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Sample records for active lubrication applied

  1. 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 furt......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...

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

    DEFF Research Database (Denmark)

    Morosi, Stefano; Santos, Ilmar

    2011-01-01

    Active bearings represent a mechatronic answer to the growing industrial need to high performance turbomachinery. The present contribution aims at demonstrate the feasibility of applying active lubrication to gas journal bearings. The principle of operation is to generate active forces by regulat...

  3. 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...... 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....

  4. 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

    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...... 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...

  5. 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....

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

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    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...... 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...

  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

    This paper reports the dynamic study of a flexible rotor-bearing test rig which resembles a large overhung centrifugal compressor. The rotor is supported by an active tilting pad journal bearing (TPJB) able to perform the adjustable lubrication regime. Such a regime is obtained by injecting...... 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...... and the experimental results are obtained. The improvements are obtained when the system response amplitudes in a bounded speed range is reduced by applying the adjustable lubrication. Results are in agreement with the established fact that a significant improvement of the rotor-bearing system dynamic performance can...

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    of 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 investigated...

  9. Validity of the modified Reynolds equation for incompressible active lubrication

    DEFF Research Database (Denmark)

    Cerda Varela, Alejandro Javier; Santos, Ilmar

    2016-01-01

    The modified Reynolds equation for active lubrication has been the cornerstone around which the theoretical investigations regarding actively lubricated bearings have evolved over the years. Introduced originally in 1994, it enables to calculate in a simplified manner the bearing pressure field...... as a function of servovalve controlled pressurized oil injection. This article deals with a preliminary critical review of the simplificatory assumptions that are introduced into the modified Reynolds equation in order to model the phenomena taking place in the interface between the injection nozzle...... and the bearing clearance. The analysis is performed by means of direct comparison of the results of the modified Reynolds equation model versus benchmark CFD calculations, applied to a geometry representative of the system analyzed. The results show that the modified Reynolds equation mathematical simplicity...

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

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    A multibody dynamic model of the main mechanical components of a hermetic reciprocating compressor is presented in this work. Considering that some of the mechanical elements are interconnected via thin fluid films, the multibody dynamic model is coupled to the equations from the dynamics...... of the 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...... and 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...

  11. Active Lubrication: Feasibility and Limitations on Reducing Vibration in Rotating Machinery

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2004-01-01

    of increasing their operational range. As a result, one achieves intelligent machines that are more flexible to operate in a fast-changing demand environment. Some limitations of the active lubrication are also discussed based on experimental data, where the response of the servo valves and the supply pressure...... play an important role: the eigenfrequency of the servo valves establishes the operational frequency range of the active lubrication, whereas the supply pressure establishes the amplitude of vibration reduction achieved with the active lubrication....

  12. 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.

  13. Pleural Lubrication

    Directory of Open Access Journals (Sweden)

    Cristina Porta

    2016-05-01

    Full Text Available During breathing, the pleural surfaces slide against each other continuously without damage. Pleural liquid and lubricating molecules should provide the lubrication of the sliding surfaces, thus protecting the mesothelium from shear-induced abrasion. D’Angelo et al. (Respir. Physiol. Neurobiol. 2004 measured the coefficient of kinetic friction (μ of rabbit parietal pleura sliding against visceral pleura in vitro at physiological velocities and under physiological loads; it was ~0.02 and did not change with sliding velocity, consistent with boundary lubrication. μ in boundary lubrication can be influenced by surface molecules like hyaluronan, sialomucin or surface active phospholipidis. Hyaluronan or sialomucin is able to restore good boundary lubrication in damaged mesothelium. Nevertheless, hyaluronidase and neuraminidase treatment of the mesothelium does not increase μ, though neuraminidase cleaves sialic acid from the mesothelium. Short pronase or phospholipase treatment, so as to affect only the mesothelial glycocalyx, increases μ, and this increase is removed by hyaluronan or sialomucin. On the other hand, addition of phospholipids after phospholipase treatment produces a small effect relative to that of hyaluronan or sialomucin, and this effect is similar with unsaturated or saturated phospholipids. In damaged mesothelium, the lubrication regimen becomes mixed, but addition of hyaluronan or sialomucin restores boundary lubrication.

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

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2004-01-01

    lubrication. The second approach based on the equivalent dynamic coefficients leads to more accurate results since it includes the frequency dependence of the active hydraulic forces. Theoretical and experimental results reveal the feasibility of reducing resonance peaks by using the active lubricated tilting...... into the model by using two different approaches: (a) linearized active oil film forces and the assumption that the hydrodynamic forces and the active hydraulic forces can be decoupled; (b) equivalent dynamic coefficients of the active oil film and the solution of the modified Reynolds' equation for the active...... their operational range by attenuating resonance peaks and reducing vibration problems....

  15. Raman chemical mapping of magnesium stearate delivered by a punch-face lubrication system on the surface of placebo and active tablets.

    Science.gov (United States)

    Šašiċ, Slobodan; Ojakovo, Peter; Warman, Martin; Sanghvi, Tapan

    2013-09-01

    Raman chemical mapping was used to determine the distribution of magnesium stearate, a lubricant, on the surface of tablets. The lubrication was carried out via a punch-face lubrication system with different spraying rates applied on placebo and active-containing tablets. Principal component analysis was used for decomposing the matrix of Raman mapping spectra. Some of the loadings associated with minuscule variation in the data significantly overlap with the Raman spectrum of magnesium stearate in placebo tablets and allow for imaging the domains of magnesium stearate via corresponding scores. Despite the negligible variation accounted for by respective principal components, the score images seem reliable as demonstrated through thresholding the one-dimensional representation and the spectra of the hot pixels that show a weak but perceivable magnesium stearate band at 1295 cm(-1). The same approach was applied on the active formulation, but no magnesium stearate was identified, presumably due to overwhelming concentration and spectral contribution of the active pharmaceutical ingredient.

  16. Lubrication fundamentals

    International Nuclear Information System (INIS)

    Wills, J.G.

    1990-01-01

    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

  17. Increased production of naphtenic lubricants using more active catalysts; Aumento da producao de lubrificantes naftenicos usando catalisadores mais ativos

    Energy Technology Data Exchange (ETDEWEB)

    Fontes, Anita Eleonora F.; Lima, Anie Daniela M.; Figueiredo, Joao B.; Nogueira, Wlamir S.; Zotin, Jose L. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    PETROBRAS produces lubricant base oil in three of its refineries: Duque de Caxias (REDUC), Landulpho Alves (RLAM) and Lubricants and Derivatives of Petroleum of Northeast (LUBNOR). LUBNOR, which began its operation in 1998, is the only refinery that produces naphtenic lubricant base oils with a current capacity of 60.000 m{sup 3}/year. It processes Brazilian naphtenic crudes in a vacuum distillation unit to produce distillates, which are then fed in to a hydrotreatment unit (HDT). This HDT unit processes 170 m{sup 3}/day to obtain base oils NH-10, NH-20, NH-140 and ISOVOLT. In 2007, an evaluation study of new catalysts was made for this unit at PETROBRAS Research Center (CENPES) aiming to increase the production capacity of the HDT unit. The concept was based on increasing the catalytic activity in the HTD unit by testing new catalysts and operating conditions in a pilot-plant unit. The results obtained were very promising showing that a selected catalyst achieved the normal production rate maintaining the same high quality product at a temperature lower than the conventional process. Alternatively, a 77% increase in the throughput capacity was achieved when the normal reaction temperature was applied to this selected catalyst. (author)

  18. Schemes for applying active lubrication to main engine bearings

    DEFF Research Database (Denmark)

    Estupinan, Edgar Alberto; Santos, Ilmar

    2009-01-01

    -difference method. The computed bearing fluid film forces are coupled to the set of nonlinear equations that describes the dynamics of the reciprocating engine, obtained with the help of multibody dynamics (rigid components) and finite elements method (flexible components). The main equations that govern...

  19. Investigation of anti-wear performance of automobile lubricants using thin layer activation analysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Biswal, Jayashree [Isotope and Radiation Application Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Thakre, G.D. [Tribology and Combustion Division, Indian Institute of Petroleum, Dehradun 248005, Uttarakhand (India); Pant, H.J., E-mail: hjpant@barc.gov.in [Isotope and Radiation Application Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Samantray, J.S. [Isotope and Radiation Application Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Arya, P.K. [Tribology and Combustion Division, Indian Institute of Petroleum, Dehradun 248005, Uttarakhand (India); Sharma, S.C.; Gupta, A.K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2017-05-15

    An investigation was carried out to examine the anti-wear behavior of automobile lubricants using thin layer activation analysis technique. For this study disc gears made of EN 31 steel were labeled with a small amount of radioactivity by irradiating with 13 MeV proton beam from a particle accelerator. Experiments on wear rate measurement of the gear were carried out by mounting the irradiated disc gear on a twin-disc tribometer under lubricated condition. The activity loss was monitored by using a NaI(Tl) scintillation detector integrated with a multichannel analyzer. The relative remnant activity was correlated with thickness loss by generating a calibration curve. The wear measurements were carried out for four different types of lubricants, named as, L1, L2, L3 and L4. At lower load L1 and L4 were found to exhibit better anti-wear properties than L2 and L3, whereas, L4 exhibited the best anti-wear performance behavior than other three lubricants at all the loads and speeds investigated.

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

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2005-01-01

    for the active lubrication. The second approach, based on the equivalent dynamic coefficients, leads to more accurate results because it includes the frequency dependence of the active hydraulic forces. Theoretical and experimental results reveal the feasibility of reducing resonance peaks by using the active...... into the model by using two different approaches: (a) linearized active oil film forces and the assumption that the hydrodynamic forces and the active hydraulic forces can be decoupled, and (b) equivalent dynamic coefficients of the active oil film and the solution of the modified Reynolds equation...... of increasing their operational range by attenuating resonance peaks and reducing vibration problems....

  1. A lubricant

    Energy Technology Data Exchange (ETDEWEB)

    Parfenova, V.A.; Belov, P.S.; Guliaev, I.A.; Korenev, K.D.

    1979-07-30

    For the purpose of improving the thermo-oxidation stability of washing and protective properties, dithiophosphate of the metal having the formula ((pi-R-C/sub 6/H/sub 4/OCH/sub 2/-CH/sub 2/O)/sub 2/P(=S)S)/sub 2/M (where R is the alkyl of C/sub 8/--C/sub 12/ isostructure, M is either cadmium, barium, or zinc) (I) is added into the petroleum oil for the lubrication of car engine units and containing polyethylene oxyphenylpolyamine (PEP). The lubricant has the following composition, in %: PEP, 1 to 5; (I), 0.5 to 5; petroleum oil, up to 100. In order to produce a lubricant for petroleum oil, for example MT-16, PEF and (I) are added (R = octyl or dodecyl), it is heated up to 80/sup 0/ and mixed in a nitrogen current for one hour. The combination of the additives in the patented composition has synergistic activities and the oil being patented, according to operative properties, surpasses the oil with industrial dithiophosphate additive MNI-IP-22k.

  2. 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

    method (flexible components). The main equations that govern the dynamics of the injection for a hydraulic-actuated, a piezoelectric-actuated and a mechanical-actuated oil injector are presented in this study. The global system is numerically solved using as a case of study a single-cylinder combustion......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...

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

    DEFF Research Database (Denmark)

    Salazar, Jorge Andrés González; Santos, Ilmar

    2015-01-01

    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......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...

  4. Active tilting-pad journal bearings supporting flexible rotors: Part II–The model-based feedback-controlled lubrication

    DEFF Research Database (Denmark)

    Salazar, Jorge Andrés González; Santos, Ilmar

    2017-01-01

    This is part II of a twofold paper series dealing with the design and implementation of model-based controllers meant for assisting the hybrid and developing the feedback-controlled lubrication regimes in active tilting pad journal bearings (active TPJBs). In both papers theoretical and experimen...... derived in part I. Results show further suppression of resonant vibrations when using the feedback-controlled or active lubrication, overweighting the reduction already achieved with hybrid lubrication, thus improving the whole machine dynamic performance.......This is part II of a twofold paper series dealing with the design and implementation of model-based controllers meant for assisting the hybrid and developing the feedback-controlled lubrication regimes in active tilting pad journal bearings (active TPJBs). In both papers theoretical...... and experimental analyses are presented with focus on the reduction of rotor lateral vibration. This part is devoted to synthesising model-based LQG optimal controllers (LQR regulator + Kalman Filter) for the feedback-controlled lubrication and is based upon the mathematical model of the rotor-bearing system...

  5. Non-Invasive Parameter Identification in Rotordynamics via Fluid Film Bearings: Linking Active Lubrication and Operational Modal Analysis

    DEFF Research Database (Denmark)

    Santos, Ilmar; Svendsen, Peter Kjær

    2017-01-01

    the rotor as a function of a suitable control signal. The servovalve 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 between hydrodynamic, hydrostatic and controllable lubrication regimes, can be used either to control or to excite rotor lateral vibrations. If non-invasive forces are generated via lubricant fluid film, in situ parameter identification can be carried out......, enabling evaluation of the mechanical condition of the rotating machine. Using the lubricant fluid film as a non-invasive calibrated shaker is troublesome, once several transfer functions among mechanical, hydraulic and electronic components become necessary. In this framework the main original...

  6. Non-Invasive Parameter Identification in Rotordynamics via Fluid Film Bearings: Linking Active Lubrication and Operational Modal Analysis

    DEFF Research Database (Denmark)

    Santos, Ilmar; Svendsen, Peter Kjær

    2016-01-01

    the rotor as a function of a suitable control signal. The servovalve 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 between hydrodynamic, hydrostatic and controllable lubrication regimes, can be used either to control or to excite rotor lateral vibrations. If non-invasive forces are generated via lubricant fluid film, in situ parameter identification can be carried out......, enabling evaluation of the mechanical condition of the rotating machine.Using the lubricant fluid film as a non-invasive calibrated shaker is troublesome, once several transfer functions among mechanical, hydraulic and electronic components become necessary. In this framework the main original contribution...

  7. 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

  8. 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

    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...

  9. Producing carbon-based boundary films from catalytically active lubricant additives

    Science.gov (United States)

    Erdemir, Ali; Mane, Anil U.; Elam, Jeffrey W.; Ramirez, Giovanni; Eryilmaz, Osman

    2018-04-24

    A lubricant composition includes an oil including a plurality of long-chain hydrocarbon molecules. A quantity of a catalytically active metal-organic additive is mixed with the oil. The metal-organic additive is formulated to fragment the long-chain hydrocarbon molecules of the oil into at least one of dimers and trimers under the influence of at least one of a mechanical loading and a thermal loading. In some embodiments, the metal-organic additive includes a compound of formula II: ##STR00001## where: X is Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg or Cn, and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are alkyl or alkyl halide.

  10. 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

  11. 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

  12. Lubrication and cartilage.

    Science.gov (United States)

    Wright, V; Dowson, D

    1976-02-01

    Mechanisms of lubrication of human synovial joints have been analysed in terms of the operating conditions of the joint, the synovial fluid and articular cartilage. In the hip and knee during a walking cycle the load may rise up to four times body weight. In the knee on dropping one metre the load may go up to 25 time body weight. The elastic modulus of cartilage is similar to that of the synthetic rubber of a car tyre. The cartilage surface is rough and in elderly specimens the centre line average is 2-75 mum. The friction force generated in reciprocating tests shows that both cartilage and synovial fluid are important in lubrication. The viscosity-shear rate relationships of normal synovial fluid show that it is non-Newtonian. Osteoarthrosic fluid is less so and rheumatoid fluid is more nearly Newtonian. Experiments with hip joints in a pendulum machine show that fluid film lubrication obtains at some phases of joint action. Boundary lubrication prevails under certain conditions and has been examined with a reciprocating friction machine. Digestion of hyaluronate does not alter the boundary lubrication, but trypsin digestion does. Surface active substances (lauryl sulphate and cetyl 3-ammonium bromide) give a lubricating ability similar to that of synovial fluid. The effectiveness of the two substances varies with pH.

  13. Limits of Lubrication in

    DEFF Research Database (Denmark)

    Olsson, David Dam

    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...... by strategic surfaces in comparison to normal stainless steel surfaces implying a larger extent of bi-axial stretching. Numerical simulations have been applied in order to evaluate limits of lubrication in the simulative strip reduction based on predictions of critical parameters appearing in terms......-models corresponds well to experimental results in terms of lubricant film breakdown and subsequently pick-up development. Punching and blanking have been investigated regarding tribological conditions in case of using stainless steel workpiece materials. However, this has called for development of a new test method...

  14. Ball Bearings Equipped for In Situ Lubrication on Demand

    Science.gov (United States)

    Marchetti, Mario; Jones, William R., Jr.; Pepper, Stephen V.; Jansen, Mark; Predmore, Roamer

    2005-01-01

    In situ systems that provide fresh lubricants to ball/race contacts on demand have been developed to prolong the operational lives of ball bearings. These systems were originally intended to be incorporated into ball bearings in mechanisms that are required to operate in outer space for years, in conditions in which lubricants tend to deteriorate and/or evaporate. These systems may also be useful for similarly prolonging bearing lifetimes on Earth. Reservoirs have been among the means used previously to resupply lubricants. Lubricant- resupply reservoirs are bulky and add complexity to bearing assemblies. In addition, such a reservoir cannot be turned on or off as needed: it supplies lubricant continuously, often leading to an excess of lubricant in the bearing. A lubricator of the present type includes a porous ring cartridge attached to the inner or the outer ring of a ball bearing (see Figure 1). Oil is stored in the porous cartridge and is released by heating the cartridge: Because the thermal expansion of the oil exceeds that of the cartridge, heating causes the ejection of some oil. A metal film can be deposited on a face of the cartridge to serve as an electrical-resistance heater. The heater can be activated in response to a measured increase in torque that signals depletion of oil from the bearing/race contacts. Because the oil has low surface tension and readily wets the bearing-ring material, it spreads over the bearing ring and eventually reaches the ball/race contacts. The Marangoni effect (a surface-tension gradient associated with a temperature gradient) is utilized to enhance the desired transfer of lubricant to the ball/race contacts during heating. For a test, a ball bearing designed for use at low speed was assembled without lubricant and equipped with a porous-ring lubricator, the resistance heater of which consumed a power of less than 1 W when triggered on by a torque-measuring device. In the test, a load of 20 lb (.89 N) was applied and the

  15. A study of mechanisms of liquid lubrication in metal forming

    DEFF Research Database (Denmark)

    Bech, Jakob Ilsted; Bay, Niels; Eriksen, Morten

    1998-01-01

    Applying a transparent tool technique the lubrication in plane strip drawing of aluminium sheet is studied providing the strip with surface pockets for entrapment of lubricant. The compression and eventual escape of trapped lubricant by Micro Plasto HydroDynamic Lubrication (MPHDL) as well as Micro...

  16. Hydrodynamic Lubrication

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 9. Hydrodynamic Lubrication Experiment with 'Floating' Drops. Jaywant H Arakeri K R Sreenivas. General Article Volume 1 Issue 9 September 1996 pp 51-58. Fulltext. Click here to view fulltext PDF. Permanent link:

  17. On the lubrication mechanism of detonation-synthesis nanodiamond additives in lubricant composites

    Science.gov (United States)

    Shepelevskii, A. A.; Esina, A. V.; Voznyakovskii, A. P.; Fadin, Yu. A.

    2017-09-01

    The lubrication of detonation-synthesis diamond additives in lubricant composites has been discussed. The mechanism of interaction between nanodiamonds and friction surface has been shown to depend on the applied load. Two models of the lubrication of nanodiamonds and the conditions for their validity have also been proposed.

  18. 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 presented...

  19. 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......-rig are backed by a comprehensive mathematical model that couples a finite element model of a flexible rotor, a thermohydrodynamic model based on a modified form of the Reynold’s equation for hybrid aerostatic-aerodynamic lubrication of compressible fluid, a piezoelectric injection system and a proportional...

  20. 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...... equations. The global system is numerically solved using as a case study a single-cylinder combustion engine, where the conventional lubrication of the main bearing is modified by applying radial oil injection using piezo-actuated injection. The performance of such a hybrid bearing is compared...

  1. Solid lubricants and surfaces

    CERN Document Server

    Braithwaite, E R

    1964-01-01

    Solid Lubricants and Surfaces deals with the theory and use of solid lubricants, particularly in colloidal form. Portions of this book are devoted to graphite and molybdenum disulfides, which are widely used solid lubricants in colloidal form. An extensive literature on the laboratory examination of hundreds of solids as potential lubricants is also provided in this text. Other topics discussed include the metals and solid lubricants; techniques for examining surfaces; other solid lubricants; metal shaping; and industrial uses of solid-lubricant dispersions. This publication is beneficial to e

  2. Soft lubrication

    Science.gov (United States)

    Skotheim, Jan; Mahadevan, Laksminarayanan

    2004-11-01

    We study the lubrication of fluid-immersed soft interfaces and show that elastic deformation couples tangential and normal forces and thus generates lift. We consider materials that deform easily, due to either geometry (e.g a shell) or constitutive properties (e.g. a gel or a rubber), so that the effects of pressure and temperature on the fluid properties may be neglected. Four different system geometries are considered: a rigid cylinder moving tangentially to a soft layer coating a rigid substrate; a soft cylinder moving tangentially to a rigid substrate; a cylindrical shell moving tangentially to a rigid substrate; and finally a journal bearing coated with a thin soft layer, which being a conforming contact allows us to gauge the influence of contact geometry. In addition, for the particular case of a soft layer coating a rigid substrate we consider both elastic and poroelastic material responses. Finally, we consider the role of contact geometry in the context of the journal bearing, a conforming contact. For all these cases we find the same generic behavior: there is an optimal combination of geometric and material parameters that maximizes the dimensionless normal force as a function of the softness.

  3. Impact of Lubricant Additives on thePhysicochemical Properties and Activity of Three‐Way Catalysts

    Directory of Open Access Journals (Sweden)

    Chao Xie

    2016-04-01

    Full Text Available As alternative lubricant anti‐wear additives are sought to reduce friction and improve overall fuel economy, it is important that these additives are also compatible with current emissions control catalysts. In the present work, an oil‐miscible phosphorous‐containing ionic liquid (IL, trihexyltetradecylphosphonium bis(2‐ethylhexyl phosphate ([P66614][DEHP], is evaluated for its impact on three‐way catalysts (TWC and benchmarked against the industry standard zinc‐dialkyl‐dithio‐phosphate (ZDDP. The TWCs are aged in different scenarios: neat gasoline (no‐additive, or NA, gasoline+ZDDP, and gasoline+IL. The aged samples, along with the as‐received TWC, are characterized through various analytical techniques including catalyst reactivity evaluation in a bench‐flow reactor. The temperatures of 50% conversion (T50 for the ZDDP‐aged TWCs increased by 30, 24, and 25 °C for NO, CO, and C3H6, respectively, compared to the no‐additive case. Although the IL‐aged TWC also increased in T50 for CO and C3H6, it was notably less than ZDDP, 7 and 9 °C, respectively. Additionally, the IL‐aged samples had higher water‐gas‐shift reactivity and oxygen storage capacity than the ZDDP‐aged TWC. Characterization of the aged samples indicated the predominant presence of CePO4 in the ZDDP‐aged TWC aged by ZDDP, while its formation was retarded in the case of IL where higher levels of AlPO4 is observed. Thus, results in this work indicate that the phosphonium‐phosphate IL potentially has less adverse impact on TWC than ZDDP.

  4. 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...... directly into the bearing clearance. The injected flow is controlled by means of a servovalve. The theoretical model includes the dynamics of servovalves and pipelines using a lumped parameter approach, whereas the coupling between the hydraulic system and the bearing oil film is modeled using a modified...

  5. 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

  6. Biodegradation of lubricant oil

    African Journals Online (AJOL)

    M

    2012-09-25

    Sep 25, 2012 ... lubricating oil, showed high biodegradation efficiency for different used lubricating oils. Capability of ..... amount after biodegradation showed no difference in the .... products polluted sites in Elele, Rivers State, Ngeria.

  7. 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...... with the result that the detection and isolation time can be long. In this paper it will be shown, that this problem can be handled by using a modification of the feedback controller. By applying the YJBK-parameterization (after Youla, Jabr, Bongiorno and Kucera) for the controller, it is possible to modify...... 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....

  8. 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...... 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 machinery....

  9. Building an applied activation analysis centre

    International Nuclear Information System (INIS)

    Bartosek, J.; Kasparec, I.; Masek, J.

    1972-01-01

    Requirements are defined and all available background material is reported and discussed for the building up of a centre of applied activation analysis in Czechoslovakia. A detailed analysis of potential users and the centre's envisaged availability is also presented as part of the submitted study. A brief economic analysis is annexed. The study covers the situation up to the end of 1972. (J.K.)

  10. Synthetic lubricating oils

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Jurado, J

    1953-01-01

    A yellow solid petroleum paraffin d/sup 60/ 0.808, I number 3.5, average molecular weight 350, chlorinated and condensed with benzene, xylene, or naphthalene by the Friedel and Crafts reaction, in the presence of anhydrous AlCl/sub 3/ or activated Al, gave synthetic lubricating oils. Xylene was the preferred aromatic compound, naphthalene required the use of less completely chlorinated paraffin, benzene produced resins difficult to remove and gave darker oils with excessive green fluorescence. Activated Al rather than anhydrous AlCl/sub 3/ gave darker oils with higher viscosity and Conradson C values. Tar from the low-temperature distillation of lignite, used as a source of a paraffin fraction melting 40/sup 0/ to 48/sup 0/ (chlorinated to 26.5 percent Cl) and an aromatic fraction, 45 percent aromatic compounds by volume (mainly polysubstituted benzenes), I number 10, was converted to a similar synthetic lubricant with the following properties: Kinematic viscosity at 210/sup 0/ F., 50.4 centistokes; viscosity index, 92; Conradson C, 1.5 percent; solidification point, 9/sup 0/; S, 0.41 percent.

  11. Wear And Tear Determination By Trace Multi-Element Analysis Of An Unused And Used Lubricant Oil Using Instrumental Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Adeyemo, D.J.

    2004-01-01

    Instrumental neutron activation analysis technique using the Imperial College Centre consort M. K. II nuclear reactor was utilized for the determination of: As, Ba Ca CI, Co, Cr, Cu, Fe, K, Mn, Mo, Na Ni, Rb, Sb, Se, Ti, V, and Zn, in an imported and used car lubricant oil. The wear of the oil lubricated parts of the car engine was monitored by establishing a correlation between the results obtained in the analysis. The result obtained from the analysis of the unused and then used samples on a low performing oil leaking four stroke car engine showed an increase on all the elements determined except for Se and Rb. The precision for the multi-element analysis is less than 12% for most of the elements. The accuracy of the measurement is also validated by the result obtained from the analysis of NBS-SRM1635 (sub-bituminous) coal standard for the elements. The results obtained indicate that analysis of unused and used lubricant oil samples can aid in locating defects in engine parts and hence facilitated maintenance procedures

  12. Dynamic Coefficients of a Tilting Pad With Active Lubrication: Comparison Between Theoretical and Experimental Results

    DEFF Research Database (Denmark)

    Cerda Varela, Alejandro Javier; Santos, Ilmar

    2015-01-01

    experimental results from the literature for industrial grade passive tilting pad bearings. This initial validation is followed by a comparison with experimental identification results obtained from a test rig featuring the active bearing design. Good overall agreement is observed in both configurations...

  13. Component level study of an actively lubricated LEG Tilting Pad Bearing: Theory and experiment

    DEFF Research Database (Denmark)

    Cerda Varela, Alejandro Javier; Santos, Ilmar Ferreira

    2018-01-01

    portrays the first experimental study for the“proof of concept” of this configuration, as well as a comparison with theoretical results. A simplified setup, featuring a rigid rotor supported by a single pad arrangement is the subject of study. The obtained results prove the viability of the proposed active...... bearing design, validate the available simulation tool and exemplify on a conceptual level the operational benefits from introducing this technology into standard LEG Tilting Pad Bearings....

  14. 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...... orifices machined in the bearing pads, one can alter the machine dynamic characteristics, thus enhancing its operational range. A mathematical model of the rotor-bearing system, as well as of the hydraulic system, is presented. Numerical results of the system frequency response show good agreement...

  15. 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

  16. 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...

  17. Lubrication method and apparatus

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, R.S.

    1988-05-03

    In a combustion turbine engine comprising a bearing member journaling a rotatable component, and compressor means providing pressurized air, the method of providing liquid lubricant to the bearing member is described comprising the steps of: providing the liquid lubricant sealed within a collapsible and penetrable bladder member; enclosing the bladder member and lubricant within a substantially closed housing sealingly cooperating with the bladder member to define a pair of chambers; arranging a penetrating lance member in one of the pair of chambers in confronting relationship with the bladder member; providing communication of the pressurized air with the other of the pair of chambers to force the bladder member into impaled sealing relationship with the lance member; communicating the lubricant to the bearing member via the lance member; and utilizing the pressurized air within the other chamber to collapse the bladder member, simultaneously flowing the lubricant to the bearing member.

  18. Applying Activity Theory in Multiagency Settings

    Directory of Open Access Journals (Sweden)

    Daniels H.,

    2016-12-01

    Full Text Available In this paper I explore the extent to which two approaches to the social formation of mind are compatible and may be used to enrich and extend each other. These are: Activity Theory (AT as derived from the work of the early Russian psychologists, Vygotsky and Leontiev, and the work of the sociologist Basil Bernstein. The purpose is to show how Bernstein provides a language of description which allows Vygotsky’s account of social formation of mind to be extended and enhanced through an understanding of the sociological processes which form specific modalities of pedagogic practice and their specialized scientific concepts. The two approaches engage with a common theme namely the social shaping of consciousness, from different perspectives and yet as Bernstein acknowledges both develop many of their core assumptions from the work of Marx and the French school of early twentieth century sociology. The work of the Russian linguist is also be used to further nuance the argument applied in multiagency settings.

  19. Epithermal neutron activation analysis in applied microbiology

    International Nuclear Information System (INIS)

    Marina Frontasyeva

    2012-01-01

    Some results from applying epithermal neutron activation analysis at FLNP JINR, Dubna, Russia, in medical biotechnology, environmental biotechnology and industrial biotechnology are reviewed. In the biomedical experiments biomass from the blue-green alga Spirulina platensis (S. platensis) has been used as a matrix for the development of pharmaceutical substances containing such essential trace elements as selenium, chromium and iodine. The feasibility of target-oriented introduction of these elements into S. platensis biocomplexes retaining its protein composition and natural beneficial properties was shown. The absorption of mercury on growth dynamics of S. platensis and other bacterial strains was observed. Detoxification of Cr and Hg by Arthrobacter globiformis 151B was demonstrated. Microbial synthesis of technologically important silver nanoparticles by the novel actinomycete strain Streptomyces glaucus 71 MD and blue-green alga S. platensis were characterized by a combined use of transmission electron microscopy, scanning electron microscopy and energy-dispersive analysis of X-rays. It was established that the tested actinomycete S. glaucus 71 MD produces silver nanoparticles extracellularly when acted upon by the silver nitrate solution, which offers a great advantage over an intracellular process of synthesis from the point of view of applications. The synthesis of silver nanoparticles by S. platensis proceeded differently under the short-term and long-term silver action. (author)

  20. Tolerance Optimization for Mechanisms with Lubricated Joints

    International Nuclear Information System (INIS)

    Choi, J.-H.; Lee, S.J.; Choi, D.-H.

    1998-01-01

    This paper addresses an analytical approach to tolerance optimization for planar mechanisms with lubricated joints based on mechanical error analysis. The mobility method is applied to consider the lubrication effects at joints and planar mechanisms are stochastically defined by using the clearance vector model for mechanical error analysis. The uncertainties considered in the analysis are tolerances on link lengths and radial clearances and these are selected as design variables. To show the validity of the proposed method for mechanical error analysis, it is applied to two examples, and the results obtained are compared with those of Monte Carlo simulations. Based on the mechanical error analysis, tolerance optimizations are applied to the examples

  1. Determination of Lubricant Bulk Modulus in Metal Forming by Means of a Simple Laboratory Test and Inverse FEM Analysis

    DEFF Research Database (Denmark)

    Hafis, S. M.; Christiansen, P.; Martins, P. A. F.

    2016-01-01

    The influence of workpiece surface topography on friction, lubrication and final surface equality in metal forming operations is well known and has been pointed out by many researchers.This is especially the case when liquid lubricants are applied in situations, where increased surface roughness ...... couples lubricant flow with plastic deformation of the metal directly. Results show that the proposed procedure allows determining an approximate bulk modulus for the lubricant.......The influence of workpiece surface topography on friction, lubrication and final surface equality in metal forming operations is well known and has been pointed out by many researchers.This is especially the case when liquid lubricants are applied in situations, where increased surface roughness...... facilitates the lubricant entrainment, pressurization and possible escape by micro-plasto-hydrodynamic lubrication. In order to model these mechanisms an important lubricant propertyd esignated as the bulk modulus is needed for characterizing the compressibility of the lubricant. The present paper describes...

  2. Practical lubrication for industrial facilities

    CERN Document Server

    Bloch, Heinz

    2016-01-01

    Now completely revised and updated, this definitive, hands-on reference provides a comprehensive resource on the fundamental principles of lubricant application, what products are available, and which lubricants are most effective for specific applications. It also offers a detailed and highly practical discussion of lubrication delivery systems. You'll gain a clearer understanding of the "why" of relevant industrial lubrication practices, and, importantly, how these practices will facilitate optimized results. Lubricant applications covered include bearings and machine elements in earthbound

  3. Thin layer activation technique applied to the measurement of wear

    Energy Technology Data Exchange (ETDEWEB)

    Humphries, P [UKAEA Research Group, Harwell. Atomic Energy Research Establishment

    1978-01-01

    A thin layer of radioactive atoms is produced in the material by bombardment with charged particles, and as the material is worn away the total activity level is monitored. If the activity to depth relationship is then known the amount of material worn away can be determined. By a selective choice of the charged particle species and energy the depth of the active layer, its natural decay rate, and the energy of the emitted radiation can be pre-determined. The Harwell Tandem Electrostatic Generator has been found very suitable for the work. The total activity level can be made as little or as large as required, but a level around 5 to 10 microcuries is usually found to be adequate, and the active layer usually has a depth of 50 to 300 ..mu..m. The activated area can be from < 1 mm/sup 2/ to 4 cm/sup 2/. Particular reference is made to the production of /sup 56/Co in Fe. Experimental arrangements for the irradiation of components are described. Some practical applications undertaken by Harwell for industry are briefly mentioned, including wear of diesel engine valve seatings and fuel injection equipment, engine testing of lubricants, surface loss of rails and railway wheels, wear of gears, wear of graphite bearing materials, and corrosion and erosion of materials. 4 references.

  4. 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...

  5. Lubrication in cold rolling : Numerical simulation using multigrid techniques

    NARCIS (Netherlands)

    Lugt, Pieter Martin

    1992-01-01

    In the cold rolling process a lubricant is applied on the rolls and/or the strip mate­rial. Due to the velocities of the rolls and the strip, part of the lubricant is sheared into the contact causing, amongst others, a reduction of the friction. In this thesis a physical-mathematical model is

  6. Applied nuclear physics group - activities report. 1977-1997

    International Nuclear Information System (INIS)

    Appoloni, Carlos Roberto

    1998-06-01

    This report presents the activities conducted by the Applied Nuclear Physics group of the Londrina State University - Applied Nuclear Physics Laboratory - Brazil, from the activities beginning (1977) up to the end of the year 1997

  7. Research on Mobile Learning Activities Applying Tablets

    Science.gov (United States)

    Kurilovas, Eugenijus; Juskeviciene, Anita; Bireniene, Virginija

    2015-01-01

    The paper aims to present current research on mobile learning activities in Lithuania while implementing flagship EU-funded CCL project on application of tablet computers in education. In the paper, the quality of modern mobile learning activities based on learning personalisation, problem solving, collaboration, and flipped class methods is…

  8. Micro-Plasto-Hydrodynamic Lubrication a Fundamental Mechanism in Cold Rolling

    DEFF Research Database (Denmark)

    Laugier, Maxime; Boman, Romain; Legrand, Nicolas

    2014-01-01

    This paper presents recent investigations in Micro-Plasto-Hydrodynamic (MPH) lubrication. Industrial evidences of the existence of MPH lubrication mechanism for cold rolling processes are presented. A new lubrication model developed for strip drawing processes is then applied to predict the MPH...

  9. Lubricating graphene with a nanometer-thick perfluoropolyether

    International Nuclear Information System (INIS)

    Kozbial, Andrew; Li, Zhiting; Iasella, Steven; Taylor, Alexander T.; Morganstein, Brittni; Wang, Yongjin; Sun, Jianing; Zhou, Bo; Randall, Nicholas X.; Liu, Haitao; Li, Lei

    2013-01-01

    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

  10. Interdisciplinary strate in applied performance and activism

    OpenAIRE

    Johansson, Ola

    2014-01-01

    The paper addresses the challenges and advantages of collaborative stratification in the continuum of theatre and fine arts, with examples from applied performance projects in international contexts. With different approaches to performance/media, acting/agency, devising/curatorship and participation/social engagement, collaborative processes have proved to be quite incongruent in method and motif, although inclusive and versatile in media tactics and political outreach. In post-Brechtian the...

  11. Towards green lubrication in machining

    CERN Document Server

    Liew Yun Hsien, Willey

    2014-01-01

    The book gives an overview of environmental friendly gaseous and vapour, refrigerated compressed gas, solid lubricant, mist lubrication, minimum quantity lubrication (MQL) and vegetable oils that can be used as lubricants and additives in industrial machining applications. This book introduces vegetable oils as viable and good alternative resources because of their environmental friendly, non-toxic and readily biodegradable nature.  The effectiveness of various types of vegetables oils as lubricants and additives in reducing wear and friction is discussed in this book. Engineers and scientist working in the field of lubrication and machining will find this book useful.

  12. Activation therapy: theoretical and applied aspects

    Directory of Open Access Journals (Sweden)

    Oleg I. Kit

    2015-11-01

    Full Text Available The paper presents a brief review on how some concepts on the organism general adaptational reactions developed, including their role in increasing the unspecific resistance in the organism. Demonstrated is periodicity of the patterns of anti-stressor type reactions (training, calm and elevated activation and stress in a wide range of stimulation values. The concepts on the organism adaptational reactions and reactivity levels have created the theoretical basis for practical applications of the activation therapy aimed at health improvement, prevention and treatment of various diseases, including oncology. Evidence data on the applications of the activation therapy as a promising approach to the organism state control are confirmed by the originators of this scientific discovery, their followers and medical experts.

  13. Power system with an integrated lubrication circuit

    Science.gov (United States)

    Hoff, Brian D [East Peoria, IL; Akasam, Sivaprasad [Peoria, IL; Algrain, Marcelo C [Peoria, IL; Johnson, Kris W [Washington, IL; Lane, William H [Chillicothe, IL

    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.

  14. Glass transitions in lubricants - Its relation to elastohydrodynamic lubrication /EHD/

    Science.gov (United States)

    Alsaad, M.; Bair, S.; Sanborn, D. M.; Winer, W. O.

    1977-01-01

    A preliminary investigation into the possible role of glass transition and glassy state behavior of lubricants in EHD contacts is reported. Measurements of the glass transition of lubricants as a function of pressure by two methods are presented along with a discussion indicating possible implications of the results to EHD lubrication.

  15. Lubricated immersed boundary method in two dimensions

    Science.gov (United States)

    Fai, Thomas G.; Rycroft, Chris H.

    2018-03-01

    Many biological examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen and the intracellular trafficking of vesicles into dendritic spines, involve the near-contact of elastic structures separated by thin layers of fluid. Motivated by such problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We demonstrate 2nd-order accurate convergence for simple two-dimensional flows with known exact solutions to showcase the increased accuracy of this method compared to the standard immersed boundary method. Motivated by the phenomenon of wall-induced migration, we apply the lubricated immersed boundary method to simulate an elastic vesicle near a wall in shear flow. We also simulate the dynamics of a vesicle traveling through a narrow channel and observe the ability of the lubricated method to capture the vesicle motion on relatively coarse fluid grids.

  16. Role of water lubricated bearings in Candu reactors

    International Nuclear Information System (INIS)

    Kumar, Ashok N.

    1999-01-01

    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)

  17. Aminodisulfides as additives to lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Balin, A.I.; Tarasevich, V.B.; Veretenova, T.N.

    1980-01-01

    A study was carried out and tehcnology developed for producing sulfur-nitrogen containing additives of the type of aminodisulfide by interaction of beta, beta-dichlordialkyl (aryl) disulfides with diethanolamine in a medium of sulfur-diethanolamine. The 2,2'-bis-(diethanol)-dialkyl(aryl) disulfides obtained do not hydrolyze in aqueous soltuions of alkalis, exhibit rather high antiscoring properties and are recommended for tests as active additives of high pressure to SOZH and technological lubricants of the oil and emulsion types.

  18. Studies on micro plasto hydrodymic lubrication in metal forming

    DEFF Research Database (Denmark)

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

    2002-01-01

    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...... characterization models the potential entrapment of a lubricant in closed reservoirs is used as a parameter to predetermine the formability of a sheet metal, Steinhoff et al. (1996), Geiger et al. (1997) and Schmoeckel et al. (1997). In experimental studies on friction in metal forming applying the strip drawing...

  19. Mixed Lubricated Line Contacts

    NARCIS (Netherlands)

    Faraon, I.C.

    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

  20. Determination of Lubricants on Ball Bearings by FT-IR using an Integrating Sphere

    Science.gov (United States)

    Street, K. W.; Pepper, S. V.; Wright, A.

    2003-01-01

    The lifetime determination of space lubricants is done at our facility by accelerated testing. Several micrograms of lubricant are deposited on the surface of a ball by syringing tens of micro liters of dilute lubricant solution. The solvent evaporates and the mass of lubricant is determined by twenty weighings near the balance reliability limit. This process is timely but does not produce a good correlation between the mass of lubricant and the volume of solution applied, as would be expected. The amount of lubricant deposited on a ball can be determined directly by Fourier Transform - Infrared Spectroscopy using an integrating sphere. In this paper, we discuss reasons for choosing this methodology, optimization of quantification conditions and potential applications for the technique. The volume of lubricant solution applied to the ball gives better correlation to the IR intensity than does the weight.

  1. CATALYTIC HYDROCRACKING OF WASTE LUBRICANT OIL INTO LIQUID FUEL FRACTION USING ZnO, Nb2O5, ACTIVATED NATURAL ZEOLITE AND THEIR MODIFICATION

    Directory of Open Access Journals (Sweden)

    Wega Trisunaryanti

    2010-06-01

    Full Text Available Catalytic hydrocracking of waste lubricant oil into liquid fuel fraction using ZnO, Nb2O5, activated natural zeolite (ZAAH and their modification has been investigated. The zeolite was produced in Wonosari, Yogyakarta. Activation of the zeolite was carried out by refluxing with HCl 3M for 30 min, produced the activated natural zeolite (ZAAH. The ZnO/ZAAH catalyst was prepared by impregnation of Zn onto the ZAAH by ion exchange method using salt precursor of Zn(NO32.4H2O. The Nb2O5/ZAAH catalyst was prepared by mixing the ZAAH sample with Nb2O5 and oxalic acid solution until the paste was formed. The impregnation of Zn onto Nb2O5/ZAAH was carried out using the same method to that of the ZnO/ZAAH catalyst resulted ZnO/Nb2O5-ZAAH catalyst. Characterization of catalyst includes determination of Zn metal by Atomic Absorption Spectroscopy (AAS, acidity by gravimetric method and catalyst porosity by Surface Area Analyzer (NOVA-1000. Catalytic hydrocracking was carried out in a semi-batch reactor system using ZnO, ZAAH, ZnO/ZAAH and ZnO/Nb2O5-ZAAH catalysts at 450 oC under the H2 flow rate of 15 mL/min. and the ratio of catalyst/feed = 1/5. The composition of liquid products was analyzed by Gas Chromatograpy (GC.The results showed that impregnation of ZnO and/or Nb2O5 on the ZAAH increased the acidity and specific surface area of catalyst. The products of the hydrocracking process were liquid, coke and gas. Conversion of liquid products was increased by the increase of catalyst acidity. The highest liquid product was produced by ZnO/Nb2O5-ZAAH catalyst, 52.97 wt-%, consist of gasoline, 38.87 wt-% and diesel, 14.10 wt-%.   Keywords: hydrocracking, waste lubricant oil, liquid fuel fraction

  2. Temperature dependence on the synthesis of Jatropha bio lubricant

    International Nuclear Information System (INIS)

    Gunam Resul, M.F.M.; Tinia Idaty Mohd Ghazi; Idris, A.

    2009-01-01

    Full text: Jatropha oil has good potential as the renewable energy as well as lubricant feedstock. The synthesis of jatropha bio lubricant was performed by transesterification of jatropha methyl ester (JME) with trimethyl-ol-propane (TMP) with sodium methoxide (NaOCH 3 ) catalyst. The effects of temperature on the synthesis were studied at a range between 120 degree Celsius and 200 degree Celsius with pressure kept at 10 mbar. The conversion of JME to jatropha bio lubricant was found to be the highest (47 %) at 200 degree Celsius. However, it was suggested that the optimum temperature of the reaction is at 150 degree Celsius due to insignificant improvement in bio lubricant production. To maintain forward reaction, the excess amount of JME was maintained at 3.9:1 ratios to TMP. Kinetic study was done and compared. The synthesis was found to follow a second order reaction with overall rate constant of 1.49 x 10 -1 (% wt/ wt.min.degree Celsius) -1 . The estimated activation energy was 3.94 kJ/mol. Pour point for jatropha bio lubricant was at -3 degree Celsius and Viscosity Index (VI) ranged from 178 to 183. The basic properties of jatropha bio lubricant, pour point and viscosities are found comparable to other plant based bio lubricant, namely palm oil and soybean based bio lubricant. (author)

  3. A preventive maintenance lubricant

    Energy Technology Data Exchange (ETDEWEB)

    Chapaykina, S A; Ol' kov, P L; Pertsev, A N; Rodzevillo, I T; Rogacheva, O I; Zinov' yev, A P

    1980-02-15

    A method is disclosed to lower the adherence of materials by reducing the viscosity of a preventive maintenance lubricant against adhesion of moist, freeflowing materials, containing extract of selective cleaning of oil fractions and asphalt. Gas oil of catalytic cracking is added having a boiling point of 190-300 degrees, with the following ratio of components (%): selective cleaning extract, 43-50; asphalt, 14-16; and gas oil of catalytic cracking, the remainder, Treating a surface with the proposed lubricant lowers the specific resistance to shift of rock compared with the prototype (g/cm/sup 2/): sand (moisture content, 18%) from 3.82 to 1.55; and clay (moisture content 16%), from 5.41 to 3.51.

  4. Men's use and perceptions of commercial lubricants: prevalence and characteristics in a nationally representative sample of American adults.

    Science.gov (United States)

    Reece, Michael; Herbenick, Debby; Schick, Vanessa; Sanders, Stephanie A; Fortenberry, J Dennis

    2014-05-01

    Most research on men's use of commercial lubricants during sexual activities is in the context of condom use and often specifically among men who have sex with men. Less is known about men's use of lubricants associated with a broader range of sexual experiences. The aims of this study are to document the prevalence of commercial lubricant use among adult U.S. men (age 18+), to document men's use of lubricants across solo and partnered sexual behaviors, and to assess men's perceptions of the contributions lubricants have to the sexual experience. Data are from the 2012 National Survey of Sexual Health and Behavior, which involved the administration of an online questionnaire to a nationally representative probability sample of U.S. adults ages 18 and older. Sociodemographic characteristics, recent and lifetime commercial lubricant use, lubricant use during specific sexual behaviors, frequency of lubricant use, and reasons for lubricant use. Most men in the United States (70%, N = 1,014) reported having used a commercial lubricant, with men older than 24 and those in a relationship more likely to report lubricant use. About one in four men had used a lubricant in the past 30 days. Intercourse was the most common behavior during which men used lubricant, though solo masturbation and partnered sexual play were also frequently linked to lubricant use. The most common reasons for lubricant use included "to make sex more comfortable," "for fun," "curiosity," and "my partner wanted to." Most American men have used a lubricant; lubricant use is common across all age groups, and some of the most common reasons why men report using lubricants have to do with sexual enhancement, comfort, and pleasure. Clinicians may find these data helpful to their efforts to educate patients about lubricant use, comfort during sex, and sexual enhancement. © 2014 International Society for Sexual Medicine.

  5. Oil and natural gas technology review-lubrication and lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Moos, J

    1966-01-01

    A summary is presented of the advances made during 1967 in the following areas: production and transmission of natural gas; geosciences; drilling and production technology; secondary recovery; transportation by tanker, pipelines, and tank cars; storage; planning of refineries; control and automation; cracking and gasification of crude oil; separation and hydrogenation processes; petrochemicals; combustion technology; fuels and additives; air and water pollution control; production of lubricants; lubrication with mist, gas, and vapors; hydraulic fluids; lubricant additives; oxidation and aging of oils; greases; solid lubricants; bearings; machining; friction and wear; and changes in materials of construction. (220 refs.)

  6. Fault lubrication during earthquakes.

    Science.gov (United States)

    Di Toro, G; Han, R; Hirose, T; De Paola, N; Nielsen, S; Mizoguchi, K; Ferri, F; Cocco, M; Shimamoto, T

    2011-03-24

    The determination of rock friction at seismic slip rates (about 1 m s(-1)) is of paramount importance in earthquake mechanics, as fault friction controls the stress drop, the mechanical work and the frictional heat generated during slip. Given the difficulty in determining friction by seismological methods, elucidating constraints are derived from experimental studies. Here we review a large set of published and unpublished experiments (∼300) performed in rotary shear apparatus at slip rates of 0.1-2.6 m s(-1). The experiments indicate a significant decrease in friction (of up to one order of magnitude), which we term fault lubrication, both for cohesive (silicate-built, quartz-built and carbonate-built) rocks and non-cohesive rocks (clay-rich, anhydrite, gypsum and dolomite gouges) typical of crustal seismogenic sources. The available mechanical work and the associated temperature rise in the slipping zone trigger a number of physicochemical processes (gelification, decarbonation and dehydration reactions, melting and so on) whose products are responsible for fault lubrication. The similarity between (1) experimental and natural fault products and (2) mechanical work measures resulting from these laboratory experiments and seismological estimates suggests that it is reasonable to extrapolate experimental data to conditions typical of earthquake nucleation depths (7-15 km). It seems that faults are lubricated during earthquakes, irrespective of the fault rock composition and of the specific weakening mechanism involved.

  7. 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

  8. Applied research of environmental monitoring using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Young Sam; Moon, Jong Hwa; Chung, Young Ju

    1997-08-01

    This technical report is written as a guide book for applied research of environmental monitoring using Instrumental Neutron Activation Analysis. The contents are as followings; sampling and sample preparation as a airborne particulate matter, analytical methodologies, data evaluation and interpretation, basic statistical methods of data analysis applied in environmental pollution studies. (author). 23 refs., 7 tabs., 9 figs.

  9. Neutron activation analysis applied to energy and environment

    International Nuclear Information System (INIS)

    Lyon, W.S.

    1975-01-01

    Neutron activation analysis was applied to a number of problems concerned with energy production and the environment. Burning of fossil fuel, the search for new sources of uranium, possible presence of toxic elements in food and water, and the relationship of trace elements to cardiovascular disease are some of the problems in which neutron activation was used. (auth)

  10. Self lubricating fluid bearings

    International Nuclear Information System (INIS)

    Kapich, D.D.

    1980-01-01

    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 [fr

  11. Self-lubricating formula

    Energy Technology Data Exchange (ETDEWEB)

    Borzenko, V.A.; Koltovskiy, L.V.; Koshelyov, Yu.I.; Kuzovlyev, G.F.; Lebedyev, S.I.; Sitnikov, S.A.; Telegin, V.D.

    1979-12-30

    To improve operation of scrubbers that operate in crystallizers for deparaffinization of oil products, a formula is being suggested which contains siliceous fibers, and a type of thermoactive resin - phenol-formaldehyde laquer, with the following component ration (% weight): carbon fiber 20-25, siliceous fibers 20-30, dry lubricant 10-15, phenolformaldehyde laquer up to 100. Phys.-mech. characteristics are flexure, compression, Ak of the suggested and known compositions (kgs/cm/sup 2/) 2150-2450 and 2550-2700, 32-37 and 1750, 2150 and 27 operation resource 2100:2500 and 1400.

  12. Applied superconductivity and cryogenic research activities in NIFS

    International Nuclear Information System (INIS)

    Mito, T.; Sagara, A.; Imagawa, S.; Yamada, S.; Takahata, K.; Yanagi, N.; Chikaraishi, H.; Maekawa, R.; Iwamoto, A.; Hamaguchi, S.; Sato, M.; Noda, N.; Yamauchi, K.; Komori, A.; Motojima, O.

    2006-01-01

    Since the foundation of National Institute for Fusion Science (NIFS) in 1989, the primary mission of the applied superconductivity and cryogenic researches has been focused on the development of the large helical device (LHD): the largest fusion experimental apparatus exclusively utilizing superconducting technologies. The applied superconductivity and cryogenics group in NIFS was organized to be responsible for this activity. As a result of extensive research activities, the construction of LHD was completed in 1997. Since then, the LHD superconducting system has been demonstrating high availability of more than 97% during eight years operation and it keeps proving high reliability of large-scale superconducting systems. This paper describes the extensive activities of the applied superconductivity and cryogenic researches in NIFS during and after the development of LHD and the fundamental researches that aim at realizing a helical-type fusion reactor

  13. Influence of Cooling Lubricants on the Surface Roughness and Energy Efficiency of the Cutting Machine Tools

    Directory of Open Access Journals (Sweden)

    Jersák J.

    2017-08-01

    Full Text Available The Technical University of Liberec and Brandenburg University of Technology Cottbus-Senftenberg investigated the influence of cooling lubricants on the surface roughness and energy efficiency of cutting machine tools. After summarizing the achieved experimental results, the authors conclude that cooling lubricants extensively influence the cutting temperature, cutting forces and energy consumption. Also, it is recognizable that cooling lubricants affect the cutting tools lifetime and the workpiece surface quality as well. Furthermore, costs of these cooling lubricants and the related environmental burden need to be considered. A current trend is to reduce the amount of lubricants that are used, e.g., when the Minimum Quantity Lubrication (MQL technique is applied. The lubricant or process liquid is thereby transported by the compressed air in the form of an aerosol to the contact area between the tool and workpiece. The cutting process was monitored during testing by the three following techniques: lubricant-free cutting, cutting with the use of a lubricant with the MQL technique, and only utilizing finish-turning and finish-face milling. The research allowed the authors to monitor the cutting power and mark the achieved surface quality in relation to the electrical power consumption of the cutting machine. In conclusions, the coherence between energy efficiency of the cutting machine and the workpiece surface quality regarding the used cooling lubricant is described.

  14. Oleoplaning droplets on lubricated surfaces

    Science.gov (United States)

    Daniel, Dan; Timonen, Jaakko V. I.; Li, Ruoping; Velling, Seneca J.; Aizenberg, Joanna

    2017-10-01

    Recently, there has been much interest in using lubricated surfaces to achieve extreme liquid repellency: a foreign droplet immiscible with the underlying lubricant layer was shown to slide off at a small tilt angle behaviour was hypothesized to arise from a thin lubricant overlayer film sandwiched between the droplet and solid substrate, but this has not been observed experimentally. Here, using thin-film interference, we are able to visualize the intercalated film under both static and dynamic conditions. We further demonstrate that for a moving droplet, the film thickness follows the Landau-Levich-Derjaguin law. The droplet is therefore oleoplaning--akin to tyres hydroplaning on a wet road--with minimal dissipative force and no contact line pinning. The techniques and insights presented in this study will inform future work on the fundamentals of wetting for lubricated surfaces and enable their rational design.

  15. Normal Contacts of Lubricated Fractal Rough Surfaces at the Atomic Scale

    NARCIS (Netherlands)

    Solhjoo, Soheil; Vakis, Antonis I.

    The friction of contacting interfaces is a function of surface roughness and applied normal load. Under boundary lubrication, this frictional behavior changes as a function of lubricant wettability, viscosity, and density, by practically decreasing the possibility of dry contact. Many studies on

  16. Pulsed Plasma Lubrication Device and Method

    Science.gov (United States)

    Hofer, Richard R. (Inventor); Bickler, Donald B. (Inventor); D'Agostino, Saverio A. (Inventor)

    2016-01-01

    Disclosed herein is a lubrication device comprising a solid lubricant disposed between and in contact with a first electrode and a second electrode dimensioned and arranged such that application of an electric potential between the first electrode and the second electrode sufficient to produce an electric arc between the first electrode and the second electrode to produce a plasma in an ambient atmosphere at an ambient pressure which vaporizes at least a portion of the solid lubricant to produce a vapor stream comprising the solid lubricant. Methods to lubricate a surface utilizing the lubrication device in-situ are also disclosed.

  17. Swimming and other activities: applied aspects of fish swimming performance

    Science.gov (United States)

    Castro-Santos, Theodore R.; Farrell, A.P.

    2011-01-01

    Human activities such as hydropower development, water withdrawals, and commercial fisheries often put fish species at risk. Engineered solutions designed to protect species or their life stages are frequently based on assumptions about swimming performance and behaviors. In many cases, however, the appropriate data to support these designs are either unavailable or misapplied. This article provides an overview of the state of knowledge of fish swimming performance – where the data come from and how they are applied – identifying both gaps in knowledge and common errors in application, with guidance on how to avoid repeating mistakes, as well as suggestions for further study.

  18. Neutron activation: an invaluable technique for teaching applied radiation

    International Nuclear Information System (INIS)

    Trainer, Matthew

    2002-01-01

    This experiment introduces students to the important method of neutron activation. A sample of aluminium was irradiated with neutrons from an isotropic 241 Am-Be source. Using γ-ray spectroscopy, two radionuclide products were identified as 27 Mg and 28 Al. Applying a cadmium cut-off filter and an optimum irradiation time of 45 min, the half-life of 27 Mg was determined as 9.46±0.50 min. The half-life of the 28 Al radionuclide was determined as 2.28±0.10 min using a polythene moderator and an optimum irradiation time of 10 min. (author)

  19. Process for the preparation of lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M

    1927-06-04

    A process is described for preparation of lubricants from mixtures of hydrocarbons or hydrocarbon derivatives of mean molecular weight and nonaromatic nature, which is characterized by halogenating the raw oil by the action of halogens or halogen-exchanging compounds and submitting the obtained product to a condensation in presence of aluminum chloride, tin chloride, iron chloride, or other condensing metal chloride or boron fluoride or activated metals, such as activated aluminum, whereby it is worked up in two steps at a temperature below 150 and preferably below 100/sup 0/C.

  20. Applied research and development of neutron activation analysis

    International Nuclear Information System (INIS)

    Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Ryel; Kim, Young Gi; Jung, Hwan Sung; Park, Kwang Won; Kang, Sang Hun; Lim, Jong Myoung

    2003-05-01

    The aims of this project are to establish the quality control system of Neutron Activation Analysis(NAA) due to increase of industrial needs for standard analytical method and to prepare and identify the standard operation procedure of NAA through practical testing for different analytical items. R and D implementations of analytical quality system using neutron irradiation facility and gamma-ray measurement system and automation of NAA facility in HANARO research reactor are as following ; 1) Establishment of NAA quality control system for the maintenance of best measurement capability and the promotion of utilization of HANARO research reactor 2) Improvement of analytical sensitivity for industrial applied technologies and establishment of certified standard procedures 3) Standardization and development of Prompt Gamma-ray Activation Analysis (PGAA) technology

  1. 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.

  2. 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.

  3. 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.

  4. Development of lubricant test for punching and blanking

    DEFF Research Database (Denmark)

    Olsson, David Dam

    2001-01-01

    The background for development of new lubricants Requirements to lubricant test for punching Methods of evaluating lubricants Test equipment developed at DTU Conclusion.......The background for development of new lubricants Requirements to lubricant test for punching Methods of evaluating lubricants Test equipment developed at DTU Conclusion....

  5. 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.

  6. Numerical analysis of all flow state lubrication performance of water-lubricated thrust bearing

    International Nuclear Information System (INIS)

    Deng Xiao; Deng Liping; Huang Wei; Liu Lizhi; Zhao Xuecen; Liu Songya

    2015-01-01

    A model enabling all different flow state lubrication performance simulation and analysis for water-lubricated thrust bearing is presented, considering the temperature influence and elastic deformation. Lubrication state in the model is changed directly from laminar lubrication to turbulent lubrication once Reynolds number exceeds the critical Reynolds number. The model is numerically solved and results show that temperature variation is too little to influence the lubrication performance; the elastic deformation can slightly reduce the load carrying capacity of the thrust bearing; and the turbulent lubrication can remarkably improve the load carrying capacity. (authors)

  7. Solar Alpha Rotary Joint (SARJ) Lubrication Interval Test and Evaluation (LITE). Post-Test Grease Analysis

    Science.gov (United States)

    Golden, Johnny L.; Martinez, James E.; Devivar, Rodrigo V.

    2015-01-01

    The Solar Alpha Rotary Joint (SARJ) is a mechanism of the International Space Station (ISS) that orients the solar power generating arrays toward the sun as the ISS orbits our planet. The orientation with the sun must be maintained to fully charge the ISS batteries and maintain all the other ISS electrical systems operating properly. In 2007, just a few months after full deployment, the starboard SARJ developed anomalies that warranted a full investigation including ISS Extravehicular Activity (EVA). The EVA uncovered unexpected debris that was due to degradation of a nitride layer on the SARJ bearing race. ISS personnel identified the failure root-cause and applied an aerospace grease to lubricate the area associated with the anomaly. The corrective action allowed the starboard SARJ to continue operating within the specified engineering parameters. The SARJ LITE (Lubrication Interval Test and Evaluation) program was initiated by NASA, Lockheed Martin, and Boeing to simulate the operation of the ISS SARJ for an extended time. The hardware was designed to test and evaluate the exact material components used aboard the ISS SARJ, but in a controlled area where engineers could continuously monitor the performance. After running the SARJ LITE test for an equivalent of 36+ years of continuous use, the test was opened to evaluate the metallography and lubrication. We have sampled the SARJ LITE rollers and plate to fully assess the grease used for lubrication. Chemical and thermal analysis of these samples has generated information that has allowed us to assess the location, migration, and current condition of the grease. The collective information will be key toward understanding and circumventing any performance deviations involving the ISS SARJ in the years to come.

  8. Activities report 1977--78. Applied mathematics department 5640

    International Nuclear Information System (INIS)

    1979-03-01

    This report is a compilation of independent articles highlighting some of the work done in the Applied Mathematics Department during the years 1977 and 1978. It is neither an exhaustive report on all activities in the department during this period nor a list of the most substantial mathematical contributions. Instead, it is a selection of topics which are thought to be of greatest interest because of their importance to Sandia. The report is divided into four principal sections which reflect the department's major areas of interest: Mathematical Physics, Computational Mathematics, Probability and Statistics, and Discrete Mathematics. To provide a smoother narrative, references are omitted from the text. However, a complete department bibliography of corporate and open publications as well as technical presentations for the period October 1977 through December 1978 is appended. 4 figures, 3 tables

  9. 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.

  10. Laboratory services series: a lubrication program

    International Nuclear Information System (INIS)

    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

  11. 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....

  12. Solid lubricants in the power station

    International Nuclear Information System (INIS)

    Gaensheimer, J.

    1981-01-01

    Example application are first outlined, followed by descriptions of inorganic solid lubricants and plastics. Waxes, soaps and salts are discussed. Notes for usage are given. Solid lubricants in oils and greases are comprehensively described, followed by the sections entitled Solid lubricants for gearboxes . References to samples, tests, standards and bibliography make up the conclusion. (orig.) [de

  13. 21 CFR 880.6375 - Patient lubricant.

    Science.gov (United States)

    2010-04-01

    ... § 880.6375 Patient lubricant. (a) Identification. A patient lubricant is a device intended for medical... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Patient lubricant. 880.6375 Section 880.6375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL...

  14. Hydrodynamic bearing lubricated with magnetic fluids

    International Nuclear Information System (INIS)

    Urreta, H; Leicht, Z; Sanchez, A; Agirre, A; Kuzhir, P; Magnac, G

    2009-01-01

    This paper summarizes the work carried out in the development of hydrodynamic lubricated journal bearings with magnetic fluids. Two different fluids have been analyzed, one ferrofluid from FERROTEC APG s10n and one magnetorheological fluid from LORD Corp., MRF122-2ED. Theoretical analysis has been carried out with numerical solutions of Reynolds equation, based on apparent viscosity modulation for ferrofluid and Bingham model for MR fluid. To validate this model, one test bench has been designed, manufactured and set up, where preliminary results shown in this paper demonstrate that magnetic fluids can be used to develop active journal bearings.

  15. Growth and opportunities in the lubricants business in Asia

    International Nuclear Information System (INIS)

    Burke, B.F.

    1995-01-01

    The demand for lubricants is increasing faster in Asia than any other part of the world. This development is being propelled largely by the expansion of the transportation and manufacturing sectors. By the year 2000, lubricant consumption in Asia will exceed that of Western Europe, Africa and the Middle East combined. Aside from this growth, most of the region is shifting from very low quality to higher quality value-added products. In view of these factors, there has been an explosion of activity over the past few years as lubricant blenders and additive suppliers attempt to position themselves within the market. Over the past year, Chem Systems has undertaken an extensive study of the lubricants business in East Asia, focusing on the evolution of this complex market structure and the identification of attractive opportunities. The overview presented in this paper is a product of these efforts. Whether you are a multinational oil company, independent blender, national oil company or multinational additive suppler, the questions are the same when developing a strategy for the region: regional overview of lubricant business structure; outlook for Asian demand; profile of lube/additives businesses; and successful competition--what is required?

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    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...

  17. Green Lubricants for Metal Forming

    DEFF Research Database (Denmark)

    Bay, Niels

    2010-01-01

    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...

  18. Self lubrication of bitumen froth in pipelines

    International Nuclear Information System (INIS)

    Joseph, D.D.

    1997-01-01

    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

  19. Controllable sliding bearings and controllable lubrication principles-an overview

    DEFF Research Database (Denmark)

    Santos, Ilmar F.

    2018-01-01

    -mechanical actuators have been coupled to such bearings. Depending on (i) the actuator type; (ii) the actuation principle, i.e., hydraulic, pneumatic, piezoelectric or magnetic among others; and (iii) how such an actuator is coupled to the sliding bearings, different regulation and control actions of fluid film...... bearing gap and its preload via moveable and compliant sliding surfaces; and (d) the control of the lubricant viscosity. All four parameters, i.e., pressure, flow (velocity profiles), gap and viscosity, are explicit parameters in the modified form of Reynolds' equations for active lubrication....... In this framework, this paper gives one main original contribution to the state-of-the-art of radial sliding bearings and controllable lubrication: a comprehensive overview about the different types of controllable sliding bearings and principles used by several authors. The paper ends with some conclusive remarks...

  20. Full Life Wind Turbine Gearbox Lubricating Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, Glenn A.; Jungk, Manfred; Bryant, Jonathan J.; Lauer, Rebecca S.; Chobot, Anthony; Mayer, Tyler; Palmer, Shane; Kauffman, Robert E.

    2012-02-28

    using PFPE as the gearbox lubricating fluid. It is important to note the largest portion of savings comes in Levelized Replacement Cost, which is dictated by the assumption on gearbox reliability. Thus, verifying and quantifying the potential of PFPE fluid to effect gearbox reliability is the key assumption that would need to be further validated. In summary the proof of concept to use PFPE fluid as wind turbine gear box lubricant was validated with this project. The increase in life time was qualitatively demonstrated and this supports the need for future activity of field trials and laboratory aging studies to quantify the predicted 20 year life. With micro-pitting being the major failure mechanism in the last years, recent publications show that white etch cracking of bearings seem to have the highest impact on wind turbine reliability. With its higher film thicknesses compared to PAO reference oils, PFPE fluids have the potential to reduce this failure occurrence as well.

  1. Risk matrix model applied to the outsourcing of logistics' activities

    Directory of Open Access Journals (Sweden)

    Fouad Jawab

    2015-09-01

    Full Text Available Purpose: This paper proposes the application of the risk matrix model in the field of logistics outsourcing. Such an application can serve as the basis for decision making regarding the conduct of a risk management in the logistics outsourcing process and allow its prevention. Design/methodology/approach: This study is based on the risk management of logistics outsourcing in the field of the retail sector in Morocco. The authors identify all possible risks and then classify and prioritize them using the Risk Matrix Model. Finally, we have come to four possible decisions for the identified risks. The analysis was made possible through interviews and discussions with the heads of departments and agents who are directly involved in each outsourced activity. Findings and Originality/value: It is possible to improve the risk matrix model by proposing more personalized prevention measures according to each company that operates in the mass-market retailing. Originality/value: This study is the only one made in the process of logistics outsourcing in the retail sector in Morocco through Label’vie as a case study. First, we had identified as thorough as we could all possible risks, then we applied the Risk Matrix Model to sort them out in an ascending order of importance and criticality. As a result, we could hand out to the decision-makers the mapping for an effective control of risks and a better guiding of the process of risk management.

  2. De-Lubrication Behavior Of Novel EBS Based Admixed Lubricant In Aluminum P/M Alloy

    Directory of Open Access Journals (Sweden)

    Oh M.C.

    2015-06-01

    Full Text Available The objective of the present research is to develop a novel lubricant for Al-Cu-Mg P/M alloy and to address the effects of the lubricant and compaction pressure on sintered properties. A lubricant mixture consisting of Ethylene Bis Stearamide, Zn-Stearate, and fatty acid was newly developed in this study, and the de-lubrication behavior was compared with that of other commercial lubricants, such as Ethylene Bis Stearamide, Zn-Stearate, and Al-Stearate. Density and transverse rupture strength of sintered materials with each lubricant were examined, respectively. The microstructural analysis was conducted using optical microscope.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    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.

  4. Identifying lubricant options for compressor bearing designs

    Science.gov (United States)

    Karnaz, J.; Seeton, C.; Dixon, L.

    2017-08-01

    Today’s refrigeration and air conditioning market is not only driven by the environmental aspects of the refrigerants, but also by the energy efficiency and reliability of system operation. Numerous types of compressor designs are used in refrigeration and air conditioning applications which means that different bearings are used; and in some cases, multiple bearing types within a single compressor. Since only one lubricant is used, it is important to try to optimize the lubricant to meet the various demands and requirements for operation. This optimization entails investigating different types of lubricant chemistries, viscosities, and various formulation options. What makes evaluating these options more challenging is the refrigerant which changes the properties of the lubricant delivered to the bearing. Once the lubricant and refrigerant interaction are understood, through various test methods, then work can start on collaborating with compressor engineers on identifying the lubricant chemistry and formulation options. These interaction properties are important to the design engineer to make decisions on the adequacy of the lubricant before compressor tests are started. This paper will discuss the process to evaluate lubricants for various types of compressors and bearing design with focus on what’s needed for current refrigerant trends. In addition, the paper will show how the lubricant chemistry choice can be manipulated through understanding of the bearing design and knowledge of interaction with the refrigerant to maximize performance. Emphasis will be placed on evaluation of synthetic lubricants for both natural and synthetic low GWP refrigerants.

  5. Single Common Powertrain Lubricant Development

    Science.gov (United States)

    2012-01-01

    this particular shortcoming of the current MIL specification lubricant lineup . Perameter: Units: Average Std. Dev. Average Std. Dev. Average...variations of each 0.2-second time block of all engagements. Test Number The run number listed on this report is a random number and is not sequential ...is not sequential . Only SwRI® can link this run number to JDQ-96, L0254054, August 3, 2010. Page 2 of3 John Deere JDQ-96 Performed using 1400

  6. Solid Lubricated Rolling Element Bearings

    Science.gov (United States)

    1979-02-15

    lubricant into uneven patches of varnish . This varnish , along with the file-like action of the exposed ball carbides on the relatively softer races, can...its structure. Fluorine , one of the most reactive elements, reacts with graphite without combustion from about 790’F to 1022°F, forming a grey-colored...to allow for molding and machining after molding. 0 Method 2 (Hughes) Impregnating these dense weaves with a Thermid 600 polyimide varnish

  7. Transition to thermohydrodynamic lubrication problem

    Czech Academy of Sciences Publication Activity Database

    Ciuperca, I. S.; Feireisl, Eduard; Jai, M.; Petrov, A.

    2017-01-01

    Roč. 75, č. 3 (2017), s. 391-414 ISSN 0033-569X EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : free boundary problems * lubrication * asymptotic approach * Stokes equation Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.788, year: 2016 http://www.ams.org/journals/qam/2017-75-03/S0033-569X-2017-01468-X/

  8. Biofluid lubrication for artificial joints

    Science.gov (United States)

    Pendleton, Alice Mae

    This research investigated biofluid lubrication related to artificial joints using tribological and rheological approaches. Biofluids studied here represent two categories of fluids, base fluids and nanostructured biofluids. Base fluids were studied through comparison of synthetic fluids (simulated body fluid and hyaluronic acid) as well as natural biofluids (from dogs, horses, and humans) in terms of viscosity and fluid shear stress. The nano-structured biofluids were formed using molecules having well-defined shapes. Understanding nano-structured biofluids leads to new ways of design and synthesis of biofluids that are beneficial for artificial joint performance. Experimental approaches were utilized in the present research. This includes basic analysis of biofluids' property, such as viscosity, fluid shear stress, and shear rate using rheological experiments. Tribological investigation and surface characterization were conducted in order to understand effects of molecular and nanostructures on fluid lubrication. Workpiece surface structure and wear mechanisms were investigated using a scanning electron microscope and a transmission electron microscope. The surface topography was examined using a profilometer. The results demonstrated that with the adding of solid additives, such as crown ether or fullerene acted as rough as the other solids in the 3-body wear systems. In addition, the fullerene supplied low friction and low wear, which designates the lubrication purpose of this particular particle system. This dissertation is constructed of six chapters. The first chapter is an introduction to body fluids, as mentioned earlier. After Chapter II, it examines the motivation and approach of the present research, Chapter III discusses the experimental approaches, including materials, experimental setup, and conditions. In Chapter IV, lubrication properties of various fluids are discussed. The tribological properties and performance nanostructured biofluids are

  9. [Research activities in applied mathematics, fluid mechanics, and computer science

    Science.gov (United States)

    1995-01-01

    This report summarizes research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, fluid mechanics, and computer science during the period April 1, 1995 through September 30, 1995.

  10. Current status of neutron activation analysis and applied nuclear chemistry

    International Nuclear Information System (INIS)

    Lyon, W.S.

    1990-01-01

    A review of recent scientometric studies of citations and publication data shows the present state of NAA and applied nuclear chemistry as compared to other analytical techniques. (author) 9 refs.; 7 tabs

  11. Used lubricants and ecological problems

    International Nuclear Information System (INIS)

    Evdokimov, A.Yu.; Dzhamalov, A.A.; Lashkhi, V.L.

    1993-01-01

    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

  12. Slippery self-lubricating polymer surfaces

    Science.gov (United States)

    Aizenberg, Joanna; Aizenberg, Michael; Cui, Jiaxi; Dunn, Stuart; Hatton, Benjamin; Howell, Caitlin; Kim, Philseok; Wong, Tak Sing; Yao, Xi

    2018-05-08

    The present disclosure describes a strategy to create self-healing, slippery self-lubricating polymers. Lubricating liquids with affinities to polymers can be utilized to get absorbed within the polymer and form a lubricant layer (of the lubricating liquid) on the polymer. The lubricant layer can repel a wide range of materials, including simple and complex fluids (water, hydrocarbons, crude oil and bodily fluids), restore liquid-repellency after physical damage, and resist ice, microorganisms and insects adhesion. Some exemplary applications where self-lubricating polymers will be useful include energy-efficient, friction-reduction fluid handling and transportation, medical devices, anti-icing, optical sensing, and as self-cleaning, and anti-fouling materials operating in extreme environments.

  13. A Review of Ionic Liquid Lubricants

    OpenAIRE

    Anthony E. Somers; Patrick C. Howlett; Douglas R. MacFarlane; Maria Forsyth

    2013-01-01

    Due to ever increasing demands on lubricants, such as increased service intervals, reduced volumes and reduced emissions, there is a need to develop new lubricants and improved wear additives. Ionic liquids (ILs) are room temperature molten salts that have recently been shown to offer many advantages in this area. The application of ILs as lubricants in a diverse range of systems has found that these materials can show remarkable protection against wear and significantly reduce friction in th...

  14. Lubricant test for punching and blanking

    DEFF Research Database (Denmark)

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

    2003-01-01

    Punching/blanking is one of the tribologically wise most severe metal forming processes.Insu $cient lubrication leads to heavy pick-up of work piece material on the punch stem,bad tolerances and eventual breakdown of the punch due to excessive backstroke force,especially in case of tribologically...... of alternative lubricants the present paper describes a new lubricant test for punching....

  15. Lubrication for hot working of titanium alloys

    International Nuclear Information System (INIS)

    Gotlib, B.M.

    1980-01-01

    The isothermal lubrication of the following composition is suggested, wt. %: aluminium powder 4-6, iron scale 15-25, vitreous enamel up to 100. The lubricant improves forming and decreases the danger of the metal fracture when titanium alloys working. It is advisable to use the suggested lubrication when stamping thin-walled products of titanium alloys at the blank temperature from 700 to 1000 deg C [ru

  16. Application of a Thermodynamic Concept for the Analysis of Structural Degradation of Soap Thickened Lubricating Greases

    Directory of Open Access Journals (Sweden)

    Erik Kuhn

    2018-01-01

    Full Text Available Lubricating greases are special lubricants with a wide range of application. The tribologically stressed grease is used as tribological system and finally modeled as an open thermodynamic system. This study investigated the phenomenon of self-optimization and applied to the process of shearing a grease. The conditions for self-optimization and the consequences of created dissipative structures are investigated according to the interpreted literature.

  17. 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.

  18. Development of High Temperature Solid Lubricant Coatings

    National Research Council Canada - National Science Library

    Bhattacharya, Rabi

    1999-01-01

    ... environment. To test this approach, UES and Cleveland State University have conducted experiments to form cesium oxythiotungstate, a high temperature lubricant, on Inconel 718 surface from composite coatings...

  19. Ecotoxicological study of used lubricating oil

    International Nuclear Information System (INIS)

    Wong, P.K.; Chan, W.L.; Wang, J.; Wong, C.K.

    1995-01-01

    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

  20. Lubrication from mixture of boric acid with oils and greases

    Science.gov (United States)

    Erdemir, Ali

    1995-01-01

    Lubricating compositions including crystalline boric acid and a base lubricant selected from oils, greases and the like. The lubricity of conventional oils and greases can also be improved by adding concentrates of boric acid.

  1. Strip reduction testing of lubricants developed during ENFORM project

    DEFF Research Database (Denmark)

    Gazvoda, S.; Andreasen, Jan Lasson; Olsson, David Dam

    Strip reduction testing of lubricants developed during ENFORM project. Experiments were conducted with the strip reduction test [1] in order to classify experimental lubricants, developed during concerned project. One reference lubricant was used during testing....

  2. Applying an Activity System to Online Collaborative Group Work Analysis

    Science.gov (United States)

    Choi, Hyungshin; Kang, Myunghee

    2010-01-01

    This study determines whether an activity system provides a systematic framework to analyse collaborative group work. Using an activity system as a unit of analysis, the research examined learner behaviours, conflicting factors and facilitating factors while students engaged in collaborative work via asynchronous computer-mediated communication.…

  3. Direct observation of lubricant additives using tomography techniques

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yunyun [Department of Materials Science and Engineering, Texas A& M University, College Station, Texas 77843 (United States); Sanchez, Carlos [Mechanical Engineering, Texas A& M University, College Station, Texas 77843 (United States); Parkinson, Dilworth Y. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Liang, Hong, E-mail: hliang@tamu.edu [Department of Materials Science and Engineering, Texas A& M University, College Station, Texas 77843 (United States); Mechanical Engineering, Texas A& M University, College Station, Texas 77843 (United States)

    2016-07-25

    Lubricants play important roles in daily activities such as driving, walking, and cooking. The current understanding of mechanisms of lubrication, particularly in mechanical systems, has been limited by the lack of capability in direct observation. Here, we report an in situ approach to directly observe the motion of additive particles in grease under the influence of shear. Using the K-edge tomography technique, it is possible to detect particular additives in a grease and observe their distribution through 3D visualization. A commercial grease as a reference was studied with and without an inorganic additive of Fe{sub 3}O{sub 4} microparticles. The results showed that it was possible to identify these particles and track their movement. Under a shear stress, Fe{sub 3}O{sub 4} particles were found to adhere to the edge of calcium complex thickeners commonly used in grease. Due to sliding, the grease formed a film with increased density. This approach enables in-line monitoring of a lubricant and future investigation in mechanisms of lubrication.

  4. Nuclear fuel handling grapple carriage with self-lubricating bearing

    International Nuclear Information System (INIS)

    Wade, E.E.

    1978-01-01

    Disclosed is a nuclear fuel handling grapple carriage having a bearing with a lubricant reservoir that is capable of being refilled when the bearing and reservoir are submerged in a lubricant pool. The lubricant reservoir supplies lubricant to the bearing while the bearing allows a small amount of lubricant to leak passed appropriately placed seals creating a positive out flow of lubricant thereby preventing foreign material from entering the bearing

  5. Use of high-molecular compounds in plastic lubricants for geological exploratory drilling

    Energy Technology Data Exchange (ETDEWEB)

    Smyk, Z.I.; Kuz' michev, S.P.; Mnishchenko, V.G.; Smertenko, M.I.

    1982-01-01

    The existing lubricants in the series KAVS (OST 81-4-70) do not correspond to the conditions of high-rotational diamond drilling for a number of operating properties. Results are presented of studying the hydrated calcium lubricants with high molecular additives (polyisobutylene KP-10, polyethylene of high density of low pressure and atactic propylene in a quantity of 1-6%) improving their operating properties. Selection of the additives is governed by their compatability with the base and the capacity to improve the adhesion-cohesion properties with relative constancy of other characteristics. As a result of the studies it was established that the use in the lubricant of polymers of the carbon-chain type of amorphous structure in a quantity of 1-2% depending on the molecular weight noticeably improves the stickiness, resistance to erosion by water, colloidal stability, and lubricant properties. When they are added in a large quantity, a sharp weakening of the lubricants is observed and in individual cases, formation of unstable systems. Polymers of the hetero-chain type because of the presence of polar groups are highly effective adhesives. Protective and packing lubricants are developed which contain rubbers. Alkyl-phenol-amine resins (octophor-N), the bottoms from the production of phenol formaldehyde resin, rosin and lignite wax introduced at the stage of cooling have a positive effect on the lubricant properties. The best operating properties with satisfactory other indicators (viscosity, colloidal stability, antiwear properties) are found in the samples containing polyisobutylene KP-10, lignite wax and rosin. Operating tests of an experimental batch of this lubricant under conditions of real drilling indicated that its use as compared to KEVS-45 makes it possible to increase the drilling rate by 40%, reduce the outlays of power to 50%, reduce the service time and the outlays of energy resources for applying the lubricant layer to the pipe surface.

  6. Idemitsu Kosan establishes the lubricating oil marketer in Shanghai; Idemitsu, Shanhai ni junkatsuyu hansha

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-01

    Idemitsu Kosan established 100% marketer 'Shanghai rising light lubricating oil trade limited company (SIL)' of the lubricating oil in China and Shanghai on 28th, and it was announced that the business activity was done from July first. Toshifumi Okubo (lubricating oil division three sections) takes to the president placed headquarters at (about 24000000 yen) 200000 dollar in the Shanghai outside high bridge bond ward new company capital. Employees are the 5 persons. The first year 3000 kilo liter is being estimated at the sales of (about six hundred million yen) 5 million dollar. (translated by NEDO)

  7. Physical Activity and Wellness: Applied Learning through Collaboration

    Science.gov (United States)

    Long, Lynn Hunt; Franzidis, Alexia

    2015-01-01

    This article describes how two university professors teamed up to initiate a university-sponsored physical activity and wellness expo in an effort to promote an authentic and transformative learning experience for preservice students.

  8. Applying activity-based costing to healthcare settings.

    Science.gov (United States)

    Canby, J B

    1995-02-01

    Activity-based costing (ABC) focuses on processes that drive cost. By tracing healthcare activities back to events that generate cost, a more accurate measurement of financial performance is possible. This article uses ABC principles and techniques to determine costs associated with the x-ray process in a midsized outpatient clinic. The article also provides several tips for initiating an ABC cost system for an entire healthcare organization.

  9. Improved Ionic Liquids as Space Lubricants, Phase I

    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. Modification of lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Kajdas, C.; Dabrowski, J.; Dominiak, M.; Sulko, M.

    1982-09-30

    Use of a powder produced during polishing of leather (as a modifying agent) is suggested. The amount is greater than or equal to 0.1% separately, or in concert with other known modifying additives. The principal component of this additive, produced during leather polishing, is collagen. It substantially increases resistance of the oil to acidic activity and formation of ferments, as well as the anticorrosion and antioxidant properties. Properties of the modifying agent depend on the technology used in tanning; the best characteristics are present when Cr compounds are used during the tanning process. Example: base oil with a 52 sSt/50/sup 0/ viscosity is placed into a mixer, and with intensive agitation gradually add 5% powder derived from leather polishing, and containing, as a tanning residue, 3% Cr/sub 2/0/sub 3/. After powder is added, agitation is continued for 1 hour and then the mixture is homogenized. On a four-bearing friction machine, the produced oil shows a sticking load of 250 kg and a diamt of wear of 1.0 mm with a load of 200 kg. For the base oil, the corresponding indicators are 130 kg and 2.7 mm with a loading of 120 kg. One more example of the process is included.

  11. Neighborhood Design, Physical Activity, and Wellbeing: Applying the Walkability Model

    Directory of Open Access Journals (Sweden)

    Adriana A. Zuniga-Teran

    2017-01-01

    Full Text Available Neighborhood design affects lifestyle physical activity, and ultimately human wellbeing. There are, however, a limited number of studies that examine neighborhood design types. In this research, we examine four types of neighborhood designs: traditional development, suburban development, enclosed community, and cluster housing development, and assess their level of walkability and their effects on physical activity and wellbeing. We examine significant associations through a questionnaire (n = 486 distributed in Tucson, Arizona using the Walkability Model. Among the tested neighborhood design types, traditional development showed significant associations and the highest value for walkability, as well as for each of the two types of walking (recreation and transportation representing physical activity. Suburban development showed significant associations and the highest mean values for mental health and wellbeing. Cluster housing showed significant associations and the highest mean value for social interactions with neighbors and for perceived safety from crime. Enclosed community did not obtain the highest means for any wellbeing benefit. The Walkability Model proved useful in identifying the walkability categories associated with physical activity and perceived crime. For example, the experience category was strongly and inversely associated with perceived crime. This study provides empirical evidence of the importance of including vegetation, particularly trees, throughout neighborhoods in order to increase physical activity and wellbeing. Likewise, the results suggest that regular maintenance is an important strategy to improve mental health and overall wellbeing in cities.

  12. Neighborhood Design, Physical Activity, and Wellbeing: Applying the Walkability Model.

    Science.gov (United States)

    Zuniga-Teran, Adriana A; Orr, Barron J; Gimblett, Randy H; Chalfoun, Nader V; Guertin, David P; Marsh, Stuart E

    2017-01-13

    Neighborhood design affects lifestyle physical activity, and ultimately human wellbeing. There are, however, a limited number of studies that examine neighborhood design types. In this research, we examine four types of neighborhood designs: traditional development, suburban development, enclosed community, and cluster housing development, and assess their level of walkability and their effects on physical activity and wellbeing. We examine significant associations through a questionnaire ( n = 486) distributed in Tucson, Arizona using the Walkability Model. Among the tested neighborhood design types, traditional development showed significant associations and the highest value for walkability, as well as for each of the two types of walking (recreation and transportation) representing physical activity. Suburban development showed significant associations and the highest mean values for mental health and wellbeing. Cluster housing showed significant associations and the highest mean value for social interactions with neighbors and for perceived safety from crime. Enclosed community did not obtain the highest means for any wellbeing benefit. The Walkability Model proved useful in identifying the walkability categories associated with physical activity and perceived crime. For example, the experience category was strongly and inversely associated with perceived crime. This study provides empirical evidence of the importance of including vegetation, particularly trees, throughout neighborhoods in order to increase physical activity and wellbeing. Likewise, the results suggest that regular maintenance is an important strategy to improve mental health and overall wellbeing in cities.

  13. Applying active learning to supervised word sense disambiguation in MEDLINE

    Science.gov (United States)

    Chen, Yukun; Cao, Hongxin; Mei, Qiaozhu; Zheng, Kai; Xu, Hua

    2013-01-01

    Objectives This study was to assess whether active learning strategies can be integrated with supervised word sense disambiguation (WSD) methods, thus reducing the number of annotated samples, while keeping or improving the quality of disambiguation models. Methods We developed support vector machine (SVM) classifiers to disambiguate 197 ambiguous terms and abbreviations in the MSH WSD collection. Three different uncertainty sampling-based active learning algorithms were implemented with the SVM classifiers and were compared with a passive learner (PL) based on random sampling. For each ambiguous term and each learning algorithm, a learning curve that plots the accuracy computed from the test set as a function of the number of annotated samples used in the model was generated. The area under the learning curve (ALC) was used as the primary metric for evaluation. Results Our experiments demonstrated that active learners (ALs) significantly outperformed the PL, showing better performance for 177 out of 197 (89.8%) WSD tasks. Further analysis showed that to achieve an average accuracy of 90%, the PL needed 38 annotated samples, while the ALs needed only 24, a 37% reduction in annotation effort. Moreover, we analyzed cases where active learning algorithms did not achieve superior performance and identified three causes: (1) poor models in the early learning stage; (2) easy WSD cases; and (3) difficult WSD cases, which provide useful insight for future improvements. Conclusions This study demonstrated that integrating active learning strategies with supervised WSD methods could effectively reduce annotation cost and improve the disambiguation models. PMID:23364851

  14. Applying active learning to supervised word sense disambiguation in MEDLINE.

    Science.gov (United States)

    Chen, Yukun; Cao, Hongxin; Mei, Qiaozhu; Zheng, Kai; Xu, Hua

    2013-01-01

    This study was to assess whether active learning strategies can be integrated with supervised word sense disambiguation (WSD) methods, thus reducing the number of annotated samples, while keeping or improving the quality of disambiguation models. We developed support vector machine (SVM) classifiers to disambiguate 197 ambiguous terms and abbreviations in the MSH WSD collection. Three different uncertainty sampling-based active learning algorithms were implemented with the SVM classifiers and were compared with a passive learner (PL) based on random sampling. For each ambiguous term and each learning algorithm, a learning curve that plots the accuracy computed from the test set as a function of the number of annotated samples used in the model was generated. The area under the learning curve (ALC) was used as the primary metric for evaluation. Our experiments demonstrated that active learners (ALs) significantly outperformed the PL, showing better performance for 177 out of 197 (89.8%) WSD tasks. Further analysis showed that to achieve an average accuracy of 90%, the PL needed 38 annotated samples, while the ALs needed only 24, a 37% reduction in annotation effort. Moreover, we analyzed cases where active learning algorithms did not achieve superior performance and identified three causes: (1) poor models in the early learning stage; (2) easy WSD cases; and (3) difficult WSD cases, which provide useful insight for future improvements. This study demonstrated that integrating active learning strategies with supervised WSD methods could effectively reduce annotation cost and improve the disambiguation models.

  15. 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.

  16. 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.

  17. The Lubricity of Glycerol and its Solutions

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, J.

    2016-01-01

    Glycerol has been recognised as an excellent diesel fuel and lubricant. It is a liquid that can originate from the transesterification of plant oil that also results in plant oil metyl (or ethyl) ester (biodiesel). Machine elements lubricated by glycerol show very low friction, in fact lower than...

  18. Ionic liquids as lubricant additives: A review

    International Nuclear Information System (INIS)

    Zhou, Yan; Qu, Jun

    2016-01-01

    In pursuit of energy efficiency and durability throughout human history, advances in lubricants have always played important roles. Ionic liquids (ILs) are room-temperature molten salts that possess unique physicochemical properties and have shown great potential in many applications with lubrication as one of the latest. While earlier work (2001–2011) primarily explored the feasibility of using ILs as neat or base lubricants, using ILs as lubricant additives has become the new focal research topic since the breakthrough in ILs’ miscibility in nonpolar hydrocarbon oils in early 2012. This work reviews the recent advances in developing ILs as additives for lubrication with an attempt to correlate among the cationic and anionic structures, oil-solubility, and other relevant physicochemical properties, and lubricating behavior. Effects of the concentration of ILs in lubricants and the compatibility between ILs and other additives in the lubricant formulation on the tribological performance are described followed by a discussion of wear protection mechanism based on tribofilm characterization. As a result, future research directions are suggested at the end.

  19. A Biomimetic Approach to Lubricate Engineering Materials

    DEFF Research Database (Denmark)

    Røn, Troels

    lubrication characteristic is dominant via ‘selfhealing’ mechanism. The glycosylated FpHYD5 revealed a better lubrication than HFBI. Two type II hydrophobins function more favorably compared to synthetic amphiphilic copolymer, PEO-PPO-PEO, with a similar molecular weight. This is ascribed to higher amount...

  20. Lubricity characteristics of marine distillate fuels

    Energy Technology Data Exchange (ETDEWEB)

    Crutchley, Ian [Innospec Fuel Specialties, Ellesmere Port (United Kingdom); Green, Michael [Intertek Lintec ShipCare Services, Darlington (United Kingdom)

    2012-08-15

    This article from Innospec Fuel Specialties, Ellesmere Port, UK, and Intertek Lintec ShipCare Services, Darlington, UK, examines the lubricity characteristics of marine distillate fuels available today in relation to the requirements and limits imposed in ISO8217:2010. It will estimate expected failure rates and also asses the perceived relationship between lubricity, sulphur content and viscosity. (orig.)

  1. Applied research and development of neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Bak, Sung Ryel; Park, Yong Chul; Kim, Young Ki; Chung, Hwan Sung; Park, Kwang Won; Kang, Sang Hun

    2000-05-01

    This report is written for results of research and development as follows : improvement of neutron irradiation facilities, counting system and development of automation system and capsules for NAA in HANARO ; improvement of analytical procedures and establishment of analytical quality control and assurance system; applied research and development of environment, industry and human health and its standardization. For identification and standardization of analytical method, environmental biological samples and polymer are analyzed and uncertainity of measurement are estimated. Also data intercomparison and proficency test were performed. Using airborne particulate matter chosen as a environmental indicators, trace elemental concentrations of sample collected at urban and rural site are determined and then the calculation of statistics and the factor analysis are carried out for investigation of emission source. International cooperation research project was carried out for utilization of nuclear techniques.

  2. Applied research and development of neutron activation analysis

    International Nuclear Information System (INIS)

    Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Bak, Sung Ryel; Park, Yong Chul; Kim, Young Ki; Chung, Hwan Sung; Park, Kwang Won; Kang, Sang Hun

    2000-05-01

    This report is written for results of research and development as follows : improvement of neutron irradiation facilities, counting system and development of automation system and capsules for NAA in HANARO ; improvement of analytical procedures and establishment of analytical quality control and assurance system; applied research and development of environment, industry and human health and its standardization. For identification and standardization of analytical method, environmental biological samples and polymer are analyzed and uncertainity of measurement are estimated. Also data intercomparison and proficency test were performed. Using airborne particulate matter chosen as a environmental indicators, trace elemental concentrations of sample collected at urban and rural site are determined and then the calculation of statistics and the factor analysis are carried out for investigation of emission source. International cooperation research project was carried out for utilization of nuclear techniques

  3. The effects of ion implantation on the tribology of perfluoropolyether-lubricated 440C stainless steel couples

    Science.gov (United States)

    Shogrin, Bradley; Jones, William R., Jr.; Wilbur, Paul J.; Pilar, Herrera-Fierro; Williamson, Don L.

    1995-01-01

    The lubricating lifetime of thin films of a perfluoropolyether (PFPE) based on hexafluoropropene oxide in the presence of ion implanted 440C stainless steel is presented. Stainless steel discs, either unimplanted or implanted with N2, C, Ti, Ti + N2, or Ti + C had a thin film of PFPE (60-400 A) applied to them reproducibly (+/- 20 percent) and uniformly (+/- 15 percent) using a device developed for this study. The lifetimes of these films were quantified by measuring the number of sliding-wear cycles required to induce an increase in the friction coefficient from an initial value characteristic of the lubricated wear couple to a final, or failure value, characteristic of an unlubricated, unimplanted couple. The tests were performed in a dry nitrogen atmosphere (less than 1 percent RH) at room temperature using a 3 N normal load with a relative sliding speed of 0.05 m/s. The lubricated lifetime of the 440C couple was increased by an order of magnitude by implanting the disc with Ti. Ranked from most to least effective, the implanted species were: Ti; Ti+C; unimplanted; N2; C approximately equals Ti+N2. The mechanism postulated to explain these results involves the formation of a passivating or reactive layer which inhibits or facilitates the production of active sites. The corresponding surface microstructures induced by ion implantation, obtained using x-ray diffraction and conversion electron Mossbauer spectroscopy, ranked from most to least effective in enhancing lubricant lifetime were: amorphous Fe-Cr-Ti; amorphous Fe-Cr-Ti-C + TiC; unimplanted; epsilon-(Fe,Cr)(sub x)N, x = 2 or 3; amorphous Fe-Cr-C approximately equals amorphous Fe-Cr-Ti-N.

  4. Neutron activation analysis applied to nutritional and foodstuff studies

    International Nuclear Information System (INIS)

    Maihara, Vera A.; Santos, Paola S.; Moura, Patricia L.C.; Castro, Lilian P. de; Avegliano, Roseane P.

    2009-01-01

    Neutron Activation Analysis, NAA, has been successfully used on a regularly basis in several areas of nutrition and foodstuffs. NAA has become an important and useful research tool due to the methodology's advantages. These include high accuracy, small quantities of samples and no chemical treatment. This technique allows the determination of important elements directly related to human health. NAA also provides data concerning essential and toxic concentrations in foodstuffs and specific diets. In this paper some studies in the area of nutrition which have been carried out at the Neutron Activation Laboratory of IPEN/CNEN-SP will be presented: a Brazilian total diet study: nutritional element dietary intakes of Sao Paulo state population; a study of trace element in maternal milk and the determination of essential trace elements in some edible mushrooms. (author)

  5. Study the active site of flavonoid applying radiation chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Wu Jilan; Sun Gang; Zhang Fugen; He Yongke; Li Jiuqiang [Department of Technical Physics, Peking Univ., Beijing (China)

    2000-03-01

    Flavonoid are a large and important class of naturally occurring, low molecular weight benzo-{gamma}-pyrone derivatives which are reported to have a myriad of biological activities, but the study on the active sites of flavonoids is still ambiguous. In this paper, rutin, quercetin and baicalin have been selected as model compounds. It is well known that rutin is used in inhibiting arteriosclerosis and baicalin is antibacterial and antiviral. They have similar basic structure, but their medicinal properties are so different, why? As most flavonoids contain carbonyl group, which can capture electron effectively, we predict that flavonoids can capture electron to form radical anion. The formation of anion radical may have influence on the mitochondrial electron transport chain. The difference in the ability of forming anion radical may cause the difference in their medicinal effects. (author)

  6. Study the active site of flavonoid applying radiation chemistry

    International Nuclear Information System (INIS)

    Wu Jilan; Sun Gang; Zhang Fugen; He Yongke; Li Jiuqiang

    2000-01-01

    Flavonoid are a large and important class of naturally occurring, low molecular weight benzo-γ-pyrone derivatives which are reported to have a myriad of biological activities, but the study on the active sites of flavonoids is still ambiguous. In this paper, rutin, quercetin and baicalin have been selected as model compounds. It is well known that rutin is used in inhibiting arteriosclerosis and baicalin is antibacterial and antiviral. They have similar basic structure, but their medicinal properties are so different, why? As most flavonoids contain carbonyl group, which can capture electron effectively, we predict that flavonoids can capture electron to form radical anion. The formation of anion radical may have influence on the mitochondrial electron transport chain. The difference in the ability of forming anion radical may cause the difference in their medicinal effects. (author)

  7. Neutron-activation analysis of natural water applied to hydrogeology

    Energy Technology Data Exchange (ETDEWEB)

    Landstroem, O [AB Atomenergi, Stockholm (Sweden); Wenner, C G [Stockholm Univ. (Sweden). Dept. of Quaternary Research

    1965-12-15

    The natural content of elements in water has been utilized to characterize different groundwater supplies and reveal the presence of groundwater streams. A neutron-activation method including chemical group separation techniques has been used for the determination of trace elements. Analyzed water samples from three different places in northern Sweden illustrate the application to common and important hydrogeological problems, such as the quality and capacity of water supplies, the origin and existence of groundwater streams and groundwater exchange with rivers.

  8. Neutron-activation analysis of natural water applied to hydrogeology

    International Nuclear Information System (INIS)

    Landstroem, O.; Wenner, C.G.

    1965-12-01

    The natural content of elements in water has been utilized to characterize different groundwater supplies and reveal the presence of groundwater streams. A neutron-activation method including chemical group separation techniques has been used for the determination of trace elements. Analyzed water samples from three different places in northern Sweden illustrate the application to common and important hydrogeological problems, such as the quality and capacity of water supplies, the origin and existence of groundwater streams and groundwater exchange with rivers

  9. Lubricants : the lifeblood of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Tremblay, Y. [Petro-Canada, Calgary, AB (Canada)

    2009-07-01

    With the significant investments in wind turbine equipment, companies need to exercise due diligence when it comes to the types of lubricants and fluids used. Mechanical and equipment issues can often be eliminated with improved maintenance practices and the appropriate selection of lubricants. This presentation discussed lubricants as being the lifeblood of wind turbines. The presentation first provided an overview and discussed wind turbine trends and application trends. The technical aspects of fluid formation were presented. Lubrication maintenance practices and oil monitoring were discussed. Last, key industry tests, and OEM specifications for bearings, gearboxes, and wind turbines were identified. It was concluded that improved maintenance practices in combination with the correct lubricant selection can address several operating problems. figs.

  10. Lubricant Test Methods for Sheet Metal Forming

    DEFF Research Database (Denmark)

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

    2008-01-01

    appearing in different sheet forming operations such as stretch forming, deep drawing, ironing and punching. The laboratory tests have been especially designed to model the conditions in industrial production. Application of the tests for evaluating new lubricants before introducing them in production has......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...... oils in order to avoid galling. The present paper describes a systematic research in the development of new, environmentally harmless lubricants focusing on the lubricant testing aspects. A system of laboratory tests has been developed to study the lubricant performance under the very varied conditions...

  11. A model of synovial fluid lubricant composition in normal and injured joints

    Directory of Open Access Journals (Sweden)

    M E Blewis

    2007-03-01

    Full Text Available The synovial fluid (SF of joints normally functions as a biological lubricant, providing low-friction and low-wear properties to articulating cartilage surfaces through the putative contributions of proteoglycan 4 (PRG4, hyaluronic acid (HA, and surface active phospholipids (SAPL. These lubricants are secreted by chondrocytes in articular cartilage and synoviocytes in synovium, and concentrated in the synovial space by the semi-permeable synovial lining. A deficiency in this lubricating system may contribute to the erosion of articulating cartilage surfaces in conditions of arthritis. A quantitative intercompartmental model was developed to predict in vivo SF lubricant concentration in the human knee joint. The model consists of a SF compartment that (a is lined by cells of appropriate types, (b is bound by a semi-permeable membrane, and (c contains factors that regulate lubricant secretion. Lubricant concentration was predicted with different chemical regulators of chondrocyte and synoviocyte secretion, and also with therapeutic interventions of joint lavage and HA injection. The model predicted steady-state lubricant concentrations that were within physiologically observed ranges, and which were markedly altered with chemical regulation. The model also predicted that when starting from a zero lubricant concentration after joint lavage, PRG4 reaches steady-state concentration ~10-40 times faster than HA. Additionally, analysis of the clearance rate of HA after therapeutic injection into SF predicted that the majority of HA leaves the joint after ~1-2 days. This quantitative intercompartmental model allows integration of biophysical processes to identify both environmental factors and clinical therapies that affect SF lubricant composition in whole joints.

  12. Prompt gamma cold neutron activation analysis applied to biological materials

    International Nuclear Information System (INIS)

    Rossbach, M.; Hiep, N.T.

    1992-01-01

    Cold neutrons at the external neutron guide laboratory (ELLA) of the KFA Juelich are used to demonstrate their profitable application for multielement characterization of biological materials. The set-up and experimental conditions of the Prompt Gamma Cold Neutron Activation Analysis (PGCNAA) device is described in detail. Results for C, H, N, S, K, B, and Cd using synthetic standards and the 'ratio' technique for calculation are reported for several reference materials and prove the method to be reliable and complementary with respect to the elements being determined by INAA. (orig.)

  13. Applying Standard Industrial Components for Active Magnetic Bearings

    Directory of Open Access Journals (Sweden)

    Bert-Uwe Koehler

    2017-02-01

    Full Text Available With the increasing number of active magnetic bearing applications, satisfying additional requirements is becoming increasingly more important. As for every technology, moving away from being a niche product and achieving a higher level of maturity, these requirements relate to robustness, reliability, availability, safety, security, traceability, certification, handling, flexibility, reporting, costs, and delivery times. Employing standard industrial components, such as those from flexible modular motion control drive systems, is an approach that allows these requirements to be satisfied while achieving rapid technological innovation. In this article, we discuss technical and non-technical aspects of using standard industrial components in magnetic bearing applications.

  14. 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...

  15. Inducing in situ, nonlinear soil response applying an active source

    Science.gov (United States)

    Johnson, P.A.; Bodin, P.; Gomberg, J.; Pearce, F.; Lawrence, Z.; Menq, F.-Y.

    2009-01-01

    [1] It is well known that soil sites have a profound effect on ground motion during large earthquakes. The complex structure of soil deposits and the highly nonlinear constitutive behavior of soils largely control nonlinear site response at soil sites. Measurements of nonlinear soil response under natural conditions are critical to advancing our understanding of soil behavior during earthquakes. Many factors limit the use of earthquake observations to estimate nonlinear site response such that quantitative characterization of nonlinear behavior relies almost exclusively on laboratory experiments and modeling of wave propagation. Here we introduce a new method for in situ characterization of the nonlinear behavior of a natural soil formation using measurements obtained immediately adjacent to a large vibrator source. To our knowledge, we are the first group to propose and test such an approach. Employing a large, surface vibrator as a source, we measure the nonlinear behavior of the soil by incrementally increasing the source amplitude over a range of frequencies and monitoring changes in the output spectra. We apply a homodyne algorithm for measuring spectral amplitudes, which provides robust signal-to-noise ratios at the frequencies of interest. Spectral ratios are computed between the receivers and the source as well as receiver pairs located in an array adjacent to the source, providing the means to separate source and near-source nonlinearity from pervasive nonlinearity in the soil column. We find clear evidence of nonlinearity in significant decreases in the frequency of peak spectral ratios, corresponding to material softening with amplitude, observed across the array as the source amplitude is increased. The observed peak shifts are consistent with laboratory measurements of soil nonlinearity. Our results provide constraints for future numerical modeling studies of strong ground motion during earthquakes.

  16. Research on a lubricating grease print process for cylindrical cylinder

    Science.gov (United States)

    Yang, Liu; Zhang, Xuan; Wang, XianYan; Tan, XiaoYan

    2017-09-01

    In vehicle braking system and clutch system of transmission, there is always a kind of cylindrical component dose reciprocating motion. The main working method is the reciprocating motion between the rubber sealing parts and cylindrical parts, the main factor affects the service life of the product is the lubricating performance of the moving parts. So the lubricating performance between cylinders and rubber sealing rings is particularly important, same as the quality of the grease applies on the surface of the surface of cylinder. Traditional method of manually applying grease has some defects such as applying unevenly, applying tools like brush and cloth easily falls off and affect the cleanness of products, contact skin easily cause allergy, waste grease due to the uncontrollable of grease quantity using in applying, low efficiency of manual operation. An automatic, quantitative and high pressure applying equipment is introduced in this document to replace the traditional manually applying method, which can guarantee the applying quality of the grease which are painted on the surface of cylinder and bring economic benefits to the company.

  17. Lubrication of ceramics in ring/cylinder applications

    International Nuclear Information System (INIS)

    Gaydos, P.A.; Dufrane, K.F.

    1989-01-01

    In support of efforts to apply ceramics to advanced heat engines, a study was performed of the wear mechanisms of ceramics at the ring/cylinder interface. A laboratory apparatus was constructed to reproduce most of the conditions of an actual engine but used easily prepared ring and cylinder specimens to facilitate their fabrication. Plasma-sprayed coatings of Cr 2 O 3 and hypersonic flame-sprayed coatings of cobalt-bonded WC performed particularly well as ring coatings. Similar performance was obtained with these coatings operating against SiC, Si 3 N 4 , SiC whisker-reinforced Al 2 O 3 and Cr 2 O 2 coatings. The study demonstrated the critical need for lubrication and evaluated the performance of two available lubricants

  18. Development of seismic support snubber using solid lubricant

    International Nuclear Information System (INIS)

    Sunakoda, Katsuaki; Akimoto, Kohichi; Uchi, Toshiyasu

    1990-01-01

    Solid lubricant MoS 2 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 MoS 2 films was maintained throughout 720 hours of exposure at a temperature of 200 degC. The endurance life of MoS 2 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)

  19. APPLYING PETRI NETS EXTENSIONS TO MODELING COMMERCIAL BANK ACTIVITY

    Directory of Open Access Journals (Sweden)

    Igor ENICOV

    2017-02-01

    Full Text Available The relevance of the study is determined by the need to improve the methods of modeling andsimulating commercial bank activity, including for the purpose of calculating, controlling and managingthe risk of the bank, in the context of the transition to the application of Basel III standards. Thisimprovement becomes necessary due to a direct transition to new regulatory standards when the internalassessments of the main risks become the initial data for calculating the capital adequacy of a bank. Thepurpose of this article is to argue the opportunity to formulate a theory of the commercial bank model onthe extensions of Petri nets theory. The main methods of research were the method of scientific abstractionand method of logical analysis. The main result obtained in the study and presented in the article is theargumentation of the possibility to analyze the quantitative and qualitative characteristics of acommercial bank with the help of Petri net extensions.

  20. Active Learning Techniques Applied to an Interdisciplinary Mineral Resources Course.

    Science.gov (United States)

    Aird, H. M.

    2015-12-01

    An interdisciplinary active learning course was introduced at the University of Puget Sound entitled 'Mineral Resources and the Environment'. Various formative assessment and active learning techniques that have been effective in other courses were adapted and implemented to improve student learning, increase retention and broaden knowledge and understanding of course material. This was an elective course targeted towards upper-level undergraduate geology and environmental majors. The course provided an introduction to the mineral resources industry, discussing geological, environmental, societal and economic aspects, legislation and the processes involved in exploration, extraction, processing, reclamation/remediation and recycling of products. Lectures and associated weekly labs were linked in subject matter; relevant readings from the recent scientific literature were assigned and discussed in the second lecture of the week. Peer-based learning was facilitated through weekly reading assignments with peer-led discussions and through group research projects, in addition to in-class exercises such as debates. Writing and research skills were developed through student groups designing, carrying out and reporting on their own semester-long research projects around the lasting effects of the historical Ruston Smelter on the biology and water systems of Tacoma. The writing of their mini grant proposals and final project reports was carried out in stages to allow for feedback before the deadline. Speakers from industry were invited to share their specialist knowledge as guest lecturers, and students were encouraged to interact with them, with a view to employment opportunities. Formative assessment techniques included jigsaw exercises, gallery walks, placemat surveys, think pair share and take-home point summaries. Summative assessment included discussion leadership, exams, homeworks, group projects, in-class exercises, field trips, and pre-discussion reading exercises

  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. 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

  3. Characterization of used lubricating oil by spectrometric techniques

    International Nuclear Information System (INIS)

    Souza, Andressa Moreira de; Correa, Sergio Machado; Silva, Glauco Correa da

    2011-01-01

    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 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 R 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

  4. Double angle seal forming lubricant film

    Science.gov (United States)

    Ernst, William D.

    1984-01-01

    A lubricated piston rod seal which inhibits gas leaking from a high pressure chamber on one side of the seal to a low pressure chamber on the other side of the seal. A liquid is supplied to the surface of the piston rod on the low pressure side of the seal. This liquid acts as lubricant for the seal and provides cooling for the rod. The seal, which can be a plastic, elastomer or other material with low elastic modulus, is designed to positively pump lubricant through the piston rod/seal interface in both directions when the piston rod is reciprocating. The capacity of the seal to pump lubricant from the low pressure side to the high pressure side is less than its capacity to pump lubricant from the high pressure side to the low pressure side which ensures that there is zero net flow of lubricant to the high pressure side of the seal. The film of lubricant between the seal and the rod minimizes any sliding contact and prevents the leakage of gas. Under static conditions gas leakage is prevented by direct contact between the seal and the rod.

  5. Nanopolishing by colloidal nanodiamond in elastohydrodynamic lubrication

    Energy Technology Data Exchange (ETDEWEB)

    Shirvani, Khosro A., E-mail: Khosro.asgharishir@bison.howard.edu; Mosleh, Mohsen; Smith, Sonya T. [Howard University, Department of Mechanical Engineering (United States)

    2016-08-15

    In this paper, the feasibility of using explosion synthesized diamond nanoparticles with an average particle size (APS) of 3–5 nm with a concentration of 1 % by weight for improving lubrication and friction in elastohydrodynamic lubrication (EHL) was investigated. Owing to the orders of magnitude increase in the viscosity of the lubricant in the EHL contact zone, diamond nanoparticles in the lubricant polish the surfaces at the nanoscale which decreases the composite roughness of contacting surfaces. The reduced composite roughness results in an increased film thickness ratio which yields lower friction. In the numerical analysis, governing equations of lubricant flow in the full elastohydrodynamic lubrication were solved, and the shear stress distribution over the fluid film was calculated. Using an abrasion model and the shear stress distribution profile, the material removal by the nanofluid containing nanoparticles and the resultant surface roughness were determined. The numerical analysis showed that in full EHL regime, the nanolubricant can reduce the composite roughness of moving surfaces. Experimental results from prior studies which exhibited surface polishing by such nanolubricants in boundary, mixed, and full elastohydrodynamic lubrication were used for comparison to the numerical model.

  6. Nanopolishing by colloidal nanodiamond in elastohydrodynamic lubrication

    Science.gov (United States)

    Shirvani, Khosro A.; Mosleh, Mohsen; Smith, Sonya T.

    2016-08-01

    In this paper, the feasibility of using explosion synthesized diamond nanoparticles with an average particle size (APS) of 3-5 nm with a concentration of 1 % by weight for improving lubrication and friction in elastohydrodynamic lubrication (EHL) was investigated. Owing to the orders of magnitude increase in the viscosity of the lubricant in the EHL contact zone, diamond nanoparticles in the lubricant polish the surfaces at the nanoscale which decreases the composite roughness of contacting surfaces. The reduced composite roughness results in an increased film thickness ratio which yields lower friction. In the numerical analysis, governing equations of lubricant flow in the full elastohydrodynamic lubrication were solved, and the shear stress distribution over the fluid film was calculated. Using an abrasion model and the shear stress distribution profile, the material removal by the nanofluid containing nanoparticles and the resultant surface roughness were determined. The numerical analysis showed that in full EHL regime, the nanolubricant can reduce the composite roughness of moving surfaces. Experimental results from prior studies which exhibited surface polishing by such nanolubricants in boundary, mixed, and full elastohydrodynamic lubrication were used for comparison to the numerical model.

  7. 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...

  8. From red cells to soft porous lubrication.

    Science.gov (United States)

    Wu, Qianhong; Zhu, Zenghao; Nathan, Rungun

    2017-11-01

    In this paper, we report a novel experimental study to examine the lubrication theory for highly compressible porous media (Feng & Weinbaum, JFM, 422, 282, 2000), which was applied to the frictionless motion of red cells over the endothelial surface layer (ESL). The experimental setup consists of a running conveyer belt covered with a porous sheet, and an upper planar board, i.e. planing surface. The pore pressure generation was captured when the planing surface glides over the porous sheet. If the lateral leakage was eliminated, we found that the overall pore pressure's contribution to the total lift, fair 80%, and the friction coefficient η = 0.0981, when U =5 m/s, L =0.381 m, λ = h2/h0 = 1 and k =h2/h1 = 3, where U is the velocity of the conveyor belt; L is the planing surface length; h0, h1 and h2 are the undeformed, leading and trailing edge porous layer thickness, respectively. fair increases with the increase in U, λ and L, while decreases with the increase in k. η decreases with the increase in fair. If lateral pressure leakage exists, the pore pressure generation is reduced by nearly 90%. All the results agreed well with the theoretical predictions. The study here lays the foundation for applying soft porous media for new type of bearing with significantly reduced friction. This research was supported by the National Science Foundation (NSF CBET) under Award No. 1511096.

  9. 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

  10. Lubrication of nuclear reactor components

    International Nuclear Information System (INIS)

    Wild, E.; Mack, K.J.

    1978-01-01

    Safe operation of liquid metal cooled nuclear reactors requires a knowledge of the tribological behaviour of contacting components at high temperatures with slow relative movement at high frictional loads in a chemically aggressive environment. Experiments have been performed on various material combinations in liquid sodium and argon. Because of the small sliding movements, hydrodynamic lubrication is not expected and thus surface finish is an important factor. Tests have been performed on brushed, ground and lapped surfaces. Among the material combinations tested a CrC-coating on a 1.4961 stainless steel substrate performed well. Friction coefficients of 0.35-0.5 in argon and 0.1-1.2 in liquid sodium were recorded. (author)

  11. 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.

  12. Shear thickening in suspensions: the lubricated-to-frictional contact scenario

    Science.gov (United States)

    Morris, Jeffrey

    2017-11-01

    Suspensions of solid particles in viscous liquids can vary from low-viscosity liquids to wet granular materials or soft solids depending on the solids loading and the forces acting between particles. When the particles are very concentrated, these mixtures are ''dense suspensions.'' Dense suspensions often exhibit shear thickening, an increase in apparent viscosity as the shear rate is increased. In its most extreme form, order of magnitude increases in viscosity over such a narrow range in shear rate occur that the term discontinuous shear thickening (DST) is applied. DST is particularly striking as it occurs in the relatively simple case of nearly hard spheres in a Newtonian liquid, and is found to take place for submicron particles in colloidal dispersions to much larger particle corn starch dispersions. We focus on simulations of a recently developed ``lubricated-to-frictional'' rheology in which the interplay of viscous lubrication, repulsive surface forces, and contact friction between particle surfaces provides a scenario to explain DST. Our simulation method brings together elements of the discrete-element method from granular flow with a simplified Stokesian Dynamics, and can rationalize not only the abrupt change in properties with imposed shear rate (or shear stress), but also the magnitude of the change. The large change in properties is associated with the breakdown of lubricating films between particles, with activation of Coulomb friction between particles. The rate dependence is caused by the shearing forces driving particles to contact, overwhelming conservative repulsive forces between surfaces; the repulsive forces are representative of colloidal stabilization by surface charge or steric effects, e.g. due to adsorbed polymer. The results of simulation are compared to developments by other groups, including a number of experimental studies and a theory incorporating the same basic elements as the simulation. The comparison to experiments of the

  13. 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.

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

    International Nuclear Information System (INIS)

    Janis, J.

    1995-01-01

    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)

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

    International Nuclear Information System (INIS)

    Darfizzi Derawi; Jumat Salimon

    2014-01-01

    Palm olein (PO o ) is widely used as edible oil in tropical countries. The lubrication properties and chemical compositions of PO o being considered to be used as renewable raw material for bio lubricant synthesis. PO o 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. PO o 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 PO o were tested by using high performance liquid chromatography (HPLC) and gas chromatography (GC) techniques. (author)

  16. Role of lubricants on friction between self-ligating brackets and archwires.

    Science.gov (United States)

    Leal, Renata C; Amaral, Flávia L B; França, Fabiana M G; Basting, Roberta T; Turssi, Cecilia P

    2014-11-01

    To evaluate the effect of different lubricants on friction between orthodontic brackets and archwires. Active (Quick, Forestadent) and passive (Damon 3MX, Ormco) self-ligating brackets underwent friction tests in the presence of mucin- and carboxymethylcellulose (CMC)-based artificial saliva, distilled water, and whole human saliva (positive control). Dry friction (no lubricant) was used as the negative control. Bracket/wire samples (0.014 × 0.025 inch, CuNiTi, SDS Ormco) underwent friction tests eight times in a universal testing machine. Two-way analysis of variance showed no significant interaction between bracket type and lubricant (P  =  .324). Friction force obtained with passive self-ligating brackets was lower than that for active brackets (P Friction observed in the presence of artificial saliva did not differ from that generated under lubrication with natural human saliva, as shown by Tukey test. Higher friction forces were found with the use of distilled water or when the test was performed under dry condition (ie, with no lubricant). Lubrication plays a role in friction forces between self-ligating brackets and CuNiTi wires, with mucin- and CMC-based artificial saliva providing a reliable alternative to human natural saliva.

  17. 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 dynamic behaviour of the main bearing of a medium-size engine is theoretically analysed when the engine operates with controllable radial oil injection and four different injection control rules. The theoretical investigation is based on a single-cylinder combustion engine model. The performance......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...... 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...

  18. Ultra Low Friction of DLC Coating with Lubricant

    International Nuclear Information System (INIS)

    Kano, M; Yoshida, K

    2010-01-01

    The objective of this study was to find a trigger to make clear a mechanism of the ultra low friction by evaluating the friction property of DLC-DLC combination under lubrication with the simple fluid. The Pin-on-disc reciprocating and rotating sliding tests were conducted to evaluate the friction property. The super low friction property of pure sliding with the ta-C(T) pair coated by the filtered arc deposition process under oleic acid lubrication was found at the mixed lubrication condition. It was thought that the low share strength tribofilm composed of water and acid seemed to be formed on ta-C sliding interface. Additionally, the smooth sliding surface formed on ta-C(T) was seemed to be required to keep this tribofilm. Then, the super low friction was thought to be obtained by this superlubrication condition. Although the accurate and direct experimental data must be required to make clear this super low friction mechanism, the advanced effect obtained by the simple material combination is expected to be applied on the large industrial fields in near future.

  19. Immobilisation of alpha contaminated lubricating oils in cement matrix

    International Nuclear Information System (INIS)

    Manohar, Smitha; Sathi Sasidharan, N.; Wattal, P.K.; Shah, N.J.; Chander, Mahesh; Bansal, N.K.

    2000-10-01

    Alpha contaminated lubricating oil wastes are generated from the reprocessing plants and other alpha handling facilities. Incineration of these spent lubricating oils requires specially designed facility to handle the aerosols of actinide oxides released to the off-gases. Hence immobilisation of these wastes into cement matrix could be a viable alternative. Work was therefore initiated to examine the possibility of immobilising such waste in cement matrix with the help of suitable additives. This work led to the selection of sodium hydroxide and silica fumes as additives for their distinct role in immobilization of such waste in cement. The selected formulation was tested extensively both on laboratory scale and full scale for acceptable waste form. The leach test on laboratory scale indicated negligible release of alpha and beta gamma activity after 180 days. This report gives a brief on the formulation of the admixture and its effect on the immobilization of waste. (author)

  20. 49 CFR 396.5 - Lubrication.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS INSPECTION, REPAIR, AND MAINTENANCE § 396.5 Lubrication. Every motor carrier shall ensure that each motor vehicle subject to its control is...

  1. Excellent lubricating behavior of Brasenia schreberi mucilage.

    Science.gov (United States)

    Li, Jinjin; Liu, Yuhong; Luo, Jianbin; Liu, Pengxiao; Zhang, Chenhui

    2012-05-22

    The present work reports an excellent lubrication property of an aquatic plant called Brasenia schreberi (BS). To investigate the lubrication characteristics of the BS mucilage, a novel measuring system is designed, and an ultralow friction coefficient about 0.005 between the mucilage and glass surface has been obtained. It is found that the ultralow friction is closely related to the structure of mucilage and water molecules in the mucilage. The microstructure analysis indicates that the mucilage surrounding BS forms a kind of polysaccharide gel with many nanosheets. A possible lubrication mechanism is proposed that the formation of hydration layers among these polymer nanosheets with plenty of bonded water molecules causes the ultralow friction. The excellent lubrication property has a potential application for reducing the friction between a glossy pill coated with such layer of mucilage and people's throats.

  2. Fundamentals of Friction and Vapor Phase Lubrication

    National Research Council Canada - National Science Library

    Gellman, Andrew

    2004-01-01

    This is the final report for the three year research program on "Fundamentals of Friction and Vapor Phase Lubrication" conducted at Carnegie Mellon with support from AFOSR grant number F49630-01-1-0069...

  3. Nanoscale Organic−Inorganic Hybrid Lubricants

    KAUST Repository

    Kim, Daniel; Archer, Lynden A.

    2011-01-01

    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

  4. Fuels and Petroleum, Oil & Lubricants (POL) Laboratories

    Data.gov (United States)

    Federal Laboratory Consortium — The Fuels and Lubricants Technology Team operates and maintains the Fuels and POL Labs at TARDEC. Lab experts adhere to standardized American Society for Testing and...

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

    International Nuclear Information System (INIS)

    Jahan, A.

    1997-01-01

    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 (CO 2 , NOx and Hx emissions and fuel savings), eco-toxicity and technical performances (wearing and cleanliness). (J.S.)

  6. Determining minimum lubrication film for machine parts

    Science.gov (United States)

    Hamrock, B. J.; Dowson, D.

    1978-01-01

    Formula predicts minimum film thickness required for fully-flooded ball bearings, gears, and cams. Formula is result of study to determine complete theoretical solution of isothermal elasto-hydrodynamic lubrication of fully-flooded elliptical contacts.

  7. Lubrication and cooling for high speed gears

    Science.gov (United States)

    Townsend, D. P.

    1985-01-01

    The problems and failures occurring with the operation of high speed gears are discussed. The gearing losses associated with high speed gearing such as tooth mesh friction, bearing friction, churning, and windage are discussed with various ways shown to help reduce these losses and thereby improve efficiency. Several different methods of oil jet lubrication for high speed gearing are given such as into mesh, out of mesh, and radial jet lubrication. The experiments and analytical results for the various methods of oil jet lubrication are shown with the strengths and weaknesses of each method discussed. The analytical and experimental results of gear lubrication and cooling at various test conditions are presented. These results show the very definite need of improved methods of gear cooling at high speed and high load conditions.

  8. 24 CFR 1000.50 - What Indian preference requirements apply to IHBG administration activities?

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false What Indian preference requirements apply to IHBG administration activities? 1000.50 Section 1000.50 Housing and Urban Development... § 1000.50 What Indian preference requirements apply to IHBG administration activities? To the greatest...

  9. Upgrading the lubricity of bio-oil via homogeneous catalytic esterification under vacuum distillation conditions

    International Nuclear Information System (INIS)

    Xu, Yufu; Zheng, Xiaojing; Peng, Yubin; Li, Bao; Hu, Xianguo; Yin, Yanguo

    2015-01-01

    In order to accelerate the application of bio-oil in the internal combustion engines, homogeneous catalytic esterification technology under vacuum distillation conditions was used to upgrade the crude bio-oil. The lubricities of the crude bio-oil (BO) and refined bio-oil with homogeneous catalytic esterification (RBO hce ) or refined bio-oil without catalyst but with distillation operation (RBO wc ) were evaluated by a high frequency reciprocating test rig according to the ASTM D 6079 standard. The basic physiochemical properties and components of the bio-oils were analyzed. The surface morphology, contents and chemical valence of active elements on the worn surfaces were investigated by scanning electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy, respectively. The results show that RBO hce has better lubricities than those of BO, but RBO wc has worse lubricities than those of BO. The tribological mechanisms of the bio-oils are attributed to the combined actions of lubricating films and factors that will break the film. Compared with BO, plenty of phenols in RBO wc results in corrosion of the substrate and destroys the integrity of the lubricating films, which is responsible for its corrosive wear. However, more esters and alkanes in RBO hce contribute to forming a complete boundary lubricating film on the rubbed surfaces which result in its excellent antifriction and antiwear properties. - Highlights: • Refined bio-oil was prepared through homogeneous catalytic esterification technology. • Properties of the bio-oils before and after refining were assessed by HFRR. • Refined bio-oil showed better lubricities than crude bio-oil. • More esters and alkanes in refined bio-oil contributed to forming superior boundary lubrication

  10. Tribology experiment. [journal bearings and liquid lubricants

    Science.gov (United States)

    Wall, W. A.

    1981-01-01

    A two-dimensional concept for Spacelab rack 7 was developed to study the interaction of liquid lubricants and surfaces under static and dynamic conditions in a low-gravity environment fluid wetting and spreading experiments of a journal bearing experiments, and means to accurately measure and record the low-gravity environment during experimentation are planned. The wetting and spreading process of selected commercial lubricants on representative surface are to the observes in a near-zero gravity environment.

  11. Investigation of lubricants under boundary friction

    Science.gov (United States)

    Heidebroek, E; Pietsch, E

    1942-01-01

    Numerous observations of such lubrication processes within range of boundary friction on journal bearings and gear tooth profiles have strengthened the supposition that it should be possible to study the attendant phenomena with engineering methods and equipment. These considerations formed the basis of the present studies, which have led to the discovery of relations governing the suitability of bearing surfaces and the concept of "lubricating quality."

  12. Noise estimation of oil lubricated journal bearings

    International Nuclear Information System (INIS)

    Rho, Byoung Hoo; Kim, Kyung Woong

    2003-01-01

    Noise estimating procedures of oil lubricated journal bearings are presented. Nonlinear analysis of rotor-bearing system including unbalance mass of the rotor is performed in order to obtain acoustical properties of the bearing. Acoustical properties of the bearing are investigated through frequency analysis of the pressure fluctuation of the fluid film calculated from the nonlinear analysis. Noise estimating procedures presented in this paper could aid in the evaluation and understanding of acoustical properties of oil lubricated journal bearings

  13. 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.

  14. 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

  15. A fully-coupled approach combining plastic deformation and liquid lubrication

    DEFF Research Database (Denmark)

    Üstünyagiz, Esmeray; Christiansen, Peter; Nielsen, Chris Valentin

    This paper presents a new approach based on a fully coupled procedure in which the lubricant flow and theplastic deformation of the metallic material are solved simultaneously. The approach is applied to strip reduction of asheet with surface pockets in order to investigate the escape of the lubr......This paper presents a new approach based on a fully coupled procedure in which the lubricant flow and theplastic deformation of the metallic material are solved simultaneously. The approach is applied to strip reduction of asheet with surface pockets in order to investigate the escape...

  16. Experimental Measurements of Journal Bearing Friction Using Mineral, Synthetic, and Bio-Based Lubricants

    Directory of Open Access Journals (Sweden)

    Pantelis G. Nikolakopoulos

    2015-04-01

    Full Text Available The environmental impact of many industrial and naval applications is becoming increasingly important. Journal bearings are crucial components related with the reliable, safe and environmentally friendly operation of rotating machinery in many applications, e.g., in hydroplants, ships, power generation stations. The maintenance activities in certain cases also have considerable environmental impact. Fortunately, it is relatively easy to reduce the impact by changing the way lubricants are being used. Selecting the proper lubricant is important to sharply reduce long-term costs. The best-fit product selection can mean longer lubricant life, reduced machine wear, reduced incipient power losses and improved safety. Suitable basestocks and additives reduce environmental impact. In this paper, three types of lubricants are used in order to examine their effects on the tribological behavior of journal bearings. A mineral oil, a synthetic oil and a bio-based lubricant are experimentally and analytically examined for several configurations of load and journal rotational velocity. The friction forces and the hydrodynamic friction coefficients are calculated and compared. This investigation can assist the correct choice of lubricant in journal bearings with minimized environmental footprint.

  17. 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.

  18. Determinan Kepuasan Pelanggan Pada Produk Pertamina Lubricants

    Directory of Open Access Journals (Sweden)

    Berto Mulia Wibawa

    2017-02-01

    Full Text Available Determinants of Customer Satisfaction at Pertamina's Lubricants ProductLubricant industry is one of the strategic industries in around the world. The potential of the lubricant industry in Indonesia grows rapidly along with the increasing demand and the number of a vehicle from year to year. This study aims to analyze factors that influencing customer satisfaction Pertamina Lubricants product and measure how far the customer satisfaction level of its product. This study observed eight categories of Pertamina Lubricants product, with quota sampling technique where each category of the product taken 30 samples, so the total number of the sample are 240 respondents. Multiple linear regression and customer satisfaction index were used in this study. The study finds brand popularity has the most significant effect on customer satisfaction, followed by price and durability. Customer satisfaction level stands at 78 percent, which means belongs in the satisfied category. Managerial implications of this study provide strategies for Pertamina Lubricants to improve their business performance and to increase the level of customer satisfactionDOI:  10.15408/ess.v7i1.4309  

  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

    2015-01-01

    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......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...

  20. Experimental analysis of influence of different lubricants types on the multi-phase ironing process

    Directory of Open Access Journals (Sweden)

    Milan Djordjević

    2013-05-01

    Full Text Available This paper is aimed at presenting results of an experimental analysis of the different types of lubricants influence on the multi-phase ironing process. Based on sliding of the metal strip between the two contact elements a special tribological model was adopted. The subject of experimental investigations was variations of the drawing force, contact pressure and the friction coefficient for each type of the applied lubricants. The ironing process was conducted in three-phases at the constant sliding velocity. The objective of this analysis was to compare all the applied lubricants in order to estimate their quality from the point of view of their applicability in the multi-phase ironing process.

  1. EXPERIMENTAL ANALYSIS OF INFLUENCE OF DIFFERENT LUBRICANTS TYPES ON THE MULTI-PHASE IRONING PROCESS

    Directory of Open Access Journals (Sweden)

    Milan Djordjević

    2013-09-01

    Full Text Available This paper is aimed at presenting results of an experimental analysis of the different types of lubricants influence on the multi-phase ironing process. Based on sliding of the metal strip between the two contact elements a special tribological model was adopted. The subject of experimental investigations was variations of the drawing force, contact pressure and the friction coefficient for each type of the applied lubricants. The ironing process was conducted in three-phases at the constant sliding velocity. The objective of this analysis was to compare all the applied lubricants in order to estimate their quality from the point of view of their applicability in the multi-phase ironing process.

  2. Reduced Need of Lubricity Additives in Soybean Oil Blends Under Boundary Lubrication Conditions

    Science.gov (United States)

    Converging prices of vegetable oils and petroleum, along with increased focus on renewable resources, gave more momentum to vegetable oil lubricants. Boundary lubrication properties of four Extreme Pressure (EP) additive blends in conventional Soy Bean Oil (SBO) and Paraffinic Mineral Oil (PMO) of ...

  3. Boundary lubrication of bearing steel in water-based lubricants with functional additives

    NARCIS (Netherlands)

    Wu, Y.

    2017-01-01

    This thesis focuses on the effect of additives on boundary lubrication of bearing steel for water-based lubrication systems. The oil-in-water (O/W) emulsion and the water-glycol based liquid were selected as the base fluids for research. Sulfur compounds, nitrogen heterocycles and graphene

  4. 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.

  5. The Role of Nano-TiO2 Lubricating Fluid on the Hot Rolled Surface and Metallographic Structure of SS41 Steel

    Directory of Open Access Journals (Sweden)

    Yanan Meng

    2018-02-01

    Full Text Available In this paper, nano-TiO2lubricating fluid was chosen as an advanced rolling lubricant to investigate its effect on the hot rolled surface and metallographic structure of SS41 steel strips. The tribological performances of nano-TiO2 lubricating fluid were measured by a four-ball tribotester. The hot rolling experiments under different lubrication conditions were carried out by a four-high rolling mill. The surface morphology, oxide scales and metallographic structure after hot rolling were observed using a confocal laser scanning microscope and scanning electron microscope (SEM, respectively. The composition of surface attachments was analyzed with X-ray photoelectron spectroscopy (XPS. The results indicate that the nano-TiO2 lubricating fluid has a better tribological performance. The surface defects on the hot rolled surface could be decreased. The phase composition of the surface still appears as a mixture of ferrite and pearlite. The surface of steel strips is not micro-alloyed with titanium as predicted. Additionally, the grain size of rolled steel strips which were lubricated with the nano-TiO2lubricating fluid decreased by nearly 50%, compared with traditional lubricating fluid. Furthermore, it was found that the thickness of the oxide layers on the surface reduced, whilst the Rockwell hardness of the oxide layers was enhanced as nano-TiO2 lubricating fluid was applied.

  6. Are Ionic Liquids Good Boundary Lubricants? A Molecular Perspective

    Directory of Open Access Journals (Sweden)

    Romain Lhermerout

    2018-01-01

    Full Text Available The application of ionic liquids as lubricants has attracted substantial interest over the past decade and this has produced a rich literature. The aim of this review is to summarize the main findings about frictional behavior of ionic liquids in the boundary lubrication regime. We first recall why the unusual properties of ionic liquids make them very promising lubricants, and the molecular mechanisms at the origin of their lubricating behavior. We then point out the main challenges to be overcome in order to optimise ionic liquid lubricant performance for common applications. We finally discuss their use in the context of electroactive lubrication.

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

    International Nuclear Information System (INIS)

    Blanc, C.

    1979-01-01

    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 C 6 steel surface innumered in tricresylphosphate at 110 0 C 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 αFe 2 -O 3 . 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 [fr

  8. Investigation of the effect of engine lubricant oil on remote temperature sensing using thermographic phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Abou Nada, Fahed, E-mail: Fahed.Abou_Nada@forbrf.lth.se; Aldén, Marcus; Richter, Mattias

    2016-11-15

    Phosphor thermometry, a remote temperature sensing technique, is widely implemented to measure the temperature of different combustion engines components. The presence of engine lubricant can influence the behavior of the applied sensor materials, known as thermographic phosphors, and thus leading to erroneous temperature measurements. The effect of two engine lubricants on decay times originating from six different thermographic phosphors was investigated. The decay time of each thermographic phosphor was investigated as a function of lubricant/phosphor mass ratio. Tests were conducted at temperatures around 293 K and 376 K for both lubricants. The investigations revealed that ZnO:Zn and ZnS:Ag are the only ones that exhibit a change of the decay time as function of the lubricant/phosphor mass ratio. While the remaining thermographic phosphors, namely BaMg{sub 2}Al{sub 16}O{sub 27}:Eu (BAM), Al{sub 2}O{sub 3}-coated BaMg{sub 2}Al{sub 16}O{sub 27}:Eu, La{sub 2}O{sub 2}S:Eu, Mg{sub 3}F{sub 2}GeO{sub 4}:Mn, displayed no sensitivity of their characteristic decay time on to the presence of lubricant on the porous coating. Biases in the calculated temperature are to be expected if the utilized thermographic phosphor displays decay time sensitivity to the existence of the engine lubricant within the sensor. Such distortions are concealed and can occur undetected leading to false temperature readings for the probed engine component.

  9. 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.

  10. Application of Terahertz Attenuated Total Reflection Spectroscopy to Detect Changes in the Physical Properties of Lactose during the Lubrication Process Required for Drug Formulation.

    Science.gov (United States)

    Dohi, Masafumi; Momose, Wataru; Yamashita, Kazunari; Hakomori, Tadashi; Sato, Shusaku; Noguchi, Shuji; Terada, Katsuhide

    2017-02-01

    Manufacturing the solid dosage form of an orally administered drug requires lubrication to enhance manufacturability, ensuring that critical quality attributes such as disintegration and dissolution of the drug product are maintained during manufacture. Here, to evaluate lubrication performance during manufacture, we used terahertz attenuated total reflection (THz-ATR) spectroscopy to detect differences in the physical characteristics of the lubricated powder. We applied a simple formulation prepared by blending granulated lactose as filler with magnesium stearate as lubricant. A flat tablet was prepared using the lubricated powder to acquire sharp THz-ATR absorption peaks of the samples. First, we investigated the effects of lubricant concentration and compression pressure on preparation of the tablet and then determined the effect of the pressure applied to samples in contact with the ATR prism on sample absorption amplitude. We focused on the differences in the magnitudes of spectra at the lactose-specific frequency. Second, we conducted the dynamic lubrication process using a 120-L mixer to investigate differences in the magnitudes of absorption corresponding to the lactose-specific frequency during lubrication. In both studies, enriching the lubricated powder with a higher concentration of magnesium stearate or prolonging blending time correlated with higher magnitudes of spectra at the lactose-specific frequency. Further, in the dynamic lubrication study, the wettability and disintegration time of the tablets were compared with the absorption spectra amplitudes at the lactose-specific frequency. We conclude that THz-ATR spectroscopy is useful for detecting differences in densities caused by a change in the physical properties of lactose during lubrication.

  11. Turbine lubrication fluid varnish mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Farooq, Khalid [Pall Corporation, Port Washington, NY (United States)

    2010-04-15

    Varnish deposits on internal surfaces in turbine lube systems result in a number of adverse operational issues, especially the restriction and sticking of the moving parts of servo- or directional control valves, resulting in their malfunction. The lubrication fluid has limited solvency for the varnish-forming material, hence a typical turbine will have the majority of this material as deposits and a relatively small portion as suspension in the fluid phase, in quasi-equilibrium with the deposits. The lube system needs to be cleaned by removing the suspended varnish-forming material from the fluid phase, which allows the deposits to re-entrain into the fluid phase, until the majority of the transferable deposits are removed and the fluid carries no significant amount of the material to have any adverse effect. The methods used for the removal of varnish from turbine lube systems include chemical cleaning/flushing, electrostatic charge induced agglomeration/retention, and the adsorption of the varnish suspended in the oil on an adsorbent medium. The paper discusses an absorption-based removal method that utilizes a fibrous medium that has pronounced affinity for the removal and retention of the varnish-forming material from the fluid as well as the deposits from surfaces that are in quasi-equilibrium with the varnish precursors in the fluid. The filtration medium is a composite, made with cellulose bonded by specially formulated, temperature-cured resins. The absorptive medium exhibits high structural and chemical integrity and has been thoroughly tested on operating turbines, showing reduction in varnish levels from the critical range to below normal range in a relatively short time. The experience with the utilization of the absorptive medium in laboratory tests and in two operating turbines is presented. (orig.)

  12. Tribology of the lubricant quantized sliding state.

    Science.gov (United States)

    Castelli, Ivano Eligio; Capozza, Rosario; Vanossi, Andrea; Santoro, Giuseppe E; Manini, Nicola; Tosatti, Erio

    2009-11-07

    In the framework of Langevin dynamics, we demonstrate clear evidence of the peculiar quantized sliding state, previously found in a simple one-dimensional boundary lubricated model [A. Vanossi et al., Phys. Rev. Lett. 97, 056101 (2006)], for a substantially less idealized two-dimensional description of a confined multilayer solid lubricant under shear. This dynamical state, marked by a nontrivial "quantized" ratio of the averaged lubricant center-of-mass velocity to the externally imposed sliding speed, is recovered, and shown to be robust against the effects of thermal fluctuations, quenched disorder in the confining substrates, and over a wide range of loading forces. The lubricant softness, setting the width of the propagating solitonic structures, is found to play a major role in promoting in-registry commensurate regions beneficial to this quantized sliding. By evaluating the force instantaneously exerted on the top plate, we find that this quantized sliding represents a dynamical "pinned" state, characterized by significantly low values of the kinetic friction. While the quantized sliding occurs due to solitons being driven gently, the transition to ordinary unpinned sliding regimes can involve lubricant melting due to large shear-induced Joule heating, for example at large speed.

  13. 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.

  14. Feasibility of Applying Controllable Lubrication Techniques to Reciprocating Machines

    DEFF Research Database (Denmark)

    Pulido, Edgar Estupinan

    of the reciprocating engine, obtained with the help of multibody dynamics (rigid components) and finite elements method (flexible components), and the global system of equations is numerically solved. The analysis of the results was carried out with focus on the behaviour of the journal orbits, maximum fluid film...

  15. Lubrication theory analysis of the permeability of rough-walled fractures

    International Nuclear Information System (INIS)

    Zimmerman, R.W.; Kumar, S.; Bodvarsson, G.S.

    1991-01-01

    The flow of a fluid between the rough surfaces of a rock fracture is very complex, due to the tortuous paths followed by the fluid particles. Exact analytical modeling of these flows is made difficult by the irregular geometry of rock fracture surfaces, while full three-dimensional numerical simulations of these flows are as yet still impractical. To overcome the difficulties of working with the three-dimensional Navier-Stokes equations, the simpler Reynolds lubrication equation has sometimes been used to model flow in fractures. This paper focuses on two aspects of lubrication theory. First, lubrication theory is applied to two simplified aperture profiles, sinusoidal and sawtooth, and analytical expressions are found for the permeabilities. These results are then compared with numerical results obtained by solving the lubrication equation for fractures with random surfaces. Secondly, the validity of the lubrication equations for modeling flow in rough fractures is studied by examining higher-order perturbation solutions, as well as numerical solutions, to the Navier-Stokes equations for flow in fractures with sinusoidally-varying apertures. 22 refs., 6 figs

  16. Mechanics of a gaseous film barrier to lubricant wetting of elastohydrodynamically lubricated conjunctions

    Science.gov (United States)

    Prahl, J. M.; Hamrock, B. J.

    1985-01-01

    Two analytical models, one based on simple hydrodynamic lubrication and the other on soft elastohydrodynamic lubrication, are presented and compared to delineate the dominant physical parameters that govern the mechanics of a gaseous film between a small droplet of lubricant and the outer race of a ball bearing. Both models are based on the balance of gravity forces, air drag forces, and air film lubrication forces and incorporate a drag coefficient C sub D and a lubrication coefficient C sub L to be determined from experiment. The soft elastohydrodynamic lubrication (EHL) model considers the effects of droplet deformation and solid-surface geometry; the simpler hydrodynamic lubrication (HL) model assumes that the droplet remains essentially spherical. The droplet's angular position depended primarily on the ratio of gas inertia to droplet gravity forces and on the gas Reynolds number and weakly on the ratio of droplet gravity forces to surface tension forces (Bond number) and geometric ratios for the soft EHL. An experimental configuration in which an oil droplet is supported by an air film on the rotating outer race of a ball bearing within a pressure-controlled chamber produced measurements of droplet angular position as a function of outer-race velocity droplet size and type, and chamber pressure.

  17. Additives for high-temperature liquid lubricants

    Science.gov (United States)

    Lawton, Emil A.; Yavrouian, Andre H.; Repar, John

    1988-01-01

    A preliminary research program was conducted to demonstrate a new concept for additives to liquid lubricants. It was demonstrated that suspensions of o-phthalonitrile and a substituted 1,2-maleonitrile in mineral oil and dilute solutions of o-phthalonitrile and tetrafluoro-o-phthalonitrile extended the lifetime of bearings under boundary lubricating conditions. The solutions exhibited coefficients of friction under high loads of 0.02-0.03. These results were consistent with the hypothesis that these compounds react with the hot metal surface to form a planar lubricating film by means of a metal or metal oxide template reaction. Also, the adherence was very strong due to the chelating action of the planar macrocycles postulated to form under the experimental conditions.

  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. RADIAL FORCE IMPACT ON THE FRICTION COEFFICIENT AND TEMPERATURE OF A SELF-LUBRICATING PLAIN BEARING

    Directory of Open Access Journals (Sweden)

    Nada Bojić

    2017-12-01

    Full Text Available Self-lubricating bearings are available in spherical, plain, flanged journal, and rod end bearing configurations. They were originally developed to eliminate the need for re-lubrication, to provide lower torque and to solve application problems where the conventional metal-to-metal bearings would not perform satisfactorily, for instance, in the presence of high frequency vibrations. Among the dominant tribological parameters of the self-lubricating bearing, two could be singled out: the coefficient of friction and temperature. To determine these parameters, an experimental method was applied in this paper. By using this method, the coefficient of friction and temperature were identified and their correlation was established. The aim of this research was to determine the effect of radial force on tribological parameters in order to predict the behavior of sliding bearings with graphite in real operating conditions.

  20. Geotribology - Friction, wear, and lubrication of faults

    Science.gov (United States)

    Boneh, Yuval; Reches, Ze'ev

    2018-05-01

    We introduce here the concept of Geotribology as an approach to study friction, wear, and lubrication of geological systems. Methods of geotribology are applied here to characterize the friction and wear associated with slip along experimental faults composed of brittle rocks. The wear in these faults is dominated by brittle fracturing, plucking, scratching and fragmentation at asperities of all scales, including 'effective asperities' that develop and evolve during the slip. We derived a theoretical model for the rate of wear based on the observation that the dynamic strength of brittle materials is proportional to the product of load stress and loading period. In a slipping fault, the loading period of an asperity is inversely proportional to the slip velocity, and our derivations indicate that the wear-rate is proportional to the ratio of [shear-stress/slip-velocity]. By incorporating the rock hardness data into the model, we demonstrate that a single, universal function fits wear data of hundreds of experiments with granitic, carbonate and sandstone faults. In the next step, we demonstrate that the dynamic frictional strength of experimental faults is well explained in terms of the tribological parameter PV factor (= normal-stress · slip-velocity). This factor successfully delineates weakening and strengthening regimes of carbonate and granitic faults. Finally, our analysis revealed a puzzling observation that wear-rate and frictional strength have strikingly different dependencies on the loading conditions of normal-stress and slip-velocity; we discuss sources for this difference. We found that utilization of tribological tools in fault slip analyses leads to effective and insightful results.

  1. REECo activities and sample logistics in support of the Nevada Applied Ecology Group

    International Nuclear Information System (INIS)

    Wireman, D.L.; Rosenberry, C.E. Jr.

    1975-01-01

    Activities and sample logistics of Reynolds Electrical and Engineering Co., Inc. (REECo), in support of the Nevada Applied Ecology Group (NAEG), are discussed in this summary report. Activities include the collection, preparation, and shipment of samples of soils, vegetation, and small animals collected at Pu-contaminated areas of the Nevada Test Site and Tonopah Test Range. (CH)

  2. Development and efficiency assessment of process lubrication for hot forging

    Science.gov (United States)

    Kargin, S.; Artyukh, Viktor; Ignatovich, I.; Dikareva, Varvara

    2017-10-01

    The article considers innovative technologies in testing and production of process lubricants for hot bulk forging. There were developed new compositions of eco-friendly water-graphite process lubricants for hot extrusion and forging. New approaches to efficiency assessment of process lubricants are developed and described in the following article. Laboratory and field results are presented.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    as 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 the cup extrusion test. For all specimens without the porous coating, high friction conditions are identified....

  4. 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.

  5. 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...

  6. Double hollow MoS{sub 2} nano-spheres: Synthesis, tribological properties, and functional conversion from lubrication to photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yueru [Department of Chemical and Materials Engineering, Hefei University, Hefei 230601 (China); Hu, Kunhong, E-mail: hukunhong@163.com [Department of Chemical and Materials Engineering, Hefei University, Hefei 230601 (China); Hu, Enzhu; Guo, Jianhua; Han, Chengliang [Department of Chemical and Materials Engineering, Hefei University, Hefei 230601 (China); Hu, Xianguo [Institute of Tribology, Hefei University of Technology, Hefei 230009 (China)

    2017-01-15

    Highlights: • Novel double-hollow-sphere MoS{sub 2} nanoparticles were synthesized on sericite. • Friction and wear decreased by 22.4 and 63.5% by the novel MoS{sub 2}/sericite. • Friction induced conversion of MoS{sub 2}/sericite from lubricant to catalyst. • MoS{sub 2}/sericite can be used as a photocatalyst after lubricating service life. • A possible approach was proposed for designing a novel green lubricant. - Abstract: Molybdenum disulfide (MoS{sub 2}) has extensive applications in industries as solid lubricants and catalysts. To improve the lubricating performance of MoS{sub 2}, novel double-hollow-sphere MoS{sub 2} (DHSM) nanoparticles with an average diameter of approximately 90 nm were synthesized on sericite mica (SM). When the DHSM/SM composite was used as an additive in polyalphaolefin oil, friction and wear decreased by 22.4% and 63.5% respectively. The low friction and wear were attributed to the easy exfoliation of DHSM. The DHSM/SM composite was then rubbed under 40 MPa for 1 h to investigate the exfoliation and functional conversion behaviors of DHSM. Results showed that DHSM (lubricating structure) on SM could be completely exfoliated into nanosheets (catalytic structure) by rubbing. The nanosheets exfoliated from DHSM presented good photocatalytic activity for the removal of organic compounds from waste water. This work provided both a novel solid lubricant for industrial applications and a possible approach to designing a novel green lubricant for use as a photocatalyst in organic-waste treatment after lubricating service life.

  7. How Work Positions Affect the Research Activity and Information Behaviour of Laboratory Scientists in the Research Lifecycle: Applying Activity Theory

    Science.gov (United States)

    Kwon, Nahyun

    2017-01-01

    Introduction: This study was conducted to investigate the characteristics of research and information activities of laboratory scientists in different work positions throughout a research lifecycle. Activity theory was applied as the conceptual and analytical framework. Method: Taking a qualitative research approach, in-depth interviews and field…

  8. Developing international alumni activities in Mikkeli University of Applied Sciences : Case Business Management degree programme

    OpenAIRE

    Honkaniemi, Meri

    2014-01-01

    My thesis focuses on international alumni activities in Mikkeli University of Applied Sciences. My aim was to find development ideas and recommendations for the international side of the alumni activities. I intended to offer realistic suggestions enough in order to make them work in practice too. I put also my effort on finding recommendations for Business Management programme, because I wanted to make sure that international alumni activities get attention in degree programme level too. ...

  9. Hard-on-hard lubrication in the artificial hip under dynamic loading conditions.

    Directory of Open Access Journals (Sweden)

    Robert Sonntag

    Full Text Available The tribological performance of an artificial hip joint has a particularly strong influence on its success. The principle causes for failure are adverse short- and long-term reactions to wear debris and high frictional torque in the case of poor lubrication that may cause loosening of the implant. Therefore, using experimental and theoretical approaches models have been developed to evaluate lubrication under standardized conditions. A steady-state numerical model has been extended with dynamic experimental data for hard-on-hard bearings used in total hip replacements to verify the tribological relevance of the ISO 14242-1 gait cycle in comparison to experimental data from the Orthoload database and instrumented gait analysis for three additional loading conditions: normal walking, climbing stairs and descending stairs. Ceramic-on-ceramic bearing partners show superior lubrication potential compared to hard-on-hard bearings that work with at least one articulating metal component. Lubrication regimes during the investigated activities are shown to strongly depend on the kinematics and loading conditions. The outcome from the ISO gait is not fully confirmed by the normal walking data and more challenging conditions show evidence of inferior lubrication. These findings may help to explain the differences between the in vitro predictions using the ISO gait cycle and the clinical outcome of some hard-on-hard bearings, e.g., using metal-on-metal.

  10. Tribology: Friction, lubrication, and wear technology

    Science.gov (United States)

    Blau, Peter J.

    1993-01-01

    The topics are presented in viewgraph form and include the following: introduction and definitions of terms; friction concepts; lubrication technology concepts; wear technology concepts; and tribological transitions. This document is designed for educators who seek to teach these concepts to their students.

  11. Physicochemical properties and lubricant potentials of Blighia ...

    African Journals Online (AJOL)

    Fatty acid methyl ester analysis (FAME) revealed 96.89 % of monounsaturated fatty acids and esters in the range ... uniformity, hardness, disintegration and dissolution characteristics. Conclusion: Blighia sapida seed oil is a potentially useful low-cost tablet lubricant. However ... Products derived from plants sources can be ...

  12. A Review of Ionic Liquid Lubricants

    Directory of Open Access Journals (Sweden)

    Anthony E. Somers

    2013-01-01

    Full Text Available Due to ever increasing demands on lubricants, such as increased service intervals, reduced volumes and reduced emissions, there is a need to develop new lubricants and improved wear additives. Ionic liquids (ILs are room temperature molten salts that have recently been shown to offer many advantages in this area. The application of ILs as lubricants in a diverse range of systems has found that these materials can show remarkable protection against wear and significantly reduce friction in the neat state. Recently, some researchers have shown that a small family of ILs can also be incorporated into non-polar base oils, replacing traditional anti-wear additives, with excellent performance of the neat IL being maintained. ILs consist of large asymmetrical ions that may readily adsorb onto a metal surface and produce a thin, protective film under boundary lubrication conditions. Under extreme pressure conditions, certain IL compounds can also react to form a protective tribofilm, in particular when fluorine, phosphorus or boron atoms are present in the constituent ions.

  13. On the lubrication of mechanical face seals

    NARCIS (Netherlands)

    Lubbinge, H.

    1999-01-01

    Hence, in this thesis, a model is presented which is able to calculate a complete Stribeck curve for a mechanical face seal and, as a consequence, the transition from full film to mixed lubrication as a function of the operational conditions. This model is based on a combination of a contact model

  14. Self-lubricating fluid bearing assembly

    International Nuclear Information System (INIS)

    Kapich, D.D.

    1981-01-01

    A sealed self-lubricating fluid bearing assembly is described for circulating fluid in the form of a gas coolant in a nuclear reactor, the power for the circulator being provided by a shaft located within the primary containment vessel. In such a system the reactor coolant is isolated from the fluid region at the far end of the drive shaft. (U.K.)

  15. 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...

  16. 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.

  17. Self-lubricating fluorine shaft seal material

    Science.gov (United States)

    Munk, W. R.

    1970-01-01

    Lubricating film is produced by a reaction of fluorine with a composite of aluminum oxide and nickel powder. The rate of nickel fluoride generation is proportional to the rate at which the fluoride is rubbed off the surface, allowing the seal to operate with the lowest possible heating.

  18. Formulation of lubricating grease using Beeswax thickener

    Science.gov (United States)

    Suhaila, N.; Japar, A.; Aizudin, M.; Aziz, A.; Najib Razali, Mohd

    2018-04-01

    The issues on environmental pollution has brought the industries to seek the alternative green solutions for lubricating grease formulation. The significant challenges in producing modified grease are in which considering the chosen thickener as one of the environmental friendly material. The main purposes of the current research were to formulate lubricant grease using different types of base oils and to study the effect of thickener on the formulated lubricant grease. Used oil and motor oil were used as the base oils for the grease preparation. Beeswax and Damar were used as thickener and additive. The grease is tested based on its consistency, stability and oil bleeding. The prepared greases achieved grease consistency of grade 2 and 3 except for grease with unfiltered used oil. Grease formulated with used oil and synthetic oil tend to harden and loss its lubricating ability under high temperature compared to motor oil’ grease. Grease modification using environmental friendly thickener were successfully formulated but it is considered as a low temperature grease as the beeswax have low melting point of 62°C-65°C.

  19. 14 CFR 33.71 - Lubrication system.

    Science.gov (United States)

    2010-01-01

    ... arranged that condensed water vapor that might freeze and obstruct the line cannot accumulate at any point... fireproof. (9) Each unpressurized oil tank may not leak when subjected to a maximum operating temperature... supply becomes depleted due to failure of any part of the lubricating system other than the tank itself...

  20. 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.

  1. The Lubrication Qualities of Dimethyl Ether (DME)

    DEFF Research Database (Denmark)

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

    2002-01-01

    by mixing the DME with reasonable amounts of additives. The main conclusion drawn from these measurements is that a combination of lubricity and viscosity comparable to one of diesel oil cannot be reached in the case of DME unless a huge amount of additive is used. This is not an attractive solution...

  2. The use of screening tests in spacecraft lubricant evaluation

    Science.gov (United States)

    Kalogeras, Chris; Hilton, Mike; Carre, David; Didziulis, Stephen; Fleischauer, Paul

    1993-01-01

    A lubricant screening test fixture has been devised in order to satisfy the need to obtain lubricant performance data in a timely manner. This fixture has been used to perform short-term tests on potential lubricants for several spacecraft applications. The results of these tests have saved time by producing qualitative performance rankings of lubricant selections prior to life testing. To date, this test fixture has been used to test lubricants for 3 particular applications. The qualitative results from these tests have been verified by life test results and have provided insight into the function of various anti-wear additives.

  3. Applied nuclear physics group - activities report. 1977-1997; Grupo de fisica nuclear aplicada - relatorio de atividades. 1977-1997

    Energy Technology Data Exchange (ETDEWEB)

    Appoloni, Carlos Roberto

    1998-06-01

    This report presents the activities conducted by the Applied Nuclear Physics group of the Londrina State University - Applied Nuclear Physics Laboratory - Brazil, from the activities beginning (1977) up to the end of the year 1997.

  4. Development of high performance lubricant through the compatibility of polyalphaolefin, polyurea and irradiated polytetrafluoroethylene

    International Nuclear Information System (INIS)

    Ratao, Natalia Torres

    2013-01-01

    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)

  5. Using stamping punch force variation for the identification of changes in lubrication and wear mechanism

    Science.gov (United States)

    Voss, B. M.; Pereira, M. P.; Rolfe, B. F.; Doolan, M. C.

    2017-09-01

    The growth in use of Advanced High Strength Steels in the automotive industry for light-weighting and safety has increased the rates of tool wear in sheet metal stamping. This is an issue that adds significant costs to production in terms of manual inspection and part refinishing. To reduce these costs, a tool condition monitoring system is required and a firm understanding of process signal variation must form the foundation for any such monitoring system. Punch force is a stamping process signal that is widely collected by industrial presses and has been linked closely to part quality and tool condition, making it an ideal candidate as a tool condition monitoring signal. In this preliminary investigation, the variation of punch force due to different lubrication conditions and progressive wear are examined. Linking specific punch force signature changes to developing lubrication and wear events is valuable for die wear and stamping condition monitoring. A series of semi-industrial channel forming trials were conducted under different lubrication regimes and progressive die wear. Punch force signatures were captured for each part and Principal Component Analysis (PCA) was applied to determine the key Principal Components of the signature data sets. These Principal Components were linked to the evolution of friction conditions over the course of the stroke for the different lubrication regimes and mechanism of galling wear. As a result, variation in punch force signatures were correlated to the current mechanism of wear dominant on the formed part; either abrasion or adhesion, and to changes in lubrication mechanism. The outcomes of this study provide important insights into punch force signature variation, that will provide a foundation for future work into the development of die wear and lubrication monitoring systems for sheet metal stamping.

  6. Removal of cobalt from lubricant oil by the use of bentonite: equilibrium, kinetic and adsorption preliminary studies

    Energy Technology Data Exchange (ETDEWEB)

    Cuccia, Valeria; Seles, Sandro R.N.; Ladeira, Ana Cláudia Queiroz, E-mail: vc@cdtn.br, E-mail: seless@cdtn.br, E-mail: acql@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-11-01

    Radionuclides may contaminate lubricant oils in nuclear power plants. In Brazil, this kind of waste has been stored in the generator's facilities, awaiting treatment alternatives. This work intends to investigate a process to treat it for final deposition, using bentonite as sorbent material. This process will result in decontaminated oil, free from radiological control, and radioactive loaded sorbent, with considerable volume reduction of the radioactive waste. The study focuses in cobalt removal from a simulated oil waste (non-active). The production of the simulated waste is described. Bentonite was used for equilibrium time determination, kinetic and adsorption studies. Cobalt adsorption equilibrium was rapidly attained after 30 minutes. The data was used for modelling the system's kinetic, applying the pseudo first and pseudo second order equation models. Experimental data fitted to pseudo second order model, supporting the assumption that the adsorption is due to chemisorption. Batch sorption tests were conducted and the results fitted to Langmuir and Freundlich sorption models. Both isotherm models chosen for this work did not fit to the experimental data. Thus, these are preliminary results and the studies must be repeated to evaluate data variability and better statistical inference. Other isotherm models must be evaluated to choose the best fitted one and describe the sorption of cobalt on bentonite in oil matrix. Even though, bentonite has considerable potential as sorbent for the removal of cobalt from lubricant oil. Finally, the results might be extended to other kinds of radioactive oils and radioactive organic wastes. (author)

  7. The Role of Interstitial Fluid Pressurization in Articular Cartilage Lubrication

    Science.gov (United States)

    Ateshian, Gerard A.

    2009-01-01

    Over the last two decades, considerable progress has been reported in the field of cartilage mechanics that impacts our understanding of the role of interstitial fluid pressurization on cartilage lubrication. Theoretical and experimental studies have demonstrated that the interstitial fluid of cartilage pressurizes considerably under loading, potentially supporting most of the applied load under various transient or steady-state conditions. The fraction of the total load supported by fluid pressurization has been called the fluid load support. Experimental studies have demonstrated that the friction coefficient of cartilage correlates negatively with this variable, achieving remarkably low values when the fluid load support is greatest. A theoretical framework that embodies this relationship has been validated against experiments, predicting and explaining various outcomes, and demonstrating that a low friction coefficient can be maintained for prolonged loading durations under normal physiological function. This paper reviews salient aspects of this topic, as well as its implications for improving our understanding of boundary lubrication by molecular species in synovial fluid and the cartilage superficial zone. Effects of cartilage degeneration on its frictional response are also reviewed. PMID:19464689

  8. 24 CFR 1000.242 - When does the requirement for exemption from taxation apply to affordable housing activities?

    Science.gov (United States)

    2010-04-01

    ... exemption from taxation apply to affordable housing activities? 1000.242 Section 1000.242 Housing and Urban... ACTIVITIES Indian Housing Plan (IHP) § 1000.242 When does the requirement for exemption from taxation apply to affordable housing activities? The requirement for exemption from taxation applies only to rental...

  9. FísicActiva: Applying Active Learning Strategies to a Large Engineering Lecture

    Science.gov (United States)

    Auyuanet, Adriana; Modzelewski, Helena; Loureiro, Silvia; Alessandrini, Daniel; Míguez, Marina

    2018-01-01

    This paper presents and analyses the results obtained by applying Active Learning techniques in overcrowded Physics lectures at the University of the Republic, Uruguay. The course referred to is Physics 1, the first Physics course that all students of the Faculty of Engineering take in their first semester for all the Engineering-related careers.…

  10. 15 CFR 20.2 - Programs or activities to which these regulations apply.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Programs or activities to which these regulations apply. 20.2 Section 20.2 Commerce and Foreign Trade Office of the Secretary of Commerce... adopted by an elected, general purpose legislative body which: (i) Provides benefits or assistance to...

  11. Squeezing Molecularly thin Lubricant Films between curved Corrugated Surfaces with long range Elasticity

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, Vladimir N.; Persson, Bo N. J.

    2010-01-01

    3H8, C4H10, C8H18, C9H20, C10H22, C14H30 and C16H34, confined between corrugated gold surfaces. Well defined molecular layers develop in the lubricant film when the width is of the order of a few atomic diameters. An external squeezing pressure induces discontinuous, thermally activated changes...

  12. Computational representation of Alzheimer's disease evolution applied to a cooking activity.

    Science.gov (United States)

    Serna, Audrey; Rialle, Vincent; Pigot, Hélène

    2006-01-01

    This article presents a computational model and a simulation of the decrease of activities of daily living performances due to Alzheimer's disease. The disease evolution is simulated thanks to the cognitive architecture ACT-R. Activities are represented according to the retrieval of semantic units in declarative memory and the trigger of rules in procedural memory. The simulation of Alzheimer's disease decrease is simulated thanks to the variation of subsymbolic parameters. The model is applied to a cooking activity. Simulation of 100 hundred subjects shows results similar to those realised in a standardized assessment with human subjects.

  13. Determination of activity of I-125 applying sum-peak methods

    International Nuclear Information System (INIS)

    Arbelo Penna, Y.; Hernandez Rivero, A.T.; Oropesa Verdecia, P.; Serra Aguila, R.; Moreno Leon, Y.

    2011-01-01

    The determination of activity of I-125 in radioactive solutions, applying sum-peak methods, by using an n-type HPGe detector of extended range is described. Two procedures were used for obtaining I-125 specific activity in solutions: a) an absolute method, which is independent of nuclear parameters and detector efficiency, and b) an option which consider constant the efficiency in the region of interest and involves calculations using nuclear parameters. The measurement geometries studied are specifically solid point sources. The relative deviations between specific activities, obtained by these different procedures are not higher than 1 %. Moreover, the activity of the radioactive solution was obtained by measuring it in NIST ampoule using a CAPINTEC CRC 35R dose calibrator. The consistency of obtained results, confirm the feasibility of applying direct methods of measurement for I-125 activity determinations, which allow us to achieve lower uncertainties in comparison with the relative methods of measurement. The establishment of these methods is aimed to be applied for the calibration of equipment and radionuclide dose calibrators used currently in clinical RIA/IRMA assays and Nuclear medicine practice respectively. (Author)

  14. Modeling of hydrothermal circulation applied to active volcanic areas. The case of Vulcano (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Todesco, M. [Dip. Scienze della Terra, Posa (Italy)

    1995-03-01

    Modeling of fluid and heat flows through porous media has been diffusely applied up to date to the study of geothermal reservoirs. Much less has been done to apply the same methodology to the study of active volcanoes and of the associated volcanic hazard. Hydrothermal systems provide direct information on dormant eruptive centers and significant insights on their state of activity and current evolution. For this reason, the evaluation of volcanic hazard is also based on monitoring of hydrothermal activity. Such monitoring, however, provides measurements of surface parameters, such as fluid temperature or composition, that often are only representative of the shallower portion of the system. The interpretation of these data in terms of global functioning of the hydrothermal circulation can therefore be highly misleading. Numerical modeling of hydrothermal activity provides a physical approach to the description of fluid circulation and can contribute to its understanding and to the interpretation of monitoring data. In this work, the TOUGH2 simulator has been applied to study the hydrothermal activity at Vulcano (Italy). Simulations involved an axisymmetric domain heated from below, and focused on the effects of permeability distribution and carbon dioxide. Results are consistent with the present knowledge of the volcanic system and suggest that permeability distribution plays a major role in the evolution of fluid circulation. This parameter should be considered in the interpretation of monitoring data and in the evaluation of volcanic hazard at Vulcano.

  15. [Cost of therapy for neurodegenerative diseases. Applying an activity-based costing system].

    Science.gov (United States)

    Sánchez-Rebull, María-Victoria; Terceño Gómez, Antonio; Travé Bautista, Angeles

    2013-01-01

    To apply the activity based costing (ABC) model to calculate the cost of therapy for neurodegenerative disorders in order to improve hospital management and allocate resources more efficiently. We used the case study method in the Francolí long-term care day center. We applied all phases of an ABC system to quantify the cost of the activities developed in the center. We identified 60 activities; the information was collected in June 2009. The ABC system allowed us to calculate the average cost per patient with respect to the therapies received. The most costly and commonly applied technique was psycho-stimulation therapy. Focusing on this therapy and on others related to the admissions process could lead to significant cost savings. ABC costing is a viable method for costing activities and therapies in long-term day care centers because it can be adapted to their structure and standard practice. This type of costing allows the costs of each activity and therapy, or combination of therapies, to be determined and aids measures to improve management. Copyright © 2012 SESPAS. Published by Elsevier Espana. All rights reserved.

  16. Evaluation on activation activity of reactor in JRR-2 applied 3 dimensional model to neutron flux calculation

    International Nuclear Information System (INIS)

    Kishimoto, Katsumi; Arigane, Kenji

    2005-03-01

    Revaluation to activation activity of reactor evaluated at the notification of dismantling submitted in 1997 was carried out in JRR-2 where decommissioning was advanced now. In the revaluation, estimation accuracy on neutron streaming at various horizontal experimental tubes was improved by applying 3 dimensional model to neutron transport calculation that had been carried out by 2 dimensional model, and calculating with TORT. As the result, excessive overestimations on horizontal experimental tubes and biological shield that had greatly contributed to total activation activity in evaluation at the notification of dismantling was revised, sum of their activation activities in the revaluation decreased to 1/18 (case after 1 year from the permanent shutdown of reactor) of evaluation at the notification of dismantling, and the structural materials that had large activation activity were changed. By the above, it was shown that introducing 3 dimensional model was effective in evaluation on activation activity of the research reactor that had a lot of various experimental tubes. Total activation activity of reactor by the revaluation depended on control rods, thermal shield plates and horizontal experimental tubes, and the value after 1 year from the permanent shutdown of reactor was 1.9x10 14 Bq. (author)

  17. USDOE Top-of-Rail Lubricant Project; FINAL

    International Nuclear Information System (INIS)

    Mohumad F. Alzoubi; George R. Fenske; Robert A. Erck; Amrit S. Boparai

    2002-01-01

    Lubrication of wheel/rail systems has been recognized for the last two decades as a very important issue for railroads. Energy savings and less friction and wear can be realized if a lubricant can be used at the wheel/rail interface. On the other hand, adverse influences are seen in operating and wear conditions if improper or excessive lubrication is used. Also, inefficiencies in lubrication need to be avoided for economic and environmental reasons. The top-of-rail (TOR) lubricant concept was developed by Texaco Corporation to lubricate wheels and rails effectively and efficiently. Tranergy Corporation has been developing its SENTRAEN 2000(trademark) lubrication system for the last ten years, and this revolutionary new high-tech on-board rail lubrication system promises to dramatically improve the energy efficiency, performance, safety, and track environment of railroads. The system is fully computer-controlled and ensures that all of the lubricant is consumed as the end of the train passes. Lubricant quantity dispensed is a function of grade, speed, curve, and axle load. Tranergy also has its LA4000(trademark) wheel and rail simulator, a lubrication and traction testing apparatus. The primary task of this project was collecting and analyzing the volatile and semivolatile compounds produced as the lubricant was used. The volatile organic compounds were collected by Carbotrap cartridges and analyzed by adsorption and gas chromatography/mass spectrometry (GC/MS). The semivolatile fraction was obtained by collecting liquid that dripped from the test wheel. The collected material was also analyzed by GC/MS. Both of these analyses were qualitative. The results indicated that in the volatile fraction, the only compounds on the Environmental Protection Agency's (EPA) Superfund List of Analytes detected were contaminants either in the room air or from other potential contamination sources in the laboratory. Similarly, in the semivolatile fraction none of the detected

  18. Lubricant effects on low Dk and silicone hydrogel lens comfort.

    Science.gov (United States)

    Ozkan, Jerome; Papas, Eric

    2008-08-01

    To investigate the influence of three lubricants of varying viscosity, on postinsertion and 6 h comfort with contact lens wear. Comfort and associated symptoms of dryness were assessed in 15 experienced contact lens wearers. Subjects wore a low Dk lens in one eye and a silicone hydrogel in the other and participated in four separate trials involving no lubricant (baseline), saline, and two commercially available lubricants of differing viscosity. The in-eye lubricants were used immediately following lens insertion and every 2 h postinsertion for a 6 h wear period. Postlens insertion comfort was significantly better for both lens types when lubricants or saline were used compared with no lubricant use. After 6 h lens wear, comfort was influenced by lens type and not by in-eye lubricant or saline use. Also after 6 h lens wear, less dryness sensation was reported for silicone hydrogel lenses when using lubricants but not saline. Although lubricant use does help reduce dryness symptoms with silicone hydrogel lens wear, there appears to be minimal longer-term benefit to comfort. Furthermore, increased lubricant viscosity did not lead to improved longer-term comfort.

  19. Peculiarities of applying complex marketing elements in the activity of public administration bodies in Ukraine

    Directory of Open Access Journals (Sweden)

    Yuriy ZBYRANIK

    2016-12-01

    Full Text Available Many practices are implemented in the activity of public administration bodies, which are used by the representatives of the business sector at the current stage of development of Ukraine. One of these practices is marketing. The article considers the theoretical aspects of marketing that can be applied in the work of public authorities. The fundamental differences between the sphere of public administration and the business are stated in this context. The main elements of the marketing mix are analysed and the peculiarities of marketing tools, which can be applied to the sphere of public administration, are noted.

  20. Experience with synthetic fluorinated fluid lubricants

    Science.gov (United States)

    Conley, Peter L.; Bohner, John J.

    1990-01-01

    Since the late 1970's, the wet lubricant of choice for space mechanisms has been one of the family of synthetic perfluoro polyalkylether (PFPE) compounds, namely Fomblin Z-25 (Bray-815Z) or DuPont's Krytox 143xx series. While offering the advantages of extremely low vapor pressures and wide temperature ranges, these oils and derived greases have a complex chemistry compared to the more familiar natural and synthetic hydrocarbons. Many aerospace companies have conducted test programs to characterize the behavior of these compounds in a space environment, resulting in a large body of hard knowledge as well as considerable space lore concerning the suitability of the lubricants for particular applications and techniques for successful application. The facts are summarized and a few myths about the compounds are dispelled, and some performance guidelines for the mechanism design engineer are provided.

  1. Noise of oil lubricated journal bearings

    International Nuclear Information System (INIS)

    Rho, Byoung Hoo; Kim, Kyung Woong

    2002-01-01

    The purpose of the paper is to provide a procedure to calculate the noise of oil lubricated journal bearings. To do this, the nonlinear transient analysis of rotor-bearing system including rotor imbalance is performed. Acoustical properties of the bearing are investigated through frequency analysis of the pressure fluctuation of the fluid film calculated from the nonlinear analysis. Furthermore, a transmission theory of plane waves on a boundary of the outer surface of the bearing is used to obtain the sound pressure level of the bearing. Results show that the sound pressure level of the bearing can be increased with the rotational speed of the rotor although the whirl amplitude of the rotor is decreased at high speed. Noise estimating procedures presented in this paper could be an aid in the evaluation and understanding of acoustical properties of oil lubricated journal bearings

  2. Technology development for indigenous water lubricated bearings

    International Nuclear Information System (INIS)

    Limaye, P.K.; Soni, N.L.; Agrawal, R.G.

    2010-01-01

    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)

  3. Wear Characteristics of Ceramic Coating Materials by Plasma Spray under the Lubricative Environment

    International Nuclear Information System (INIS)

    Kim, Chang Ho

    2001-02-01

    This paper is to investigate the wear behaviors of two types of ceramics, Al 2 O 3 and TiO 2 , by coated plasma thermal spray method under the lubricative environment. The lubricative environments are grease fluids, a general hydraulic fluids, and bearing fluids. The wear testing machine used a pin on disk type. Wear characteristics, which were friction force, friction coefficient and the specific wear rate, according to the lubricative environments were obtained at the four kinds of load, and the sliding velocity is 0.2m/sec. After the wear experiments, the wear surfaces of the each test specimen were observed by a scanning electronic microscope. The obtained results are as follows. : 1. The friction coefficients of TiO 2 coating materials are 0.11 ∼ 0.16 range and those of Al 2 O 3 are 0.24 ∼ 0.39. The friction coefficient of two coating materials is relative to the hardness of these materials. 2. The friction coefficient of TiO 2 coating materials in three lubricative environments is almost same to each other in spite of changing of applied loads. 3. The friction coefficient of Al 2 O 3 coating materials is more large in low load than high load. And the friction coefficient in grease is more large than a general hydraulic and bearing fluids had almost same friction coefficient. 4. The specific wear rate in TiO 2 is greatly increasing according to change the applied loads, but that in Al 2 O 3 is slightly. And the wear in grease is the least among three lubricating environments. 5. On the wear mechanism by SEM image observation, the wear of Al 2 O 3 is adhesive wear and TiO 3 is abrasive wear

  4. ASPECTS OF OBSTACLES FOR APPLYING ACTIVITY BASED COSTING (ABC SYSTEM IN EGYPTIAN FIRMS

    Directory of Open Access Journals (Sweden)

    Petru STEFEA

    2013-10-01

    Full Text Available The following investigation aims to determine the aspects of obstacles for applying Activity Based Costing (ABC system in the Egyptian case and the significant differences among the effects of such obstacles . The Study used the survey method to describe and analyze the obstacles in some Egyptian firms. The population of the study is Egyptian manufacturing firms. This survey used the number of 392 questionnaires that were used throughout the total of 23 Egyptian manufacturing firms, during the first half of 2013. Finally, the study found some influencing obstacles for applying this system (ABC and there were significant differences among the aspects of obstacles for applying ABC system in the Egyptian manufacturing firms.

  5. Universal water-dilutable inhibited protective lubricants

    International Nuclear Information System (INIS)

    Mamtseva, M.V.; Kardash, N.V.; Latynina, M.B.

    1993-01-01

    In the interest of environmental protection, improvement of working conditions, and reduced fire hazard in production operations, water-based protective lubricants are now available in a wide assortment, and the production volume has increased greatly. The term water-dilutable inhibited protective lubricants (WDIPL) means water-soluble, water-emulsifiable, or water-dispersible products with the dual function of reducing friction and wear and protecting metal surfaces against corrosion for specified periods of time. According to the standard Unified System of Protection Against Corrosion and Aging (COST 9.103-78), WDIPLs are classed as products for the temporary corrosion protection of metals and end-items. In the general class of WDIPLs one can identify water-dilutable combination corrosion inhibitors, film-forming inhibited petroleum compositions (FIPC-d), detergent-preservative fluids, operational-preservative lubricating-cooling process compounds (ICPC), and, finally, universal multifunctional products. Combined corrosion inhibitors may consist of water-soluble organic and inorganic compounds; water/oil and oil-soluble surfactants - corrosion inhibitors of the chemisorption type or donor and/or acceptor types; shielding inhibitors of the adsorption type; and fast-acting water-displacing components. 23 refs

  6. Numerical study on the lubrication performance of compression ring-cylinder liner system with spherical dimples.

    Directory of Open Access Journals (Sweden)

    Cheng Liu

    Full Text Available The effects of surface texture on the lubrication performance of a compression ring-cylinder liner system are studied in this paper. By considering the surface roughness of the compression ring and cylinder liner, a mixed lubrication model is presented to investigate the tribological behaviors of a barrel-shaped compression ring-cylinder liner system with spherical dimples on the liner. In order to determine the rupture and reformulation positions of fluid film accurately, the Jacoboson-Floberg-Olsson (JFO cavitation boundary condition is applied to the mixed lubrication model for ensuring the mass-conservative law. On this basis, the minimum oil film thickness and average friction forces in the compression ring-cylinder liner system are investigated under the engine-like conditions by changing the dimple area density, radius, and depth. The wear load, average friction forces, and power loss of the compression ring-cylinder liner system with and without dimples are also compared for different compression ring face profiles. The results show that the spherical dimples can produce a larger reduction of friction in mixed lubrication region, and reduce power loss significantly in the middle of the strokes. In addition, higher reduction percentages of average friction forces and wear are obtained for smaller crown height or larger axial width.

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

    International Nuclear Information System (INIS)

    Washizu, Hitoshi; Sanda, Shuzo; Hyodo, Shi-aki; Ohmori, Toshihide; Nishino, Noriaki; Suzuki, Atsushi

    2007-01-01

    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

  8. Lubricant flow analysis for effective lubrication of tractor forward/reverse clutch

    Directory of Open Access Journals (Sweden)

    Daekyung Noh

    2017-04-01

    Full Text Available Owing to the high power requirements of tractors, their low-power transmission gears often experience durability problems such as burning of the clutch. The operation of tractors under high load conditions also causes clutch slip, with the consequent longer operation duration exacerbating the burning of the friction plate. Solving this problem requires effective lubricant distribution. This was achieved in the present study by the development of an analysis model for predicting the lubricant flow rate. The reliability of the model was verified by comparing its predictions for various operation conditions with experimental measurements. Using the model, it was determined that effective distribution of the lubricant could be achieved without significant modification of the system, by only adjusting the gaps between the clutch piston and the housing, and between the separation plates and the case. Keywords: Mechanical engineering

  9. Tribological properties of self-lubricating Ta-Cu films

    Science.gov (United States)

    Qin, Wen; Fu, Licai; Zhu, Jiajun; Yang, Wulin; Li, Deyi; Zhou, Lingping

    2018-03-01

    In this paper, Ta and TaCu films were deposited by using magnetron sputtering, and the tribological properties of the films against Si3N4 balls were investigated under the loads of 2 N and 5 N. The average grain sizes of both films are below 25 nm. Ta and TaCu films have approximate hardness. While the wear rate of TaCu film is much smaller than that of Ta film. Post-wear testing XRD, Raman and XPS revealed the formation of tantalum oxide on the worn surface of both Ta and TaCu films. Tantalum oxidation is effectively lubricating to reduce friction coefficient. So the friction coefficient of both Ta and TaCu film is about 0.45 under different applied loads. Meanwhile, the addition of Cu could increase the toughness of the film, and avoid the generation of wear debris, resulting in a significant increase in wear resistance.

  10. Professional-applied pedagogical teaching of junior school future teachers to working activity.

    Directory of Open Access Journals (Sweden)

    Kozhevnikova L.K.

    2012-03-01

    Full Text Available A purpose of work is determination of maintenance and most meaningful features of activity of teachers of initial classes in the after hours forms of work with students on a section «physical culture». The program is presented professionally-applied preparations and directions of forming professional readiness of students to their future professional activity. 323 students of pedagogical faculty and 253 students - future teachers of initial classes took part in the questionnaire questioning. The most essential sides of preparation of students are selected: motivation, awareness of the future profession as a process of decision of pedagogical tasks, independent participating in the real process of teaching.

  11. Applying Activity Based Costing (ABC) Method to Calculate Cost Price in Hospital and Remedy Services.

    Science.gov (United States)

    Rajabi, A; Dabiri, A

    2012-01-01

    Activity Based Costing (ABC) is one of the new methods began appearing as a costing methodology in the 1990's. It calculates cost price by determining the usage of resources. In this study, ABC method was used for calculating cost price of remedial services in hospitals. To apply ABC method, Shahid Faghihi Hospital was selected. First, hospital units were divided into three main departments: administrative, diagnostic, and hospitalized. Second, activity centers were defined by the activity analysis method. Third, costs of administrative activity centers were allocated into diagnostic and operational departments based on the cost driver. Finally, with regard to the usage of cost objectives from services of activity centers, the cost price of medical services was calculated. The cost price from ABC method significantly differs from tariff method. In addition, high amount of indirect costs in the hospital indicates that capacities of resources are not used properly. Cost price of remedial services with tariff method is not properly calculated when compared with ABC method. ABC calculates cost price by applying suitable mechanisms but tariff method is based on the fixed price. In addition, ABC represents useful information about the amount and combination of cost price services.

  12. Molecular dynamics study of lubricant depletion by pulsed laser heating

    Science.gov (United States)

    Seo, Young Woo; Rosenkranz, Andreas; Talke, Frank E.

    2018-05-01

    In this study, molecular dynamics simulations were performed to numerically investigate the effect of pulsed laser heating on lubricant depletion. The maximum temperature, the lubricant depletion width, the number of evaporated lubricant beads and the number of fragmented lubricant chains were studied as a function of laser peak power, pulse duration and repetition rate. A continuous-wave laser and a square pulse laser were simulated and compared to a Gaussian pulse laser. With increasing repetition rate, pulsed laser heating was found to approach continuous-wave laser heating.

  13. Effect of gamma radiation on graphite - PTFE dry lubrication system

    Science.gov (United States)

    Singh, Sachin; Tyagi, Mukti; Seshadri, Geetha; Tyagi, Ajay Kumar; Varshney, Lalit

    2017-12-01

    An effect of gamma radiation on lubrication behavior of graphite -PTFE dry lubrication system has been studied using (TR-TW-30L) tribometer with thrust washer attachment in plane contact. Different compositions of graphite and PTFE were prepared and irradiated by gamma rays. Gamma radiation exposure significantly improves the tribological properties indicated by decrease in coefficient of friction and wear properties of graphite -PTFE dry lubrication system. SEM and XRD analysis confirm the physico-chemical modification of graphite-PTFE on gamma radiation exposure leading to a novel dry lubrication system with good slip and anti friction properties.

  14. ACTIVITY THEORY APPLIED AT CHANNEL EXPANSIONS IN SMALL AND MEDIUM ENTERPRISES

    Directory of Open Access Journals (Sweden)

    Siw Lundqvist

    2017-06-01

    Full Text Available Today’s commonly carried out channel expansions of commerce could be both costly and problematic to manage. Especially for small and medium-sized enterprises (SMEs that often suffer from a lack of digital competence, time and monetary resources in generally. Still, these transitions would be necessary to carry out because of customer demands and expectations concerning 24/7 availability, and access to digital commerce alternatives. Scarce resources are important reasons to search for how to carry out channel expansions with minimized problems. Activity theory (AT focuses on the whole in order to detect problems that hinder successful outcomes. Hence, this theory was applied to prior findings, from a project about SME’s channel expansions, highlighting several problems that could appear during these activities. Implications for research foremost involve issues connected to the use of AT; implications for practice particularly concern if and how AT could be used to support channel broadening activities.

  15. Applied research and service activities at the University of Missouri Research Reactor Facility (MURR)

    International Nuclear Information System (INIS)

    Alger, D.M.

    1987-01-01

    The University Of Missouri operates MURR to provide an intense source of neutron and gamma radiation for research and applications by experimenters from its four campuses and by experimenters from other universities, government and industry. The 10 MW reactor, which has been operating an average of 155 hours per week for the past eight years, produces thermal neutron fluxes up to 6-7x10 14 n/cm 2 -s in the central flux trap and beamport source fluxes of up to 1.2x10 14 n/cm 2 -s. The mission of the reactor facility, to promote research, education and service, is the same as the overall mission of the university and therefore, applied research and service supported by industrial firms have been welcomed. The university recognized after a few years of reactor operation that in order to build utilization, it would be necessary to develop in-house research programs including people, equipment and activity so that potential users could more easily and quickly obtain the results needed. Nine research areas have been developed to create a broadly based program to support the level of activity needed to justify the cost of operating the facility. Applied research and service generate financial support for about one-half of the annual budget. The applied and service programs provide strong motivation for university/industry association in addition to the income generated. (author)

  16. 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

    2010-01-01

    , during upsetting and strip drawing, by means of a rigid-viscoplastic finite-element formulation. Special emphasis is placed on the effect of pocket geometry on the build-up of hydrostatic pressure, which is responsible for the onset of micro-lubrication mechanisms. A good agreement is found between......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 mechanisms...

  17. Ultralow Friction Self-Lubricating Nanocomposites with Mesoporous Metal-Organic Frameworks as Smart Nanocontainers for Lubricants.

    Science.gov (United States)

    Zhang, Guoliang; Xie, Guoxin; Si, Lina; Wen, Shizhu; Guo, Dan

    2017-11-01

    Smart nanocontainers with stimuli-responsive property can be used to fabricate a new kind of self-lubricating nanocomposite, while the practical potential of the metal-organic frameworks (MOFs) as nanocontainers for lubricants has not been realized. In this work, mesoporous Cu-BTC MOFs storing oleylamine nanocomposites were explored from synthesis and microstructure to self-lubricating characterization. The stress stimuli-responsiveness behavior of the Cu-BTC storing oleylamine (Cu-BTCO) for lubrication has been investigated by subjecting it to macroscopic ball-on-disc friction tests. The steady-state coefficients of friction (COFs) of the Cu-BTC nanocomposites without lubricants were ca. 0.5. In contrast, after oleylamine as the lubricant was incorporated into the Cu-BTC container in the nanocomposite, ultralow friction (COF, ca. 0.03) was achieved. It has been demonstrated that the improved lubricating performance was associated with the lubricating film which was in situ produced by the chemical reaction between the oleylamine released from the nanocontainer and the friction pairs. Therefore, the nanocomposite with smart Cu-BTC container holds the promise of realizing extraordinary self-lubricating properties under stress stimuli.

  18. MEMS Lubrication by In-Situ Tribochemical Reactions From the Vapor Phase.

    Energy Technology Data Exchange (ETDEWEB)

    Dugger, Michael Thomas; Asay, David B.; Kim, Seong H.

    2008-01-01

    Vapor Phase Lubrication (VPL) of silicon surfaces with pentanol has been demonstrated. Two potential show stoppers with respect to application of this approach to real MEMS devices have been investigated. Water vapor was found to reduce the effectiveness of VPL with alcohol for a given alcohol concentration, but the basic reaction mechanism observed in water-free environments is still active, and devices operated much longer in mixed alcohol and water vapor environments than with chemisorbed monolayer lubricants alone. Complex MEMS gear trains were successfully lubricated with alcohol vapors, resulting in a factor of 104 improvement in operating life without failure. Complex devices could be made to fail if operated at much higher frequencies than previously used, and there is some evidence that the observed failure is due to accumulation of reaction products at deeply buried interfaces. However, if hypothetical reaction mechanisms involving heated surfaces are valid, then the failures observed at high frequency may not be relevant to operation at normal frequencies. Therefore, this work demonstrates that VPL is a viable approach for complex MEMS devices in conventional packages. Further study of the VPL reaction mechanisms are recommended so that the vapor composition may be optimized for low friction and for different substrate materials with potential application to conventionally fabricated, metal alloy parts in weapons systems. Reaction kinetics should be studied to define effective lubrication regimes as a function of the partial pressure of the vapor phase constituent, interfacial shear rate, substrate composition, and temperature.

  19. Likelihood of cesarean delivery after applying leading active labor diagnostic guidelines.

    Science.gov (United States)

    Neal, Jeremy L; Lowe, Nancy K; Phillippi, Julia C; Ryan, Sharon L; Knupp, Amy M; Dietrich, Mary S; Thung, Stephen F

    2017-06-01

    Friedman, the United Kingdom's National Institute for Health and Care Excellence (NICE), and the American College of Obstetricians and Gynecologists/Society for Maternal-Fetal Medicine (ACOG/SMFM) support different active labor diagnostic guidelines. Our aims were to compare likelihoods for cesarean delivery among women admitted before vs in active labor by diagnostic guideline (within-guideline comparisons) and between women admitted in active labor per one or more of the guidelines (between-guideline comparisons). Active labor diagnostic guidelines were retrospectively applied to cervical examination data from nulliparous women with spontaneous labor onset (n = 2573). Generalized linear models were used to determine outcome likelihoods within- and between-guideline groups. At admission, 15.7%, 48.3%, and 10.1% of nulliparous women were in active labor per Friedman, NICE, and ACOG/SMFM diagnostic guidelines, respectively. Cesarean delivery was more likely among women admitted before vs in active labor per the Friedman (AOR 1.75 [95% CI 1.08-2.82] or NICE guideline (AOR 2.55 [95% CI 1.84-3.53]). Between guidelines, cesarean delivery was less likely among women admitted in active labor per the NICE guideline, as compared with the ACOG/SMFM guideline (AOR 0.55 [95% CI 0.35-0.88]). Many nulliparous women are admitted to the hospital before active labor onset. These women are significantly more likely to have a cesarean delivery. Diagnosing active labor before admission or before intervention to speed labor may be one component of a multi-faceted approach to decreasing the primary cesarean rate in the United States. The NICE diagnostic guideline is more inclusive than Friedman or ACOG/SMFM guidelines and its use may be the most clinically useful for safely lowering cesarean rates. © 2017 Wiley Periodicals, Inc.

  20. 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...... 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...... are used as actuators and the flexible rotor lateral movements as feedback control signals. To synthesise the PD controller gains an objective function is optimized in the stabilizing gain domain and then chosen from a subdomain imposed by the servovalves restrictions. The D-decomposition approach expanded...

  1. 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 mechani...... is used to show the benefits of applying a controllable lubrication regime, by means of the modification of the thermal and dynamic behaviour of the bearing....

  2. Two methodologies for optical analysis of contaminated engine lubricants

    International Nuclear Information System (INIS)

    Aghayan, Hamid; Yang, Jun; Bordatchev, Evgueni

    2012-01-01

    The performance, efficiency and lifetime of modern combustion engines significantly depend on the quality of the engine lubricants. However, contaminants, such as gasoline, moisture, coolant and wear particles, reduce the life of engine mechanical components and lubricant quality. Therefore, direct and indirect measurements of engine lubricant properties, such as physical-mechanical, electro-magnetic, chemical and optical properties, are intensively utilized in engine condition monitoring systems and sensors developed within the last decade. Such sensors for the measurement of engine lubricant properties can be used to detect a functional limit of the in-use lubricant, increase drain interval and reduce the environmental impact. This paper proposes two new methodologies for the quantitative and qualitative analysis of the presence of contaminants in the engine lubricants. The methodologies are based on optical analysis of the distortion effect when an object image is obtained through a thin random optical medium (e.g. engine lubricant). The novelty of the proposed methodologies is in the introduction of an object with a known periodic shape behind a thin film of the contaminated lubricant. In this case, an acquired image represents a combined lubricant–object optical appearance, where an a priori known periodic structure of the object is distorted by a contaminated lubricant. In the object shape-based optical analysis, several parameters of an acquired optical image, such as the gray scale intensity of lubricant and object, shape width at object and lubricant levels, object relative intensity and width non-uniformity coefficient are newly proposed. Variations in the contaminant concentration and use of different contaminants lead to the changes of these parameters measured on-line. In the statistical optical analysis methodology, statistical auto- and cross-characteristics (e.g. auto- and cross-correlation functions, auto- and cross-spectrums, transfer function

  3. 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

    2004-01-01

    mechanisms, during upsetting and strip drawing, by means of a rigid viscoplastic finite element formulation. Special emphasis is placed on the effect of pocket geometry on the build up of hydrostatic pressure, which is responsible for the onset of micro lubrication mechanisms. A good agreement is found...... between the numerically predicted and the experimentally measured distributions of hydrostatic stress....

  4. Numerical analysis of capillary compensated micropolar fluid lubricated hole-entry journal bearings

    Directory of Open Access Journals (Sweden)

    Nathi Ram

    2016-06-01

    Full Text Available The micropolar lubricated symmetric/asymmetric hole-entry bearings using capillary restrictor have been analyzed in the present work. Reynolds equation for micropolar lubricant has been derived and solved by FEM. The results have been computed using selected parameters of micropolar lubricant for hole-entry hydrostatic/hybrid journal bearings. A significant increase in damping and stiffness coefficients is observed for bearings having micropolar parameter N2=0.9, lm=10 than similar bearings under Newtonian lubricant. The threshold speed gets increased when symmetric bearing lubricated under micropolar fluid than Newtonian lubricant. The threshold speed gets increased when symmetric bearing lubricated under micropolar fluid than Newtonian lubricant.

  5. Modified Ionic Liquid-Based High-Performance Lubricants for Robotic Operations, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA needs an advanced lubrication solution for its future robotic systems and planetary surface assets. The required lubrication technology must offer...

  6. The Applied Behavior Analysis Research Paradigm and Single-Subject Designs in Adapted Physical Activity Research.

    Science.gov (United States)

    Haegele, Justin A; Hodge, Samuel Russell

    2015-10-01

    There are basic philosophical and paradigmatic assumptions that guide scholarly research endeavors, including the methods used and the types of questions asked. Through this article, kinesiology faculty and students with interests in adapted physical activity are encouraged to understand the basic assumptions of applied behavior analysis (ABA) methodology for conducting, analyzing, and presenting research of high quality in this paradigm. The purposes of this viewpoint paper are to present information fundamental to understanding the assumptions undergirding research methodology in ABA, describe key aspects of single-subject research designs, and discuss common research designs and data-analysis strategies used in single-subject studies.

  7. Borax as a lubricant in powder metallurgy

    Directory of Open Access Journals (Sweden)

    Héctor Geovanny Ariza-Suarez

    2014-12-01

    were compacted at 700 MPa in a uniaxial press of 15 tons. DSC-TGA analysis of the mixture with borax was realized. The specimens were sintered in a plasma reactor at 1000 for 30 minutes, with a combined atmosphere of hydrogen and argon. Microhardness and density of the sintered samples was haracterized. XRD analysis was realized to detect possible compounds formation by interaction of borax. This paper shows that borax can be used as a lubricant in powder metallurgy.

  8. Nanotribology of Symmetric and Asymmetric Liquid Lubricants

    Directory of Open Access Journals (Sweden)

    Shinji Yamada

    2010-03-01

    Full Text Available When liquid molecules are confined in a narrow gap between smooth surfaces, their dynamic properties are completely different from those of the bulk. The molecular motions are highly restricted and the system exhibits solid-like responses when sheared slowly. This solidification behavior is very dependent on the molecular geometry (shape of liquids because the solidification is induced by the packing of molecules into ordered structures in confinement. This paper reviews the measurements of confined structures and friction of symmetric and asymmetric liquid lubricants using the surface forces apparatus. The results show subtle and complex friction mechanisms at the molecular scale.

  9. Piston-Skirt Lubrication System For Compressor

    Science.gov (United States)

    Schroeder, Edgar C.; Burzynski, Marion, Jr.

    1994-01-01

    Piston-skirt lubrication system provides steady supply of oil to piston rings of gas compressor. No need for oil-filled crankcase or external oil pump. Instead, part of each piston acts as its own oil pump circulating oil from reservoir. Annular space at bottom of piston and cylinder constitutes working volume of small oil pump. Depending on application, reservoir open to atmosphere, or sealed and pressurized in bellows to prevent contact between oil and atmosphere. Filter removes particles worn away from piston rings and cylinder wall during normal operation.

  10. Ionic liquids containing symmetric quaternary phosphonium cations and phosphorus-containing anions, and their use as lubricant additives

    Science.gov (United States)

    Qu, Jun; Luo, Huimin

    2018-05-01

    An ionic liquid composition having the following generic structural formula: ##STR00001## wherein R1, R2, R3, and R4 are equivalent and selected from hydrocarbon groups containing at least three carbon atoms, and X- is a phosphorus-containing anion, particularly an organophosphate, organophosphonate, or organophosphinate anion, or a thio-substituted analog thereof containing hydrocarbon groups with at least three carbon atoms. Also described are lubricant compositions comprising the above ionic liquid and a base oil, wherein the ionic liquid is dissolved in the base oil. Further described are methods for applying the ionic liquid or lubricant composition onto a mechanical device for which lubrication is beneficial, with resulting improvement in friction reduction, wear rate, and/or corrosion inhibition.

  11. Specific-activity and concentration model applied to cesium movement in an oligotrophic lake

    International Nuclear Information System (INIS)

    Vanderploeg, H.A.; Booth, R.S.; Clark, F.H.

    1975-01-01

    A linear systems-analysis model was derived to simulate the time-dependent dynamics of specific activity and concentration of radionuclides in aquatic systems. Transfer coefficients were determined for movement of 137 Cs in the components of an oligotrophic lake. These coefficients were defined in terms of basic environmental and ecological data so that the model can be applied to a wide variety of sites. Simulations with a model that ignored sediment--water interactions predicted much higher 137 Cs specific activities in the lake water and biota than did those with the complete model. Comparing 137 Cs concentrations predicted by the model with concentrations reported for the biota of an experimentally contaminated oligotrophic lake indicated that the transfer coefficients derived for the biota are adequate

  12. Self-lubricating polymer composites : Tribology and interface

    NARCIS (Netherlands)

    Shen, Jintao

    2015-01-01

    In cooperation with SKF, this PhD project focus on the improvement of the tribological performance of self-lubricating composites for dry sliding bearings. Several novel self-lubricating composites with very good performance and low production cost is developed in this research, which perform better

  13. Testing of environmentally friendly lubricants for sheet metal forming

    DEFF Research Database (Denmark)

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

    2005-01-01

    the authors have especially been involved in the development of a system of test methods for sheet metal forming and in testing of friction and limits of lubrication of new, environmentally friendly lubricants. An overview of the developed tests is presented together with selected results....

  14. Prediction of limits of lubrication in strip reduction testing

    DEFF Research Database (Denmark)

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

    2004-01-01

    Pick-up and galling due to lubricant film breakdown is a severe limitation in cold forming of tribologically difficult metals like stainless steel and aluminium. The present paper describes a method of combined experimental and numerical analysis to quantify the limits of lubrication in a dedicated...

  15. Hydrophobins as aqueous lubricant additive for a soft sliding contact

    DEFF Research Database (Denmark)

    Lee, Seunghwan; Røn, Troels; Pakkanen, Kirsi I.

    2015-01-01

    lubrication characteristic is dominant via ‘self-healing’ mechanism. FpHYD5 revealed a better lubrication than HFBI presumably due to the presence of glycans and improved hydration of the sliding interface. Two type II hydrophobins function more favorably compared to a synthetic amphiphilic copolymer, PEO-PPO...

  16. Piston ring lubrication and hydrocarbon emissions from internal combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Froelund, K.

    1997-11-01

    Is it the intention with this project to improve the existing hydrocarbon emission model at the Institute by combining it with a model for predicting the piston ring lubrication. The piston ring lubrication model should be experimentally verified to ensure the validity of the model. The following items were the objectives of the current study: Develop a piston ring lubrication model. This implies the development of a ring-pack gas flow model; Examine the response of the piston ring lubrication model to changing engineer conditions. Especially, it would be interesting to look at the engine warm-up phase since this is the phase where the engine-out emissions are highest and where the commonly used three way catalyst is not capable of converting the engine-out emissions, thereby leading the engine-out emissions directly out in to the environment with the exhaust gases; In order to verify the piston ring lubrication model the lubricant distribution on the cylinder liner should be investigated experimentally. Here again it would be of great interesting to look at the engine warm-up phase; The piston ring lubrication model should be adjusted for application together with the new hydrocarbon emission model for SI-engines at the Institute in order to increase the accuracy of the latter; The piston ring lubrication model could be used for describing the transport of PAH`s in diesel engines. (EG)

  17. Mild wear modeling in the boundary lubrication regime

    NARCIS (Netherlands)

    Bosman, Rob

    2011-01-01

    Currently, the increasing demand for smaller and more efficient systems is increasing the stress put on interacting components. This forces components to operate in the boundary lubrication regime. In this lubrication regime, the normal load put on the components is no longer carried by the

  18. Surface effects in adhesion, friction, wear, and lubrication

    National Research Council Canada - National Science Library

    Buckley, Donald H

    1981-01-01

    ... for carbon bodies to improve their wear resistance in high altitude aircraft generator applications. Basic researchers found that moisture in the carbon was critical t o its lubrication. Therefore, the presence of moisture o n the surface of the carbon was important. With it present, the carbon lubricated very effectively and very low wear was ...

  19. Adaptive system of supplying lubricant to the internal combustion engine

    Science.gov (United States)

    Barylnikova, E. P.; Kulakov, A. T.; Kulakov, O. A.

    2017-09-01

    This paper assesses the impact of reducing the pressure in the lubrication system on the failures of the crankshaft bearings. The method of adapting lubricating system of the diesel engine as the wear in operation and depending on the operation modes.

  20. Lubricant reflow after laser heating in heat assisted magnetic recording

    Science.gov (United States)

    Wu, Haoyu; Mendez, Alejandro Rodriguez; Xiong, Shaomin; Bogy, David B.

    2015-05-01

    In heat assisted magnetic recording (HAMR) technology for hard disk drives, the media will be heated to about 500 °C during the writing process in order to reduce its magnetic coercivity and thus allow data writing with the magnetic head transducers. The traditional lubricants such as Z-dol and Z-tetraol may not be able to perform in such harsh heating conditions due to evaporation, decomposition and thermal depletion. However, some of the lubricant depletion can be recovered due to reflow after a period of time, which can help to reduce the chance of head disk interface failure. In this study, experiments of lubricant thermal depletion and reflow were performed using a HAMR test stage for a Z-tetraol type lubricant. Various lubricant depletion profiles were generated using different laser heating conditions. The lubricant reflow process after thermal depletion was monitored by use of an optical surface analyzer. In addition, a continuum based lubrication model was developed to simulate the lubricant reflow process. Reasonably good agreement between simulations and experiments was achieved.

  1. Electronics department progress report. Basic and applied research activity 1975-1977

    International Nuclear Information System (INIS)

    1978-10-01

    The electronics department at Risoe National Laboratory, Denmark, comprises about 80 people and is made up of essentially two main divisions. One deals with the provision of instrumentation and measurement expertise for the different groups at Risoe who conduct basic research or technological R and D. This division employs a group of scientific electronics consultants, a production group, a maintenance facility and a central instrument pool for the complete site. The other division, whose work is reported here, is engaged in both basic and applied research in topics and areas of direct interest to the department itself. These involve the development and evaluation of methods, for example, in the field of plant reliability and safety as well as in a group engaged in nuclear geophysical activities - including mineral prospecting in Greenland. Another team is working with man-machine problems in highly automated systems and the associated needs for computer support in connection with proper job allocation and design. Finally, a group is active in the field of applied laser physics. The time period covered is 1975-1977. (author/BP)

  2. Cold Atmospheric-Pressure Plasmas Applied to Active Packaging of Fruits and Vegetables

    Science.gov (United States)

    Pedrow, Patrick; Fernandez, Sulmer; Pitts, Marvin

    2008-10-01

    Active packaging of fruits and vegetables uses films that absorb molecules from or contribute molecules to the produce. Applying uniform film to specific parts of a plant will enhance safe and economic adoption of expensive biofilms and biochemicals which would damage the plant or surrounding environment if misapplied. The pilot application will be to apply wax film to apples, replacing hot wax which is expensive and lowers the textural quality of the apple. The plasma zone will be obtained by increasing the voltage on an electrode structure until the electric field in the feed material (Argon + monomer) is sufficiently high to yield electron avalanches. The ``corona onset criterion'' is used to design the cold plasma reactor. The apple will be placed in a treatment chamber downstream from the activation zone. Key physical properties of the film will be measured. The deposition rate will be optimized in terms of economics and fruit surface quality for the purpose of determining if the technique is competitive in food processing plants.

  3. Applied neuroanatomy elective to reinforce and promote engagement with neurosensory pathways using interactive and artistic activities.

    Science.gov (United States)

    Dao, Vinh; Yeh, Pon-Hsiu; Vogel, Kristine S; Moore, Charleen M

    2015-01-01

    One in six Americans is currently affected by neurologic disease. As the United States population ages, the number of neurologic complaints is expected to increase. Thus, there is a pressing need for more neurologists as well as more neurology training in other specialties. Often interest in neurology begins during medical school, so improving education in medical neural courses is a critical step toward producing more neurologists and better neurology training in other specialists. To this end, a novel applied neuroanatomy elective was designed at the University of Texas Health Science Center at San Antonio (UTHSCSA) to complement the traditional first-year medical neuroscience course and promote engagement and deep learning of the material with a focus on neurosensory pathways. The elective covered four neurosensory modalities (proprioception/balance, vision, auditory, and taste/olfaction) over four sessions, each with a short classroom component and a much longer activity component. At each session, students reviewed the neurosensory pathways through structured presentations and then applied them to preplanned interactive activities, many of which allowed students to utilize their artistic talents. Students were required to complete subjective pre-course and post-course surveys and reflections. The survey results and positive student comments suggest that the elective was a valuable tool when used in parallel with the traditional medical neuroscience course in promoting engagement and reinforcement of the neurosensory material. © 2014 American Association of Anatomists.

  4. Application of a Biodegradable Lubricant in a Diesel Vehicle

    DEFF Research Database (Denmark)

    Schramm, Jesper

    2003-01-01

    The IEA Advanced Motor Fuels Agreement has initiated this project concerning the application of biodegradable lubricants to diesel and gasoline type vehicles. Emission measurements on a chassis dynamometer were carried out. The purpose of these measurements was to compare the emissions of CO, CO2......, 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...... that have been evaluated during the experiments. Both vehicle types were operated on conventional crude oil based fuels and alternative fuels. The diesel vehicle was operated on conventional diesel fuel from a Danish fuel station, low sulfur diesel from Sweden and biodiesel, which was bought at a fuel...

  5. Tribological performance of nanoparticles as lubricating oil additives

    Energy Technology Data Exchange (ETDEWEB)

    Gulzar, M., E-mail: mubashir-nustian@hotmail.com; Masjuki, H. H., E-mail: masjuki@um.edu.my; Kalam, M. A.; Varman, M.; Zulkifli, N. W. M. [University of Malaya, Department of Mechanical Engineering, Faculty of Engineering, Centre for Energy Sciences (Malaysia); Mufti, R. A. [National University of Sciences and Technology (NUST) (Pakistan); Zahid, Rehan [University of Malaya, Department of Mechanical Engineering, Faculty of Engineering, Centre for Energy Sciences (Malaysia)

    2016-08-15

    The prospect of modern tribology has been expanded with the advent of nanomaterial-based lubrication systems, whose development was facilitated by the nanotechnology in recent years. In literature, a variety of nanoparticles have been used as lubricant additives with potentially interesting friction and wear properties. To date, although there has been a great deal of experimental research on nanoparticles as lubricating oil additives, many aspects of their tribological behavior are yet to be fully understood. With growing number of possibilities, the key question is: what types of nanoparticles act as a better lubricating oil additive and why? To answer this question, this paper reviews main types of nanoparticles that have been used as lubricants additives and outlines the mechanisms by which they are currently believed to function. Significant aspects of their tribological behavior such as dispersion stability and morphology are also highlighted.

  6. Compressibilities and viscosities of reference, vegetable, and synthetic gear lubricants

    DEFF Research Database (Denmark)

    Regueira Muñiz, Teresa; Lugo, Luis; Fernández, Josefa

    2014-01-01

    Nowadays, one of the primary choices of base oils for environmentally aware lubricants is vegetable oils. This is due to their good natural biodegradability and very low toxicity in combination with very good lubricity characteristics. The development of new vegetable-based lubricants requires...... values of six gear lubricants, two of them reference mineral oils and the other four developed biodegradable oils based in high oleic sunflower oil or in synthetic esters. It was found that all of the lubricants have both similar compressibilities and similar expansivities. Dowson and Higginson, Zhu.......06%. Dowson and Higginson and Zhu and Wen equations of state do not predict well the isothermal compressibilities, with AAD % being around 45% for both equations. Moreover, the viscosities were measured in the temperature range from 278.15 to 373.15 K at atmospheric pressure for these oils, and the viscosity...

  7. Tribological performance of nanoparticles as lubricating oil additives

    International Nuclear Information System (INIS)

    Gulzar, M.; Masjuki, H. H.; Kalam, M. A.; Varman, M.; Zulkifli, N. W. M.; Mufti, R. A.; Zahid, Rehan

    2016-01-01

    The prospect of modern tribology has been expanded with the advent of nanomaterial-based lubrication systems, whose development was facilitated by the nanotechnology in recent years. In literature, a variety of nanoparticles have been used as lubricant additives with potentially interesting friction and wear properties. To date, although there has been a great deal of experimental research on nanoparticles as lubricating oil additives, many aspects of their tribological behavior are yet to be fully understood. With growing number of possibilities, the key question is: what types of nanoparticles act as a better lubricating oil additive and why? To answer this question, this paper reviews main types of nanoparticles that have been used as lubricants additives and outlines the mechanisms by which they are currently believed to function. Significant aspects of their tribological behavior such as dispersion stability and morphology are also highlighted.

  8. Biodiesel as a lubricity additive for ultra low sulfur diesel

    Directory of Open Access Journals (Sweden)

    Subongkoj Topaiboul1 and 2,*

    2010-05-01

    Full Text Available With the worldwide trend to reduce emission from diesel engines, ultra low sulfur diesel has been introduced with thesulfur concentration of less than 10 ppm. Unfortunately, the desulfurization process inevitably reduces the lubricity of dieselfuel significantly. Alternatively, biodiesel, with almost zero sulfur content, has been added to enhance lubricity in an ultralow sulfur diesel. This work has evaluated the effectiveness of the biodiesel amount, sourced from palm and jatropha oil,and origin in ultra low sulfur diesel locally available in the market. Wear scar from a high-frequency reciprocating rig isbenchmarked to the standard value (460 m of diesel fuel lubricity. It was found that very small amount (less than 1% ofbiodiesel from either source significantly improves the lubricity in ultra low sulfur diesel, and the biodiesel from jatropha oilis a superior lubricity enhancer.

  9. 24 CFR 1000.40 - Do lead-based paint poisoning prevention requirements apply to affordable housing activities...

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Do lead-based paint poisoning prevention requirements apply to affordable housing activities under NAHASDA? 1000.40 Section 1000.40 Housing... AMERICAN HOUSING ACTIVITIES General § 1000.40 Do lead-based paint poisoning prevention requirements apply...

  10. 45 CFR 660.6 - What procedures apply to the selection of programs and activities under these regulations?

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false What procedures apply to the selection of programs... Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION INTERGOVERNMENTAL REVIEW OF THE NATIONAL SCIENCE FOUNDATION PROGRAMS AND ACTIVITIES § 660.6 What procedures apply to the selection of programs and activities...

  11. Atomistic study of ternary oxides as high-temperature solid lubricants

    Science.gov (United States)

    Gao, Hongyu

    Friction and wear are important tribological phenomena tightly associated with the performance of tribological components/systems such as bearings and cutting machines. In the process of contact and sliding, friction and wear lead to energy loss, and high friction and wear typically result in shortened service lifetime. To reduce friction and wear, solid lubricants are generally used under conditions where traditional liquid lubricants cannot be applied. However, it is challenging to maintain the functionality of those materials when the working environment becomes severe. For instance, at elevated temperatures (i.e., above 400 °C), most traditional solid lubricants, such as MoS2 and graphite, will easily oxidize or lose lubricity due to irreversible chemical changes. For such conditions, it is necessary to identify materials that can remain thermally stable as well as lubricious over a wide range of temperatures. Among the currently available high-temperature solid lubricants, Ag-based ternary metal oxides have recently drawn attention due to their low friction and ability to resist oxidation. A recent experimental study showed that the Ag-Ta-O ternary exhibited an extremely low coefficient of friction (0.06) at 750 °C. To fully uncover the lubricious nature of this material as a high-temperature solid lubricant, a series of tribological investigations were carried out based on one promising candidate - silver tantalate (AgTaO3). The study was then extended to alternative materials, Cu-Ta-O ternaries, to accommodate a variety of application requirements. We aimed to understand, at an atomic level, the effects of physical and chemical properties on the thermal, mechanical and tribological behavior of these materials at high temperatures. Furthermore, we investigated potassium chloride films on a clean iron surface as a representative boundary lubricating system in a nonextreme environment. This investigation complemented the study of Ag/Cu-Ta-O and enhanced the

  12. Bayesian statistics applied to neutron activation data for reactor flux spectrum analysis

    International Nuclear Information System (INIS)

    Chiesa, Davide; Previtali, Ezio; Sisti, Monica

    2014-01-01

    Highlights: • Bayesian statistics to analyze the neutron flux spectrum from activation data. • Rigorous statistical approach for accurate evaluation of the neutron flux groups. • Cross section and activation data uncertainties included for the problem solution. • Flexible methodology applied to analyze different nuclear reactor flux spectra. • The results are in good agreement with the MCNP simulations of neutron fluxes. - Abstract: In this paper, we present a statistical method, based on Bayesian statistics, to analyze the neutron flux spectrum from the activation data of different isotopes. The experimental data were acquired during a neutron activation experiment performed at the TRIGA Mark II reactor of Pavia University (Italy) in four irradiation positions characterized by different neutron spectra. In order to evaluate the neutron flux spectrum, subdivided in energy groups, a system of linear equations, containing the group effective cross sections and the activation rate data, has to be solved. However, since the system’s coefficients are experimental data affected by uncertainties, a rigorous statistical approach is fundamental for an accurate evaluation of the neutron flux groups. For this purpose, we applied the Bayesian statistical analysis, that allows to include the uncertainties of the coefficients and the a priori information about the neutron flux. A program for the analysis of Bayesian hierarchical models, based on Markov Chain Monte Carlo (MCMC) simulations, was used to define the problem statistical model and solve it. The first analysis involved the determination of the thermal, resonance-intermediate and fast flux components and the dependence of the results on the Prior distribution choice was investigated to confirm the reliability of the Bayesian analysis. After that, the main resonances of the activation cross sections were analyzed to implement multi-group models with finer energy subdivisions that would allow to determine the

  13. Boundary mode lubrication of articular cartilage by recombinant human lubricin.

    Science.gov (United States)

    Gleghorn, Jason P; Jones, Aled R C; Flannery, Carl R; Bonassar, Lawrence J

    2009-06-01

    Lubrication of cartilage involves a variety of physical and chemical factors, including lubricin, a synovial glycoprotein that has been shown to be a boundary lubricant. It is unclear how lubricin boundary lubricates a wide range of bearings from tissue to artificial surfaces, and if the mechanism is the same for both soluble and bound lubricin. In the current study, experiments were conducted to investigate the hypothesis that recombinant human lubricin (rh-lubricin) lubricates cartilage in a dose-dependent manner and that soluble and bound fractions of rh-lubricin both contribute to the lubrication process. An rh-lubricin dose response was observed with maximal lubrication achieved at concentrations of rh-lubricin greater than 50 microg/mL. A concentration-response variable-slope model was fit to the data, and indicated that rh-lubricin binding to cartilage was not first order. The pattern of decrease in equilibrium friction coefficient indicated that aggregation of rh-lubricin or steric arrangement may regulate boundary lubrication. rh-lubricin localized at the cartilage surface was found to lubricate a cartilage-glass interface in boundary mode, as did soluble rh-lubricin at high concentrations (150 microg/mL); however, the most effective lubrication occurred when both soluble and bound rh-lubricin were present at the interface. These findings point to two distinct mechanisms by which rh-lubricin lubricates, one mechanism involving lubricin bound to the tissue surface and the other involving lubricin in solution. Copyright 2008 Orthopaedic Research Society

  14. Carbohydrate metabolism teaching strategy for the Pharmacy course, applying active teaching methodology

    Directory of Open Access Journals (Sweden)

    Uderlei Donizete Silveira Covizzi

    2012-12-01

    Full Text Available The traditional teaching method has been widely questioned on the development of skills and abilities in training healthcare professionals. In the traditional methodology the main transmitter of knowledge is the teacher while students assume passive spectator role. Some Brazilian institutions broke with this model, structuring the curriculum to student-centered learning. Some medical schools have adopted the Problem Based Learning (PBL, a methodology that presents problem questions, to be encountered by future physicians, for resolution in small tutorial groups. Our work proposes to apply an active teaching-learning methodology addressing carbohydrate metabolism during the discipline of biochemistry for under graduation students from pharmacy course. Thus, the academic content was presented through brief and objective talks. Later, learners were split into tutorial groups for the resolution of issues in context. During the activities, the teacher drove the discussion to the issues elucidation. At the end of the module learners evaluated the teaching methodology by means of an applied questionnaire and the developed content was evaluated by an usual individual test. The questionnaire analysis indicates that students believe they have actively participated in the teaching-learning process, being encouraged to discuss and understand the theme. The answers highlight closer ties between students and tutor. According to the professor, there is a greater student engagement with learning. It is concluded that an innovative methodology, where the primary responsibility for learning is centered in the student himself, besides to increase the interest in learning, facilitates learning by cases discussion in groups. The issues contextualization establishes a narrowing between theory and practice.

  15. Activities for the Promotion of Gender Equality in Japan—Japan Society of Applied Physics

    Science.gov (United States)

    Kodate, Kashiko; Tanaka, Kazuo

    2005-10-01

    Since 1946, the Japan Society of Applied Physics (JSAP) has strived to promote research and development in applied physics for benefits beyond national boundaries. Activities of JSAP involve multidisciplinary fields, from physics and engineering to life sciences. Of its 23,000 members, 48% are from industry, 29% from academia, and about 7% from semi-autonomous national research laboratories. Its large industrial membership is one of the distinctive features of JSAP. In preparation for the First IUPAP International Conference on Women in Physics (Paris, 2002), JSAP members took the first step under the strong leadership of then-JSAP President Toshio Goto, setting up the Committee for the Promotion Equal Participation of Men and Women in Science and Technology. Equality rather than women's advancement is highlighted to further development in science and technology. Attention is also paid to balancing the number of researchers from different age groups and affiliations. The committee has 22 members: 12 female and 10 male; 7 from corporations, 12 from universities, and 3 from semi-autonomous national research institutes. Its main activities are to organize symposia and meetings, conduct surveys among JSAP members, and provide child-care facilities at meetings and conferences. In 2002 the Japan Physics Society and the Chemical Society of Japan jointly created the Japan Inter-Society Liaison Association for the Promotion of Equal Participation of Men and Women in Science and Engineering. Membership has grown to 44 societies (of which 19 are observers) ranging from mathematics, information, and life sciences to civil engineering. Joint activities across sectors and empower the whole. The Gender Equality Bureau in the Cabinet Office recently launched a large-scale project called "Challenge Campaign" to encourage girls to major in natural science and engineering, which JSAP is co-sponsoring.

  16. Tribological properties and lubrication mechanism of in situ graphene-nickel matrix composite impregnated with lubricating oil

    Science.gov (United States)

    Lei, Yu; Du, Jinfang; Pang, Xianjuan; Wang, Haizhong; Yang, Hua; Jiang, Jinlong

    2018-05-01

    A solid-liquid synergetic lubricating system has been designed to develop a novel self-lubricating nickel matrix composite. The graphene-nickel (G-Ni) matrix composite with porous structure was fabricated by in situ growing graphene in bulk nickel using a powder metallurgy method. The porous structures of the composite were used to store polyalphaolefin (PAO) oil for self-lubricating. It is found that the G-Ni matrix composite under oil lubrication condition exhibited superior tribological properties as compared to pure nickel and the composite under dry sliding condition. The prestored oil was released from pores to the sliding surface forming a lubricating oil film during friction process. This lubricating oil film can protect the worn surface from severe oxidation, and help the formation and transfer of a carbon-based solid tribofilm derived from graphene and lubricating oil. This solid (graphene)-liquid (oil) synergistic lubricating mechanism is responsible for the reduction of friction coefficient and improvement of wear resistance of the in situ fabricated G-Ni matrix composite.

  17. National youth sedentary behavior and physical activity daily patterns using latent class analysis applied to accelerometry.

    Science.gov (United States)

    Evenson, Kelly R; Wen, Fang; Hales, Derek; Herring, Amy H

    2016-05-03

    Applying latent class analysis (LCA) to accelerometry can help elucidated underlying patterns. This study described the patterns of accelerometer-determined sedentary behavior and physical activity among youth by applying LCA to a nationally representative United States (US) sample. Using 2003-2006 National Health and Nutrition Examination Survey data, 3998 youths 6-17 years wore an ActiGraph 7164 accelerometer for one week, providing > =3 days of wear for > =8 h/day from 6:00 am-midnight. Cutpoints defined sedentary behavior ( = 2296 counts/minute), and vigorous activity (> = 4012 counts/minute). To account for wear time differences, outcomes were expressed as percent of day in a given intensity. LCA was used to classify daily (Monday through Sunday) patterns of average counts/minute, sedentary behavior, light activity, MVPA, and vigorous activity separately. The latent classes were explored overall and by age (6-11, 12-14, 15-17 years), gender, and whether or not youth attended school during measurement. Estimates were weighted to account for the sampling frame. For average counts/minute/day, four classes emerged from least to most active: 40.9% of population (mean 323.5 counts/minute/day), 40.3% (559.6 counts/minute/day), 16.5% (810.0 counts/minute/day), and 2.3% (1132.9 counts/minute/day). For percent of sedentary behavior, four classes emerged: 13.5% of population (mean 544.6 min/day), 30.1% (455.1 min/day), 38.5% (357.7 min/day), and 18.0% (259.2 min/day). For percent of light activity, four classes emerged: 12.3% of population (mean 222.6 min/day), 29.3% (301.7 min/day), 41.8% (384.0 min/day), and 16.6% (455.5 min/day). For percent of MVPA, four classes emerged: 59.9% of population (mean 25.0 min/day), 33.3% (60.9 min/day), 3.1% (89.0 min/day), and 3.6% (109.3 min/day). For percent of vigorous activity, three classes emerged: 76.8% of population (mean 7.1 min/day), 18.5% (23.9 min/day), and 4.7% (47.4 min/day). Classes were developed by age

  18. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 2. Induction of mixed function oxidase enzymes in barramundi, Lates calcarifer, a tropical fish species

    Energy Technology Data Exchange (ETDEWEB)

    Mercurio, Philip; Burns, Kathryn A.; Cavanagh, Joanne

    2004-05-01

    An increasing number of vegetable-based oils are being developed as environmentally friendly alternatives to petroleum products. However, toxicity towards key tropical marine species has not been investigated. In this study we used laboratory-based biomarker induction experiments to compare the relative stress of a vegetable-based lubricating oil for marine 2-stroke engines with its mineral oil-based counterpart on tropical fish. The sub-lethal stress of 2-stoke outboard lubricating oils towards the fish Lates calcarifer (barramundi) was examined using liver microsomal mixed function oxidase (MFO) induction assays. This study is the first investigation into the use of this key commercial species in tropical North Queensland, Australia in stress assessment of potential hydrocarbon pollution using ethoxyresorufin O-deethylase (EROD) induction. Our results indicated that barramundi provide a wide range of inducible rates of EROD activity in response to relevant organic stressors. The vegetable- and mineral-based lubricants induced significant EROD activity at 1.0 mg kg{sup -1} and there was no significant difference between the two oil treatments at that concentration. At increasing concentrations of 2 and 3 mg kg{sup -1}, the mineral-based lubricant resulted in slightly higher EROD activity than the vegetable-based lubricant. The EROD activity of control and treated barramundi are found to be within ranges for other species from temperate and tropical environments. These results indicate that vegetable-based lubricants may be less stressful to barramundi than their mineral counterparts at concentrations of lubricant {>=}2 mg kg{sup -1}. There is great potential for this species to be used in the biomonitoring of waterways around tropical North Queensland and SE Asia. - Vegetable-based lubricating oils appear to cause a tropical fish species less stress than mineral oils.

  19. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 2. Induction of mixed function oxidase enzymes in barramundi, Lates calcarifer, a tropical fish species

    International Nuclear Information System (INIS)

    Mercurio, Philip; Burns, Kathryn A.; Cavanagh, Joanne

    2004-01-01

    An increasing number of vegetable-based oils are being developed as environmentally friendly alternatives to petroleum products. However, toxicity towards key tropical marine species has not been investigated. In this study we used laboratory-based biomarker induction experiments to compare the relative stress of a vegetable-based lubricating oil for marine 2-stroke engines with its mineral oil-based counterpart on tropical fish. The sub-lethal stress of 2-stoke outboard lubricating oils towards the fish Lates calcarifer (barramundi) was examined using liver microsomal mixed function oxidase (MFO) induction assays. This study is the first investigation into the use of this key commercial species in tropical North Queensland, Australia in stress assessment of potential hydrocarbon pollution using ethoxyresorufin O-deethylase (EROD) induction. Our results indicated that barramundi provide a wide range of inducible rates of EROD activity in response to relevant organic stressors. The vegetable- and mineral-based lubricants induced significant EROD activity at 1.0 mg kg -1 and there was no significant difference between the two oil treatments at that concentration. At increasing concentrations of 2 and 3 mg kg -1 , the mineral-based lubricant resulted in slightly higher EROD activity than the vegetable-based lubricant. The EROD activity of control and treated barramundi are found to be within ranges for other species from temperate and tropical environments. These results indicate that vegetable-based lubricants may be less stressful to barramundi than their mineral counterparts at concentrations of lubricant ≥2 mg kg -1 . There is great potential for this species to be used in the biomonitoring of waterways around tropical North Queensland and SE Asia. - Vegetable-based lubricating oils appear to cause a tropical fish species less stress than mineral oils

  20. Enhancement of tribofilm formation from water lubricated PEEK composites by copper nanowires

    Science.gov (United States)

    Gao, Chuanping; Fan, Shuguang; Zhang, Shengmao; Zhang, Pingyu; Wang, Qihua

    2018-06-01

    A high-performance tribofilm is crucial to enhance the tribological performance of tribomaterials. In order to promote tribofilm formation under water lubrication conditions, copper nanowires as a functional nanomaterial were filled into neat polyetheretherketone (PEEK) and PEEK10SCF8Gr (i.e., PEEK filled with 10 vol.% short carbon fibers and 8 vol.% graphite flakes). The results show that the addition of copper nanowires and a greater applied load can enhance materials transfer and tribofilm formation during sliding process. Moreover, copper nanowires can share a part of applied load, and retard the fatigue effect to some extent. In addition, copper nanowires, carbon fibers and graphite can synergistically improve the tribological performance and the tribofilm formation under water lubrication and severe working conditions. In particular, only 0.5 vol.% copper nanowires can form a high-performance tribofilm, which endows superior lubricating property and wear resistance capacity of the PEEK10SCF8Gr. Furthermore, the surface analysis indicates that the tribofilm contains some transferred materials and the products from tribochemical reactions as well.

  1. Performance of Metal Cutting on Endmills Manufactured by Cooling-Air and Minimum Quantity Lubrication Grinding

    Science.gov (United States)

    Inoue, Shigeru; Aoyama, Tojiro

    Grinding fluids have been commonly used during the grinding of tools for their cooling and lubricating effect since the hard, robust materials used for cutting tools are difficult to grind. Grinding fluids help prevent a drop in hardness due to burning of the cutting edge and keep chipping to an absolute minimum. However, there is a heightened awareness of the need to improve the work environment and protect the global environment. Thus, the present study is aimed at applying dry grinding, cooling-air grinding, cooling-air grinding with minimum quantity lubrication (MQL), and oil-based fluid grinding to manufacturing actual endmills (HSS-Co). Cutting tests were performed by a vertical machining center. The results indicated that the lowest surface inclination values and longest tool life were obtained by cooling-air grinding with MQL. Thus, cooling-air grinding with MQL has been demonstrated to be at least as effective as oil-based fluid grinding.

  2. Commercial lubricant use among HIV-negative men who have sex with men in Los Angeles: implications for the development of rectal microbicides for HIV prevention.

    Science.gov (United States)

    Pines, Heather A; Gorbach, Pamina M; Reback, Cathy J; Landovitz, Raphael J; Mutchler, Matt G; Mitsuyasu, Ronald

    2014-01-01

    To inform the development and assess potential use of rectal microbicide gels for HIV prevention among men who have sex with men (MSM), we examined the dynamics and contexts of commercial lubricant use during receptive anal intercourse (RAI) within this population. From 2007 to 2010, 168 HIV-negative MSM living in Los Angeles who practice RAI completed computer-assisted self-interviews, which collected information on their last sexual event with ≤3 recent partners, at baseline, three months, and one-year study visits. Logistic generalized linear mixed models were used to identify individual- and sexual event-level characteristics associated with commercial lubricant use during RAI at the last sexual event within 421 partnerships reported by participants over the course of follow-up. During RAI at their last sexual event, 57% of partnerships used a condom and 69% used commercial lubricant. Among partnerships that used commercial lubricant, 56% reported lubricant application by both members of the partnership, 66% first applied lubricant during sex, but before penetration, and 98% applied lubricant at multiple locations. The relationship between substance use and commercial lubricant use varied by condom use (interaction p-value = 0.01). Substance use was positively associated with commercial lubricant use within partnerships that did not use condoms during RAI at their last sexual event (AOR = 4.47, 95% [corrected] [CI]: 1.63-12.28), but no association was observed within partnerships that did use condoms (AOR = 0.66, 95% CI: 0.23-1.85). Commercial lubricant use during RAI was also positively associated with reporting more sexual partners (AOR = 1.18, 95% CI: 1.05-1.31), while older age (units = 5 years; AOR = 0.75, 95% CI: 0.61-0.94), homelessness (past year; AOR = 0.32, 95% CI: 0.13-0.76), and having sex with an older (>10 years) partner (AOR = 0.37, 95% CI: 0.14-0.95) were negatively associated with commercial lubricant use. These factors should be considered

  3. FísicActiva: applying active learning strategies to a large engineering lecture

    Science.gov (United States)

    Auyuanet, Adriana; Modzelewski, Helena; Loureiro, Silvia; Alessandrini, Daniel; Míguez, Marina

    2018-01-01

    This paper presents and analyses the results obtained by applying Active Learning techniques in overcrowded Physics lectures at the University of the Republic, Uruguay. The course referred to is Physics 1, the first Physics course that all students of the Faculty of Engineering take in their first semester for all the Engineering-related careers. Qualitative and quantitative data corresponding to three semesters are shown and discussed, indicating that the students that attended these lectures outperformed the students that followed the course in the traditional way: the pass rates increased, whereas the failure rates decreased. The students highly valued this methodology, in particular, the interactive and relaxed dynamics, highlighting the concern of professors to answer questions by means of new questions so as to promote reasoning. The results obtained point to a work path that deserves to be deepened and extended to other Engineering courses.

  4. Pretreatment procedures applied to samples to be analysed by neutron activation analysis at CDTN/CNEN

    International Nuclear Information System (INIS)

    Francisco, Dovenir; Menezes, Maria Angela de Barros Correia

    2009-01-01

    The neutron activation technique - using several methods - has been applied in 80% of the analytical demand of Division for Reactor and Analytical Techniques at CDTN/CNEN, Belo Horizonte, Minas Gerais. This scenario emphasizes the responsibility of the Laboratory to provide and assure the quality of the measurements. The first step to assure the results quality is the preparation of the samples. Therefore, this paper describes the experimental procedures adopted at CDTN/CNEN in order to uniform conditions of analysis and to avoid contaminations by elements present everywhere. Some of the procedures are based on methods described in the literature; others are based on many years of experience preparing samples from many kinds of matrices. The procedures described are related to geological material - soil, sediment, rock, gems, clay, archaeological ceramics and ore - biological materials - hair, fish, plants, food - water, etc. Analytical results in sediment samples are shown as n example pointing out the efficiency of the experimental procedure. (author)

  5. Experimental investigation of an active magnetic regenerative heat circulator applied to self-heat recuperation technology

    International Nuclear Information System (INIS)

    Kotani, Yui; Kansha, Yasuki; Ishizuka, Masanori; Tsutsumi, Atsushi

    2014-01-01

    An experimental investigation into an active magnetic regenerative (AMR) heat circulator based on self-heat recuperation technology, was conducted to evaluate its energy saving potential in heat circulation. In an AMR heat circulator, magnetocaloric effect is applied to recuperate the heat exergy of the process fluid. The recuperated heat can be reused to heat the feed process fluid and realize self-heat recuperation. In this paper, AMR heat circulator has newly been constructed to determine the amount of heat circulated when applied to self-heat recuperation and the energy consumption of the heat circulator. Gadolinium and water was used as the magnetocaloric working material and the process fluid, respectively. The heat circulated amount was determined by measuring the temperature of the process fluid and gadolinium. The net work input for heat circulation was obtained from the magnetizing and demagnetizing forces and the distance travelled by the magnetocaloric bed. The results were compared with the minimum work input needed for heat circulation derived from exergy loss during heat exchange. It was seen that the experimentally obtained value was close to the minimum work input needed for heat circulation. - Highlights: • AMR heat circulator has newly been constructed for experimental evaluation. • Heat circulation in the vicinity of Curie temperature was observed. • Energy consumption of an AMR heat circulator has been measured. • Energy saving for processes near Curie temperature of working material was seen

  6. Active filtering applied to radiographic images unfolded by the Richardson-Lucy algorithm

    International Nuclear Information System (INIS)

    Almeida, Gevaldo L. de; Silvani, Maria Ines; Lopes, Ricardo T.

    2011-01-01

    Degradation of images caused by systematic uncertainties can be reduced when one knows the features of the spoiling agent. Typical uncertainties of this kind arise in radiographic images due to the non - zero resolution of the detector used to acquire them, and from the non-punctual character of the source employed in the acquisition, or from the beam divergence when extended sources are used. Both features blur the image, which, instead of a single point exhibits a spot with a vanishing edge, reproducing hence the point spread function - PSF of the system. Once this spoiling function is known, an inverse problem approach, involving inversion of matrices, can then be used to retrieve the original image. As these matrices are generally ill-conditioned, due to statistical fluctuation and truncation errors, iterative procedures should be applied, such as the Richardson-Lucy algorithm. This algorithm has been applied in this work to unfold radiographic images acquired by transmission of thermal neutrons and gamma-rays. After this procedure, the resulting images undergo an active filtering which fairly improves their final quality at a negligible cost in terms of processing time. The filter ruling the process is based on the matrix of the correction factors for the last iteration of the deconvolution procedure. Synthetic images degraded with a known PSF, and undergone to the same treatment, have been used as benchmark to evaluate the soundness of the developed active filtering procedure. The deconvolution and filtering algorithms have been incorporated to a Fortran program, written to deal with real images, generate the synthetic ones and display both. (author)

  7. Origins of extreme boundary lubrication by phosphatidylcholine liposomes.

    Science.gov (United States)

    Sorkin, Raya; Kampf, Nir; Dror, Yael; Shimoni, Eyal; Klein, Jacob

    2013-07-01

    Phosphatidylcholine (PC) vesicles have been shown to have remarkable boundary lubricating properties under physiologically-high pressures. Here we carry out a systematic study, using a surface force balance, of the normal and shear (frictional) forces between two opposing surfaces bearing different PC vesicles across water, to elucidate the origin of these properties. Small unilamellar vesicles (SUVs, diameters < 100 nm) of the symmetric saturated diacyl PCs DMPC (C(14)), DPPC (C(16)) and DSPC (C(18)) attached to mica surfaces were studied in their solid-ordered (SO) phase on the surface. Overall liposome lubrication ability improves markedly with increasing acyl chain length, and correlates strongly with the liposomes' structural integrity on the substrate surface: DSPC-SUVs were stable on the surface, and provided extremely efficient lubrication (friction coefficient μ ≈ 10(-4)) at room temperature at pressures up to at least 18 MPa. DMPC-SUVs ruptured following adsorption, providing poor high-pressure lubrication, while DPPC-SUVs behavior was intermediate between the two. These results can be well understood in terms of the hydration-lubrication paradigm, but suggest that an earlier conjecture, that highly-efficient lubrication by PC-SUVs depended simply on their being in the SO rather than in the liquid-disordered phase, should be more nuanced. Our results indicate that the resistance of the SUVs to mechanical deformation and rupture is the dominant factor in determining their overall boundary lubrication efficiency in our system. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Diesel fuel lubricity testing revisited : Tests von Dieselkraftstoffschmierfähigkeit erneut betrachtet

    NARCIS (Netherlands)

    van Leeuwen, H.J.

    2017-01-01

    Fuel is used as a lubricant in several engine components. Diesel fuel is known for its good lubrication properties, better than gasoline. These properties are examined in standard tests, as prescribed by ASTM. Good lubrication properties are designated as a good lubricity. Most commonly, fuel

  9. On the performance of laser-induced breakdown spectroscopy for direct determination of trace metals in lubricating oils

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Lijuan [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex (France); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Cao, Fan; Xiu, Junshan; Bai, Xueshi; Motto-Ros, Vincent [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex (France); Gilon, Nicole [Institut des Sciences Analytiques, UMR5280 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex (France); Zeng, Heping [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Yu, Jin, E-mail: jin.yu@univ-lyon1.fr [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex (France); Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astrophysics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2014-09-01

    Laser-induced breakdown spectroscopy (LIBS) provides a technique to directly determine metals in viscous liquids and especially in lubricating oils. A specific laser ablation configuration of a thin layer of oil applied on the surface of a pure aluminum target was used to evaluate the analytical figures of merit of LIBS for elemental analysis of lubricating oils. Among the analyzed oils, there were a certified 75cSt blank mineral oil, 8 virgin lubricating oils (synthetic, semi-synthetic, or mineral and of 2 different manufacturers), 5 used oils (corresponding to 5 among the 8 virgin oils), and a cooking oil. The certified blank oil and 4 virgin lubricating oils were spiked with metallo-organic standards to obtain laboratory reference samples with different oil matrix. We first established calibration curves for 3 elements, Fe, Cr, Ni, with the 5 sets of laboratory reference samples in order to evaluate the matrix effect by the comparison among the different oils. Our results show that generalized calibration curves can be built for the 3 analyzed elements by merging the measured line intensities of the 5 sets of spiked oil samples. Such merged calibration curves with good correlation of the merged data are only possible if no significant matrix effect affects the measurements of the different oils. In the second step, we spiked the remaining 4 virgin oils and the cooking oils with Fe, Cr and Ni. The accuracy and the precision of the concentration determination in these prepared oils were then evaluated using the generalized calibration curves. The concentrations of metallic elements in the 5 used lubricating oils were finally determined. - Highlights: • Direct determination of wear metals in lubricating oils using LIBS. • Generalized calibration curves for different oils. • Ablation of a thin oil layer on a pure metallic target.

  10. Enhanced Biodegradability, Lubricity and Corrosiveness of Lubricating Oil by Oleic Acid Diethanolamide Phosphate

    Directory of Open Access Journals (Sweden)

    Fang Jianhua

    2012-09-01

    Full Text Available Impacts of oleic acid diethanolamide phosphate (abbreviated as ODAP as an additive on biodegradability, anti-wear capacity, friction-reducing ability and corrosiveness of an unreadily biodegradable HVI 350 mineral lubricating oil was studied. The biodegradabilities of neat lubricating oil and its formulations with ODAP were evaluated on a biodegradation tester. Furthermore, the anti-wear and friction-reducing abilities and the corrosiveness of neat oil and the formulated oils were determined on a four-ball tribotester and a copper strip corrosion tester, respectively. The results indicated that ODAP markedly enhanced biodegradability as well as anti-wear and friction-reducing abilities of the lubricating oil. On the other hand, excellent color ratings of copper strips for both neat oil and the ODAP-doped oil were obtained in the corrosion tests, demonstrating that the corrosiveness of neat oil and the doped oil was negligible, although the latter seemed to provide slightly better anti-corrosion ability.

  11. The mechanics of motorised momentum exchange tethers when applied to active debris removal from LEO

    Energy Technology Data Exchange (ETDEWEB)

    Caldecott, Ralph; Kamarulzaman, Dayangku N. S.; Kirrane, James P.; Cartmell, Matthew P.; Ganilova, Olga A. [Department of Mechanical Engineering, University of Sheffield, Mappin St., Sheffield, S1 3JD, England (United Kingdom)

    2014-12-10

    The concept of momentum exchange when applied to space tethers for propulsion is well established, and a considerable body of literature now exists on the on-orbit modelling, the dynamics, and also the control of a large range of tether system applications. The authors consider here a new application for the Motorised Momentum Exchange Tether by highlighting three key stages of development leading to a conceptualisation that can subsequently be developed into a technology for Active Debris Removal. The paper starts with a study of the on-orbit mechanics of a full sized motorised tether in which it is shown that a laden and therefore highly massasymmetrical tether can still be forced to spin, and certainly to librate, thereby confirming its possible usefulness for active debris removal (ADR). The second part of the paper concentrates on the modelling of the centripetal deployment of a symmetrical MMET in order to get it initialized for debris removal operations, and the third and final part of the paper provides an entry into scale modelling for low cost mission design and testing. It is shown that the motorised momentum exchange tether offers a potential solution to the removal of large pieces of orbital debris, and that dynamic methodologies can be implemented to in order to optimise the emergent design.

  12. Experimental design technique applied to the validation of an instrumental Neutron Activation Analysis procedure

    International Nuclear Information System (INIS)

    Santos, Uanda Paula de M. dos; Moreira, Edson Gonçalves

    2017-01-01

    In this study optimization of procedures and standardization of Instrumental Neutron Activation Analysis (INAA) method were carried out for the determination of the elements bromine, chlorine, magnesium, manganese, potassium, sodium and vanadium in biological matrix materials using short irradiations at a pneumatic system. 2 k experimental designs were applied for evaluation of the individual contribution of selected variables of the analytical procedure in the final mass fraction result. The chosen experimental designs were the 2 3 and the 2 4 , depending on the radionuclide half life. Different certified reference materials and multi-element comparators were analyzed considering the following variables: sample decay time, irradiation time, counting time and sample distance to detector. Comparator concentration, sample mass and irradiation time were maintained constant in this procedure. By means of the statistical analysis and theoretical and experimental considerations, it was determined the optimized experimental conditions for the analytical methods that will be adopted for the validation procedure of INAA methods in the Neutron Activation Analysis Laboratory (LAN) of the Research Reactor Center (CRPq) at the Nuclear and Energy Research Institute (IPEN /CNEN-SP). Optimized conditions were estimated based on the results of z-score tests, main effect, interaction effects and better irradiation conditions. (author)

  13. 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.

  14. Specific activity and concentration model applied to 137Cs movement in a eutrophic lake

    International Nuclear Information System (INIS)

    Vanderploeg, H.A.; Booth, R.S.; Clark, F.H.

    1976-01-01

    A linear systems-analysis model which simulates time-dependent dynamics of specific activity and concentration of radiocesium in lake ecosystems was applied to a shallow, eutrophic lake that had received a pulse input of 137 Cs. Best estimates of transfer coefficients for abiotic compartments (sediment, interstitial water and lake water) and the macrophyte compartment which controlled the mass balance of cesium in water were determined by ''tuning'' our initial estimates of the transfer coefficients to observed data on 137 Cs concentrations and contents of these compartments. In most cases, the optimized transfer coefficients for the abiotic compartments were not greatly different from our independently derived initial estimates, and the simulations for optimized coefficients were close to those based on initial estimates. The 137 Cs concentrations in water as predicted by the optimized transfer coefficients were then used to calculate 137 Cs kinetics in biota other than macrophytes. In general, model simulations were close to concentrations observed in the biota. The agreement between 137 Cs concentrations and simulations in bottom invertebrates supported our assumption that bottom sediments are not a major source of Cs to the biota. Our specific activity and concentration model was compared to the radionuclide content model, the model used in terrestrial ecosystems. For biotic components of aquatic ecosystems, values of α/sub ij/, the transfer coefficients of our model, are easily estimated from turnover rates of radiocesium in individual organisms in the laboratory

  15. Experimental design technique applied to the validation of an instrumental Neutron Activation Analysis procedure

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Uanda Paula de M. dos; Moreira, Edson Gonçalves, E-mail: uandapaula@gmail.com, E-mail: emoreira@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    In this study optimization of procedures and standardization of Instrumental Neutron Activation Analysis (INAA) method were carried out for the determination of the elements bromine, chlorine, magnesium, manganese, potassium, sodium and vanadium in biological matrix materials using short irradiations at a pneumatic system. 2{sup k} experimental designs were applied for evaluation of the individual contribution of selected variables of the analytical procedure in the final mass fraction result. The chosen experimental designs were the 2{sup 3} and the 2{sup 4}, depending on the radionuclide half life. Different certified reference materials and multi-element comparators were analyzed considering the following variables: sample decay time, irradiation time, counting time and sample distance to detector. Comparator concentration, sample mass and irradiation time were maintained constant in this procedure. By means of the statistical analysis and theoretical and experimental considerations, it was determined the optimized experimental conditions for the analytical methods that will be adopted for the validation procedure of INAA methods in the Neutron Activation Analysis Laboratory (LAN) of the Research Reactor Center (CRPq) at the Nuclear and Energy Research Institute (IPEN /CNEN-SP). Optimized conditions were estimated based on the results of z-score tests, main effect, interaction effects and better irradiation conditions. (author)

  16. The Study of Mining Activities and their Influences in the Almaden Region Applying Remote Sensing Techniques

    International Nuclear Information System (INIS)

    Rico, C.; Schmid, T.; Millan, R.; Gumuzzio, J.

    2010-01-01

    This scientific-technical report is a part of an ongoing research work carried out by Celia Rico Fraile in order to obtain the Diploma of Advanced Studies as part of her PhD studies. This work has been developed in collaboration with the Faculty of Science at The Universidad Autonoma de Madrid and the Department of Environment at CIEMAT. The main objective of this work was the characterization and classification of land use in Almaden (Ciudad Real) during cinnabar mineral exploitation and after mining activities ceased in 2002, developing a methodology focused on the integration of remote sensing techniques applying multispectral and hyper spectral satellite data. By means of preprocessing and processing of data from the satellite images as well as data obtained from field campaigns, a spectral library was compiled in order to obtain representative land surfaces within the study area. Monitoring results show that the distribution of areas affected by mining activities is rapidly diminishing in recent years. (Author) 130 refs

  17. The mechanics of motorised momentum exchange tethers when applied to active debris removal from LEO

    International Nuclear Information System (INIS)

    Caldecott, Ralph; Kamarulzaman, Dayangku N. S.; Kirrane, James P.; Cartmell, Matthew P.; Ganilova, Olga A.

    2014-01-01

    The concept of momentum exchange when applied to space tethers for propulsion is well established, and a considerable body of literature now exists on the on-orbit modelling, the dynamics, and also the control of a large range of tether system applications. The authors consider here a new application for the Motorised Momentum Exchange Tether by highlighting three key stages of development leading to a conceptualisation that can subsequently be developed into a technology for Active Debris Removal. The paper starts with a study of the on-orbit mechanics of a full sized motorised tether in which it is shown that a laden and therefore highly massasymmetrical tether can still be forced to spin, and certainly to librate, thereby confirming its possible usefulness for active debris removal (ADR). The second part of the paper concentrates on the modelling of the centripetal deployment of a symmetrical MMET in order to get it initialized for debris removal operations, and the third and final part of the paper provides an entry into scale modelling for low cost mission design and testing. It is shown that the motorised momentum exchange tether offers a potential solution to the removal of large pieces of orbital debris, and that dynamic methodologies can be implemented to in order to optimise the emergent design

  18. Frictional lubricity enhanced by quantum mechanics.

    Science.gov (United States)

    Zanca, Tommaso; Pellegrini, Franco; Santoro, Giuseppe E; Tosatti, Erio

    2018-04-03

    The quantum motion of nuclei, generally ignored in the physics of sliding friction, can affect in an important manner the frictional dissipation of a light particle forced to slide in an optical lattice. The density matrix-calculated evolution of the quantum version of the basic Prandtl-Tomlinson model, describing the dragging by an external force of a point particle in a periodic potential, shows that purely classical friction predictions can be very wrong. The strongest quantum effect occurs not for weak but for strong periodic potentials, where barriers are high but energy levels in each well are discrete, and resonant Rabi or Landau-Zener tunneling to states in the nearest well can preempt classical stick-slip with nonnegligible efficiency, depending on the forcing speed. The resulting permeation of otherwise unsurmountable barriers is predicted to cause quantum lubricity, a phenomenon which we expect should be observable in the recently implemented sliding cold ion experiments.

  19. Tribofilms Forming in Oil-Lubricated Contacts

    Directory of Open Access Journals (Sweden)

    Matthias Scherge

    2016-07-01

    Full Text Available The subject of the present paper is the characterization of third bodies of run-in systems. By means of continuous friction and wear measurement, lubricated steel-steel and steel-aluminum contacts were evaluated. Microstructure, chemical composition and response of the materials to shear were analyzed by XPS/AES and focused ion beam technique. After a proper running-in, both systems developed a third body. The third body differs significantly from the base materials. In addition to adapted microstructure and near-surface chemistry, the third body exhibited a substructure characterized by a near-surface zone that accommodates shear and a second, deeper region that ensures strengthening.

  20. Lubricant distribution determination by neutron radiography

    International Nuclear Information System (INIS)

    Stewart, P.A.E.

    1979-01-01

    Cold neutron radiation of energy less than 0.025 eV having a flux greater than 1 x 10 3 neutrons/square centimeter/second is used to diagnose temporal information about the spatial distribution of hydrocarbon fuel and lubrication oils in internal combustion engines, gas turbine engines and fuel systems. Images of the movement of fuel or oil are recorded by directing a beam of neutrons through an engine and using an image intensifier responsive to low light levels to intensify an image formed by neutrons which have been directed through the engine onto a fluorescent screen. The output image from the intensifier is recorded by a video or cine camera

  1. Lubrication analysis of the thrust bearing in the main coolant pump of SMART

    International Nuclear Information System (INIS)

    Lee, J. S.; Park, J. S.; Kim, J. H.; Hur, H.; Kim, J. I.

    2001-01-01

    Thrust bearing and journal bearings are installed in the main coolant pump for SMART to support the rotating shaft with proper lubrication. The canned motor type main coolant pumps are arranged vertically on the reactor vessel and especially the MCP bearings are lubricated with water without external lubricating oil supply. Because axial load capacity of the thrust bearing can hardly meet requirement to acquire hydrodynamic or fluid film lubrication state, self-lubrication characteristics of silicon graphite meterials would be needed. Lubricational analysis method for thrust bearing for the main coolant pump of SMART is proposed, and lubricational characteristics of the bearing generated by solving the Reynolds equation are examined in this paper

  2. Formation of metal-F bonds during frictional sliding : Influence of water and applied load

    NARCIS (Netherlands)

    Shen, J. T.; Pei, Y. T.; De Hosson, J. Th. M.

    2016-01-01

    Effects of water lubrication and applied load on the formation of PTFE transfer films and metal-F bonds during sliding when PTFE filled composites sliding against steel and Al2O3 are investigated. In water lubricated conditions, XPS analysis reveals that a thin layer of water molecules at the

  3. Nanomaterials in Lubricants: An Industrial Perspective on Current Research

    Directory of Open Access Journals (Sweden)

    Boris Zhmud

    2013-11-01

    Full Text Available This paper presents an overview on the use of various classes of nanomaterials in lubricant formulations. The following classes of nanomaterials are considered: fullerenes, nanodiamonds, ultradispersed boric acid and polytetrafluoroethylene (PTFE. Current advances in using nanomaterials in engine oils, industrial lubricants and greases are discussed. Results of numerous studies combined with formulation experience of the authors strongly suggest that nanomaterials do indeed have potential for enhancing certain lubricant properties, yet there is a long way to go before balanced formulations are developed.

  4. Numerical simulation of lubrication mechanisms at mesoscopic scale

    DEFF Research Database (Denmark)

    Hubert, C.; Bay, Niels; Christiansen, Peter

    2011-01-01

    The mechanisms of liquid lubrication in metal forming are studied at a mesoscopic scale, adopting a 2D sequential fluid-solid weak coupling approach earlier developed in the first author's laboratory. This approach involves two computation steps. The first one is a fully coupled fluid-structure F...... of pyramidal indentations. The tests are performed with variable reduction and drawing speed under controlled front and back tension forces. Visual observations through a transparent die of the fluid entrapment and escape from the cavities using a CCD camera show the mechanisms of Micro......PlastoHydroDynamic Lubrication (MPHDL) as well as cavity shrinkage due to lubricant compression and escape and strip deformation....

  5. Numerical methods and computers used in elastohydrodynamic lubrication

    Science.gov (United States)

    Hamrock, B. J.; Tripp, J. H.

    1982-01-01

    Some of the methods of obtaining approximate numerical solutions to boundary value problems that arise in elastohydrodynamic lubrication are reviewed. The highlights of four general approaches (direct, inverse, quasi-inverse, and Newton-Raphson) are sketched. Advantages and disadvantages of these approaches are presented along with a flow chart showing some of the details of each. The basic question of numerical stability of the elastohydrodynamic lubrication solutions, especially in the pressure spike region, is considered. Computers used to solve this important class of lubrication problems are briefly described, with emphasis on supercomputers.

  6. Regeneration of used lubricating oil as a source of energy

    Directory of Open Access Journals (Sweden)

    A. T. Abdulrahim

    2001-10-01

    Full Text Available Conservation of natural resources by refining used lubricating oil was attempted in this work. Used lubricating oil was purified and distilled. The distillates obtained were divided into two temperature ranges of 60 - 210°C and 210 - 310°C. Analyses of the physicochemical properties of the two samples revealed that they have similar properties with gasoline and diesel fuels respectively. This result shows that used lubricating oils, which are usually regarded as waste, can be regenerated to obtain useful hydrocarbons that can be used as fuels to power internal combustion engines

  7. Investigation of Lubrication Properties of Petroleum Fuel and Biohydrocarbon Blends

    Directory of Open Access Journals (Sweden)

    Gawron Bartosz

    2016-07-01

    Full Text Available The paper covers issues regarding lubricity of petroleum fuels used in piston and turbine engines, containing hydrocarbon biocomponents. Basing on available literature it can be said that the most prospective fuel components are biohydrocarbons. The paper describes effect of biohydrocarbons included in aviation fuel and diesel fuel on lubricity of such blends. The analysis covers two processes for obtaining biohydrocarbons, the HVO and the Fischer-Tropsch process. Due to problems with actual products acquiring, biohydrocarbons models representing chemically the actual ones from specific process. Lubricity testing was carried out according to standard test methods.

  8. GPU-BASED MONTE CARLO DUST RADIATIVE TRANSFER SCHEME APPLIED TO ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Heymann, Frank; Siebenmorgen, Ralf

    2012-01-01

    A three-dimensional parallel Monte Carlo (MC) dust radiative transfer code is presented. To overcome the huge computing-time requirements of MC treatments, the computational power of vectorized hardware is used, utilizing either multi-core computer power or graphics processing units. The approach is a self-consistent way to solve the radiative transfer equation in arbitrary dust configurations. The code calculates the equilibrium temperatures of two populations of large grains and stochastic heated polycyclic aromatic hydrocarbons. Anisotropic scattering is treated applying the Heney-Greenstein phase function. The spectral energy distribution (SED) of the object is derived at low spatial resolution by a photon counting procedure and at high spatial resolution by a vectorized ray tracer. The latter allows computation of high signal-to-noise images of the objects at any frequencies and arbitrary viewing angles. We test the robustness of our approach against other radiative transfer codes. The SED and dust temperatures of one- and two-dimensional benchmarks are reproduced at high precision. The parallelization capability of various MC algorithms is analyzed and included in our treatment. We utilize the Lucy algorithm for the optical thin case where the Poisson noise is high, the iteration-free Bjorkman and Wood method to reduce the calculation time, and the Fleck and Canfield diffusion approximation for extreme optical thick cells. The code is applied to model the appearance of active galactic nuclei (AGNs) at optical and infrared wavelengths. The AGN torus is clumpy and includes fluffy composite grains of various sizes made up of silicates and carbon. The dependence of the SED on the number of clumps in the torus and the viewing angle is studied. The appearance of the 10 μm silicate features in absorption or emission is discussed. The SED of the radio-loud quasar 3C 249.1 is fit by the AGN model and a cirrus component to account for the far-infrared emission.

  9. Nutrição aplicada à atividade motora Nutrition applied to motor activity

    Directory of Open Access Journals (Sweden)

    Antonio Herbert Lancha Junior

    2011-12-01

    Full Text Available A Nutrição aplicada a atividade motora se divide em quatro áreas do movimento humano, a saber: esporte, educação física, dança, recreação/lazer. Essa definição conceitual diferencia a população alvo da intervenção nutricional. O organismo humano sempre apresentou o movimento como parte de sua atividade cotidiana e selecionou evolutivamente os organismos mais econômicos. Em contrapartida por conta de demandas, sociais, financeiras dentre outras a vida moderna impôs o sedentarismo como padrão de comportamento motor que aliado ao padrão genético de economia resultaram nas doenças modernas como obesidade, diabetes, etc. Assim a sociedade institucionalizou o movimento humano criando manifestações distintas descritas acima e suas necessidades específicas passaram a ser de interesse acadêmico/cientifico. Nutricionalmente os estudos se concentram no balanço energético, na necessidade de carboidratos, proteínas, lipídios assim como dos micronutrientes e outros compostos biologicamente ativos. Estes estudos definem estas substancias sob critérios de essencialidade ou efeito ergogênico superior a capacidade fisiológica. O primeiro determina mudanças nas necessidades nutricionais e o segundo substâncias consideradas ilícitas. No presente momento grande parte da comunidade cientifica dedicada à nutrição aplicada à atividade motora, dirige sua vocação na tentativa de descobrir as necessidades específicas provocadas pela pratica regular da atividade motora permitindo seu exercício regular para que a mesma propicie os benefícios na manutenção da saúde de forma plena nas quatro áreas descritas acima.Nutrition applied to motor activity is divided in four areas of human movement, namely: sports, physical education, dance, recreation/leisure. This conceptual definition differentiates the target population of nutritional intervention. The human body has always presented the movement as part of their daily activity and

  10. Optimization of Minimum Quantity Lubricant Conditions and Cutting Parameters in Hard Milling of AISI H13 Steel

    OpenAIRE

    The-Vinh Do; Quang-Cherng Hsu

    2016-01-01

    As a successful solution applied to hard machining, the minimum quantity lubricant (MQL) has already been established as an alternative to flood coolant processing. The optimization of MQL parameters and cutting parameters under MQL condition are essential and pressing. The study was divided into two parts. In the first part of this study, the Taguchi method was applied to find the optimal values of MQL condition in the hard milling of AISI H13 with consideration of reduced surface roughness....

  11. Electromagnetic Linear Vibration Energy Harvester Using Sliding Permanent Magnet Array and Ferrofluid as a Lubricant

    Directory of Open Access Journals (Sweden)

    Song Hee Chae

    2017-09-01

    Full Text Available We present an electromagnetic linear vibration energy harvester with an array of rectangular permanent magnets as a springless proof mass. Instead of supporting the magnet assembly with spring element, ferrofluid has been used as a lubricating material. When external vibration is applied laterally to the harvester, magnet assembly slides back and forth on the channel with reduced friction and wear due to ferrofluid, which significantly improves the long-term reliability of the device. Electric power is generated across an array of copper windings formed at the bottom of the aluminum housing. A proof-of-concept harvester has been fabricated and tested with a vibration exciter at various input frequencies and accelerations. For the device where 5 μL of ferrofluid was used for lubrication, maximum output power of 493 μW has been generated, which was 4.37% higher than that without ferrofluid. Long-term reliability improvement due to ferrofluid lubrication has also been verified. For the device with ferrofluid, 1.02% decrease of output power has been observed, in contrast to 59.73% decrease of output power without ferrofluid after 93,600 cycles.

  12. Effect of boundary conditions on the performances of gas-lubricated micro journal bearing

    International Nuclear Information System (INIS)

    Wang Sheng; Lei Kangbin; Kiwamu, Kase; Luo Xilian; Gu Zhaolin

    2010-01-01

    As significant components of micromechanics, gas-lubricated microbearings are more prevalent for their special advantages than other types. The fluid dynamics of the microbearing is different from their larger cousins due to the noncontinuum effect and surface-dominated effect, which may make the Navier-Stokes equations invalid. In this paper, by considering the accommodation coefficients on journal (α i ) and that on bearing (α o ) separately, the microbearings with different bearing numbers under the assumption of large L/D (length to diameter) are simulated using direct simulation Monte Carlo (DSMC) program incorporated with a Volume-CAD software. The diffuse reflection model and Cercignani-Lampis-Lord (CLL) model are applied to model the molecule-surface interaction. The flow field characteristics, as well as the performances of gas-lubricated journal bearings including load-carrying capacity, attitude angle and bearing drag are obtained. The results reveal that α i and α o have different effects to flow field characteristics and bearing performances. The bearing number has significantly impact on the bearing performances. The method developed in this paper would be very useful for designing and evaluating the gas-lubricated journal microbearing.

  13. Influence of Base Oil Polarity on the Transient Shear Flow of Biodegradable Lubricating Greases

    Directory of Open Access Journals (Sweden)

    Martin Fiedler

    2015-09-01

    Full Text Available The scope of this study is to elucidate the physical mechanisms influencing the transient flow behavior of lubricating greases based on biogenic oleochemicals from a polarity point of view. This includes the mutually interacting influence of base oil polarity and thickening agents on the rheologically-measured mechanical structural degradation in transient shear flow. Due to the high temperature dependence of Keesom forces in the background of polar-active bond mechanisms, the analysis of the transient flow response as a function of temperature allows to attribute the observed influences to differences in base oil polarity. In general, clay-thickened greases show a greater tendency to be rheologically influenced by base oil polarities than soap-thickened lubricating greases.

  14. Biodegradation Capability of Some Bacteria Isolates to Use Lubricant Oil in Vitro

    Science.gov (United States)

    Ahda, Y.; Azhar, M.; Fitri, L.; Afnida, A.; Adha, G. S.; Alifa, W. N.; Handayani, D.; Putri, D. H.; Irdawati, I.; Chatri, M.

    2018-04-01

    Our previous study identified three species of bacteria, i.e. Alcaligenes sp., Bacillus spl, and Bacillus sp2 isolated from using lubricant oil-contaminated soil in a Padang’s workshop. However, its ability to degrade hydrocarbon were not known yet. In this extension study, we explore a wider area to find more hydrocarbonoclastic bacteria and examined its capability to degrade hydrocarbon in vitro. Seventeen isolates were characterized its capability using NA + used lubricant oil + tween + neutral red medium. Isolates A1, B2, D1 and D4 shows the high degradation index, whereas isolates A2, A3, A5, D2, B1, B3 and isolates A4, B4, D3 have medium and low degradation index, respectively. These potential hydrocarbonoclastic bacteria need in situ characterization to know their actual activities for bioremediation.

  15. Specific activity and concentration model applied to cesium-137 movement in a eutrophic lake

    International Nuclear Information System (INIS)

    Vanderploeg, H.A.; Booth, R.S.; Clark, F.H.

    1975-01-01

    A linear systems-analysis model which simulates time-dependent dynamics of specific activity and concentration of radiocesium in lake ecosystems was applied to a shallow, eutrophic lake that had received a pulse input of 137 Cs. Best estimates of transfer coefficients for abiotic compartments (sediment, interstitial water, and water) and macrophyte compartment which control mass balance of cesium in water were determined by tuning our initial estimates of the transfer coefficients to observed data on 137 Cs concentrations and contents of these compartments. In most cases, the optimized transfer coefficients of the abiotic compartments were not greatly different from our independently-derived initial estimates, and the simulations for optimized coefficients were close to those based on initial estimates. The simulations of 137 Cs concentration in water predicted by the optimized transfer coefficients were used to derive 137 Cs kinetics in biota other than macrophytes. In general, model simulations were close to concentrations observed in the biota. The agreement between 137 Cs concentrations and simulations in bottom invertebrates supported our assumption that bottom sediments are not a major source of Cs to the biota. (U.S.)

  16. Recent progress in the field of automated welding applied to maintenance activities

    International Nuclear Information System (INIS)

    Cullafroz, M.

    2004-01-01

    Automated and robot welding has 5 advantages compared to manual welding: -) under some conditions the automated circular welding does not require requalification testing as manual welding does, -) welding heads in robots have a reduced size compared to manual gears so they can enter and treat complex piping, -) by using an adequate viewing system the operator can be more than 10 meters away from the welding site which means that the radiation doses he receives is cut by a factor 1.5 to 2, -) whatever the configuration is, the deposition rate in automated welding stays high, the quality standard is steady and the risk of repairing is low, -) a gain in productivity if adequate equipment is used. In general, automated welding requires a TIG welding process and is applied in maintenance activities to: -) the main primary system and other circuits in stainless austenitic steels, -) the main secondary system and other circuits in low-percentage carbon steels, and -) the closure of spent fuel canisters. An application to the repairing of BWR's pipes is shown. (A.C.)

  17. Kinetics approach to modeling of polymer additive degradation in lubricants

    Institute of Scientific and Technical Information of China (English)

    llyaI.KUDISH; RubenG.AIRAPETYAN; Michael; J.; COVITCH

    2001-01-01

    A kinetics problem for a degrading polymer additive dissolved in a base stock is studied.The polymer degradation may be caused by the combination of such lubricant flow parameters aspressure, elongational strain rate, and temperature as well as lubricant viscosity and the polymercharacteristics (dissociation energy, bead radius, bond length, etc.). A fundamental approach tothe problem of modeling mechanically induced polymer degradation is proposed. The polymerdegradation is modeled on the basis of a kinetic equation for the density of the statistical distribu-tion of polymer molecules as a function of their molecular weight. The integrodifferential kineticequation for polymer degradation is solved numerically. The effects of pressure, elongational strainrate, temperature, and lubricant viscosity on the process of lubricant degradation are considered.The increase of pressure promotes fast degradation while the increase of temperature delaysdegradation. A comparison of a numerically calculated molecular weight distribution with an ex-perimental one obtained in bench tests showed that they are in excellent agreement with eachother.

  18. Nuclear fuel handling grapple carriage with self-lubricating bearing

    International Nuclear Information System (INIS)

    1977-01-01

    This invention relates to the provision of a fuel handling grapple carriage for a sodium cooled fast breeder reactor with sodium coolant lubricated bearings in which contamination of the bearings is prevented. (UK)

  19. Friction and Lubrication of Large Tilting-Pad Thrust Bearings

    Directory of Open Access Journals (Sweden)

    Michał Wasilczuk

    2015-04-01

    Full Text Available Fluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient, despite a very low coefficient of friction dissipation of energy being noticeable, especially in large bearings. Lubricating systems of large tilting pad thrust bearings utilized in large, vertical shaft hydrogenerators are presented in this paper. A large amount of heat is generated due to viscous shearing of the lubricant large tilting pad thrust bearings, and this requires systems for forced cooling of the lubricant. In the dominant bath lubrication systems, cooling is realized by internal coolers or external cooling systems, with the latter showing some important advantages at the cost of complexity and also, potentially, lower reliability. Substantial losses in the bearings, reaching 1 MW in extreme cases, are a good motivation for the research and development aimed at reducing them. Some possible methods and their potential efficiency, along with some effects already documented, are also described in the paper.

  20. Supporting Information Synthesis of fatty monoester lubricant base ...

    Indian Academy of Sciences (India)

    Synthesis of fatty monoester lubricant base oil catalyzed by Fe-Zn ... Physical properties of fatty acid monoesters viz., kinematic viscosity, viscosity index, density ... The analysis method involves titration of the diluted sample with ethanolic alkali ...

  1. Effects of Vaginal Lubricants on In-Vitro Progressive Spermatozoa ...

    African Journals Online (AJOL)

    USER

    African Journal of Reproductive Health September 2017; 21 (3): 96. ORIGINAL ... *For Correspondence: E-mail: Sureshk@dut.ac.za; Phone: +27-31-373-5291 .... marketed around the world. ... of many top selling brands of sexual lubricants to.

  2. Impact of lubrication on the tribological behaviour of PTFE ...

    Indian Academy of Sciences (India)

    bronze and bronze + molybdenum disulfide (MoS2) were considered. These composites were ... the PTFE composites have significantly been reduced in the lubricated condition ... there are no strong bonds between the fillers and the matrix in.

  3. Sexual lubricants in South Africa may potentially disrupt mucosal ...

    African Journals Online (AJOL)

    more likely to result in HIV transmission than unprotected vaginal intercourse due to ... Distribution of condoms and water-based sexual lubricants forms a cornerstone of .... Organisations such as the US Centers for Disease. Control and the ...

  4. On the energy economics of air lubrication drag reduction

    Directory of Open Access Journals (Sweden)

    Simo A. Mäkiharju

    2012-12-01

    Full Text Available Air lubrication techniques for frictional drag reduction on ships have been proposed by numerous researchers since the 19th century. However, these techniques have not been widely adopted as questions persist about their drag reduction performance beyond the laboratory, as well as energy and economic cost-benefit. This paper draws on data from the literature to consider the suitability of air lubrication for large ocean going and U.S. Great Lakes ships, by establishing the basic energy economic calculations and presenting results for a hypothetical air lubricated ship. All the assumptions made in the course of the analysis are clearly stated so that they can be refined when considering application of air lubrication to a specific ship. The analysis suggests that, if successfully implemented, both air layer and partial cavity drag reduction could lead to net energy savings of 10 to 20%, with corresponding reductions in emissions.

  5. Compatibility of refrigerants and lubricants with elastomers. Final report

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-01-01

    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. In part I of the program the swell behavior in the test fluids has 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 fro the refrigerant test fluids and 24 hours after removal from the lubricants. Part II of the testing program includes the evaluation of tensile strength, hardness, weight, and dimensional changes after immersion aging in refrigerant/lubricant mixtures of selected elastomer formulations at elevated temperature and pressure.

  6. Biomarkers of oxidative stress and cataract. Novel drug delivery therapeutic strategies targeting telomere reduction and the expression of telomerase activity in the lens epithelial cells with N-acetylcarnosine lubricant eye drops: anti-cataract which helps to prevent and treat cataracts in the eyes of dogs and other animals.

    Science.gov (United States)

    Babizhayev, Mark A; Yegorov, Yegor E

    2014-01-01

    Cataracts in small animals are shown to be at least partially caused by oxidative damage to lens epithelial cells (LECs) and the internal lens; biomarkers of oxidative stress in the lens are considered as general biomarkers for life expectancy in the canine and other animals. Telomeres lengths and expressed telomerase activity in canine LECs may serve as important monitors of oxidative damage in normal LECs with documented higher levels of telomerase activity in cataractous LECs during cells' lifespan. Loss of functional telomere length below a critical threshold in LECs of canines during the effect of UV and chronic oxidative stress or metabolic failure, can activate programs leading to LEC senescence or death. Telomerase is induced in LECs of canines at critical stages of cataractogenesis initiation and exposure to oxidative stress through the involvement of catalytically active prooxidant transition metal (iron) ions. This work documents that transition metal ions (such as, ferrous ions- catalytic oxidants) might induce premature senescence in LECs of canines, telomere shortening with increased telomerase activity as adaptive response to UV light, oxidative and metabolic stresses. The therapeutic treatment with 1% N-acetylcarnosine (NAC) prodrug delivery is beneficial for prevention and dissolution of ripe cataracts in canines. This biological activity is based on the findings of ferroxidase activity pertinent to the dipeptide carnosine released ophthalmically from NAC prodrug of L-carnosine, stabilizing properties of carnosine on biological membranes based on the ability of the imidazole-containing dipeptides to interact with lipid peroxidation products and reactive oxygen species (ROS), to prevent membrane damage and delute the associated with membrane fragements protein aggregates. The advent of therapeutic treatment of cataracts in canines with N-acetylcarnosine lubricant eye drops through targeting the prevention of loss of functional telomere length below

  7. Evaluation of cleaning methods applied in home environments after renovation and remodeling activities

    International Nuclear Information System (INIS)

    Yiin, L.-M.; Lu, S.-E.; Sannoh, Sulaiman; Lim, B.S.; Rhoads, G.G.

    2004-01-01

    We conducted a cleaning trial in 40 northern New Jersey homes where home renovation and remodeling (R and R) activities were undertaken. Two cleaning protocols were used in the study: a specific method recommended by the US Department of Housing and Urban Development (HUD), in the 1995 'Guidelines for the Evaluation and Control of Lead-Based Paint Hazards in Housing', using a high-efficiency particulate air (HEPA)-filtered vacuum cleaner and a tri-sodium phosphate solution (TSP); and an alternative method using a household vacuum cleaner and a household detergent. Eligible homes were built before the 1970s with potential lead-based paint and had recent R and R activities without thorough cleaning. The two cleaning protocols were randomly assigned to the participants' homes and followed the HUD-recommended three-step procedure: vacuuming, wet washing, and repeat vacuuming. Wipe sampling was conducted on floor surfaces or windowsills before and after cleaning to evaluate the efficacy. All floor and windowsill data indicated that both methods (TSP/HEPA and non-TSP/non-HEPA) were effective in reducing lead loading on the surfaces (P<0.001). When cleaning was applied to surfaces with initial lead loading above the clearance standards, the reductions were even greater, above 95% for either cleaning method. The mixed-effect model analysis showed no significant difference between the two methods. Baseline lead loading was found to be associated with lead loading reduction significantly on floors (P<0.001) and marginally on windowsills (P=0.077). Such relations were different between the two cleaning methods significantly on floors (P<0.001) and marginally on windowsills (P=0.066), with the TSP/HEPA method being favored for higher baseline levels and the non-TSP/non-HEPA method for lower baseline levels. For the 10 homes with lead abatement, almost all post-cleaning lead loadings were below the standards using either cleaning method. Based on our results, we recommend that

  8. Engineered Joint Lubrication for OA Prevention and Treatment

    Science.gov (United States)

    2015-09-01

    that work together with liquid lubricants to achieve low-friction systems. Lubrication between tissues is also important to maintain low-friction...movement within a number of biological systems, including the pleural cavity, the surface of the eye, visceral organs, and diarthroidal joints3. In...purified using reverse-phase high-performance liquid chromatography (C18 Grace-Vydac column) on a water/acetonitrile gradient. Purified peptides were

  9. Thermo-Rheometric Studies of New Class Ionic Liquid Lubricants

    Science.gov (United States)

    Bakhtiyarov, Sayavur; Street, Kenneth; Scheiman, Daniel; van Dyke, Alan

    2010-11-01

    Due to their specific properties, such as small volatility, nonflammability, extreme thermal stability, low melting point, wide liquid range, and good miscibility with organic materials, ionic liquids attracted particular interest in various industrial processes. Recently, the unique properties of ionic liquids caught the attention of space tribologists. The traditional lubricating materials used in space have limited lifetimes in vacuum due to the catalytic degradation on metal surfaces, high vaporization at high temperatures, dewetting, and other disadvantages. The lubricants for the space applications must have vacuum stability, high viscosity index, low creep tendency, good elastohydrodynamic and boundary lubrication properties, radiation atomic oxygen resistance, optical or infrared transparency. Unfortunately, the properties such as heat flow, heat capacity, thermogravimetric weight loss, and non-linearity in the rheological behavior of the lubricants are not studied well for newly developed systems. These properties are crucial to analyzing thermodynamic and energy dissipative aspects of the lubrication process. In this paper we will present the rheological and heat and mass transfer measurements for the ionic liquid lubricants, their mixtures with and without additive.

  10. Polyelectrolyte brushes: a novel stable lubrication system in aqueous conditions.

    Science.gov (United States)

    Kobayashi, Motoyasu; Terada, Masami; Takahara, Atsushi

    2012-01-01

    Surface-initiated controlled radical copolymerizations of 2-dimethylaminoethyl methacrylate (DMAEMA), 2-(methacryloyloxy)ethyl phosphorylcholine (MPC), 2-(methacryloyloxy)ethyltrimethylammonium chloride) (MTAC), and 3-sulfopropyl methacrylate potassium salt (SPMK) were carried out on a silicon wafer and glass ball to prepare polyelectrolyte brushes with excellent water wettability. The frictional coefficient of the polymer brushes was recorded on a ball-on-plate type tribometer by linear reciprocating motion of the brush specimen at a selected velocity of 1.5 x 10(-3) m s-1 under a normal load of 0.49 N applied to the stationary glass ball (d = 10 mm) at 298 K. The poly(DMAEMA-co-MPC) brush partially cross-linked by bis(2-iodoethoxy)ethane maintained a relatively low friction coefficient around 0.13 under humid air (RH > 75%) even after 200 friction cycles. The poly(SPMK) brush revealed an extremely low friction coefficient around 0.01 even after 450 friction cycles. We supposed that the abrasion of the brush was prevented owing to the good affinity of the poly(SPMK) brush for water forming a water lubrication layer, and electrostatic repulsive interactions among the brushes bearing sulfonic acid groups. Furthermore, the poly(SPMK-co-MTAC) brush with a chemically cross-linked structure showed a stable low friction coefficient in water even after 1400 friction cycles under a normal load of 139 MPa, indicating that the cross-linking structure improved the wear resistance of the brush layer.

  11. Electrotunable lubricity with ionic liquids: the influence of nanoscale roughness.

    Science.gov (United States)

    David, Alessio; Fajardo, Oscar Y; Kornyshev, Alexei A; Urbakh, Michael; Bresme, Fernando

    2017-07-01

    The properties of ionic liquids can be modified by applying an external electrostatic potential, providing a route to control their performance in nanolubrication applications. Most computational studies to date have focused on the investigation of smooth surfaces. Real surfaces are generally inhomogeneous and feature roughness of different length scales. We report here a study of the possible effects that surface roughness may have on electrotunable lubricity with ionic liquids, performed here by means of non-equilibrium molecular dynamics simulations. In order to advance our understanding of the interplay of friction and substrate structure we investigate coarse grained models of ionic liquids confined in model surfaces with nanometer roughness. The friction is shown to depend on the roughness of the substrate and the direction of shear. For the investigated systems, the friction coefficient is found to increase with roughness. These results are in contrast with previous studies, where roughness induced reduction of friction was reported, and they highlight the strong sensitivity of the friction process to the structure of the surfaces. The friction force features a maximum at a specific surface charge density. This behaviour is reminiscent of the one reported in ionic liquids confined by flat surfaces, showing the generality of this physical effect in confined ionic liquids. We find that an increase of the substrate-liquid dispersion interactions shifts the maximum to lower surface charges. This effect opens a route to control electrotunable friction phenomena by tuning both the electrostatic potential and the composition of the confining surfaces.

  12. 20 CFR 667.274 - What health and safety standards apply to the working conditions of participants in activities...

    Science.gov (United States)

    2010-04-01

    ... and safety standards apply to the working conditions of participants in activities under title I of... working conditions of participants in activities under title I of WIA? 667.274 Section 667.274 Employees... working conditions of employees are equally applicable to working conditions of participants engaged in...

  13. 49 CFR 17.6 - What procedures apply to the selection of programs and activities under these regulations?

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false What procedures apply to the selection of programs and activities under these regulations? 17.6 Section 17.6 Transportation Office of the Secretary of Transportation INTERGOVERNMENTAL REVIEW OF DEPARTMENT OF TRANSPORTATION PROGRAMS AND ACTIVITIES § 17.6 What...

  14. Capturing ecology in modeling approaches applied to environmental risk assessment of endocrine active chemicals in fish.

    Science.gov (United States)

    Mintram, Kate S; Brown, A Ross; Maynard, Samuel K; Thorbek, Pernille; Tyler, Charles R

    2018-02-01

    Endocrine active chemicals (EACs) are widespread in freshwater environments and both laboratory and field based studies have shown reproductive effects in fish at environmentally relevant exposures. Environmental risk assessment (ERA) seeks to protect wildlife populations and prospective assessments rely on extrapolation from individual-level effects established for laboratory fish species to populations of wild fish using arbitrary safety factors. Population susceptibility to chemical effects, however, depends on exposure risk, physiological susceptibility, and population resilience, each of which can differ widely between fish species. Population models have significant potential to address these shortfalls and to include individual variability relating to life-history traits, demographic and density-dependent vital rates, and behaviors which arise from inter-organism and organism-environment interactions. Confidence in population models has recently resulted in the EU Commission stating that results derived from reliable models may be considered when assessing the relevance of adverse effects of EACs at the population level. This review critically assesses the potential risks posed by EACs for fish populations, considers the ecological factors influencing these risks and explores the benefits and challenges of applying population modeling (including individual-based modeling) in ERA for EACs in fish. We conclude that population modeling offers a way forward for incorporating greater environmental relevance in assessing the risks of EACs for fishes and for identifying key risk factors through sensitivity analysis. Individual-based models (IBMs) allow for the incorporation of physiological and behavioral endpoints relevant to EAC exposure effects, thus capturing both direct and indirect population-level effects.

  15. Chemical discrimination of lubricant marketing types using direct analysis in real time time-of-flight mass spectrometry.

    Science.gov (United States)

    Maric, Mark; Harvey, Lauren; Tomcsak, Maren; Solano, Angelique; Bridge, Candice

    2017-06-30

    In comparison to other violent crimes, sexual assaults suffer from very low prosecution and conviction rates especially in the absence of DNA evidence. As a result, the forensic community needs to utilize other forms of trace contact evidence, like lubricant evidence, in order to provide a link between the victim and the assailant. In this study, 90 personal bottled and condom lubricants from the three main marketing types, silicone-based, water-based and condoms, were characterized by direct analysis in real time time of flight mass spectrometry (DART-TOFMS). The instrumental data was analyzed by multivariate statistics including hierarchal cluster analysis, principal component analysis, and linear discriminant analysis. By interpreting the mass spectral data with multivariate statistics, 12 discrete groupings were identified, indicating inherent chemical diversity not only between but within the three main marketing groups. A number of unique chemical markers, both major and minor, were identified, other than the three main chemical components (i.e. PEG, PDMS and nonoxynol-9) currently used for lubricant classification. The data was validated by a stratified 20% withheld cross-validation which demonstrated that there was minimal overlap between the groupings. Based on the groupings identified and unique features of each group, a highly discriminating statistical model was then developed that aims to provide the foundation for the development of a forensic lubricant database that may eventually be applied to casework. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Tribological Performance of Hydrogenated Amorphous Carbon (a-C: H DLC Coating when Lubricated with Biodegradable Vegetal Canola Oil

    Directory of Open Access Journals (Sweden)

    H.M. Mobarak

    2014-06-01

    Full Text Available Increasing environmental awareness and demands for lowering energy consumptions are strong driving forces behind the development of the vehicles of tomorrow. Without the advances of lubricant chemistry and adequate lubricant formulation, expansion of modern engines would not have been possible. Considering environmental awareness factors as compared to mineral oils, vegetal oil based biolubricants are renewable, biodegradable, non-toxic and have a least amount of greenhouse gases. Furthermore, improvement in engine performance and transmission components, which were impossible to achieve by applying only lubricants design, is now possible through diamond like carbon (DLC coatings. DLC coatings exhibit brilliant tribological properties, such as good wear resistance and low friction. In this regard, tribological performance of a-C: H DLC coating when lubricated with Canola vegetal oil has been investigated by the help of a ball-on-flat geometry. Experimental results demonstrated that the a-C: H DLC coating exhibited better performance with Canola oil in terms of friction and wear as compared to the uncoated materials. Large amount of polar components in the Canola oil significantly improved the tribological properties of the a-C:H coating. Thus, usage of a-C: H DLC coating with Canola oil in the long run may have a positive impact on engine life.

  17. Tendency of lubricating oil manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Toshio

    1988-09-30

    The manufacturing method of paraffin base oil and the tendency are explained in details. The base oil is distillate of petroleum which is obtained at the high boiling of 400/degree/C or higher. The base oil is made from the distillate which is obtained through solvent deasphalting of the vacuum distillated residual oil. The refining process of those material is classified into the two different process steps such as refining and modifying process step in which the quality of the material is improved while eliminating unstable resin, aromatic compound, and sulfur contained in the material, and dewaxing process step in which the wax contained in the material is removed. The former is combination of the two different process steps such as solvent extraction process and hydrogen finishing process or hydroforming process. The latter is a combination of the two different process steps such as solvent dewaxing and catalytic dewaxing (hydro-dewaxing). Various examples of reactions, features and industrial processes are given in accordance with each of these process steps. Regarding the tendency toward the future, the kinds of materials will be expanded in the way that naphthene base oil will adopted as the material oil along with diversification of the quality of lubricating oil, and the processing technology including two-stage processing, catalytic dewaxing, etc. will be expected to be improved. 18 references, 11 figures, 7 tables.

  18. 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

    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......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...

  19. Tribology and energy efficiency: from molecules to lubricated contacts to complete machines.

    Science.gov (United States)

    Taylor, Robert Ian

    2012-01-01

    The impact of lubricants on energy efficiency is considered. Molecular details of base oils used in lubricants can have a great impact on the lubricant's physical properties which will affect the energy efficiency performance of a lubricant. In addition, molecular details of lubricant additives can result in significant differences in measured friction coefficients for machine elements operating in the mixed/boundary lubrication regime. In single machine elements, these differences will result in lower friction losses, and for complete systems (such as cars, trucks, hydraulic circuits, industrial gearboxes etc.) lower fuel consumption or lower electricity consumption can result.

  20. Method to improve lubricity of low-sulfur diesel and gasoline fuels

    Science.gov (United States)

    Erdemir, Ali

    2004-08-31

    A method for providing lubricity in fuels and lubricants includes adding a boron compound to a fuel or lubricant to provide a boron-containing fuel or lubricant. The fuel or lubricant may contain a boron compound at a concentration between about 30 ppm and about 3,000 ppm and a sulfur concentration of less than about 500 ppm. A method of powering an engine to minimize wear, by burning a fuel containing boron compounds. The boron compounds include compound that provide boric acid and/or BO.sub.3 ions or monomers to the fuel or lubricant.

  1. Analysis of fluid lubrication mechanisms in metal forming at mesoscopic scale

    DEFF Research Database (Denmark)

    Dubar, L.; Hubert, C.; Christiansen, Peter

    2012-01-01

    The lubricant entrapment and escape phenomena in metal forming are studied experimentally as well as numerically. Experiments are carried out in strip reduction of aluminium sheet applying a transparent die to study the fluid flow between mesoscopic cavities. The numerical analysis involves two...... computation steps. The first one is a fully coupled fluid-structure Finite Element computation, where pockets in the surface are plastically deformed leading to the pressurization of the entrapped fluid. The second step computes the fluid exchange between cavities through the plateaus of asperity contacts...

  2. Effects of Velocity-Slip and Viscosity Variation in Squeeze Film Lubrication of Two Circular Plates

    Directory of Open Access Journals (Sweden)

    R.R. Rao

    2013-03-01

    Full Text Available A generalized form of Reynolds equation for two symmetrical surfaces is taken by considering velocity-slip at the bearing surfaces. This equation is applied to study the effects of velocity-slip and viscosity variation for the lubrication of squeeze films between two circular plates. Expressions for the load capacity and squeezing time obtained are also studied theoretically for various parameters. The load capacity and squeezing time decreases due to slip. They increase due to the presence of high viscous layer near the surface and decrease due to low viscous layer.

  3. Active and passive infrared thermography applied to the detection and characterization of hidden defects in structure

    Science.gov (United States)

    Dumoulin, Jean

    2013-04-01

    direct thermal modelling or inverse thermal modelling will be presented and discussed. Conclusion and perspectives will be proposed in link with structure monitoring or cultural heritage applications. References [1] Maldague, X.P.V. "Theory and practice of infrared technology for non-destructive testing", John Wiley & sons Inc., 2001. [2] Dumoulin J. and Averty R., « Development of an infrared system coupled with a weather station for real time atmospheric corrections using GPU computing: Application to bridge monitoring", QIRT 2012, Naples, Italy, June 2012. [3] J. Dumoulin, L. Ibos, C. Ibarra-Castanedo, A Mazioud, M. Marchetti, X. Maldague and A. Bendada, « Active infrared thermography applied to defect detection and characterization on asphalt pavement samples: comparison between experiments and numerical simulations », Journal of Modern Optics, Special Issue on Advanced Infrared Technology and Applications, Volume 57, Issue 18, October 2010 , pages 1759 - 1769, doi:10.1080/09500340.2010.522738 [4] F. Taillade, M. Quiertant, K. Benzarti, J. Dumoulin, Ch. Aubagnac, Chapter 9: "Nondestructive Evaluation of FRP Strengthening Systems Bonded on Concrete Structures using Pulsed Stimulated Infrared Thermography ", pp 193-208, Book title "Infrared Thermography", Editeur Raghu V. Prakash, ISBN 978-953-51-0242-7, Intech, open access at the following address http://www.intechopen.com/books/editor/infrared-thermography, march 2012. [5] Cooley J.W., Tukey J.W., "An algorithm for the machine calculation of complex Fourier series", Mathematics of Computation, vol. 19, n° 90, 1965, p. 297-301. [6] Rajic N., "Principal component thermography for flaw contrast enhancement and flaw depth characterization in composite structures", Composite Structures, vol 58, pp 521-528, 2002. [7] Marinetti S., Grinzato E., Bison P. G., Bozzi E., Chimenti M., Pieri G. and Salvetti O. "Statistical analysis of IR thermographic sequences by PCA," Infrared Physics & Technology vol 46 pp 85-91, 2004.

  4. Neutron activation analysis applied to the determination of trace elements in human nails

    International Nuclear Information System (INIS)

    Aguiar, Amilton Reinaldo

    2001-01-01

    There is a considerable interest in the determination of trace elements in human nails in order to use this tissue as a monitor of nutritional and healthy status of individuals, of occupational exposure diseases and of the environmental contamination. In this work, instrumental neutron activation analysis was applied to determine trace elements in finger nail clippings to make comparisons between the elemental concentrations obtained in nails from healthy individuals of a control group and those from cystic fibrosis (CF) patients. Firstly, a protocol for sample collection and preparation for analysis was established. Finger and toe nail samples from CF patients were collected at the Instituto da Crianca of Medicine School, University of Sao Paulo, SP. The nail samples from control group were collected from healthy adults and from children living in Sao Paulo city, SP. These samples were cleaned by stirring them witha a diluted Triton X100 solution and then by washing with distilled water and acetone. The analytical procedure consisted of irradiation nail samples and elemental standards in the IEA-R1m nuclear reactor under thermal neutro flux of about 10 12 n cm -2 s -1 , for short and long period irradiations. The activities of the radionuclides were measured using a gamma-ray spectrometer comprising an hyperpure Ge detector and associated electronic system. The biological reference materials Bovine Liver 1577b and Oyster Tissue 1566a, both from National Institute of Standards and Technology, USA were analysed in order to evaluate the accuracy and precision of the results. The analysis of variance (ANOVA) and F-test at the significance level of 5% were used to make a comparison between the sets of results obtained in this work. In the comparison of the results obtained for finger and toe nails from CF patients, the Br concentrations were higher in finger nails that those obtained for toe nails. For the control group of children, the finger nails presented different

  5. Enhanced lubricant film formation through micro-dimpled hard-on-hard artificial hip joint: An in-situ observation of dimple shape effects.

    Science.gov (United States)

    Choudhury, Dipankar; Rebenda, David; Sasaki, Shinya; Hekrle, Pavel; Vrbka, Martin; Zou, Min

    2018-05-01

    This study evaluates the impact of dimple shapes on lubricant film formation in artificial hip joints. Micro-dimples with 20-50 µm lateral size and 1 ± 0.2 µm depths were fabricated on CrCoMo hip joint femoral heads using a picosecond laser. Tribological studies were performed using a pendulum hip joint simulator to apply continuous swing flexion-extension motions. The results revealed a significantly enhanced lubricant film thickness (≥ 500 nm) with micro-dimpled prosthesis heads at equilibrium position after the lubricant film has fully developed. The average lubricant film thickness of dimpled prostheses with square- and triangular-shaped dimple arrays over time is about 3.5 that of the non-dimpled prosthesis (204 nm). Remarkably, the prosthesis with square-shaped dimple arrays showed a very fast lubricant film formation reaching their peak values within 0.5 s of pendulum movement, followed by prosthesis with triangular-shaped dimple arrays with a transition period of 42.4 s. The fully developed lubricant film thicknesses (≥ 700 nm) are significantly higher than the surface roughness (≈ 25 nm) demonstrating a hydrodynamic lubrication. Hardly any scratches appeared on the post-experimental prosthesis with square-shaped dimple array and only a few scratches were found on the post-experimental prosthesis with triangular-shaped dimple arrays. Thus, prostheses with square-shaped dimple arrays could be a potential solution for durable artificial hip joints. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Lubrication of Space Shuttle Main Engine Turbopump Bearings

    Science.gov (United States)

    Gibson, Howard; Munafo, Paul (Technical Monitor)

    2001-01-01

    The Space Shuttle has three main engines that are used for propulsion into orbit. These engines are fed propellants by four turbopumps on each engine. A main element in the turbopump is the bearings supporting the rotor that spins the turbine blades and the pump impeller. These bearings are required to spin at very high speeds, support radial and thrust loads, and have high wear resistance without the benefit of lubrication. The liquid hydrogen and oxygen propellants flow through the bearings to cool the surfaces. The volatile nature of the propellants excludes any conventional means of lubrication. Lubrication for these bearings is provided by the ball separator inside the bearing. The separator is a composite material that supplies a transfer film of lubrication to the rings and balls. New separator materials and lubrication schemes have been investigated at Marshall Space Flight Center in a bearing test rig with promising results. Hybrid bearings with silicon nitride balls have also been evaluated. The use of hybrid, silicon nitride ball bearings in conjunction -with better separator materials has shown excellent results. The work that Marshall has done is being utilized in turbopumps flying on the space shuttle fleet and will be utilized in future space travel. This result of this work is valuable for all aerospace and commercial applications where high-speed bearings are used.

  7. Agriculture: Laws and Regulations that Apply to Your Agricultural Operation by Farm Activity

    Science.gov (United States)

    A general description of EPA’s requirements applicable to agriculture, and should only be used as a guide. Since rules and regulations may change use this information is a starting place to determine which regulations apply to your agricultural operation.

  8. How High Is the Tramping Track? Mathematising and Applying in a Calculus Model-Eliciting Activity

    Science.gov (United States)

    Yoon, Caroline; Dreyfus, Tommy; Thomas, Michael O. J.

    2010-01-01

    Two complementary processes involved in mathematical modelling are mathematising a realistic situation and applying a mathematical technique to a given realistic situation. We present and analyse work from two undergraduate students and two secondary school teachers who engaged in both processes during a mathematical modelling task that required…

  9. The Challenge of Finding Faculty Time for Applied Research Activities in Ontario Colleges

    Science.gov (United States)

    Rosenkrantz, Otte

    2013-01-01

    The purpose of this study was to explore how the role of Ontario college faculty has evolved since the advent of the Post-Secondary Education Choice and Excellence Act of 2000 and the Colleges of Applied Arts and Technology Act of 2002 in terms of whether or not the decision to create a research culture at the colleges included making time…

  10. Applied CATIA Secondary Development to Parametric Design of Active Magnetic Bearing

    Directory of Open Access Journals (Sweden)

    Zhang Li

    2016-01-01

    Full Text Available Based on the properties of active magnetic bearing, the electromagnetic parameters and structure parameters are analyzed, parametric design method is introduced to study the structure of active magnetic bearing. Through a program personalization process that is in accordance with active magnetic bearing is established. Personalization process aims to build the parametric model of active magnetic bearings and component library by use of CATIA secondary development. Component library is to build assembly model for a multiple degree of freedom magnetic bearing system. Parametric design is a method that provides the direction for its structural design.

  11. Effect of the External Lubrication Method for a Rotary Tablet Press on the Adhesion of the Film Coating Layer.

    Science.gov (United States)

    Kondo, Hisami; Toyota, Hiroyasu; Kamiya, Takayuki; Yamashita, Kazunari; Hakomori, Tadashi; Imoto, Junko; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

    2017-01-01

    External lubrication is a useful method which reduces the adhesion of powder to punches and dies by spraying lubricants during the tableting process. However, no information is available on whether the tablets prepared using an external lubrication system can be applicable for a film coating process. In this study, we evaluated the adhesion force of the film coating layer to the surface of tablets prepared using an external lubrication method, compared with those prepared using internal lubrication method. We also evaluated wettability, roughness and lubricant distribution state on the tablet surface before film coating, and investigated the relationship between peeling of the film coating layer and these tablet surface properties. Increasing lubrication through the external lubrication method decreased wettability of the tablet surface. However, no change was observed in the adhesion force of the film coating layer. On the other hand, increasing lubrication through the internal lubrication method, decreased both wettability of the tablet surface and the adhesion force of the film coating layer. The magnesium stearate distribution state on the tablet surface was assessed using an X-ray fluorescent analyzer and lubricant agglomerates were observed in the case of the internal lubrication method. However, the lubricant was uniformly dispersed in the external lubrication samples. These results indicate that the distribution state of the lubricant affects the adhesion force of the film coating layer, and external lubrication maintained sufficient lubricity and adhesion force of the film coating layer with a small amount of lubricant.

  12. Performance of two-lobe hole-entry hybrid journal bearing system under the combined influence of textured surface and couple stress lubricant

    Science.gov (United States)

    Khatri, Chandra B.; Sharma, Satish C.

    2018-02-01

    Textured surface in journal bearings is becoming an important area of investigation during the last few years. Surface textures have the shapes of micro-dimple with a small diameter and depth having order of magnitude of bearing clearance. This paper presents the influence of couple stress lubricant on the circular and non-circular hole-entry hybrid journal bearing system and reports the comparative study between the textured and non-textured circular/non-circular hybrid journal bearing system. The governing Reynolds equation has been modified for the couple stress lubricant flow in the clearance of bearing and journal. The FEM technique has been applied to solve the modified Reynolds equation together with restrictor flow equation. The numerically simulated results indicate that the influence of couple stress lubricant is significantly more in textured journal bearing than that of non-textured journal bearing. Further, it has been observed that the textured two-lobe (δ = 1.1) hybrid journal bearing lubricated with couple stress lubricant provides larger values of fluid film stiffness coefficients and stability threshold speed against other bearings studied in the present paper.

  13. Low Temperature Irradiation Applied to Neutron Activation Analysis of Mercury In Human Whole Blood

    International Nuclear Information System (INIS)

    Brune, D.

    1966-02-01

    The distribution of mercury in human whole blood has been studied by means of neutron activation analysis. During the irradiation procedure the samples were kept at low temperature by freezing them in a cooling device in order to prevent interferences caused by volatilization and contamination. The mercury activity was separated by means of distillation and ion exchange techniques

  14. Brief Report: The Theory of Planned Behaviour Applied to Physical Activity in Young People Who Smoke

    Science.gov (United States)

    Everson, Emma S.; Daley, Amanda J.; Ussher, Michael

    2007-01-01

    It has been hypothesised that physical activity may be useful as a smoking cessation intervention for young adults. In order to inform such interventions, this study evaluated the theory of planned behaviour (TPB) for understanding physical activity behaviour in young smokers. Regular smokers aged 16-19 years (N=124), self-reported physical…

  15. The Impact of Agriculture on Other Business Activity: A Nationwide Analysis Applied to Fayette County, Kentucky

    OpenAIRE

    Maynard, Leigh J.; Dunaway, Tarrah; Garkovich, Lorraine; Davis, Alison F.

    2013-01-01

    This study evaluated the county-level impact of equine sales and horse racing on business activity in six other industries. In Fayette County, Kentucky, the results suggested that equine activities substantially increase the number of establishments, payroll, and sales in the hospitality, recreation, finance, professional services, real estate, and retail industries.

  16. Applying Active Learning at the Graduate Level: Merger Issues at Newco.

    Science.gov (United States)

    Berger, Bruce K.

    2002-01-01

    Suggests that active learning can benefit students in public relations and integrated communication courses at the graduate level. Describes how three active learning approaches--research and field work, student accountabilities for learning, and student reflection and reflexive exercises--were used in a graduate class project to help a Fortune 50…

  17. Low Temperature Irradiation Applied to Neutron Activation Analysis of Mercury In Human Whole Blood

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D

    1966-02-15

    The distribution of mercury in human whole blood has been studied by means of neutron activation analysis. During the irradiation procedure the samples were kept at low temperature by freezing them in a cooling device in order to prevent interferences caused by volatilization and contamination. The mercury activity was separated by means of distillation and ion exchange techniques.

  18. User Activity Recognition in Smart Homes Using Pattern Clustering Applied to Temporal ANN Algorithm.

    Science.gov (United States)

    Bourobou, Serge Thomas Mickala; Yoo, Younghwan

    2015-05-21

    This paper discusses the possibility of recognizing and predicting user activities in the IoT (Internet of Things) based smart environment. The activity recognition is usually done through two steps: activity pattern clustering and activity type decision. Although many related works have been suggested, they had some limited performance because they focused only on one part between the two steps. This paper tries to find the best combination of a pattern clustering method and an activity decision algorithm among various existing works. For the first step, in order to classify so varied and complex user activities, we use a relevant and efficient unsupervised learning method called the K-pattern clustering algorithm. In the second step, the training of smart environment for recognizing and predicting user activities inside his/her personal space is done by utilizing the artificial neural network based on the Allen's temporal relations. The experimental results show that our combined method provides the higher recognition accuracy for various activities, as compared with other data mining classification algorithms. Furthermore, it is more appropriate for a dynamic environment like an IoT based smart home.

  19. User Activity Recognition in Smart Homes Using Pattern Clustering Applied to Temporal ANN Algorithm

    Directory of Open Access Journals (Sweden)

    Serge Thomas Mickala Bourobou

    2015-05-01

    Full Text Available This paper discusses the possibility of recognizing and predicting user activities in the IoT (Internet of Things based smart environment. The activity recognition is usually done through two steps: activity pattern clustering and activity type decision. Although many related works have been suggested, they had some limited performance because they focused only on one part between the two steps. This paper tries to find the best combination of a pattern clustering method and an activity decision algorithm among various existing works. For the first step, in order to classify so varied and complex user activities, we use a relevant and efficient unsupervised learning method called the K-pattern clustering algorithm. In the second step, the training of smart environment for recognizing and predicting user activities inside his/her personal space is done by utilizing the artificial neural network based on the Allen’s temporal relations. The experimental results show that our combined method provides the higher recognition accuracy for various activities, as compared with other data mining classification algorithms. Furthermore, it is more appropriate for a dynamic environment like an IoT based smart home.

  20. 28 CFR 30.6 - What procedures apply to the selection of programs and activities under these regulations?

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false What procedures apply to the selection of programs and activities under these regulations? 30.6 Section 30.6 Judicial Administration DEPARTMENT OF... consult with local elected officials. (b) Each state that adopts a process shall notify the Attorney...

  1. Assessment of lubricating oil degradation in small motorcycle engine fueled with gasohol

    Directory of Open Access Journals (Sweden)

    Nakorn Tippayawong

    2010-05-01

    Full Text Available Assessment of the degradation of lubricating oil was performed on the lubricants which had been used in a small motorcycle engine fueled with gasohol in comparison with the lubricants from gasoline-run engine. The lubricant properties examined in the assessment were lubricating capacity, viscosity and stability to oxidation. Lubricating capacity was evaluated by accelerated wear test on the Timken tester. Lubricating oils from gasohol-run engine appeared to produce about 10% greater wear than that made in oils from gasoline-run engine. There was no significant difference between the effect of gasohol and gasoline on the viscosity of the used lubricating oils. Moreover, no oxidation products in any used oil samples could be detected.

  2. WATER-EMULSION LUBRICANTS FOR PRESS-MODES OF CASTING UNDER PRESSURE

    Directory of Open Access Journals (Sweden)

    A. M. Mihaltsov

    2005-01-01

    Full Text Available It is shown that for more successful using of wateremulsion lubricants it is necessary to use new lubricating component. One of such component is complex component on the basis of siloxanes.

  3. Fe-Modeling Of Starved Hydrodynamic Lubrication With Free Surface Effects

    DEFF Research Database (Denmark)

    Poulios, Konstantinos; Vølund, Anders; Klit, Peder

    2017-01-01

    This work concerns a new finite-element formulation for solving hydrody-namic lubrication problems that include partially flooded regions, where the lubricant film behavior is governed by free surface flow....

  4. Boundary Lubrication of PEO-PPO-PEO Triblock Copolymer Physisorbed on Polypropylene, Polyethylene, and Cellulose Surfaces

    KAUST Repository

    Li, Yangyang; Rojas, O. J.; Hinestroza, J. P.

    2012-01-01

    to the affinity of the polymer with the substrate. Further experiments were performed to mimic practical operations involving lubricant addition during manufacturing and postprocessing removal. XPS was used to verify the presence of the lubricant on the polymeric

  5. Applying GPS to enhance understanding of transport-related physical activity.

    Science.gov (United States)

    Duncan, Mitch J; Badland, Hannah M; Mummery, W Kerry

    2009-09-01

    The purpose of the paper is to review the utility of the global positioning system (GPS) in the study of health-related physical activity. The paper draws from existing literature to outline the current work performed using GPS to examine transport-related physical activity, with a focus on the relative utility of the approach when combined with geographic information system (GIS) and other data sources including accelerometers. The paper argues that GPS, especially when used in combination with GIS and accelerometery, offers great promise in objectively measuring and studying the relationship of numerous environmental attributes to human behaviour in terms of physical activity and transport-related activity. Limitations to the use of GPS for the purpose of monitoring health-related physical activity are presented, and recommendations for future avenues of research are discussed.

  6. Friction and lubrication modelling in sheet metal forming: Influence of lubrication amount, tool roughness and sheet coating on product quality

    Science.gov (United States)

    Hol, J.; Wiebenga, J. H.; Carleer, B.

    2017-09-01

    In the stamping of automotive parts, friction and lubrication play a key role in achieving high quality products. In the development process of new automotive parts, it is therefore crucial to accurately account for these effects in sheet metal forming simulations. This paper presents a selection of results considering friction and lubrication modelling in sheet metal forming simulations of a front fender product. For varying lubrication conditions, the front fender can either show wrinkling or fractures. The front fender is modelled using different lubrication amounts, tool roughness’s and sheet coatings to show the strong influence of friction on both part quality and the overall production stability. For this purpose, the TriboForm software is used in combination with the AutoForm software. The results demonstrate that the TriboForm software enables the simulation of friction behaviour for varying lubrication conditions, i.e. resulting in a generally applicable approach for friction characterization under industrial sheet metal forming process conditions.

  7. The State of the Art in Cold Forging Lubrication

    DEFF Research Database (Denmark)

    Bay, Niels

    1994-01-01

    The manufature of components in steel, aluminium and copper alloys by cold forging production has increased ever since the 1950's. Typical processes are forward rod extrusion and backward can extrusion, upsetting, ironing, tube extrusion and radial extrusion. The tribological conditions in cold...... forging are extremely severe due to large surface expansion and normal pressure in the tool/workpiece interface combined with elevated tool temperatures. Except for the more simple cold forging operations successful production therefore requires advanced lubrication systems. The present paper gives...... a detailed description of the state of art for lubricant systems for cold forging of C-steels and low alloy steels as well as aluminium alloys including all the basic operations such as cleaning of the slugs, application of eventual conversion coating and lubrication. As regards cold forging of steel...

  8. Coefficient of friction of a starved lubricated spur gear pair

    International Nuclear Information System (INIS)

    Liu, Huaiju; Zhu, Caichao; Sun, Zhangdong; Zhang, Yuanyuan; Song, Chaosheng

    2016-01-01

    The frictional power loss issue of gear pairs becomes an important concern in both industry and academia due to the requirement of the energy saving and the improvement of power density of gear drives. A thermal starved elastohydrodynamic lubrication model is developed to study the tribological performance of a spur gear pair under starved lubrication conditions. The contact pressure, the film thickness, the temperature rise, the frictional power loss, as well as the coefficient of friction are evaluated by considering the variation of the curvature radius, the sliding/rolling motion, and the load distribution of gear tooth within the meshing period. Effects of lubrication starvation condition, load and speed on the coefficient of friction are studied.

  9. Feasibility study of self-lubrication by chlorine implantation

    International Nuclear Information System (INIS)

    Akhajdenung, T.; Aizawa, T.; Yoshitake, M.; Mitsuo, A.

    2003-01-01

    Implantation of chlorine into titanium nitride (TiN) coating on the high-speed steel substrate has succeeded in significant reduction of wear rate and friction coefficient for original TiN under dry wear condition. Through precise investigation on the surface reaction in the wear track, in situ formation of oxygen-deficient titanium oxides was found to play a role as a lubricious oxide. In the present paper, this self-lubrication mechanism is further investigated for various wearing conditions. For wide range of sliding speed and normal load in the wear map, the wear volume of a counter material is actually reduced with comparison to the un-implanted TiN. Effect of the ion implantation dose on this self-lubrication mechanism is also studied for practical use. Some comments are made on further application of this self-lubrication to manufacturing

  10. Oils; lubricants; paraffin-wax compositions; hydrocarbon condensation products

    Energy Technology Data Exchange (ETDEWEB)

    1934-04-04

    Petroleum hydrocarbons such as gasoline, kerosene, Diesel fuel oil, lubricating-oil, and paraffin wax, and like hydrocarbons such as are obtainable from shale oil and by the hydrogenation of carbonaceous materials, are improved by addition of products obtained by condensing a cyclic hydrocarbon with a saturated dihalogen derivative of an aliphatic hydrocarbon containing less than five carbon atoms. The addition of the condensation products increases the viscosity of the hydrocarbon oils specified, and is particularly useful in the case of lubricating-oils; addition of the condensation products to paraffin wax increases the transparency and adherent properties of the wax, and is useful in the manufacture of moulded articles such as candles; the products may also be used in solid lubricating-compositions.

  11. Elastic model of the traction behavior of two traction lubricants

    Science.gov (United States)

    Loewenthal, S. H.; Rohn, D. A.

    1984-01-01

    In the analysis of rolling-sliding concentrated contacts, such as gears, bearings and traction drives, the traction characteristics of the lubricant are of prime importance. The elastic shear modulus and limiting shear stress properties of the lubricant dictate the traction/slip characteristics and power loss associated with an EHD contact undergoing slip and/or spin. These properties can be deducted directly from the initial slope m and maximum traction coefficient micron of an experimental traction curve. In this investigation, correlation equations are presented to predict m and micron for two modern traction fluids based on the regression analysis of 334 separate traction disk machine experiments. The effects of contact pressure, temperature, surface velocity, ellipticity ratio are examined. Problems in deducing lubricant shear moduli from disk machine tests are discussed. Previously announced in STAR as N83-20116

  12. An Advanced Microturbine System with Water-Lubricated Bearings

    Directory of Open Access Journals (Sweden)

    Susumu Nakano

    2009-01-01

    Full Text Available A prototype of the next-generation, high-performance microturbine system was developed for laboratory evaluation. Its unique feature is its utilization of water. Water is the lubricant for the bearings in this first reported application of water-lubricated bearings in gas turbines. Bearing losses and limitations under usage conditions were found from component tests done on the bearings and load tests done on the prototype microturbine. The rotor system using the water-lubricated bearings achieved stable rotating conditions at a rated rotational speed of 51,000 rpm. An electrical output of 135 kW with an efficiency of more than 33% was obtained. Water was also utilized to improve electrical output and efficiency through water atomizing inlet air cooling (WAC and a humid air turbine (HAT. The operation test results for the WAC and HAT revealed the WAC and HAT operations had significant effects on both electrical output and electrical efficiency.

  13. IUTAM Symposium on Lubricated Transport of Viscous Materials

    CERN Document Server

    1998-01-01

    The main objective of the First International Symposium on Lubricated Transport of Viscous Materials was to bring together scientists and engineers from academia and industryto discuss current research work and exchange ideas in this newly emerging field. It is an area offluid dynamics devoted to laying bare the principlesofthe lubricated transport of viscous materials such as crude oil, concentrated oil/water emulsion, slurries and capsules. It encompasses several types of problem. Studies of migration of particulates away from walls, Segre-Silverberg effects, lubrication versus lift and shear-induced migration belong to one category. Some of the technological problems are the fluid dynamics ofcore flows emphasizing studies ofstability, problems of start-up, lift-off and eccentric flow where gravity causes the core flow to stratify. Another category of problems deals with the fouling of pipe walls with oil, with undesirable increases in pressure gradients and even blocking. This study involves subjects like ...

  14. Using Magnets and Magnetic Beads to Dissect Signaling Pathways Activated by Mechanical Tension Applied to Cells

    Science.gov (United States)

    Marjoram, R.J.; Guilluy, C; Burridge, K.

    2015-01-01

    Cellular tension has implications in normal biology and pathology. Membrane adhesion receptors serve as conduits for mechanotransduction that lead to cellular responses. Ligand-conjugated magnetic beads are a useful tool in the study of how cells sense and respond to tension. Here we detail methods for their use in applying tension to cells and strategies for analyzing the results. We demonstrate the methods by analyzing mechanotransduction through VE-cadherin on endothelial cells using both permanent magnets and magnetic tweezers. PMID:26427549

  15. Applying Active Learning to Assertion Classification of Concepts in Clinical Text

    Science.gov (United States)

    Chen, Yukun; Mani, Subramani; Xu, Hua

    2012-01-01

    Supervised machine learning methods for clinical natural language processing (NLP) research require a large number of annotated samples, which are very expensive to build because of the involvement of physicians. Active learning, an approach that actively samples from a large pool, provides an alternative solution. Its major goal in classification is to reduce the annotation effort while maintaining the quality of the predictive model. However, few studies have investigated its uses in clinical NLP. This paper reports an application of active learning to a clinical text classification task: to determine the assertion status of clinical concepts. The annotated corpus for the assertion classification task in the 2010 i2b2/VA Clinical NLP Challenge was used in this study. We implemented several existing and newly developed active learning algorithms and assessed their uses. The outcome is reported in the global ALC score, based on the Area under the average Learning Curve of the AUC (Area Under the Curve) score. Results showed that when the same number of annotated samples was used, active learning strategies could generate better classification models (best ALC – 0.7715) than the passive learning method (random sampling) (ALC – 0.7411). Moreover, to achieve the same classification performance, active learning strategies required fewer samples than the random sampling method. For example, to achieve an AUC of 0.79, the random sampling method used 32 samples, while our best active learning algorithm required only 12 samples, a reduction of 62.5% in manual annotation effort. PMID:22127105

  16. Predicting Factors Associated with Regular Physical Activity among College Students: Applying BASNEF Model

    Directory of Open Access Journals (Sweden)

    B. Moeini

    2011-10-01

    Full Text Available Introduction & Objective: One of the important problems in modern society is people's sedentary life style. The aim of this study was to determine factors associated with regular physical activity among college students based on BASNEF model.Materials & Methods: This study was a cross-sectional study carried out on 400 students in Hamadan University of Medical Sciences. Based on the assignment among different schools, classified sampling method was chosen for data gathering using a questionnaire in three parts including: demographic information, constructs of BASNEF model, and standard international physical activity questionnaire (IPAQ. Data were analyzed by SPSS-13, and using appropriate statistical tests (Chi-square, T-test and regression. Results: Based on the results, 271 students(67.8 % had low, 124 (31% moderate ,and 5 (1.2% vigorous physical activity. There was a significant relationship (c2=6.739, df= 1, P= 0.034 between their residence and physical activity and students living in dormitory were reported to have higher level of physical activity. Behavioral intention and enabling factors from the constructs of BASNEF model were the best predictors for having physical activity in students (OR=1.215, P = 0.000 and (OR=1.119, P= 0.000 respectively.Conclusion: With regard to the fact that majority of the students did not engage in enough physical activity and enabling factors were the most effective predictors for having regular physical activity in them, it seems that providing sports facilities can promote physical activity among the students.(Sci J Hamadan Univ Med Sci 2011;18(3:70-76

  17. Predictive modelling of fatigue failure in concentrated lubricated contacts.

    Science.gov (United States)

    Evans, H P; Snidle, R W; Sharif, K J; Bryant, M J

    2012-01-01

    Reducing frictional losses in response to the energy agenda will require use of less viscous lubricants causing hydrodynamically-lubricated bearings to operate with thinner films leading to "mixed lubrication" conditions in which a degree of direct interaction occurs between surfaces protected only by boundary tribofilms. The paper considers the consequences of thinner films and mixed lubrication for concentrated contacts such as those occurring between the teeth of power transmission gears and in rolling element bearings. Surface fatigue in gears remains a serious problem in demanding applications, and its solution will become more pressing with the tendency towards thinner oils. The particular form of failure examined here is micropitting, which is identified as a fatigue phenomenon occurring at the scale of the surface roughness asperities. It has emerged recently as a systemic difficulty in the operation of large scale wind turbines where it occurs in both power transmission gears and their support bearings. Predictive physical modelling of these contacts requires a transient mixed lubrication analysis for conditions in which the predicted lubricant film thickness is of the same order or significantly less than the height of surface roughness features. Numerical solvers have therefore been developed which are able to deal with situations in which transient solid contacts occur between surface asperity features under realistic engineering conditions. Results of the analysis, which reveal the detailed time-varying behaviour of pressure and film clearance, have been used to predict fatigue and damage accumulation at the scale of surface asperity features with the aim of improving understanding of the micropitting phenomenon. The possible consequences on fatigue of residual stress fields resulting from plastic deformation of surface asperities is also considered.

  18. The effect of inertia force in water lubricated thrust bearings of canned reactor coolant pump

    International Nuclear Information System (INIS)

    Deng Liping

    1994-01-01

    The water lubricated thrust bearings are analyzed. According to characteristic of low viscosity of water the lubricated equation for design and calculation of water lubricated thrust bearings is established. The calculation and analyses show that the effect of inertia force in water lubricated thrust bearings should not be neglected except the conditions of low speed, high angle of inclination and low radius ratio of pad

  19. INVESTIGATION OF FLOW BEHAVIOR IN MINIMUM QUANTITY LUBRICATION NOZZLE FOR END MILLING PROCESSES

    OpenAIRE

    M.S. Najiha; M.M.Rahman; A.R. Yusoff; K. Kadirgama

    2012-01-01

    Minimum quantity lubrication (MQL) is a sustainable manufacturing technique that has replaced conventional flooded lubrication methods and dry machining. In the MQL technique, the lubricant is sprayed onto the friction surfaces through nozzles through small pneumatically-operated pumps. This paper presents an investigation into the flow behavior of the lubricant and air mixture under certain pressures at the tip of a nozzle specially designed for MQL. The nozzle used is an MQL stainless steel...

  20. Applying Cross-Decking and Activity-Based Costing to Military Distribution Centers: A Proposed Framework

    National Research Council Canada - National Science Library

    Elliott, Jonathan

    1997-01-01

    .... Cross-docking is a commercially proven approach to material distribution through a distribution center that can help reduce inventories, speed material flows, and cut related logistics activity costs...

  1. Carcinogenicity of petroleum lubricating oil distillates: effects of solvent refining, hydroprocessing, and blending.

    Science.gov (United States)

    Halder, C A; Warne, T M; Little, R Q; Garvin, P J

    1984-01-01

    Certain refining processes were investigated to determine their influence on the dermal carcinogenic activity of petroleum-derived lubricating oil distillates. Specifically, the effects of solvent refining, hydroprocessing, a combination of both processes, and the blending of oils processed using each technique were evaluated in standard mouse skin-painting bioassays. The refining process used as well as the level or severity of treatment greatly influenced the carcinogenic outcome of processed lubricating oils. Solvent refining at severities normally used appeared to eliminate carcinogenicity. In contrast, hydroprocessing alone at mild levels of treatment was successful only in reducing the carcinogenic potency; severe hydroprocessing conditions were necessary to eliminate carcinogenic activity without the use of additional refining processes. Carcinogenic activity could also be eliminated by following moderate solvent refining with mild hydroprocessing. Blending of hydroprocessed oils with solvent-refined oils resulted in a substantial reduction or even elimination of carcinogenic activity. However, the degree of protection obtained varied with the particular distillates used and appeared largely dependent on the inherent biological activity of the hydroprocessed oil.

  2. Adaptive Neuro-Fuzzy Inference System Applied QSAR with Quantum Chemical Descriptors for Predicting Radical Scavenging Activities of Carotenoids.

    Science.gov (United States)

    Jhin, Changho; Hwang, Keum Taek

    2015-01-01

    One of the physiological characteristics of carotenoids is their radical scavenging activity. In this study, the relationship between radical scavenging activities and quantum chemical descriptors of carotenoids was determined. Adaptive neuro-fuzzy inference system (ANFIS) applied quantitative structure-activity relationship models (QSAR) were also developed for predicting and comparing radical scavenging activities of carotenoids. Semi-empirical PM6 and PM7 quantum chemical calculations were done by MOPAC. Ionisation energies of neutral and monovalent cationic carotenoids and the product of chemical potentials of neutral and monovalent cationic carotenoids were significantly correlated with the radical scavenging activities, and consequently these descriptors were used as independent variables for the QSAR study. The ANFIS applied QSAR models were developed with two triangular-shaped input membership functions made for each of the independent variables and optimised by a backpropagation method. High prediction efficiencies were achieved by the ANFIS applied QSAR. The R-square values of the developed QSAR models with the variables calculated by PM6 and PM7 methods were 0.921 and 0.902, respectively. The results of this study demonstrated reliabilities of the selected quantum chemical descriptors and the significance of QSAR models.

  3. Adaptive Neuro-Fuzzy Inference System Applied QSAR with Quantum Chemical Descriptors for Predicting Radical Scavenging Activities of Carotenoids.

    Directory of Open Access Journals (Sweden)

    Changho Jhin

    Full Text Available One of the physiological characteristics of carotenoids is their radical scavenging activity. In this study, the relationship between radical scavenging activities and quantum chemical descriptors of carotenoids was determined. Adaptive neuro-fuzzy inference system (ANFIS applied quantitative structure-activity relationship models (QSAR were also developed for predicting and comparing radical scavenging activities of carotenoids. Semi-empirical PM6 and PM7 quantum chemical calculations were done by MOPAC. Ionisation energies of neutral and monovalent cationic carotenoids and the product of chemical potentials of neutral and monovalent cationic carotenoids were significantly correlated with the radical scavenging activities, and consequently these descriptors were used as independent variables for the QSAR study. The ANFIS applied QSAR models were developed with two triangular-shaped input membership functions made for each of the independent variables and optimised by a backpropagation method. High prediction efficiencies were achieved by the ANFIS applied QSAR. The R-square values of the developed QSAR models with the variables calculated by PM6 and PM7 methods were 0.921 and 0.902, respectively. The results of this study demonstrated reliabilities of the selected quantum chemical descriptors and the significance of QSAR models.

  4. Industrial tribology tribosystems, friction, wear and surface engineering, lubrication

    CERN Document Server

    Mang, Theo; Bartels, Thorsten

    2010-01-01

    Integrating very interesting results from the most important R & D project ever made in Germany, this book offers a basic understanding of tribological systems and the latest developments in reduction of wear and energy consumption by tribological measures. This ready reference and handbook provides an analysis of the most important tribosystems using modern test equipment in laboratories and test fields, the latest results in material selection and wear protection by special coatings and surface engineering, as well as with lubrication and lubricants.This result is a quick introductio

  5. Testing of Lubricant Performance in Sheet Metal Forming

    DEFF Research Database (Denmark)

    Bay, Niels; Olsson, David Dam; Friis, Kasper Leth

    2008-01-01

    Increasing focus on environmental issues in industrial production has urged a number of sheet metal forming companies to look for new tribo-systems in order to substitute hazardous lubricants such as chlorinated paraffin oils. The problems are especially pronounced, when forming tribologically...... of the lubricant film causing pick-up of work piece material on the tool surface and scoring of subsequent work piece surfaces. The present paper gives an overview of more than 10 years work by the authors’ research group through participation in national as well as international framework programmes on developing...

  6. Mixed Mechanism of Lubrication by Lipid Bilayer Stacks.

    Science.gov (United States)

    Boţan, Alexandru; Joly, Laurent; Fillot, Nicolas; Loison, Claire

    2015-11-10

    Although the key role of lipid bilayer stacks in biological lubrication is generally accepted, the mechanisms underlying their extreme efficiency remain elusive. In this article, we report molecular dynamics simulations of lipid bilayer stacks undergoing load and shear. When the hydration level is reduced, the velocity accommodation mechanism changes from viscous shear in hydration water to interlayer sliding in the bilayers. This enables stacks of hydrated lipid bilayers to act as efficient boundary lubricants for various hydration conditions, structures, and mechanical loads. We also propose an estimation for the friction coefficient; thanks to the strong hydration forces between lipid bilayers, the high local viscosity is not in contradiction with low friction coefficients.

  7. Tribology - friction, lubrication and wear: fifty years on. 2 v

    International Nuclear Information System (INIS)

    1987-01-01

    The paper presents the proceedings of the International Tribology Conference held in London (United Kingdom), 1987, and organised by the Institution of Mechanical Engineers. The aim of the conference was to address the current status and future developments in all aspects of tribology. The conference proceedings contained 121 papers, and the sessions were structured under six headings: hydrodynamic, elastohydrodynamic and mixed lubrication; friction and wear; contact mechanics; materials; design and applications; and lubricants. Four papers were chosen for INIS and indexed separately. (U.K.)

  8. Analysis of a thioether lubricant by infrared Fourier microemission spectrophotometry

    Science.gov (United States)

    Jones, W. R., Jr.; Morales, W.; Lauer, J. L.

    1986-01-01

    An infrared Fourier microemission spectrophotometer is used to obtain spectra (wavenumber range, 630 to 1230 0.1 cm) from microgram quantities of thioether lubricant samples deposited on aluminum foil. Infrared bands in the spectra are reproducible and could be identified as originating from aromatic species (1,3-disubstituted benzenes). Spectra from all samples (neat and formulated, used and unused) are very similar. Additives (an acid and a phosphinate) present in low concentration (0.10 percent) in the formulated fluid are not detected. This instrument appears to be a viable tool in helping to identify lubricant components separated by liquid chromatography.

  9. Light-scattering study of the glass transition in lubricants

    Science.gov (United States)

    Alsaad, M. A.; Winer, W. O.; Medina, F. D.; Oshea, D. C.

    1977-01-01

    The sound velocity of four lubricants has been measured as a function of temperature and pressure using Brillouin scattering. A change in slope of the velocity as a function of temperature or pressure allowed the determination of the glass transition temperature and pressure. The glass transition data were used to construct a phase diagram for each lubricant. The data indicate that the glass transition temperature increased with pressure at a rate which ranged from 120 to 200 C/GPa. The maximum pressure attained was 0.69 GPa and the temperature range was from 25 to 100 C.

  10. Investigation on Capability of Reaming Process using Minimal Quantity Lubrication

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Tosello, Guido; Piska, Miroslav

    2008-01-01

    An investigation on reaming using minimal quantity lubrication (MQL) was carried out with the scope of documenting process capability using a metrological approach. Reaming tests were carried out on austenitic stainless steel, using HSS reamers with different cutting data and lubrication conditions...... depth of cut was employed. The suitability of MQL for reaming was proven under the investigated process conditions, concerning both the quality of the machined holes, in terms of geometrical characteristics and surface finishing, and the process quality, with respect to reaming torque and thrust, along...

  11. Development of measures from the theory of planned behavior applied to leisure-time physical activity.

    Science.gov (United States)

    Kerner, Matthew S

    2005-06-01

    Using the theory of planned behavior as a conceptual framework, scales assessing Attitude to Leisure-time Physical Activity, Expectations of Others, Perceived Control, and Intention to Engage in Leisure-time Physical Activity were developed for use among middle-school students. The study sample included 349 boys and 400 girls, 10 to 14 years of age (M=11.9 yr., SD=.9). Unipolar and bipolar scales with seven response choices were developed, with each scale item phrased in a Likert-type format. Following revisions, 22 items were retained in the Attitude to Leisure-time Physical Activity Scale, 10 items in the Expectations of Others Scale, 3 items in the Perceived Control Scale, and 17 items in the Intention to Engage in Leisure-time Physical Activity Scale. Adequate internal consistency was indicated by standardized coefficients alpha ranging from .75 to .89. Current results must be extended to assess discriminant and predictive validities and to check various reliabilities with new samples, then evaluation of intervention techniques for promotion of positive attitudes about leisure-time physical activity, including perception of control and intentions to engage in leisure-time physical activity.

  12. Nitrate reductase activity and its relationship with applied nitrogen in soybean

    International Nuclear Information System (INIS)

    Ge Wenting; Jin Xijun; Ma Chunmei; Dong Shoukun; Gong Zhenping; Zhang Lei

    2011-01-01

    Field experiments were conducted to study the nitrate reductase activity and its relationship to nitrogen by using frame tests (pot without bottom), sand culture and 15 N-urea at transplanting in soybean variety Suinong 14. Results showed that the activity of nitrate reductase in leaf changed as a signal peak curve with the soybean growth, lower in vegetative growth phase, higher in reproductive growth period and reached the peak in blooming period, then decreased gradually. Nitrogen application showed obvious effect on the nitrate reductase activity. The activities of nitrate reductase in leaves followed the order of N 135 > N 90 > N 45 > N 0 in vegetative growth stage, no clear regularity was found during the whole reproductive growth period. The activities of nitrate reductase in leaves were accorded with the order of upper leaves > mid leaves > lower leaves, and it was very significant differences (P 15 N labeling method during beginning seed stage and full seed stage shown that 15 N abundance in various organs at different node position also followed the same order, suggesting that high level of nitrate reductase activity at upper leaves of soybean promoted the assimilation of NO 3 - . (authors)

  13. Solid lubricant mass contact transfer technology usage for vacuum ball bearings longevity increasing

    Science.gov (United States)

    Arzymatov, B.; Deulin, E.

    2016-07-01

    A contact mass transfer technological method of solid lubricant deposition on components of vacuum ball bearings is presented. Physics-mathematical model of process contact mass transfer is being considered. The experimental results of ball bearings covered with solid lubricant longevity in vacuum are presented. It is shown that solid lubricant of contact mass transfer method deposition is prospective for ball bearing longevity increasing.

  14. Lubrication of soft and hard interfaces with thermo-responsive F127 hydrogel

    DEFF Research Database (Denmark)

    Røn, Troels; Chronakis, Ioannis S.; Lee, Seunghwan

    2014-01-01

    of F127-20 also displayed varying lubricating properties, both in the lubricating mechanism and efficacy, as a function of temperature, speed and tribopairs. F127-20 was most effective in lubricating a soft interface (PDMSePDMS) based on its gel-forming properties in 22.5-60 °C and feasible formation...

  15. 21 CFR 178.3910 - Surface lubricants used in the manufacture of metallic articles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Surface lubricants used in the manufacture of... lubricants used in the manufacture of metallic articles. The substances listed in this section may be safely used in surface lubricants employed in the manufacture of metallic articles that contact food, subject...

  16. Raman spectroscopy applied to identify metabolites in urine of physically active subjects.

    Science.gov (United States)

    Moreira, Letícia Parada; Silveira, Landulfo; da Silva, Alexandre Galvão; Fernandes, Adriana Barrinha; Pacheco, Marcos Tadeu Tavares; Rocco, Débora Dias Ferraretto Moura

    2017-11-01

    Raman spectroscopy is a rapid and non-destructive technique suitable for biological fluids analysis. In this work, dispersive Raman spectroscopy has been employed as a rapid and nondestructive technique to detect the metabolites in urine of physically active subjects before and after vigorous 30min pedaling or running compared to sedentary subjects. For so, urine samples from 9 subjects were obtained before and immediately after physical activities and submitted to Raman spectroscopy (830nm excitation, 250mW laser power, 20s integration time) and compared to urine from 5 sedentary subjects. The Raman spectra of urine from sedentary showed peaks related to urea, creatinine, ketone bodies, phosphate and other nitrogenous compounds. These metabolic biomarkers presented peaks with different intensities in the urine of physically active individuals after exercises compared to before, measured by the intensity of selected peaks the Raman spectra, which means different concentrations after training. These peaks presented different intensity values for each subject before physical activity, also behaving differently compared to the post-training: some subjects presented increase while others decrease the intensity. Raman spectroscopy may allow the development of a rapid and non-destructive test for metabolic evaluation of the physical training in active and trained subjects using urine samples, allowing nutrition adjustment with the sport's performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials

    International Nuclear Information System (INIS)

    English, G.A.; Firestone, R.B.; Perry, D.L.; Reijonen, J.P.; Ka-Ngo Leung; Garabedian, G.F.; Molnar, G.L.; Revay, Zs.

    2008-01-01

    Without quality historical records that provide the composition of legacy materials, the elemental and/or chemical characterization of such materials requires a manual analytical strategy that may expose the analyst to unknown toxicological hazards. In addition, much of the existing legacy inventory also incorporates radioactivity, and, although radiological composition may be determined by various nuclear-analytical methods, most importantly, gamma-spectroscopy, current methods of chemical characterization still require direct sample manipulation, thereby presenting special problems with broad implications for both the analyst and the environment. Alternately, prompt gamma activation analysis (PGAA) provides a 'single-shot' in-situ, non-destructive method that provides a complete assay of all major entrained elemental constituents. Additionally, neutron activation analysis (NAA) using short-lived activation products complements PGAA and is especially useful when NAA activation surpasses the PGAA in elemental sensitivity. (author)

  18. Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials

    International Nuclear Information System (INIS)

    Firestone, Richard B; English, G.A.; Firestone, R.B.; Perry, D.L.; Reijonen, J.P.; Leung, Ka-Ngo; Garabedian, G.F.; Molnar, G.L.; Revay, Zs.

    2008-01-01

    Without quality historical records that provide the composition of legacy materials, the elemental and/or chemical characterization of such materials requires a manual analytical strategy that may expose the analyst to unknown toxicological hazards. In addition, much of the existing legacy inventory also incorporates radioactivity, and, although radiological composition may be determined by various nuclear-analytical methods, most importantly, gamma-spectroscopy, current methods of chemical characterization still require direct sample manipulation, thereby presenting special problems with broad implications for both the analyst and the environment. Alternately, prompt gamma activation analysis (PGAA) provides a 'single-shot' in-situ, non-destructive method that provides a complete assay of all major entrained elemental constituents.1-3. Additionally, neutron activation analysis (NAA) using short-lived activation products complements PGAA and is especially useful when NAA activation surpasses the PGAA in elemental sensitivity

  19. Comparative evaluation of physicochemical properties of jatropha curcas seed oil for coolant-lubricant application

    Science.gov (United States)

    Murad, Muhamad Nasir; Sharif, Safian; Rahim, Erween Abd.; Abdullah, Rozaini

    2017-09-01

    Increased attention to environmental issues due to industrial activities has forced the authorities raise awareness and implement regulations to reduce the use of mineral oil. Some vegetable oils unexplored or less explored, particularly the non-edible oils such as Jatropha curcas oil (JCO) and others. Physicochemical properties of JCO is compared with others edible oils, synthetic ester and fatty alcohol to obtain a viable alternative in metal cutting fluids. The oil was found to show the suitability of properties for coolant-lubricant applications in term of its physicochemical properties and better in flash point and viscosity value.

  20. 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.

  1. Ordinary and Activated Bone Grafts: Applied Classification and the Main Features

    Directory of Open Access Journals (Sweden)

    R. V. Deev

    2015-01-01

    Full Text Available Bone grafts are medical devices that are in high demand in clinical practice for substitution of bone defects and recovery of atrophic bone regions. Based on the analysis of the modern groups of bone grafts, the particularities of their composition, the mechanisms of their biological effects, and their therapeutic indications, applicable classification was proposed that separates the bone substitutes into “ordinary” and “activated.” The main differential criterion is the presence of biologically active components in the material that are standardized by qualitative and quantitative parameters: growth factors, cells, or gene constructions encoding growth factors. The pronounced osteoinductive and (or osteogenic properties of activated osteoplastic materials allow drawing upon their efficacy in the substitution of large bone defects.

  2. Tribological properties of solid lubricants filled glass fiber reinforced polyamide 6 composites

    International Nuclear Information System (INIS)

    Li, Du-Xin; You, Yi-Lan; Deng, Xin; Li, Wen-Juan; Xie, Ying

    2013-01-01

    Highlights: ► The tribological properties of GF/PA6 improved by the incorporation of PTFE. ► PTFE and UHMWPE exhibited a synergism effect on reducing friction coefficient. ► Solid lubricants enlarged the range of applied velocity for GF/PA6 composite. - Abstract: The main purpose of this paper is to further optimize the tribological properties of the glass fiber reinforced PA6 (GF/PA6,15/85 by weight) for high performance friction materials using single or combinative solid lubricants such as Polytetrafluroethylene (PTFE), ultra-high molecular weight polyethylene (UHMWPE) and the combination of both of them. Various polymer blends, where GF/PA6 acts as the polymer matrix and solid lubricants as the dispersed phase were prepared by injection molding. The tribological properties of these materials and the synergism as a result of the incorporation of both PTFE and UHMWPE were investigated. The results showed that, at a load of 40 N and a velocity of 200 rpm, PTFE was effective in improving the tribological capabilities of matrix material. On the contrary, UHMWPE was not conductive to maintain the structure integrity of GF/PA6 composite and harmful to the friction and wear properties. The combination of PTFE and UHMWPE showed synergism on further reducing the friction coefficient of the composites filled with either PTFE or UHMWPE only. Effects of load and velocity on tribological behavior were also discussed. To further understand the wear mechanism, the worn surfaces were examined by scanning electron microscopy

  3. Activity Theory applied to Global Software Engineering: Theoretical Foundations and Implications for Tool Builders

    DEFF Research Database (Denmark)

    Tell, Paolo; Ali Babar, Muhammad

    2012-01-01

    Although a plethora of tools are available for Global Software Engineering (GSE) teams, it is being realized increasingly that the most prevalent desktop metaphor underpinning the majority of tools have several inherent limitations. We have proposed that Activity-Based Computing (ABC) can be a pr...... in building supporting infrastructure for GSE, and describe a proof of concept prototype....

  4. Life Science Start-up Activities at the Universities of Applied Sciences (UAS).

    Science.gov (United States)

    Huber, Gerda

    2014-12-01

    The universities of applied sciences (UAS) provide several values for the society and economy of a country. Besides education of high level professionals, transfer of knowledge from research to applications in industry or as new start-up companies is an important task. This is done in different ways in the various disciplines. In Life Sciences, a key industry branch in Switzerland, innovation is a competitive success factor and research findings from UAS/Life Sciences contribute to the valorization of new technologies to products, services and to business performance. In order to foster awareness for the innovation need of industry, UAS install processes and support for transfer of research and technology results to marketable applications. Furthermore they may facilitate contacts of researchers and students with entrepreneurs in order to animate start-up founding as a true alternative to being employed. Access to coaching and entrepreneurial training completes the essential basis.

  5. A study on risk factors associated with inconsistent condom and lubricant use among men who have sex with men in central Karnataka, India

    Directory of Open Access Journals (Sweden)

    DK Mahabalaraju

    2011-11-01

    Full Text Available BackgroundAmong the sexual minority groups, the Men who have Sexwith Men (MSM community is a large and scatterednetwork. Sexual activity among MSM is frequent and oftenunplanned. STI and HIV are major medical problems facedby this vulnerable group. Stigma and discriminationtowards this group result in poor access to preventiveservices that encourage condom and lubricant usage.MethodA cross-sectional, community-based study of 309 MSM wascarried out in the Davangere district between December2008 and February 2010. Participants were identified inthree stages: cruising venue identification and mapping;determining eligibility and willingness to participate; andrecruitment to the study. Consecutive sampling was used torecruit the participants with the help of a snowballtechnique, obtaining informed and written consent.ResultsOf the participants 79.61% and 88.03% reportedinconsistent use of condom and lubricant during the threemonths prior to the interview, respectively. In multivariateanalysis, middle socioeconomic class, sex in a public placeand increased frequency of sex were significantly associatedwith inconsistent condom use. Whereas, practising bothtypes of anal sex (receptive and insertive, not using acondom during the last sexual encounter and increasedfrequency of sex were significantly associated withinconsistent lubricant use.ConclusionMany social and behavioural factors are involved in theinconsistent use of condom and lubricant among MSM.Preventive programmes must identify these factors in orderto target consistent condom and lubricant use among theMSM community.

  6. Neutron activation analysis as applied to instrumental analysis of trace elements from seawater

    International Nuclear Information System (INIS)

    Boniforti, R.; Moauro, A.; Madaro, M.

    1983-01-01

    Particulate matter collected from the coastal area delimited by the mouth of the river Volturno and the Sabaudia lake has been analyzed by instrumental neutron activation analysis for its content of twenty-two trace elements. The results for surface water and bottom water are reported separately, thus evidencing the effect of sampling depth on the concentration of many elements. The necessity of accurately 'cleaning' the filters before use is stressed

  7. Activating institutional innovations for hunger and poverty reduction : potential of applied international agricultural research

    OpenAIRE

    Kamanda, Josey

    2015-01-01

    The CGIAR system has made several attempts to improve its organizational structure, the latest being a reform process initiated in 2009. A key issue that has been debated over the years is how the CGIAR centres are best placed within the range of institutions involved in agricultural research and development. The CGIAR still faces the unresolved dilemma between a focus on upstream research that produces international public goods versus downstream activities that ensure impact. Therefore, the...

  8. Radon removal from different types of groundwater applying granular activated carbon filtration

    International Nuclear Information System (INIS)

    Turtiainen, T.; Salonen, L.; Myllymaeki, P.

    2000-01-01

    Granular activated carbon (CAC) filters were installed in 12 private homes or vacation homes for removing unacceptably high concentrations of radon from household water. Radon removal efficiency was nearly 100% in most locations, although different water types were encountered. Other radionuclides such as uranium, radium, lead and polonium were removed less efficiently. Treated water quality remained good and no significant external radiation dose was caused to the residents. (author)

  9. Applying activity theory to computer-supported collaborative learning and work-based activities in corporate settings

    NARCIS (Netherlands)

    Collis, Betty; Margaryan, A.

    2004-01-01

    Business needs in many corporations call for learning outcomes that involve problem solutions, and creating and sharing new knowledge within worksplace situation that may involve collaboration among members of a team. We argue that work-based activities (WBA) and computer-supported collaborative

  10. Hybrid n-Alkylamine Intercalated Layered Titanates for Solid Lubrication

    NARCIS (Netherlands)

    Gonzalez Rodriguez, P.; Yuan, H.; van den Nieuwenhuijzen, Karin Jacqueline Huberta; Lette, W.; Schipper, Dirk J.; ten Elshof, Johan E.

    2016-01-01

    The intercalation of different primary n-alkylamines in the structure of a layered titanate of the lepidocrocite type (H1.07Ti1.73O4) for application in high-temperature solid lubrication is reported. The intercalation process of the amines was explored by means of in situ small-angle X-ray

  11. Bioinspired lubricating films of cellulose nanofibrils and hyaluronic acid.

    Science.gov (United States)

    Valle-Delgado, Juan José; Johansson, Leena-Sisko; Österberg, Monika

    2016-02-01

    The development of materials that combine the excellent mechanical strength of cellulose nanofibrils (CNF) with the lubricating properties of hyaluronic acid (HA) is a new, promising approach to cartilage implants not explored so far. A simple, solvent-free method to produce a very lubricating, strong cellulosic material by covalently attaching HA to the surface of CNF films is described in this work. A detailed analysis of the tribological properties of the CNF films with and without HA is also presented. Surface and friction forces at micro/nanoscale between model hard surfaces (glass microspheres) and the CNF thin films were measured using an atomic force microscope and the colloid probe technique. The effect of HA attachment, the pH and the ionic strength of the aqueous medium on the forces was examined. Excellent lubrication was observed for CNF films with HA attached in conditions where the HA layer was highly hydrated. These results pave the way for the development of new nanocellulose-based materials with good lubrication properties that could be used in biomedical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. 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...

  13. Environmentally Benign Lubricant Systems For Cold, Warm And Hot Forging

    DEFF Research Database (Denmark)

    Bay, Niels

    2010-01-01

    paper gives an overview of these efforts substituting environmentally hazardous lubricants in cold, warm and hot forging. The paper is an extract of the keynote paper [3] written by the author together with eight co-authors referring to collected papers and other information from more than 30 different...

  14. Evaluation of lubricity of methanolic extract of mango (Mangifera ...

    African Journals Online (AJOL)

    Methanolic extract of mango seed oil (Mangifera Indica) was evaluated for suitability as lubricant for machini-ng mild steel at various speeds, feeds and depths of cut. The coefficient of friction between the tool and chip in- dicated that the methanolic extract reduced friction between the tool and work piece. The oil also ...

  15. Organic-Modified Silver Nanoparticles as Lubricant Additives.

    Science.gov (United States)

    Kumara, Chanaka; Luo, Huimin; Leonard, Donovan N; Meyer, Harry M; Qu, Jun

    2017-10-25

    Advanced lubrication is essential in human life for improving mobility, durability, and efficiency. Here we report the synthesis, characterization, and evaluation of two groups of oil-suspendable silver nanoparticles (NPs) as candidate lubricant additives. Two types of thiolated ligands, 4-(tert-butyl)benzylthiol (TBBT) and dodecanethiol (C12), were used to modify Ag NPs in two size ranges, 1-3 and 3-6 nm. The organic surface layer successfully suspended the Ag NPs in a poly-alpha-olefin (PAO) base oil with concentrations up to 0.19-0.50 wt %, depending on the particle type. Use of the Ag NPs in the base oil reduced friction by up to 35% and wear by up to 85% in boundary lubrication. The two TBBT-modified NPs produced a lower friction coefficient than the C12-modified one, while the two larger NPs (3-6 nm) had better wear protection than the smaller one (1-3 nm). Results suggested that the molecular structure of the organic ligand might have a dominant effect on the friction behavior, while the NP size could be more influential in the wear protection. No mini-ball-bearing or surface smoothening effects were observed in the Stribeck scans. Instead, the wear protection in boundary lubrication was attributed to the formation of a silver-rich 50-100 nm thick tribofilm on the worn surface, as revealed by morphology examination and composition analysis from both the top surface and cross section.

  16. Lubrication of the Human Ankle Joint in Walking

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Miroslav

    2010-01-01

    Roč. 132, č. 1 (2010), s. 1-8 ISSN 0742-4787 R&D Projects: GA ČR(CZ) GA103/07/0043 Institutional research plan: CEZ:AV0Z20710524 Keywords : articular cartilage * human ankle joint * lubrication * walking Subject RIV: JJ - Other Materials Impact factor: 0.449, year: 2010

  17. Development of a quantitative lubricant test for deep drawing

    DEFF Research Database (Denmark)

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

    2004-01-01

    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 due to sliding friction between tool and work piece surface. The forming force is found not to give useful information...

  18. Biodegradability of unused lubricating brake fluids in fresh and ...

    African Journals Online (AJOL)

    The biodegradability of four unused lubricating brake fluids (Total brake fluid, Allied brake fluid, Oando brake fluid and Ate brake fluid) was carried out in fresh and marine water obtained from Isiokpo stream and Bonny river of the Niger Delta, South South Nigeria. Biodegradability, of the brake fluids were obtained after a 56 ...

  19. Numerical analysis of hydrodynamic journal bearings lubricated with ferrofluid

    NARCIS (Netherlands)

    Montazeri, H.

    2008-01-01

    The current work focuses on studying the hydrodynamic characteristics of flow in journal bearings lubricated with ferrofluid. The bearing has an infinite length and operates under incompressible laminar flow and steady conditions. Assuming linear behaviour for the magnetic material of the

  20. Impact of Water on the Rheology of Lubricating Greases

    NARCIS (Netherlands)

    Cyriac, F.; Lugt, Pieter Martin; Bosman, Rob

    2016-01-01

    The operational life of bearings is often determined by the performance of the lubricating grease. The consistency of the grease prevents it from leaking out of the bearing and provides good sealing properties. The possible ingress of water into the bearing will have a considerable impact not only

  1. Base Oil-Extreme Pressure Additive Synergy in Lubricants

    Science.gov (United States)

    Extreme pressure (EP) additives are those containing reactive elements such as sulfur, phosphorus, and chlorine. In lubrication processes that occur under extremely severe conditions (e.g., high pressure and/or slow speed), these elements undergo chemical reactions generating new materials (tribofi...

  2. On the design of lubricant free piston compressors

    NARCIS (Netherlands)

    Owczarek, P.

    2010-01-01

    This thesis describes the development on long lifetime and an efficient piston compressor operating in a clean environment where oil lubrication must be excluded. Particularly in cooling systems including cryocoolers the presence of oil is a well known problem. A growing number of applications of

  3. Analysis of BJ493 diesel engine lubrication system properties

    Science.gov (United States)

    Liu, F.

    2017-12-01

    The BJ493ZLQ4A diesel engine design is based on the primary model of BJ493ZLQ3, of which exhaust level is upgraded to the National GB5 standard due to the improved design of combustion and injection systems. Given the above changes in the diesel lubrication system, its improved properties are analyzed in this paper. According to the structures, technical parameters and indices of the lubrication system, the lubrication system model of BJ493ZLQ4A diesel engine was constructed using the Flowmaster flow simulation software. The properties of the diesel engine lubrication system, such as the oil flow rate and pressure at different rotational speeds were analyzed for the schemes involving large- and small-scale oil filters. The calculated values of the main oil channel pressure are in good agreement with the experimental results, which verifies the proposed model feasibility. The calculation results show that the main oil channel pressure and maximum oil flow rate values for the large-scale oil filter scheme satisfy the design requirements, while the small-scale scheme yields too low main oil channel’s pressure and too high. Therefore, application of small-scale oil filters is hazardous, and the large-scale scheme is recommended.

  4. Re-Refining of Waste Lubricating Oil by Solvent Extraction

    Directory of Open Access Journals (Sweden)

    Hassan Ali Durrani

    2011-04-01

    Full Text Available Re-refining of waste lubricating oil by solvent extraction is one of the potential techniques. The advantages of solvent extraction technique practically offers from environmental and economic points of view have received due attention. In this paper selection of composite solvent and technique to upgrade the used lubricant oil into base oil has been made. The composite solvent 2-propanol, 1-butanol and butanone have two alcohols that make a binary system reasonably effective. This work also attempts to study the performance of the composite solvent in the extraction process for recovering waste lubricating oil. The key parameters considered were vacuum pressure, temperature and the weight ratio of solvent to waste lubricating oil. The performance was investigated on the PSR (Percentage Sludge Removal and POL (Percent Oil Loss. The best results were obtained using composite solvent 25% 2-propanol, 37% 1-butanol and 38% butanone by a solvent to oil ratio of 6:1 at vacuum pressure 600mmHg and distillation temperature 250oC. The vacuum distilled oil pretreated with the composite solvents was matched to the standard base oil 500N and 150N, found in close agreement and could be used for similar purpose.

  5. Phase and viscosity behaviour of refrigerant-lubricant mixtures

    DEFF Research Database (Denmark)

    Cisneros, Sergio; Garcia, J.; Fernandez, J.

    2005-01-01

    , mainly as a function of the molecular asymmetry. This also has a profound effect in the mixture transport properties. Thus, in this work the general aspects of phase and viscosity behaviour linked to the type of asymmetry found in refrigerant-lubricant mixtures are discussed in the context of phase...

  6. Microstructural modelling and lubrication study during zirconium alloy hot extrusion

    International Nuclear Information System (INIS)

    Gaudout, B.

    2009-01-01

    Using torsion tests (with strain rate jumps) and an experimental hot mini-extrusion apparatus, several samples zirconium alloy have been deformed: Zircaloy-4 (high α range) and Zr-1Nb (α + β domain). The fragmentation of the microstructure and post-dynamic grain growth have been examined. The main difference between these two alloys is that Zr-1Nb does not show grain growth during a heat treatment within the α + β domain after hot deformation. The recrystallization volume fraction has been measured on extruded samples with or without heat treatment. These rheological and microstructural data have been used to determine the parameters of a microstructural model including: a work-hardening model (Laaasraoui/Jonas), a continuous dynamic recrystallization model (Gourdet/Montheillet) and a grain growth model. This model leads to a good prediction of recrystallization volume fraction for Zircaloy-4 extrusion. However, the Zr-1Nb model cannot be validated because of the difficulty to observe deformed microstructures. Extrusion process is lubricated with a solid film. Trapping tests show that this lubricant is thermoviscoplastic. Friction along the container and several observations show the lubrication is not realized by a continuous film. Indeed, the heterogeneousness of deformation of these alloys causes a rupture of the lubricant film. Experiments and numerical simulations show that the radial gradient of axial displacement is affected by friction but also by stress softening of the alloys. (author)

  7. [Lubricant-free piston compressors for mechanized medical instruments].

    Science.gov (United States)

    Sabitov, V Kh; Repin, V A; Kil'kinov, A A

    1988-01-01

    Piston compressor without lubrication with air blow to packing rings by plunger, disposed in subpiston space, is recommended as the basic scheme of construction of a power supply unit for medical pneumatic tooling. The construction reduces a leak of the compressive medium, increasing the efficiency of a compressor and seal reliability.

  8. Multilayered antifriction nanostraction covering for lubrication in the tribocoupling

    Directory of Open Access Journals (Sweden)

    Vladimir KOLESNIKOV

    2010-01-01

    Full Text Available In article principles of creation of a new way of the lubrication a wheel-rail tribosystem by drawing on a lateral side of a rail head of a multilayered antifriction nanostructurial covering possessing property of blocking negative segregation phenomena in metals of a wheel and a rail are considered.

  9. Making Self-Lubricating Parts By Powder Metallurgy

    Science.gov (United States)

    Sliney, Harold E.; Dellacorte, Christopher

    1990-01-01

    Compositions and parameters of powder-metallurgical fabrication processes determined for new class of low-friction, low-wear, self-lubricating materials. Used in oxidizing or reducing atmospheres in bearings and seals, at temperatures from below 25 degrees C to as high as 900 degrees C. Thick parts made with minimal waste.

  10. Lubrication of the human ankle joint in running

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Miroslav

    2009-01-01

    Roč. 3, č. 5 (2009), s. 619-626 ISSN 1970-8734 R&D Projects: GA ČR(CZ) GA103/07/0043 Institutional research plan: CEZ:AV0Z20710524 Keywords : human ankle joint * lubrication * running Subject RIV: JJ - Other Materials

  11. Squeezing molecularly thin alkane lubrication films: Layering transistions and wear

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V. N.; Persson, B. N. J.

    2004-01-01

    The properties of alkane lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and the elastic properties of the solid surfaces. We consider linear alkane molecules of different chain lengths, C(3)H(8); C(4)H(10); C(8)H(18); C(9)H(20); C(10)H...

  12. The Lubricant Properties of LUBRITAB | Onyechi | Journal of ...

    African Journals Online (AJOL)

    The effect of the lubricants on tablet hardness, friability, disintegration and dissolution rate were also determined. Tablets containing LUBRITAB at a concentration level of 3 - 4 (% w/w) gave values of unit ejection force comparable with those of tablets containing 2% magnesium stearate. The tablets containing LUBRITAB ...

  13. Synthetics, mineral oils, and bio-based lubricants chemistry and technology

    CERN Document Server

    Rudnick, Leslie R

    2005-01-01

    As the field of tribology has evolved, the lubrication industry is also progressing at an extraordinary rate. Updating the author's bestselling publication, Synthetic Lubricants and High-Performance Functional Fluids, this book features the contributions of over 60 specialists, ten new chapters, and a new title to reflect the evolving nature of the field: Synthetics, Mineral Oils, and Bio-Based Lubricants: Chemistry and Technology. The book contains chapters on all major lubricant fluids used in a wide range of applications. For each type of lubricant, the authors discuss the historical develo

  14. Lubrication analysis of the journal bearing in the main coolant pump of SMART

    International Nuclear Information System (INIS)

    Lee, J. S.; Park, J. S.; Kim, J. H.; Kim, J. I.; Jang, M. H.

    2000-01-01

    Special type journal bearings are installed in the main coolant pump for SMART to support the rotating shaft with proper lubrication. The canned motor type main coolant pumps are arranged vertically on the reactor vessel. The MCP bearings are lubricated with water without external lubricating oil supply. Long bearing with vertical grooves is designed with relatively large bearing clearance to accommodate the long shaft. Lubricational analysis method for journal bearing with vertical grooves in the main coolant pump of SMART is proposed, and lubricational characteristics of the bearings are examined in this paper

  15. Experience and regulatory activities on advanced instrumentation and control systems applied to nuclear power plants in Korea

    International Nuclear Information System (INIS)

    Kim, B.R.

    1995-01-01

    This paper describes the status for applying microprocessor-based systems to nuclear power plants in Korea and the regulatory activities performed by Korea Institute of Nuclear Safety (KINS). And this presents the development of safety and regulatory technology for advanced I and C systems that has been carried out as a part of the next generation reactor development program in Korea. (author). 3 refs, 4 figs, 1 tab

  16. Matrix suites applying when making the commercial-company-activity-andfinancial-risks-express-diagnostics

    Directory of Open Access Journals (Sweden)

    Valentina Petrovn Neganova

    2011-09-01

    Full Text Available This paper describes an original technique and peculiarities of its use for the express diagnostics of a company and analysis of financial risks. The feature of this technique is potential Russian reality accountance of optimizational transformations of statements in order to minimize taxation and refract the information field of a business system for the apperception. It is based on the conceptual principle of studies of the University of Ghent, according to which, these three cycles affect stability of the companies to the important risk - the risk of bankruptcy. It is noted that the use of matrix analysis can become an additional powerful tool for solving the conceptual verification problem of financial permanence of business systems operation in the marketplace because it allows to determine the internal nature of the underlying processes that occur within an atomic business system and to make every effort to minimize potential and actual manifestations of instability of the external and internal environment of the business system. This method satisfies the multiple set of conditions-equations: apperceptive, asymptotic and simplificational functions that form the basis of calculations for model creation. The technique can be applied by commercial banks in the analysis of the elements of their loan portfolio. Application of this technique allows analyzing the performance of a commercial company in the features of Russian life with minimal iterations.

  17. Applying the Weighted Horizontal Magnetic Gradient Method to a Simulated Flaring Active Region

    Science.gov (United States)

    Korsós, M. B.; Chatterjee, P.; Erdélyi, R.

    2018-04-01

    Here, we test the weighted horizontal magnetic gradient (WG M ) as a flare precursor, introduced by Korsós et al., by applying it to a magnetohydrodynamic (MHD) simulation of solar-like flares. The preflare evolution of the WG M and the behavior of the distance parameter between the area-weighted barycenters of opposite-polarity sunspots at various heights is investigated in the simulated δ-type sunspot. Four flares emanated from this sunspot. We found the optimum heights above the photosphere where the flare precursors of the WG M method are identifiable prior to each flare. These optimum heights agree reasonably well with the heights of the occurrence of flares identified from the analysis of their thermal and ohmic heating signatures in the simulation. We also estimated the expected time of the flare onsets from the duration of the approaching–receding motion of the barycenters of opposite polarities before each single flare. The estimated onset time and the actual time of occurrence of each flare are in good agreement at the corresponding optimum heights. This numerical experiment further supports the use of flare precursors based on the WG M method.

  18. Sustainable Effectiveness of Applying Trauma Team Activation in Managing Trauma Patients in the Emergency Department.

    Science.gov (United States)

    Wuthisuthimethawee, Prasit; Molloy, Michael S; Ciottone, Gregory R

    2015-09-01

    To determine long term effectiveness of trauma team activation criteria by measuring emergency department length of stay (EDLOS) and 28-day mortality. A 3-year retrospective cohort study conducted in adult trauma patients who met one of the trauma team activation criteria (shock, penetrating torso injury, post traumatic arrest, respiratory rate of less than 12 or more than 30, and pulse rate of more than 120). Specific demographic data, physiologic parameters, EDLOS, injury severity score (ISS), and 28-day mortality were prospectively recorded into the Trauma Registry database. Multiple logistic regression analysis was used to determine factors affecting mortality. The Institutional Review Board approval was obtained prior to undertaking the project. Two hundred eighty two patients with a mean age of35.1 years old were eligible. The median ISS was 25 (range, 13-30). The median EDLOS was 85 minutes (range, 50-135) and the 28-day mortality rate was 46.5%. The mean age was 31.7 years in the survival group and 38.7 years in the fatal group (p = 0.001). The median ISS was 17 in the survival group and 26 in the fatal group (p = 0.000) and the median EDLOS was 110 minutes in the survival group and 82 minutes in the fatal group (p = 0.034). When compared to data prior to the TTA application, the median time of EDLOS improvedsustainably from 184 to 85 minutes (p = 0.000) and the mortality rate decreased from 66.7% to 46.5% (p = 0.057). The parameters affecting patient mortality were older age, high ISS, and shorter EDLOS. Trauma team activation criteria significantly improved acute trauma care in the emergency department and decreased mortality.

  19. Activity-based costing applied to the internal logistics of a chemical company

    OpenAIRE

    Vasconcellos, Themis Castro de; Marins, Fernando Augusto Silva [UNESP; Muniz Junior, Jorge [UNESP

    2008-01-01

    Este trabalho tem como objetivo apresentar como o método ABC - activity based costing foi implantado para realizar o custeio da logística interna da empresa química BASF SA., situada na cidade de Guaratinguetá - SP. Apresentam-se: a descrição do processo de mudança do método de custeio tradicional para o método ABC, as dificuldades encontradas e como foram ultrapassadas, bem como as vantagens constatadas pela empresa. O departamento de logística da empresa funciona como um prestador de serviç...

  20. Determination of selenium in Ni + Co concentrates applying epithermal neutron activation analysis

    International Nuclear Information System (INIS)

    Capote Rodriguez, G.; Perez Sayaz, G.; Hernandez Rivero, A.; Moreno Bermudez, J.; Ribeiro Guevara, S.; Arribere, M.A.; Molina Insfran, J.

    1996-01-01

    Concentration of Se in Ni + Co concentrates obtained in nickel industry has to be determined as that is a quality control requirement for its commercialization. At present, analysis of Se, specially at a minor and trace levels is relatively complicated and destructive procedures are frequently required. In this work determination of Se by epithermal neutron activation analysis (ENAA) in 17 samples of nickel industry was investigated. Application of ENAA allowed nondestructive determination of Se concentration down to ppm level in spite of presence of high Co, Fe, Ni, and Cr contents in the samples