WorldWideScience

Sample records for applying controllable lubrication

  1. Feasibility of Applying Controllable Lubrication Techniques to Reciprocating Machines

    DEFF Research Database (Denmark)

    Pulido, Edgar Estupinan

    The use of active lubrication in journal bearings helps to enhance the thin fluid films by increasing the fluid film thickness and consequently reducing viscous friction losses and vibrations. One refers to active lubrication when conventional hydrodynamic lubrication is combined with dynamically...... conventional lubrication conditions, a mathematical model of a reciprocating mechanism connected to a rigid / flexible rotor via thin fluid films was developed. The mathematical model involves the use of multibody dynamics theory for the modelling of the reciprocating mechanism (rigid bodies), finite elements...... method for the modelling of the flexible rotor (crankshaft) and hydrodynamic fluid film theory for describing the dynamics of the thin fluid films. When active lubrication is introduced to modify conventional hydrodynamic lubrication, by means of aplying radial oil injection at controllable oil pressures...

  2. Feasibility of Applying Controllable Lubrication to Dynamically Loaded Journal Bearings

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    fluid films, based on fluid film theory. For a dynamically loaded journal bearing, the fluid film pressure distribution can be computed by numerically solving the Reynolds equation, by means of finite-difference method. Particularly, in this study the main focus is on the lubrication behavior of the...... reaction forces in a reciprocating compressor have a cyclic behavior, periodic oil pressure injection rules based on the instantaneous crank angle and load bearing condition can be established. In this paper, several bearing configurations working under different oil pressure injection rules conditions are...... analyzed. The behavior of the following parameters is investigated when the system operates with hybrid controllable lubrication conditions: a) maximum fluid film pressure, b) minimum fluid film thickness, c) maximum vibration levels and d) injection oil pressures....

  3. Linear and Non-Linear Control Techniques Applied to Actively Lubricated Journal Bearings

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2003-01-01

    The main objectives of actively lubricated bearings are the simultaneous reduction of wear and vibration between rotating and stationary machinery parts. For reducing wear and dissipating vibration energy until certain limits, one can count with the conventional hydrodynamic lubrication....... For further reduction of shaft vibrations one can count with the active lubrication action, which is based on injecting pressurised oil into the bearing gap through orifices machined in the bearing sliding surface. The design and efficiency of some linear (PD, PI and PID) and non-linear controllers, applied...... vibration reduction of unbalance response of a rigid rotor, where the PD and the non-linear P controllers show better performance for the frequency range of study (0 to 80 Hz). The feasibility of eliminating rotor-bearing instabilities (phenomena of whirl) by using active lubrication is also investigated...

  4. Linear and Non-Linear Control Techniques Applied to Actively Lubricated Journal Bearings

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2003-01-01

    The main objectives of actively lubricated bearings are the simultaneous reduction of wear and vibration between rotating and stationary machinery parts. For reducing wear and dissipating vibration energy until certain limits, one can count with the conventional hydrodynamic lubrication. For...... further reduction of shaft vibrations one can count with the active lubrication action, which is based on injecting pressurised oil into the bearing gap through orifices machined in the bearing sliding surface. The design and efficiency of some linear (PD, PI and PID) and non-linear controllers, applied...... to a tilting-pad journal bearing, are analysed and discussed. Important conclusions about the application of integral controllers, responsible for changing the rotor-bearing equilibrium position and consequently the "passive" oil film damping coefficients, are achieved. Numerical results show an...

  5. Linear and non-linear control techniques applied to actively lubricated journal bearings

    Science.gov (United States)

    Nicoletti, R.; Santos, I. F.

    2003-03-01

    The main objectives of actively lubricated bearings are the simultaneous reduction of wear and vibration between rotating and stationary machinery parts. For reducing wear and dissipating vibration energy until certain limits, one can use the conventional hydrodynamic lubrication. For further reduction of shaft vibrations one can use the active lubrication action, which is based on injecting pressurized oil into the bearing gap through orifices machined in the bearing sliding surface. The design and efficiency of some linear (PD, PI and PID) and a non-linear controller, applied to a tilting-pad journal bearing, are analysed and discussed. Important conclusions about the application of integral controllers, responsible for changing the rotor-bearing equilibrium position and consequently the "passive" oil film damping coefficients, are achieved. Numerical results show an effective vibration reduction of unbalance response of a rigid rotor, where the PD and the non-linear P controllers show better performance for the frequency range of study (0-80 Hz). The feasibility of eliminating rotor-bearing instabilities (phenomena of whirl) by using active lubrication is also investigated, illustrating clearly one of its most promising applications.

  6. Active lubrication applied to internal combustion engines - evaluation of control strategies

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    The performance of fluid film bearings in a combustion engine affects key functions such as durability, noise and vibration. Therefore, this work evaluates different control strategies for applying active radial oil injection in the main bearings of internal combustion engines with the aim of...... reducing friction losses and vibrations between the crankshaft and the bearings. The conventional hydrodynamic lubrication is combined with hydrostatic lubrication which is actively modified by radially injecting oil at controllable pressures, through orifices circumferentially located around the bearing...... surface. The behaviour of a main bearing of a medium size combustion engine, operating with radial oil injection and with four different control strategies is analyzed, giving some insights into the minimum fluid film thickness, maximum fluid film pressure, friction losses and maximum vibration levels...

  7. Schemes for applying active lubrication to main engine bearings

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    The work presented here is a theoretical study that describes two different schemes for the oil injection system in actively lubricated main engine bearings. The use of active lubrication in journal bearings helps to enhance the hydrodynamic fluid film by increasing the fluid film thickness and...... orifices circumferentially located around the bearing surface. The pressure distribution of the hydrodynamic fluid film in journal bearings is governed by the Reynolds equation, which is modified to accommodate the dynamics of active lubrication, and which can be numerically solved using finite...... consequently reducing viscous friction losses and vibrations. One refers to active lubrication when conventional hydrodynamic lubrication is combined with dynamically modified hydrostatic lubrication. In this case, the hydrostatic lubrication is modified by injecting oil at controllable pressures, through...

  8. Creation of solid lubricant firms by nanostructure control

    International Nuclear Information System (INIS)

    The friction coefficient can be decreased by increasing the hardness of a sliding plane while maintaining low shear resistance parallel to its substrate using nanostructural control techniques. Herein, nanoperiodic multilayer films composed of solid lubricant materials were proposed to develop a new solid lubricant film having lower friction than that of conventional solid lubricant films. The applied solid lubricant materials were soft metals including Au and Ag, polymers such as PTFE (polytetrafluoroethylene), and crystallizing layered inorganic compounds such as MoS2 (molybdenum disulfide), WS2 (tungsten disulfide), graphite, and hexagonal-BN. The nanoindentation properties of the obtained films were evaluated. Multilayered films with a suitable period showed a high hardness and elastic modulus. These nanoperiod multilayer solid lubricant films exhibited lower friction, higher nanowear resistance, and superior friction endurance than those of monolayer films. (author)

  9. Actively lubricated bearings applied as calibrated shakers to aid parameter identification in rotordynamics

    DEFF Research Database (Denmark)

    Santos, Ilmar; Cerda Varela, Alejandro Javier

    2013-01-01

    between hydrodynamic, hydrostatic and controllable lubrication regimes, can be used either to control or to excite rotor lateral vibrations. An accurate characterization of the active oil film forces is of fundamental importance to elucidate the feasibility of applying the active lubrication as non......-invasive perturbation forces, or in other words, as a "calibrated shaker", to perform in-situ rotordynamic tests. The main original contributions of this paper are three: a) the experimental characterization of the active fluid film forces generated in an actively-lubricated tilting-pad journal bearing in the frequency...... systems; c) experimental indication of how small such active fluid film forces (perturbation forces) should be, in order to perturb the rotor-journal bearing system without significantly changing its dynamic characteristics. To validate the experimental procedure and results obtained via actively-lubricated...

  10. Lubrication control of motors in paper mills

    Energy Technology Data Exchange (ETDEWEB)

    Kano, Yasuo

    1987-12-01

    This review is focused lubrication control of motors in paper mills. Smaller motors use deep groove ball bearings and lubricating grease. They need no make-up grease. Medium-size motors incorporate both sealed and open bearings or only open bearings and the grade, make-up intervals and make-up volume of the lubricating grease to be used are specified. Methods for automatic grease supply include the use of an automatic grease cup with improved injection mechanism, use of an injection pump for automatic supply to each motor, and group-control for parallel supply to several motors through distribution valves. For large-size motors, oil-bath lubricating is usually adopted in combination with a circulating oil supply device, etc. Improved techniques are currently available for automatization of the main systems and for automatization and reduction in cost of electric instrumentation. However, grease up of bearings, especially for medium-size motors, is performed by hand. Effective lubrication control and increased productivity are expected to be achieved by the combined use of automatic oil supply and monitoring devices. (14 figs, 4 tabs)

  11. A randomized controlled trial comparing nonoxynol-9 lubricated condoms with silicone lubricated condoms for prophylaxis

    OpenAIRE

    Roddy, R E; M. Cordero; Ryan, K.A.; Figueroa, J.

    1998-01-01

    OBJECTIVE: We tested the effect of nonoxynol-9 (N-9) in condom lubrication on the risk of acquiring STD and genital discomfort. METHODS: The study was a triple masked, randomised controlled trial comparing N-9 lubricated condoms with plain silicone lubricated condoms among Dominican female sex workers. RESULTS: Randomisation provided two groups (313 for N-9 and 322 for plain) similar in baseline characteristics, but extensive loss to follow up occurred (56 women in each group completed ...

  12. Active lubrication applied to radial gas journal bearings. Part 2: Modelling improvement and experimental validation

    DEFF Research Database (Denmark)

    Pierart, Fabián G.; Santos, Ilmar F.

    2016-01-01

    Actively-controlled lubrication techniques are applied to radial gas bearings aiming at enhancing one of their most critical drawbacks, their lack of damping. A model-based control design approach is presented using simple feedback control laws, i.e. proportional controllers. The design approach...... combines three main domains: tribology, dynamics and control. The Reynolds equation with radial injection, including piezoelectrically controlled jet, describes the non-linear interaction between bearing surface and rotating shaft. Dynamics of the flexible shaft and rotating parts are modelled aid by...... finite element method and the global model is used as control design tool. Active lubrication allows for significant increase in damping factor of the rotor-bearing system. Very good agreement between theory and experiment is obtained, supporting the multi-physic design tool developed....

  13. Application of contamination control of lubricant to proactive maintenance

    International Nuclear Information System (INIS)

    Lubricant management is very important to maintain the integrity of rotating equipment Lubricant is periodically replaced and monitored on its aging degradation between replacement times. On the other hand, only the confirmation of specification document has been performed as acceptance inspection in case of new lubricant. However, a comparatively large amount of impurity substances has been found in new lubricant by sample analysis. Therefore, the introduction of contamination control of new lubricant is programmed as a step of proactive maintenance, and the outline of the program is described in this paper. (author)

  14. Tilting-Pad Journal Bearings with Active Lubrication Applied as Calibrated Shakers: Theory and Experiment

    DEFF Research Database (Denmark)

    Cerda Varela, Alejandro Javier; Santos, Ilmar

    2014-01-01

    In recent years, a continuous research effort has transformed the conventional tilting-pad journal bearing into a mechatronic machine element. The addition of electromechanical elements provides the possibility of generating controllable forces over the rotor as a function of a suitable control...... dependent calibration function, i.e. the transfer function between control signal and force over the rotor. This work presents a theoretical model of the calibration function for a tilting-pad journal bearing with active lubrication. The bearing generates controllable forces by injecting pressurized oil...... signal. Such forces can be applied in order to perform parameter identification procedures in-situ, which enables evaluation of the mechanical condition of the machine in a non-invasive way. The usage of a controllable bearing as a calibrated shaker requires obtaining the bearing specific frequency...

  15. Feasibility of Applying Active Lubrication to Dynamically Loaded Fluid Film Bearings

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    The feasibility of modifying the dynamics of the thin fluid films of dynamically loaded journal bearings, using different strategies of active lubrication is studied in this work. A significant reduction in the vibration levels, wear and power friction losses, is expected. Particularly, the focus...... of this study is on the analysis of main crankshaft bearings, where the conventional hydrodynamic lubrication is modified by injecting oil at actively controllable pressures, through orifices circumferentially located along the bearing surface....

  16. Solid film lubricants and thermal control coatings flown aboard the EOIM-3 MDA sub-experiment

    Science.gov (United States)

    Murphy, Taylor J.; David, Kaia E.; Babel, Hank W.

    1995-01-01

    Additional experimental data were desired to support the selection of candidate thermal control coatings and solid film lubricants for the McDonnell Douglas Aerospace (MDA) Space Station hardware. The third Evaluation of Oxygen Interactions With Materials Mission (EOIM-3) flight experiment presented an opportunity to study the effects of the low Earth orbit environment on thermal control coatings and solid film lubricants. MDA provided five solid film lubricants and two anodic thermal control coatings for EOIM-3. The lubricant sample set consisted of three solid film lubricants with organic binders one solid film lubricant with an inorganic binder, and one solid film lubricant with no binder. The anodize coating sample set consisted of undyed sulfuric acid anodize and cobalt sulfide dyed sulfuric acid anodize, each on two different substrate aluminum alloys. The organic and inorganic binders in the solid film lubricants experienced erosion, and the lubricating pigments experienced oxidation. MDA is continuing to assess the effect of exposure to the low Earth orbit environment on the life and friction properties of the lubricants. Results to date support the design practice of shielding solid film lubricants from the low Earth orbit environment. Post-flight optical property analysis of the anodized specimens indicated that there were limited contamination effects and some atomic oxygen and ultraviolet radiation effects. These effects appeared to be within the values predicted by simulated ground testing and analysis of these materials, and they were different for each coating and substrate.

  17. Nanoscale Lubrication of Ionic Surfaces Controlled via a Strong Electric Field

    Science.gov (United States)

    Strelcov, Evgheni; Kumar, Rajeev; Bocharova, Vera; Sumpter, Bobby G.; Tselev, Alexander; Kalinin, Sergei V.

    2015-01-01

    Frictional forces arise whenever objects around us are set in motion. Controlling them in a rational manner means gaining leverage over mechanical energy losses and wear. This paper presents a way of manipulating nanoscale friction by means of in situ lubrication and interfacial electrochemistry. Water lubricant is directionally condensed from the vapor phase at a moving metal-ionic crystal interface by a strong confined electric field, thereby allowing friction to be tuned up or down via an applied bias. The electric potential polarity and ionic solid solubility are shown to strongly influence friction between the atomic force microscope (AFM) tip and salt surface. An increase in friction is associated with the AFM tip digging into the surface, whereas reducing friction does not influence its topography. No current flows during friction variation, which excludes Joule heating and associated electrical energy losses. The demonstrated novel effect can be of significant technological importance for controlling friction in nano- and micro-electromechanical systems.

  18. Applied Control Systems Design

    CERN Document Server

    Mahmoud, Magdi S

    2012-01-01

    Applied Control System Design examines several methods for building up systems models based on real experimental data from typical industrial processes and incorporating system identification techniques. The text takes a comparative approach to the models derived in this way judging their suitability for use in different systems and under different operational circumstances. A broad spectrum of control methods including various forms of filtering, feedback and feedforward control is applied to the models and the guidelines derived from the closed-loop responses are then composed into a concrete self-tested recipe to serve as a check-list for industrial engineers or control designers. System identification and control design are given equal weight in model derivation and testing to reflect their equality of importance in the proper design and optimization of high-performance control systems. Readers’ assimilation of the material discussed is assisted by the provision of problems and examples. Most of these e...

  19. Actively lubricated bearings applied as calibrated shakers to aid parameter identification in rotordynamics

    DEFF Research Database (Denmark)

    Santos, Ilmar; Cerda Varela, Alejandro Javier

    2013-01-01

    -invasive perturbation forces, or in other words, as a "calibrated shaker", to perform in-situ rotordynamic tests. The main original contributions of this paper are three: a) the experimental characterization of the active fluid film forces generated in an actively-lubricated tilting-pad journal bearing in the frequency......The servo valve input signal and the radial injection pressure are the two main parameters responsible for dynamically modifying the journal oil film pressure and generating active fluid film forces in controllable fluid film bearings. Such fluid film forces, resulting from a strong coupling...... domain and the application of such a controllable bearing as a calibrated shaker aiming at determining the frequency response function (FRF) of rotordynamic systems; b) experimental quantification of the influence of the supply pressure and servo valve input signal on the FRF of rotor-journal bearing...

  20. Radial oil injection applied to main engine bearings: evaluation of injection control rules

    DEFF Research Database (Denmark)

    Estupiñan, EA; Santos, Ilmar

    2012-01-01

    The performance of main bearings in a combustion engine affects key functions such as durability, noise and vibration. Thus, with the aim of reducing friction losses and vibrations between the crankshaft and the bearings, the work reported here evaluates different strategies for applying controll...... actively lubricated bearing is compared with the performance of the conventional lubricated bearing, giving some insights into the minimum fluid film thickness, maximum fluid film pressure, friction losses and maximum vibration levels....... controllable radial oil injection to main crankshaft journal bearings. In an actively lubricated bearing, conventional hydrodynamic lubrication is combined with controllable hydrostatic lubrication, where the oil injection pressures can be modified depending on the operational conditions. In this study, the...

  1. Statistical tools and control of internal lubricant content of inhalation grade HPMC capsules during manufacture.

    Science.gov (United States)

    Ayala, Guillermo; Díez, Fernando; Gassó, María T; Jones, Brian E; Martín-Portugués, Rafael; Ramiro-Aparicio, Juan

    2016-04-30

    The internal lubricant content (ILC) of inhalation grade HPMC capsules is a key factor to ensure good powder release when the patient inhales a medicine from a dry powder inhaler (DPI). Powder release from capsules has been shown to be influenced by the ILC. The characteristics used to measure this are the emitted dose, fine particle fraction and mass median aerodynamic diameter. In addition the ILC level is critical for capsule shell manufacture because it is an essential part of the process that cannot work without it. An experiment has been applied to the manufacture of inhalation capsules with the required ILC. A full factorial model was used to identify the controlling factors and from this a linear model has been proposed to improve control of the process. PMID:26899981

  2. Nanoscale Lubrication of Ionic Surfaces Controlled via a Strong Electric Field

    OpenAIRE

    Strelcov, Evgheni; Kumar, Rajeev; Bocharova, Vera; Sumpter, Bobby G.; Tselev, Alexander; Sergei V Kalinin

    2015-01-01

    Frictional forces arise whenever objects around us are set in motion. Controlling them in a rational manner means gaining leverage over mechanical energy losses and wear. This paper presents a way of manipulating nanoscale friction by means of in situ lubrication and interfacial electrochemistry. Water lubricant is directionally condensed from the vapor phase at a moving metal-ionic crystal interface by a strong confined electric field, thereby allowing friction to be tuned up or down via an ...

  3. The Wear Characteristics of Heat Treated Manganese Phosphate Coating Applied to AlSi D2 Steel with Oil Lubricant

    Directory of Open Access Journals (Sweden)

    Venkatesan Alankaram

    2012-12-01

    Full Text Available Today, in the area of material design conversion coatings play an important role in the applications where temperature, corrosion, oxidation and wear come in to play. Wear of metals occurs when relative motion between counter-surfaces takes place, leading to physical or chemical destruction of the original top layers. In this study, the tribological behaviour of heat treated Manganese phosphate coatings on AISI D2 steel with oil lubricant was investigated. The Surface morphology of manganese phosphate coatings was examined by Scanning Electron Microscope (SEM and Energy Dispersive X-ray Spectroscopy (EDX .The wear tests were performed in a pin on disk apparatus as per ASTM G-99 Standard. The wear resistance of the coated steel was evaluated through pin on disc test using a sliding velocity of 3.0m/s under Constant loads of 40 N and 100 N with in controlled condition of temperature and humidity. The Coefficient of friction and wear rate were evaluated. Wear pattern of Manganese phosphate coated pins with oil lubricant, Heat treated Manganese phosphate coated pins with oil lubricant were captured using Scanning Electron Microscope (SEM. The results of the wear test established that the heat treated manganese phosphate coating with oil lubricant exhibited the lowest average coefficient of friction and the lowest wear loss up to 6583 m sliding distance under 40 N load and 3000 m sliding distance even under 100 N load respectively. The Wear volume and temperature rise in heat treated Manganese Phosphate coated pins with oil lubricant is lesser than the Manganese Phosphate coated pins with oil lubricant

  4. Lubrication fundamentals

    CERN Document Server

    Pirro, DM

    2001-01-01

    This work discusses product basics, machine elements that require lubrication, methods of application, lubricant storage and handling, and lubricant conservation. This edition emphasizes the need for lubrication and careful lubricant selection.

  5. Feasibility of Applying Active Lubrication to Reduce Vibration in Industrial Compressors

    DEFF Research Database (Denmark)

    Santos, Ilmar; Nicoletti, Rodrigo; Scalabrin, A.

    2004-01-01

    the orifices distributed over the sliding surface. The dynamic coefficients of tilting-pad bearings with and without active lubrication and their influence on an industrial compressor of 391 Kg, which operates with a maximum speed of 10,200 rpm, are analyzed. In the original compressor design, the...... bearing housings are mounted on squeeze-film dampers in order to ensure reasonable stability margins during full load condition (high maximum continuous speed). Instead of having a combination of tilting-pad bearings and squeeze-film dampers, another design solution is proposed and theoretically......In this paper the complete set of modified Reynolds´ equations for the active lubrication is presented. The solution of such a set of equations allows the determination of stiffness and damping coefficients of actively lubricated bearings. These coefficients are not just dependent on Sommerfeld...

  6. Liquid-liquid extraction and adsorption on solid surfaces applied to used lubricant oils recovery

    Directory of Open Access Journals (Sweden)

    J. L. Assunção Filho

    2010-12-01

    Full Text Available In this work, the recovery of base oils from waste lubricants following the steps of solvent extraction, adsorption on solids and solvent removal by evaporation was evaluated. In the step of solvent extraction, the most efficient was 1-butanol, followed by tert-butanol, 2-propanol and ethanol; for the step of adsorption, activated carbon was the most effective solid for PAH removal, confirming the similarity of these compounds with petroleum aromatic fractions. Thus, the optimum solvent-adsorbent pair for the recovery of used lubricant oils through the proposed methodology was 1-butanol/activated carbon. At the end of the process, it was possible to establish a set of steps that permit the recovery of lubricant base oils with lower content of contaminants.

  7. Active lubrication applied to radial gas journal bearings. Part 1: Modeling

    DEFF Research Database (Denmark)

    Morosi, Stefano; Santos, Ilmar

    2011-01-01

    regulating radial injection of lubricant through the means of piezoelectric actuators mounted on the back of the bearing sleeves. A feedback law is used to couple the dynamic of a simplified rotor-bearing system with the pneumatic and dynamic characteristics of a piezoelectric actuated valve system. Selected...

  8. Three-DOF dynamic model with lubricant contact for thermal fly-height control nanotechnology

    Science.gov (United States)

    Vakis, Antonis I.; Hadjicostis, Christoforos N.; Polycarpou, Andreas A.

    2012-04-01

    A three-degree-of-freedom dynamic contact model with friction and lubricant contact is introduced for thermal fly-height control of a near-contact flying slider. The proposed model addresses the issue of contact with a molecularly thin lubricant layer and includes a third degree-of-freedom, roll. Neither lubricant contact nor roll has been accounted for in previous models of the head-disk interface. Roll angle rotations allow for possible contact at other slider features such as the contact pads, which may induce destabilizing moments to the slider motion and lead to unwanted slider-disk contact. While roll is important primarily during operational shock, the inclusion of lubricant contact is found to be an important determinant of the severity of steady contact while lubricant properties are shown to affect the transient properties of the jump-to- and out-of-contact slider behaviour for near- and light-contact operation. The model's validity is examined using available experimental and simulation data that predict flying height gain due to air bearing stiffening as well as significant vibration zones before and after steady-state contact.

  9. Liquid-liquid extraction and adsorption on solid surfaces applied to used lubricant oils recovery

    OpenAIRE

    J. L. Assunção Filho; L. G. M. Moura; A.C.S. RAMOS

    2010-01-01

    In this work, the recovery of base oils from waste lubricants following the steps of solvent extraction, adsorption on solids and solvent removal by evaporation was evaluated. In the step of solvent extraction, the most efficient was 1-butanol, followed by tert-butanol, 2-propanol and ethanol; for the step of adsorption, activated carbon was the most effective solid for PAH removal, confirming the similarity of these compounds with petroleum aromatic fractions. Thus, the optimum solvent-adsor...

  10. Exploring integral controllers in actively-lubricated tilting-pad journal bearings

    DEFF Research Database (Denmark)

    Salazar, Jorge Andrés González; Santos, Ilmar

    2015-01-01

    Active tilting-pad journal bearings with radial oil injection combine good stability properties of conventional tilting-pad journal bearings with the capability of improving their dynamic properties even more by control techniques. The main contribution of this work is the experimental...... investigation of integral controllers for feedback-controlled lubrication with the aim of: a) presetting the static journal center and consequently exploring the changes of bearing dynamic properties; b) obtaining an integral controller capable of re-positioning the static journal eccentricity for matching...... equilibria under conventional hydrodynamic and feedback-controlled lubrication regimes. A novel application is proposed, that tries to build non-invasive perturbation forces and uses the active fluid film forces of the bearing as a calibrated shaker....

  11. Lubrication fundamentals

    International Nuclear Information System (INIS)

    This book is organized under the following headings: lubricating oils; lubricating greases; synthetic lubricants; machine elements; lubricant application; internal combustion engines; stationary gas turbines; steam turbines; hydraulic turbines; nuclear power plants; automotive chassis components; automotive power transmissions; compressors; handling, storing, and dispensing lubricants, in-plant handling for lubricant conservation

  12. Lubricants and lubrication

    Energy Technology Data Exchange (ETDEWEB)

    Mang, T.; Dresel, W. [eds.] [Fuchs Petrolub AG, Mannheim (Germany)

    2001-07-01

    The use of lubricants is as old as mankind but the scientific analysis of lubrication, friction and wear, as an aspect of tribology is relatively new. Only recently have lubricants begun to be viewed as functional elements in engineering and this group of substances is also receiving increased attention from engineers. This book provides chemists and engineers with a clear interdisciplinary introduction and orientation to all major lubricant applications, focusing not only on the various products but also on specific application engineering criteria. (orig.)

  13. Post Irradiation Evaluation of Thermal Control Coatings and Solid Lubricants to Support Fission Surface Power Systems

    Science.gov (United States)

    Bowman, Cheryl L.; Jaworske, Donald A.; Stanford, Malcolm K.; Persinger, Justin A.; Khorsandi, Behrooz; Blue, Thomas E.

    2007-01-01

    The development of a nuclear power system for space missions, such as the Jupiter Icy Moons Orbiter or a lunar outpost, requires substantially more compact reactor design than conventional terrestrial systems. In order to minimize shielding requirements and hence system weight, the radiation tolerance of component materials within the power conversion and heat rejection systems must be defined. Two classes of coatings, thermal control paints and solid lubricants, were identified as material systems for which limited radiation hardness information was available. Screening studies were designed to explore candidate coatings under a predominately fast neutron spectrum. The Ohio State Research Reactor Facility staff performed irradiation in a well characterized, mixed energy spectrum and performed post irradiation analysis of representative coatings for thermal control and solid lubricant applications. Thermal control paints were evaluated for 1 MeV equivalent fluences from 10(exp 13) to 10(exp 15) n per square centimeters. No optical degradation was noted although some adhesive degradation was found at higher fluence levels. Solid lubricant coatings were evaluated for 1 MeV equivalent fluences from 10(exp 15) to 10(exp 16) n per square centimeters with coating adhesion and flexibility used for post irradiation evaluation screening. The exposures studied did not lead to obvious property degradation indicating the coatings would have survived the radiation environment for the previously proposed Jupiter mission. The results are also applicable to space power development programs such as fission surface power for future lunar and Mars missions.

  14. Post Irradiation Evaluation of Thermal Control Coatings and Solid Lubricants to Support Fission Surface Power Systems

    International Nuclear Information System (INIS)

    The development of a nuclear power system for space missions, such as the Jupiter Icy Moons Orbiter or a lunar outpost, requires substantially more compact reactor design than conventional terrestrial systems. In order to minimize shielding requirements and hence system weight, the radiation tolerance of component materials within the power conversion and heat rejection systems must be defined. Two classes of coatings, thermal control paints and solid lubricants, were identified as material systems for which limited radiation hardness information was available. Screening studies were designed to explore candidate coatings under a predominately fast neutron spectrum. The Ohio State Research Reactor Facility staff performed irradiation in a well characterized, mixed energy spectrum and performed post irradiation analysis of representative coatings for thermal control and solid lubricant applications. Thermal control paints were evaluated for 1 MeV equivalent fluences from 1013 to 1015 n/cm2. No optical degradation was noted although some adhesive degradation was found at higher fluence levels. Solid lubricant coatings were evaluated for 1 MeV equivalent fluences from 1015 to 1016 n/cm2 with coating adhesion and flexibility used for post irradiation evaluation screening. The exposures studied did not lead to obvious property degradation indicating the coatings would have survived the radiation environment for the previously proposed Jupiter mission. The results are also applicable to space power development programs such as fission surface power for future lunar and Mars missions

  15. The Phan-Thien and Tanner model applied to thin film spherical coordinates: applications for lubrication of hip joint replacement.

    Science.gov (United States)

    Tichy, John; Bou-Saïd, Benyebka

    2008-04-01

    The Phan-Thien and Tanner (PTT) model is one of the most widely used rheological models. It can properly describe the common characteristics of viscoelastic non-Newtonian fluids. There is evidence that synovial fluid in human joints, which also lubricates artificial joints, is viscoelastic. Modeling the geometry of the total hip replacement, the PTT model is applied in spherical coordinates for a thin confined fluid film. A modified Reynolds equation is developed for this geometry. Several simplified illustrative problems are solved. The effect of the edge boundary condition on load-carrying normal stress is discussed. Solutions are also obtained for a simple squeezing flow. The effect of both the relaxation time and the PTT shear parameter is to reduce the load relative to a Newtonian fluid with the same viscosity. This implies that the Newtonian model is not conservative and may overpredict the load capacity. The PTT theory is a good candidate model to use for joint replacement lubrication. It is well regarded and derivable from molecular considerations. The most important non-Newtonian characteristics can be described with only three primary material parameters. PMID:18412499

  16. Stick-Slip Control in Nanoscale Boundary Lubrication by Surface Wettability

    Science.gov (United States)

    Chen, Wei; Foster, Adam S.; Alava, Mikko J.; Laurson, Lasse

    2015-03-01

    We study the effect of atomic-scale surface-lubricant interactions on nanoscale boundary-lubricated friction by considering two example surfaces—hydrophilic mica and hydrophobic graphene—confining thin layers of water in molecular dynamics simulations. We observe stick-slip dynamics for thin water films confined by mica sheets, involving periodic breaking-reforming transitions of atomic-scale capillary water bridges formed around the potassium ions of mica. However, only smooth sliding without stick-slip events is observed for water confined by graphene, as well as for thicker water layers confined by mica. Thus, our results illustrate how atomic-scale details affect the wettability of the confining surfaces and consequently control the presence or absence of stick-slip dynamics in nanoscale friction.

  17. Tribological Investigations of Hard-Faced Layers and Base Materials of Forging Dies with Different Kinds of Lubricants Applied

    Directory of Open Access Journals (Sweden)

    V. Lazić

    2010-12-01

    Full Text Available This paper gives a procedure for choosing the right technology for reparative hard facing of damaged forging dies. Since they are subject to impact loads and cyclic temperature elevations, forging dies should be made of steel that is able to withstand great impact loads, maintain good mechanical properties at elevated temperatures and that is resistant to wear and thermal fatigue. For these reasons, forging dies are made of conditionally weldable alloy tool steels; however it makes hard facing of damaged tools even more difficult. In this paper, wear resistance of base materials, hard-faced layers and heat-affected zones are tribologically investigated when two different lubricants - pure synthetical oil LM 76 and LM 76 with 6% molybdenum disulfide (MoS2 are applied. Tribological investigations have shown that the wear resistance of the hard faced layers is considerably greater than the wear resistance of the base material. However, the base material has better properties concerning friction.

  18. Feedback-controlled lubrication for reducing the lateral vibration of flexible rotors supported by tilting-pad journal bearings

    DEFF Research Database (Denmark)

    Salazar, Jorge Andrés González; Santos, Ilmar

    2015-01-01

    The feedback-controlled lubrication regime, based on a model-free designed proportional–derivative controller, is experimentally investigated in a flexible rotor mounted on an actively-lubricated tilting-pad journal bearing. With such a lubrication regime, both the resulting pressure distribution...... function is optimized in the stabilizing gain domain and then chosen from a subdomain imposed by servovalve restrictions. This work demonstrates enhancements of the dynamic response of flexible rotor-bearing systems supported by an active tilting-pad journal bearing by means of the feedback...... over the pads and hence the bearing dynamic properties are dynamically modified. The control strategy is focused on reducing the lateral vibrations of the system around its operational equilibrium within a wide frequency range. To synthesize the proportional–derivative controller gains, an objective...

  19. Feedback-Controlled Lubrication for Reducing the Lateral Vibration of Flexible Rotors supported by Tilting-Pad Journal Bearings

    DEFF Research Database (Denmark)

    Salazar, Jorge Andrés González; Santos, Ilmar

    2014-01-01

    In this work, the feedback-controlled lubrication regime, based on a model-free designed proportional-derivative (PD) controller, is studied and experimentally tested in a flexible rotor mounted on an actively-lubricated tilting-pad journal bearing (active TPJB). With such a lubrication regime......, both the resulting pressure distribution over the pads and hence the bearing dynamic properties are dynamically modified. The control strategy is focused on reducing the system lateral vibration around its operational equilibrium position in a wide frequency range. For this purpose, servovalves are...... to experimentally characterized multi-input multi-output systems is used to determine the stabilizing PD gain domain. The main contribution of this work is to demonstrate the enhancement of the dynamic response of a flexible rotor-bearing system supported by an active TPJB by means of the feedback...

  20. Three Types of Active Lubrication Systems for the Main Bearings of Reciprocating Machines

    DEFF Research Database (Denmark)

    Santos, Ilmar; Pulido, E. E.

    2010-01-01

    In the paper the authors investigate three different schemes for the realization of the controllable oil injection system to be couple to the main engine bearings. The use of active lubrication in fluid film bearings helps to enhance the hydrodynamic fluid film by increasing the fluid film...... engine, where the conventional lubrication of the main bearing is modified by applying radial oil injection. The performance of such a hybrid bearing is compared to an equivalent conventional lubricated bearing in terms of the maximum fluid film pressures, minimum fluid film thicknesses and reduction of...... thickness and consequently reducing viscous friction losses and vibrations. One refers to active lubrication when conventional hydrodynamic lubrication is combined with dynamically modified hydrostatic lubrication. In this case, the hydrostatic lubrication is modified by injecting oil at controllable...

  1. Water drilling fluids: evaluation of lubricity and clay swelling control; Fluidos de perfuracao a base de agua: avaliacao de lubricidade e controle de inchamento de argilas

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Thiago de Freitas; Arruda, Jefferson Teixeira; Medeiros, Ana Catarina; Garcia, Rosangela Balaban [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    During the oil well drilling, drilling fluids are used in order to transport the cuttings until the surface. This fluid is also responsible for the mechanical sustentation of the well walls, the control of undesirable production of fluids in the formation, the lubricity and the cooling of the bit. The drilling fluids based on water are extensively applied due to their lower cost, thermal stability, biodegradability, easiness of pumping and treatment, resulting in smaller environmental impacts. However, some situations, such as hydrophilic shale drilling, request the use of additives to avoid the hydration of them and, consequently, the tool imprisonment or migration (filtration) of the drilling fluids into the rock. The goal of this work was to develop and test formulations of water-base drilling fluids with high capacity of inhibition of clay swelling and lubricity, obtaining drillings with larger penetration rate and calipers without enlargements. The results showed that the appropriate combination of commonly used commercial products can promote the obtaining of fluids with equal or better performance than those used by world companies. (author)

  2. Performance Improvement of tilting-pad journal bearings by means of controllable lubrication

    DEFF Research Database (Denmark)

    Cerda, Alejandro; Santos, Ilmar

    2012-01-01

    Tilting-Pad Journal Bearings (TPJB) are commonly used on high-performance turbomachinery due to their excellent stability properties at high speed when compared to other designs for oil film bearings. Hence, efforts have been made to improve the accuracy for the available models for these...... mechanical devices, achieving nowadays an elasto-thermo-hydrodynamic formulation. On the other hand, the basic design of the Tilting-Pad Journal Bearing has been modified in order to transform it into a smart machine element. One approach to do so is to inject pressurized oil directly into the bearing...... presenting an elasto-thermo-hydrodynamic model (ETHD) for the Tilting-Pad Journal Bearing, including the effect of the controllable lubrication system. The basic model is validated by comparing its results against theoretical and experimental results available in the literature. Then, the validated code is...

  3. Reduction of friction and wear by grooves applied on the nanoscale polished surface in boundary lubrication conditions

    Science.gov (United States)

    Stelmakh, Alexander U.; Pilgun, Yuriy V.; Kolenov, Sergiy O.; Kushchev, Alexey V.

    2014-05-01

    The evolution of a friction surface geometry with initially directed microscale grooves on a nanoscale polished surface in ring-on-block sliding contact is studied experimentally. Reduced wear and friction is observed when the orientation of grooves coincides with the direction of sliding. A new compressive-vacuum hypothesis of friction force nature under a condition of boundary lubrication is proposed, which successfully explains the observed phenomena. Grooves supply lubricant into the contact zone and facilitate its devacuumization, which lead to substantial reduction of surface wear. The obtained results enable developing optimized roughness profiles of friction surfaces to create high-performance durable friction units.

  4. Lubrication scheme of flow control valve used in space%空间流量调节阀的润滑

    Institute of Scientific and Technical Information of China (English)

    陈展; 王可立; 赫伟涛; 祁增强

    2012-01-01

    流量调节阀运动件较多,工作环境压力〈10^-11Pa,流体润滑不适应该环境条件。阀芯与推进剂(N2O4和MON-1)接触,无成熟解决方案。本文提出的阀门运动件润滑方案,非接触介质运动件采用自润滑材料或固体润滑膜。阀芯润滑,提出了物理气象沉积类金刚石膜(DLC)、TiN—Au复合膜及单质纯金膜三种方案。通过试验研究,确定阀芯采用全新的润滑方式一离子镀金。%Since there are many movement components in the flow control valve which works in the pressure of less than 10^-11 Pa, the liquid-lubrication is unsuitable for it. The valve pintle is marinated in the propellant (N2O4 and MON-1), so there is no mature solve scheme at present. In this paper, a lubrication scheme for the movement components of the valve is presented, in which the pairs of movement components that do not contact with propellant are made up of self-lubrication material or are wrapped up in a solid lubrication film; as for the the lubrication of the valve pintle, three methods are proposed such as physical vapor deposition diamond-like carbon (DLC) film, TiN-Au compound film and pure Au film. A brand-new ion-gilding scheme for the pintle lubrication was chosen accord- ing to the results of the tests and the comparison.

  5. Controllable Lubrication for Main Engine Bearings Using Mechanical and Piezoelectric Actuators

    DEFF Research Database (Denmark)

    Estupinan, Edgar; Santos, Ilmar

    2012-01-01

    Although mechatronic systems are nowadays implemented in a large number of systems in vehicles, active lubrication systems are still incipient in industrial applications. This study is an attempt to extend the active lubrication concept to combustion engines and gives a theoretical contribution t...

  6. Apply for Cancer Control Grants

    Science.gov (United States)

    The Division of Cancer Control and Population Sciences funds a large portfolio of grants and contracts. The portfolio currently includes approximately 800 grants valued at nearly $450 million. Here we provide a listing of funding opportunities that are currently accepting applications. Please visit this page regularly as new funding opportunities are added upon approval by NCI.

  7. Adjustable ETHD lubrication applied to the improvement of dynamic performance of flexible rotors supported by active TPJB

    DEFF Research Database (Denmark)

    Salazar, Jorge Andrés González; Cerda Varela, Alejandro Javier; Santos, Ilmar

    2013-01-01

    pressurized oil directly into the bearing clearance through a nozzle placed in a radial bore at the middle of the pad and connected to a high pressure supply unit by servovalves. The theoretical model is based on a finite element model, where the active TPJB with adjustable lubrication is included using...

  8. CrN–Ag nanocomposite coatings: Control of lubricant transport by diffusion barriers

    International Nuclear Information System (INIS)

    1-μm-thick self-lubricating CrN–Ag composite coatings containing 16 at.% Ag were deposited on Si substrates by reactive co-sputtering at Ts = 400 °C, and were covered with CrN cap layers with a columnar microstructure and a thickness d = 0–1000 nm. Vacuum annealing at Ta = 500 and 600 °C for 1 h causes Ag transport to the sample surface and the formation of Ag surface grains. Quantitative scanning electron microscopy and energy dispersive spectroscopy analyses show that increasing d from 0 to 10 to 100 nm for Ta = 500 °C leads to a decrease in the areal density of Ag surface grains from 0.86 to 0.45 to 0.04 μm−2, while their lateral size remains constant at 360 ± 60 nm. However, increasing Ta to 600 °C causes a doubling of the Ag grain size, and a 4–30 times larger overall Ag transport. These results are explained by kinetic barriers for Ag diffusion through the porous cap layer with a porosity that decreases with increasing d, resulting in an effective activation barrier for Ag transport that increases from 0.78 eV in the absence of a cap layer to 0.89 eV for d = 10 nm and 1.07 eV for d = 30 nm. Auger electron spectroscopy depth profile analyses of annealed layers reveal no detectable Ag within the CrN cap layer and a uniform depletion of the Ag reservoir throughout the composite coating thickness, indicating unhindered Ag transport within the composite. The overall results show that a CrN diffusion barrier cap layer is an effective approach to control Ag lubricant transport to the surface of CrN–Ag composite coatings. - Highlights: ► CrN–Ag composite coatings are capped with CrN diffusion barriers. ► Ag diffuses to the surface during annealing at 500 or 600 °C. ► The Ag transport is controlled by the cap thickness d = 0–1000 nm. ► The activation energy for Ag transport increases with increasing d.

  9. CrN-Ag nanocomposite coatings: Control of lubricant transport by diffusion barriers

    Energy Technology Data Exchange (ETDEWEB)

    Papi, P.A. [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Mulligan, C.P. [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); U.S. Army Armament Research Development and Engineering Center, Benet Laboratories, Watervliet, NY 12189 (United States); Gall, D., E-mail: galld@rpi.edu [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

    2012-12-01

    1-{mu}m-thick self-lubricating CrN-Ag composite coatings containing 16 at.% Ag were deposited on Si substrates by reactive co-sputtering at T{sub s} = 400 Degree-Sign C, and were covered with CrN cap layers with a columnar microstructure and a thickness d = 0-1000 nm. Vacuum annealing at T{sub a} = 500 and 600 Degree-Sign C for 1 h causes Ag transport to the sample surface and the formation of Ag surface grains. Quantitative scanning electron microscopy and energy dispersive spectroscopy analyses show that increasing d from 0 to 10 to 100 nm for T{sub a} = 500 Degree-Sign C leads to a decrease in the areal density of Ag surface grains from 0.86 to 0.45 to 0.04 {mu}m{sup -2}, while their lateral size remains constant at 360 {+-} 60 nm. However, increasing T{sub a} to 600 Degree-Sign C causes a doubling of the Ag grain size, and a 4-30 times larger overall Ag transport. These results are explained by kinetic barriers for Ag diffusion through the porous cap layer with a porosity that decreases with increasing d, resulting in an effective activation barrier for Ag transport that increases from 0.78 eV in the absence of a cap layer to 0.89 eV for d = 10 nm and 1.07 eV for d = 30 nm. Auger electron spectroscopy depth profile analyses of annealed layers reveal no detectable Ag within the CrN cap layer and a uniform depletion of the Ag reservoir throughout the composite coating thickness, indicating unhindered Ag transport within the composite. The overall results show that a CrN diffusion barrier cap layer is an effective approach to control Ag lubricant transport to the surface of CrN-Ag composite coatings. - Highlights: Black-Right-Pointing-Pointer CrN-Ag composite coatings are capped with CrN diffusion barriers. Black-Right-Pointing-Pointer Ag diffuses to the surface during annealing at 500 or 600 Degree-Sign C. Black-Right-Pointing-Pointer The Ag transport is controlled by the cap thickness d = 0-1000 nm. Black-Right-Pointing-Pointer The activation energy for Ag

  10. Lubrication background

    Science.gov (United States)

    Hamrock, B. J.; Dowson, D.

    1981-01-01

    Surface topography, including the various physical methods of measuring surfaces, and the various lubrication regimes (hydrodynamic, elastohydrodynamic, boundary, and mixed) are discussed. The historical development of elastohydrodynamic lubrication is outlined. The major accomplishments in four periods, the pre-1950's, the 1950's, the 1960's, and the 1970's are presented.

  11. Control of Nanoscale Friction on Gold in an Ionic Liquid by a Potential-Dependent Ionic Lubricant Layer

    Science.gov (United States)

    Sweeney, James; Hausen, Florian; Hayes, Robert; Webber, Grant B.; Endres, Frank; Rutland, Mark W.; Bennewitz, Roland; Atkin, Rob

    2012-10-01

    The lubricating properties of an ionic liquid on gold surfaces can be controlled through application of an electric potential to the sliding contact. A nanotribology approach has been used to study the frictional behavior of 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate ([Py1,4]FAP) confined between silica colloid probes or sharp silica tips and a Au(111) substrate using atomic force microscopy. Friction forces vary with potential because the composition of a confined ion layer between the two surfaces changes from cation-enriched (at negative potentials) to anion-enriched (at positive potentials). This offers a new approach to tuning frictional forces reversibly at the molecular level without changing the substrates, employing a self-replenishing boundary lubricant of low vapor pressure.

  12. Lubrication a practical guide to lubricant selection

    CERN Document Server

    Lansdown, A R

    1982-01-01

    Lubrication: A Practical Guide to Lubricant Selection provides a guide to modern lubrication practice in industry, with emphasis on practical application, selection of lubricants, and significant factors that determine suitability of a lubricant for a specific application. Organized into 13 chapters, this book begins with a brief theoretical opening chapter on the basic principles of lubrication. A chapter then explains the choice of lubricant type, indicating how to decide whether to use oil, grease, dry lubricant, or gas lubrication. Subsequent chapters deal with detailed selection of lubric

  13. Lubrication by glycoprotein brushes.

    Science.gov (United States)

    Zappone, Bruno; Ruths, Marina; Greene, George W.; Israelachvili, Jacob

    2006-03-01

    Grafted polyelectrolyte brushes show excellent lubricating properties under water and have been proposed as a model to study boundary lubrication in biological system. Lubricin, a glycoprotein of the synovial fluid, is considered the major boundary lubricant of articular joints. Using the Surface Force Apparatus, we have measured normal and friction forces between model surfaces (negatively charged mica, positively charged poly-lysine and aminothiol, hydrophobic alkanethiol) bearing adsorbed layers of lubricin. Lubricin layers acts like a versatile anti-adhesive, adsorbing on all the surfaces considered and creating a repulsion similar to the force between end-grafted polymer brushes. Analogies with polymer brushes also appear from bridging experiment, where proteins molecules are end-adsorbed on two opposing surfaces at the same time. Lubricin `brushes' show good lubricating ability at low applied pressures (P<0.5MPa), especially on negatively charged surfaces like mica. At higher load, the adsorbed layers wears and fails lubricating the surfaces, while still protecting the underlying substrate from wearing. Lubricin might thus be a first example of biological polyelectrolytes providing `brush-like' lubrication and wear-protection.

  14. Applied behavior analysis and statistical process control?

    OpenAIRE

    Hopkins, B. L.

    1995-01-01

    This paper examines Pfadt and Wheeler's (1995) suggestions that the methods of statistical process control (SPC) be incorporated into applied behavior analysis. The research strategies of SPC are examined and compared to those of applied behavior analysis. I argue that the statistical methods that are a part of SPC would likely reduce applied behavior analysts' intimate contacts with the problems with which they deal and would, therefore, likely yield poor treatment and research decisions. Ex...

  15. Applied Behavior Analysis and Statistical Process Control?

    Science.gov (United States)

    Hopkins, B. L.

    1995-01-01

    Incorporating statistical process control (SPC) methods into applied behavior analysis is discussed. It is claimed that SPC methods would likely reduce applied behavior analysts' intimate contacts with problems and would likely yield poor treatment and research decisions. Cases and data presented by Pfadt and Wheeler (1995) are cited as examples.…

  16. Adaptive Control Applied to Financial Market Data

    Czech Academy of Sciences Publication Activity Database

    Šindelář, Jan; Kárný, Miroslav

    Strasbourg cedex: European Science Foundation, 2007, s. 1-6. [Advanced Mathematical Methods for Finance. Vídeň (AT), 17.09.2007-22.09.2007] R&D Projects: GA MŠk(CZ) 2C06001 Institutional research plan: CEZ:AV0Z10750506 Keywords : bayesian statistics * portfolio optimization * finance * adaptive control Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2007/si/sindelar-adaptive control applied to financial market data.pdf

  17. Evaluating Solid-Lubricant Films

    Science.gov (United States)

    Fusaro, Robert L.

    1988-01-01

    Report describes experimental techniques for measuring properties of solid-lubricant films. Discusses experimental parameters. Reviews basic pin-on-disk configurations and methods of preparing disks and applying solid lubricants. Techniques for constant-temperature testing, low-contact-stress testing, and temperature-versus-time testing presented. Suggests methods of measuring pin-wear volume and recommends ways of presenting data.

  18. Developments in lubricant technology

    CERN Document Server

    Srivastava, S P

    2014-01-01

    Provides a fundamental understanding of lubricants and lubricant technology including emerging lubricants such as synthetic and environmentally friendly lubricants Teaches the reader to understand the role of technology involved in the manufacture of lubricants Details both major industrial oils and automotive oils for various engines Covers emerging lubricant technology such as synthetic and environmentally friendly lubricants Discusses lubricant blending technology, storage, re-refining and condition monitoring of lubricant in equipment

  19. Marine Lubricants

    Science.gov (United States)

    Carter, B. H.; Green, D.

    Marine diesel engines are classified by speed, either large (medium speed) or very large (slow speed) with high efficiencies and burning low-quality fuel. Slow-speed engines, up to 200 rpm, are two-stroke with separate combustion chamber and sump connected by a crosshead, with trunk and system oil lubricants for each. Medium-speed diesels, 300-1500 rpm, are of conventional automotive design with one lubricant. Slow-speed engines use heavy fuel oil of much lower quality than conventional diesel with problems of deposit cleanliness, acidity production and oxidation. Lubricants are mainly SAE 30/40/50 monogrades using paraffinic basestocks. The main types of additives are detergents/dispersants, antioxidants, corrosion inhibitors, anti-wear/load-carrying/ep, pour-point depressants and anti-foam compounds. There are no simple systems for classifying marine lubricants, as for automotive, because of the wide range of engine design, ratings and service applications they serve. There are no standard tests; lubricant suppliers use their own tests or the Bolnes 3DNL, with final proof from field tests. Frequent lubricant analyses safeguard engines and require standard sampling procedures before determination of density, viscosity, flash point, insolubles, base number, water and wear metal content.

  20. Adaptive Control Applied to Financial Market Data

    Czech Academy of Sciences Publication Activity Database

    Šindelář, Jan; Kárný, Miroslav

    Vol. I. Praha : Matfyz press, 2007, s. 1-6. ISBN 978-80-7378-023-4. [Week of Doctoral Students 2007. Praha (CZ), 05.06.2007-08.06.2007] R&D Projects: GA MŠk(CZ) 2C06001 Institutional research plan: CEZ:AV0Z10750506 Keywords : baysian statistics * finance * financial engineering * stochastic control Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2007/si/sindelar-adaptive control applied to financial market data.pdf

  1. Robust control applied to minimize NOx emissions

    OpenAIRE

    Nelson Gruel, Dominique; Chamaillard, Yann; Charlet, Alain; Colin, Guillaume

    2014-01-01

    — Legislation concerning pollutant emissions of diesel passenger cars is becoming increasingly restrictive, especially for nitrogen oxide (NOx) and particulate matter (PM). This article proposes to apply a CRONE control design methodology on a diesel engine in order to adapt the air-path and fuel-path of the engine and minimize NOx emissions. As the multivariable CRONE control strategies need a nominal transfer function and some frequency response of the system (G(s)), several test-bench expe...

  2. Computational Chemistry and Lubrication

    Science.gov (United States)

    Zehe, Michael J.

    1998-01-01

    Members of NASA Lewis Research Center's Tribology and Surface Science Branch are applying high-level computational chemistry techniques to the development of new lubrication systems for space applications and for future advanced aircraft engines. The next generation of gas turbine engines will require a liquid lubricant to function at temperatures in excess of 350 C in oxidizing environments. Conventional hydrocarbon-based lubricants are incapable of operating in these extreme environments, but a class of compounds known as the perfluoropolyether (PFAE) liquids (see the preceding illustration) shows promise for such applications. These commercially available products are already being used as lubricants in conditions where low vapor pressure and chemical stability are crucial, such as in satellite bearings and composite disk platters. At higher temperatures, however, these compounds undergo a decomposition process that is assisted (catalyzed) by metal and metal oxide bearing surfaces. This decomposition process severely limits the applicability of PFAE's at higher temperatures. A great deal of laboratory experimentation has revealed that the extent of fluid degradation depends on the chemical properties of the bearing surface materials. Lubrication engineers would like to understand the chemical breakdown mechanism to design a less vulnerable PFAE or to develop a chemical additive to block this degradation.

  3. Applied intelligent control of induction motor drives

    CERN Document Server

    Chan, Tze Fun

    2011-01-01

    Induction motors are the most important workhorses in industry. They are mostly used as constant-speed drives when fed from a voltage source of fixed frequency. Advent of advanced power electronic converters and powerful digital signal processors, however, has made possible the development of high performance, adjustable speed AC motor drives.This book aims to explore new areas of induction motor control based on artificial intelligence (AI) techniques in order to make the controller less sensitive to parameter changes. Selected AI techniques are applied for different induction motor control s.

  4. Control system design for flexible rotors supported by actively lubricated bearings

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2008-01-01

    and keeping the lengths of the two eigenvalues constant in the real-imaginary plane. The methodology is applied to an industrial gas compressor supported by active tilting-pad journal bearings. The unbalance response functions and mode shapes of the flexible rotor with and without active control are...... displacement and velocity of the shaft at the bearing positions....

  5. Applying vision feedback to crane controller design

    Science.gov (United States)

    Lee, Lun-Hui; Huang, Pei-Hsiang; Pan, Shing-Tai; Wijaya Lie, Handra; Chiang, Tung-Chien; Chang, Cheng-Yuan

    2015-01-01

    Encoders are generally used to track the motion of industrial mechanisms. However, the information obtained by encoders may have errors due to encoder aging or mechanism-design problem. Therefore, information by visual feedback is a better way to track the movement of industrial mechanisms. However, image information costs lots of computing effort so it is not easy to be used in real-time control applications. This manuscript derives a simple but effective visual feedback method to follow the target and the image information is obtained only by a general handy camcorder. Besides, the proposed method can track multi-locations in a meantime. Fast image pattern recognition and localisation of the colour histogram by using a moving tracking block is applied to increase the calculation speed. Finally, the obtained locations information by the proposed visual feedback method is applied in an industrial crane control system to verify the effectiveness.

  6. Controller modification applied for active fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob; Poulsen, Niels Kjølstad

    2014-01-01

    This paper is focusing on active fault detection (AFD) for parametric faults in closed-loop systems. This auxiliary input applied for the fault detection will also disturb the external output and consequently reduce the performance of the controller. Therefore, only small auxiliary inputs are used...... modify the feedback controller with a minor effect on the external output in the fault free case. Further, in the faulty case, the signature of the auxiliary input can be optimized. This is obtained by using a band-pass filter for the YJBK parameter that is only effective in a small frequency range where...... the frequency for the auxiliary input is selected. This gives that it is possible to apply an auxiliary input with a reduced amplitude. An example is included to show the results....

  7. Chaos control applied to heart rhythm dynamics

    International Nuclear Information System (INIS)

    Highlights: → A natural cardiac pacemaker is modeled by a modified Van der Pol oscillator. → Responses related to normal and chaotic, pathological functioning of the heart are investigated. → Chaos control methods are applied to avoid pathological behaviors of heart dynamics. → Different approaches are treated: stabilization of unstable periodic orbits and chaos suppression. - Abstract: The dynamics of cardiovascular rhythms have been widely studied due to the key aspects of the heart in the physiology of living beings. Cardiac rhythms can be either periodic or chaotic, being respectively related to normal and pathological physiological functioning. In this regard, chaos control methods may be useful to promote the stabilization of unstable periodic orbits using small perturbations. In this article, the extended time-delayed feedback control method is applied to a natural cardiac pacemaker described by a mathematical model. The model consists of a modified Van der Pol equation that reproduces the behavior of this pacemaker. Results show the ability of the chaos control strategy to control the system response performing either the stabilization of unstable periodic orbits or the suppression of chaotic response, avoiding behaviors associated with critical cardiac pathologies.

  8. Chaos control applied to heart rhythm dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Borem Ferreira, Bianca, E-mail: biaborem@gmail.com [Universidade Federal do Rio de Janeiro, COPPE, Department of Mechanical Engineering, P.O. Box 68.503, 21.941.972 Rio de Janeiro, RJ (Brazil); Souza de Paula, Aline, E-mail: alinedepaula@unb.br [Universidade de Brasi' lia, Department of Mechanical Engineering, 70.910.900 Brasilia, DF (Brazil); Amorim Savi, Marcelo, E-mail: savi@mecanica.ufrj.br [Universidade Federal do Rio de Janeiro, COPPE, Department of Mechanical Engineering, P.O. Box 68.503, 21.941.972 Rio de Janeiro, RJ (Brazil)

    2011-08-15

    Highlights: > A natural cardiac pacemaker is modeled by a modified Van der Pol oscillator. > Responses related to normal and chaotic, pathological functioning of the heart are investigated. > Chaos control methods are applied to avoid pathological behaviors of heart dynamics. > Different approaches are treated: stabilization of unstable periodic orbits and chaos suppression. - Abstract: The dynamics of cardiovascular rhythms have been widely studied due to the key aspects of the heart in the physiology of living beings. Cardiac rhythms can be either periodic or chaotic, being respectively related to normal and pathological physiological functioning. In this regard, chaos control methods may be useful to promote the stabilization of unstable periodic orbits using small perturbations. In this article, the extended time-delayed feedback control method is applied to a natural cardiac pacemaker described by a mathematical model. The model consists of a modified Van der Pol equation that reproduces the behavior of this pacemaker. Results show the ability of the chaos control strategy to control the system response performing either the stabilization of unstable periodic orbits or the suppression of chaotic response, avoiding behaviors associated with critical cardiac pathologies.

  9. Steady state characteristics of a tilting pad journal bearing with controllable lubrication: Comparison between theoretical and experimental results

    DEFF Research Database (Denmark)

    Cerda Varela, Alejandro Javier; Nielsen, Bo Bjerregaard; Santos, Ilmar

    2013-01-01

    direction. The modification of the injection pressure enables to modify the bearing static and dynamic properties according to the operational needs. The results presented are obtained using a theoretical model, which considers all the effects that determine the bearing behavior (controllable......This paper is aimed at presenting results regarding the static and thermal behavior of a tilting-pad journal bearing operating under controllable regime. The bearing is rendered controllable by injecting high pressure oil into the clearance using holes drilled across the bearing pads in the radial...... elastothermohydrodynamic lubrication regime), as well as using a test rig designed and built to this effect. The comparison between experimental and theoretical results provides solid ground to determine the accuracy of the available model for the the prediction of the steady-state behavior of the tilting-pad bearing with...

  10. Fluid film force control in lubricated journal bearings by means of a travelling wave generated with a piezoelectric actuators' system

    Science.gov (United States)

    Iula, Antonio; Lamberti, Nicola; Savoia, Alessandro; Caliano, Giosue

    2012-05-01

    In this work an experimental evaluation of the possiblity to influence and control the fluid film forces in the gap of a lubricated journal bearing by means of a rotating travelling wave is carried out. The travellig wave is generated by two power actuators opportunely positioned on the outer surface of the bearing and electrically driven with a phase shift of 90°. Each transducer is designed to work at the natural frequency of the radial nonaxisymmetrical mode 0-5 (23.6 kHz). Experimental results show that the travelling wave is capable to control the motion of an oil drop on the inner surface of the bearing and that it is capable to put in rotation a rotor layed on the drop oil via the viscous forces in the oil drop itself.

  11. Aviation Lubricants

    Science.gov (United States)

    Lansdown, A. R.; Lee, S.

    Aviation lubricants must be extremely reliable, withstand high specific loadings and extreme environmental conditions within short times. Requirements are critical. Piston engines increasingly use multi-grade oils, single grades are still used extensively, with anti-wear and anti-corrosion additives for some classes of engines. The main gas turbine lubricant problem is transient heat exposure, the main base oils used are synthetic polyol esters which minimise thermal degradation. Aminic anti-oxidants are used together with anti-wear/load-carrying, corrosion inhibitor and anti-foam additives. The majority of formulation viscosities are 5 cSt at 100°C. Other considerations are seal compatibility and coking tendency.

  12. Vibration active control of tilting pad journal bearing rotor system based on the active lubrication%基于主动润滑可倾瓦轴承转子系统的振动主动控制

    Institute of Scientific and Technical Information of China (English)

    刘宏; 宫晓春; 王晋麟

    2011-01-01

    研究一类可倾瓦支承的单盘非对称转子系统的振动主动控制问题.首先建立了系统的非线性动力学方程,针对主动润滑控制系统设计了BP神经网络PID控制器对转子系统进行振动主动控制.通过计算分析可知,采用基于BP-PID的主动润滑系统能够很好的抑制系统的振幅,使系统在很高的转速时才发生油膜失稳,拓宽转子系统稳定运转的转速范围,在转子系统发生油膜失稳时系统的振幅也能够得到极大程度的控制.%The vibration active control of an unsymmetrical rotor supported by two tilting pad journal bearings is investigated in this paper. Firstly, the nonlinear governing equation of the rotor system is formulated. Then the BP neural network PID controller is designed with regard to the active lubricated control system is applied to suppress the vibration of the concerning rotor system. After calculation and analysis the persuasive results are obtained. The vibration amplitude of the rotor system is greatly reduced by means of the active lubricated control system through the BP neural network PID controller. The whip instability of the controlled system occurs at a very high rotational speed and the stable operation range is greatly broadened. The vibration amplitude can be significantly suppressed by the active lubricated control system when the rotor runs up against the whip instability.

  13. Lubricant composition

    International Nuclear Information System (INIS)

    Lubricating compositions and shaped articles composed thereof are described which consist essentially of about 30 to about 60% by weight of an oil of lubricating viscosity, about 20 to about 50% by weight of a high molecular weight polymer, and about 20 about 50% by weight of a heat conductive agent capable of conducting heat away from a bearing surface where it is generated. The high molecular weight polymer may, for example, be polyethylene, having average molecular weights in the range from about 1.0 X 105 to about 5.0 X 106. The oil may be a mineral oil, a diester oil or preferably a synthetic hydrocarbon oil having a viscosity in the range from about 13 to about 1200 mm''/s (Mm2/s) at 380C. (1000F.) the heat conductive agent may be powdered zinc oxide, aluminum powder, or equivalents thereof in this invention. The compositions are semi-rigid gels which may be formed in a mold and used as is, or which may be shaped further after molding. The gels are formed by blending the heat conductive agent and polymer and then blending that mixture with the oil and heating to a temperature above the softening temperature of the polymer for a period of time (About 5 to about 75 minutes) sufficient that the mixture will form a firm, tough solid gel on cooling having an oily surface provided by oil exuding from the gel thus producing a lubricative mass operable for extended periods of time. The heat conductive substance dispersed in the gel aids in dissipating heat produced at the bearing surfaces during use thus improving the performance of the gel both in withstanding higher bulk operating temperatures and in resisting breakdown of the gel under prolonged use

  14. Limits of Lubrication in

    DEFF Research Database (Denmark)

    Olsson, David Dam

    Strategic stainless steel surfaces have been developed and investigated during the project in close cooperation with the Department of Chemistry, DTU with the purpose of enhancing the tribological properties. This has been achieved successfully by applying electrochemical treatments of normal as...... delivered stainless steel surfaces implying microstructure changes in terms of larger ratio of closed lubricant pockets due to selective grain boundary etching. Strategic surfaces have also been created by macroscopic texturing using spherical indentations having a very small edge slope in order to promote...... using plain mineral oil is possible without any lubricant breakdown. In deep drawing, 2mm stainless steel blanks can be drawn to drawing ratio of DR=2.0 over a die entry radius of rd=3mm again using a plain mineral oil containing no additives. In stretch forming, friction is reduced considerably by...

  15. Robustness analysis applied to substructure controller synthesis

    Science.gov (United States)

    Gonzalez-Oberdoerffer, Marcelo F.; Craig, Roy R., Jr.

    1993-01-01

    The stability and robustness of the controlled system obtained via the substructure control synthesis (SCS) method of Su et al. (1990) were examined using a six-bay truss model, and employing an LQG control design method to obtain controllers for two separate structures. It is found that the assembled controller provides a stability in this instance. A qualitative assessment of the stability robustness of the system with controller designed with the SCS method is provided by obtaining a controller using the complete truss model and comparing the robustness of the corresponding closed-loop systems.

  16. Experimental study and modelling of mixed particulate lubrication with MoS2 powder solid lubricant

    Directory of Open Access Journals (Sweden)

    H. Wiśniewska-Weinert

    2011-12-01

    Full Text Available Purpose: The purpose of the paper is experimental study and modelling of mixed particulate lubrication with MoS2 powder solid lubricant.Design/methodology/approach: In the present investigation, ball-on-disc experiments were carried out to determine the lubrication performance of MoS2 solid lubricant powder that could be used for hard PVD coatings applied for forging and stamping tools.Findings: The proposed solid lubricant nano- and submicroparticles mixture demonstrates excellent potential for use in mixed lubrication regimes The quasi-hydrodynamic behaviour of solid lubricant and wear debris particles results in low friction coefficients of hard coating – steel ball friction pairs.Research limitations/implications: The solid lubricant particle exfoliation and formation of tribofilms on micro-asperities allow to achieve the boundary lubrication effects which is found to more preferable for steel contacts rather than for hard coatings.Originality/value: The model of mixed lubrication based on non Newtonian behaviour of powder solid lubricant was validated based on the experimental results. Results of calculation of Stribeck curves demonstrate the potential of modelling of friction process by sharing boundary and quasi-hydrodynamic processes.

  17. Optical Imaging of Water Condensation on Lubricant Impregnated Micropillar Arrays

    Science.gov (United States)

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2015-11-01

    We explored the condensation of water drops on a lubricant-impregnated surface, i.e., a micropillar patterned surface impregnated with a ionic liquid. Growing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. On a lubricant-impregnated hydrophobic micropillar array, different stages of condensation can be discriminated: - Nucleation on a lubricant surface. - Regular alignement between micropillars and formation of a three-phase contact line on a bottom of the substrate. - Deformation and bridging by coalescence, leading to a detachment of the drops from the bottom substrate to pillars'top faces. However, on a lubricant-impregnated hydrophilic micropillar array, the condensed water covers the micropillars by dewetting the lubricant. As a result, the surface loses its slippery property. Our results provide fundamental concepts how these solid/liquid hybrid surfaces can be applied for facile removal of condensed water, as well as necessity of the appropriate surface treatment. Financial support from ERC for the advanced grant 340391-SUPRO is gratefully acknowledged.

  18. 航空发动机滑油泵试验台测控系统设计与实现%Design and Realization of Measurement and Control System for Aero-engine Lubricating Oil Pump Test-bed

    Institute of Scientific and Technical Information of China (English)

    尹飞佳; 樊丁; 缑林峰; 彭凯

    2011-01-01

    According to the function and requirement of measurement and control system of aero - engine lubrication system test - bed, a new measurement and control system for lubricating oil pump test - bed was designed based on PLC hardware device and iFIX software. Active X technology was used to develop special control library applied to this system. Moreover, FIR filter was designed to improve the data accuracy. The application shows the system runs stably, operates easily and has friendly interface. It has achieved design requirements.%根据航空发动机滑油泵试验台的功能及要求,设计了基于PLC硬件系统和iFIX监控软件的滑油泵试验台测控系统;应用Active X控件开发技术,在Visual Basic 6.0环境下开发适用于本系统的控件库;同时引入FIR数字滤波器,对采集的信号进行滤波,以提高数据的准确度;试验台的调试运行表明,该系统可靠、稳定,操作简便,达到了设计要求.

  19. Solid lubrication technology of HTGR under helium

    International Nuclear Information System (INIS)

    Because Helium is used as coolant in High Temperature Gas-cooled Reactor (HTGR), the change of tribological properties of HTGR structure component under Helium is a big problem. Under Helium, tribological properties of material becomes worse and fluid lubrication can not be used. Bonded solid lubrication film and fusion sintering solid film are used in control rod and can solve the tribological problem well. Methods of replenishment solid lubricant are discussed for continuously operating friction components. The necessity and possibility for solid lubrication film used in Helium fan is also discussed

  20. Applying GPS to check horizontal control quality

    OpenAIRE

    Jakub Vincent; Weiss Gabriel; Sabová Jana

    2004-01-01

    GPS technologies can also be used for check quality in available horizontal point set with coordinates CJ of the frame S-JTSK. When survey and setting-out tasks should be performed in certain area, one can found in it allways some points of the fundamental and detail state controls. To use these points for some actual aims, it is necessary to investigate their compatibility (among the point mark positions and the point coordinate of control points). This can be done using GPS surveying that m...

  1. Elasto-hydrodynamic lubrication

    CERN Document Server

    Dowson, D; Hopkins, D W

    1977-01-01

    Elasto-Hydrodynamic Lubrication deals with the mechanism of elasto-hydrodynamic lubrication, that is, the lubrication regime in operation over the small areas where machine components are in nominal point or line contact. The lubrication of rigid contacts is discussed, along with the effects of high pressure on the lubricant and bounding solids. The governing equations for the solution of elasto-hydrodynamic problems are presented.Comprised of 13 chapters, this volume begins with an overview of elasto-hydrodynamic lubrication and representation of contacts by cylinders, followed by a discussio

  2. Applying interactive control to waste processing operations

    International Nuclear Information System (INIS)

    At present waste and residue processing includes steps that require human interaction. The risk of exposure to unknown hazardous materials and the potential for radiation contamination motivates the desire to remove operators from these processes. Technologies that facilitate this include glove box robotics, modular systems for remote and automated servicing, and interactive controls that minimize human intervention. LLNL is developing an automated system which is designed to supplant the operator for glove box tasks, thus protecting the operator from the risk of radiation exposure and minimizing operator-associated waste. Although most of the processing can be automated with minimal human interaction, there are some tasks where intelligent intervention is both desirable and necessary to adapt to Enexpected circumstances and events. These activities require that the operator interact with the process using a remote manipulator which provides or reflects a natural feel to the operator. The remote manipulation system which was developed incorporates sensor fusion and interactive control, and provides the operator with an effective means of controlling the robot in a potentially unknown environment. This paper describes recent accomplishments in technology development and integration, and outlines the future goals of Lawrence Livermore National Laboratory for achieving this integrated interactive control capability

  3. Control System Design for Active Lubrication with Theoretical and Experimental Examples

    DEFF Research Database (Denmark)

    Santos, Ilmar; Scalabrin, A.

    2003-01-01

    This work focuses on the theoretical and experimental behavior of rigid rotors controlled by tilting-pad journal bearings with active oil injection. Initially the mathematical model of the active bearing is presented: The equations that describe the dynamics of hydraulic actuators are introduced...... the control system of the active bearing based on root locus curves. The active system stability is analyzed by calculating its eigenvalues and frequency response curves. The theoretical and experimental results show that this kind of bearing can significantly reduce the vibration level of rotating...

  4. Active Lubrication for Reducing Wear and Vibration: A combination of Fluid Power Control and Tribology

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2002-01-01

    The use of fluid power to reduce and control rotor vibration in rotating machines is investigated. An active hybrid bearing is studied, whose main objective is to reduce wear and vibration between rotating and stationary machinery parts. By injecting pressurised oil into the oil film, through...

  5. Applied optimal control theory of distributed systems

    CERN Document Server

    Lurie, K A

    1993-01-01

    This book represents an extended and substantially revised version of my earlierbook, Optimal Control in Problems ofMathematical Physics,originally published in Russian in 1975. About 60% of the text has been completely revised and major additions have been included which have produced a practically new text. My aim was to modernize the presentation but also to preserve the original results, some of which are little known to a Western reader. The idea of composites, which is the core of the modern theory of optimization, was initiated in the early seventies. The reader will find here its implementation in the problem of optimal conductivity distribution in an MHD-generatorchannel flow.Sincethen it has emergedinto an extensive theory which is undergoing a continuous development. The book does not pretend to be a textbook, neither does it offer a systematic presentation of the theory. Rather, it reflects a concept which I consider as fundamental in the modern approach to optimization of dis­ tributed systems. ...

  6. Solid Lubricant For Alumina

    Science.gov (United States)

    Dellacorte, Christopher; Pepper, Stephen V.; Honecy, Frank S.

    1993-01-01

    Outer layer of silver lubricates, while intermediate layer of titanium ensures adhesion. Lubricating outer films of silver deposited on thin intermediate films of titanium on alumina substrates found to reduce sliding friction and wear. Films provide effective lubrication for ceramic seals, bearings, and other hot sliding components in advanced high-temperature engines.

  7. From Hybrid to Actively-Controlled Gas Lubricated Bearings – Theory and Experiment

    DEFF Research Database (Denmark)

    Morosi, Stefano

    bearings, tilting pad and flexure pivot gas bearings. These solutions proved to be effective in improving static and dynamic properties of the bearings, however issues related to the manufacturing and accuracy of predictions has so far limited their applications. Another drawback is that passive bearings...... determined by the appearance of subsynchronous whirl instability. In fact, postponing the onset speed of instability poses one of the greatest challenges in high-speed gas bearing design. A great deal of research is devoted to attack such issues, where most propose passive designs such as compliant foil...... offer a low degree of robustness, meaning that an accurate optimization is necessary for each application. Another way of improving gas bearings operation performance is by using active control systems, transforming conventional gas bearings in an electro-mechanical machine component. In this framework...

  8. Lubrication in Hot Tube Extrusion of Superalloys and Ti Alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tubular products made of superalloys and titanium alloys usually work in high temperature environment and applied heavy loading. Hot extrusion is the best technology to form tubular billets with fine microstructures and good mechanical properties. Lubrication is one of the key techniques in hot extrusion, glass lubricants are most suitable for hot extrusion. Lubrication technique in hot extrusion is dealt with in this paper, the lubrication principle of hot tube extrusion is presented. Experiments of glass lubricated backward tube extrusion of titanium alloys and forward tube extrusion of superalloys are also discussed.

  9. Molecular dynamics evidence of a three-term kinetic friction law for mixed- and boundary-lubricated nanotribological systems

    International Nuclear Information System (INIS)

    In this work a three-term kinetic friction law at nanoscale is proposed and proven to hold. It includes the Amontons-Coulomb term describing the load-controlled contribution and the Bowden-Tabor term providing the adhesion-controlled contribution to the friction force, as well as the load-independent Derjaguin-offset ascribed to adhesion in the lubricant. The proposed law can reproduce the non-linearities and discontinuities in the load-vs.-friction behavior commonly encountered when shearing atomistic tribological systems under mixed lubrication conditions. The solid-solid contact area occurring between two rough solid surfaces when the lubrication film fails is calculated using a self-developed smooth particle approach (SPM) which allows one to map the discrete data obtained from molecular dynamics (MD) simulations to continuum. This MD+SPM method is successfully applied to analyze the run-in period of nanotribological systems exhibiting strong solid-solid contact at the beginning and almost none at the end. Furthermore, an attempt is made to relate the Derjaguin-offset in boundary lubricated systems without solid-solid contact to the degree of disorder in the lubricant, which is quantified by its configurational entropy and estimated using the single macromolecule approach based on covariance (super)matrices of the carbon backbone atoms in the lubricant. The main finding of this work is that the coefficient of friction loses its macroscopic meaning, i.e., it cannot be identified with the friction force per applied load as the lubrication gap thickness decreases to a few monolayers of lubricant molecules, which eventually may lead to lubricant failure and subsequent solid-solid contact. However, the coefficient of friction, effective shear strength, and Derjaguin-offset following from the proposed three-term kinetic friction law constitute the three load-independent system parameters which uniquely characterize the tribological response of nanosystems. (author)

  10. Linear and Nonlinear Controllers Applied to Fixed-Wing UAV

    Directory of Open Access Journals (Sweden)

    Tadeo Espinoza

    2013-01-01

    Full Text Available This article presents a comparison of controllers which have been applied to a fixed‐wing Unmanned Aerial Vehicle (UAV. The comparison is realized between classical linear controllers and nonlinear control laws. The concerned linear controllers are: Proportional‐ Derivative (PD and Proportional‐Integral‐Derivative (PID, while the nonlinear controllers are: backstepping, sliding modes, nested saturation and fuzzy control. These controllers are compared and analysed for altitude, yaw and roll by using simulation tests.

  11. Linear and Nonlinear Controllers Applied to Fixed-Wing UAV

    OpenAIRE

    Tadeo Espinoza; Alejandro Dzul; Miguel Llama

    2013-01-01

    This article presents a comparison of controllers which have been applied to a fixed‐wing Unmanned Aerial Vehicle (UAV). The comparison is realized between classical linear controllers and nonlinear control laws. The concerned linear controllers are: Proportional‐ Derivative (PD) and Proportional‐Integral‐Derivative (PID), while the nonlinear controllers are: backstepping, sliding modes, nested saturation and fuzzy control. These controllers are compared and analysed for altitude, yaw and rol...

  12. Ultrasonic monitoring of lubricating conditions of hydrodynamic bearing

    International Nuclear Information System (INIS)

    The performance of a hydrodynamic bearing is illustrated by the lubricating conditions which transfer from ones to another when working condition is changed. The thickness of lubricant film is the key parameter of lubricating conditions. The lubricating conditions of hydrodynamic bearing can be monitored by the measured film thickness and the relationship between them. For thin lubricant film layers less than ultrasonic wavelength, the spring model method is applied to measure the film thickness. The proportion of the ultrasound reflected from film layer, depended on the film stiffness, is determined and then can be readily converted to the film thickness. For the thicker films ranging from several microns to tens microns, ultrasonic resonance method was employed. An adaptive measurement algorithm is presented to automatically choice appropriate ultrasonic measurement method according to the different lubricating stage. All the range of lubricant film thickness of a hydrodynamic bearing can then be measured by the automatic selection of spring model and resonance methods. Simulation device of lubricant film layers with PZT positioning stage is designed to verify the accuracy of the adaptive measurement algorithm. Hydrodynamic bearing experimental setup is used to generate varies of lubricating condition by changing the shaft speed, radial direction loading force, and lubricant temperature. The lubricating condition of hydrodynamic bearing is then evaluated according to the measured lubricant film thickness and the working conditions.

  13. Intelligent control schemes applied to Automatic Generation Control

    Directory of Open Access Journals (Sweden)

    Dingguo Chen

    2016-04-01

    Full Text Available Integrating ever increasing amount of renewable generating resources to interconnected power systems has created new challenges to the safety and reliability of today‟s power grids and posed new questions to be answered in the power system modeling, analysis and control. Automatic Generation Control (AGC must be extended to be able to accommodate the control of renewable generating assets. In addition, AGC is mandated to operate in accordance with the NERC‟s Control Performance Standard (CPS criteria, which represent a greater flexibility in relaxing the control of generating resources and yet assuring the stability and reliability of interconnected power systems when each balancing authority operates in full compliance. Enhancements in several aspects to the traditional AGC must be made in order to meet the aforementioned challenges. It is the intention of this paper to provide a systematic, mathematical formulation for AGC as a first attempt in the context of meeting the NERC CPS requirements and integrating renewable generating assets, which has not been seen reported in the literature to the best knowledge of the authors. Furthermore, this paper proposes neural network based predictive control schemes for AGC. The proposed controller is capable of handling complicated nonlinear dynamics in comparison with the conventional Proportional Integral (PI controller which is typically most effective to handle linear dynamics. The neural controller is designed in such a way that it has the capability of controlling the system generation in the relaxed manner so the ACE is controlled to a desired range instead of driving it to zero which would otherwise increase the control effort and cost; and most importantly the resulting system control performance meets the NERC CPS requirements and/or the NERC Balancing Authority’s ACE Limit (BAAL compliance requirements whichever are applicable.

  14. Evaluation of Controller Tuning Methods Applied to Distillation Column Control

    DEFF Research Database (Denmark)

    Nielsen, Kim; W. Andersen, Henrik; Kümmel, Professor Mogens;

    1998-01-01

    A frequency domain approach is used to compare the nominal performance and robustness of dual composition distillation column control tuned according to Ziegler-Nichols (ZN) and Biggest Log Modulus Tuning (BLT) for three binary distillation columns, WOBE, LUVI and TOFA. The scope of this is to...... examine whether ZN and BLT design yield satisfactory control of distillation columns. Further, PI controllers are tuned according to a proposed multivariable frequency domain method. A major conclusion is that the ZN tuned controllers yield undesired overshoot and oscillation and poor stability robustness...

  15. Oscillating system design applying universal formula for control

    OpenAIRE

    Efimov, Denis; Perruquetti, Wilfrid

    2011-01-01

    The problem of oscillating system design applying the homogeneity approach is studied. The Anti-control Lyapunov Function (ALF) is introduced as a counterpart of Control Lyapunov Function (CLF) for the control design that destabilizes a nonlinear system. A universal anti-control formula is proposed. Next, the universal control formulas based on ALF and CLF are used to design an oscillating system. Efficiency of the proposed approach is demonstrated on example.

  16. Applying Statistical Process Control to Clinical Data: An Illustration.

    Science.gov (United States)

    Pfadt, Al; And Others

    1992-01-01

    Principles of statistical process control are applied to a clinical setting through the use of control charts to detect changes, as part of treatment planning and clinical decision-making processes. The logic of control chart analysis is derived from principles of statistical inference. Sample charts offer examples of evaluating baselines and…

  17. Research on Applying Bluetooth to an Elevator Wireless Control System

    Institute of Scientific and Technical Information of China (English)

    MA Jian-cang; LUO Ya-jun; ZHAO Yu-ting

    2003-01-01

    Compared with other elevator control systems, the wireless control system has many advanta ges such as easy to install and maintain. Bluetooth is a new technology of short-range wireless communication, and the idea of applying Bluetooth to the elevator wireless control system is expected to get wide application. In this paper, a wireless control prototype system is introduced, and the experimentsof this system proved the feasibility of this idea.

  18. Design of lubricating equipment of stud hole's threads of reactor pressure vessel

    International Nuclear Information System (INIS)

    It is determined that lubrication method of reactor pressure vessel (RPV) stud hole's thread is brushing lubrication by flow test of N5000 grease. The basic requirements of RPV stud hole's thread lubrication are all-surface and uniformity of greasing. The RPV stud hole lubricating machine is mainly composed of control panel, cable hanging device, automatic trolley and lubricating device. The lubricating device is the key part of RPV stud hole lubricating machine, therefore, the structure and principle of lubricating device are described. Besides, its operating principle, technical characteristics and design features are briefly described. During refuelling and repairing of No.1 unit of Daya Bay Nuclear Power Plant RPV, stud hole's lubricating machine are practically used. The practical using of RPV stud hole's lubricating machine proved that its all technical characteristics and functions have already met requirements of technical specification of the proprietor

  19. CALCIUM SOAP LUBRICANTS

    OpenAIRE

    Alaz, Izer; Tugce, Nefise; Devrim, Balköse

    2014-01-01

    The article studies the properties of calcium stearate (CaSt2) and lubricants produced on its basis. These lubricants were prepared using sodium stearate and calcium chloride by subsidence from aqueous solutions. The CaSt2 and the light fraction of crude oil were mixed together to obtain lubricating substances. The article shows that CaSt2 had the melting temperature of 142.8 C that is higher than the melting temperature of crude oil (128 C). The compositions of obtained lubricants were stu...

  20. Grease lubrication in rolling bearings

    CERN Document Server

    Lugt, Piet M

    2012-01-01

    The definitive book on the science of grease lubrication for roller and needle bearings in industrial and vehicle engineering. Grease Lubrication in Rolling Bearings provides an overview of the existing knowledge on the various aspects of grease lubrication (including lubrication systems) and the state of the art models that exist today. The book reviews the physical and chemical aspects of grease lubrication, primarily directed towards lubrication of rolling bearings. The first part of the book covers grease composition, properties and rheology, including thermal

  1. Finite element models applied in active structural acoustic control

    NARCIS (Netherlands)

    Oude Nijhuis, Marco H.H.; Boer, de André; Rao, Vittal S.

    2002-01-01

    This paper discusses the modeling of systems for active structural acoustic control. The finite element method is applied to model structures including the dynamics of piezoelectric sensors and actuators. A model reduction technique is presented to make the finite element model suitable for controll

  2. Frequency Response Analysis of an Actively Lubricated Rotor/Tilting-Pad Bearing System

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2004-01-01

    In the present paper, the dynamic response of a rotor supported by an active lubricated tilting-pad bearing is investigated in the frequency domain. The theoretical part of the investigation is based on a mathematical model obtained by means of rigid body dynamics. The oil film forces are inserted...... lubricated tilting-pad bearing. By applying a simple proportional controller, it is possible to reach 30% reduction of the resonance peak associated with the first rigid body mode shape of the system. One of the most important consequences of such a vibration reduction in rotating machines is the feasibility...

  3. Frequency Response Analysis of an Actively Lubricated Rotor/Tilting-Pad Bearing System

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2005-01-01

    In the present paper the dynamic response of a rotor supported by an active lubricated tilting-pad bearing is investigated in the frequency domain. The theoretical part of the investigation is based on a mathematical model obtained by means of rigid body dynamics. The oil film forces are inserted...... active lubricated tilting-pad bearing. By applying a simple proportional controller it is possible to reach 30% reduction of the resonance peak associated with the first rigid body mode shape of the system. One of the most important consequences of such a vibration reduction in rotating machines is the...

  4. Statistical modeling of bowing control applied to violin sound synthesis

    OpenAIRE

    Maestre E.; Blaauw M.; Bonada J.; Guaus E.; Perez A.

    2010-01-01

    Excitation-continuous music instrument control patterns are often not explicitly represented in current sound synthesis techniques when applied to automatic performance. Both physical model-based and sample-based synthesis paradigms would benefit from a flexible and accurate instrument control model, enabling the improvement of naturalness and realism. We present a framework for modeling bowing control parameters in violin performance. Nearly non-intrusive sensing techniques allow fo...

  5. Metal forming and lubrication

    DEFF Research Database (Denmark)

    Bay, Niels

    2000-01-01

    Lubrication is essential in most metal forming processes. The lubricant film has two basic functions, [1]: i. to separate the work piece and tool surfaces and ii. to cool the workpiece and the tool. Separation of the two surfaces implies lower friction facilitating deformation and lowering the tool...

  6. Adaptive Control Using Residual Mode Filters Applied to Wind Turbines

    Science.gov (United States)

    Frost, Susan A.; Balas, Mark J.

    2011-01-01

    Many dynamic systems containing a large number of modes can benefit from adaptive control techniques, which are well suited to applications that have unknown parameters and poorly known operating conditions. In this paper, we focus on a model reference direct adaptive control approach that has been extended to handle adaptive rejection of persistent disturbances. We extend this adaptive control theory to accommodate problematic modal subsystems of a plant that inhibit the adaptive controller by causing the open-loop plant to be non-minimum phase. We will augment the adaptive controller using a Residual Mode Filter (RMF) to compensate for problematic modal subsystems, thereby allowing the system to satisfy the requirements for the adaptive controller to have guaranteed convergence and bounded gains. We apply these theoretical results to design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed wind turbine that has minimum phase zeros.

  7. Finite element models applied in active structural acoustic control

    OpenAIRE

    Oude Nijhuis, Marco H.H.; de Boer; Rao, Vittal S.

    2002-01-01

    This paper discusses the modeling of systems for active structural acoustic control. The finite element method is applied to model structures including the dynamics of piezoelectric sensors and actuators. A model reduction technique is presented to make the finite element model suitable for controller design. The reduced structural model is combined with an acoustic model which uses the radiation mode concept. For a test case consisting of a rectangular plate with one piezo patch the model re...

  8. Sub-LSB DAC resolution enhancement applied to LLRF control.

    CERN Document Server

    Grecki, M

    2010-01-01

    The digital control systems use the ADCs/DACs as a front-end for analogue signals processing. The paper proposes the solution to enhance the DAC resolution by PWM. The modulation scheme is optimized to the parameters of of LLRF control in FLASH accelerator. For that purpose the genetic algorithm was implemented and applied. The distributed computing was used to speed-up the computations.

  9. Dairy Equipment Lubrication

    Science.gov (United States)

    1978-01-01

    Lake To Lake Dairy Cooperative, Manitowoc, Wisconsin, operates four plants in Wisconsin for processing milk, butter and cheese products from its 1,300 member farms. The large co-op was able to realize substantial savings by using NASA information for improved efficiency in plant maintenance. Under contract to Marshall Space Flight Center, Midwest Research Institute compiled a handbook consolidating information about commercially available lubricants. The handbook details chemical and physical properties, applications, specifications, test procedures and test data for liquid and solid lubricants. Lake To Lake's plant engineer used the handbook to effect savings in maintenance labor and materials costs by reducing the number of lubricants used on certain equipment. Strict U.S. Department of Agriculture and Food and Drug Administration regulations preclude lubrication changes n production equipment, but the co-op's maintenance chief was able to eliminate seven types of lubricants for ancillary equipment, such as compressors and high pressure pumps. Handbook data enabled him to select comparable but les expensive lubricants in the materials consolidation process, and simplified lubrication schedules and procedures. The handbook is in continuing use as a reference source when a new item of equipment is purchased.

  10. Human-Machine Systems concepts applied to Control Engineering Education

    OpenAIRE

    Marangé, Pascale; Gellot, François; Riera, Bernard

    2008-01-01

    In this paper, we interest us to Human-Machine Systems (HMS) concepts applied to Education. It is shown how the HMS framework enables to propose original solution in matter of education in the field of control engineering. We focus on practical courses on control of manufacturing systems. The proposed solution is based on an original use of real and large-scale systems instead of simulation. The main idea is to enable the student, whatever his/her level to control the whole system, from novic...

  11. Predictive control applied to an evaporator mathematical model

    Directory of Open Access Journals (Sweden)

    Daniel Alonso Giraldo Giraldo

    2010-07-01

    Full Text Available This paper outlines designing a predictive control model (PCM applied to a mathematical model of a falling film evaporator with mechanical steam compression like those used in the dairy industry. The controller was designed using the Connoisseur software package and data gathered from the simulation of a non-linear mathematical model. A control law was obtained from minimising a cost function sublect to dynamic system constraints, using a quadratic programme (QP algorithm. A linear programming (LP algorithm was used for finding a sub-optimal operation point for the process in stationary state.

  12. Advanced lubrication systems and materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, S.

    1998-05-07

    This report described the work conducted at the National Institute of Standards and Technology under an interagency agreement signed in September 1992 between DOE and NIST for 5 years. The interagency agreement envisions continual funding from DOE to support the development of fuel efficient, low emission engine technologies in terms of lubrication, friction, and wear control encountered in the development of advanced transportation technologies. However, in 1994, the DOE office of transportation technologies was reorganized and the tribology program was dissolved. The work at NIST therefore continued at a low level without further funding from DOE. The work continued to support transportation technologies in the development of fuel efficient, low emission engine development. Under this program, significant progress has been made in advancing the state of the art of lubrication technology for advanced engine research and development. Some of the highlights are: (1) developed an advanced high temperature liquid lubricant capable of sustaining high temperatures in a prototype heat engine; (2) developed a novel liquid lubricant which potentially could lower the emission of heavy duty diesel engines; (3) developed lubricant chemistries for ceramics used in the heat engines; (4) developed application maps for ceramic lubricant chemistry combinations for design purpose; and (5) developed novel test methods to screen lubricant chemistries for automotive air-conditioning compressors lubricated by R-134a (Freon substitute). Most of these findings have been reported to the DOE program office through Argonne National Laboratory who manages the overall program. A list of those reports and a copy of the report submitted to the Argonne National Laboratory is attached in Appendix A. Additional reports have also been submitted separately to DOE program managers. These are attached in Appendix B.

  13. 基于ARM9的轨道油气润滑系统控制器设计%Oil-gas Lubrication System Controller Design for Rail Based on ARM9

    Institute of Scientific and Technical Information of China (English)

    蔡胜年; 李鑫; 庞宝麟; 徐承韬

    2015-01-01

    以三星公司生产的S3C2410作为控制系统核心,设计有轨机车轮缘油气润滑控制系统,介绍控制系统的主要功能和系统结构。根据有轨机车轮缘油气润滑系统的控制要求,完成系统的硬件设计和软件设计。通过实验验证控制系统的实用性。对影响油气润滑效果及润滑油消耗量等重要参数进行专项实验,实验结果对完善油气润滑控制系统的性能和进一步提高系统的实用性具有重要参考价值。%In this paper,the S3C2410 chip produced by Samsung company was used as a core of the control system to design the trolley locomotive wheel rim lubrication system of oil and gas,and the main functions and architecture of the system were introduced. Hardware design and software design were given by the control requests of the trolley locomotive wheel rim lubrication system of oil and gas. And the prac-ticability of control system was verified by the experiment. Special experiment was carried out for impor-tant parameters influencing oil-gas lubrication effect and lubricating oil consumption. The experimental re-sults had an important reference value for improving the performance of the oil and gas lubrication control system and further increasing the practicality of system.

  14. Nanorheometry of Molecularly Thin Liquid Lubricant Films Coated on Magnetic Disks

    OpenAIRE

    Shintaro Itoh; Yuya Hamamoto; Koki Ishii; Kenji Fukuzawa; Hedong Zhang

    2012-01-01

    Molecularly thin lubricant films are used for the lubrication of head disk interfaces in hard disk drives. The film thickness is reduced to 1-2 nm to minimize the magnetic spacing, and optimal, precise design is required to obtain sufficient lubrication. However, until now, there was no generally applicable method for investigating such thin films. Therefore, we developed a highly sensitive shear force measuring method and have applied it to the viscoelastic measurement of lubricant films coa...

  15. Importance of lubricant analysis

    Directory of Open Access Journals (Sweden)

    Sreten R. Perić

    2012-04-01

    Full Text Available Monitoring the performance of lubricants in practical application has multiple significance for both the consumer and the lubricant manufacturer. The primary significance for the consumer is extended life and timely change of lubricants, which keeps the costs of maintenance down. The lubricant manufacturer gains by creating a partner relationship with the consumer, as well as creating the possibility of gathering information about the performance of his product which will serve as the foundation for its further improvement and development. If we wish to maintain technical systems so that they have minimum halts and costs caused by halt removal or system failures, we must monitor data indicating equipment condition throughout the system operation. It is especially difficult to obtain data on equipment condition for parts which cannot be observed due to their position. In such cases, the oil analysis enables a continuous equipment condition monitoring and timely response in order to prevent undesirable prolonged halts.

  16. Fuels and Lubricants Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Modern naval aircraft and turbine-powered craft require reliable and high-quality fuels and lubricants to satisfy the demands imposed upon them for top performance...

  17. Lubricating graphene with a nanometer-thick perfluoropolyether

    International Nuclear Information System (INIS)

    Due to its atomic thickness (thinness), the wear of graphene in nanoscale devices or as a protective coating is a serious concern. It is highly desirable to develop effective methods to reduce the wear of graphene. In the current paper, the effect of a nano-lubricant, perfluoropolyether, on the wear of graphene on different substrates is investigated. Graphene was synthesized by chemical vapor deposition (CVD) and characterized by Raman spectroscopy. The nano-lubricant is applied on the graphene by dip-coating. The friction and wear of graphene samples are characterized by nanotribometer, AFM, optical microscopy and Raman spectroscopy. The results showed that lubricating silicon/graphene with nano-lubricant reduces the friction but increases the wear. However, lubricating nickel/graphene with nano-lubricant has little effect on the friction but reduce the wear significantly. The underlying mechanism has been discussed on the basis of the graphene–substrate adhesion and the roughness. The current study provides guidance to the future design of graphene-containing devices. - Highlights: • The effect of a nano-lubricant on the friction and wear of CVD graphene was studied. • Lubricating Graphene/Si results in lower friction but higher wear. • Lubricating Ggraphene/Ni results in lower wear but unchanged friction. • The mechanisms were discussed based on the roughness and interfacial adhesion

  18. Lubricating graphene with a nanometer-thick perfluoropolyether

    Energy Technology Data Exchange (ETDEWEB)

    Kozbial, Andrew [Department of Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Li, Zhiting [Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Iasella, Steven; Taylor, Alexander T.; Morganstein, Brittni; Wang, Yongjin [Department of Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Sun, Jianing [J.A. Woollam Co., Inc., 645 M Street, Suite 102, Lincoln, NE 68508 (United States); Zhou, Bo; Randall, Nicholas X. [CSM Instruments, 197 1st Avenue, Needham, MA 02494 (United States); Liu, Haitao, E-mail: hliu@pitt.edu [Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Li, Lei, E-mail: lel55@pitt.edu [Department of Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2013-12-31

    Due to its atomic thickness (thinness), the wear of graphene in nanoscale devices or as a protective coating is a serious concern. It is highly desirable to develop effective methods to reduce the wear of graphene. In the current paper, the effect of a nano-lubricant, perfluoropolyether, on the wear of graphene on different substrates is investigated. Graphene was synthesized by chemical vapor deposition (CVD) and characterized by Raman spectroscopy. The nano-lubricant is applied on the graphene by dip-coating. The friction and wear of graphene samples are characterized by nanotribometer, AFM, optical microscopy and Raman spectroscopy. The results showed that lubricating silicon/graphene with nano-lubricant reduces the friction but increases the wear. However, lubricating nickel/graphene with nano-lubricant has little effect on the friction but reduce the wear significantly. The underlying mechanism has been discussed on the basis of the graphene–substrate adhesion and the roughness. The current study provides guidance to the future design of graphene-containing devices. - Highlights: • The effect of a nano-lubricant on the friction and wear of CVD graphene was studied. • Lubricating Graphene/Si results in lower friction but higher wear. • Lubricating Ggraphene/Ni results in lower wear but unchanged friction. • The mechanisms were discussed based on the roughness and interfacial adhesion.

  19. Lubricants for HFC-134a Compatible Rotary Compressors

    Science.gov (United States)

    Takaichi, Kenji; Sakai, Hisakazu

    In replacing CFC-12 with HFC-134a for refrigerator compressors, the compatibility with lubricating oil, and lubrication in general, are of major concern. HFC-134a dose not have adequate solubility with current lubricating oils because of its molecular structure. Current oils also do not provide enough lubricating action when using HFC-134a. A new oil and new materials have to be utilized in order to use HFC-134a. Developing a new lubricating oil involved numerous tests of different combinations of many polyolester synthetic oils and additives. One of the pre-evaluated methods was pursued via sealed tube tests. Lubricated parts were selected by studies involving a plane-on-roller type of wear test machine and by analyzing the traces of acid material commonly created during the lubricating action. The matrices of new lubricating oils and new lubricated materials were estimated based on durability tests conducted on compressors and refrigerators. Results showed that polyolester synthetic oils having a low total acid value and including certain quantities of additives did not break down into a tar-like substance and they did not produce composite particles in the operating compressors and refrigerators. The study also found that ceramics and anti-corrosion alloy steel possessed good adrasion-reducing qualities. Based on our evaluation, we will implement compressor reliability tests and apply HFC-134a to rotary compressors for refrigerators.

  20. Evaluation of hand applied naled thermal fog for Wyeomyia control.

    Science.gov (United States)

    Curtis, G A; Carlson, D B

    1990-09-01

    Tests on the effect of hand applied naled thermal fog, both as a single treatment on one day/week and a single treatment on 3 successive days, did not control Wyeomyia vanduzeei and Wy. mitchellii. Five-min landing/biting counts in a native oak/palm woodland demonstrated that single applications produced an average landing rate decrease of 13%. Treatments 3 days in succession did not suppress the landing rate. PMID:1977876

  1. Power system with an integrated lubrication circuit

    Science.gov (United States)

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

    2009-11-10

    A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

  2. Influence of Workpiece Surface Topography on the Mechanisms of Liquid Lubrication in Strip Drawing

    DEFF Research Database (Denmark)

    Shimizu, I; Andreasen, Jan Lasson; Bech, Jakob Ilsted; Bay, Niels

    2001-01-01

    The workpiece surface topography is an important factor controlling the mechanisms of lubrication in metal forming processes. In the present work, the microscopic lubrication mechanisms induced by lubricant trapped in pockets of the surface in strip drawing are studied. The experiments are perfor...

  3. Lubricant test for punching and blanking

    DEFF Research Database (Denmark)

    Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson

    di $cult work piece materials like stainless steels.For this group of materials few alternatives exist as regards appropriate lubricants and many companies apply the environmentally hazardous chlorinated para $n oils in order to insure a uccessful production.In connection with development of...

  4. Sputtering technology in solid film lubrication

    Science.gov (United States)

    Spalvins, T.

    1978-01-01

    Potential and present sputtering technology is discussed as it applies to the deposition of solid film lubricants particularly MoS2, WS2, and PTFE. Since the sputtered films are very thin, the selection of the sputtering parameters and substrate condition is very critical as reflected by the lubricating properties. It was shown with sputtered MoS2 films that the lubricating characteristics are directly affected by the selected sputtering parameters (power density, pressure, sputter etching, dc-biasing, etc.) and the substrate temperature, chemistry, topography and the environmental conditions during the friction tests. Electron microscopy and other surface sensitive analytical techniques illustrate the resulting changes in sputtered MoS2 film morphology and chemistry which directly influence the film adherence and frictional properties.

  5. Role of water lubricated bearings in Candu reactors

    International Nuclear Information System (INIS)

    During the twentieth century a great emphasis was placed in understanding and defining the operating regime of oil and grease lubricated components. Major advances have been made through elastohydrodynamic lubrication theory in the quantifying the design life of heavily loaded components such as rolling element bearings and gears. Detailed guidelines for the design of oil and grease lubricated components are widely available and are being applied to the successful design of these components. However similar guidelines for water lubricated components are either not available or not well documented. It is often forgotten that the water was used as a lubricant in several components as far back as 1884 B.C. During the twentieth century the water lubricated components continued to play a major role in some high technology industries such as in the power generation plants. In CANDU nuclear reactors water lubrication of several critical components always occupied a pride place and in most cases the only practical mode of lubrication of several critical components always occupied a pride place and in most cases the only practical mode of lubrication. This paper presents some examples of the major water lubricated components in a CANDU reactors. Major part of the paper is focused on presenting an example of successful operating history of water lubricated bearings used in the HT pumps are presented. Both types of bearings have been qualified by tests for operation under normal as well as under more severe postulated condition of loss-of-coolant-accident (LOCA). These bearings have been designed to operate for the 30 years in the existing CANDU 6 (600 MW) reactors. However for the next generation of CANDU 6 reactors which go into service in the year 2003, the HT pump bearing life has been extended to 40 years. (author)

  6. Determination of Zinc-Based Additives in Lubricating Oils by Flow-Injection Analysis with Flame-AAS Detection Exploiting Injection with a Computer-Controlled Syringe

    Directory of Open Access Journals (Sweden)

    Gustavo Pignalosa

    2005-01-01

    Full Text Available A flow-injection system is proposed for the determination of metal-based additives in lubricating oils. The system, operating under computer control uses a motorised syringe for measuring and injecting the oil sample (200 μL in a kerosene stream, where it is dispersed by means of a packed mixing reactor and carried to an atomic absorption spectrometer which is used as detector. Zinc was used as model analyte. Two different systems were evaluated, one for low concentrations (range 0–10 ppm and the second capable of providing higher dilution rates for high concentrations (range 0.02%–0.2% w/w. The sampling frequency was about 30 samples/h. Calibration curves fitted a second-degree regression model (r2 = 0.996. Commercial samples with high and low zinc levels were analysed by the proposed method and the results were compared with those obtained with the standard ASTM method. The t test for mean values showed no significant differences at the 95% confidence level. Precision (RSD% was better than 5% (2% typical for the high concentrations system. The carryover between successive injections was found to be negligible.

  7. Friction and lubrication performances of magnesium alloy sheet in numerically controlled hot incremental forming%镁合金板料数控热渐进成形时的摩擦和润滑性能

    Institute of Scientific and Technical Information of China (English)

    冯甜甜; 张青来; 肖富贵; 韩寅奔; 高霖; 韩伟东

    2012-01-01

    利用数控实验机床和摩擦实验研究AZ31镁合金板料数控热渐进成形时的摩擦和润滑机理.结果表明:镁合金薄板在加热条件下可以实现单点渐进成形;固体润滑膜可分为粘结型和吸附陶瓷型两种;固体石墨和MoS2润滑剂的初始摩擦因数均小于0.12,均可保证热渐进成形件获得良好的内外表面质量,没有任何划痕和裂纹等缺陷;吸附多孔陶瓷型固体润滑膜具有润滑和自润滑作用,固体润滑剂颗粒大小对初始摩擦因数有一定影响;固体BN粉末没有起到润滑作用,不能单独作为热渐进成形用固体润滑剂;当温度小于500℃时,固体石墨和MoS2粉末按一定比例配置的润滑复合喷剂的初始摩擦因数均小于为0.2,且表现出一定的协同作用.%The friction and lubrication mechanism of AZ31 magnesium alloy sheets in numerically controlled hot incremental forming were investigated by numerically controlled machine tools and friction tests. The results show that the single point incremental forming (SPIF) of magnesium alloy sheets can be achieved by heating. The solid lubricant film can be divided into two types, bonded and adsorbed ceramic coatings. The initial friction coefficients of graphite and M0S2 solid lubricant are both less than 0.12, which can ensure to obtain good inner and outer surface of hot incremental forming parts, without any defects such as scratches or cracks. The adsorbed porous ceramic solid lubricant film works as both lubrication and self-lubrication. The size of solid lubricant particles has an influence on the initial friction coefficient. The solid BN powder does not play the role of lubrication. As a result it can not be employed alone as a solid lubricant in hot incremental forming. When the temperature is lower than 500 'C, the initial friction coefficient of the composite sprays mixed with solid graphite and M0S2 powders by a certain proportion is less than 0.2, exhibiting a synergistic

  8. Urban drainage control applying rational method and geographic information technologies

    Science.gov (United States)

    Aldalur, Beatriz; Campo, Alicia; Fernández, Sandra

    2013-09-01

    The objective of this study is to develop a method of controlling urban drainages in the town of Ingeniero White motivated by the problems arising as a result of floods, water logging and the combination of southeasterly and high tides. A Rational Method was applied to control urban watersheds and used tools of Geographic Information Technology (GIT). A Geographic Information System was developed on the basis of 28 panchromatic aerial photographs of 2005. They were georeferenced with control points measured with Global Positioning Systems (basin: 6 km2). Flow rates of basins and sub-basins were calculated and it was verified that the existing open channels have a low slope with the presence of permanent water and generate stagnation of water favored by the presence of trash. It is proposed for the output of storm drains, the use of an existing channel to evacuate the flow. The solution proposed in this work is complemented by the placement of three pumping stations: one on a channel to drain rain water which will allow the drain of the excess water from the lower area where is located the Ingeniero White city and the two others that will drain the excess liquid from the port area.

  9. Analysis and treatment for abnormal loss of RCP motor lubrication

    International Nuclear Information System (INIS)

    RCP, as the 'heat' of a nuclear power plant, is one of the vital equipment of RCP Coolant System, ensuring the regular coolant flow for core heat transmission. In this case, it is a must to ensure the safety and reliability of RCP operation. During the 11th cycle of QNPC, the lubrication of RCP-A motor lost abnormally. To ensure normal operation of the motor, we performed 5 emergency lubrication-feeding. Against this problem, we analyzed the cause of abnormal lubrication loss of RCP motor and the transfer pathway for oil-gas, and according to the analysis we performed RCP motor disassembly maintenance during refueling overhaul. The paper discusses the specific treatment for the abnormal lubrication loss. It was testified useful to control the abnormal lubrication loss by the specific treatment. (authors)

  10. Hierarchical control of intelligent machines applied to space station telerobots

    Science.gov (United States)

    Albus, J. S.; Lumia, R.; Mccain, H.

    1987-01-01

    A hierarchical architecture is described which supports space station telerobots in a variety of modes. The system is divided into three hierarchies: task decomposition, world model, and sensory processing. Goals at each level of the task decomposition hierarchy are divided both spatially and temporally into simpler commands for the next lower level. This decomposition is repeated until, at the lowest level, the drive signals to the robot actuators are generated. To accomplish its goals, task decomposition modules must often use information stored in the world model. The purpose of the sensory system is to update the world model as rapidly as possible to keep the model in registration with the physical world. The architecture of the entire control system hierarchy and how it can be applied to space telerobot applications are discussed.

  11. Mixed lubricated line contacts

    NARCIS (Netherlands)

    Faraon, Irinel Cosmin

    2005-01-01

    The present work deals with friction in mixed lubricated line contacts. Components in systems are becoming smaller and due to, for instance power transmitted, partial contact may occur. In industrial applications, friction between the moving contacting surfaces cannot be avoided, therefore it is ess

  12. Genetic Algorithm and Fuzzy Tuning PID Controller Applied on Speed Control System for Marine Diesel Engines

    Directory of Open Access Journals (Sweden)

    Naeim Farouk

    2012-11-01

    Full Text Available The degree of speed control of ship machinery effects on the economics and optimization of the machinery configuration and operation. All marine vessel ranging need some sort of speed control system to control and govern the speed of the marine diesel engines. The main focus of this study is to apply and comparative between two specific soft-computing techniques. Fuzzy logic controller and genetic algorithm to design and tuning of PID controller for applied on speed control system of marine diesel engine to get an output with better dynamic and static performance. Simulation results show that the response of system when using genetic algorithm is better and faster than when using fuzzy tuning PID controller.

  13. Glass microsphere lubrication

    Science.gov (United States)

    Geiger, Michelle; Goode, Henry; Ohanlon, Sean; Pieloch, Stuart; Sorrells, Cindy; Willette, Chris

    1991-01-01

    The harsh lunar environment eliminated the consideration of most lubricants used on earth. Considering that the majority of the surface of the moon consists of sand, the elements that make up this mixture were analyzed. According to previous space missions, a large portion of the moon's surface is made up of fine grained crystalline rock, about 0.02 to 0.05 mm in size. These fine grained particles can be divided into four groups: lunar rock fragments, glasses, agglutinates (rock particles, crystals, or glasses), and fragments of meteorite material (rare). Analysis of the soil obtained from the missions has given chemical compositions of its materials. It is about 53 to 63 percent oxygen, 16 to 22 percent silicon, 10 to 16 percent sulfur, 5 to 9 percent aluminum, and has lesser amounts of magnesium, carbon, and sodium. To be self-supporting, the lubricant must utilize one or more of the above elements. Considering that the element must be easy to extract and readily manipulated, silicon or glass was the most logical choice. Being a ceramic, glass has a high strength and excellent resistance to temperature. The glass would also not contaminate the environment as it comes directly from it. If sand entered a bearing lubricated with grease, the lubricant would eventually fail and the shaft would bind, causing damage to the system. In a bearing lubricated with a solid glass lubricant, sand would be ground up and have little effect on the system. The next issue was what shape to form the glass in. Solid glass spheres was the only logical choice. The strength of the glass and its endurance would be optimal in this form. To behave as an effective lubricant, the diameter of the spheres would have to be very small, on the order of hundreds of microns or less. This would allow smaller clearances between the bearing and the shaft, and less material would be needed. The production of glass microspheres was divided into two parts, production and sorting. Production includes the

  14. Applying Standard Interfaces to a Process-Control Language

    Science.gov (United States)

    Berthold, Richard T.

    2005-01-01

    A method of applying open-operating-system standard interfaces to the NASA User Interface Language (UIL) has been devised. UIL is a computing language that can be used in monitoring and controlling automated processes: for example, the Timeliner computer program, written in UIL, is a general-purpose software system for monitoring and controlling sequences of automated tasks in a target system. In providing the major elements of connectivity between UIL and the target system, the present method offers advantages over the prior method. Most notably, unlike in the prior method, the software description of the target system can be made independent of the applicable compiler software and need not be linked to the applicable executable compiler image. Also unlike in the prior method, it is not necessary to recompile the source code and relink the source code to a new executable compiler image. Abstraction of the description of the target system to a data file can be defined easily, with intuitive syntax, and knowledge of the source-code language is not needed for the definition.

  15. Studies on micro plasto hydrodymic lubrication in metal forming

    DEFF Research Database (Denmark)

    Bay, Niels; Bech, Jakob Ilsted; Andreasen, Jan Lasson; Shimizu, I

    The influence of work piece surface topography on friction and lubrication and final surface quality in metal forming operations is well known and has been pointed out by many researchers, see Schey (1983) and Bay and Wanheim (1990). This is especially the case when liquid lubrication is applied,......, friction and pocket geometry and establishing a mathematical model predicting the onset of lubricant escape. The present paper presents an overview of these studies on MPHDL in metal forming carried out at the Technical University of Denmark....

  16. Selection of lubricant material for the roller chains of the AHM grapple drive system for the CRBRP

    International Nuclear Information System (INIS)

    Properties of Anderol 732 lubricating grease are evaluated to meet the design requirements for the Clinch River Breeder Reactor Plant (CRBRP) auxiliary handling machine (AHM) chain lubrication. Based on the evaluation made in this report, the material is recommended as a lubricant for the specified application. The material is to be applied by the chain manufacturer prior to installation in the AHM. 1 tab

  17. Identification, Uncertainty Characterization and Robust Control Synthesis Applied to Large Flexible Structures Control

    Science.gov (United States)

    Bayard, David S.; Chiang, Richard Y.

    1996-01-01

    This paper demonstrates an approach to frequency domain identification for the explicit purpose of designing robust H(infinity) controllers. The approach transforms raw experimental data into a plant set estimate directly usable by modern robust control design software(e.g., Matlab Robust Control Toolboxes [11][2]). A key issue in control design from raw data is the question of whether the controller will work when applied to the true system. The main feature fo this approach is that the resulting controller in guaranteed to work as designed(when applied to the true system) to a prescribed statistical confidence. While the overall methodology addresses key theoretical issues, it has at the same time been specifically designed to support practical implementations. A simulation example is included to demonstrate the overall approach.

  18. Compensation of Cross-Coupling Stiffness and Increase of Direct Damping in Multirecess Journal Bearings using Active Hybrid Lubrication

    DEFF Research Database (Denmark)

    Santos, Ilmar; Watanabe, F.Y.

    2004-01-01

    Fluid film forces are generated in hydrostatic journal bearings by two types of lubrication mechanisms: the hydrostatic lubrication in the bearing recesses and hydrodynamic lubrication in the bearing lands, when operating in rotation. The combination of both lubrication mechanisms leads to hybrid...... journal bearings (HJB). When part of hydrostatic pressure is also dynamically modified by means of hydraulic control systems, one refers to the active lubrication. The main contribution of the present theoretical work is to show that it is possible to reduce cross-coupling stiffness and increase the...... direct damping coefficients by means of the active lubrication, what leads to rotor-bearing systems with larger threshold of stability....

  19. A new Friction and Lubrication Test for Cold Forging

    DEFF Research Database (Denmark)

    Bay, Niels; Wibom, Ole; Aalborg Nielsen, J

    1995-01-01

    This paper presents a new friction and lubrication test for cold forging. The test allows controlled variation of the surface expansion in the range 0-2000%, the tool temperature in the range 20-270°C and the sliding length between 0 and infinite. Friction is decreasing with increasing temperature...... in the range 30-150°C. Above this temperature range friction increases. As regards lubricant performance Lubrication Limit Curves (LLC) are plotted in a sliding length-surface enlargement diagram with the tool temperature as a parameter. Larger tool temperature implies lower acceptable surface...

  20. Modeling and Optimal Control applied to a vector borne disease

    OpenAIRE

    Rodrigues, Helena Sofia; Monteiro, M. Teresa T.; Torres, Delfim F. M.

    2012-01-01

    A model with six mutually-exclusive compartments related to Dengue disease is presented. In this model there are three vector control tools: insecticides (larvicide and adulticide) and mechanical control. The problem is studied using an Optimal Control (OC) approach. The human data for the model is based on the Cape Verde Dengue outbreak. Some control measures are simulated and their consequences analyzed.

  1. Cooling lubricants; Kuehlschmierstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Pfeiffer, W. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Breuer, D. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Blome, H. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Deininger, C. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Hahn, J.U. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Kleine, H. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Nies, E. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Pflaumbaum, W. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Stockmann, R. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Willert, G. [Berufsgenossenschaftliches Inst. fuer Arbeitssicherheit, St. Augustin (Germany); Sonnenschein, G. [Maschinenbau- und Metall-Berufsgenossenschaft, Duesseldorf (Germany)

    1996-08-01

    As a rule, the base substances used are certain liquid hydrocarbons from mineral oils as well as from native and synthetic oils. Through the addition of further substances the cooling lubricant takes on the particular qualities required for the use in question. Employees working with cooling lubricants are exposed to various hazards. The assessment of the concentrations at the work station is carried out on the basis of existing technical rules for contact with hazardous substances. However, the application/implementation of compulsory investigation and supervision in accordance with these rules is made difficult by the fact that cooling lubricants are, as a rule, made up of complicated compound mixtures. In addition to protecting employees from exposure to mists and vapours from the cooling lubricants, protection for the skin is also of particular importance. Cooling lubricants should not, if at all possible, be brought into contact with the skin. Cleansing the skin and skin care is just as important as changing working clothes regularly, and hygiene and cleanliness at the workplace. Unavoidable emissions are to be immediately collected at the point where they arise or are released and safely disposed of. This means taking into account all sources of emissions. The programme presented in this report therefore gives a very detailed account of the individual protective measures and provides recommendations for the design of technical protection facilities. (orig./MG) [Deutsch] Als Basisstoffe dienen in der Regel bestimmte fluessige Kohlenwasserstoffverbindungen aus Mineraloelen sowie aus nativen oder synthetischen Oelen. Durch die Zugabe von weiteren Stoffen erlangt der Kuehlschmierstoff seine fuer den jeweiligen Anwendungsabfall geforderten Eigenschaften. Beschaeftigte, die mit Kuehlschmierstoffen umgehen, sind unterschiedliche Gefahren ausgesetzt. Die Beurteilung der Kuehlschmierstoffkonzentrationen in der Luft am Arbeitsplatz erfolgt auf der Grundlage bestehender

  2. Predictive control applied to a water canal prototype

    OpenAIRE

    Canarias, Daniel; Figueiredo, João; Rijo, Manuel

    2006-01-01

    Predictive control is an intelligent tool to manage complex systems. This control strategy is getting more and more application in industrial fields. This paper shows the application of the predictive control methodology to a water distribution canal. Water canals are complex hydraulic systems because they are open and big scale systems, characterized by big delays and great inertia. Many models and control strategies have already been simulated using linear control theory. In the present stu...

  3. Green Lubricants for Metal Forming

    DEFF Research Database (Denmark)

    Bay, Niels

    The increasing focus on legislation towards diminishing the impact on working environment as well as external environment has driven efforts to develop new, environmentally benign lubricants for metal forming. The present paper gives an overview of these efforts to substitute environmentally haza...... hazardous lubricants in cold, warm and hot forging as well as sheet forming and punching/blanking with new, less harmful lubricants.......The increasing focus on legislation towards diminishing the impact on working environment as well as external environment has driven efforts to develop new, environmentally benign lubricants for metal forming. The present paper gives an overview of these efforts to substitute environmentally...

  4. Molecular dynamics simulations of elasto-hydrodynamic lubrication and boundary lubrication for automotive tribology

    International Nuclear Information System (INIS)

    Friction control of machine elements on a molecular level is a challenging subject in vehicle technology. We describe the molecular dynamics studies of friction in two significant lubrication regimes. As a case of elastohydrodynamic lubrication, we introduce the mechanism of momentum transfer related to the molecular structure of the hydrocarbon fluids, phase transition of the fluids under high pressure, and a submicron thickness simulation of the oil film using a tera-flops computer. For boundary lubrication, the dynamic behavior of water molecules on hydrophilic and hydrophobic silicon surfaces under a shear condition is studied. The dynamic structure of the hydrogen bond network on the hydrophilic surface is related to the low friction of the diamond-like carbon containing silicon (DLC-Si) coating

  5. Design of multivariable feedback control systems via spectral assignment. [as applied to aircraft flight control

    Science.gov (United States)

    Liberty, S. R.; Mielke, R. R.; Tung, L. J.

    1981-01-01

    Applied research in the area of spectral assignment in multivariable systems is reported. A frequency domain technique for determining the set of all stabilizing controllers for a single feedback loop multivariable system is described. It is shown that decoupling and tracking are achievable using this procedure. The technique is illustrated with a simple example.

  6. Comparison of three controllers applied to helicopter vibration

    Science.gov (United States)

    Leyland, Jane A.

    1992-01-01

    A comparison was made of the applicability and suitability of the deterministic controller, the cautious controller, and the dual controller for the reduction of helicopter vibration by using higher harmonic blade pitch control. A randomly generated linear plant model was assumed and the performance index was defined to be a quadratic output metric of this linear plant. A computer code, designed to check out and evaluate these controllers, was implemented and used to accomplish this comparison. The effects of random measurement noise, the initial estimate of the plant matrix, and the plant matrix propagation rate were determined for each of the controllers. With few exceptions, the deterministic controller yielded the greatest vibration reduction (as characterized by the quadratic output metric) and operated with the greatest reliability. Theoretical limitations of these controllers were defined and appropriate candidate alternative methods, including one method particularly suitable to the cockpit, were identified.

  7. Applying Statistical Process Quality Control Methodology to Educational Settings.

    Science.gov (United States)

    Blumberg, Carol Joyce

    A subset of Statistical Process Control (SPC) methodology known as Control Charting is introduced. SPC methodology is a collection of graphical and inferential statistics techniques used to study the progress of phenomena over time. The types of control charts covered are the null X (mean), R (Range), X (individual observations), MR (moving…

  8. On the control of structures by applied thermal gradients

    Science.gov (United States)

    Edberg, Don; Chen, JAY-C.

    1987-01-01

    Some preliminary results of research on control of flexible structures performed at the Jet Propulsion Laboratory are presented. It was shown that the thermoelectric device is a feasible actuator and may effectively be used to control structures, provided the structure has a relatively low thermal inertia. The control law only depends on the open-loop system natural frequency.

  9. Improved Ionic Liquids as Space Lubricants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ionic liquids are candidate lubricant materials. However for application in low temperature space mechanisms their lubrication performance needs to be enhanced. UES...

  10. High Performing PFPE Nanofluid Lubricants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space missions could benefit from improved lubricant technology. PSI intends to develop novel liquid lubricant formulations which are applicable for future NASA...

  11. Touch-sensitive graphics terminal applied to process control

    International Nuclear Information System (INIS)

    Limited initial demonstrations of the system described took place during September 1980. A single CRT was used an an input device in the control center while operating a furnace and a pellet inspection gage. These two process line devices were completely controlled, despite the longer than desired response times noted, using a single control station located in the control center. The operator could conveniently execute any function from this remote location which could be performed locally at the hard-wired control panels. With the installation of the enhancements, the integrated touchscreen/graphics terminal will provide a preferable alternative to normal keyboard command input devices

  12. Investigating the effective factors on management internal controls applying

    Directory of Open Access Journals (Sweden)

    Ahmad Ahmadkhani

    2012-08-01

    Full Text Available Information technology plays an important role on increasing internal control in many organizations. In this paper, we present an empirical study to measure the impact of information technology, hiring high quality skilled management team, using high quality standards and increasing employees' awareness on managing internal control. The survey uses a questionnaire based on Likert scale and distributes among the people who work in either administration or financial sectors of governmental agencies in province of Zanjan, Iran. The results of the study indicate that the implementation of information technology positively influences management team to control their system, more effectively, using more skilled and specialized managers positively influences management internal control, an organization with suitable standard positively influences management internal control and increasing employees' awareness positively influences management internal control.

  13. H∞ Control Theory Applied to Xenon Control for Load-Following Operation of a Nuclear Reactor

    International Nuclear Information System (INIS)

    A robust controller is designed by applying the H∞ optimal control theory to the xenon control for the load-following operation of a nuclear reactor. The set of reactor model equations for controller design is a stiff system. This singularly perturbed system arises from the interaction of slow dynamics modes (iodine and xenon concentrations) and fast dynamics modes (neutron density, fuel and coolant temperatures). The singular perturbation technique is used to overcome this stiffness problem. The design specifications are incorporated by the frequency weights using the mixed-sensitivity problem approach. The robustness of H∞ control is demonstrated by comparing it with linear quadratic Gaussian (LQG) control in the case of a measurement delay of the power measurement system.Since the gains and phase margins of H∞ control are larger than those of LQG control, the H∞ control is expected to provide excellent stability robustness and performance robustness against external disturbances and noises, model parameter variations, and modeling errors as well as hardware failures. It may also provide a practical design method because the design specifications can be easily implemented by the frequency weights

  14. Applying the CobiT Control Framework to Spreadsheet Developments

    OpenAIRE

    Butler, Raymond J.

    2008-01-01

    One of the problems reported by researchers and auditors in the field of spreadsheet risks is that of getting and keeping managements attention to the problem. Since 1996, the Information Systems Audit & Control Foundation and the IT Governance Institute have published CobiT which brings mainstream IT control issues into the corporate governance arena. This paper illustrates how spreadsheet risk and control issues can be mapped onto the CobiT framework and thus brought to managers attention i...

  15. Applying the CobiT Control Framework to Spreadsheet Developments

    CERN Document Server

    Butler, Raymond J

    2008-01-01

    One of the problems reported by researchers and auditors in the field of spreadsheet risks is that of getting and keeping managements attention to the problem. Since 1996, the Information Systems Audit & Control Foundation and the IT Governance Institute have published CobiT which brings mainstream IT control issues into the corporate governance arena. This paper illustrates how spreadsheet risk and control issues can be mapped onto the CobiT framework and thus brought to managers attention in a familiar format.

  16. Parameter Identification and Adaptive Control Applied to the Inverted Pendulum

    OpenAIRE

    Carlos A. Saldarriaga-Cortés; Víctor D. Correa-Ramírez; Didier Giraldo-Buitrago

    2012-01-01

    This paper presents a methodology to implement an adaptive control of the inverted pendulum system; which uses the recursive square minimum method for the identification of a dynamic digital model of the plant and then, with its estimated parameters, tune in real time a pole placement control. The plant to be used is an unstable and nonlinear system. This fact, combined with the adaptive controller characteristics, allows the obtained results to be extended to a great variety of systems. The ...

  17. New electrohydraulic control system applied to steam turbines

    International Nuclear Information System (INIS)

    A new electrohydraulic control system (EHC) for steam turbines has been developed on the basis of rich operational experience and new requirements on control systems. Its reliability and maintenance have been greatly improved by the use of standardized module circuits. Various new control methods have also been added to meet customers' requirements. A full-size proto-type EHC cabinet has been tested in the EHC test shop in Toshiba, demonstrating its superior performance. (author)

  18. Applied Research of Enterprise Cost Control Based on Linear Programming

    OpenAIRE

    Yu Shuo

    2015-01-01

    As the economic globalization constantly advancing, the competition in the market economy has become even more intense, especially the growing nationalization in the competition among enterprises. The enterprise cost control is essential. Only when the enterprise cost control is within a reasonable range, the corresponding competitiveness of enterprises will be greatly enhanced, so the enterprise cost control is currently the strategy commanding point contended for by all parties. The linear ...

  19. Applying Operating System Principles to SDN Controller Design

    OpenAIRE

    Monaco, Matthew; Michel, Oliver; Keller, Eric

    2015-01-01

    Rather than creating yet another network controller which provides a framework in a specific (potentially new) programming language and runs as a monolithic application, in this paper we extend an existing operating system and leverage its software ecosystem in order to serve as a practical SDN controller. This paper introduces yanc, a controller platform for software-defined networks which exposes the network configuration and state as a file system, enabling user and system applications to ...

  20. Dynamic Control Applied to a Laboratory Antilock Braking System

    Directory of Open Access Journals (Sweden)

    Cuauhtémoc Acosta Lúa

    2015-01-01

    Full Text Available The control of an antilock braking system is a difficult problem due to the existence of nonlinear dynamics and uncertainties of its characteristics. To overcome these issues, in this work, a dynamic nonlinear controller is proposed, based on a nonlinear observer. To evaluate its performance, this controller has been implemented on an ABS Laboratory setup, representing a quarter car model. The nonlinear observer reconstructs some of the state variables of the setup, assumed not measurable, to establish a fair benchmark for an ABS system of a real automobile. The dynamic controller ensures exponential convergence of the state estimation, as well as robustness with respect to parameter variations.

  1. Self lubricating fluid bearings

    International Nuclear Information System (INIS)

    The invention concerns self lubricating fluid bearings, which are used in a shaft sealed system extending two regions. These regions contain fluids, which have to be isolated. A first seal is fluid tight for the first region between the carter shaft and the shaft. The second seal is fluid tight between the carter and the shaft, it communicates with the second region. The first fluid region is the environment surrounding the shaft carter. The second fluid region is a part of a nuclear reactor which contains the cooling fluid. The shaft is conceived to drive a reactor circulating and cooling fluid

  2. Fuzzy control applied to nuclear power plant pressurizer system

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Mauro V.; Almeida, Jose C.S., E-mail: mvitor@ien.gov.b, E-mail: jcsa@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

  3. Chaos control applied to cardiac rhythms represented by ECG signals

    International Nuclear Information System (INIS)

    The control of irregular or chaotic heartbeats is a key issue in cardiology. In this regard, chaos control techniques represent a good alternative since they suggest treatments different from those traditionally used. This paper deals with the application of the extended time-delayed feedback control method to stabilize pathological chaotic heart rhythms. Electrocardiogram (ECG) signals are employed to represent the cardiovascular behavior. A mathematical model is employed to generate ECG signals using three modified Van der Pol oscillators connected with time delay couplings. This model provides results that qualitatively capture the general behavior of the heart. Controlled ECG signals show the ability of the strategy either to control or to suppress the chaotic heart dynamics generating less-critical behaviors. (paper)

  4. Software factory techniques applied to Process Control at CERN

    CERN Multimedia

    Dutour, MD

    2007-01-01

    The CERN Large Hadron Collider (LHC) requires constant monitoring and control of quantities of parameters to guarantee operational conditions. For this purpose, a methodology called UNICOS (UNIfied Industrial COntrols Systems) has been implemented to standardize the design of process control applications. To further accelerate the development of these applications, we migrated our existing UNICOS tooling suite toward a software factory in charge of assembling project, domain and technical information seamlessly into deployable PLC (Programmable logic Controller) – SCADA (Supervisory Control And Data Acquisition) systems. This software factory delivers consistently high quality by reducing human error and repetitive tasks, and adapts to user specifications in a cost-efficient way. Hence, this production tool is designed to encapsulate and hide the PLC and SCADA target platforms, enabling the experts to focus on the business model rather than specific syntaxes and grammars. Based on industry standard software...

  5. Chaos control applied to cardiac rhythms represented by ECG signals

    Science.gov (United States)

    Borem Ferreira, Bianca; Amorim Savi, Marcelo; Souza de Paula, Aline

    2014-10-01

    The control of irregular or chaotic heartbeats is a key issue in cardiology. In this regard, chaos control techniques represent a good alternative since they suggest treatments different from those traditionally used. This paper deals with the application of the extended time-delayed feedback control method to stabilize pathological chaotic heart rhythms. Electrocardiogram (ECG) signals are employed to represent the cardiovascular behavior. A mathematical model is employed to generate ECG signals using three modified Van der Pol oscillators connected with time delay couplings. This model provides results that qualitatively capture the general behavior of the heart. Controlled ECG signals show the ability of the strategy either to control or to suppress the chaotic heart dynamics generating less-critical behaviors.

  6. Water lubricates hydrogen-bonded molecular machines.

    Science.gov (United States)

    Panman, Matthijs R; Bakker, Bert H; den Uyl, David; Kay, Euan R; Leigh, David A; Buma, Wybren Jan; Brouwer, Albert M; Geenevasen, Jan A J; Woutersen, Sander

    2013-11-01

    The mechanical behaviour of molecular machines differs greatly from that of their macroscopic counterparts. This applies particularly when considering concepts such as friction and lubrication, which are key to optimizing the operation of macroscopic machinery. Here, using time-resolved vibrational spectroscopy and NMR-lineshape analysis, we show that for molecular machinery consisting of hydrogen-bonded components the relative motion of the components is accelerated strongly by adding small amounts of water. The translation of a macrocycle along a thread and the rotation of a molecular wheel around an axle both accelerate significantly on the addition of water, whereas other protic liquids have much weaker or opposite effects. We tentatively assign the superior accelerating effect of water to its ability to form a three-dimensional hydrogen-bond network between the moving parts of the molecular machine. These results may indicate a more general phenomenon that helps explain the function of water as the 'lubricant of life'. PMID:24153370

  7. Water lubricates hydrogen-bonded molecular machines

    Science.gov (United States)

    Panman, Matthijs R.; Bakker, Bert H.; den Uyl, David; Kay, Euan R.; Leigh, David A.; Buma, Wybren Jan; Brouwer, Albert M.; Geenevasen, Jan A. J.; Woutersen, Sander

    2013-11-01

    The mechanical behaviour of molecular machines differs greatly from that of their macroscopic counterparts. This applies particularly when considering concepts such as friction and lubrication, which are key to optimizing the operation of macroscopic machinery. Here, using time-resolved vibrational spectroscopy and NMR-lineshape analysis, we show that for molecular machinery consisting of hydrogen-bonded components the relative motion of the components is accelerated strongly by adding small amounts of water. The translation of a macrocycle along a thread and the rotation of a molecular wheel around an axle both accelerate significantly on the addition of water, whereas other protic liquids have much weaker or opposite effects. We tentatively assign the superior accelerating effect of water to its ability to form a three-dimensional hydrogen-bond network between the moving parts of the molecular machine. These results may indicate a more general phenomenon that helps explain the function of water as the ‘lubricant of life’.

  8. Lubrication of soft viscoelastic solids

    CERN Document Server

    Pandey, Anupam; Venner, Kees; Snoeijer, Jacco

    2015-01-01

    Lubrication flows appear in many applications in engineering, biophysics, and in nature. Separation of surfaces and minimisation of friction and wear is achieved when the lubrication fluid builds up a lift force. In this paper we analyse soft lubricated contacts by treating the solid walls as viscoelastic: soft materials are typically not purely elastic, but dissipate energy under dynamical loading conditions. We present a method for viscoelastic lubrication and focus on three canonical examples, namely Kelvin-Voigt-, Standard Linear-, and Power Law-rheology. It is shown how the solid viscoelasticity affects the lubrication process when the timescale of loading becomes comparable to the rheological timescale. We derive asymptotic relations between lift force and sliding velocity, which give scaling laws that inherit a signature of the rheology. In all cases the lift is found to decrease with respect to purely elastic systems.

  9. Biopolymer Green Lubricant for Sustainable Manufacturing

    OpenAIRE

    Shih-Chen Shi; Fu-I Lu

    2016-01-01

    We report on the preparation of a biopolymer thin film by hydroxypropyl methylcellulose (HPMC), which can be used as a dry green lubricant in sustainable manufacturing. The thin films were characterized through scanning electron microscopy, energy-dispersive spectroscopy, and Raman spectroscopy; the films showed desirable levels of thickness, controllability, and uniformity. Tribology tests also showed desirable tribological and antiwear behaviors, caused by the formation of transfer layers. ...

  10. Parameter Identification and Adaptive Control Applied to the Inverted Pendulum

    Directory of Open Access Journals (Sweden)

    Carlos A. Saldarriaga-Cortés

    2012-06-01

    Full Text Available This paper presents a methodology to implement an adaptive control of the inverted pendulum system; which uses the recursive square minimum method for the identification of a dynamic digital model of the plant and then, with its estimated parameters, tune in real time a pole placement control. The plant to be used is an unstable and nonlinear system. This fact, combined with the adaptive controller characteristics, allows the obtained results to be extended to a great variety of systems. The results show that the above methodology was implemented satisfactorily in terms of estimation, stability and control of such a system. It was established that adaptive techniques have a proper performance even in systems with complex features such as nonlinearity and instability.

  11. The Application Research of Inventory Control with Multi -objective Constraints under the Perspective of Supply Chain---A Case Analysis of Industrial Lubricating Oil Supply Chain%库存控制之供应链多目标视角下的应用研究--以工业润滑油供应链为例

    Institute of Scientific and Technical Information of China (English)

    王丽娟; 李英英

    2016-01-01

    〔Abstract〕 Study on inventory control of supply chain has become a trend , different from the conventional single target study on in-ventory control , the author made the emphasis on the study on minimizing inventory cost and maximizing the average satisfaction rate of cus -tomer demand and built a multi -objective inventory control model . In the end , the model and the solution were applied to the lubricating oil supply chain , which was helpful for making decisions for these enterprises in the lubricating oil supply chain .%供应链环境下库存控制的研究已经成为趋势,区别于常规的单目标库存控制的研究,本文以工业润滑油供应链为依托,提出了在供应链背景下考虑供应链库存成本最小化和客户平均需求满足率最大化为目标的库存控制研究思路,构建了多目标库存控制模型。最后将所建的供应链视角下多目标库存控制决策模型进行实证分析,为目标供应链上的企业做出生产、销售等决策提供依据。

  12. INCAP ? Applying short-term flexibility to control inventories

    OpenAIRE

    Lödding, Hermann; Lohmann, Steffen

    2011-01-01

    Abstract Inventory Based Capacity Control (INCAP) is a very simple method that allows inventory levels to be effectively controlled by using short-term capacity flexibility in make-to-stock settings. Moreover, INCAP can be used for finished goods inventories as well as for semi-finished goods inventories. The basic idea is to define upper and lower inventory limits and to adjust capacities if the inventory level reaches either limit. Should the inventory fall below the lower limit,...

  13. Designing Crane Controls with applied Mechanical and Electrical Safety Features

    Science.gov (United States)

    Lytle, Bradford P.; Walczak, Thomas A.; Delgado, H. (Technical Monitor)

    2002-01-01

    The use of overhead traveling bridge cranes in many varied applications is common practice. In particular, the use of cranes in the nuclear, military, commercial, aerospace, and other industries can involve safety critical situations. Considerations for Human Injury or Casualty, Loss of Assets, Endangering the Environment, or Economic Reduction must be addressed. Traditionally, in order to achieve additional safety in these applications, mechanical systems have been augmented with a variety of devices. These devices assure that a mechanical component failure shall reduce the risk of a catastrophic loss of the correct and/or safe load carrying capability. ASME NOG-1-1998, (Rules for Construction of Overhead and Gantry Cranes, Top Running Bridge, and Multiple Girder), provides design standards for cranes in safety critical areas. Over and above the minimum safety requirements of todays design standards, users struggle with obtaining a higher degree of reliability through more precise functional specifications while attempting to provide "smart" safety systems. Electrical control systems also may be equipped with protective devices similar to the mechanical design features. Demands for improvement of the cranes "control system" is often recognized, but difficult to quantify for this traditionally "mechanically" oriented market. Finite details for each operation must be examined and understood. As an example, load drift (or small motions) at close tolerances can be unacceptable (and considered critical). To meet these high functional demands encoders and other devices are independently added to control systems to provide motion and velocity feedback to the control drive. This paper will examine the implementation of Programmable Electronic Systems (PES). PES is a term this paper will use to describe any control system utilizing any programmable electronic device such as Programmable Logic Controllers (PLC), or an Adjustable Frequency Drive (AID) 'smart' programmable

  14. Control theory and splines, applied to signature storage

    Science.gov (United States)

    Enqvist, Per

    1994-01-01

    In this report the problem we are going to study is the interpolation of a set of points in the plane with the use of control theory. We will discover how different systems generate different kinds of splines, cubic and exponential, and investigate the effect that the different systems have on the tracking problems. Actually we will see that the important parameters will be the two eigenvalues of the control matrix.

  15. OPTIMAL CONTROL APPLIED IN AUTOMATIC CLUTCH ENGAGEMENTS OF VEHICLES

    Institute of Scientific and Technical Information of China (English)

    Sun Chengshun; Zhang Jianwu

    2004-01-01

    Start-up working condition is the key to the research of optimal engagement of automatic clutch for AMT.In order to guarantee an ideal dynamic performance of the clutch engagement,an optimal controller is designed by considering throttle angle,engine speed,gear ratio,vehicle acceleration and road condition.The minimum value principle is also introduced to achieve an optimal dynamic performance of the nonlinear system compromised in friction plate wear and vehicle drive quality.The optimal trajectory of the clutch engagement can be described in the form of explicit and analytical expressions and characterized by the deterministic and accurate control strategy in stead of indeterministic and soft control techniques which need thousands of experiments.For validation of the controller,test work is carried out for the automated clutch engagements in a commercial car with an traditional mechanical transmission,a hydraulic actuator,a group of sensors and a portable computer system.It is shown through experiments that dynamic behaviors of the clutch engagement operated by the optimal control are more effective and efficient than those by fuzzy control.

  16. Nanorheometry of Molecularly Thin Liquid Lubricant Films Coated on Magnetic Disks

    Directory of Open Access Journals (Sweden)

    Shintaro Itoh

    2012-01-01

    Full Text Available Molecularly thin lubricant films are used for the lubrication of head disk interfaces in hard disk drives. The film thickness is reduced to 1-2 nm to minimize the magnetic spacing, and optimal, precise design is required to obtain sufficient lubrication. However, until now, there was no generally applicable method for investigating such thin films. Therefore, we developed a highly sensitive shear force measuring method and have applied it to the viscoelastic measurement of lubricant films coated on magnetic disk surfaces. In this paper, we review the method and summarize the useful findings we have demonstrated so far.

  17. Applied Research of Enterprise Cost Control Based on Linear Programming

    Directory of Open Access Journals (Sweden)

    Yu Shuo

    2015-01-01

    This paper researches the enterprise cost control through the linear programming model, and analyzes the restriction factors of the labor of enterprise production, raw materials, processing equipment, sales price, and other factors affecting the enterprise income, so as to obtain an enterprise cost control model based on the linear programming. This model can calculate rational production mode in the case of limited resources, and acquire optimal enterprise income. The production guiding program and scheduling arrangement of the enterprise can be obtained through calculation results, so as to provide scientific and effective guidance for the enterprise production. This paper adds the sensitivity analysis in the linear programming model, so as to learn about the stability of the enterprise cost control model based on linear programming through the sensitivity analysis, and verify the rationality of the model, and indicate the direction for the enterprise cost control. The calculation results of the model can provide a certain reference for the enterprise planning in the market economy environment, which have strong reference and practical significance in terms of the enterprise cost control.

  18. A GOMS model applied to a simplified control panel design

    International Nuclear Information System (INIS)

    The design of the user interface for a new system requires many decisions to be considered. To develop sensitivity to user needs requires understanding user behavior. The how-to-do-it knowledge is a mixture of task-related and interface-related components. A conscientious analysis of these components, allows the designer to construct a model in terms of goals, operators, methods, and selection (GOMS model) rules that can be advantageously used in the design process and evaluation of a user interface. The emphasis of the present work is on describing the importance and use of a GOMS model as a formal user interface analysis tool in the development of a simplified panel for the control of a nuclear power plant. At Pennsylvania State University, a highly automated control system with a greatly simplified human interface has been proposed to improve power plant safety. Supervisory control is to be conducted with a simplified control panel with the following functions: startup, shutdown, increase power, decrease power, reset, and scram. Initial programming of the operator interface has been initiated within the framework of a U.S. Department of Energy funded university project for intelligent distributed control. A hypothesis to be tested is that this scheme can be also used to estimate mental work load content and predict human performance

  19. Robust sliding mode control applied to double Inverted pendulum system

    International Nuclear Information System (INIS)

    A three hierarchical sliding mode control is presented for a class of an underactuated system which can overcome the mismatched perturbations. The considered underactuated system is a double inverted pendulum (DIP), can be modeled by three subsystems. Such structure allows the construction of several designs of hierarchies for the controller. For all hierarchical designs, the asymptotic stability of every layer sliding mode surface and the sliding mode surface of subsystems are proved theoretically by Barbalat's lemma. Simulation results show the validity of these methods.

  20. COMPUTER VISION APPLIED IN THE PRECISION CONTROL SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Computer vision and its application in the precision control system are discussed. In the process of fabricating, the accuracy of the products should be controlled reasonably and completely. The precision should be kept and adjusted according to the information of feedback got from the measurement on-line or out-line in different procedures. Computer vision is one of the useful methods to do this. Computer vision and the image manipulation are presented, and based on this, a n-dimensional vector to appraise on precision of machining is given.

  1. Metamodeling Techniques Applied to the Design of Reconfigurable Control Applications

    Directory of Open Access Journals (Sweden)

    Luca Ferrarini

    2008-02-01

    Full Text Available In order to realize autonomous manufacturing systems in environments characterized by high dynamics and high complexity of task, it is necessary to improve the control system modelling and performance. This requires the use of better and reusable abstractions. In this paper, we explore the metamodel techniques as a foundation to the solution of this problem. The increasing popularity of model-driven approaches and a new generation of tools to support metamodel techniques are changing software engineering landscape, boosting the adoption of new methodologies for control application development.

  2. Trajectory control with continuous thrust applied to a rendezvous maneuver

    International Nuclear Information System (INIS)

    A rendezvous mission can be divided into the following phases: launch, phasing, far range rendezvous, close range rendezvous and mating (docking or berthing). This paper aims to present a close range rendezvous with closed loop controlled straight line trajectory. The approaching is executed on V-bar axis. A PID controller and continuous thrust are used to eliminate the residual errors in the trajectory. A comparative study about the linear and nonlinear dynamics is performed and the results showed that the linear equations become inaccurate insofar as the chaser moves away from the target

  3. Design of a Neuro-Fuzzy Controller for Speed Control Applied to DC Servo Motor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.H.; Kang, Y.H.; Kim, L.K. [Konkuk University, Seoul (Korea); Ko, B.W. [Cheju College of Technology, Cheju (Korea)

    2002-02-01

    In this study, a neuro-fuzzy controller which has the characteristic of fuzzy control and artificial neural network is designed. A fuzzy rule to be applied is automatically selected by the allocated neurons. The neurons correspond to fuzzy rules are created by an expert. To adapt the more precise model is implemented by error back-propagation learning algorithm to adjust the link-weight of fuzzy membership function in the neuro-fuzzy controller. The more classified fuzzy rule is used to include the property of dual mode method. In order to verify the effectiveness of the proposed algorithm designed above, an operating characteristic of a DC servo motor with variable load is investigated. (author). 10 refs., 12 figs., 9 tabs.

  4. Automotive gear oil lubricant from soybean oil

    Science.gov (United States)

    The use of lubricants that are based on renewable materials is rapidly increasing. Vegetable oils have good lubricity, wear protection and low volatility which are desired properties for automotive gear lubricant applications. Soybean oil is used widely in the lubricant industry due to its properti...

  5. Applying Distributed Object Technology to Distributed Embedded Control Systems

    DEFF Research Database (Denmark)

    Jørgensen, Bo Nørregaard; Dalgaard, Lars

    2012-01-01

    In this paper, we describe our Java RMI inspired Object Request Broker architecture MicroRMI for use with networked embedded devices. MicroRMI relieves the software developer from the tedious and error-prone job of writing communication protocols for interacting with such embedded devices. Micro...... developing control systems for distributed embedded platforms possessing severe resource restrictions....

  6. Object oriented programming techniques applied to device access and control

    International Nuclear Information System (INIS)

    In this paper a model, called the device server model, has been presented for solving the problem of device access and control faced by all control systems. Object Oriented Programming techniques were used to achieve a powerful yet flexible solution. The model provides a solution to the problem which hides device dependancies. It defines a software framework which has to be respected by implementors of device classes - this is very useful for developing groupware. The decision to implement remote access in the root class means that device servers can be easily integrated in a distributed control system. A lot of the advantages and features of the device server model are due to the adoption of OOP techniques. The main conclusion that can be drawn from this paper is that 1. the device access and control problem is adapted to being solved with OOP techniques, 2. OOP techniques offer a distinct advantage over traditional programming techniques for solving the device access problem. (J.P.N.)

  7. The development of control technologies applied to waste processing operations

    International Nuclear Information System (INIS)

    Typical waste and residue processes involve some level of human interaction. The risk of exposure to unknown hazardous materials and the potential for radiation contamination provide the impetus for physically separating or removing operators from such processing steps. Technologies that facilitate separation of the operator from potential contamination include glove box robotics; modular systems for remote and automated servicing; and interactive controls that minimize human intervention. Lawrence Livermore National Laboratory (LLNL) is developing an automated system which by design will supplant the operator for glove box tasks, thus affording protection from the risk of radiation exposure and minimizing operator associated waste.This paper describes recent accomplishments in technology development and integration, and outlines the future goals at LLNL for achieving this integrated, interactive control capability

  8. Decision theory applied to image quality control in radiology

    OpenAIRE

    Arantes Paula R; Caous Cristofer A; Lessa Patrícia S; Amaro Edson; de Souza Fernando

    2008-01-01

    Abstract Background The present work aims at the application of the decision theory to radiological image quality control (QC) in diagnostic routine. The main problem addressed in the framework of decision theory is to accept or reject a film lot of a radiology service. The probability of each decision of a determined set of variables was obtained from the selected films. Methods Based on a radiology service routine a decision probability function was determined for each considered group of c...

  9. Calibration of the ultrasonic lubricant-film thickness measurement technique

    Science.gov (United States)

    Zhang, Jie; Drinkwater, Bruce W.; Dwyer-Joyce, Rob S.

    2005-09-01

    This paper describes an experimental apparatus and procedure for the calibration of the ultrasonic lubricant-film thickness measurement technique. It also presents a study of the accuracy of the technique. The calibration apparatus is demonstrated on a three layer steel-mineral oil-steel system. This was chosen to be representative of a typical bearing system which is the industrial application of the technique. In such bearing systems the lubricant-film thickness typically ranges from 0.1 to 100 µm. The calibration apparatus uses a high precision piezoelectric displacement translator to controllably displace one of the steel surfaces relative to the other and hence alter the lubricant-film thickness by a known amount. Through-thickness resonant frequency measurements are then used to accurately measure a thick lubricant film (h > 10 µm). These resonant frequency measurements form the starting point of the calibration. The displacement translator is then used to reduce the lubricant-film thickness into the, more practically interesting, low micron range. In this range the amplitude of the measured reflection coefficient is used via a spring interface model to calculate the lubricant-film thickness. Issues of ultrasonic beam alignment and frequency of operation are discussed. A detailed study of the effect of reflection-coefficient errors on the resultant thickness measurement is presented. Practical guidelines for use of the calibration are then defined and calibration is demonstrated experimentally over the range 0.5-1.3 µm.

  10. Machine vision algorithms applied to dynamic traffic light control

    Directory of Open Access Journals (Sweden)

    Fabio Andrés Espinosa Valcárcel

    2013-01-01

    número de autos presentes en imágenes capturadas por un conjunto de cámaras estratégicamente ubicadas en cada intersección. Usando esta información, el sistema selecciona la secuencia de acciones que optimicen el flujo vehicular dentro de la zona de control, en un escenario simulado. Los resultados obtenidos muestran que el sistema disminuye en un 20% los tiempos de retraso para cada vehículo y que además es capaz de adaptarse rápida y eficientemente a los cambios de flujo.

  11. Applying Econometrics to the Carbon Dioxide “Control Knob”

    Directory of Open Access Journals (Sweden)

    Timothy Curtin

    2012-01-01

    Full Text Available This paper tests various propositions underlying claims that observed global temperature change is mostly attributable to anthropogenic noncondensing greenhouse gases, and that although water vapour is recognized to be a dominant contributor to the overall greenhouse gas (GHG effect, that effect is merely a “feedback” from rising temperatures initially resulting only from “non-condensing” GHGs and not at all from variations in preexisting naturally caused atmospheric water vapour (i.e., [H2O]. However, this paper shows that “initial radiative forcing” is not exclusively attributable to forcings from noncondensing GHG, both because atmospheric water vapour existed before there were any significant increases in GHG concentrations or temperatures and also because there is no evidence that such increases have produced measurably higher [H2O]. The paper distinguishes between forcing and feedback impacts of water vapour and contends that it is the primary forcing agent, at much more than 50% of the total GHG gas effect. That means that controlling atmospheric carbon dioxide is unlikely to be an effective “control knob” as claimed by Lacis et al. (2010.

  12. Durability evaluation of perfluoropolyether-lubricant-coated protective diamond-like carbon film by the lateral vibration friction test

    International Nuclear Information System (INIS)

    An investigation of the perfluoropolyether (PFPE) lubricant effect on the tribological properties of diamond-like carbon (DLC) film magnetic hard disks was conducted. On the basis of friction force microscopy techniques, we carried out lateral oscillation wear tests to detect DLC film disks with and without PFPE lubricant. The results reveal that the DLC film without lubricant easily fractures and swells. In contrast, the transfer of free lubricant and the progressive destruction of bonding lubricant were observed on the DLC film coated with a PFPE lubricant. The dynamic deformation and durability evaluation of the PFPE lubricant and DLC film system were observed in the lateral oscillation wear test by changing the experimental load and amplitude of lateral vibration applied to a cantilever tip. The destruction of the PFPE-DLC film occurred in the test of the 10 nm oscillation amplitude due to the breaking off of the molecular chain of PFPE

  13. Forging tools modification with graphene-like solid lubricant nanoparticles

    Directory of Open Access Journals (Sweden)

    V. Leshchynsky

    2010-11-01

    Full Text Available Purpose: Working conditions of forging tools have become severer with the years. To increase their wear andheat resistance the surface of the tool is coated by CVD/PVD methods. Relatively high friction coefficientof coatings results in high friction losses and low durability of coating films due to high shear stress at tool–workpiece interface. That is why improved self-lubricating system should be developed. Combination of moderncoatings (nanostructured, nanolayers, nanocomposites, etc. with self-lubricating tool design and application ofsolid lubricant MoS2 and WS2 graphene-like nanoparticles is very promising and effective way to solve existingforging tool problems.Design/methodology/approach: Laser micro-machining technology was applied to fabricate the network ofmicro-channels which serve like reservoirs for encapsulation of solid lubricant nanoparticles into tool body.Wide ranges of tribological tests on T-10 ball-on-disc tester were carried out to define the optimal geometryand network configuration of micro-channels ensuring generation of a lubricious transfer film at the tribologicalcontact.Findings: As a result, increased tool durability and high forging precision could be reached. Analysis of failuremechanisms for different forging tools were carried out. It was found that one of the important reasons of toolwear is a high friction coefficient between treated material and the tool. Graphene-like nanoparticles of MoS2solid lubricant were produced by Rolling Cleavage Technology. Paper consist SEM, TEM and AFM analysis ofapplied coatings and solid lubricant particles.Research limitations/implications: The continuous supply to a sliding area of nanoparticles will be for thefirst time applied to decrease high shear stress at an interface between forging tool and treated material.Thenext research step will be the transfer of the developed methods of self-lubrication from samples to real coldforging tools.Originality/value: Analysis of

  14. Elasto hydrodynamic lubrication by traction fluid applied to the design of a continuously variable toroidal transmission; La lubrification elastohydrodynamique par un fluide de traction appliquee a la conception d'un variateur toroidal

    Energy Technology Data Exchange (ETDEWEB)

    Makala, J.; Villechaise, B. [Poitiers Univ., Lab. de Mecanique des Solides, UMR CNRS 6610, 86 (France); Dalmaz, G.; Chaomleffel, J.P. [Institut National des Sciences Appliquees (INSA), Lab. de Mecanique des Contacts, UMR CNRS 5514, 69 - Villeurbanne (France); Kargar, K. [Renault, Dir. de la Recherche, Technocentre, 78 - Guyancourt (France)

    2001-07-01

    Continuously variable toroidal transmissions for automotive use has been the focus of considerable research and development efforts in recent years. They can bring improved fuel economy benefit under good speed ratio changes for automotive propulsion systems in which engines can produce their power under optimum conditions. In this transmission, power is transmitted by means of lubricated point contacts that transmit friction forces. A special fluid, named traction fluid, is used to develop a high friction coefficient at high pressure. The problems in this context are the power efficiency and the evaluation of the mechanism in term of performance. Some elements like roller bearings or gears are lubricated by the same fluid. They are the cause of important power dissipations in their contacts that decrease the transmission efficiency. To predict these power losses, a theoretical model of traction fluid behaviour and the best experimental analysis of rheological fluid properties are needed In order to be close to real working conditions, both in the transmission and the roller bearing contacts, a specific apparatus that can give simultaneously friction forces and film thicknesses is used. (authors)

  15. Applying Space Technology to Enhance Control of an Artificial Arm

    Science.gov (United States)

    Atkins, Diane; Donovan, William H.; Novy, Mara; Abramczyk, Robert

    1997-01-01

    At the present time, myoelectric prostheses perform only one function of the hand: open and close with the thumb, index and middle finger coming together to grasp various shaped objects. To better understand the limitations of the current single-function prostheses and the needs of the individuals who use them, The Institute for Rehabilitation and Research (TIRR), sponsored by the National Institutes of Health (August 1992 - November 1994), surveyed approximately 2500 individuals with upper limb loss. When asked to identify specific features of their current electric prosthesis that needed improvement, the survey respondents overwhelmingly identified the lack of wrist and finger movement as well as poor control capability. Simply building a mechanism with individual finger and wrist motion is not enough. Individuals with upper limb loss tend to reject prostheses that require continuous visual monitoring and concentration to control. Robotics researchers at NASA's Johnson Space Center (JSC) and Rice University have made substantial progress in myoelectric teleoperation. A myoelectric teleoperation system translates signals generated by an able-bodied robot operator's muscles during hand motions into commands that drive a robot's hand through identical motions. Farry's early work in myoelectric teleoperation used variations over time in the myoelectric spectrum as inputs to neural networks to discriminate grasp types and thumb motions. The resulting schemes yielded up to 93% correct classification on thumb motions. More recently, Fernandez achieved 100% correct non-realtime classification of thumb abduction, extension, and flexion on the same myoelectric data. Fernandez used genetic programming to develop functions that discriminate between thumb motions using myoelectric signal parameters. Genetic programming (GP) is an evolutionary programming method where the computer can modify the discriminating functions' form to improve its performance, not just adjust

  16. Controllability of brushite structural parameters using an applied magnetic field.

    Science.gov (United States)

    Kuznetsov, V N; Yanovska, A A; Stanislavov, A S; Danilchenko, S N; Kalinkevich, A N; Sukhodub, L F

    2016-03-01

    The paper studies the influence of low intensity static magnetic field on brushite structural and microstructural parameters using the X-ray diffraction and the transmission electron microscopy. This effect was shown to have various influences on DCPD (Dicalcium Phosphate Dihydrate) structure depending on a magnetic field configuration or time of synthesis, which allows achieving controllability of the main properties of an obtained material. The influence of the magnetic field leads mostly to the decrease of crystallite sizes with no impact on the crystal lattice parameters. In (0 2 0) and (1 5 0) planes the growth of crystallite sizes is observed after 2 and 3 days of crystallization, respectively. The analysis of different contributions to peak broadening in [0 b 0] direction showed a similar trend for the crystallite sizes with the lower lattice microstrains after 2 days of synthesis. The effect similar to the preferred orientation was observed and classified with the Harris method. PMID:26706562

  17. Requirements control system applied to collider dipole magnet development

    International Nuclear Information System (INIS)

    A number of Myths abound in the area of requirements development. The Requirements Control System (RCS) developed and used by General Dynamics on the CDM contract aims to dispel these myths and ensure comprehensive requirements flowdown to elements of the Collider Dipole Magnet (CDM) and the supporting Analysis, Demonstration, Quality Assurance and Master Test Plans. RCS also provides requirements traceability information by providing the source for each requirement, whether it be from a higher level specification, or from a supporting analysis or trade study. The computer is put to work doing what it does best, keeping track of details and checking for consistency and completeness. The myths that the use of RCS attempts to drive away are: I have to design it first so I can determine what the requirements are; I don't have time to write down the requirements; I'm too busy designing; I know what the requirements are; I don't see why I should write them down; If I have to wait for requirements, I'll never get done; The requirements are changing, so why document them until they are finalized? For the CDM program, the source requirements documents are the SSCL 15 Metre CDM Magnet System Specification and the SSCL CDM Interface Control Document. RCS has been used to generate: CDM Prime Item Development Specification; CDM Prime Item Product Fabrication Specification; Prime Item Product Function Specifications [Cold Mass, Cryostat, and Interconnect Region]; Critical Item Specifications [Beam Tube Assembly, and Superconducting Inner and Outer Cables]. Requirements have been further developed for major subassemblies such as the Cold Mass Support Post and other major items of tooling, test equipment, and transportation equipment. The use of RCS has enabled us to accomplish more work in a shorter time than conventional methods would allow

  18. PIXE and PDMS techniques applied to environmental control

    International Nuclear Information System (INIS)

    The airborne particles containing metals are the one of main sources of workers and environmental exposure during mineral mining and milling processes. In order to evaluate the risk of the workers and to the environment due to mineral processes, it is necessary to determine, the concentration and the kinetics of the particles. Furthermore, the chemical composition, particle size and the elemental mass concentration in the fine fraction of aerosol are necessary for evaluation of the risk. Mineral sands are processed to obtain rutile (TiO2), ilmenite (TiFeO3), zircon (ZrSiO4 and monazite (RE3(PO4)) concentrates. The aim of this work was to apply PIXE (Particle Induced X ray Emission) and PDMS (Plasma Desorption Mass Spectrometry) methods to characterize mineral dust particles generated at this plant. The mass spectrum of positive ions of cerium oxide shows that the cerium is associated to oxygen (CeOn). Compounds of thorium (ThO2) and (ThSiO4), Sr, Ca, Zr were also observed in this spectrum. The positive ions mass spectrum of the concentrate of monazite shows that Th was associated to oxygen (ThOn) and Ce was associated to (POn). Also shows compounds of other rare earth as La, Nd and Y. Ions of ZrSiO3, TiO2 and TiFeO3 present in the mass spectra indicate that the concentrate of monazite contains zircon, rutile and ilmenite. Compounds of Cl, Ca, Mn, V, Cu, Zn and Pb also were identified in the mass spectrum. This study shows that PIXE and PDMS techniques can be used as complementary methods for the aerosol analysis. (author)

  19. Multivariable control theory applied to hierarchial attitude control for planetary spacecraft

    Science.gov (United States)

    Boland, J. S., III; Russell, D. W.

    1972-01-01

    Multivariable control theory is applied to the design of a hierarchial attitude control system for the CARD space vehicle. The system selected uses reaction control jets (RCJ) and control moment gyros (CMG). The RCJ system uses linear signal mixing and a no-fire region similar to that used on the Skylab program; the y-axis and z-axis systems which are coupled use a sum and difference feedback scheme. The CMG system uses the optimum steering law and the same feedback signals as the RCJ system. When both systems are active the design is such that the torques from each system are never in opposition. A state-space analysis was made of the CMG system to determine the general structure of the input matrices (steering law) and feedback matrices that will decouple the axes. It is shown that the optimum steering law and proportional-plus-rate feedback are special cases. A derivation of the disturbing torques on the space vehicle due to the motion of the on-board television camera is presented. A procedure for computing an upper bound on these torques (given the system parameters) is included.

  20. Structural lubricity under ambient conditions

    Science.gov (United States)

    Cihan, Ebru; İpek, Semran; Durgun, Engin; Baykara, Mehmet Z.

    2016-01-01

    Despite its fundamental importance, physical mechanisms that govern friction are poorly understood. While a state of ultra-low friction, termed structural lubricity, is expected for any clean, atomically flat interface consisting of two different materials with incommensurate structures, some associated predictions could only be quantitatively confirmed under ultra-high vacuum (UHV) conditions so far. Here, we report structurally lubric sliding under ambient conditions at mesoscopic (∼4,000–130,000 nm2) interfaces formed by gold islands on graphite. Ab initio calculations reveal that the gold–graphite interface is expected to remain largely free from contaminant molecules, leading to structurally lubric sliding. The experiments reported here demonstrate the potential for practical lubrication schemes for micro- and nano-electromechanical systems, which would mainly rely on an atomic-scale structural mismatch between the slider and substrate components, via the utilization of material systems featuring clean, atomically flat interfaces under ambient conditions. PMID:27350035

  1. Diffusing wave spectroscopy applied to material analysis and process control

    International Nuclear Information System (INIS)

    Diffusing Wave Spectroscopy (DWS) was studied as a method of laboratory analysis of sub-micron particles, and developed as a prospective in-line, industrial, process control sensor, capable of near real-time feedback. No sample pre-treatment was required and measurement was via a non-invasive, flexible, dip in probe. DWS relies on the concept of the diffusive migration of light, as opposed to the ballistic scatter model used in conventional dynamic light scattering. The specific requirements of the optoelectronic hardware, data analysis methods and light scattering model were studied experimentally and, where practical, theoretically resulting in a novel technique of analysis of particle suspensions and emulsions of volume fractions between 0.01 and 0.4. Operation at high concentrations made the technique oblivious to dust and contamination. A pure homodyne (autodyne) experimental arrangement described was resilient to environmental disturbances, unlike many other systems which utilise optical fibres or heterodyne operation. Pilot and subsequent prototype development led to a highly accurate method of size ranking, suitable for analysis of a wide range of suspensions and emulsions. The technique was shown to operate on real industrial samples with statistical variance as low as 0.3% with minimal software processing. Whilst the application studied was the analysis of TiO2 suspensions, a diverse range of materials including polystyrene beads, cell pastes and industrial cutting fluid emulsions were tested. Results suggest that, whilst all sizing should be comparative to suitable standards, concentration effects may be minimised and even completely modelled-out in many applications. Adhesion to the optical probe was initially a significant problem but was minimised after the evaluation and use of suitable non stick coating materials. Unexpected behaviour in the correlation in the region of short decay times led to consideration of the effects of rotational diffusion

  2. Biodegradable lubricants for road vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, J. [Denmark Technical Univ., Lyngby (Denmark). Dept. of Mechanical Engineering

    2004-07-01

    This presentation outlined the characteristics of biolubricants and their use in vehicles. Experiments with compression ignition (CI) and spark ignition (SI) engines were also presented. Biolubes can be used in 4-stroke and 2-stroke engines, bearing compressors and hydraulic equipment. Studies have shown that biolubes do not cause unusual engine wear. They are produced from biomass, with the base material being vegetable oils and synthetic esters. Conventional lubricants are produced from fossil fuels, with the base material being mineral oils, polyglycol or synthetic ester. This presentation rated the characteristics of various lubricants in terms of viscosity temperature behaviour, low temperature behaviour, liquid range, oxidation stability, thermal stability, volatility, fire resistance, hydrolytic stability, corrosion protection, seal material compatibility, paints compatibility, miscibility with mineral oil, solubility of additives, lubricating properties, toxicity, and biodegradability. The environmental impacts of biolubes regarding emissions of carbon dioxide, nitrous oxide and particulate matter were discussed along with the impact of combining biolubes with alternative fuels. The future beneficial applications include outboard engines, off road vehicle engines and road vehicle engines. Currently, vegetable oil based biolubricants are 2 to 3 times more expensive than mineral based oils, and synthetic lubricants are even more expensive. It was suggested that future studies should examine the biodegradability of used lubricants, the performance of biodegradable lubricants, alternative fuels and fuel economy. tabs., figs.

  3. Analysis on mechanism of thin film lubrication

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chaohui; LUO Jianbin; HUANG Zhiqiang

    2005-01-01

    It is an important concern to explore the properties and principles of lubrication at nano or molecularscale. For a long time, measurement apparatus for filmthickness of thin film lubrication (TFL) at nano scale havebeen devised on the basis of superthin interferometry technique. Many experiments were carried out to study the lubrication principles of TFL by taking advantages of aforementioned techniques, in an attempt to unveil the mechanism of TFL. Comprehensive experiments were conducted to explore the distinctive characteristics of TFL. Results show that TFL is a distinctive lubrication state other than any known lubrication ones, and serves as a bridge between elastohydrodynamic lubrication (EHL) and boundary lubrication (BL). Two main influence factors of TFL are the solid surface effects and the molecular properties of the lubricant, whose combination effects result in alignment of liquid molecules near the solid surfaces and subsequently lubrication with ordered film emerged. Results of theoretical analysis considering microstructure are consistent with experimental outcomes, thus validating the proposed mechanism.

  4. Molecular-Scale Lubricants for Micromachine Applications: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Burns, A.R.; Dugger, M.T.; Houston, J.E.; Lopez, G.P.; Mayer, T.M.; Michalske, T.A.; Miller, S.L.; Sniegowski, J.J.; Stevens, M.J.; Zhou, Y.

    1998-12-01

    The nature of this work was to develop the physics and chemistry base for understanding molecular-scale lubricants used to reduce of friction- and adhesion-induced failure in silicon micromachines (MEMS). We acquired this new knowledge by tailoring the molecular properties of the lubricants, applying local probes that can directly monitor the response of lubricants in contact conditions, and evaluating the performance of model lubricants MEMS devices. Model lubricants under investigation were the silane coupling agents that form monolayer films on native oxide silicon surfaces, which is the substrate in MEMS. These molecules bind via strong surface bonds and produce a layer of hydro- or fluoro-carbon chains normal to the substrate. "Tailoring" the lubricants entails modifying the chain length, the chain chemical reactivity (H or F), and the density of chain structures. Thus much effort went into understanding the surface chemistry of silane-silicon oxide coupling. With proximal probes such as atomic force microscopy (AFM), interracial force microscopy (FM), and shear force microscopy in combination with IFM, we examined the frictional and adhesive properties of the silane films with very high spatial resolution (< 100 nm) and sensitivity. MEMS structures are treated with silanes under identical conditions, and examined for friction and adhesion under operating conditions. Proper assessment of the lubricants required quantitative analysis of MEMS performance at high speeds and long operating times. Our proximal probe measurements and WS performance analyses form a very important link for future molecular dynamics simulations, that, in turn, should be able to predict MEMS performance under all conditions.

  5. Investigation of the Wheel-Flange Lubrication of Railway Trains

    International Nuclear Information System (INIS)

    A tracer method was applied to investigate the wheel-flange lubrication action of the new Austrian multiple-unit train ''Transalpin''. On electric engines the flanges of the first pair of wheels are lubricated by a pendulum oil pump. This pump starts to work when there is lateral movement of the engine in curves or at high speed on straight lines. The lubricating oil is transferred, while the train is underway, from the first wheel to the inner surface of the rail. From there it should be taken up by the following wheels of the train. In this way the friction between the rails and the wheel flanges can be reduced and as a consequence the wear of material is decreased. Until the present investigation it has not been possible to get quantitative information about the action of this type of lubrication. By adding the tracer 198Au in the form of a colloid to the lubricating oil (specific activity 0.5 Ci/litre), quantitative measurements of the oil transport mechanism could be made on the moving train. The detection of the labelled lubricant was possible even on the last wheels of a train of 44 axles. The oil films which were still detectable on the wheel flanges had a thickness of about 0. 3 microns. By this tracer method, the dependence of lubrication on the speed and the line conditions can also be determined. The tracer method has a wide range of applications in the study of underway conditions in railroad operation including the investigation of the sine movement of trains. (author)

  6. TRIBOLOGICAL PROPERTIES OF CrN COATING UNDER LUBRICATION CONDITIONS

    OpenAIRE

    JANUSZ LUBAS

    2012-01-01

    The paper presents research results of the influence of CrN coating on the friction parameters in friction pairs under lubricated friction conditions. The formed CrN homogeneous coating and CrN-steel 46Cr2 "ring" structure coating was matched under test conditions with a counterpart made from SAE-48 and SAE-783 bearing alloys. Tested sliding pairs were lubricated with 5W/40 Lotos synthetic engine oil. The tribological test was conducted on block-on-ring tester. The applied modification techno...

  7. Gear Mesh Loss-of-Lubrication Experiments and Analytical Simulation

    Science.gov (United States)

    Handschuh, Robert F.; Polly, Joseph; Morales, Wilfredo

    2011-01-01

    An experimental program to determine the loss-of-lubrication (LOL) characteristics of spur gears in an aerospace simulation test facility has been completed. Tests were conducted using two different emergency lubricant types: (1) an oil mist system (two different misted lubricants) and (2) a grease injection system (two different grease types). Tests were conducted using a NASA Glenn test facility normally used for conducting contact fatigue. Tests were run at rotational speeds up to 10000 rpm using two different gear designs and two different gear materials. For the tests conducted using an air-oil misting system, a minimum lubricant injection rate was determined to permit the gear mesh to operate without failure for at least 1 hr. The tests allowed an elevated steady state temperature to be established. A basic 2-D heat transfer simulation has been developed to investigate temperatures of a simulated gear as a function of frictional behavior. The friction (heat generation source) between the meshing surfaces is related to the position in the meshing cycle, the load applied, and the amount of lubricant in the contact. Experimental conditions will be compared to those from the 2-D simulation.

  8. ES and H-compatible lubrication for duplex bearings

    Energy Technology Data Exchange (ETDEWEB)

    Steinhoff, R.G.

    1997-10-01

    Two ES and H-compatible lubricants (environment, safety, and health) for duplex bearing applications and one hybrid material duplex bearing were evaluated and compared against duplex bearings with trichlorotrifluoroethane (Freon) deposition of low molecular weight polytetrafluoroethylene (PTFE) bearing lubricant extracted from Vydax{trademark}. Vydax is a product manufactured by DuPont consisting of various molecular weights of PTFE suspended in trichlorotrifluoroethane (Freon), which is an ozone-depleting solvent. Vydax has been used as a bearing lubricant in strong link mechanisms since 1974. Hybrid duplex bearings with silicon nitride balls and molded glass-nylon-Teflon retainers, duplex bearings lubricated with sputtered MoS{sub 2} on races and retainers, and duplex bearings lubricated with electrophoretic deposited MoS{sub 2} were evaluated. Bearings with electrophoretic deposited MoS{sub 2} performed as well as bearings with Freon deposition of PTFE from Freon-based Vydax. Hybrid bearings with silicon nitride balls performed worse than bearings lubricated with Vydax, but their performance would still be acceptable for most applications. Bearings lubricated with sputtered MoS{sub 2} on the races and retainers had varying amounts of film on the bearings. This affected the performance of the bearings. Bearings with a uniform coating performed to acceptable levels, but bearings with no visible MoS{sub 2} on the races and retainers did not perform as well as bearings with the other coatings. Unless process controls are incorporated in the sputtering process or the bearings are screened, they do not appear to be acceptable for duplex bearing applications.

  9. Thermal, Squeezing and Compressibility Effects in Lubrication of Asymmetric Rollers

    Directory of Open Access Journals (Sweden)

    D. Prasad

    2014-09-01

    Full Text Available Hydrodynamically heavily loaded rigid cylindrical rollers, lubricated by a thin compressible fluid film, are investigated for normal squeezing motion and cavitations. The lubricant is assumed to follow the non-Newtonian power-law fluid model where consistency and density of the lubricant vary with one dimensional pressure and temperature. The modified Reynolds pressure equation and thermal energy equation are derived and solved simultaneously by R-K Fehlberg method. Secant method is also applied in order to enforce the boundary condition at the outlet. It is observed that temperature has significant effects on consistency and density both. It is also to be noted that compressibility effect is even more significant when squeezing is taken into account.

  10. Ionic Liquids as Novel Lubricants and /or Lubricant Additives

    Energy Technology Data Exchange (ETDEWEB)

    Qu, J. [ORNL; Viola, M. B. [General Motors Company

    2013-10-31

    This ORNL-GM CRADA developed ionic liquids (ILs) as novel lubricants or oil additives for engine lubrication. A new group of oil-miscible ILs have been designed and synthesized with high thermal stability, non-corrosiveness, excellent wettability, and most importantly effective anti-scuffing/anti-wear and friction reduction characteristics. Mechanistic analysis attributes the superior lubricating performance of IL additives to their physical and chemical interactions with metallic surfaces. Working with a leading lubricant formulation company, the team has successfully developed a prototype low-viscosity engine oil using a phosphonium-phosphate IL as an anti-wear additive. Tribological bench tests of the IL-additized formulated oil showed 20-33% lower friction in mixed and elastohydrodynamic lubrication and 38-92% lower wear in boundary lubrication when compared with commercial Mobil 1 and Mobil Clean 5W-30 engine oils. High-temperature, high load (HTHL) full-size engine tests confirmed the excellent anti-wear performance for the IL-additized engine oil. Sequence VID engine dynamometer tests demonstrated an improved fuel economy by >2% for this IL-additized engine oil benchmarked against the Mobil 1 5W-30 oil. In addition, accelerated catalyst aging tests suggest that the IL additive may potentially have less adverse impact on three-way catalysts compared to the conventional ZDDP. Follow-on research is needed for further development and optimization of IL chemistry and oil formulation to fully meet ILSAC GF-5 specifications and further enhance the automotive engine efficiency and durability.

  11. Cost-Cutting Powdered Lubricant

    Science.gov (United States)

    2005-01-01

    Scientists at NASA's Glenn Research Center developed a high-temperature, solid lubricant coating material that is saving the manufacturing industry millions of dollars. The material came out of 3 decades of tribological research, work studying high-temperature friction, lubrication, and the wearing of interacting surfaces that are in relative motion. It was developed as a shaft coating deposited by thermal spraying to protect foil air bearings used in oil-free turbomachinery, like gas turbines, and is meant to be part of a larger project: an oil-free aircraft engine capable of operating at high temperatures with increased reliability, lowered weight, reduced maintenance requirements, and increased power. This advanced coating, PS300, is a self-lubricating bearing material containing chromium oxide, with additions of a low-temperature start up lubricant (silver) and a high-temperature lubricant, making it remarkably stable at high temperatures, and better suited than previously available materials for high-stress conditions. It improves efficiency, lowers friction, reduces emissions, and has been used by NASA in advanced aeropropulsion engines, refrigeration compressors, turbochargers, and hybrid electrical turbogenerators. PS300 is ideal in any application where lowered weight and reduced maintenance are desired, and high-temperature uses and heavy operating speeds are expected. It has notable uses for the Space Agency, but it has even further-reaching potential for the industrial realm.

  12. Top-of-Rail lubricant

    Energy Technology Data Exchange (ETDEWEB)

    Alzoubi, M. F.; Fenske, G. R.; Erck, R. A.; Boparai, A. S.

    2000-07-14

    Analysis of the volatile and semivolatile fractions collected after use of the TOR lubricant indicated that other than contaminants in the collection laboratory, no compounds on the EPA's Target Compound Lists (Tables 2 and 5) were detected in these fractions. The data of these qualitative analyses, given in the various tables in the text, indicate only the relative amounts of the tentatively identified compounds. The authors recommend that quantitative analysis be performed on the volatile and semivolatile fractions to allow confirmation of the tentatively identified compounds and to obtain absolute amounts of the detected compounds. Additionally, the semivolatile fraction should be analyzed by liquid chromatography/mass spectrometry to identify compounds that are not chromatographable under the temperature program used for determination of semivolatile compounds. Introducing the top-of-rail (TOR) lubricant into the wheel/rail interface results in a reduction of almost 60% of lateral friction force over the forces encountered under dry conditions. This reveals good potential for energy savings, as well as wear reduction, for railroad companies. In TOR lubrication, an increase in the angle of attack and axle load results in increased lateral friction and rate of lubricant consumption. The most efficient TOR lubricant quantity to be used in the wheel/rail interface must be calculated precisely according to the number of cars, axle loads, train speed, and angle of attack.

  13. Metalworking corrosion inhibition/drawing lubricant

    Energy Technology Data Exchange (ETDEWEB)

    Lipinski, H.F.; Wantling, S.J.

    1980-05-06

    A metalworking lubricant composition is disclosed which is effective as both a corrosion inhibitor and drawing lubricant and comprises a mineral oil and an additive combination of barium lanolate soap and barium sulfonate.

  14. Studies of lubricants and punch design in punching of stainless steel

    DEFF Research Database (Denmark)

    Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson

    Environmentally hazardous lubricants such as chlorinated paraffin oils are often applied in punching and blanking operations especially involving stainless steel workpiece materials. This is due to the fact that punching and blanking are among the tribologically most difficult forming operations...

  15. How to evaluate solid lubricant films using a pin-on-disk tribometer

    Science.gov (United States)

    Fusaro, R. L.

    1986-01-01

    Over the years, the author has evaluated and compared hundreds of solid lubricant films using a pin-on-disk tribometer. The intent of this paper is to describe to the reader experimental techniques and some of parameters that have been observed to be important for the evaluation and development of new solid lubricant films. Pin-on-disk tribometers will be described and discussed as will experimental methods for evaluating solid lubricant materials. Methods of preparing surfaces for the coating of the thin films and different methods for applying the films will be reviewed. Factors that affect solid lubricant performance will also be discussed. Two different macroscopic mechanisms of solid lubricant film wear exist. These will be characterized schematically, and methods of measuring wear will be examined.

  16. Biodegradation and toxicological evaluation of lubricant oils

    OpenAIRE

    Ivo Shodji Tamada; Paulo Renato Matos Lopes; Renato Nallin Montagnolli; Ederio Dino Bidoia

    2012-01-01

    The aim of this work was to compare different toxicity levels of lubricant oils. The tests were performed using the earthworm (Eisenia andrei), arugula seeds (Eruca sativa) and lettuce seeds (Lactuca sativa), with three types of contaminants (mineral lubricant oil, synthetic lubricant oil and used lubricant oil) for various biodegradation periods in the soil. The toxicity tests indirectly measured the biodegradation of the contaminants. The samples were analyzed at t0, t60, t120 and t180 days...

  17. CYLINDER AND SYSTEM LUBRICATING OILS

    Directory of Open Access Journals (Sweden)

    ION ADRIAN GIRBA

    2016-06-01

    Full Text Available Increased thermal efficiency, savings in the fuel consumption and the possibility to burn low quality fuels conducted to an intense development of marine engines in past 20 years, this progress being emphasized by the increased combustion pressures and better combustion properties. These improvements represent a continuous challenge for lubricating oil manufacturers: the rise in combustion temperatures and pressures is making difficult to preserve the oil film in critical areas and the longer strokes of the piston leads to issues of spreading the oil. Adding here the new type of engines using gas or biofuel which requires different types of lubricating oils. Therefore, the success of new generation of engines will depend on lubricating oils quality. :

  18. Tethered Lubricants for Small Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lynden A. Archer

    2006-01-09

    The objective of this research project is two-fold. First, to fundamentally understand friction and relaxation dynamics of polymer chains near surfaces; and second, to develop novel self-lubricated substrates suitable for MEMS devices. During the three-year performance period of this study the PI and his students have shown using theory and experiments that systematic introduction of disorder into tethered lubricant coatings (e.g. by using self-assembled monolayer (SAM) mixtures or SAMs with nonlinear, branched architectures) can be used to significantly reduce the friction coefficient of a surface. They have also developed a simple procedure based on dielectric spectroscopy for quantifying the effect of surface disorder on molecular relaxation in lubricant coatings. Details of research accomplishments in each area of the project are described in the body of the report.

  19. Hybrid model predictive control applied to switching control of burner load for a compact marine boiler design

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Maciejowski, Jan;

    2008-01-01

    This paper discusses the application of hybrid model predictive control to control switching between different burner modes in a novel compact marine boiler design. A further purpose of the present work is to point out problems with finite horizon model predictive control applied to systems for w...

  20. Analysis, Modelling, and Simulation of Droop Control with Virtual Impedance Loop Applied to Parallel UPS Systems

    DEFF Research Database (Denmark)

    Lima, Francisco Kleber A.; Branco, Carlos Gustavo C.; Guerrero, Josep M.;

    2013-01-01

    This paper explores a control strategy for parallel uninterruptible power systems (UPS). The control technique used in that work was based on the droop control method. This method is usually applied to achieve good active and reactive power sharing when communication between the inverters is diff...

  1. 40 CFR 1060.103 - What permeation emission control requirements apply for fuel tanks?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What permeation emission control requirements apply for fuel tanks? 1060.103 Section 1060.103 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT...

  2. 40 CFR 1060.102 - What permeation emission control requirements apply for fuel lines?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What permeation emission control requirements apply for fuel lines? 1060.102 Section 1060.102 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT...

  3. 40 CFR 1060.104 - What running loss emission control requirements apply?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What running loss emission control requirements apply? 1060.104 Section 1060.104 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Emission Standards...

  4. Plug and Play Process Control Applied to a District Heating System

    DEFF Research Database (Denmark)

    Knudsen, Torben; Trangbæk, Klaus; Kallesøe, Carsten Skovmose

    2008-01-01

    The general ideas within plug and play process control (PTC) are to initialize and reconfigure control systems just by plug and play. In this paper these ideas are applied to a district heating pressure control problem. First of all this serves as a concrete example of PTC, secondly some of the f...

  5. Laboratory services series: a lubrication program

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, H.B.; Miller, T.L.

    1976-05-01

    The diversity of equipment and operating conditions at a major national research and development laboratory requires a systematic, effective lubrication program. The various phases of this program and the techniques employed in formulating and administering this program are discussed under the following topics: Equipment Identification, Lubrication Requirements, Assortment of Lubricants, Personnel, and Scheduling.

  6. A new lubricant carrier for metal forming

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Bay, Niels; Tang, Peter Torben;

    2009-01-01

    A lubricant carrier for metal forming processes is developed. Surfaces with pores of micrometer size for entrapping lubricant are generated by electrochemical deposition of an alloy, consisting of two immiscible metals, of which one metal subsequently is etched away leaving 5 mu m layers with a s...... extrusion at high reduction and excessive stroke comparing with conventionally lubrication using phosphate coating and soap....

  7. Lubrication greases for nuclear reactors

    International Nuclear Information System (INIS)

    Lubricating greases are essential components of many machines used in nuclear power plants. Where these machines are subject to radiation the life of the grease will be reduced due to deterioration of the components of the grease. According to the chemical nature of the grease used a greater or lesser resistance to radiation will be observed. Tests and techniques to evaluate the performance of greases before and after irradiation are described. The results of these tests show that conventional premium greases will resist comparatively low levels of irradiation, whilst greases formulated from correctly selected components can tolerate quite high levels of radiation permitting the machines they lubricate to attain their designed service lives

  8. New approach in lubrication engineering using neutron reflectometry

    International Nuclear Information System (INIS)

    According to historic papers in lubrication engineering, lubrication modes between two solids are essentially classified into three groups - boundary lubrication, mixed lubrication and full-film lubrication. This paper proposed some novel approaches for elucidation of lubrication phenomena using neutron reflectometry. For the studies on boundary lubrication, the neutron reflectometry is helpful to in-situ observe the 'absorbed layer' near the solid surface, while for the studies on full-film lubrication, it can reveal the density of lubricants at the solid-liquid interface. Those information will help to clarify the friction mechanism under lubrication in the field of tribology. (author)

  9. FUZZY CONTROLLER AND NEURAL ESTIMATOR APPLIED TO CONTROL A SYSTEM POWERED BY THREE-PHASE INDUCTION MOTOR

    OpenAIRE

    Élida Fernanda Xavier Júlio; Simplício Arnaud da Silva; Cícero da Rocha Souto

    2015-01-01

    In this study, a control strategy is presented to control the position and the feed rate of a table of a milling machine powered by three-phase induction motor, when machining pieces constituted by different types of materials: steel, brass and nylon. For development of the control strategy, the vector control technique was applied to drive the three-phase induction machines. The estimation of the electromagnetic torque of the motor was used to determine the machining feed rate fo...

  10. Analysis, Modelling, and Simulation of Droop Control with Virtual Impedance Loop Applied to Parallel UPS Systems

    OpenAIRE

    Lima, Francisco Kleber A.; Branco, Carlos Gustavo C.; Josep M. Guerrero; Neto, Luis Juarez C.; Carvalho, Samuel S.; Torrico-Bascope, Rene P.

    2013-01-01

    This paper explores a control strategy for parallel uninterruptible power systems (UPS). The control technique used in that work was based on the droop control method. This method is usually applied to achieve good active and reactive power sharing when communication between the inverters is difficult due to its physical location. This paper has considered that the UPS systems there were no comunication between their controls. A detailed mathematical model about the explored system is shown i...

  11. 40 CFR 1065.122 - Engine cooling and lubrication.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Engine cooling and lubrication. 1065.122 Section 1065.122 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.122 Engine cooling...

  12. Self lubrication of bitumen froth in pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, D.D. [Univ. of Minnesota, Minneapolis, MN (United States)

    1997-12-31

    In this paper I will review the main properties of water lubricated pipelines and explain some new features which have emerged from studies of self-lubrication of Syncrudes` bitumen froth. When heavy oils are lubricated with water, the water and oil are continuously injected into a pipeline and the water is stable when in a lubricating sheath around the oil core. In the case of bitumen froth obtained from the Alberta tar sands, the water is dispersed in the bitumen and it is liberated at the wall under shear; water injection is not necessary because the froth is self-lubricating.

  13. DSC: software tool for simulation-based design of control strategies applied to wastewater treatment plants.

    Science.gov (United States)

    Ruano, M V; Ribes, J; Seco, A; Ferrer, J

    2011-01-01

    This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communication protocol for different industrial process applications. The potential capabilities of the DSC tool are illustrated through the example of a full-scale application. An aeration control system applied to a nutrient removing WWTP was designed, tuned and evaluated with the DSC tool before its implementation in the full scale plant. The control parameters obtained by simulation were suitable for the full scale plant with only few modifications to improve the control performance. With the DSC tool, the control systems performance can be easily evaluated by simulation. Once developed and tuned by simulation, the control systems can be directly applied to the full-scale WWTP. PMID:21330730

  14. A decentralized Fuzzy Logic enhanced variable structure controller applied to load frequency control system

    International Nuclear Information System (INIS)

    This paper present a variable structure based approach to the load frequency control system problem in electric power generation systems. This approach combines the salient features of both variable structure and Fuzzy systems to achieve high-performance and robustness. The control signal consists of equivalent control, switching control and Fuzzy control components. The influence of system nonlinearities such as generation rate constraint and governor dead band is considered. In results show that the system responses are strongly robust for parameter variations

  15. Some consideration regarding the political control of constitutionality as a primary applied form of control (France)

    OpenAIRE

    DANIELA CRISTINA VALEA

    2007-01-01

    France is the state where the political control of constitutionality has found its full consecration, where the opposition to the jurisdictional control of constitutionality was so strong that, when the political control failed, transfer was made directly to the political-jurisdictional control of constitutionality. This paper has attempted to provide an overview of the historical evolution of the control of constitutionality, which was present in the French constitutional system only under i...

  16. Vegetable oil basestocks for lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Garces, R.; Martinez-Force, E.; Salas, J.

    2011-07-01

    The use of vegetable biodegradable basestocks for lubricant oils present several advantages over the much more extended mineral bases. These advantages refer to biodegradability, a renewable feedstock of local production, lubricant and viscosity index and lower costs than synthetic lubricant bases. Despite these benefits, their use in industry and motor vehicles is not yet extensive due their lower stability and higher pour points. Vegetable oils are esters of fatty acids and glycerol, and their physicochemical properties rely mainly on the composition of their acyl moieties. Thus, to assure the maximum levels of stability while maintaining acceptable behavior at low temperatures, monounsaturated fatty acids are preferred for this purpose. The presence of natural antioxidants also improves the properties of these vegetable based stocks as lubricants. These oils usually require additives to improve their viscosity value, oxidative stability and properties at low temperatures. In the present work, the different sources of vegetable oils appropriate for biolubricant production were reviewed. Their properties and the future improvement of the oil bases, oil based stock production, uses and additives are discussed. (Author).

  17. Longevity Of Dry Film Lubricants

    Science.gov (United States)

    Kannel, J. W.; Stockwell, R. D.

    1993-01-01

    Report describes evaluation of dry film lubricants candidate for use in rotary joints of proposed Space Station. Study included experiments and theoretical analyses focused on longevity of sputtered molybdenum disulfide films and ion-plated lead films under conditions partially simulating rolling contact.

  18. Thin Film Solid Lubricant Development

    Science.gov (United States)

    Benoy, Patricia A.

    1997-01-01

    Tribological coatings for high temperature sliding applications are addressed. A sputter-deposited bilayer coating of gold and chromium is investigated as a potential solid lubricant for protection of alumina substrates during sliding at high temperature. Evaluation of the tribological properties of alumina pins sliding against thin sputtered gold films on alumina substrates is presented.

  19. Automotive Cooling and Lubricating Systems.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide new mechanics with a source of study materials to assist them in becoming more proficient in their jobs. The course contains four study units covering automotive cooling system maintenance, cooling system repair, lubricating systems, and lubrication…

  20. New lubricating material for hydraulic turbine equipment

    International Nuclear Information System (INIS)

    The release of lubricant into the water stream after passage through hydraulic turbines is an environmental issue of concern. To address concerns about the self-lubricating bearing materials being used to replace the standard grease lubricated bronze bearings for wicket gates, a survey was carried out to determine the availability and use of self-lubricating bearing materials. Included in the survey were users, bearing suppliers and turbine manufacturers. Information derived from the survey included extent of use, historical data, bearing design parameters, lubrication practices, maintenance activity, and environmental issues. Results of the survey are tabulated. It was found that the use of self-lubricating bearing materials is the predominant technology available to satisfy environmental concerns for hydraulic equipment. A number of materials are available based on both metallic and polymer materials. A numer of materials are available that have demonstrated satisfactory service life for at least 10 years. As an alternative, hydraulic equipment can be lubricated with an environmentally friendly lubricant, although there are none commercially available that are biodegradable and non-toxic. In new equipment the cost of using self-lubricating bearings could be less than grease lubricated bronze bearings with automatic lubrication system. 3 refs., 4 figs., 3 tabs

  1. Airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 for treatment of lubricants in wastewater

    International Nuclear Information System (INIS)

    Highlights: ► Sphingobium sp. P2 effectively degraded various lubricant samples. ► Efficiency of Sphingobium sp. P2 increased after immobilization on chitosan. ► High removal efficiency was due to both sorption and degradation processes. ► The immobilized bacteria (4 g L−1) were applied in internal loop airlift bioreactor. ► The bioreactor continuously removed lubricant from emulsified wastewater. - Abstract: An internal loop airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 was applied for the removal of automotive lubricants from emulsified wastewater. The chitosan-immobilized bacteria had higher lubricant removal efficiency than free and killed-immobilized cells because they were able to sorp and degrade the lubricants simultaneously. In a semi-continuous batch experiment, the immobilized bacteria were able to remove 80–90% of the 200 mg L−1 total petroleum hydrocarbons (TPH) from both synthetic and carwash wastewater. The internal loop airlift bioreactor, containing 4 g L−1 immobilized bacteria, was later designed and operated at 2.0 h HRT (hydraulic retention time) for over 70 days. At a steady state, the reactor continuously removed 85 ± 5% TPH and 73 ± 11% chemical oxygen demand (COD) from the carwash wastewater with 25–200 mg L−1 amended lubricant. The internal loop airlift reactor's simple operation and high stability demonstrate its high potential for use in treating lubricants in emulsified wastewater from carwashes and other industries.

  2. Friction Regimes in the Lubricants Solid-State Regime

    OpenAIRE

    Schipper, D.J.; Maathuis, O.; Dowson, D; Taylor, C.M.; Childs, T.H.C.; Dalmaz, G.

    1995-01-01

    Friction measurements were performed in the lubricant's solid-state regime to study the transition from full-film lubrication, in which the separation is maintained by a solidified lubricant, to mixed lubrication. Special attention is paid to the influence of temperature (inlet viscosity) and roughness on this transition. The friction measurements showed that in the lubricants solid-state region three lubrication modes can be distinguished: A) full-film lubrication; separation is maintained b...

  3. ELASTOHYDRODYNAMIC LUBRICATION OF LOGARITHMIC PROFILE ROLLER CONTACTS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An account of numerical solutions to the isothermal and flooded elastohydrodynamic lubrication(EHL)of a logarithmic profile roller, which is rolling over a flat plane,is givenThe analysis takes account of sidew ays flow of lubricant in the inlet region of the contactWhen the results are p resented in suitable nondimensional groups,it is shown that more uniformly pre ssure and shape of the film distributing in axial direction is taken place under light loadingAs the increase of the load,the end closure is displayed and the oil pressure rises sharply at the endsThe seal action formed by the end closu re makes the film thickness a littleAnd the minimum film thickness is transfer red from the central to the ends and the value is reduced rapidlyAs the increa se of the speed,the end closure becomes much seriousThe optimum crowning value obtained in EHL state is larger than the design value obtained in elastostatic contact state for the same working conditionsIn order to verify the correctnes s of theory,optical interferometry is applied to measure the oil film thickness between a logarithmic profiled roller and a glass plate under pure rolling condi tionsIt is found the agreement between numerical solutions and experiments is very good

  4. Case Study of Various Parameters by Applying Swing Up Control for Inverted Pendulum

    OpenAIRE

    Kunal Chakraborty; Amit Kumar Sen; Rahul Dev Basak; Rahul Raushan

    2015-01-01

    This paper investigates behavior of the system in terms of time response e.g., steady state error, rise time & overshoot & then compare it with FLC. Being an unstable system, Inverted Pendulum is very common control problem being assigned to control its dynamics. It is almost impossible to balance a pendulum in the inverted position except applying some force from outside to the system.

  5. AFC applied to HVDC interconnected systems and multivariable control. Chokuryu renkeiyo AFC to tahensu seigyo

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, M. (Electric Power Development Co. Ltd., Tokyo (Japan)); Tsumenaga, M. (Toshiba Corp., Tokyo (Japan))

    1993-06-20

    Together with a growth of the power demand as well as becoming to be a higher degree and diversification of the social function, the power system has been getting more and more complicated. By the digital technology, which has remarkably developed in recent years, in addition, the control theory in a high level, which had been hard to be handled by the conventional technology, has become possible to be applied for the control devices, also in the control system of the power system. In this paper, an example applied the multivariable control, the modern control theory has been utilized, for the automatic frequency control(AFC) of the HVDC interconnected systems, which connect two power systems, is introduced. In order to verify the control performance of AFC applied the multivariable control, in addition, the AFC device is manufactured, and then the simulation is performed by combining it with the power system simulator simulated two AC systems and one DC interconnected system. When the multivariable controlled AFC is compared with the conventional AFC as for the frequency fluctuation, it is clearly found that the control performance of the former is better than the latter. 2 refs., 5 figs., 1 tab.

  6. Manual-control Analysis Applied to the Money-supply Control Task

    Science.gov (United States)

    Wingrove, R. C.

    1984-01-01

    The recent procedure implemented by the Federal Reserve Board to control the money supply is formulated in the form of a tracking model as used in the study of manual-control tasks. Using this model, an analysis is made to determine the effect of monetary control on the fluctuations in economic output. The results indicate that monetary control can reduce the amplitude of fluctuations at frequencies near the region of historic business cycles. However, with significant time lags in the control loop, monetary control tends to increase the amplitude of the fluctuations at the higher frequencies. How the investigator or student can use the tools developed in the field of manual-control analysis to study the nature of economic fluctuations and to examine different strategies for stabilization is examined.

  7. Design and Experiment of Slave Computer Control System for Applying Variable-rate Liquid Fertilizer

    Institute of Scientific and Technical Information of China (English)

    Zhang Ying-zi; Chen Hai-tao; Hou Shou-yin; Ji Wen-yi; Ouyang Bin-lin; Dun Guo-qiang; Zhang Ji-cheng

    2015-01-01

    In order to increase the applying rate of liquid fertilizer and reduce environmental pollution, a slave computer control system for applying variable-rate liquid fertilizer was designed. The system used SMC as core processor and electrically controlled pressure regulator as execution component. The characteristic equation of the system was obtained by using classical control theory. Results indicated that the characteristic equation met the requirements of routh-criterion, which indicated the working process of the system was stable. Performance of the slave computer was verified via bench tests. Results demonstrated that there was no significant influence on the response from interclass error. The fertilization error was less than 0.9, and the fertilization accuracy was larger than 97%. The liquid fertilizer emitted by the fertilizing devices had no significant difference in uniformity, which met the demands of the slave computer control system for applying variable-rate liquid fertilizer.

  8. Active Vibration Isolation Control: Comparison of Feedback and Feedforward Control Strategies Applied to Coriolis Mass-Flow Meters (I)

    OpenAIRE

    Ridder, de, J.; Hakvoort, W.B.J.; van Dijk

    2015-01-01

    In this paper we describe the design, implementation and results of multi degree of freedom (DOF) active vibration control for a Coriolis mass-flow meter (CMFM). Without vibration control, environmental vibrational disturbances results in nanometre movement of the fluid-conveying tube which causes erroneous mass-flow measurements. In order to reduce the transmissibility from external vibrations to the internal tube displacement active vibration control is applied. A comparison of a feedback c...

  9. Experimental identification of dynamic coefficients of lightly loaded tilting-pad bearings under several lubrication regimes

    DEFF Research Database (Denmark)

    Salazar, Jorge G.; Santos, Ilmar F.

    2016-01-01

    ) radial injection nozzles, (d) displacement sensors and (e) well-tuned digital controllers. A scaled-down industrial rotor featuring active lubrication, composed of a flexible rotor supported by a four-rocker load-between-pads tilting-pad bearing under light load condition, is used for this objective. The......This paper presents the identified dynamic coefficients of a lightly loaded actively lubricated bearing under three lubrication regimes: passive, hybrid and feedback-controlled. The goal is to experimentally demonstrate the feasibility of modifying the bearing dynamic properties via active...... lubrication. Dominated by the latest two regimes, the bearing properties become adjustable or controllable due to the injection of either a constant or variable pressurized oil flow. Such a flow is regulated by a hydraulic control system composed of (a) a high-pressure oil supply unit, (b) servovalves, (c...

  10. Database Security System for Applying Sophisticated Access Control via Database Firewall Server

    OpenAIRE

    Eun-Ae Cho; Chang-Joo Moon; Dae-Ha Park; Kang-Bin Yim

    2014-01-01

    Database security, privacy, access control, database firewall, data break masking Recently, information leakage incidents have occurred due to database security vulnerabilities. The administrators in the traditional database access control methods grant simple permissions to users for accessing database objects. Even though they tried to apply more strict permissions in recent database systems, it was difficult to properly adopt sophisticated access control policies to commercial databases...

  11. Operational proving of flame resistant governor and lubricating oil in two district heating power station turbine generators

    International Nuclear Information System (INIS)

    For six years positive operating experience has been available from two different types of oil produced by the leading manufacturers of flame resistant governor and lubricating oil for a turbine-generator set filled with phosphoric acid esters in the control and lubricating circuits. In September 1979 flame resitant governor and lubricating oil was inserted into a second, larger machine with a higher load factor. The paper reports on action on and results and experience from both plants which were not originally designed for operation with flame resistant governor and lubricating oils. (orig.)

  12. Analysis of modern optimal control theory applied to plasma position and current control in TFTR

    International Nuclear Information System (INIS)

    The strong compression TFTR discharge has been segmented into regions where linear dynamics can approximate the plasma's interaction with the OH and EF power supply systems. The dynamic equations for these regions are utilized within the linear optimal control theory framework to provide active feedback gains to control the plasma position and current. Methods are developed to analyze and quantitatively evaluate the quality of control in a nonlinear, more realistic simulation. Tests are made of optimal control theory's assumptions and requirements, and the feasibility of this method for TFTR is assessed

  13. The influence oil film lubrication of the piston-cylinder dynamic

    Directory of Open Access Journals (Sweden)

    Adriana Tokar

    2008-10-01

    Full Text Available An analytical study of the dynamics of a piston in a reciprocating engine was conducted. The equation of Reynolds and moving of piston are derived. The analysis, which incorporates a hydrodynamic lubrication model, was applied to M501 diesel engine. The results of this study indicate that piston dynamics were found to be sensitive to piston-cylinder bore clearance, location of the wrist pin and lubricant viscosity, underscoring their importance in engine design.

  14. Estimation of appropriate lubricating film thickness in ceramic-on-ceramic hip prostheses

    Science.gov (United States)

    Tauviqirrahman, M.; Muchammad, Bayuseno, A. P.; Ismail, R.; Saputra, E.; Jamari, J.

    2016-04-01

    Artificial hip prostheses, consisting of femoral head and acetabular cup are widely used and have affected the lives of many people.However, the primary issue associated with the long term performance of hip prostheses is loosening induced by excessive wear during daily activity. Therefore, an effective lubrication is necessary to significantly decrease the wear. To help understand the lubricating performance of such typical hip joint prostheses, in the present paper a hydrodynamic lubrication model based on Reynolds equationwas introduced. The material pairs of ceramic acetabular cup against ceramic femoral head was investegated.The main aim of this study is to investigate of the effect of loading on the formation of lubricating film thickness.The model of a ball-in-socket configuration was considered assuming that the cup was stationary while the ball was to rotate at a steady angular velocityvarying loads.Based on simulation result, it was found that to promote fluid film lubrication and prevent the contacting components leading to wear, the film thickness of lubricant should be determined carefully based on the load applied. This finding may have useful implication in predicting the failure of lubricating synovial fluid film and wear generation in hip prostheses.

  15. True Stability of Lubricants Determined Using the Ball-on-Disk Test

    Directory of Open Access Journals (Sweden)

    Angela Maria Tortora

    2016-01-01

    Full Text Available True stability of lubricants can be determined when there is minimum change in the contact area and also the intervention of wear debris in the contact zone. Here, we have used the ball-on-disk instrument with the migrating point contact, that is, relative motion between the ball and disk condition to fix the contact area and minimize the wear debris at the contact zone. The jump in the friction coefficient indicates the film failure, which appeared earlier for the motor oil 5W30 compared to 5W40. Such profile was not recorded in absence of relative motion. Therefore, 5W40 was considered to have a better lubricant stability than 5W30. Applying the same test condition to the natural lubricants shows that glycerol has better lubricant stability than glycerol-water mixture. Superior true lubricant stability by glycerol and 5W40 can be related to its high viscosity. However, they were less wear resistant compared to low viscosity lubricants like 5W30 and glycerol-water. We suspect the role of microscopic wear debris at the contact zone for this behavior although it should have been avoided in the migrating point contact condition. Overall, ball-on-disk instrument with a migrating point contact condition is an effective technique to determine the stability of lubricants.

  16. ¬Mesenchymal Stem Cell Fate: Applying Biomaterials for Control of Stem Cell Behaviour

    OpenAIRE

    Hilary Jane Anderson; Matthew John Dalby; Jugal eSahoo; Rein eUljin

    2016-01-01

    Mesenchymal Stem Cell Fate: Applying Biomaterials for Control of Stem Cell BehaviourHilary J Anderson1, Jugal Kishore Sahoo2, Rein V Ulijn2,3, Matthew J Dalby1*1 Centre for Cell Engineering, University of Glasgow, Glasgow, UK.2 Technology and Innovation centre, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK. 3 Advanced Science Research Centre (ASRC) and Hunter College, City University of New York, NY 10031, NY, USA. Correspondence:*Hilary Andersonh.anderson...

  17. Experimental Identification of Dynamic Coefficients of Tilting-Pad Bearings with Active Lubrication

    DEFF Research Database (Denmark)

    Salazar, Jorge Andrés González; Cerda Varela, Alejandro Javier; Santos, Ilmar

    supply unit, b) servovalves, c) radial injection nozzles, d) displacement sensors and e) well-tuned digital controllers which turn the bearing static and dynamic properties controllable. A scaled-down industrial rotor, composed by a flexible rotor supported by a four rocker LBP tilting-pad journal......This article presents the experimental identification of the equivalent dynamic coefficients of an activelylubricated bearing under different lubrication regimes, namely: passive (no injection flow), hybrid (constant injection flow) and feedback-controlled (variable injection flow) lubrication. The...... bearing featuring active lubrication under light load conditions, is used for such a goal. The experimental identification is performed in the frequency domain by means of the measured FRFs and a finite element model of the rotor. The comparison between results under the different lubrication regimes...

  18. Interoperability for Space Mission Monitor and Control: Applying Technologies from Manufacturing Automation and Process Control Industries

    Science.gov (United States)

    Jones, Michael K.

    1998-01-01

    Various issues associated with interoperability for space mission monitor and control are presented in viewgraph form. Specific topics include: 1) Space Project Mission Operations Control Architecture (SuperMOCA) goals and methods for achieving them; 2) Specifics on the architecture: open standards ad layering, enhancing interoperability, and promoting commercialization; 3) An advertisement; 4) Status of the task - government/industry cooperation and architecture and technology demonstrations; and 5) Key features of messaging services and virtual devices.

  19. [Effects of applying controlled-release compound fertilizer on Platycodon grandiflorum growth].

    Science.gov (United States)

    Zhu, Li-xiang; Wang, Jian-hua

    2010-09-01

    A pot experiment was conducted in 2008 to study the effects of applying controlled-release compound fertilizer (N:P2O5:K2O = 14:14:14) on the growth of Platycodon grandiflorum in the medicinal herbal farm of Shandong Agricultural University. Comparing with the application of common compound fertilizer (N:P2O5: K2O=15: 15: 15), applying equivalent amount of the controlled-release fertilizer increased the leaf chlorophyll content, root volume, root activity, and root diameter of P. grandiflorum at the late growth stage, but decreased the root length. When the N application rate was 0.24 and 0.32 g x kg(-1) soil, applying the controlled-release compound fertilizer increased the root yield by 26.78% and 22.50%, and the root soluble sugar, protein, and total saponin contents by 9.77% and 6.99%, 11.38% and 2.20%, and 8.85% and 5.47%, respectively, compared with applying the common compound fertilizer. More nitrogen application made the root soluble sugar content decreased but the total saponin content increased. Under our experimental condition, applying the controlled-release compound fertilizer with an application rate of 0.24 g N x kg(-1) soil could obtain the best effect for P. grandiflorum. PMID:21265152

  20. Lubricated friction between incommensurate substrates

    OpenAIRE

    Vanossi, Andrea; Santoro, Giuseppe E.; Manini, Nicola; Tosatti, Erio; Braun, O. M.

    2007-01-01

    This paper is part of a study of the frictional dynamics of a confined solid lubricant film - modelled as a one-dimensional chain of interacting particles confined between two ideally incommensurate substrates, one of which is driven relative to the other through an attached spring moving at constant velocity. This model system is characterized by three inherent length scales; depending on the precise choice of incommensurability among them it displays a strikingly different tribological beha...

  1. Applied Joint-Space Torque and Stiffness Control of Tendon-Driven Fingers

    Science.gov (United States)

    Abdallah, Muhammad E.; Platt, Robert, Jr.; Wampler, Charles W.; Hargrave, Brian

    2010-01-01

    Existing tendon-driven fingers have applied force control through independent tension controllers on each tendon, i.e. in the tendon-space. The coupled kinematics of the tendons, however, cause such controllers to exhibit a transient coupling in their response. This problem can be resolved by alternatively framing the controllers in the joint-space of the manipulator. This work presents a joint-space torque control law that demonstrates both a decoupled and significantly faster response than an equivalent tendon-space formulation. The law also demonstrates greater speed and robustness than comparable PI controllers. In addition, a tension distribution algorithm is presented here to allocate forces from the joints to the tendons. It allocates the tensions so that they satisfy both an upper and lower bound, and it does so without requiring linear programming or open-ended iterations. The control law and tension distribution algorithm are implemented on the robotic hand of Robonaut-2.

  2. Control Method for Electromagnetic Unmanned Robot Applied to Automotive Test Based on Improved Smith Predictor Compensator

    Directory of Open Access Journals (Sweden)

    Gang Chen

    2015-07-01

    Full Text Available A new control method for an electromagnetic unmanned robot applied to automotive testing (URAT and based on improved Smith predictor compensator, and considering a time delay, is proposed. The mechanical system structure and the control system structure are presented. The electromagnetic URAT adopts pulse width modulation (PWM control, while the displacement and the current doubles as a closed-loop control strategy. The coordinated control method of multiple manipulators for the electromagnetic URAT, e.g., a skilled human driver with intelligent decision-making ability is provided, and the improved Smith predictor compensator controller for the electromagnetic URAT considering a time delay is designed. Experiments are conducted using a Ford FOCUS automobile. Comparisons between the PID control method and the proposed method are conducted. Experimental results show that the proposed method can achieve the accurate tracking of the target vehicle’s speed and reduce the mileage derivation of autonomous driving, which meets the requirements of national test standards.

  3. Preparation and Tribological Study of Biodegradable Lubrication Films on Si Substrate

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2015-04-01

    Full Text Available A novel method for preparing eco-biodegradable lubricant based on hydroxypropyl methylcellulose (HPMC via hydration process is demonstrated. The smooth and homogeneous HPMC coating has a uniform thickness (~35 μm. It has been demonstrated that the preparation parameters play a critical role in controlling the lubricating behavior of the coating; in addition, excess HPMC and water concentration suppress the tribology properties. Nevertheless, a remarkable friction-reduction and anti-wear performance has been obtained. Impressively, the preparation parameter of 5% HPMC + 30 mL water significantly improves lubricant performance and durability. A simple approach for the water-degradability evaluation of HPMC is proposed.

  4. Used lubricants and ecological problems

    International Nuclear Information System (INIS)

    This planet is undergoing a severe ecological crisis. The consequent problems include not only how to prevent the destruction of contemporary civilization, but also how to preserve mankind as a biological species. In the onset of this crisis, used lubricants (ULs) play a role that is by no means the least important. Every year, the worldwide discharge of petroleum products to the biosphere is approximately 6 million tonnes, of which more than 50% consists of ULs. The ecologically dangerous components of both commercial lubricants and used lubricants are the polycyclic aromatic hydrocarbons (PAHs) that are originally present in crude oil; polyhalobiphenyls, mainly polychlorobiphenyls (PCBs) of anthropogenic origin; sulfur- and chlorine-containing additives; a number of biocides; organic compounds of metals (lead, barium, antimony, zinc); and nitrites. These substances are distributed in the atmosphere, water, and soil, entering the food chain and appearing in foodstuffs. Moreover, hydrocarbons of petroleum and synthetic oils with a low degree of biodegradability (10-30%) accumulate in the environment and may shift the ecological equilibrium (accelerated multiplication and mutation of microorganisms that assimilate petroleum products). 32 refs., 1 fig

  5. Wet friction materials and lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Takayuki

    1988-02-01

    There are wet and dry friction materials used for friction clutches and friction brakes. Wet friction materials include sintered alloys and semimetallic substances. Paper friction materials which are the most common wet friction materials used in automobiles were studied for their performance and their relation to lubricants. All present paper friction materials are non-asbestos paper friction materials. The requirements for paper friction material performance are as follows: (1) The heat resistance and durability are so high that the material can stand sliding for a long time. (2) The friction curve is flat. (3) The mechanical strength, wear resistance, and resistance to oil pressure are high. (4) The coefficient of friction (particularly, of static friction) is very high. (5) Variations in the coefficient of friction with time are low. The friction characteristics and wear of paper friction materials are influenced by the lubricant used together with the paper friction materials. It is necessary to develop materials which are immune to the influence of the lubricant. (11 figs, 3 tabs, 21 refs)

  6. A Study of Advanced Modern Control Techniques Applied to a Twin Rotor MIMO System

    Science.gov (United States)

    Phillips, Andrew E.

    The twin rotor MIMO system (TRMS) is a helicopter-like system that is restricted to two degrees of freedom, pitch and yaw. It is a complicated nonlinear, coupled, MIMO system used for the verification of control methods and observers. There have been many methods successfully applied to the system ranging from simple proportional integral derivative (PID) controllers, to machine learning algorithms, nonlinear control methods and other less explored methods like deadbeat control and various optimal methodologies. This thesis details the design procedure for two different control methods. The first is a suboptimal tracking controller using a linear quadratic regulator (LQR) with integral action. The second is the design of several adaptive sliding mode controller to provide robust tracking control of the TRMS. Once the design is complete the controllers are tested in simulation and their performance is compared against a PID controller experimentally. The performance of the controllers are also compared against other controllers in the literature. The ability of the sliding mode controllers (SMC) to suppress chattering is also be explored.

  7. Effect of Lubricant Additives on the WDLC Coating Structure When Tested in Boundary Lubrication Regime

    OpenAIRE

    Yang, L; Neville, A; Brown, A; Ransom, P; Morina, A

    2015-01-01

    Improvements in coating deposition technology enable the mass production of high-quality diamond-like carbon (DLC) coatings at an industrial scale and also increase their use in lubricated contacts. However, the understanding of the interactions of different lubricant additives with this material is not yet fully developed. This study focuses on several fundamental aspects of the tungsten-doped DLC coating (denoted as WDLC) behaviour under boundary lubrication conditions with model lubricants...

  8. Case Study of Various Parameters by Applying Swing Up Control for Inverted Pendulum

    Directory of Open Access Journals (Sweden)

    Kunal Chakraborty

    2015-09-01

    Full Text Available This paper investigates behavior of the system in terms of time response e.g., steady state error, rise time & overshoot & then compare it with FLC. Being an unstable system, Inverted Pendulum is very common control problem being assigned to control its dynamics. It is almost impossible to balance a pendulum in the inverted position except applying some force from outside to the system.

  9. Simulations of modal active control applied to the self-sustained oscillations of the clarinet

    OpenAIRE

    Meurisse, Thibaut; MAMOU-MANI, Adrien; Caussé, René; SHARP, David

    2013-01-01

    Modal active control enables modifications of the damping and the frequencies of the different resonances of a system. A self-sustained oscillating wind instrument is modelled as a disturbance coupled to a resonator through a non-linear coupling. The aim of this study is to present simulations of modal active control applied to a modeled simplified self-sustained oscillating wind instrument (e.g. a cylindrical tube coupled to a reed, which is considered to approximate a simplified clarinet), ...

  10. Physical Mechanisms of Failure, Ultralow Partial Pressure Lubrication, and the Reservoir Effect in MEMS

    Science.gov (United States)

    Hook, David Adam

    The aim of this work is to examine the effectiveness of self-assembled monolayer (SAM) coatings as long term lubrication coatings in microsystems, to examine the failure regimes of SAM coated devices, to examine the role of mobility in adsorbed lubricating films, and to examine evolution of the coefficient of friction of devices surrounded by ultralow partial pressures of alcohols up to saturation. Finally the role of self assembled monlayers in vapor phase lubrication is examined. Self-assembled monolayers are ubiquitous in fabrication of free-standing microdevices because of their ability to prevent release related and dormancy related stiction. However their ability to lubricate under sliding and normal contact conditions is not well documented. It can be shown that the energy dissipated per unit area in one sliding cycle due to friction is significant under general loading conditions. Therefore from an energy dissipated standpoint the bond energies of the silane molecules should not be enough to withstand even a short number of cycles. An extension of this is the energy imparted to the surface through a normal loading cycle through a loss of kinetic energy. It can also be shown that this is enough to break the silicon oxygen bonds however this is over a longer time scale than in sliding. Also there is an open question on the role of mobile and non-mobile adsorbed species on friction. Is the mobility of a molecule/layer on a surface an indicator of the effectiveness of the lubrication potential of the layer? Do submonolayer coverages of alcohols "lock-up" to contacting surfaces by disrupting non-corrogated potentials? Is there a distinct lowering of frictional forces at the formation of a monolayer? Controlled adsorption of mobile and non-mobile species on rubbing contacts is necessary to elucidate this physical relationship. To accomplish this one must take into account that friction measurements are highly scale dependant. Therefore to ensure the accuracy of

  11. Influence of Lubricant Pocket Geometry upon Lubrication Mechanisms on Tool-Workpiece Interfaces in Metal Forming

    DEFF Research Database (Denmark)

    Shimizu, I; Martins, P.A.F.; Bay, Niels; Andreasen, Jan Lasson; Bech, Jakob I.

    Micro lubricant pockets located on the surface of plastically deforming workpieces are recognized to improve the performance of fluid lubrication in a metal forming processes. This work investigates the joint influence of pocket geometry and process working conditions on micro lubrication mechani...

  12. Experimental rig for measuring lubricant film thickness in rolling bearings

    OpenAIRE

    Zhang, Xingnan; Jablonka, Karolina Anna; Glovnea, Romeo

    2014-01-01

    Electrical capacitance has been applied in the past for measuring the lubricant film thickness in rolling element bearings. The main difficulty arises from the fact that the measured capacitance is a combination of the capacitances of many rolling elements, which come in contact with both the inner and outer rings. Besides, the capacitance of the Hertzian contact itself and the surrounding area must also be separated. It results in a complex system which, in order to be solved for the film ...

  13. Lubricants in Pharmaceutical Solid Dosage Forms

    Directory of Open Access Journals (Sweden)

    Jinjiang Li

    2014-02-01

    Full Text Available Lubrication plays a key role in successful manufacturing of pharmaceutical solid dosage forms; lubricants are essential ingredients in robust formulations to achieve this. Although many failures in pharmaceutical manufacturing operations are caused by issues related to lubrication, in general, lubricants do not gain adequate attention in the development of pharmaceutical formulations. In this paper, the fundamental background on lubrication is introduced, in which the relationships between lubrication and friction/adhesion forces are discussed. Then, the application of lubrication in the development of pharmaceutical products and manufacturing processes is discussed with an emphasis on magnesium stearate. In particular, the effect of its hydration state (anhydrate, monohydrate, dihydrate, and trihydrate and its powder characteristics on lubrication efficiency, as well as product and process performance is summarized. In addition, the impact of lubrication on the dynamics of compaction/compression processes and on the mechanical properties of compacts/tablets is presented. Furthermore, the online monitoring of magnesium stearate in a blending process is briefly mentioned. Finally, the chemical compatibility of active pharmaceutical ingredient (API with magnesium stearate and its reactive impurities is reviewed with examples from the literature illustrating the various reaction mechanisms involved.

  14. Lubricant for cold stamping of metal

    Energy Technology Data Exchange (ETDEWEB)

    Tulik, V.T.; Movshovich, V.S.; Speranskiy, B.S.; Tseloval' nikov, V.M.; Yudovich, S.Z.

    1980-03-19

    Hydrogenated thermally thickened vegetable oil and the product of condensation of triethanolamine with the bottoms of synthetic fatty acids are added to the oil, which contains petroleum oil, lanolin and a nonionogenic wetting agent, in order to increase the lubricating properties and to give it mothballing properties. The contents of the components are in %: lanolin, 10-20; nonionogenic wetting agent, 1-5; vegetable oil, 10-50; product of condensation, 1-5 and petroleum oil to 100%. The lubricant is produced through the introduction of the cited components in petroleum oil heated to 65-75/sup 0/C with careful mixing. Comparative laboratory tests of the lubricant samples were conducted through identifying the degree of drawing, the drawing force and the degree of deformation. The tests showed that the new lubricant has high lubricating and washing properties. Also studied was the corrosion stability in a moisture chamber as compared with I-20 A lubricant. The time after which the corrosion appeared in days for the I-20 A is 1 and the sample of the lubricant, 28. Industrial tests showed that the proposed lubricant may be used in sheet stamping production in the manufacture of complex parts of motor vehicles without the additional application of industrial lubricant in conditions of press production.

  15. Lubrication System with Tolerance for Reduced Gravity

    Science.gov (United States)

    Portlock, Lawrence E. (Inventor); McCune, Michael E. (Inventor); Dobek, Louis J. (Inventor)

    2013-01-01

    A lubrication system includes an auxiliary lubricant tank 48, a supply conduit 58 extending from a source of lubricant 26 to the auxiliary lubricant tank. A reduced-G bypass line 108 branches from the conduit and enters the auxiliary tank at a first elevation E.sub.1. The system also includes an auxiliary tank discharge conduit 116, a portion of which resides within the tank. The resident portion has an opening 122 at least partially at a second elevation E.sub.2 higher than the first elevation.

  16. Aqueous lubrication natural and biomimetic approaches

    CERN Document Server

    Spencer, Nicholas D

    2014-01-01

    Man lubricates mostly with oil. Nature lubricates exclusively with water. Pure water is a poor lubricant, but the addition of proteins, especially glycoproteins, can modify surfaces to make them far more lubricating at slow speeds. Understanding how nature does this, and the physical structures involved, is not only important for the understanding of diseases such as osteoarthritis, but also essential for the successful application of articulating implants, such as hips and knees, as well as the development of medical devices such as catheters and contact lenses. A host of important applicati

  17. Ecotoxicological study of used lubricating oil

    International Nuclear Information System (INIS)

    Used lubricating oil is more toxic than crude oil and fuel oil since it contains comparatively high levels of heavy metals and polycyclic aromatic hydrocarbons (PAHs). No detail toxicological study has been conducted to evaluate the hazards of used lubricating oil to the environment. This study reports a battery of bioassays using bacteria (Microtox test and Mutatox test), algae, amphipod and shrimp larvae to determine the toxicity of water soluble fraction of used lubricating oil. The results will be used to formulate a complete and extensive ecotoxicological assessment of the impacts of used lubricating oil on aquatic environment

  18. Open-air type plasma chemical vaporization machining by applying pulse-width modulation control

    Science.gov (United States)

    Takeda, Yoshiki; Hata, Yuki; Endo, Katsuyoshi; Yamamura, Kazuya

    2014-03-01

    Photolithography techniques have been used to enable the low-cost and high-speed transfer of a pattern onto a silicon wafer. However, owing to the high integration of semiconductors, extreme ultraviolet will be increasingly used as the exposure light source and all optics must be reflective to focus light because the wavelength of the light will be so short that it cannot pass through a lens. The form accuracy of reflective optics affects the accuracy of transfer, and a flatness of less than 32 nm on a 6 inch photomask substrate is required according to the International Technology Roadmap for Semiconductors roadmap. Plasma chemical vaporization machining is an ultraprecise figuring technique that enables a form accuracy of nanometre order to be obtained. In our previous study, the removal volume was controlled by changing the scanning speed of the worktable. However, a discrepancy between the theoretical scanning speed and the actual scanning speed occurred owing to the inertia of the worktable when the change in speed was rapid. As an attempt to resolve this issue, we controlled the removal volume by controlling the electric power applied during plasma generation while maintaining a constant scanning speed. The methods that we adapted to control the applied electric power were amplitude-modulation (AM) control and pulse-width modulation (PWM) control. In this work, we evaluate the controllability of the material removal rate in the AM and PWM control modes.

  19. Open-air type plasma chemical vaporization machining by applying pulse-width modulation control

    International Nuclear Information System (INIS)

    Photolithography techniques have been used to enable the low-cost and high-speed transfer of a pattern onto a silicon wafer. However, owing to the high integration of semiconductors, extreme ultraviolet will be increasingly used as the exposure light source and all optics must be reflective to focus light because the wavelength of the light will be so short that it cannot pass through a lens. The form accuracy of reflective optics affects the accuracy of transfer, and a flatness of less than 32 nm on a 6 inch photomask substrate is required according to the International Technology Roadmap for Semiconductors roadmap. Plasma chemical vaporization machining is an ultraprecise figuring technique that enables a form accuracy of nanometre order to be obtained. In our previous study, the removal volume was controlled by changing the scanning speed of the worktable. However, a discrepancy between the theoretical scanning speed and the actual scanning speed occurred owing to the inertia of the worktable when the change in speed was rapid. As an attempt to resolve this issue, we controlled the removal volume by controlling the electric power applied during plasma generation while maintaining a constant scanning speed. The methods that we adapted to control the applied electric power were amplitude-modulation (AM) control and pulse-width modulation (PWM) control. In this work, we evaluate the controllability of the material removal rate in the AM and PWM control modes. (paper)

  20. Burn control via regulated ripple applied to reactor-grade plasmas

    International Nuclear Information System (INIS)

    An investigation is made of the possibility of dynamically controlling the operating point of an ignited tokamak plasma by variation of the current in ripple 'correction' coils. The analysis is applied to designs presently under consideration for engineering test devices. (author)

  1. Surface Modification Of The High Temperature Porous Sliding Bearings With Solid Lubricant Nanoparticles

    Directory of Open Access Journals (Sweden)

    Wiśniewska-Weinert H.

    2015-09-01

    Full Text Available A surface modification of stainless steel bearing sleeves is developed to improve the tribology characteristics at high temperature. Solid lubricant nano- and microparticles are applied for this purpose. To create the quasi-hydrodynamic lubrication regimes, the solid lubricant powder layer is made by developed pressure impregnation technique. Porous sliding bearing sleeve prototypes were made by powder metallurgy technique. The purpose of the paper is to define the friction and wear characteristics of the sleeves and to determine the influence of sealing of the sliding interface on these characteristics. It is found that application of WS2 sold lubricant nano- and micro-particles and preservation of a particle leakage out of interface allows to achieve at the high temperature the friction coefficients comparable to those at ambient temperature.

  2. Evaluation of replacement thread lubricants for red lead and graphite in mineral oil

    Energy Technology Data Exchange (ETDEWEB)

    Jungling, T.L.; Rauth, D.R.; Goldberg, D.

    1998-04-30

    Eight commercially available thread lubricants were evaluated to determine the best replacement for Red Lead and Graphite in Mineral Oil (RLGMO). The evaluation included coefficient of friction testing, high temperature anti-seizing testing, room temperature anti-galling testing, chemical analysis for detrimental impurities, corrosion testing, off-gas testing, and a review of health and environmental factors. The coefficient of friction testing covered a wide variety of factors including stud, nut, and washer materials, sizes, manufacturing methods, surface coatings, surface finishes, applied loads, run-in cycles, and relubrication. Only one lubricant, Dow Corning Molykote P37, met all the criteria established for a replacement lubricant. It has a coefficient of friction range similar to RLGMO. Therefore, it can be substituted directly for RLGMO without changing the currently specified fastener torque values for the sizes, materials and conditions evaluated. Other lubricants did not perform as well as Molykote P37 in one or more test or evaluation categories.

  3. COMPARATIVE STUDY OF CHELATION VALUE OF SEVENTEEN PERCENT SELF DEVELOPED AND COMMERCIALLY AVAILABLE ROOT CANAL LUBRICANTS

    Directory of Open Access Journals (Sweden)

    Ingale Satish Dinkarrao

    2013-06-01

    Full Text Available The main objective of this study is to compare chelation values of 17% self developed & commercially available root canal Lubricants or dental chelating gels as well as to see whether their performance depends on the chelation value or not. The Chelating agent bounds Ca2+ ions of the smear layer & the extent of chelate formation between chelating agent and metal ion is nothing but Chelation Value. Sodium carbonate indicator method is used for determinations of chelation value. Commercially available gel incorporated in this study was File Rite which has little bit higher chelation value. Self developed chelating gel or root canal lubricants have comparatively lower chelation value. Root canal lubricants having higher chelation value should perform better in shaping & cleaning of root canal better. However because of slight difference in chelation value of self developed & commercially available gel, no significant difference was found out as root canal lubricants, when applied in root canal for 5 minutes.

  4. Dynamics of SAMs in Boundary Lubrication

    Directory of Open Access Journals (Sweden)

    J. Manojlović

    2013-09-01

    Full Text Available Surfactant molecules have some properties responsible for a number ofremarkable phenomena, such as oriented adsorption of surfactants at surfaces and interfaces. The capability to self -assemble into well- defined structures is often seen as being more important than their surface activity. When a surfactant solution is in contact with a solid surface, the surfactant molecules adsorb onto the surface, ideally forming an adsorbed layer of a high order, termed as a self- assembled monolayer (SAM. Many surface properties are influenced bysuch a film, and therefore, SAMs offer the capability to form ordered organic surface coatings, suitable for various applications, such as wetting or corrosion protection. Due to the flexibility in choosing the molecular architecture, organic molecules have many interesting applications, such as biosensors, in Photoelectronics, in controlling water adsorption or boundary lubricant coating. This paper Focuses on cationic surfactants (quaternary ammonium surfactants with some unique properties that are not present in other surfactants.

  5. Analysis results for the stereotypes regarding colors applied to the nuclear power plant control room

    International Nuclear Information System (INIS)

    The general public not engaged in the nuclear power plant industry have no idea of the color usage in the nuclear control room. So we converted the specific color usage situation into similar but general situations. In questionnaire, we gave subjects the general situation where color coding is applied and alternative colors which were applied to the HF010 guidelines. And we asked the subjects to choose the colors proper to the situation and to rank the colors according to the degree of suitability. Two hundred fifty college students participated in the experiment. The results suggest that we can use any color coding system in the conventional control room and the CRT in the control deck because most people have no special previous color-meaning association but red-emergency relation

  6. A comparison of the tribological behaviour of steel/steel, steel/DLC and DLC/DLC contact when lubricated with mineral and biodegradable oils

    OpenAIRE

    Kalin, Mitjan; Vižintin, Jože

    2015-01-01

    Diamond-like carbon (DLC) coatings, which can nowadays be applied to many highly loaded mechanical components, sometimes need to operate under lubricated conditions. It is reasonable to expect that in steel/DLC contacts, at least the steel counter body will behave according to conventional lubrication mechanisms and will interact with lubricants and additives in the contact. However, in DLC/DLC contacts, such mechanisms are still unclear. For example, the "inertness" of DLC coatings raises se...

  7. Preparation and Tribological Study of Biodegradable Lubrication Films on Si Substrate

    OpenAIRE

    Shih-Chen Shi; Teng-Feng Huang; Jhen-Yu Wu

    2015-01-01

    A novel method for preparing eco-biodegradable lubricant based on hydroxypropyl methylcellulose (HPMC) via hydration process is demonstrated. The smooth and homogeneous HPMC coating has a uniform thickness (~35 μm). It has been demonstrated that the preparation parameters play a critical role in controlling the lubricating behavior of the coating; in addition, excess HPMC and water concentration suppress the tribology properties. Nevertheless, a remarkable friction-reduction and anti-wear per...

  8. Nonlinear Model-Based Predictive Control applied to Large Scale Cryogenic Facilities

    CERN Document Server

    Blanco Vinuela, Enrique; de Prada Moraga, Cesar

    2001-01-01

    The thesis addresses the study, analysis, development, and finally the real implementation of an advanced control system for the 1.8 K Cooling Loop of the LHC (Large Hadron Collider) accelerator. The LHC is the next accelerator being built at CERN (European Center for Nuclear Research), it will use superconducting magnets operating below a temperature of 1.9 K along a circumference of 27 kilometers. The temperature of these magnets is a control parameter with strict operating constraints. The first control implementations applied a procedure that included linear identification, modelling and regulation using a linear predictive controller. It did improve largely the overall performance of the plant with respect to a classical PID regulator, but the nature of the cryogenic processes pointed out the need of a more adequate technique, such as a nonlinear methodology. This thesis is a first step to develop a global regulation strategy for the overall control of the LHC cells when they will operate simultaneously....

  9. DIII-D integrated plasma control tools applied to next generation tokamaks

    International Nuclear Information System (INIS)

    A complete software suite for integrated tokamak plasma control has been developed within the DIII-D program. The suite consists of software for real-time control of all aspects of the plasma, modeling, simulation and design tools for analysis and development of controllers, a flexible and modular architecture for implementation and testing of algorithms and many fully validated models. Many elements of the system have been applied to and implemented on NSTX and MAST. The DIII-D realtime plasma control system together with the integrated modeling and simulation suite have been selected for operational use by both the KSTAR and EAST tokamaks, and are also being used at General Atomics to investigate control issues for ITER

  10. Total quality control: the deming management philosophy applied to nuclear power plants

    International Nuclear Information System (INIS)

    In recent years, a call has come for the development of inherently safe nuclear reactor systems that cannot have large-scale accidents. In the search for the perfect inherently safe reactor system, some are calling for the institution of computerized automated control of reactors eliminating most human operators from the control room. A different approach to the problem of the control of inherently safe reactors is that both future and present nuclear power plants need to institute total quality control (TQC) to plant operations and management. The Deming management philosophy of TQC has been implemented in a wide range of industries - particularly in Japan and the US. Specific attention is given, however, to TQC implementation in the electric power industry as applied to nuclear plants. The Kansai Electric Power Company and Florida Power and Light Company have recently implemented TQC. Statistical quality control methods have been applied to monitor and control reactor variables (for example, to the steam generator water level important to start-up operations of pressurized water reactors)

  11. Identifying a cooperative control mechanism between an applied field and the environment of open quantum systems

    Science.gov (United States)

    Gao, Fang; Rey-de-Castro, Roberto; Wang, Yaoxiong; Rabitz, Herschel; Shuang, Feng

    2016-05-01

    Many systems under control with an applied field also interact with the surrounding environment. Understanding the control mechanisms has remained a challenge, especially the role played by the interaction between the field and the environment. In order to address this need, here we expand the scope of the Hamiltonian-encoding and observable-decoding (HE-OD) technique. HE-OD was originally introduced as a theoretical and experimental tool for revealing the mechanism induced by control fields in closed quantum systems. The results of open-system HE-OD analysis presented here provide quantitative mechanistic insights into the roles played by a Markovian environment. Two model open quantum systems are considered for illustration. In these systems, transitions are induced by either an applied field linked to a dipole operator or Lindblad operators coupled to the system. For modest control yields, the HE-OD results clearly show distinct cooperation between the dynamics induced by the optimal field and the environment. Although the HE-OD methodology introduced here is considered in simulations, it has an analogous direct experimental formulation, which we suggest may be applied to open systems in the laboratory to reveal mechanistic insights.

  12. Pressure-viscosity coefficient of biobased lubricants

    Science.gov (United States)

    Film thickness is an important tribological property that is dependent on the combined effect of lubricant properties, material property of friction surfaces, and the operating conditions of the tribological process. Pressure-viscosity coefficient (PVC) is one of the lubricant properties that influe...

  13. 30 CFR 56.14204 - Machinery lubrication.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machinery lubrication. 56.14204 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Machinery and Equipment Safety Practices and Operational Procedures § 56.14204 Machinery lubrication. Machinery...

  14. 30 CFR 57.14204 - Machinery lubrication.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machinery lubrication. 57.14204 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Practices and Operational Procedures § 57.14204 Machinery lubrication. Machinery...

  15. Lubricity studies with biodiesel and related compounds

    Science.gov (United States)

    Biodiesel, the alkyl esters of vegetable oils or animal fats, possesses excellent lubricity. This feature has rendered biodiesel of special interest for blending with ultra-low sulfur diesel fuels with poor lubricity. However, some minor components, mainly free fatty acids and monoacylglycerols, of ...

  16. An emulsion lubricant for metallic molds

    Energy Technology Data Exchange (ETDEWEB)

    Dovzhik, O.I.; Cherkayev, V.G.; Min' kovskiy, M.M.; Romanyuk, V.G.; Shapiro, L.D.; Sokolov, V.A.

    1980-02-26

    An emulsion lubricant for metallic molds used in production of concrete products for eliminating adhesion of concrete with the metallic mold, and to eliminate potential for air pore formation on surface of product, contains lanolin production waste materials. Compos. of lubricant %: Synthetic emulsol oxide 5-10; wastes from lanolin production in conversion to wax 5-10; water the rest.

  17. A Biomimetic Approach to Lubricate Engineering Materials

    DEFF Research Database (Denmark)

    Røn, Troels

    electrostatic repulsion between charged PAA blocks, hindering the facile formation of the lubricating layer under cyclic tribological stress. It is well known that graft copolymers anchor more efficiently to surfaces than their diblock counterparts, thus the synthesis and study on lubricating capabilities of...

  18. VOLATILIZED LUBRICANT EMISSIONS FROM STEEL ROLLING OPERATIONS

    Science.gov (United States)

    The report gives results of a study of the volatilization of lubricants used in steel rolling. Data from nine steel mills were used to: define the volatilized portion of lubricants used in rolling; and prepare total oil, grease, and hydraulic material balances for actual and typi...

  19. Turbulence Models of Hydrodynamic Lubrication

    Institute of Scientific and Technical Information of China (English)

    张直明; 王小静; 孙美丽

    2003-01-01

    The main theoretical turbulence models for application to hydrodynamic lubrication problems were briefly reviewed, and the course of their development and their fundamentals were explained. Predictions by these models on flow fields in turbulent Couette flows and shear-induced countercurrent flows were compared to existing measurements, and Zhang & Zhang' s combined k-ε model was shown to have surpassingly satisfactory results. The method of application of this combined k-ε model to high speed journal bearings and annular seals was summarized, and the predicted results were shown to be satisfactory by comparisons with existing experiments of journal bearings and annular seals.

  20. PERFORMANCE OF LUBRICATING OIL FILM IN ALUMINIUM FOIL ROLLING

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The surface of the aluminum foil rolled has been observed with microscope on the basis of industrial experiments, and the structure of the surface adsorption film has been analyzed by means of low angle X-ray diffraction. It is advanced that the lubrication in aluminum foil rolling is in the state of thin film lubrication, surface adsorption film is an ordered multi-layered molecule film with more than 7 layers; and the layers of the ordered molecule film is influenced by the concentration of the additive in certain range; the concentration of the additive in oil is the main factor affecting the stability of rolling, controling the concentration of the additive can control the ratio of fluid friction, boundary friction, and local holding-on in deformation zone,thus obtaining good rolling deformation conditions.

  1. Experimental Analysis of Damping and Tribological Characteristics of Nano-CuO Particle Mixed Lubricant in Ball Bearings

    Science.gov (United States)

    Prakash, E.; Sivakumar, K.

    2015-12-01

    Experimental analysis of damping capacity and tribological characteristics of nano CuO added Servosystem 68 lubricant is attempted. CuO nano particles were synthesized by aqueous precipitation method and characterized. Prior to dispersion into lubricant, CuO nano particles were coated with 0.2 wt.% surfactant (Span-80) to stabilize the nano fluid. Tribological characteristics of particle added lubricant were tested in ASTM D 4172 four ball wear tester. Scanning electron microscopy test results of worn surfaces of nano CuO particle added lubricant were smoother than base lubricant. The particle added lubricant was applied in a new ball bearing and three defected ball bearings. When particle added lubricant was used, the ball defected bearing's vibration amplitude was reduced by 21.94% whereas it was 16.46% for new bearing and was ≤ 11% for other defected bearings. The formation of protection film of CuO over ball surface and regime of full film lubrication near the ball zone were observed to be reason for improved damping of vibrations.

  2. Ordered molecular layer structure of lubricating oil adsorbed films

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Low-angle X-ray diffraction has been applied to analyze the structure of stearic acid LB films and self-grown surface adsorbed films of aluminium product metalworking lubricants. The results show that LB films exhibit a good layer-like ordered structure in the normal direction of film-carrying surface, while in the tangential direction, they do not show a cyclically ordered molecular arrangement; as for the self-grown surface adsorbed films of aluminium sheet and strip metalworking lubricants, their molecules are orderly arranged to certain degree in both the tangential and the normal directions of film-carrying surface, and they have a short-range ordered structure. Moreover, the better the orientation of normal molecules is, the higher the oil film strength is, and the smaller the friction factor is.

  3. Development of seismic support snubber using solid lubricant

    International Nuclear Information System (INIS)

    Solid lubricant MoS2 films deposited by radio-frequency sputtering and a new physical process were applied to bearings and ball screws used in seismic support mechanical snubbers. The lubricity of MoS2 films was maintained throughout 720 hours of exposure at a temperature of 200 degC. The endurance life of MoS2 films using both radio-frequency sputtering and a new physical process was investigated by subjecting the mechanical snubber to a drag force test. Cumulative drag length reached 100 meters and 400 meters, respectively, for the two methods. The dynamic characteristics and durability of mechanical snubbers in an abnormal environment were also investigated. (author)

  4. New lubricating material for hydraulic turbine generators

    International Nuclear Information System (INIS)

    The current state-of-the-art of lubricating practices for major hydraulic equipment which is in contact with water, such as wicket gates, were surveyed by the Canadian Electrical Association by means of a questionnaire. Participants in the survey included owners and operators, designers and bearing and lubricant suppliers. Current practices, major technical issues and potential constraints of using alternative, environmentally friendly lubricant practices were identified. It was found that self lubricating bearing materials were commonly used to address environmental concerns. Results of the survey also revealed that regulations for underwater hydraulic equipment have not been established in Canada nor the U.S. Several recommendations for adopting environmentally friendly lubricants into current practices were made

  5. Biodegradation and toxicological evaluation of lubricant oils

    Directory of Open Access Journals (Sweden)

    Ivo Shodji Tamada

    2012-12-01

    Full Text Available The aim of this work was to compare different toxicity levels of lubricant oils. The tests were performed using the earthworm (Eisenia andrei, arugula seeds (Eruca sativa and lettuce seeds (Lactuca sativa, with three types of contaminants (mineral lubricant oil, synthetic lubricant oil and used lubricant oil for various biodegradation periods in the soil. The toxicity tests indirectly measured the biodegradation of the contaminants. The samples were analyzed at t0, t60, t120 and t180 days of biodegradation. The used lubricant oil was proved very toxic in all the tests and even after biodegradation its toxicity was high. The mineral and synthetic oils were biodegraded efficiently in the soil although their toxicity did not disappear completely after 180 days.

  6. Evaluation of fire-resistant fluid lubricants for water reactor coolant pump motors

    International Nuclear Information System (INIS)

    Fires occurred in different reactor coolant pumps, caused by lubricant leakage and impregnation of lagging. The application of phosphate esters in steam turbine control systems eliminated fire hazard. The use of fire resistant fluids for the lubrication of reactor coolant pump motor would eliminate these fires. In 1985, it was decided to evaluate these fluids after 1977 EDF tests' results and 1980 EPRI Reports. Commercially available lubricating fluids were evaluated in the laboratory, using representative tests, to develop data to permit to select a fluid. The recommended fluid has the best results for long-term hydrolysis and showed good radiation tolerance at exposure tests at TRICASTIN power plant. The fluid should now be tests in the actual motor to confirm its properties for the lubrication of reactor coolant pumps. (author). 11 refs., 2 figs., 3 tabs

  7. Coherent control with shaped femtosecond laser pulses applied to ultracold molecules

    International Nuclear Information System (INIS)

    We report on coherent control of excitation processes of translationally ultracold rubidium dimers in a magneto-optical trap by using shaped femtosecond laser pulses. Evolution strategies are applied in a feedback loop in order to optimize the photoexcitation of the Rb2 molecules, which subsequently undergo ionization or fragmentation. A superior performance of the resulting pulses compared to unshaped pulses of the same pulse energy is obtained by distributing the energy among specific spectral components. The demonstration of coherent control to ultracold ensembles opens a path to actively influence fundamental photoinduced processes in molecular quantum gases

  8. Coherent control with shaped femtosecond laser pulses applied to ultracold molecules

    CERN Document Server

    Salzmann, W; Wester, R; Weidemüller, M; Merli, A; Weber, S M; Sauer, F; Plewicki, M; Weise, F; Esparza, A M; Wöste, L; Lindinger, A; Salzmann, Wenzel; Poschinger, Ulrich; Wester, Roland; Weidemueller, Matthias; Merli, Andrea; Weber, Stefan M.; Sauer, Franziska; Plewicki, Mateusz; Weise, Fabian; Esparza, Aldo Mirabal; Woeste, Ludger; Lindinger, Albrecht

    2005-01-01

    We report on coherent control of excitation processes of translationally ultracold rubidium dimers in a magneto-optical trap by using shaped femtosecond laser pulses. Evolution strategies are applied in a feedback loop in order to optimize the photoexcitation of the Rb2 molecules, which subsequently undergo ionization or fragmentation. A superior performance of the resulting pulses compared to unshaped pulses of the same pulse energy is obtained by distributing the energy among specific spectral components. The demonstration of coherent control to ultracold ensembles opens a path to actively influence fundamental photo-induced processes in molecular quantum gases.

  9. APPLIED ECONOMIC ORDER QUANTITY (EOQ) INLOGS RAW MATERIAL INVENTORY CONTROL FOR PLYWOOD INDUSTRY

    OpenAIRE

    Makkarennu; Nakayasu, A.; Osozawa, K.; Ichikawa, M

    2013-01-01

    One of the most difficult aspect of plywood industry is control inventory. Logs as the main raw material for plywood industry are the first and foremost form of inventory.Without proper planning, a manufacturing company can run out of raw material, negatively impacting the company and its customers. The aim of this study was to evaluate logs raw material inventory control applied at a plywood in South Sulawesi, Indonesia.For the purpose of the study, the data of logs raw material consumption ...

  10. Simulations of modal active control applied to the self-sustained oscillations of the clarinet

    OpenAIRE

    Meurisse, Thibaut; MAMOU-MANI, Adrien; Causse, René; Chomette, Baptiste; SHARP, David

    2014-01-01

    This paper reports a new approach to modifying the sound produced by a wind instrument. The approach is based on modal active control, which enables adjustment of the damping and the frequencies of the different resonances of a system. A self-sustained oscillating wind instrument can be modeled as an excitation source coupled to a resonator via a non-linear coupling. The aim of this study is to present simulations of modal active control applied to a modeled self-sustained oscillating wind in...

  11. Two fiber optics communication adapters apply to the control system of HIRFL-CSR

    International Nuclear Information System (INIS)

    The authors introduced two kinds of fiber adapters that apply to the engineering HIRFL-CSR. Including design of two adapters, operational principle, and hardware construction, field of application. How to control equipment which have the standard RS232 or RS485 interface at long distance by two adapters. Replace the RS485 bus with the fiber and the 485-Fiber Adapter, solved the problem of communication disturb. The requirements of control in the national great science engineering HIRFL-CSR are fulfilled. (authors)

  12. A composite controller for trajectory tracking applied to the Furuta pendulum.

    Science.gov (United States)

    Aguilar-Avelar, Carlos; Moreno-Valenzuela, Javier

    2015-07-01

    In this paper, a new composite scheme is proposed, where the total control action is composed of the sum of a feedback-linearization-based controller and an energy-based compensation. This new proposition is applied to the rotary inverted pendulum or Furuta pendulum. The Furuta pendulum is a well-known underactuated mechanical system with two degrees of freedom. The control objective in this case is the tracking of a desired periodic trajectory in the actuated joint, while the unactuated link is regulated at the upward position. The closed-loop system is analyzed showing uniformly ultimately boundedness of the error trajectories. The design procedure is shown in a constructive form, such that it may be applied to other underactuated mechanical systems, with the proper definitions of the output function and the energy function. Numerical simulations and real-time experiments show the practical viability of the controller. Finally, the proposed algorithm is compared with a tracking controller previously reported in the literature. The new algorithm shows better performance in both arm trajectory tracking and pendulum regulation. PMID:25792518

  13. Experimental Investigation on Adaptive Robust Controller Designs Applied to Constrained Manipulators

    Directory of Open Access Journals (Sweden)

    Marco H. Terra

    2013-04-01

    Full Text Available In this paper, two interlaced studies are presented. The first is directed to the design and construction of a dynamic 3D force/moment sensor. The device is applied to provide a feedback signal of forces and moments exerted by the robotic end-effector. This development has become an alternative solution to the existing multi-axis load cell based on static force and moment sensors. The second one shows an experimental investigation on the performance of four different adaptive nonlinear H∞ control methods applied to a constrained manipulator subject to uncertainties in the model and external disturbances. Coordinated position and force control is evaluated. Adaptive procedures are based on neural networks and fuzzy systems applied in two different modeling strategies. The first modeling strategy requires a well-known nominal model for the robot, so that the intelligent systems are applied only to estimate the effects of uncertainties, unmodeled dynamics and external disturbances. The second strategy considers that the robot model is completely unknown and, therefore, intelligent systems are used to estimate these dynamics. A comparative study is conducted based on experimental implementations performed with an actual planar manipulator and with the dynamic force sensor developed for this purpose.

  14. Quality Control Procedures Applied to the CMS Muon Chambers Built at CIEMAT

    International Nuclear Information System (INIS)

    In this document the quality control procedures applied to the CMS muon drift chambers built at CIEMAT are described. It includes a description of the high voltage and front electronics associated to the chambers. Every procedure is described with detail and a list of the more common problems and possible solutions is given. This document can be considered as a chamber test handbook for beginners. (Author) 3 refs

  15. Chance-constrained model predictive control applied to inventory management in hospitalary pharmacy

    OpenAIRE

    Maestre, Jose Maria; Ocampo-Martinez, Carlos

    2014-01-01

    This extended abstract addresses the preliminary results of applying uncertainty handling strategies and advanced control techniques to the inventary management of hospitality pharmacy. Inventory management is one of the main tasks that a pharmacy department has to carry out in a hospital. It is a complex problem because it requires to establish a tradeoff between contradictory optimization criteria. The final goal of the proposed research is to update the inventory management system of hospi...

  16. When you lubricate well, you go well? A cause analysis of damages on bearer rings at a hydrogen compressor recently brought into service with the aid of monitoring the lubricating points of cylinder liners; Wer gut schmiert, der gut faehrt? Ursachenanalyse an Tragringschaeden bei einem neu in Betrieb genommenen Wasserstoffverdichter mit Hilfe einer Zylinderschmierstellenueberwachung

    Energy Technology Data Exchange (ETDEWEB)

    Klinger, Lars [Bayernoil Raffineriegesellschaft mbH, Neustadt a.d. Donau (Germany)

    2013-02-15

    For humans the blood circuit transports the ''lifeblood''. It supplies the body with the different essential nutrients and disposes adverse waste. The circuit of lubricant in recip compressors has quiet similar functions. It provides all relevant components with lubricant. This lubricant circuit supplies i.a. the crosshead slide way and bearings, where a hydrodynamic flooding is created. At the same time frictional heat is conducted and pollutions as well as deposits are washed away. But especially for recip compressors there is also another lubricating system, which is barely applied in the real operating process. It is about the supply of the packing glands and the piston liners with lubricant inside the compression chamber at ''wet running machines''. In the case of the lubricant supply at cylinder liners the lubricating oil is dispatched to the appropriate areas by an external lubricating system, which consists of a reservoir and an oil pump. This is a loss lubrication, i.e. the used lubricate is transported into the process by the transfer medium. The mechanical quality of this lubricating system can have great influence on the durability of bearer rings and sealing rings in a recip compressor. Especially the homogeneity of the dispatched lubricating oil amount and the absolute dispatched amount are two very important factors. The absolute amount is within the range of cm{sup 3} per hour. The influences of the cylinder liner lubricant supply on the durability of piston seal rings and bearer rings are shown with the concrete example of one recip compressor. Analytical measures to clearly detect such damages at the bearer rings are disclosed, just as which possibility there is to measure the low quantity of lubricant to the cylinder liners reliably. Furthermore a solution is presented, which allows the solid operation of the compressor.

  17. Theoretical analysis and experimental study on the influence of electric double layer on thin film lubrication

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-jie; BAI Shao-xian; HUANG Ping

    2006-01-01

    A new mathematical model for thin film lubrication is established by taking into account the effect of an electric double layer.In the present paper,experiments are carried out on a self-made tester.With a composite block and a rotating disk,influence of electric double layer on thin film lubrication is studied.Two different methods are used to reconstruct the field of electric double layer so as to change its effect.One is to change the ionic concentration of lubricants by adding additives,and the other is to apply an external electric field on friction pairs.According theoretical analysis,both the methods will apparently change the electro-viscosity of the lubricant film so as to change the lubrication performances.After theoretical calculation of electro-viscosity is amended according to the experimental results,the equations of electro-viscosity are presented.The results show that the equivalent viscosity of fluid induced by the effect of electric double layer apparently increases with the decrease of thickness of the film while the lubrication film is thin enough.The effect of electro-viscosity is weakened as the thickness of the film increases.Moreover,the effect of electro-viscosity increases with the increase of external electric field at first.When the voltage reaches a certain value,the electro-viscosity begins to decrease.

  18. Measurement of Lubricating Condition between Swashplate and Shoe in Swashplate Compressors under Practical Operating Conditions

    Science.gov (United States)

    Suzuki, Hisashi; Fukuta, Mitsuhiro; Yanagisawa, Tadashi

    In this paper, lubricating conditions between a swashplate and a shoe in a swashplate compressor for automotive air conditioners is investigated experimentally. The conditions are measured with an electric resistance method that utilizes the swash plate and the shoe as electrodes respectively. The instrumented compressor is connected to an experimental cycle with R134a and operated under various operating conditions of pressure and rotational speed. An improved measurement technique and applying a solid contact ratio to the measurement results permit to measure the lubricating condition at high rotational speed (more than 8000 rpm) and to predic an occurrence of scuffing between the swashplate and the shoe, and therefore enables a detailed study of lubricating characteristics. It is shown by the measurement that the voltage of the contact signal decreases, which means better lubricating condition, with the decrease of the compression pressure and with the increase of the rotational speed from 1000 rpm through 5000 rpm. The lubricating condition tends to worsen at more than 5000 rpm. Furthermore, it is confirmed that the lubricating condition under transient operation is worse obviously as compared with that under steady-state operation.

  19. Wide-temperature-spectrum self-lubricating coatings prepared by plasma spraying

    Science.gov (United States)

    Sliney, H. E.

    1979-01-01

    Self-lubricating, multicomponent coatings, which lubricate over a wide range of operating conditions, are described. The coatings have been successfully applied by plasma-spraying mixed powders onto superalloy substrates. They have been evaluated in friction and wear experiments, and in sliding contact bearing tests. These coatings are wear resistant by virtue of their self-lubricating characteristics rather than because of extreme hardness; a further benefit is low friction. Experiments with simple pin on disk sliding specimens and oscillating plain cylindrical bearing tests were performed to evaluate the tribological properties of the coatings. It was shown that coatings of nichrome, glass and calcium fluoride are self-lubricating from about 500 to 900 C, but give high friction at the lower temperatures. The addition of silver to the coating composition improved the low temperature bearing properties and resulted in coatings which are self-lubricating from cryogenic temperatures to at least 870 C; they are therefore 'wide temperature spectrum,' self-lubricating compositions.

  20. Characterization of used lubricating oil by spectrometric techniques

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Andressa Moreira de, E-mail: andressa@ctaa.embrapa.br [Embrapa Agroindustria de Alimentos, Guaratiba, Rio de Janeiro, RJ (Brazil); Correa, Sergio Machado [Faculdade de Engenharia. Universidade do Estado do Rio de Janeiro (UERJ), Resende, RJ (Brazil); Silva, Glauco Correa da [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: The engine lubricating oil drags all kinds of impurities generated by wear of internal components. Thus, it is necessary to monitor the physical and chemical properties and concentration of metals in lubricants used to determine the appropriate time to replace them. Moreover, one can monitor the wear of the engines through the levels of metals in oils. To achieve these goals, some detection techniques such as Flame atomic absorption spectrometry (FAAS), Inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF), have been widely used to determine metals in lubricating oils and also in other oil derivatives. Thus, some of these techniques were used in this study. Also the technique used was Gas chromatography mass spectrometry (GC / MS) for characterization of chromatographic profile of the engine lubricating oil after use. Through the technique of ICP-OES for method of United States Environmental Protection Agency (USEPA) METHOD 6010B - Inductively coupled plasma optical emission spectrometry was performed to characterize metals in lubricating oil motor, using equipment from ICP-OES Perkin-Elmer{sup R} OPTIMA 3000 ICP-Winlab and software, obtaining the following identification of metals: barium (Ba), calcium (Ca), lead (Pb), copper (Cu), Chromium (Cr), iron (Fe), magnesium (Mg), molybdenum (Mo) and zinc (Zn). Using the XRF technique, through the equipment EDFRX Shimadzu{sup R} model 800HS EDX, Rh tube, applied voltage of 50kV, amperage 100{mu}A, detector Si (Li) cooled with liquid nitrogen and collimator 10mm, we analyzed all the components comprised in the range of Ti to U and Na to SC, identified the following metals: calcium (Ca), zinc (Zn), iron (Fe), copper (Cu), molybdenum (Mo) and nickel (Ni). The characterization was performed by chromatographic methods: USEPA METHOD 5021A - Volatile organic compounds in various sample matrices using equilibrium headspace analysis, USEPA METHOD 8015B - Nonhalogenated Organics

  1. Characterization of used lubricating oil by spectrometric techniques

    International Nuclear Information System (INIS)

    Full text: The engine lubricating oil drags all kinds of impurities generated by wear of internal components. Thus, it is necessary to monitor the physical and chemical properties and concentration of metals in lubricants used to determine the appropriate time to replace them. Moreover, one can monitor the wear of the engines through the levels of metals in oils. To achieve these goals, some detection techniques such as Flame atomic absorption spectrometry (FAAS), Inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF), have been widely used to determine metals in lubricating oils and also in other oil derivatives. Thus, some of these techniques were used in this study. Also the technique used was Gas chromatography mass spectrometry (GC / MS) for characterization of chromatographic profile of the engine lubricating oil after use. Through the technique of ICP-OES for method of United States Environmental Protection Agency (USEPA) METHOD 6010B - Inductively coupled plasma optical emission spectrometry was performed to characterize metals in lubricating oil motor, using equipment from ICP-OES Perkin-ElmerR OPTIMA 3000 ICP-Winlab and software, obtaining the following identification of metals: barium (Ba), calcium (Ca), lead (Pb), copper (Cu), Chromium (Cr), iron (Fe), magnesium (Mg), molybdenum (Mo) and zinc (Zn). Using the XRF technique, through the equipment EDFRX ShimadzuR model 800HS EDX, Rh tube, applied voltage of 50kV, amperage 100μA, detector Si (Li) cooled with liquid nitrogen and collimator 10mm, we analyzed all the components comprised in the range of Ti to U and Na to SC, identified the following metals: calcium (Ca), zinc (Zn), iron (Fe), copper (Cu), molybdenum (Mo) and nickel (Ni). The characterization was performed by chromatographic methods: USEPA METHOD 5021A - Volatile organic compounds in various sample matrices using equilibrium headspace analysis, USEPA METHOD 8015B - Nonhalogenated Organics Using GC

  2. Application of a Biodegradable Lubricant in a Diesel Vehicle

    DEFF Research Database (Denmark)

    Schramm, Jesper

    2003-01-01

    , NOx, THC, PM, lubricant-SOF and PAH from one diesel and one gasoline type vehicle using biodegradable lubricants and conventional lubricants. This paper describes the results of the experiments with the diesel type vehicle only. Lubricant consumption and fuel consumption are other important parameters...

  3. Friction Regimes in the Lubricants Solid-State Regime

    NARCIS (Netherlands)

    Schipper, D.J.; Maathuis, O.; Dowson, D.; Taylor, C.M.; Childs, T.H.C.; Dalmaz, G.

    1995-01-01

    Friction measurements were performed in the lubricant's solid-state regime to study the transition from full-film lubrication, in which the separation is maintained by a solidified lubricant, to mixed lubrication. Special attention is paid to the influence of temperature (inlet viscosity) and roughn

  4. A numerical comparison of control strategies applied to an existing ice storage system

    International Nuclear Information System (INIS)

    While ice storage systems are designed according to a defined strategy for warm day loads, it is interesting to consider other conventional control strategies for mid-season day loads. Three different charging-discharging control strategies are applied to an existing cooling plant and compared in terms of operating costs and energy consumption. A cooling plant model is built. A time stage equal to 15 min is considered to simulate numerically a whole charging-discharging process and compare the different control strategies. These simulations take into account existing technical constraints and set points. EES software is used. The operating costs of the cooling plant are evaluated by taking into account both the energy and the demand cost rate. It is shown that an ice storage system can allow savings of operating costs. However, they can increase energy consumption

  5. Quantitative Feedback Theory (QFT) applied to the design of a rotorcraft flight control system

    Science.gov (United States)

    Hess, R. A.; Gorder, P. J.

    1992-01-01

    Quantitative Feedback Theory describes a frequency-domain technique for the design of multi-input, multi-output control systems which meet time or frequency domain performance criteria when specified uncertainty exists in the linear description of the vehicle dynamics. Quantitative Feedback Theory is applied to the design of the longitudinal flight control system for a linear uncertain model of the AH-64 rotorcraft. In this model, the uncertainty is assigned, and is assumed to be attributable to actual uncertainty in the dynamic model and to the changes in the vehicle aerodynamic characteristics which occur near hover. The model includes an approximation to the rotor and actuator dynamics. The design example indicates the manner in which handling qualities criteria may be incorporated into the design of realistic rotorcraft control systems in which significant uncertainty exists in the vehicle model.

  6. Field tests applying multi-agent technology for distributed control. Virtual power plants and wind energy

    International Nuclear Information System (INIS)

    Multi-agent technology is state of the art ICT. It is not yet widely applied in power control systems. However, it has a large potential for bottom-up, distributed control of a network with large-scale renewable energy sources (RES) and distributed energy resources (DER) in future power systems. At least two major European R and D projects (MicroGrids and CRISP) have investigated its potential. Both grid-related as well as market-related applications have been studied. This paper will focus on two field tests, performed in the Netherlands, applying multi-agent control by means of the PowerMatcher concept. The first field test focuses on the application of multi-agent technology in a commercial setting, i.e. by reducing the need for balancing power in the case of intermittent energy sources, such as wind energy. In this case the flexibility is used of demand and supply of industrial and residential consumers and producers. Imbalance reduction rates of over 40% have been achieved applying the PowerMatcher, and with a proper portfolio even larger rates are expected. In the second field test the multi-agent technology is used in the design and implementation of a virtual power plant (VPP). This VPP digitally connects a number of micro-CHP units, installed in residential dwellings, into a cluster that is controlled to reduce the local peak demand of the common low-voltage grid segment the micro-CHP units are connected to. In this way the VPP supports the local distribution system operator (DSO) to defer reinforcements in the grid infrastructure (substations and cables)

  7. Load-Induced Confinement Activates Diamond Lubrication by Water

    Science.gov (United States)

    Zilibotti, G.; Corni, S.; Righi, M. C.

    2013-10-01

    Tribochemical reactions are chemical processes, usually involving lubricant or environment molecules, activated at the interface between two solids in relative motion. They are difficult to be monitored in situ, which leaves a gap in the atomistic understanding required for their control. Here we report the real-time atomistic description of the tribochemical reactions occurring at the interface between two diamond films in relative motion, by means of large scale ab initio molecular dynamics. We show that the load-induced confinement is able to catalyze diamond passivation by water dissociative adsorption. Such passivation decreases the energy of the contacting surfaces and increases their electronic repulsion. At sufficiently high coverages, the latter prevents surface sealing, thus lowering friction. Our findings elucidate effects of the nanoscale confinement on reaction kinetics and surface thermodynamics, which are important for the design of new lubricants.

  8. Determining the Thermal Properties of Space Lubricants

    Science.gov (United States)

    Maldonado, Christina M.

    2004-01-01

    Many mechanisms used in spacecrafts, such as satellites or the space shuttle, employ ball bearings or gears that need to be lubricated. Normally this is not a problem, but in outer space the regular lubricants that are used on Earth will not function properly. Regular lubricants will quickly vaporize in the near vacuum of space. A unique liquid called a perfluoropolyalkylether (PFPE) has an extremely low vapor pressure, around l0(exp -10) torr at 20 C, and has been used in numerous satellites and is currently used in the space shuttle. Many people refer to the PFPEs as "liquid Teflon". PFPE lubricants however, have a number of problems with them. Lubricants need many soluble additives, especially boundary and anti-wear additives, in them to function properly. All the regular known boundary additives are insoluble in PFPEs and so PFPEs lubricate poorly under highly loaded conditions leading to many malfunctioning ball bearings and gears. JAXA, the Japanese Space Agency, is designing and building a centrifuge rotor to be installed in the International Space Station. The centrifuge rotor is part of a biology lab module. They have selected a PFPE lubricant to lubricate the rotor s ball bearings and NASA bearing experts feel this is not a wise choice. An assessment of the centrifuge rotor design is being conducted by NASA and part of the assessment entails knowing the physical and thermal properties of the PFPE lubricant. One important property, the thermal diffusivity, is not known. An experimental apparatus was set up in order to measure the thermal diffusivity of the PFPE. The apparatus consists of a constant temperature heat source, cylindrical Pyrex glassware, a thermal couple and digital thermometer. The apparatus was tested and calibrated using water since the thermal diffusivity of water is known.

  9. The use of radioactive tracers in lubrication and wear research

    International Nuclear Information System (INIS)

    In many lubrication and wear problems, processes occurring on a very small scale have to be studied and the great sensitivity of radioactive tracer methods has been successfully applied. Several examples of such applications are cited from the work of the Lubrication and Wear Division of the National Engineering Laboratory in the United Kingdom. The quantitative relation between metal transfer and boundary friction is studied as a function of sliding velocity, surface roughness and the presence of lubricants. In order to study the distribution of wear, cast iron plugs containing Ir192 are inserted in the liners of a Diesel engine and the radioactivity present in oil samples is measured. Radioactive iron and iron oxide particles are used to study then role in the wear process. The reactivity of strained metal surface is studied with the aid of C14- labelled stearic acid and of S35 in solution. The reaction rates of gear oil additive are being studied by passing short electric-current pulses through metal wires immersed in solutions of compounds labelled with S35 and P32. The build-up of anti-wear films on the surface of gear teeth is being studied as a function of lead, speed and running time. A problem encountered in many of these applications is the conversion of the measured activity into absolute quantities of materials present in surface films or in wear debris. Calibration methods have been developed for this purpose. (author)

  10. An integrated lubricant oil conditioning sensor using signal multiplexing

    International Nuclear Information System (INIS)

    One effective approach to detect signs of potential failure of a rotating or reciprocating machine is to examine the conditions of its lubrication oil. Here we present an integrated oil condition sensor for detecting both wear debris and lubricant properties. The integrated sensor consists of miniature multiplexed sensing elements for detection of wear debris and measurements of viscosity and moisture. The oil debris sensing element consists of eight sensing channels to detect wear debris in parallel; the elements for measuring oil viscosity and moisture, based on interdigital electrode sensing, were fabricated using micromachining. The integrated sensor was installed and tested in a laboratory lubricating system. Signal multiplexing was applied to the outputs of the three sensing elements such that responses from all sensing elements were obtained within two measurements, and the signal-to-noise ratio was improved. Testing results show that the integrated sensor is capable of measuring wear debris (>50 µm), moisture (>50 ppm) and viscosity (>12.4 cSt) at a high throughput (200 ml min−1). The device can be potentially used for online health monitoring of rotating machines. (paper)

  11. The role of lubricant analysis in maximizing lubricant and equipment life

    International Nuclear Information System (INIS)

    Lubricant analysis has always played an important yet somewhat invisible role in equipment health monitoring. At its most primitive, simple observations and field testing alert equipment operators to changing conditions. At its most advanced, data from performance and analytical tests are used to develop or select optimum lubricants for service, stretch drain intervals, predict remaining equipment life and identify potential equipment or system problems at an incipient stage. Coupled with thermography and vibration analysis, lubricant analysis can become a major component of a comprehensive predictive maintenance (PM) program. Ontario Hydro finds itself at a turning point regarding the use and monitoring of lubricants. Increasing emphasis on equipment reliability and plant life extension, coupled with major, recent changes in lubricant composition in response to environmental, energy and safety concerns, forces an upgrading of many aspects of lubricant monitoring so that it may establish itself as a key part of modern PM practices. This paper discusses some of these aspects. (author)

  12. Potential of Palm Olein as Green Lubricant Source: Lubrication Analysis and Chemical Characterisation

    International Nuclear Information System (INIS)

    Palm olein (POo) is widely used as edible oil in tropical countries. The lubrication properties and chemical compositions of POo being considered to be used as renewable raw material for bio lubricant synthesis. POo is suitable to be used directly as bio lubricant for medium temperature industrial applications. Palm olein has good viscosity index, oxidative stability, flash and fire point as a lubricant source. POo contains unsaturated triacylglycerols (TAG): Palmitin-Olein-Olein, POO (33.3 %), Palmitin-Olein-Palmitin, POP (29.6 %), which are very important to produce good lubricant properties. This unsaturated bond is preferable in chemical modification to produce bio lubricant. The chemical compositions of POo were tested by using high performance liquid chromatography (HPLC) and gas chromatography (GC) techniques. (author)

  13. Impact of individually controlled facially applied air movement on perceived air quality at high humidity

    Energy Technology Data Exchange (ETDEWEB)

    Skwarczynski, M.A. [Faculty of Environmental Engineering, Institute of Environmental Protection Engineering, Department of Indoor Environment Engineering, Lublin University of Technology, Lublin (Poland); International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Copenhagen (Denmark); Melikov, A.K.; Lyubenova, V. [International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Copenhagen (Denmark); Kaczmarczyk, J. [Faculty of Energy and Environmental Engineering, Department of Heating, Ventilation and Dust Removal Technology, Silesian University of Technology, Gliwice (Poland)

    2010-10-15

    The effect of facially applied air movement on perceived air quality (PAQ) at high humidity was studied. Thirty subjects (21 males and 9 females) participated in three, 3-h experiments performed in a climate chamber. The experimental conditions covered three combinations of relative humidity and local air velocity under a constant air temperature of 26 C, namely: 70% relative humidity without air movement, 30% relative humidity without air movement and 70% relative humidity with air movement under isothermal conditions. Personalized ventilation was used to supply room air from the front toward the upper part of the body (upper chest, head). The subjects could control the flow rate (velocity) of the supplied air in the vicinity of their bodies. The results indicate an airflow with elevated velocity applied to the face significantly improves the acceptability of the air quality at the room air temperature of 26 C and relative humidity of 70%. (author)

  14. Study of fieldbus technology applied in a sterilization plant control and safety systems

    International Nuclear Information System (INIS)

    Several sterilization processes have been used in these years for treatment of countless products. Some processes use high temperatures, thermal shocks and chemical agents. With the discovery of the ionizing radiation and its posterior technological developments turned possible application of that process, in 1960, also in the the sterilization, denominated radiation sterilization. This process became also applied in another areas of health and industrial as food conservation, gemstones enhancement and others. The radiation sterilization requests an effective control and it needs a high level of safety. The commercial use of the computers applied in industrial automation provides and the domain of new technologies in this field provides new applications then new designs now is possible. The Fieldbus technology, a new digital communication protocol, like a Local Area Network, can be an alternative in the cobalt-60 irradiation plant. The present work suggests, evaluates, qualifies and quantifies this possibility. (author)

  15. Graphite and Hybrid Nanomaterials as Lubricant Additives

    Directory of Open Access Journals (Sweden)

    Zhenyu J. Zhang

    2014-04-01

    Full Text Available Lubricant additives, based on inorganic nanoparticles coated with organic outer layer, can reduce wear and increase load-carrying capacity of base oil remarkably, indicating the great potential of hybrid nanoparticles as anti-wear and extreme-pressure additives with excellent levels of performance. The organic part in the hybrid materials improves their flexibility and stability, while the inorganic part is responsible for hardness. The relationship between the design parameters of the organic coatings, such as molecular architecture and the lubrication performance, however, remains to be fully elucidated. A survey of current understanding of hybrid nanoparticles as lubricant additives is presented in this review.

  16. Lubrication Influence on Wear Evolution of Xylan 1052 Coated Disk Tested at Various Rotational Speed and High Contact Stress

    Directory of Open Access Journals (Sweden)

    Ion-Cornel Mituletu

    2013-05-01

    Full Text Available This paper relates the lubrication influence on the Xylan 1052 coating applied as the surface layer of a testing disk. By pressing a coated and uncoated bearing ball against the surface of coated disk having different rotational speeds, wear evolution diagrams have been achieved. Tests were performed in three specific conditions, when the disk coated surface is: dry, under poor or continuous lubrication. These conditions allow understanding the influence of poor or continuous lubrication on the behavior of coated disk surface at the contact stress. Such conditions could practically occur due to some problems appearing in industrial environment.

  17. Development of the water-lubricated thrust bearing of the hydraulic turbine generator

    International Nuclear Information System (INIS)

    In hydropower plant, a large quantities of turbine oil is used as machine control pressure oil and lubricating oil. If the oil leak out from hydropower plant, it flows into a river. And such oil spill has an adverse effect on natural environment because the oil does not degrade easily. Therefore the KANSAI and Hitachi Mitsubishi Hydro developed the water-lubricated thrust bearing for vertical type hydraulic turbine generator. The water-lubricated bearing has advantages in risk avoidance of river pollution because it does not need oil. For proceeding the development of the water-lubricated thrust bearing, we studied following items. The first is the examination of the trial products of water lubricating liquid. The second is the study of bearing structure which can satisfy bearing performance such as temperature characteristic and so on. The third is the mock-up testing for actual application in the future. As a result, it was found that the water-lubricated thrust bearing was technically applicable to actual equipments.

  18. Development of the water-lubricated thrust bearing of the hydraulic turbine generator

    Science.gov (United States)

    Inoue, K.; Deguchi, K.; Okude, K.; Fujimoto, R.

    2012-11-01

    In hydropower plant, a large quantities of turbine oil is used as machine control pressure oil and lubricating oil. If the oil leak out from hydropower plant, it flows into a river. And such oil spill has an adverse effect on natural environment because the oil does not degrade easily. Therefore the KANSAI and Hitachi Mitsubishi Hydro developed the water-lubricated thrust bearing for vertical type hydraulic turbine generator. The water-lubricated bearing has advantages in risk avoidance of river pollution because it does not need oil. For proceeding the development of the water-lubricated thrust bearing, we studied following items. The first is the examination of the trial products of water lubricating liquid. The second is the study of bearing structure which can satisfy bearing performance such as temperature characteristic and so on. The third is the mock-up testing for actual application in the future. As a result, it was found that the water-lubricated thrust bearing was technically applicable to actual equipments.

  19. PetroChina Continues to Restructure Lubricants Assets

    Institute of Scientific and Technical Information of China (English)

    Zhang Bingxing

    2002-01-01

    @@ PetroChina has recently separated the lubricants assets of the two oil refining enterprises at Liaohe Oil Field and Yumen Oil Field and transferred them to PetroChina Lubricating Oil Company. As a result,the lubricating oil company has currently nine regional lubricants production plants nationwide with six regional sales centers and two research centers,forming a large-scale lubricants complex with integration of production, marketing and technical development.

  20. Developments and unsolved problems in nano-lubrication*

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The main achievements in the area of nano liquid film, e.g. the distinction between different lubrication regimes, properties of thin film lubrication, the transition between liquid and solid state, ordered and disordered state, the failure of thin lubricant film, the equivalent viscosity and flowing characteristics of micro-fluid, the influence of solid surfaces on nano-lubrication, thin film lubrication of polymer, superlubricity, have been reviewed and some unsolved problems are discussed.

  1. Device for lubricating sealed support of a cutter bit

    Energy Technology Data Exchange (ETDEWEB)

    Grushkin, B.N.; Balabashin, B.P.; Popov, L.N.; Spivak, A.I.; Yudin, A.S.; Zhulayev, V.P.

    1982-01-01

    A device is proposed for lubricating the sealed support of a cutter bit. It contains a vessel arranged in the bit clamp for supplying the lubricant material, a pump with piston and a closed system of lubricant-supplying channels. In order to improve the efficiency of lubrication during drilling with above-bit shock absorbers by accelerating the circulation of the lubricating material, the pump piston is installed with the potential of interacting with the shock absorber.

  2. Vegetable oil basestocks for lubricants

    Directory of Open Access Journals (Sweden)

    Garcés, Rafael

    2011-03-01

    Full Text Available The use of vegetable biodegradable basestocks for lubricant oils present several advantages over the much more extended mineral bases. These advantages refer to biodegradability, a renewable feedstock of local production, lubricant and viscosity index and lower costs than synthetic lubricant bases. Despite these benefits, their use in industry and motor vehicles is not yet extensive due their lower stability and higher pour points. Vegetable oils are esters of fatty acids and glycerol, and their physicochemical properties rely mainly on the composition of their acyl moieties. Thus, to assure the maximum levels of stability while maintaining acceptable behavior at low temperatures, monounsaturated fatty acids are preferred for this purpose. The presence of natural antioxidants also improves the properties of these vegetable based stocks as lubricants. These oils usually require additives to improve their viscosity value, oxidative stability and properties at low temperatures. In the present work, the different sources of vegetable oils appropriate for biolubricant production were reviewed. Their properties and the future improvement of the oil bases, oil based stock production, uses and additives are discussed.

    El uso de bases vegetales biodegradables para aceites lubricantes presenta varias ventajas sobre las mucho más extendidas bases minerales. Estas ventajas se centran sobre todo en su biodegradabilidad, en ser un recurso renovable de producción local, en su lubricidad y en su índice de viscosidad, presentando además costes más bajos que las bases sintéticas. Sin embargo, estas ventajas no han extendido el uso de bases vegetales ni en industria ni en automoción debido a su menor estabilidad y sus mayores puntos críticos de fluidez. Los aceites vegetales son ésteres de ácidos grasos y glicerol y sus propiedades físico-químicas dependen principalmente de su composición acílica. Así, para asegurar los máximos niveles de

  3. Airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 for treatment of lubricants in wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Khondee, Nichakorn; Tathong, Sitti [International Postgraduate Programs in Environmental Management, Graduate School, Chulalongkorn University, Bangkok (Thailand); Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Pinyakong, Onruthai [Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management (NCE-EHWM), Chulalongkorn University, Bangkok (Thailand); Powtongsook, Sorawit [Center of Excellence for Marine Biotechnology (c/o Department of Marine Science, Chulalongkorn University), National Center for Genetic Engineering and Biotechnology, Pathum Thani (Thailand); Chatchupong, Thawach; Ruangchainikom, Chalermchai [Environmental Research and Management Department, PTT Research and Technology Institute, Ayutthaya (Thailand); Luepromchai, Ekawan, E-mail: ekawan.l@chula.ac.th [Bioremediation Research Unit, Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management (NCE-EHWM), Chulalongkorn University, Bangkok (Thailand)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Sphingobium sp. P2 effectively degraded various lubricant samples. Black-Right-Pointing-Pointer Efficiency of Sphingobium sp. P2 increased after immobilization on chitosan. Black-Right-Pointing-Pointer High removal efficiency was due to both sorption and degradation processes. Black-Right-Pointing-Pointer The immobilized bacteria (4 g L{sup -1}) were applied in internal loop airlift bioreactor. Black-Right-Pointing-Pointer The bioreactor continuously removed lubricant from emulsified wastewater. - Abstract: An internal loop airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 was applied for the removal of automotive lubricants from emulsified wastewater. The chitosan-immobilized bacteria had higher lubricant removal efficiency than free and killed-immobilized cells because they were able to sorp and degrade the lubricants simultaneously. In a semi-continuous batch experiment, the immobilized bacteria were able to remove 80-90% of the 200 mg L{sup -1} total petroleum hydrocarbons (TPH) from both synthetic and carwash wastewater. The internal loop airlift bioreactor, containing 4 g L{sup -1} immobilized bacteria, was later designed and operated at 2.0 h HRT (hydraulic retention time) for over 70 days. At a steady state, the reactor continuously removed 85 {+-} 5% TPH and 73 {+-} 11% chemical oxygen demand (COD) from the carwash wastewater with 25-200 mg L{sup -1} amended lubricant. The internal loop airlift reactor's simple operation and high stability demonstrate its high potential for use in treating lubricants in emulsified wastewater from carwashes and other industries.

  4. Robust design of reactor power control system with genetic algorithm-applied weighting functions

    International Nuclear Information System (INIS)

    The H∞ algorithms of the mixed weight sensitivity is used for the robust design of the reactor power control system. The mixed weight sensitivity method requires the selection of the proper weighting functions for the loop shaping in frequency domain. The complexity of the system equation and the non-convexity of the problem make it very difficult to determine the weighting functions. The genetic algorithm which is improved and hybridized with the simulated annealing is applied to determine the weighting functions. This approach permits an automatic calculation and the resultant system shows good robustness and performance. (author)

  5. Implementation of a Fuzzy Logic System to Tune a PI Controller Applied to an Induction Motor

    Directory of Open Access Journals (Sweden)

    LAROUSSI, K.

    2009-10-01

    Full Text Available The simplicity of traditional regulators makes them popular and the most used solution in the nowadays industry. However, they suffer from some limitations and cannot deal with nonlinear dynamics and system parameters variation. In the literature, several strategies of adaptation are developed to alleviate these limitations. In this paper, we propose a combination of two strategies for PI parameters supervision and adaptation. We apply the obtained structure to the control of induction machine speed. Simulation and experimental results of the proposed schema show good performances as compared to two strategies.

  6. New tuning formulae for the PI controller applied to processes with integral actions

    Directory of Open Access Journals (Sweden)

    Tomislav B. Šekara

    2013-02-01

    Full Text Available A new model Gm(s, defined by the four measurable parameters ultimate gain, ultimate frequency, amplitude of ultimate oscillation and dead-time, is obtained from tangent to the Nyquist curve at the critical point. This model represents the generalization of the Ziegler-Nichols process dynamics characterization method, for a large class of stable, integrating and unstable processes Gp(s. In the present paper, by applying time and amplitude scaling technique to the model Gm(s, a new tuning formulae are developed for the PI controller. These tuning formulae guarantee almost optimal performance/robustness tradeoff for a large class of processes with integral action.

  7. The fiber optics router apply to the control system of HIRFL-CSR

    International Nuclear Information System (INIS)

    The authors introduced a kind of Fiber Optic Router that we had designed specially applies to the engineering HIRFL-CSR (Heavy Ion Research Facility in Lanzhou). Including design principle, operational principle, and hardware construction, field of application. The router has standard communication interface such as RS232, RS485, Ethernet and Optics; setup of an optical communication network is simplified. It solved problems such as communication disturb. The requirements of control in the national great science engineering HIRFL-CSR are fulfilled. (authors)

  8. Classical linear-control analysis applied to business-cycle dynamics and stability

    Science.gov (United States)

    Wingrove, R. C.

    1983-01-01

    Linear control analysis is applied as an aid in understanding the fluctuations of business cycles in the past, and to examine monetary policies that might improve stabilization. The analysis shows how different policies change the frequency and damping of the economic system dynamics, and how they modify the amplitude of the fluctuations that are caused by random disturbances. Examples are used to show how policy feedbacks and policy lags can be incorporated, and how different monetary strategies for stabilization can be analytically compared. Representative numerical results are used to illustrate the main points.

  9. Optimal control theory (OWEM) applied to a helicopter in the hover and approach phase

    Science.gov (United States)

    Born, G. J.; Kai, T.

    1975-01-01

    A major difficulty in the practical application of linear-quadratic regulator theory is how to choose the weighting matrices in quadratic cost functions. The control system design with optimal weighting matrices was applied to a helicopter in the hover and approach phase. The weighting matrices were calculated to extremize the closed loop total system damping subject to constraints on the determinants. The extremization is really a minimization of the effects of disturbances, and interpreted as a compromise between the generalized system accuracy and the generalized system response speed. The trade-off between the accuracy and the response speed is adjusted by a single parameter, the ratio of determinants. By this approach an objective measure can be obtained for the design of a control system. The measure is to be determined by the system requirements.

  10. Color control of electrochemiluminescence based on duty ratio of applied waveform voltage

    Science.gov (United States)

    Nishimura, Ryoichi; Nihei, Eisuke

    2016-04-01

    In this research, we succeeded in controlling the light-emitting color obtained from the light-emitting surface of an organic electrochemiluminescence (ECL) device with a duty ratio of the applied voltage. The color change was based on the absorption of light by the light-emitting layer. Because we were able to control the light-emitting relative quantities in each electrode by changing the duty ratio. Long light-emitting lifetime will be expected in the future, because the light-emitting material used was poly(3-hexylthiophene-2,5-diyl) (P3HT), a conductive polymer. We fabricated the ECL device with a light-emitting layer thickness of 25.0 µm. In this device, the ECL color was changed from orange to red by changing the duty ratio from 50 to 10%. More ECL colors are expected to be realized by selecting the light-emitting material with appropriate absorption and ECL spectra.

  11. On the future of controllable fluid film bearings

    OpenAIRE

    Santos, Ilmar

    2011-01-01

    This work gives an overview of the theoretical and experimental achievements of mechatronics applied to fluid film bearings. Compressible and uncompressible fluids are addressed. Rigid and elastic (deformable) bearing profiles are investigated. Hydraulic, pneumatic, magnetic and piezoelectric actuators are used. The ideas of combining control techniques, informatics with hydrodynamic, thermo-hydrodynamic, elasto-hydrodynamic and thermo-elasto-hydrodynamic lubrication techniques are carefully ...

  12. Solid lubricating films for extreme environments

    International Nuclear Information System (INIS)

    Advances in solid lubricating films for vacuum and high temperature applications are reviewed. Traditional lubricants (e.g. graphite and dichalcogenides) are being improved and new lubricating materials (e.g. amorphous carbons) are being discovered with the aid of recent developments in deposition processes and surface analytical methods. Ion bombardment treatments have increased film adhesion, lowered friction coefficients and enhanced the wear life of MoS2 films, as well as created new forms of lubricating carbons (amorphous, polymeric and diamond-like). Composite films and multilayer coating treatments are providing extra protection for surface and films against environmental degradation. Ultralow friction coefficients (2 as well as diamond-like carbon films. Material selection, in some cases (e.g. thin metal films), can now be made on scientific, principles, although many tribomaterials are still being developed by trial and error methods

  13. Ionic Liquids as Advanced Lubricant Fluids

    Directory of Open Access Journals (Sweden)

    Francisco-José Carrión

    2009-08-01

    Full Text Available Ionic liquids (ILs are finding technological applications as chemical reaction media and engineering fluids. Some emerging fields are those of lubrication, surface engineering and nanotechnology. ILs are thermally stable, non-flammable highly polar fluids with negligible volatility, these characteristics make them ideal candidates for new lubricants under severe conditions, were conventional oils and greases or solid lubricants fail. Such conditions include ultra-high vacuum and extreme temperatures. Other very promising areas which depend on the interaction between IL molecules and material surfaces are the use of ILs in the lubrication of microelectromechanic and nanoelectromechanic systems (MEMS and NEMS, the friction and wear reduction of reactive light alloys and the modification of nanophases.

  14. Numerical Simulation of Piston Ring Lubrication

    DEFF Research Database (Denmark)

    Felter, Christian Lotz

    2006-01-01

    and the angle between the normals of the solid and the free surface. The numerical model is compared with the results from an analytical solution of Reynolds equation for a fixed incline slider bearing. Then results from a more compli- cated simulation of piston ring lubrication is given and discussed.......This paper describes a numerical method that can be used to model the lubrication of piston rings. Classical lubrication theory is based on the Reynolds equation which is ap- plicable to confined geometries and open geometries where the flooding conditions are known. Lubrication of piston rings...... extended to include also the oil film outside the piston rings. The numerical model consists of a 2D free surface code that solves the time dependent compressible Navier-Stokes equations. The equations are cast in Lagrangian form and discretized by a meshfree moving least squares method using the primitive...

  15. Biodegradable lubricants - ''the solution for future?''

    International Nuclear Information System (INIS)

    The environmental impact of lubricants use concern the direct effects from spills but also the indirect effects such as their lifetime and the emissions from thermal engines. The biodegradable performances and the toxicity are the environmental criteria that must be taken into account in the development and application of lubricants together with their technical performances. This paper recalls first the definition of biodegradable properties of hydrocarbons and the standardized tests, in particular the CEC and AFNOR tests. Then, the biodegradable performances of basic oils (mineral, vegetal, synthetic esters, synthetic hydrocarbons etc..), finite lubricants (hydraulic fluids..) and engine oils is analyzed according to these tests. Finally, the definition of future standards would take into account all the environmental characteristics of the lubricant: biodegradable performances, energy balance (CO2, NOx and Hx emissions and fuel savings), eco-toxicity and technical performances (wearing and cleanliness). (J.S.)

  16. Reducing Runoff Loss of Applied Nutrients in Oil Palm Cultivation Using Controlled-Release Fertilizers

    Directory of Open Access Journals (Sweden)

    A. Bah

    2014-01-01

    Full Text Available Controlled-release fertilizers are expected to minimize nutrient loss from crop fields due to their potential to supply plant-available nutrients in synchrony with crop requirements. The evaluation of the efficiency of these fertilizers in tropical oil palm agroecological conditions is not yet fully explored. In this study, a one-year field trial was conducted to determine the impact of fertilization with water soluble conventional mixture and controlled-release fertilizers on runoff loss of nutrients from an immature oil palm field. Soil and nutrient loss were monitored for one year in 2012/2013 under erosion plots of 16 m2 on 10% slope gradient. Mean sediments concentration in runoff amounted to about 6.41 t ha−1. Conventional mixture fertilizer posed the greatest risk of nutrient loss in runoff following fertilization due to elevated nitrogen (6.97%, potassium (13.37%, and magnesium (14.76% as percentage of applied nutrients. In contrast, this risk decreased with the application of controlled-release fertilizers, representing 0.75–2.44% N, 3.55–5.09% K, and 4.35–5.43% Mg loss. Meanwhile, nutrient loss via eroded sediments was minimal compared with loss through runoff. This research demonstrates that the addition of controlled-release fertilizers reduced the runoff risks of nutrient loss possibly due to their slow-release properties.

  17. Knowledge-Based Trajectory Error Pattern Method Applied to an Active Force Control Scheme

    Directory of Open Access Journals (Sweden)

    Endra Pitowarno, Musa Mailah, Hishamuddin Jamaluddin

    2012-08-01

    Full Text Available The active force control (AFC method is known as a robust control scheme that dramatically enhances the performance of a robot arm particularly in compensating the disturbance effects. The main task of the AFC method is to estimate the inertia matrix in the feedback loop to provide the correct (motor torque required to cancel out these disturbances. Several intelligent control schemes have already been introduced to enhance the estimation methods of acquiring the inertia matrix such as those using neural network, iterative learning and fuzzy logic. In this paper, we propose an alternative scheme called Knowledge-Based Trajectory Error Pattern Method (KBTEPM to suppress the trajectory track error of the AFC scheme. The knowledge is developed from the trajectory track error characteristic based on the previous experimental results of the crude approximation method. It produces a unique, new and desirable error pattern when a trajectory command is forced. An experimental study was performed using simulation work on the AFC scheme with KBTEPM applied to a two-planar manipulator in which a set of rule-based algorithm is derived. A number of previous AFC schemes are also reviewed as benchmark. The simulation results show that the AFC-KBTEPM scheme successfully reduces the trajectory track error significantly even in the presence of the introduced disturbances.Key Words:  Active force control, estimated inertia matrix, robot arm, trajectory error pattern, knowledge-based.

  18. Mathematical model of Lame Problem for Simplified Elastic Theory applied to Controlled-Clearance Pressure Balances

    CERN Document Server

    Silvano, Saragosa

    2010-01-01

    This paper is based on the original work of the master degree thesis [1] and also represents a revision of the models and the correlations with the analytical solutions given by other authors in the previous publications from 2003 to 2007. All the publications from 2003 to 2007 about simplified analytical methods applied to controlled-clearance pressure balances are not original re-elaborations (with some errors) of the thesis[1]. The analysis described in this paper starts with the mathematical model of thick-walled cylinder based on the solution of the Lame Equations applied to Mechanical theory of elastic equilibrium [5] for the formulation of the so called Simplified Elastic Theory that represents an analytical approach used in the study of the pressure balances. This analysis is well known as Lame problem. The solution of the Lame problem is used to determine the pressure distortion coefficient of controlled-clearance pressure balances. The analysis in this paper includes the case of pressure balances wi...

  19. Study of fieldbus technology confiability when applied in a Sterilization plant control and safety systems

    International Nuclear Information System (INIS)

    Several sterilization processes have been used in these years for treatment of countless products. Some processes use high temperatures, thermal shocks and chemical agents. With the discovery of the ionizing radiation and its posterior technological developments turned possible the application of that process, in 1960, also in the sterilization, denominated radiation sterilization. This process became also applied in another areas of health and industrial as food conservation, gemstones enhancement and others. The radiation sterilization requests an effective control and it needs a high level of safety. The commercial use of the computers applied in industrial automation provides and the domain of new technologies in this field provides news applications then new designs now is possible. The Fieldbus technology, a new digital communication protocol, like a Local Area Network, can be an alternative in the cobalt-60 irradiation plant. This paper show preliminary study about confiability in systems using Fieldbus technology. This technology was simulated in sterilization plant control and safety systems and the fail probability was quantified using Fail Tree Analysis Method. Fieldbus technology can be used in sterilization plants because the confiability in this systems is like PLCs and relays systems, was the conclusion

  20. Boundary friction on molecular lubricants: rolling mode?

    International Nuclear Information System (INIS)

    A theoretical model is proposed for low-temperature friction between two smooth rigid solid surfaces separated by lubricant molecules, admitting their deformations and rotations. The appearance of different modes of energy dissipation (by 'rocking' or 'rolling' of lubricants) at slow relative displacement of the surfaces is shown to be accompanied by stick-and-slip features and reveals a nonmonotonic (mean) friction force vs external load

  1. New Lubricants Protect Machines and the Environment

    Science.gov (United States)

    2007-01-01

    In 1994, NASA and Lockheed Martin Space Operations commissioned Sun Coast Chemicals of Daytona Inc to develop a new type of lubricant that would be safe for the environment and help "grease the wheels" of the shuttle-bearing launcher platform. Founded in 1989, Sun Coast Chemicals is known amongst the racing circuit for effective lubricants that help overcome engine and transmission problems related to heat and wear damage. In a matter of weeks, Sun Coast Chemical produced the biodegradable, high-performance X-1R Crawler Track Lube. In 1996, Sun Coast Chemical determined there was a market for this new development, and introduced three derivative products, Train Track Lubricant, Penetrating Spray Lubricant, and Biodegradable Hydraulic Fluid, and then quickly followed with a gun lubricant/cleaner and a fishing rod and reel lubricant. Just recently, Sun Coast introduced the X-1R Corporation, which folds the high-performance, environmentally safe benefits into a full line of standard automotive and specially formulated racing products. The entire X-1R automotive product line has stood up to rigorous testing by groups such as the American Society of Mechanical Engineers, the Swedish National Testing and Research Institute, the Department of Mechanical Engineering at Oakland University (Rochester, Michigan), and Morgan-McClure Motorsports (Abingdon, Virginia). The X-1R Corporation also markets "handy packs" for simple jobs around the house, consisting of a multi-purpose, multi-use lubricant and grease. In 2003, The X-1R Corporation teamed up with Philadelphia-based Penn Tackle Manufacturing Co., a leading manufacturer of fishing tackle since 1932, to jointly develop and market a line of advanced lubrication products for saltwater and freshwater anglers

  2. A formula for lubrication of journal boxes

    Energy Technology Data Exchange (ETDEWEB)

    Gimayev, R.N.; Aliyev, R.A.; Dolukhanov, R.Ts.; Kondrasheva, N.K.; Ol' kov, P.L.; Rogacheva, O.I.; Spivak, Ye.A.

    1982-01-01

    In order to improve lubricating properties of oils used for journal boxes, an extract that boils off at 275-470/sup 0/, 60-75, is used, with a thermal cracking residue that is ADS 25-40. The latter consists of oil fraction extracts in a mixture with a catalytically cracked heavy gasoil (low-coking). Thus, content of aromatic hydrocarbons and asphalt-tar substances determines its positive lubricating properties. Example: the lubricant derived by direct compounding of a selectively cleaned oil fraction extract (SE), having a boiling temp. of 275-470/sup 0/, thermal ADS cracking residue and density of 1.100 is prepared with a component ratio 75:25. The derived oil has a viscosity of 42.0 sSt/50/sup 0/; dynamic viscosity 110 pz/-10/sup 0/; boiling temp. in an open crucible is 140/sup 0/; congelation temp. -42/sup 0/; critical loading, determined by a four-bearing friction machine, 85 kgs; thickness of lubricating layer, determined by centrifuge, 3.35 mkm. Comparison of physicochemical properties of the given and known lubricants shows that the tested item has better viscosity and lubricating characteristics. Oil test samples satisfy all GOST 610-72 requirements for summer-type axle oils.

  3. PRODUCTION OF HIGH QUALITY LUBRICATING BASE OIL

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@High VI lubricating oil is produced in hydrocracker through hydrocracking (HDC) and hydroisome-rization reactions. In order to effectively produce high VI component, such as iso-pafaffins and monocyclic naphtenes, it is important to load suitable HDC catalysts and operate them in the appropriate reaction conditions.   Nippon Mitsubishi Oil Corporation (NMOC) and its affiliate company, Nippon Mitsubishi Petroleum Refining Company (NMPRC) reported their original HDC catalysts four years ago in this Japan-China joint se-minar in Beijing[1]. NMOC and NMPRC operate their hydrocracker both in fuel oil production mode and in lubricating oil production mode. In lubricating oil production mode, high VI lubricating oil called VHDC are produced.   In this paper, at first, the advantages of high VI lubricating oil are described. And then it is announced that NMOC and NMPRC have developed a new generation of HDC catalyst with higher cracking activity, higher middle distillate selectivity and longer life than the other commercial HDC catalysts. In addition to those properties, the catalyst is able to yield high VI lubricating oil as well.

  4. Foaming characteristics of refigerant/lubricant mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, D.Y.; Shah, D.O.; Jotshi, C.K.; Bhagwat, S.; Leung, M.; Gregory, A.

    1997-04-01

    The air-conditioning and refrigeration industry has moved to HFC refrigerants which have zero ozone depletion and low global warming potential due to regulations on CFC and HCFC refrigerants and concerns for the environment. The change in refrigerants has prompted the switch from mineral oil and alkylbenzene lubricants to polyolester-based lubricants. This change has also brought about a desire for lubricant, refrigerant and compressor manufacturers to understand the foaming properties of alternative refrigerant/ lubricant mixtures, as well as the mechanisms which affect these properties. The objectives of this investigation are to experimentally determine the foaming absorption and desorption rates of HFC and blended refrigerants in polyolester lubricant and to define the characteristics of the foam formed when the refrigerant leaves the refrigerant/ lubricant mixture after being exposed to a pressure drop. The refrigerants being examined include baseline refrigerants: CFC-12 (R-12) and HCFC-22 (R-22); alternative refrigerants: HFC-32 (R-32), R-125, R-134a, and R-143a; and blended refrigerants: R-404A, R-407C, and R-410A. The baseline refrigerants are tested with ISO 32 (Witco 3GS) and ISO 68 (4GS) mineral oils while the alternative and blended refrigerants are tested with two ISO 68 polyolesters (Witco SL68 and ICI RL68H).

  5. Solubility modeling of refrigerant/lubricant mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Michels, H.H.; Sienel, T.H.

    1996-12-31

    A general model for predicting the solubility properties of refrigerant/lubricant mixtures has been developed based on applicable theory for the excess Gibbs energy of non-ideal solutions. In our approach, flexible thermodynamic forms are chosen to describe the properties of both the gas and liquid phases of refrigerant/lubricant mixtures. After an extensive study of models for describing non-ideal liquid effects, the Wohl-suffix equations, which have been extensively utilized in the analysis of hydrocarbon mixtures, have been developed into a general form applicable to mixtures where one component is a POE lubricant. In the present study we have analyzed several POEs where structural and thermophysical property data were available. Data were also collected from several sources on the solubility of refrigerant/lubricant binary pairs. We have developed a computer code (NISC), based on the Wohl model, that predicts dew point or bubble point conditions over a wide range of composition and temperature. Our present analysis covers mixtures containing up to three refrigerant molecules and one lubricant. The present code can be used to analyze the properties of R-410a and R-407c in mixtures with a POE lubricant. Comparisons with other models, such as the Wilson or modified Wilson equations, indicate that the Wohl-suffix equations yield more reliable predictions for HFC/POE mixtures.

  6. Study of turbocharger shaft motion by means of non-invasive optical techniques: Application to the behaviour analysis in turbocharger lubrication failures

    Science.gov (United States)

    Pastor, J. V.; Serrano, J. R.; Dolz, V.; López, M. A.; Bouffaud, F.

    2012-10-01

    This paper presents a novel non-invasive technique to estimate the turbocharger shaft whirl motion. The aim of this article is to present a system for monitoring the shaft motion of a turbocharger, which will be used in turbocharger destructive testing. To achieve this, a camera and a light source were installed in a turbocharger test bench with a controlled lubrication circuit. An image recording methodology and a process algorithm have been developed, in order to estimate the shaft motion. This processing consists on differentiating specific zones of the image, in order to obtain their coordinates. Two reference points have been configured on the compressor side, which help to calculate the relative position of the shaft, avoiding the errors due to structural vibrations. Maximum eccentricity of the turbocharger has been determined and it has been compared with shaft motion when it is spinning in different conditions. A luminosity study has been also done, in order to improve the process and to obtain locus of shaft position in a picture exposition time period. The technique has been applied to diagnosis of a lubrication failure test and the main results will be presented in this article: like shaft motion figures; thermodynamic variables and pictures of the shaft while it is spinning at abnormal lubrication conditions. The measuring components used in this technique have the ability to withstand the catastrophic failure of the turbocharger in this type of test.

  7. Estimating the Impacts of Local Policy Innovation: The Synthetic Control Method Applied to Tropical Deforestation.

    Science.gov (United States)

    Sills, Erin O; Herrera, Diego; Kirkpatrick, A Justin; Brandão, Amintas; Dickson, Rebecca; Hall, Simon; Pattanayak, Subhrendu; Shoch, David; Vedoveto, Mariana; Young, Luisa; Pfaff, Alexander

    2015-01-01

    Quasi-experimental methods increasingly are used to evaluate the impacts of conservation interventions by generating credible estimates of counterfactual baselines. These methods generally require large samples for statistical comparisons, presenting a challenge for evaluating innovative policies implemented within a few pioneering jurisdictions. Single jurisdictions often are studied using comparative methods, which rely on analysts' selection of best case comparisons. The synthetic control method (SCM) offers one systematic and transparent way to select cases for comparison, from a sizeable pool, by focusing upon similarity in outcomes before the intervention. We explain SCM, then apply it to one local initiative to limit deforestation in the Brazilian Amazon. The municipality of Paragominas launched a multi-pronged local initiative in 2008 to maintain low deforestation while restoring economic production. This was a response to having been placed, due to high deforestation, on a federal "blacklist" that increased enforcement of forest regulations and restricted access to credit and output markets. The local initiative included mapping and monitoring of rural land plus promotion of economic alternatives compatible with low deforestation. The key motivation for the program may have been to reduce the costs of blacklisting. However its stated purpose was to limit deforestation, and thus we apply SCM to estimate what deforestation would have been in a (counterfactual) scenario of no local initiative. We obtain a plausible estimate, in that deforestation patterns before the intervention were similar in Paragominas and the synthetic control, which suggests that after several years, the initiative did lower deforestation (significantly below the synthetic control in 2012). This demonstrates that SCM can yield helpful land-use counterfactuals for single units, with opportunities to integrate local and expert knowledge and to test innovations and permutations on policies

  8. Estimating the Impacts of Local Policy Innovation: The Synthetic Control Method Applied to Tropical Deforestation.

    Directory of Open Access Journals (Sweden)

    Erin O Sills

    Full Text Available Quasi-experimental methods increasingly are used to evaluate the impacts of conservation interventions by generating credible estimates of counterfactual baselines. These methods generally require large samples for statistical comparisons, presenting a challenge for evaluating innovative policies implemented within a few pioneering jurisdictions. Single jurisdictions often are studied using comparative methods, which rely on analysts' selection of best case comparisons. The synthetic control method (SCM offers one systematic and transparent way to select cases for comparison, from a sizeable pool, by focusing upon similarity in outcomes before the intervention. We explain SCM, then apply it to one local initiative to limit deforestation in the Brazilian Amazon. The municipality of Paragominas launched a multi-pronged local initiative in 2008 to maintain low deforestation while restoring economic production. This was a response to having been placed, due to high deforestation, on a federal "blacklist" that increased enforcement of forest regulations and restricted access to credit and output markets. The local initiative included mapping and monitoring of rural land plus promotion of economic alternatives compatible with low deforestation. The key motivation for the program may have been to reduce the costs of blacklisting. However its stated purpose was to limit deforestation, and thus we apply SCM to estimate what deforestation would have been in a (counterfactual scenario of no local initiative. We obtain a plausible estimate, in that deforestation patterns before the intervention were similar in Paragominas and the synthetic control, which suggests that after several years, the initiative did lower deforestation (significantly below the synthetic control in 2012. This demonstrates that SCM can yield helpful land-use counterfactuals for single units, with opportunities to integrate local and expert knowledge and to test innovations and

  9. Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

    Science.gov (United States)

    Li, Shuo; Bhushan, Bharat

    2016-08-01

    Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.

  10. Characteristics of lubrication at nanoscale in two-phasefluid system

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Chaohui(张朝辉); WEN; Shizhu(温诗铸); LUO; Jianbin(雒建斌)

    2002-01-01

    Thin film lubrication (TFL) is a condition in which the lubricating features between two surfaces in relative motion are determined by the combination of the properties of the surfaces and the lubricant and viscosity of the lubricant. The effects imposed by couple stress on lubrication characteristics cannot be disregarded in this regime where the ordered molecules dominate the fluid field. There are different tensor measures and constitutive equations in this case other than Newtonian case. The lubrication of two-phase (solid phase and liquid phase) fluid is investigated in this paper. The existence of couple stress will enhance the lubricant viscosity and hence increase the film thickness and improve the load-carrying capability. Size-dependent effects can be seen in the lubrication with couple stress, and the thinner the lubricating film is, the more obvious the effect will be.

  11. NetCDF based data archiving system applied to ITER Fast Plant System Control prototype

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R., E-mail: rodrigo.castro@visite.es [Asociacion EURATOM/CIEMAT para Fusion, Madrid (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, Madrid (Spain); Ruiz, M.; De Arcas, G.; Barrera, E.; Lopez, J.M.; Sanz, D. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, UPM, Madrid (Spain); Goncalves, B.; Santos, B. [Associacao EURATOM/IST, IPFN - Laboratorio Associado, IST, Lisboa (Portugal); Utzel, N.; Makijarvi, P. [ITER Organization, St. Paul lez Durance Cedex (France)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Implementation of a data archiving solution for a Fast Plant System Controller (FPSC) for ITER CODAC. Black-Right-Pointing-Pointer Data archiving solution based on scientific NetCDF-4 file format and Lustre storage clustering. Black-Right-Pointing-Pointer EPICS control based solution. Black-Right-Pointing-Pointer Tests results and detailed analysis of using NetCDF-4 and clustering technologies on fast acquisition data archiving. - Abstract: EURATOM/CIEMAT and Technical University of Madrid (UPM) have been involved in the development of a FPSC (Fast Plant System Control) prototype for ITER, based on PXIe (PCI eXtensions for Instrumentation). One of the main focuses of this project has been data acquisition and all the related issues, including scientific data archiving. Additionally, a new data archiving solution has been developed to demonstrate the obtainable performances and possible bottlenecks of scientific data archiving in Fast Plant System Control. The presented system implements a fault tolerant architecture over a GEthernet network where FPSC data are reliably archived on remote, while remaining accessible to be redistributed, within the duration of a pulse. The storing service is supported by a clustering solution to guaranty scalability, so that FPSC management and configuration may be simplified, and a unique view of all archived data provided. All the involved components have been integrated under EPICS (Experimental Physics and Industrial Control System), implementing in each case the necessary extensions, state machines and configuration process variables. The prototyped solution is based on the NetCDF-4 (Network Common Data Format) file format in order to incorporate important features, such as scientific data models support, huge size files management, platform independent codification, or single-writer/multiple-readers concurrency. In this contribution, a complete description of the above mentioned solution

  12. Specific grinding energy and surface roughness of nanoparticle jet minimum quantity lubrication in grinding

    Directory of Open Access Journals (Sweden)

    Zhang Dongkun

    2015-04-01

    Full Text Available Nanoparticles with the anti-wear and friction reducing features were applied as cooling lubricant in the grinding fluid. Dry grinding, flood grinding, minimal quantity of lubrication (MQL, and nanoparticle jet MQL were used in the grinding experiments. The specific grinding energy of dry grinding, flood grinding and MQL were 84, 29.8, 45.5 J/mm3, respectively. The specific grinding energy significantly decreased to 32.7 J/mm3 in nanoparticle MQL. Compared with dry grinding, the surface roughness values of flood grinding, MQL, and nanoparticle jet MQL were significantly reduced with the surface topography profile values reduced by 11%, 2.5%, and 10%, respectively, and the ten point height of microcosmic unflatness values reduced by 1.5%, 0.5%, and 1.3%, respectively. These results verified the satisfactory lubrication effects of nanoparticle MQL. MoS2, carbon nanotube (CNT, and ZrO2 nanoparticles were also added in the grinding fluid of nanoparticle jet MQL to analyze their grinding surface lubrication effects. The specific grinding energy of MoS2 nanoparticle was only 32.7 J/mm3, which was 8.22% and 10.39% lower than those of the other two nanoparticles. Moreover, the surface roughness of workpiece was also smaller with MoS2 nanoparticle, which indicated its remarkable lubrication effects. Furthermore, the role of MoS2 particles in the grinding surface lubrication at different nanoparticle volume concentrations was analyzed. MoS2 volume concentrations of 1%, 2%, and 3% were used. Experimental results revealed that the specific grinding energy and the workpiece surface roughness initially increased and then decreased as MoS2 nanoparticle volume concentration increased. Satisfactory grinding surface lubrication effects were obtained with 2% MoS2 nanoparticle volume concentration.

  13. Contribution of surface analysis spectroscopic methods to the lubrication field

    International Nuclear Information System (INIS)

    The analytical surface technics such as ESCA, AES and SIMS are tested to be applied to a particular lubrication field. One deals with a 100 C6 steel surface innumered in tricresylphosphate at 1100C for 15 days. The nature of the first layers is studied after relevant solvant cleaning. An iron oxide layer is produced on the bearing surface, namely αFe2-O3. ESCA, AES and SIMS studies show an overlayer of iron phosphate. The exact nature of iron phosphate is not clearly established but the formation of a ferrous phosphate coating can be assumed from ESCA analysis

  14. STARCH-LUBRICANT COMPOSITION FOR IMPROVED LUBRICITY AND FLUID LOSS IN WATER-BASED DRILLING MUDS

    Science.gov (United States)

    Water-based mud systems that approach the performance of oil-based muds are an ongoing effort. Starch-lubricant compositons were developed as environmentally safe, non-toxic, stable dispersions in water-based drilling muds. Starch-lubricant compositions were prepared by jet cooking mixtures of wat...

  15. Compatibility of lubricant additives with HFC refrigerants and synthetic lubricants. Final report, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Cavestri, R.C. [Imagination Resources, Inc., Dublin, OH (United States)

    1997-07-01

    Part one of this research provides manufacturers of components of air-conditioning and refrigeration equipment with a useful list of lubricant additives, sources, functional properties and chemical species. The list in part one is comprised of domestic lubricant additive suppliers and the results of a literature search that was specifically targeted for additives reported to be useful in polyolester chemistry.

  16. A comparative study of the active force control schemes applied to robot arm

    International Nuclear Information System (INIS)

    In this paper, a comparative study of three different types of active force control (AFC) schemes applied to a robotic arm is described. The study particularly focuses on the techniques to compute the estimated inertia matrix (ΙΝ) of a robotic manipulator necessary for the execution of the AFC strategy since the computation of (ΙΝ) is the common central theme to all AFC-based schemes. The first of the three AFC schemes is based on the conventional method of obtaining (ΙΝ), the second uses artificial neural network while the third incorporates an iterative learning algorithm. The study also discusses the characteristics of the (ΙΝ) curves obtained, the trajectory track performance of the schemes and the effects of the modelled disturbances. The robustness of all the AFC schemes are also ascertained in the study. (Author)

  17. Pollution control technologies applied to coal-fired power plant operation

    International Nuclear Information System (INIS)

    Burning of fossil fuels is the major source of energy in today's global economy with over one-third of the world's power generation derived from coal combustion. Although coal has been a reliable, abundant, and relatively inexpensive fuel source for most of the 20th century, its future in electric power generation is under increasing pressure as environmental regulations become more stringent worldwide. Current pollution control technologies for combustion exhaust gas generally treat the release of regulated pollutants: sulfur dioxide, nitrogen oxides and particulate matter as three separate problems instead of as parts of one problem. New and improved technologies have greatly reduced the emissions produced per ton of burning coal. The term 'Clean Coal Combustion Technology' applies generically to a range of technologies designed to greatly reduce the emissions from coal-fired power plants. The wet methods of desulfurization at present are the widest applied technology in professional energetics. This method is economic and gives good final results but a future for clean technologies is the biomass. Power from biomass is a proven commercial option of the electricity generation in the World. An increasing number of power marketers are starting to offer environmentally friendly electricity, including biomass power, in response to the consumer demand and regulatory requirements. (authors)

  18. Mechanisms of lubrication and wear of a bonded solid lubricant film

    Science.gov (United States)

    Fusaro, R. L.

    1980-01-01

    To obtain a better understanding of how bonded solid lubricant films lubricate and wear (in general), the tribological properties of polyimide-bonded graphite fluoride films were studied (in specific). A pin-on-disk type of testing apparatus was used; but in addition to sliding a hemispherically tipped rider, a rider with a 0.95 mm diameter flat area was slid against the film. This was done so that a lower, less variable contact stress could be achieved. Two stages of lubrication occurred. In the first, the film supported the load. The lubricating mechanism consisted of the shear of a thin surface layer (of the film) between the rider and the bulk of the film. The second occurred after the bonded film had worn to the substrate, and consisted of the shear of very thin lubricant films between the rider and flat plateaus generated on the metallic substrate asperities. The film wear mechanism was strongly dependent on contact stress.

  19. Lubricity of bio-based lubricant derived from chemically modified jatropha methyl ester

    Directory of Open Access Journals (Sweden)

    N.W.M. Zulkifli

    2014-06-01

    Full Text Available Many studies have been undertaken with a view to using chemically modified vegetable oil as a bio-based lubricant. This research focused on tribological properties of trimethylolpropane (TMP ester, which is derived from renewable resource. This TMP ester was produced from jatropha methyl ester; it is biodegradable and has high lubricity properties. Two different conditions of lubrication are being investigated: extreme pressure and anti-wear. It was found that the TMP ester (Jatropha has better lubricity in terms of wear and friction compared to paraffin oil under extreme pressure conditions. TMP ester (Jatropha has similar characteristics to fully formulated lubricant (FFL, in terms of the coefficient of friction (CoF. In terms of the anti-wear condition, TMP ester (Jatropha has the lowest CoF; however it also has the high wear scar diameter. This is due to corrosion and chemical attack.

  20. Determination of service life of aviation lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, V.G.; Novosartov, G.T.; Echin, A.I.; Bakunin, V.N.

    1985-11-01

    A method of evaluating the quality of expensive lubricants was developed based on determination of thermo-oxidative stability on a TSM-1 apparatus. This allowed measurement of the content of additives and qualitative properties associated with them during oxidation under laboratory conditions. By developing graphs showing dependence of operating properties sharply degrade was determined. This minimum additive content became the criterion for assessing the working capability of the lubricant and determining the limiting length of its service. Thus, for lubricant B-3V, the most important operating characteristics are thermooxidative stability and critical loading. Samples were tested for the additives PODFA and kaptaks and for indicators of antioxidative and antiseizing properties. Experiments showed little change in characteristics during 10 h of oxidation. Laboratory tests showed that the critical loading began to drop when the kaptaks level fell below 0.2%, so this was taken as the minimal acceptable level. Similarly, for lubricant IPM-10, the most important operating property is its thermo-oxidative stability. Tests showed that indicators of thermo-oxidative stability all began to fall when the antioxidative additive fell below 0.1%. This approach allows rapid determination of service criteria for any aviation lubricant with critical additives. In a practical test, B-3V lubricant had been changed in the MI-8 helicopter every 200-300 h, although its kaptaks level was still 0.65%; even at 900 hours it had fallen to only 0.36%. This would allow the service life to be tripled, a conclusion verified by determination of physicochemical and operating properties of the lubricant at that point. 4 references, 2 figures.

  1. Effects of nano-LaF3 on the friction and wear behaviors of PTFE-based bonded solid lubricating coatings under different lubrication conditions

    Science.gov (United States)

    Jia, Yulong; Wan, Hongqi; Chen, Lei; Zhou, Huidi; Chen, Jianmin

    2016-09-01

    Influence of nanometer lanthanum fluoride (nano-LaF3) on the tribological behaviors of polytetrafluoroethylene (PTFE) bonded solid lubricating coatings were investigated using a ring-on-block friction-wear tester under dry friction and RP-3 jet fuel lubrication conditions. The worn surfaces and transfer films formed on the counterpart steel rings were observed by scanning electron microscope (SEM) and optical microscope (OM), respectively. The microstructures of the nano-LaF3 modified coatings and the distribution states of nano-LaF3 were studied by field-emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM), respectively. The results show that incorporation of nano-LaF3 improves the microhardness and the friction-reduced and anti-wear abilities of PTFE bonded solid lubricating coatings. The wear life of the modified coating is about 6 times longer than that of the coating without nano-LaF3 filler at a relatively low applied load (200 N) and rotary speed (1000 rev/min) under dry friction condition. The friction coefficient and wear life of the modified coating decrease with increase of applied load under dry friction, but the friction coefficient has hardly any variation and wear life decreases under RP-3 jet fuel lubrication condition. In addition, the friction coefficient of the modified coating reduces with the rotary speed increasing under dry sliding but has little change under RP-3 lubrication, the wear life increases firstly and then decreases. The results indicated that the wear failure mechanism is dominated by applied load, which plays an important role in guidance of application of nano-LaF3 modified PTFE bonded coating under different working environment.

  2. Influence of tool roughness and lubrication on contact conditions in skin-pass rolling

    DEFF Research Database (Denmark)

    Kijima, Hideo; Bay, Niels

    2009-01-01

    The special contact conditions in skin-pass rolling of steel strip are examined by experimental as well as numerical analysis studying plane strain upsetting of thin sheet with low reduction applying long narrow tools with smooth and roughened surfaces under dry friction and lubricated conditions...

  3. Airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 for treatment of lubricants in wastewater.

    Science.gov (United States)

    Khondee, Nichakorn; Tathong, Sitti; Pinyakong, Onruthai; Powtongsook, Sorawit; Chatchupong, Thawach; Ruangchainikom, Chalermchai; Luepromchai, Ekawan

    2012-04-30

    An internal loop airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 was applied for the removal of automotive lubricants from emulsified wastewater. The chitosan-immobilized bacteria had higher lubricant removal efficiency than free and killed-immobilized cells because they were able to sorp and degrade the lubricants simultaneously. In a semi-continuous batch experiment, the immobilized bacteria were able to remove 80-90% of the 200 mg L(-1) total petroleum hydrocarbons (TPH) from both synthetic and carwash wastewater. The internal loop airlift bioreactor, containing 4 g L(-1) immobilized bacteria, was later designed and operated at 2.0 h HRT (hydraulic retention time) for over 70 days. At a steady state, the reactor continuously removed 85±5% TPH and 73±11% chemical oxygen demand (COD) from the carwash wastewater with 25-200 mg L(-1) amended lubricant. The internal loop airlift reactor's simple operation and high stability demonstrate its high potential for use in treating lubricants in emulsified wastewater from carwashes and other industries. PMID:22398031

  4. Analysis and self-lubricating treatment of porous anodic alumina film formed in a compound solution

    International Nuclear Information System (INIS)

    A porous anodic film on aluminum was prepared in a mixed electrolyte of phosphoric acid and organic acid and cerium salt, and ultrasonic impregnation technology was applied on it to form self-lubricating surface composite. The structure and chemical composition of the film and its lubricity after self-lubricating treatment were investigated in detail. EPMA indicates the cross-section of anodized film has two distinct oxide layers. Al, O and P are found in the film with different distribution in the two layers. XPS analysis on the electron binding energy of the component elements show the chemical composition of film surface are Al2O3, Ce(OH) and some phosphates. The structure of anodized film is amorphous with XRD analysis. The tribological tests shows the frictional coefficient of the self-lubricating surface composite coating is 0.25, much lower than anodized aluminum and aluminum substrate, which is about 0.55 and 0.85, respectively, and it is also durable for a long period of time in comparison with the lubricating coating fabricated by hot-dipping method. SEM images show some PTFE particles are added into the nanoholes of anodic oxide film

  5. Markets for lubricants at a time of upheaval; Schmierstoffmarkt im Umbruch

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, Lutz [Fuchs Petrolub AG (Germany)

    2011-05-15

    The presentation considers the lubricants market and the lubricants under three different points of view. I will discuss the lubricants market under view of the development of the upcoming and existing regulatory risks. The requirements out of the regulations, which need to be fulfilled in the future by the lubricants manufacturer to handle the supply chain in a globalized economy are highlighted. The raw material world will be analyzed, since the raw material becomes a more and more dominating part of the lubricants world. Due to technical requirements the complexity of used raw material becomes a problem in view of the regulatory conditions we are working in. The latest development in the base oil landscape will be discussed. The influence of the changing refinery landscape in Europe and the influence on availability in Europe, USA and Asia are shown. Further more alternative base oils, inorganic additives, i.e. Mo and Li compounds and of course the special chemistry are part of the considerations as well. The third point of view considers the complexity of the lubricant development. The modern lubricant has seen a dramatic change from being a commodity to a process or construction element. The tribology as young discipline in science with a lot of cross-functional aspects requires a lot of additional research to understand more the mechanisms working in the tribosystem. In the farer future this may lead to more predictability than today. The necessity of research in research communities together with universities is mandatory to get the complexity under control. We have to leave the path of phenomenological research to knowledge based development. This is a necessary condition to be faster in development and more effective, which is needed to maintain our European first class position in the globalized world. (orig.)

  6. Experimental investigation of deep drawing of C-rail benchmark using various lubricants

    Directory of Open Access Journals (Sweden)

    Liao Juan

    2015-01-01

    Full Text Available This paper deals with the deep drawing of C-rail experimental benchmark, which has a complex deformation path. The influence of various lubricants, including the dry friction, low and high viscosity mineral oil, semisolid grease and PTFE film on the drawability of dual-phase steel sheets, was performed. The digital image correlation technique was applied for component tests as well as the deformation analysis. The drawability was experimentally assessed by comparing surface roughness, thickness reduction, and springback of drawn component. The experimental results indicate that the interfacial lubrication between tools and work-piece plays an important role on the drawability of advanced high strength steel sheets. The quality of component was improved obviously by using PTFE film compared to the other lubricants.

  7. Lubrication of Piston Rings in Large 2–and 4–stroke Diesel Engines

    DEFF Research Database (Denmark)

    Felter, Christian Lotz

    numerical models implemented as computer programs. The classical Reynolds equation can be used to calculate the pressure distribution in thin films of fluid. In relation to piston ring lubrication it is, however, less straight forward to apply the Reynolds equation since the inlet (and outlet) point of the......Piston rings are vital components of any internal combustion engine, and their performance affect important properties such as frictional losses, oil consumption, and wear of parts. This thesis deals with the lubrication of piston rings from a theoretical point of view. Predictions are made using...... lubricated conjunction is not known before hand. In order to overcome this problem, which is the main topic of this work, two different paths are followed. First an equation for the inlet point location is derived under the assumption of steady-state running conditions. Assuming that this limitation is...

  8. Temperature effect of friction and wear characteristics for solid lubricating graphite

    Science.gov (United States)

    Kim, Yeonwook; Kim, Jaehoon

    2015-03-01

    Graphite is one of the effective lubricant additives due to its excellent high-temperature endurance and self-lubricating properties. In this study, wear behavior of graphite used as sealing materials to cut off hot gas is evaluated at room and elevated temperature. Wear occurs on graphite seal due to the friction of driving shaft and graphite. Thus, a reciprocating wear test to evaluate the wear generated for the graphite by means of the relative motion between a shaft material and a graphite seal was carried out. The friction coefficient and specific wear rate for the changes of applied load and sliding speed were compared under different temperature conditions considering the actual operating environment. Through SEM observation of the worn surface, the lubricating film was observed and compared with test conditions.

  9. Vegetable oil base stocks for lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Garces, R.; Martinez-Force, E.; Salas, J.

    2011-07-01

    The use of vegetable biodegradable base stocks for lubricant oils present several advantages over the much more extended mineral bases. These advantages refer to biodegradability, a renewable feedstock of local production, lubricant and viscosity index and lower costs than synthetic lubricant bases. Despite these benefits, their use in industry and motor vehicles is not yet extensive due their lower stability and higher pour points. Vegetable oils are esters of fatty acids and glycerol, and their physicochemical properties rely mainly on the composition of their acyl moieties. Thus, to assure the maximum levels of stability while maintaining acceptable behavior at low temperatures, monounsaturated fatty acids are preferred for this purpose. The presence of natural antioxidants also improves the properties of these vegetable based stocks as lubricants. These oils usually require additives to improve their viscosity value, oxidative stability and properties at low temperatures. In the present work, the different sources of vegetable oils appropriate for bio lubricant production were reviewed. Their properties and the future improvement of the oil bases, oil based stock production, uses and additives are discussed. (Author).

  10. Asphalt modification with used lubricating oil

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva, A.; Ho, S.; Zanzotto, L. [Calgary Univ., AB (Canada). Schulich School of Engineering, Bituminous Materials Research Laboratory

    2008-02-15

    A method of recycling waste lubricating oil from vehicles was presented. Various asphalt materials were modified with different amounts of lubricating oil and analyzed using standard Superpave tests. Dynamic shear rheometer (DSR) tests were then conducted to in order to obtain high temperature samples. Bending beam rheometer (BBR) and direct tension tests (DTT) were used to obtain low temperature sample profiles. Potential applications for the materials were reviewed. Environmental impacts and costs associated with using the materials were also presented. The study demonstrated that waste lubricating oil can be used as a softening agent in modified asphalt binders using a low temperature grade technique. It was concluded that the low cost of waste lubricating oil in Alberta makes it a potential resource for asphalt modification. The oil modified samples lowered the high-temperature grade and did not improve the overall quality of the asphalt. Further testing is needed to examine the quality and consistency of lubricating oils. 19 refs., 7 tabs., 12 figs.

  11. Nanoscale Organic−Inorganic Hybrid Lubricants

    KAUST Repository

    Kim, Daniel

    2011-03-15

    Silica (SiO2) nanoparticles densely grafted with amphiphilic organic chains are used to create a family of organic-inorganic hybrid lubricants. Short sulfonate-functionalized alkylaryl chains covalently tethered to the particles form a dense corona brush that stabilizes them against aggregation. When these hybrid particles are dispersed in poly-α-olefin (PAO) oligomers, they form homogeneous nanocomposite fluids at both low and high particle loadings. By varying the volume fraction of the SiO2 nanostructures in the PAO nanocomposites, we show that exceptionally stable hybrid lubricants can be created and that their mechanical properties can be tuned to span the spectrum from simple liquids to complex gels. We further show that these hybrid lubricants simultaneously exhibit lower interfacial friction coefficients, enhanced wear and mechanical properties, and superior thermal stability in comparison with either PAO or its nanocomposites created at low nanoparticle loadings. Profilometry and energy dispersive X-ray spectroscopic analysis of the wear track show that the enhanced wear characteristics in PAO-SiO2 composite lubricants originate from two sources: localization of the SiO2 particles into the wear track and extension of the elastohydrodynamic lubrication regime to Sommerfeld numbers more than an order of magnitude larger than for PAO. © 2011 American Chemical Society.

  12. High temperature solid lubricants - When and where to use them.

    Science.gov (United States)

    Sliney, H. E.

    1973-01-01

    This paper reviews the state of the art of solid lubrication for moderate to extremely high temperature lubrication (to 1600 F). Lubricating characteristics, stability in various environments, and relevant machine design considerations are discussed. Lubricating materials discussed include MoS2, WS2, graphite, graphite fluoride, the high temperature polymide polymer, and calcium fluoride based coatings and composites. The scope of the information includes results from wear testers, ball bearings, and journal bearings.

  13. Practical Applications and Uses of Solid Lubricant Films

    Science.gov (United States)

    Stupp, B. C.

    1984-01-01

    Practical applications are illustrated with discussions covering the reasons for use of solid lubricants, required performance, lubricant selection, and results obtained for the various examples shown. The applications described cover a broad range of solid lubricants. Included are soft lamellar compounds, organic polymers, soft elemental metals, oxides and compounds for high temperature use. The illustrations selected cover a broad range of lubricant application techniques delineating the reasons for the different processing procedures which include bonded films, plasma spraying, sputtering, ion plating and electrodeposition.

  14. Edge-Localized mode control and transport generated by externally applied magnetic perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, I. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

    2012-06-15

    This article reviews the subject of edge localized mode (ELM) control using externally applied magnetic perturbations and proposes theoretical mechanisms that may be responsible for the induced transport changes. The first question that must be addressed is: what is the structure of magnetic field within the plasma? Although initial hypotheses focused on the possibility of the creation of a region of stochastic field lines at the tokamak edge, drift magnetohydrodynamics theory predicts that magnetic reconnection is strongly suppressed over the region of the pedestal with steep gradients and fast perpendicular rotation. Reconnection can only occur near the location where the perpendicular electron velocity vanishes, and hence the electron impedance nearly vanishes, or near the foot of the pedestal, where the plasma is sufficiently cold and resistive. The next question that must be addressed is: which processes are responsible for the observed transport changes, nonlinearity, turbulence, or stochasticity? Over the pedestal region where ions and electrons rotate in opposite directions relative to the perturbation, the quasilinear Lorentz force decelerates the electron fluid and accelerates the ion fluid. The quasilinear magnetic flutter flux is proportional to the force and produces an outward convective transport that can be significant. Over the pedestal region where the E x B flow and the electrons rotate in opposite directions relative to the perturbation, magnetic islands with a width on the order of the ion gyroradius can directly radiate drift waves. In addition, the combination of quasilinear electron transport and ion viscous transport can lead to a large net particle flux. Since there are many transport mechanisms that may be active simultaneously, it is important to determine which physical mechanisms are responsible for ELM control and to predict the scaling to future devices (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Data on radiation resistance of lubricating oil

    International Nuclear Information System (INIS)

    This report presents data of radiation resistance of commercial lubricating oils. Data included are the radiation induced change of properties such as kinematic viscosity, total acid number, flash point, pour point, specific gravity and color, and the results by instrumental analysis such as gas analysis by gas chromatography, ESR spectra, infrared spectra, mass spectra, and molecular weight distribution by liquid chromatography. Twenty-seven different kinds of commercial lubricating oils including mineral oils, a synthetic hydrocarbon oil, ester lubricants, a polyether, silicone oils, florinated oils and aromatic oils were irradiated with 60Co γ-rays at room temperature in a vacuum, in air and under bubbling oxygen. The irradiation was carried out up to 30 MGy at a dose rate of 10 kGy/h. (author)

  16. Rheology and lubricity of hyaluronic acid

    Science.gov (United States)

    Liang, Jing; Krause, Wendy E.

    2007-03-01

    The polyelectrolyte hyaluronic acid (HA, hyaluronan) is an important component in synovial fluid (i.e., the fluid that lubricates our freely moving joints). Its presence results in highly viscoelastic solutions. In comparison to healthy synovial fluid, diseased fluid has a reduced viscosity and loss of lubricity. In osteoarthritis the reduction in viscosity results from a decline in both the molecular weight and concentration of HA. In our investigation, we attempt to correlate the rheological properties of HA solutions to changes in lubrication and wear. A nanoindenter will be used to evaluate the coefficient of friction and wear properties between the nanoindenter tip and ultrahigh molecular weight polyethylene in both the presence and absence of a thin film of HA solution.

  17. Compatibility of refrigerants and lubricants with elastomers

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, G.R.; Seiple, R.H.

    1992-10-01

    Information contained in this report is designed to assist the air-conditioning and refrigeration industry in the selection of suitable elastomeric gasket and seal materials that will prove useful in various refrigerant and refrigeration lubricant environments. 97% of the swell measurements have been made to date. The other 3% of the measurements are contingent on the availability of additional quantities of R-32. Swell behavior in the fluids have been determined using weight and in situ diameter measurements for the refrigerants and weight, diameter and thickness measurements for the lubricants. Weight and diameter measurements are repeated after 2 hours and 24 hours for samples removed from the refrigerant test fluids and 24 hours after removal from the lubricants.

  18. Compatibility of refrigerants and lubricants with elastomers

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, G.R.; Seiple, R.H.

    1993-01-01

    The information contained in this report is designed to assist the air-conditioning and refrigeration industry in the selection of suitable elastomeric gasket and seal materials that will prove useful in various refrigerant and refrigeration lubricant environments. 97% of the swell measurements have been made to date. The other 3% of the measurements are contingent on availability of additional R-32. Swell behavior in the fluids have been determined using weight and in situ diameter measurements for the refrigerants and weight, diameter and thickness measurements for the lubricants. Weight and diameter measurements are repeated after 2 and 24 hours for samples removed from the refrigerant test fluids and 24 hours after removal from the lubricants.

  19. Electrophoretically-deposited solid film lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Dugger, M.T.; Panitz, J.K.J.; Vanecek, C.W.

    1995-04-01

    An aqueous-based process that uses electrophoresis to attract powdered lubricant in suspension to a charged target was developed. The deposition process yields coatings with low friction, complies with environmental safety regulations, requires minimal equipment, and has several advantages over processes involving organic binders or vacuum techniques. This work focuses on development of the deposition process, includes an analysis of the friction coefficient of the material in sliding contact with stainless steel under a range of conditions, and a functional evaluation of coating performance in a precision mechanical device application. Results show that solid lubricant films with friction coefficients as low as 0.03 can be produced. A 0.03 friction coefficient is superior to solid lubricants with binder systems and is comparable to friction coefficients generated with more costly vacuum techniques.

  20. The Lubrication Qualities of Dimethyl Ether (DME)

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Sorenson, Spencer C; Jakobsen, J.

    2002-01-01

    Dimethyl Ether (DME) has been recognised as a clean alternative for diesel oil for some years now. Fuelling diesel engines with DME solves their two most significant problems: The emission of particulate matter is virtually eliminated and the level of NOx can be reduced considerably by exhaust gas...... the viscosity, which plays a major role in the hydrodynamic lubrication regime. The lubricity of DME has been established by the medium frequency pressurised reciprocating rig (MFPRR) to be very low compared to the one of diesel oil. But the DME film limits the wear extent significantly compared to...... the case of dry sliding. By mixing DME with additives, the lubricity level is easily raised even above the one of diesel oil. The viscosity of DME has been established by the volatile fuel viscometer (VFVM) to be as low as 0.185 cSt @ 25 oC. It is also shown that this viscosity cannot be raised...

  1. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces

    Science.gov (United States)

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-04-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity.

  2. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces.

    Science.gov (United States)

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-01-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity. PMID:27040483

  3. How tests of lubricating and transformer oils became part of power plant chemistry in Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, H. [I/S Nordjyllandsvaerket, Vodskov (Denmark)

    1996-12-01

    Lubricating, hydraulic and transformer oils based on refined crude oil are used in nearly all power station components, such as gear, turbines, hydraulic stations, feed pumps and transformers. The function of these components totally depends on the condition of the oils and their properties. Seen from this point one may wonder why examination and evaluation of oils did not become part of the power station chemistry within the ELSAM utility area until during the middle of the eighties. We started to examine the properties of lubricating oils at the time when several steam turbines experienced serious problems with formation of deposits in their hydraulic control circuits. This work was intensified in connection with the significant number of CHPs and wind turbines erected within the Danish electricity sector during the past 10 years or so. The majority of the CHPs are natural gas fired turbines or motors, equipment which severely stresses the lubricating oil. In collaboration with KEMA, the Netherlands, we have carried through with a large examination of lubricating oils in gas turbines and we have found suitable oil types. The objectives of our work with lubricating and transformer oils have been to link together the laboratory measurements with operational experience. Only by doing this is it possible to utilize the laboratory measurements in a correct way. It must be remembered that the main part of all oil specifications concerns the properties of new oils. Only very little is published about the requirements concerning used oils. (EG)

  4. A Review of Auditing Methods Applied to the Content of Controlled Biomedical Terminologies

    Science.gov (United States)

    Zhu, Xinxin; Fan, Jung-Wei; Baorto, David M.; Weng, Chunhua; Cimino, James J.

    2012-01-01

    Although controlled biomedical terminologies have been with us for centuries, it is only in the last couple of decades that close attention has been paid to the quality of these terminologies. The result of this attention has been the development of auditing methods that apply formal methods to assessing whether terminologies are complete and accurate. We have performed an extensive literature review to identify published descriptions of these methods and have created a framework for characterizing them. The framework considers manual, systematic and heuristic methods that use knowledge (within or external to the terminology) to measure quality factors of different aspects of the terminology content (terms, semantic classification, and semantic relationships). The quality factors examined included concept orientation, consistency, non-redundancy, soundness and comprehensive coverage. We reviewed 130 studies that were retrieved based on keyword search on publications in PubMed, and present our assessment of how they fit into our framework. We also identify which terminologies have been audited with the methods and provide examples to illustrate each part of the framework. PMID:19285571

  5. A safety assessment methodology applied to CNS/ATM-based air traffic control system

    International Nuclear Information System (INIS)

    In the last decades, the air traffic system has been changing to adapt itself to new social demands, mainly the safe growth of worldwide traffic capacity. Those changes are ruled by the Communication, Navigation, Surveillance/Air Traffic Management (CNS/ATM) paradigm , based on digital communication technologies (mainly satellites) as a way of improving communication, surveillance, navigation and air traffic management services. However, CNS/ATM poses new challenges and needs, mainly related to the safety assessment process. In face of these new challenges, and considering the main characteristics of the CNS/ATM, a methodology is proposed at this work by combining 'absolute' and 'relative' safety assessment methods adopted by the International Civil Aviation Organization (ICAO) in ICAO Doc.9689 , using Fluid Stochastic Petri Nets (FSPN) as the modeling formalism, and compares the safety metrics estimated from the simulation of both the proposed (in analysis) and the legacy system models. To demonstrate its usefulness, the proposed methodology was applied to the 'Automatic Dependent Surveillance-Broadcasting' (ADS-B) based air traffic control system. As conclusions, the proposed methodology assured to assess CNS/ATM system safety properties, in which FSPN formalism provides important modeling capabilities, and discrete event simulation allowing the estimation of the desired safety metric.

  6. A new bio-inspired perceptual control architecture applied to solving navigation tasks

    Science.gov (United States)

    Arena, P.; De Fiore, S.; Patané, L.; Vitanza, A.

    2009-05-01

    In this paper a new general purpose perceptual control architecture is presented and applied to robot navigation in cluttered environments. In nature, insects show the ability to react to certain stimuli with simple reflexes using direct sensory-motor pathways, which can be considered as basic behaviors, while high brain regions provide secondary pathway allowing the emergence of a cognitive behavior which modulates the basic abilities. Taking inspiration from this evidence, our architecture modulates, through a reinforcement learning, a set of competitive and concurrent basic behaviors in order to accomplish the task assigned through a reward function. The core of the architecture is constituted by the Representation layer, where different stimuli, triggering competitive reflexes, are fused to form a unique abstract picture of the environment. The representation is formalized by means of Reaction-Diffusion nonlinear partial differential equations, under the paradigm of the Cellular Neural Networks, whose dynamics converges to steady-state Turing patterns. A suitable unsupervised learning, introduced at the afferent (input) stage, leads to the shaping of the basins of attractions of the Turing patterns in order to incrementally drive the association between sensor stimuli and patterns. In this way, at the end of the leaning stage, each pattern is characteristic of a particular behavior modulation, while its trained basin of attraction contains the set of all the environment conditions, as recorded through the sensors, leading to the emergence of that particular behavior modulation. Robot simulations are reported to demonstrate the potentiality and the effectiveness of the approach.

  7. FTIR-ATR spectroscopy applied to quality control of grape-derived spirits.

    Science.gov (United States)

    Anjos, Ofélia; Santos, António J A; Estevinho, Letícia M; Caldeira, Ilda

    2016-08-15

    The Fourier transform infrared (FTIR) spectroscopic method with attenuated total reflectance (ATR) was used for predicting the alcoholic strength, the methanol, acetaldehyde and fusel alcohols content of grape-derived spirits. FTIR-ATR spectrum in the mid-IR region (4000-400cm(-1)) was used for the quantitative estimation by applying partial least square (PLS) regression models and the results were correlated with those obtained from reference methods. In the developed method, a cross-validation with 50% of the samples was used for PLS analysis along with a validation test set with 50% of the remaining samples. Good correlation models with a great accuracy were obtained for methanol (r(2)=99.4; RPD=12.8), alcoholic strength (r(2)=97.2; RPD=6.0), acetaldehyde (r(2)=98.2; RPD=7.5) and fusel alcohols (r(2) from 97.4 to 94.1; RPD from 6.2 to 4.1). These results corroborate the hypothesis that FTIR-ATR is a useful technique for the quality control of grape-derived spirits, whose practical application may improve the efficiency and quickness of the current laboratory analysis. PMID:27006210

  8. Advances in control of frost on evaporator coils with an applied electric field

    Energy Technology Data Exchange (ETDEWEB)

    Tudor, V. [Advanced Thermal Research Laboratory, Mechanical Engineering Department, US Naval Academy, Annapolis, MD 21402 (United States); Ohadi, M. [Smart and Small Thermal Systems Laboratory, Mechanical Engineering Department, University of Maryland, College park, MD 20742 (United States); Salehi, M.A.; Lawler, J.V. [ATEC Inc., College Park, MD 20742 (United States)

    2005-10-01

    This paper introduces an innovative technique on use of an applied electric field for control of frost over evaporator coils with fin density and geometric configuration of interest to freezer/refrigerator applications. The technique discussed in this paper, referred to as the 'dielectric barrier discharge' (DBD) method, may be particularly suitable for application in evaporator coils with high fin density. Experiments conducted with a small-scale laboratory test-module, as well as a full-scale supermarket evaporator are presented. The DBD technique is based on generating localized non-resistive heating within fins of an evaporator coil via application of a high-voltage, alternating current through electrodes. Our experiments demonstrate that the defrosting time using DBD is substantially shorter than conventional techniques, while the energy consumption associated with the process is less than one half of the corresponding energy of the electrical resistance heating methods. Basic operational principles of the technique, its advantages and limitations when compared to conventional electrical defrosting techniques are discussed and presented for the first time in this paper. (author)

  9. Improved Broadband Liner Optimization Applied to the Advanced Noise Control Fan

    Science.gov (United States)

    Nark, Douglas M.; Jones, Michael G.; Sutliff, Daniel L.; Ayle, Earl; Ichihashi, Fumitaka

    2014-01-01

    The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more desirable. This paper describes improvements to a previously established broadband acoustic liner optimization process using the Advanced Noise Control Fan rig as a demonstrator. Specifically, in-duct attenuation predictions with a statistical source model are used to obtain optimum impedance spectra over the conditions of interest. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Constant-depth, double-degree of freedom and variable-depth, multi-degree of freedom designs are carried through design, fabrication, and testing to validate the efficacy of the design process. Results illustrate the value of the design process in concurrently evaluating the relative costs/benefits of these liner designs. This study also provides an application for demonstrating the integrated use of duct acoustic propagation/radiation and liner modeling tools in the design and evaluation of novel broadband liner concepts for complex engine configurations.

  10. Carbon-based tribofilms from lubricating oils.

    Science.gov (United States)

    Erdemir, Ali; Ramirez, Giovanni; Eryilmaz, Osman L; Narayanan, Badri; Liao, Yifeng; Kamath, Ganesh; Sankaranarayanan, Subramanian K R S

    2016-08-01

    Moving mechanical interfaces are commonly lubricated and separated by a combination of fluid films and solid 'tribofilms', which together ensure easy slippage and long wear life. The efficacy of the fluid film is governed by the viscosity of the base oil in the lubricant; the efficacy of the solid tribofilm, which is produced as a result of sliding contact between moving parts, relies upon the effectiveness of the lubricant's anti-wear additive (typically zinc dialkyldithiophosphate). Minimizing friction and wear continues to be a challenge, and recent efforts have focused on enhancing the anti-friction and anti-wear properties of lubricants by incorporating inorganic nanoparticles and ionic liquids. Here, we describe the in operando formation of carbon-based tribofilms via dissociative extraction from base-oil molecules on catalytically active, sliding nanometre-scale crystalline surfaces, enabling base oils to provide not only the fluid but also the solid tribofilm. We study nanocrystalline catalytic coatings composed of nitrides of either molybdenum or vanadium, containing either copper or nickel catalysts, respectively. Structurally, the resulting tribofilms are similar to diamond-like carbon. Ball-on-disk tests at contact pressures of 1.3 gigapascals reveal that these tribofilms nearly eliminate wear, and provide lower friction than tribofilms formed with zinc dialkyldithiophosphate. Reactive and ab initio molecular-dynamics simulations show that the catalytic action of the coatings facilitates dehydrogenation of linear olefins in the lubricating oil and random scission of their carbon-carbon backbones; the products recombine to nucleate and grow a compact, amorphous lubricating tribofilm. PMID:27488799

  11. Unified Desktop for Monitoring & Control Applications - The Open Navigator Framework Applied for Control Centre and EGSE Applications

    Science.gov (United States)

    Brauer, U.

    2007-08-01

    The Open Navigator Framework (ONF) was developed to provide a unified and scalable platform for user interface integration. The main objective for the framework was to raise usability of monitoring and control consoles and to provide a reuse of software components in different application areas. ONF is currently applied for the Columbus onboard crew interface, the commanding application for the Columbus Control Centre, the Columbus user facilities specialized user interfaces, the Mission Execution Crew Assistant (MECA) study and EADS Astrium internal R&D projects. ONF provides a well documented and proven middleware for GUI components (Java plugin interface, simplified concept similar to Eclipse). The overall application configuration is performed within a graphical user interface for layout and component selection. The end-user does not have to work in the underlying XML configuration files. ONF was optimized to provide harmonized user interfaces for monitoring and command consoles. It provides many convenience functions designed together with flight controllers and onboard crew: user defined workspaces, incl. support for multi screens efficient communication mechanism between the components integrated web browsing and documentation search &viewing consistent and integrated menus and shortcuts common logging and application configuration (properties) supervision interface for remote plugin GUI access (web based) A large number of operationally proven ONF components have been developed: Command Stack & History: Release of commands and follow up the command acknowledges System Message Panel: Browse, filter and search system messages/events Unified Synoptic System: Generic synoptic display system Situational Awareness : Show overall subsystem status based on monitoring of key parameters System Model Browser: Browse mission database defintions (measurements, commands, events) Flight Procedure Executor: Execute checklist and logical flow interactive procedures Web

  12. Developments of New Lubricants for Cold Forging of Stainless Steel

    DEFF Research Database (Denmark)

    Steenberg, Thomas; Christensen, Erik; Olesen, P.;

    1997-01-01

    Two new lubricant systems for cold forging of stainless steel have been developed. The main component of these systems are FeCl3 and ZnCa2(PO4)2, respectively. Both lubricant systems have been tested using a backward extrusion test. The results show excellent lubricating properties with respect to...

  13. FY2014 Fuel & Lubricant Technologies Annual Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Stork, Kevin [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2016-02-01

    Annual progress report for Fuel & Lubricant Technologies. The Fuel & Lubricant Technologies Program supports fuels and lubricants research and development (R&D) to provide vehicle manufacturers and users with cost-competitive options that enable high fuel economy with low emissions, and contribute to petroleum displacement.

  14. Deposited Micro Porous Layer as Lubricant Carrier in Metal Forming

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Bay, Niels; Tang, Peter Torben; Jensen, Jørgen Dai; Paldan, Nikolas Aulin; Mizushima, Io; Eriksen, Rasmus Solmer

    lubricant reservoirs. Conventional friction tests for cold forming; ring compression and double cup extrusion tests are carried out with Molykote DX paste and mineral oil as lubricant. Both lubricants act as intended for the ring compressions test whereas only the low viscosity oil perform successfully in...

  15. Quality control procedures applied to nuclear instruments. Proceedings of a technical meeting

    International Nuclear Information System (INIS)

    Quality Control (QC), test procedures for Nuclear Instrumentation are important for assurance of proper and safe operation of the instruments, especially with regard to equipment related to radiological safety, human health and national safety. Correct measurements of radiation parameters must be ensured, i.e., accurate measurement of the number of radioactive events, counting times and in some cases accurate measurements of the radiation energy and occurring time of the nuclear events. There are several kinds of testing on nuclear instruments, for example, type-testing done by suppliers, acceptance testing made by the end users, Quality Control tests after repair and Quality Assurance/Quality Controls tests made by end-users. All of these tests are based in many cases on practical guidelines or on the experience of the own specialist, the available standards on this topic also need to be adapted to specific instruments. The IAEA has provided nuclear instruments and supported the operational maintenance efforts of the Member States. Although Nuclear Instrumentation is continuously upgraded, some older or aged instruments are still in use and in good working condition. Some of these instruments may not, however, meet modern requirements for the end-user therefore, Member States, mostly those with emerging economies, modernize/refurbish such instruments to meet the end-user demands. As a result, new instrumentation which is not commercially available, or modernized/refurbished instruments, need to be tested or verified with QC procedures to meet national or international certification requirements. A technical meeting on QC procedures applied to nuclear instruments was organized in Vienna from 23 to 24 August 2007. Existing and required QC test procedures necessary for the verification of operation and measurement of the main characteristics of nuclear instruments was the focus of discussion at this meeting. Presentations made at the technical meeting provided

  16. Design of linear controllers applied to an ethanol steam reformer for PEM fuel cell applications

    OpenAIRE

    García, Vanesa M.; Serra, Maria; Llorca, Jordi; Riera, Jordi

    2013-01-01

    This paper focuses on the design of a controller for a low temperature ethanol steam reformer for the production of hydrogen to feed a protonic exchange membrane (PEM) fuel cell. It describes different control structures for the reformer and treats the control structure selection of this multiple input multiple output (MIMO) system. For each considered control structure, decentralised 2 × 2 controllers with proportional integral (PI) control actions in each control loop are implemented. The t...

  17. Design and Construction of Wireless Control System for Drilling Machine

    OpenAIRE

    Nang Su Moan Hsam; Myo Maung Maung; Hla Myo Tun

    2015-01-01

    Abstract Drilling machine is used for boring holes in various materials and used in woodworking metalworking construction and do-it-yourself projects. When the machine operate for a long time the temperature increases and so we need to control the temperature of the machine and some lubrication system need to apply to reduce the temperature. Due to the improvement of technology the system can be controlled with wireless network. This control system use Window Communication Foundation WCF whic...

  18. Self-lubricating non-oxidizing composites

    International Nuclear Information System (INIS)

    Aluminum nitride - boron nitride ceramic composites were fabricated by pressureless sintering following the method of X. E. Chen et al. It is believed that hexagonal boron nitride incorporated into an aluminum nitride matrix will produce a composite that exploits desirable properties of both materials. The composite should exhibit lubricating qualities of the boron nitride and hardness of the aluminum nitride. The material was studied by X-ray analysis, flexure strength testing and friction testing. This composite has potential use for wear applications in oxidizing environments, where high temperatures prevent the use of conventional lubricants

  19. Lubrication Oil Flow Simulation in Connecting Rod

    OpenAIRE

    Alendal, Ivar Audun Lothe

    2015-01-01

    Lubrication oil-flow in the crank system of an medium size diesel engine running at 750 RPM was modeled and analyzed. The model was built up by combining models from several studies in both engine lubrication systems and pipe flow modal analysis. The model is first used to analyze a system where the oil supply lines are fully open during the complete engine cycle. The result showed that these designs need a very high oil supply pressure to maintain a positive pressure in the connecting rod at...

  20. Ionic liquid lubrication at electrified interfaces

    Science.gov (United States)

    Kong, Lingling; Huang, Wei; Wang, Xiaolei

    2016-06-01

    The lubrication performances of ionic liquids at electrified interfaces have been investigated by using a reciprocating sliding tribometer. Experimental results indicated that the lubricity of the confined ionic liquids was markedly affected by the application of external electric field and strong interface electric field strength could result in high friction. The influence was more pronounced for the ionic liquid with a shorter alkyl side chain in particular. The main reason of the friction increment might be ascribed to the electrically influenced surface adsorption where the charged ions were structured to form robust and ordered layers.

  1. Modes of lubrication in human hip joints.

    OpenAIRE

    Roberts, B J; Unsworth, A; Mian, N.

    1982-01-01

    Cadaveric hip joints were tested in a hip function simulator which subjected the femoral head to a cycle of loading and oscillation similar to that experienced during walking and measured the frictional torque transmitted to the acetabulum. Silicone fluids with viscosities from 10-2 Pa s (pascal second) to 30 Pa s were used as lubricants and the transition from mixed to full fluid film lubrication was observed around 5 x 10(-2) Pa s. Sodium carboxymethylcellulose solutions were also tested at...

  2. Alkylphenoxyalkylstannanes as biocidal additives to lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Belov, P.S.; Gulo, R.A.; Komarova, N.N.; Korenev, K.D.; Poddubnyi, V.N.; Tsvetkov, O.N.

    1980-01-01

    The synthesis of akylphenoxyalkylstannanes with different numbers and lengths of akyl radicals on the tin atom and different structures and lengths of radicals on the aromatic ring is described. They were investigated as biocidal additives to lubricants. Alkylphenoxytriethylstannanes have the best protective properties. In 0.25% concentration (by wt) neither the structure nor the alkyl substituent (C/sub 1/-C/sub 16/) length has an effect on their antiseptic properties. From the results of the conducted studies, for antiseptization of lubricating compositions, the additive AFOTAS a reaction product of an industrial alkylphenol and bis(triethylol) oxide is recommended.

  3. Shear thinning behavior of monolayer liquid lubricant films measured by fiber wobbling method

    International Nuclear Information System (INIS)

    It is essential to clarify mechanical properties of monolayer lubricant films coated on magnetic disks under shearing motion for designing future hard disk drives with ultra-low flying height. Many of previous researchers reported that strong shear rate dependence of viscoelasticity was one of the typical phenomena observed with molecularly thin liquid films. However, it has not been clarified whether or not perfluoropolyether (PFPE) lubricant films, which are used for the head-disk interface (HDI) lubrication, show shear thinning behavior under actual HDI conditions. In this study, we used the fiber wobbling method that can achieve both highly-sensitive shear force measurement and precise gap control and measured shear rate dependence of viscoelastic properties of monolayer PFPE films coated on the magnetic disk. Our experimental results showed that shear thinning does occur at high shear rate ranged from 102 to 106 s-1.

  4. Design of Multimodel based MPC and IMC control schemes applied to injection molding machine

    Directory of Open Access Journals (Sweden)

    Kanaga Lakshmi

    2014-03-01

    Full Text Available Good control of plastic melt temperature for injection molding is very important in reducing operator setup time, ensuring product quality, and preventing thermal degradation of the melt. The controllability and set points of barrel temperature also depend on the precise monitoring and control of plastic melt temperature. Motivated by the practical temperature control of injection molding, this paper proposes MPC and IMC based control scheme. A robust system identification and control methodology is developed which uses canonical varieties analysis for identification and model predictive control for regulation. The injection molding process consists of three zones and the mathematical model for each of the zone is different. The control output for each zone controller is assigned a weight based on the computed probability of each model and the resulting action is the weighted average of the control moves of the individual zone controllers.   Keywords: Injection-Molding Machine (IMM, IMC Control, Temperature Control.

  5. Influences of lubricant pocket geometry and working conditions upon micro lubrication mechanisms in upsetting and strip drawing

    DEFF Research Database (Denmark)

    Shimizu, Ichiro; Martins, P. A. F.; Bay, Niels; Andresen, Jan Lasson; Bech, Jakob Ilsted

    2010-01-01

    Micro-lubricant pockets located in the surface of plastically deforming workpieces are recognised to improve the performance of fluid lubrication in a metal-forming process. This work investigates the joint influence of pocket geometry and process working conditions on micro-lubrication mechanism...

  6. Enhanced basal lubrication and the contribution of the Greenland ice sheet to future sea-level rise

    Science.gov (United States)

    Shannon, Sarah R.; Payne, Antony J.; Bartholomew, Ian D.; van den Broeke, Michiel R.; Edwards, Tamsin L.; Fettweis, Xavier; Gagliardini, Olivier; Gillet-Chaulet, Fabien; Goelzer, Heiko; Hoffman, Matthew J.; Huybrechts, Philippe; Mair, Douglas W. F.; Nienow, Peter W.; Perego, Mauro; Price, Stephen F.; Smeets, C. J. P. Paul; Sole, Andrew J.; van de Wal, Roderik S. W.; Zwinger, Thomas

    2013-01-01

    We assess the effect of enhanced basal sliding on the flow and mass budget of the Greenland ice sheet, using a newly developed parameterization of the relation between meltwater runoff and ice flow. A wide range of observations suggest that water generated by melt at the surface of the ice sheet reaches its bed by both fracture and drainage through moulins. Once at the bed, this water is likely to affect lubrication, although current observations are insufficient to determine whether changes in subglacial hydraulics will limit the potential for the speedup of flow. An uncertainty analysis based on our best-fit parameterization admits both possibilities: continuously increasing or bounded lubrication. We apply the parameterization to four higher-order ice-sheet models in a series of experiments forced by changes in both lubrication and surface mass budget and determine the additional mass loss brought about by lubrication in comparison with experiments forced only by changes in surface mass balance. We use forcing from a regional climate model, itself forced by output from the European Centre Hamburg Model (ECHAM5) global climate model run under scenario A1B. Although changes in lubrication generate widespread effects on the flow and form of the ice sheet, they do not affect substantial net mass loss; increase in the ice sheet’s contribution to sea-level rise from basal lubrication is projected by all models to be no more than 5% of the contribution from surface mass budget forcing alone. PMID:23940337

  7. Enhanced basal lubrication and the contribution of the Greenland ice sheet to future sea-level rise.

    Science.gov (United States)

    Shannon, Sarah R; Payne, Antony J; Bartholomew, Ian D; van den Broeke, Michiel R; Edwards, Tamsin L; Fettweis, Xavier; Gagliardini, Olivier; Gillet-Chaulet, Fabien; Goelzer, Heiko; Hoffman, Matthew J; Huybrechts, Philippe; Mair, Douglas W F; Nienow, Peter W; Perego, Mauro; Price, Stephen F; Smeets, C J P Paul; Sole, Andrew J; van de Wal, Roderik S W; Zwinger, Thomas

    2013-08-27

    We assess the effect of enhanced basal sliding on the flow and mass budget of the Greenland ice sheet, using a newly developed parameterization of the relation between meltwater runoff and ice flow. A wide range of observations suggest that water generated by melt at the surface of the ice sheet reaches its bed by both fracture and drainage through moulins. Once at the bed, this water is likely to affect lubrication, although current observations are insufficient to determine whether changes in subglacial hydraulics will limit the potential for the speedup of flow. An uncertainty analysis based on our best-fit parameterization admits both possibilities: continuously increasing or bounded lubrication. We apply the parameterization to four higher-order ice-sheet models in a series of experiments forced by changes in both lubrication and surface mass budget and determine the additional mass loss brought about by lubrication in comparison with experiments forced only by changes in surface mass balance. We use forcing from a regional climate model, itself forced by output from the European Centre Hamburg Model (ECHAM5) global climate model run under scenario A1B. Although changes in lubrication generate widespread effects on the flow and form of the ice sheet, they do not affect substantial net mass loss; increase in the ice sheet's contribution to sea-level rise from basal lubrication is projected by all models to be no more than 5% of the contribution from surface mass budget forcing alone. PMID:23940337

  8. Development of high performance lubricant through the compatibility of polyalphaolefin, polyurea and irradiated polytetrafluoroethylene

    International Nuclear Information System (INIS)

    Lubricants are gaseous, liquid, semi solid or solid (powder) materials those form a film between two parties preventing friction. High performance lubricants are designed to work under severe conditions of temperature, pressure, and contamination. The most used are liquids (oils) and semi solids (greases). Greases are applied where oils can drain or in inaccessible places and are divided generally into two classes, soap and no soap. The most used non soap grease is polyurea, obtained by the reaction between amine and isocyanate, has highly thixotropic, high dielectric strength and excellent anticorrosive property, so it is widely used for lubrication of electric motors and shipbuilding machinery. For a grease with high performance, in this study was used a synthetic lubricant fluid, polyalphaolefin, and was also employed solid lubricant additive polytetrafluoroethylene (PTFE) due its lowest coefficient of friction, is found commercially irradiated in air to obtain smaller particles and to produce oxygenated terminal groups those are more compatible with the metal surface. The tests conducted were comparatively between pure polyurea grease and with PTFE additive. The characterizations were made by infrared spectroscopy and elemental analysis of C, N and H and Free NCO index, proving the formation of four carbons polyurea (tetraurea). The functional analysis of drop point and oil separation showed high stability and compatibility between the polymers increased when PTFE was added. The excellent resistance of pure tetraurea grease to wear and extreme pressure were demonstrated by four-ball and practical bearings tests, characterizing this grease as a high performance lubricant, when compared to most used greases in the market. (author)

  9. Multiclassifier system with hybrid learning applied to the control of bioprosthetic hand.

    Science.gov (United States)

    Kurzynski, Marek; Krysmann, Maciej; Trajdos, Pawel; Wolczowski, Andrzej

    2016-02-01

    In this paper the problem of recognition of the intended hand movements for the control of bio-prosthetic hand is addressed. The proposed method is based on recognition of electromiographic (EMG) and mechanomiographic (MMG) biosignals using a multiclassifier system (MCS) working in a two-level structure with a dynamic ensemble selection (DES) scheme and original concepts of competence function. Additionally, feedback information coming from bioprosthesis sensors on the correct/incorrect classification is applied to the adjustment of the combining mechanism during MCS operation through adaptive tuning competences of base classifiers depending on their decisions. Three MCS systems operating in decision tree structure and with different tuning algorithms are developed. In the MCS1 system, competence is uniformly allocated to each class belonging to the group indicated by the feedback signal. In the MCS2 system, the modification of competence depends on the node of decision tree at which a correct/incorrect classification is made. In the MCS3 system, the randomized model of classifier and the concept of cross-competence are used in the tuning procedure. Experimental investigations on the real data and computer-simulated procedure of generating feedback signals are performed. In these investigations classification accuracy of the MCS systems developed is compared and furthermore, the MCS systems are evaluated with respect to the effectiveness of the procedure of tuning competence. The results obtained indicate that modification of competence of base classifiers during the working phase essentially improves performance of the MCS system and that this improvement depends on the MCS system and tuning method used. PMID:25982067

  10. Slippery but Tough: The Rapid Fracture of Lubricated Frictional Interfaces

    Science.gov (United States)

    Bayart, E.; Svetlizky, I.; Fineberg, J.

    2016-05-01

    We study the onset of friction for rough contacting blocks whose interface is coated with a thin lubrication layer. High speed measurements of the real contact area and stress fields near the interface reveal that propagating shear cracks mediate lubricated frictional motion. While lubricants reduce interface resistances, surprisingly they significantly increase the energy dissipated Γ during rupture. Moreover, lubricant viscosity affects the onset of friction but has no effect on Γ . Fracture mechanics provide a new way to view the otherwise hidden complex dynamics of the lubrication layer.

  11. Elastohydrodynamic Lubrication with Polyolester Lubricants and HFC Refrigerants, Final Report, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Gunsel, Selda; Pozebanchuk, Michael

    1999-04-01

    The objective of this study was to investigate the film formation properties of refrigeration lubricants using the ultrathin film elastohydrodynamic (EHD) interferometry technique and to study the effects of refrigerants on film formation. Film thickness measurements were conducted as a function of lubricant viscosity, speed, temperature, and refrigerant concentration. Based on the EHD film thickness data, effective pressure-viscosity coefficients were calculated for the test fluids at different temperatures and the effects of refrigerants on pressure-viscosity properties were investigated.

  12. A fuzzy-split range control system applied to a fermentation process.

    Science.gov (United States)

    Fonseca, Rodolpho Rodrigues; Schmitz, Jones Erni; Fileti, Ana Maria Frattini; da Silva, Flavio Vasconcelos

    2013-08-01

    In this study it was proposed the application of a fuzzy-PI controller in tandem with a split range control strategy to regulate the temperature inside a fermentation vat. Simulations were carried out using different configurations of fuzzy controllers and split range combinations for regulatory control. The performance of these control systems were compared using conventional integral of error criteria, the demand of utilities and the control effort. The proposed control system proved able to adequately regulate the temperature in all the tests. Besides, considering a similar ITAE index and using the energetically most efficient split range configuration, fuzzy-PI controller provided a reduction of approximately 84.5% in the control effort and of 6.75% in total demand of utilities by comparison to a conventional PI controller. PMID:23759431

  13. A REVIEW OF INTELLIGENT CONTROL SYSTEMS APPLIED TO THE INVERTED-PENDULUM PROBLEM

    OpenAIRE

    Pedro Ponce; Arturo Molina; Eugenio Eugenio

    2014-01-01

    This study shows the latest advances in the application of intelligent control to the inverted-pendulum problem. A complete review regarding intelligent control design is presented in this study in order to show the most important artificial intelligence methods used for controlling an Inverted-Pendulum. Also this study proposed the use of a neural-fuzzy-with-genetic-algorithms controller for the inverted pendulum problem which gives good results. Conventional controllers are presented in ord...

  14. 7 CFR 2902.14 - Penetrating lubricants.

    Science.gov (United States)

    2010-01-01

    ... re-refined lubricating oil products. Under the Resource Conservation and Recovery Act of 1976... ingredients, re-refined oil, and/or any other recovered material, in addition to biobased ingredients, and... Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF ENERGY POLICY AND NEW...

  15. 7 CFR 2902.47 - Gear lubricants.

    Science.gov (United States)

    2010-01-01

    ... lubricating oils and which product should be afforded the preference in purchasing. Note to paragraph (d... whether or not the product contains any recovered material, in addition to biobased ingredients, and... Regulations of the Department of Agriculture (Continued) OFFICE OF ENERGY POLICY AND NEW USES, DEPARTMENT...

  16. Biobased Lubricant Development - Problems and Opportunities

    Science.gov (United States)

    Biobased lubricants are those comprising ingredients derived from natural sources such as those harvested from farms, forests, etc. Biolubricants provide a number of economic, environmental and health benefits over petroleum-based products. Among these are: biodegradability, renewability and non-t...

  17. Current Trends in Biobased Lubricant Development

    Science.gov (United States)

    Biobased lubricants are those comprising ingredients derived from natural raw materials such as those harvested from farms, forests, etc. Biolubricants provide a number of benefits over petroleum-based products including: biodegradability, renewability, and non-toxicity. As a result, manufacture ...

  18. Lubricant effect of rate-of-loading

    International Nuclear Information System (INIS)

    A series of tests were conducted to establish the performance of a motor operated valve (MOV) stem lubricant. Battelle has assembled a MOV test stand to provide a means to test valve actuators and stems with representative valve load profiles and to accurately measure the actuator performance. The facility duplicates an actual MOV except that the stem thrust loads are generated hydraulically and seating loads are generated by mechanical stops. These tests were conducted at a high torque switch setting on a Limitorque SMB-0. Stem-stemnut pairs with known rate-of-loading (ROL) effects ranging from approximately zero to 30% were tested. The stems were lubricated with Mobil 28; a nuclear-grade synthetic grease. A test with a slow, linearly increasing load profile with torque switch trip occurring prior to seating (ramp test), was used to establish the magnitude of the ROL effect for a particular stem-stemnut. Data from these experiments were compared with results of similar EPRI tests which used different stem lubricants. Results with Mobil 28 yielded unexpected, consistent reduced ROL effects. In addition, the thread pressure threshold for limiting ROL effects was significantly reduced. A model of the squeeze film phenomena was developed to explain the experimental results. The model shows that the basic rheological properties of the lubricant, the thread composite surface roughness, and the thread type all have a significant influence on the magnitude of ROL effects

  19. Classification of lubricants according to cavitation criteria

    NARCIS (Netherlands)

    Meged, Y.; Venner, C.H.; Napel, ten W.E

    1995-01-01

    Cavitation in lubrication liquids has long been known to be detrimental to components in hydraulic systems. Damage has been detected in journal bearings, especially under severe dynamic loading, gears, squeeze film dampers and valves. These findings have led to intensive studies of metal resistance

  20. Thermo-hydrodynamic lubrication in hydrodynamic bearings

    CERN Document Server

    Bonneau, Dominique; Souchet, Dominique

    2014-01-01

    This Series provides the necessary elements to the development and validation of numerical prediction models for hydrodynamic bearings. This book describes the thermo-hydrodynamic and the thermo-elasto-hydrodynamic lubrication. The algorithms are methodically detailed and each section is thoroughly illustrated.

  1. Study on Lubricating Oil Monitoring Technology

    Institute of Scientific and Technical Information of China (English)

    LIU Feng-bi

    2006-01-01

    Lubricating oil monitoring has been proven to be an effective method for detecting and diagnosing machinery failures and essential for realizing condition based maintenance. In this paper, mathematical statistics methods for determining the oil parameters featuring machinery failures and the parameters' probability distribution functions and their thresholds are put forward.

  2. Lubricant Test Methods for Sheet Metal Forming

    DEFF Research Database (Denmark)

    Bay, Niels; Olsson, David Dam; Andreasen, Jan Lasson

    Sheet metal forming of tribologically difficult materials such as stainless steel, Al-alloys and Ti-alloys or forming in tribologically difficult operations like ironing, punching or deep drawing of thick plate requires often use of environmentally hazardous lubricants such as chlorinated paraffin...

  3. A quantitative lubricant test for deep drawing

    DEFF Research Database (Denmark)

    Olsson, David Dam; Bay, Niels; Andreasen, Jan L.

    2010-01-01

    A tribological test for deep drawing has been developed by which the performance of lubricants may be evaluated quantitatively measuring the maximum backstroke force on the punch owing to friction between tool and workpiece surface. The forming force is found not to give useful information...

  4. Improvement of lubricant materials using ruthenium isomerization

    Science.gov (United States)

    Production of an effective industrial lubricant additive from vegetable oils is a high profile and difficult undertaking. One candidate is alkyl 9(10)-dibutylphosphonostearate, which has been made through a radical transformation of alkyl 9-cis-octadecanoate. It is effective, but still suffers from ...

  5. Exploring Low Emission Lubricants for Diesel Engines

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J. M.

    2000-07-06

    A workshop to explore the technological issues involved with the removal of sulfur from lubricants and the development of low emission diesel engine oils was held in Scottsdale, Arizona, January 30 through February 1, 2000. It presented an overview of the current technology by means of panel discussions and technical presentations from industry, government, and academia.

  6. Friction and lubrication in artificial joints

    Czech Academy of Sciences Publication Activity Database

    Vocel, Jan; Musil, Jan; Šída, V.

    Vol. 2. Brno: VUT, 1999 - (Kratochvíl, C.; Kotek, V.; Krejsa, J.), s. 31-34 ISBN 80-214-1325-5. [International conference Engineering mechanics '99.. Svratka (CZ), 17.05.1999-20.05.1999] R&D Projects: GA ČR GA106/98/1373 Keywords : synovial fluid * tribology * lubrication Subject RIV: BO - Biophysics

  7. AFM study of polymer lubricants on hard disk surfaces

    Science.gov (United States)

    Bao, G. W.; Troemel, M.; Li, S. F. Y.

    Thin liquid films of PFPE (perfluoropolyether) lubricants dip-coated on hard disk surfaces were imaged with non-contact mode AFM. Demnum lubricants with phosphazene additives exhibited strong interactions with a silicon tip due to the formation of liquid bridges between the lubricants and the tip, as indicated by a remarkable hysteresis loop between approach and retraction curves in force vs. distance measurements. Features resulting from capillary forces due to tip tapping to the lubricants were revealed, which demonstrated that the capillary forces could be used to lock the non-contacting tip at a certain separation from the substrate surface to obtain AFM images. Force vs. distance curves for Fomblin Z-dol lubricants showed negligible hysteresis effects and features corresponding to lateral distortion of the tip by the lubricants only were observed. In both cases, only when the tip was positioned far above the surfaces could the natural distributions of the lubricants be imaged.

  8. SDRE control strategy applied to a nonlinear robotic including drive motor

    International Nuclear Information System (INIS)

    A robotic control design considering all the inherent nonlinearities of the robot-engine configuration is developed. The interactions between the robot and joint motor drive mechanism are considered. The proposed control combines two strategies, one feedforward control in order to maintain the system in the desired coordinate, and feedback control system to take the system into a desired coordinate. The feedback control is obtained using State-Dependent Riccati Equation (SDRE). For link positioning two cases are considered. Case I: For control positioning, it is only used motor voltage; Case II: For control positioning, it is used both motor voltage and torque between the links. Simulation results, including parametric uncertainties in control shows the feasibility of the proposed control for the considered system

  9. SDRE control strategy applied to a nonlinear robotic including drive motor

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Jeferson J. de, E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br; Tusset, Angelo M., E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br; Janzen, Frederic C., E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br; Piccirillo, Vinicius, E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br; Nascimento, Claudinor B., E-mail: jefersonjl82@gmail.com, E-mail: tusset@utfpr.edu.br, E-mail: fcjanzen@utfpr.edu.br, E-mail: piccirillo@utfpr.edu.br, E-mail: claudinor@utfpr.edu.br [UTFPR-PONTA GROSSA, PR (Brazil); Balthazar, José M., E-mail: jmbaltha@rc.unesp.br [UNESP-BAURU, SP (Brazil); Brasil, Reyolando M. L. R. da Fonseca, E-mail: reyolando.brasil@ufabc.edu.br [UFABC-SANTO ANDRE, SP (Brazil)

    2014-12-10

    A robotic control design considering all the inherent nonlinearities of the robot-engine configuration is developed. The interactions between the robot and joint motor drive mechanism are considered. The proposed control combines two strategies, one feedforward control in order to maintain the system in the desired coordinate, and feedback control system to take the system into a desired coordinate. The feedback control is obtained using State-Dependent Riccati Equation (SDRE). For link positioning two cases are considered. Case I: For control positioning, it is only used motor voltage; Case II: For control positioning, it is used both motor voltage and torque between the links. Simulation results, including parametric uncertainties in control shows the feasibility of the proposed control for the considered system.

  10. Carbon-based tribofilms from lubricating oils

    Science.gov (United States)

    Erdemir, Ali; Ramirez, Giovanni; Eryilmaz, Osman L.; Narayanan, Badri; Liao, Yifeng; Kamath, Ganesh; Sankaranarayanan, Subramanian K. R. S.

    2016-08-01

    Moving mechanical interfaces are commonly lubricated and separated by a combination of fluid films and solid ‘tribofilms’, which together ensure easy slippage and long wear life. The efficacy of the fluid film is governed by the viscosity of the base oil in the lubricant; the efficacy of the solid tribofilm, which is produced as a result of sliding contact between moving parts, relies upon the effectiveness of the lubricant’s anti-wear additive (typically zinc dialkyldithiophosphate). Minimizing friction and wear continues to be a challenge, and recent efforts have focused on enhancing the anti-friction and anti-wear properties of lubricants by incorporating inorganic nanoparticles and ionic liquids. Here, we describe the in operando formation of carbon-based tribofilms via dissociative extraction from base-oil molecules on catalytically active, sliding nanometre-scale crystalline surfaces, enabling base oils to provide not only the fluid but also the solid tribofilm. We study nanocrystalline catalytic coatings composed of nitrides of either molybdenum or vanadium, containing either copper or nickel catalysts, respectively. Structurally, the resulting tribofilms are similar to diamond-like carbon. Ball-on-disk tests at contact pressures of 1.3 gigapascals reveal that these tribofilms nearly eliminate wear, and provide lower friction than tribofilms formed with zinc dialkyldithiophosphate. Reactive and ab initio molecular-dynamics simulations show that the catalytic action of the coatings facilitates dehydrogenation of linear olefins in the lubricating oil and random scission of their carbon–carbon backbones; the products recombine to nucleate and grow a compact, amorphous lubricating tribofilm.

  11. A dynamic rheological model for thin-film lubrication

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiang-Jun; Huang Ying; Guo Yan-Bao; Tian Yu; Meng Yong-Gang

    2013-01-01

    In this study,the effects of the non-Newtonian rheological properties of the lubricant in a thin-film lubrication regime between smooth surfaces were investigated.The thin-film lubrication regime typically appears in Stribeck curves with a clearly observable minimum coefficient of friction (COF) and a low-COF region,which is desired for its lower energy dissipation.A dynamic rheology of the lubricant from the hydrodynamic lubrication regime to the thin-film lubrication regime was proposed based on the convected Maxwell constitutive equation.This rheology model includes the increased relaxation time and the yield stress of the confined lubricant thin film,as well as their dependences on the lubricant film thickness.The Deborah number (De number) was adopted to describe the liquid-solid transition of the confined lubricant thin film under shearing.Then a series of Stribeck curves were calculated based on Tichy's extended lubrication equations with a perturbation of the De number.The results show that the minimum COF points in the Stribeck curve correspond to a critical De number of 1.0,indicating a liquid-to-solid transition of the confined lubricant film.Furthermore,the two proposed parameters in the dynamic rheological model,namely negative slipping length b (indicating the lubricant interfacial effect) and the characteristic relaxation time λ0,were found to determine the minimum COF and the width of the low-COF region,both of which were required to optimize the shape of the Stribeck curve.The developed dynamic rheological model interprets the correlation between the rheological and interfacial properties of lubricant and its lubrication behavior in the thin-film regime.

  12. A dynamic rheological model for thin-film lubrication

    International Nuclear Information System (INIS)

    In this study, the effects of the non-Newtonian rheological properties of the lubricant in a thin-film lubrication regime between smooth surfaces were investigated. The thin-film lubrication regime typically appears in Stribeck curves with a clearly observable minimum coefficient of friction (COF) and a low-COF region, which is desired for its lower energy dissipation. A dynamic rheology of the lubricant from the hydrodynamic lubrication regime to the thin-film lubrication regime was proposed based on the convected Maxwell constitutive equation. This rheology model includes the increased relaxation time and the yield stress of the confined lubricant thin film, as well as their dependences on the lubricant film thickness. The Deborah number (De number) was adopted to describe the liquid-solid transition of the confined lubricant thin film under shearing. Then a series of Stribeck curves were calculated based on Tichy's extended lubrication equations with a perturbation of the De number. The results show that the minimum COF points in the Stribeck curve correspond to a critical De number of 1.0, indicating a liquid-to-solid transition of the confined lubricant film. Furthermore, the two proposed parameters in the dynamic rheological model, namely negative slipping length b (indicating the lubricant interfacial effect) and the characteristic relaxation time λ0, were found to determine the minimum COF and the width of the low-COF region, both of which were required to optimize the shape of the Stribeck curve. The developed dynamic rheological model interprets the correlation between the rheological and interfacial properties of lubricant and its lubrication behavior in the thin-film regime. (condensed matter: structural, mechanical, and thermal properties)

  13. A dynamic rheological model for thin-film lubrication

    Science.gov (United States)

    Zhang, Xiang-Jun; Huang, Ying; Guo, Yan-Bao; Tian, Yu; Meng, Yong-Gang

    2013-01-01

    In this study, the effects of the non-Newtonian rheological properties of the lubricant in a thin-film lubrication regime between smooth surfaces were investigated. The thin-film lubrication regime typically appears in Stribeck curves with a clearly observable minimum coefficient of friction (COF) and a low-COF region, which is desired for its lower energy dissipation. A dynamic rheology of the lubricant from the hydrodynamic lubrication regime to the thin-film lubrication regime was proposed based on the convected Maxwell constitutive equation. This rheology model includes the increased relaxation time and the yield stress of the confined lubricant thin film, as well as their dependences on the lubricant film thickness. The Deborah number (De number) was adopted to describe the liquid-solid transition of the confined lubricant thin film under shearing. Then a series of Stribeck curves were calculated based on Tichy's extended lubrication equations with a perturbation of the De number. The results show that the minimum COF points in the Stribeck curve correspond to a critical De number of 1.0, indicating a liquid-to-solid transition of the confined lubricant film. Furthermore, the two proposed parameters in the dynamic rheological model, namely negative slipping length b (indicating the lubricant interfacial effect) and the characteristic relaxation time λ0, were found to determine the minimum COF and the width of the low-COF region, both of which were required to optimize the shape of the Stribeck curve. The developed dynamic rheological model interprets the correlation between the rheological and interfacial properties of lubricant and its lubrication behavior in the thin-film regime.

  14. Supervisory System and Multivariable Control Applying Weighted Fuzzy-PID Logic in an Alcoholic Fermentation Process

    Directory of Open Access Journals (Sweden)

    Márcio Mendonça

    2015-10-01

    Full Text Available In this work, it is analyzed a multivariate system control of an alcoholic fermentation process with no minimum phase. The control is made with PID classic controllers associated with a supervisory system based on Fuzzy Systems. The Fuzzy system, a priori, send set-points to PID controllers, but also adds protection functions, such as if the biomass valued is at zero or very close. The Fuzzy controller changes the campaign to prevent or mitigate the paralyzation of the process. Three control architectures based on Fuzzy Control Systems are presented and compared in performance with classic control in different campaigns. The third architecture, in particular, adds an adaptive function. A brief summary of Fuzzy theory and correlated works will be presented. And, finally simulations results, conclusions and future works end the article.

  15. A systematic approach for fine-tuning of fuzzy controllers applied to WWTPs

    DEFF Research Database (Denmark)

    Ruano, M.V.; Ribes, J.; Sin, Gürkan; Seco, A.; Ferrer, J.

    2010-01-01

    A systematic approach for fine-tuning fuzzy controllers has been developed and evaluated for an aeration control system implemented in a WWTR The challenge with the application of fuzzy controllers to WWTPs is simply that they contain many parameters, which need to be adjusted for different WWTP...... of 33, which improved the quality of the optimization of the control system by a minimization algorithm. Overall the systematic approach considerably improved the performance of the control system as measured by the Integral Absolute Error (deviation between the set-point and the controlled variable...... fine-tune the identifiable parameter subset of the controller. Indeed, the initial location found by Monte-Carlo simulations provided better results than using trial and error approach when identifying parameters of the fuzzy controller. The identifiable subset was reduced to 4 parameters from a total...

  16. A Neuro-fuzzy-sliding Mode Controller Using Nonlinear Sliding Surface Applied to the Coupled Tanks System

    Institute of Scientific and Technical Information of China (English)

    Ahcene Boubakir; Fares Boudjema; Salim Labiod

    2009-01-01

    The aim of this paper is to develop a neuro-fuzzy-sliding mode controller (NFSMC) with a nonlinear sliding surface for a coupled tank system.The main purpose is to eliminate the chattering phenomenon and to overcome the problem of the equivalent control computation.A first-order nonlinear sliding surface is presented,on which the developed sliding mode controller (SMC) is based.Mathematical proof for the stability and convergence of the system is presented.In order to reduce the chattering in SMC,a fixed boundary layer around the switch surface is used.Within the boundary layer,where the fuzzy logic control is applied,the chattering phenomenon,which is inherent in a sliding mode control,is avoided by smoothing the switch signal.Outside the boundary,the sliding mode control is applied to drive the system states into the boundary layer.Moreover,to compute the equivalent controller,a feed-forward neural network (NN) is used.The weights of the net are updated such that the corrective control term of the NFSMC goes to zero.Then,this NN also alleviates the chattering phenomenon because a big gain in the corrective control term produces a more serious chattering than a small gain.Experimental studies carried out on a coupled tank system indicate that the proposed approach is good for control applications.

  17. Design New PID like Fuzzy CTC Controller: Applied to Spherical Motor

    Directory of Open Access Journals (Sweden)

    Mohammad shamsodini

    2014-05-01

    Full Text Available The minimum rule base Proportional Integral Derivative (PID Fuzzy Computed Torque Controller with application to spherical motor is presented in this research. The popularity of PID Fuzzy Computed Torque Controller can be attributed to their robust performance in a wide range of operating conditions and partly to their functional simplicity. PID methodology has three inputs and if any input is described with seven linguistic values, and any rule has three conditions we will need 343 rules. It is too much work to write 343 rules and have lots of problem to design embedded control system e.g., Field Programmable Gate Array (FPGA. In this research the PID-like fuzzy controller can be constructed as a parallel structure of a PD-like fuzzy controller and a conventional PI controller to have the minimum rule base and acceptable trajectory follow disturbance to control of spherical motor. However computed torque controller is work based on cancelling decoupling and nonlinear terms of dynamic parameters for each direction of three degree of freedom spherical motor, this controller is work based on motor dynamic model and this technique is highly sensitive to the knowledge of all parameters of nonlinear spherical motor’s dynamic equation. This research is used to reduce or eliminate the computed torque controller problem based on minimum rule base fuzzy logic theory to control of three degrees of freedom spherical motor system and testing of the quality of process control in the simulation environment of MATLAB/SIMULINK Simulator.

  18. Using LDR as Sensing Element for an External Fuzzy Controller Applied in Photovoltaic Pumping Systems with Variable-Speed Drives

    Directory of Open Access Journals (Sweden)

    Geraldo Neves De A. Maranhão

    2015-09-01

    Full Text Available In the present paper, a fuzzy controller applied to a Variable-Speed Drive (VSD for use in Photovoltaic Pumping Systems (PVPS is proposed. The fuzzy logic system (FLS used is embedded in a microcontroller and corresponds to a proportional-derivative controller. A Light-Dependent Resistor (LDR is used to measure, approximately, the irradiance incident on the PV array. Experimental tests are executed using an Arduino board. The experimental results show that the fuzzy controller is capable of operating the system continuously throughout the day and controlling the direct current (DC voltage level in the VSD with a good performance.

  19. A REVIEW OF INTELLIGENT CONTROL SYSTEMS APPLIED TO THE INVERTED-PENDULUM PROBLEM

    Directory of Open Access Journals (Sweden)

    Pedro Ponce

    2014-01-01

    Full Text Available This study shows the latest advances in the application of intelligent control to the inverted-pendulum problem. A complete review regarding intelligent control design is presented in this study in order to show the most important artificial intelligence methods used for controlling an Inverted-Pendulum. Also this study proposed the use of a neural-fuzzy-with-genetic-algorithms controller for the inverted pendulum problem which gives good results. Conventional controllers are presented in order to observe implementation problems. The study goes deeply in the details that have to take into account in order to understand design problems and limitations.

  20. Virtual reality applied in the ergonomic evaluation of nuclear power plant control room

    International Nuclear Information System (INIS)

    A nuclear power plant control room is a complex system that controls a nuclear and thermodynamic process used to produce electrical energy. The operators interact with the control room through interfaces that have significant implications to nuclear power plant safety and influence the operator activity. The operator activity presents complexity features and shows a series of mechanisms absents from the human factors guidelines, important to the evaluation and update of control rooms. The ergonomics approach considers the operation strategies, the interaction between the operators, the operator-system interaction, and interaction between operators and support groups. The main objective of this paper is propose the modeling of a nuclear control room, with the support of a game engine core. This tool will be used in the ergonomic evaluation of nuclear control room, generating information and data that will make possible the adequacy of control rooms features to the legal requirements of the regulating agency, assisting the nuclear licensing. (author)

  1. Distributed Active Traction Control System Applied to the RoboCup Middle Size League

    Directory of Open Access Journals (Sweden)

    José Almeida

    2013-10-01

    Full Text Available This work addresses the problem of traction control in mobile wheeled robots in the particular case of the RoboCup Middle Size League (MSL. The slip control problem is formulated using simple friction models for ISePorto Team Robots with a differential wheel configuration. Traction was also characterized experimentally in the MSL scenario for relevant game events. This work proposes a hierarchical traction control architecture which relies on local slip detection and control at each wheel, with relevant information being relayed to a higher level responsible for global robot motion control. A dedicated one axis control embedded hardware subsystem allowing complex local control, high frequency current sensing and odometric information procession was developed. This local axis control board is integrated in a distributed system using CAN bus communications. The slipping observer was implemented in the axis control hardware nodes integrated in the ISePorto Robots and was used to control and detect loss of traction. An external vision system was used to perform a qualitative analysis of the slip detection and observer performance results are presented.

  2. A predictive current control applied to a permanent magnet synchronous machine, comparison with a classical direct torque control

    Energy Technology Data Exchange (ETDEWEB)

    Morel, Florent; Lin-Shi, Xuefang; Retif, Jean-Marie; Allard, Bruno [AMPERE, INSA de Lyon, 20, avenue Albert Einstein, 69621 Villeurbanne cedex (France)

    2008-08-15

    This paper presents a new predictive current control (PCC) for permanent magnet synchronous machines (PMSM) drivers. Based on a hybrid model including an inverter model and a PMSM model, the proposed scheme selects more than one inverter configuration and allows to reach exactly the reference state vector. It appears attractive when compared to conventional direct torque control (DTC). Hysteresis comparators are not used. The switching frequency is fixed and it does not have to be very high. The control scheme has been verified experimentally with a 1.6 kW PMSM drive. Comparative studies with DTC control are performed with the same test bench. The results show that the proposed control obtains the same fast torque dynamics if not better than DTC control schemes but with smaller ripples. (author)

  3. Sequential Adaptive RBF-Fuzzy Variable Structure Control Applied to Robotics Systems

    Directory of Open Access Journals (Sweden)

    Mohammed Salem

    2014-08-01

    Full Text Available In this paper, we present a combination of sequential trained radial basis function networks and fuzzy techniques to enhance the variable structure controllers dedicated to robotics systems. In this aim, four RBFs networks were used to estimate the model based part parameters (Inertia, Centrifugal and Coriolis, Gravity and Friction matrices of a variable structure controller so to respond to model variation and disturbances, a sequential online training algorithm based on Growing-Pruning "GAP" strategy and Kalman filter was implemented. To eliminate the chattering effect, the corrective control of the VS control was computed by a fuzzy controller. Simulations are carried out to control three degrees of freedom SCARA robot manipulator where the obtained results show good disturbance rejection and chattering elimination.

  4. Preventing Control Constraint Violations by Use of Energy Balances for a Class of Coupled Systems: Applied to a Power Plant

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2007-01-01

    In this paper a scheme is presented for preventing violations of control signal constraints in a class of coupled systems. The scheme is an add-on solution to the existing control system; it works like a fault tolerant scheme, by accommodating the problem then occurring. The proposed scheme recom...... and not to optimize performance during all conditions. The scheme is applied to an example with a coal mill pulverizing coal for a power plant.  ...

  5. Maximum Principle for Linear-Convex Boundary Control Problems applied to Optimal Investment with Vintage Capital

    OpenAIRE

    Faggian, Silvia

    2007-01-01

    The paper concerns the study of the Pontryagin Maximum Principle for an infinite dimensional and infinite horizon boundary control problem for linear partial differential equations. The optimal control model has already been studied both in finite and infinite horizon with Dynamic Programming methods in a series of papers by the same author, or by Faggian and Gozzi. Necessary and sufficient optimality conditions for open loop controls are established. Moreover the co-state variable is shown t...

  6. Efficiency of particle swarm optimization applied on fuzzy logic DC motor speed control

    Directory of Open Access Journals (Sweden)

    Allaoua Boumediene

    2008-01-01

    Full Text Available This paper presents the application of Fuzzy Logic for DC motor speed control using Particle Swarm Optimization (PSO. Firstly, the controller designed according to Fuzzy Logic rules is such that the systems are fundamentally robust. Secondly, the Fuzzy Logic controller (FLC used earlier was optimized with PSO so as to obtain optimal adjustment of the membership functions only. Finally, the FLC is completely optimized by Swarm Intelligence Algorithms. Digital simulation results demonstrate that in comparison with the FLC the designed FLC-PSO speed controller obtains better dynamic behavior and superior performance of the DC motor, as well as perfect speed tracking with no overshoot.

  7. Applying human factors to the design of control centre and workstation of a nuclear reactor

    International Nuclear Information System (INIS)

    Human factors is a body of scientific factors about human characteristics, covering biomedical, psychological and psychosocial considerations, including principles and applications in the personnel selection areas, training, job performance aid tools and human performance evaluation. Control Centre is a combination of control rooms, control suites and local control stations which are functionally related and all on the same site. Digital control room includes an arrangement of systems, equipment such as computers and communication terminals and workstations at which control and monitoring functions are conducted by operators. Inadequate integration between control room and operators reduces safety, increases the operation complexity, complicates operator training and increases the likelihood of human errors occurrence. The objective of this paper is to present a specific approach for the conceptual and basic design of the control centre and workstation of a nuclear reactor used to produce radioisotope. The approach is based on human factors standards, guidelines and the participation of a multidisciplinary team in the conceptual and basic phases of the design. Using the information gathered from standards and from the multidisciplinary team, an initial sketch 3D of the control centre and workstation are being developed. (author)

  8. Sulphur removal from used automotive lubricating oil by ionizing radiation

    International Nuclear Information System (INIS)

    Following the worldwide evolution with the purpose of a higher control of vehicular emissions, the specialists have looked for clean technologies and efficient procedures to make vehicular emissions free of pollutants. Much attention is given to the sulphur concentration in the gasoline, diesel and lubricating oils. The ionizing radiation is a promising technology for the removal of this pollutant when compared to other conventional treatment methods. In this work, the ionizing radiation was used to remove in significant levels the presence of sulphur in automotive motor oil. A 1000 mL sample of used automotive lubricating oil from a gas station was collected. This sample was fractioned and irradiated with 10, 20 50, 100, 200 and 500 kGy doses in a 60Co irradiator (GAMMACELL-220 - 12 kCi). The 50 and 70% (v/v) of MilliQ water and 30% (v/v) of hydrogen peroxide was used to improve the radiolysis The sulphur element before and after the irradiation was determined by X-ray fluorescence technique (WDXRF) using the Fundamental Parameters Method. The results showed approximately 70% sulphur removal at 500 kGy irradiation dose with 70% (v/v) of MilliQ water addition. (author)

  9. Materials and lubrication for gear and bearing surfaces in uhv

    International Nuclear Information System (INIS)

    During design and construction of the SLAC polarized LEED (PLEED) system, a search was made for a dependable gear, bearing, and lubrication system for the computer-controlled Faraday cup used to measure diffracted beams. Components must be nonmagnetic, bakeable to 2500C, and at room temperature must operate at pressures in the 10-9 to 10-10 Pa range. A test system was constructed which incorporated a meshed pair of dissimilar pitch diameter spur gears, one of which was confined to (by bushings) and rotated on a fixed shaft, while the other gear was driven by a commercial rotary motion feedthrough which was rotated by a servo motor driven in sine fashion with a direction reversal every six turns and peak speeds of 50 rpm. The criterion for a successful pair was approx. 105 turns, the life rating for the feedthrough. Pairs had actual turn counts from less than 1 to 91,000. Materials for gears included stainless steel, beryllium copper, and aluminum alloys. Lubricants used singly and in concert were MoS2, WS2, Ag, hard chrome, and a MoS2-graphite-sodium silicate mixture. The successful gear pair was Ag-plated Al alloy and MoS2-graphite-sodium silicate-coated Be-Cu. Subsequent performance in the PLEED system after repeated bakeouts will also be discussed

  10. Water Lubrication of Stainless Steel using Reduced Graphene Oxide Coating

    Science.gov (United States)

    Kim, Hae-Jin; Kim, Dae-Eun

    2015-11-01

    Lubrication of mechanical systems using water instead of conventional oil lubricants is extremely attractive from the view of resource conservation and environmental protection. However, insufficient film thickness of water due to low viscosity and chemical reaction of water with metallic materials have been a great obstacle in utilization of water as an effective lubricant. Herein, the friction between a 440 C stainless steel (SS) ball and a 440 C stainless steel (SS) plate in water lubrication could be reduced by as much as 6-times by coating the ball with reduced graphene oxide (rGO). The friction coefficient with rGO coated ball in water lubrication was comparable to the value obtained with the uncoated ball in oil lubrication. Moreover, the wear rate of the SS plate slid against the rGO coated ball in water lubrication was 3-times lower than that of the SS plate slid against the uncoated ball in oil lubrication. These results clearly demonstrated that water can be effectively utilized as a lubricant instead of oil to lower the friction and wear of SS components by coating one side with rGO. Implementation of this technology in mechanical systems is expected to aid in significant reduction of environmental pollution caused by the extensive use of oil lubricants.

  11. THE INFLUENCE OF SOLID LUBRICANT IN MACHINING PARAMETER OF MILLING OPERATION

    Directory of Open Access Journals (Sweden)

    M.F.M.A Hamzas,

    2011-06-01

    Full Text Available Milling is a widely material removal process for different materials. It is characterized by high material removal rate. Machining leads to high friction between tool and workpiece, and can result in high temperatures, impairing the dimensional accuracy and the surface quality of the products. Application of conventional cutting fluid may not effectively control the heat generation in milling. Besides, cutting fluids are major source of pollution. Solid lubricant assisted machining is an environmental clean technology for desirable control of cutting temperature. Hence, this project investigates the role of solid lubricant assisted machining with graphite powder extra pure on surface quality and tool wear while machining mild steel. There are four conditions of lubricants will be analyzed for this experiment. The conditions are fully ordinary coolant, and the mixture between ordinary coolant with 50 grams, 100 grams and 150 grams of graphite powder extra pure. The performance of solid lubricant assisted machining will be analyzed in measuring the reduction in tool wear and surface roughness and compare with wetmachining.

  12. The effect of multi-scale laser textured surface on lubrication regime

    International Nuclear Information System (INIS)

    Laser surface texturing (LST) is a surface engineering process used to improve tribological characteristics of materials by creating patterned microstructures on the mechanical contact surface. In LST technology, a pulsated laser beam is used to create arranged dimples on surface by a material ablation process, which can improve load capacity, wear resistances, lubrication lifetime, and reduce friction coefficients. In the present study, the effect of multi-scale LST on lubricant regime was investigated. A pulsed Nd:YAG laser was applied on steel (AISI 52100) to create arranged dimples. To optimize the surface texturing effect on friction, multi-scale texture dimples with some specific formula arrays were fabricated by laser ablation process by combining circles and ellipses. The tribological testing of multi-scale textured surface was performed by a flat-on-flat unidirectional tribometer under lubrication, and the results compared with that of untextured surface. Through an increase in sliding speed and dimple depth the beneficial effect of multi-scale LST performance was achieved. The multi-scale textured surface had lower friction coefficient performance than the untextured surface due to hydrodynamic lubrication effect.

  13. Apply Pesticides Correctly, A Guide for Commercial Applicators: Aquatic Pest Control.

    Science.gov (United States)

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    This guide presents information needed to meet the requirements for pesticide applicator certification. The first part deals with recognition and control of aquatic pests such as aquatic weeds, fish and other vertebrates. Environmental concerns in aquatic pest control are discussed in the second section. (CS)

  14. Evaluation of Linear and Non-Linear Control Schemes Applied to a Hydraulic Servo System

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik Clemmensen

    2005-01-01

    Due to the innovation of low-cost electronics such as sensors, microcontrollers etc., the focus on highperformance motion control is increasing. This work focuses on position control of single-input single-output hydraulic servo-systems in general. A hydraulically actuated robotic manipulator...

  15. Control of mushroom sciarid fly Lycoriella ingenua populations with insect growth regulators applied by soil drench.

    Science.gov (United States)

    Erler, F; Polat, E; Demir, H; Catal, M; Tuna, G

    2011-06-01

    Mushroom sciarid fly Lycoriella ingenua (Dufour, 1839) comb. nov., is one of the most common fly pests affecting the cultivation of Agaricus bisporus (Lange) Imbach in Turkey. In this study, eight insect growth regulators (IGRs)--diflubenzuron, flufenoxuron, lufenuron, methoprene, novaluron, pyriproxyfen, teflubenzuron, and triflumuron-were tested for their potential to control L. ingenua populations in two successive growing periods. Treatments were targeted at larvae as soil drenches; treatment efficacy was evaluated by assessing adult emergence and larval damage. These products were compared with a control treated with water (negative control) and a conventional chemical insecticide (chlorpyrifos ethyl) (positive control). Treatments with the IGRs caused significant reductions in emerging adult numbers and sporophore damage rates compared with the water-treated control over the two growing periods. Of the IGRs tested, novaluron, diflubenzuron, and teflubenzuron had significantly lower numbers of emerging adults than the rest of the IGRs and chlorpyrifos ethyl-treated control in both periods. Treatments with teflubenzuron, pyriproxyfen, novaluron, and diflubenzuron resulted in significantly lower sporophore damage rates than all other treatments. Compared with negative control, there were no significant yield reductions due to applications of selected IGRs. The results suggest that all the IGRs tested can be used as alternatives to conventional pesticides in controlling L. ingenua populations on mushroom. PMID:21735902

  16. Determination of Q-function optimum grid applied on active magnetic bearing control task

    Czech Academy of Sciences Publication Activity Database

    Březina, Tomáš; Krejsa, Jiří

    Brno: VUT, 2003, s. 55-56. ISBN 80-214-2312-9. [Mechatronics, robotics and biomechanics 2003. Hrotovice (CZ), 24.03.2003-27.03.2003] R&D Projects: GA ČR GA101/00/1471 Institutional research plan: CEZ:AV0Z2076919 Keywords : control * magnetic bearing Subject RIV: BC - Control Systems Theory

  17. Optimal control applied to native-invasive species competition via a PDE model

    Directory of Open Access Journals (Sweden)

    Wandi Ding

    2012-12-01

    Full Text Available We consider an optimal control problem of a system of parabolic partial differential equations modelling the competition between an invasive and a native species. The motivating example is cottonwood-salt cedar competition, where the effect of disturbance in the system (such as flooding is taken to be a control variable. Flooding being detrimental at low and high levels, and advantageous at medium levels led us to consider the quadratic growth function of the control. The objective is to maximize the native species and minimize the invasive species while minimizing the cost of implementing the control. An existence result for an optimal control is given. Numerical examples are presented to illustrate the results.

  18. Statistical process control applied to the liquid-fed ceramic melter process

    International Nuclear Information System (INIS)

    In this report, an application of control charts to the apparent feed composition of a Liquid-Fed Ceramic Melter (LFCM) is demonstrated by using results from a simulation of the LFCM system. Usual applications of control charts require the assumption of uncorrelated observations over time. This assumption is violated in the LFCM system because of the heels left in tanks from previous batches. Methods for dealing with this problem have been developed to create control charts for individual batches sent to the feed preparation tank (FPT). These control charts are capable of detecting changes in the process average as well as changes in the process variation. All numbers reported in this document were derived from a simulated demonstration of a plausible LFCM system. In practice, site-specific data must be used as input to a simulation tailored to that site. These data directly affect all variance estimates used to develop control charts. 64 refs., 3 figs., 2 tabs

  19. Simplified control and display concepts for space vehicle control, applied to space station, space shuttle and unmanned satellites

    Science.gov (United States)

    Barry, John M.

    NASA and the Air Force are constantly exploring ways to reduce launch vehicle, satellite, and planetary mission life cycle costs. A significant amount of these costs has been devoted to the control of these missions. This control is labor-intensive and requires a diversity of equipment and control devices. The diagnostic procedures involved in this control are duplicated in the development, testing, and operation of the space assets. This control philosophy tends to inhibit technological growth. Such growth is necessary in space systems which are being designed and modified over decades. This paper advocates and demonstrates an innovative approach to simplify the control and display concepts and improve the development and operational process for space assets. It visualizes traditional system engineering techniques in a concurrent engineering environment. This approach captures the knowledge of functional decomposition, failure modes and effects analysis and configuration management in a dynamic prototyping process. It can use existing testing and checkout information to control and operate the space asset during assembly, test, and operation. The implementation of this technique will reduce space development and operations costs, cycle time, and allow for technological growth.

  20. Infection prevention and control measures currently applied in South African audiology

    Directory of Open Access Journals (Sweden)

    Katerina Ehlert

    2014-06-01

    Full Text Available Background: To counter the global increase in infection-related deaths, infection control has recently developed into an active area of research. Many diseases can be prevented by infection control. In the confines of the audiology clinic, cross-contamination by micro-organisms associated with opportunistic infections remains a real concern.Objective: The primary aim of the study was to ascertain the methods that audiologists in South Africa use to prevent and control the spread of infections during and after consultation with clients.Method: A survey study was conducted, using a self-administered questionnaire. Fifty currently practising audiologists participated in the study.Results: The majority (84%; n = 42 of respondents acknowledged the importance of hand hygiene for the purpose of infection control, with 76% (n = 38 making use of no-rinse hand sanitisers. Approximately a third of audiologists wear gloves during procedures such as otoscopy and immittance, and while handling hearing aids. Disinfecting audiological equipment seem to be the preferred choice of infection control, with only 60% (n = 30 of respondents sterilising audiological equipment after each individual patient consultation. Less than half of the respondents disinfected touch surfaces and toys in the reception area.Conclusions: Based on the results, further education and training should focus on measures implemented in infection control, awareness of possible risk factors at work settings, and vaccination as an effective means of infection control.

  1. Research on Friction Properties of Mineral Lubricants in Thin-Film-Lubricating Regime

    Institute of Scientific and Technical Information of China (English)

    Zhang Jie; Guan Tingting; Piao Jicheng

    2014-01-01

    On the basis of thin iflm lubrication theory, the inlfuence of lfuid iflm (disordered iflm), ordered iflm and ad-sorbed iflm on tribological behavior of lubricating oil in thin-iflm lubrication (TFL) regime was studied. Theμ-L (friction coefifcient versus load) curves of different oil viscosity and additive dosage were obtained by a high frequency reciprocat-ing test rig and the adsorption capacity of additive on steel surface were measured by QCM-D. Based on the Stribeck curve and thin iflm lubrication theory model, some conclusions can be drawn up, namely:(1) Theμ-L curves and the parameters of L0 andμ0, obtained from the high frequency reciprocating test rig with ball-disc contact, can be used to study tribologi-cal behaviors of lubricating oil under TFL conditions. (2) In comparison with the high viscosity base lfuid, the lower one can enter into TFL regime under lower load and keeps a lower friction coefifcient in TFL regime. (3) The polar molecules in additive formulation produce ordered adsorbed layer on steel surface to reduce friction coefifcient. And in TFL regime, the molecule’s polarity, layer thickness and saturation degree on steel surface probably can inlfuence lubricant’s tribological behaviors between the moving interfaces. Moreover, the further study would be focused on the competitive adsorption of different additives, the formation of dual-and/or tri-molecular adsorption layers, and other aspects.

  2. Applying Human Factors Evaluation and Design Guidance to a Nuclear Power Plant Digital Control System

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Ulrich; Ronald Boring; William Phoenix; Emily Dehority; Tim Whiting; Jonathan Morrell; Rhett Backstrom

    2012-08-01

    The United States (U.S.) nuclear industry, like similar process control industries, has moved toward upgrading its control rooms. The upgraded control rooms typically feature digital control system (DCS) displays embedded in the panels. These displays gather information from the system and represent that information on a single display surface. In this manner, the DCS combines many previously separate analog indicators and controls into a single digital display, whereby the operators can toggle between multiple windows to monitor and control different aspects of the plant. The design of the DCS depends on the function of the system it monitors, but revolves around presenting the information most germane to an operator at any point in time. DCSs require a carefully designed human system interface. This report centers on redesigning existing DCS displays for an example chemical volume control system (CVCS) at a U.S. nuclear power plant. The crucial nature of the CVCS, which controls coolant levels and boration in the primary system, requires a thorough human factors evaluation of its supporting DCS. The initial digital controls being developed for the DCSs tend to directly mimic the former analog controls. There are, however, unique operator interactions with a digital vs. analog interface, and the differences have not always been carefully factored in the translation of an analog interface to a replacement DCS. To ensure safety, efficiency, and usability of the emerging DCSs, a human factors usability evaluation was conducted on a CVCS DCS currently being used and refined at an existing U.S. nuclear power plant. Subject matter experts from process control engineering, software development, and human factors evaluated the DCS displays to document potential usability issues and propose design recommendations. The evaluation yielded 167 potential usability issues with the DCS. These issues should not be considered operator performance problems but rather opportunities

  3. The efficiency of some fungicides applied to control the Phytophthora infestans (Mont de Bary fungus on potato

    Directory of Open Access Journals (Sweden)

    Daniela POPA

    2008-05-01

    Full Text Available The research was carried on at Targu - Secuiesc within 2002-2004 and its objective was to determine the most efficient fungicides to control the late potato blight caused by the fungus Phytophthora infestans. All the applied products were efficient in controlling the disease in comparison to the untreated control variant.The results of the research show that during the observed period the products Curzate and Acrobat proved to be highly efficient in a constant manner at the three varieties: Ostara, Sante and Desiree. The lowest frequency of infected tubers was registered at the varieties treated with Altima, Acrobat, Tatoo C.

  4. Lubricant additive concentrate containing isomerized jojoba oil

    Energy Technology Data Exchange (ETDEWEB)

    Arndt, G.

    1987-05-12

    This patent describes a crankcase motor oil additive concentrate intended to be added to a conventional crankcase motor oil to improve its ability to lubricate and protect the engine. The additive concentrate comprises the following components: A petroleum base stock of lubricating quality and viscosity. The base stock comprises from about 13.5 to 90 weight percent of the additive concentrate; a detergent-inhibitor package. The package is present at from about 7 to about 40 weight percent of the concentrate; a supplemental antiwear additive selected from the salts of dialkyl dithiophosporic acids. The additive is present at a level of from about 1 to about 10 weight percent of the concentrate; and a supplemental antiwear additive selected from the class of sulfurized olefins. The additive is present at a level of from about 1 to about 10 weight percent of the concentrate.

  5. Graphene oxide film as solid lubricant.

    Science.gov (United States)

    Liang, Hongyu; Bu, Yongfeng; Zhang, Junyan; Cao, Zhongyue; Liang, Aimin

    2013-07-10

    As a layered material, graphene oxide (GO) film is a good candidate for improving friction and antiwear performance of silicon-based MEMS devices. Via a green electrophoretic deposition (EPD) approach, GO films with tunable thickness in nanoscale are fabricated onto silicon wafer in a water solution. The morphology, microstructure, and mechanical properties as well as the friction coefficient and wear resistance of the films were investigated. The results indicated that the friction coefficient of silicon wafer was reduced to 1/6 its value, and the wear volume was reduced to 1/24 when using GO film as solid lubricant. These distinguished tribology performances suggest that GO films are expected to be good solid lubricants for silicon-based MEMS/NEMS devices. PMID:23786494

  6. Lubricants for Metal Belt Continuously Variable Transmissions

    Directory of Open Access Journals (Sweden)

    Keiichi Narita

    2014-02-01

    Full Text Available This paper reviews the effects of lubricant additives and base stock used in metal belt continuously variable transmissions (CVT fluids on the CVT transmission torque capacity. Additive formulation composed of phosphorus anti-wear agent, calcium detergent, and dispersant improved the friction coefficient between the metals. The analysis on the post-test surface suggests that the friction behavior strongly depends on the local morphology of the tribofilms derived from lubricant additives. Examining the effect of base stock on the torque capacity in actual belt CVTs revealed that SN (synthetic naphthene exhibited 10% higher torque capacity than that of PAO (polyalphaolefin. It is believed that the difference in the torque capacity is due to the difference in the oil-film shearing force generated by the relative sliding between the belt and pulley.

  7. Agents Modeling Experience Applied To Control Of Semi-Continuous Production Process

    Directory of Open Access Journals (Sweden)

    Gabriel Rojek

    2014-01-01

    Full Text Available The lack of proper analytical models of some production processes prevents us from obtaining proper values of process parameters by simply computing optimal values. Possible solutions of control problems in such areas of industrial processes can be found using certain methods from the domain of artificial intelligence: neural networks, fuzzy logic, expert systems, or evolutionary algorithms. Presented in this work, a solution to such a control problem is an alternative approach that combines control of the industrial process with learning based on production results. By formulating the main assumptions of the proposed methodology, decision processes of a human operator using his experience are taken into consideration. The researched model of using and gathering experience of human beings is designed with the contribution of agent technology. The presented solution of the control problem coincides with case-based reasoning (CBR methodology.

  8. A deadbeat control method for a PWM converter applied to a superconducting magnet

    International Nuclear Information System (INIS)

    Current-type pulse-width-modulated (PWM) converter is regarded as one of the candidates for the superconducting magnet power supplies in next generation tokamak devices. However, this type PWM converter has a problem of the transient oscillation of the reactor current and capacitor voltage in an AC-side harmonic filter, which occurs owing to the LC resonance of the filter when the reference of the DC output current is changed rapidly. In this paper, the new PWM control method based on the deadbeat control theory is proposed to suppress the transient oscillation. The converter employing this method can control the reactor current and capacitor voltage in one sampling period under ideal conditions. In addition, the effect of dead time on the control is discussed. The performance of the newly proposed method is demonstrated through numerical circuit simulation

  9. Fuzzy-Skyhook Control for Active Suspension Systems Applied to a Full Vehicle Model

    Directory of Open Access Journals (Sweden)

    Aref M.A. Soliman

    2012-04-01

    Full Text Available Nowadays, most modern vehicles are equipped with controlled suspension systems for improving the vehicle ride comfort. Therefore, this paper is concerned with a theoretical study for the ride comfort performance of the vehicle. The theoretical investigation includes a suggestion of an active suspension system controller using fuzzy-skyhook control theory, which offers new opportunities for the improvement of vehicle ride performance. The ride comfort of the active suspension system has been evaluated using a 7 degree of freedom full vehicle mathematical model. The simulation results are presented in the time and frequency domain, also in terms of RMS values, and it’s shown that the proposed active suspension system with fuzzy-skyhook control improved the vehicle ride quality in terms of body acceleration, suspension working space and dynamic tyre load in comparison with the passive and skyhook suspension systems.

  10. Apply Pesticides Correctly, A Guide for Commercial Applicators: Forest Pest Control.

    Science.gov (United States)

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    This guide contains basic information to meet specific standards for pesticide applicators. Common forest pests and their control are discussed. Special attention is given to the effectiveness of different application techniques and potential human and environmental hazards. (CS)

  11. Applying the sterile insect technique to the control of insect pests

    International Nuclear Information System (INIS)

    The sterile insect technique (SIT) is basically a novel twentieth century approach to insect birth control. It is species specific and exploits the mate seeking behaviour of the insect. The basic principle is simple. Insects are mass reared in 'factories' and sexually sterilized by gamma rays from a 60Co source. The sterile insects are then released in a controlled fashion into nature. Matings between the sterile insects released and native insects produced no progeny. If enough of these matings take place, reproduction of the pest population decreases. With continued release, the pest population can be controlled and in some cases eradicated. In the light of the many important applications of the SIT worldwide and the great potential that SIT concepts hold for insect and pest control in developing countries, two special benefits should be stressed. Of greatest significance is the fact that the SIT permits suppression and eradication of insect pests in an environmentally harmless manner. It combines nuclear techniques with genetic approaches and, in effect, replaces intensive use of chemicals in pest control. Although chemicals are used sparingly at the outset in some SIT programmes to reduce the size of the pest population before releases of sterilized insects are started, the total amount of chemicals used in an SIT programme is a mere fraction of what would be used without the SIT. It is also of great importance that the SIT is not designed strictly for the eradication of pest species but can readily be used in the suppression of insect populations. In fact, the SIT is ideally suited for use in conjunction with other agricultural pest control practices such as the use of parasites and predators, attractants and cultural controls (e.g. ploughing under or destruction of crop residues) in integrated pest management programmes to achieve control at the lowest possible price and with a minimum of chemical contamination of the environment

  12. Reducing Runoff Loss of Applied Nutrients in Oil Palm Cultivation Using Controlled-Release Fertilizers

    OpenAIRE

    Bah, A.; M. H.A. Husni; C. B. S. Teh; Rafii, M. Y.; S. R. SYED OMAR; Ahmed, O. H.

    2014-01-01

    Controlled-release fertilizers are expected to minimize nutrient loss from crop fields due to their potential to supply plant-available nutrients in synchrony with crop requirements. The evaluation of the efficiency of these fertilizers in tropical oil palm agroecological conditions is not yet fully explored. In this study, a one-year field trial was conducted to determine the impact of fertilization with water soluble conventional mixture and controlled-release fertilizers on runoff loss of ...

  13. Technology development for indigenous water lubricated bearings

    International Nuclear Information System (INIS)

    Water Lubricated Bearings (WLB) are used in various mechanisms of fuel handling systems of PHWRs and AHWR. Availability and random failures of these bearings was a major factor in refuelling operations. Indigenous development of these bearings was taken up and 7 types of antifriction bearings in various sizes (totaling 37 variants) for PHWR, AHWR and Dhruva applications were successfully developed. This paper deals with various aspects of WLB development. (author)

  14. Classification of lubricants according to cavitation criteria

    OpenAIRE

    Meged, Y.; Venner, C.H.; Napel, ten, H.M.Th.D.

    1995-01-01

    Cavitation in lubrication liquids has long been known to be detrimental to components in hydraulic systems. Damage has been detected in journal bearings, especially under severe dynamic loading, gears, squeeze film dampers and valves. These findings have led to intensive studies of metal resistance to cavitation erosion, in order to minimize the damage. Results of these studies have been: 1. (a) classification of known materials according to their resistance to cavitation erosion; 2. (b) deve...

  15. Applied Research on Flood Control and Disaster Reduction based on GIS Technology

    OpenAIRE

    QIANG, Xiaohuan; ZHU, Liujuan

    2010-01-01

    Geographic Information System is able to collect, manage, analyze and send out various geo-spatial information, very spacious and dynamic. Based on GIS technology, applying Digital Elevation Model, Flood Evolution Models, Humane and Economic information the scope of flooding and flood-stricken area, simulate flooding process, development trend and flood losses to provide timely information of towns, roads, water conservancy facilities, distribution of rivers and lakes can be confirmed. The be...

  16. Ammonia Volatilization from Urea Applied to Acid Paddy Soil in Southern China and Its Control

    Institute of Scientific and Technical Information of China (English)

    CAIGUI-XIN; PENGGUANG-HAO; 等

    1992-01-01

    Results showed that ammonia loss from urea broadcast into floodwater and incorporated into soil at transplanting was as high as 40% of applied N,and the corresponding total nitrogen (N) loss was 56%.Ammonia loss was measured with simplified micrometeorological method (ammonia sampler),and total N loss was concurrently measured using 15N balance technique.The experiment was conducted under strong sunshine conditions on acid paddy soil derived from Quaternary red clay.The ammonia loss in this particular condition was much greater than those obtained from previous studies when urea was also applied to acid paddy soil but under cloudy conditions.It is concluded that the strong sunshine conditions with high temperature and shallow floodwater during the period of present experiment favoured ammonia volatilization.Application of stearyl alcohol on the surface of the floodwater reduced ammonia loss to 23% of applied N.However,the effect of stearyl alcohol was short-lived,probably due to the microbiological decomposition.

  17. Nanoscale lubricating film formation by linear polymer in aqueous solution

    Science.gov (United States)

    Liu, Shuhai; Guo, Dan; Xie, Guoxin

    2012-11-01

    Film-forming properties of polymer in aqueous solution flowing through a nanogap have been investigated by using a thin film interferometry. The film properties of linear polymer in aqueous solution flowing through a confined nanogap depend on the ratio of water film thickness to averaged radius of polymer chains H0/RPolymer. It was found that the lubrication film thickness of linear polymer in aqueous solution decreases as the polymer molecular weight increasing when H0/RPolymer < 2 ˜ 3. A new lubrication map was proposed, which includes the lubrication regime of weak confinement influence, the lubrication regime of strong confinement influence (LRSCI), and the transition regime of confinement influence. It is very difficult to increase the lubrication film thickness using the higher molecule weight in the LRSCI regime. The lubrication mechanism inferred from our experimental results may help to better understand the dynamic film properties of linear polymer in aqueous solution flowing through a nanogap.

  18. Phenomenological theory of kinetic friction for the solid lubricant film

    International Nuclear Information System (INIS)

    Molecular dynamics based on the Langevin equations with the coordinate- and velocity-dependent damping coefficients is used to investigate the friction properties of a 'hard' lubricant film confined between two solids, when the lubricant remains in the solid state during sliding. The dependence of the friction force on the temperature and sliding velocity in the smooth sliding regime is studied in detail for all three states of the lubricant: a lubricant with a crystalline structure, when the system exhibits a very low friction (superlubricity), an amorphous lubricant structure, which results in a high friction, and the liquid state of the lubricant film at high temperatures or velocities. A phenomenological theory of the kinetic friction is developed, which allows us to explain the simulation results and predict a variation of the friction properties with model parameters analytically

  19. Property Analysis of the Agricultural Machinery Lubricants

    Directory of Open Access Journals (Sweden)

    Tone Ploj

    2000-03-01

    Full Text Available We need to produce enough healthy and cheap food as well as to preserve the ecologic equilibrium. This can be achived by using modern machinery and up- to-date knowledge and technology. Agricultural machinery, in which 40-60% of all funds are invested, is poorly maintained and underused. The main causes for this are poor knowledge and extensive farm land fragmentation. The fact that over 140,000 tractors in Slovenia are on average 9.6 years old, i.e. that more than 80% of overall agricultural machinery is obsolete, should be a matter of serious concern. In the paper we follow tribological conditions in particular tractor assemblies. In the first part of the paper we have treated the required conditions of tractor manufacturers in Europe and primarily in Slovenia, what has served us in the final phase of the research for elaboration of the model. In this way we have got data about the presence of particular tractor types. We have separately elaborated the necessary specifications of engine lubricants, transmission, gears, hydraulics and wet breaks. We have carried out chemical and mechanical analyses of all accessible lubricants in agricultural mechanisation. The results of the new oils were coordinated with the required specifications of tractor manufacturers and so we have got such a model, that certainly meet all lubricating requirements of our tractors.

  20. Lubricant for hot processing of metals

    Energy Technology Data Exchange (ETDEWEB)

    Forostyan, Yu.N.; D' yachenko, K.A.; Grudev, A.P.; Lobarev, M.I.; Sigalov, Yu.B.

    1980-04-30

    The compositon of lubricant for hot processing of metals is based on water, hydrolysis lignin, phosphoric acid salt and an antiseptic. In order to increase the wear resistance of the instrument, it contains Ca(OH)/sub 2/, a soap stock of vegetable oil (SRM), dichlorstearic acid (I), tetrachlorstearic acid (II) and as the phosphoric acid salt, the lubricant contains trisodium phosphate. The % composition of the content are: hydrolysis lignin, 5-25; trisodium phosphate, 1-5; Ca(OH)/sub 2/, 0-5; vegetable oil soap stock, 10-30; I, 0.5-2; II, 0.5-10; antiseptic, 0.01-5 and water to 100%. The calculated volumes of lignin, Ca(OH)/sub 2/ and water are ground in a ball mill to a powder dispersion of 10-20 mkm, after which the SRM and the trisodium phosphate are added and the griding is continued for 1.5-2 hours. The formed mixture is reloaded into the reactor, heated to 75-80/sup 0/C with mixing, I and II, preheated to 70-80/sup 0/C are introduced. The heating and mixing are continued until the formation of a uniform gel. After cooling, the antiseptic is added. The use of the lubricant provides for a reduction in the rolling pressures from 17.3 to 15.6-16.8 t.