hydrogen ignitors distributed within the containment to selectively burn-off hydrogen at low concentrations. The criteria for the placement of these igniters are discussed along with an assessment of the effectiveness of the igniters to control the hydrogen concentrations. This assessment, which was performed using the generalized containment model of the MAAP 4 code, evaluated the potential for hydrogen build-up in the containment and calculated the best-estimate response of the igniters. (author)

  16. Hydrogen, a bridge between mobility and distributed generation. Some consideration towards the hydrogen economy

    International Nuclear Information System (INIS)

    Valentino Romeri

    2006-01-01

    In this paper were analysed the most recent energy initiatives started by some national and international institution, with particular focus on hydrogen and fuel cell. It were also overviewed the national road-maps towards the hydrogen economy. In 2004, based on the most authoritative available data regarding future FCVs penetration it was observed that, if vehicle power-generation system fuel cell based becomes more sophisticated, the role of the vehicles within the power grid might change. Fuel Cell Vehicle (FVC) could become a new power-generation source, supplying electricity to home and to the grid. Also, it was defined the dimension of this new kind of power generation source in different areas and it was compared with the related power grid installed generation capacity and it was found that this new source could be a multiple of the foreseeable installed capacity in year 2030. In the present work it was revised the analysis with the most recent scenarios and it was found that the results do not change significantly. Unfortunately this kind of analysis is still not considered in the energy debate or in the road-maps towards the hydrogen economy. (author)

  17. Controlling hydrogen behavior in light water reactors

    International Nuclear Information System (INIS)

    Cullingford, H.S.; Edeskuty, F.J.

    1981-01-01

    In the aftermath of the incident at Three Mile Island Unit 2 (TMI-2), a new and different treatment of the Light Water Reactor (LWR) risks is needed for public safety because of the specific events involving hydrogen generation, transport, and behavior following the core damage. Hydrogen behavior in closed environments such as the TMI-2 containment building is a complex phenomenon that is not fully understood. Hence, an engineering approach is presented for prevention of loss of life, equipment, and environment in case of a large hydrogen generation in an LWR. A six-level defense strategy is described that minimizes the possibility of ignition of released hydrogen gas and otherwise mitigates the consequences of hydrogen release. Guidance is given to reactor manufacturers, utility companies, regulatory agencies, and research organizations committed to reducing risk factors and insuring safety of life, equipment, and environment

  18. Superconducting phases of phosphorus hydride under pressure. Stabilization by mobile molecular hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Bi, Tiange; Miller, Daniel P.; Shamp, Andrew; Zurek, Eva [Department of Chemistry, State University of New York, Buffalo, NY (United States)

    2017-08-14

    At 80 GPa, phases with the PH{sub 2} stoichiometry, which are composed of simple cubic like phosphorus layers capped with hydrogen atoms and layers of H{sub 2} molecules, are predicted to be important species contributing to the recently observed superconductivity in compressed phosphine. The electron-phonon coupling in these phases results from the motions of the phosphorus atoms and the hydrogen atoms bound to them. The role of the mobile H{sub 2} layers is to decrease the Coulomb repulsion between the negatively charged hydrogen atoms capping the phosphorus layers. An insulating PH{sub 5} phase, the structure and bonding of which is reminiscent of diborane, is also predicted to be metastable at this pressure. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Proton NMR investigation of heme pocket mobility in hemoglobin via hydrogen isotope exchange kinetics

    International Nuclear Information System (INIS)

    Han, K.

    1985-01-01

    Dynamic mobility of heme cavity, the active site of Hb, was investigated by analyzing the hydrogen isotope exchange kinetics of the proximal histidyl ring NH of various kinds of Hbs with the aid of the high field Fourier Transform 1 H NMR spectroscopy. The exchange reaction occurs faster in oxy or R-state Hb than in deoxy or T-state Hb and there exists a good correlation between the oxygen affinity of Hb and the heme pocket mobility reflected in the hydrogen exchange rate. The effect of pH on the exchange is dramatically different for the two subunits of Hb A. Studying the exchange characteristics of mutant Hbs and chemically modified Hbs not only showed the existence of three well-defined localized paths for transmission of conformational changes between different heme pockets through a 1 b 2 subunit interface, but also indicated that the heme pocket mobility is regulated by the quaternary state of Hb as well as by the ligation state of Hb. Finally, the effect of the quaternary state on the heme pocket mobility is separated from that of the ligation by following the exchange reactions in Hbs where only their quaternary structure transition can be achieved without changing their ligation states by adjusting experimental conditions such as adding inositol hexaphosphate

  20. Controlled Hydrogen Fleet and Infrastructure Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Scott Staley

    2010-03-31

    This program was undertaken in response to the US Department of Energy Solicitation DE-PS30-03GO93010, resulting in this Cooperative Agreement with the Ford Motor Company and BP to demonstrate and evaluate hydrogen fuel cell vehicles and required fueling infrastructure. Ford initially placed 18 hydrogen fuel cell vehicles (FCV) in three geographic regions of the US (Sacramento, CA; Orlando, FL; and southeast Michigan). Subsequently, 8 advanced technology vehicles were developed and evaluated by the Ford engineering team in Michigan. BP is Ford's principal partner and co-applicant on this project and provided the hydrogen infrastructure to support the fuel cell vehicles. BP ultimately provided three new fueling stations. The Ford-BP program consists of two overlapping phases. The deliverables of this project, combined with those of other industry consortia, are to be used to provide critical input to hydrogen economy commercialization decisions by 2015. The program's goal is to support industry efforts of the US President's Hydrogen Fuel Initiative in developing a path to a hydrogen economy. This program was designed to seek complete systems solutions to address hydrogen infrastructure and vehicle development, and possible synergies between hydrogen fuel electricity generation and transportation applications. This project, in support of that national goal, was designed to gain real world experience with Hydrogen powered Fuel Cell Vehicles (H2FCV) 'on the road' used in everyday activities, and further, to begin the development of the required supporting H2 infrastructure. Implementation of a new hydrogen vehicle technology is, as expected, complex because of the need for parallel introduction of a viable, available fuel delivery system and sufficient numbers of vehicles to buy fuel to justify expansion of the fueling infrastructure. Viability of the fuel structure means widespread, affordable hydrogen which can return a reasonable profit to

  1. Hydrogen mobility from wind energy – A life cycle assessment focusing on the fuel supply

    International Nuclear Information System (INIS)

    Burkhardt, Jörg; Patyk, Andreas; Tanguy, Philippe; Retzke, Carsten

    2016-01-01

    Highlights: • Environmental performance, focusing on production and provision of hydrogen. • Primary data collected from a 700 bar refueling station incl. alkaline electrolyser. • Construction of facilities dominates the primary energy demand and emissions. • Refueling station contributes to same extent to GHG emissions as electricity supply. • Remarkably high expenditures for provision of supplies. - Abstract: In the current debates on reducing greenhouse gas emissions in the mobility sector, hydrogen produced via water electrolysis from renewable electricity is commonly regarded to be a sustainable energy carrier with large potential for decarbonisation of the mobility sector. Directly produced at the refueling stations site, hydrogen greenhouse gas emissions are presently defined to be zero in e.g. the Directives of the European Union since emissions arising from the facilities construction are defined to be negligible. In order to check the validity of this assumption with respect to the latest technical developments in hydrogen supply, the present article aims to report the environmental performance of hydrogen being produced and compressed for mobility purposes. To this end, a state-of-the-art hydrogen refueling station (HRS) with an on-site alkaline electrolyser is assessed, which was built and operated in Berlin. Assuming electricity supply from wind energy generation, a life cycle assessment for the complete value chain was carried out where primary data for the build-up of electrolyser and HRS were obtained during decommissioning of the station. The results show that the construction of HRS and on-site electrolyser requires higher material and energy expenditures compared to previous investigations on similar but technically less advanced systems. These expenditures generate a significant footprint in the specific e.g. greenhouse gas emissions if the electrolyser is operated at a reduced load factor as it may be foreseen for grid stabilisation

  2. Charge mobility increase in indium-molybdenum oxide thin films by hydrogen doping

    Energy Technology Data Exchange (ETDEWEB)

    Catalán, S.; Álvarez-Fraga, L. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (ICMM-CSIC), Cantoblanco, E-28049 Madrid (Spain); Salas, E. [Spline CRG, ESRF, 38043 Grenoble (France); Ramírez-Jiménez, R. [Departamento de Física, Escuela Politécnica Superior, Universidad Carlos III de Madrid, Avenida Universidad 30, Leganés, 28911 Madrid (Spain); Rodriguez-Palomo, A.; Andrés, A. de [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (ICMM-CSIC), Cantoblanco, E-28049 Madrid (Spain); Prieto, C., E-mail: cprieto@icmm.csic.es [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (ICMM-CSIC), Cantoblanco, E-28049 Madrid (Spain)

    2016-11-15

    Highlights: • The charge mobility in IMO films is correlated with its hydrogen content. • The mobility behavior is explained by the presence of OH{sup −} groups in IMO films. • Mo{sup 4+} is identified in transparent conductive IMO by X-ray absorption spectroscopy. - Abstract: The increase of charge mobility in transparent conductive indium molybdenum oxide (IMO) films is correlated with the presence of hydroxyl groups. The introduction of H{sub 2} in the chamber during sputtering deposition compensates the excess charge introduced by cationic Mo doping of indium oxide either by oxygen or hydroxyl interstitials. Films present a linear increase of carrier mobility correlated with H{sub 2} content only after vacuum annealing. This behavior is explained because vacuum annealing favors the removal of oxygen interstitials over that of hydroxyl groups. Since hydroxyl groups offer lower effective charge and smaller lattice distortions than those associated with interstitial oxygen, this compensation mechanism offers the conditions for the observed increase in mobility. Additionally, the short-range order around molybdenum is evaluated by extended X-ray absorption fine structure (EXAFS) spectroscopy, showing that Mo{sup 4+} is placed at the In site of the indium oxide.

  3. Hydrogen and nitrogen control in ladle and casting operations

    Energy Technology Data Exchange (ETDEWEB)

    Fruehan, R. J. [Carnegie Mellon Univ., Pittsburgh, PA (United States); Misra, Siddhartha [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2005-01-15

    In recent years there has been an increasing demand to reduce and control the amount of dissolved gases in steel. Hydrogen and nitrogen are two of the most important gases which when dissolved in liquid steel affect its properties significantly.

  4. Adaptive learning fuzzy control of a mobile robot

    International Nuclear Information System (INIS)

    Tsukada, Akira; Suzuki, Katsuo; Fujii, Yoshio; Shinohara, Yoshikuni

    1989-11-01

    In this report a problem is studied to construct a fuzzy controller for a mobile robot to move autonomously along a given reference direction curve, for which control rules are generated and acquired through an adaptive learning process. An adaptive learning fuzzy controller has been developed for a mobile robot. Good properties of the controller are shown through the travelling experiments of the mobile robot. (author)

  5. Control of wheeled mobile robot in restricted environment

    Science.gov (United States)

    Ali, Mohammed A. H.; En, Chang Yong

    2018-03-01

    This paper presents a simulation and practical control system for wheeled mobile robot in restricted environment. A wheeled mobile robot with 3 wheels is fabricated and controlled by proportional derivative active force control (PD-AFC) to move in a pre-planned restricted environment to maintain the tracking errors at zero level. A control system with two loops, outer by PD controller and inner loop by Active Force Control, are designed to control the wheeled mobile robot. Fuzzy logic controller is implemented in the Active force Control to estimate the inertia matrix that will be used to calculate the actual torque applied on the wheeled mobile robot. The mobile robot is tested in two different trajectories, namely are circular and straight path. The actual path and desired path are compared.

  6. Shuttle Gaseous Hydrogen Venting Risk from Flow Control Valve Failure

    Science.gov (United States)

    Drummond, J. Philip; Baurle, Robert A.; Gafney, Richard L.; Norris, Andrew T.; Pellett, Gerald L.; Rock, Kenneth E.

    2009-01-01

    This paper describes a series of studies to assess the potential risk associated with the failure of one of three gaseous hydrogen flow control valves in the orbiter's main propulsion system during the launch of Shuttle Endeavour (STS-126) in November 2008. The studies focused on critical issues associated with the possibility of combustion resulting from release of gaseous hydrogen from the external tank into the atmosphere during assent. The Shuttle Program currently assumes hydrogen venting from the external tank will result in a critical failure. The current effort was conducted to increase understanding of the risk associated with venting hydrogen given the flow control valve failure scenarios being considered in the Integrated In-Flight Anomaly Investigation being conducted by NASA.

  7. Formal-Language-Theoretic Control & Coordination of Mobile Robots

    National Research Council Canada - National Science Library

    Ray, Asok

    2007-01-01

    .... The research has formulated and experimentally validated robust adaptive algorithms and software codes for decision and control of mobile robotic platforms, as applied to real-time computation...

  8. First-principles calculation for the effect of hydrogen atoms on the mobility of a screw dislocation in BCC iron

    International Nuclear Information System (INIS)

    Itakura, Mitsuhiro; Kaburaki, Hideo; Yamaguchi, Masatake; Endo, Tatsuro; Higuchi, Kenji; Ogata, Shigenobu; Kimizuka, Hajime

    2012-01-01

    Effect of hydrogen atoms on the mobility of a screw dislocation in BCC iron has been evaluated using the first-principles calculation. The stable position of a hydrogen atom is found to be near the screw dislocation core and inside the core respectively when the dislocation is at the easy-core or hard-core configuration in BCC iron. The intrinsically unstable hard-core configuration of the screw dislocation is stabilized when a hydrogen atom is trapped inside the core. On the basis of this first-principles result, an elastic string model of a dislocation is developed to predict the kink motion in the presence of a hydrogen atom. It is found that a double-kink formation is facilitated when a hydrogen atom is located near a dislocation line, however, a kink motion is retarded when a hydrogen atom is behind the kink. (author)

  9. Wireless Control of Miniaturized Mobile Vehicle for Indoor Surveillance

    International Nuclear Information System (INIS)

    Saquib, Syed M Taha; Hameed, Sarmad; Jafri, Raza; Usman Ali, Syed M; Amin, Imran

    2013-01-01

    This work is based upon electronic automation and Smart Control techniques, which constitute the basis of Control Area Network (CAN) and Personal Area Network (PAN). Bluetooth technology has been interfaced with a programmable controller to provide multi-dimensional vehicle control. A network is proposed which contains a remote, mobile host controller and an android operating system based mobile set (Client). The client communicates with a host controller through a Bluetooth device. The system incorporates duplex communication after successful confirmation between the host and the client; the android based mobile unit controls the vehicle through the Bluetooth module

  10. EMBEDDED CONTROL SYSTEM FOR MOBILE ROBOTS WITH DIFFERENTIAL DRIVE

    Directory of Open Access Journals (Sweden)

    Michal KOPČÍK

    2017-09-01

    Full Text Available This article deals with design and implementation of control system for mobile robots with differential drive using embedded system. This designed embedded system consists of single control board featuring ARM based microcontroller which control the peripherals in real time and perform all low-level motion control. Designed embedded system can be easily expanded with additional sensors, actuators or control units to enhance applicability of mobile robot. Designed embedded system also features build-in communication module, which can be used for data for data acquisition and control of the mobile robot. Control board was implemented on two different types of mobile robots with differential drive, one of which was wheeled and other was tracked. These mobile robots serve as testing platform for Fault Detection and Isolation using hardware and analytical redundancy using Multisensor Data Fusion based on Kalman filters.

  11. Composite high-pressure vessels for hydrogen storage in mobile application. Pt. 1 / Light weight composite cylinders for compressed hydrogen. Pt. 2 - custom made hydrogen storage tanks and vessels

    Energy Technology Data Exchange (ETDEWEB)

    Rasche, C. [MCS Cylinder Systems GmbH, Dinslaken (Germany)

    2000-07-01

    Recent developments on fuel cell technology demonstrated the feasibility of propelling vehicles by converting fuel directly into electricity. Fuel cells conveniently use either compressed (CGH{sub 2}) or liquid hydrogen (LH{sub 2}) or methanol as the fuel source from a tank. Mobile storage of these fuelling will become an urgent need as this technology will come into series production expected for 2010. Due to the requirements on mobile hydrogen storage and the energy losses in the hydrogen-to-application-chain, a light-weight and energetic qualities and minimise ist bulky nature. Mobile storage of hydrogen can be realised either at high pressure values (> 20 MPa) or at deep temperatures (<-253 C). CGH{sub 2}: In the last few years, the introduction of natural gas driven vehicles has seen the development of compact mobile pressurised gas tanks in principle, this storage technique is also applicable for the compressed storage of hydrogen at filling pressures of > 20 MPa. LH{sub 2} : Storing hydrogen or natural gases in general in the liquid phase is accomplished either by applying a overpressure or keeping it below the phase transition temperature at ambient pressure in super insulated devices. (orig.)

  12. LEDs for the Implementation of Advanced Hydrogenation Using Hydrogen Charge-State Control

    Directory of Open Access Journals (Sweden)

    Chee Mun Chong

    2018-01-01

    Full Text Available Light-induced degradation (LID of p-type Cz solar cells has plagued the industry for many decades. However, in recent years, new techniques for solving this LID have been developed, with hydrogen passivation of the boron-oxygen defects appearing to be an important contributor to the solution. Advanced hydrogenation approaches involving the control of the charge state for the hydrogen atoms in silicon to enhance their diffusivity and reactivity are developed and evaluated in this work for commercial application using a prototype industrial tool in conjunction with solar cells manufactured on commercial production lines. This prototype tool, unlike the previous successful laser-based laboratory approaches, is based on the use of LEDs for controlling the charge state of the hydrogen atoms. The illumination from the LEDs is also used in this work to passivate process-induced defects and contamination from the respective production lines with significant improvements in both efficiency and stability. The results indicate that the low-cost LED-based industrial tool performs as well as the laser-based laboratory tool for implementing these advanced hydrogen passivation approaches.

  13. Solid state cloaking for electrical charge carrier mobility control

    Science.gov (United States)

    Zebarjadi, Mona; Liao, Bolin; Esfarjani, Keivan; Chen, Gang

    2015-07-07

    An electrical mobility-controlled material includes a solid state host material having a controllable Fermi energy level and electrical charge carriers with a charge carrier mobility. At least one Fermi level energy at which a peak in charge carrier mobility is to occur is prespecified for the host material. A plurality of particles are distributed in the host material, with at least one particle disposed with an effective mass and a radius that minimize scattering of the electrical charge carriers for the at least one prespecified Fermi level energy of peak charge carrier mobility. The minimized scattering of electrical charge carriers produces the peak charge carrier mobility only at the at least one prespecified Fermi level energy, set by the particle effective mass and radius, the charge carrier mobility being less than the peak charge carrier mobility at Fermi level energies other than the at least one prespecified Fermi level energy.

  14. Atomic-scale investigation of point defects and hydrogen-solute atmospheres on the edge dislocation mobility in alpha iron

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, M. A.; Solanki, K. N., E-mail: kiran.solanki@asu.edu [School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287 (United States); Groh, S. [Institute of Mechanics and Fluid Dynamics, TU Bergakademie Freiberg, Freiberg 09556 (Germany)

    2014-08-14

    In this study, we present atomistic mechanisms of 1/2 [111](11{sup ¯}0) edge dislocation interactions with point defects (hydrogen and vacancies) and hydrogen solute atmospheres in body centered cubic (bcc) iron. In metals such as iron, increases in hydrogen concentration can increase dislocation mobility and/or cleavage-type decohesion. Here, we first investigate the dislocation mobility in the presence of various point defects, i.e., change in the frictional stress as the edge dislocation interacts with (a) vacancy, (b) substitutional hydrogen, (c) one substitutional and one interstitial hydrogen, (d) interstitial hydrogen, (e) vacancy and interstitial hydrogen, and (f) two interstitial hydrogen. Second, we examine the role of a hydrogen-solute atmosphere on the rate of local dislocation velocity. The edge dislocation simulation with a vacancy in the compression side of the dislocation and an interstitial hydrogen atom at the tension side exhibit the strongest mechanical response, suggesting a higher potential barrier and hence, the higher frictional stress (i.e., ∼83% higher than the pure iron Peierls stress). In the case of a dislocation interacting with a vacancy on the compressive side, the vacancy binds with the edge dislocation, resulting in an increase in the friction stress of about 28% when compared with the Peierls stress of an edge dislocation in pure iron. Furthermore, as the applied strain increases, the vacancy migrates through a dislocation transportation mechanism by attaining a velocity of the same order as the dislocation velocity. For the case of the edge dislocation interacting with interstitial hydrogen on the tension side, the hydrogen atom jumps through one layer perpendicular to the glide plane during the pinning-unpinning process. Finally, our simulation of dislocation interactions with hydrogen show first an increase in the local dislocation velocity followed by a pinning of the dislocation core in the atmosphere, resulting in

  15. Biogeochemical Controls on Technetium Mobility in Biogeochemical Controls on Technetium Mobility in FRC Sediments

    International Nuclear Information System (INIS)

    Lloyd, J.R.; McBeth, J.M.; Livens, F.R.; Bryan, N.D.; Ellis, B.; Sharma, H.; Burke, I.T.; Morris, K.

    2004-01-01

    Technetium-99 is a priority pollutant at numerous DOE sites, due to its long half-life (2.1 x 10 5 years), high mobility as Tc(VII) in oxic waters, and bioavailability as a sulfate analog. 99 Tc is far less mobile under anaerobic conditions, forming insoluble Tc(IV) precipitates. As anaerobic microorganisms can reduce soluble Tc(VII) to insoluble Tc(IV), microbial metabolism may have the potential to treat sediments and waters contaminated with Tc. Baseline studies of fundamental mechanisms of Tc(VII) bioreduction and precipitation (reviewed by Lloyd et al, 2002) have generally used pure cultures of metal-reducing bacteria, in order to develop conceptual models for the biogeochemical cycling of Tc. There is, however, comparatively little known about interactions of metal-reducing bacteria with environmentally relevant trace concentrations of Tc, against a more complex biogeochemical background provided by mixed microbial communities in the subsurface. The objective of this new NABIR project is to probe the site specific biogeochemical conditions that control the mobility of Tc at the FRC (Oak Ridge, TN). This information is required for the rational design of in situ bioremediation strategies for technetium-contaminated subsurface environments. We will use a combination of geochemical, mineralogical, microbiological and spectroscopic techniques to determine the solubility and phase associations of Tc in FRC sediments, and characterize the underpinning biogeochemical controls. A key strength of this project is that many of the techniques we are using have already been optimized by our research team, who are also studying the biogeochemical controls on Tc mobility in marine and freshwater sediments in the UK in a NERC funded companion study.

  16. Can hydrogen bonds improve the hole-mobility in amorphous organic semiconductors? Experimental and theoretical insights

    KAUST Repository

    Mimaite, Viktorija; Grazulevicius, Juozas Vidas; Laurinaviciute, Rasa; Volyniuk, Dmytro; Jankauskas, Vygintas; Sini, Gjergji

    2015-01-01

    © The Royal Society of Chemistry 2015. Five hole-transporting triphenylamine derivatives containing methoxy and methyl groups are synthesized and investigated. The hole-mobility increases in the presence of methyl and methoxy substituents, exceeding 10-2 cm2 V-1 s-1 in the case of methyl groups. Quantum mechanical calculations on these compounds indicate very different dipole moments and intermolecular interaction strengths, with intriguing correlations with the trend in hole-mobility. Temperature dependent hole-mobility measurements indicate disorder dominated hole transport. The values of the energetic disorder parameter (σ) decrease upon methyl and methoxy substitutions despite the increase in dipole moments. This trend is discussed as a function of the interaction energy between adjacent molecules, the dipole moment, the molecular polarizability, and the conformational degree of freedom. Our results indicate that the global decrease of σ upon methyl and methoxy substitutions is dominated by the larger decrease in the geometrical randomness component of the energetic disorder. A direct correlation is established between the decrease in geometrical randomness and the increase in intermolecular interaction energies, mainly stemming from the additional C-H⋯π, O, N hydrogen bonds induced by methyl and methoxy groups.

  17. Controlling hydrogenation activity and selectivity of bimetallic surfaces and catalysts

    Science.gov (United States)

    Murillo, Luis E.

    Studies of bimetallic systems are of great interest in catalysis due to the novel properties that they often show in comparison with the parent metals. The goals of this dissertation are: (1) to expand the studies of self-hydrogenation and hydrogenation reactions on bimetallic surfaces under ultra high vacuum conditions (UHV) using different hydrocarbon as probe molecules; (2) to attempt to correlate the surface science findings with supported catalyst studies under more realistic conditions; and (3) to investigate the competitive hydrogenation of C=C versus C=O bonds on Pt(111) modified by different 3d transition metals. Hydrogenation studies using temperature programmed desorption (TPD) on Ni/Pt(111) bimetallic surfaces have demonstrated an enhancement in the low temperature hydrogenation activity relative to that of clean Pt(111). This novel hydrogenation pathway can be achieved under UHV conditions by controlling the structures of the bimetallic surfaces. A low temperature hydrogenation activity of 1-hexene and 1-butene has been observed on a Pt-Ni-Pt(111) subsurface structure, where Ni atoms are mainly present on the second layer of the Pt(111) single crystal. These results are in agreement with previous studies of self-hydrogenation and hydrogenation of cyclohexene. However, a much higher dehydrogenation activity is observed in the reaction of cyclohexene to produce benzene, demonstrating that the hydrocarbon structure has an effect on the reaction pathways. On the other hand, self-hydrogenation of 1-butene is not observed on the Pt-Ni-Pt(111) surface, indicating that the chain length (or molecular weight) has a significant effect on the selfhydrogenation activity. The gas phase reaction of cyclohexene on Ni/Pt supported on alumina catalysts has also shown a higher self-hydrogenation activity in comparison with the same reaction performed on supported monometallic catalysts. The effects of metal loading and impregnation sequence of the metal precursors are

  18. Hierarchical coordination control of mobile robots

    NARCIS (Netherlands)

    Adinandra, S.

    2012-01-01

    In the last decade, robotic systems have penetrated human life more than human can imagine. In particular, the multi-mobile robotic systems have faced a fast growing due to the fact that by deploying a large collection of mobile robots the overall system has a high redundancy and offers the

  19. Mechanisms controlling radionuclide mobility in forest soils

    International Nuclear Information System (INIS)

    Delvaux, B.; Kruyts, N.; Maes, E.; Agapkina, G.I.; Kliashtorin, A.; Bunzl, K.; Rafferty, B.

    1996-01-01

    Soil processes strongly influence the radionuclide mobility in soils. The mobility of radionuclides in forest soils is governed by several processes involving both abiotic and biotic factors. The sorption-desorption process chiefly governs the activity of radionuclides in the soil solution, hence thereby their mobility and biological availability. Radiocaesium exhibits a very low mobility in mineral soils. Both mobility and bioavailability however increase as the thickness of organic layers and their content in organic matter increases. Clay minerals of micaceous origin strongly act as slinks for radiocaesium in forest soils. The magnitude of cesium mineral fixation in topsoils is expected to be the highest in mineral soils of Eutric cambisol type, and, to a lesser extent, of type of Distric cambisol and Podzoluvisol. A low mobility of radiocaesium in the surface horizons of forest soils may also be partially explained by a biological mobilization: fungi absorb radiocaesium and transport it to upper layers, thereby contributing to constantly recycle the radioelement in the organic horizons. This mechanism is probably important in soils with thick organic layers (Podsol, Histosol, and, to a lesser extent, Distric cambisol and Podzoluvisol). Radionuclides can be associated with soluble organic anions in the soil solution of forest acid soils. Such associations are highly mobile: they are stable in conditions of poor biological activity (low temperatures, acid soil infertility, water excess, etc.). Their magnitude is expected to be the highest in thick acid organic layers (soils of type Podzol and Histosol)

  20. Residential Mobility, Inhibitory Control, and Academic Achievement in Preschool

    Science.gov (United States)

    Schmitt, Sara A.; Finders, Jennifer K.; McClelland, Megan M.

    2015-01-01

    Research Findings: The present study investigated the direct effects of residential mobility on children's inhibitory control and academic achievement during the preschool year. It also explored fall inhibitory control and academic skills as mediators linking residential mobility and spring achievement. Participants included 359 preschool children…

  1. Hydrogen: it's now. Hydrogen, essential today, indispensable tomorrow. Power-to-Gas or how to meet the challenge of electricity storage. To develop hydrogen mobility. Hydrogen production modes and scope of application of the IED directive - Interview. Regulatory evolutions needed for an easier deployment of hydrogen energy technologies for a clean mobility. Support of the Community's policy to hydrogen and to fuel cells

    International Nuclear Information System (INIS)

    Mauberger, Pascal; Boucly, Philippe; Quint, Aliette; Pierre, Helene; Lucchese, Paul; Bouillon-Delporte, Valerie; Chauvet, Bertrand; Ferrari, Fabio; Boivin, Jean-Pierre

    2015-01-01

    Published by the French Association for Hydrogen and Fuel Cells (AFHYPAC), this document first outlines how hydrogen can reduce our dependence on fossil energies, how it supports the development of electric mobility to reduce CO 2 emissions by transports, how it enables a massive storage of energy as a support to renewable energies deployment and integration, and how hydrogen can be a competitiveness driver. Then two contributions address technical solutions, the first one being Power-to-Gas as a solution to energy storage (integration of renewable energies, a mean for massive storage of electricity, economic conditions making the first deployments feasible, huge social and economical benefits, necessity of creation of an adapted legal and economic framework), and the second one being the development of hydrogen-powered mobility (a major societal concern for air quality, strategies of car manufacturers in the world, necessity of a favourable framework, the situation of recharging infrastructures). Two contributions address the legal framework regarding hydrogen production modes and the scope of application of the European IED directive on industrial emissions, and the needed regulatory evolutions for an easier deployment of Hydrogen-energy technologies for a clean mobility. A last article comments the evolution of the support of European policies to hydrogen and fuel cells through R and d programs, presents the main support program (FCH JU) and its results, other European financing and support policy, and discusses perspectives, notably for possible financing mechanisms

  2. Mobile robot navigation in unknown static environments using ANFIS controller

    Directory of Open Access Journals (Sweden)

    Anish Pandey

    2016-09-01

    Full Text Available Navigation and obstacle avoidance are the most important task for any mobile robots. This article presents the Adaptive Neuro-Fuzzy Inference System (ANFIS controller for mobile robot navigation and obstacle avoidance in the unknown static environments. The different sensors such as ultrasonic range finder sensor and sharp infrared range sensor are used to detect the forward obstacles in the environments. The inputs of the ANFIS controller are obstacle distances obtained from the sensors, and the controller output is a robot steering angle. The primary objective of the present work is to use ANFIS controller to guide the mobile robot in the given environments. Computer simulations are conducted through MATLAB software and implemented in real time by using C/C++ language running Arduino microcontroller based mobile robot. Moreover, the successful experimental results on the actual mobile robot demonstrate the effectiveness and efficiency of the proposed controller.

  3. Hydrogen as a link between sustainable mobility and transition of the German energy system

    Energy Technology Data Exchange (ETDEWEB)

    Conreder, Alexander [EnBW Energie Baden-Wuerttemberg AG, Karlsruhe (Germany)

    2013-06-01

    Even 15 years ago, the predictions with regard to the market penetration of fuel cell automobiles or of so-called fuel cell heaters were communicated with differing statements. Daimler Benz AG, as it still was back then, had put their faith in the rapid integration of a fuel cell into the vehicle, whereas companies such as Vaillant, Hamburger Gas Consult, Sulzer Hexis or even MTU and Siemens were working on stationary fuel cell systems. The expectations at that time with regard to market and technology development have still not yet been fulfilled. Today, the subject has been given a new lease of life thanks to the public discussions regarding the energy transition and the current framework conditions. Many concepts that have already been under consideration, but which very few have considered realistic in the short-term, now appear at least to have come within reach. As a result of the fluctuations in the generation of renewable energies, Germany needs loads that can be switched and, above all, methods of storing energy. In conjunction with new technologies, such as PEM electrolysis and the pressure which has been put on politics to react and to create the necessary framework conditions, a new momentum has developed with regard to the use of hydrogen. This article analyses to what extent synergies between energy transition and mobility can be expected within the context of hydrogen. With a view to quantity, times and local relationships, quality and price, we have been able to determine that the relevant amounts and dependencies have a positive and relevant magnitude to one another, thus synergies are present. It should be noted that hydrogen will not be the sole solution for the Federal Government when it comes to achieving CO{sub 2} reduction aims. Electrical mobility with approaches for bidirectional charging, new storage technologies and alternative energy carriers, switchable loads as well as the local public transport systems and new mobility concepts will

  4. Analysis of Hydrogen Control Strategy Using Igniter during Severe Accident

    International Nuclear Information System (INIS)

    Lee, Sung Bok; Kim, Hyeong Taek; Lee, Keo Hyoung

    2008-01-01

    The Severe Accident Management Guidelines (SAMGs) for the operating pressurized water reactor (PWR) have been completed within 2006. Among the SAMG strategies, mitigation-07 is the most important strategy for managing a severe accident of a PWR in order to reduce containment hydrogen. The fastest way to reduce the containment hydrogen concentration is to intentionally ignite the hydrogen. For this strategy, igniters exist in Optimized Power Reactor 1000 (OPR 1000) to burn hydrogen for a severe accident. For using the igniters during a severe accident, the adverse effects such as the explosion of the hydrogen mixture should be considered for containment integrity. However, an applicable discrimination method to activate the igniters does not exist, so that the hydrogen control strategy using the igniters cannot be chosen during a severe accident. Thus, this study focused on suggesting an applicable discrimination method to carry out the strategy of using the igniters. In this study, the specific plant used for this analysis is Ulchin Unit 5 and 6, OPR 1000 plant, in Korea

  5. Design of a hybrid command and control mobile botnet

    CSIR Research Space (South Africa)

    Pieterse, H

    2013-05-01

    Full Text Available and control mobile botnet. The hybrid design explores the efficiency of multiple command and control channels against the following objectives: no single point of failure within the topology, low cost for command dissemination, limited network activities...

  6. Experimental analysis and management issues of a hydrogen fuel cell system for stationary and mobile application

    Energy Technology Data Exchange (ETDEWEB)

    Corbo, Pasquale; Migliardini, Fortunato; Veneri, Ottorino [Istituto Motori of Italian National Research Council, Via Marconi 8, 80125 Napoli (Italy)

    2007-08-15

    A laboratory fuel cell system based on a 20 kW H{sub 2}/air proton exchange membrane stack was designed, realized and characterized with the aim to elucidate specific concerns to be considered for both hydrogen stationary power systems and automotive applications. The overall system characterization permitted the effect of the main operative variables (temperature, pressure and stoichiometric ratio) on stack power and efficiency to be evaluated. Reactant feeding, humidification and cooling problems are discussed, evidencing in particular the roles of air compressor, fuel purge, stack temperature and humidification strategy in system management. The characterization results are analyzed in terms of H{sub 2} consumption and available power, evidencing the energy losses of the individual fuel cell system components. In particular, the data obtained on key components (stack, reactants, heat and water management devices) are used for a critical discussion about their specifications and operation characteristics as demanded by both stationary and mobile applications. (author)

  7. Experimental analysis and management issues of a hydrogen fuel cell system for stationary and mobile application

    International Nuclear Information System (INIS)

    Corbo, Pasquale; Migliardini, Fortunato; Veneri, Ottorino

    2007-01-01

    A laboratory fuel cell system based on a 20 kW H 2 /air proton exchange membrane stack was designed, realized and characterized with the aim to elucidate specific concerns to be considered for both hydrogen stationary power systems and automotive applications. The overall system characterization permitted the effect of the main operative variables (temperature, pressure and stoichiometric ratio) on stack power and efficiency to be evaluated. Reactant feeding, humidification and cooling problems are discussed, evidencing in particular the roles of air compressor, fuel purge, stack temperature and humidification strategy in system management. The characterization results are analyzed in terms of H 2 consumption and available power, evidencing the energy losses of the individual fuel cell system components. In particular, the data obtained on key components (stack, reactants, heat and water management devices) are used for a critical discussion about their specifications and operation characteristics as demanded by both stationary and mobile applications

  8. Self-control and problematic mobile phone use in Chinese college students: the mediating role of mobile phone use patterns

    OpenAIRE

    Jiang, Zhaocai; Zhao, Xiuxin

    2016-01-01

    Background With the popularity of mobile phones, problematic mobile phone use is getting increasing attention in recent years. Although self-control was found to be a critical predictor of problematic mobile phone use, no study has ever explored the association between self-control and mobile phone use patterns as well as the possible pathway how self-control affects problematic mobile phone use. Methods Four hundred sixty-eight college students were randomly selected in this study. Data were...

  9. Controlling the amplification of chirality in hydrogen-bonded assemblies

    NARCIS (Netherlands)

    Mateos timoneda, Miguel; Crego Calama, Mercedes; Reinhoudt, David

    2005-01-01

    The amplification of chirality (a high enantiomeric or diastereomeric excess induced by a small initial amount of chiral bias) on hydrogen-bonded assemblies has been studied using “sergeants-and-soldiers” experiments under thermodynamically controlled conditions. Here it is shown that different

  10. Microbial control of hydrogen sulfide production

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, A.D.; Bhupathiraju, V.K.; Wofford, N.; McInerney, M.J. [Univ. of Oklahoma, Tulsa, OK (United States)] [and others

    1995-12-31

    A sulfide-resistant strain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. The ability of a strain F to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa, natural gas storage facility was also investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F while the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5 mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200 to 460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70 to 110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3,800 {mu}M, and then decreased to about 1,100 {mu}M after 5 weeks. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160 to 330 {mu}M.

  11. Flow-Control Unit For Nitrogen And Hydrogen Gases

    Science.gov (United States)

    Chang, B. J.; Novak, D. W.

    1990-01-01

    Gas-flow-control unit installed and removed as one piece replaces system that included nine separately serviced components. Unit controls and monitors flows of nitrogen and hydrogen gases. Designed for connection via fluid-interface manifold plate, reducing number of mechanical fluid-interface connections from 18 to 1. Unit provides increasing reliability, safety, and ease of maintenance, and for reducing weight, volume, and power consumption.

  12. Resolution of Unresolved Safety Issue A-48, ''Hydrogen control measures and effects of hydrogen burns on safety equipment''

    International Nuclear Information System (INIS)

    Ferrell, C.M.; Soffer, L.

    1989-09-01

    Unresolved Safety Issue (USI) A-48 arose as a result of the large amount of hydrogen generated and burned within containment during the Three Mile Island accident. This issue covers hydrogen control measures for recoverable degraded-core accidents for all boiling-water reactors (BWRs) and those pressurized-water reactors (PWRs) with ice-condenser containments. The Commission and the nuclear industry have sponsored extensive research in this area, which has led to significant revision of the Commission's hydrogen control regulations, given in Title 10, Code of Federal Regulations, Part 50 (10 CFR 50), Section 50.44. BWRs having Mark I and II containments are presently required to operate with inerted containment atmospheres that effectively prevent hydrogen combustion. BWRs with Mark III containments and PWRs with ice-condenser containments are now required to be equipped with hydrogen control systems to protect containment integrity and safety systems inside containment. Industry has chosen to use hydrogen igniter systems to burn hydrogen produced in a controlled fashion to prevent damage. An independent review by a Committee of the National Research Council concluded that, for most accident scenarios, current regulatory requirements make it highly unlikely that hydrogen detonation would be the cause of containment failure. On the basis of the extensive research effort conducted and current regulatory requirements, including their implementation, the staff concludes that no new regulatory guidance on hydrogen control for recoverable degraded-core accidents for these types of plants is necessary and that USI A-48 is resolved

  13. Design of a hybrid command and control mobile botnet: Presentation

    CSIR Research Space (South Africa)

    Pieterse, H

    2013-03-01

    Full Text Available smartphones controlled by a botmaster through a command and control network to serve a malicious purpose. This study presents the design of a hybrid command and control mobile botnet. It describes the propagation vectors, command and control channels...

  14. Controlled delamination of metal films by hydrogen loading

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, Eugen

    2008-11-18

    n this work we quantitatively determine the adhesion energy between metal films and their substrates. Therefore a new controlled buckling technique is established, applying the strong compressive in-plane stress that results in thin films clamped on rigid substrates during hydrogen loading. When the elastic energy stored in the H-loaded thin film exceeds the adhesion energy between film and substrate, delamination occurs. At the onset of delamination, a critical hydrogen concentration, a critical stress value and a critical bending of the substrate are present, which are quantitative measures for the adhesion energy and permit its calculation. As the critical values are determined at the onset of delamination, plastic deformation is negligible, which denies the quantitative determination of adhesion energies in conventional test setups. In multilayer-systems, adhesion energies between substrates and films that hardly absorb hydrogen can be measured by the controlled buckling technique, when the films of interest are coated with hydrogen absorbing films (active layer). The measurements are performed easily and can be repeated under the same test conditions, while variables such as the thickness of the coating materials or the boundary surface structure can be varied and optimized. In this work the adhesion energies of different materials on polycarbonate and niobium on sapphire are investigated. (orig.)

  15. Flexible and Safe Control of Mobile Surface Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary innovation of this work is a novel approach for flexible and safe control of highly capable mobile surface systems, such as long-duration science rovers,...

  16. Integrated Control Strategies Supporting Autonomous Functionalities in Mobile Robots

    National Research Council Canada - National Science Library

    Sights, B; Everett, H. R; Pacis, E. B; Kogut, G; Thompson, M

    2005-01-01

    High-level intelligence allows a mobile robot to create and interpret complex world models, but without a precise control system, the accuracy of the world model and the robot's ability to interact...

  17. Flexible and Safe Control of Mobile Surface Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary innovation of this work is a novel Petri net based approach for safe and flexible control of highly capable mobile surface systems, such as long-duration...

  18. Surface Magnetism of Cobalt Nanoislands Controlled by Atomic Hydrogen.

    Science.gov (United States)

    Park, Jewook; Park, Changwon; Yoon, Mina; Li, An-Ping

    2017-01-11

    Controlling the spin states of the surface and interface is key to spintronic applications of magnetic materials. Here, we report the evolution of surface magnetism of Co nanoislands on Cu(111) upon hydrogen adsorption and desorption with the hope of realizing reversible control of spin-dependent tunneling. Spin-polarized scanning tunneling microscopy reveals three types of hydrogen-induced surface superstructures, 1H-(2 × 2), 2H-(2 × 2), and 6H-(3 × 3), with increasing H coverage. The prominent magnetic surface states of Co, while being preserved at low H coverage, become suppressed as the H coverage level increases, which can then be recovered by H desorption. First-principles calculations reveal the origin of the observed magnetic surface states by capturing the asymmetry between the spin-polarized surface states and identify the role of hydrogen in controlling the magnetic states. Our study offers new insights into the chemical control of magnetism in low-dimensional systems.

  19. Hydrogen and Nitrogen Control in Ladle and Casting Operations

    Energy Technology Data Exchange (ETDEWEB)

    Richard J. Fruehan; Siddhartha Misra

    2005-01-15

    In recent years there has been an increasing demand to reduce and control the amount of dissolved gases in steel. Hydrogen and nitrogen are two of the most important gases which when dissolved in liquid steel affect its properties significantly. Several steelmaking additions have been investigated in this research for their effect on the hydrogen and nitrogen content of steels. It has been established that calcium hydroxide (hydrated lime) acts as a source of hydrogen. Carburizers, such as metallurgical coke, were found to result in no hydrogen pickup when added to liquid steel. Addition of petroleum coke, on the other hand, increased the hydrogen content of liquid steel. Ferroalloy such as medium carbon ferromanganese when added to the liquid iron was found to increase its nitrogen content, the increase being proportional to the amount of ferroalloy added. Similarly, addition of pitch coke, which had a significant nitrogen impurity, increased the nitrogen content of liquid iron. A mathematical model was developed to quantify the absorption of nitrogen and hydrogen from the air bubbles entrained during tapping of liquid steel. During the bottom stirring of liquid metal in a ladle, the inert gas escaping from the top displaces the slag layer and often forms an open eye. The absorption of atmospheric nitrogen through the spout eye was estimated for different slag thickness and gas flow rate. The ultimate goal of this research was to develop a comprehensive set of equations which could predict the nitrogen and hydrogen pickup from their various sources. Estimates of hydrogen and nitrogen pickup during the steel transfer operations such as tapping and ladle stirring and the predicted pickup from steelmaking additions were integrated into empirical equations. The comprehensive model is designed to predict the gas pickup under varying operating conditions such as the metal oxygen and sulfur content, the total tapping or stirring time, the stirring gas flow rate and the

  20. Navigation Algorithm Using Fuzzy Control Method in Mobile Robotics

    Directory of Open Access Journals (Sweden)

    Cviklovič Vladimír

    2016-03-01

    Full Text Available The issue of navigation methods is being continuously developed globally. The aim of this article is to test the fuzzy control algorithm for track finding in mobile robotics. The concept of an autonomous mobile robot EN20 has been designed to test its behaviour. The odometry navigation method was used. The benefits of fuzzy control are in the evidence of mobile robot’s behaviour. These benefits are obtained when more physical variables on the base of more input variables are controlled at the same time. In our case, there are two input variables - heading angle and distance, and two output variables - the angular velocity of the left and right wheel. The autonomous mobile robot is moving with human logic.

  1. Bake-Out Mobile Controls for Large Vacuum Systems

    CERN Document Server

    Blanchard, S; Gomes, P; Pereira, H; Kopylov, L; Merker, S; Mikheev, M

    2014-01-01

    Large vacuum systems at CERN (Large Hadron Collider - LHC, Low Energy Ion Rings - LEIR...) require bake-out to achieve ultra-high vacuum specifications. The bake-out cycle is used to decrease the outgassing rate of the vacuum vessel and to activate the Non-Evaporable Getter (NEG) thin film. Bake-out control is a Proportional-Integral-Derivative (PID) regulation with complex recipes, interlocks and troubleshooting management and remote control. It is based on mobile Programmable Logic Controller (PLC) cabinets, fieldbus network and Supervisory Control and Data Acquisition (SCADA) application. The CERN vacuum installations include more than 7 km of baked vessels; using mobile cabinets reduces considerably the cost of the control system. The cabinets are installed close to the vacuum vessels during the time of the bake-out cycle. Mobile cabinets can be used in any of the CERN vacuum facilities. Remote control is provided through a fieldbus network and a SCADA application

  2. Rethinking the economics of capital mobility and capital controls

    Directory of Open Access Journals (Sweden)

    Thomas I. Palley

    2009-09-01

    Full Text Available This paper reexamines the issue of international financial capital mobility, which is today's economic orthodoxy. Discussion is often framed in terms of the impossible trinity. That framing distorts discussion by representing capital mobility as having equal significance with sovereign monetary policy and control over exchange rates. It also distorts discussion by ignoring possibilities for coordinated monetary policy and exchange rates, and for managed capital flows. The case for capital mobility rests on neo-classical economic efficiency arguments and neo-liberal political arguments. The case against capital mobility is based on Keynesian macroeconomic inefficiency arguments, neo-Walrasian market failure arguments, and neo-Marxian arguments regarding distortion of the social structure of accumulation. Close examination shows the case for capital mobility to be extremely flimsy, pointing to the ideological dimension behind today's policy orthodoxy.

  3. Moving protons with pendant amines: proton mobility in a nickel catalyst for oxidation of hydrogen.

    Science.gov (United States)

    O'Hagan, Molly; Shaw, Wendy J; Raugei, Simone; Chen, Shentan; Yang, Jenny Y; Kilgore, Uriah J; DuBois, Daniel L; Bullock, R Morris

    2011-09-14

    Proton transport is ubiquitous in chemical and biological processes, including the reduction of dioxygen to water, the reduction of CO(2) to formate, and the production/oxidation of hydrogen. In this work we describe intramolecular proton transfer between Ni and positioned pendant amines for the hydrogen oxidation electrocatalyst [Ni(P(Cy)(2)N(Bn)(2)H)(2)](2+) (P(Cy)(2)N(Bn)(2) = 1,5-dibenzyl-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane). Rate constants are determined by variable-temperature one-dimensional NMR techniques and two-dimensional EXSY experiments. Computational studies provide insight into the details of the proton movement and energetics of these complexes. Intramolecular proton exchange processes are observed for two of the three experimentally observable isomers of the doubly protonated Ni(0) complex, [Ni(P(Cy)(2)N(Bn)(2)H)(2)](2+), which have N-H bonds but no Ni-H bonds. For these two isomers, with pendant amines positioned endo to the Ni, the rate constants for proton exchange range from 10(4) to 10(5) s(-1) at 25 °C, depending on isomer and solvent. No exchange is observed for protons on pendant amines positioned exo to the Ni. Analysis of the exchange as a function of temperature provides a barrier for proton exchange of ΔG(‡) = 11-12 kcal/mol for both isomers, with little dependence on solvent. Density functional theory calculations and molecular dynamics simulations support the experimental observations, suggesting metal-mediated intramolecular proton transfers between nitrogen atoms, with chair-to-boat isomerizations as the rate-limiting steps. Because of the fast rate of proton movement, this catalyst may be considered a metal center surrounded by a cloud of exchanging protons. The high intramolecular proton mobility provides information directly pertinent to the ability of pendant amines to accelerate proton transfers during catalysis of hydrogen oxidation. These results may also have broader implications for proton movement in

  4. A mobile console for local access to accelerator control systems.

    CERN Multimedia

    1981-01-01

    Microprocessors were installed as auxiliary crate controllers (ACCs) in the CAMAC interface of control systems for various accelerators. The same ACC was also at the hearth of a stand-alone system in the form of a mobile console. This was also used for local access to the control systems for tests and development work (Annual Report 1981, p. 80, Fig. 10).

  5. Car-Like Mobile Robot Oriented Positioning by Fuzzy Controllers

    Directory of Open Access Journals (Sweden)

    Noureddine Ouadah

    2008-11-01

    Full Text Available In this paper, fuzzy logic controllers (FLC are used to implement an efficient and accurate positioning of an autonomous car-like mobile robot, respecting final orientation. To accomplish this task, called "Oriented Positioning", two FLC have been developed: robot positioning controller (RPC and robot following controller (RFC. Computer simulation results illustrate the effectiveness of the proposed technique. Finally, real-time experiments have been made on an autonomous car-like mobile robot called "Robucar", developed to perform people transportation. Obtained results from experiments demonstrate the effectiveness of the proposed control strategy.

  6. Car-Like Mobile Robot Oriented Positioning by Fuzzy Controllers

    Directory of Open Access Journals (Sweden)

    Noureddine Ouadah

    2008-09-01

    Full Text Available In this paper, fuzzy logic controllers (FLC are used to implement an efficient and accurate positioning of an autonomous car-like mobile robot, respecting final orientation. To accomplish this task, called “Oriented Positioning”, two FLC have been developed: robot positioning controller (RPC and robot following controller (RFC. Computer simulation results illustrate the effectiveness of the proposed technique. Finally, real-time experiments have been made on an autonomous car-like mobile robot called “Robucar”, developed to perform people transportation. Obtained results from experiments demonstrate the effectiveness of the proposed control strategy.

  7. Exception detection and handling in mission control for mobile robots

    DEFF Research Database (Denmark)

    Andersen, Thomas Timm; Andersen, Nils Axel; Ravn, Ole

    2013-01-01

    This paper introduces a method for robust, rule-based mission control for mobile robots in a modular framework. Due to the modularity of the framework, it is possible to use both hierarchical control and reactive behavior seamlessly to find solutions to both planned and unplanned event in the mis......This paper introduces a method for robust, rule-based mission control for mobile robots in a modular framework. Due to the modularity of the framework, it is possible to use both hierarchical control and reactive behavior seamlessly to find solutions to both planned and unplanned event...

  8. Connection adaption for control of networked mobile chaotic agents.

    Science.gov (United States)

    Zhou, Jie; Zou, Yong; Guan, Shuguang; Liu, Zonghua; Xiao, Gaoxi; Boccaletti, S

    2017-11-22

    In this paper, we propose a strategy for the control of mobile chaotic oscillators by adaptively rewiring connections between nearby agents with local information. In contrast to the dominant adaptive control schemes where coupling strength is adjusted continuously according to the states of the oscillators, our method does not request adaption of coupling strength. As the resulting interaction structure generated by this proposed strategy is strongly related to unidirectional chains, by investigating synchronization property of unidirectional chains, we reveal that there exists a certain coupling range in which the agents could be controlled regardless of the length of the chain. This feature enables the adaptive strategy to control the mobile oscillators regardless of their moving speed. Compared with existing adaptive control strategies for networked mobile agents, our proposed strategy is simpler for implementation where the resulting interaction networks are kept unweighted at all time.

  9. Controlled Delegation Protocol in Mobile RFID Networks

    Directory of Open Access Journals (Sweden)

    Yang MingHour

    2010-01-01

    Full Text Available To achieve off-line delegation for mobile readers, we propose a delegation protocol for mobile RFID allowing its readers access to specific tags through back-end server. That is to say, reader-tag mutual authentication can be performed without readers being connected to back-end server. Readers are also allowed off-line access to tags' data. Compared with other delegation protocols, our scheme uniquely enables back-end server to limit each reader's reading times during delegation. Even in a multireader situation, our protocol can limit reading times and reading time periods for each of them and therefore makes back-end server's delegation more flexible. Besides, our protocol can prevent authorized readers from transferring their authority to the unauthorized, declining invalid access to tags. Our scheme is proved viable and secure with GNY logic; it is against certain security threats, such as replay attacks, denial of service (DoS attacks, Man-in-the-Middle attacks, counterfeit tags, and breaches of location and data privacy. Also, the performance analysis of our protocol proves that current tags can afford the computation load required in this scheme.

  10. Ion mobility spectrometry-hydrogen deuterium exchange mass spectrometry of anions: part 1. Peptides to proteins.

    Science.gov (United States)

    Donohoe, Gregory C; Khakinejad, Mahdiar; Valentine, Stephen J

    2015-04-01

    Ion mobility spectrometry (IMS) coupled with hydrogen deuterium exchange (HDX)-mass spectrometry (MS) has been used to study the conformations of negatively-charged peptide and protein ions. Results are presented for ion conformers of angiotensin 1, a synthetic peptide (SP), bovine insulin, ubiquitin, and equine cytochrome c. In general, the SP ion conformers demonstrate a greater level of HDX efficiency as a greater proportion of the sites undergo HDX. Additionally, these ions exhibit the fastest rates of exchange. Comparatively, the angiotensin 1 ions exhibit a lower rate of exchange and HDX level presumably because of decreased accessibility of exchange sites by charge sites. The latter are likely confined to the peptide termini. Insulin ions show dramatically reduced HDX levels and exchange rates, which can be attributed to decreased conformational flexibility resulting from the disulfide bonds. For the larger ubiquitin and protein ions, increased HDX is observed for larger ions of higher charge state. For ubiquitin, a conformational transition from compact to more elongated species (from lower to higher charge states) is reflected by an increase in HDX levels. These results can be explained by a combination of interior site protection by compact conformers as well as decreased access by charge sites. The elongated cytochrome c ions provide the largest HDX levels where higher values correlate with charge state. These results are consistent with increased exchange site accessibility by additional charge sites. The data from these enhanced IMS-HDX experiments are described in terms of charge site location, conformer rigidity, and interior site protection.

  11. Control of malodorous hydrogen sulfide compounds using microbial fuel cell.

    Science.gov (United States)

    Eaktasang, Numfon; Min, Hyeong-Sik; Kang, Christina; Kim, Han S

    2013-10-01

    In this study, a microbial fuel cell (MFC) was used to control malodorous hydrogen sulfide compounds generated from domestic wastewaters. The electricity production demonstrated a distinct pattern of a two-step increase during 170 h of system run: the first maximum current density was 118.6 ± 7.2 mA m⁻² followed by a rebound of current density increase, reaching the second maximum of 176.8 ± 9.4 mA m⁻². The behaviors of the redox potential and the sulfate level in the anode compartment indicated that the microbial production of hydrogen sulfide compounds was suppressed in the first stage, and the hydrogen sulfide compounds generated from the system were removed effectively as a result of their electrochemical oxidation, which contributed to the additional electricity production in the second stage. This was also directly supported by sulfur deposits formed on the anode surface, which was confirmed by analyses on those solids using a scanning electron microscope equipped with energy dispersive X-ray spectroscopy as well as an elemental analyzer. To this end, the overall reduction efficiencies for HS⁻ and H₂S(g) were as high as 67.5 and 96.4 %, respectively. The correlations among current density, redox potential, and sulfate level supported the idea that the electricity signal generated in the MFC can be utilized as a potential indicator of malodor control for the domestic wastewater system.

  12. Controlled area for mobile medical X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, B; Taschner, P; Koenig, W [Staatliches Amt fuer Atomsicherheit und Strahlenschutz, Berlin (German Democratic Republic); Fuehr, K P; Kucharz, R [Rostock Univ. (German Democratic Republic). Radiologische Klinik

    1976-10-01

    On the basis of dose rate measurements the radiation protection situation during operation of mobile X-ray machines is described. According to these results, the controlled area has been definitely fixed by the National Board of Nuclear Safety and Radiation Protection with respect to the following fields of application: stomatology, mobile radiography of patients confined to bed as well as performing radiological examinations in the operating theatre.

  13. FUZZY CONTROLLER FOR THE CONTROL OF THE MOBILE PLATFORM OF THE CORBYS ROBOTIC GAIT REHABILITATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Maria Kyrarini

    2014-12-01

    Full Text Available In this paper, an inverse kinematics based control algorithm for the joystick control of the mobile platform of the novel mobile robot-assisted gait rehabilitation system CORBYS is presented. The mobile platform has four independently steered and driven wheels. Given the linear and angular velocities of the mobile platform, the inverse kinematics algorithm gives as its output the steering angle and the driving angular velocity of each of the four wheels. The paper is focused on the steering control of the platform for which a fuzzy logic controller is developed and implemented. The experimental results of the real-world steering of the platform are presented in the paper.

  14. Dynamic Modelling and Adaptive Traction Control for Mobile Robots

    Directory of Open Access Journals (Sweden)

    A. Albagul

    2004-09-01

    Full Text Available Mobile robots have received a great deal of research in recent years. A significant amount of research has been published in many aspects related to mobile robots. Most of the research is devoted to design and develop some control techniques for robot motion and path planning. A large number of researchers have used kinematic models to develop motion control strategy for mobile robots. Their argument and assumption that these models are valid if the robot has low speed, low acceleration and light load. However, dynamic modelling of mobile robots is very important as they are designed to travel at higher speed and perform heavy duty work. This paper presents and discusses a new approach to develop a dynamic model and control strategy for wheeled mobile robot which I modelled as a rigid body that roles on two wheels and a castor. The motion control strategy consists of two levels. The first level is dealing with the dynamic of the system and denoted as ‘Low’ level controller. The second level is developed to take care of path planning and trajectory generation.

  15. Learning feedforward controller for a mobile robot vehicle

    NARCIS (Netherlands)

    Starrenburg, J.G.; Starrenburg, J.G.; van Luenen, W.T.C.; van Luenen, W.T.C.; Oelen, W.; Oelen, W.; van Amerongen, J.

    1996-01-01

    This paper describes the design and realisation of an on-line learning posetracking controller for a three-wheeled mobile robot vehicle. The controller consists of two components. The first is a constant-gain feedback component, designed on the basis of a second-order model. The second is a learning

  16. A framework for evaluating hydrogen control and management

    International Nuclear Information System (INIS)

    Lee, Seung Dong; Suh, Kune Yul; Jae, Moosung

    2003-01-01

    The present paper presents a new framework for assessing accident management strategies using decision trees. The containment event tree (CET) model considers characteristics associated with the implementation of each strategy. It is constructed and quantified using data obtained from NUREG-1150, other probabilistic risk assessments, and the MAAP4 calculations. The proposed framework for evaluating hydrogen control strategies is based on the concept of a measure using a risk triplet. Ulchin units of nuclear power plants 3 and 4 are used as the reference plant. On the basis of best-estimate assessment, it is shown that it is beneficial to execute hydrogen igniters rather than to do nothing with respect to expected value of hydrogen concentration in the containment during an accident. The proposed approach is shown to be flexible in that it can be applied to various accident management strategies based on the timing of mitigation. The advantage of using the CET for assessing an accident management strategy lies with its capability for modeling both the positive and negative aspects associated with progression of the accident, which may in turn affect the containment failure mode

  17. Differential Mobility Spectrometry-Hydrogen Deuterium Exchange (DMS-HDX) as a Probe of Protein Conformation in Solution.

    Science.gov (United States)

    Zhu, Shaolong; Campbell, J Larry; Chernushevich, Igor; Le Blanc, J C Yves; Wilson, Derek J

    2016-06-01

    Differential mobility spectrometry (DMS) is an ion mobility technique that has been adopted chiefly as a pre-filter for small- to medium-sized analytes (DMS-field asymmetric waveform ion mobility spectroscopy (FAIMS)-the application of DMS to intact biomacromolecules remains largely unexplored. In this work, we employ DMS combined with gas-phase hydrogen deuterium exchange (DMS-HDX) to probe the gas-phase conformations generated from proteins that were initially folded, partially-folded, and unfolded in solution. Our findings indicate that proteins with distinct structural features in solution exhibit unique deuterium uptake profiles as function of their optimal transmission through the DMS. Ultimately we propose that DMS-HDX can, if properly implemented, provide rapid measurements of liquid-phase protein structural stability that could be of use in biopharmaceuticals development. Graphical Abstract ᅟ.

  18. Hydrogen: the great debate. 'Power to Gas - how to cope with the challenge of electricity storage?; Hydrogen in energy transition: which challenges to be faced?; Hydrogen, essential today, indispensable tomorrow; Electrolytic hydrogen, a solution for energy transition?; Development of high power electrolysis systems: need and approach; Hydrogen as energy vector, Potential and stakes: a perspective; The Toyota Fuel Cell System: a new era for the automotive industry; Three key factors: production, applications to mobility, and public acceptance; Hydrogen, benevolent fairy or tempting demon

    International Nuclear Information System (INIS)

    Hauet, Jean-Pierre; Boucly, Philippe; Beeker, Etienne; Mauberger, Pascal; Quint, Aliette; Pierre, Helene; Lucchese, Paul; Bouillon-Delporte, Valerie; Chauvet, Bertrand; Brisse, Annabelle; Gautier, Ludmila; Hercberg, Sylvain; De Volder, Marc; Gruson, Jean-Francois; Marion, Pierre; Grellier, Sebastien; Devezeaux, Jean-Guy; Mansilla, Christine; Le Net, Elisabeth; Le Duigou, Alain; Maire, Jacques

    2015-01-01

    This publication proposes a set of contributions which address various issues related to the development of the use of hydrogen as an energy source. More precisely, these contributions discuss how to face the challenge of electricity storage by using the Power-to-Gas technology, the challenges to be faced regarding the role of hydrogen in energy transition, the essential current role of hydrogen and its indispensable role for tomorrow, the possible role of electrolytic hydrogen as a solution for energy transition, the need of and the approach to a development of high power electrolysis systems, the potential and stakes of hydrogen as an energy vector, the Toyota fuel cell system as a sign for new era for automotive industry, the three main factors (production, applications to mobility, and public acceptance) for the use of hydrogen in energy transition, and the role of hydrogen perceived either as a benevolent fairy or a tempting demon

  19. Autonomous Visual Control of a Mobile Robot

    National Research Council Canada - National Science Library

    Blackburn, Michael

    1994-01-01

    .... We propose that efficient and extensible solutions to the target acquisition and maintenance problem may be found when the machine sensor-effector control algorithms emulate the mechanisms employed...

  20. Intelligent control and cooperation for mobile robots

    Science.gov (United States)

    Stingu, Petru Emanuel

    The topic discussed in this work addresses the current research being conducted at the Automation & Robotics Research Institute in the areas of UAV quadrotor control and heterogenous multi-vehicle cooperation. Autonomy can be successfully achieved by a robot under the following conditions: the robot has to be able to acquire knowledge about the environment and itself, and it also has to be able to reason under uncertainty. The control system must react quickly to immediate challenges, but also has to slowly adapt and improve based on accumulated knowledge. The major contribution of this work is the transfer of the ADP algorithms from the purely theoretical environment to the complex real-world robotic platforms that work in real-time and in uncontrolled environments. Many solutions are adopted from those present in nature because they have been proven to be close to optimal in very different settings. For the control of a single platform, reinforcement learning algorithms are used to design suboptimal controllers for a class of complex systems that can be conceptually split in local loops with simpler dynamics and relatively weak coupling to the rest of the system. Optimality is enforced by having a global critic but the curse of dimensionality is avoided by using local actors and intelligent pre-processing of the information used for learning the optimal controllers. The system model is used for constructing the structure of the control system, but on top of that the adaptive neural networks that form the actors use the knowledge acquired during normal operation to get closer to optimal control. In real-world experiments, efficient learning is a strong requirement for success. This is accomplished by using an approximation of the system model to focus the learning for equivalent configurations of the state space. Due to the availability of only local data for training, neural networks with local activation functions are implemented. For the control of a formation

  1. Solar-hydrogen energy as an alternative energy source for mobile robots and the new-age car

    International Nuclear Information System (INIS)

    Sulaiman, A; Inambao, F; Bright, G

    2014-01-01

    The disastrous effects of climate change as witnessed in recent violent storms, and the stark reality that fossil fuels are not going to last forever, is certain to create renewed demands for alternative energy sources. One such alternative source, namely solar energy, although unreliable because of its dependence on available sunlight, can nevertheless be utilised to generate a secondary source of energy, namely hydrogen, which can be stored and thereby provide a constant and reliable source of energy. The only draw-back with hydrogen, though, is finding efficient means for its storage. This study demonstrates how this problem can be overcome by the use of metal hydrides which offers a very compact and safe way of storing hydrogen. It also provides a case study of how solar and hydrogen energy can be combined in an energy system to provide an efficient source of energy that can be applied for modern technologies such as a mobile robot. Hydrogen energy holds out the most promise amongst the various alternative energy sources, so much so that it is proving to be the energy source of choice for automobile manufacturers in their quest for alternative fuels to power their cars of the future

  2. Solar-hydrogen energy as an alternative energy source for mobile robots and the new-age car

    Science.gov (United States)

    Sulaiman, A.; Inambao, F.; Bright, G.

    2014-07-01

    The disastrous effects of climate change as witnessed in recent violent storms, and the stark reality that fossil fuels are not going to last forever, is certain to create renewed demands for alternative energy sources. One such alternative source, namely solar energy, although unreliable because of its dependence on available sunlight, can nevertheless be utilised to generate a secondary source of energy, namely hydrogen, which can be stored and thereby provide a constant and reliable source of energy. The only draw-back with hydrogen, though, is finding efficient means for its storage. This study demonstrates how this problem can be overcome by the use of metal hydrides which offers a very compact and safe way of storing hydrogen. It also provides a case study of how solar and hydrogen energy can be combined in an energy system to provide an efficient source of energy that can be applied for modern technologies such as a mobile robot. Hydrogen energy holds out the most promise amongst the various alternative energy sources, so much so that it is proving to be the energy source of choice for automobile manufacturers in their quest for alternative fuels to power their cars of the future.

  3. Wireless Sensor/Actuator Network Design for Mobile Control Applications

    Directory of Open Access Journals (Sweden)

    Youxian Sung

    2007-10-01

    Full Text Available Wireless sensor/actuator networks (WSANs are emerging as a new generationof sensor networks. Serving as the backbone of control applications, WSANs will enablean unprecedented degree of distributed and mobile control. However, the unreliability ofwireless communications and the real-time requirements of control applications raise greatchallenges for WSAN design. With emphasis on the reliability issue, this paper presents anapplication-level design methodology for WSANs in mobile control applications. Thesolution is generic in that it is independent of the underlying platforms, environment,control system models, and controller design. To capture the link quality characteristics interms of packet loss rate, experiments are conducted on a real WSAN system. From theexperimental observations, a simple yet efficient method is proposed to deal withunpredictable packet loss on actuator nodes. Trace-based simulations give promisingresults, which demonstrate the effectiveness of the proposed approach.

  4. DEVELOPMENT OF TRAJECTORY CONTROL SYSTEM FOR THE OMNIDIRECTIONAL MOBILE ROBOT

    Directory of Open Access Journals (Sweden)

    Y. A. Kapitanyuk

    2014-03-01

    Full Text Available The article deals with a trajectory control system development for the omnidirectional mobile robot. This kind of robots gives the possibility to control separately each degree of freedom due to special design of the wheels, which greatly facilitates the solution of the spatial control tasks and makes it possible to focus directly on the development of algorithms. Control law synthesis is based on kinematic model of a solid body on a plane. Desired trajectory is defined as a smooth implicit function in a fixed coordinate system. Procedure of control design is represented by using a differential-geometric method of nonlinear transformation of the original model to the task-oriented form, which describes the longitudinal motion along a trajectory and orthogonal deviation. Proportional controllers with direct compensation of nonlinear terms are synthesized for the transformed model. Main results are represented by nonlinear control algorithms and experimental data. Practical implementation of considered control laws for the Robotino mobile robot by Festo Didactics Company is done for illustration of this approach workability. The cases of straight line motion and movement along a circle are represented as desirable trajectories, and the majority of practical tasks for mobile robots control can be implemented by their combination.

  5. Fuzzy Behaviors for Control of Mobile Robots

    Directory of Open Access Journals (Sweden)

    Saleh Zein-Sabatto

    2003-02-01

    Full Text Available In this research work, an RWI B-14 robot has been used as the development platform to embody some basic behaviors that can be combined to build more complex robotics behaviors. Emergency, avoid-obstacle, left wall- following, right wall-following, and move-to-point behaviors have been designed and embodied as basic robot behaviors. The basic behaviors developed in this research are designed based on fuzzy control technique and are integrated and coordinated to from complex robotics system. More behaviors can be added into the system as needed. A robot task can be defined by the user and executed by the intelligent robot control system. Testing results showed that fuzzy behaviors made the robot move intelligently and adapt to changes in its environment.

  6. Hydrogen.

    Science.gov (United States)

    Bockris, John O'M

    2011-11-30

    The idea of a "Hydrogen Economy" is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO₂ in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H₂ from the electrolyzer. Methanol made with CO₂ from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan). Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs) by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  7. Mobile Interfaces for Building Control Surveyors

    OpenAIRE

    Chmielewski , Jacek; Walczak , Krzysztof; Wiza , Wojciech

    2010-01-01

    International audience; The problem of integrating heterogeneous back-end platforms used in public administration has been widely addressed in a number of research and development projects. In such a complex and heterogeneous environment, application of the SOA paradigm can be particularly beneficial. However, in some application domains - such as the Building Control Administration - there is an additional requirement: integration of heterogeneous front-end platforms - including access throu...

  8. Formation of polyhedral ceria nanoparticles with enhanced catalytic CO oxidation activity in thermal plasma via a hydrogen mediated shape control mechanism

    International Nuclear Information System (INIS)

    Zheng Jie; Zhang Yaohua; Song Xubo; Li Xingguo

    2011-01-01

    Ceria nanoparticles with well defined facets are prepared in argon–hydrogen thermal plasma followed by controlled oxidation. With increasing hydrogen fraction in the plasma, a clear sphere-to-polyhedron shape transition is observed. The heat released during the hydrogenation of cerium, which significantly enhances the species mobility on the surface, favors the growth of well defined facets. The polyhedron ceria nanoparticles, though lower in specific surface area, exhibit superior catalytic performance for CO oxidation over the round particles, which is attributed to the higher density of the reactive {200} and {220} facets on the surface. The hydrogen mediated shape control mechanism provides new insights into the shape control of nanoparticles during thermal plasma processing.

  9. Tracking control of mobile robots: a case study in backstepping

    NARCIS (Netherlands)

    Jiang, Zhong-Ping; Nijmeijer, Henk

    1997-01-01

    A tracking control methodology via time-varying state feedback based on the backstepping technique is proposed for both a kinematic and simplified dynamic model of a two-degrees-of-freedom mobile robot. We first address the local tracking problem where initial tracking errors are sufficiently small.

  10. Remote-controlled vision-guided mobile robot system

    Science.gov (United States)

    Ande, Raymond; Samu, Tayib; Hall, Ernest L.

    1997-09-01

    Automated guided vehicles (AGVs) have many potential applications in manufacturing, medicine, space and defense. The purpose of this paper is to describe exploratory research on the design of the remote controlled emergency stop and vision systems for an autonomous mobile robot. The remote control provides human supervision and emergency stop capabilities for the autonomous vehicle. The vision guidance provides automatic operation. A mobile robot test-bed has been constructed using a golf cart base. The mobile robot (Bearcat) was built for the Association for Unmanned Vehicle Systems (AUVS) 1997 competition. The mobile robot has full speed control with guidance provided by a vision system and an obstacle avoidance system using ultrasonic sensors systems. Vision guidance is accomplished using two CCD cameras with zoom lenses. The vision data is processed by a high speed tracking device, communicating with the computer the X, Y coordinates of blobs along the lane markers. The system also has three emergency stop switches and a remote controlled emergency stop switch that can disable the traction motor and set the brake. Testing of these systems has been done in the lab as well as on an outside test track with positive results that show that at five mph the vehicle can follow a line and at the same time avoid obstacles.

  11. RoCoMAR: Robots’ Controllable Mobility Aided Routing and Relay Architecture for Mobile Sensor Networks

    Directory of Open Access Journals (Sweden)

    Seokhoon Yoon

    2013-07-01

    Full Text Available In a practical deployment, mobile sensor network (MSN suffers from a low performance due to high node mobility, time-varying wireless channel properties, and obstacles between communicating nodes. In order to tackle the problem of low network performance and provide a desired end-to-end data transfer quality, in this paper we propose a novel ad hoc routing and relaying architecture, namely RoCoMAR (Robots’ Controllable Mobility Aided Routing that uses robotic nodes’ controllable mobility. RoCoMAR repeatedly performs link reinforcement process with the objective of maximizing the network throughput, in which the link with the lowest quality on the path is identified and replaced with high quality links by placing a robotic node as a relay at an optimal position. The robotic node resigns as a relay if the objective is achieved or no more gain can be obtained with a new relay. Once placed as a relay, the robotic node performs adaptive link maintenance by adjusting its position according to the movements of regular nodes. The simulation results show that RoCoMAR outperforms existing ad hoc routing protocols for MSN in terms of network throughput and end-to-end delay.

  12. RoCoMAR: Robots' Controllable Mobility Aided Routing and Relay Architecture for Mobile Sensor Networks

    Science.gov (United States)

    Van Le, Duc; Oh, Hoon; Yoon, Seokhoon

    2013-01-01

    In a practical deployment, mobile sensor network (MSN) suffers from a low performance due to high node mobility, time-varying wireless channel properties, and obstacles between communicating nodes. In order to tackle the problem of low network performance and provide a desired end-to-end data transfer quality, in this paper we propose a novel ad hoc routing and relaying architecture, namely RoCoMAR (Robots' Controllable Mobility Aided Routing) that uses robotic nodes' controllable mobility. RoCoMAR repeatedly performs link reinforcement process with the objective of maximizing the network throughput, in which the link with the lowest quality on the path is identified and replaced with high quality links by placing a robotic node as a relay at an optimal position. The robotic node resigns as a relay if the objective is achieved or no more gain can be obtained with a new relay. Once placed as a relay, the robotic node performs adaptive link maintenance by adjusting its position according to the movements of regular nodes. The simulation results show that RoCoMAR outperforms existing ad hoc routing protocols for MSN in terms of network throughput and end-to-end delay. PMID:23881134

  13. Electrochemical mass-flow control of hydrogen using a fullerene-based proton conductor

    International Nuclear Information System (INIS)

    Maruyama, Ryuichiro

    2002-01-01

    A membrane electrode assembly (MEA) was fabricated using proton conductive hydrogensulfated fullerenol (C 60 (OSO 3 H) n (OH) n ). Rate-controlled mass flow of hydrogen was performed by applying voltage to both electrodes of the MEA without humidification. The amount of the electrochemically transported hydrogen through the MEA increased as the applied current increased, obeying Faraday's law. Residual gas analysis of the transported hydrogen showed that the transported hydrogen contains trace amounts of water less than 1%

  14. Control of microbially generated hydrogen sulfide in produced waters

    Energy Technology Data Exchange (ETDEWEB)

    Burger, E.D.; Vance, I.; Gammack, G.F.; Duncan, S.E.

    1995-12-31

    Production of hydrogen sulfide in produced waters due to the activity of sulfate-reducing bacteria (SRB) is a potentially serious problem. The hydrogen sulfide is not only a safety and environmental concern, it also contributes to corrosion, solids formation, a reduction in produced oil and gas values, and limitations on water discharge. Waters produced from seawater-flooded reservoirs typically contain all of the nutrients required to support SRB metabolism. Surface processing facilities provide a favorable environment in which SRB flourish, converting water-borne nutrients into biomass and H{sub 2}S. This paper will present results from a field trial in which a new technology for the biochemical control of SRB metabolism was successfully applied. A slip stream of water downstream of separators on a produced water handling facility was routed through a bioreactor in a side-steam device where microbial growth was allowed to develop fully. This slip stream was then treated with slug doses of two forms of a proprietary, nonbiocidal metabolic modifier. Results indicated that H{sub 2}S production was halted almost immediately and that the residual effect of the treatment lasted for well over one week.

  15. Hydrogen

    Directory of Open Access Journals (Sweden)

    John O’M. Bockris

    2011-11-01

    Full Text Available The idea of a “Hydrogen Economy” is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO2 in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H2 from the electrolyzer. Methanol made with CO2 from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan. Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  16. An iterative learning controller for nonholonomic mobile robots

    International Nuclear Information System (INIS)

    Oriolo, G.; Panzieri, S.; Ulivi, G.

    1998-01-01

    The authors present an iterative learning controller that applies to nonholonomic mobile robots, as well as other systems that can be put in chained form. The learning algorithm exploits the fact that chained-form. The learning algorithm exploits the fact that chained-form systems are linear under piecewise-constant inputs. The proposed control scheme requires the execution of a small number of experiments to drive the system to the desired state in finite time, with nice convergence and robustness properties with respect to modeling inaccuracies as well as disturbances. To avoid the necessity of exactly reinitializing the system at each iteration, the basic method is modified so as to obtain a cyclic controller, by which the system is cyclically steered through an arbitrary sequence of states. As a case study, a carlike mobile robot is considered. Both simulation and experimental results are reported to show the performance of the method

  17. Fuzzy Logic Supervised Teleoperation Control for Mobile Robot

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The supervised teleoperation control is presented for a mobile robot to implement the tasks by using fuzzy logic. The teleoperation control system includes joystick based user interaction mechanism, the high level instruction set and fuzzy logic behaviors integrated in a supervised autonomy teleoperation control system for indoor navigation. These behaviors include left wall following, right wall following, turn left, turn right, left obstacle avoidance, right obstacle avoidance and corridor following based on ultrasonic range finders data. The robot compares the instructive high level command from the operator and relays back a suggestive signal back to the operator in case of mismatch between environment and instructive command. This strategy relieves the operator's cognitive burden, handle unforeseen situations and uncertainties of environment autonomously. The effectiveness of the proposed method for navigation in an unstructured environment is verified by experiments conducted on a mobile robot equipped with only ultrasonic range finders for environment sensing.

  18. Control of a mobile robot through brain computer interface

    Directory of Open Access Journals (Sweden)

    Robinson Jimenez Moreno

    2015-07-01

    Full Text Available This paper poses a control interface to command the movement of a mobile robot according to signals captured from the user's brain. These signals are acquired and interpreted by Emotiv EPOC device, a 14-electrode type sensor which captures electroencephalographic (EEG signals with high resolution, which, in turn, are sent to a computer for processing. One brain-computer interface (BCI was developed based on the Emotiv software and SDK in order to command the mobile robot from a distance. Functionality tests are performed with the sensor to discriminate shift intentions of a user group, as well as with a fuzzy controller to hold the direction in case of concentration loss. As conclusion, it was possible to obtain an efficient system for robot movements by brain commands.

  19. Control of an automated mobile manipulator using artificial immune system

    Science.gov (United States)

    Deepak, B. B. V. L.; Parhi, Dayal R.

    2016-03-01

    This paper addresses the coordination and control of a wheeled mobile manipulator (WMM) using artificial immune system. The aim of the developed methodology is to navigate the system autonomously and transport jobs and tools in manufacturing environments. This study integrates the kinematic structures of a four-axis manipulator and a differential wheeled mobile platform. The motion of the developed WMM is controlled by the complete system of parametric equation in terms of joint velocities and makes the robot to follow desired trajectories by the manipulator and platform within its workspace. The developed robot system performs its action intelligently according to the sensed environmental criteria within its search space. To verify the effectiveness of the proposed immune-based motion planner for WMM, simulations as well as experimental results are presented in various unknown environments.

  20. Alcohol control: Mobile sensor system and numerical signal analysis

    OpenAIRE

    Seifert, Rolf; Keller, Hubert B.; Conrad, Thorsten; Peter, Jens

    2016-01-01

    An innovative mobile sensor system for alcohol control in the respiratory air is introduced. The gas sensor included in the sensor system is thermo-cyclically operated. Ethanol is the leading component in this context. However, other components occur in the breathing air which can influence the concentration determination of ethanol. Therefore, mono- ethanol samples and binary gas mixtures are measured by the sensor system and analyzed with a new calibration and evaluation procedure which is ...

  1. Ion Mobility Spectrometry-Mass Spectrometry Coupled with Gas-Phase Hydrogen/Deuterium Exchange for Metabolomics Analyses

    Science.gov (United States)

    Maleki, Hossein; Karanji, Ahmad K.; Majuta, Sandra; Maurer, Megan M.; Valentine, Stephen J.

    2018-02-01

    Ion mobility spectrometry-mass spectrometry (IMS-MS) in combination with gas-phase hydrogen/deuterium exchange (HDX) and collision-induced dissociation (CID) is evaluated as an analytical method for small-molecule standard and mixture characterization. Experiments show that compound ions exhibit unique HDX reactivities that can be used to distinguish different species. Additionally, it is shown that gas-phase HDX kinetics can be exploited to provide even further distinguishing capabilities by using different partial pressures of reagent gas. The relative HDX reactivity of a wide variety of molecules is discussed in light of the various molecular structures. Additionally, hydrogen accessibility scoring (HAS) and HDX kinetics modeling of candidate ( in silico) ion structures is utilized to estimate the relative ion conformer populations giving rise to specific HDX behavior. These data interpretation methods are discussed with a focus on developing predictive tools for HDX behavior. Finally, an example is provided in which ion mobility information is supplemented with HDX reactivity data to aid identification efforts of compounds in a metabolite extract.

  2. Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 2. Assessing Charge Site Location and Isotope Scrambling

    Science.gov (United States)

    Khakinejad, Mahdiar; Ghassabi Kondalaji, Samaneh; Donohoe, Gregory C.; Valentine, Stephen J.

    2016-03-01

    Ion mobility spectrometry (IMS) coupled with gas-phase hydrogen deuterium exchange (HDX)-mass spectrometry (MS) and molecular dynamic simulations (MDS) has been used for structural investigation of anions produced by electrospraying a sample containing a synthetic peptide having the sequence KKDDDDDIIKIIK. In these experiments the potential of the analytical method for locating charge sites on ions as well as for utilizing collision-induced dissociation (CID) to reveal the degree of deuterium uptake within specific amino acid residues has been assessed. For diffuse (i.e., more elongated) [M - 2H]2- ions, decreased deuterium content along with MDS data suggest that the D4 and D6 residues are charge sites, whereas for the more diffuse [M - 3H]3- ions, the data suggest that the D4, D7, and the C-terminus are deprotonated. Fragmentation of mobility-selected, diffuse [M - 2H]2- ions to determine deuterium uptake at individual amino acid residues reveals a degree of deuterium retention at incorporation sites. Although the diffuse [M - 3H]3- ions may show more HD scrambling, it is not possible to clearly distinguish HD scrambling from the expected deuterium uptake based on a hydrogen accessibility model. The capability of the IMS-HDX-MS/MS approach to provide relevant details about ion structure is discussed. Additionally, the ability to extend the approach for locating protonation sites on positively-charged ions is presented.

  3. DYNAMICS BASED CONTROL OF A SKID STEERING MOBILE ROBOT

    Directory of Open Access Journals (Sweden)

    Osama Elshazly

    2016-06-01

    Full Text Available In this paper, development of a reduced order, augmented dynamics-drive model that combines both the dynamics and drive subsystems of the skid steering mobile robot (SSMR is presented. A Linear Quadratic Regulator (LQR control algorithm with feed-forward compensation of the disturbances part included in the reduced order augmented dynamics-drive model is designed. The proposed controller has many advantages such as its simplicity in terms of design and implementation in comparison with complex nonlinear control schemes that are usually designed for this system. Moreover, the good performance is also provided by the controller for the SSMR comparable with a nonlinear controller based on the inverse dynamics which depends on the availability of an accurate model describing the system. Simulation results illustrate the effectiveness and enhancement provided by the proposed controller.

  4. High hole mobility p-type GaN with low residual hydrogen concentration prepared by pulsed sputtering

    Science.gov (United States)

    Arakawa, Yasuaki; Ueno, Kohei; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

    2016-08-01

    We have grown Mg-doped GaN films with low residual hydrogen concentration using a low-temperature pulsed sputtering deposition (PSD) process. The growth system is inherently hydrogen-free, allowing us to obtain high-purity Mg-doped GaN films with residual hydrogen concentrations below 5 × 1016 cm-3, which is the detection limit of secondary ion mass spectroscopy. In the Mg profile, no memory effect or serious dopant diffusion was detected. The as-deposited Mg-doped GaN films showed clear p-type conductivity at room temperature (RT) without thermal activation. The GaN film doped with a low concentration of Mg (7.9 × 1017 cm-3) deposited by PSD showed hole mobilities of 34 and 62 cm2 V-1 s-1 at RT and 175 K, respectively, which are as high as those of films grown by a state-of-the-art metal-organic chemical vapor deposition apparatus. These results indicate that PSD is a powerful tool for the fabrication of GaN-based vertical power devices.

  5. Applying virtual reality to remote control of mobile robot

    Directory of Open Access Journals (Sweden)

    Chen Chin-Shan

    2017-01-01

    Full Text Available The purpose of this research is based on virtual reality to assisted pick and place tasks. Virtual reality can be utilized to control remote robot for pick and place element. The operator monitored and controlled the situation information of working site by Human Machine Interface. Therefore, we worked in harsh or dangerous environments that thing can be avoided. The procedure to operate mobile robot in virtual reality describes as follow: An experiment site with really experimental equipment is first established. Then, the experimental equipment and scene modeling are input to virtual reality for establishing a environment similar to the reality. Finally, the remote mobile robot is controlled to operate pick and place tasks through wireless communication by the object operation in virtual reality. The robot consists of a movable robot platform and robotic arm. The virtual reality is constructed by EON software; the Human Machine Interface is established by Visual Basic. The wireless connection is equipped the wireless Bluetooth, which is set the PC and PLC controller. With experimental tests to verify the robot in virtual reality and the wireless remote control, the robot could be operated and controlled to successfully complete pick and place tasks in reality by Human Machine Interface.

  6. Regulatory Research of the PWR Severe Accident. Information Needs and Instrumentation for Hydrogen Control and Management

    International Nuclear Information System (INIS)

    Park, Gun Chul; Suh, Kune Y.; Lee, Jin Yong; Lee, Seung Dong

    2001-03-01

    The current research is concerned with generation of basic engineering data needed in the process of developing hydrogen control guidelines as part of accident management strategies for domestic nuclear power plants and formulating pertinent regulatory requirements. Major focus is placed on identification of information needs and instrumentation methods for hydrogen control and management in the primary system and in the containment, development of decision-making trees for hydrogen management and their quantification, the instrument availability under severe accident conditions, critical review of relevant hydrogen generation model and phenomena In relation to hydrogen behavior, we analyzed the severe accident related hydrogen generation in the UCN 3·4 PWR with modified hydrogen generation model. On the basis of the hydrogen mixing experiment and related GASFLOW calculation, the necessity of 3-dimensional analysis of the hydrogen mixing was investigated. We examined the hydrogen control models related to the PAR(Passive Autocatalytic Recombiner) and performed MAAP4 calculation in relation to the decision tree to estimate the capability and the role of the PAR during a severe accident

  7. Regulatory Research of the PWR Severe Accident. Information Needs and Instrumentation for Hydrogen Control and Management

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gun Chul; Suh, Kune Y.; Lee, Jin Yong; Lee, Seung Dong [Seoul Nat' l Univ., Seoul (Korea, Republic of)

    2001-03-15

    The current research is concerned with generation of basic engineering data needed in the process of developing hydrogen control guidelines as part of accident management strategies for domestic nuclear power plants and formulating pertinent regulatory requirements. Major focus is placed on identification of information needs and instrumentation methods for hydrogen control and management in the primary system and in the containment, development of decision-making trees for hydrogen management and their quantification, the instrument availability under severe accident conditions, critical review of relevant hydrogen generation model and phenomena In relation to hydrogen behavior, we analyzed the severe accident related hydrogen generation in the UCN 3{center_dot}4 PWR with modified hydrogen generation model. On the basis of the hydrogen mixing experiment and related GASFLOW calculation, the necessity of 3-dimensional analysis of the hydrogen mixing was investigated. We examined the hydrogen control models related to the PAR(Passive Autocatalytic Recombiner) and performed MAAP4 calculation in relation to the decision tree to estimate the capability and the role of the PAR during a severe accident.

  8. Augmented models for improving vision control of a mobile robot

    DEFF Research Database (Denmark)

    Andersen, Gert Lysgaard; Christensen, Anders C.; Ravn, Ole

    1994-01-01

    obtain good performance even when using standard low cost equipment and a comparatively low sampling rate. The plant model is a compound of kinematic, dynamic and sensor submodels, all integrated into a discrete state space representation. An intelligent strategy is applied for the vision sensor......This paper describes the modelling phases for the design of a path tracking vision controller for a three wheeled mobile robot. It is shown that, by including the dynamic characteristics of vision and encoder sensors and implementing the total system in one multivariable control loop, one can...

  9. Remote Control of a Mobile Robot for Indoor Patrol

    Directory of Open Access Journals (Sweden)

    Shih-Yao Juang

    2016-03-01

    Full Text Available This study applies smartphone, Bluetooth, and Wi-Fi wireless network to control a wheeled mobile robot (WMR remotely. The first part of this study demonstrates that the WMR can be controlled manually by a smartphone. The smartphone can remotely control the WMR for forward, backward, left-turn, and right-turn operations. The second part of this article presents object tracking. The WMR can follow a moving object through the use of image processing for object tracking and distance detection. In the third part, infrared sensor and fuzzy system algorithms are integrated into the control scheme. Through wall-following and obstacle-avoidance control, the WMR can successfully perform indoor patrol.

  10. Cooperative control of a squad of mobile vehicles

    International Nuclear Information System (INIS)

    Lewis, C.; Feddema, J.; Klarer, P.

    1998-01-01

    Tasks such as the localization of chemical sources, demining, perimeter control, surveillance and search and rescue missions are usually performed by teams of people. At least conceptually, large groups of relatively cheap mobile vehicles outfitted with sensors should be able to automatically accomplish some of these tasks. Sandia National Labs is currently developing a swarm of semi-autonomous all terrain vehicles for remote cooperative sensing applications. This paper will describe the capabilities of this system and outline some of its possible applications. Cooperative control and sensing strategies will also be described. Eight Roving All Terrain Lunar Explorer Rovers (RATLERs) have been built at Sandia as a test platform for cooperative control and sensing applications. This paper will first describe the hardware capabilities of the RATLER system. Then it will describe the basic control algorithm for GPS based navigation and obstacle avoidance. A higher level cooperative control task will then be described

  11. Control of mobility in molecular organic semiconductors by dendrimer generation

    Science.gov (United States)

    Lupton, J. M.; Samuel, I. D.; Beavington, R.; Frampton, M. J.; Burn, P. L.; Bässler, H.

    2001-04-01

    Conjugated dendrimers are of interest as novel materials for light-emitting diodes. They consist of a luminescent chromophore at the core with highly branched conjugated dendron sidegroups. In these materials, light emission occurs from the core and is independent of generation. The dendron branching controls the separation between the chromophores. We present here a family of conjugated dendrimers and investigate the effect of dendron branching on light emission and charge transport. We apply a number of transport measurement techniques to thin films of a conjugated dendrimer in a light-emitting diode configuration to determine the effect of chromophore spacing on charge transport. We find that the mobility is reduced by two orders of magnitude as the size of the molecule doubles with increased branching or dendrimer generation. The degree of branching allows a unique control of mobility by molecular structure. An increase in chromophore separation also results in a reduction of intermolecular interactions, which reduces the red emission tail in film photoluminescence. We find that the steady-state charge transport is well described by a simple device model incorporating the effect of generation, and use the materials to shed light on the interpretation of transient electroluminescence data. We demonstrate the significance of the ability to tune the mobility in bilayer devices, where a more balanced charge transport can be achieved.

  12. Hydrogen from renewable energy: A pilot plant for thermal production and mobility

    Science.gov (United States)

    Degiorgis, L.; Santarelli, M.; Calì, M.

    In the mainframe of a research contract, a feasibility pre-design study of a hydrogen-fuelled Laboratory-Village has been carried out: the goals are the design and the simulation of a demonstration plant based on hydrogen as primary fuel. The hydrogen is produced by electrolysis, from electric power produced by a mix of hydroelectric and solar photovoltaic plants. The plant will be located in a small remote village in Valle d'Aosta (Italy). This country has large water availability from glaciers and mountains, so electricity production from fluent water hydroelectric plants is abundant and cheap. Therefore, the production of hydrogen during the night (instead of selling the electricity to the grid at very low prices) could become a good economic choice, and hydrogen could be a competitive local fuel in term of costs, if compared to oil or gas. The H 2 will be produced and stored, and used to feed a hydrogen vehicle and for thermal purposes (heating requirement of three buildings), allowing a real field test (Village-Laboratory). Due to the high level of pressure requested for H 2 storage on-board in the vehicle, the choice has been the experimental test of a prototype laboratory-scale high-pressure PEM electrolyzer: a test laboratory has been designed, to investigate the energy savings related to this technology. In the paper, the description of the dynamic simulation of the plant (developed with TRNSYS) together with a detailed design and an economic analysis (proving the technical and economical feasibility of the installation) has been carried out. Moreover, the design of the high-pressure PEM electrolyzer is described.

  13. Mobile source pollution control in the United States and China

    International Nuclear Information System (INIS)

    Menz, Fredric C

    2002-01-01

    This paper reviews policies for the control of mobile source pollution and their potential application in China. The first section of the paper reviews the U.S. experience with mobile source pollution control since regulations were first established in the Clean Air Act of 1970. Highlights in the policy and trends in vehicle emissions over the 1970 to 2000 time period are discussed. The second section of the paper discusses the range of policy instruments that could be used to control vehicle pollution, ranging from traditional direct regulations to market-based instruments. Experiences with the use of economic incentives in the United States and elsewhere are also discussed. The third section of the paper discusses possible implications of the U.S. experience for controlling vehicle pollution in China. While market-based instruments might be particularly appropriate for use in several aspects of China's pollution control policies, important differences between the institutional structures in China and the United States suggest that they should be phased in gradually. The paper closes with concluding remarks. (author)

  14. Mobile source pollution control in the United States and China

    Energy Technology Data Exchange (ETDEWEB)

    Menz, Fredric C

    2002-07-01

    This paper reviews policies for the control of mobile source pollution and their potential application in China. The first section of the paper reviews the U.S. experience with mobile source pollution control since regulations were first established in the Clean Air Act of 1970. Highlights in the policy and trends in vehicle emissions over the 1970 to 2000 time period are discussed. The second section of the paper discusses the range of policy instruments that could be used to control vehicle pollution, ranging from traditional direct regulations to market-based instruments. Experiences with the use of economic incentives in the United States and elsewhere are also discussed. The third section of the paper discusses possible implications of the U.S. experience for controlling vehicle pollution in China. While market-based instruments might be particularly appropriate for use in several aspects of China's pollution control policies, important differences between the institutional structures in China and the United States suggest that they should be phased in gradually. The paper closes with concluding remarks. (author)

  15. Position Control of the Single Spherical Wheel Mobile Robot by Using the Fuzzy Sliding Mode Controller

    OpenAIRE

    Hamed Navabi; Soroush Sadeghnejad; Sepehr Ramezani; Jacky Baltes

    2017-01-01

    A spherical wheel robot or Ballbot—a robot that balances on an actuated spherical ball—is a new and recent type of robot in the popular area of mobile robotics. This paper focuses on the modeling and control of such a robot. We apply the Lagrangian method to derive the governing dynamic equations of the system. We also describe a novel Fuzzy Sliding Mode Controller (FSMC) implemented to control a spherical wheel mobile robot. The nonlinear nature of the equations makes the controller nontrivi...

  16. Best Management Practices to Prevent and Control Hydrogen ...

    Science.gov (United States)

    Hydrogen sulfide (H2S) gas can be emitted from both construction and demolition (C&D) debris and municipal solid waste (MSW) landfills. H2S emissions may be problematic at a landfill as they can cause odor, impact surrounding communities, cause wear or damage to landfill gas (LFG) collection and energy utilization components, or contribute to the formation of explosive conditions. H2S emissions at landfills have often been attributed to the disposal of gypsum drywall, though other sources such as sulfur-containing industrial wastes and biosolids from municipal wastewater treatment facilities can also contribute to H2S production. Addressing problems from H2S emissions at landfills can be costly and time consuming for landfill owners and operators. Several years of operational experience and research efforts have identified several key pieces of information regarding the conditions that can cause H2S production, factors that result in H2S production at landfills, and strategies to prevent these conditions from occurring and to minimize the release of H2S to the surrounding environment when it is produced. The U.S. Environmental Protection Agency (U.S. EPA) Office of Research and Development, in coordination with U.S. EPA Region 5, commissioned the development of a document designed to provide landfill owners and operators with guidance on pertinent subject matter associated with H2S production, emissions, prevention, and control at landfill sites. A previous

  17. Mobilities

    DEFF Research Database (Denmark)

    to social networks, personal identities, and our relationship to the built environment. The omnipresence of mobilities within everyday life, high politics, technology, and tourism (to mention but a few) all point to a key insight harnessed by the ‘mobilities turn’. Namely that mobilities is much more than......The world is on the move. This is a widespread understanding by many inhabitants of contemporary society across the Globe. But what does it actually mean? During over one decade the ‘mobilities turn’ within the social sciences have provided a new set of insights into the repercussions of mobilities...... and environmental degradation. The spaces and territories marked by mobilities as well as the sites marked by the bypassing of such are explored. Moreover, the architectural and technological dimensions to infrastructures and sites of mobilities will be included as well as the issues of power, social exclusion...

  18. Efficient Control Law Simulation for Multiple Mobile Robots

    Energy Technology Data Exchange (ETDEWEB)

    Driessen, B.J.; Feddema, J.T.; Kotulski, J.D.; Kwok, K.S.

    1998-10-06

    In this paper we consider the problem of simulating simple control laws involving large numbers of mobile robots. Such simulation can be computationally prohibitive if the number of robots is large enough, say 1 million, due to the 0(N2 ) cost of each time step. This work therefore uses hierarchical tree-based methods for calculating the control law. These tree-based approaches have O(NlogN) cost per time step, thus allowing for efficient simulation involving a large number of robots. For concreteness, a decentralized control law which involves only the distance and bearing to the closest neighbor robot will be considered. The time to calculate the control law for each robot at each time step is demonstrated to be O(logN).

  19. The Bluetooth Based LED Control For Arduino Test Platform By Using Mobile APP

    OpenAIRE

    Yi-Jen Mon

    2015-01-01

    Abstract The Bluetooth is a commonly known convenient and famous communication protocol. In this paper it is used to control LED mounted on Arduino test platform by using the APP of mobile phone. At first the control program is completed by Arduino development software environment then the Android APP is installed in mobile phone. Finally by using the Bluetooth of mobile phone the test platform will be connected. The LED can be controlled by APP of mobile phone. The experiment results are dem...

  20. New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

    Directory of Open Access Journals (Sweden)

    Nazim Mir-Nasiri

    2008-11-01

    Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion..

  1. New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

    Directory of Open Access Journals (Sweden)

    Nazim Mir-Nasiri

    2005-09-01

    Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion.

  2. Hydrogen formation and control under postulated LMFBR accident conditions

    International Nuclear Information System (INIS)

    Armstrong, G.R.; Wierman, R.W.

    1976-09-01

    The objective of this study is to experimentally investigate the potential for autoignition and combustion of hydrogen-sodium mixtures which may be produced in LMFBR accidents. The purpose and ultimate usefulness of this work is to provide data that will establish the validity and acceptability of mechanisms inherent to the LMFBR that could either prevent or delay the accumulation of hydrogen gas to less than 4 percent (V) in the Reactor Containment Building (RCB) under accident conditions. The results to date indicate that sodium and sodium-hydrogen mixtures such as may be expected during LMFBR postulated accidents will ignite upon entering an air atmosphere and that the hydrogen present will be essentially all consumed until such time that the oxygen concentration is depleted

  3. Position Control of the Single Spherical Wheel Mobile Robot by Using the Fuzzy Sliding Mode Controller

    Directory of Open Access Journals (Sweden)

    Hamed Navabi

    2017-01-01

    Full Text Available A spherical wheel robot or Ballbot—a robot that balances on an actuated spherical ball—is a new and recent type of robot in the popular area of mobile robotics. This paper focuses on the modeling and control of such a robot. We apply the Lagrangian method to derive the governing dynamic equations of the system. We also describe a novel Fuzzy Sliding Mode Controller (FSMC implemented to control a spherical wheel mobile robot. The nonlinear nature of the equations makes the controller nontrivial. We compare the performance of four different fuzzy controllers: (a regulation with one signal, (b regulation and position control with one signal, (c regulation and position control with two signals, and (d FSMC for regulation and position control with two signals. The system is evaluated in a realistic simulation and the robot parameters are chosen based on a LEGO platform, so the designed controllers have the ability to be implemented on real hardware.

  4. Modeling and control design of hydrogen production process for an active hydrogen/wind hybrid power system

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Tao; Francois, Bruno [L2EP, Ecole Centrale de Lille, Cite Scientifique, BP48, 59651, Villeneuve d' Ascq (France)

    2009-01-15

    This paper gives a control oriented modeling of an electrolyzer, as well as the ancillary system for the hydrogen production process. A Causal Ordering Graph of all necessary equations has been used to illustrate the global scheme for an easy understanding. The model is capable of characterizing the relations among the different physical quantities and can be used to determine the control system ensuring efficient and reliable operation of the electrolyzer. The proposed control method can manage the power flow and the hydrogen flow. The simulation results have highlighted the variation domains and the relations among the different physical quantities. The model has also been experimentally tested in real time with a Hardware-In-the-Loop Simulation before being integrated in the test bench of the active wind energy conversion system. (author)

  5. Alcohol Control: Mobile Sensor System and Numerical Signal Analysis

    Directory of Open Access Journals (Sweden)

    Rolf SEIFERT

    2016-10-01

    Full Text Available An innovative mobile sensor system for alcohol control in the respiratory air is introduced. The gas sensor included in the sensor system is thermo-cyclically operated. Ethanol is the leading component in this context. However, other components occur in the breathing air which can influence the concentration determination of ethanol. Therefore, mono- ethanol samples and binary gas mixtures are measured by the sensor system and analyzed with a new calibration and evaluation procedure which is also incorporated in the system. The applications demonstrate a good substance identification capability of the sensor system and a very good concentration determination of the components.

  6. Non linear predictive control of a LEGO mobile robot

    Science.gov (United States)

    Merabti, H.; Bouchemal, B.; Belarbi, K.; Boucherma, D.; Amouri, A.

    2014-10-01

    Metaheuristics are general purpose heuristics which have shown a great potential for the solution of difficult optimization problems. In this work, we apply the meta heuristic, namely particle swarm optimization, PSO, for the solution of the optimization problem arising in NLMPC. This algorithm is easy to code and may be considered as alternatives for the more classical solution procedures. The PSO- NLMPC is applied to control a mobile robot for the tracking trajectory and obstacles avoidance. Experimental results show the strength of this approach.

  7. Autonomous Power Control MAC Protocol for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Battery energy limitation has become a performance bottleneck for mobile ad hoc networks. IEEE 802.11 has been adopted as the current standard MAC protocol for ad hoc networks. However, it was developed without considering energy efficiency. To solve this problem, many modifications on IEEE 802.11 to incorporate power control have been proposed in the literature. The main idea of these power control schemes is to use a maximum possible power level for transmitting RTS/CTS and the lowest acceptable power for sending DATA/ACK. However, these schemes may degrade network throughput and reduce the overall energy efficiency of the network. This paper proposes autonomous power control MAC protocol (APCMP, which allows mobile nodes dynamically adjusting power level for transmitting DATA/ACK according to the distances between the transmitter and its neighbors. In addition, the power level for transmitting RTS/CTS is also adjustable according to the power level for DATA/ACK packets. In this paper, the performance of APCMP protocol is evaluated by simulation and is compared with that of other protocols.

  8. Enhanced dispersion stability and mobility of carboxyl-functionalized carbon nanotubes in aqueous solutions through strong hydrogen bonds

    International Nuclear Information System (INIS)

    Bahk, Yeon Kyoung; He, Xu; Gitsis, Emmanouil; Kuo, Yu-Ying; Kim, Nayoung; Wang, Jing

    2015-01-01

    Dispersion of carbon nanotubes has been heavily studied due to its importance for their technical applications, toxic effects, and environmental impacts. Common electrolytes, such as sodium chloride and potassium chloride, promote agglomeration of nanoparticles in aqueous solutions. On the contrary, we discovered that acetic electrolytes enhanced the dispersion of multi-walled carbon nanotubes (MWCNTs) with carboxyl functional group through the strong hydrogen bond, which was confirmed by UV–Vis spectrometry, dispersion observations and aerosolization-quantification method. When concentrations of acetate electrolytes such as ammonium acetate (CH 3 CO 2 NH 4 ) and sodium acetate (CH 3 CO 2 Na) were lower than 0.03 mol per liter, MWCNT suspensions showed better dispersion and had higher mobility in porous media. The effects by the acetic environment are also applicable to other nanoparticles with the carboxyl functional group, which was demonstrated with polystyrene latex particles as an example

  9. Enhanced dispersion stability and mobility of carboxyl-functionalized carbon nanotubes in aqueous solutions through strong hydrogen bonds

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Yeon Kyoung; He, Xu; Gitsis, Emmanouil; Kuo, Yu-Ying [ETH Zurich, Institute of Environmental Engineering (Switzerland); Kim, Nayoung [EMPA, Building Energy Materials and Components (Switzerland); Wang, Jing, E-mail: jing.wang@ifu.baug.ethz.ch [ETH Zurich, Institute of Environmental Engineering (Switzerland)

    2015-10-15

    Dispersion of carbon nanotubes has been heavily studied due to its importance for their technical applications, toxic effects, and environmental impacts. Common electrolytes, such as sodium chloride and potassium chloride, promote agglomeration of nanoparticles in aqueous solutions. On the contrary, we discovered that acetic electrolytes enhanced the dispersion of multi-walled carbon nanotubes (MWCNTs) with carboxyl functional group through the strong hydrogen bond, which was confirmed by UV–Vis spectrometry, dispersion observations and aerosolization-quantification method. When concentrations of acetate electrolytes such as ammonium acetate (CH{sub 3}CO{sub 2}NH{sub 4}) and sodium acetate (CH{sub 3}CO{sub 2}Na) were lower than 0.03 mol per liter, MWCNT suspensions showed better dispersion and had higher mobility in porous media. The effects by the acetic environment are also applicable to other nanoparticles with the carboxyl functional group, which was demonstrated with polystyrene latex particles as an example.

  10. Integrated Control Strategies Supporting Autonomous Functionalities in Mobile Robots

    Directory of Open Access Journals (Sweden)

    Brandon Sights

    2006-10-01

    Full Text Available High-level intelligence allows a mobile robot to create and interpret complex world models, but without a precise control system, the accuracy of the world model and the robot's ability to interact with its surroundings are greatly diminished. This problem is amplified when the environment is hostile, such as in a battlefield situation where an error in movement or a slow response may lead to destruction of the robot. As the presence of robots on the battlefield continues to escalate and the trend toward relieving the human of the low-level control burden advances, the ability to combine the functionalities of several critical control systems on a single platform becomes imperative.

  11. Hydrogen metal hydride storage with integrated catalytic recombiner for mobile application

    Energy Technology Data Exchange (ETDEWEB)

    Marinescu-Pasoi, L.; Behrens, U.; Langer, G.; Gramatte, W.; Rastogi, A.K.; Schmitt, R.E. (Battelle-Institut e.V., Frankfurt am Main (DE). Dept. of Energy Technology)

    1991-01-01

    A novel, thermodynamically efficient device is under development at Battelle in Frankfurt, by which the range of hydrogen-driven cars with a metal hydride tank might be roughly doubled. The device makes use of the properties of metal hydrides, combined with catalytic combustion. Its development is funded by the Hessian Ministry of Economic Affairs and Technology; it is to be completed by the end of 1990. High-temperature hydrides (HTH) have about three times the storage capacity of low temperature hydrides (LTH), but require relatively large amounts of heat at high temperatures to release the hydrogen. The exhaust heat from combustion-engine-driven vehicles is insufficient for this, and vehicles with electric (fuel cell) drive produce practically no exhaust heat at all. The Battelle-developed device is a combination of an HTH storage cell, an LTH storage cell and a catalyst. (author).

  12. Optimal Trajectory Tracking Control for a Wheeled Mobile Robot Using Fractional Order PID Controller

    Directory of Open Access Journals (Sweden)

    Ameer L. Saleh

    2018-02-01

    Full Text Available This paper present an optimal Fractional Order PID (FOPID controller based on Particle Swarm Optimization (PSO for controlling the trajectory tracking of Wheeled Mobile Robot(WMR.The issue of trajectory tracking with given a desired reference velocity is minimized to get the distance and deviation angle equal to zero, to realize the objective of trajectory tracking a two FOPID controllers are used for velocity control and azimuth control to implement the trajectory tracking control. A path planning and path tracking methodologies are used to give different desired tracking trajectories.  PSO algorithm is using to find the optimal parameters of FOPID controllers. The kinematic and dynamic models of wheeled mobile robot for desired trajectory tracking with PSO algorithm are simulated in Simulink-Matlab. Simulation results show that the optimal FOPID controllers are more effective and has better dynamic performance than the conventional methods.

  13. NRC Information No. 89-44: Hydrogen storage on the roof of the control room

    International Nuclear Information System (INIS)

    Rossi, C.E.

    1992-01-01

    During the Region V Chemistry Team Inspection at the Trojan Nuclear Plant the week of April 17, 1989, the inspectors identified a potential safety problem concerning the location of the hydrogen storage facility. Hydrogen is used on pressurized water reactor (PWR) plants for (1) providing a cover gas in the volume control tank, and (2) for cooling the main turbine generator. At boiling water reactor (BWR) plants, hydrogen is also used for cooling the main turbine generator and for injection into the feed system for plants which have implemented hydrogen water chemistry. The Trojan hydrogen storage facility is located on the control room roof which is 30-inch-thick reinforced concrete. The Trojan plant hydrogen facility does not meet guidelines from the standpoint of (1) the separation distance needed between a hydrogen pipe break and the control room ventilation intake to prevent buildup of a flammable or explosive gas mixture inside the control room, and (2) the separation distance needed to prevent damage to safety-related structures resulting from the explosion of an 8,000-scf hydrogen tank

  14. Control Scheme Formulation for the Production of Hydrogen on Demand to Feed an Internal Combustion Engine

    Directory of Open Access Journals (Sweden)

    Jarniel García Morales

    2016-12-01

    Full Text Available In this work, a control strategy is presented to produce hydrogen on demand to feed an internal combustion (IC engine. For this purpose, the modeling of the IC engine fueled by gasoline blended with 10 % v/v of anhydrous ethanol (E10 and hydrogen as an additive is developed. It is considered that the hydrogen gas is produced according to the IC engine demand, and that the hydrogen gas is obtained by an alkaline electrolyzer. The gasoline–ethanol blend added into the combustion chamber is determined according to the stoichiometric ratio and the production of hydrogen gas is regulated by a proportional and integral controller (P.I.. The controller reference is varying according to the mass flow air induced into the cylinder, in order to ensure an adequate production of hydrogen gas for any operating condition of the IC engine. The main contribution of this work is the control scheme developed, through simulation, in order to produce hydrogen on demand for any operating point of an internal combustion engine fueled by an E10 blend. The simulation results showed that the use of hydrogen gas as an additive in an E10 blend decreases the E10 fuel consumption 23 % on average, and the thermal efficiency is increased approximately 2.13 % , without brake power loss in the IC engine.

  15. Intelligent control system for nuclear power plant mobile robot

    International Nuclear Information System (INIS)

    Koenig, A.; Lecoeur-Taibi, I.; Crochon, E.; Vacherand, F.

    1991-01-01

    In order to fully optimize the efficiency of the perception and navigation components available on a mobile robot, the upper level of a mobile robot control requires intelligence support to unload the work of the teleoperator. This knowledge-based system has to manage a priori data such as the map of the workspace, the mission, the characteristics of sensors and robot, but also, the current environment state and the running mission. It has to issue a plan to drive the sensors to focus on relevant objects or to scan the environment and to select the best algorithms depending on the current situation. The environment workspace is a nuclear power plant building. The teleoperated robot is a mobile wheeled or legged vehicle that moves inside the different floors of the building. There are three types of mission: radio-activity survey, inspection and intervention. To perform these goals the robot must avoid obstacles, pass through doors, possibly climb stairs and recognize valves and pipes. The perception control system has to provide the operator with a synthetic view of the surroundings. It manages background tasks such as obstacle detection and free space map building, and specific tasks such as beacon recognition for odometry relocalization and valve detection for maintenance. To do this, the system solves perception resources conflicts, taking into account the current states of the sensors and the current conditions such as lightness or darkness, cluttered scenes, sensor failure. A perception plan is issued from the mission goals, planned path, relocalization requirements and available perception resources. Basically, the knowledge-based system is implemented on a blackboard architecture which includes two parts: a top-down planning part and a bottom-up perception part. The results of the perception are continuously sent to the operator who can trigger new perception actions. (author)

  16. Hydrogen-control systems for severe LWR accident conditions - a state-of-technology report

    International Nuclear Information System (INIS)

    Hilliard, R.K.; Postma, A.K.; Jeppson, D.W.

    1983-03-01

    This report reviews the current state of technology regarding hydrogen safety issues in light water reactor plants. Topics considered in this report relate to control systems and include combustion prevention, controlled combustion, minimization of combustion effects, combination of control concepts, and post-accident disposal. A companion report addresses hydrogen generation, distribution, and combustion. The objectives of the study were to identify the key safety issues related to hydrogen produced under severe accident conditions, to describe the state of technology for each issue, and to point out ongoing programs aimed at resolving the open issues

  17. Using real-time stereopsis for mobile robot control

    Science.gov (United States)

    Bonasso, R. P.; Nishihara, H. K.

    1991-02-01

    This paper describes on-going work in using range and motion data generated at video-frame rates as the basis for long-range perception in a mobile robot. A current approach in the artificial intelligence community to achieve timecritical perception for situated reasoning is to use low-level perception for motor reflex-like activity and higher-level but more computationally intense perception for path planning reconnaissance and retrieval activities. Typically inclinometers and a compass or an infra-red beacon system provide stability and orientation maintenance and ultrasonic or infra-red sensors serve as proximity detectors for obstacle avoidance. For distant ranging and area occupancy determination active imaging systems such as laser scanners can be prohibitivtly expensive and heretofore passive systems typically performed more slowly than the cycle time of the control system causing the robot to halt periodically along its way. However a recent stereo system developed by Nishihara known as PRISM (Practical Real-time Imaging Stereo Matcher) matches stereo pairs using a sign-correlation technique that gives range and motion at video frame rates. We are integrating this technique with constant-time control software for distant ranging and object detection at a speed that is comparable with the cycle-times of the low-level sensors. Possibilities for a variety of uses in a leader-follower mobile robot situation are discussed.

  18. Improving crystallization and electron mobility of indium tin oxide by carbon dioxide and hydrogen dual-step plasma treatment

    Science.gov (United States)

    Wang, Fengyou; Du, Rongchi; Ren, Qianshang; Wei, Changchun; Zhao, Ying; Zhang, Xiaodan

    2017-12-01

    Obtaining high conductivity indium tin oxide (ITO) films simultaneously with a "soft-deposited" (low temperature, low ions bombardment) and cost-efficient deposition process are critical aspect for versatile photo-electronic devices application. Usually, the low-cost "soft-deposited" process could be achieved via evaporation technique, but with scarifying the conductivity of the films. Here, we show a CO2 and H2 two-step plasma (TSP) post-treatment applied to ITO films prepared by reactive thermal evaporation (RTE), allows to meet the special trade-off between the deposition techniques and the electrical properties. Upon treatment, an increase in electron concentration and electron mobility is observed, which subsequently resulting a low sheet resistivity. The mobility reaches high values of 80.9 cm2/Vs for the TSP treated ∼100 nm thickness samples. From a combination of X-ray photoelectron spectroscopy and opto-electronic measurements, it demonstrated that: during the TSP process, the first-step CO2 plasma treatment could promote the crystallinity of the RTE ITO films. While the electron traps density at grain boundaries of polycrystalline RTE ITO films could be passivated by hydrogen atom during the second-step H2 plasma treatment. These results inspired that the TSP treatment process has significant application prospects owing to the outstanding electrical properties enhancement for "soft-deposited" RTE ITO films.

  19. Thermal generation and mobility of charge carriers in collective proton transport in hydrogen-bonded chains

    International Nuclear Information System (INIS)

    Peyrard, M.; Boesch, R.; Kourakis, I.

    1991-01-01

    The transport of protons in hydrogen-bonded systems is a long standing problem which has not yet obtained a satisfactorily theoretical description. Although this problem was examined first for ice, it is relevant in many systems and in particular in biology for the transport along proteins or for proton conductance across membranes, an essential process in cell life. The broad relevance makes the study of proton conduction very appealing. Since the original work of Bernal and Fowler on ice, the idea that the transport occurs through chains of hydrogen bonds has been well accepted. Such ''proton wires'' were invoked by Nagle and Morowitz for proton transport across membranes proteins and more recently across lipid bilayers. In this report, we assume the existence of such an hydrogen-bonded chain and discuss its consequences on the dynamics of the charge carriers. We show that this assumption leads naturally to the idea of soliton transport and we put a special emphasis on the role of the coupling between the protons and heavy ions motions. The model is presented. We show how the coupling affects strongly the dynamics of the charge carriers and we discuss the role it plays in the thermal generation of carriers. The work presented has been performed in 1986 and 87 with St. Pnevmatikos and N. Flyzanis and was then completed in collaboration with D. Hochstrasser and H. Buettner. Therefore the results presented in this part are not new but we think that they are appropriate in the context of this multidisciplinary workshop because they provide a rather complete example of the soliton picture for proton conduction. This paper discusses the thermal generation of the charge carriers when the coupling between the protons and heavy ions dynamics is taken into account. The results presented in this part are very recent and will deserve further analysis but they already show that the coupling can assist for the formation of the charge carriers

  20. Mobility of hydrogen-helium clusters in tungsten studied by molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Grigorev, Petr, E-mail: grigorievpit@gmail.com [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, Mol, 2400 (Belgium); Ghent University, Applied Physics EA17 FUSION-DC, St.Pietersnieuwstraat, 41 B4, B-9000, Gent (Belgium); Department of Experimental Nuclear Physics K-89, Institute of Physics, Nanotechnologies, and Telecommunications, Peter the Great St.Petersburg Polytechnic University, St. Petersburg (Russian Federation); Terentyev, Dmitry; Bonny, Giovanni [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, Mol, 2400 (Belgium); Zhurkin, Evgeny E. [Department of Experimental Nuclear Physics K-89, Institute of Physics, Nanotechnologies, and Telecommunications, Peter the Great St.Petersburg Polytechnic University, St. Petersburg (Russian Federation); Oost, Guido van [Ghent University, Applied Physics EA17 FUSION-DC, St.Pietersnieuwstraat, 41 B4, B-9000, Gent (Belgium); Noterdaeme, Jean-Marie [Ghent University, Applied Physics EA17 FUSION-DC, St.Pietersnieuwstraat, 41 B4, B-9000, Gent (Belgium); Max-Planck-Institut für Plasmaphysik, Garching (Germany)

    2016-06-15

    Tungsten is a primary candidate material for plasma facing components in fusion reactors. Interaction of plasma components with the material is unavoidable and will lead to degradation of the performance and the lifetime of the in-vessel components. In order to gain better understanding the mechanisms driving the material degradation at atomic level, atomistic simulations are employed. In this work we study migration, stability and self-trapping properties of pure helium and mixed helium-hydrogen clusters in tungsten by means of molecular dynamics simulations. We test two versions of an embedded atom model interatomic potential by comparing it with ab initio data regarding the binding properties of He clusters. By analysing the trajectories of the clusters during molecular dynamics simulations at finite temperatures we obtain the diffusion parameters. The results show that the diffusivity of mixed clusters is significantly lower, than that of pure helium clusters. The latter suggest that the formation of mixed clusters during mixed hydrogen helium plasma exposure will affect the helium diffusivity in the material.

  1. Fuzzy logic control for selective hydrogenation of acetylene in ethylene rich streams using visual basic

    International Nuclear Information System (INIS)

    Malik, S.R.; Suleman, H.; Khan, J.R.

    2010-01-01

    Presence of acetylene is technically disadvantageous in the ethylene rich gas streams from steam crackers. Acetylene tends to polymerize and inactivates the transition metal catalysts, forming highly explosive compounds. The acetylene content has to be selectively reduced to less than one part per million for such streams. The acetylene hydrogenation unit requires stringent control parameters and needs specialized process control techniques for its operation. This study is concerned with application of Fuzzy Logic Control to manipulate and control the process plant with higher precision and greater simplicity. The control program has been written in visual Basic and entails all major scenarios of work modes for successful hydrogenation of Acetylene. (author)

  2. Universally applicable design concept of stably controlling an HTGR-hydrogen production system

    International Nuclear Information System (INIS)

    Hada, Kazuhiko; Shibata, Taiju; Nishihara, Tetsuo; Shiozawa, Shusaku

    1996-01-01

    An HTGR-hydrogen production system should be designed to have stable controllability because of a large difference in thermal dynamics between reactor and hydrogen production system and such a control design concept should be universally applicable to a variety of hydrogen production processes by the use of nuclear heat from HTGR. A transient response analysis of an HTGR-steam reforming hydrogen production system showed that a steam generator installed in a helium circuit for cooling the nuclear reactor provides stable controllability of the total system, resulting in avoiding a reactor scram. A survey of control design-related characteristics among several hydrogen production processes revealed the similarity of endothermic chemical reactions by the use of high temperature heat and that steam is required as a reactant of the endothermic reaction or for preheating a reactant. Based on these findings, a system design concept with stable controllability and universal applicability was proposed to install a steam generator as a downstream cooler of an endothermic reactor in the helium circuit of an HTGR-hydrogen production system. (author)

  3. Genesis and mobility of natural hydrogen: energy source or storable energy carrier?

    International Nuclear Information System (INIS)

    Vacquand, Ch.

    2011-01-01

    This PhD thesis is a study of the production of hydrogen (H 2 ) in several types of continental contexts and an experimental approach of its migration in geological media. In a first part, H 2 -rich gases that were associated with methane CH 4 and nitrogen N 2 from Oman, the Philippines, Turkey and Kansas (USA) were analyzed. Systematic analyses of stable isotopes of carbon, hydrogen and noble gases indicate a relatively low-temperature and shallow aquifer origin for this H 2 . At the surface, we made clear that the H 2 seepage was associated with high-pH sources that capture the atmospheric CO 2 , forming calcite and aragonite. The very heavy carbon isotopic signatures for most of the measured methane suggest a reduction of the inorganic dissolved carbon by this H 2 . We propose that, as in the case of hydrothermal oceanic serpentinization, but at much lower temperatures, the connection between H 2 production and the ultra basic rocks is due to the presence of abundant iron (II) and to adequate redox conditions that allow the reduction of water to H 2 and a good conservation of this H 2 , a variable part of which is converted to methane, depending on the CO 2 activity. The combination of this H 2 generation model with noble gases migration, hydrogeological and geological data allowed us to estimate a global flux of H 2 production from the large ophiolitic belts in the world of 10 13 to 10 18 m 3 /yr. In a second part, we realized migration experiments of H 2 in natural or reconstituted geological media in a laboratory. We showed that this migration is not particularly important compared to that of other gases and quite close to that of argon. This moderate migration, lower than that of CO 2 in porous saturated media is due to a relatively low solubility of H 2 in water and to an effective diffusion coefficient in porous media lower than for helium and close to that of argon. Since H 2 does neither migrate faster nor more efficiently than CH 4 for example, these

  4. Robust tracking control of two-degrees-of-freedom mobile robots

    NARCIS (Netherlands)

    Oelen, W.; Oelen, W.; van Amerongen, J.

    1994-01-01

    A robust tracking controller for a mobile robot with two degrees of freedom has been developed. It is implemented and tested on a real mobile robot. Where other controllers show decreasing performance for low reference velocities, the performance of this controller depends only on the geometry of

  5. Study of Hydrogen Consumption by Control System in Proton Exchange Membrane Fuel Cell

    International Nuclear Information System (INIS)

    Ros Emilia Rosli; Edy Herianto Majlan; Siti Afiqah Abd Hamid; Wan Ramli Wan Daud; Ramizi Mohamed; Dedi Rohendi

    2016-01-01

    Efficient operation results from a proper control strategy. In the operation and performance of a Proton Exchange Membrane Fuel Cell (PEMFC), the hydrogen gas flow rate is one of the most essential control parameter in addition to operating pressure, water management, temperature and humidity. This is because of the high cost and amount of energy are required to produce the purity hydrogen gas. In this paper, a Proportional Integral Derivative (PID) feedback control system is used to control the hydrogen flow rate. A strategy is adapted to balance the hydrogen use based on the loading requirements, especially during start-ups and sudden power demands. This system is implemented using National Instrument (NI) devices powered by the LabVIEW program. This is due to its simplicity and customization flexibility for measuring, processing and recording data. Designed structure allows the real-time implementation of a robust control law that is able to address the related nonlinearities and uncertainties without incurring a heavy computational load for the controller algorithm. While it facilitating a fast sampling rate according to the needs of the power system. Test results from the controller show that the new fuel control system provides good performance by reducing the amount of wasted hydrogen gas compared with that of the previous open loop system by 30 % to over 80 % saved by the varied load. This improvement is beneficial for any PEMFC that experiences fluctuating power demand, especially for vehicle applications. (author)

  6. Local system for control by console-mobile crane for russian depository of fissionable materials

    International Nuclear Information System (INIS)

    Troshchenko, V.G.; Kapustin, V.N.; Zinina, N.V.; Derbyshev, S.A.

    2005-01-01

    Description of crane of console-mobile type used for transportation of fissionable materials in depository with local control system is represented. Local control system realizes program control in real time [ru

  7. Hydrogen from methanol for fuel cells in mobile systems: development of a compact reformer

    Energy Technology Data Exchange (ETDEWEB)

    Hoehlein, B [Forschungszentrum Juelich GmbH (Germany); Boe, M [H. Topsoee A/S, Lyngby (Denmark); Boegild-Hansen, J [H. Topsoee A/S, Lyngby (Denmark); Broeckerhoff, P [Forschungszentrum Juelich GmbH (Germany); Colsman, G [Forschungszentrum Juelich GmbH (Germany); Emonts, B [Forschungszentrum Juelich GmbH (Germany); Menzer, R [Forschungszentrum Juelich GmbH (Germany); Riedel, E

    1996-07-01

    On-board generation of hydrogen from methanol with a reformer in connection with the use of a proton-exchange membrane fuel cell (PEMFC) is an attractive option for a passenger car drive. Special considerations are required to obtain low weight and volume. Furthermore, the PEMFC of today cannot tolerate more than 10 ppm of carbon monoxide in the fuel. Therefore a gas conditioning step is needed after the methanol reformer. Our main research activities focus on the conceptual design of a drive system for a passenger car with methanol reformer and PEMFC: Engineering studies with regard to different aspects of this design including reformer, catalytic burner, gas conditioning, balances of the fuel cycles and basic design of a compact methanol reformer. The work described here was carried out within the framework of a JOULE II project of the European Union (1993-1995). Extensive experimental studies have been carried out at the Forschungszentrum Juelich GmbH (KFA) in Germany and at Haldor Topsoee A/S in Denmark. (orig.)

  8. Embedded system based on PWM control of hydrogen generator with SEPIC converter

    Science.gov (United States)

    Fall, Cheikh; Setiawan, Eko; Habibi, Muhammad Afnan; Hodaka, Ichijo

    2017-09-01

    The objective of this paper is to design and to produce a micro electrical plant system based on fuel cell for teaching material-embedded systems in technical vocational training center. Based on this, the student can experience generating hydrogen by fuel cells, controlling the rate of hydrogen generation by the duty ration of single-ended primary-inductor converter(SEPIC), drawing the curve rate of hydrogen to duty ratio, generating electrical power by using hydrogen, and calculating the fuel cell efficiency when it is used as electrical energy generator. This project is of great importance insofar as students will need to acquire several skills to be able to realize it such as continuous DC DC conversion and the scientific concept behind the converter, the regulation of systems with integral proportional controllers, the installation of photovoltaic cells, the use of high-tech sensors, microcontroller programming, object-oriented programming, mastery of the fuel cell syste

  9. Three omni-directional wheels control on a mobile robot

    OpenAIRE

    Ribeiro, António Fernando; Moutinho, Ivo; Silva, Pedro; Fraga, Carlos; Pereira, Nino

    2004-01-01

    Traditional two wheels differential drive normally used on mobile robots have manoeuvrability limitations and take time to sort out. Most teams use two driving wheels (with one or two cast wheels), four driving wheels and even three driving wheels. A three wheel drive with omni-directional wheel has been tried with success, and was implemented on fast moving autonomous mobile robots. This paper deals with the mathematical kinematics description of such mobile platform, it describes the advant...

  10. SMR-CL, A Real-time Control Language for Mobile Robots

    DEFF Research Database (Denmark)

    Andersen, Nils Axel; Ravn, Ole

    2004-01-01

    The paper describes requirements and implementation of a tactical control lan¬guage for mobile robots. Emphasis is given to the real-time issues of the language especially the isolation of the hard real-time and the soft real-time layers of the mobile robot control system. The language may be used...

  11. Control of dealkylation vs ring hydrogenation by use of ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Gultekin, S.; Satterfield, C.N. [King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia). Chemical Engineering Dept.

    1995-05-01

    Hydrotreating studies with propylbenzene as a model compound on a commercial NiMo/Al{sub 2}O{sub 3} catalyst at 300-360{degree}C and 6.9 MPa showed that selectivity to ring hydrogenation vs dealkylation was increased by addition of ammonia at partial pressures up to 49 kPa, although overall activity decreased. Both reactions followed first-order kinetics. Selectivity was markedly increased at the lowest temperatures but again was accompanied by the lowest overall activity. The poisoning effect of ammonia here is much greater than that previously observed on hydrodesulfurization of thiophene or hydrodeoxygenation of dibenzofuran under identical reaction conditions. 6 refs., 3 figs., 3 tabs.

  12. Kinematics, dynamics and control design of 4WIS4WID mobile robots

    Directory of Open Access Journals (Sweden)

    Ming-Han Lee

    2015-01-01

    Full Text Available Kinematic and dynamic modelling and corresponding control design of a four-wheel-independent steering and four-wheel-independent driving (4WIS4WID mobile robot are presented in this study. Different from the differential or car-like mobile robot, the 4WIS4WID mobile robot is controlled by four steering and four driving motors, so the control scheme should possess the ability to integrate and manipulate the four independent wheels. A trajectory tracking control scheme is developed for the 4WIS4WID mobile robot, where both non-linear kinematic control and dynamic sliding-mode control are designed. All of the stabilities of the kinematic and dynamic control laws are proved by Lyapunov stability analysis. Finally, the feasibility and validity of the proposed trajectory tracking control scheme are confirmed through computer simulations.

  13. Migration control for mobile agents based on passport and visa

    OpenAIRE

    Guan, SU; Wang, T; Ong, SH

    2003-01-01

    Research on mobile agents has attracted much attention as this paradigm has demonstrated great potential for the next-generation e-commerce. Proper solutions to security-related problems become key factors in the successful deployment of mobile agents in e-commerce systems. We propose the use of passport and visa (P/V) for securing mobile agent migration across communities based on the SAFER e-commerce framework. P/V not only serves as up-to-date digital credentials for agent-host authentica...

  14. Dynamic optimization and robust explicit model predictive control of hydrogen storage tank

    KAUST Repository

    Panos, C.

    2010-09-01

    We present a general framework for the optimal design and control of a metal-hydride bed under hydrogen desorption operation. The framework features: (i) a detailed two-dimension dynamic process model, (ii) a design and operational dynamic optimization step, and (iii) an explicit/multi-parametric model predictive controller design step. For the controller design, a reduced order approximate model is obtained, based on which nominal and robust multi-parametric controllers are designed. © 2010 Elsevier Ltd.

  15. Dynamic optimization and robust explicit model predictive control of hydrogen storage tank

    KAUST Repository

    Panos, C.; Kouramas, K.I.; Georgiadis, M.C.; Pistikopoulos, E.N.

    2010-01-01

    We present a general framework for the optimal design and control of a metal-hydride bed under hydrogen desorption operation. The framework features: (i) a detailed two-dimension dynamic process model, (ii) a design and operational dynamic optimization step, and (iii) an explicit/multi-parametric model predictive controller design step. For the controller design, a reduced order approximate model is obtained, based on which nominal and robust multi-parametric controllers are designed. © 2010 Elsevier Ltd.

  16. A Matlab-Based Graphical User Interface for Simulation and Control Design of a Hydrogen Mixer

    Science.gov (United States)

    Richter, Hanz; Figueroa, Fernando

    2003-01-01

    A Graphical User Interface (GUI) that facilitates prediction and control design tasks for a propellant mixer is described. The Hydrogen mixer is used in rocket test stand operations at the NASA John C. Stennis Space Center. The mixer injects gaseous hydrogen (GH2) into a stream of liquid hydrogen (LH2) to obtain a combined flow with desired thermodynamic properties. The flows of GH2 and LH2 into the mixer are regulated by two control valves, and a third control valve is installed at the exit of the mixer to regulate the combined flow. The three valves may be simultaneously operated in order to achieve any desired combination of total flow, exit temperature and mixer pressure within the range of operation. The mixer, thus, constitutes a three-input, three-output system. A mathematical model of the mixer has been obtained and validated with experimental data. The GUI presented here uses the model to predict mixer response under diverse conditions.

  17. Real-time Non-linear Target Tracking Control of Wheeled Mobile Robots

    Institute of Scientific and Technical Information of China (English)

    YU Wenyong

    2006-01-01

    A control strategy for real-time target tracking for wheeled mobile robots is presented. Using a modified Kalman filter for environment perception, a novel tracking control law derived from Lyapunov stability theory is introduced. Tuning of linear velocity and angular velocity with mechanical constraints is applied. The proposed control system can simultaneously solve the target trajectory prediction, real-time tracking, and posture regulation problems of a wheeled mobile robot. Experimental results illustrate the effectiveness of the proposed tracking control laws.

  18. Spread and Control of Mobile Benign Worm Based on Two-Stage Repairing Mechanism

    Directory of Open Access Journals (Sweden)

    Meng Wang

    2014-01-01

    Full Text Available Both in traditional social network and in mobile network environment, the worm is a serious threat, and this threat is growing all the time. Mobile smartphones generally promote the development of mobile network. The traditional antivirus technologies have become powerless when facing mobile networks. The development of benign worms, especially active benign worms and passive benign worms, has become a new network security measure. In this paper, we focused on the spread of worm in mobile environment and proposed the benign worm control and repair mechanism. The control process of mobile benign worms is divided into two stages: the first stage is rapid repair control, which uses active benign worm to deal with malicious worm in the mobile network; when the network is relatively stable, it enters the second stage of postrepair and uses passive mode to optimize the environment for the purpose of controlling the mobile network. Considering whether the existence of benign worm, we simplified the model and analyzed the four situations. Finally, we use simulation to verify the model. This control mechanism for benign worm propagation is of guiding significance to control the network security.

  19. Studies on impurity control and hydrogen pumping with chromium gettering in ISX-B

    International Nuclear Information System (INIS)

    Mioduszewski, P.; Simpkins, J.E.; Edmonds, P.H.; Isler, R.C.; Lazarus, E.A.; Ma, C.H.; Murakami, M.; Wootton, A.J.

    1984-01-01

    Chromium gettering has been proven to be a trouble-free and efficient method of surface pumping in tokamaks. The impurity control capabilities are excellent and comparable to that of titanium. The hydrogen uptake is reduced to monolayer quantities on the surface. The expansion of the operating space is similar to that seen with titanium without the disadvantage of strongly increased hydrogen fluxes. Possible applications of chromium gettering are: impurity control in contemporary tokamaks; surface pumping in short pulse DT-burning devices to minimize tritium inventory, and wall conditioning of future large machines prior to operation

  20. Control of hydrogen concentration in reactor containment buildings by using passive catalytic recombiners

    International Nuclear Information System (INIS)

    Wolff, U.

    1993-01-01

    Severe accidents in nuclear power plants have the potential to generate hydrogen within the reactor containment building in concentrations likely to deflagrate or even detonate. This could endanger the containment integrity. Autocatalytic devices have been developed by the NIS company in Hanau, Germany, to control the hydrogen concentration within the containment. These devices have been tested by the Battelle Institute in Frankfurt, Germany, under conditions relevant to severe accidents. The catalytic device functions as required in a wide band of gas mixtures ranging from inerted conditions with low-hydrogen and/or low-oxygen concentrations up to detonable mixtures. The device starts up quickly, and has a high resistance against catalyst poisons including the effects of oil or cable fires. The device makes a strong contribution to gas mixing in the containment atmosphere. The paper summarizes the development work done and describes the final design of the device. Theoretical tools for analysis and prediction of catalyst performance in containment environments have been developed by the Battelle Institute and the Technical University of Munich. These tools have been verified and validated against experimental data. A phenomenological discussion of accident scenarios is used to explain the functional requirements for the autocatalytic devices in the control of hydrogen. Both the potential for and limitations of such devices for hydrogen control are discussed for large dry containments (PWRs) and for those which are originally inerted (BWRs)

  1. Multimodal exercise training in multiple sclerosis: A randomized controlled trial in persons with substantial mobility disability.

    Science.gov (United States)

    Sandroff, Brian M; Bollaert, Rachel E; Pilutti, Lara A; Peterson, Melissa L; Baynard, Tracy; Fernhall, Bo; McAuley, Edward; Motl, Robert W

    2017-10-01

    Mobility disability is a common, debilitating feature of multiple sclerosis (MS). Exercise training has been identified as an approach to improve MS-related mobility disability. However, exercise randomized controlled trials (RCTs) on mobility in MS have generally not selectively targeted those with the onset of irreversible mobility disability. The current multi-site RCT compared the efficacy of 6-months of supervised, multimodal exercise training with an active control condition for improving mobility, gait, physical fitness, and cognitive outcomes in persons with substantial MS-related mobility disability. 83 participants with substantial MS-related mobility disability underwent initial mobility, gait, fitness, and cognitive processing speed assessments and were randomly assigned to 6-months of supervised multimodal (progressive aerobic, resistance, and balance) exercise training (intervention condition) or stretching-and-toning activities (control condition). Participants completed the same outcome assessments halfway through and immediately following the 6-month study period. There were statistically significant improvements in six-minute walk performance (F(2158)=3.12, p=0.05, η p 2 =0.04), peak power output (F(2150)=8.16, pmobility disability. This is critical for informing the development of multi-site exercise rehabilitation programs in larger samples of persons with MS-related mobility disability. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Difficulties in controlling mobilization pain using a standardized patient-controlled analgesia protocol in burns.

    Science.gov (United States)

    Nilsson, Andreas; Kalman, Sigga; Sonesson, Lena Karin; Arvidsson, Anders; Sjöberg, Folke

    2011-01-01

    The aim of this study was to evaluate pain relief for patients with burns during rest and mobilization with morphine according to a standard protocol for patient-controlled analgesia (PCA). Eighteen patients with a mean (SD) burned TBSA% of 26 (20) were studied for 10 days. Using a numeric rating scale (NRS, 0 = no pain and 10 = unbearable pain), patients were asked to estimate their acceptable and worst experienced pain by specifying a number on a scale and at what point they would like additional analgesics. Patients were allowed free access to morphine with a PCA pump device. Bolus doses were set according to age, (100 - age)/24 = bolus dose (mg), and 6 minutes lockout time. Degrees of pain, morphine requirements, doses delivered and demanded, oral intake of food, and antiemetics given were used as endpoints. Acceptable pain (mean [SD]) was estimated to be 3.8 (1.3) on the NRS, and additional treatment was considered necessary at scores of 4.3 (1.6) or more. NRS at rest was 2.7 (2.2) and during mobilization 4.7 (2.6). Required mean morphine per day was 81 (15) mg, and the number of doses requested increased during the first 6 days after the burn. The authors found no correlation between dose of morphine required and any other variables. Background pain can be controlled adequately with a standard PCA protocol. During mobilization, the pain experienced was too intense, despite having the already high doses of morphine increased. The present protocol must be refined further to provide analgesia adequate to cover mobilization as well.

  3. Integrated hydrogen control solutions for severe accidents using passive autocatalytic recombiners

    International Nuclear Information System (INIS)

    Bauer, M.; Tietsch, W.; Sabate Farnos, R.

    2012-01-01

    In a severe accident or a beyond-design-basis-accident, the reaction of water with zirconium alloy cladding, radiolysis of water, corium-concrete reactions and other corrosion phenomena generate hydrogen (H2). The detonation of this H2 in containment or in auxiliary buildings can result in damage to structures or loss of containment integrity. Identifying the generation and special distribution of hydrogen and controlling its concentration with Passive Autocatalytic Recombiners (PARs) solves this concern. Westinghouse's approach for hydrogen management starts by defining the quantities and transport/distribution of H 2 in-containment and out of containment with analysis tools such as MAAP, MELCOR, GASFLOW or FATE. Based on the results of these analyses, an optimized H2 Control Strategy is proposed in terms of number and location of PARs, and efficient integration with other H 2 management devices like e.g. existing igniters, H 2 monitors, etc.

  4. Propriety check for quenching meshes for control of hydrogen combustion between two compartments

    International Nuclear Information System (INIS)

    Yang, S. Y.; Jeong, S. H.; Kim, H. Z.; Kim, H. D.; Hong, S. W.

    2001-01-01

    In our previous study, the quenching meshes have been proposed for the control of hydrogen combustion under nuclear severe accident. It has been investigated whether the method of installation of quenching mesh to prevent flame from propagating to the other compartment is proper or not. Schlieren photograph is used to visualize the propagation of flame between two compartments. Without the quenching mesh equipped between the compartments, it has been observed that the flame always propagates from a compartment to the other. The data on quencing distance of hydrogen premixed flames gotten in our previous study is alayzed to setup of optimum quenching mesh, too. Such experimental results establish that the quenching meshes proposed for the control of hydrogen combustion are resonably available

  5. Control of oxygen impurity and hydrogen recycling in the compact helical system (CHS)

    International Nuclear Information System (INIS)

    Noda, N.; Okamura, S.; Aoki, T.; Yamada, H.; Tsuzuki, K.; Matsuoka, K.; Iguchi, H.; Hosokawa, M.; Kaneko, O.; Kubo, S.; Morita, S.; Nishimura, K.; Sagara, A.; Shoji, T.; Takahashi, C.; Takeiri, Y.; Takita, Y.; Amemiya, H.; Okazaki, K.; Oyama, Y.; Shimizu, K.; Yano, K.

    1990-01-01

    In order to reduce oxygen impurity and hydrogen recycling, ECR discharge cleaning with hydrogen, glow discharge with helium, and titanium gettering have been applied. The ECR discharge cleaning was found to be effective in reducing oxygen impurities in ECRH discharges. However, it was not sufficiently effective to give a wide operational density range in NBI heated discharges. Titanium gettering is essential for this purpose, and controllable discharges have been achieved in the density range 1-10x10 19 m -3 , with discharge length more than 850 ms with the aid of titanium gettering. Both helium-glow discharge and Ti gettering are useful to control hydrogen recycling even with a stainless steel wall. (orig.)

  6. Web Environment for Programming and Control of a Mobile Robot in a Remote Laboratory

    Science.gov (United States)

    dos Santos Lopes, Maísa Soares; Gomes, Iago Pacheco; Trindade, Roque M. P.; da Silva, Alzira F.; de C. Lima, Antonio C.

    2017-01-01

    Remote robotics laboratories have been successfully used for engineering education. However, few of them use mobile robots to to teach computer science. This article describes a mobile robot Control and Programming Environment (CPE) and its pedagogical applications. The system comprises a remote laboratory for robotics, an online programming tool,…

  7. A passive apparatus for controlled-flux delivery of biocides: hydrogen peroxide as an example

    DEFF Research Database (Denmark)

    Olsen, Stefan Møller; Pedersen, L.T.; Dam-Johansen, Kim

    2010-01-01

    A new test method has been developed to estimate the required release rate of hydrogen peroxide (H2O2) to prevent marine biofouling. The technique exploits a well-defined concentration gradient of biocide across a cellulose acetate membrane. A controlled flux of H2O2, an environmentally friendly ...

  8. Electricity versus hydrogen for passenger cars under stringent climate change control

    NARCIS (Netherlands)

    Rösler, H.; van der Zwaan, B.; Keppo, I.; Bruggink, J.

    2014-01-01

    In this article we analyze how passenger car transportation in Europe may change this century under permanent high oil prices and stringent climate control policy. We focus on electricity and hydrogen as principal candidate energy carriers, because these two options are increasingly believed to

  9. Status report on controlled nuclear fusion as a source of hydrogen energy

    International Nuclear Information System (INIS)

    Powell, J.

    1975-01-01

    The present status of controlled fusion research is reviewed. Possible future reseach is also described. Tokamak systems using both fusion and fissionable fuels are discussed. Various aspects of hydrogen production by fusion reactors are described according to cost and economics. auth)

  10. Butterfly valve with metal seals controls flow of hydrogen from cryogenic through high temperatures

    Science.gov (United States)

    Johnson, L. D.

    1967-01-01

    Butterfly valve with metal seals operates over a temperature range of minus 423 degrees to plus 440 degrees F with hydrogen as a medium and in a radiation environment. Media flow is controlled by an internal butterfly disk which is rotated by an actuation shaft.

  11. Dicyclopentadiene Hydrogenation in Trickle Bed Reactor under Forced Periodic Control

    Czech Academy of Sciences Publication Activity Database

    Skála, D.; Hanika, Jiří

    2008-01-01

    Roč. 62, č. 2 (2008), s. 215-218 ISSN 1336-7242 R&D Projects: GA MPO(CZ) FT-TA/039 Institutional research plan: CEZ:AV0Z40720504 Keywords : periodic control * trickle -bed reactor * dicyclopentadiene Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  12. Difficulties in Controlling Mobilization Pain Using a Standardized Patient-Controlled Analgesia Protocol in Burns

    OpenAIRE

    Nilsson, Andreas; Kalman, Sigga; Arvidsson, Anders; Sjöberg, Folke

    2011-01-01

    The aim of this study was to evaluate pain relief for patients with burns during rest and mobilization with morphine according to a standard protocol for patient-controlled analgesia (PCA). Eighteen patients with a mean (SD) burned TBSA% of 26 (20) were studied for 10 days. Using a numeric rating scale (NRS, 0 = no pain and 10 = unbearable pain), patients were asked to estimate their acceptable and worst experienced pain by specifying a number on a scale and at what point they would like addi...

  13. Optimizing the Binding Energy of Hydrogen on Nanostructured Carbon Materials through Structure Control and Chemical Doping

    Energy Technology Data Exchange (ETDEWEB)

    Jie Liu

    2011-02-01

    The DOE Hydrogen Sorption Center of Excellence (HSCoE) was formed in 2005 to develop materials for hydrogen storage systems to be used in light-duty vehicles. The HSCoE and two related centers of excellence were created as follow-on activities to the DOE Office of Energy Efficiency and Renewable Energy’s (EERE’s) Hydrogen Storage Grand Challenge Solicitation issued in FY 2003. The Hydrogen Sorption Center of Excellence (HSCoE) focuses on developing high-capacity sorbents with the goal to operate at temperatures and pressures approaching ambient and be efficiently and quickly charged in the tank with minimal energy requirements and penalties to the hydrogen fuel infrastructure. The work was directed at overcoming barriers to achieving DOE system goals and identifying pathways to meet the hydrogen storage system targets. To ensure that the development activities were performed as efficiently as possible, the HSCoE formed complementary, focused development clusters based on the following four sorption-based hydrogen storage mechanisms: 1. Physisorption on high specific surface area and nominally single element materials 2. Enhanced H2 binding in Substituted/heterogeneous materials 3. Strong and/or multiple H2 binding from coordinated but electronically unsatruated metal centers 4. Weak Chemisorption/Spillover. As a member of the team, our group at Duke studied the synthesis of various carbon-based materials, including carbon nanotubes and microporous carbon materials with controlled porosity. We worked closely with other team members to study the effect of pore size on the binding energy of hydrogen to the carbon –based materials. Our initial project focus was on the synthesis and purification of small diameter, single-walled carbon nanotubes (SWNTs) with well-controlled diameters for the study of their hydrogen storage properties as a function of diameters. We developed a chemical vapor deposition method that synthesized gram quantities of carbon nanotubes with

  14. Development of a green bipropellant hydrogen peroxide thruster for attitude control on satellites

    Science.gov (United States)

    Woschnak, A.; Krejci, D.; Schiebl, M.; Scharlemann, C.

    2013-03-01

    This document describes the selection assessment of propellants for a 1-newton green bipropellant thruster for attitude control on satellites. The development of this thruster was conducted as a part of the project GRASP (Green Advanced Space Propellants) within the European FP7 research program. The green propellant combinations hydrogen peroxide (highly concentrated with 87.5 %(wt.)) with kerosene or hydrogen peroxide (87.5 %(wt.)) with ethanol were identified as interesting candidates and were investigated in detail with the help of an experimental combustion chamber in the chemical propulsion laboratory at the Forschungsund Technologietransfer GmbH ― Fotec. Based on the test results, a final selection of propellants was performed.

  15. Hybrid Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bak, Thomas; Bendtsen, Jan Dimon; Ravn, Anders Peter

    We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory tracking...

  16. Hybrid Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bak, Thomas; Bendtsen, Jan Dimon; Ravn, Anders Peter

    2003-01-01

    We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory tracking...

  17. Control design for a mobile robot Including tire behavior

    NARCIS (Netherlands)

    Ploeg, J.; Schouten, H.E.; Nijmeijer, H.

    2008-01-01

    In order to support the development process of Advanced Driver Assistance systems for road vehicles, TNO is operating a hardware-in-the-loop test setup. In this facility, called VeHIL, vehicles in the direct neighborhood of the test vehicle are simulated using wheeled mobile robots. Due to the

  18. Control design for a mobile robot including tire behavior

    NARCIS (Netherlands)

    Ploeg, J.; Schouten, H.E.; Nijmeijer, H.

    2008-01-01

    In order to support the development process of Advanced Driver Assistance systems for road vehicles, TNO is operating a hardware-in-the-loop test setup. In this facility, called VeHIL, vehicles in the direct neighborhood of the test vehicle are simulated using wheeled mobile robots. Due to the

  19. Hybrid Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bak, Thomas; Bendtsen, Jan Dimon; Ravn, Anders Peter

    2003-01-01

    We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory trackin...

  20. Interface-controlled, high-mobility organic transistors

    NARCIS (Netherlands)

    Jurchescu, Oana D.; Popinciuc, Mihaita; van Wees, Bart J.; Palstra, Thomas T. M.

    2007-01-01

    The achievement of high mobilities in field-effect transistors (FETs) is one of the main challenges for the widespread application of organic conductors in devices. Good device performance of a single-crystal pentacene FET requires both removal of impurity molecules from the bulk and the

  1. Decentralized coverage control problems for mobile robotic sensor and actuator networks

    CERN Document Server

    Savkin, A; Xi, Z; Javed, F; Matveev, A; Nguyen, H

    2015-01-01

    This book introduces various coverage control problems for mobile sensor networks including barrier, sweep and blanket. Unlike many existing algorithms, all of the robotic sensor and actuator motion algorithms developed in the book are fully decentralized or distributed, computationally efficient, easily implementable in engineering practice and based only on information on the closest neighbours of each mobile sensor and actuator and local information about the environment. Moreover, the mobile robotic sensors have no prior information about the environment in which they operation. These various types of coverage problems have never been covered before by a single book in a systematic way. Another topic of this book is the study of mobile robotic sensor and actuator networks. Many modern engineering applications include the use of sensor and actuator networks to provide efficient and effective monitoring and control of industrial and environmental processes. Such mobile sensor and actuator networks are abl...

  2. 40 CFR 266.107 - Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Standards to control hydrogen chloride... WASTES AND SPECIFIC TYPES OF HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.107 Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions...

  3. Model predictive control in light naphtha distillation column of gasoline hydrogenation process

    Directory of Open Access Journals (Sweden)

    Kornkrit Chiewchanchairat

    2015-03-01

    Full Text Available The main scope of this research is for designing and implementing of model predictive control (MPC on the light naphtha distillation column of gasoline hydrogenation process. This model is designed by using robust multivariable predictive control technology (RMPCT. The performance of MPC controller is better than PID controllers 32.1 % those are comparing by using as the same of objective function and also in the MPC controller can be used for steam optimization that is shown in this research, stream consumption is reduced 6.6 Kg/ m3 of fresh feed.

  4. Path tracking control of mobile robots with techniques based on the use of curved abscissa

    International Nuclear Information System (INIS)

    Micaelli, A.

    1992-01-01

    The paper describes a particular method, developed by the CEA, for the control of mobile robot trajectories based on Cornu's spiral, i.e; sections of trajectories with constant curvature. New approaches are discussed for methods more convenient

  5. Learning Mobility: Adaptive Control Algorithms for the Novel Unmanned Ground Vehicle (NUGV)

    National Research Council Canada - National Science Library

    Blackburn, Mike

    2003-01-01

    Mobility is a serious limiting factor in the usefulness of unmanned ground vehicles, This paper contains a description of our approach to develop control algorithms for the Novel Unmanned Ground Vehicle (NUGV...

  6. Consensus Formation Control for a Class of Networked Multiple Mobile Robot Systems

    Directory of Open Access Journals (Sweden)

    Long Sheng

    2012-01-01

    for investigating the sufficient conditions to linear control gain design for the system with constant time delays. Simulation results as well as experimental studies on Pioneer 3 series mobile robots are shown to verify the effectiveness of the proposed approach.

  7. Visual Servo Tracking Control of a Wheeled Mobile Robot with a Monocular Fixed Camera

    National Research Council Canada - National Science Library

    Chen, J; Dixon, W. E; Dawson, D. M; Chitrakaran, V. K

    2004-01-01

    In this paper, a visual servo tracking controller for a wheeled mobile robot (WMR) is developed that utilizes feedback from a monocular camera system that is mounted with a fixed position and orientation...

  8. Effects of joint mobilization on chronic ankle instability: a randomized controlled trial.

    Science.gov (United States)

    Cruz-Díaz, David; Lomas Vega, Rafael; Osuna-Pérez, Maria Catalina; Hita-Contreras, Fidel; Martínez-Amat, Antonio

    2015-01-01

    To evaluate the effects of joint mobilization, in which movement is applied to the ankle's dorsiflexion range of motion, on dynamic postural control and on the self-reported instability of patients with chronic ankle instability (CAI). A double-blind, placebo-controlled, randomized trial with repeated measures and a follow-up period. Ninety patients with a history of recurrent ankle sprain, self-reported instability, and a limited dorsiflexion range of motion, were randomly assigned to either the intervention group (Joint Mobilizations, 3 weeks, two sessions per week) the placebo group (Sham Mobilizations, same duration as joint mobilization) or the control group, with a 6 months follow-up. Dorsiflexion Range of Motion (DFROM), Star Excursion Balance Test (SEBT) and CAI Tool (CAIT) were outcome measures. A separate 3 × 4 mixed model analysis of variance was performed to examine the effect of treatment conditions and time, and intention-to-treat (ITT) analysis was applied to evaluate the effect of the independent variable. The application of joint mobilization resulted in better scores of DFROM, CAIT, and SEBTs in the intervention group when compared with the placebo or the control groups (p ankle DFROM, postural control, and self-reported instability. These results suggest that joint mobilization could be applied to patients with recurrent ankle sprain to help restore their functional stability. Implications for Rehabilitation Functional instability is a very common sequela in patients with CAI, resulting in reduced quality of living due to the limitations it imposes on daily life activities. The mobilization with movement technique presented by Mulligan, and based on the joint mobilization accompanied by active movement, appears as a valuable tool to be employed by physical therapists to restore ankle function after a recurrent ankle sprain history. ROM restriction, subjective feeling of instability and dynamic postural control are benefiting from the joint

  9. Nanostructuring of Aluminum Alloy Powders by Cryogenic Attrition with Hydrogen-Free Process Control Agent

    Science.gov (United States)

    2015-02-01

    Nanostructuring of Aluminum Alloy Powders by Cryogenic Attrition with Hydrogen-Free Process Control Agent by Frank Kellogg , Clara Hofmeister...Process Control Agent Frank Kellogg Bowhead Science and Technology Clara Hofmeister Advanced Materials Processing and Analysis Center...NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Frank Kellogg , Clara Hofmeister, Anit Giri, and Kyu Cho 5d. PROJECT NUMBER 5e

  10. Robust balancing and position control of a single spherical wheeled mobile platform

    OpenAIRE

    Yavuz, Fırat; Yavuz, Firat; Ünel, Mustafa; Unel, Mustafa

    2016-01-01

    Self-balancing mobile platforms with single spherical wheel, generally called ballbots, are suitable example of underactuated systems. Balancing control of a ballbot platform, which aims to maintain the upright orientation by rejecting external disturbances, is important during station keeping or trajectory tracking. In this paper, acceleration based balancing and position control of a single spherical wheeled mobile platform that has three single-row omniwheel drive m...

  11. Central Vehicle Dynamics Control of the Robotic Research Platform ROboMObil

    OpenAIRE

    Bünte, Tilman; Ho, Lok Man; Satzger, Clemens; Brembeck, Jonathan

    2014-01-01

    The ROboMObil is DLR’s space-robotics driven by-wire electro-mobile research platform for mechatronic actuators, vehicle dynamics control, human machine interfaces, and autonomous driving (DLR = German Aerospace Center). Due to its four highly integrated identical Wheel Robots it exhibits an extraordinary manoeuvrability even allowing for driving sideward or rotating on the spot. Topics related to vehicle dynamics control are addressed in this article.

  12. An Optimal Mobile Service for Telecare Data Synchronization using a Role-based Access Control Model and Mobile Peer-to-Peer Technology.

    Science.gov (United States)

    Ke, Chih-Kun; Lin, Zheng-Hua

    2015-09-01

    The progress of information and communication technologies (ICT) has promoted the development of healthcare which has enabled the exchange of resources and services between organizations. Organizations want to integrate mobile devices into their hospital information systems (HIS) due to the convenience to employees who are then able to perform specific healthcare processes from any location. The collection and merage of healthcare data from discrete mobile devices are worth exploring possible ways for further use, especially in remote districts without public data network (PDN) to connect the HIS. In this study, we propose an optimal mobile service which automatically synchronizes the telecare file resources among discrete mobile devices. The proposed service enforces some technical methods. The role-based access control model defines the telecare file resources accessing mechanism; the symmetric data encryption method protects telecare file resources transmitted over a mobile peer-to-peer network. The multi-criteria decision analysis method, ELECTRE (Elimination Et Choice Translating Reality), evaluates multiple criteria of the candidates' mobile devices to determine a ranking order. This optimizes the synchronization of telecare file resources among discrete mobile devices. A prototype system is implemented to examine the proposed mobile service. The results of the experiment show that the proposed mobile service can automatically and effectively synchronize telecare file resources among discrete mobile devices. The contribution of this experiment is to provide an optimal mobile service that enhances the security of telecare file resource synchronization and strengthens an organization's mobility.

  13. Power control algorithms for mobile ad hoc networks

    Directory of Open Access Journals (Sweden)

    Nuraj L. Pradhan

    2011-07-01

    We will also focus on an adaptive distributed power management (DISPOW algorithm as an example of the multi-parameter optimization approach which manages the transmit power of nodes in a wireless ad hoc network to preserve network connectivity and cooperatively reduce interference. We will show that the algorithm in a distributed manner builds a unique stable network topology tailored to its surrounding node density and propagation environment over random topologies in a dynamic mobile wireless channel.

  14. Novel CO{sub 2}-thickeners for improved mobility control

    Energy Technology Data Exchange (ETDEWEB)

    Enick, Dr. Robert M.; Beckman, Dr. Eric J.; Hamilton, Dr. Andrew

    2000-02-02

    The objective of this study was to design, synthesize, and characterize thickening agents for dense carbon dioxide and to evaluate their solubility and viscosity-enhancing potential in CO{sub 2}. Hydrocarbon-fluorocarbon random copolymers, sulfated hydrocarbon-fluorocarbon random copolymers, semifluorinated trialkyltin fluorides and small hydrogen-bonding compounds were evaluated. Random copolymers of styrene and heptadecafluorodecyl acrylate were characterized by high solubility ion dense carbon dioxide and the most substantial increases in solution viscosity. Falling cylinder viscometry results indicated that the 29%styrene--71%fluoroacylate bulk-polymerized copolymer induced 2--250 fold increases in viscosity at copolymer concentrations of 0.2--5.0wt%.

  15. Novel CO{sub 2}-thickeners for improved mobility control

    Energy Technology Data Exchange (ETDEWEB)

    Enick, Dr. Robert M.; Beckman, Dr. Eric J.; Hamilton, Dr. Andrew

    2000-02-02

    The objective of this study was to design, synthesize, and characterize thickening agents for dense carbon dioxide and to evaluate their solubility and viscosity-enhancing potential in CO{sub 2}. Previously, fluoroacrylate homopolymers and fluorinated telechelic ionomers were shown to increase the viscosity of carbon dioxide by a factor of 3--4 at concentrations of 2--3 at concentrations of 4--5 wt%. This report details the findings for several new types of carbon dioxide thickening candidates. Hydrocarbon-fluorocarbon random copolymers, sulfonated hydrocarbon-fluorocarbon random copolymers, semifluorinated trialkyltin fluorides and small hydrogen-bounding compounds were evaluated.

  16. Control of accidental releases of hydrogen selenide in vented storage cabinets

    Science.gov (United States)

    Fthenakis, V. M.; Moskowitz, P. D.; Sproull, R. D.

    1988-07-01

    Highly toxic hydrogen selenide and hydrogen sulfide gases are used in the production of copper-indium-diselenide photovoltaic cells by reactive sputtering. In the event of an accident, these gases may be released to the atmosphere and pose hazards to public and occupational safety and health. This paper outlines an approach for designing systems for the control of these releases given the uncertainty in release conditions and lack of data on the chemical systems involved. Accidental releases of these gases in storage cabinets can be controlled by either a venturi and packed-bed scrubber and carbon adsorption bed, or containment scrubbing equipment followed by carbon adsorption. These systems can effectively reduce toxic gas emissions to levels needed to protect public health. The costs of these controls (˜0.012/Wp) are samll in comparison with current (˜6/Wp) and projected (˜I/Wp) production costs.

  17. Discrete Globalised Dual Heuristic Dynamic Programming in Control of the Two-Wheeled Mobile Robot

    OpenAIRE

    Marcin Szuster; Zenon Hendzel

    2014-01-01

    Network-based control systems have been emerging technologies in the control of nonlinear systems over the past few years. This paper focuses on the implementation of the approximate dynamic programming algorithm in the network-based tracking control system of the two-wheeled mobile robot, Pioneer 2-DX. The proposed discrete tracking control system consists of the globalised dual heuristic dynamic programming algorithm, the PD controller, the supervisory term, and an additional control signal...

  18. Redox control of arsenic mobilization in Bangladesh groundwater

    International Nuclear Information System (INIS)

    Zheng, Y.; Stute, M.; Geen, A. van; Gavrieli, I.; Dhar, R.; Simpson, H.J.; Schlosser, P.; Ahmed, K.M.

    2004-01-01

    Detailed hydrochemical measurements, δ 34 S SO4 and 3 H analyses were performed on 37 groundwater samples collected during February 1999, January and March 2000 from 6 locations in eastern and southeastern Bangladesh to examine redox processes that lead to As mobilization in groundwater. The study sites were chosen based on available nation-wide As surveys to span the entire spectrum of As concentrations in Bangladesh groundwater, and to represent 3 of 5 major geological units of the Ganges-Brahmaputra Delta: uplifted Pleistocene terrace, fluvial flood plain and delta plain. Arsenic was found to be mobilized under Fe-reducing conditions in shallow aquifers ( 4 -reducing conditions, suggesting that authigenic sulfide precipitation does not constitute a significant sink for As in these groundwaters. The redox state of the water was characterized by a variety of parameters including dissolved O 2 , NO 3 - , Mn 2+ , Fe 2+ concentrations, and SO 4 2- /Cl - ratios. High dissolved [As] (> 50 μg/l; or > 0.7 μM ) were always accompanied by high dissolved [HCO 3 - ] (> 4 mM), and were close to saturation with respect to calcite. Groundwater enriched in As (200-800 μg/l; or 2.7-10.7 μM) and phosphate (30-100 μM) but relatively low in dissolved Fe (5-40 μM) probably resulted from re-oxidation of reducing, As and Fe enriched water. This history was deduced from isotopic signatures of δ 34 S SO4 and 3 H 2 O ( 3 H) to delineate the nature of redox changes for some of the reducing groundwaters. In contrast, As is not mobilized in presumed Pleistocene aquifers, both shallow (30-60 m) and deep (150-270 m), because conditions were not reducing enough due to lack of sufficient O 2 demand

  19. Study on control characteristics for HTTR hydrogen production system with mock-up test facility

    International Nuclear Information System (INIS)

    Inaba, Yoshitomo; Ohashi, Hirofumi; Nishihara, Tetsuo; Sato, Hiroyuki; Inagaki, Yoshiyuki; Takeda, Tetsuaki; Hayashi, Koji; Takada, Shoji

    2005-01-01

    The Japan Atomic Energy Research Institute has a demonstration test plan of a hydrogen production system by steam reforming of methane coupling with the High-Temperature Engineering Test Reactor (HTTR). Prior to the coupling of a hydrogen production plant with the HTTR, simulation tests with a mock-up test facility of the HTTR hydrogen production system (HTTR-H2) is underway. The test facility is a 1/30-scale of the HTTR-H2 and simulates key components downstream from an intermediate heat exchanger of the HTTR. The main objective of the simulation tests is the establishment and demonstration of control technology, focusing on the mitigation of a thermal disturbance to the reactor by a steam generator (SG) and on the controllability of the pressure difference between the helium and process gases at the reaction tube in a steam reformer (SR). It was confirmed that the fluctuation of the outlet helium gas temperature at the SG and the pressure difference in the SR can be controlled within the allowable range for the HTTR-H2 in the case of the system controllability test for the fluctuation of chemical reaction. In addition, a dynamic simulation code for the HTTR-H2 was verified with the obtained test data

  20. Authenticated Blind Issuing of Symmetric Keys for Mobile Access Control System without Trusted Parties

    Directory of Open Access Journals (Sweden)

    Shin-Yan Chiou

    2013-01-01

    Full Text Available Mobile authentication can be used to verify a mobile user’s identity. Normally this is accomplished through the use of logon passwords, but this can raise the secret-key agreement problem between entities. This issue can be resolved by using a public-key cryptosystem, but mobile devices have limited computation ability and battery capacity and a PKI is needed. In this paper, we propose an efficient, non-PKI, authenticated, and blind issued symmetric key protocol for mobile access control systems. An easy-to-deploy authentication and authenticated key agreement system is designed such that empowered mobile devices can directly authorize other mobile devices to exchange keys with the server upon authentication using a non-PKI system without trusted parties. Empowered mobile users do not know the key value of the other mobile devices, preventing users from impersonating other individuals. Also, for security considerations, this system can revoke specific keys or keys issued by a specific user. The scheme is secure, efficient, and feasible and can be implemented in existing environments.

  1. Unexpected Effects of a System-Distributed Mobile Application in Maternity Care: A Randomized Controlled Trial.

    Science.gov (United States)

    Ledford, Christy J W; Womack, Jasmyne J; Rider, Heather A; Seehusen, Angela B; Conner, Stephen J; Lauters, Rebecca A; Hodge, Joshua A

    2018-06-01

    As pregnant mothers increasingly engage in shared decision making regarding prenatal decisions, such as induction of labor, the patient's level of activation may influence pregnancy outcomes. One potential tool to increase patient activation in the clinical setting is mobile applications. However, research is limited in comparing mobile apps with other modalities of patient education and engagement tools. This study was designed to test the effectiveness of a mobile app as a replacement for a spiral notebook guide as a patient education and engagement tool in the prenatal clinical setting. This randomized controlled trial was conducted in the Women's Health Clinic and Family Health Clinic of three hospitals. Repeated-measures analysis of covariance was used to test intervention effects in the study sample of 205 patients. Mothers used a mobile app interface to more frequently record information about their pregnancy; however, across time, mothers using a mobile app reported a significant decrease in patient activation. The unexpected negative effects in the group of patients randomized to the mobile app prompt these authors to recommend that health systems pause before distributing their own version of mobile apps that may decrease patient activation. Mobile apps can be inherently empowering and engaging, but how a system encourages their use may ultimately determine their adoption and success.

  2. Microcontroller based instrumentation for heater control circuit of tin oxide based hydrogen sensor

    International Nuclear Information System (INIS)

    Premalatha, S.; Krithika, P.; Gunasekaran, G.; Ramakrishnan, R.; Ramanarayanan, R.R.; Prabhu, E.; Jayaraman, V.; Parthasarathy, R.

    2015-01-01

    A thin film sensor based on tin oxide developed in IGCAR is used to monitor very low levels of hydrogen (concentration ranging from 2 ppm to 80 ppm). The heater and the sensor patterns are integrated on a miniature alumina substrate and necessary electrical leads are taken out. For proper functioning of the sensor, the heater has to be maintained at a constant temperature of 350°C. The sensor output (voltage signal) varies with H 2 concentration. In fast breeder reactors, liquid sodium is used as coolant. The sensor is used to detect water/steam leak in secondary sodium circuit. During the start up of the reactor, steam leak into sodium circuit generates hydrogen gas as a product that doesn't dissolve in sodium, but escapes to the surge tank containing argon i.e. in cover gas plenum of sodium circuit. On-line monitoring of hydrogen in cover gas is done to detect an event of water/steam leakage. The focus of this project is on the instrumentation pertaining to the temperature control for the sensor heater. The tin oxide based hydrogen sensor is embedded in a substrate which consists of a platinum heater, essentially a resistor. There is no provision of embedding a temperature sensor on the heater surface due to the physical constraints, without which maintaining a constant heater temperature is a complex task

  3. THE REMOTE AND MOBILE AIR TRAFFIC CONTROL TOWER AND ITS POSSIBLE APPLICATION TO THE OPERATIONAL AREA

    Directory of Open Access Journals (Sweden)

    Tímea VAS

    2014-10-01

    Full Text Available The concept of remote and mobile Air Traffic Control Tower (ATC TWR and its development has started in Europe, Australia and also in the USA, in order to improve the efficiency of Air Traffic Management (ATM systems in terms of air transportation safety. These new technologies are applicable in many countries in peace time, but on mobility reasons these are promoted to achieve commitments in the operational area. This article describes the devices and range of equipment of mobile and remote tower, and their specifications, which can even serve a medium sized airport, furthermore examines, whether how can those provide the air traffic services at an operational airfield.

  4. Control of Hydrogen Embrittlement in High Strength Steel Using Special Designed Welding Wire

    Science.gov (United States)

    2016-03-01

    microstructure 4. A low near ambient temperature is reached. • All four factor must be simultaneously present 3 Mitigating HIC and Improving Weld Fatigue...Performance Through Weld Residual Stress Control UNCLASIFIED:DISTRIBUTION A. Approved for public release: distribution unlimited. Click to edit Master...title style 4 • Welding of Armor Steels favors all these conditions for HIC • Hydrogen Present in Sufficient Degree – Derived from moisture in the

  5. The new realized mobile device for extremal control research and presentation

    Directory of Open Access Journals (Sweden)

    Matej URBANSKÝ

    2015-12-01

    Full Text Available At our department we deal with torsional oscillating mechanical systems (TOMS continuous tuning during its operation in terms of torsional oscillation size. Therefore was build the new mobile device for research and presentation purposes of the TOMS continuous tuning using extremal control method. This paper deals mainly with design of the mobile device and its special compressed air distribution system, which is necessary for its regular function.

  6. Research on Open-Closed-Loop Iterative Learning Control with Variable Forgetting Factor of Mobile Robots

    Directory of Open Access Journals (Sweden)

    Hongbin Wang

    2016-01-01

    Full Text Available We propose an iterative learning control algorithm (ILC that is developed using a variable forgetting factor to control a mobile robot. The proposed algorithm can be categorized as an open-closed-loop iterative learning control, which produces control instructions by using both previous and current data. However, introducing a variable forgetting factor can weaken the former control output and its variance in the control law while strengthening the robustness of the iterative learning control. If it is applied to the mobile robot, this will reduce position errors in robot trajectory tracking control effectively. In this work, we show that the proposed algorithm guarantees tracking error bound convergence to a small neighborhood of the origin under the condition of state disturbances, output measurement noises, and fluctuation of system dynamics. By using simulation, we demonstrate that the controller is effective in realizing the prefect tracking.

  7. Calibration and control for range imaging in mobile robot navigation

    Energy Technology Data Exchange (ETDEWEB)

    Dorum, O.H. [Norges Tekniske Hoegskole, Trondheim (Norway). Div. of Computer Systems and Telematics; Hoover, A. [University of South Florida, Tampa, FL (United States). Dept. of Computer Science and Engineering; Jones, J.P. [Oak Ridge National Lab., TN (United States)

    1994-06-01

    This paper addresses some issues in the development of sensor-based systems for mobile robot navigation which use range imaging sensors as the primary source for geometric information about the environment. In particular, we describe a model of scanning laser range cameras which takes into account the properties of the mechanical system responsible for image formation and a calibration procedure which yields improved accuracy over previous models. In addition, we describe an algorithm which takes the limitations of these sensors into account in path planning and path execution. In particular, range imaging sensors are characterized by a limited field of view and a standoff distance -- a minimum distance nearer than which surfaces cannot be sensed. These limitations can be addressed by enriching the concept of configuration space to include information about what can be sensed from a given configuration, and using this information to guide path planning and path following.

  8. Mobile soak pits improve spray team mobility, productivity and safety of PMI malaria control programs.

    Science.gov (United States)

    Mitchell, David F; Brown, Annie S; Bouare, Sory Ibrahima; Belemvire, Allison; George, Kristen; Fornadel, Christen; Norris, Laura; Longhany, Rebecca; Chandonait, Peter J

    2016-09-15

    In the President's Malaria Initiative (PMI)-funded Africa Indoor Residual Spraying Project (AIRS), end-of-day clean-up operations require the safe disposal of wash water resulting from washing the exterior of spray tanks and spray operators' personal protective equipment. Indoor residual spraying (IRS) programs typically use soak pits - large, in-ground filters - to adsorb, filter and then safely degrade the traces of insecticide found in the wash water. Usually these soak pits are permanent installations serving 30 or more operators, located in a central area that is accessible to multiple spray teams at the end of their workday. However, in remote areas, it is often impractical for teams to return to a central soak pit location for cleanup. To increase operational efficiency and improve environmental compliance, the PMI AIRS Project developed and tested mobile soak pits (MSP) in the laboratory and in field applications in Madagascar, Mali, Senegal, and Ethiopia where the distance between villages can be substantial and the road conditions poor. Laboratory testing confirmed the ability of the easily-assembled MSP to reduce effluent concentrations of two insecticides (Actellic 300-CS and Ficam VC) used by the PMI AIRS Project, and to generate the minimal practicable environmental "footprint" in these remote areas. Field testing in the Mali 2014 IRS campaign demonstrated ease of installation and use, resulted in improved and more consistent standards of clean-up, decreased transportation requirements, improved spray team working conditions, and reduced potential for operator exposure to insecticide. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Velocity Tracking Control of Wheeled Mobile Robots by Iterative Learning Control

    Directory of Open Access Journals (Sweden)

    Xiaochun Lu

    2016-05-01

    Full Text Available This paper presents an iterative learning control (ILC strategy to resolve the trajectory tracking problem of wheeled mobile robots (WMRs based on dynamic model. In the previous study of WMRs’ trajectory tracking, ILC was usually applied to the kinematical model of WMRs with the assumption that desired velocity can be tracked immediately. However, this assumption cannot be realized in the real world at all. The kinematic and dynamic models of WMRs are deduced in this chapter, and a novel combination of D-type ILC algorithm and dynamic model of WMR with random bounded disturbances are presented. To analyze the convergence of the algorithm, the method of contracting mapping, which shows that the designed controller can make the velocity tracking errors converge to zero completely when the iteration times tend to infinite, is adopted. Simulation results show the effectiveness of D-type ILC in the trajectory tracking problem of WMRs, demonstrating the effectiveness and robustness of the algorithm in the condition of random bounded disturbance. A comparative study conducted between D-type ILC and compound cosine function neural network (NN controller also demonstrates the effectiveness of the ILC strategy.

  10. Design and control of mobile traction energy storage system; Auslegung und Steuerung mobiler Traktionsenergiespeicher

    Energy Technology Data Exchange (ETDEWEB)

    Lehnert, Martin; Klausner, Sven [Fraunhofer-Institut fuer Verkehrs- und Infrastruktursysteme IVI, Dresden (Germany). Abt. fuer Fahrzeug- und Verkehrssystemtechnik

    2009-07-01

    Energy storage systems in trams may contribute to a noticeable reduction of energy consumption. Whether this or another operating purpose is to be pursued by the use of an energy store, major importance must in any case be attached to the type of storage technology to be selected, the design of the storage system and the kind of storage control strategy to be used. The latter has an influence on the efficiency of the store usage. It is especially predicative control strategies that offer a high potential to this effect. (orig.)

  11. Adaptive training of neural networks for control of autonomous mobile robots

    NARCIS (Netherlands)

    Steur, E.; Vromen, T.; Nijmeijer, H.; Fossen, T.I.; Nijmeijer, H.; Pettersen, K.Y.

    2017-01-01

    We present an adaptive training procedure for a spiking neural network, which is used for control of a mobile robot. Because of manufacturing tolerances, any hardware implementation of a spiking neural network has non-identical nodes, which limit the performance of the controller. The adaptive

  12. A virtual structure approach to formation control of unicycle mobile robots using mutual coupling

    NARCIS (Netherlands)

    Sadowska, A.D.; van den Broek, T.H.A.; Huijberts, H.J.C.; Wouw, van de N.; Kostic, D.; Nijmeijer, H.

    2011-01-01

    In this article, the formation control problem for unicycle mobile robots is studied. A distributed virtual structure control strategy with mutual coupling between the robots is proposed. The rationale behind the introduction of the coupling terms is the fact that these introduce additional

  13. G-CSF maintains controlled neutrophil mobilization during acute inflammation by negatively regulating CXCR2 signaling

    Science.gov (United States)

    Bajrami, Besnik; Zhu, Haiyan; Zhang, Yu C.

    2016-01-01

    Cytokine-induced neutrophil mobilization from the bone marrow to circulation is a critical event in acute inflammation, but how it is accurately controlled remains poorly understood. In this study, we report that CXCR2 ligands are responsible for rapid neutrophil mobilization during early-stage acute inflammation. Nevertheless, although serum CXCR2 ligand concentrations increased during inflammation, neutrophil mobilization slowed after an initial acute fast phase, suggesting a suppression of neutrophil response to CXCR2 ligands after the acute phase. We demonstrate that granulocyte colony-stimulating factor (G-CSF), usually considered a prototypical neutrophil-mobilizing cytokine, was expressed later in the acute inflammatory response and unexpectedly impeded CXCR2-induced neutrophil mobilization by negatively regulating CXCR2-mediated intracellular signaling. Blocking G-CSF in vivo paradoxically elevated peripheral blood neutrophil counts in mice injected intraperitoneally with Escherichia coli and sequestered large numbers of neutrophils in the lungs, leading to sterile pulmonary inflammation. In a lipopolysaccharide-induced acute lung injury model, the homeostatic imbalance caused by G-CSF blockade enhanced neutrophil accumulation, edema, and inflammation in the lungs and ultimately led to significant lung damage. Thus, physiologically produced G-CSF not only acts as a neutrophil mobilizer at the relatively late stage of acute inflammation, but also prevents exaggerated neutrophil mobilization and the associated inflammation-induced tissue damage during early-phase infection and inflammation. PMID:27551153

  14. Visually and force controlled opening and closing of doors by means of a mobile robot arm

    OpenAIRE

    Milighetti, G.; Hoffmann, E.; Fetzner, Angelika; Kuntze, Helge-Björn

    2012-01-01

    A multi-sensory discrete-continuous control concept has been developed to realize interactive basic skills for humanoid and mobile service robots. In the upper hierarchy level a discrete task control structure enables the flexible execution of primitive skill sequences. In the lower continuous level a suitable controller is chosen with control parameters adapted to the current primitive skill. The basic skill for the frequently occurring task of unlocking and opening a door by means of a mobi...

  15. Development of control technology for HTTR hydrogen production system with mock-up test facility

    International Nuclear Information System (INIS)

    Ohashi, Hirofumi; Inaba, Yoshitomo; Nishihara, Tetsuo; Takeda, Tetsuaki; Hayashi, Koji; Takada, Shoji; Inagaki, Yoshiyuki

    2006-01-01

    The Japan Atomic Energy Agency has been planning the demonstration test of hydrogen production with the High Temperature Engineering Test Reactor (HTTR). In a HTTR hydrogen production system (HTTR-H2), it is required to control a primary helium temperature within an allowable value at a reactor inlet to prevent a reactor scram. A cooling system for a secondary helium with a steam generator (SG) and a radiator is installed at the downstream of a chemical rector in a secondary helium loop in order to mitigate the thermal disturbance caused by the hydrogen production system. Prior to HTTR-H2, the simulation test with a mock-up test facility has been carried out to establish the controllability on the helium temperature using the cooling system against the loss of chemical reaction. It was confirmed that the fluctuations of the helium temperature at chemical reactor outlet, more than 200 K, at the loss of chemical reaction could be successfully mitigated within the target of ±10 K at SG outlet. A dynamic simulation code of the cooling system for HTTR-H2 was verified with the obtained test data

  16. Dynamic flowgraph modeling of process and control systems of a nuclear-based hydrogen production plant

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dabbagh, Ahmad W. [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario (Canada); Lu, Lixuan [Faculty of Energy Systems and Nuclear Science, Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario (Canada)

    2010-09-15

    Modeling and analysis of system reliability facilitate the identification of areas of potential improvement. The Dynamic Flowgraph Methodology (DFM) is an emerging discrete modeling framework that allows for capturing time dependent behaviour, switching logic and multi-state representation of system components. The objective of this research is to demonstrate the process of dynamic flowgraph modeling of a nuclear-based hydrogen production plant with the copper-chlorine (Cu-Cl) cycle. Modeling of the thermochemical process of the Cu-Cl cycle in conjunction with a networked control system proposed for monitoring and control of the process is provided. This forms the basis for future component selection. (author)

  17. Process for forming a nickel foil with controlled and predetermined permeability to hydrogen

    Science.gov (United States)

    Engelhaupt, Darell E.

    1981-09-22

    The present invention provides a novel process for forming a nickel foil having a controlled and predetermined hydrogen permeability. This process includes the steps of passing a nickel plating bath through a suitable cation exchange resin to provide a purified nickel plating bath free of copper and gold cations, immersing a nickel anode and a suitable cathode in the purified nickel plating bath containing a selected concentration of an organic sulfonic acid such as a napthalene-trisulfonic acid, electrodepositing a nickel layer having the thickness of a foil onto the cathode, and separating the nickel layer from the cathode to provide a nickel foil. The anode is a readily-corrodible nickel anode. The present invention also provides a novel nickel foil having a greater hydrogen permeability than palladium at room temperature.

  18. Process for forming a nickel foil with controlled and predetermined permeability to hydrogen

    International Nuclear Information System (INIS)

    Engelhaupt, D. E.

    1981-01-01

    The present invention provides a novel process for forming a nickel foil having a controlled and predetermined hydrogen permeability. This process includes the steps of passing a nickel plating bath through a suitable cation exchange resin to provide a purified nickel plating bath free of copper and gold cations, immersing a nickel anode and a suitable cathode in the purified nickel plating bath containing a selected concentration of an organic sulfonic acid such as a napthalene-trisulfonic acid, electrodepositing a nickel layer having the thickness of a foil onto the cathode, and separating the nickel layer from the cathode to provide a nickel foil. The anode is a readilycorrodible nickel anode. The present invention also provides a novel nickel foil having a greater hydrogen permeability than palladium at room temperature

  19. Application of the remote microphone method to active noise control in a mobile phone.

    Science.gov (United States)

    Cheer, Jordan; Elliott, Stephen J; Oh, Eunmi; Jeong, Jonghoon

    2018-04-01

    Mobile phones are used in a variety of situations where environmental noise may interfere with the ability of the near-end user to communicate with the far-end user. To overcome this problem, it might be possible to use active noise control technology to reduce the noise experienced by the near-end user. This paper initially demonstrates that when an active noise control system is used in a practical mobile phone configuration to minimise the noise measured by an error microphone mounted on the mobile phone, the attenuation achieved at the user's ear depends strongly on the position of the source generating the acoustic interference. To help overcome this problem, a remote microphone processing strategy is investigated that estimates the pressure at the user's ear from the pressure measured by the microphone on the mobile phone. Through an experimental implementation, it is demonstrated that this arrangement achieves a significant improvement in the attenuation measured at the ear of the user, compared to the standard active control strategy. The robustness of the active control system to changes in both the interfering sound field and the position of the mobile device relative to the ear of the user is also investigated experimentally.

  20. Sensory feedback in artificial control of human mobility

    NARCIS (Netherlands)

    Veltink, Petrus H.

    1999-01-01

    Artificial motor control systems may reduce the handicap of motor impaired individuals. Sensors are essential components in feedback control of these systems and in the information exchange with the user. The objective of this paper is to give an overview of the applications of sensors in the

  1. Remotely controlled working equipment and mobile systems for damage assessment

    International Nuclear Information System (INIS)

    Koehler, G.W.; Salaske, M.

    1975-01-01

    All functions of the MF3 vehicle with its variable geometry chassis were verified in accordance with specifications. Fixed price bids have now been submitted by industries on the action control system and the EMSM II manipulators. Tests of the EMSM I manipulator with supplements especially the remotely controlled application of tools, have been started. (orig.) [de

  2. Study of the controllable reactivity of aluminum alloys and their promising application for hydrogen generation

    International Nuclear Information System (INIS)

    Fan Meiqiang; Sun Lixian; Xu Fen

    2010-01-01

    The hydrolysis performances of two aluminum alloys are investigated as their reactivity can be controlled via the different additives. The additive of NaCl has the positive effect to improve the hydrolysis properties of the aluminum alloys with quicker hydrolysis kinetic and lower hydrolysis temperature. For examples, in 6 min of hydrolysis reaction, the Al-5 wt%Hg-5 wt%NaCl can produce 971 mL g -1 hydrogen, higher than 917 mL g -1 hydrogen from Al-10 wt%Hg alloy. The Al-In-NaCl alloy has lower hydrolysis temperature about 10 K than that of Al-In alloy. Meanwhile, the reactivity of Al alloys can be improved or reduced via the additive metals. It can be found that the additive cadmium can reduce the reactivity of Al-Hg alloy. The Al-Hg-Cd alloys can keep good stability at the moist atmosphere below 343 K and have excellent hydrolysis performance around 343-373 K. The debased reactivity of Al-Hg-Cd composite comes from the formation of CdHg 2 compounds in the milling process. But the additive Zn and Ga doped into the Al-In-NaCl alloys can quickly increase the reactivity of the alloy which can quickly react with water at room temperature and have high hydrogen yield up to the theoretic value. Therefore, it is a promising possibility that the controllable reactivity of aluminum alloys can be obtained through the different additive according to the practical request, and the Al alloys can produce pure hydrogen for the fuel cell via the hydrolysis reaction.

  3. Use of a mobile phone for potentiostatic control with low cost paper-based microfluidic sensors

    International Nuclear Information System (INIS)

    Delaney, Jacqui L.; Doeven, Egan H.; Harsant, Anthony J.; Hogan, Conor F.

    2013-01-01

    Graphical abstract: -- Highlights: •The ability to generate ECL emission using the audio output of a mobile phone is demonstrated. •Electrochemical control can be achieved by controlling the amplitude and waveform of the sound. •A mobile phone “app” synchronises the electrochemical stimulation with detection via the camera. •In combination with paper-based microfluidic sensors, extremely low cost analysis is possible. •Detection of proline at levels suitable for diagnosis of hyperprolinemia is demonstrated. -- Abstract: By exploiting its ability to play sounds, a mobile phone with suitable software installed can serve the basic functions of a potentiostat in controlling an applied potential to oxidise ECL-active molecules, while the resultant photonic signal is monitored using the camera in video mode. In combination with paper microfluidic sensors this opens significant new possibilities for low-cost, instrument-free sensing

  4. Use of a mobile phone for potentiostatic control with low cost paper-based microfluidic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Delaney, Jacqui L.; Doeven, Egan H.; Harsant, Anthony J.; Hogan, Conor F., E-mail: c.hogan@latrobe.edu.au

    2013-08-06

    Graphical abstract: -- Highlights: •The ability to generate ECL emission using the audio output of a mobile phone is demonstrated. •Electrochemical control can be achieved by controlling the amplitude and waveform of the sound. •A mobile phone “app” synchronises the electrochemical stimulation with detection via the camera. •In combination with paper-based microfluidic sensors, extremely low cost analysis is possible. •Detection of proline at levels suitable for diagnosis of hyperprolinemia is demonstrated. -- Abstract: By exploiting its ability to play sounds, a mobile phone with suitable software installed can serve the basic functions of a potentiostat in controlling an applied potential to oxidise ECL-active molecules, while the resultant photonic signal is monitored using the camera in video mode. In combination with paper microfluidic sensors this opens significant new possibilities for low-cost, instrument-free sensing.

  5. Managing mobility outcomes in vulnerable seniors ( MMOVeS): a randomized controlled pilot study.

    Science.gov (United States)

    Figueiredo, Sabrina; Morais, Jose A; Mayo, Nancy

    2017-12-01

    To estimate feasibility and potential for efficacy of an individualized, exercise-focused, self-management program (i.e. Managing Mobility Outcomes In Vulnerable Seniors ( MMOVeS)), in comparison to exercise information in improving mobility after six months among seniors recently discharged from hospital. Randomized pilot study. Two McGill University-teaching hospitals. Community dwelling seniors, aged 70 years and older, recently discharged from either participating hospitals. The physiotherapy-facilitated intervention consisted of (1) evaluation of mobility capacity, (2) setting short- and long-term goals, (3) delineation of an exercise treatment plan, (4) an educational booklet to enhance mobility self-management skills, and (5) six monthly telephone calls. Control group received a booklet with information on exercises targeting mobility limitations in seniors. Mobility, pain, and health status were assessed at baseline and at six months using multiple indicators drawn from Disabilities of the Arm, Shoulder, and Hand (DASH) Score, Lower Extremity Functional Scale (LEFS) and Short-Form (SF)-36. In all, 26 people were randomized to the intervention (mean age: 81 ± 8; 39% women), and 23 were randomized to the control (mean age: 79 ± 7; 33% women). The odds ratio for the mobility outcomes combined was 3.08 and the 95% confidence interval excluded 1 (1.65-5.77). The odds ratio for pain and health perception favored the MMOVeS group, but the 95% confidence interval included the null value. This feasibility study highlights the potential for efficacy of an individualized, exercise-focused, self-management program in comparison to exercise information in improving mobility outcome for seniors. Furthermore, a home-program combining self-management skills and exercise taught with minimal supervision prove to be feasible. Finally, data from this study can be used to estimate sample size for a confirmatory trial.

  6. Distributed Consensus-Based Robust Adaptive Formation Control for Nonholonomic Mobile Robots with Partial Known Dynamics

    Directory of Open Access Journals (Sweden)

    Zhaoxia Peng

    2014-01-01

    Full Text Available This paper investigates the distributed consensus-based robust adaptive formation control for nonholonomic mobile robots with partially known dynamics. Firstly, multirobot formation control problem has been converted into a state consensus problem. Secondly, the practical control strategies, which incorporate the distributed kinematic controllers and the robust adaptive torque controllers, are designed for solving the formation control problem. Thirdly, the specified reference trajectory for the geometric centroid of the formation is assumed as the trajectory of a virtual leader, whose information is available to only a subset of the followers. Finally, numerical results are provided to illustrate the effectiveness of the proposed control approaches.

  7. Electroencephalography (EEG) Based Control in Assistive Mobile Robots: A Review

    International Nuclear Information System (INIS)

    Krishnan, N Murali; Mariappan, Muralindran; Muthukaruppan, Karthigayan; Hijazi, Mohd Hanafi Ahmad; Kitt, Wong Wei

    2016-01-01

    Recently, EEG based control in assistive robot usage has been gradually increasing in the area of biomedical field for giving quality and stress free life for disabled and elderly people. This study reviews the deployment of EGG based control in assistive robots, especially for those who in need and neurologically disabled. The main objective of this paper is to describe the methods used for (i) EEG data acquisition and signal preprocessing, (ii) feature extraction and (iii) signal classification methods. Besides that, this study presents the specific research challenges in the designing of these control systems and future research directions. (paper)

  8. Method for Reading Sensors and Controlling Actuators Using Audio Interfaces of Mobile Devices

    Science.gov (United States)

    Aroca, Rafael V.; Burlamaqui, Aquiles F.; Gonçalves, Luiz M. G.

    2012-01-01

    This article presents a novel closed loop control architecture based on audio channels of several types of computing devices, such as mobile phones and tablet computers, but not restricted to them. The communication is based on an audio interface that relies on the exchange of audio tones, allowing sensors to be read and actuators to be controlled. As an application example, the presented technique is used to build a low cost mobile robot, but the system can also be used in a variety of mechatronics applications and sensor networks, where smartphones are the basic building blocks. PMID:22438726

  9. Epigenetic control of mobile DNA as an interface between experience and genome change

    Directory of Open Access Journals (Sweden)

    James A. Shapiro

    2014-04-01

    Full Text Available Mobile DNA in the genome is subject to RNA-targeted epigenetic control. This control regulates the activity of transposons, retrotransposons and genomic proviruses. Many different life history experiences alter the activities of mobile DNA and the expression of genetic loci regulated by nearby insertions. The same experiences induce alterations in epigenetic formatting and lead to trans-generational modifications of genome expression and stability. These observations lead to the hypothesis that epigenetic formatting directed by non-coding RNA provides a molecular interface between life history events and genome alteration.

  10. Method for reading sensors and controlling actuators using audio interfaces of mobile devices.

    Science.gov (United States)

    Aroca, Rafael V; Burlamaqui, Aquiles F; Gonçalves, Luiz M G

    2012-01-01

    This article presents a novel closed loop control architecture based on audio channels of several types of computing devices, such as mobile phones and tablet computers, but not restricted to them. The communication is based on an audio interface that relies on the exchange of audio tones, allowing sensors to be read and actuators to be controlled. As an application example, the presented technique is used to build a low cost mobile robot, but the system can also be used in a variety of mechatronics applications and sensor networks, where smartphones are the basic building blocks.

  11. Walking Pattern Generation of Dual-Arm Mobile Robot Using Preview Controller

    OpenAIRE

    P. Wu; W. Wu

    2012-01-01

    Based on the stability request of robot’s moving on the ground, the motion planning of dual-arm mobile robot when moving on the ground is studied and the preview control system is applied in the robot walking pattern generation. Direct question of robot kinematics in the extended task space is analyzed according to Degrees of Freedom configuration of the dual-arm mobile robot. It is proved that the preview control system could be used in the generation of robot Center of Mass forward trajecto...

  12. A Null Space Control of Two Wheels Driven Mobile Manipulator Using Passivity Theory

    Science.gov (United States)

    Shibata, Tsuyoshi; Murakami, Toshiyuki

    This paper describes a control strategy of null space motion of a two wheels driven mobile manipulator. Recently, robot is utilized in various industrial fields and it is preferable for the robot manipulator to have multiple degrees of freedom motion. Several studies of kinematics for null space motion have been proposed. However stability analysis of null space motion is not enough. Furthermore, these approaches apply to stable systems, but they do not apply unstable systems. Then, in this research, base of manipulator equips with two wheels driven mobile robot. This robot is called two wheels driven mobile manipulator, which becomes unstable system. In the proposed approach, a control design of null space uses passivity based stabilizing. A proposed controller is decided so that closed-loop system of robot dynamics satisfies passivity. This is passivity based control. Then, control strategy is that stabilizing of the robot system applies to work space observer based approach and null space control while keeping end-effector position. The validity of the proposed approach is verified by simulations and experiments of two wheels driven mobile manipulator.

  13. Virtual Simulator for Autonomous Mobile Robots Navigation System Using Concepts of Control Rapid Prototyping

    Directory of Open Access Journals (Sweden)

    Leonimer Flavio de Melo

    2013-09-01

    Full Text Available This work presents the proposal of virtual environment implementation for project simulation and conception of supervision and control systems for mobile robots, that are capable to operate and adapting in different environments and conditions. This virtual system has as purpose to facilitate the development of embedded architecture systems, emphasizing the implementation of tools that allow the simulation of the kinematic conditions, dynamic and control, with real time monitoring of all important system points. For this, open control architecture is proposal, integrating the two main techniques of robotic control implementation in the hardware level: systems microprocessors and reconfigurable hardware devices. The implemented simulator system is composed of a trajectory generating module, a kinematic and dynamic simulator module and of a analysis module of results and errors. The kinematic and dynamic simulator module makes all simulation of the mobile robot following the pre-determined trajectory of the trajectory generator. All the kinematic and dynamic results shown during the simulation can be evaluated and visualized in graphs and tables formats, in the results analysis module, allowing an improvement in the system, minimizing the errors with the necessary adjustments optimization. For controller implementation in the embedded system, it uses the rapid prototyping, which is the technology that allows, in set with the virtual simulation environment, the development of a controller project for mobile robots. The validation and tests had been accomplishing with nonholonomics mobile robots models with differential transmission.

  14. Finite-time tracking control for multiple non-holonomic mobile robots based on visual servoing

    Science.gov (United States)

    Ou, Meiying; Li, Shihua; Wang, Chaoli

    2013-12-01

    This paper investigates finite-time tracking control problem of multiple non-holonomic mobile robots via visual servoing. It is assumed that the pinhole camera is fixed to the ceiling, and camera parameters are unknown. The desired reference trajectory is represented by a virtual leader whose states are available to only a subset of the followers, and the followers have only interaction. First, the camera-objective visual kinematic model is introduced by utilising the pinhole camera model for each mobile robot. Second, a unified tracking error system between camera-objective visual servoing model and desired reference trajectory is introduced. Third, based on the neighbour rule and by using finite-time control method, continuous distributed cooperative finite-time tracking control laws are designed for each mobile robot with unknown camera parameters, where the communication topology among the multiple mobile robots is assumed to be a directed graph. Rigorous proof shows that the group of mobile robots converges to the desired reference trajectory in finite time. Simulation example illustrates the effectiveness of our method.

  15. Mobile-Based Video Learning Outcomes in Clinical Nursing Skill Education: A Randomized Controlled Trial.

    Science.gov (United States)

    Lee, Nam-Ju; Chae, Sun-Mi; Kim, Haejin; Lee, Ji-Hye; Min, Hyojin Jennifer; Park, Da-Eun

    2016-01-01

    Mobile devices are a regular part of daily life among the younger generations. Thus, now is the time to apply mobile device use to nursing education. The purpose of this study was to identify the effects of a mobile-based video clip on learning motivation, competence, and class satisfaction in nursing students using a randomized controlled trial with a pretest and posttest design. A total of 71 nursing students participated in this study: 36 in the intervention group and 35 in the control group. A video clip of how to perform a urinary catheterization was developed, and the intervention group was able to download it to their own mobile devices for unlimited viewing throughout 1 week. All of the students participated in a practice laboratory to learn urinary catheterization and were blindly tested for their performance skills after participation in the laboratory. The intervention group showed significantly higher levels of learning motivation and class satisfaction than did the control. Of the fundamental nursing competencies, the intervention group was more confident in practicing catheterization than their counterparts. Our findings suggest that video clips using mobile devices are useful tools that educate student nurses on relevant clinical skills and improve learning outcomes.

  16. Mobile phone intervention to improve diabetes care in rural areas of Pakistan: a randomized controlled trial.

    Science.gov (United States)

    Shahid, Muhammad; Mahar, Saeed Ahmed; Shaikh, Shiraz; Shaikh, Zuhaib-u-ddin

    2015-03-01

    To determine the effect of mobile phone intervention on HbA1c in type-2 Diabetes Mellitus (DM) patients living in rural areas of Pakistan. Randomized controlled trial. Department of Endocrinology, Liaquat National Hospital, Karachi, from December 2013 to June 2014. A total of 440 patients in intervention and control groups were enrolled. All patients between 18 - 70 years of age, residing in rural areas of Pakistan, HbA1c ³ 8.0% and having personal functional mobile phone were included. The intervention group patients were called directly on mobile phone after every 15 days for a period of 4 months. They were asked about the self-monitoring blood glucose, intake of medications, physical activity, healthy eating and were physically examined after 4 months. However, the control group was examined initially and after 4 months physically in the clinic and there were no mobile phone contacts with these patients. Patients in intervention group showed improvement (p Mobile phone technology in rural areas of Pakistan was helpful in lowering HbA1c levels in intervention group through direct communication with the diabetic patients. Lowering LDL and following diabetic diet plan can reduce HbA1c in these patients and help in preventing future complications.

  17. Pituitary tumor risk in relation to mobile phone use: A case-control study.

    Science.gov (United States)

    Shrestha, Mithila; Raitanen, Jani; Salminen, Tiina; Lahkola, Anna; Auvinen, Anssi

    2015-01-01

    The number of mobile phone users has grown rapidly, which has generated mounting public concern regarding possible health hazards. This study aims to assess pituitary tumor risk, as it has rarely been investigated. A case-control study was conducted with 80 eligible cases identified from all five university hospitals in Finland and frequency-matched 240 controls from the national population register. Controls were matched to cases by age, sex, region of residence and date of interview. A detailed history of mobile phone use was obtained using a structured interview. Several indicators of mobile phone use were assessed using conditional logistic regression. A reduced odds ratio was seen among regular mobile phone users [OR 0.39, 95% confidence interval (CI) 0.21, 0.72] relative to never/non-regular users, possibly reflecting methodological limitations. Pituitary tumor risk was not increased after 10 or more years since first use (OR 0.69, 95% CI 0.25, 1.89). The risk was not increased in relation to duration, cumulative hours of use, or cumulative number of calls. The results were similar for analog and digital phones. We found no excess risk associated with self-reported short- or medium-term use of mobile phones. This is consistent with most of the published studies. However, uncertainties remained for longer duration of use, as a very small proportion of study participants reported use beyond 10 years.

  18. Proportional-integral control modes for a hydrogen isotope distillation column

    International Nuclear Information System (INIS)

    Kinoshita, M.; Bartlit, J.R.; Sherman, R.H.

    1984-01-01

    The dynamics and control of a hydrogen isotope distillation column are discussed. The proportionalintegral (PI) controller parameter setting method previously reported by one of the authors is further investigated and extended by applying the method to two different experimental control modes. The method accounts for the nonlinearity of the column to some extent and allows us to predict the unstable region or the region of the proportional-only control behavior. The method can also be applied to the cases where the measurement of the controlled variable is accompanied by a significant time lag. The mean delay time depends greatly on the controlled variable and manipulated variable chosen and the upset condition assumed, varying by over two orders of magnitude. The PI control presents great stability, and a rather long time lag is permissible in the measurement of the controlled variable if the flow rate of the top product is chosen for the manipulated variable. On the other hand, if the reflux ratio is manipulated for controlling the lightest key element in the bottom product, the great stability is no longer present and the time lag must be adequately short. Once several response curves of the controlled variable are calculated for different magnitudes of the manipulated variable upset, the parameter setting method proposed makes it possible to study how long a time lag is allowable in the measurement of the controlled variable

  19. Control of group of mobile autonomous agents via local strategies

    Institute of Scientific and Technical Information of China (English)

    Lixin GAO; Daizhan CHENG; Yiguang HONG

    2008-01-01

    This paper considers the formation control problem of multi-agent systems in a distributed fashion.Two cases of the information propagating topologies among multiple agents,characterized by graphics model,are considered.One is fixed topology.The other is switching topology which represents the limited and less reliable information exchange.The local formation control strategies established in this paper are based on a simple modification of the existing consensus control strategies.Moreover,some existing convergence conditions ale shown to be a special case of our model even in the continuous-time consensus case.Therefore.the results of this paper extend the existing results about the consensus problem.

  20. Real-Time Inverse Optimal Neural Control for Image Based Visual Servoing with Nonholonomic Mobile Robots

    Directory of Open Access Journals (Sweden)

    Carlos López-Franco

    2015-01-01

    Full Text Available We present an inverse optimal neural controller for a nonholonomic mobile robot with parameter uncertainties and unknown external disturbances. The neural controller is based on a discrete-time recurrent high order neural network (RHONN trained with an extended Kalman filter. The reference velocities for the neural controller are obtained with a visual sensor. The effectiveness of the proposed approach is tested by simulations and real-time experiments.

  1. On the comparison of stochastic model predictive control strategies applied to a hydrogen-based microgrid

    Science.gov (United States)

    Velarde, P.; Valverde, L.; Maestre, J. M.; Ocampo-Martinez, C.; Bordons, C.

    2017-03-01

    In this paper, a performance comparison among three well-known stochastic model predictive control approaches, namely, multi-scenario, tree-based, and chance-constrained model predictive control is presented. To this end, three predictive controllers have been designed and implemented in a real renewable-hydrogen-based microgrid. The experimental set-up includes a PEM electrolyzer, lead-acid batteries, and a PEM fuel cell as main equipment. The real experimental results show significant differences from the plant components, mainly in terms of use of energy, for each implemented technique. Effectiveness, performance, advantages, and disadvantages of these techniques are extensively discussed and analyzed to give some valid criteria when selecting an appropriate stochastic predictive controller.

  2. Controllable pneumatic generator based on the catalytic decomposition of hydrogen peroxide

    International Nuclear Information System (INIS)

    Kim, Kyung-Rok; Kim, Kyung-Soo; Kim, Soohyun

    2014-01-01

    This paper presents a novel compact and controllable pneumatic generator that uses hydrogen peroxide decomposition. A fuel micro-injector using a piston-pump mechanism is devised and tested to control the chemical decomposition rate. By controlling the injection rate, the feedback controller maintains the pressure of the gas reservoir at a desired pressure level. Thermodynamic analysis and experiments are performed to demonstrate the feasibility of the proposed pneumatic generator. Using a prototype of the pneumatic generator, it takes 6 s to reach 3.5 bars with a reservoir volume of 200 ml at the room temperature, which is sufficiently rapid and effective to maintain the repetitive lifting of a 1 kg mass

  3. Controllable pneumatic generator based on the catalytic decomposition of hydrogen peroxide

    Science.gov (United States)

    Kim, Kyung-Rok; Kim, Kyung-Soo; Kim, Soohyun

    2014-07-01

    This paper presents a novel compact and controllable pneumatic generator that uses hydrogen peroxide decomposition. A fuel micro-injector using a piston-pump mechanism is devised and tested to control the chemical decomposition rate. By controlling the injection rate, the feedback controller maintains the pressure of the gas reservoir at a desired pressure level. Thermodynamic analysis and experiments are performed to demonstrate the feasibility of the proposed pneumatic generator. Using a prototype of the pneumatic generator, it takes 6 s to reach 3.5 bars with a reservoir volume of 200 ml at the room temperature, which is sufficiently rapid and effective to maintain the repetitive lifting of a 1 kg mass.

  4. Remotely controlled working gear and mobile systems for damage assessment

    International Nuclear Information System (INIS)

    Koehler, G.W.; Salaske, M.; Selig, M.

    1975-01-01

    The chassis of the light MF3 manipulator vehicle and the necessary electric control system have reached and advanced stage of construction. Bids will soon be invited for the mission control system with multiplexers of whole MF3 unit and for simple equipment for damage assessment. All major problems have been clarified in the course of the design phase of the light electric EMSM II Master-Slave manipulators intended for this service. The prototype of the electric EMSM I Master-Slave manipulator has been equipped with some of the supplementary tools required for test missions. (orig.) [de

  5. Fracture resistance of the VNC-2USh steel with different content of diffusion-mobile hydrogen at low temperature

    International Nuclear Information System (INIS)

    Yablonskij, I.S.; Sankho, K.

    1979-01-01

    Presented are the investigation results for the diffusible hydrogen (DH) content effect on cracking resistance and mechanical properties of the VNC-2USh steel in the temperature range from -75-100 deg C. In this range σsub(B), σsub(0.2) and σ are not practically sensitive to the DH content change from 0.27 to 3 cm 3 /100g. At room temperature the increase of DH content in the above concentration range results in 45 % decrease of cracking resistance under static loading. At -75 deg C the cracking resistance does not depend on DH content. Within the temperature range from -40-75 deg C placed is a temperature boundary, separating the regions of predominant effects of hydrogen and low temperature embrittlement on repture strength of the VNC-2 steel at moderated rates of deformation

  6. Optimizing a mobile robot control system using GPU acceleration

    Science.gov (United States)

    Tuck, Nat; McGuinness, Michael; Martin, Fred

    2012-01-01

    This paper describes our attempt to optimize a robot control program for the Intelligent Ground Vehicle Competition (IGVC) by running computationally intensive portions of the system on a commodity graphics processing unit (GPU). The IGVC Autonomous Challenge requires a control program that performs a number of different computationally intensive tasks ranging from computer vision to path planning. For the 2011 competition our Robot Operating System (ROS) based control system would not run comfortably on the multicore CPU on our custom robot platform. The process of profiling the ROS control program and selecting appropriate modules for porting to run on a GPU is described. A GPU-targeting compiler, Bacon, is used to speed up development and help optimize the ported modules. The impact of the ported modules on overall performance is discussed. We conclude that GPU optimization can free a significant amount of CPU resources with minimal effort for expensive user-written code, but that replacing heavily-optimized library functions is more difficult, and a much less efficient use of time.

  7. Position control of a wheeled mobile robot including tire behavior

    NARCIS (Netherlands)

    Ploeg, J.; Schouten, H.E.; Nijmeijer, H.

    2009-01-01

    Advanced driver assistance systems are increasingly available on road vehicles. These systems require a thorough development procedure, an important part of which consists of hardware-in-the-loop experiments in a controlled environment. To this end, a facility called Vehicle Hardware-In-the-Loop

  8. Remote control and motion coordination of mobile robots

    NARCIS (Netherlands)

    Alvarez Aguirre, A.

    2011-01-01

    As robots destined for personal and professional applications advance towards becoming part of our daily lives, the importance and complexity of the control algorithms which regulate them should not be underestimated. This thesis is related to two fields within robotics which are of major importance

  9. An overview on real-time control schemes for wheeled mobile robot

    Science.gov (United States)

    Radzak, M. S. A.; Ali, M. A. H.; Sha’amri, S.; Azwan, A. R.

    2018-04-01

    The purpose of this paper is to review real-time control motion algorithms for wheeled mobile robot (WMR) when navigating in environment such as road. Its need a good controller to avoid collision with any disturbance and maintain a track error at zero level. The controllers are used with other aiding sensors to measure the WMR’s velocities, posture, and interference to estimate the required torque to be applied on the wheels of mobile robot. Four main categories for wheeled mobile robot control systems have been found in literature which are namely: Kinematic based controller, Dynamic based controllers, artificial intelligence based control system, and Active Force control. A MATLAB/Simulink software is the main software to simulate and implement the control system. The real-time toolbox in MATLAB/SIMULINK are used to receive/send data from sensors/to actuator with presence of disturbances, however others software such C, C++ and visual basic are rare to be used.

  10. Motion control of multi-actuator hydraulic systems for mobile machineries: Recent advancements and future trends

    Science.gov (United States)

    Xu, Bing; Cheng, Min

    2018-06-01

    This paper presents a survey of recent advancements and upcoming trends in motion control technologies employed in designing multi-actuator hydraulic systems for mobile machineries. Hydraulic systems have been extensively used in mobile machineries due to their superior power density and robustness. However, motion control technologies of multi-actuator hydraulic systems have faced increasing challenges due to stringent emission regulations. In this study, an overview of the evolution of existing throttling control technologies is presented, including open-center and load sensing controls. Recent advancements in energy-saving hydraulic technologies, such as individual metering, displacement, and hybrid controls, are briefly summarized. The impact of energy-saving hydraulic technologies on dynamic performance and control solutions are also discussed. Then, the advanced operation methods of multi-actuator mobile machineries are reviewed, including coordinated and haptic controls. Finally, challenges and opportunities of advanced motion control technologies are presented by providing an overall consideration of energy efficiency, controllability, cost, reliability, and other aspects.

  11. Control of arsenic mobilization in paddy soils by manganese and iron oxides.

    Science.gov (United States)

    Xu, Xiaowei; Chen, Chuan; Wang, Peng; Kretzschmar, Ruben; Zhao, Fang-Jie

    2017-12-01

    Reductive mobilization of arsenic (As) in paddy soils under flooded conditions is an important reason for the relatively high accumulation of As in rice, posing a risk to food safety and human health. The extent of As mobilization varies widely among paddy soils, but the reasons are not well understood. In this study, we investigated As mobilization in six As-contaminated paddy soils (total As ranging from 73 to 122 mg kg -1 ) in flooded incubation and pot experiments. Arsenic speciation in the solution and solid phases were determined. The magnitude of As mobilization into the porewater varied by > 100 times among the six soils. Porewater As concentration correlated closely with the concentration of oxalate-extractable As, suggesting that As associated with amorphous iron (oxyhydr)oxides represents the potentially mobilizable pool of As under flooded conditions. Soil containing a high level of manganese oxides showed the lowest As mobilization, likely because Mn oxides retard As mobilization by slowing down the drop of redox potential upon soil flooding and maintaining a higher arsenate to arsenite ratio in the solid and solution phases. Additions of a synthetic Mn oxide (hausmannite) to two paddy soils increased arsenite oxidation, decreased As mobilization into the porewater and decreased As concentrations in rice grain and straw. Consistent with previous studies using simplified model systems or pure mineral phases, the present study shows that Mn oxides and amorphous Fe (oxyhydr)oxides are important factors controlling reductive As mobilization in As-contaminated paddy soils. In addition, this study also suggests a potential mitigation strategy using exogenous Mn oxides to decrease As uptake by rice in paddy soils containing low levels of indigenous Mn oxides, although further work is needed to verify its efficacy and possible secondary effects under field conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Cooperative Control of Mobile Sensor Networks for Environmental Monitoring: An Event-Triggered Finite-Time Control Scheme.

    Science.gov (United States)

    Lu, Qiang; Han, Qing-Long; Zhang, Botao; Liu, Dongliang; Liu, Shirong

    2017-12-01

    This paper deals with the problem of environmental monitoring by developing an event-triggered finite-time control scheme for mobile sensor networks. The proposed control scheme can be executed by each sensor node independently and consists of two parts: one part is a finite-time consensus algorithm while the other part is an event-triggered rule. The consensus algorithm is employed to enable the positions and velocities of sensor nodes to quickly track the position and velocity of a virtual leader in finite time. The event-triggered rule is used to reduce the updating frequency of controllers in order to save the computational resources of sensor nodes. Some stability conditions are derived for mobile sensor networks with the proposed control scheme under both a fixed communication topology and a switching communication topology. Finally, simulation results illustrate the effectiveness of the proposed control scheme for the problem of environmental monitoring.

  13. Enhancement of hydrogen production during waste activated sludge anaerobic fermentation by carbohydrate substrate addition and pH control.

    Science.gov (United States)

    Chen, Yinguang; Xiao, Naidong; Zhao, Yuxiao; Mu, Hui

    2012-06-01

    The effects of carbohydrate/protein ratio (CH/Pr) and pH on hydrogen production from waste activated sludge (WAS) were investigated. Firstly, the optimal pH value for hydrogen production was influenced by the CH/Pr ratio, which was pH 10, 9, 8, 8, 8 and 6 at the CH/Pr ratio (COD based) of 0.2 (sole sludge), 1, 2.4, 3.8, 5 and 6.6, respectively. The maximal hydrogen production (100.6 mL/g-COD) was achieved at CH/Pr of 5 and pH 8, which was due to the synergistic effect of carbohydrate addition on hydrogen production, the enhancement of sludge protein degradation and protease and amylase activities, and the suitable fermentation pathway for hydrogen production. As hydrogen consumption was observed at pH 8, in order to further increase hydrogen production a two-step pH control strategy (pH 8+pH 10) was developed and the hydrogen production was further improved by 17.6%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Aminopropyl groups of the functionalized Mobil Crystalline Material 41 as a carrier for controlled diclofenac sodium and piroxicam delivery.

    Science.gov (United States)

    Khodaverdi, Elham; Ahmadi, Mina; Kamali, Hossein; Hadizadeh, Farzin

    2017-01-01

    Synthetic Mobil Crystalline Material 41 (MCM-41) as a mesoporous material and functionalized MCM-41 using aminopropyl groups were studied in order to investigate their ability to encapsulate and to control the release of diclofenac sodium and piroxicam. MCM-41 was synthesized through sol-gel procedure and functionalized with aminopropyl groups. The physicochemical properties of MCM-41 were studied through particle size analysis, infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and carbon-hydrogen-nitrogen analysis. Diclofenac sodium and piroxicam were loaded into the MCM-41 matrix using the filtration and solvent evaporation methods. The drug-loading capacity was determined by ultraviolet, Fourier transform infrared, X-ray diffraction, and Brunauer-Emmett-Teller analysis. According to the results for pure drug release, >57% was released in the 1 st h, but when these drugs were loaded into pure Mobil Crystalline Material 41 (MCM-41) and functionalized MCM-41, the release into the simulated gastrointestinal medium was less, continuous, and slower. The release of piroxicam from functionalized MCM-41 was slower than that from MCM-41 in the simulated intestinal medium because of the formation of electrostatic bonds between piroxicam and the aminopropyl groups of the functionalized MCM-41. However, in the case of diclofenac sodium, there was no significant difference between pure MCM-41 and functionalized MCM-41. The difference between piroxicam and diclofenac sodium was due to the high solubility of diclofenac sodium in the intestinal medium (pH 6.8), which caused more rapid release from the matrixes than for piroxicam. Our findings indicate that, after functionalization of MCM-41, it could offer a good means of delivering controlled diclofenac sodium and piroxicam.

  15. A computed torque method based attitude control with optimal force distribution for articulated body mobile robots

    International Nuclear Information System (INIS)

    Fukushima, Edwardo F.; Hirose, Shigeo

    2000-01-01

    This paper introduces an attitude control scheme based in optimal force distribution using quadratic programming which minimizes joint energy consumption. This method shares similarities with force distribution for multifingered hands, multiple coordinated manipulators and legged walking robots. In particular, an attitude control scheme was introduced inside the force distribution problem, and successfully implemented for control of the articulated body mobile robot KR-II. This is an actual mobile robot composed of cylindrical segments linked in series by prismatic joints and has a long snake-like appearance. These prismatic joints are force controlled so that each segment's vertical motion can automatically follow the terrain irregularities. An attitude control is necessary because this system acts like a system of wheeled inverted pendulum carts connected in series, being unstable by nature. The validity and effectiveness of the proposed method is verified by computer simulation and experiments with the robot KR-II. (author)

  16. Mobile monitoring and embedded control system for factory environment.

    Science.gov (United States)

    Lian, Kuang-Yow; Hsiao, Sung-Jung; Sung, Wen-Tsai

    2013-12-17

    This paper proposes a real-time method to carry out the monitoring of factory zone temperatures, humidity and air quality using smart phones. At the same time, the system detects possible flames, and analyzes and monitors electrical load. The monitoring also includes detecting the vibrations of operating machinery in the factory area. The research proposes using ZigBee and Wi-Fi protocol intelligent monitoring system integration within the entire plant framework. The sensors on the factory site deliver messages and real-time sensing data to an integrated embedded systems via the ZigBee protocol. The integrated embedded system is built by the open-source 32-bit ARM (Advanced RISC Machine) core Arduino Due module, where the network control codes are built in for the ARM chipset integrated controller. The intelligent integrated controller is able to instantly provide numerical analysis results according to the received data from the ZigBee sensors. The Android APP and web-based platform are used to show measurement results. The built-up system will transfer these results to a specified cloud device using the TCP/IP protocol. Finally, the Fast Fourier Transform (FFT) approach is used to analyze the power loads in the factory zones. Moreover, Near Field Communication (NFC) technology is used to carry out the actual electricity load experiments using smart phones.

  17. Lower limb control and mobility following exercise training

    Directory of Open Access Journals (Sweden)

    Kim Sukwon

    2012-02-01

    Full Text Available Abstract The objective of the present study was to evaluate the effects of 8-week balance or weight training on ankle joint stiffness and limb stability for older adults, furthermore, on outcomes of slips while walking. Eighteen older adults volunteered for the study and randomly were assigned to the three groups, such as, weight, balance, or control group. While walking on a walking track, three-dimensional posture data were sampled and ankle joint stiffness and limb stability were computed to evaluate the effects of training. 2 (pre and post × 3 (weight, balance, and control × 2 (dominant and non-dominant legs mixed factor repeated ANOVA was performed. The results indicated that only balance training group showed an improvement in joint stiffness and both the training groups showed improvements in limb stability. Also, fall frequency results suggested that joint stiffness and limb stability had an effect on the likelihood of slip-induced falls. In conclusion, training can facilitate improvements in joint and limb control mechanism for older adults contributing to an improvement in the likelihood of slip-induced falls.

  18. Controlling Oxygen Mobility in Ruddlesden–Popper Oxides

    Directory of Open Access Journals (Sweden)

    Dongkyu Lee

    2017-03-01

    Full Text Available Discovering new energy materials is a key step toward satisfying the needs for next-generation energy conversion and storage devices. Among the various types of oxides, Ruddlesden–Popper (RP oxides (A2BO4 are promising candidates for electrochemical energy devices, such as solid oxide fuel cells, owing to their attractive physicochemical properties, including the anisotropic nature of oxygen migration and controllable stoichiometry from oxygen excess to oxygen deficiency. Thus, understanding and controlling the kinetics of oxygen transport are essential for designing optimized materials to use in electrochemical energy devices. In this review, we first discuss the basic mechanisms of oxygen migration in RP oxides depending on oxygen nonstoichiometry. We then focus on the effect of changes in the defect concentration, crystallographic orientation, and strain on the oxygen migration in RP oxides. We also briefly review their thermal and chemical stability. Finally, we conclude with a perspective on potential research directions for future investigation to facilitate controlling oxygen ion migration in RP oxides.

  19. Mobile Monitoring and Embedded Control System for Factory Environment

    Science.gov (United States)

    Lian, Kuang-Yow; Hsiao, Sung-Jung; Sung, Wen-Tsai

    2013-01-01

    This paper proposes a real-time method to carry out the monitoring of factory zone temperatures, humidity and air quality using smart phones. At the same time, the system detects possible flames, and analyzes and monitors electrical load. The monitoring also includes detecting the vibrations of operating machinery in the factory area. The research proposes using ZigBee and Wi-Fi protocol intelligent monitoring system integration within the entire plant framework. The sensors on the factory site deliver messages and real-time sensing data to an integrated embedded systems via the ZigBee protocol. The integrated embedded system is built by the open-source 32-bit ARM (Advanced RISC Machine) core Arduino Due module, where the network control codes are built in for the ARM chipset integrated controller. The intelligent integrated controller is able to instantly provide numerical analysis results according to the received data from the ZigBee sensors. The Android APP and web-based platform are used to show measurement results. The built-up system will transfer these results to a specified cloud device using the TCP/IP protocol. Finally, the Fast Fourier Transform (FFT) approach is used to analyze the power loads in the factory zones. Moreover, Near Field Communication (NFC) technology is used to carry out the actual electricity load experiments using smart phones. PMID:24351642

  20. Mobile Monitoring and Embedded Control System for Factory Environment

    Directory of Open Access Journals (Sweden)

    Kuang-Yow Lian

    2013-12-01

    Full Text Available This paper proposes a real-time method to carry out the monitoring of factory zone temperatures, humidity and air quality using smart phones. At the same time, the system detects possible flames, and analyzes and monitors electrical load. The monitoring also includes detecting the vibrations of operating machinery in the factory area. The research proposes using ZigBee and Wi-Fi protocol intelligent monitoring system integration within the entire plant framework. The sensors on the factory site deliver messages and real-time sensing data to an integrated embedded systems via the ZigBee protocol. The integrated embedded system is built by the open-source 32-bit ARM (Advanced RISC Machine core Arduino Due module, where the network control codes are built in for the ARM chipset integrated controller. The intelligent integrated controller is able to instantly provide numerical analysis results according to the received data from the ZigBee sensors. The Android APP and web-based platform are used to show measurement results. The built-up system will transfer these results to a specified cloud device using the TCP/IP protocol. Finally, the Fast Fourier Transform (FFT approach is used to analyze the power loads in the factory zones. Moreover, Near Field Communication (NFC technology is used to carry out the actual electricity load experiments using smart phones.

  1. Controlling the Local Electronic Properties of Si(553)-Au through Hydrogen Doping

    Science.gov (United States)

    Hogan, C.; Speiser, E.; Chandola, S.; Suchkova, S.; Aulbach, J.; Schäfer, J.; Meyer, S.; Claessen, R.; Esser, N.

    2018-04-01

    We propose a quantitative and reversible method for tuning the charge localization of Au-stabilized stepped Si surfaces by site-specific hydrogenation. This is demonstrated for Si(553)-Au as a model system by combining density functional theory simulations and reflectance anisotropy spectroscopy experiments. We find that controlled H passivation is a two-step process: step-edge adsorption drives excess charge into the conducting metal chain "reservoir" and renders it insulating, while surplus H recovers metallic behavior. Our approach illustrates a route towards microscopic manipulation of the local surface charge distribution and establishes a reversible switch of site-specific chemical reactivity and magnetic properties on vicinal surfaces.

  2. Materials towards carbon-free, emission-free and oil-free mobility: hydrogen fuel-cell vehicles--now and in the future.

    Science.gov (United States)

    Hirose, Katsuhiko

    2010-07-28

    In the past, material innovation has changed society through new material-induced technologies, adding a new value to society. In the present world, engineers and scientists are expected to invent new materials to solve the global problem of climate change. For the transport sector, the challenge for material engineers is to change the oil-based world into a sustainable world. After witnessing the recent high oil price and its adverse impact on the global economy, it is time to accelerate our efforts towards this change. Industries are tackling global energy issues such as oil and CO2, as well as local environmental problems, such as NO(x) and particulate matter. Hydrogen is the most promising candidate to provide carbon-free, emission-free and oil-free mobility. As such, engineers are working very hard to bring this technology into the real society. This paper describes recent progress of vehicle technologies, as well as hydrogen-storage technologies to extend the cruise range and ensure the easiness of refuelling and requesting material scientists to collaborate with industry to fight against global warming.

  3. Admission Control for Multiservices Traffic in Hierarchical Mobile IPv6 Networks by Using Fuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Jung-Shyr Wu

    2012-01-01

    Full Text Available CAC (Call Admission Control plays a significant role in providing QoS (Quality of Service in mobile wireless networks. In addition to much research that focuses on modified Mobile IP to get better efficient handover performance, CAC should be introduced to Mobile IP-based network to guarantee the QoS for users. In this paper, we propose a CAC scheme which incorporates multiple traffic types and adjusts the admission threshold dynamically using fuzzy control logic to achieve better usage of resources. The method can provide QoS in Mobile IPv6 networks with few modifications on MAP (Mobility Anchor Point functionality and slight change in BU (Binding Update message formats. According to the simulation results, the proposed scheme presents good performance of voice and video traffic at the expenses of poor performance on data traffic. It is evident that these CAC schemes can reduce the probability of the handoff dropping and the cell overload and limit the probability of the new call blocking.

  4. A case-control study of risk of leukaemia in relation to mobile phone use.

    Science.gov (United States)

    Cooke, R; Laing, S; Swerdlow, A J

    2010-11-23

    Mobile phone use is now ubiquitous, and scientific reviews have recommended research into its relation to leukaemia risk, but no large studies have been conducted. In a case-control study in South East England to investigate the relation of acute and non-lymphocytic leukaemia risk to mobile phone use, 806 cases with leukaemia incident 2003-2009 at ages 18-59 years (50% of those identified as eligible) and 585 non-blood relatives as controls (provided by 392 cases) were interviewed about mobile phone use and other potentially aetiological variables. No association was found between regular mobile phone use and risk of leukaemia (odds ratio (OR)=1.06, 95% confidence interval (CI)=0.76, 1.46). Analyses of risk in relation to years since first use, lifetime years of use, cumulative number of calls and cumulative hours of use produced no significantly raised risks, and there was no evidence of any trends. A non-significantly raised risk was found in people who first used a phone 15 or more years ago (OR=1.87, 95% CI=0.96, 3.63). Separate analyses of analogue and digital phone use and leukaemia subtype produced similar results to those overall. This study suggests that use of mobile phones does not increase leukaemia risk, although the possibility of an effect after long-term use, while biologically unlikely, remains open.

  5. Robust Feedback Linearization-based Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Andersen, Palle; Pedersen, Tom Søndergaard

    This paper considers the trajectory tracking problem for a four-wheel driven, four-wheel steered mobile robot moving in outdoor terrain. The robot is modeled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. A nonlinear trajectory tracking feedback control law based...

  6. Performance of high-level and low-level control for coordination of mobile robots

    NARCIS (Netherlands)

    Adinandra, S.; Caarls, J.; Kostic, D.; Nijmeijer, H.

    2010-01-01

    We analyze performance of different strategies for coordinated control of mobile robots. By considering an environment of a distribution center, the robots should transport goods from place A to place B while maintaining the desired formation and avoiding collisions. We evaluate performance of two

  7. Mobile Phone-Delivered Cognitive Behavioral Therapy for Insomnia : A Randomized Waitlist Controlled Trial

    NARCIS (Netherlands)

    Horsch, C.H.G.; Lancee, J.; Griffioen-Both, F.; Spruit, S.; Fitrianie, S.; Neerincx, M.A.; Beun, R.J.; Brinkman, W.-P.

    Background: This study is one of the first randomized controlled trials investigating cognitive behavioral therapy for insomnia (CBT-I) delivered by a fully automated mobile phone app. Such an app can potentially increase the accessibility of insomnia treatment for the 10% of people who have

  8. Mobile Phone-Delivered Cognitive Behavioral Therapy for Insomnia : A Randomized Waitlist Controlled Trial

    NARCIS (Netherlands)

    Horsch, C.H.G.; Lancee, J; Griffioen-Both, Fiemke; Spruit, Sandor; Fitrianie, S.; Neerincx, M.A.; Beun, RJ; Brinkman, W.P.

    2017-01-01

    Background: This study is one of the first randomized controlled trials investigating cognitive behavioral therapy for insomnia (CBT-I) delivered by a fully automated mobile phone app. Such an app can potentially increase the accessibility of insomnia treatment for the 10% of people who have

  9. Nonlinear smith-predictor based control strategy for a unicycle mobile robot subject to transport delay

    NARCIS (Netherlands)

    Alvarez Aguirre, A.; Velasco-Villa, M.; Del Muro Cuellar, B.

    2008-01-01

    This paper consider the remote control of an unicycle mobile robot subject to transport delay. The communication delay effects are considered by means of a discrete time approach that allows to solve the path tracking problem in terms of the delayed input. The causality problem involved in the

  10. Design of an arbitrary path-following controller for a non-holonomic mobile platform

    CSIR Research Space (South Africa)

    Sabatta, DG

    2009-11-01

    Full Text Available required for the platform to asymptotically track the path. The controller derived in this paper is implemented on the Seekur platform from Mobile Robots. Results showing the following of a pre-recorded path from differential GPS are discussed....

  11. Dynamics of hydrogen in hydrogenated amorphous silicon

    Indian Academy of Sciences (India)

    is mobile and can easily move through the material). Hydrogen diffuses ... The determination of the relationship of light-enhanced hydrogen motion to ... term is negligible, and using the thermodynamic relation given below f(c) = kBT .... device-applications problematic but the normal state can be recovered by a thermal an-.

  12. Nuclear magnetic resonance study of hydrogen mobility in LaY2Ni9Hx and CeY2Ni9Hx

    International Nuclear Information System (INIS)

    Soloninin, A.V.; Buzlukov, A.L.; Skripov, A.V.; Latroche, M.; Paul-Boncour, V.

    2009-01-01

    In order to investigate the mobility of hydrogen in the ternary compounds LaY 2 Ni 9 and CeY 2 Ni 9 , we have measured the proton nuclear magnetic resonance (NMR) spectra and the proton spin-lattice relaxation rates R 1 for LaY 2 Ni 9 H x (x=0.78 and 10.3) and CeY 2 Ni 9 H x (x=0.79 and 7.2). The measurements have been performed at the resonance frequencies of 14, 23.8 and 90 MHz over the temperature range of 11-404 K. For LaY 2 Ni 9 H x , the behavior of R 1 is consistent with the presence of a considerable contribution due to motionally modulated dipole-dipole interaction between nuclear spins. This contribution can be satisfactorily described in terms of the Bloembergen-Purcell-Pound model with a Gaussian distribution of activation energies for hydrogen diffusion; the value of the average activation energy resulting from such a description for LaY 2 Ni 9 H 10.3 is approximately 0.36 eV. For CeY 2 Ni 9 H x compounds, the measured proton spin-lattice relaxation rates are dominated by the contribution due to the interaction between proton spins and paramagnetic centers over the entire temperature range studied. Only qualitative information on H mobility in these compounds has been obtained from the narrowing of NMR spectra. Possible paths of H diffusion in LaY 2 Ni 9 H x and CeY 2 Ni 9 H x are discussed in terms of the distances between the interstitial sites occupied by hydrogen. - Graphical abstract: The temperature dependences of the proton spin-lattice relaxation rates R 1 measured at 14, 23.8 and 90 MHz for LaY 2 Ni 9 H 10.3 . The frequency-dependent increase in R 1 at T>250 K indicates the onset of the motional contribution to the relaxation rates

  13. Adaptive Tracking and Obstacle Avoidance Control for Mobile Robots with Unknown Sliding

    Directory of Open Access Journals (Sweden)

    Mingyue Cui

    2012-11-01

    Full Text Available An adaptive control approach is proposed for trajectory tracking and obstacle avoidance for mobile robots with consideration given to unknown sliding. A kinematic model of mobile robots is established in this paper, in which both longitudinal and lateral sliding are considered and processed as three time-varying parameters. A sliding model observer is introduced to estimate the sliding parameters online. A stable tracking control law for this nonholonomic system is proposed to compensate the unknown sliding effect. From Lyapunov-stability analysis, it is proved, regardless of unknown sliding, that tracking errors of the controlled closed-loop system are asymptotically stable, the tracking errors converge to zero outside the obstacle detection region and obstacle avoidance is guaranteed inside the obstacle detection region. The efficiency and robustness of the proposed control system are verified by simulation results.

  14. Optimal control of hydrogen production in a continuous anaerobic fermentation bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Aceves-Lara, Cesar-Arturo [INRA, UMR792, Ingenierie des Systemes Biologiques et des Procedes, Toulouse (France); CNRS, UMR5504, Toulouse, France 135 Avenue de Rangueil, Toulouse Cedex F-31077 (France); INRA, UR050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, Narbonne F-11100 (France); Latrille, Eric; Steyer, Jean-Philippe [INRA, UR050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, Narbonne F-11100 (France)

    2010-10-15

    This paper addresses the problem of optimization of hydrogen production in continuous anaerobic digesters using a model predictive control (MPC) strategy. The process is described by a dynamic nonlinear model. The influent concentration of molasses together with the effluent substrate and product concentrations of acetate, propionate, butyrate and biomass were estimated by an asymptotic online observer from measurements of gas composition in H{sub 2} and CO{sub 2} and gas flow rate. The observer was tested experimentally before to apply MPC online. The combined strategy (MPC and observer) was used in order to optimize a bioreactor of 2 L. The hydrogen production was increased by 75% up to 8.27mL{sub H{sub 2}} L{sup -1}min{sup -1}, using the influent flow rate as the main control variable while keeping the conversion of the influent concentration higher than 95% and maintaining the temperature at 37 C and pH at 5.5. (author)

  15. Bioinspired Intelligent Algorithm and Its Applications for Mobile Robot Control: A Survey

    Directory of Open Access Journals (Sweden)

    Jianjun Ni

    2016-01-01

    Full Text Available Bioinspired intelligent algorithm (BIA is a kind of intelligent computing method, which is with a more lifelike biological working mechanism than other types. BIAs have made significant progress in both understanding of the neuroscience and biological systems and applying to various fields. Mobile robot control is one of the main application fields of BIAs which has attracted more and more attention, because mobile robots can be used widely and general artificial intelligent algorithms meet a development bottleneck in this field, such as complex computing and the dependence on high-precision sensors. This paper presents a survey of recent research in BIAs, which focuses on the research in the realization of various BIAs based on different working mechanisms and the applications for mobile robot control, to help in understanding BIAs comprehensively and clearly. The survey has four primary parts: a classification of BIAs from the biomimetic mechanism, a summary of several typical BIAs from different levels, an overview of current applications of BIAs in mobile robot control, and a description of some possible future directions for research.

  16. Bioinspired Intelligent Algorithm and Its Applications for Mobile Robot Control: A Survey.

    Science.gov (United States)

    Ni, Jianjun; Wu, Liuying; Fan, Xinnan; Yang, Simon X

    2016-01-01

    Bioinspired intelligent algorithm (BIA) is a kind of intelligent computing method, which is with a more lifelike biological working mechanism than other types. BIAs have made significant progress in both understanding of the neuroscience and biological systems and applying to various fields. Mobile robot control is one of the main application fields of BIAs which has attracted more and more attention, because mobile robots can be used widely and general artificial intelligent algorithms meet a development bottleneck in this field, such as complex computing and the dependence on high-precision sensors. This paper presents a survey of recent research in BIAs, which focuses on the research in the realization of various BIAs based on different working mechanisms and the applications for mobile robot control, to help in understanding BIAs comprehensively and clearly. The survey has four primary parts: a classification of BIAs from the biomimetic mechanism, a summary of several typical BIAs from different levels, an overview of current applications of BIAs in mobile robot control, and a description of some possible future directions for research.

  17. Bioinspired Intelligent Algorithm and Its Applications for Mobile Robot Control: A Survey

    Science.gov (United States)

    Ni, Jianjun; Wu, Liuying; Fan, Xinnan; Yang, Simon X.

    2016-01-01

    Bioinspired intelligent algorithm (BIA) is a kind of intelligent computing method, which is with a more lifelike biological working mechanism than other types. BIAs have made significant progress in both understanding of the neuroscience and biological systems and applying to various fields. Mobile robot control is one of the main application fields of BIAs which has attracted more and more attention, because mobile robots can be used widely and general artificial intelligent algorithms meet a development bottleneck in this field, such as complex computing and the dependence on high-precision sensors. This paper presents a survey of recent research in BIAs, which focuses on the research in the realization of various BIAs based on different working mechanisms and the applications for mobile robot control, to help in understanding BIAs comprehensively and clearly. The survey has four primary parts: a classification of BIAs from the biomimetic mechanism, a summary of several typical BIAs from different levels, an overview of current applications of BIAs in mobile robot control, and a description of some possible future directions for research. PMID:26819582

  18. Channel Access and Power Control for Mobile Crowdsourcing in Device-to-Device Underlaid Cellular Networks

    Directory of Open Access Journals (Sweden)

    Yue Ma

    2018-01-01

    Full Text Available With the access of a myriad of smart handheld devices in cellular networks, mobile crowdsourcing becomes increasingly popular, which can leverage omnipresent mobile devices to promote the complicated crowdsourcing tasks. Device-to-device (D2D communication is highly desired in mobile crowdsourcing when cellular communications are costly. The D2D cellular network is more preferable for mobile crowdsourcing than conventional cellular network. Therefore, this paper addresses the channel access and power control problem in the D2D underlaid cellular networks. We propose a novel semidistributed network-assisted power and a channel access control scheme for D2D user equipment (DUE pieces. It can control the interference from DUE pieces to the cellular user accurately and has low information feedback overhead. For the proposed scheme, the stochastic geometry tool is employed and analytic expressions are derived for the coverage probabilities of both the cellular link and D2D links. We analyze the impact of key system parameters on the proposed scheme. The Pareto optimal access threshold maximizing the total area spectral efficiency is obtained. Unlike the existing works, the performances of the cellular link and D2D links are both considered. Simulation results show that the proposed method can improve the total area spectral efficiency significantly compared to existing schemes.

  19. Adaptive Control for Autonomous Navigation of Mobile Robots Considering Time Delay and Uncertainty

    Science.gov (United States)

    Armah, Stephen Kofi

    Autonomous control of mobile robots has attracted considerable attention of researchers in the areas of robotics and autonomous systems during the past decades. One of the goals in the field of mobile robotics is development of platforms that robustly operate in given, partially unknown, or unpredictable environments and offer desired services to humans. Autonomous mobile robots need to be equipped with effective, robust and/or adaptive, navigation control systems. In spite of enormous reported work on autonomous navigation control systems for mobile robots, achieving the goal above is still an open problem. Robustness and reliability of the controlled system can always be improved. The fundamental issues affecting the stability of the control systems include the undesired nonlinear effects introduced by actuator saturation, time delay in the controlled system, and uncertainty in the model. This research work develops robustly stabilizing control systems by investigating and addressing such nonlinear effects through analytical, simulations, and experiments. The control systems are designed to meet specified transient and steady-state specifications. The systems used for this research are ground (Dr Robot X80SV) and aerial (Parrot AR.Drone 2.0) mobile robots. Firstly, an effective autonomous navigation control system is developed for X80SV using logic control by combining 'go-to-goal', 'avoid-obstacle', and 'follow-wall' controllers. A MATLAB robot simulator is developed to implement this control algorithm and experiments are conducted in a typical office environment. The next stage of the research develops an autonomous position (x, y, and z) and attitude (roll, pitch, and yaw) controllers for a quadrotor, and PD-feedback control is used to achieve stabilization. The quadrotor's nonlinear dynamics and kinematics are implemented using MATLAB S-function to generate the state output. Secondly, the white-box and black-box approaches are used to obtain a linearized

  20. Promise of a low power mobile CPU based embedded system in artificial leg control.

    Science.gov (United States)

    Hernandez, Robert; Zhang, Fan; Zhang, Xiaorong; Huang, He; Yang, Qing

    2012-01-01

    This paper presents the design and implementation of a low power embedded system using mobile processor technology (Intel Atom™ Z530 Processor) specifically tailored for a neural-machine interface (NMI) for artificial limbs. This embedded system effectively performs our previously developed NMI algorithm based on neuromuscular-mechanical fusion and phase-dependent pattern classification. The analysis shows that NMI embedded system can meet real-time constraints with high accuracies for recognizing the user's locomotion mode. Our implementation utilizes the mobile processor efficiently to allow a power consumption of 2.2 watts and low CPU utilization (less than 4.3%) while executing the complex NMI algorithm. Our experiments have shown that the highly optimized C program implementation on the embedded system has superb advantages over existing PC implementations on MATLAB. The study results suggest that mobile-CPU-based embedded system is promising for implementing advanced control for powered lower limb prostheses.

  1. Quantifying the impact of selection bias caused by nonparticipation in a case-control study of mobile phone use

    DEFF Research Database (Denmark)

    Vrijheid, Martine; Richardson, Lesley; Armstrong, Bruce K

    2009-01-01

    To quantitatively assess the impact of selection bias caused by nonparticipation in a multinational case-control study of mobile phone use and brain tumor.......To quantitatively assess the impact of selection bias caused by nonparticipation in a multinational case-control study of mobile phone use and brain tumor....

  2. An Approach to Understanding Cohesive Slurry Settling, Mobilization, and Hydrogen Gas Retention in Pulsed Jet Mixed Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Gauglitz, Phillip A.; Wells, Beric E.; Fort, James A.; Meyer, Perry A.

    2009-05-22

    The Hanford Waste Treatment and Immobilization Plant (WTP) is being designed and built to pretreat and vitrify a large portion of the waste in Hanford’s 177 underground waste storage tanks. Numerous process vessels will hold waste at various stages in the WTP. Some of these vessels have mixing-system requirements to maintain conditions where the accumulation of hydrogen gas stays below acceptable limits, and the mixing within the vessels is sufficient to release hydrogen gas under normal conditions and during off-normal events. Some of the WTP process streams are slurries of solid particles suspended in Newtonian fluids that behave as non-Newtonian slurries, such as Bingham yield-stress fluids. When these slurries are contained in the process vessels, the particles can settle and become progressively more concentrated toward the bottom of the vessels, depending on the effectiveness of the mixing system. One limiting behavior is a settled layer beneath a particle-free liquid layer. The settled layer, or any region with sufficiently high solids concentration, will exhibit non-Newtonian rheology where it is possible for the settled slurry to behave as a soft solid with a yield stress. In this report, these slurries are described as settling cohesive slurries.

  3. Mobile application as a prenatal education and engagement tool: A randomized controlled pilot.

    Science.gov (United States)

    Ledford, Christy J W; Canzona, Mollie Rose; Cafferty, Lauren A; Hodge, Joshua A

    2016-04-01

    Research has shown that mobile applications provide a powerful alternative to traditional paper diaries; however, little data exists in comparing apps to the traditional mode of paper as a patient education and engagement tool in the clinical setting. This study was designed to compare the effectiveness of a mobile app versus a spiral-notebook guide throughout prenatal care. This randomized (n=173) controlled pilot was conducted at an East Coast community hospital. Chi-square and repeated-measures analysis of variance was used to test intervention effects in the sample of 127 pregnant mothers who completed their prenatal care in the healthcare system. Patients who were distributed the mobile application used the tool to record information about pregnancy more frequently (p=.04) and developed greater patient activation (p=.02) than patients who were distributed notebooks. No difference was detected on interpersonal clinical communication. A mobile application successfully activated a patient population in which self-management is a critical factor. This study shows that mobile apps can prompt greater use and result in more activated patients. Findings may be translated to other patient populations who receive recurring care for chronic disease. Published by Elsevier Ireland Ltd.

  4. A leptin-regulated circuit controls glucose mobilization during noxious stimuli.

    Science.gov (United States)

    Flak, Jonathan N; Arble, Deanna; Pan, Warren; Patterson, Christa; Lanigan, Thomas; Goforth, Paulette B; Sacksner, Jamie; Joosten, Maja; Morgan, Donald A; Allison, Margaret B; Hayes, John; Feldman, Eva; Seeley, Randy J; Olson, David P; Rahmouni, Kamal; Myers, Martin G

    2017-08-01

    Adipocytes secrete the hormone leptin to signal the sufficiency of energy stores. Reductions in circulating leptin concentrations reflect a negative energy balance, which augments sympathetic nervous system (SNS) activation in response to metabolically demanding emergencies. This process ensures adequate glucose mobilization despite low energy stores. We report that leptin receptor-expressing neurons (LepRb neurons) in the periaqueductal gray (PAG), the largest population of LepRb neurons in the brain stem, mediate this process. Application of noxious stimuli, which often signal the need to mobilize glucose to support an appropriate response, activated PAG LepRb neurons, which project to and activate parabrachial nucleus (PBN) neurons that control SNS activation and glucose mobilization. Furthermore, activating PAG LepRb neurons increased SNS activity and blood glucose concentrations, while ablating LepRb in PAG neurons augmented glucose mobilization in response to noxious stimuli. Thus, decreased leptin action on PAG LepRb neurons augments the autonomic response to noxious stimuli, ensuring sufficient glucose mobilization during periods of acute demand in the face of diminished energy stores.

  5. Questioning hydrogen

    International Nuclear Information System (INIS)

    Hammerschlag, Roel; Mazza, Patrick

    2005-01-01

    As an energy carrier, hydrogen is to be compared to electricity, the only widespread and viable alternative. When hydrogen is used to transmit renewable electricity, only 51% can reach the end user due to losses in electrolysis, hydrogen compression, and the fuel cell. In contrast, conventional electric storage technologies allow between 75% and 85% of the original electricity to be delivered. Even when hydrogen is extracted from gasified coal (with carbon sequestration) or from water cracked in high-temperature nuclear reactors, more of the primary energy reaches the end user if a conventional electric process is used instead. Hydrogen performs no better in mobile applications, where electric vehicles that are far closer to commercialization exceed fuel cell vehicles in efficiency, cost and performance. New, carbon-neutral energy can prevent twice the quantity of GHG's by displacing fossil electricity than it can by powering fuel cell vehicles. The same is true for new, natural gas energy. New energy resources should be used to displace high-GHG electric generation, not to manufacture hydrogen

  6. Effect of a mobile app intervention on vegetable consumption in overweight adults: a randomized controlled trial.

    Science.gov (United States)

    Mummah, Sarah; Robinson, Thomas N; Mathur, Maya; Farzinkhou, Sarah; Sutton, Stephen; Gardner, Christopher D

    2017-09-15

    Mobile applications (apps) have been heralded as transformative tools to deliver behavioral health interventions at scale, but few have been tested in rigorous randomized controlled trials. We tested the effect of a mobile app to increase vegetable consumption among overweight adults attempting weight loss maintenance. Overweight adults (n=135) aged 18-50 years with BMI=28-40 kg/m 2 near Stanford, CA were recruited from an ongoing 12-month weight loss trial (parent trial) and randomly assigned to either the stand-alone, theory-based Vegethon mobile app (enabling goal setting, self-monitoring, and feedback and using "process motivators" including fun, surprise, choice, control, social comparison, and competition) or a wait-listed control condition. The primary outcome was daily vegetables servings, measured by an adapted Harvard food frequency questionnaire (FFQ) 8 weeks post-randomization. Daily vegetable servings from 24-hour dietary recalls, administered by trained, certified, and blinded interviewers 5 weeks post-randomization, was included as a secondary outcome. All analyses were conducted according to principles of intention-to-treat. Daily vegetable consumption was significantly greater in the intervention versus control condition for both measures (adjusted mean difference: 2.0 servings; 95% CI: 0.1, 3.8, p=0.04 for FFQ; and 1.0 servings; 95% CI: 0.2, 1.9; p=0.02 for 24-hour recalls). Baseline vegetable consumption was a significant moderator of intervention effects (p=0.002) in which effects increased as baseline consumption increased. These results demonstrate the efficacy of a mobile app to increase vegetable consumption among overweight adults. Theory-based mobile interventions may present a low-cost, scalable, and effective approach to improving dietary behaviors and preventing associated chronic diseases. ClinicalTrials.gov NCT01826591. Registered 27 March 2013.

  7. Particle swarm optimization based fuzzy logic controller for autonomous green power energy system with hydrogen storage

    International Nuclear Information System (INIS)

    Safari, S.; Ardehali, M.M.; Sirizi, M.J.

    2013-01-01

    Highlights: ► Optimized fuzzy logic controller for a hybrid green power system is developed. ► PSO algorithm is used to optimize membership functions of controller. ► Optimized fuzzy logic controller results in lower O and M costs and LPSP. ► Optimization results in less variation of battery state of charge. - Abstract: The objective of this study is to develop an optimized fuzzy logic controller (FLC) for operating an autonomous hybrid green power system (HGPS) based on the particle swarm optimization (PSO) algorithm. An electrolyzer produces hydrogen from surplus energy generated by the wind turbine and photovoltaic array of HGPS for later use by a fuel cell. The PSO algorithm is used to optimize membership functions of the FLC. The FLC inputs are (a) net power flow and (b) batteries state of charge (SOC) and FLC output determines the time for hydrogen production or consumption. Actual data for weekly residential load, wind speed, ambient temperature, and solar irradiation are used for performance simulation and analysis of the HGPS examined. The weekly operation and maintenance (O and M) costs and the loss of power supply probability (LPSP) are considered in the optimization procedure. It is determined that FLC optimization results in (a) reduced fluctuations in batteries SOC which translates into longer life for batteries and the average SOC is increased by 6.18% and (b) less working hours for fuel cell, when the load is met by wind and PV. It is found that the optimized FLC results in lower O and M costs and LPSP by 57% and 33%, respectively, as compared to its un-optimized counterpart. In addition, a reduction of 18% in investment cost is achievable by optimal sizing and reducing the capacity of HGPS equipment.

  8. MPC-Based Path Following Control of an Omnidirectional Mobile Robot with Consideration of Robot Constraints

    Directory of Open Access Journals (Sweden)

    Kiattisin Kanjanawanishkul

    2015-01-01

    Full Text Available In this paper, the path following problem of an omnidirectional mobile robot (OMR has been studied. Unlike nonholonomic mobile robots, translational and rotational movements of OMRs can be controlled simultaneously and independently. However the constraints of translational and rotational velocities are coupled through the OMR's orientation angle. Therefore, a combination of a virtual-vehicle concept and a model predictive control (MPC strategy is proposed in this work to handle both robot constraints and the path following problem. Our proposed control scheme allows the OMR to follow the reference path successfully and safely, as illustrated in simulation experiments. The forward velocity is close to the desired one and the desired orientation angle is achieved at a given point on the path, while the robot's wheel velocities are maintained within boundaries.

  9. Hierarchical Brokering with Feedback Control Framework in Mobile Device-Centric Clouds

    Directory of Open Access Journals (Sweden)

    Chao-Lieh Chen

    2016-01-01

    Full Text Available We propose a hierarchical brokering architecture (HiBA and Mobile Multicloud Networking (MMCN feedback control framework for mobile device-centric cloud (MDC2 computing. Exploiting the MMCN framework and RESTful web-based interconnection, each tier broker probes resource state of its federation for control and management. Real-time and seamless services were developed. Case studies including intrafederation energy-aware balancing based on fuzzy feedback control and higher tier load balancing are further demonstrated to show how HiBA with MMCN relieves the embedding of algorithms when developing services. Theoretical performance model and real-world experiments both show that an MDC2 based on HiBA features better quality in terms of resource availability and network latency if it federates devices with enough resources distributed in lower tier hierarchy. The proposed HiBA realizes a development platform for MDC2 computing which is a feasible solution to User-Centric Networks (UCNs.

  10. Discrete Globalised Dual Heuristic Dynamic Programming in Control of the Two-Wheeled Mobile Robot

    Directory of Open Access Journals (Sweden)

    Marcin Szuster

    2014-01-01

    Full Text Available Network-based control systems have been emerging technologies in the control of nonlinear systems over the past few years. This paper focuses on the implementation of the approximate dynamic programming algorithm in the network-based tracking control system of the two-wheeled mobile robot, Pioneer 2-DX. The proposed discrete tracking control system consists of the globalised dual heuristic dynamic programming algorithm, the PD controller, the supervisory term, and an additional control signal. The structure of the supervisory term derives from the stability analysis realised using the Lyapunov stability theorem. The globalised dual heuristic dynamic programming algorithm consists of two structures: the actor and the critic, realised in a form of neural networks. The actor generates the suboptimal control law, while the critic evaluates the realised control strategy by approximation of value function from the Bellman’s equation. The presented discrete tracking control system works online, the neural networks’ weights adaptation process is realised in every iteration step, and the neural networks preliminary learning procedure is not required. The performance of the proposed control system was verified by a series of computer simulations and experiments realised using the wheeled mobile robot Pioneer 2-DX.

  11. Ultrafast quenching of metals to liquid-helium temperatures - investigation of the low-temperature mobility of hydrogen in niobium

    International Nuclear Information System (INIS)

    Blanz, M.; Blocher, R.; Carstanjen, H.D.; Messer, R.; Plachke, D.; Seeger, A.

    1989-01-01

    A novel technique for ultrafast quenching from 300 K to 4.2 K has been developed. It employs a fast jet of liquid helium with a speed of about 10 2 m/s and allows us to quench metal samples in about 6 ms. This corresponds to a quenching rate of about 4.5x10 4 K/s, which exceeds that achievable by conventional quenching in liquid helium by more than one order of magnitude. The technique has been used for a resistometric study of the behaviour of hydrogen in niobium quenched-in from the α-phase by means of isochronal and isothermal annealing. Even in the low-temperature region below 20 K a considerable recovery of the resistivity has been found, which cannot be seen in conventional quenching experiments. (orig.)

  12. Tracking Control for Mobile Robots Considering the Dynamics of All Their Subsystems: Experimental Implementation

    Directory of Open Access Journals (Sweden)

    José Rafael García-Sánchez

    2017-01-01

    Full Text Available The trajectory tracking task in a wheeled mobile robot (WMR is solved by proposing a three-level hierarchical controller that considers the mathematical model of the mechanical structure (differential drive WMR, actuators (DC motors, and power stage (DC/DC Buck power converters. The highest hierarchical level is a kinematic control for the mechanical structure; the medium level includes two controllers based on differential flatness for the actuators; and the lowest hierarchical level consists of two average controllers also based on differential flatness for the power stage. In order to experimentally validate the feasibility of the proposed control scheme, the hierarchical controller is implemented via a Σ–Δ-modulator in a differential drive WMR prototype that we have built. Such an implementation is achieved by using MATLAB-Simulink and the real-time interface ControlDesk together with a DS1104 board. The experimental results show the effectiveness and robustness of the proposed control scheme.

  13. End-Point Contact Force Control with Quantitative Feedback Theory for Mobile Robots

    Directory of Open Access Journals (Sweden)

    Shuhuan Wen

    2012-12-01

    Full Text Available Robot force control is an important issue for intelligent mobile robotics. The end-point stiffness of a robot is a key and open problem in the research community. The control strategies are mostly dependent on both the specifications of the task and the environment of the robot. Due to the limited stiffness of the end-effector, we may adopt inherent torque to feedback the oscillations of the controlled force. This paper proposes an effective control strategy which contains a controller using quantitative feedback theory. The nested loop controllers take into account the physical limitation of the system's inner variables and harmful interference. The biggest advantage of the method is its simplicity in both the design process and the implementation of the control algorithm in engineering practice. Taking the one-link manipulator as an example, numerical experiments are carried out to verify the proposed control method. The results show the satisfactory performance.

  14. Design and Control of Integrated Systems for Hydrogen Production and Power Generation

    Science.gov (United States)

    Georgis, Dimitrios

    Growing concerns on CO2 emissions have led to the development of highly efficient power plants. Options for increased energy efficiencies include alternative energy conversion pathways, energy integration and process intensification. Solid oxide fuel cells (SOFC) constitute a promising alternative for power generation since they convert the chemical energy electrochemically directly to electricity. Their high operating temperature shows potential for energy integration with energy intensive units (e.g. steam reforming reactors). Although energy integration is an essential tool for increased efficiencies, it leads to highly complex process schemes with rich dynamic behavior, which are challenging to control. Furthermore, the use of process intensification for increased energy efficiency imposes an additional control challenge. This dissertation identifies and proposes solutions on design, operational and control challenges of integrated systems for hydrogen production and power generation. Initially, a study on energy integrated SOFC systems is presented. Design alternatives are identified, control strategies are proposed for each alternative and their validity is evaluated under different operational scenarios. The operational range of the proposed control strategies is also analyzed. Next, thermal management of water gas shift membrane reactors, which are a typical application of process intensification, is considered. Design and operational objectives are identified and a control strategy is proposed employing advanced control algorithms. The performance of the proposed control strategy is evaluated and compared with classical control strategies. Finally SOFC systems for combined heat and power applications are considered. Multiple recycle loops are placed to increase design flexibility. Different operational objectives are identified and a nonlinear optimization problem is formulated. Optimal designs are obtained and their features are discussed and compared

  15. Controls and diagnostics on a fuseless railgun for solid hydrogen pellet acceleration

    International Nuclear Information System (INIS)

    King, T.L.; Zhang, J.; Haywood, R.G.; Manns, W.C.; Kim, K.

    1993-01-01

    A two-stage railgun system has been built incorporating several controls and diagnostics, some including unique features to account for the fact that the projectile is a frozen hydrogen pellet for fusion reactor refueling. A timing circuit has been developed to monitor projectile breech and muzzle velocities and to automatically trigger a sequence of events critical for effective plasma armature railgun operation. This circuit can initiate electrical breakdown of the propellant gas directly behind an incoming projectile, thus enabling fuseless operation. It also triggers a streak camera and a flashlamp for photographing the arc and the outgoing projectile, respectively. The automatic timing circuit is expandable and has been extended to incorporate a trigger for transaugmentation. The timing circuit is immune to mistriggering due to electromagnetic interference or fragmentation of the fragile hydrogen pellets. Railgun diagnostics also include Pearson coils and B probes for monitoring rail and armature currents, respectively. Laser interferometry and optical spectroscopy are also employed to measure plasma density and temperature. Digitizing oscilloscopes are used to acquire data. The data is transferred to a computer via GPIB

  16. Unmodified versus caustics-impregnated carbons for control of hydrogen sulfide emissions from sewage treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Bandosz, T.J.; Bagreev, A.; Adib, F.; Turk, A.

    2000-03-15

    Unmodified and caustic-impregnated carbons were compared as adsorbents for hydrogen sulfide in the North River Water Pollution Control Plant in New York City over a period of 2 years. The carbons were characterized using accelerated H{sub 2}S breakthrough capacity tests, sorption of nitrogen, potentiometric titration, and thermal analysis. The accelerated laboratory tests indicate that the initial capacity of caustic-impregnated carbons exceeds that of unmodified carbon, but the nature of real-life challenge streams, particularly their lower H{sub 2}S concentrations, nullifies this advantage. As the caustic content of the impregnated carbon is consumed, the situation reverses, and the unmodified carbon becomes more effective. When the concentration of H{sub 2}S is low, the developed surface area and pore volume along with the affinity to retain water create a favorable environment for dissociative adsorption of hydrogen sulfide and its oxidation to elemental sulfur, S{sup 4+}, and S{sup 6+}. In the case of the caustic carbon, the catalytic impact of the carbon surface is limited, and its good performance lasts only while active base is present. The results also show the significant differences in performance of unmodified carbons due to combined effects of their porosity and surface chemistry.

  17. Synthesis and thermal decomposition behaviors of magnesium borohydride ammoniates with controllable composition as hydrogen storage materials.

    Science.gov (United States)

    Yang, Yanjing; Liu, Yongfeng; Li, You; Gao, Mingxia; Pan, Hongge

    2013-02-01

    An ammonia-redistribution strategy for synthesizing metal borohydride ammoniates with controllable coordination number of NH(3) was proposed, and a series of magnesium borohydride ammoniates were easily synthesized by a mechanochemical reaction between Mg(BH(4))(2) and its hexaammoniate. A strong dependence of the dehydrogenation temperature and purity of the released hydrogen upon heating on the coordination number of NH(3) was elaborated for Mg(BH(4))(2)·xNH(3) owing to the change in the molar ratio of H(δ+) and H(δ-), the charge distribution on H(δ+) and H(δ-), and the strength of the coordinate bond N:→Mg(2+). The monoammoniate of magnesium borohydride (Mg(BH(4))(2)·NH(3)) was obtained for the first time. It can release 6.5% pure hydrogen within 50 minutes at 180 °C. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. LabVIEW-based control software for para-hydrogen induced polarization instrumentation

    International Nuclear Information System (INIS)

    Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

    2014-01-01

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10 000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ( 13 C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (B o ), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of 13 C based endogenous contrast agents used in molecular imaging

  19. LabVIEW-based control software for para-hydrogen induced polarization instrumentation.

    Science.gov (United States)

    Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

    2014-04-01

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10,000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ((13)C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (Bo), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of (13)C based endogenous contrast agents used in molecular imaging.

  20. Mobile phones improve antenatal care attendance in Zanzibar: a cluster randomized controlled trial

    Science.gov (United States)

    2014-01-01

    Background Applying mobile phones in healthcare is increasingly prioritized to strengthen healthcare systems. Antenatal care has the potential to reduce maternal morbidity and improve newborns’ survival but this benefit may not be realized in sub-Saharan Africa where the attendance and quality of care is declining. We evaluated the association between a mobile phone intervention and antenatal care in a resource-limited setting. We aimed to assess antenatal care in a comprehensive way taking into consideration utilisation of antenatal care as well as content and timing of interventions during pregnancy. Methods This study was an open label pragmatic cluster-randomised controlled trial with primary healthcare facilities in Zanzibar as the unit of randomisation. 2550 pregnant women (1311 interventions and 1239 controls) who attended antenatal care at selected primary healthcare facilities were included at their first antenatal care visit and followed until 42 days after delivery. 24 primary health care facilities in six districts were randomized to either mobile phone intervention or standard care. The intervention consisted of a mobile phone text-message and voucher component. Primary outcome measure was four or more antenatal care visits during pregnancy. Secondary outcome measures were tetanus vaccination, preventive treatment for malaria, gestational age at last antenatal care visit, and antepartum referral. Results The mobile phone intervention was associated with an increase in antenatal care attendance. In the intervention group 44% of the women received four or more antenatal care visits versus 31% in the control group (OR, 2.39; 95% CI, 1.03-5.55). There was a trend towards improved timing and quality of antenatal care services across all secondary outcome measures although not statistically significant. Conclusions The wired mothers’ mobile phone intervention significantly increased the proportion of women receiving the recommended four antenatal care

  1. Limited mobility of target pests crucially lowers controllability when sterile insect releases are spatiotemporally biased.

    Science.gov (United States)

    Ikegawa, Yusuke; Himuro, Chihiro

    2017-05-21

    The sterile insect technique (SIT) is a genetic pest control method wherein mass-reared sterile insects are periodically released into the wild, thereby impeding the successful reproduction of fertile pests. In Okinawa Prefecture, Japan, the SIT has been implemented to eradicate the West Indian sweet potato weevil Euscepes postfasciatus (Fairmaire), which is a flightless agricultural pest of sweet potatoes. It is known that E. postfasciatus is much less mobile than other insects to which the SIT has been applied. However, previous theoretical studies have rarely examined effects of low mobility of target pests and variation in the spatiotemporal evenness of sterile insect releases. To theoretically examine the effects of spatiotemporal evenness on the regional eradication of less mobile pests, we constructed a simple two-patch population model comprised of a pest and sterile insect moving between two habitats, and numerically simulated different release strategies (varying the number of released sterile insects and release intervals). We found that spatially biased releases allowed the pest to spatially escape from the sterile insect, and thus intensively lowered its controllability. However, we showed that the temporally counterbalancing spatially biased releases by swapping the number of released insects in the two habitats at every release (called temporal balancing) could greatly mitigate this negative effect and promote the controllability. We also showed that the negative effect of spatiotemporally biased releases was a result of the limited mobility of the target insect. Although directed dispersal of the insects in response to habitats of differing quality could lower the controllability in the more productive habitat, the temporal balancing could promote and eventually maximize the controllability as released insects increased. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Obstacle negotiation control for a mobile robot suspended on overhead ground wires by optoelectronic sensors

    Science.gov (United States)

    Zheng, Li; Yi, Ruan

    2009-11-01

    Power line inspection and maintenance already benefit from developments in mobile robotics. This paper presents mobile robots capable of crossing obstacles on overhead ground wires. A teleoperated robot realizes inspection and maintenance tasks on power transmission line equipment. The inspection robot is driven by 11 motor with two arms, two wheels and two claws. The inspection robot is designed to realize the function of observation, grasp, walk, rolling, turn, rise, and decline. This paper is oriented toward 100% reliable obstacle detection and identification, and sensor fusion to increase the autonomy level. An embedded computer based on PC/104 bus is chosen as the core of control system. Visible light camera and thermal infrared Camera are both installed in a programmable pan-and-tilt camera (PPTC) unit. High-quality visual feedback rapidly becomes crucial for human-in-the-loop control and effective teleoperation. The communication system between the robot and the ground station is based on Mesh wireless networks by 700 MHz bands. An expert system programmed with Visual C++ is developed to implement the automatic control. Optoelectronic laser sensors and laser range scanner were installed in robot for obstacle-navigation control to grasp the overhead ground wires. A novel prototype with careful considerations on mobility was designed to inspect the 500KV power transmission lines. Results of experiments demonstrate that the robot can be applied to execute the navigation and inspection tasks.

  3. Mobile diabetes intervention study: testing a personalized treatment/behavioral communication intervention for blood glucose control.

    Science.gov (United States)

    Quinn, Charlene C; Gruber-Baldini, Ann L; Shardell, Michelle; Weed, Kelly; Clough, Suzanne S; Peeples, Malinda; Terrin, Michael; Bronich-Hall, Lauren; Barr, Erik; Lender, Dan

    2009-07-01

    National data find glycemic control is within target (A1ccommunication system, using mobile phones and patient/physician portals to allow patient-specific treatment and communication. All physicians receive American Diabetes Association (ADA) Guidelines for diabetes care. Patients with poor diabetes control (A1c> or =7.5%) at baseline (n=260) are enrolled in study groups based on PCP randomization. All study patients receive blood glucose (BG) meters and a year's supply of testing materials. Patients in three treatment groups select one of two mobile phone models, receive one-year unlimited mobile phone data and service plan, register on the web-based individual patient portal and receive study treatment phone software based on study assignment. Control group patients receive usual care from their PCP. The primary outcome is mean change in A1c over a 12-month intervention period. Traditional methods of disease management have not achieved adequate control for BG and other conditions important to persons with diabetes. Tools to improve communication between patients and PCPs may improve patient outcomes and be satisfactory to patients and physicians. This RCT is ongoing.

  4. Prediction based active ramp metering control strategy with mobility and safety assessment

    Science.gov (United States)

    Fang, Jie; Tu, Lili

    2018-04-01

    Ramp metering is one of the most direct and efficient motorway traffic flow management measures so as to improve traffic conditions. However, owing to short of traffic conditions prediction, in earlier studies, the impact on traffic flow dynamics of the applied RM control was not quantitatively evaluated. In this study, a RM control algorithm adopting Model Predictive Control (MPC) framework to predict and assess future traffic conditions, which taking both the current traffic conditions and the RM-controlled future traffic states into consideration, was presented. The designed RM control algorithm targets at optimizing the network mobility and safety performance. The designed algorithm is evaluated in a field-data-based simulation. Through comparing the presented algorithm controlled scenario with the uncontrolled scenario, it was proved that the proposed RM control algorithm can effectively relieve the congestion of traffic network with no significant compromises in safety aspect.

  5. Motion Control Design for an Omnidirectional Mobile Robot Subject to Velocity Constraints

    Directory of Open Access Journals (Sweden)

    Ollin Peñaloza-Mejía

    2015-01-01

    Full Text Available A solution to achieve global asymptotic tracking with bounded velocities in an omnidirectional mobile robot is proposed in this paper. It is motivated by the need of having a useful in-practice motion control scheme, which takes into account the physical limits of the velocities. To this end, a passive nonlinear controller is designed and combined with a tracking controller in a negative feedback connection structure. By using Lyapunov theory and passivity tools, global asymptotic tracking with desired bounded velocities is proved. Simulations and experimental results are provided to show the effectiveness of the proposal.

  6. New Control Paradigms for Resources Saving: An Approach for Mobile Robots Navigation

    Directory of Open Access Journals (Sweden)

    Rafael Socas

    2018-01-01

    Full Text Available In this work, an event-based control scheme is presented. The proposed system has been developed to solve control problems appearing in the field of Networked Control Systems (NCS. Several models and methodologies have been proposed to measure different resources consumptions. The use of bandwidth, computational load and energy resources have been investigated. This analysis shows how the parameters of the system impacts on the resources efficiency. Moreover, the proposed system has been compared with its equivalent discrete-time solution. In the experiments, an application of NCS for mobile robots navigation has been set up and its resource usage efficiency has been analysed.

  7. New Control Paradigms for Resources Saving: An Approach for Mobile Robots Navigation.

    Science.gov (United States)

    Socas, Rafael; Dormido, Raquel; Dormido, Sebastián

    2018-01-18

    In this work, an event-based control scheme is presented. The proposed system has been developed to solve control problems appearing in the field of Networked Control Systems (NCS). Several models and methodologies have been proposed to measure different resources consumptions. The use of bandwidth, computational load and energy resources have been investigated. This analysis shows how the parameters of the system impacts on the resources efficiency. Moreover, the proposed system has been compared with its equivalent discrete-time solution. In the experiments, an application of NCS for mobile robots navigation has been set up and its resource usage efficiency has been analysed.

  8. Behavior coordination of mobile robotics using supervisory control of fuzzy discrete event systems.

    Science.gov (United States)

    Jayasiri, Awantha; Mann, George K I; Gosine, Raymond G

    2011-10-01

    In order to incorporate the uncertainty and impreciseness present in real-world event-driven asynchronous systems, fuzzy discrete event systems (DESs) (FDESs) have been proposed as an extension to crisp DESs. In this paper, first, we propose an extension to the supervisory control theory of FDES by redefining fuzzy controllable and uncontrollable events. The proposed supervisor is capable of enabling feasible uncontrollable and controllable events with different possibilities. Then, the extended supervisory control framework of FDES is employed to model and control several navigational tasks of a mobile robot using the behavior-based approach. The robot has limited sensory capabilities, and the navigations have been performed in several unmodeled environments. The reactive and deliberative behaviors of the mobile robotic system are weighted through fuzzy uncontrollable and controllable events, respectively. By employing the proposed supervisory controller, a command-fusion-type behavior coordination is achieved. The observability of fuzzy events is incorporated to represent the sensory imprecision. As a systematic analysis of the system, a fuzzy-state-based controllability measure is introduced. The approach is implemented in both simulation and real time. A performance evaluation is performed to quantitatively estimate the validity of the proposed approach over its counterparts.

  9. Mobility of Cs137 and Sr90 in organic soils and its control

    International Nuclear Information System (INIS)

    Rovdan, E.

    2002-01-01

    In the management of the radionuclide contaminated areas and application of a countermeasure strategy for reduction of both the external and internal doses to the population it is extremely important to know the environmental mechanisms governing the behaviour of radionuclides in soil ecosystems. The purpose of work is to investigate by means of laboratory, field experiments and mathematical modelling the mechanisms and dynamics of radionuclide transfer in the organic soil to propose measures for control their mobility. The Chernobyl radionuclides behaviour was studied for ameliorated peat-mire soil (peat deposit Pogonyanskoye, 21 km off the ChNPP). To control the mobility of radionuclides in soils the characteristics of the migration and sorption of Cs 137 and Sr 90 in sedge peat, quartz sand, bentonite, kaolin, sapropel as well as the electrolytes impact upon the radionuclide behaviour have been experimentally investigated

  10. Optimal Design for PID Controller Based on DE Algorithm in Omnidirectional Mobile Robot

    Directory of Open Access Journals (Sweden)

    Wu Peizhang

    2017-01-01

    Full Text Available This paper introduces a omnidirectional mobile robot based on Mecanum wheel, which is used for conveying heavy load in a small space of the automatic warehousing logistics center. Then analyzes and establishes the omnidirectional chassis inverse and forward kinematic model. In order to improve the performance of motion, the paper proposes the optimal PID controller based on differential evolution algorithm. Finally, through MATLAB simulation, the results show that the kinematic model of mobile robot chassis is correct, further more the controller optimized by the DE algorithm working better than the traditional Z-N PID tuned. So the optimal scheme is reasonable and feasible, which has a value for engineering applications.

  11. Hydrogen bonding controlled catalysis of a porous organic framework containing benzimidazole moieties

    KAUST Repository

    Liu, Bing

    2014-01-01

    A microporous organic framework (JUC-Z12) was synthesized quantitatively from tetra(4-formylphenyl)methane and 3,3′-diaminobenzidine. JUC-Z12 shows high thermal stability (>400 °C), a large surface area (SBET = 750 m2 g-1), a well-defined uniform micropore distribution (1.09 nm) and high Qst for H2 (-8.1 kJ mol-1), CO2 (-29.5 kJ mol-1), and CH 4 (-22.2 kJ mol-1). It also exhibits selective catalytic activities in the Knoevenagel reaction, which is supposed to be controlled by hydrogen bonding between substrates and JUC-Z12. The JUC-Z12 catalyst can be easily isolated from the reaction mixture by simple filtration and reused with high activity. This journal is © the Partner Organisations 2014.

  12. Noncondensable hydrogen sulfide incineration with brine scrubbing air emissions control system

    International Nuclear Information System (INIS)

    Goddard, W.B.; Goddard, C.B.; McClain, D.W.

    1990-01-01

    This paper reports on the technical and institutional feasibility of incinerating hydrogen sulfide (H2S) contained in geothermal noncondensable gases, and the use of geothermal brine for sulfur dioxide scrubbing and absorption as an Air Emissions Control System (AECS), for geothermal power plant, that have been documented through engineering analysis in the Phase I grant study funded through the California Department of Health Services (DOHS), Hazardous Materials Reduction Grant Program and hosted by California Energy Company (CECI). Grant funding for Phase II now has been approved to proceed with the project through the pilot plant design phase. This innovative AECS does not necessitate the use of hazardous materials or produce hazardous wastes. Cost savings were documented compared to injection pump operation or conventional AECS without the use of hazardous materials. The phase II project is to design, improve, research and develop a source reduction demonstration pilot plant geothermal noncondensable H2S incineration AECS

  13. Aggregation control of quantum dots through ion-mediated hydrogen bonding shielding.

    Science.gov (United States)

    Liu, Jianbo; Yang, Xiaohai; Wang, Kemin; He, Xiaoxiao; Wang, Qing; Huang, Jin; Liu, Yan

    2012-06-26

    Nanoparticle stabilization against detrimental aggregation is a critical parameter that needs to be well controlled. Herein, we present a facile and rapid ion-mediated dispersing technique that leads to hydrophilic aggregate-free quantum dots (QDs). Because of the shielding of the hydrogen bonds between cysteamine-capped QDs, the presence of F(-) ions disassembled the aggregates of QDs and afforded their high colloidal stability. The F(-) ions also greatly eliminated the nonspecific adsorption of the QDs on glass slides and cells. Unlike the conventional colloidal stabilized method that requires the use of any organic ligand and/or polymer for the passivation of the nanoparticle surface, the proposed approach adopts the small size and large diffusion coefficient of inorganic ions as dispersant, which offers the disaggregation a fast reaction dynamics and negligible influence on their intrinsic surface functional properties. Therefore, the ion-mediated dispersing strategy showed great potential in chemosensing and biomedical applications.

  14. Web-Based and Mobile Stress Management Intervention for Employees: A Randomized Controlled Trial

    OpenAIRE

    Heber, Elena; Lehr, Dirk; Ebert, David Daniel; Berking, Matthias; Riper, Heleen

    2016-01-01

    Background: Work-related stress is highly prevalent among employees and is associated with adverse mental health consequences. Web-based interventions offer the opportunity to deliver effective solutions on a large scale; however, the evidence is limited and the results conflicting. Objective: This randomized controlled trial evaluated the efficacy of guided Web-and mobile-based stress management training for employees. Methods: A total of 264 employees with elevated symptoms of stress (Perce...

  15. Investigation of humidity control via membrane separation for advanced Extravehicular Mobility Unit (EMU) application

    Science.gov (United States)

    Newbold, D. D.; Ray, R. J.; Pledger, W. A.; Mccray, S. B.; Brown, M. F.

    1989-01-01

    This paper describes the development of a membrane-based process for dehumidifying the Extravehicular Mobility Unit (EMU). The membrane process promises to be smaller, lighter, and more energy efficient than the other technologies for dehumidification. The dehydration membranes were tested for 90 days at conditions expected to be present in the EMU. The results of these tests indicate that membrane-based technology can effectively control humidity in the EMU.

  16. Sulfuric acid and hydrogen peroxide surface passivation effects on AlGaN/GaN high electron mobility transistors

    International Nuclear Information System (INIS)

    Zaidi, Z. H.; Lee, K. B.; Qian, H.; Jiang, S.; Houston, P. A.; Guiney, I.; Wallis, D. J.; Humphreys, C. J.

    2014-01-01

    In this work, we have compared SiN x passivation, hydrogen peroxide, and sulfuric acid treatment on AlGaN/GaN HEMTs surface after full device fabrication on Si substrate. Both the chemical treatments resulted in the suppression of device pinch-off gate leakage current below 1 μA/mm, which is much lower than that for SiN x passivation. The greatest suppression over the range of devices is observed with the sulfuric acid treatment. The device on/off current ratio is improved (from 10 4 –10 5 to 10 7 ) and a reduction in the device sub-threshold (S.S.) slope (from ∼215 to 90 mV/decade) is achieved. The sulfuric acid is believed to work by oxidizing the surface which has a strong passivating effect on the gate leakage current. The interface trap charge density (D it ) is reduced (from 4.86 to 0.90 × 10 12  cm −2 eV −1 ), calculated from the change in the device S.S. The gate surface leakage current mechanism is explained by combined Mott hopping conduction and Poole Frenkel models for both untreated and sulfuric acid treated devices. Combining the sulfuric acid treatment underneath the gate with the SiN x passivation after full device fabrication results in the reduction of D it and improves the surface related current collapse

  17. Self adaptive internal combustion engine control for hydrogen mixtures using piezoelectric transducers for dynamic cylinder pressure monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Courteau, R.; Bose, T.K. [Quebec Univ., Trois-Rivieres, PQ (Canada). Institut de recherche sur l' hydrogene

    2004-07-01

    Hydrogen internal combustion engine research at the Hydrogen Research Institute includes the following infrastructure: a 20 square metre test cell, an engine preparation room, a 150 hp dynamometer, exhaust gas analysers and a hydrogen supply. The goal of the research is to develop internal combustion engine technologies that can use hydrogen as a fuel without knocking, backfires, excessive engine wear, and with low emissions. As well as hydrogen, fuels such as biogas are also investigated. Technologies under investigation include adaptive control algorithms, as well as advanced sensors and actuators. The latter include piezolelectrics, optical fibres, nitrogen oxide detectors, and chemical composition detectors. Developments include microprocessor-controlled injection and ignition control systems for both single cylinder and multicylinder engines. Research on the influence of fuel composition on best ignition timing is presented. There is also dynamic cylinder pressure monitoring to prevent knocking make engine state assessments and perform engine calibration. Piezoelectric cylinder pressure sensors are employed, either integrated with the spark plugs, or stand-alone, inserted through separate holes through the cylinder head. tabs, figs.

  18. Enhanced Photoelectrochemical Behavior of H-TiO2 Nanorods Hydrogenated by Controlled and Local Rapid Thermal Annealing.

    Science.gov (United States)

    Wang, Xiaodan; Estradé, Sonia; Lin, Yuanjing; Yu, Feng; Lopez-Conesa, Lluis; Zhou, Hao; Gurram, Sanjeev Kumar; Peiró, Francesca; Fan, Zhiyong; Shen, Hao; Schaefer, Lothar; Braeuer, Guenter; Waag, Andreas

    2017-12-01

    Recently, colored H-doped TiO 2 (H-TiO 2 ) has demonstrated enhanced photoelectrochemical (PEC) performance due to its unique crystalline core-disordered shell nanostructures and consequent enhanced conduction behaviors between the core-shell homo-interfaces. Although various hydrogenation approaches to obtain H-TiO 2 have been developed, such as high temperature hydrogen furnace tube annealing, high pressure hydrogen annealing, hydrogen-plasma assisted reaction, aluminum reduction and electrochemical reduction etc., there is still a lack of a hydrogenation approach in a controlled manner where all processing parameters (temperature, time and hydrogen flux) were precisely controlled in order to improve the PEC performance of H-TiO 2 and understand the physical insight of enhanced PEC performance. Here, we report for the first time a controlled and local rapid thermal annealing (RTA) approach to prepare hydrogenated core-shell H-TiO 2 nanorods grown on F:SnO 2 (FTO) substrate in order to address the degradation issue of FTO in the typical TiO 2 nanorods/FTO system observed in the conventional non-RTA treated approaches. Without the FTO degradation in the RTA approach, we systematically studied the intrinsic relationship between the annealing temperature, structural, optical, and photoelectrochemical properties in order to understand the role of the disordered shell on the improved photoelectrochemical behavior of H-TiO 2 nanorods. Our investigation shows that the improvement of PEC performance could be attributed to (i) band gap narrowing from 3.0 to 2.9 eV; (ii) improved optical absorption in the visible range induced by the three-dimensional (3D) morphology and rough surface of the disordered shell; (iii) increased proper donor density; (iv) enhanced electron-hole separation and injection efficiency due to the formation of disordered shell after hydrogenation. The RTA approach developed here can be used as a suitable hydrogenation process for TiO 2 nanorods

  19. A Universal Communication Framework and Navigation Control Software for Mobile Prototyping Platforms

    Directory of Open Access Journals (Sweden)

    Andreas Mitschele-Thiel

    2010-09-01

    Full Text Available In our contribution we would like to describe two new aspects of our low-cost mobile prototyping platform concept: a new hardware communication framework as well as new software features for navigation and control of our mobile platform. The paper is an extension of the ideas proposed in REV2009 [1] and is based on the therein used hardware platform and the monitoring and management software. This platform is based on the Quadrocopter concept – autonomous flying helicopter-style robots – and includes additional off-the-shelf parts. This leads to a universal mobile prototyping platform for communication tasks providing both mobile phone and WiFi access. However, the platform can provide these functions far more quickly than a technician on the ground might be able to. We will show that with our concept we can easily adapt the platform to the individual needs of the user, which leads to a very flexible and semi-autonomous system.

  20. Positioning and tracking control system analysis for mobile free space optical network

    Science.gov (United States)

    Li, Yushan; Refai, Hazem; Sluss, , James J., Jr.; Verma, Pramode; LoPresti, Peter

    2005-08-01

    Free Space Optical (FSO) communication has evolved to be applied to the mobile network, because it can provide up to 2.5Gbps or higher data rate wireless communication. One of the key challenges with FSO systems is to maintain the Line of Sight (LOS) between transmitter and receiver. In this paper, the feasibility and performance of applying the FSO technology to the mobile network is explored, and the design plan of the attitude positioning and tracking control system of the FSO transceiver is investigated. First, the system architecture is introduced, the requirements for the control system are analyzed, the involved reference frames and frame transformation are presented. Second, the control system bandwidth is used to evaluate the system performance in controlling a positioning system consisting of a gimbal and a steering mirror, some definitions to describe the positioning accuracy and tracking capacity are given. The attitude control of a FSO transceiver is split into 2 similar channels: pitch and yaw. Using an equivalent linear control system model, the simulations are carried out, with and without the presence of uncertainties that includes GPS data errors and sensor measurement errors. Finally, based on the simulation results in the pitch channel, the quantitative evaluation on the performance of the control system is given, including positioning accuracy, tracking capability and uncertainty tolerance.

  1. Congestion Control and Traffic Scheduling for Collaborative Crowdsourcing in SDN Enabled Mobile Wireless Networks

    Directory of Open Access Journals (Sweden)

    Dawei Shen

    2018-01-01

    Full Text Available Currently, a number of crowdsourcing-based mobile applications have been implemented in mobile networks and Internet of Things (IoT, targeted at real-time services and recommendation. The frequent information exchanges and data transmissions in collaborative crowdsourcing are heavily injected into the current communication networks, which poses great challenges for Mobile Wireless Networks (MWN. This paper focuses on the traffic scheduling and load balancing problem in software-defined MWN and designs a hybrid routing forwarding scheme as well as a congestion control algorithm to achieve the feasible solution. The traffic scheduling algorithm first sorts the tasks in an ascending order depending on the amount of tasks and then solves it using a greedy scheme. In the proposed congestion control scheme, the traffic assignment is first transformed into a multiknapsack problem, and then the Artificial Fish Swarm Algorithm (AFSA is utilized to solve this problem. Numerical results on practical network topology reveal that, compared with the traditional schemes, the proposed congestion control and traffic scheduling schemes can achieve load balancing, reduce the probability of network congestion, and improve the network throughput.

  2. Mobilities Mobilities

    Directory of Open Access Journals (Sweden)

    César Pompeyo

    2011-12-01

    Full Text Available Urry, John (2007 Mobilities.Oxford: Polity Press.Urry, John (2007 Mobilities.Oxford: Polity Press.John Urry (1946-, profesor en la Universidad de Lancaster, es un sociólogo de sobra conocido y altamente reputado en el panorama internacional de las ciencias sociales. Su dilatada carrera, aparentemente dispersa y diversificada, ha seguido senderos bastante bien definidos dejando tras de sí un catálogo extenso de obras sociológicas de primer nivel. Sus primeros trabajos se centraban en el campo de la teoría social y la filosofía de las ciencias sociales o de la sociología del poder [...

  3. Near-Optimal Tracking Control of Mobile Robots Via Receding-Horizon Dual Heuristic Programming.

    Science.gov (United States)

    Lian, Chuanqiang; Xu, Xin; Chen, Hong; He, Haibo

    2016-11-01

    Trajectory tracking control of wheeled mobile robots (WMRs) has been an important research topic in control theory and robotics. Although various tracking control methods with stability have been developed for WMRs, it is still difficult to design optimal or near-optimal tracking controller under uncertainties and disturbances. In this paper, a near-optimal tracking control method is presented for WMRs based on receding-horizon dual heuristic programming (RHDHP). In the proposed method, a backstepping kinematic controller is designed to generate desired velocity profiles and the receding horizon strategy is used to decompose the infinite-horizon optimal control problem into a series of finite-horizon optimal control problems. In each horizon, a closed-loop tracking control policy is successively updated using a class of approximate dynamic programming algorithms called finite-horizon dual heuristic programming (DHP). The convergence property of the proposed method is analyzed and it is shown that the tracking control system based on RHDHP is asymptotically stable by using the Lyapunov approach. Simulation results on three tracking control problems demonstrate that the proposed method has improved control performance when compared with conventional model predictive control (MPC) and DHP. It is also illustrated that the proposed method has lower computational burden than conventional MPC, which is very beneficial for real-time tracking control.

  4. The role of sleep in the relation between young children’s mobile media use and effortful control

    NARCIS (Netherlands)

    Nathanson, A.I.; Beyens, I.

    We explored the relations among young children's mobile media use, sleep, and a form of self‐regulation, temperamental effortful control (EC), among a national sample of 402 mothers who completed an online survey. We found that the relation between mobile media use and EC was moderated by children's

  5. Sulfuric acid and hydrogen peroxide surface passivation effects on AlGaN/GaN high electron mobility transistors

    Energy Technology Data Exchange (ETDEWEB)

    Zaidi, Z. H., E-mail: zaffar.zaidi@sheffield.ac.uk; Lee, K. B.; Qian, H.; Jiang, S.; Houston, P. A. [Department of Electronic and Electrical Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Guiney, I.; Wallis, D. J.; Humphreys, C. J. [Department of Materials Science and Metallurgy, The University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

    2014-12-28

    In this work, we have compared SiN{sub x} passivation, hydrogen peroxide, and sulfuric acid treatment on AlGaN/GaN HEMTs surface after full device fabrication on Si substrate. Both the chemical treatments resulted in the suppression of device pinch-off gate leakage current below 1 μA/mm, which is much lower than that for SiN{sub x} passivation. The greatest suppression over the range of devices is observed with the sulfuric acid treatment. The device on/off current ratio is improved (from 10{sup 4}–10{sup 5} to 10{sup 7}) and a reduction in the device sub-threshold (S.S.) slope (from ∼215 to 90 mV/decade) is achieved. The sulfuric acid is believed to work by oxidizing the surface which has a strong passivating effect on the gate leakage current. The interface trap charge density (D{sub it}) is reduced (from 4.86 to 0.90 × 10{sup 12 }cm{sup −2} eV{sup −1}), calculated from the change in the device S.S. The gate surface leakage current mechanism is explained by combined Mott hopping conduction and Poole Frenkel models for both untreated and sulfuric acid treated devices. Combining the sulfuric acid treatment underneath the gate with the SiN{sub x} passivation after full device fabrication results in the reduction of D{sub it} and improves the surface related current collapse.

  6. Mobile phone intervention reduces perinatal mortality in zanzibar: secondary outcomes of a cluster randomized controlled trial.

    Science.gov (United States)

    Lund, Stine; Rasch, Vibeke; Hemed, Maryam; Boas, Ida Marie; Said, Azzah; Said, Khadija; Makundu, Mkoko Hassan; Nielsen, Birgitte Bruun

    2014-03-26

    Mobile phones are increasingly used in health systems in developing countries and innovative technical solutions have great potential to overcome barriers of access to reproductive and child health care. However, despite widespread support for the use of mobile health technologies, evidence for its role in health care is sparse. We aimed to evaluate the association between a mobile phone intervention and perinatal mortality in a resource-limited setting. This study was a pragmatic, cluster-randomized, controlled trial with primary health care facilities in Zanzibar as the unit of randomization. At their first antenatal care visit, 2550 pregnant women (1311 interventions and 1239 controls) who attended antenatal care at selected primary health care facilities were included in this study and followed until 42 days after delivery. Twenty-four primary health care facilities in six districts were randomized to either mobile phone intervention or standard care. The intervention consisted of a mobile phone text message and voucher component. Secondary outcome measures included stillbirth, perinatal mortality, and death of a child within 42 days after birth as a proxy of neonatal mortality. Within the first 42 days of life, 2482 children were born alive, 54 were stillborn, and 36 died. The overall perinatal mortality rate in the study was 27 per 1000 total births. The rate was lower in the intervention clusters, 19 per 1000 births, than in the control clusters, 36 per 1000 births. The intervention was associated with a significant reduction in perinatal mortality with an odds ratio (OR) of 0.50 (95% CI 0.27-0.93). Other secondary outcomes showed an insignificant reduction in stillbirth (OR 0.65, 95% CI 0.34-1.24) and an insignificant reduction in death within the first 42 days of life (OR 0.79, 95% CI 0.36-1.74). Mobile phone applications may contribute to improved health of the newborn and should be considered by policy makers in resource-limited settings. Clinical

  7. A sub-target approach to the kinodynamic motion control of a wheeled mobile robot

    Science.gov (United States)

    Motonaka, Kimiko; Watanabe, Keigo; Maeyama, Shoichi

    2018-02-01

    A mobile robot with two independently driven wheels is popular, but it is difficult to stabilize it by a continuous controller with a constant gain, due to its nonholonomic property. It is guaranteed that a nonholonomic controlled object can always be converged to an arbitrary point using a switching control method or a quasi-continuous control method based on an invariant manifold in a chained form. From this, the authors already proposed a kinodynamic controller to converge the states of such a two-wheeled mobile robot to the arbitrary target position while avoiding obstacles, by combining the control based on the invariant manifold and the harmonic potential field (HPF). On the other hand, it was confirmed in the previous research that there is a case that the robot cannot avoid the obstacle because there is no enough space to converge the current state to the target state. In this paper, we propose a method that divides the final target position into some sub-target positions and moves the robot step by step, and it is confirmed by the simulation that the robot can converge to the target position while avoiding obstacles using the proposed method.

  8. Field-controlled electron transfer and reaction kinetics of the biological catalytic system of microperoxidase-11 and hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Yongki Choi

    2011-12-01

    Full Text Available Controlled reaction kinetics of the bio-catalytic system of microperoxidase-11 and hydrogen peroxide has been achieved using an electrostatic technique. The technique allowed independent control of 1 the thermodynamics of the system using electrochemical setup and 2 the quantum mechanical tunneling at the interface between microperoxidase-11 and the working electrode by applying a gating voltage to the electrode. The cathodic currents of electrodes immobilized with microperoxidase-11 showed a dependence on the gating voltage in the presence of hydrogen peroxide, indicating a controllable reduction reaction. The measured kinetic parameters of the bio-catalytic reduction showed nonlinear dependences on the gating voltage as the result of modified interfacial electron tunnel due to the field induced at the microperoxidase-11-electrode interface. Our results indicate that the kinetics of the reduction of hydrogen peroxide can be controlled by a gating voltage and illustrate the operation of a field-effect bio-catalytic transistor, whose current-generating mechanism is the conversion of hydrogen peroxide to water with the current being controlled by the gating voltage.

  9. Photocatalytic hydrogen generation enhanced by band gap narrowing and improved charge carrier mobility in AgTaO3 by compensated co-doping.

    Science.gov (United States)

    Li, Min; Zhang, Junying; Dang, Wenqiang; Cushing, Scott K; Guo, Dong; Wu, Nianqiang; Yin, Penggang

    2013-10-14

    The correlation of the electronic band structure with the photocatalytic activity of AgTaO3 has been studied by simulation and experiments. Doping wide band gap oxide semiconductors usually introduces discrete mid-gap states, which extends the light absorption but has limited benefit for photocatalytic activity. Density functional theory (DFT) calculations show that compensated co-doping in AgTaO3 can overcome this problem by increasing the light absorption and simultaneously improving the charge carrier mobility. N/H and N/F co-doping can delocalize the discrete mid-gap states created by sole N doping in AgTaO3, which increases the band curvature and the electron-to-hole effective mass ratio. In particular, N/F co-doping creates a continuum of states that extend the valence band of AgTaO3. N/F co-doping thus improves the light absorption without creating the mid-gap states, maintaining the necessary redox potentials for water splitting and preventing from charge carrier trapping. The experimental results have confirmed that the N/F-codoped AgTaO3 exhibits a red-shift of the absorption edge in comparison with the undoped AgTaO3, leading to remarkable enhancement of photocatalytic activity toward hydrogen generation from water.

  10. Automatic dosage of hydrogen peroxide in solar photo-Fenton plants: Development of a control strategy for efficiency enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Ortega-Gomez, E. [Department of Chemical Engineering, University of Almeria, 04120 Almeria (Spain); CIESOL, Joint Centre of the University of Almeria-CIEMAT, 04120 Almeria (Spain); Moreno Ubeda, J.C. [Department of Language and Computation, University of Almeria, 04120 Almeria (Spain); Alvarez Hervas, J.D. [Department of Language and Computation, University of Almeria, 04120 Almeria (Spain); Department of Language and Computation, University of Sevilla, 41092 Sevilla (Spain); Casas Lopez, J.L.; Santos-Juanes Jorda, L. [Department of Chemical Engineering, University of Almeria, 04120 Almeria (Spain); CIESOL, Joint Centre of the University of Almeria-CIEMAT, 04120 Almeria (Spain); Sanchez Perez, J.A., E-mail: jsanchez@ual.es [Department of Chemical Engineering, University of Almeria, 04120 Almeria (Spain); CIESOL, Joint Centre of the University of Almeria-CIEMAT, 04120 Almeria (Spain)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Dissolved oxygen monitoring is used for automatic dosage of H{sub 2}O{sub 2} in photo-Fenton. Black-Right-Pointing-Pointer PI with anti-windup minimises H{sub 2}O{sub 2} consumption. Black-Right-Pointing-Pointer The H{sub 2}O{sub 2} consumption was reduced up to 50% with respect to manual addition strategies. Black-Right-Pointing-Pointer Appropriate H{sub 2}O{sub 2} dosage is achieved by PI with anti-windup under disturbances. - Abstract: The solar photo-Fenton process is widely used for the elimination of pollutants in aqueous effluent and, as such, is amply cited in the literature. In this process, hydrogen peroxide represents the highest operational cost. Up until now, manual dosing of H{sub 2}O{sub 2} has led to low process performance. Consequently, there is a need to automate the hydrogen peroxide dosage for use in industrial applications. As it has been demonstrated that a relationship exists between dissolved oxygen (DO) concentration and hydrogen peroxide consumption, DO can be used as a variable in optimising the hydrogen peroxide dosage. For this purpose, a model was experimentally obtained linking the dynamic behaviour of DO to hydrogen peroxide consumption. Following this, a control system was developed based on this model. This control system - a proportional and integral controller (PI) with an anti-windup mechanism - has been tested experimentally. The assays were carried out in a pilot plant under sunlight conditions and with paracetamol used as the model pollutant. In comparison with non-assisted addition methods (a sole initial or continuous addition), a decrease of 50% in hydrogen peroxide consumption was achieved when the automatic controller was used, driving an economic saving and an improvement in process efficiency.

  11. EFFECT OF HYDROGEN SULFIDE ON ATRIUM CONTRACTILITY IN CONTROL AND DIABETHIC MICE

    Directory of Open Access Journals (Sweden)

    A. S. Lifanova

    2014-01-01

    Full Text Available Hydrogen sulfide (H2S is endogenously synthesized gasotransmitter that has a regulatory effect in cardiovascular system. Diabetes mellitus leads to an increased risk of hypertension and cardiovascular diseases, so the purpose of the study was to analyze the contractility of the atria mice after application of L-cysteine and H2S. Contractile activity of the myocardium was investigated in the experiment on isolated mouse atria. Alloxan was used for modeling diabetes. Intraperitoneal injection of alloxan resulted in a significant increase of glucose concentration in blood, whereas the concentration of glucose didn’t change at the injection of physiological solution. In control, the addition of NaHS resulted in a significant dose-dependent decrease of the amplitude of contraction of the myocardium, whereas the negative inotropic effect of NaHS was significantly lower in terms of modeling diabetes compare to control conditions. In the control, L-cysteine reduced the amplitude contractions significantly, whereas L-cysteine did not lead to significant changes in the amplitude of contractions in terms of modeling diabetes. These data indicate that the sensitivity of mice’s atria reduced for H2S and L-cysteine in diabetes mellitus.

  12. Hydrogen Peroxide- and Nitric Oxide-mediated Disease Control of Bacterial Wilt in Tomato Plants

    Directory of Open Access Journals (Sweden)

    Jeum Kyu Hong

    2013-12-01

    Full Text Available Reactive oxygen species (ROS generation in tomato plants by Ralstonia solanacearum infection and the role of hydrogen peroxide (H₂O₂ and nitric oxide in tomato bacterial wilt control were demonstrated. During disease development of tomato bacterial wilt, accumulation of superoxide anion (O₂− and H₂O₂ was observed and lipid peroxidation also occurred in the tomato leaf tissues. High doses of H₂O₂and sodium nitroprusside (SNP nitric oxide donor showed phytotoxicity to detached tomato leaves 1 day after petiole feeding showing reduced fresh weight. Both H₂O₂and SNP have in vitro antibacterial activities against R. solanacearum in a dose-dependent manner, as well as plant protection in detached tomato leaves against bacterial wilt by 10⁶ and 10⁷ cfu/ml of R. solanacearum. H₂O₂- and SNP-mediated protection was also evaluated in pots using soil-drench treatment with the bacterial inoculation, and relative ‘area under the disease progressive curve (AUDPC’ was calculated to compare disease protection by H₂O₂ and/or SNP with untreated control. Neither H₂O₂ nor SNP protect the tomato seedlings from the bacterial wilt, but H₂O₂+ SNP mixture significantly decreased disease severity with reduced relative AUDPC. These results suggest that H₂O₂ and SNP could be used together to control bacterial wilt in tomato plants as bactericidal agents.

  13. NHS connecting for health: healthcare professionals, mobile technology, and infection control.

    Science.gov (United States)

    Brady, Richard R W; Chitnis, Shruti; Stewart, Ross W; Graham, Catriona; Yalamarthi, Satheesh; Morris, Keith

    2012-05-01

    Mobile phones improve the efficiency of clinical communication and are increasingly involved in all areas of healthcare delivery. Despite this, healthcare workers' mobile phones provide a known reservoir of pathogenic bacteria, with the potential to undermine infection control efforts aimed at the reducing bacterial cross-contamination in hospitals. This potential could be amplified further when employers require doctors to carry additional electronic devices for communication, without concurrently providing appropriate guidance on decontamination or use. Eighty-seven on-call doctors' mobile phones were sampled for bacterial growth prior to, and 12 h after, a cleaning intervention involving 70% isopropyl alcohol. Seventy-eight percent of doctors were aware that mobile phones could carry pathogenic bacteria, but only 8% cleaned their phones regularly. The cleaning intervention reduced the number of phones that grew bacteria by 79% (55% [48 of 87] before versus 16% [14 of 87] after cleaning). Eight percent of the phones grew Staphyloccus aureus, and 44.8% of phones grew Gram-positive cocci. All S. aureus isolates were methicillin-sensitive. Bacterial contamination was not associated with gender, specialty, or seniority of the phone user (p>0.05). Simple cleaning interventions can reduce the surface bioburden of hospital-provided doctors' mobile phones and therefore the potential for cross-contamination. This cleaning intervention is inexpensive, easily instituted, and effective. Healthcare workers should carry the minimum number of electronic devices on their person, maintain good hand hygiene, and clean their device appropriately in order to minimize the potential for cross-contamination in the work place.

  14. Wearable computer for mobile augmented-reality-based controlling of an intelligent robot

    Science.gov (United States)

    Turunen, Tuukka; Roening, Juha; Ahola, Sami; Pyssysalo, Tino

    2000-10-01

    An intelligent robot can be utilized to perform tasks that are either hazardous or unpleasant for humans. Such tasks include working in disaster areas or conditions that are, for example, too hot. An intelligent robot can work on its own to some extent, but in some cases the aid of humans will be needed. This requires means for controlling the robot from somewhere else, i.e. teleoperation. Mobile augmented reality can be utilized as a user interface to the environment, as it enhances the user's perception of the situation compared to other interfacing methods and allows the user to perform other tasks while controlling the intelligent robot. Augmented reality is a method that combines virtual objects into the user's perception of the real world. As computer technology evolves, it is possible to build very small devices that have sufficient capabilities for augmented reality applications. We have evaluated the existing wearable computers and mobile augmented reality systems to build a prototype of a future mobile terminal- the CyPhone. A wearable computer with sufficient system resources for applications, wireless communication media with sufficient throughput and enough interfaces for peripherals has been built at the University of Oulu. It is self-sustained in energy, with enough operating time for the applications to be useful, and uses accurate positioning systems.

  15. J-controlled crack growth as an indicator of hydrogen-stainless steel compatibility

    International Nuclear Information System (INIS)

    Dietrich, M.R.; Caskey, G.R. Jr.; Donovan, J.A.

    1980-01-01

    The J-integral was evaluated as a parameter to characterize fracture of stainless steels and as a measure of hydrogen damage. C-shaped specimens of type 304L, 316, and 21-6-9 stainless steels were tested in high pressure helium and hydrogen. The critical force for crack initiation (Jm), and tearing resistance (dJ/da) were decreased by hydrogen in all three alloys. The J-integral appears useful as a measure of hydrogen compatibility because it is sensitive to both test environment and microstructure

  16. Visual Trajectory-Tracking Model-Based Control for Mobile Robots

    Directory of Open Access Journals (Sweden)

    Andrej Zdešar

    2013-09-01

    Full Text Available In this paper we present a visual-control algorithm for driving a mobile robot along the reference trajectory. The configuration of the system consists of a two-wheeled differentially driven mobile robot that is observed by an overhead camera, which can be placed at arbitrary, but reasonable, inclination with respect to the ground plane. The controller must be capable of generating appropriate tangential and angular control velocities for the trajectory-tracking problem, based on the information received about the robot position obtained in the image. To be able to track the position of the robot through a sequence of images in real-time, the robot is marked with an artificial marker that can be distinguishably recognized by the image recognition subsystem. Using the property of differential flatness, a dynamic feedback compensator can be designed for the system, thereby extending the system into a linear form. The presented control algorithm for reference tracking combines a feedforward and a feedback loop, the structure also known as a two DOF control scheme. The feedforward part should drive the system to the vicinity of the reference trajectory and the feedback part should eliminate any errors that occur due to noise and other disturbances etc. The feedforward control can never achieve accurate reference following, but this deficiency can be eliminated with the introduction of the feedback loop. The design of the model predictive control is based on the linear error model. The model predictive control is given in analytical form, so the computational burden is kept at a reasonable level for real-time implementation. The control algorithm requires that a reference trajectory is at least twice differentiable function. A suitable approach to design such a trajectory is by exploiting some useful properties of the Bernstein-Bézier parametric curves. The simulation experiments as well as real system experiments on a robot normally used in the

  17. SREBP controls oxygen-dependent mobilization of retrotransposons in fission yeast.

    Directory of Open Access Journals (Sweden)

    Alfica Sehgal

    2007-08-01

    Full Text Available Retrotransposons are mobile genetic elements that proliferate through an RNA intermediate. Transposons do not encode transcription factors and thus rely on host factors for mRNA expression and survival. Despite information regarding conditions under which elements are upregulated, much remains to be learned about the regulatory mechanisms or factors controlling retrotransposon expression. Here, we report that low oxygen activates the fission yeast Tf2 family of retrotransposons. Sre1, the yeast ortholog of the mammalian membrane-bound transcription factor sterol regulatory element binding protein (SREBP, directly induces the expression and mobilization of Tf2 retrotransposons under low oxygen. Sre1 binds to DNA sequences in the Tf2 long terminal repeat that functions as an oxygen-dependent promoter. We find that Tf2 solo long terminal repeats throughout the genome direct oxygen-dependent expression of adjacent coding and noncoding sequences, providing a potential mechanism for the generation of oxygen-dependent gene expression.

  18. Cross-Layer Design Approach for Power Control in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    A. Sarfaraz Ahmed

    2015-03-01

    Full Text Available In mobile ad hoc networks, communication among mobile nodes occurs through wireless medium The design of ad hoc network protocol, generally based on a traditional “layered approach”, has been found ineffective to deal with receiving signal strength (RSS-related problems, affecting the physical layer, the network layer and transport layer. This paper proposes a design approach, deviating from the traditional network design, toward enhancing the cross-layer interaction among different layers, namely physical, MAC and network. The Cross-Layer design approach for Power control (CLPC would help to enhance the transmission power by averaging the RSS values and to find an effective route between the source and the destination. This cross-layer design approach was tested by simulation (NS2 simulator and its performance over AODV was found to be better.

  19. Application Of Electronic Nose And Ion Mobility Spectrometer To Quality Control Of Spice Mixtures

    International Nuclear Information System (INIS)

    Banach, U.; Tiebe, C.; Huebert, Th.

    2009-01-01

    The aim of the paper is to demonstrate the application of electronic nose (e-nose) and ion mobility spectrometry (IMS) to quality control and to find out product adulteration of spice mixtures. Therefore the gaseous head space phase of four different spice mixtures (spices for sausages and saveloy) was differed from original composition and product adulteration. In this set of experiments metal-oxide type e-nose (KAMINA-type) has been used, and characteristic patterns of data corresponding to various complex odors of the four different spice mixtures were generated. Simultaneously an ion mobility spectrometer was coupled also to an emission chamber for the detection of gaseous components of spice mixtures. The two main methods that have been used show a clear discrimination between the original spice mixtures and product adulteration could be distinguished from original spice mixtures.

  20. Distributed estimation and control for mobile sensor networks with coupling delays.

    Science.gov (United States)

    Su, Housheng; Chen, Xuan; Chen, Michael Z Q; Wang, Lei

    2016-09-01

    This paper deals with the issue of distributed estimation and control for mobile sensor networks with coupling delays. Based on the Kalman-Consensus filter and the flocking algorithm, all mobile sensors move to a target to increase the quality of gathered data, and achieve consensus on the estimation values of the target in the presence of time-delay and noises. By applying an effective cascading Lyapunov method and matrix theory, stability analysis is carried out. Furthermore, a necessary condition for the convergence is presented via the boundary conditions of feedback coefficients. Some numerical examples are provided to validate the effectiveness of theoretical results. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  1. A systematic review of randomised control trials of sexual health interventions delivered by mobile technologies.

    Science.gov (United States)

    Burns, Kara; Keating, Patrick; Free, Caroline

    2016-08-12

    Sexually transmitted infections (STIs) pose a serious public health problem globally. The rapid spread of mobile technology creates an opportunity to use innovative methods to reduce the burden of STIs. This systematic review identified recent randomised controlled trials that employed mobile technology to improve sexual health outcomes. The following databases were searched for randomised controlled trials of mobile technology based sexual health interventions with any outcome measures and all patient populations: MEDLINE, EMBASE, PsycINFO, Global Health, The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, NHS Health Technology Assessment Database, and Web of Science (science and social science citation index) (Jan 1999-July 2014). Interventions designed to increase adherence to HIV medication were not included. Two authors independently extracted data on the following elements: interventions, allocation concealment, allocation sequence, blinding, completeness of follow-up, and measures of effect. Trials were assessed for methodological quality using the Cochrane risk of bias tool. We calculated effect estimates using intention to treat analysis. A total of ten randomised trials were identified with nine separate study groups. No trials had a low risk of bias. The trials targeted: 1) promotion of uptake of sexual health services, 2) reduction of risky sexual behaviours and 3) reduction of recall bias in reporting sexual activity. Interventions employed up to five behaviour change techniques. Meta-analysis was not possible due to heterogeneity in trial assessment and reporting. Two trials reported statistically significant improvements in the uptake of sexual health services using SMS reminders compared to controls. One trial increased knowledge. One trial reported promising results in increasing condom use but no trial reported statistically significant increases in condom

  2. Driving a Semiautonomous Mobile Robotic Car Controlled by an SSVEP-Based BCI.

    Science.gov (United States)

    Stawicki, Piotr; Gembler, Felix; Volosyak, Ivan

    2016-01-01

    Brain-computer interfaces represent a range of acknowledged technologies that translate brain activity into computer commands. The aim of our research is to develop and evaluate a BCI control application for certain assistive technologies that can be used for remote telepresence or remote driving. The communication channel to the target device is based on the steady-state visual evoked potentials. In order to test the control application, a mobile robotic car (MRC) was introduced and a four-class BCI graphical user interface (with live video feedback and stimulation boxes on the same screen) for piloting the MRC was designed. For the purpose of evaluating a potential real-life scenario for such assistive technology, we present a study where 61 subjects steered the MRC through a predetermined route. All 61 subjects were able to control the MRC and finish the experiment (mean time 207.08 s, SD 50.25) with a mean (SD) accuracy and ITR of 93.03% (5.73) and 14.07 bits/min (4.44), respectively. The results show that our proposed SSVEP-based BCI control application is suitable for mobile robots with a shared-control approach. We also did not observe any negative influence of the simultaneous live video feedback and SSVEP stimulation on the performance of the BCI system.

  3. A Low Cost Mobile Robot Based on Proportional Integral Derivative (PID) Control System and Odometer for Education

    Science.gov (United States)

    Haq, R.; Prayitno, H.; Dzulkiflih; Sucahyo, I.; Rahmawati, E.

    2018-03-01

    In this article, the development of a low cost mobile robot based on PID controller and odometer for education is presented. PID controller and odometer is applied for controlling mobile robot position. Two-dimensional position vector in cartesian coordinate system have been inserted to robot controller as an initial and final position. Mobile robot has been made based on differential drive and sensor magnetic rotary encoder which measured robot position from a number of wheel rotation. Odometry methode use data from actuator movements for predicting change of position over time. The mobile robot is examined to get final position with three different heading angle 30°, 45° and 60° by applying various value of KP, KD and KI constant.

  4. Characteristics of a high-power RF source of negative hydrogen ions for neutral beam injection into controlled fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Abdrashitov, G. F.; Belchenko, Yu. I.; Gusev, I. A.; Ivanov, A. A.; Kondakov, A. A.; Sanin, A. L.; Sotnikov, O. Z., E-mail: O.Z.Sotnikov@inp.nsk.su; Shikhovtsev, I. V. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

    2017-01-15

    An injector of hydrogen atoms with an energy of 0.5–1 MeV and equivalent current of up to 1.5 A for purposes of controlled fusion research is currently under design at the Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences. Within this project, a multiple-aperture RF surface-plasma source of negative hydrogen ions is designed. The source design and results of experiments on the generation of a negative ion beam with a current of >1 A in the long-pulse mode are presented.

  5. Method of controlling injection of oxygen into hydrogen-rich fuel cell feed stream

    Science.gov (United States)

    Meltser, Mark Alexander; Gutowski, Stanley; Weisbrod, Kirk

    2001-01-01

    A method of operating a H.sub.2 --O.sub.2 fuel cell fueled by hydrogen-rich fuel stream containing CO. The CO content is reduced to acceptable levels by injecting oxygen into the fuel gas stream. The amount of oxygen injected is controlled in relation to the CO content of the fuel gas, by a control strategy that involves (a) determining the CO content of the fuel stream at a first injection rate, (b) increasing the O.sub.2 injection rate, (c) determining the CO content of the stream at the higher injection rate, (d) further increasing the O.sub.2 injection rate if the second measured CO content is lower than the first measured CO content or reducing the O.sub.2 injection rate if the second measured CO content is greater than the first measured CO content, and (e) repeating steps a-d as needed to optimize CO consumption and minimize H.sub.2 consumption.

  6. The role of cassiterite controlling arsenic mobility in an abandoned stanniferous tailings impoundment at Llallagua, Bolivia.

    Science.gov (United States)

    Romero, Francisco Martín; Canet, Carles; Alfonso, Pura; Zambrana, Rubén N; Soto, Nayelli

    2014-05-15

    The surface water contamination by potentially toxic elements (PTE) leached from mine tailings is a major environmental concern. However, the formation of insoluble solid phases can control the mobility of PTE, with subsequent decrease of the risk that tailings suppose to the environment. We characterized the tailings from a tin inactive mine in Llallagua, Bolivia in order to assess the risk for surface water quality. These tailings contain high concentrations of PTE, with up to 94,344 mg/kg Fe, 9,135 mg/kg Sn, 4,606 mg/kg As, 1,362 mg/kg Cu, 1,220 mg/kg Zn, 955 mg/kg Pb and 151 mg/kg Cd. Oxidation of sulfide minerals in these tailings generates acid leachates (pH=2.5-3.5), rich in SO4(2-) and dissolved PTE, thereby releasing contaminants to the surface waters. Nevertheless, the concentrations of dissolved Sn, As and Pb in acid leachates are low (Sntailing deposits; it should be the main solid phase controlling Sn and As mobility in the impoundment. Additionally, jarosite and plumbojarosite, identified among the secondary minerals, could also play an important role controlling the mobility of As and Pb. Taking into account (a) the low solubility constants of cassiterite (Ksp=10(-64.2)), jarosite (Ksp=10(-11)) and plumbojarosite (Ksp=10(-28.66)), and (b) the stability of these minerals under acidic conditions, we can conclude that they control the long-term fate of Sn, As and Pb in the studied tailings. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. MIMO H∞ control of three-axis ship-mounted mobile antenna systems

    Science.gov (United States)

    Kuseyri, İ. Sina

    2018-02-01

    The need for on-line information in any environment has led to the development of mobile satellite communication terminals. These high data-rate terminals require inertial antenna pointing error tolerance within fractions of a degree. However, the base motion of the antenna platform in mobile applications complicates this pointing problem and must be accounted for. Gimbaled motorised pedestals are used to eliminate the effect of disturbance and maintain uninterrupted communication. In this paper, a three-axis ship-mounted antenna on a pedestal gimbal system is studied. Based on the derived dynamic model of the antenna pedestal multi input-multi output PID and H∞ linear controllers are designed to stabilise the antenna to keep its orientation unaltered towards the satellite while the sea waves disturb the antenna. Simulation results are presented to show the stabilisation performance of the system with the synthesised controllers. It is shown through performance comparison and analysis that the proposed H∞ control structure is preferable over PID controlled system in terms of system stability and the disturbance rejection.

  8. Evaluation of a mobile phone telemonitoring system for glycaemic control in patients with diabetes.

    Science.gov (United States)

    Istepanian, Robert S H; Zitouni, Karima; Harry, Diane; Moutosammy, Niva; Sungoor, Ala; Tang, Bee; Earle, Kenneth A

    2009-01-01

    We conducted a randomized controlled trial using mobile health technology in an ethnically diverse sample of 137 patients with complicated diabetes. Patients in the intervention group (n = 72) were trained to measure their blood glucose with a sensor which transmitted the readings to a mobile phone via a Bluetooth wireless link. Clinicians were then able to examine and respond to the readings which were viewed with a web-based application. Patients in the control arm of the study (n = 65) did not transmit their readings and received care with their usual doctor in the outpatient and/or primary care setting. The mean follow-up period was 9 months in each group. The default rate was higher in the patients in the intervention arm due to technical problems. In an intention-to-treat analysis there were no differences in HbA(1c) between the intervention and control groups. In a sub-group analysis of the patients who completed the study, the telemonitoring group had a lower HbA(1c) than those in the control group: 7.76% and 8.40%, respectively (P = 0.06).

  9. Control of Redox Events by Dye Encapsulation Applied to Light-Driven Splitting of Hydrogen Sulfide

    NARCIS (Netherlands)

    Jing, X.; Yang, Y.; He, C.; Chang, Z.; Reek, J.N.H.; Duan, C.

    2017-01-01

    Solar production of hydrogen by consuming low-value waste products is an attractive pathway that has both economic and environmental benefits. Inspired by the reactive pocket of enzymes, a synthetic platform to combine photocatalytic hydrogen evolution with sulfide oxidation in a one-pot process via

  10. Suppression of hydrogenated carbon film deposition by scavenger techniques and their application to the tritium inventory control of fusion devices

    International Nuclear Information System (INIS)

    Tabares, F.L.; Tafalla, D.; Tanarro, I.; Herrero, V.J.; Islyaikin, A.; Maffiotte, C.

    2002-01-01

    The well-known radical and ion scavenger techniques of application in amorphous hydrogenated carbon film deposition studies are investigated in relation to the mechanism of tritium and deuterium co-deposition in carbon-dominated fusion devices. A particularly successful scheme results from the injection of nitrogen into methane/hydrogen plasmas for conditions close to those prevailing in the divertor region of present fusion devices. A complete suppression of the a-C : H film deposition has been achieved for N 2 /CH 4 ratios close to one in methane (5%)/hydrogen DC plasma. The implications of these findings in the tritium retention control in future fusion reactors are addressed. (author). Letter-to-the-editor

  11. Toward semi-autonomous control of mobile robots for constrained environments

    International Nuclear Information System (INIS)

    Mercier, O.; Cara, O.

    1991-01-01

    Drawing from long-time experience in nuclear maintenance robotics, FRAMATOME leads with several partners an important effort with the goal of developing the decision and operator assistance capabilities of mobile robots. Future robots shall be better adapted (in size and configuration) to the operational requirements of nuclear plants work than current demonstrators. Due regards shall be paid to safety aspects and qualification procedure shall be specified soon. Also, dosimetry gains (e.g. as evaluated by DOSIANA) shall be evaluated to establish further the advantages of robotic solutions. Current achievements and plans for the next two years are expected to provide the necessary know-how for semi-autonomous control of various mobile robots in actual missions in nuclear plant environment. These advances in many closely connected disciplines and technologies should put FRAMATOME in a leader position as systems integrator or as developer for future markets in autonomous mobile robotics, not only in the nuclear field but in other domains as well. (author)

  12. Transport control of forest fuels by fleet manager, mobile terminals and GPS

    International Nuclear Information System (INIS)

    Sikanen, Lauri; Asikainen, Antti; Lehikoinen, Mikko

    2005-01-01

    Chip transportation is undertaken by private transportation enterprises that are contracted by a larger wood fuel trader. Compared with industrial roundwood supply the volumes and value of wood fuel supply are markedly lower. As a result, the possibilities to invest in information systems for transport management are limited. New portable, wireless communication techniques and internet-based systems for fleet management enable more cost-efficient control systems with low investment costs in hard and software and also low operating costs. Mobile handsets with GPS, digital road map display and global positioning systems (GPS) or general purpose radio service data transfer protocol can be used as mobile terminals in chippers and trucks. In addition, transport management personnel can use them to locate in-forest wood fuel storage piles into the map database as well as point suitable routing to the storage piles. In a pilot study, conducted in Central Finland, an internet based management tool, Arbonaut Fleet ManagerTM, was tailored for forest fuel supply chain management and trailed for three months. It was found that use of mobile handsets with GPS and map display assisted especially in exact location of in-forest wood fuel storage piles by managers. They assisted also trucks and chippers in navigation to storages and landings, but the screen was too small for reading during driving. The management system was found helpful in stock accounting and GPS-based vehicle tracking gave transportation distances directly for invoicing

  13. An efficient contents-adaptive backlight control method for mobile devices

    Science.gov (United States)

    Chen, Qiao Song; Yan, Ya Xing; Zhang, Xiao Mou; Cai, Hua; Deng, Xin; Wang, Jin

    2015-03-01

    For most of mobile devices with a large screen, image quality and power consumption are both of the major factors affecting the consumers' preference. Contents-adaptive backlight control (CABC) method can be utilized to adjust the backlight and promote the performance of mobile devices. Unlike the previous works mostly focusing on the reduction of power consumption, both of image quality and power consumption are taken into account in the proposed method. Firstly, region of interest (ROI) is detected to divide image into two parts: ROI and non-ROI. Then, three attributes including entropy, luminance, and saturation information in ROI are calculated. To achieve high perceived image quality in mobile devices, optimal value of backlight can be calculated by a linear combination of the aforementioned attributes. Coefficients of the linear combination are determined by applying the linear regression to the subjective scores of human visual experiments and objective values of the attributes. Based on the optimal value of backlight, displayed image data are processed brightly and backlight is darkened to reduce the power consumption of backlight later. Here, the ratios of increasing image data and decreasing backlight functionally depend on the luminance information of displayed image. Also, the proposed method is hardware implemented. Experimental results indicate that the proposed technique exhibits better performance compared to the conventional methods.

  14. Application of a model of instrumental conditioning to mobile robot control

    Science.gov (United States)

    Saksida, Lisa M.; Touretzky, D. S.

    1997-09-01

    Instrumental conditioning is a psychological process whereby an animal learns to associate its actions with their consequences. This type of learning is exploited in animal training techniques such as 'shaping by successive approximations,' which enables trainers to gradually adjust the animal's behavior by giving strategically timed reinforcements. While this is similar in principle to reinforcement learning, the real phenomenon includes many subtle effects not considered in the machine learning literature. In addition, a good deal of domain information is utilized by an animal learning a new task; it does not start from scratch every time it learns a new behavior. For these reasons, it is not surprising that mobile robot learning algorithms have yet to approach the sophistication and robustness of animal learning. A serious attempt to model instrumental learning could prove fruitful for improving machine learning techniques. In the present paper, we develop a computational theory of shaping at a level appropriate for controlling mobile robots. The theory is based on a series of mechanisms for 'behavior editing,' in which pre-existing behaviors, either innate or previously learned, can be dramatically changed in magnitude, shifted in direction, or otherwise manipulated so as to produce new behavioral routines. We have implemented our theory on Amelia, an RWI B21 mobile robot equipped with a gripper and color video camera. We provide results from training Amelia on several tasks, all of which were constructed as variations of one innate behavior, object-pursuit.

  15. The mPED randomized controlled clinical trial: applying mobile persuasive technologies to increase physical activity in sedentary women protocol

    Directory of Open Access Journals (Sweden)

    Fukuoka Yoshimi

    2011-12-01

    Full Text Available Abstract Background Despite the significant health benefits of regular physical activity, approximately half of American adults, particularly women and minorities, do not meet the current physical activity recommendations. Mobile phone technologies are readily available, easily accessible and may provide a potentially powerful tool for delivering physical activity interventions. However, we need to understand how to effectively apply these mobile technologies to increase and maintain physical activity in physically inactive women. The purpose of this paper is to describe the study design and protocol of the mPED (mobile phone based physical activity education randomized controlled clinical trial that examines the efficacy of a 3-month mobile phone and pedometer based physical activity intervention and compares two different 6-month maintenance interventions. Methods A randomized controlled trial (RCT with three arms; 1 PLUS (3-month mobile phone and pedometer based physical activity intervention and 6-month mobile phone diary maintenance intervention, 2 REGULAR (3-month mobile phone and pedometer based physical activity intervention and 6-month pedometer maintenance intervention, and 3 CONTROL (pedometer only, but no intervention will be conducted. A total of 192 physically inactive women who meet all inclusion criteria and successfully complete a 3-week run-in will be randomized into one of the three groups. The mobile phone serves as a means of delivering the physical activity intervention, setting individualized weekly physical activity goals, and providing self-monitoring (activity diary, immediate feedback and social support. The mobile phone also functions as a tool for communication and real-time data capture. The primary outcome is objectively measured physical activity. Discussion If efficacy of the intervention with a mobile phone is demonstrated, the results of this RCT will be able to provide new insights for current behavioral

  16. The mPED randomized controlled clinical trial: applying mobile persuasive technologies to increase physical activity in sedentary women protocol.

    Science.gov (United States)

    Fukuoka, Yoshimi; Komatsu, Judith; Suarez, Larry; Vittinghoff, Eric; Haskell, William; Noorishad, Tina; Pham, Kristin

    2011-12-14

    Despite the significant health benefits of regular physical activity, approximately half of American adults, particularly women and minorities, do not meet the current physical activity recommendations. Mobile phone technologies are readily available, easily accessible and may provide a potentially powerful tool for delivering physical activity interventions. However, we need to understand how to effectively apply these mobile technologies to increase and maintain physical activity in physically inactive women. The purpose of this paper is to describe the study design and protocol of the mPED (mobile phone based physical activity education) randomized controlled clinical trial that examines the efficacy of a 3-month mobile phone and pedometer based physical activity intervention and compares two different 6-month maintenance interventions. A randomized controlled trial (RCT) with three arms; 1) PLUS (3-month mobile phone and pedometer based physical activity intervention and 6-month mobile phone diary maintenance intervention), 2) REGULAR (3-month mobile phone and pedometer based physical activity intervention and 6-month pedometer maintenance intervention), and 3) CONTROL (pedometer only, but no intervention will be conducted). A total of 192 physically inactive women who meet all inclusion criteria and successfully complete a 3-week run-in will be randomized into one of the three groups. The mobile phone serves as a means of delivering the physical activity intervention, setting individualized weekly physical activity goals, and providing self-monitoring (activity diary), immediate feedback and social support. The mobile phone also functions as a tool for communication and real-time data capture. The primary outcome is objectively measured physical activity. If efficacy of the intervention with a mobile phone is demonstrated, the results of this RCT will be able to provide new insights for current behavioral sciences and mHealth. ClinicalTrials.gov#:NCTO1280812.

  17. Catalyst support effects on hydrogen spillover

    Science.gov (United States)

    Karim, Waiz; Spreafico, Clelia; Kleibert, Armin; Gobrecht, Jens; Vandevondele, Joost; Ekinci, Yasin; van Bokhoven, Jeroen A.

    2017-01-01

    Hydrogen spillover is the surface migration of activated hydrogen atoms from a metal catalyst particle, on which they are generated, onto the catalyst support. The phenomenon has been much studied and its occurrence on reducible supports such as titanium oxide is established, yet questions remain about whether hydrogen spillover can take place on nonreducible supports such as aluminium oxide. Here we use the enhanced precision of top-down nanofabrication to prepare controlled and precisely tunable model systems that allow us to quantify the efficiency and spatial extent of hydrogen spillover on both reducible and nonreducible supports. We place multiple pairs of iron oxide and platinum nanoparticles on titanium oxide and aluminium oxide supports, varying the distance between the pairs from zero to 45 nanometres with a precision of one nanometre. We then observe the extent of the reduction of the iron oxide particles by hydrogen atoms generated on the platinum using single-particle in situ X-ray absorption spectromicroscopy applied simultaneously to all particle pairs. The data, in conjunction with density functional theory calculations, reveal fast hydrogen spillover on titanium oxide that reduces remote iron oxide nanoparticles via coupled proton-electron transfer. In contrast, spillover on aluminium oxide is mediated by three-coordinated aluminium centres that also interact with water and that give rise to hydrogen mobility competing with hydrogen desorption; this results in hydrogen spillover about ten orders of magnitude slower than on titanium oxide and restricted to very short distances from the platinum particle. We anticipate that these observations will improve our understanding of hydrogen storage and catalytic reactions involving hydrogen, and that our approach to creating and probing model catalyst systems will provide opportunities for studying the origin of synergistic effects in supported catalysts that combine multiple functionalities.

  18. Virtual reality exercise improves mobility after stroke: an inpatient randomized controlled trial.

    Science.gov (United States)

    McEwen, Daniel; Taillon-Hobson, Anne; Bilodeau, Martin; Sveistrup, Heidi; Finestone, Hillel

    2014-06-01

    Exercise using virtual reality (VR) has improved balance in adults with traumatic brain injury and community-dwelling older adults. Rigorous randomized studies regarding its efficacy, safety, and applicability with individuals after stroke are lacking. The purpose of this study was to determine whether an adjunct VR therapy improves balance, mobility, and gait in stroke rehabilitation inpatients. A blinded randomized controlled trial studying 59 stroke survivors on an inpatient stroke rehabilitation unit was performed. The treatment group (n=30) received standard stroke rehabilitation therapy plus a program of VR exercises that challenged balance (eg, soccer goaltending, snowboarding) performed while standing. The control group (n=29) received standard stroke rehabilitation therapy plus exposure to identical VR environments but whose games did not challenge balance (performed in sitting). VR training consisted of 10 to 12 thirty-minute daily sessions for a 3-week period. Objective outcome measures of balance and mobility were assessed before, immediately after, and 1 month after training. Confidence intervals and effect sizes favored the treatment group on the Timed Up and Go and the Two-Minute Walk Test, with both groups meeting minimal clinical important differences after training. More individuals in the treatment group than in the control group showed reduced impairment in the lower extremity as measured by the Chedoke McMaster Leg domain (P=0.04) immediately after training. This VR exercise intervention for inpatient stroke rehabilitation improved mobility-related outcomes. Future studies could include nonambulatory participants as well as the implementation strategies for the clinical use of VR. http://www.ANZCTR.org.au/. Unique identifier: ACTRN12613000710729. © 2014 American Heart Association, Inc.

  19. Mobile technology habits: patterns of association among device usage, intertemporal preference, impulse control, and reward sensitivity.

    Science.gov (United States)

    Wilmer, Henry H; Chein, Jason M

    2016-10-01

    Mobile electronic devices are playing an increasingly pervasive role in our daily activities. Yet, there has been very little empirical research investigating how mobile technology habits might relate to individual differences in cognition and affect. The research presented in this paper provides evidence that heavier investment in mobile devices is correlated with a relatively weaker tendency to delay gratification (as measured by a delay discounting task) and a greater inclination toward impulsive behavior (i.e., weaker impulse control, assessed behaviorally and through self-report) but is not related to individual differences in sensitivity to reward. Analyses further demonstrated that individual variation in impulse control mediates the relationship between mobile technology usage and delay of gratification. Although based on correlational results, these findings lend some backing to concerns that increased use of portable electronic devices could have negative impacts on impulse control and the ability to appropriately valuate delayed rewards.

  20. Data Collection Method for Mobile Control Sink Node in Wireless Sensor Network Based on Compressive Sensing

    Directory of Open Access Journals (Sweden)

    Ling Yongfa

    2016-01-01

    Full Text Available The paper proposes a mobile control sink node data collection method in the wireless sensor network based on compressive sensing. This method, with regular track, selects the optimal data collection points in the monitoring area via the disc method, calcu-lates the shortest path by using the quantum genetic algorithm, and hence determines the data collection route. Simulation results show that this method has higher network throughput and better energy efficiency, capable of collecting a huge amount of data with balanced energy consumption in the network.

  1. An optimal control strategy for collision avoidance of mobile robots in non-stationary environments

    Science.gov (United States)

    Kyriakopoulos, K. J.; Saridis, G. N.

    1991-01-01

    An optimal control formulation of the problem of collision avoidance of mobile robots in environments containing moving obstacles is presented. Collision avoidance is guaranteed if the minimum distance between the robot and the objects is nonzero. A nominal trajectory is assumed to be known from off-line planning. The main idea is to change the velocity along the nominal trajectory so that collisions are avoided. Furthermore, time consistency with the nominal plan is desirable. A numerical solution of the optimization problem is obtained. Simulation results verify the value of the proposed strategy.

  2. A Study of Mobile Robot Control using EEG Emotiv Epoch Sensor

    Directory of Open Access Journals (Sweden)

    Victorio Yasin Timothius

    2018-01-01

    Full Text Available The study was using an EEG Emotiv Epoc+ sensor to recognize brain activity for controlling a mobile robot's movement. The study used Emotiv Control Panel software for EEG command identification. The commands will be interfaced inside Mind Your OSCs software and processing software which processed inside an Arduino Controller. The output of the Arduino is a movement command (ie. forward, backward, turn left, and turn right. The training methods of the system composed of three sets of thinking mode. First, thinking with doing facial expressions. Second, thinking with visual help. Third, thinking mentally without any help. In the first set, there are two configurations thinking with facial expression help as command of the mobile robot. Final results of the system are the second facial expressions configuration as the best facial expressions method with success rate 88.33 %. The second facial expression configuration has overall response time 1.60175 s faster than the first facial expressions configuration. In these two methods have dominant signals on the frontal lobe. The second facial expressions method have overall respond time 6.12 and 9.53 s faster than thinking with visual, and thinking without help respectively.

  3. Multidimensional control using a mobile-phone based brain-muscle-computer interface.

    Science.gov (United States)

    Vernon, Scott; Joshi, Sanjay S

    2011-01-01

    Many well-known brain-computer interfaces measure signals at the brain, and then rely on the brain's ability to learn via operant conditioning in order to control objects in the environment. In our lab, we have been developing brain-muscle-computer interfaces, which measure signals at a single muscle and then rely on the brain's ability to learn neuromuscular skills via operant conditioning. Here, we report a new mobile-phone based brain-muscle-computer interface prototype for severely paralyzed persons, based on previous results from our group showing that humans may actively create specified power levels in two separate frequency bands of a single sEMG signal. Electromyographic activity on the surface of a single face muscle (Auricularis superior) is recorded with a standard electrode. This analog electrical signal is imported into an Android-based mobile phone. User-modulated power in two separate frequency band serves as two separate and simultaneous control channels for machine control. After signal processing, the Android phone sends commands to external devices via Bluetooth. Users are trained to use the device via biofeedback, with simple cursor-to-target activities on the phone screen.

  4. Design of tracking mount and controller for mobile satellite laser ranging system

    Science.gov (United States)

    Park, Cheol Hoon; Son, Young Su; Kim, Byung In; Ham, Sang Young; Lee, Sung Whee; Lim, Hyung Chul

    2012-01-01

    In this study, we have proposed and implemented a design for the tracking mount and controller of the ARGO-M (Accurate Ranging system for Geodetic Observation - Mobile) which is a mobile satellite laser ranging (SLR) system developed by the Korea Astronomy and Space Science Institute (KASI) and Korea Institute of Machinery and Materials (KIMM). The tracking mount comprises a few core components such as bearings, driving motors and encoders. These components were selected as per the technical specifications for the tracking mount of the ARGO-M. A three-dimensional model of the tracking mount was designed. The frequency analysis of the model predicted that the first natural frequency of the designed tracking mount was high enough. The tracking controller is simulated using MATLAB/xPC Target to achieve the required pointing and tracking accuracy. In order to evaluate the system repeatability and tracking accuracy of the tracking mount, a prototype of the ARGO-M was fabricated, and repeatability tests were carried out using a laser interferometer. Tracking tests were conducted using the trajectories of low earth orbit (LEO) and high earth orbit (HEO) satellites. Based on the test results, it was confirmed that the prototype of the tracking mount and controller of the ARGO-M could achieve the required repeatability along with a tracking accuracy of less than 1 arcsec.

  5. Social Welfare Control in Mobile Crowdsensing Using Zero-Determinant Strategy.

    Science.gov (United States)

    Hu, Qin; Wang, Shengling; Bie, Rongfang; Cheng, Xiuzhen

    2017-05-03

    As a promising paradigm, mobile crowdsensing exerts the potential of widespread sensors embedded in mobile devices. The greedy nature of workers brings the problem of low-quality sensing data, which poses threats to the overall performance of a crowdsensing system. Existing works often tackle this problem with additional function components. In this paper, we systematically formulate the problem into a crowdsensing interaction process between a requestor and a worker, which can be modeled by two types of iterated games with different strategy spaces. Considering that the low-quality data submitted by the workers can reduce the requestor's payoff and further decrease the global income, we turn to controlling the social welfare in the games. To that aim, we take advantage of zero-determinant strategy, based on which we propose two social welfare control mechanisms under both game models. Specifically, we consider the requestor as the controller of the games and, with proper parameter settings for the to-be-adopted zero-determinant strategy, social welfare can be optimized to the desired level no matter what strategy the worker adopts. Simulation results demonstrate that the requestor can achieve the maximized social welfare and keep it stable by using our proposed mechanisms.

  6. Wheeled mobility skills of wheelchair basketball players: a randomized controlled study.

    Science.gov (United States)

    Saltan, Asuman; Bakar, Yeşim; Ankarali, Handan

    2017-05-01

    The aim of this study was to assess the influence of wheelchair basketball sport on the functional abilities of wheelchair users. This is a randomized controlled study. Wheelchair basketball players (n = 111) and non-player (n = 85) were included in this study. We administered the questionnaire version of the wheelchair skills test questionnaire (WST_Q), recording the participants' capacity and performance scores on each of 32 skills. Player group have the baseline values of WST_Q higher than control group. The mean total percentage score of player group was significantly greater than control group (p skills-sports relationship is reciprocal. With increased wheelchair skills, people may be more inclined to engage in sports; subsequently, with greater sports, wheelchair skills could improve. Wheelchair mobility skills during clinical rehabilitation should reflect the daily activities and needs of each wheelchair user. WST-Q provides advantages in terms of requiring less time and material in using of clinical.

  7. Control system and method for payload control in mobile platform cranes

    Science.gov (United States)

    Robinett, III, Rush D.; Groom, Kenneth N.; Feddema, John T.; Parker, Gordon G.

    2002-01-01

    A crane control system and method provides a way to generate crane commands responsive to a desired payload motion to achieve substantially pendulation-free actual payload motion. The control system and method apply a motion compensator to maintain a payload in a defined payload configuration relative to an inertial coordinate frame. The control system and method can further comprise a pendulation damper controller to reduce an amount of pendulation between a sensed payload configuration and the defined payload configuration. The control system and method can further comprise a command shaping filter to filter out a residual payload pendulation frequency from the desired payload motion.

  8. Cystathionine γ-Lyase-Produced Hydrogen Sulfide Controls Endothelial NO Bioavailability and Blood Pressure.

    Science.gov (United States)

    Szijártó, István András; Markó, Lajos; Filipovic, Milos R; Miljkovic, Jan Lj; Tabeling, Christoph; Tsvetkov, Dmitry; Wang, Ning; Rabelo, Luiza A; Witzenrath, Martin; Diedrich, André; Tank, Jens; Akahoshi, Noriyuki; Kamata, Shotaro; Ishii, Isao; Gollasch, Maik

    2018-06-01

    Hydrogen sulfide (H 2 S) and NO are important gasotransmitters, but how endogenous H 2 S affects the circulatory system has remained incompletely understood. Here, we show that CTH or CSE (cystathionine γ-lyase)-produced H 2 S scavenges vascular NO and controls its endogenous levels in peripheral arteries, which contribute to blood pressure regulation. Furthermore, eNOS (endothelial NO synthase) and phospho-eNOS protein levels were unaffected, but levels of nitroxyl were low in CTH-deficient arteries, demonstrating reduced direct chemical interaction between H 2 S and NO. Pretreatment of arterial rings from CTH-deficient mice with exogenous H 2 S donor rescued the endothelial vasorelaxant response and decreased tissue NO levels. Our discovery that CTH-produced H 2 S inhibits endogenous endothelial NO bioavailability and vascular tone is novel and fundamentally important for understanding how regulation of vascular tone is tailored for endogenous H 2 S to contribute to systemic blood pressure function. © 2018 American Heart Association, Inc.

  9. Evaluation of feed COD/sulfate ratio as a control criterion for the biological hydrogen sulfide production and lead precipitation

    International Nuclear Information System (INIS)

    Velasco, Antonio; Ramirez, Martha; Volke-Sepulveda, Tania; Gonzalez-Sanchez, Armando; Revah, Sergio

    2008-01-01

    The ability of sulfate-reducing bacteria to produce hydrogen sulfide and the high affinity of sulfide to react with divalent metallic cations represent an excellent option to remove heavy metals from wastewater. Different parameters have been proposed to control the hydrogen sulfide production by anaerobic bacteria, such as the organic and sulfate loading rates and the feed COD/SO 4 2- ratio. This work relates the feed COD/SO 4 2- ratio with the hydrogen sulfide production and dissolved lead precipitation, using ethanol as carbon and energy source in an up-flow anaerobic sludge blanket reactor. A maximum dissolved sulfide concentration of 470 ± 7 mg S/L was obtained at a feed COD/SO 4 2- ratio of 2.5, with sulfate and ethanol conversions of approximately 94 and 87%, respectively. The lowest dissolved sulfide concentration (145 ± 10 mg S/L) was observed with a feed COD/SO 4 2- ratio of 0.67. Substantial amounts of acetate (510-1730 mg/L) were produced and accumulated in the bioreactor from ethanol oxidation. Although only incomplete oxidation of ethanol to acetate was observed, the consortium was able to remove 99% of the dissolved lead (200 mg/L) with a feed COD/SO 4 2- ratio of 1.5. It was found that the feed COD/SO 4 2- ratio could be an adequate parameter to control the hydrogen sulfide production and the consequent precipitation of dissolved lead

  10. Computer system requirements specification for 101-SY hydrogen mitigation test project data acquisition and control system (DACS-1)

    International Nuclear Information System (INIS)

    McNeece, S.G.; Truitt, R.W.

    1994-01-01

    The system requirements specification for SY-101 hydrogen mitigation test project (HMTP) data acquisition and control system (DACS-1) documents the system requirements for the DACS-1 project. The purpose of the DACS is to provide data acquisition and control capabilities for the hydrogen mitigation testing of Tank SY-101. Mitigation testing uses a pump immersed in the waste, directed at varying angles and operated at different speeds and time durations. Tank and supporting instrumentation is brought into the DACS to monitor the status of the tank and to provide information on the effectiveness of the mitigation test. Instrumentation is also provided for closed loop control of the pump operation. DACS is also capable for being expanded to control and monitor other mitigation testing. The intended audience for the computer system requirements specification includes the SY-101 hydrogen mitigation test data acquisition and control system designers: analysts, programmers, instrument engineers, operators, maintainers. It is intended for the data users: tank farm operations, mitigation test engineers, the Test Review Group (TRG), data management support staff, data analysis, Hanford data stewards, and external reviewers

  11. A theory-based video messaging mobile phone intervention for smoking cessation: randomized controlled trial.

    Science.gov (United States)

    Whittaker, Robyn; Dorey, Enid; Bramley, Dale; Bullen, Chris; Denny, Simon; Elley, C Raina; Maddison, Ralph; McRobbie, Hayden; Parag, Varsha; Rodgers, Anthony; Salmon, Penny

    2011-01-21

    Advances in technology allowed the development of a novel smoking cessation program delivered by video messages sent to mobile phones. This social cognitive theory-based intervention (called "STUB IT") used observational learning via short video diary messages from role models going through the quitting process to teach behavioral change techniques. The objective of our study was to assess the effectiveness of a multimedia mobile phone intervention for smoking cessation. A randomized controlled trial was conducted with 6-month follow-up. Participants had to be 16 years of age or over, be current daily smokers, be ready to quit, and have a video message-capable phone. Recruitment targeted younger adults predominantly through radio and online advertising. Registration and data collection were completed online, prompted by text messages. The intervention group received an automated package of video and text messages over 6 months that was tailored to self-selected quit date, role model, and timing of messages. Extra messages were available on demand to beat cravings and address lapses. The control group also set a quit date and received a general health video message sent to their phone every 2 weeks. The target sample size was not achieved due to difficulty recruiting young adult quitters. Of the 226 randomized participants, 47% (107/226) were female and 24% (54/226) were Maori (indigenous population of New Zealand). Their mean age was 27 years (SD 8.7), and there was a high level of nicotine addiction. Continuous abstinence at 6 months was 26.4% (29/110) in the intervention group and 27.6% (32/116) in the control group (P = .8). Feedback from participants indicated that the support provided by the video role models was important and appreciated. This study was not able to demonstrate a statistically significant effect of the complex video messaging mobile phone intervention compared with simple general health video messages via mobile phone. However, there was

  12. PERIPHERAL APPLICATION OF REPETITIVE PULSE MAGNETIC STIMULATION ON JOINT CONTRACTURE FOR MOBILITY RESTORATION: CONTROLLED RANDOMIZED STUDY

    Directory of Open Access Journals (Sweden)

    Efthimios J. Kouloulas

    2016-10-01

    Full Text Available Background: Joint contracture is a limitation in the passive or active range of motion (ROM of a joint, where in addition to the mobility limiting factor the pain is also present. Repetitive pulsed Magnetic Stimulation (rPMS appears to be an effective, non-invasive and safety solution for treating this condition. Therefore aim of this study was to evaluate the effect of rPMS in treating joint contracture. Methods: 30 subjects with joint contracture in the knee were enrolled in this study and divided respectively into Treatment and Control group. The treatment group were delivered with rPMS therapy. The control group was delivered with conventional physiotherapy method (ultrasound. The primary outcome measurements were: 1. Mobility evaluation by goniometry (ROM in degrees while performing flexion and Patient Functional Assessment Questionnaire (PFAQ for ability to perform Activities of Daily Living (ADL and 2. Pain evaluation by 10-point Visual Analog Scale (VAS for pain perception. Absence of adverse events was set as a secondary measure. Results: The results of the study show statistical difference (p<0.05 between the levels of improvement of all studied parameters while comparing between both groups. The results suggest greater immobility restoration and pain relieving effect of the rPMS in comparison to conventional physiotherapy method. Conclusion: rPMS an effective and safe non-invasive method for mobility restoration and pain relief in case of joint contractures. This study suggests the method as beneficial and quality of life ameliorating among patients suffering from immobilized joints accompanied by pain.

  13. Multiband Planar Inverted-F Antenna with Independent Operating Bands Control for Mobile Handset Applications

    Directory of Open Access Journals (Sweden)

    Mustapha El Halaoui

    2017-01-01

    Full Text Available A new compact multiband PIFA (Planar Inverted-F Antenna for mobile handset is proposed in this article. The proposed PIFA has a simple geometry with four slots integrated in the radiating patch and ground plane. The PIFA occupies a small volume of 51 × 14 × 7.2 mm3 and is placed on the top portion of mobile phone. The optimized PIFA is worked in the 790 MHz band (737–831 MHz, the 1870 MHz band (1794–1977 MHz, the 2550 MHz band (2507–2615 MHz, and the 3400 MHz band (3341–3545 MHz, to cover LTE700, LTE800, DCS1800, PCS1900, LTE1800, LTE1900, LTE2500, and WIMAX3400 bands. Each of the four operating bands can be controlled independently by the variation of a single parameter of the proposed design, with a wide control range. An omnidirectional radiation pattern to each resonant frequency is obtained with a maximum gain of 2.15 dBi at 790 MHz, 3.99 dBi at 1870 MHz, 4.57 dBi at 2550 MHz, and 6.43 dBi at 3400 MHz. The proposed PIFA is studied in the free space and in the presence of other mobile phone components such as the battery, LCD (liquid crystal display, camera, microphone, speaker, buttons, and a plastic housing. The distribution of specific absorption rate for both European and American standards for each operating band and at various distances between the antenna and the human head is also studied.

  14. Valorizing waste iron powder in biogas production: Hydrogen sulfide control and process performances.

    Science.gov (United States)

    Andriamanohiarisoamanana, Fetra J; Shirai, Tomoya; Yamashiro, Takaki; Yasui, Seiichi; Iwasaki, Masahiro; Ihara, Ikko; Nishida, Takehiro; Tangtaweewipat, Suchon; Umetsu, Kazutaka

    2018-02-15

    Biogas is composed of different gases including hydrogen sulfide (H 2 S), which is a hazardous gas that damages pipes and generators in anaerobic digestion system. The objective of this study was to control H 2 S by waste iron powder produced by laser cutting machine in a steel and iron industry. Waste iron powder was mixed with dairy manure at a concentration between 2.0 and 20.0 g/L in batch experiments, while the concentration was varied between 1.0 and 4.0 g/L in bench experiment. In batch experiment, a reduction of up to 93% of H 2 S was observed at waste iron powder of 2.0 g/L (T1), while the reduction was of more than 99% at waste iron powder beyond 8.0 g/L (T4 ∼ T6). The total sulfide concentration (S T ) increased together with waste iron powder concentration and was fitted with a quadratic equation with a maximum S T of 208.0 mg/L at waste iron powder of 20.2 g/L. Waste iron powder did not have significant effect on methane yield in batch and bench experiments. However, hydrolysis rate constant was increased by almost 100%, while the lag-phase period was reduced to half in test digesters compared to that in control digester. In bench experiment, H 2 S concentration was reduced by 89% at 2.0 g/L, while 50% at 1.0 g/L. Therefore, waste iron powder was effectively removed H 2 S and did not affect negatively anaerobic digestion process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Control of entanglement following the photoionization of trapped, hydrogen-like ions

    International Nuclear Information System (INIS)

    Radtke, Thomas; Fritzsche, Stephan; Surzhykov, Andrey

    2005-01-01

    Density matrix theory is applied to re-investigate the entanglement in the spin state of pairs of electrons following the photoionization of trapped, hydrogen-like ions. For the ionization of one out of two non-interacting atoms, in particular, we analyzed how the entanglement between the electrons is changed owing to their interaction with the radiation field. Detailed calculations on the concurrence of the final spin-state of the electrons have been performed for the photoionization of hydrogen as well as for hydrogen-like Xe 53+ and U 91+ ions. From these computations it is shown that the degree of entanglement, which is quite well preserved for neutral hydrogen, will be strongly affected by relativistic and non-dipole effects of the radiation field as the nuclear charge of the ions is increased

  16. Differential-drive mobile robot control using a cloud of particles approach

    Directory of Open Access Journals (Sweden)

    Walter Fetter Lages

    2016-12-01

    Full Text Available Common control systems for mobile robots include the use of some deterministic control law coupled with some pose estimation method, such as the extended Kalman filter, by considering the certainty equivalence principle. Recent approaches consider the use of partially observable Markov decision process strategies together with Bayesian estimators. These methods are well suited to handle the uncertainty in pose estimation but demand significant processing power. In order to reduce the required processing power and still allow for multimodal or non-Gaussian uncertain distributions, we propose a scheme based on a particle filter and a corresponding cloud of control signals. The approach avoids the use of the certainty equivalence principle by postponing the decision on the optimal estimate to the control stage. As the mapping between the pose space and the control action space is nonlinear and the best estimation of robot pose is uncertain, postponing the decision to the control space makes it possible to select a better control action in the presence of multimodal and non-Gaussian uncertainty models. Simulation results are presented.

  17. Review of Design Data for Safety Assessment of Tokai Reprocessing Plant. Control of hydrogen gas produced by radiolysis of reprocessing solutions at Tokai Reprocessing Plant

    International Nuclear Information System (INIS)

    Omori, E.; Surugaya, N.; Takaya, A.; Nakamura, H.; Maki, A.; Yamanouchi, T.

    1999-10-01

    Radioactive materials in aqueous solution at a nuclear fuel reprocessing plant causes radiolytic generation of several gases including hydrogen. Hydrogen accumulating in equipment can be an explosion hazard. In such plants, though the consideration in the design has been fundamentally made in order to remove the ignition source from the equipment, the hydrogen concentration in the equipment should not exceed the explosion threshold. It is, therefore, desired to keep the hydrogen concentration lower than the explosion threshold by dilution with the air introduced into equipment, from the viewpoint which previously prevents the explosion. This report describes the calculation of hydrogen generation, evaluation of hydrogen concentration under abnormal operation and consideration of possible improvement at Tokai Reprocessing Plant. The amount of hydrogen generation was calculated for each equipment from available data on radiolysis induced by radioactive materials. Taking into consideration for abnormal condition that is single failure of air supply and loss of power supply, the investigation was made on the method for controlling so that the hydrogen concentration may not exceed the explosion threshold. Possible means which can control the concentration of hydrogen gas under the explosion threshold have been also investigated. As the result, it was found that hydrogen concentration of most equipment was kept under the explosion threshold. It was also shown that improvement of the facility was necessary on the equipment in which the concentration of the hydrogen may exceed the explosion threshold. Proposals based on the above results are also given in this report. The above content has been described in 'Examination of the hydrogen produced by the radiolysis' which is a part of 'Reviews of Design Data for Safety Assessment of Tokai Reprocessing Plant' (JNC TN8410 99-002) published in February 1999. This report incorporates the detail evaluation so that operation

  18. Final Technical Report: Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project

    Energy Technology Data Exchange (ETDEWEB)

    Ronald Grasman

    2011-12-31

    This report summarizes the work conducted under U.S. Department of Energy (DOE) under contract DE-FC36-04GO14285 by Mercedes-Benz & Research Development, North America (MBRDNA), Chrysler, Daimler, Mercedes Benz USA (MBUSA), BP, DTE Energy and NextEnergy to validate fuel cell technologies for infrastructure, transportation as well as assess technology and commercial readiness for the market. The Mercedes Team, together with its partners, tested the technology by operating and fueling hydrogen fuel cell vehicles under real world conditions in varying climate, terrain and driving conditions. Vehicle and infrastructure data was collected to monitor the progress toward the hydrogen vehicle and infrastructure performance targets of $2.00 to 3.00/gge hydrogen production cost and 2,000-hour fuel cell durability. Finally, to prepare the public for a hydrogen economy, outreach activities were designed to promote awareness and acceptance of hydrogen technology. DTE, BP and NextEnergy established hydrogen filling stations using multiple technologies for on-site hydrogen generation, storage and dispensing. DTE established a hydrogen station in Southfield, Michigan while NextEnergy and BP worked together to construct one hydrogen station in Detroit. BP constructed another fueling station in Burbank, California and provided a full-time hydrogen trailer at San Francisco, California and a hydrogen station located at Los Angeles International Airport in Southern, California. Stations were operated between 2005 and 2011. The Team deployed 30 Gen I Fuel Cell Vehicles (FCVs) in the beginning of the project. While 28 Gen I F-CELLs used the A-Class platform, the remaining 2 were Sprinter delivery vans. Fuel cell vehicles were operated by external customers for real-world operations in various regions (ecosystems) to capture various driving patterns and climate conditions (hot, moderate and cold). External operators consisted of F-CELL partner organizations in California and Michigan

  19. Effectiveness of a mobile cooperation intervention during the clinical practicum of nursing students: a parallel group randomized controlled trial protocol.

    Science.gov (United States)

    Strandell-Laine, Camilla; Saarikoski, Mikko; Löyttyniemi, Eliisa; Salminen, Leena; Suomi, Reima; Leino-Kilpi, Helena

    2017-06-01

    The aim of this study was to describe a study protocol for a study evaluating the effectiveness of a mobile cooperation intervention to improve students' competence level, self-efficacy in clinical performance and satisfaction with the clinical learning environment. Nursing student-nurse teacher cooperation during the clinical practicum has a vital role in promoting the learning of students. Despite an increasing interest in using mobile technologies to improve the clinical practicum of students, there is limited robust evidence regarding their effectiveness. A multicentre, parallel group, randomized, controlled, pragmatic, superiority trial. Second-year pre-registration nursing students who are beginning a clinical practicum will be recruited from one university of applied sciences. Eligible students will be randomly allocated to either a control group (engaging in standard cooperation) or an intervention group (engaging in mobile cooperation) for the 5-week the clinical practicum. The complex mobile cooperation intervention comprises of a mobile application-assisted, nursing student-nurse teacher cooperation and a training in the functions of the mobile application. The primary outcome is competence. The secondary outcomes include self-efficacy in clinical performance and satisfaction with the clinical learning environment. Moreover, a process evaluation will be undertaken. The ethical approval for this study was obtained in December 2014 and the study received funding in 2015. The results of this study will provide robust evidence on mobile cooperation during the clinical practicum, a research topic that has not been consistently studied to date. © 2016 John Wiley & Sons Ltd.

  20. Free hydrogen atom collision cross sections of interest in controlled thermonuclear research

    Energy Technology Data Exchange (ETDEWEB)

    Fite, W L [John Jay Hopkins Laboratory for Pure and Applied Science, General Atomic Division of General Dynamics Corporation, San Diego, CA (United States)

    1958-07-01

    The present paper summarizes the results of measurements of the cross sections of hydrogen atoms for: (1) ionization, (2) excitation of Lyman alpha radiation on electron impact, and (3) elastic scattering of electrons of energy less than 10 eV; and also describes the approach of measurements now in progress on (4) charge-exchange between deuterons and deuterium atoms and (5) ionization of the hydrogen atom on proton impact.

  1. Passivity-based model predictive control for mobile vehicle motion planning

    CERN Document Server

    Tahirovic, Adnan

    2013-01-01

    Passivity-based Model Predictive Control for Mobile Vehicle Navigation represents a complete theoretical approach to the adoption of passivity-based model predictive control (MPC) for autonomous vehicle navigation in both indoor and outdoor environments. The brief also introduces analysis of the worst-case scenario that might occur during the task execution. Some of the questions answered in the text include: • how to use an MPC optimization framework for the mobile vehicle navigation approach; • how to guarantee safe task completion even in complex environments including obstacle avoidance and sideslip and rollover avoidance; and  • what to expect in the worst-case scenario in which the roughness of the terrain leads the algorithm to generate the longest possible path to the goal. The passivity-based MPC approach provides a framework in which a wide range of complex vehicles can be accommodated to obtain a safer and more realizable tool during the path-planning stage. During task execution, the optimi...

  2. Using unconstrained tongue motion as an alternative control mechanism for wheeled mobility.

    Science.gov (United States)

    Huo, Xueliang; Ghovanloo, Maysam

    2009-06-01

    Tongue drive system (TDS) is a tongue-operated, minimally invasive, unobtrusive, noncontact, and wireless assistive technology that infers users' intentions by detecting and classifying their voluntary tongue motions, and translating them to user-defined commands. We have developed customized interface circuitry between an external TDS (eTDS) prototype and a commercial powered wheelchair (PWC) as well as three control strategies to evaluate the tongue motion as an alternative control input for wheeled mobility. We tested the eTDS performance in driving PWCs on 12 able-bodied human subjects, of which 11 were novice. The results showed that all subjects could complete navigation tasks by operating the PWC using their tongue motions. Despite little prior experience, the average time using the eTDS and the tongue was only approximately three times longer than using a joystick and the fingers. Navigation time was strongly dependant on the number of issued commands, which reduced by gaining experience. Particularly, the unintended issued commands (the Midas touch problem) were rare, demonstrating the effectiveness of the tongue tracking and external magnetic field cancellation algorithms as well as the safety of the TDS for wheeled mobility.

  3. ALLIANCE: An architecture for fault tolerant, cooperative control of heterogeneous mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Parker, L.E.

    1995-02-01

    This research addresses the problem of achieving fault tolerant cooperation within small- to medium-sized teams of heterogeneous mobile robots. The author describes a novel behavior-based, fully distributed architecture, called ALLIANCE, that utilizes adaptive action selection to achieve fault tolerant cooperative control in robot missions involving loosely coupled, largely independent tasks. The robots in this architecture possess a variety of high-level functions that they can perform during a mission, and must at all times select an appropriate action based on the requirements of the mission, the activities of other robots, the current environmental conditions, and their own internal states. Since such cooperative teams often work in dynamic and unpredictable environments, the software architecture allows the team members to respond robustly and reliably to unexpected environmental changes and modifications in the robot team that may occur due to mechanical failure, the learning of new skills, or the addition or removal of robots from the team by human intervention. After presenting ALLIANCE, the author describes in detail experimental results of an implementation of this architecture on a team of physical mobile robots performing a cooperative box pushing demonstration. These experiments illustrate the ability of ALLIANCE to achieve adaptive, fault-tolerant cooperative control amidst dynamic changes in the capabilities of the robot team.

  4. Increasing Physical Activity in Mothers Using Video Exercise Groups and Exercise Mobile Apps: Randomized Controlled Trial.

    Science.gov (United States)

    Mascarenhas, Maya Nina; Chan, June Maylin; Vittinghoff, Eric; Van Blarigan, Erin Lynn; Hecht, Frederick

    2018-05-18

    Women significantly decrease their activity levels in the transition to motherhood. Digital health technologies are low cost, scalable, and can provide an effective delivery mechanism for behavior change. This is the first study that examines the use of videoconferencing and mobile apps to create exercise groups for mothers. The aim of the study was to test the feasibility, acceptability, and effectiveness of an individually adaptive and socially supportive physical activity intervention incorporating videoconferencing and mobile apps for mothers. The Moms Online Video Exercise Study was an 8-week, 2-armed, Web-based randomized trial comparing the effectiveness of a group exercise intervention with a waitlist control. Healthy mothers with at least 1 child under the age of 12 years were recruited through Facebook and email listservs. Intervention participants joined exercise groups using videoconferencing (Google Hangouts) every morning on weekdays and exercised together in real time, guided by exercise mobile apps (eg, Nike+, Sworkit) of their choice. Waitlist control participants had access to recommended mobile apps and an invitation to join an exercise group after the 8-week study period. Main outcomes assessed included changes in self-reported moderate, vigorous, and moderate to vigorous physical activity (MVPA) minutes per week in aggregate and stratified by whether women met Centers for Disease Control and Prevention guidelines for sufficient aerobic activity at baseline. Outcomes were measured through self-assessed Web-based questionnaires at baseline and 8 weeks. The intervention was effective at increasing exercise for inactive women and proved to be feasible and acceptable to all participants. A total of 64 women were randomized, 30 to intervention and 34 to control. Women attended 2.8 sessions per week. There was a strong, but not statistically significant, trend toward increasing moderate, vigorous, and MVPA minutes for all women. As hypothesized, in

  5. Hydrogen energy applications

    International Nuclear Information System (INIS)

    Okken, P.A.

    1992-10-01

    For the Energy and Material consumption Scenarios (EMS), by which emission reduction of CO 2 and other greenhouse gases can be calculated, calculations are executed by means of the MARKAL model (MARket ALlocation, a process-oriented dynamic linear programming model to minimize the costs of the energy system) for the Netherlands energy economy in the period 2000-2040, using a variable CO 2 emission limit. The results of these calculations are published in a separate report (ECN-C--92-066). The use of hydrogen can play an important part in the above-mentioned period. An overview of several options to produce or use hydrogen is given and added to the MARKAL model. In this report techno-economical data and estimates were compiled for several H 2 -application options, which subsequently also are added to the MARKAL model. After a brief chapter on hydrogen and the impact on the reduction of CO 2 emission attention is paid to stationary and mobile applications. The stationary options concern the mixing of natural gas with 10% hydrogen, a 100% substitution of natural gas by hydrogen, the use of a direct steam generator (combustion of hydrogen by means of pure oxygen, followed by steam injection to produce steam), and the use of fuel cells. The mobile options concern the use of hydrogen in the transportation sector. In brief, attention is paid to a hydrogen passenger car with an Otto engine, and a hydrogen passenger car with a fuel cell, a hybrid (metal)-hydride car, a hydrogen truck, a truck with a methanol fuel cell, a hydrogen bus, an inland canal boat with a hydrogen fuel cell, and finally a hydrogen airplane. 2 figs., 15 tabs., 1 app., 26 refs

  6. Design and control strategy for a hybrid green energy system for mobile telecommunication sites

    Science.gov (United States)

    Okundamiya, Michael S.; Emagbetere, Joy O.; Ogujor, Emmanuel A.

    2014-07-01

    The rising energy costs and carbon footprint of operating mobile telecommunication sites in the emerging world have increased research interests in green technology. The intermittent nature of most green energy sources creates the problem of designing the optimum configuration for a given location. This study presents the design analysis and control strategy for a cost effective and reliable operation of the hybrid green energy system (HGES) for GSM base transceiver station (BTS) sites in isolated regions. The design constrains the generation and distribution of power to reliably satisfy the energy demand while ensuring safe operation of the system. The overall process control applies the genetic algorithm-based technique for optimal techno-economic sizing of system's components. The process simulation utilized meteorological data for 3 locations (Abuja, Benin City and Sokoto) with varying climatic conditions in Nigeria. Simulation results presented for green GSM BTS sites are discussed and compared with existing approaches.

  7. Neural Network Observer-Based Finite-Time Formation Control of Mobile Robots

    Directory of Open Access Journals (Sweden)

    Caihong Zhang

    2014-01-01

    Full Text Available This paper addresses the leader-following formation problem of nonholonomic mobile robots. In the formation, only the pose (i.e., the position and direction angle of the leader robot can be obtained by the follower. First, the leader-following formation is transformed into special trajectory tracking. And then, a neural network (NN finite-time observer of the follower robot is designed to estimate the dynamics of the leader robot. Finally, finite-time formation control laws are developed for the follower robot to track the leader robot in the desired separation and bearing in finite time. The effectiveness of the proposed NN finite-time observer and the formation control laws are illustrated by both qualitative analysis and simulation results.

  8. Reduction of external noise of mobile energy facilities by using active noise control system in muffler

    Science.gov (United States)

    Polivaev, O. I.; Kuznetsov, A. N.; Larionov, A. N.; Beliansky, R. G.

    2018-03-01

    The paper describes a method for the reducing emission of low-frequency noise of modern automotive vehicles into the environment. The importance of reducing the external noise of modern mobile energy facilities made in Russia is substantiated. Standard methods for controlling external noise in technology are of low efficiency when low-frequency sound waves are reduced. In this case, it is in the low-frequency zone of the sound range that the main power of the noise emitted by the machinery lies. The most effective way to reduce such sound waves is to use active noise control systems. A design of a muffler using a similar system is presented. This muffler allowed one to reduce the emission of increased noise levels into the environment by 7-11 dB and to increase acoustic comfort at the operator's workplace by 3-5 dB.

  9. Wheels Optimization and Vision Control of Omni-directional Mobile Microrobot

    Directory of Open Access Journals (Sweden)

    Jianghao Li

    2008-06-01

    Full Text Available This paper presents a millimeters scale omni-directional mobile microrobot with special dual-wheel structure. The microrobot was actuated by three electromagnetic micromotors of 2mm diameter. Dynamic analysis of translational and steering movements presented the relationship between the sizes of the dual-wheel structure and the output torque of the micromotor. Genetic algorithm (GA was employed to optimize the dual-wheel's sizes for reducing the unnecessary torque consumption and improving the driving ability of the microrobot. A computer vision system contained two sets of feedback control is devised for the microrobot. Torque self-balance and current-limiting control approach are presented to ensure the accuracy of step movement. Experiment results demonstrate the feasibility of these concepts.

  10. Wheels Optimization and Vision Control of Omni-directional Mobile Microrobot

    Directory of Open Access Journals (Sweden)

    Jianghao Li

    2008-11-01

    Full Text Available This paper presents a millimeters scale omni-directional mobile microrobot with special dual-wheel structure. The microrobot was actuated by three electromagnetic micromotors of 2mm diameter. Dynamic analysis of translational and steering movements presented the relationship between the sizes of the dual-wheel structure and the output torque of the micromotor. Genetic algorithm (GA was employed to optimize the dualwheel's sizes for reducing the unnecessary torque consumption and improving the driving ability of the microrobot. A computer vision system contained two sets of feedback control is devised for the microrobot. Torque self-balance and current-limiting control approach are presented to ensure the accuracy of step movement. Experiment results demonstrate the feasibility of these concepts.

  11. Flocking Control of Multiple Mobile Agents with the Rules of Avoiding Collision

    Directory of Open Access Journals (Sweden)

    Hongtao Zhou

    2015-01-01

    Full Text Available This paper investigates the flocking and the coordinative control problems of multiple mobile agents with the rules of avoiding collision. We propose a set of control laws using hysteresis in adding new links and applying new potential function to guarantee that the fragmentation of the network can be avoided, under which all agents approach a common velocity vector, and asymptotically converge to a fixed value of interagent distances and collisions between agents can be avoided throughout the motion. Furthermore, we extend the flocking algorithm to solve the flocking situation of the group with a virtual leader agent. The laws can make all agents asymptotically approach the virtual leader and collisions can be avoided between agents in the motion evolution. Finally, some numerical simulations are showed to illustrate the theoretical results.

  12. Image-based Fuzzy Parking Control of a Car-like Mobile Robot

    Directory of Open Access Journals (Sweden)

    Yin Yin Aye

    2017-03-01

    Full Text Available This paper develops a novel automatic parking system using an image-based fuzzy controller, where in the reasoning the slope and intercept of the desired target line are used for the inputs, and the steering angle of the robot is generated for the output. The objective of this study is that a robot equipped with a camera detects a rectangular parking frame, which is drawn on the floor, based on image processing. The desired target line to be followed by the robot is generated by using Hough transform from a captured image. The fuzzy controller is designed according to experiments of skilled driver, and the fuzzy rules are tuned and the fuzzy membership functions are optimized by experimentally for output. The effectiveness of the proposed method is demonstrated through some experimental results with an actual mobile robot

  13. Event-Based Control Strategy for Mobile Robots in Wireless Environments.

    Science.gov (United States)

    Socas, Rafael; Dormido, Sebastián; Dormido, Raquel; Fabregas, Ernesto

    2015-12-02

    In this paper, a new event-based control strategy for mobile robots is presented. It has been designed to work in wireless environments where a centralized controller has to interchange information with the robots over an RF (radio frequency) interface. The event-based architectures have been developed for differential wheeled robots, although they can be applied to other kinds of robots in a simple way. The solution has been checked over classical navigation algorithms, like wall following and obstacle avoidance, using scenarios with a unique or multiple robots. A comparison between the proposed architectures and the classical discrete-time strategy is also carried out. The experimental results shows that the proposed solution has a higher efficiency in communication resource usage than the classical discrete-time strategy with the same accuracy.

  14. Mobile Phones as a Citizen-Controlled Anti-corruption Tool in East Africa - A Literature Review

    OpenAIRE

    Strand , Cecilia; Hatakka , Mathias

    2017-01-01

    Part 14: Current Issues; International audience; Despite agreement amongst donors, business and political leaders concerning the negative effects of corruption, levels have not fallen in East Africa. The continued high levels of corruption, reassert the need for a better understanding if mobile phones, if prolific enough, can be an effective tool against corruption. Through a literature review of ten years M4D and ICT4D research on mobiles as a citizens-controlled tool for (a) accessing gover...

  15. A randomised controlled trial of an SMS-based mobile epilepsy education system.

    Science.gov (United States)

    Lua, Pei Lin; Neni, Widiasmoro Selamat

    2013-01-01

    We evaluated an epilepsy education programme based on text messaging (SMS). Epilepsy outpatients from three hospitals in Malaysia were randomised into two groups: intervention and control. Patients in the control group were supplied with printed epilepsy educational material while those in the intervention group also received text messages from the Mobile Epilepsy Educational System (MEES). A total of 136 patients completed the study (mean age 31 years; 91% Malay; 51% with an illness duration of more than 5 years). A between-group analysis showed that the awareness, knowledge and attitudes (AKA) about epilepsy did not significantly differ between the groups at baseline (P > 0.05). The intervention patients reported better AKA levels during follow-up compared to the control patients (P < 0.05). A within-group analysis showed that in intervention patients, there were significant improvements in all AKA domains with larger effect sizes (P < 0.01) while control patients also exhibited significant improvement in most domains except for Awareness but with smaller effect sizes. After controlling for possible confounding variables (age, gender, educational qualification, monthly income and baseline mean for each domain), the intervention group still reported significantly higher AKA than the control group particularly in Awareness (P < 0.001) and Total AKA (P = 0.003). There was also significantly better medication adherence and clinic attendance in the intervention group (P < 0.05). The results suggest that the addition of the MEES to conventional epilepsy education is effective in improving AKA.

  16. Safety considerations for compressed hydrogen storage systems

    International Nuclear Information System (INIS)

    Gleason, D.

    2006-01-01

    An overview of the safety considerations for various hydrogen storage options, including stationary, vehicle storage, and mobile refueling technologies. Indications of some of the challenges facing the industry as the demand for hydrogen fuel storage systems increases. (author)

  17. Morphology-controllable synthesis and characterization of carbon nanotube/polypyrrole composites and their hydrogen storage capacities

    Energy Technology Data Exchange (ETDEWEB)

    Okan, Burcu Saner, E-mail: bsanerokan@sabanciuniv.edu [Sabancı University Nanotechnology Research and Application Center, SUNUM, Tuzla, Istanbul 34956 (Turkey); Zanjani, Jamal Seyyed Monfared [Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla, Istanbul 34956 (Turkey); Letofsky-Papst, Ilse [Institute for Electron Microscopy, Graz University of Technology, Steyrergasse 17, A-8010, Graz (Austria); Cebeci, Fevzi Çakmak; Menceloglu, Yusuf Z. [Sabancı University Nanotechnology Research and Application Center, SUNUM, Tuzla, Istanbul 34956 (Turkey); Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla, Istanbul 34956 (Turkey)

    2015-11-01

    Sphere-like and layer-by-layer growth mechanisms of polypyrrole are controlled by changing pyrrole monomer concentration and using carbon nanotubes (CNT) as template. Pristine polypyrrole has sphere-like structures but remarkable change in types of polypyrrole growth is observed from spherical-like to layer-by-layer structures in the presence of CNT. Acid treatment enhances polypyrrole coverage on CNT surface by preventing agglomeration of polypyrrole due to an increase in surface oxygen groups and sp{sup 2} bonds in CNT structure. The crystallinity of powders comparably decreases after polypyrrole coating due to the amorphous structure of polypyrrole and a sharp decrease in the intensity of 002 peak. The influence of surface functionalization and polymer coating on the structural parameters of multi-walled CNT and their composites is investigated by tailoring the feeding ratio of polypyrrole. The hydrogen sorption measurements at ambient conditions by Intelligent Gravimetric Analyzer demonstrate that hydrogen uptake of CNT/polypyrrole composite is 1.66 wt.% which is almost 3 times higher than that of pristine CNT. Higher hydrogen uptake values are obtained by keeping the mass ratio of pyrrole monomer and CNT equal by using non-functionalized CNT in composite production. Hydrogen adsorption/desorption kinetics of polypyrrole/CNT composites is improved by increasing adsorption sites after polymer coating and acid treatment. The desorption curves of these modified surfaces are higher than their adsorption curves at lower pressures and hysteresis loop is observed in their isotherms since hydrogen is chemically bonded to the modified surfaces by the conversion of carbon atoms from sp{sup 2} to sp{sup 3} hybridization. - Highlights: • Growth mechanisms of polypyrrole are controlled by changing monomer concentration. • Lamellar structure is formed by using pristine CNT at high monomer concentration. • Homogeneous polymer coating is achieved on the surface of

  18. Mobile Workforce, Mobile Technology, Mobile Threats

    International Nuclear Information System (INIS)

    Garcia, J.

    2015-01-01

    Mobile technologies' introduction into the world of safeguards business processes such as inspection creates tremendous opportunity for novel approaches and could result in a number of improvements to such processes. Mobile applications are certainly the wave of the future. The success of the application ecosystems has shown that users want full fidelity, highly-usable, simple purpose applications with simple installation, quick responses and, of course, access to network resources at all times. But the counterpart to opportunity is risk, and the widespread adoption of mobile technologies requires a deep understanding of the threats and vulnerabilities inherent in mobile technologies. Modern mobile devices can be characterized as small computers. As such, the threats against computing infrastructure apply to mobile devices. Meanwhile, the attributes of mobile technology that make it such an obvious benefit over traditional computing platforms all have elements of risk: pervasive, always-on networking; diverse ecosystems; lack of centralized control; constantly shifting technological foundations; intense competition among competitors in the marketplace; the scale of the installation base (from millions to billions); and many more. This paper will explore the diverse and massive environment of mobile, the number of attackers and vast opportunities for compromise. The paper will explain how mobile devices prove valuable targets to both advanced and persistent attackers as well as less-skilled casual hackers. Organized crime, national intelligence agencies, corporate espionage are all part of the landscape. (author)

  19. Mobile Phone Multilevel and Multimedia Messaging Intervention for Breast Cancer Screening: Pilot Randomized Controlled Trial.

    Science.gov (United States)

    Lee, Hee; Ghebre, Rahel; Le, Chap; Jang, Yoo Jeong; Sharratt, Monica; Yee, Douglas

    2017-11-07

    Despite the increasing breast cancer incidence and mortality rates, Korean American immigrant women have one of the lowest rates of breast cancer screening across racial groups in the United States. Mobile health (mHealth), defined as the delivery of health care information or services through mobile communication devices, has been utilized to successfully improve a variety of health outcomes. This study adapted the principles of mHealth to advance breast cancer prevention efforts among Korean American immigrant women, an underserved community. Using a randomized controlled trial design, 120 Korean American women aged 40 to 77 years were recruited and randomly assigned to either the mMammogram intervention group (n=60) to receive culturally and personally tailored multilevel and multimedia messages through a mobile phone app along with health navigator services or the usual care control group (n=60) to receive a printed brochure. Outcome measures included knowledge, attitudes, and beliefs about breast cancer screening, readiness for mammography, and mammogram receipt. The feasibility and acceptability of the mMammogram intervention was also assessed. The intervention group showed significantly greater change on scores of knowledge of breast cancer and screening guidelines (P=.01). The intervention group also showed significantly greater readiness for mammography use after the intervention compared with the control group. A significantly higher proportion of women who received the mMammogram intervention (75%, 45/60) completed mammograms by the 6-month follow-up compared with the control group (30%, 18/60; Pservice was a feasible, acceptable, and effective intervention mechanism to promote breast cancer screening in Korean American immigrant women. A flexible, easily tailored approach that relies on recent technological advancements can reach underserved and hard-to-recruit populations that bear disproportionate cancer burdens. Clinicaltrials.gov NCT01972048;

  20. Arsenic mobilization in the Brahmaputra plains of Assam: groundwater and sedimentary controls.

    Science.gov (United States)

    Sailo, Lalsangzela; Mahanta, Chandan

    2014-10-01

    Arsenic (As) mobilization to the groundwater of Brahmaputra floodplains was investigated in Titabor, Jorhat District, located in the North Eastern part of India. The groundwater and the aquifer geochemistry were characterized in the study area. The range of As concentration in the groundwater varies from 10 to 440 μg/l with mean concentration 210 μg/l. The groundwaters are characterized by high dissolved Fe, Mn, and HCO₃(-) and low concentrations of NO₃(-) and SO₄(2-) indicating the reduced conditions prevailing in the groundwater. In order to understand the actual mobilization processes in the area, six core drilling surrounding the two target tube wells (T1 and T2) with high As concentration (three drill-cores surrounds each tube well closely) was done. The sediment was analyzed its chemical, mineralogical, and elemental compositions. A selective sequential extraction suggested that most of the As in the sediment is bound to Fe oxides fractions (32 to 50%) and the competition for adsorption site by anions (PO₄(3-)) also accounts to significant fractions of the total arsenic extracted. High variability in the extraction as well as properties of the sediment was observed due to the heterogeneity of the sediment samples with different chemical properties. The SEM and EDX results indicate the presence of Fe, Mn coating along with As for most of the sample, and the presence of As associated minerals were calculated using PHREEQC. The mobilization of As into the groundwater was anticipated to be largely controlled by the reductive dissolution of Fe oxides and partly by the competitive anions viz. PO₄(3-).

  1. Controls on the Mobility of Antimony in Mine Waste from Three Deposit Types

    Science.gov (United States)

    Jamieson, H.; Radková, A. B.; Fawcett, S.

    2017-12-01

    Antimony can be considered both a critical metal and an environmental hazard, with a toxicity similar to arsenic. It is concentrated in stibnite deposits, but also present in polymetallic and precious metal ores, frequently accompanied by arsenic. We have studied the mineralogical controls on the mobility of antimony in three types of mine waste: stibnite tailings from an antimony mine, tetrahedrite-bearing waste rock from copper mining, and gold mine tailings and ore roaster waste. Our results demonstrate that the tendency of antimony to leach into the aqueous environment or remain sequestered in solid phases depends on the primary host minerals and conditions governing the precipitation of secondary antimony-hosting phases. In tailings at the Beaver Brook antimony mine in Newfoundland, Canada, stibnite oxidizes rapidly, and secondary minerals such as the relatively insoluble Sb-Fe tripuhyite-like phase and Sb-bearing goethite. However, under dry conditions, the most important secondary Sb host is the Mg-Sb hydroxide brandholzite, but this easily soluble mineral disappears when it rains. Antimony that was originally hosted in tetrahedrite, a complex multi-element sulfosalt, in the historic waste rock piles at Špania Dolina-Piesky, Slovakia, is not as mobile as Cu and As during weathering but reprecipiates to a mixture of tripuhyite and romeite. Finally, the original antimony-hosting minerals, both stibnite and sulphosalts, in the gold ore at Giant Mine, Yellowknife, Canada were completely destroyed during ore roasting. In tailings-contaminated sediments, antimony persists in roaster-generated iron oxide phases, except under reducing conditions where some of the antimony forms a Sb-S phase. The combined presence of antimony and arsenic in mine waste complicates risk assessment but in general, our findings suggest that antimony is less mobile than arsenic in the environment.

  2. Formation of hydrogenated amorphous carbon films of controlled hardness from a methane plasma

    International Nuclear Information System (INIS)

    Vandentop, G.J.; Kawasaki, M.; Nix, R.M.; Brown, I.G.; Salmeron, M.; Somorjai, G.A.; Department of Chemistry, University of California at Berkeley, Berkeley, California 94720)

    1990-01-01

    Studies of amorphous hydrogenated carbon (a-C:H) film deposition revealed that methyl radicals are the precursor species responsible for the bulk mass deposition of the films, while the ions act to improve the mechanical properties. The films were deposited on Si(100) substrates both on the powered (negatively self-biased) and on the grounded electrodes from a methane rf plasma (13.56 MHz) at 68 to 70 mTorr and 300 to 370 K. The films produced on the powered electrode exhibited superior mechanical properties, such as high hardness. A mass spectrometer was used to identify neutral species and positive ions incident on the electrodes from the plasma, and also to measure ion energies. Methyl radicals were incident on the electrode surface with an estimated flux of 10 16 cm -2 s -1 , for a rf power of 50 W. Methyl radicals appear to be the dominant intermediates in the growth of the soft carbon polymer, and there is a remarkable decrease in deposition rate due to the introduction of NO, a radical scavenger. A novel pulsed biasing technique was used so that the role of ions in the plasma could be studied separately. It was found that the hardness of the films depends on the power supplied by the ions to the growing film surface (the time averaged difference between the plasma potential and the electrode potential), but not on the energy of individual ions. The pulsed biasing technique offers an efficient method to adjust the film hardness by independent control of the neutral radical and ion fluxes to the surface

  3. Acoustic neuroma risk in relation to mobile telephone use: Results of the INTERPHONE international case-control study

    DEFF Research Database (Denmark)

    Berg-Beckhoff, Gabi

    2011-01-01

    Background: The rapid increase in mobile telephone use has generated concern about possible health risks of radiofrequency electromagnetic fields from these devices. Methods: A case-control study of 1105 patients with newly diagnosed acoustic neuroma (vestibular schwannoma) and 2145 controls...... was conducted in 13 countries using a common protocol. Past mobile phone use was assessed by personal interview. In the primary analysis, exposure time was censored at one year before the reference date (date of diagnosis for cases and date of diagnosis of the matched case for controls); analyses censoring...

  4. Hydrogen gains further momentum

    International Nuclear Information System (INIS)

    Anon.

    2017-01-01

    As first industrial production projects should become a reality in the next few years, hydrogen as a source of energy will find important applications with mobility, which momentum is rapid and irresistible. Next steps will be the (large capacity) storage of hydrogen associated to power-to-gas systems and the generalization of renewable energies. This document presents 5 articles, which themes are: Description and explanation of the process of hydrogen production; Presentation of the H2V project for the construction, in Normandy, of the first operational industrial hydrogen production plant using electric power 100 pc generated by renewable energies; The conversion of electric power from renewable energies through hydrogen storage and fuel cells for buildings applications (Sylfen project); The development of a reversible fuel cell at Mines-Paris Tech University, that will be adapted to the storage of renewable electric power; Hydrogen as a lever for the development of zero-emission vehicles, from trucks to cars and bicycles

  5. Incentive-Rewarding Mechanism for User-position Control in Mobile Services

    Science.gov (United States)

    Yoshino, Makoto; Sato, Kenichiro; Shinkuma, Ryoichi; Takahashi, Tatsuro

    When the number of users in a service area increases in mobile multimedia services, no individual user can obtain satisfactory radio resources such as bandwidth and signal power because the resources are limited and shared. A solution for such a problem is user-position control. In the user-position control, the operator informs users of better communication areas (or spots) and navigates them to these positions. However, because of subjective costs caused by subjects moving from their original to a new position, they do not always attempt to move. To motivate users to contribute their resources in network services that require resource contributions for users, incentive-rewarding mechanisms have been proposed. However, there are no mechanisms that distribute rewards appropriately according to various subjective factors involving users. Furthermore, since the conventional mechanisms limit how rewards are paid, they are applicable only for the network service they targeted. In this paper, we propose a novel incentive-rewarding mechanism to solve these problems, using an external evaluator and interactive learning agents. We also investigated ways of appropriately controlling rewards based on user contributions and system service quality. We applied the proposed mechanism and reward control to the user-position control, and demonstrated its validity.

  6. Mobile robot nonlinear feedback control based on Elman neural network observer

    Directory of Open Access Journals (Sweden)

    Khaled Al-Mutib

    2015-12-01

    Full Text Available This article presents a new approach to control a wheeled mobile robot without velocity measurement. The controller developed is based on kinematic model as well as dynamics model to take into account parameters of dynamics. These parameters related to dynamic equations are identified using a proposed methodology. Input–output feedback linearization is considered with a slight modification in the mathematical expressions to implement the dynamic controller and analyze the nonlinear internal behavior. The developed controllers require sensors to obtain the states needed for the closed-loop system. However, some states may not be available due to the absence of the sensors because of the cost, the weight limitation, reliability, induction of errors, failure, and so on. Particularly, for the velocity measurements, the required accuracy may not be achieved in practical applications due to the existence of significant errors induced by stochastic or cyclical noise. In this article, Elman neural network is proposed to work as an observer to estimate the velocity needed to complete the full state required for the closed-loop control and account for all the disturbances and model parameter uncertainties. Different simulations are carried out to demonstrate the feasibility of the approach in tracking different reference trajectories in comparison with other paradigms.

  7. Redox Control and Hydrogen Production in Sediment Caps Using Carbon Cloth Electrodes

    Science.gov (United States)

    Sun, Mei; Yan, Fei; Zhang, Ruiling; Reible, Danny D.; Lowry, Gregory V.; Gregory, Kelvin B.

    2010-01-01

    Sediment caps that degrade contaminants can improve their ability to contain contaminants relative to sand and sorbent-amended caps, but few methods to enhance contaminant degradation in sediment caps are available. The objective of this study was to determine if, carbon electrodes emplaced within a sediment cap at poised potential could create a redox gradient and provide electron donor for the potential degradation of contaminants. In a simulated sediment cap overlying sediment from the Anacostia River (Washington, DC), electrochemically induced redox gradients were developed within 3 days and maintained over the period of the test (~100 days). Hydrogen and oxygen were produced by water electrolysis at the electrode surfaces and may serve as electron donor and acceptor for contaminant degradation. Electrochemical and geochemical factors that may influence hydrogen production were studied. Hydrogen production displayed zero order kinetics with ~75% coulombic efficiency and rates were proportional to the applied potential between 2.5V to 5V and not greatly affected by pH. Hydrogen production was promoted by increasing ionic strength and in the presence of natural organic matter. Graphite electrode-stimulated degradation of tetrachlorobenzene in a batch reactor was dependent on applied voltage and production of hydrogen to a concentration above the threshold for biological dechlorination. These findings suggest that electrochemical reactive capping can potentially be used to create “reactive” sediments caps capable of promoting chemical or biological transformations of contaminants within the cap. PMID:20879761

  8. Development of a 10 kGy(Si) rad hard controller for a mobile robot using COTS

    International Nuclear Information System (INIS)

    Alexandre, J.M.; Marceau, M.

    1999-01-01

    The CEA has developed a 10 kGy(Si) hardened controller using only COTS (Commercial-Off-The-Shelf devices), to equip the mobile robot Andros. An electronic architecture adapted to the constraint of hardening have been carried out, leading to the construction of a complete set of electronics modules (power electronic, control computer). (authors)

  9. Dynamics and control for Constrained Multibody Systems modeled with Maggi's equation: Application to Differential Mobile Robots Partll

    International Nuclear Information System (INIS)

    Amengonu, Yawo H; Kakad, Yogendra P

    2014-01-01

    Quasivelocity techniques were applied to derive the dynamics of a Differential Wheeled Mobile Robot (DWMR) in the companion paper. The present paper formulates a control system design for trajectory tracking of this class of robots. The method develops a feedback linearization technique for the nonlinear system using dynamic extension algorithm. The effectiveness of the nonlinear controller is illustrated with simulation example

  10. The Mobile Limiters of TJ-II: Power and Particle Control

    International Nuclear Information System (INIS)

    Cal, E. de la

    1998-01-01

    For mobile limiters have been designed for the TJ-II stellerator to reduce thermal loads on the vacuum vessel and its protections at the region of the central hard core (groove) and to characterise the scrap off layer plasma. The role of the mobile limiters for particle and thermal load control is analysed for the different operating phases of TJ-II. The task of impurity control will be treated in a future report. A simplified model has been used to estimate the termal loads on the limiters. The conclusion is that a new design for the limiter heads will be necessary for the neutral beam injection (NBI)-phase at high power density, if acceptable efficiencies of thermal removal is desired. The rexperimental measurements which will be made in the first phase (ECH) with the temperature and Lagmuir probes installed in the diagnosed limiter-heads will be essential for the optimisation of the future limiter-shape. For particle control it will be absolutely necessary to use first wall conditioning techniques (e.g. boronization), since no active pumping method is foreseen for TJ-II. Again, this point will be more critical in the NBI-phase, due to the large particle fluxes to the first wall and due to possible thermal gas, desorption caused by local overheating of plasma-facing surfaces. The role of magnetic topology on plasma-wall interaction is finally analysed. A configuration has been found in which the limiters act as divertor plates (Natural Island Divertor). This inherent flexibility for changing the magnetic topology of TJ-II should be exploited in order to find the most favourable operating scenarios for the high powder injection phase

  11. Mobile phone SMS messages can enhance healthy behaviour: a meta-analysis of randomised controlled trials.

    Science.gov (United States)

    Orr, Jayne A; King, Robert J

    2015-01-01

    Healthy behaviour, such as smoking cessation and adherence to prescribed medications, mitigates illness risk factors but health behaviour change can be challenging. Mobile phone short-message service (SMS) messages are increasingly used to deliver interventions designed to enhance healthy behaviour. This meta-analysis used a random-effects model to synthesise 38 randomised controlled trials that investigated the efficacy of SMS messages to enhance healthy behaviour. Participants (N = 19,641) lived in developed and developing countries and were diverse with respect to age, ethnicity, socioeconomic background and health behaviours targeted for change. SMS messages had a small, positive, significant effect (g = 0.291) on a broad range of healthy behaviour. This effect was maximised when multiple SMS messages per day were used (g = 0.395) compared to using lower frequencies (daily, multiple per week and once-off) (g = 0.244). The low heterogeneity in this meta-analysis (I (2) = 38.619) supports reporting a summary effect size and implies that the effect of SMS messaging is robust, regardless of population characteristics or healthy behaviour targeted. SMS messaging is a simple, cost-effective intervention that can be automated and can reach any mobile phone owner. While the effect size is small, potential health benefits are well worth achieving.

  12. Mobile Phone-Delivered Cognitive Behavioral Therapy for Insomnia: A Randomized Waitlist Controlled Trial

    Science.gov (United States)

    Lancee, Jaap; Griffioen-Both, Fiemke; Spruit, Sandor; Fitrianie, Siska; Neerincx, Mark A; Beun, Robbert Jan; Brinkman, Willem-Paul

    2017-01-01

    Background This study is one of the first randomized controlled trials investigating cognitive behavioral therapy for insomnia (CBT-I) delivered by a fully automated mobile phone app. Such an app can potentially increase the accessibility of insomnia treatment for the 10% of people who have insomnia. Objective The objective of our study was to investigate the efficacy of CBT-I delivered via the Sleepcare mobile phone app, compared with a waitlist control group, in a randomized controlled trial. Methods We recruited participants in the Netherlands with relatively mild insomnia disorder. After answering an online pretest questionnaire, they were randomly assigned to the app (n=74) or the waitlist condition (n=77). The app packaged a sleep diary, a relaxation exercise, sleep restriction exercise, and sleep hygiene and education. The app was fully automated and adjusted itself to a participant’s progress. Program duration was 6 to 7 weeks, after which participants received posttest measurements and a 3-month follow-up. The participants in the waitlist condition received the app after they completed the posttest questionnaire. The measurements consisted of questionnaires and 7-day online diaries. The questionnaires measured insomnia severity, dysfunctional beliefs about sleep, and anxiety and depression symptoms. The diary measured sleep variables such as sleep efficiency. We performed multilevel analyses to study the interaction effects between time and condition. Results The results showed significant interaction effects (Papp condition on the primary outcome measures of insomnia severity (d=–0.66) and sleep efficiency (d=0.71). Overall, these improvements were also retained in a 3-month follow-up. Conclusions This study demonstrated the efficacy of a fully automated mobile phone app in the treatment of relatively mild insomnia. The effects were in the range of what is found for Web-based treatment in general. This supports the applicability of such technical

  13. Structure Sensitivity Study of Waterborne Contaminant Hydrogenation Using Shape- and Size-Controlled Pd Nanoparticles

    KAUST Repository

    Shuai, Danmeng; McCalman, Dorrell C.; Choe, Jong Kwon; Shapley, John R.; Schneider, William F.; Werth, Charles J.

    2013-01-01

    Catalytic reduction with Pd has emerged as a promising technology to remove a suite of contaminants from drinking water, such as oxyanions, disinfection byproducts, and halogenated pollutants, but low activity is a major challenge for application. To address this challenge, we synthesized a set of shape- and size-controlled Pd nanoparticles and evaluated the activity of three probe contaminants (i.e., nitrite, N-nitrosodimethylamine (NDMA), and diatrizoate) as a function of facet type (e.g., (100), (110), (111)), ratios of low- to high-coordination sites, and ratios of surface sites to total Pd (i.e., dispersion). Reduction results for an initial contaminant concentration of 100 μM show that initial turnover frequency (TOF0) for nitrite increases 4.7-fold with increasing percent of (100) surface Pd sites (from 0% to 95.3%), whereas the TOF0 for NDMA and for diatrizoate increases 4.5- and 3.6-fold, respectively, with an increasing percent of terrace surface Pd sites (from 79.8% to 95.3%). Results for an initial nitrite concentration of 2 mM show that TOF0 is the same for all shape- and size-controlled Pd nanoparticles. Trends for TOF0 were supported by results showing that all catalysts but one were stable in shape and size up to 12 days; for the exception, iodide liberation in diatrizoate reduction appeared to be responsible for a shape change of 4 nm octahedral Pd nanoparticles. Density functional theory (DFT) simulations for the free energy change of hydrogen (H2), nitrite, and nitric oxide (NO) adsorption and a two-site model based on the Langmuir-Hinshelwood mechanism suggest that competition of adsorbates for different Pd sites can explain the TOF0 results. Our study shows for the first time that catalytic reduction activity for waterborne contaminant removal varies with the Pd shape and size, and it suggests that Pd catalysts can be tailored for optimal performance to treat a variety of contaminants for drinking water. © 2013 American Chemical Society.

  14. Structure Sensitivity Study of Waterborne Contaminant Hydrogenation Using Shape- and Size-Controlled Pd Nanoparticles

    KAUST Repository

    Shuai, Danmeng

    2013-03-01

    Catalytic reduction with Pd has emerged as a promising technology to remove a suite of contaminants from drinking water, such as oxyanions, disinfection byproducts, and halogenated pollutants, but low activity is a major challenge for application. To address this challenge, we synthesized a set of shape- and size-controlled Pd nanoparticles and evaluated the activity of three probe contaminants (i.e., nitrite, N-nitrosodimethylamine (NDMA), and diatrizoate) as a function of facet type (e.g., (100), (110), (111)), ratios of low- to high-coordination sites, and ratios of surface sites to total Pd (i.e., dispersion). Reduction results for an initial contaminant concentration of 100 μM show that initial turnover frequency (TOF0) for nitrite increases 4.7-fold with increasing percent of (100) surface Pd sites (from 0% to 95.3%), whereas the TOF0 for NDMA and for diatrizoate increases 4.5- and 3.6-fold, respectively, with an increasing percent of terrace surface Pd sites (from 79.8% to 95.3%). Results for an initial nitrite concentration of 2 mM show that TOF0 is the same for all shape- and size-controlled Pd nanoparticles. Trends for TOF0 were supported by results showing that all catalysts but one were stable in shape and size up to 12 days; for the exception, iodide liberation in diatrizoate reduction appeared to be responsible for a shape change of 4 nm octahedral Pd nanoparticles. Density functional theory (DFT) simulations for the free energy change of hydrogen (H2), nitrite, and nitric oxide (NO) adsorption and a two-site model based on the Langmuir-Hinshelwood mechanism suggest that competition of adsorbates for different Pd sites can explain the TOF0 results. Our study shows for the first time that catalytic reduction activity for waterborne contaminant removal varies with the Pd shape and size, and it suggests that Pd catalysts can be tailored for optimal performance to treat a variety of contaminants for drinking water. © 2013 American Chemical Society.

  15. Hydrogen energy

    International Nuclear Information System (INIS)

    2005-03-01

    This book consists of seven chapters, which deals with hydrogen energy with discover and using of hydrogen, Korean plan for hydrogen economy and background, manufacturing technique on hydrogen like classification and hydrogen manufacture by water splitting, hydrogen storage technique with need and method, hydrogen using technique like fuel cell, hydrogen engine, international trend on involving hydrogen economy, technical current for infrastructure such as hydrogen station and price, regulation, standard, prospect and education for hydrogen safety and system. It has an appendix on related organization with hydrogen and fuel cell.

  16. The Effect of Joint Mobilization on Dynamic Postural Control in Patients With Chronic Ankle Instability: A Critically Appraised Topic.

    Science.gov (United States)

    Kosik, Kyle B; Gribble, Phillip A

    2018-01-01

    Clinical Scenario: Dorsiflexion range of motion is an important factor in the performance of the Star Excursion Balance Test (SEBT). While patients with chronic ankle instability (CAI) commonly experience decreased reach distances on the SEBT, ankle joint mobilization has been suggested to be an effective therapeutic intervention for targeting dorsiflexion range of motion. What is the evidence to support ankle joint mobilization for improving performance on the SEBT in patients with CAI? Summary of Key Findings: The literature was searched for articles examining the effects of ankle joint mobilization on scores of the SEBT. A total of 3 peer-reviewed articles were retrieved, 2 prospective individual cohort studies and 1 randomized controlled trial. Only 2 articles demonstrated favorable results following 6 sessions of ankle joint mobilization. Clinical Bottom Line: Despite the mixed results, the majority of the available evidence suggests that ankle joint mobilization improves dynamic postural control. Strength of Recommendation: In accordance with the Centre of Evidence Based Medicine, the inconsistent results and the limited high-quality studies indicate that there is level C evidence to support the use of ankle joint mobilization to improve performance on the SEBT in patients with CAI.

  17. Some hydrogen-control considerations for ice-condenser nuclear plants

    International Nuclear Information System (INIS)

    Hubbard, H.W.; Hammond, R.P.; Zivi, S.M.

    1981-02-01

    The proposal of the Tennessee Valley Authority (TVA) for coping with the problem of accident generated hydrogen gas in its Sequoyah ice-condenser plant was to put in place glow-plug igniters so that any hydrogen that is evolved during an accident could be burnt before accumulating into a dangerously large mass. Since it was desired to install these igniters in the Sequoyah and other plants as quickly as possible, the NRC asked the Lawrence Livermore National Laboratory (LLNL) to carry out some experiments on these igniters to delineate the region of their applicability

  18. Joint Optimized CPU and Networking Control Scheme for Improved Energy Efficiency in Video Streaming on Mobile Devices

    Directory of Open Access Journals (Sweden)

    Sung-Woong Jo

    2017-01-01

    Full Text Available Video streaming service is one of the most popular applications for mobile users. However, mobile video streaming services consume a lot of energy, resulting in a reduced battery life. This is a critical problem that results in a degraded user’s quality of experience (QoE. Therefore, in this paper, a joint optimization scheme that controls both the central processing unit (CPU and wireless networking of the video streaming process for improved energy efficiency on mobile devices is proposed. For this purpose, the energy consumption of the network interface and CPU is analyzed, and based on the energy consumption profile a joint optimization problem is formulated to maximize the energy efficiency of the mobile device. The proposed algorithm adaptively adjusts the number of chunks to be downloaded and decoded in each packet. Simulation results show that the proposed algorithm can effectively improve the energy efficiency when compared with the existing algorithms.

  19. Reprint of: Use of a mobile phone for potentiostatic control with low cost paper-based microfluidic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Delaney, Jacqui L.; Doeven, Egan H.; Harsant, Anthony J.; Hogan, Conor F., E-mail: c.hogan@latrobe.edu.au

    2013-11-25

    Graphical abstract: -- Highlights: •The ability to generate ECL emission using the audio output of a mobile phone is demonstrated. •Electrochemical control can be achieved by controlling the amplitude and waveform of the sound. •A mobile phone “app” synchronises the electrochemical stimulation with detection via the camera. •In combination with paper-based microfluidic sensors, extremely low cost analysis is possible. •Detection of proline at levels suitable for diagnosis of hyperprolinemia is demonstrated. -- Abstract: By exploiting its ability to play sounds, a mobile phone with suitable software installed can serve the basic functions of a potentiostat in controlling an applied potential to oxidise ECL-active molecules, while the resultant photonic signal is monitored using the camera in video mode. In combination with paper microfluidic sensors this opens significant new possibilities for low-cost, instrument-free sensing.

  20. Reprint of: Use of a mobile phone for potentiostatic control with low cost paper-based microfluidic sensors

    International Nuclear Information System (INIS)

    Delaney, Jacqui L.; Doeven, Egan H.; Harsant, Anthony J.; Hogan, Conor F.

    2013-01-01

    Graphical abstract: -- Highlights: •The ability to generate ECL emission using the audio output of a mobile phone is demonstrated. •Electrochemical control can be achieved by controlling the amplitude and waveform of the sound. •A mobile phone “app” synchronises the electrochemical stimulation with detection via the camera. •In combination with paper-based microfluidic sensors, extremely low cost analysis is possible. •Detection of proline at levels suitable for diagnosis of hyperprolinemia is demonstrated. -- Abstract: By exploiting its ability to play sounds, a mobile phone with suitable software installed can serve the basic functions of a potentiostat in controlling an applied potential to oxidise ECL-active molecules, while the resultant photonic signal is monitored using the camera in video mode. In combination with paper microfluidic sensors this opens significant new possibilities for low-cost, instrument-free sensing

  1. Trajectory planning of mobile robots using indirect solution of optimal control method in generalized point-to-point task

    Science.gov (United States)

    Nazemizadeh, M.; Rahimi, H. N.; Amini Khoiy, K.

    2012-03-01

    This paper presents an optimal control strategy for optimal trajectory planning of mobile robots by considering nonlinear dynamic model and nonholonomic constraints of the system. The nonholonomic constraints of the system are introduced by a nonintegrable set of differential equations which represent kinematic restriction on the motion. The Lagrange's principle is employed to derive the nonlinear equations of the system. Then, the optimal path planning of the mobile robot is formulated as an optimal control problem. To set up the problem, the nonlinear equations of the system are assumed as constraints, and a minimum energy objective function is defined. To solve the problem, an indirect solution of the optimal control method is employed, and conditions of the optimality derived as a set of coupled nonlinear differential equations. The optimality equations are solved numerically, and various simulations are performed for a nonholonomic mobile robot to illustrate effectiveness of the proposed method.

  2. Heliostat-field gain-scheduling control applied to a two-step solar hydrogen production plant

    International Nuclear Information System (INIS)

    Roca, Lidia; Calle, Alberto de la; Yebra, Luis J.

    2013-01-01

    Highlights: ► A control system is proposed for a solar reactor system which produces hydrogen. ► The controller chooses which heliostats from the solar field must be focused. ► A gain scheduling scheme is included to deal with different system dynamics. ► The scheme is tested and tunned in simulation. ► Real experiments show the promising results of this work. -- Abstract: This article describes a temperature control structure designed for the interior of a solar hydrogen reactor based on a two-step ferrite-redox technology. Until now, this temperature has been controlled by manual selection of the heliostats to be focused on the receiver targets. However, the strong system dependency on operating conditions suggests that the procedure be automated in order to ensure the desired setpoint change response. The aims are to maintain the desired temperatures and to make the setpoint switch as fast as possible, keeping plant conditions within the margins of safety. The scheme proposed includes a procedure for selecting the heliostats to be focused on the reactor by using a simple model of the solar field and a gain scheduling control system which changes the control tuning parameters to deal with the varying dynamics observed during the process. Real experiments show the promising results of this work.

  3. A neural learning classifier system with self-adaptive constructivism for mobile robot control.

    Science.gov (United States)

    Hurst, Jacob; Bull, Larry

    2006-01-01

    For artificial entities to achieve true autonomy and display complex lifelike behavior, they will need to exploit appropriate adaptable learning algorithms. In this context adaptability implies flexibility guided by the environment at any given time and an open-ended ability to learn appropriate behaviors. This article examines the use of constructivism-inspired mechanisms within a neural learning classifier system architecture that exploits parameter self-adaptation as an approach to realize such behavior. The system uses a rule structure in which each rule is represented by an artificial neural network. It is shown that appropriate internal rule complexity emerges during learning at a rate controlled by the learner and that the structure indicates underlying features of the task. Results are presented in simulated mazes before moving to a mobile robot platform.

  4. Cooperative control of UAVs for localization of intermittently emitting mobile targets.

    Science.gov (United States)

    Pack, Daniel J; Delima, Pedro; Toussaint, Gregory J; York, George

    2009-08-01

    Compared with a single platform, cooperative autonomous unmanned aerial vehicles (UAVs) offer efficiency and robustness in performing complex tasks. Focusing on ground mobile targets that intermittently emit radio frequency signals, this paper presents a decentralized control architecture for multiple UAVs, equipped only with rudimentary sensors, to search, detect, and locate targets over large areas. The proposed architecture has in its core a decision logic which governs the state of operation for each UAV based on sensor readings and communicated data. To support the findings, extensive simulation results are presented, focusing primarily on two success measures that the UAVs seek to minimize: overall time to search for a group of targets and the final target localization error achieved. The results of the simulations have provided support for hardware flight tests.

  5. SDN Controlled mmWave Massive MIMO Hybrid Precoding for 5G Heterogeneous Mobile Systems

    Directory of Open Access Journals (Sweden)

    Na Chen

    2016-01-01

    Full Text Available In 5G mobile network, millimeter wave (mmWave and heterogeneous networks (Hetnets are significant techniques to sustain coverage and spectral efficiency. In this paper, we utilize the hybrid precoding to overcome hardware constraints on the analog-only beamforming in mmWave systems. Particularly, we identify the complicated antenna coordination and vast spatial domain information as the outstanding challenges in mmWave Hetnets. In our work, we employ software defined network (SDN to accomplish radio resource management (RRM and achieve flexible spacial coordination in mmWave Hetnets. In our proposed scheme, SDN controller is responsible for collecting the user channel state information (CSI and applying hybrid precoding based on the calculated null-space of victim users. Simulation results show that our design can effectively reduce the interference to victim users and support high quality of service.

  6. Guaranteed cost control of mobile sensor networks with Markov switching topologies.

    Science.gov (United States)

    Zhao, Yuan; Guo, Ge; Ding, Lei

    2015-09-01

    This paper investigates the consensus seeking problem of mobile sensor networks (MSNs) with random switching topologies. The network communication topologies are composed of a set of directed graphs (or digraph) with a spanning tree. The switching of topologies is governed by a Markov chain. The consensus seeking problem is addressed by introducing a global topology-aware linear quadratic (LQ) cost as the performance measure. By state transformation, the consensus problem is transformed to the stabilization of a Markovian jump system with guaranteed cost. A sufficient condition for global mean-square consensus is derived in the context of stochastic stability analysis of Markovian jump systems. A computational algorithm is given to synchronously calculate both the sub-optimal consensus controller gains and the sub-minimum upper bound of the cost. The effectiveness of the proposed design method is illustrated by three numerical examples. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  7. System design description for SY-101 hydrogen mitigation test project data acquisition and control system (DACS-1)

    International Nuclear Information System (INIS)

    Truitt, R.W.; Pounds, T.S.; Smith, S.O.

    1994-01-01

    This document describes the hardware subsystems of the data acquisition and control system (DACS) used in mitigation tests conducted on waste tank SY-101 at the Hanford Nuclear Reservation. The system was designed and implemented by Los Alamos National Laboratory (LANL) and supplied to Westinghouse Hanford Company (WHC). The mitigation testing uses a pump immersed in the waste tank, directed at certain angles and operated at different speeds and time durations. The SY-101 tank has experienced recurrent periodic gas releases of hydrogen, nitrous oxide, ammonia, and (recently discovered) methane. The hydrogen gas represents a danger, as some of the releases are in amounts above the lower flammability limit (LFL). These large gas releases must be mitigated. Several instruments have been added to the tank to monitor the gas compositions, the tank level, the tank temperature, and other parameters. A mixer pump has been developed to stir the tank waste to cause the gases to be released at a slow rate. It is the function of the DACS to monitor those instruments and to control the mixer pump in a safe manner. During FY93 and FY94 the mixer pump was installed with associated testing operations support equipment and a mitigation test project plan was implemented. These activities successfully demonstrated the mixer pump's ability to mitigate the SY-101 tank hydrogen gas hazard

  8. Stand-alone power systems for the future: Optimal design, operation and control of solar-hydrogen energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Ulleberg, Oeystein

    1999-12-31

    This thesis gives a systematic review of the fundamentals of energy systems, the governing physical and chemical laws related to energy, inherent characteristics of energy system, and the availability of the earth`s energy. It shows clearly why solar-hydrogen systems are one of the most viable options for the future. The main subject discussed is the modelling of SAPS (Stand-Alone Power Systems), with focus on photovoltaic-hydrogen energy systems. Simulation models for a transient simulation program are developed for PV-H{sub 2} components, including models for photovoltaics, water electrolysis, hydrogen storage, fuel cells, and secondary batteries. A PV-H{sub 2} demonstration plant in Juelich, Germany, is studied as a reference plant and the models validated against data from this plant. Most of the models developed were found to be sufficiently accurate to perform short-term system simulations, while all were more than accurate enough to perform long-term simulations. Finally, the verified simulation models are used to find the optimal operation and control strategies of an existing PV-H{sub 2} system. The main conclusion is that the simulation methods can be successfully used to find optimal operation and control strategies for a system with fixed design, and similar methods could be used to find alternative system designs. 148 refs., 78 figs., 31 tabs.

  9. Controllable synthesis and electrochemical hydrogen storage properties of Sb₂Se₃ ultralong nanobelts with urchin-like structures.

    Science.gov (United States)

    Jin, Rencheng; Chen, Gang; Pei, Jian; Sun, Jingxue; Wang, Yang

    2011-09-01

    The controlled synthesis of one-dimensional and three-dimensional Sb(2)Se(3) nanostructures has been achieved by a facile solvothermal process in the presence of citric acid. By simply controlling the concentration of citric acid, the nucleation, growth direction and exposed facet can be readily tuned, which brings the different morphologies and nanostructures to the final products. The as-prepared products have been characterized by means of X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM and selected area electron diffraction. Based on the electron microscope observations, a possible growth mechanism of Sb(2)Se(3) with distinctive morphologies including ultralong nanobelts, hierarchical urchin-like nanostructures is proposed and discussed in detail. The electrochemical hydrogen storage measurements reveal that the morphology plays a key role on the hydrogen storage capacity of Sb(2)Se(3) nanostructures. The Sb(2)Se(3) ultralong nanobelts with high percentage of {-111} facets exhibit higher hydrogen storage capacity (228.5 mA h g(-1)) and better cycle stability at room temperature.

  10. Stand-alone power systems for the future: Optimal design, operation and control of solar-hydrogen energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Ulleberg, Oeystein

    1998-12-31

    This thesis gives a systematic review of the fundamentals of energy systems, the governing physical and chemical laws related to energy, inherent characteristics of energy system, and the availability of the earth`s energy. It shows clearly why solar-hydrogen systems are one of the most viable options for the future. The main subject discussed is the modelling of SAPS (Stand-Alone Power Systems), with focus on photovoltaic-hydrogen energy systems. Simulation models for a transient simulation program are developed for PV-H{sub 2} components, including models for photovoltaics, water electrolysis, hydrogen storage, fuel cells, and secondary batteries. A PV-H{sub 2} demonstration plant in Juelich, Germany, is studied as a reference plant and the models validated against data from this plant. Most of the models developed were found to be sufficiently accurate to perform short-term system simulations, while all were more than accurate enough to perform long-term simulations. Finally, the verified simulation models are used to find the optimal operation and control strategies of an existing PV-H{sub 2} system. The main conclusion is that the simulation methods can be successfully used to find optimal operation and control strategies for a system with fixed design, and similar methods could be used to find alternative system designs. 148 refs., 78 figs., 31 tabs.

  11. Happier Healers: Randomized Controlled Trial of Mobile Mindfulness for Stress Management.

    Science.gov (United States)

    Yang, Elaine; Schamber, Elizabeth; Meyer, Rika M L; Gold, Jeffrey I

    2018-05-01

    Medical students have higher rates of depression and psychologic distress than the general population, which may negatively impact academic performance and professional conduct. This study assessed whether 10-20 min of daily mindfulness meditation for 30 days, using a mobile phone application, could decrease perceived stress and improve well-being for medical students. Eighty-eight medical students were stratified by class year and randomized to either intervention or control groups to use the mobile application Headspace, an audio-guided mindfulness meditation program, for 30 days. All participants completed the Perceived Stress Scale (PSS), Five-Facet Mindfulness Questionnaire (FFMQ), and General Well-Being Schedule (GWBS) at baseline (T1), 30 days (T2), and 60 days (T3). Repeated measures analysis of variance (rANOVA) was conducted for intervention versus control groups across T1, T2, and T3 to examine differences in stress, mindfulness, and well-being. There was a significant interaction between time and treatment group for perceived stress and well-being. Perceived stress significantly decreased for the intervention group from T1 to T3 (F[2,142] = 3.98, p mindfulness meditation program is an effective means to decrease perceived stress in medical students, which may have implications on patient care. Integrating mindfulness training into medical school curricula for management of school- and work-related stress may lead to fewer negative physician outcomes (e.g., burnout, anxiety, and depression) and improved physician and patient outcomes. This has implications for a broad group of therapists and healthcare providers, ultimately improving quality of healing and patient care.

  12. Simultaneous influence of indigenous microorganism along with abiotic factors controlling arsenic mobilization in Brahmaputra floodplain, India

    Science.gov (United States)

    Sathe, Sandip S.; Mahanta, Chandan; Mishra, Pushpanjali

    2018-06-01

    In the dynamic cycling of oxic and anoxic aqueous alluvial aquifer environments, varying Arsenic (As) concentrations are controlled by both abiotic and biotic factors. Studies have shown a significant form of toxic As (III) being released through the reductive dissolution of iron-oxy/hydroxide minerals and microbial reduction mechanisms, which leads to a serious health concern. The present study was performed in order to assess the abiotic and biotic factors influencing As release into the alluvial aquifer groundwater in Brahmaputra floodplain, India. The groundwater chemistry, characterization of the sediments, isolation, identification and characterization of prominent As releasing indigenous bacterium were conducted. The measured solid and liquid phases of total As concentration were ranged between 0.02 and 17.2 mg kg-1 and 8 to 353 μg L-1, respectively. The morphology and mineralogy showed the presence of detrital and authigenic mineral assemblages whereas primary and secondary As bearing Realgar and Claudetite minerals were identified, respectively. Furthermore, significant non-labile As fraction was found associated with the amorphous oxides of Fe, Mn and Al. The observed groundwater chemistry and sediment color, deduced a sub-oxic reducing aquifer conditions in As-contaminated regions. In addition, 16S rDNA sequencing results of the isolated bacterium showed the prominent Pseudomonas aeruginosa responsible for the mobilization of As, reducing condition, biomineralization and causing grey color to the sediments at the shallower and deeper aquifers in the study area. These findings suggest that microbial metabolic activities are equally responsible in iron-oxy/hydroxide reductive dissolution, controlling As mobilization in dynamic fluvial flood plains.

  13. Toward Understanding Pore Formation and Mobility during Controlled Directional Solidification in a Microgravity Environment Investigation (PFMI)

    Science.gov (United States)

    Grugel, Richard N.; Anilkumar, A. V.; Luz, Paul; Jeter, Linda; Volz, Martin P.; Spivey, Reggie; Smith, G.

    2003-01-01

    The generation and inclusion of detrimental porosity, e.g., pipes and rattails can occur during controlled directional solidification processing. The origin of these defects is generally attributed to gas evolution and entrapment during solidification of the melt. On Earth, owing to buoyancy, an initiated bubble can rapidly rise through the liquid melt and pop at the surface; this is obviously not ensured in a low gravity or microgravity environment. Clearly, porosity generation and inclusion is detrimental to conducting any meaningful solidification-science studies in microgravity. Thus it is essential that model experiments be conducted in microgravity, to understand the details of the generation and mobility of porosity, so that methods can be found to eliminate it. In hindsight, this is particularly relevant given the results of the previous directional solidification experiments conducted in Space. The current International Space Station (ISS) Microgravity Science Glovebox (MSG) investigation addresses the central issue of porosity formation and mobility during controlled directional solidification processing in microgravity. The study will be done using a transparent metal-analogue material, succinonitrile (SCN) and succinonitrile-water 'alloys', so that direct observation and recording of pore generation and mobility can be made during the experiments. Succinonitrile is particularly well suited for the proposed investigation because it is transparent, it solidifies in a manner analogous to most metals, it has a convenient melting point, its material properties are well characterized and, it has been successfully used in previous microgravity experiments. The PFMI experiment will be launched on the UF-2, STS-111 flight. Highlighting the porosity development problem in metal alloys during microgravity processing, the poster will describe: (i) the intent of the proposed experiments, (ii) the theoretical rationale behind using SCN as the study material for

  14. Control of structural isomerism in noncovalent hydrogen-bonded assemblies using peripheral chiral information

    NARCIS (Netherlands)

    Prins, L.J.; Jolliffe, K.A.; Hulst, A.J.R.L.; Timmerman, P.; Reinhoudt, David

    2000-01-01

    The results of a systematic study of the structural isomerism in more than 30 noncovalent hydrogen-bonded assemblies are described. These dynamic assemblies, composed of three calix[4]arene dimelamines and six barbiturates/cyanurates, can be present in three isomeric forms with either D3, C3h, or Cs

  15. Model of parameters controlling resistance of pipeline steels to hydrogen-induced cracking

    KAUST Repository

    Traidia, Abderrazak; El-Sherik, A. M.; Duval, Sé bastien; Lubineau, Gilles; El Yagoubi, Jalal

    2014-01-01

    NACE MR0175/ISO 15156-2 standard provides test conditions and acceptance criteria to evaluate the resistance of carbon and low-alloy steels to hydrogen-induced cracking (HIC). The second option proposed by this standard offers a large flexibility

  16. Evaluation of feed COD/sulfate ratio as a control criterion for the biological hydrogen sulfide production and lead precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Velasco, Antonio [Direccion General del Centro Nacional de Investigacion y Capacitacion Ambiental-Instituto Nacional de Ecologia, Av. San Rafael Atlixco 186, Col. Vicentina. Iztapalapa, Mexico 09340, D.F. (Mexico)], E-mail: jvelasco@ine.gob.mx; Ramirez, Martha [Direccion General del Centro Nacional de Investigacion y Capacitacion Ambiental-Instituto Nacional de Ecologia, Av. San Rafael Atlixco 186, Col. Vicentina. Iztapalapa, Mexico 09340, D.F. (Mexico); Volke-Sepulveda, Tania [Departamento de Biotecnologia, UAM-Cuajimalpa, San Rafael Atlixco 186, Col. Vicentina. Iztapalapa, Mexico 09340, D.F. (Mexico); Gonzalez-Sanchez, Armando [Departamento de Ingenieria de Procesos, Universidad Autonoma Metropolitana-Iztapalapa, UAM-Cuajimalpa, San Rafael Atlixco 186, Col. Vicentina. Iztapalapa, Mexico 09340, D.F. (Mexico); Revah, Sergio [Departamento de Procesos y Tecnologia, UAM-Cuajimalpa, San Rafael Atlixco 186, Col. Vicentina. Iztapalapa, Mexico 09340, D.F. (Mexico)

    2008-03-01

    The ability of sulfate-reducing bacteria to produce hydrogen sulfide and the high affinity of sulfide to react with divalent metallic cations represent an excellent option to remove heavy metals from wastewater. Different parameters have been proposed to control the hydrogen sulfide production by anaerobic bacteria, such as the organic and sulfate loading rates and the feed COD/SO{sub 4}{sup 2-} ratio. This work relates the feed COD/SO{sub 4}{sup 2-} ratio with the hydrogen sulfide production and dissolved lead precipitation, using ethanol as carbon and energy source in an up-flow anaerobic sludge blanket reactor. A maximum dissolved sulfide concentration of 470 {+-} 7 mg S/L was obtained at a feed COD/SO{sub 4}{sup 2-} ratio of 2.5, with sulfate and ethanol conversions of approximately 94 and 87%, respectively. The lowest dissolved sulfide concentration (145 {+-} 10 mg S/L) was observed with a feed COD/SO{sub 4}{sup 2-} ratio of 0.67. Substantial amounts of acetate (510-1730 mg/L) were produced and accumulated in the bioreactor from ethanol oxidation. Although only incomplete oxidation of ethanol to acetate was observed, the consortium was able to remove 99% of the dissolved lead (200 mg/L) with a feed COD/SO{sub 4}{sup 2-} ratio of 1.5. It was found that the feed COD/SO{sub 4}{sup 2-} ratio could be an adequate parameter to control the hydrogen sulfide production and the consequent precipitation of dissolved lead.

  17. Microscale packed bed reactor for controlled hydrogen peroxide decomposition as a fuel cell oxidant aboard unmanned undersea vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Lennon, E.; Ocampo, M.; Besser, R.S. [Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030 (United States); Burke, A.A. [Naval Undersea Warfare Center, Newport, RI 02841 (United States)

    2010-01-01

    The multiphase catalytic decomposition of hydrogen peroxide into water and oxygen is notoriously susceptible to thermal runaway (heat of reaction: -98 kJ mol{sup -1}). The high surface area to volume ratio (S/V) in a microscale packed bed (MPB) reactor (radius 0.5 mm) was investigated for reducing the risk of thermal runaway during hydrogen peroxide decomposition to oxygen intended as a fuel cell oxidant aboard an unmanned undersea vehicle (UUV). A microscale reactor channel with a S/V of {proportional_to}2 x 10{sup 3} m{sup 2} m{sup -3} simulated under convective cooling generated a significant heat rise (T rise {proportional_to} 100 K), whereas a microreactor with a higher S/V ({proportional_to}200 x 10{sup 3} m{sup 2} m{sup -3}) achieved thermal control (T rise < 10 K) over the simulated reaction zone. Although thermal management was successfully accomplished using the higher S/V, experimental conversions of hydrogen peroxide to oxygen (5-18%) measured from the outlet were lower than simulated conversions (38-63%). Simulation assumptions, such as homogeneously dispersed flow and perfect catalyst interaction among other factors, contributed to the discrepancies between the simulated and experimental degrees of peroxide conversion to oxygen. Even though thermal control of the MPB was achieved, this work indicates that mass transfer limitations are a factor in the MPB reactor during a multiphase reaction, like decomposition of hydrogen peroxide to oxygen and water, and suggests means to overcome them even on the microscale level. (author)

  18. Advanced Software Ground Station and UAV Development for NLoS Control Using Mobile Communications

    Directory of Open Access Journals (Sweden)

    Amr AbdElHamid

    2015-01-01

    Full Text Available Over the last decades, Unmanned Aerial Systems (UASs have gained much attention due to their various applications in different sections. However, their communication range is limited to utilized communication equipment. Therefore, utilization of GSM channels opens a new prospect towards long distance UAV missions and mobile command and control centers. This paper demonstrates new design and development of a small-scale UAV and a Ground Control Station (GCS using GSM bidirectional communications for Non-Line of Sight (NLoS long range control. GCSs are considered the front end node in UAV guidance process. Therefore, the proposed GCS employs a two-layer framework to consider all ground pilot requirements. Moreover, a new exploitation of global weather forecast data is added to the GCS. On the other hand, the proposed airborne system utilizes a new integration of different Commercial off-the-Shelf (COTS components and excludes short range receivers. The ground and flight tests show that stable bidirectional GSM communication is established, reliable hardware integration is accomplished, real time performance is achieved, GCS functional fidelity is obtained, and low cost is maintained. Finally, some qualitative aspects of the proposed platform are presented to address the detailed features.

  19. Real-Time Performance of Hybrid Mobile Robot Control Utilizing USB Protocol

    Directory of Open Access Journals (Sweden)

    Jacek Augustyn

    2015-02-01

    Full Text Available This article discusses the problem of usability of the USB 2.0 protocol in the area of real-time control of a mobile robot. Optimization methods of data transfer handling were proposed. The impact of the optimization results on the entire system's performance was examined in practice. As a test-bed, a hybrid system composed of two devices communicating by direct USB connection was implemented. The first of the mentioned devices was a 32-bit SoC micro-system serving as a direct control unit, and the second one was an off-the-shelf PDA providing supervisory control and logging. Due to this design, the system meets regimes of the real-time constraints and maintains continuity of a data stream at a large bandwidth. The real-time performances of subsystems and the entire system were experimentally examined depending on various operating conditions. Thanks to the performed experiments, the dependency of real-time limits on operational parameters has been determined.

  20. Design of a Mobile Brain Computer Interface-Based Smart Multimedia Controller

    Science.gov (United States)

    Tseng, Kevin C.; Lin, Bor-Shing; Wong, Alice May-Kuen; Lin, Bor-Shyh

    2015-01-01

    Music is a way of expressing our feelings and emotions. Suitable music can positively affect people. However, current multimedia control methods, such as manual selection or automatic random mechanisms, which are now applied broadly in MP3 and CD players, cannot adaptively select suitable music according to the user’s physiological state. In this study, a brain computer interface-based smart multimedia controller was proposed to select music in different situations according to the user’s physiological state. Here, a commercial mobile tablet was used as the multimedia platform, and a wireless multi-channel electroencephalograph (EEG) acquisition module was designed for real-time EEG monitoring. A smart multimedia control program built in the multimedia platform was developed to analyze the user’s EEG feature and select music according his/her state. The relationship between the user’s state and music sorted by listener’s preference was also examined in this study. The experimental results show that real-time music biofeedback according a user’s EEG feature may positively improve the user’s attention state. PMID:25756862

  1. Path Planning of Mobile Elastic Robotic Arms by Indirect Approach of Optimal Control

    Directory of Open Access Journals (Sweden)

    Moharam Habibnejad Korayem

    2011-03-01

    Full Text Available Finding optimal trajectory is critical in several applications of robot manipulators. This paper is applied the open-loop optimal control approach for generating the optimal trajectory of the flexible mobile manipulators in point-to-point motion. This method is based on the Pontryagin-s minimum principle that by providing a two-point boundary value problem is solved the problem. This problem is known to be complex in particular when combined motion of the base and manipulator, non-holonomic constraint of the base and highly non-linear and complicated dynamic equations as a result of flexible nature of links are taken into account. The study emphasizes on modeling of the complete optimal control problem by remaining all nonlinear state and costate variables as well as control constraints. In this method, designer can compromise between different objectives by considering the proper penalty matrices and it yields to choose the proper trajectory among the various paths. The effectiveness and capability of the proposed approach are demonstrated through simulation studies. Finally, to verify the proposed method, the simulation results obtained from the model are compared with the results of those available in the literature.

  2. Supervisory control of mobile sensor networks: math formulation, simulation, and implementation.

    Science.gov (United States)

    Giordano, Vincenzo; Ballal, Prasanna; Lewis, Frank; Turchiano, Biagio; Zhang, Jing Bing

    2006-08-01

    This paper uses a novel discrete-event controller (DEC) for the coordination of cooperating heterogeneous wireless sensor networks (WSNs) containing both unattended ground sensors (UGSs) and mobile sensor robots. The DEC sequences the most suitable tasks for each agent and assigns sensor resources according to the current perception of the environment. A matrix formulation makes this DEC particularly useful for WSN, where missions change and sensor agents may be added or may fail. WSN have peculiarities that complicate their supervisory control. Therefore, this paper introduces several new tools for DEC design and operation, including methods for generating the required supervisory matrices based on mission planning, methods for modifying the matrices in the event of failed nodes, or nodes entering the network, and a novel dynamic priority assignment weighting approach for selecting the most appropriate and useful sensors for a given mission task. The resulting DEC represents a complete dynamical description of the WSN system, which allows a fast programming of deployable WSN, a computer simulation analysis, and an efficient implementation. The DEC is actually implemented on an experimental wireless-sensor-network prototyping system. Both simulation and experimental results are presented to show the effectiveness and versatility of the developed control architecture.

  3. Design of a Mobile Brain Computer Interface-Based Smart Multimedia Controller

    Directory of Open Access Journals (Sweden)

    Kevin C. Tseng

    2015-03-01

    Full Text Available Music is a way of expressing our feelings and emotions. Suitable music can positively affect people. However, current multimedia control methods, such as manual selection or automatic random mechanisms, which are now applied broadly in MP3 and CD players, cannot adaptively select suitable music according to the user’s physiological state. In this study, a brain computer interface-based smart multimedia controller was proposed to select music in different situations according to the user’s physiological state. Here, a commercial mobile tablet was used as the multimedia platform, and a wireless multi-channel electroencephalograph (EEG acquisition module was designed for real-time EEG monitoring. A smart multimedia control program built in the multimedia platform was developed to analyze the user’s EEG feature and select music according his/her state. The relationship between the user’s state and music sorted by listener’s preference was also examined in this study. The experimental results show that real-time music biofeedback according a user’s EEG feature may positively improve the user’s attention state.

  4. An optimal hydrogen control analysis for the in-containment refueling storage tank (IRWST) of the Korean next generation reactor (KNGR) containment under severe accidents

    International Nuclear Information System (INIS)

    Byung-Chul, Lee; Hee-Jin, Ko; Se-Won, Lee

    2001-01-01

    Under severe accidents that a large amount of hydrogen is expected to release, the In-Containment Refueling Water Storage Tank (IRWST) air space has more worse condition with respect to the hydrogen control since, as one of hydrogen source compartment, normally it is separated from the other compartments and has relatively small volume. The hydrogen concentrations in the IRWST gas space, when the hydrogen was directly released into this area, were analyzed using the MAAP4 code in order to investigate if locally very high concentrations could be reduced so that inadvertent detonation or detonation-to-deflagration (DDT) in this area might be prevented. For this purpose, the thermo-hydraulic and combustion phenomena being capable of occurring in the IRWST were also considered. As a result of numerical calculations with 12-compartment containment model, the time duration that the flammable gas mixture was formed was greatly decreased via oxygen-starved or steam-rich conditions, although instantaneously peak concentration itself could not be avoided. Moreover, if the diffusion flame or steam stripping can be occurred in the IRWST, it was expected to have more chance to control the hydrogen in the IRWST gas space. After the hydrogen finished to be rapidly released, the hydrogen in this area could be controlled by the PARs' hydrogen depletion and by igniter's deliberate burning. Especially, the review on the analyses for two typical, but most probable sequences of quite a different hydrogen release modes gives an insight that the flammable gas mixture in the IRWST can be avoid by rapid depressurization operation, which is recommendable for being implemented into accident management program. (authors)

  5. Mobile phone base stations and early childhood cancers: case-control study.

    Science.gov (United States)

    Elliott, Paul; Toledano, Mireille B; Bennett, J; Beale, L; de Hoogh, K; Best, N; Briggs, D J

    2010-06-22

    To investigate the risk of early childhood cancers associated with the mother's exposure to radiofrequency from and proximity to macrocell mobile phone base stations (masts) during pregnancy. Case-control study. Cancer registry and national birth register data in Great Britain. 1397 cases of cancer in children aged 0-4 from national cancer registry 1999-2001 and 5588 birth controls from national birth register, individually matched by sex and date of birth (four controls per case). Incidence of cancers of the brain and central nervous system, leukaemia, and non-Hodgkin's lymphomas, and all cancers combined, adjusted for small area measures of education level, socioeconomic deprivation, population density, and population mixing. Mean distance of registered address at birth from a macrocell base station, based on a national database of 76,890 base station antennas in 1996-2001, was similar for cases and controls (1107 (SD 1131) m v 1073 (SD 1130) m, P=0.31), as was total power output of base stations within 700 m of the address (2.89 (SD 5.9) kW v 3.00 (SD 6.0) kW, P=0.54) and modelled power density (-30.3 (SD 21.7) dBm v -29.7 (SD 21.5) dBm, P=0.41). For modelled power density at the address at birth, compared with the lowest exposure category the adjusted odds ratios were 1.01 (95% confidence interval 0.87 to 1.18) in the intermediate and 1.02 (0.88 to 1.20) in the highest exposure category for all cancers (P=0.79 for trend), 0.97 (0.69 to 1.37) and 0.76 (0.51 to 1.12), respectively, for brain and central nervous system cancers (P=0.33 for trend), and 1.16 (0.90 to 1.48) and 1.03 (0.79 to 1.34) for leukaemia and non-Hodgkin's lymphoma (P=0.51 for trend). There is no association between risk of early childhood cancers and estimates of the mother's exposure to mobile phone base stations during pregnancy.

  6. Wrench tectonics control on Neogene-Quaternary sedimentation along the Mid-Hungarian Mobile Belt

    Science.gov (United States)

    Pogacsas, Gyorgy; Juhász, Györgyi; Mádl-Szőnyi, Judit; Simon, Szilvia; Lukács, Szilveszter; Csizmeg, János

    2010-05-01

    The Neogene Pannonian basin is underlain by a large orogenic collage which is built up by several tectonostratigraphic terrains. The basement of the Pannonian Basin became imbricate nappes during the Cretaceous Alpine collision. Nappes of Late Cretaceous in age have been proven below the Great Hungarian Plain (Grow et al 1994). The boundary of the two main terrains, the northwestern ALCAPA (Alpine-Carpathian-Pannonian) and the southeastern TISZA, is the Mid-Hungarian Mobile Belt. It is the most significant neotectonic zone of the Pannonian Basin. The structural analysis of the middle section of the Mid-Hungarian Mobile Belt was carried out on a 120km x 50km area, between the Danube and the Tisza river, on the basis of interpretation of seismic data. The structural analysis of the Neogene-Quaternary sediments was supported by sequence stratigraphic interpretation of seismic, well log and core-sample data. Regional seismic profiles were both oriented in the dip direction, which highlights sediment supply routes into the basin, and strike-oriented. The studied segment of the Mid-Hungarian Mobile Belt consists of several long (some ten kilometres long) strike slip fault zones. The offset lengths of the individual strike slipe faults varies between a few and a dozens of kilometres. Activity along the Mid-Hungarian Mobile Belt can be characterised by four periods, the size and shape of facies zones of each development period were controlled by tectonics: 1. During the early Miocene, the ALPACA moved eastward, bounded by sinistral strike-slipe system along its northern side and dextral strike-slipe fault system along its contact with the Southern Alps and the TISZA terrain. The largest movement took part during the Ottnangian-Karpatian (19-16.5 Ma). The TISZA unit moved northeastward over the remnant Carpathian Flysch Basin (Nemcok et al 2006). These terrains movements resulted in right lateral, convergent wide wrench along the Mid-Hungarian Mobile Belt. The ALPACA

  7. Long-term effect of physical activity counseling on mobility limitation among older people: a randomized controlled study

    DEFF Research Database (Denmark)

    Mänty, Minna Regina; Heinonen, Ari; Leinonen, Raija

    2009-01-01

    counseling-induced benefits persist after cessation of the intervention. METHODS: In a 2-year, single-blinded, randomized controlled study, 632 sedentary participants aged 75-81 years were randomly assigned into the intervention (n = 318) or control (n = 314) group. The intervention group received a single......BACKGROUND: Physical activity counseling increases physical activity among older people, but its effectiveness on mobility, that is, maintaining the ability to move independently, is unknown. We studied the effect of physical activity counseling on mobility among older people and evaluated whether...... individualized physical activity counseling session with a supportive telephone contact every 4 months for 2 years. The outcome measures-perceived difficulty in advanced (walking 2 km) and basic (walking 0.5 km) mobility-were gathered semiannually during the intervention and the 1.5-year postintervention follow...

  8. Reaching the unreachable: providing STI control services to female sex workers via mobile team outreach.

    Directory of Open Access Journals (Sweden)

    Pablo E Campos

    Full Text Available As part of a community-randomized trial of a multicomponent intervention to prevent sexually transmitted infections, we created Mobile Teams (MTs in ten intervention cities across Peru to improve outreach to female sex workers (FSW for strengthened STI prevention services.Throughout 20 two-month cycles, MTs provided counseling; condoms; screening and specific treatment for Neisseria gonorrhoeae (NG, Chlamydia trachomatis (CT, and vaginal Trichomonas vaginalis (TV infections; and periodic presumptive metronidazole treatment for vaginal infections.MTs had 48,207 separate encounters with 24,814 FSW; numbers of sex work venues and of FSW reached increased steadily over several cycles. Approximately 50% of FSW reached per cycle were new. Reported condom use with last client increased from 73% to 93%. Presumptive metronidazole treatment was accepted 83% of times offered. Over 38 months, CT prevalence declined from 15.4% to 8.2%, and TV prevalence from 7.3% to 2.6%. Among participants in ≥ 9 cycles, CT prevalence decreased from 12.9% to 6.0% (p <0.001; TV from 4.6% to 1.5% (p <0.001; and NG from 0.8% to 0.4% (p = 0.07.Mobile outreach to FSW reached many FSW not utilizing government clinics. Self-reported condom use substantially increased; CT and TV prevalences declined significantly. The community-randomized trial, reported separately, demonstrated significantly greater reductions in composite prevalence of CT, NG, TV, or high-titer syphilis serology in FSW in these ten intervention cities than in ten matched control cities.

  9. Proposal of emergency systems for the liberations control in a hydrogen producer plant with the cycle S-I

    International Nuclear Information System (INIS)

    Ruiz S, T.; Francois, J. L.; Nelson, P. F.; Cruz G, M. J.

    2012-10-01

    At present, one of the processes that theoretically has demonstrated to be of the most efficient for the hydrogen production is the thermal-chemistry cycle Sulfur-Iodine (S-I) coupled to a nuclear reactor of very high temperature (VHTR). Because this chemical process of hydrogen production requires of a great inventory of toxic materials (sulfurous compounds, hydriodic acid and iodine) is necessary the emergency systems design with the purpose of protecting the facilitates and equipment s, the atmosphere and population. Inside the important considerations for this design are the obtained results in the liberations simulations of the substances involved in the process. These simulations were realized with the computer code Phast, including the leak through a small failure of the pipe, as well as the catastrophic failure. To determine the good localization of the equipment s, as well as the inventory required for the liberations control. The operation conditions were taken of a combination of the preliminary design proposed by the General Atomics and the optimized conditions by the Korea Advanced Institute of Science and Technology, considering a hydrogen production of 1 kg-mol/s. The proposed materials for the neutralization of the liberated substances were selected considering that they did not increase the inventory of process toxic substances. (Author)

  10. Improved control for distributed parameter systems with time-dependent spatial domains utilizing mobile sensor–actuator networks

    International Nuclear Information System (INIS)

    Zhang Jian-Zhong; Cui Bao-Tong; Zhuang Bo

    2017-01-01

    A guidance policy for controller performance enhancement utilizing mobile sensor–actuator networks (MSANs) is proposed for a class of distributed parameter systems (DPSs), which are governed by diffusion partial differential equations (PDEs) with time-dependent spatial domains. Several sufficient conditions for controller performance enhancement are presented. First, the infinite dimensional operator theory is used to derive an abstract evolution equation of the systems under some rational assumptions on the operators, and a static output feedback controller is designed to control the spatial process. Then, based on Lyapunov stability arguments, guidance policies for collocated and non-collocated MSANs are provided to enhance the performance of the proposed controller, which show that the time-dependent characteristic of the spatial domains can significantly affect the design of the mobile scheme. Finally, a simulation example illustrates the effectiveness of the proposed policy. (paper)

  11. Regional Variation in Gravel Riverbed Mobility, Controlled by Hydrologic Regime and Sediment Supply

    Science.gov (United States)

    Pfeiffer, Allison M.; Finnegan, Noah J.

    2018-04-01

    The frequency and intensity of riverbed mobility are of paramount importance to the inhabitants of river ecosystems as well as to the evolution of bed surface structure. Because sediment supply varies by orders of magnitude across North America, the intensity of bedload transport varies by over an order of magnitude. Climate also varies widely across the continent, yielding a range of flood timing, duration, and intermittency. Together, the differences in sediment supply and hydroclimate result in diverse regimes of bed surface stability. To quantitatively characterize this regional variation, we calculate multidecadal time series of estimated bed surface mobility for 29 rivers using sediment transport equations. We use these data to compare predicted bed mobility between rivers and regions. There are statistically significant regional differences in the (a) exceedance probability of bed-mobilizing flows (W* > 0.002), (b) maximum bed mobility, and (c) number of discrete bed-mobilizing events in a year.

  12. Roles of texture in controlling oxidation, hydrogen ingress and hydride formation in Zr alloys

    International Nuclear Information System (INIS)

    Szpunar, Jerzy A.; Qin, Wen; Li, Hualong; Kumar, Kiran

    2011-01-01

    Experimental observations shows that the oxide formed on Zr alloys are strongly textured. The texture and grain-boundary characteristics of oxide are dependent on the texture of metal substrate. Computer simulation and thermodynamic modeling clarify the effect of metal substrate on structure of oxide film, and intrinsic factors affecting the microstructure. Models of diffusion process of hydrogen atoms and oxygen diffusion through oxide are presented. Both intra-granular and inter-granular hydrides were found following (0001) α-Zr //(111) δ-ZrH1.5 relationship. The through-thickness texture inhomogeneity in cladding tubes, the effects of hoop stress on the hydride orientation and the formation of interlinked hydride structure were studied. A thermodynamic model was developed to analyze the nucleation and the stress-induced reorientation of intergranular hydrides. These works provide a framework for understanding the oxidation, the hydrogen ingress and the hydride formation in Zr alloys. (author)

  13. Control of discharge conditions to reduce hydrogen content in low Z films produced with DC glow

    International Nuclear Information System (INIS)

    Natsir, M.; Sagara, A.; Tsuzuki, K.; Tsuchiya, B.; Hasegawa, Y.; Motojima, O.

    1995-09-01

    Boronization at near room temperature has been performed in plasma processing teststand (PPT) by using a 5 % diborane gases B 2 H 6 in He on electrically floating or unfloating Al samples under various conditions on DC glow discharge power or total gas pressure. The hydrogen concentration was analyzed by using elastic recoil detection method (ERD) and a new modified normalizing technique with Rutherford back scattering (RBS). Results showed that a high growth rate of film formation and floating surface were effective in reducing hydrogen concentration in B films. This result was in good agreement with earlier measurements of H with flash filament (FF) desorption method. In particular the H/B ratio was reduced by decreasing ions but increasing radicals for B film formation. (author)

  14. Optimised photocatalytic hydrogen production using core–shell AuPd promoters with controlled shell thickness

    DEFF Research Database (Denmark)

    Jones, Wilm; Su, Ren; Wells, Peter

    2014-01-01

    of these materials towards the reforming of alcohols for hydrogen production. The core–shell structured Au–Pd bimetallic nanoparticle supported on TiO2 has being of interest as it exhibited extremely high quantum efficiencies for hydrogen production. However, the effect of shell composition and thickness...... of the nanoparticles by a combination of X-ray absorption fine structure and X-ray photoelectron spectroscopy. Photocatalytic ethanol reforming showed that the core–shell structured Au–Pd promoters supported on TiO2 exhibit enhanced activity compared to that of monometallic Au and Pd as promoters, whilst the core......–shell Au–Pd promoters containing one ML equivalent Pd provide the optimum reactivity....

  15. The Director of Mobility Forces' Role in the Command Control of Air Mobility Assets During Humanitarian Relief Operations

    National Research Council Canada - National Science Library

    Bush, Timothy E

    2000-01-01

    ...). Air Force doctrine recommends a command and control (C2) structure that permits the same organizational concept to be used throughout the spectrum of conflict, tailored to suit the specific operational objectives of a Joint Task Force (JFT...

  16. A Model for Trust-based Access Control and Delegation in Mobile Clouds (Post Print)

    Science.gov (United States)

    2013-10-01

    the access-granter knowing the identity of access requester beforehand and authenticating the requester, can no longer be applied. Mobile Wallet Cloud...TktC) for a reservation and con- tacts the user’s mobile wallet provider (MobWC) to purchase the ticket from TktC. For accessing different services...receiving regular services. For example, the human user in our scenario can be an elite member with the mobile wallet service provider that

  17. Symmetric caging formation for convex polygonal object transportation by multiple mobile robots based on fuzzy sliding mode control.

    Science.gov (United States)

    Dai, Yanyan; Kim, YoonGu; Wee, SungGil; Lee, DongHa; Lee, SukGyu

    2016-01-01

    In this paper, the problem of object caging and transporting is considered for multiple mobile robots. With the consideration of minimizing the number of robots and decreasing the rotation of the object, the proper points are calculated and assigned to the multiple mobile robots to allow them to form a symmetric caging formation. The caging formation guarantees that all of the Euclidean distances between any two adjacent robots are smaller than the minimal width of the polygonal object so that the object cannot escape. In order to avoid collision among robots, the parameter of the robots radius is utilized to design the caging formation, and the A⁎ algorithm is used so that mobile robots can move to the proper points. In order to avoid obstacles, the robots and the object are regarded as a rigid body to apply artificial potential field method. The fuzzy sliding mode control method is applied for tracking control of the nonholonomic mobile robots. Finally, the simulation and experimental results show that multiple mobile robots are able to cage and transport the polygonal object to the goal position, avoiding obstacles. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  18. Mobility potential of a robotic six-wheeled omnidirectional drive vehicle (ODV) with z-axis and tire inflation control

    Science.gov (United States)

    Witus, Gary

    2000-07-01

    Robot vehicle mobility is the product of the physical configuration, mechatronics (sensors, actuators, and control) and the motion programs for different obstacles, terrain conditions, and maneuver objectives. This paper examines the mobility potential of a robotic 6-by-6 wheeled omni-directional drive vehicle (ODV) with z-axis and tire inflation control. Ad ODV can steer and drive all wheels independently. The direction of motion is independent of the orientation of the body. Z- axis control refers to independent control of the suspension elevation at each wheel. Pneumatic tire inflation control provides the ability to inflate and deflate individual tires. The paper describes motion programs for various discrete obstacles and challenging terrain conditions. The paper illustrates how ODV control, z-axis control and tire inflation control interact to provide high mobility with respect to cornering, maneuvering on slopes, negotiating vertical step and horizontal gap obstacles, and braking/acceleration on soft soil and slick surfaces. The paper derives guidelines for the physical dimensions of the vehicle needed to achieve these capabilities.

  19. A study of hydrogen isotopes fuel control by wall effect in magnetic fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Motevalli, S.M., E-mail: motavali@umz.ac.ir; Safari, M.

    2016-11-15

    Highlights: • A particle balance model for the main plasma and wall inventory in magnetic fusion device has been represented. • The dependence of incident particles energy on the wall has been considered in 10–300 eV for the sputtering yield and recycling coefficient. • The effect of fueling methods on plasma density behavior has been studied. - Abstract: Determination of plasma density behavior in magnetic confinement system needs to study the plasma materials interaction in the facing components such as first wall, limiter and divertor. Recycling of hydrogen isotope is an effective parameter in plasma density rate and plasma fueling. Recycling coefficient over the long pulse operation, gets to the unity, so it has a significant effect on steady state in magnetic fusion devices. Typically, sputtered carbon atoms from the plasma facing components form hydrocarbons and they redeposit on the wall. In this case little rate of hydrogen loss occurs. In present work a zero dimensional particle equilibrium model has been represented to determine particles density rate in main plasma and wall inventory under recycling effect and codeposition of hydrogen in case of continues and discontinues fueling methods and effective parameters on the main plasma decay has been studied.

  20. Control of wettability of hydrogenated amorphous carbon thin films by laser-assisted micro- and nanostructuring

    International Nuclear Information System (INIS)

    Pfleging, Wilhelm; Kohler, Robert; Torge, Maika; Trouillet, Vanessa; Danneil, Friederike; Stueber, Michael

    2011-01-01

    A flexible and rapid surface functionalization of amorphous carbon films shows a great potential for various application fields such as biological surfaces and tribological systems. For this purpose, the combination of thin film deposition and subsequent laser material processing was investigated. Amorphous carbon layers doped with hydrogen were deposited on silicon wafers by reactive direct-current magnetron sputtering. Films with three different hydrogen contents were synthesized. Subsequent to the thin film deposition process, UV laser material processing at wavelengths of 193 nm or 248 nm was performed with respect to chemical surface modification and surface structuring on micro- and nanometer scale. Depending on structure size and laser-induced chemical surface modification the adjustment of the surface energy and wetting behaviour in a broad range from hydrophobic to hydrophilic was possible. The chemical modification and the ablation mechanisms near the ablation threshold were strongly influenced by the hydrogen content in amorphous carbon thin films. Structural and chemical information of the as-deposited and modified films was obtained by Raman spectroscopy, X-ray photoelectron spectroscopy and contact angle measurements.

  1. Improved CO sub 2 enhanced oil recovery -- Mobility control by in-situ chemical precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Ameri, S.; Aminian, K.; Wasson, J.A.; Durham, D.L.

    1991-06-01

    The overall objective of this study has been to evaluate the feasibility of chemical precipitation to improve CO{sub 2} sweep efficiency and mobility control. The laboratory experiments have indicated that carbonate precipitation can alter the permeability of the core samples under reservoir conditions. Furthermore, the relative permeability measurements have revealed that precipitation reduces the gas permeability in favor of liquid permeability. This indicates that precipitation is occurring preferentially in the larger pores. Additional experimental work with a series of connected cores have indicated that the permeability profile can be successfully modified. However, Ph control plays a critical role in propagation of the chemical precipitation reaction. A numerical reservoir model has been utilized to evaluate the effects of permeability heterogeneity and permeability modification on the CO{sub 2} sweep efficiency. The computer simulation results indicate that the permeability profile modification can significantly enhance CO{sub 2} vertical and horizontal sweep efficiencies. The scoping studies with the model have further revealed that only a fraction of high permeability zones need to be altered to achieve sweep efficiency enhancement. 64 refs., 30 figs., 16 tabs.

  2. Differential mobility analysis of nanoparticles generated by laser vaporization and controlled condensation (LVCC)

    International Nuclear Information System (INIS)

    Abdelsayed, Victor; El-Shall, M. Samy; Seto, Takafumi

    2006-01-01

    Silicon and iron aluminide (FeAl) nanoparticles were synthesized by a laser vaporization controlled condensation (LVCC) method. The particles generated by the laser ablation of solid targets were transported and deposited in the presence of well-defined thermal and electric field in a newly designed flow-type LVCC chamber. The deposition process of nanoparticles was controlled by the balance of the external forces; i.e., gas flow, thermophoretic and electrostatic forces. The size distributions of generated nanoparticles were analyzed using a low-pressure differential mobility analyzer (LP-DMA). The effect of synthesis condition on the size distribution was analyzed by changing the pressure of the carrier gas (20-200 Torr), the temperature gradient in the LVCC chamber (ΔT=0-190 deg. C) and the electric field applied between the LVCC chamber plates (E=0-3000 V/m). It was found that electrostatic field was effective to selectively deposit small size nanoparticles (about 10 nm) with expelling large droplet-like particles

  3. Validating the Use of Rectus Muscle Fragment Welding to Control Presacral Bleeding During Rectal Mobilization

    Directory of Open Access Journals (Sweden)

    Eduardo Ayuste, Jr.

    2004-01-01

    Full Text Available The incidence of presacral bleeding during rectal mobilization is low, but such bleeding may be massive and even fatal. Haemostasis can be difficult to achieve using conventional methods because of the complex interlacing of the venous network at the sacral periosteum. Historically, pelvic packing and metallic thumbtacks have been the more commonly used methods in our institution. However, the need for repeat surgery to remove the packs and the difficulties encountered in tack application have forced us to explore other methods. In 1994, the procedure termed muscle fragment welding, which uses electrocautery through a rectus muscle fragment, was introduced to control presacral bleeding. From January 1999 to February 2002, six of 416 patients undergoing pelvic surgery in our institution developed massive presacral haemorrhage and, therefore, this technique was used. Haemostasis was immediate and permanent. No major untoward postoperative events such as re-bleeding or infection were noted. One case developed a second-degree burn in the right elbow due to a misplaced ground conduction plate. Rectus muscle fragment welding is, in our experience, an effective and practical method of controlling presacral haemorrhage.

  4. A Randomised Controlled Trial Using Mobile Advertising to Promote Safer Sex and Sun Safety to Young People

    Science.gov (United States)

    Gold, J.; Aitken, C. K.; Dixon, H. G.; Lim, M. S. C.; Gouillou, M.; Spelman, T.; Wakefield, M.; Hellard, M. E.

    2011-01-01

    Mobile phone text messages (SMS) are a promising method of health promotion, but a simple and low cost way to obtain phone numbers is required to reach a wide population. We conducted a randomised controlled trial with simultaneous brief interventions to (i) evaluate effectiveness of messages related to safer sex and sun safety and (ii) pilot the…

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

    Science.gov (United States)

    Mascarenas, David; Stull, Christopher; Farrar, Charles

    2011-06-01

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

  6. Collision cascades enhanced hydrogen redistribution in cobalt implanted hydrogenated diamond-like carbon films

    International Nuclear Information System (INIS)

    Gupta, P.; Becker, H.-W.; Williams, G.V.M.; Hübner, R.; Heinig, K.-H.; Markwitz, A.

    2017-01-01

    Highlights: • This paper reports for the first time redistribution of hydrogen atoms in diamond like carbon thin films during ion implantation of low energy magnetic ions. • The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. • Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications. - Abstract: Hydrogenated diamond-like carbon films produced by C_3H_6 deposition at 5 kV and implanted at room temperature with 30 keV Co atoms to 12 at.% show not only a bimodal distribution of Co atoms but also a massive redistribution of hydrogen in the films. Resonant nuclear reaction analysis was used to measure the hydrogen depth profiles (15N-method). Depletion of hydrogen near the surface was measured to be as low as 7 at.% followed by hydrogen accumulation from 27 to 35 at.%. A model is proposed considering the thermal energy deposited by collision cascade for thermal insulators. In this model, sufficient energy is provided for dissociated hydrogen to diffuse out of the sample from the surface and diffuse into the sample towards the interface which is however limited by the range of the incoming Co ions. At a hydrogen concentration of ∼35 at.%, the concentration gradient of the mobile unbounded hydrogen atoms is neutralised effectively stopping diffusion towards the interface. The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications.

  7. Collision cascades enhanced hydrogen redistribution in cobalt implanted hydrogenated diamond-like carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, P. [National Isotope Centre, GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand); Becker, H.-W. [RUBION, Ruhr-University Bochum (Germany); Williams, G.V.M. [The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand); Hübner, R.; Heinig, K.-H. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Markwitz, A., E-mail: a.markwitz@gns.cri.nz [National Isotope Centre, GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand)

    2017-03-01

    Highlights: • This paper reports for the first time redistribution of hydrogen atoms in diamond like carbon thin films during ion implantation of low energy magnetic ions. • The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. • Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications. - Abstract: Hydrogenated diamond-like carbon films produced by C{sub 3}H{sub 6} deposition at 5 kV and implanted at room temperature with 30 keV Co atoms to 12 at.% show not only a bimodal distribution of Co atoms but also a massive redistribution of hydrogen in the films. Resonant nuclear reaction analysis was used to measure the hydrogen depth profiles (15N-method). Depletion of hydrogen near the surface was measured to be as low as 7 at.% followed by hydrogen accumulation from 27 to 35 at.%. A model is proposed considering the thermal energy deposited by collision cascade for thermal insulators. In this model, sufficient energy is provided for dissociated hydrogen to diffuse out of the sample from the surface and diffuse into the sample towards the interface which is however limited by the range of the incoming Co ions. At a hydrogen concentration of ∼35 at.%, the concentration gradient of the mobile unbounded hydrogen atoms is neutralised effectively stopping diffusion towards the interface. The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications.

  8. New hydrogen technologies

    International Nuclear Information System (INIS)

    1992-01-01

    This report presents an overview of the overall hydrogen system. There are separate sections for production, distribution, transport, storage; and applications of hydrogen. The most important methods for hydrogen production are steam reformation of natural gas and electrolysis of water. Of the renewable energy options, production of hydrogen by electrolysis using electricity from wind turbines or by gasification of biomass were found to be the most economic for Finland. Direct use of this electricity or the production of liquid fuels from biomass will be competing alternatives. When hydrogen is produced in the solar belt or where there is cheap hydropower it must be transported over long distances. The overall energy consumed for the transport is from 25 to 40 % of the initial available energy. Hydrogen storage can be divided into stationary and mobile types. The most economic, stationary, large scale hydrogen storage for both long and short periods is underground storage. When suitable sites are not available, then pressure vessels are the best for short period and liquid H 2 for long period. Vehicle storage of hydrogen is by either metal hydrides or liquid H 2 . Hydrogen is a very versatile energy carrier. It can be used to produce heat directly in catalytic burners without flame, to produce electricity in fuel cells with high efficiency for use in vehicles or for peak power shaving, as a fuel component with conventional fuels to reduce emissions, as a way to store energy and as a chemical reagent in reactions

  9. Sub-10 nm Platinum Nanocrystals with Size and Shape Control: Catalytic Study for Ethylene and Pyrrole Hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Tsung, Chia-Kuang; Kuhn, John N.; Huang, Wenyu; Aliaga, Cesar; Hung, Ling-I; Somorjai, Gabor A.; Yang, Peidong

    2009-03-02

    Platinum nanocubes and nanopolyhedra with tunable size from 5 to 9 nm were synthesized by controlling the reducing rate of metal precursor ions in a one-pot polyol synthesis. A two-stage process is proposed for the simultaneous control of size and shape. In the first stage, the oxidation state of the metal ion precursors determined the nucleation rate and consequently the number of nuclei. The reaction temperature controlled the shape in the second stage by regulation of the growth kinetics. These well-defined nanocrystals were loaded into MCF-17 mesoporous silica for examination of catalytic properties. Pt loadings and dispersions of the supported catalysts were determined by elemental analysis (ICP-MS) and H2 chemisorption isotherms, respectively. Ethylene hydrogenation rates over the Pt nanocrystals were independent of both size and shape and comparable to Pt single crystals. For pyrrole hydrogenation, the nanocubes enhanced ring-opening ability and thus showed a higher selectivity to n-butylamine as compared to nanopolyhedra.

  10. Breaking and Fixing Origin-Based Access Control in Hybrid Web/Mobile Application Frameworks

    Science.gov (United States)

    Georgiev, Martin; Jana, Suman; Shmatikov, Vitaly

    2014-01-01

    Hybrid mobile applications (apps) combine the features of Web applications and “native” mobile apps. Like Web applications, they are implemented in portable, platform-independent languages such as HTML and JavaScript. Like native apps, they have direct access to local device resources—file system, location, camera, contacts, etc. Hybrid apps are typically developed using hybrid application frameworks such as PhoneGap. The purpose of the framework is twofold. First, it provides an embedded Web browser (for example, WebView on Android) that executes the app's Web code. Second, it supplies “bridges” that allow Web code to escape the browser and access local resources on the device. We analyze the software stack created by hybrid frameworks and demonstrate that it does not properly compose the access-control policies governing Web code and local code, respectively. Web code is governed by the same origin policy, whereas local code is governed by the access-control policy of the operating system (for example, user-granted permissions in Android). The bridges added by the framework to the browser have the same local access rights as the entire application, but are not correctly protected by the same origin policy. This opens the door to fracking attacks, which allow foreign-origin Web content included into a hybrid app (e.g., ads confined in iframes) to drill through the layers and directly access device resources. Fracking vulnerabilities are generic: they affect all hybrid frameworks, all embedded Web browsers, all bridge mechanisms, and all platforms on which these frameworks are deployed. We study the prevalence of fracking vulnerabilities in free Android apps based on the PhoneGap framework. Each vulnerability exposes sensitive local resources—the ability to read and write contacts list, local files, etc.—to dozens of potentially malicious Web domains. We also analyze the defenses deployed by hybrid frameworks to prevent resource access by foreign

  11. Breaking and Fixing Origin-Based Access Control in Hybrid Web/Mobile Application Frameworks.

    Science.gov (United States)

    Georgiev, Martin; Jana, Suman; Shmatikov, Vitaly

    2014-02-01

    Hybrid mobile applications (apps) combine the features of Web applications and "native" mobile apps. Like Web applications, they are implemented in portable, platform-independent languages such as HTML and JavaScript. Like native apps, they have direct access to local device resources-file system, location, camera, contacts, etc. Hybrid apps are typically developed using hybrid application frameworks such as PhoneGap. The purpose of the framework is twofold. First, it provides an embedded Web browser (for example, WebView on Android) that executes the app's Web code. Second, it supplies "bridges" that allow Web code to escape the browser and access local resources on the device. We analyze the software stack created by hybrid frameworks and demonstrate that it does not properly compose the access-control policies governing Web code and local code, respectively. Web code is governed by the same origin policy, whereas local code is governed by the access-control policy of the operating system (for example, user-granted permissions in Android). The bridges added by the framework to the browser have the same local access rights as the entire application, but are not correctly protected by the same origin policy. This opens the door to fracking attacks, which allow foreign-origin Web content included into a hybrid app (e.g., ads confined in iframes) to drill through the layers and directly access device resources. Fracking vulnerabilities are generic: they affect all hybrid frameworks, all embedded Web browsers, all bridge mechanisms, and all platforms on which these frameworks are deployed. We study the prevalence of fracking vulnerabilities in free Android apps based on the PhoneGap framework. Each vulnerability exposes sensitive local resources-the ability to read and write contacts list, local files, etc.-to dozens of potentially malicious Web domains. We also analyze the defenses deployed by hybrid frameworks to prevent resource access by foreign-origin Web content

  12. The Effects of Locus of Control on University Students' Mobile Learning Adoption

    Science.gov (United States)

    Hsia, Jung-Wen

    2016-01-01

    Since mobile devices have become cheaper, easily accessible, powerful, and popular and the cost of wireless access has declined gradually, mobile learning (m-learning) has begun to spread rapidly. To further improve the effectiveness and efficiency of m-learning for university students, it is critical to understand whether they use m-learning.…

  13. Relationship between the mobility of medial longitudinal arch and postural control

    Directory of Open Access Journals (Sweden)

    Tansu Birinci

    2017-05-01

    Conclusion: Our results suggest that decrease of arch mobility on the dominant foot is associated with posterior sway by causing knee or hip strategy and preventing ankle strategy even in small perturbations. The rate of deviation from the equilibrium point and the degree of total swaying increase when arch mobility decreases.

  14. A randomized controlled trial of 8-form Tai chi improves symptoms and functional mobility in fibromyalgia patients

    OpenAIRE

    Jones, Kim D.; Sherman, Christy A.; Mist, Scott D.; Carson, James W.; Bennett, Robert M.; Li, Fuzhong

    2012-01-01

    Previous researchers have found that 10-form Tai chi yields symptomatic benefit in patients with fibromyalgia (FM). The purpose of this study was to further investigate earlier findings and add a focus on functional mobility. We conducted a parallel-group randomized controlled trial FM-modified 8-form Yang-style Tai chi program compared to an education control. Participants met in small groups twice weekly for 90 min over 12 weeks. The primary endpoint was symptom reduction and improvement in...

  15. A novel control and physical realization of a clean hybrid hydrogen fuel-cell/battery low-power personal electric vehicle

    Science.gov (United States)

    Watkins, Andrew N.

    With the rapid continuation of global warming, high concentrations of pollutants, and foreign oil conflicts, the green energy push has now begun to manifest into great advancements in renewable or clean energies. Fuel-cells have a promising future for mobile power such as the automotive industry, distributed generation, and portable auxiliary power supplies. The type of fuel-cell that has the most focus today is the hydrogen Proton Exchange Membrane (PEM) fuel-cell. It is widely accepted that a fuel-cell cannot effectively supply a dynamic load on its own. In order to correct this drawback and make the fuel-cell system useful for all occasions, a hybrid FC/storage device system needs to be implemented. In this type of system, a balance is created between the high-energy fuel-cell and the high-power storage devices. In this thesis, a hybrid fuel-cell system topology favorable for use in a "personal" electric vehicle such as a scooter is proposed. This topology consists of a fuel-cell connected directly to the batteries and load via a DC link converter. The converter is used to manage the flow of power within the system. In order to have this flow of power to be stable and within operational limits of the devices, a novel adaptive control algorithm implementing six transfer functions based on six major operating conditions is developed. The development of the adaptive algorithm and the implementation of hardware tests were carried out by Matlab/Simulink and dSPACE. The results of the tests showed that the control algorithm was successful at regulating power flow as well as facilitating DC link stability and accuracy at the major operating points.

  16. The Empowering Role of Mobile Apps in Behavior Change Interventions: The Gray Matters Randomized Controlled Trial.

    Science.gov (United States)

    Hartin, Phillip J; Nugent, Chris D; McClean, Sally I; Cleland, Ian; Tschanz, JoAnn T; Clark, Christine J; Norton, Maria C

    2016-08-02

    Health education and behavior change programs targeting specific risk factors have demonstrated their effectiveness in reducing the development of future diseases. Alzheimer disease (AD) shares many of the same risk factors, most of which can be addressed via behavior change. It is therefore theorized that a behavior change intervention targeting these risk factors would likely result in favorable rates of AD prevention. The objective of this study was to reduce the future risk of developing AD, while in the short term promoting vascular health, through behavior change. The study was an interventional randomized controlled trial consisting of subjects who were randomly assigned into either treatment (n=102) or control group (n=42). Outcome measures included various blood-based biomarkers, anthropometric measures, and behaviors related to AD risk. The treatment group was provided with a bespoke "Gray Matters" mobile phone app designed to encourage and facilitate behavior change. The app presented evidence-based educational material relating to AD risk and prevention strategies, facilitated self-reporting of behaviors across 6 behavioral domains, and presented feedback on the user's performance, calculated from reported behaviors against recommended guidelines. This paper explores the rationale for a mobile phone-led intervention and details the app's effect on behavior change and subsequent clinical outcomes. Via the app, the average participant submitted 7.3 (SD 3.2) behavioral logs/day (n=122,719). Analysis of these logs against primary outcome measures revealed that participants who improved their high-density lipoprotein cholesterol levels during the study duration answered a statistically significant higher number of questions per day (mean 8.30, SD 2.29) than those with no improvement (mean 6.52, SD 3.612), t97.74=-3.051, P=.003. Participants who decreased their body mass index (BMI) performed significantly better in attaining their recommended daily goals

  17. Effect of Mobile Phone Text Message Reminders on Routine Immunization Uptake in Pakistan: Randomized Controlled Trial.

    Science.gov (United States)

    Kazi, Abdul Momin; Ali, Murtaza; Zubair, Khurram; Kalimuddin, Hussain; Kazi, Abdul Nafey; Iqbal, Saleem Perwaiz; Collet, Jean-Paul; Ali, Syed Asad

    2018-03-07

    Improved routine immunization (RI) coverage is recommended as the priority public health strategy to decrease vaccine-preventable diseases and eradicate polio in Pakistan and worldwide. The objective of this study was to ascertain whether customized, automated, one-way text messaging (short message service, SMS) reminders delivered to caregivers via mobile phones when a child is due for an RI visit can improve vaccination uptake and timelines in Pakistan. This was a randomized controlled trial, conducted in an urban squatter settlement area of Karachi, Pakistan. Infants less than 2 weeks of age with at least one family member who had a valid mobile phone connection and was comfortable receiving and reading SMS text messages were included. Participants were randomized to the intervention (standard care + one-way SMS reminder) or control (standard care) groups. The primary outcome was to compare the proportion of children immunized up to date at 18 weeks of age. Vaccine given at 6, 10, and 14 weeks schedule includes DPT-Hep-B-Hib vaccine (ie, diphtheria, pertussis, and tetanus; hepatitis B; and Haemophilus influenza type b) and oral poliovirus vaccine (OPV). Data were analyzed using chi-square tests of independence and tested for both per protocol (PP) and intention-to-treat (ITT) analyses. Out of those approached, 84.3% (300/356) of the participants were eligible for enrollment and 94.1% (318/338) of the participants had a working mobile phone. Only children in the PP analyses, who received an SMS reminder for vaccine uptake at 6 weeks visit, showed a statistically significant difference (96.0%, 86/90 vs 86.4%, 102/118; P=.03).The immunization coverage was consistently higher in the intervention group according to ITT analyses at the 6 weeks scheduled visit (76.0% vs 71.3%, P=.36). The 10 weeks scheduled visit (58.7% vs 52.7%, P=.30) and the 14 weeks scheduled visit (31.3% vs 26.0%, P=.31), however, were not statistically significant. Automated simple one-way SMS

  18. Production of liquid alkanes by controlling reactivity of sorbitol hydrogenation with a Ni/HZSM-5 catalyst in water

    International Nuclear Information System (INIS)

    Zhang, Qing; Wang, Tiejun; Xu, Ying; Zhang, Qi; Ma, Longlong

    2014-01-01

    Graphical abstract: MCM-41-modified Ni/HZSM-5 catalyst was developed by impregnation method with high catalytic performance for sorbitol hydrogenation in water. Appropriate amount of MCM-41 addition can distinctly promote the improvement in the surface structure and modulation of acidic sites of the catalyst. The scission of C–O bond in the sorbitol molecule into liquid alkanes was easily carried out on the catalyst containing more Lewis acidic sites. - Highlights: • Ni/HZSM-5 promoted with MCM-41 is active for sorbitol hydrogenation to liquid alkanes. • Lewis acidic sites of Ni/HZSM-5 can be modulated by pure silica MCM-41. • MCM-41 added can distinctly decrease carbon deposition on the catalyst surface. - Abstract: Liquid fuels derived from renewable biomass are of great importance on the potential substitution for diminishing fossil fuels. The conversion of sorbitol (a product of biomass-derived glucose hydrogenation) into liquid alkanes such as pentane and hexane over the Ni/HZSM-5 catalysts with or without MCM-41 addition was investigated in the presence of hydrogen in water medium. The production distribution of sorbitol hydrogenation can be controlled by adjusting the acidity of the catalyst. The scission of C–C bond in the sorbitol molecule into light C 1 –C 4 alkanes was mainly carried out over Ni/HZSM-5 containing strong Brønsted acid sites, while C–O bond scission into heavier alkanes was dominated over the catalysts added by MCM-41 containing weak Lewis acid sites. The sorbitol conversion and total liquid alkanes selectivity were found to be 67.1% and 98.7% over 2%Ni/HZSM-5 modified by 40 wt% of MCM-41, whereas the corresponding value was 40% and 35.6% over 2%Ni/HZSM-5 in the absence of MCM-41. The effect of MCM-41 on the structure, acidity, and reducibility of Ni/HZSM-5 was investigated by using XRD, Py-IR, IR, and H 2 -TPR. Meanwhile, the resistance of carbon deposition over the catalyst modified by MCM-41 was studied by using TG

  19. Gate control of the spin mobility through the modification of the spin-orbit interaction in two-dimensional systems

    Science.gov (United States)

    Luengo-Kovac, M.; Moraes, F. C. D.; Ferreira, G. J.; Ribeiro, A. S. L.; Gusev, G. M.; Bakarov, A. K.; Sih, V.; Hernandez, F. G. G.

    2017-06-01

    Spin drag measurements were performed in a two-dimensional electron system set close to the crossed spin helix regime and coupled by strong intersubband scattering. In a sample with an uncommon combination of long spin lifetime and high charge mobility, the drift transport allows us to determine the spin-orbit field and the spin mobility anisotropies. We used a random walk model to describe the system dynamics and found excellent agreement for the Rashba and Dresselhaus couplings. The proposed two-subband system displays a large tuning lever arm for the Rashba constant with gate voltage, which provides a new path towards a spin transistor. Furthermore, the data show large spin mobility controlled by the spin-orbit constants setting the field along the direction perpendicular to the drift velocity. This work directly reveals the resistance experienced in the transport of a spin-polarized packet as a function of the strength of anisotropic spin-orbit fields.

  20. Mobility-electron density relation probed via controlled oxygen vacancy doping in epitaxial BaSnO3

    Directory of Open Access Journals (Sweden)

    Koustav Ganguly

    2017-05-01

    Full Text Available The recently discovered high room temperature mobility in wide band gap semiconducting BaSnO3 is of exceptional interest for perovskite oxide heterostructures. Critical open issues with epitaxial films include determination of the optimal dopant and understanding the mobility-electron density (μ-n relation. These are addressed here through a transport study of BaSnO3(001 films with oxygen vacancy doping controlled via variable temperature vacuum annealing. Room temperature n can be tuned from 5 × 1019 cm−3 to as low as 2 × 1017 cm−3, which is shown to drive a weak- to strong-localization transition, a 104-fold increase in resistivity, and a factor of 28 change in μ. The data reveal μ ∝ n0.65 scaling over the entire n range probed, important information for understanding mobility-limiting scattering mechanisms.