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1

Friction-Induced Fluid Heating in Nanoscale Helium Flows  

SciTech Connect

We investigate the mechanism of friction-induced fluid heating in nanoconfinements. Molecular dynamics simulations are used to study the temperature variations of liquid helium in nanoscale Poiseuille flows. It is found that the fluid heating is dominated by different sources of friction as the external driving force is changed. For small external force, the fluid heating is mainly caused by the internal viscous friction in the fluid. When the external force is large and causes fluid slip at the surfaces of channel walls, the friction at the fluid-solid interface dominates over the internal friction in the fluid and is the major contribution to fluid heating. An asymmetric temperature gradient in the fluid is developed in the case of nonidentical walls and the general temperature gradient may change sign as the dominant heating factor changes from internal to interfacial friction with increasing external force.

Li Zhigang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2010-05-21T23:59:59.000Z

2

Heat transfer and fluid friction in bundles of twisted tubes  

Science Journals Connector (OSTI)

The results of heat-transfer and friction studies in bundles of twisted tubes and rods with spiral wire-wrap spacers are analyzed, and recommendations are given for calculating the heat-transfer coefficient in...

B. V. Dzyubenko; G. A. Dreitser

1986-06-01T23:59:59.000Z

3

Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow  

E-Print Network (OSTI)

Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE M@niu.edu * www.kostic.niu.edu Abstract: - An apparatus for exploring friction and heat transfer characteristics flow. Initial turbulent friction and heat transfer measurements for silica and carbon nanotube (CNT

Kostic, Milivoje M.

4

Heat transport by residual gases in multilayer vacuum insulation  

Science Journals Connector (OSTI)

The results of an experimental investigation of residual gas heat-transfer in multilayer vacuum insulation are reported. The “thermal paradox” observed ... variation of the residual gas pressure in the insulation

R. S. Mikhal'chenko; A. G. Gerzhin; V. T. Arkhipov…

1968-01-01T23:59:59.000Z

5

Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a,  

E-Print Network (OSTI)

Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a, , Chia September 2011 Keywords: Microtube Heat transfer Liquid Crystal Thermography a b s t r a c t Several researches dealing with the single-phase forced convection heat transfer inside microchannels have been

Kandlikar, Satish

6

Frictional heat from faulting of the 1999 Chi-Chi, Taiwan earthquake H. Tanaka,1  

E-Print Network (OSTI)

Profile [3] A borehole was drilled into the northern portion of the fault in the year 2000 (Figure 1-Chi, Taiwan, earthquake. The borehole was drilled at an angle of about 50° to the west and penetrated of the heat generated by a large earthquake. We present an estimate of the frictional heat produced

Ma, Kuo-Fong

7

Determination of heat transfer and friction characteristics of an adapted inclined louvered fin  

SciTech Connect

An experimental study of a fin-and-tube heat exchanger was performed. To this end a test rig was constructed to measure the heat transfer rate on the air and waterside of the heat exchanger. A wide range of Reynolds numbers on the airside was investigated. The resulting data was used to determine the convective heat transfer correlation (expressed using the Colburn factor) and the friction factor on the airside. The fin type used in the heat exchanger of this research is an adaptation of the standard inclined louvered type. A thorough error analysis was performed, to validate the results. (author)

T'Joen, C.; Steeman, H.-J.; Willockx, A.; De Paepe, M. [Department of Flow, Heat and Combustion Mechanics, Ghent University-UGent, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium)

2006-03-01T23:59:59.000Z

8

Alternative cooling resource for removing the residual heat of reactor  

SciTech Connect

The Recirculated Cooling Water (RCW) system of a Candu reactor is a closed cooling system which delivers demineralized water to coolers and components in the Service Building, the Reactor Building, and the Turbine Building and the recirculated cooling water is designed to be cooled by the Raw Service Water (RSW). During the period of scheduled outage, the RCW system provides cooling water to the heat exchangers of the Shutdown Cooling System (SDCS) in order to remove the residual heat of the reactor, so the RCW heat exchangers have to operate at all times. This makes it very hard to replace the inlet and outlet valves of the RCW heat exchangers because the replacement work requires the isolation of the RCW. A task force was formed to prepare a plan to substitute the recirculated water with the chilled water system in order to cool the SDCS heat exchangers. A verification test conducted in 2007 proved that alternative cooling was possible for the removal of the residual heat of the reactor and in 2008 the replacement of inlet and outlet valves of the RCW heat exchangers for both Wolsong unit 3 and 4 were successfully completed. (authors)

Park, H. C.; Lee, J. H.; Lee, D. S.; Jung, C. Y.; Choi, K. Y. [Korea Hydro and Nuclear Power Co., Ltd., 260 Naa-ri Yangnam-myeon Gyeongju-si, Gyeonasangbuk-do, 780-815 (Korea, Republic of)

2012-07-01T23:59:59.000Z

9

Heat transfer deterioration in tubes caused by bulk flow acceleration due to thermal and frictional influences  

SciTech Connect

Severe deterioration of forced convection heat transfer can be encountered with compressible fluids flowing through strongly heated tubes of relatively small bore as the flow accelerates and turbulence is reduced because of the fluid density falling (as the temperature rises and the pressure falls due to thermal and frictional influence). The model presented here throws new light on how the dependence of density on both temperature and pressure can affect turbulence and heat transfer and it explains why the empirical equations currently available for calculating effectiveness of forced convection heat transfer under conditions of strong non-uniformity of fluid properties sometimes fail to reproduce observed behaviour. It provides a criterion for establishing the conditions under which such deterioration of heat transfer might be encountered and enables heat transfer coefficients to be determined when such deterioration occurs. The analysis presented here is for a gaseous fluid at normal pressure subjected strong non-uniformity of fluid properties by the application of large temperature differences. Thus the model leads to equations which describe deterioration of heat transfer in terms of familiar parameters such as Mach number, Reynolds number and Prandtl number. It is applicable to thermal power plant systems such as rocket engines, gas turbines and high temperature gas-cooled nuclear reactors. However, the ideas involved apply equally well to fluids at supercritical pressure. Impairment of heat transfer under such conditions has become a matter of growing interest with the active consideration now being given to advanced water-cooled nuclear reactors designed to operate at pressures above the critical value. (authors)

Jackson, J. D. [Univ. of Manchester, Manchester (United Kingdom)

2012-07-01T23:59:59.000Z

10

J. Materials Science, 37, 3965-3972 (2002) Author prepared reprint Experimental Verification of the Effects of Friction and Residual Stress on the  

E-Print Network (OSTI)

were done on AS4 carbon fiber/epoxy and E-glass/epoxy specimens. Using a new interpretation for carbon-fiber/epoxy and 120 J/m2 for glass-fiber/epoxy. Keywords: Interfacial, Friction, Energy Method, Fragmentation Test, Single Fiber Composites, Carbon Fiber, Glass Fiber, Residual Stresses Introduction

Nairn, John A.

11

Evaporation heat transfer and friction characteristics of R-134a flowing downward in a vertical corrugated tube  

SciTech Connect

Differently from most previous studies, the heat transfer and friction characteristics of the pure refrigerant HFC-134a during evaporation inside a vertical corrugated tube are experimentally investigated. The double tube test sections are 0.5 m long with refrigerant flowing in the inner tube and heating water flowing in the annulus. The inner tubes are one smooth tube and two corrugated tubes, which are constructed from smooth copper tube of 8.7 mm inner diameter. The test runs are performed at evaporating temperatures of 10, 15, and 20 C, heat fluxes of 20, 25, and 30 kW/m{sup 2}, and mass fluxes of 200, 300, and 400 kg/m{sup 2} s. The quality of the refrigerant in the test section is calculated using the temperature and pressure obtained from the experiment. The pressure drop across the test section is measured directly by a differential pressure transducer. The effects of heat flux, mass flux, and evaporation temperature on the heat transfer coefficient and two-phase friction factor are also discussed. It is found that the percentage increases of the heat transfer coefficient and the two-phase friction factor of the corrugated tubes compared with those of the smooth tube are approximately 0-10% and 70-140%, respectively. (author)

Aroonrat, Kanit; Wongwises, Somchai [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab. (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)

2011-01-15T23:59:59.000Z

12

RCS pressure under reduced inventory conditions following a loss of residual heat removal  

SciTech Connect

The thermal-hydraulic response of a closed-reactor coolant system to loss of residual heat removal (RHR) cooling is investigated. The processes examined include: core coolant boiling and steam generator reflux condensation, pressure increase on the primary side, heat transfer mechanisms on the steam generator primary and secondary sides, and effects of noncondensible gas on heat transfer processes.

Palmrose, D.E.; Hughes, E.D.; Johnsen, G.W.

1992-08-01T23:59:59.000Z

13

Experimental investigation on heat transfer and frictional characteristics of vertical upward rifled tube in supercritical CFB boiler  

Science Journals Connector (OSTI)

Water wall design is a key issue for supercritical Circulating Fluidized Bed (CFB) boiler. On account of the good heat transfer performance, rifled tube is applied in the water wall design of a 600 MW supercritical CFB boiler in China. In order to investigate the heat transfer and frictional characteristics of the rifled tube with vertical upward flow, an in-depth experiment was conducted in the range of pressure from 12 to 30 MPa, mass flux from 230 to 1200 kg/(m2 s), and inner wall heat flux from 130 to 720 kW/m2. The wall temperature distribution and pressure drop in the rifled tube were obtained in the experiment. The normal, enhanced and deteriorated heat transfer characteristics were also captured. In this paper, the effects of pressure, inner wall heat flux and mass flux on heat transfer characteristics are analyzed, the heat transfer mechanism and the frictional resistance performance are discussed, and the corresponding empirical correlations are presented. The experimental results show that the rifled tube can effectively prevent the occurrence of Departure from Nucleate Boiling (DNB) and keep the tube wall temperature in a permissible range under the operating condition of supercritical CFB boiler.

Dong Yang; Jie Pan; Chenn Q. Zhou; Xiaojing Zhu; Qincheng Bi; Tingkuan Chen

2011-01-01T23:59:59.000Z

14

Sustainable Heat and Electricity from Sugarcane Residues Gasification in Brazil  

Science Journals Connector (OSTI)

Sugarcane residues, in the form of bagasse and cane tops and leaves, represent a large renewable biomass energy resource in Brazil. Bagasse is currently used to satisfy the energy needs of the sugar and alcohol i...

Ausilio Bauen

2002-01-01T23:59:59.000Z

15

Transient Heat and Material Flow Modeling of Friction Stir Processing of Magnesium Alloy using Threaded Tool  

SciTech Connect

A three-dimensional transient computational fluid dynamics (CFD) model was developed to investigate the material flow and heat transfer during friction stir processing (FSP) in an AZ31B magnesium alloy. The material was assumed to be a non-Newtonian viscoplastic fluid, and the Zener-Hollomon parameter was used to describe the dependence of material viscosity on temperature and strain rate. The material constants used in the constitutive equation were determined experimentally from compression tests of the AZ31B Mg alloy under a wide range of strain rates and temperatures. A dynamic mesh method, combining both Lagrangian and Eulerian formulations, was used to capture the material flow induced by the movement of the threaded tool pin. Massless inert particles were embedded in the simulation domain to track the detailed history of material flow. The actual FSP was also carried out on a wrought Mg plate where temperature profiles were recorded by embedding thermocouples. The predicted transient temperature history was found to be consistent with that measured during FSP. Finally, the influence of the thread on the simulated results of thermal history and material flow was studied by comparing two models: one with threaded pin and the other with smooth pin surface.

Yu, Zhenzhen [ORNL; Zhang, Wei [ORNL; Choo, Hahn [ORNL; Feng, Zhili [ORNL

2012-01-01T23:59:59.000Z

16

Heat transfer and friction factor analysis in a circular tube with Al2O3 nanofluid by using computational fluid dynamics  

Science Journals Connector (OSTI)

Turbulent fully developed flow heat transfer coefficient and friction factor of Al2O3 nanoparticles are dispersed in water and ethylene glycol in circular tube is discussed in this paper. In order to validate the heat transfer coefficient and friction factor of nanofluid in circular tube commercially available CFD software FLUENT 6.0 is used. To achieve the fully developed flow condition, the aspect ratio (L/D) of the test section is equal to 94. The thermo-physical properties of the Al2O3 nanofluid are estimated by using the equations available in literature. Thermo-physical properties of the nanofluid are considered for heat transfer coefficient and friction factor by assuming nanofluid is a single-phase fluid. Constant Wall Heat Flux (CWHF) boundary condition is incorporated for heat transfer analysis and adiabatic boundary condition is incorporated for friction factor analysis. The analysis is conducted in the volume concentration range from 0.1% to 4%. A maximum of 2.25 times heat transfer enhancement and 1.42 times of friction is obtained by using nanofluid as working medium.

L. Syam Sundar; K.V. Sharma; Shabana Parveen

2009-01-01T23:59:59.000Z

17

Nuclear reactor with makeup water assist from residual heat removal system  

DOE Patents (OSTI)

A pressurized water nuclear reactor uses its residual heat removal system to make up water in the reactor coolant circuit from an in-containment refueling water supply during staged depressurization leading up to passive emergency cooling by gravity feed from the refueling water storage tank, and flooding of the containment building. When depressurization commences due to inadvertence or a manageable leak, the residual heat removal system is activated manually and prevents flooding of the containment when such action is not necessary. Operation of the passive cooling system is not impaired. A high pressure makeup water storage tank is coupled to the reactor coolant circuit, holding makeup coolant at the operational pressure of the reactor. The staged depressurization system vents the coolant circuit to the containment, thus reducing the supply of makeup coolant. The level of makeup coolant can be sensed to trigger opening of successive depressurization conduits. The residual heat removal pumps move water from the refueling water storage tank into the coolant circuit as the coolant circuit is depressurized, preventing reaching the final depressurization stage unless the makeup coolant level continues to drop. The residual heat removal system can also be coupled in a loop with the refueling water supply tank, for an auxiliary heat removal path.

Corletti, Michael M. (New Kensington, PA); Schulz, Terry L. (Murrysville, PA)

1993-01-01T23:59:59.000Z

18

Variance Decomposition Sensitivity Analysis of a Passive Residual Heat Removal System Model  

E-Print Network (OSTI)

for improved reliability and safety. Sensitivity analysis can provide relevant insights on the responseVariance Decomposition Sensitivity Analysis of a Passive Residual Heat Removal System Model YU Yua Removal system (RHRs) in the High Temperature Gas-Cooled Reactor (HTGR). Keywords: Uncertainty

Paris-Sud XI, Université de

19

In situ recovery from residually heated sections in a hydrocarbon containing formation  

DOE Patents (OSTI)

Methods of treating a tar sands formation is described herein. The methods may include providing heat to a first section of a hydrocarbon layer in the formation from a plurality of heaters located in the first section of the formation. Heat is transferred from the heaters so that at least a first section of the formation reaches a selected temperature. At least a portion of residual heat from the first section transfers from the first section to a second section of the formation. At least a portion of hydrocarbons in the second section are mobilized by providing a solvation fluid and/or a pressurizing fluid to the second section of the formation.

Vinegar, Harold J. (Bellaire, TX); Karanikas, John Michael (Houston, TX); Ryan, Robert Charles (Houston, TX)

2010-12-14T23:59:59.000Z

20

Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel Castings  

SciTech Connect

Heat treatment and associated processing, such as quenching, are critical during high strength steel casting production. These processes must be managed closely to prevent thermal and residual stresses that may result in distortion, cracking (particularly after machining), re-work, and weld repair. The risk of casting distortion limits aggressive quenching that can be beneficial to the process and yield an improved outcome. As a result of these distortions, adjustments must be made to the casting or pattern design, or tie bars must be added. Straightening castings after heat treatments can be both time-consuming and expensive. Residual stresses may reduce a casting���¢��������s overall service performance, possibly resulting in catastrophic failure. Stress relieving may help, but expends additional energy in the process. Casting software is very limited in predicting distortions during heat treatment, so corrective measures most often involve a tedious trial-and-error procedure. An extensive review of existing heat treatment residual stress and distortion modeling revealed that it is vital to predict the phase transformations and microstructure of the steel along with the thermal stress development during heat treatment. After reviewing the state-of-the-art in heat treatment residual stress and distortion modeling, an existing commercial code was selected because of its advanced capabilities in predicting phase transformations, the evolving microstructure and related properties along with thermal stress development during heat treatment. However, this software was developed for small parts created from forgings or machined stock, and not for steel castings. Therefore, its predictive capabilities for heat treatment of steel castings were investigated. Available experimental steel casting heat treatment data was determined to be of insufficient detail and breadth, and so new heat treatment experiments were designed and performed, casting and heat treating modified versions of the Navy-C ring (a classical test shape for heat treatment experiments) for several carbon and low alloy steels in order to generate data necessary to validate the code. The predicted distortions were in reasonable agreement with the experimentally measured values. However, the final distortions in the castings were small, making it difficult to determine how accurate the predictions truly are. It is recommended that further validation of the software be performed with the aid of additional experiments with large production steel castings that experience significant heat treatment distortions. It is apparent from this research that the mechanical properties of the bonded sand used for cores and sand molds are key in producing accurate stress simulation results. Because of this, experiments were performed to determine the temperature-dependent elastic modulus of a resin-bonded sand commonly utilized in the steel casting industry. The elastic modulus was seen to vary significantly with heating and cooling rates. Also, the retained room temperature elastic modulus after heating was seen to degrade significantly when the sand was heated above 125�������°C. The elastic modulus curves developed in this work can readily be utilized in casting simulation software. Additional experiments with higher heating rates are recommended to determine the behavior of the elastic modulus in the sand close to the mold-metal interface. The commercial heat treatment residual stress and distortion code, once fully validated, is expected to result in an estimated energy savings of 2.15 trillion BTU���¢��������s/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology.

Christoph Beckermann; Kent Carlson

2011-07-22T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Comments on Several Friction Phenomena  

Science Journals Connector (OSTI)

It is suggested that the term dry friction be limited to phenomena observed under highly outgassed conditions. Two theorems are suggested one on the distribution of heat energy between two friction surfaces and the other on the independence of the heat loss in certain clutches on the coefficient of friction.

G. P. Brewington

1951-01-01T23:59:59.000Z

22

Effects of Post-Weld Heat Treatment on the Mechanical Properties of Similar- and Dissimilar-Alloy Friction Stir Welded Blanks  

SciTech Connect

Friction stir welding is a solid state joining process with relatively low welding temperatures. Nevertheless, the mechanical properties of friction stir welded blanks are degraded after welding. Indeed, both strength and ductility of the welds are decreased after welding. Often, the resulting friction stir welded blanks need to be formed to their final structural shape. Therefore, the formability of friction stir welded blanks is of primary importance in the manufacturing of structural parts. This paper studies how the mechanical properties and particularly formability of friction stir welded blanks can be improved by applying a post weld heat treatment. Two aluminum alloys from 2000 and 7000 series, namely 2024-T3 and 7075-T6, are selected for the study. The sheet thickness of both materials is 2,0 mm. The selected alloys are welded in three configurations: 2024-T3 and 2024-T3, 7075-T6 and 7075-T6, and 2024-T3 and 7075-T6. The resulting welds are naturally aged for a few months. Three sets of standard dog bone shape tensile test specimens are then machined from the welds. The first set of the specimens is tested without any heat treatment. The second set of the specimens is solution heat treated and quenched before testing. The third set of the specimens is solution heat treated, quenched, and naturally aged for a week before testing. The mechanical properties of the three different sets of specimens are compared with each other. It is shown that careful selection of post weld heat-treatment can greatly improve the formability of friction stir welded blanks.

Zadpoor, Amir Abbas [Materials Innovation Institute (M2i), Mekelweg 2, Delft 2628CD (Netherlands); Faculty of Aerospace Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2629HS (Netherlands); Sinke, Jos [Faculty of Aerospace Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2629HS (Netherlands)

2011-01-17T23:59:59.000Z

23

Characterizations of 21-4N to 4Cr9Si2 stainless steel dissimilar joint bonded by electric-resistance-heat-aided friction welding  

Science Journals Connector (OSTI)

A new welding process, electric-resistance-heat-aided friction welding (ERHAFW), was introduced in this study. To further improve the joint quality and energy-saving, electric resistance welding was combined with the conventional continuous-drive friction welding. 21-4N (austenitic stainless steel) and 4Cr9Si2 (martensitic stainless steel) valve steel rods of 4 mm diameter were used as base metals. The results show that electric-resistance-heat-aided friction welding can be applied to join thin rods within a relatively short time, which is very difficult for conventional friction welding (FW). The microstructure of ERHAFW bonded 21-4N to 4Cr9Si2 presents non-uniform across the joint. Different structure zones are observed from the weld line to both sides, which are the weld center, thermo-mechanically affected zone (TMAZ) and heat affected zone (HAZ). These regions exhibit different structures owing to the difference in the thermophysical and mechanical properties of these two steels under the fast heating and cooling during welding. The variation of microhardness in the joint is attributed to the microstructure change. The higher microhardness is obtained in the weld center and TMAZ of 4Cr9Si2 corresponding to the presence of fine tempered martensite and carbides.

Wen-Ya Li; Min Yu; Jinglong Li; Guifeng Zhang; Shiyuan Wang

2009-01-01T23:59:59.000Z

24

Minimum entropy generation due to heat transfer and fluid friction in a parabolic trough receiver with non-uniform heat flux at different rim angles and concentration ratios  

Science Journals Connector (OSTI)

Abstract In this paper, Monte Carlo ray-tracing and computational fluid dynamics are used to numerically investigate the minimum entropy generation due to heat transfer and fluid friction in a parabolic trough receiver. The analysis was carried out for rim angles in the range 40°–120°, concentration ratios in the range 57–143, Reynolds numbers in the range 1.02 × 104–1.36 × 106 and fluid temperatures in the range 350–650 K. Results show existence of an optimal Reynolds number at any given combination of fluid temperature, concentration ratio and rim angle for which the total entropy generation is a minimum. The total entropy generation was found to increase as the rim angle reduced, concentration ratio increased and fluid temperature reduced. The high entropy generation rates at low rim angles are mainly due to high peak temperatures in the absorber tube at these low rim angles.

Aggrey Mwesigye; Tunde Bello-Ochende; Josua P. Meyer

2014-01-01T23:59:59.000Z

25

Turbulent heat transfer and friction in a square channel with discrete rib turbulators  

E-Print Network (OSTI)

in which two opposite walls are roughened with parallel and crossed arrays of full ribs, cross-cut discrete ribs, and beveled discrete ribs. The discrete ribs are staggered in alternate rows of three and two ribs The rib-roughened channel models... and length on the convective heat transfer in nb-roughened triangular ducts. Ribs were placed on two of the three walls of the test ducts to model the internal cooling passage at the leading edge of a. turbine airfoil. The local heat transfer augmentation...

McMillin, Robert Dale

2012-06-07T23:59:59.000Z

26

Determination of thermal conductivity and formation temperature from cooling history of friction-heated probes  

Science Journals Connector (OSTI)

......dissipation at the rising cost of ship operational time...penetrations for measurements of geothermal gradients at closely...paves the way at no extra cost for the determination...imposing heat flow as an energy constraint in transient...typical measurement of geothermal gradient in the ocean......

Tien-Chang Lee; A. D. Duchkov; S. G. Morozov

2003-02-01T23:59:59.000Z

27

Deformation, Heating and Melting of Solids in High-Speed Friction  

Science Journals Connector (OSTI)

...4}$ mm Hg, at sliding speeds up to 700 m/s, is determined...decrease with increasing sliding speed. The general behaviour is similar to that observed at light loads but there are important...that it may now increase as the speed rises. The heating due to the...

1961-01-01T23:59:59.000Z

28

Effect of flow topology on the calculation of two-phase frictional multipliers in uniformly heated flow of R-134a in a rectangular duct  

SciTech Connect

The two-phase frictional multipliers for SUVA R-134a flowing in a rectangular duct (with D{sub H} = 4.8 mm) have been measured for three nominal system pressures (0.88, 1.34 and 2.34 MPa) and four nominal mass fluxes (510, 1020 and 1740, 2040 kg/m{sup 2}/s) under uniform heat flux conditions. The data is compared with adiabatic data previously taken at similar flow conditions, as well as with several classical multiplier correlations. The comparisons reveal a strong effect of pressure and mass flux on the flow topology and, by extension, a large effect on the calculation of acceleration and frictional pressure drop components. For this fluid and this geometry, entrainment and fluid separation is enhanced at higher pressures and mass flux such that most of the liquid exists in the test section edges and as dispersed droplets in the core. For these cases, the classical simplified approach to calculate acceleration pressure drop fails to adequately predict the acceleration component and leads to erroneous calculations of frictional pressure drop from the measured total pressure drop. Best estimates of the true acceleration component are given, based on void profiles measured with a gamma densitometer system, comparisons to the adiabatic data, and recasting the data in terms of the total pressure drop multiplier as a function of the Martinelli parameter, X{sub tt}. (author)

Vassallo, Peter; Kevin Cope, W.; Smith, Walter C. [Bechtel Marine Propulsion Corporation, Niskayuna, NY 12309 (United States)

2010-11-15T23:59:59.000Z

29

Heat transfer and friction factor of water based TiO2 and SiO2 nanofluids under turbulent flow in a tube  

Science Journals Connector (OSTI)

Abstract The heat transfer coefficient and friction factor of TiO2 and SiO2 water based nanofluids flowing in a circular tube under turbulent flow are investigated experimentally under constant heat flux boundary condition. TiO2 and SiO2 nanofluids with an average particle size of 50 nm and 22 nm respectively are used in the working fluid for volume concentrations up to 3.0%. Experiments are conducted at a bulk temperature of 30 °C in the turbulent Reynolds number range of 5000 to 25,000. The enhancements in viscosity and thermal conductivity of TiO2 are greater than SiO2 nanofluid. However, a maximum enhancement of 26% in heat transfer coefficients is obtained with TiO2 nanofluid at 1.0% concentration, while SiO2 nanofluid gave 33% enhancement at 3.0% concentration. The heat transfer coefficients are lower at all other concentrations. The particle concentration at which the nanofluids give maximum heat transfer has been determined and validated with property enhancement ratio. It is observed that the pressure drop is directly proportional to the density of the nanoparticle.

W.H. Azmi; K.V. Sharma; P.K. Sarma; Rizalman Mamat; G. Najafi

2014-01-01T23:59:59.000Z

30

Frictional Phenomena. XIV  

Science Journals Connector (OSTI)

IN this chapter technical applications of the solid friction concept in four different fields are discussed. These are: (1) mechanical engineering (a) damping of unwanted vibrations in machinery—for instance crank?shaft vibrations (b) vibrations excited by internal friction—for instance whirl of rotating shafts; (2) metallurgy in which damping measurement promises to be a useful new tool; (3) rubber technology as applied to automobile tires with regard to the heat generated therein; and (4) electrical engineering specifically dielectric losses in electrical insulating materials.

Andrew Gemant

1943-01-01T23:59:59.000Z

31

RELAP5/MOD3 simulation of the loss of residual heat removal during midloop operation experiment conducted at the ROSA-IV/ Large Scale Test Facility  

E-Print Network (OSTI)

The modeling of the complex thermal hydraulics Of reactor systems involves the use Of experimental test systems as well as numerical codes. A simulation of the loss of residual heat removal (RHR) during midloop operations was performed using...

Banerjee, Sibashis Sanatkumar

2012-06-07T23:59:59.000Z

32

Experimental Analysis of the Single-Phase Heat Transfer and Friction Factor inside the Horizontal Internally Micro-Fin Tube  

E-Print Network (OSTI)

and shell-side condensers to increase heat transfer. This enables water chillers to reach high efficiency, it was observed that the buoyancy effect is present in the laminar region. The efficiency index (the ratio of tube is widely used in high flow rate applications because the heat transfer enhancement in high flow

Ghajar, Afshin J.

33

Turbulent heat transfer and friction in a segmental channel that simulates leading-edge cooling channels of modern turbine blades  

E-Print Network (OSTI)

. Steady state heat transfer experiments for three channel cross sections, ribbed curved wall-to-smooth flat wall heat flux ratio of 0.0, 1.0, 2.0, 4.0, 6.0, and infinity, and mass flow rates corresponding to Reynolds numbers between 10 000 and 70 000...

Spence, Rodney Brian

2012-06-07T23:59:59.000Z

34

Friction Induced Skin Tags  

E-Print Network (OSTI)

Duplantis KL, Jones BH. Friction blisters. Pathophysiology,Friction Induced Skin Tags Francisco Allegue MD 1 , Carmenetiopathogenic role for friction. Introduction Skin tags (

Allegue, Francisco; Fachal, Carmen; Pérez-Pérez, Lidia

2008-01-01T23:59:59.000Z

35

Introduction Rolling and Friction  

E-Print Network (OSTI)

Introduction Kinematics Solutions Rolling and Friction in Discrete Element Simulations Matthew R of rolling resistance Creep-friction definition Creep-friction vs. Cattaneo-Mindlin friction Classification / papers / EMI2011.pdf #12;Introduction Kinematics Solutions Classification of rolling resistance Creep-friction

Kuhn, Matthew R.

36

Modelling of the Effects of Friction and Compression on Explosives ESGI80 Modelling of the Effects of Friction and  

E-Print Network (OSTI)

Modelling of the Effects of Friction and Compression on Explosives ESGI80 Modelling of the Effects of Friction and Compression on Explosives Problem presented by John Curtis Atomic Weapons Establishment, based on the compression of a sample of the explosive. The study group identified frictional heating

Purvis, Richard

37

Quantum friction  

E-Print Network (OSTI)

The Brownian motion of a light quantum particle in a heavy classical gas is theoretically described and a new expression for the friction coefficient is obtained for arbitrary temperature. At zero temperature it equals to the de Broglie momentum of the mean free path divided by the mean free path. Alternatively, the corresponding mobility of the quantum particle in the classical gas is equal to the square of the mean free path divided by the Planck constant. The Brownian motion of a quantum particle in a quantum environment is also discussed.

R. Tsekov

2012-03-12T23:59:59.000Z

38

Roles of Dry Friction in Fluctuating Motion of Adiabatic Piston  

E-Print Network (OSTI)

The motion of an adiabatic piston under dry friction is investigated to clarify the roles of dry friction in non-equilibrium steady states. We clarify that dry friction can reverse the direction of the piston motion and causes a discontinuity or a cusp-like singularity for velocity distribution functions of the piston. We also show that the heat fluctuation relation is modified under dry friction.

Tomohiko G. Sano; Hisao Hayakawa

2014-03-08T23:59:59.000Z

39

Vacuum friction in rotating particles  

E-Print Network (OSTI)

We study the frictional torque acting on particles rotating in empty space. At zero temperature, vacuum friction transforms mechanical energy into light emission and produces particle heating. However, particle cooling relative to the environment occurs at finite temperatures and low rotation velocities. Radiation emission is boosted and its spectrum significantly departed from a hot-body emission profile as the velocity increases. Stopping times ranging from hours to billions of years are predicted for materials, particle sizes, and temperatures accessible to experiment. Implications for the behavior of cosmic dust are discussed.

A. Manjavacas; F. J. García de Abajo

2010-09-21T23:59:59.000Z

40

Skin friction blistering: computer model.  

E-Print Network (OSTI)

on blisters produced by friction. I. Results of linearDuplantis KL, Jones BH. Friction blisters. Pathophysiology,WA, Sulzberger MB. The friction blister. Mil Med 6. Cortese

Xing, Malcolm; Pan, Ning; Zhong, Wen; Maibach, Howard

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Friction in Mid-latitude Bob Plant, Stephen Belcher, Bob Beare, Andy Brown  

E-Print Network (OSTI)

Friction in Mid-latitude Cyclones Ian Boutle Bob Plant, Stephen Belcher, Bob Beare, Andy Brown #12;Motivation · Many studies have shown the significance of friction in formation and dissipation of cyclones Dt = + � . F . Diabatic Term: · Surface heat fluxes · Latent heat fluxes Frictional Term

Plant, Robert

42

Frictional Widgets: Enhancing Touch Interfaces with Programmable Friction  

E-Print Network (OSTI)

Frictional Widgets: Enhancing Touch Interfaces with Programmable Friction Abstract Touch the design possibilities offered by augmenting touchscreens with programmable surface friction. Four exemplar of touch interactions can be enhanced when using a touchscreen with dynamically varied surface friction. We

Levesque, Vincent

43

Tool Wear in Friction Drilling  

SciTech Connect

This study investigated the wear of carbide tools used in friction drilling, a nontraditional hole-making process. In friction drilling, a rotating conical tool uses the heat generated by friction to soften and penetrate a thin workpiece and create a bushing without generating chips. The wear of a hard tungsten carbide tool used for friction drilling a low carbon steel workpiece has been investigated. Tool wear characteristics were studied by measuring its weight change, detecting changes in its shape with a coordinate measuring machine, and making observations of wear damage using scanning electron microscopy. Energy dispersive spectroscopy was applied to analyze the change in chemical composition of the tool surface due to drilling. In addition, the thrust force and torque during drilling and the hole size were measured periodically to monitor the effects of tool wear. Results indicate that the carbide tool is durable, showing minimal tool wear after drilling 11000 holes, but observations also indicate progressively severe abrasive grooving on the tool tip.

Miller, Scott F [ORNL; Blau, Peter Julian [ORNL; Shih, Albert J. [University of Michigan

2007-01-01T23:59:59.000Z

44

The Friction of Wood  

Science Journals Connector (OSTI)

...1958 research-article The Friction of Wood D. Atack D. Tabor Earlier work, especially...following paper shows that the friction of wood may be explained in a similar way, that...The friction was studied between balsam wood (Abies balsamea) and surfaces of steel...

1958-01-01T23:59:59.000Z

45

Rubber friction: role of the flash temperature  

E-Print Network (OSTI)

When a rubber block is sliding on a hard rough substrate, the substrate asperities will exert time-dependent deformations of the rubber surface resulting in viscoelastic energy dissipation in the rubber, which gives a contribution to the sliding friction. Most surfaces of solids have roughness on many different length scales, and when calculating the friction force it is necessary to include the viscoelastic deformations on all length scales. The energy dissipation will result in local heating of the rubber. Since the viscoelastic properties of rubber-like materials are extremely strongly temperature dependent, it is necessary to include the local temperature increase in the analysis. At very low sliding velocity the temperature increase is negligible because of heat diffusion, but already for velocities of order 0.01 m/s the local heating may be very important. Here I study the influence of the local heating on the rubber friction, and I show that in a typical case the temperature increase results in a decrease in rubber friction with increasing sliding velocity for v > 0.01 m/s. This may result in stick-slip instabilities, and is of crucial importance in many practical applications, e.g., for the tire-road friction, and in particular for ABS-breaking systems.

B. N. J. Persson

2006-05-10T23:59:59.000Z

46

Rotational Quantum Friction  

E-Print Network (OSTI)

We investigate the frictional forces due to quantum fluctuations acting on a small sphere rotating near a surface. At zero temperature, we find the frictional force near a surface to be several orders of magnitude larger than that for the sphere rotating in vacuum. For metallic materials with typical conductivity, quantum friction is maximized by matching the frequency of rotation with the conductivity. Materials with poor conductivity are favored to obtain large quantum frictions. For semiconductor materials that are able to support surface plasmon polaritons, quantum friction can be further enhanced by several orders of magnitude due to the excitation of surface plasmon polaritons.

Rongkuo Zhao; Alejandro Manjavacas; F. Javier García de Abajo; J. B. Pendry

2012-08-21T23:59:59.000Z

47

Friction in Forming of UD Composites  

SciTech Connect

Inter-ply and tool/ply friction play a dominant role in hot stamp forming of UD fiber-reinforced thermoplastic laminates. This research treats friction measurements of a PEEK-AS4 composite system. To this end, an in-house developed friction tester is utilized to pull a laminate through two heat controlled clamping platens. The friction coefficient is determined by relating the clamp force to the pull force. The geometry of the gap between the clamping platens is monitored with micrometer accuracy. A first approach to describe the relation between the geometry and frictional behavior is undertaken by applying a standard thin-film theory for hydrodynamic lubrication. Experimental measurements showed that the thin-film theory does not entirely cover the underlying physics. Thus a second model is utilized, which employs a Leonov-model to describe the shear deformation of the matrix material, while its viscosity is described with a multi-mode Maxwell model. The combination of both models shows the potential to capture the complete frictional behavior.

Sachs, U.; Haanappel, S. P. [Thermoplastic Composite Research Center, University of Twente, Horst building, P.O. Box 217, 7500AE Enschede (Netherlands); Akkerman, R. [Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500AE Enschede (Netherlands); Thermoplastic Composite Research Center, University of Twente, Horst building, P.O. Box 217, 7500AE Enschede (Netherlands); Thije, R. H. W. ten [Aniform Virtual Forming, Nieuwstraat 116, 7411 LP Deventer (Netherlands); Rooij, M. B. de [Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500AE Enschede (Netherlands)

2011-05-04T23:59:59.000Z

48

Skin friction blistering: computer model.  

E-Print Network (OSTI)

K. L.Jones, B. H. , Friction blisters. Pathophysiology,and M.B. Sulzberger, The friction blister. Mil Med, 1972.on blisters produced by friction. II. The blister fluid. J

Xing, Malcolm; Pan, Ning; Zhong, Wen; Maibach, Howard

2007-01-01T23:59:59.000Z

49

Factors affecting piston ring friction  

E-Print Network (OSTI)

The piston ring pack friction is a major contributor to the internal combustion engine mechanical friction loss. The oil control ring decides the oil supply to the top two rings in addition to being the major friction ...

Liao, Kai, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

50

Friction Stir Processing for Efficient Manufacturing  

SciTech Connect

Friction at contacting surfaces in relative motion is a major source of parasitic energy loss in machine systems and manufacturing processes. Consequently, friction reduction usually translates to efficiency gain and reduction in energy consumption. Furthermore, friction at surfaces eventually leads to wear and failure of the components thereby compromising reliability and durability. In order to reduce friction and wear in tribological components, material surfaces are often hardened by a variety of methods, including conventional heat treatment, laser surface hardening, and thin-film coatings. While these surface treatments are effective when used in conjunction with lubrication to prevent failure, they are all energy intensive and could potentially add significant cost. A new concept for surface hardening of metallic materials and components is Friction Stir Processing (FSP). Compared to the current surface hardening technologies, FSP is more energy efficient has no emission or waste by products and may result in better tribological performance. FSP involves plunging a rotating tool to a predetermined depth (case layer thickness) and translating the FSP tool along the area to be processed. This action of the tool produces heating and severe plastic deformation of the processed area. For steel the temperature is high enough to cause phase transformation, ultimately forming hard martensitic phase. Indeed, FSP has been used for surface modification of several metals and alloys so as to homogenize the microstructure and refine the grain size, both of which led to improved fatigue and corrosion resistance. Based on the effect of FSP on near-surface layer material, it was expected to have beneficial effects on friction and wear performance of metallic materials. However, little or no knowledge existed on the impact of FSP concerning friction and wear performance the subject of the this project and final report. Specifically for steel, which is the most dominant tribological material, FSP can replace the current conventional surface hardening techniques used for friction and wear performance. Friction Stir Link Inc. (FSL) is teamed with Argonne National Laboratory (ANL) to develop and optimize FSP for friction and wear performance enhancement. The ultimate goal is to offer FSP and an effective alternative to some of the current energy intensive and high-cost surface hardening processes.

Mr. Christopher B. Smith; Dr. Oyelayo Ajayi

2012-01-31T23:59:59.000Z

51

Effect of rib spacing on heat transfer and friction in a rotating two-pass rectangular (AR=1:2) channel  

E-Print Network (OSTI)

The research focuses on testing the heat transfer enhancement in a channel for different spacing of the rib turbulators. Those ribs are put on the surface in the two pass rectangular channel with an aspect ratio of AR=1:2. The cross section...

Liu, Yao-Hsien

2006-10-30T23:59:59.000Z

52

Action of friction Frictional processes are not often considered in  

E-Print Network (OSTI)

Action of friction Frictional processes are not often considered in any detail in studies are switched off, the pressure falls to just 921mb. Frictional processes can be thought of in terms of changes. The first term on the right­hand­side represents barotropic damping by friction, and the second

Plant, Robert

53

Static Friction Phenomena The following static friction phenomena have a direct dependency on velocity.  

E-Print Network (OSTI)

Coulomb Friction Viscous Friction Stribeck Friction Static Friction Phenomena The following static friction phenomena have a direct dependency on velocity. Static Friction Model: Friction force opposes the direction of motion when the sliding velocity is zero. Coulomb Friction Model: Friction force

Simpkins, Alex

54

Friction stir welding tool  

DOE Patents (OSTI)

A friction stir welding tool is described and which includes a shank portion; a shoulder portion which is releasably engageable with the shank portion; and a pin which is releasably engageable with the shoulder portion.

Tolle, Charles R. (Idaho Falls, ID); Clark, Denis E. (Idaho Falls, ID); Barnes, Timothy A. (Ammon, ID)

2008-04-15T23:59:59.000Z

55

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated Tropical Cyclone  

E-Print Network (OSTI)

0 Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated) viewed as a heat engine converts heat energy extracted from the ocean to kinetic energy of the TC, which is eventually dissipated due to surface friction. Since the energy production rate is a linear function while

Wang, Yuqing

56

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated Tropical Cyclone*  

E-Print Network (OSTI)

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated as a heat engine converts heat energy extracted from the ocean into the kinetic energy of the TC, which is eventually dissipated due to surface friction. Since the energy production rate is a linear function while

Wang, Yuqing

57

Journal of Enhanced Heat Transfer, 19 (5): 457476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT  

E-Print Network (OSTI)

Journal of Enhanced Heat Transfer, 19 (5): 457­476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT microfin tubes, most of the heat transfer and friction factor studies were focused on the turbulent region. However, there is a lack of information about the heat transfer and friction factor behavior of microfin

Ghajar, Afshin J.

58

Friction coefficient for deep-inelastic heavy-ion collisions  

Science Journals Connector (OSTI)

Based on the microscopic model, the friction coefficient for the relative motion of nuclei in deep-inelastic heavy-ion collisions is calculated. An advantage of the suggested method is that it allows one to consider the relative motion of nuclei and the intrinsic motion self-consistently. The radial dependence of the friction coefficient is studied and the results are compared with those found by other methods. It was demonstrated that the kinetic energy dissipation in deep-inelastic heavy-ion collisions is a gradual process which takes up a significant part of a reaction time. A decrease of the radial friction coefficient with a heating of nuclei is shown.

G. G. Adamian; 1; 2; R. V. Jolos; 1; A. K. Nasirov; 1; 2; A. I. Muminov2

1997-07-01T23:59:59.000Z

59

Nanoscale friction and wear maps  

Science Journals Connector (OSTI)

...The nanoscale friction force follows a complex nonlinear...Studies have shown that the fundamental laws of friction, as...measurements using friction force microscopy: part I...J. N. 2007 Surface forces and nanorheology of molecularly...thin films. In Springer handbook of nanotechnology (ed...

2008-01-01T23:59:59.000Z

60

Nonlinear friction in quantum mechanics  

E-Print Network (OSTI)

The effect of nonlinear friction forces in quantum mechanics is studied via dissipative Madelung hydrodynamics. A new thermo-quantum diffusion equation is derived, which is solved for the particular case of quantum Brownian motion with a cubic friction. It is extended also by a chemical reaction term to describe quantum reaction-diffusion systems with nonlinear friction as well.

Roumen Tsekov

2010-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

PEBBLES Simulation of Static Friction and New Static Friction Benchmark  

SciTech Connect

Pebble bed reactors contain large numbers of spherical fuel elements arranged randomly. Determining the motion and location of these fuel elements is required for calculating certain parameters of pebble bed reactor operation. This paper documents the PEBBLES static friction model. This model uses a three dimensional differential static friction approximation extended from the two dimensional Cundall and Strack model. The derivation of determining the rotational transformation of pebble to pebble static friction force is provided. A new implementation for a differential rotation method for pebble to container static friction force has been created. Previous published methods are insufficient for pebble bed reactor geometries. A new analytical static friction benchmark is documented that can be used to verify key static friction simulation parameters. This benchmark is based on determining the exact pebble to pebble and pebble to container static friction coefficients required to maintain a stable five sphere pyramid.

Joshua J. Cogliati; Abderrafi M. Ougouag

2010-05-01T23:59:59.000Z

62

4 - Friction–vibration interactions  

Science Journals Connector (OSTI)

Abstract: Generally, friction could be treated as a dynamical variable in a dynamical system with a sliding interface. For convenience, the effect of friction on vibrations and the effect of vibrations on friction have been treated separately. The close-loop feedback effects of friction–vibration interactions have rarely been paid attention due to limited engineering applications. Both friction and vibration have been simplified and quantified by order-reduced models. There are many unique dynamic phenomena and underlying mechanisms associated with the vibrations of a system with friction, just to name a few: stick-slip, self-excited vibrations, modal coupling, sprag-slip, loss of contact, parametric resonance, etc. Friction-induced vibrations usually exhibit time-varying, nonlinear and stochastic properties. On the other hand, there are certain underlying mechanisms associated with the effect of vibrations on the friction reductions. This chapter will comprehensively survey varied characteristics of vibrations in systems having friction. Then a detailed consideration of the current understanding of vibration-induced friction reduction will be given. Also the single-degree-of-freedom system, multiple-degree-of-freedom system and continuous system are discussed. Finally, several applications in science and engineering are presented, which include stick-slip associated with earthquakes, friction vibrations of rod in sucker pumping system, and automotive brake vibrations and noise.

2014-01-01T23:59:59.000Z

63

Friction surfaced Stellite6 coatings  

SciTech Connect

Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: Black-Right-Pointing-Pointer Stellite6 used as coating material for friction surfacing. Black-Right-Pointing-Pointer Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. Black-Right-Pointing-Pointer Finer and uniformly distributed carbides in friction surfaced coatings. Black-Right-Pointing-Pointer Absence of melting results compositional homogeneity in FS Stellite6 coatings.

Rao, K. Prasad; Damodaram, R. [Department of Metallurgical and Materials Engineering - Indian Institute of Technology Madras, Chennai 600 036 (India); Rafi, H. Khalid, E-mail: khalidrafi@gmail.com [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Ram, G.D. Janaki [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Reddy, G. Madhusudhan [Metal Joining Group, Defence Metallurgical Research Laboratory (DMRL) Kanchanbagh, Hyderabad 500 058 (India); Nagalakshmi, R. [Welding Research Institute, Bharat Heavy Electricals Limited, Tiruchirappalli 620 014 (India)

2012-08-15T23:59:59.000Z

64

Anomalous friction in suspended graphene  

Science Journals Connector (OSTI)

Since the discovery of the Amonton's law and with support of modern tribological models, friction between surfaces of three-dimensional materials is known to generally increase when the surfaces are in closer contact. Here, using molecular dynamics simulations of friction force microscopy on suspended graphene, we demonstrate an increase of? friction when the scanning tip is retracted away from the sample. We explain the observed behavior and address why this phenomenon has not been observed for isotropic 3D materials.

A. Smolyanitsky and J. P. Killgore

2012-09-20T23:59:59.000Z

65

Magnetic Low-Friction Track  

Science Journals Connector (OSTI)

The standard low-friction tracks used to test Newton's laws are the air track and the low-friction cart track. Both are commercially available and provide low-friction environments to test various physics concepts. At a recent science fair one of the authors (JG) presented a magnetically levitated cart and track. A literature search found no previous testing of magnetically levitated carts.1 This paper compares a magnetically levitated cart against the two standard low-friction tracks.

Mark Paetkau; Manpreet Bahniwal; James Gamblen

2008-01-01T23:59:59.000Z

66

Friction of wood on steel.  

E-Print Network (OSTI)

?? This thesis deals with the experimental description of friction between steel and wood materials, specifically laminated veneer lumber (LVL) and pine wood with two… (more)

Koubek, Radek

2014-01-01T23:59:59.000Z

67

Internal Heat Transfer Coefficient Determination in a Packed Bed From the Transient Response Due to Solid Phase Induction Heating  

E-Print Network (OSTI)

the Hydraulic Drag and Heat Transfer Coefficients in PorousT. E. W. , 1929, “Heat Transfer: A Liquid Flowing Through a5] Locke, G. L. , 1950, “Heat Transfer and Flow Friction

Geb, David; Zhou, Feng; Catton, Ivan

2012-01-01T23:59:59.000Z

68

Elastic model of dry friction  

SciTech Connect

Friction of elastic bodies is connected with the passing through the metastable states that arise at the contact of surfaces rubbing against each other. Three models are considered that give rise to the metastable states. Friction forces and their dependence on the pressure are calculated. In Appendix A, the contact problem of elasticity theory is solved with adhesion taken into account.

Larkin, A. I.; Khmelnitskii, D. E., E-mail: dekl2@cam.ac.uk [Landau Institute for Theoretical Physics (Russian Federation)

2013-09-15T23:59:59.000Z

69

residual magnetism  

Science Journals Connector (OSTI)

The magnetization, i.e., the magnetic polarization, that remains in a magnetized material after all attempts to remove the magnetization have been made. Note: An example of residual magnetization is the magnetiza...

2001-01-01T23:59:59.000Z

70

Friction, Brownian Motion, and Energy Dissipation Mechanisms in Adsorbed  

NLE Websites -- All DOE Office Websites (Extended Search)

Friction, Brownian Motion, and Energy Dissipation Mechanisms in Adsorbed Friction, Brownian Motion, and Energy Dissipation Mechanisms in Adsorbed Molecules and Molecularly Thin Films: Heating, Electrostatic and Magnetic Effects January 15, 2014 4:00PM to 5:00PM Presenter Jacqueline Krim, North Carolina State University Location Building 440, Room A105-106 Type Seminar Series NST Nanoscience Colloquium Abstract: In the study of friction at the nanoscale, phononic, electrostatic, conduction electron and magnetic effects all contribute to the dissipation mechanisms [1,2]. Electrostatic and magnetic contributions are increasingly alluded to in the current literature, but remain poorly characterized. I will first overview the nature of these various contributions, and then report on our observations of magnetic and electrostatic contributions to

71

Irreversible work and inner friction in quantum thermodynamic processes  

E-Print Network (OSTI)

We discuss the thermodynamics of closed quantum systems driven out of equilibrium by a change in a control parameter and undergoing a unitary process. We compare the work actually done on the system with the one that would be performed along ideal adiabatic and isothermal transformations. The comparison with the latter leads to the introduction of irreversible work, while that with the former leads to the introduction of inner friction. We show that these two quantities can be treated on equal footing, as both can be linked with the heat exchanged in thermalization processes and both can be expressed as relative entropies. Furthermore, we show that a specific fluctuation relation for the entropy production associated with the inner friction exists, which allows the inner friction to be written in terms of its cumulants.

F. Plastina; A. Alecce; T. J. G. Apollaro; G. Falcone; G. Francica; F. Galve; N. Lo Gullo; R. Zambrini

2014-07-13T23:59:59.000Z

72

3 - Fundamentals of contact mechanics and friction  

Science Journals Connector (OSTI)

Abstract: The subjects of contact and friction are introduced here in the context of friction–vibration interactions. The chapter begins with a brief presentation of the fundamentals of contact mechanics and friction phenomena, and continues with an examination of classic formulations and laws of contact and friction. The various steps involved in contact and friction analysis of an engineering system are outlined, and essential definitions and concepts of contact and friction are introduced. There follows a presentation of the detailed contact and friction analysis, which can be used for the analysis of general contact and friction phenomena encountered in dealing with friction–vibration interaction problems. The comprehensive treatment of interface contact and friction from macro-to micro-level are presented.

2014-01-01T23:59:59.000Z

73

Rubber friction and tire dynamics  

E-Print Network (OSTI)

We propose a simple rubber friction law, which can be used, e.g., in models of tire (and vehicle) dynamics. The friction law is tested by comparing numerical results to the full rubber friction theory (B.N.J. Persson, J. Phys.: Condensed Matter 18, 7789 (2006)). Good agreement is found between the two theories. We describe a two-dimensional (2D) tire model which combines the rubber friction model with a simple mass-spring description of the tire body. The tire model is very flexible and can be used to calculate accurate mu-slip (and the self-aligning torque) curves for braking and cornering or combined motion (e.g., braking during cornering). We present numerical results which illustrate the theory. Simulations of Anti-Blocking System (ABS) braking are performed using two simple control algorithms.

B. N. J. Persson

2010-07-16T23:59:59.000Z

74

Development of Friction Factor Correlation for Single-phase Flow in Micro-fin Tube Using Logistic Dose Response Curve  

E-Print Network (OSTI)

@umac.mo Abstract: Tam et al. [1] conducted simultaneous heat transfer and friction factor experiments for the plain the same as the plain tube. However, the friction factor characteristics of the micro-fin tubes in the transition region were different compared to the plain tube. This type of data cannot be easily correlated

Ghajar, Afshin J.

75

Friction Anisotropy: A unique and intrinsic property of decagonal quasicrystals  

E-Print Network (OSTI)

Quasi-Crystalline Low-Friction Coatings. Journal ofContact Mechanics, Friction and Adhesion with Application toEds. ), Fundamentals of Friction and Wear, Springer Berlin

Park, Jeong Young

2008-01-01T23:59:59.000Z

76

Epistemic Friction: Reflections on Knowledge, Truth, and Logic  

E-Print Network (OSTI)

ARTICLE Epistemic Friction: Re?ections on Knowledge, Truth,requires both freedom and friction. Freedom to set up ourprograms, etc. , and friction (constraint) coming from two

Sher, Gila

2010-01-01T23:59:59.000Z

77

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated Tropical Cyclone  

Science Journals Connector (OSTI)

A tropical cyclone (TC) viewed as a heat engine converts heat energy extracted from the ocean into the kinetic energy of the TC, which is eventually dissipated due to surface friction. Since the energy production rate is a linear function while ...

Yuqing Wang; Jing Xu

2010-01-01T23:59:59.000Z

78

Friction between Ring Polymer Brushes  

E-Print Network (OSTI)

Friction between ring-polymer brushes at melt densities sliding past each other are studied using extensive course-grained molecular dynamics simulations and scaling arguments, and the results are compared to the friction between linear-polymer brushes. We show that for a velocity range spanning over three decades, the frictional forces measured for ring-polymer brushes are half the corresponding friction in case of linear brushes. In the linear-force regime, the weak inter-digitation of two ring brushes compared to linear brushes also leads to a lower number of binary collisions between the monomers of opposing brushes. At high velocities, where the thickness of the inter-digitation layer between two opposing brushes is on the order monomer size regardless of brush topology, stretched segments of ring polymers take a double-stranded conformation. As a result, monomers of the double-stranded segments collide less with the monomers of the opposing ring brush even though a similar number of monomers occupies the inter-digitation layer for ring and linear-brush bilayers. The numerical data obtained from our simulations is consistent with the proposed scaling analysis. Conformation-dependent frictional reduction observed in ring brushes can have important consequences in non-equilibrium bulk systems.

A. Erbas; J. Paturej

2015-01-07T23:59:59.000Z

79

Additive manufacturing with friction welding and friction deposition processes  

Science Journals Connector (OSTI)

Most of the commercially available additive manufacturing processes that are meant for fabrication of fully dense metallic parts involve melting and solidification. Consequently, these processes suffer from a variety of metallurgical problems. Processes that can facilitate material addition in solid-state are therefore ideally suited for additive manufacturing. In this work, we explore two new solid-state processes, viz. friction welding and friction deposition, for additive manufacturing. Stainless steel samples produced using these processes showed excellent layer bonding and Z-direction tensile properties. The authors believe that these processes are uniquely capable and can offer significant benefits over existing commercial additive manufacturing processes.

J.J.S. Dilip; G.D. Janaki Ram; B.E. Stucker

2012-01-01T23:59:59.000Z

80

Microstructural issues in a friction-stir-welded aluminum alloy  

SciTech Connect

Recent observations of microstructures associated with friction-stir welding (FSW) in a number of aluminum alloys have consistently demonstrated the actual weld zone to consist of a (dynamically) recrystallized grain structure resulting from the extreme, solid-state, plastic deformation characterizing the process. Because of solubilities associated with the various precipitates in 7075 and 6061 aluminum alloys, and the fact that the precipitates were either homogeneously distributed throughout both the original (unwelded) work-piece plates and the well zones (or formed varying densities of Widmanstaetten patterns within the original and recrystallized grains), it has been difficult to follow the stirring of stable, second-phase particles from the base metal (work-piece) into the weld zone. In the present investigation, a compositionally modified 1100 aluminum alloy (nominally 99.2% Al, 0.5% Fe, 0.15% Cu, 0.12% Si, 0.05 Mn, 0.04 Ti, balance in weight percent of Be and Mg), forming a stable microdendritic (second-phase), equiaxed, cell structure was friction-stir welded. These thermally stable, geometrically specific, precipitates in the base metal were compared with their disposition within the friction-stir-weld zone. In addition, as-cast plates of this alloy were cold-rolled 50% and friction-stir-welded in order to compare these two schedules (as-cast and 50% cold-rolled) in terms of residual hardness variations and related microstructural issues as well as the effect of prior deformation on the friction-stir welding process.

Flores, O.V.; Kennedy, C.; Murr, L.E.; Brown, D.; Pappu, S.; Nowak, B.M.; McClure, J.C. [Univ. of Texas, El Paso, TX (United States)] [Univ. of Texas, El Paso, TX (United States)

1998-02-03T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

A comparison of RETRAN-02 and TRAC-PF1 simulations of a loss of off-site power cooldown to residual heat removal entry conditions at Calvert Cliffs Nuclear Power Plant  

SciTech Connect

As a part of the U.S. Nuclear Regulatory Commission's unresolved safety issue A-45 decay heat removal program, the Los Alamos National Laboratory (LANL) performed a TRAC-PF1 simulation of the Calvert Cliffs Unit 1 pressurized water reactor in a cooldown to residual heat removal (RHR) entry conditions after a loss of off-site power (LOSP). A detailed four-loop TRAC model developed for the A-49 pressurized thermal shock program was used. The LANL results indicated an inability to both cool down and depressurize the primary system sufficiently to meet RHR entry conditions using only the atmospheric dump valves and auxiliary pressurizer spray. A RETRAN-02/MOD3 analysis was performed for the same transient, using assumptions consistent with those in the LANL analysis. A fast-running one loop RETRAN model was selected because of the inherent symmetry of the transient. The RETRAN results compared well with sensitivity analyses indicating that the pressurizer model dominates the transient signatures. A best estimate RETRAN analysis of the cooldown was performed using a more accurate set of assumptions to better understand actual plant operational responses. These results indicate that RHR entry could be achieved after an LOSP using only existing plant equipment and procedures.

Cook, T.L.; Mirsky, S.M.

1987-01-01T23:59:59.000Z

82

Heat Transfer at Low Temperatures between Tube Walls and Gases in Turbulent Flow  

Science Journals Connector (OSTI)

...September 1947 research-article Heat Transfer at Low Temperatures between Tube...counter-flow system to study heat transfer between tube walls and gases at...Determinations on friction accompanying heat transfer with gases in turbulent flow at...

1947-01-01T23:59:59.000Z

83

Heat transfer in the flow of a viscoelastic fluid over a stretching sheet  

Science Journals Connector (OSTI)

The problem of heat transfer in the viscoelastic fluid flow over a stretching sheet is examined. ... such as the skin-friction coefficient and the heat transfer coefficient, are determined. It is found that the heat

P. Sam Lawrence; Dr. B. Nageswara Rao

1992-01-01T23:59:59.000Z

84

Predicting residual stresses in gas turbine components  

Science Journals Connector (OSTI)

This article describes work carried out by a major aircraft-engine builder and one of its suppliers to validate the numerical prediction of heat-treatment-induced residual stresses. For verification, the proje...

R. A. Wallis Ph.D.; I. W. Craighead B.Sc. Eng.

1995-10-01T23:59:59.000Z

85

The Power of Friction: Quantifying the ``Goodness'' of Frictional Grasps \\Lambda  

E-Print Network (OSTI)

The Power of Friction: Quantifying the ``Goodness'' of Frictional Grasps \\Lambda Marek Teichmann of fingers, coefficient of friction and the the goodness of a grasp. In particular, we give a general framework for defining a grasp metric that takes friction into account. Our approach rectifies a flaw

Mishra, Bud

86

Pulling by Pushing, Slip with Infinite Friction,  

E-Print Network (OSTI)

Pulling by Pushing, Slip with Infinite Friction, and Perfectly Rough Surfaces Kevin M. Lynch the two objects even with an infinite coefficient of friction. Thus the common conception that infinite friction prevents slip is in error. This paper shows examples of the phenomena with both quasi

87

Automotive friction-induced noises A. Elmaiana  

E-Print Network (OSTI)

Automotive friction-induced noises A. Elmaiana , J.-M. Duffala , F. Gautiera , C. Pezeratb and J, France 3143 #12;Friction-induced noises are numerous in the automotive field. They also involve a large friction-induced noises with simple structures and automotive materials. Qualitative sensitivity studies

Paris-Sud XI, Université de

88

Friction in full view A. P. Merklea  

E-Print Network (OSTI)

Friction in full view A. P. Merklea and L. D. Marksb Materials Science and Engineering proposed friction mechanisms explaining the unique tribological properties of graphite. Wear of graphite chemical or struc- tural information from the interface during a friction experi- ment. Examples

Marks, Laurence D.

89

The friction of wrinkles Hamid Mohammadi1  

E-Print Network (OSTI)

The friction of wrinkles Hamid Mohammadi1 and Martin H. M¨user2 1 Dept. of Applied Mathematics pattern has asymmetries not present in the counterbody. The instabilities then cause Coulomb's friction Likewise, the presence of friction - as observed for the much investigated keratocytes on silicon rubber15

Mueser, Martin

90

Dynamical friction on satellite galaxies  

E-Print Network (OSTI)

For a rigid model satellite, Chandrasekhar's dynamical friction formula describes the orbital evolution quite accurately, when the Coulomb logarithm is chosen appropriately. However, it is not known if the orbital evolution of a real satellite with the internal degree of freedom can be described by the dynamical friction formula. We performed N-body simulation of the orbital evolution of a self-consistent satellite galaxy within a self-consistent parent galaxy. We found that the orbital decay of the simulated satellite is significantly faster than the estimate from the dynamical friction formula. The main cause of this discrepancy is that the stars stripped out of the satellite are still close to the satellite, and increase the drag force on the satellite through two mechanisms. One is the direct drag force from particles in the trailing tidal arm, a non-axisymmetric force that slows the satellite down. The other is the indirect effect that is caused by the particles remaining close to the satellite after escape. The force from them enhances the wake caused in the parent galaxy by dynamical friction, and this larger wake in turn slows the satellite down more than expected from the contribution of its bound mass. We found these two have comparable effects, and the combined effect can be as large as 20% of the total drag force on the satellite.

Michiko Fujii; Yoko Funato; Junichiro Makino

2005-11-22T23:59:59.000Z

91

Friction forces in cosmological models  

E-Print Network (OSTI)

We investigate the dynamics of test particles undergoing friction forces in a Friedmann-Robertson-Walker (FRW) spacetime. The interaction with the background fluid is modeled by introducing a Poynting-Robertson-like friction force in the equations of motion, leading to measurable (at least in principle) deviations of the particle trajectories from geodesic motion. The effect on the peculiar velocities of the particles is investigated for various equations of state of the background fluid and different standard cosmological models. The friction force is found to have major effects on particle motion in closed FRW universes, where it turns the time-asymptotic value (approaching the recollapse) of the peculiar particle velocity from ultra-relativistic (close to light speed) to a co-moving one, i.e., zero peculiar speed. On the other hand, for open or flat universes the effect of the friction is not so significant, because the time-asymptotic peculiar particle speed is largely non-relativistic also in the geodesi...

Bini, Donato; Gregoris, Daniele; Succi, Sauro

2014-01-01T23:59:59.000Z

92

Friction forces in cosmological models  

E-Print Network (OSTI)

We investigate the dynamics of test particles undergoing friction forces in a Friedmann-Robertson-Walker (FRW) spacetime. The interaction with the background fluid is modeled by introducing a Poynting-Robertson-like friction force in the equations of motion, leading to measurable (at least in principle) deviations of the particle trajectories from geodesic motion. The effect on the peculiar velocities of the particles is investigated for various equations of state of the background fluid and different standard cosmological models. The friction force is found to have major effects on particle motion in closed FRW universes, where it turns the time-asymptotic value (approaching the recollapse) of the peculiar particle velocity from ultra-relativistic (close to light speed) to a co-moving one, i.e., zero peculiar speed. On the other hand, for open or flat universes the effect of the friction is not so significant, because the time-asymptotic peculiar particle speed is largely non-relativistic also in the geodesic case.

Donato Bini; Andrea Geralico; Daniele Gregoris; Sauro Succi

2014-08-23T23:59:59.000Z

93

Steam turbine: Alternative emergency drive for the secure removal of residual heat from the core of light water reactors in ultimate emergency situation  

SciTech Connect

In 2011 the nuclear power generation has suffered an extreme probation. That could be the meaning of what happened in Fukushima Nuclear Power Plants. In those plants, an earthquake of 8.9 on the Richter scale was recorded. The quake intensity was above the trip point of shutting down the plants. Since heat still continued to be generated, the procedure to cooling the reactor was started. One hour after the earthquake, a tsunami rocked the Fukushima shore, degrading all cooling system of plants. Since the earthquake time, the plant had lost external electricity, impacting the pumping working, drive by electric engine. When operable, the BWR plants responded the management of steam. However, the lack of electricity had degraded the plant maneuvers. In this paper we have presented a scheme to use the steam as an alternative drive to maintain operable the cooling system of nuclear power plant. This scheme adds more reliability and robustness to the cooling systems. Additionally, we purposed a solution to the cooling in case of lacking water for the condenser system. In our approach, steam driven turbines substitute electric engines in the ultimate emergency cooling system. (authors)

Souza Dos Santos, R. [Instituto de Engenharia Nuclear CNEN/IEN, Cidade Universitaria, Rua Helio de Almeida, 75 - Ilha do Fundiao, 21945-970 Rio de Janeiro (Brazil); Instituto Nacional de Ciencia e Tecnologia de Reatores Nucleares Inovadores / CNPq (Brazil)

2012-07-01T23:59:59.000Z

94

Friction domination with superconducting strings  

Science Journals Connector (OSTI)

We investigate the evolution of a superconducting string network with arbitrary, constant string current in the friction dominated regime. In the absence of an external magnetic field the network always reaches a scaling solution. However, for string current stronger than a critical value, it is different than the usual horizon scaling of the nonsuperconducting string case. In this case the friction domination era never ends. Whilst the superconducting string network can be much denser than usually assumed, it can never dominate the universe energy density. It can, however, influence the cosmic microwave background radiation and the formation of large scale structure. When embedded in a primordial magnetic field of sufficient strength, the network never reaches scaling and, thus, eventually dominates the universe evolution.

Konstantinos Dimopoulos and Anne-Christine Davis

1998-01-15T23:59:59.000Z

95

Rubber friction on smooth surfaces  

E-Print Network (OSTI)

We study the sliding friction for viscoelastic solids, e.g., rubber, on hard flat substrate surfaces. We consider first the fluctuating shear stress inside a viscoelastic solid which results from the thermal motion of the atoms or molecules in the solid. At the nanoscale the thermal fluctuations are very strong and give rise to stress fluctuations in the MPa-range, which is similar to the depinning stresses which typically occur at solid-rubber interfaces, indicating the crucial importance of thermal fluctuations for rubber friction on smooth surfaces. We develop a detailed model which takes into account the influence of thermal fluctuations on the depinning of small contact patches (stress domains) at the rubber-substrate interface. The theory predicts that the velocity dependence of the macroscopic shear stress has a bell-shaped f orm, and that the low-velocity side exhibits the same temperature dependence as the bulk viscoelastic modulus, in qualitative agreement with experimental data. Finally, we discuss the influence of small-amplitude substrate roughness on rubber sliding friction.

B. N. J. Persson; A. I. Volokitin

2006-07-04T23:59:59.000Z

96

Residual stress patterns in steel welds  

SciTech Connect

Neutron strain scanning of residual stress is a valuable nondestructive tool for evaluation of residual stress in welds. The penetrating characteristic of neutrons permits mapping of strain patterns with a spatial resolution approaching 1mm at depths of 20mm in steels. While the overall patterns of the residual stress tensor in a weld are understood, the detailed patterns depend on welding process parameters and the effects of solid state transformation. The residual strain profiles in two multi-pass austenitic welds and a ferritic steel weld are presented. The stress-free lattice parameters within the fusion zone and the adjacent heat affected zone in the two austenitic welds show that the interpretation of residual stress from strains are affected by welding parameters. An interpretation of the residual strain pattern in the ferritic steel plate can be made using the strain measurements of a Gleeble test bar which has undergone the solid state austenite decomposition.

Spooner, S.; Hubbard, C.R.; Wang, X.L.; David, S.A.; Holden, T.M. [Oak Ridge National Lab., TN (United States); Root, J.H.; Swainson, I. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

1994-12-31T23:59:59.000Z

97

Rubber friction on (apparently) smooth lubricated surfaces  

E-Print Network (OSTI)

We study rubber sliding friction on hard lubricated surfaces. We show that even if the hard surface appears smooth to the naked eye, it may exhibit short wavelength roughness, which may give the dominant contribution to rubber friction. That is, the observed sliding friction is mainly due to the viscoelastic deformations of the rubber by the substrate surface asperities. The presented results are of great importance for rubber sealing and other rubber applications involving (apparently) smooth surfaces.

M. Mofidi; B. Prakash; B. N. J. Persson; O. Albohl

2007-10-18T23:59:59.000Z

98

Friction as Basis for a Phonon Maser  

E-Print Network (OSTI)

Evidence is provided from experiment, for the hypothesis that defect organization (internal friction) is a means for operation of a phonon maser.

Randall D. Peters

2003-08-08T23:59:59.000Z

99

Frictionally damped SDOF oscillator: experimental realization and friction modeling for small displacements  

Science Journals Connector (OSTI)

The damping of structural vibrations using dry friction is an effective control method for many vibration problems. The strong nonlinear nature of friction has however made the theoretical and experimental investigations much more difficult than for ... Keywords: dry friction damping, modelling, simulation

M. Couillard; P. Micheau; P. Masson

2007-05-01T23:59:59.000Z

100

Brief Friction induced hunting limit cycles: A comparison between the LuGre and switch friction model  

Science Journals Connector (OSTI)

In this paper, friction induced limit cycles are predicted for a simple motion system consisting of a motor-driven inertia subjected to friction and a PID-controlled regulator task. The two friction models used, i.e., (i) the dynamic LuGre friction model ... Keywords: Friction, Limit cycles, PID control, Stability analysis

R. H. A. Hensen; M. J. G. Van De Molengraft; M. Steinbuch

2003-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Abstract--Friction modeling is essential for joint dynamic identification and control. Joint friction is composed of a  

E-Print Network (OSTI)

Abstract--Friction modeling is essential for joint dynamic identification and control. Joint friction is composed of a viscous and a dry friction force. According to Coulomb law, dry friction depends linearly on the load in the transmission. However, in robotics field, a constant dry friction is frequently

Paris-Sud XI, Université de

102

Some Hamiltonian Models of Friction  

E-Print Network (OSTI)

Mathematical results on some models describing the motion of a tracer particle through a Bose-Einstein condensate are described. In the limit of a very dense, very weakly interacting Bose gas and for a very large particle mass, the dynamics of the coupled system is determined by classical non-linear Hamiltonian equations of motion. The particle's motion exhibits deceleration corresponding to friction (with memory) caused by the emission of Cerenkov radiation of gapless modes into the gas. Precise results are stated and outlines of proofs are presented. Some technical details are deferred to forthcoming papers.

Juerg Froehlich; Zhou Gang; Avy Soffer

2010-11-04T23:59:59.000Z

103

Non-equilibrium Statistical Approach to Friction Models  

E-Print Network (OSTI)

A geometric approach to the friction phenomena is presented. It is based on the holographic view which has recently been popular in the theoretical physics community. We see the system in one-dimension-higher space. The heat-producing phenomena are most widely treated by using the non-equilibrium statistical physics. We take 2 models of the earthquake. The dissipative systems are here formulated from the geometric standpoint. The statistical fluctuation is taken into account by using the (generalized) Feynman's path-integral.

Shoichi Ichinose

2014-04-26T23:59:59.000Z

104

Stress Wave Source Characterization: Impact, Fracture, and Sliding Friction  

E-Print Network (OSTI)

tremor like signals in friction experiments, Geophys. Res.analysis of the state- and rate-dependent friction law:Static friction, Physical Rev. B 59, 14313-14327. Bisschop,

McLaskey, Gregory Christofer

2011-01-01T23:59:59.000Z

105

Evaluation of microstructure and mechanical properties in friction stir processed SKD61 tool steel  

SciTech Connect

A SKD61 tool steel was friction stir processed using a polycrystalline cubic boron nitride tool. Microstructure, tensile properties and wear characteristic were evaluated. Fine grains with a martensite structure were produced in the friction stir processed zone, which led to the increase of the microindentation hardness. The grains became finer when the heat input was lowered. The transverse tensile strength of the friction stir processed zone was equal to that of base metal and all the tensile specimens fractured at base metal zone. The wear width and depth of the friction stir processed zone at the load of 1.96 N were 339 {mu}m and 6 {mu}m, as compared to 888 {mu}m and 42 {mu}m of the base metal, decreased by 62% and 86%. Findings of the present study suggest that low heat input is an effective method to produce a friction stir processed zone composed of relatively fine grain martensitic structure with good tensile properties and wear characteristic.

Chen, Y.C., E-mail: armstrong@hit.edu.cn [Joining and Welding Research Institute, Osaka University, Osaka 567-0047 (Japan); Nakata, K. [Joining and Welding Research Institute, Osaka University, Osaka 567-0047 (Japan)

2009-12-15T23:59:59.000Z

106

EVALUATION OF A LOW FRICTION - HIGH EFFICIENCY ROLLER BEARING ENGINE  

SciTech Connect

This Low Friction (High Efficiency Roller Bearing) Engine (LFE) report presents the work done by The Timken Company to conduct a technology demonstration of the benefits of replacing hydrodynamic bearings with roller bearings in the crankshaft and camshaft assemblies of an internal combustion engine for the purpose of collecting data sufficient to prove merit. The engines in the present study have been more extensively converted to roller bearings than any previous studies (40 needle roller bearings per engine) to gain understanding of the full potential of application of bearing technology. The project plan called for comparative testing of a production vehicle which was already respected for having demonstrated low engine friction levels with a rollerized version of that engine. Testing was to include industry standard tests for friction, emissions and fuel efficiency conducted on instrumented dynamometers. Additional tests for fuel efficiency, cold start resistance and other measures of performance were to be made in the actual vehicle. Comparative measurements of noise, vibration and harshness (NVH), were planned, although any work to mitigate the suspected higher NVH level in the rollerized engine was beyond the scope of this project. Timken selected the Toyota Avalon with a 3.5L V-6 engine as the test vehicle. In an attempt to minimize cost and fabrication time, a ‘made-from’ approach was proposed in which as many parts as possible would be used or modified from production parts to create the rollerized engine. Timken commissioned its test partner, FEV Engine Technology, to do a feasibility study in which they confirmed that using such an approach was possible to meet the required dimensional restrictions and tolerances. In designing the roller bearing systems for the crank and cam trains, Timken utilized as many production engine parts as possible. The crankshafts were produced from production line forgings, which use Timken steel, modified with special machining and heat treatment. Timken designed and manufactured all of the roller bearing related components such as the thrust bearing package. The production connecting rods and camshafts could not be used for the roller bearing engine, so new ones were produced according to the team’s designs using Timken steel. The remaining miscellaneous components were designed and procured by FEV. Timken prepared a display version of the crankshaft portion of the production engine without connecting rods which could be driven by a motor through a cogged-belt and electrically actuated clutch arrangement. A modified version was also made in which the engine was outfitted with roller bearings on the main bearing positions. Preliminary tests showed that the rollerized engine was running with 1/3 less friction than the standard display engine. Additional friction testing and noise characterization was cut short because of shipping damage to the rollerized engine display and because of other project priorities. The team did successfully demonstrate the ability to package roller bearings satisfactorily in numerous locations in a typical automotive engine. The scope of this project did not include durability demonstration and that subject would have to be addressed in any follow-on work. In the actual test phase, the rollerized engine did show significantly less friction in motored dynamometer tests compared to its production equivalent. The 5-10% improvement measured in this study was about half that seen in other studies. However, the fired test results did not show a reduction in friction which did not match prior experience or expectations. Subsequent teardown and inspection of the rollerized engine revealed potential sources of excessive friction in the experimental application. These features would be eliminated in a design not based on modification of production parts. The team is confident (based on experience) that friction reduction would be realized with proper modifications.

Kolarik, Robert V. II; Shattuck, Charles W.; Copper, Anthony P.

2009-06-30T23:59:59.000Z

107

Dissimilar friction welding of titanium alloys to alloy 718  

SciTech Connect

The design of advanced, high-performance gas-turbine engines will require the utilization of elevated-temperature titanium-based materials, including conventional alloys, titanium aluminides, and titanium metal-matrix composites. The most efficient utilization of these materials in the engine compressor section would be achieved by directly joining these materials to existing nickel-base superalloys, such as Alloy 718. To date, the dissimilar welding of titanium alloys to nickel-based alloys has not been common practice because intermetallic compounds form in the weld and cause embrittlement. Special welding techniques must be developed to inhibit this compound formation and to provide high strength welds. In this investigation, a friction welding process was developed for joining titanium alloys (Ti-6Al-2Sn-4Zr-2Mo and Ti-6Al-4V) to nickel-based superalloy Alloy 718. An interlayer system comprised of copper and niobium sheet layers was employed as a diffusion barrier and weld deformation enhancer. A postweld heat treatment (PWHT, 700{degrees}C for 20 min in vacuum) under axial pressure (Ksi) was used to improve the joint strength consistency. The following conclusions can be drawn from this investigation: (1) A friction welding technique has been developed for joining titanium alloys (Ti-6Al-2Sn-4Zr-2Mo and Ti-6Al-4V) to Alloy 718 using an interlayer system of niobium and copper. Joint strengths averaging approximately 50 Ksi were achieved. (2) Deformation was concentrated in the interlayers, especially the copper interlayer, during friction welding. Increased reduction in length (RIL) during friction welding resulted in a decrease in the interlayer thicknesses. (3) The EDS results showed that the niobium and copper interlayers prevent interdiffusion between the two parent metals, producing formation of detrimental phases.

Kuo, M.; Albright, C.E.; Baeslack, W.A. III

1994-12-31T23:59:59.000Z

108

Friction Coefficient for Quarks in Supergravity Duals  

E-Print Network (OSTI)

We study quarks moving in strongly-coupled plasmas that have supergravity duals. We compute the friction coefficient of strings dual to such quarks for general static supergravity backgrounds near the horizon. Our results also show that a previous conjecture on the bound has to be modified and higher friction coefficients can be achieved.

E. Antonyan

2006-11-22T23:59:59.000Z

109

Efficiency Improvement through Reduction in Friction and Wear...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Efficiency Improvement through Reduction in Friction and Wear in Powertrain Systems Efficiency Improvement through Reduction in Friction and Wear in Powertrain Systems Presentation...

110

Friction forces on phase transition fronts  

SciTech Connect

In cosmological first-order phase transitions, the microscopic interaction of the phase transition fronts with non-equilibrium plasma particles manifests itself macroscopically as friction forces. In general, it is a nontrivial problem to compute these forces, and only two limits have been studied, namely, that of very slow walls and, more recently, ultra-relativistic walls which run away. In this paper we consider ultra-relativistic velocities and show that stationary solutions still exist when the parameters allow the existence of runaway walls. Hence, we discuss the necessary and sufficient conditions for the fronts to actually run away. We also propose a phenomenological model for the friction, which interpolates between the non-relativistic and ultra-relativistic values. Thus, the friction depends on two friction coefficients which can be calculated for specific models. We then study the velocity of phase transition fronts as a function of the friction parameters, the thermodynamic parameters, and the amount of supercooling.

Mégevand, Ariel, E-mail: megevand@mdp.edu.ar [IFIMAR (CONICET–UNMdP), Departamento de Física, Facultad de Ciencias Exactas y Naturales, UNMdP, Deán Funes 3350, (7600) Mar del Plata (Argentina)

2013-07-01T23:59:59.000Z

111

Dynamical Friction on extended perturbers  

E-Print Network (OSTI)

Following a wave-mechanical treatment we calculate the drag force exerted by an infinite homogeneous background of stars on a perturber as this makes its way through the system. We recover Chandrasekhar's classical dynamical friction (DF) law with a modified Coulomb logarithm. We take into account a range of models that encompasses all plausible density distributions for satellite galaxies by considering the DF exerted on a Plummer sphere and a perturber having a Hernquist profile. It is shown that the shape of the perturber affects only the exact form of the Coulomb logarithm. The latter converges on small scales, because encounters of the test and field stars with impact parameters less than the size of the massive perturber become inefficient. We confirm this way earlier results based on the impulse approximation of small angle scatterings.

O. Esquivel; B. Fuchs

2008-04-01T23:59:59.000Z

112

Cryostat including heater to heat a target  

DOE Patents (OSTI)

A cryostat is provided which comprises a vacuum vessel; a target disposed within the vacuum vessel; a heat sink disposed within the vacuum vessel for absorbing heat from the detector; a cooling mechanism for cooling the heat sink; a cryoabsorption mechanism for cryoabsorbing residual gas within the vacuum vessel; and a heater for maintaining the target above a temperature at which the residual gas is cryoabsorbed in the course of cryoabsorption of the residual gas by the cryoabsorption mechanism. 2 figs.

Pehl, R.H.; Madden, N.W.; Malone, D.F.

1990-09-11T23:59:59.000Z

113

Residual stresses in annealed zircaloy  

SciTech Connect

Neutron diffraction has been used to measure the lattice constants of single crystal and rod-textured polycrystalline Zircaloy-2 in the temperature range 300-900 K. While the single crystal remains strain-free during heating or cooling, large residual grain-interaction strains occur in the polycrystalline sample as the result of compatibility being maintained among grains with anisotropic thermal expansion coefficients. These residual thermal strains have been determined as a function of temperature from the difference between the single and polycrystal lattice constants. Analysis of the data has been done using a polycrystalline deformation model, QUEST, which accounts for anisotropic elasticity, plasticity and thermal expansion, and for crystallographic texture of the sample. It is found that slow cooling from 900 K introduces residual stresses of the order of 100 MPa in the polycrystalline sample. The calculations demonstrate that these residual stresses can explain not only the difference in the proportional limits in tension and compression (strength differential) but also differences in the initial work hardening behaviour when Zircaloy-2 is deformed in tension or compression.

Tome, C.; Faber, J.; MacEwen, S.R.

1989-03-01T23:59:59.000Z

114

Friction Problems in Servomechanisms: Modeling and Compensation Techniques  

E-Print Network (OSTI)

Friction Problems in Servomechanisms: Modeling and Compensation Techniques Jan Tommy Gravdahl of this presentation Introduction Friction models 1. Static models 2. Models with time delay 3. Dynamic models Friction compensation 1. Non-model based compensation 2. Compensation based on static friction models 3

Gravdahl, Jan Tommy

115

Adsorption and friction in the UHV tribometer  

Science Journals Connector (OSTI)

Some aspects of the effect of adsorption on friction have beenexperimentally investigated by using a multi-technique AES/XPSUHV tribotester. Actually, testing in-vacuo gives the opportunityto clean, to create ...

J.M. Martin; Th. Le Mogne; C. Grossiord; Th. Palermo

1997-01-01T23:59:59.000Z

116

Frictional forces in helical buckling of tubing  

SciTech Connect

Previous analyses of helical buckling of tubing have not considered frictional forces. This paper describes the modifications to helical buckling theory necessary to include friction. The first need is a relationship between the buckling force and the casing to tubing contact force. This contact force is determined through use of the principle of virtual work. The next need is the relationship between the friction forces, the buckling force, and the geometry of the tubing helix. Differential equations are derived and solved for two cases of interest: buckling during the landing of the tubing and thermal and differential pressure loading subsequent to landing. Several example problems are examined to evaluate the relative importance of friction.

Mitchell, R.F.

1984-09-01T23:59:59.000Z

117

Postulated Mesoscale Quantum of Internal Friction Hysteresis  

E-Print Network (OSTI)

Evidence is provided, from yet another experiment, for the existence of a mesoscale quantum of internal friction hysteresis, having the value of the electron rest energy divided by the fine structure constant.

Randall D. Peters

2004-05-27T23:59:59.000Z

118

Compton-Energy Scale of Friction Quantization  

E-Print Network (OSTI)

Numerous different experiments by the author, approaching nearly two decades of study, point strongly toward the possibility that friction operates around a mesoscale quantum of energy having the value 11 pJ.

Randall D. Peters

2006-07-03T23:59:59.000Z

119

A critique of some modern applications of the Carnot heat engine concept: the dissipative heat engine cannot exist  

Science Journals Connector (OSTI)

...Calvo Hernandez2008Coupled heat devices in linear irreversible...output: new results for old heat enginesAm. J. Phys. 55 602610...and V. G. Gorshkov2007Biotic pump of atmospheric moisture as driver...Carnot engines with friction and heat lossesAm. J. Phys. 70 11431149...

2010-01-01T23:59:59.000Z

120

Enhancing Thermal Conductivity and Reducing Friction  

NLE Websites -- All DOE Office Websites (Extended Search)

Laboratory currently has several projects underway to develop advanced fluids, films, coatings, and Laboratory currently has several projects underway to develop advanced fluids, films, coatings, and processes to improve thermal conductivity and reduce friction. These measures are helping to increase energy efficiency for next-generation transportation applications. Superhard and Slick Coating (SSC) Opportunity: Friction, wear, and lubrication strongly affect the energy efficiency, durability, and environmental compatibility of

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Friction of Materials for Automotive Applications  

SciTech Connect

This brief overview of friction-related issues in materials for automobiles is invited for a special issue on automotive materials in the ASM journal AM&P. It describes a range of areas in a ground vehicle in which friction must be controlled or minimized. Applications range from piston rings to tires, and from brakes to fuel injector components. A perspective on new materials and lubricants, and the need for validation testing is presented.

Blau, Peter Julian [ORNL

2013-01-01T23:59:59.000Z

122

REDUCED ENGINE FRICTION AND WEAR  

SciTech Connect

Progress was made on experimental and numerical subtasks during the second 6-month period of this project. One of the experimental subtasks scheduled for completion during the first 6 months was delayed due to a delay in receiving the prototype RLE face seal from the vendor. This component was acquired and testing was completed during the second 6 months. The test results indicate that this face seal fulfills the engineering objectives. The other experimental subtask scheduled for completion during the second 6-month period was final assembly of the prototype rotating liner engine. This subtask was completed on schedule. No results from this subtask were scheduled for this reporting period. One numerical subtask, development of the governing equations, was scheduled for completion during the first 6-month period but was completed during the second 6 months. However, we expect to re-explore these as we learn more throughout the course of the project. Two other numerical subtasks were scheduled to begin during the second 6 months: formulating the numerical equations governing piston assembly friction and coding/testing the resulting model. These subtasks were not scheduled for completion during this reporting period. Satisfactory progress was made.

Ron Matthews

2003-07-08T23:59:59.000Z

123

First university owned district heating system using biomass heat  

E-Print Network (OSTI)

Components 4.3 m diameter gasifier 4.4 MW flue gas boiler 60 t hog fuel storage Electrostatic precipitator Residue Gasifier Oxidizer Flue Gas Boiler Electrostatic Precipitator Heat to campus district energy loop

Northern British Columbia, University of

124

Casimir Friction I: Friction of a vacuum on a spinning dielectric  

E-Print Network (OSTI)

We introduce the concept of Casimir friction, i.e. friction due to quantum fluctuations. In this first article we describe the calculation of a constant torque, arising from the scattering of quantum fluctuations, on a dielectric rotating in an electromagnetic vacuum.

Yves Pomeau; David C. Roberts

2007-04-17T23:59:59.000Z

125

Status of Stellite 6 friction testing  

SciTech Connect

For the past several years, researchers at the Idaho National Engineering and Environmental Laboratory, under the sponsorship of the US Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, have been investigating the performance of motor-operated valves subjected to design basis flow and pressure loads. Part of this research addresses the friction that occurs at the interface between the valve disc and the valve body seats during operation of a gate valve. In most gate valves, these surfaces are hardfaced with Stellite 6, a cobalt-based alloy. Analytical methods exist for predicting the thrust needed to operate these valves at specific pressure conditions. To produce accurate valve thrust predictions, the analyst must have a reasonably accurate, though conservative, estimate of the coefficient of friction at the disc-to-seat interface. One of the questions that remains to be answered is whether, and to what extent, aging of the disc and seat surfaces effects the disc-to-seat coefficient of friction. Specifically, does the environment in a nuclear plants piping system cause the accumulation of an oxide film on these surfaces that increases the coefficient of friction; and if so, how great is the increase? This paper presents results of specimen tests addressing this issue, with emphasis on the following: (1) the characteristics and thickness of the oxide film that develops on Stellite 6 as it ages; (2) the change in the friction coefficient of Stellite 6 as it ages, including the question of whether the friction coefficient eventually reaches a plateau; and (3) the effect in-service cycling has on the characteristics and thickness of the oxide film and on the friction coefficient.

Watkins, J.C.; DeWall, K.G. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.; Weidenhamer, G.H. [Nuclear Regulatory Commission (United States)

1998-06-01T23:59:59.000Z

126

Casimir Friction Force Between Polarizable Media  

E-Print Network (OSTI)

This work is a continuation of our recent series of papers on Casimir friction, for a pair of particles of low relative particle velocity. Each particle is modeled as a simple harmonic oscillator. Our basic method, as before, is the use of quantum mechanical statistical mechanics, involving the Kubo formula, at finite temperature. In this work we begin by analyzing the Casimir friction between two particles polarizable in all spatial directions, this being a generalization of our study in EPL 91, 60003 (2010), which was restricted to a pair of particles with longitudinal polarization only. For simplicity the particles are taken to interact via the electrostatic dipole-dipole interaction. Thereafter, we consider the Casimir friction between one particle and a dielectric half-space, and also the friction between two dielectric half-spaces. Finally, we consider general polarizabilities (beyond the simple one-oscillator form), and show how friction occurs at finite temperature when finite frequency regions of the imaginary parts of polarizabilities overlap.

Johan S. Høye; Iver Brevik

2012-01-18T23:59:59.000Z

127

Method and device for frictional welding  

DOE Patents (OSTI)

A method for friction welding that produces a seal having essentially no gas porosity, comprises two rotationally symmetric, generally cylindrical members, spaced apart and coaxially aligned, that are rotated with respect to each other and brought together under high pressure. One member is preferably a generally cylindrical cannister that stores uranium within its hollow walls. The other member is preferably a generally cylindrical, hollow weld ring. An annular channel formed in the weld ring functions as an internal flash trap and is uniquely designed so that substantially all of the welding flash generated from the friction welding is directed into the channel`s recessed bottom. Also, the channel design limits distortion of the two members during the friction welding, process, further contributing to the complete seal that is obtained.

Peacock, H.B.

1991-01-01T23:59:59.000Z

128

Macroscopic approach to the Casimir friction force  

E-Print Network (OSTI)

The general formula is derived for the vacuum friction force between two parallel perfectly flat planes bounding two material media separated by a vacuum gap and moving relative to each other with a constant velocity $\\mathbf{v}$. The material media are described in the framework of macroscopic electrodynamics whereas the nonzero temperature and dissipation are taken into account by making use of the Kubo formulae from non-equilibrium statistical thermodynamics. The formula obtained provides a rigorous basis for calculation of the vacuum friction force within the quantum field theory methods in the condensed matter physics. The revealed $v$-dependence of the vacuum friction force proves to be the following: for zero temperature ($T=0$) it is proportional to $(v/c)^3$ and for $T>0$ this force is linear in $(v/c)$.

V. V. Nesterenko; A. V. Nesterenko

2014-03-13T23:59:59.000Z

129

Casimir friction at zero and finite temperatures  

E-Print Network (OSTI)

The Casimir friction problem for dielectric plates that move parallel to each other is treated by assuming one of the plates to be at rest. The other performs a closed loop motion in the longitudinal direction. Therewith by use of energy dissipation the formalism becomes more manageable and transparent than in the conventional setting where uniform sliding motion is assumed from $t=-\\infty$ to $t=+\\infty$. One avoids separating off a reversible interparticle force (independent of friction) from the total force. Moreover, the cases of temperatures $T=0$ and finite $T$ are treated on the same footing. For metal plates we find the friction force to be proportional to $v^3$ at $T=0$ while at finite $T$ it is proportional to $v$ for small $v$ as found earlier. Comparisons with earlier results of Pendry (1997, 2010) and Barton (2011) are made.

Johan S. Høye; Iver Brevik

2014-03-26T23:59:59.000Z

130

Friction and dilatancy in immersed granular matter  

E-Print Network (OSTI)

The friction of a sliding plate on a thin immersed granular layer obeys Amonton-Coulomb law. We bring to the fore a large set of experimental results which indicate that, over a few decades of values, the effective dynamical friction-coefficient depends neither on the viscosity of the interstitial fluid nor on the size of beads in the sheared layer, which bears out the analogy with the solid-solid friction in a wide range of experimental parameters. We accurately determine the granular-layer dilatancy, which dependance on the grain size and slider velocity can be qualitatively accounted by considering the rheological behaviour of the whole slurry. However, additional results, obtained after modification of the grain surface by a chemical treatment, demonstrate that the theoretical description of the flow properties of granular matter, even immersed, requires the detailed properties of the grain surface to be taken into account.

Thibaut Divoux; Jean-Christophe Géminard

2008-06-10T23:59:59.000Z

131

Method and device for frictional welding  

DOE Patents (OSTI)

A method for friction welding that produces a seal having essentially no gas porosity, comprises two rotationally symmetric, generally cylindrical members, spaced apart and coaxially aligned, that are rotated with respect to each other and brought together under high pressure. One member is preferably a generally cylindrical cannister that stores uranium within its hollow walls. The other member is preferably a generally cylindrical, hollow weld ring. An annular channel formed in the weld ring functions as an internal flash trap and is uniquely designed so that substantially all of the welding flash generated from the friction welding is directed into the channel's recessed bottom. Also, the channel design limits distortion of the two members during the friction welding process, further contributing to the complete seal that is obtained.

Peacock, Harold B. (867 N. Belair Rd., Evans, GA 30809)

1992-01-01T23:59:59.000Z

132

Dynamical friction in modified Newtonian dynamics  

E-Print Network (OSTI)

We have tested a previous analytical estimate of the dynamical friction timescale in Modified Newtonian Dynamics (MOND) with fully non-linear N-body simulations. The simulations confirm that the dynamical friction timescale is significantly shorter in MOND than in equivalent Newtonian systems, i.e. systems with the same phase-space distribution of baryons and additional dark matter. An apparent conflict between this result and the long timescales determined for bars to slow and mergers to be completed in previous N-body simulations of MOND systems is explained. The confirmation of the short dynamical-friction timescale in MOND underlines the challenge that the Fornax dwarf spheroidal poses to the viability of MOND.

C. Nipoti; L. Ciotti; J. Binney; P. Londrillo

2008-02-08T23:59:59.000Z

133

E-Print Network 3.0 - anomalous specific heat Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

is, the adjustment to the residual anomalous heating (or cooling) is Newtonian... ). The heat loss is mainly through meridional ... Source: Clarke, Allan J. - Department of...

134

Friction Control Solutions Inc FriCSo | Open Energy Information  

Open Energy Info (EERE)

Friction Control Solutions Inc FriCSo Friction Control Solutions Inc FriCSo Jump to: navigation, search Name Friction Control Solutions Inc. (FriCSo) Place Farmington Hills, Michigan Zip 48331 Product FriCSo offers surface engineering solutions to reduce friction between metal parts and its resulting costs. Main market targeted is engine manufacturing for the shipping and military industries. References Friction Control Solutions Inc. (FriCSo)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Friction Control Solutions Inc. (FriCSo) is a company located in Farmington Hills, Michigan . References ↑ "Friction Control Solutions Inc. (FriCSo)" Retrieved from "http://en.openei.org/w/index.php?title=Friction_Control_Solutions_Inc_FriCSo&oldid=345507"

135

IMPROVING MIX DESIGN AND CONSTRUCTION OF PERMEABLE FRICTION COURSE MIXTURES  

E-Print Network (OSTI)

Permeable friction course (PFC), or new generation open-graded friction course (OGFC) mixtures, are hot mix asphalt (HMA) characterized by high total air voids (AV) content (minimum 18 %) as compared to the most commonly used dense-graded HMA...

Alvarez Lugo, Allex Eduardo

2012-02-14T23:59:59.000Z

136

UHV friction of tribofilms derived from metal dithiophosphates  

Science Journals Connector (OSTI)

The friction?reduction mechanisms of Modtp and Zndtp were highlighted by submitting tribofilms to friction in ultra?high vacuum (UHV). The use of an UHV tribometer to understand these phenomena is justified ... t...

C. Grossiord; J.M. Martin; Th. Le Mogne; Th. Palermo

137

10 - Friction and lubrication in diesel engine system design  

Science Journals Connector (OSTI)

Abstract: This chapter addresses engine friction and lubrication dynamics modeling in diesel engine system design. It starts by introducing important fundamental principles of engine tribology and builds up a three-level system modeling approach of engine friction. The chapter summarizes the friction characteristics and friction-reduction design measures for both the overall engine system and individual subsystems such as the piston assembly, the piston rings, the bearings, and the valvetrain.

Qianfan Xin

2013-01-01T23:59:59.000Z

138

Enhancing Physicality in Touch Interaction with Programmable Friction  

E-Print Network (OSTI)

Enhancing Physicality in Touch Interaction with Programmable Friction Vincent Lévesque1 , Louise possibilities and outcomes when touch interactions are enhanced with variable surface friction. In a series of four studies, we first confirm that variable friction gives significant performance advantages in low

Levesque, Vincent

139

Friction versus dilation revisited: Insights from theoretical and numerical models  

E-Print Network (OSTI)

Friction versus dilation revisited: Insights from theoretical and numerical models N. Makedonska,1 controlled by the frictional strength of the fault gouge, a granular layer that accumulates between the fault friction coefficient) of such granular layers is the systems resistance to dilation, a byprocess

Einat, Aharonov

140

ORIGINAL PAPER Modeling of Thermal-Assisted Dislocation Friction  

E-Print Network (OSTI)

ORIGINAL PAPER Modeling of Thermal-Assisted Dislocation Friction Y. Liao · L. D. Marks Received: 25+Business Media, LLC 2009 Abstract We generalize a model for friction at a sliding interface involving the motion of thermally activated friction. Going further, we suggest a plausible method for generalizing the fric- tional

Marks, Laurence D.

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Dry friction avalanches: Experiment and theory Sergey V. Buldyrev,1  

E-Print Network (OSTI)

Dry friction avalanches: Experiment and theory Sergey V. Buldyrev,1 John Ferrante,2 and Fredy R and theoretical models are presented supporting the conjecture that dry friction stick-slip is described by self the variation of the friction force as a function of time. We study nominally flat surfaces of matching aluminum

Buldyrev, Sergey

142

Friction-Induced Vibrations in Railway Transportation Chandra Prakash Sharma  

E-Print Network (OSTI)

Friction-Induced Vibrations in Railway Transportation by Chandra Prakash Sharma B. Tech., Sardar;Abstract Controlling friction at the wheel-rail interface is indispensable for extending track life implementation of friction modifier system consists of a stick-tube assembly, attached through a bracket which

Phani, A. Srikantha

143

Friction and Adhesion Hysteresis between Surfactant Monolayers in Water  

E-Print Network (OSTI)

Friction and Adhesion Hysteresis between Surfactant Monolayers in Water Wuge H. Briscoe Physical friction between two surfaces in adhesive contact with the loading­unloading adhesion hysteresis between them. We then examine in light of this model the observed low friction between two mica surfaces coated

Klein, Jacob

144

Analysis and Model-Based Control of Servomechanisms With Friction  

E-Print Network (OSTI)

Analysis and Model-Based Control of Servomechanisms With Friction Evangelos G. Papadopoulos e Engineering, National Technical University of Athens, 15780 Athens, Greece Friction is responsible for several, model-based feedback compensation is studied for servomechanism tracking tasks. Several kinetic friction

Papadopoulos, Evangelos

145

Solid friction in gel electrophoresis S. F. Burlatskya)  

E-Print Network (OSTI)

Solid friction in gel electrophoresis S. F. Burlatskya) and John M. Deutch Department of Chemistry 1995 We study the influence of solid frictional forces acting on polymer chains moving in a random environment. We show that the total reduction in the chain tension resulting from the small friction between

Deutch, John

146

Molecular friction and epitactic coupling between monolayers in supported bilayers  

E-Print Network (OSTI)

1535 Molecular friction and epitactic coupling between monolayers in supported bilayers R. Merkel un substrat de membrane couplée (Evans et Sackmann, 1988), on détermine la friction moléculaire coefficients de friction entre les couches en fixant la couche mononucléaire proximale sur le substrat par des

Boyer, Edmond

147

Friction as an activated process Ondej Soucek, Frantisek Gallovic  

E-Print Network (OSTI)

Friction as an activated process Ondej Soucek, Frantisek Gallovic Mathematical Institute University in Prague 30.11.2011 (Geodynamical seminar) Friction as an activated process 30.11.2011 1 / 19 #12 - non-smoothness of the "potentials" (Geodynamical seminar) Friction as an activated process 30

Cerveny, Vlastislav

148

Sliding Friction with Polymer Brushes Rafael Tadmor,* Joanna Janik,  

E-Print Network (OSTI)

Sliding Friction with Polymer Brushes Rafael Tadmor,* Joanna Janik, and Jacob Klein Department) Using high-resolution shear force measurements, we examine in detail the frictional drag between rubbing characteristic of kinetic friction. This has a very weak velocity dependence, attributed to chain moieties

Klein, Jacob

149

ON THE IDENTIFICATION AND HAPTIC DISPLAY OF FRICTION  

E-Print Network (OSTI)

ON THE IDENTIFICATION AND HAPTIC DISPLAY OF FRICTION A DISSERTATION SUBMITTED TO THE DEPARTMENT by Christopher Richard All Rights Reserved #12;iv Abstract Although friction is an important phenomenon and greatly affects the way in which individ- uals interact with the world, friction is all but absent from

Stanford University

150

Effect of Nanoclay Reinforcement on the Friction Braking Performance of Hybrid Phenolic Friction Composites  

Science Journals Connector (OSTI)

Friction composite formulation consisting of decreasing nanoclay/lapinus fibres content, increasing graphite/aramid fibres ... is adopted for evaluating braking performance. The nanoclay content (?2.25 wt.%) enha...

Tej Singh; Amar Patnaik…

2013-03-01T23:59:59.000Z

151

Friction enhancement in concertina locomotion of snakes  

Science Journals Connector (OSTI)

...video S4 shows side and top views of a corn snake performing concertina in which...This behaviour is favourable if the energy required for lifting, m i gz i , is...We first discuss our measurements of corn snake frictional properties, body...

2012-01-01T23:59:59.000Z

152

Critical length limiting super-low friction  

E-Print Network (OSTI)

Since the demonstration of super-low friction (superlubricity) in graphite at nanoscale, one of the main challenges in the field of nano- and micro-mechanics was to scale this phenomenon up. A key question to be addressed is to what extent superlubricity could persist, and what mechanisms could lead to its failure. Here, using an edge-driven Frenkel-Kontorova model, we establish a connection between the critical length above which superlubricity disappears and both intrinsic material properties and experimental parameters. A striking boost in dissipated energy with chain length emerges abruptly due to a high-friction stick-slip mechanism caused by deformation of the slider leading to a local commensuration with the substrate lattice. We derived a parameter-free analytical model for the critical length that is in excellent agreement with our numerical simulations. Our results provide a new perspective on friction and nano-manipulation and can serve as a theoretical basis for designing nano-devices with super-low friction, such as carbon nanotubes.

Ming Ma; Andrea Benassi; Andrea Vanossi; Michael Urbakh

2015-01-02T23:59:59.000Z

153

Casimir Friction Force for Moving Harmonic Oscillators  

E-Print Network (OSTI)

Casimir friction is analyzed for a pair of dielectric particles in relative motion. We first adopt a microscopic model for harmonically oscillating particles at finite temperature T moving non-relativistically with constant velocity. We use a statistical-mechanical description where time-dependent correlations are involved. This description is physical and direct, and, in spite of its simplicity, is able to elucidate the essentials of the problem. This treatment elaborates upon, and extends, an earlier theory of ours back in 1992. The energy change Delta E turns out to be finite in general, corresponding to a finite friction force. In the limit of zero temperature the formalism yields, however, Delta E ->0, this being due to our assumption about constant velocity, meaning slowly varying coupling. For couplings varying more rapidly, there will also be a finite friction force at T=0. As second part of our work, we consider the friction problem using time-dependent perturbation theory. The dissipation, basically a second order effect, is obtainable with the use of first order theory, the reason being the absence of cross terms due to uncorrelated phases of eigenstates. The third part of the present paper is to demonstrate explicitly the equivalence of our results with those recently obtained by Barton (2010); this being not a trivial task since the formal results are seemingly quite different from each other.

Johan S. Høye; Iver Brevik

2011-11-21T23:59:59.000Z

154

Heat transfer and pressure drop data for high heat flux densities to water at high subcritical pressures  

E-Print Network (OSTI)

Local surface ooeffioients of heat t-ansfer, overall pressure drop data and mean friction factor are presented for heat flamms up to 3.52106 BtuAr ft2 for water flowing in a nickel tabe isder the following conditions: mass ...

Rohsenow, Warren M.

1951-01-01T23:59:59.000Z

155

Shear Jamming in Granular Experiments without Basal Friction  

E-Print Network (OSTI)

Jammed states of frictional granular systems can be induced by shear strain at densities below the isostatic jamming density ($\\phi_c$). It remains unclear, however, how much friction affects this so-called shear-jamming. Friction appears in two ways in this type of experiment: friction between particles, and friction between particles and the base on which they rest. Here, we study how particle-bottom friction, or basal friction, affects shear jamming in quasi-two dimensional experiments. In order to study this issue experimentally, we apply simple shear to a disordered packing of photoelastic disks. We can tune the basal friction of the particles by immersing the particles in a density matched liquid, thus removing the normal force, hence the friction, between the particles and base. We record the overall shear stress, and particle motion, and the photoelastic response of the particles. We compare the shear response of dry and immersed samples, which enables us to determine how basal friction affects shear jamming. Our findings indicate that changing the basal friction shifts the point of shear jamming, but it does not change the basic phenomenon of shear jamming.

Hu Zheng; Joshua A. Dijksman; Robert P. Behringer

2014-04-29T23:59:59.000Z

156

On Surface Structure and Friction Regulation in Reptilian Limbless Locomotion  

E-Print Network (OSTI)

One way of controlling friction and associated energy losses is to engineer a deterministic structural pattern on the surface of the rubbing parts (i.e., texture engineering). Custom texturing enhances the quality of lubrication, reduces friction, and allows the use of lubricants of lower viscosity. To date, a standardized procedure to generate deterministic texture constructs is virtually non-existent. Many engineers, therefore, study natural species to explore surface construction and to probe the role surface topography assumes in friction control. Snakes offer rich examples of surfaces where topological features allow the optimization and control of frictional behavior. In this paper, we investigate the frictional behavior of a constrictor type reptile, Python regius. The study employed a specially designed tribo-acoustic probe capable of measuring the coefficient of friction and detecting the acoustical behavior of the skin in vivo. The results confirm the anisotropy of the frictional response of snakesk...

Abdel-Aal, Hisham A

2012-01-01T23:59:59.000Z

157

Friction Tests in Magnesium Tube Hydroforming at Elevated Temperatures  

SciTech Connect

In metal forming, lubricants have a variety of functions. The top priority is usually reduction of friction in order to increase the formability of the materials and reduce tool wear. Because magnesium alloys have very poor formability at room temperature, it is essential to manufacture a part from Magnesium alloys at elevated temperatures. The aim of this paper is to present a friction test method to evaluate the performance of different kinds of lubricants and determine their coefficients of friction at elevated temperatures in tube hydroforming of magnesium alloys. A self-designed experimental apparatus is used to carry out the experiments of friction tests. The coefficient of friction between the tube and die at guiding zone is determined. The effects of the internal pressure, the axial feeding velocity and temperatures on the friction forces and coefficients of friction for different lubricants are discussed.

Hwang, Yeong-Maw; Wang, Kuo-Hsing; Kuo, Tsung-Yu [National Sun Yat-Sen University-Department of Mechanical and Electro-mechanical Engineering, No.70, Lien-Hai Rd., Kaohsiung, Taiwan (China)

2011-05-04T23:59:59.000Z

158

Site clean up of coal gasification residues  

SciTech Connect

The coal gasification plant residues tested in this research consists of various particle sizes of rock, gravel, tar-sand agglomerates, fine sand and soil. Most of the soils particles were tar free. One of the fractions examined contained over 3000 ppM polyaromatic hydrocarbons (PAHs). The residues were subjected to high pressure water jet washing, float and sink tests, and soil washing. Subsequent PAH analyses found less than 1 ppM PAHs in the water jet washing water. Soils washed with pure water lowered PAH concentrations to 276 ppM; the use of surfactants decreased PAHs to 47, 200, and 240 ppM for different test conditions. In the 47 ppM test, the surfactant temperature had been increased to 80 C, suggesting that surfactant washing efficiency can be greatly improved by increasing the solution temperature. The coal tar particles were not extracted by the surfactants used. Coke and tar-sand agglomerates collected from the float and sink gravimetric separation were tested for heating value. The tar exhibited a very high heating value, while the coke had a heating value close to that of bituminous coal. These processes are believed to have the potential to clean up coal gasification plant residues at a fairly low cost, pending pilot-scale testing and a feasibility study.

Wilson, J.W.; Ding, Y. [Univ. of Missouri, Rolla, MO (United States)

1995-12-31T23:59:59.000Z

159

Computational Analysis of Fluid Flow and Heat Transfer Characteristics of Obliquely Impinging Slot Jets  

Science Journals Connector (OSTI)

The skin friction and heat transfer characteristics due to a slot jet impinging obliquely on a flat plate are presented. The boundary layer equations are solved by a finite difference marching technique, detai...

S. Jayaraj; Vijay K. Garg

1988-01-01T23:59:59.000Z

160

Numerical Modeling of Non-adiabatic Heat-Recirculating Combustors C. H. Kuo and P. D. Ronney  

E-Print Network (OSTI)

of temperature-dependent gas and solid properties, viscous flow, surface-to-surface radiative heat transfer, heat affect the performance of heat-recirculating combustors, but the relative importance of such effects, however, heat and friction losses become more significant, thus fuel-to-electricity conversion devices

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Materials - Recycling - Shredder Residue  

NLE Websites -- All DOE Office Websites (Extended Search)

Recovering Materials from Shredder Residue Recovering Materials from Shredder Residue Obsolete automobiles, home appliances and other metal-containing scrap are shredded for the recovery of metals. More than 50% of the material shredded is automobiles. In the United States, shredders generate about 5 million tons of shredder residue every year. Similar amounts are produced in Europe and in the Pacific Rim. Because recycling shredder waste has not been profitable, most of it ends up in landfills; smaller amounts are incinerated. Argonne researchers have developed and tested a process to recover polymers and metals from shredder residue. A 2-ton/hr pilot plant, consisting of a mechanical separation facility and a six-stage wet density/froth flotation plant, was built at Argonne. In the mechanical part of the plant, the shredder waste was separated into five primary components: a polymer fraction (about 45% by weight), a residual metals concentrate (about 10% by weight), a polyurethane foam portion (about 5% by weight), an organic-rich fraction (about 25% by weight) and a metal oxides fraction (about 15% by weight). The polymer fraction was then separated further in the wet density/froth flotation system to recover individual plastic types or compatible families of polymers.

162

Dynamical friction in constant density cores: a failure of the Chandrasekhar formula  

E-Print Network (OSTI)

Using analytic calculations and N-body simulations we show that in constant density (harmonic) cores, sinking satellites undergo an initial phase of very rapid (super-Chandrasekhar) dynamical friction, after which they experience no dynamical friction at all. For density profiles with a central power law profile of log-slope, $-\\alpha$, the infalling satellite heats the background and causes $\\alpha$ to decrease. For $\\alpha < 0.5$ initially, the satellite generates a small central constant density core and stalls as in the $\\alpha = 0$ case. We discuss some astrophysical applications of our results to decaying satellite orbits, galactic bars and mergers of supermassive black hole binaries. In a companion paper we show that a central constant density core can provide a natural solution to the timing problem for Fornax's globular clusters.

J. I. Read; Tobias Goerdt; Ben Moore; A. P. Pontzen; Joachim Stadel; George Lake

2006-06-26T23:59:59.000Z

163

"Table A10. Total Consumption of LPG, Distillate Fuel Oil, and Residual Fuel"  

U.S. Energy Information Administration (EIA) Indexed Site

0. Total Consumption of LPG, Distillate Fuel Oil, and Residual Fuel" 0. Total Consumption of LPG, Distillate Fuel Oil, and Residual Fuel" " Oil for Selected Purposes by Census Region and Economic Characteristics of the" " Establishment, 1991" " (Estimates in Barrels per Day)" ,,,," Inputs for Heat",,," Primary Consumption" " "," Primary Consumption for all Purposes",,," Power, and Generation of Electricity",,," for Nonfuel Purposes",,,"RSE" ," ------------------------------------",,," ------------------------------------",,," -------------------------------",,,"Row" "Economic Characteristics(a)","LPG","Distillate(b)","Residual","LPG","Distillate(b)","Residual","LPG","Distillate(b)","Residual","Factors"

164

Friction- and wear-reducing coating  

DOE Patents (OSTI)

A coating includes a first layer of a ceramic alloy and a second layer disposed on the first layer and including carbon. The coating has a hardness of from 10 to 20 GPa and a coefficient of friction of less than or equal to 0.12. A method of coating a substrate includes cleaning the substrate, forming the first layer on the substrate, and depositing the second layer onto the first layer to thereby coat the substrate.

Zhu, Dong (Farmington Hills, MI); Milner, Robert (Warren, MI); Elmoursi, Alaa AbdelAzim (Troy, MI)

2011-10-18T23:59:59.000Z

165

Mutual Friction in Superfluid Neutron Stars  

E-Print Network (OSTI)

We discuss vortex-mediated mutual friction in the two-fluid model for superfluid neutron star cores. Our discussion is based on the general formalism developed by Carter and collaborators, which makes due distinction between transport velocity and momentum for each fluid. This is essential for an implementation of the so-called entrainment effect, whereby the flow of one fluid imparts momentum in the other and vice versa. The mutual friction follows by balancing the Magnus force that acts on the quantised neutron vortices with a resistive force due to the scattering of electrons off of the magnetic field with which each vortex core is endowed. We derive the form of the macroscopic mutual friction force which is relevant for a model based on smooth-averaging over a collection of vortices. We discuss the coefficients that enter the expression for this force, and the timescale on which the two interpenetrating fluids in a neutron star core are coupled. This discussion confirms that our new formulation accords well with previous work in this area.

N. Andersson; T. Sidery; G. L. Comer

2005-10-03T23:59:59.000Z

166

Some Hamiltonian models of friction II  

SciTech Connect

In the present paper we consider the motion of a very heavy tracer particle in a medium of a very dense, non-interacting Bose gas. We prove that, in a certain mean-field limit, the tracer particle will be decelerated and come to rest somewhere in the medium. Friction is caused by emission of Cerenkov radiation of gapless modes into the gas. Mathematically, a system of semilinear integro-differential equations, introduced in Froehlich et al. ['Some hamiltonian models of friction,' J. Math. Phys. 52(8), 083508 (2011)], describing a tracer particle in a dispersive medium is investigated, and decay properties of the solution are proven. This work is an extension of Froehlich et al. ['Friction in a model of hamiltonian dynamics,' Commun. Math. Phys. 315(2), 401-444 (2012)]; it is an extension because no weak coupling limit for the interaction between tracer particle and medium is assumed. The technical methods used are dispersive estimates and a contraction principle.

Egli, Daniel; Gang Zhou [Institute for Theoretical Physics, ETH Zurich, CH-8093 Zuerich (Switzerland)

2012-10-15T23:59:59.000Z

167

Dynamic recrystallization in friction surfaced austenitic stainless steel coatings  

SciTech Connect

Friction surfacing involves complex thermo-mechanical phenomena. In this study, the nature of dynamic recrystallization in friction surfaced austenitic stainless steel AISI 316L coatings was investigated using electron backscattered diffraction and transmission electron microscopy. The results show that the alloy 316L undergoes discontinuous dynamic recrystallization under conditions of moderate Zener-Hollomon parameter during friction surfacing. - Highlights: Black-Right-Pointing-Pointer Dynamic recrystallization in alloy 316L friction surfaced coatings is examined. Black-Right-Pointing-Pointer Friction surfacing leads to discontinuous dynamic recrystallization in alloy 316L. Black-Right-Pointing-Pointer Strain rates in friction surfacing exceed 400 s{sup -1}. Black-Right-Pointing-Pointer Estimated grain size matches well with experimental observations in 316L coatings.

Puli, Ramesh, E-mail: rameshpuli2000@gmail.com; Janaki Ram, G.D.

2012-12-15T23:59:59.000Z

168

Fact or friction: Inferring rheology from nonvolcanic tremor and low-frequency earthquakes on the deep San Andreas fault  

E-Print Network (OSTI)

2.5 Optimal friction coefficient . . . . . . . . . . . . . .effective coefficient of friction. Values for the tremor,procedure on each friction value for each catalogue. Maximum

Thomas, Amanda

2012-01-01T23:59:59.000Z

169

Effective friction law for smallscale fault heterogeneity in 3D dynamic rupture  

E-Print Network (OSTI)

Effective friction law for smallscale fault heterogeneity in 3D dynamic rupture S. Latour,1 M friction, we numerically construct effective friction laws that integrate the effects of smallscale, the static friction heterogeneities and the friction law. We first define a periodic smallscale heterogeneous

Nicolas, Chamot-Rooke

170

Friction (Chapter 5, section 8) & Circular Motion (Chapter 6,  

E-Print Network (OSTI)

1 Week 5 Friction (Chapter 5, section 8) & Circular Motion (Chapter 6, sections 1-2) Lecture Quiz 1 travels in time t is: A. x B. 1.5x C. 3x D. 4.5x E. 9x Forces of Friction When an object to the interactions between the object and its environment This resistance is called the force of friction Forces

171

Advances in induction heating  

SciTech Connect

Electric induction heating, in situ, can distill (underground) high-heat-value (HHV) gas, coal tar, bitumen, and shale oil. This technique permits potentially lower cost exploitation of the solid fossil fuels: coal, oil shale, tar sand, and heavy oil. The products, when brought to the surface in gaseous form and processed, yield chemical feedstocks, natural gas, and petroleum. Residual coke can be converted, in situ, to low-heat-value (LHV) gas by a conventional water-gas process. LHV can be burned at the surface to generate electricity at low cost. The major cost of the installation will have been paid for by the HHV gas and tar distilled from the coal. There are 2 mechanisms of heating by electric induction. One uses displacement currents induced from an electric field. The other uses eddy currents induced by a magnetic field.

Not Available

1980-06-16T23:59:59.000Z

172

Immobilization of Rocky Flats Graphite Fines Residues  

SciTech Connect

The Savannah River Technology Center (SRTC) is developing an immobilization process for graphite fines residues generated during nuclear materials production activities at the Rocky Flats Environmental Technology Site (Rocky Flats). The continued storage of this material has been identified as an item of concern. The residue was generated during the cleaning of graphite casting molds and potentially contains reactive plutonium metal. The average residue composition is 73 wt percent graphite, 15 wt percent calcium fluoride (CaF2), and 12 wt percent plutonium oxide (PuO2). Approximately 950 kilograms of this material are currently stored at Rocky Flats. The strategy of the immobilization process is to microencapsulate the residue by mixing with a sodium borosilicate (NBS) glass frit and heating at nominally 700 degrees C. The resulting waste form would be sent to the Waste Isolation Pilot Plant (WIPP) for disposal. Since the PuO2 concentration in the residue averages 12 wt percent, the immobilization process was required to meet the intent of safeguards termination criteria by limiting plutonium recoverability based on a test developed by Rocky Flats. The test required a plutonium recovery of less than 4 g/kg of waste form when a sample was leached using a nitric acid/CaF2 dissolution flowsheet. Immobilization experiments were performed using simulated graphite fines with cerium oxide (CeO2) as a surrogate for PuO2 and with actual graphite fines residues. Small-scale surrogate experiments demonstrated that a 4:1 frit to residue ratio was adequate to prevent recovery of greater than 4 g/kg of cerium from simulated waste forms. Additional experiments investigated the impact of varying concentrations of CaF2 and the temperature/heating time cycle on the cerium recovery. Optimal processing conditions developed during these experiments were subsequently demonstrated at full-scale with surrogate materials and on a smaller scale using actual graphite fines.In general, the recovery of cerium from the full-scale waste forms was higher than for smaller scale experiments. The presence of CaF2 also caused a dramatic increase in cerium recovery not seen in the small-scale experiments. However, the results from experiments with actual graphite fines were encouraging. A 4:1 frit to residue ratio, a temperature of 700 degrees C, and a 2 hr heating time produced waste forms with plutonium recoveries of 4 plus/minus 1 g/kg. With an increase in the frit to residue ratio, waste forms fabricated at this scale should meet the Rocky Flats product specification. The scale-up of the waste form fabrication process to nominally 3 kg is expected to require a 5:1 to 6:1 frit to residue ratio and maintaining the waste form centerline temperature at 700 degrees C for 2 hr.

Rudisill, T. S.

1998-11-06T23:59:59.000Z

173

Engine Friction Reduction Through Surface Finish and Coatings...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

and Coatings Opportunities exist for friction reduction in piston rings and valve trains using durable, advanced material technologies, such as diamond-like carbon (DLC)...

174

Friction Stir Spot Welding of Advanced High Strength Steels II...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

II Friction Stir Spot Welding of Advanced High Strength Steels II 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation...

175

Friction and Wear Enhancement of Titanium Alloy Engine Components...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Merit Review and Peer Evaluation pm007blau2011o.pdf More Documents & Publications Friction and Wear Enhancement of Titanium Alloy Engine Components Vehicle Technologies Office...

176

Friction Modeling for Lubricated Engine and Drivetrain Components...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Modeling for Lubricated Engine and Drivetrain Components Friction Modeling for Lubricated Engine and Drivetrain Components 2010 DOE Vehicle Technologies and Hydrogen Programs...

177

Engine Friction Reduction Through Surface Finish and Coatings  

Energy.gov (U.S. Department of Energy (DOE))

Opportunities exist for friction reduction in piston rings and valve trains using durable, advanced material technologies, such as diamond-like carbon (DLC) coatings, and new lubricants.

178

Evaluation of friction loss in flexible and galvanized duct  

E-Print Network (OSTI)

for Friction Loss in Straight Runs of Duct (a'Ipha=0. 10). 21 Ill Static Pressure Data Converted to Equivalent Lengths. 23 IV Duncan's Multiple Range Test of Variability for Equivalent Lengths of 90 Degree Elbows (al pha=0. IO). 26 V Student t Test... because of the higher Friction losses obtained in the first 1. 5 hours of testing. The Investigators concluded that when flex'ible duct was properly installed the Friction losses compared reasonably well with the friction losses in galvanized duct. i...

Zimmermann, Carlos Michael Alberto

2012-06-07T23:59:59.000Z

179

Vehicle Technologies Office Merit Review 2014: Engine Friction Reduction Technologies  

Energy.gov (U.S. Department of Energy (DOE))

Presentation given by Argonne National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about engine friction...

180

A STUDY OF THE PROPERTIES OF CP: COEFFICIENT OF THERMAL EXPANSION, DECOMPOSITION KINETICS AND REACTION TO SPARK, FRICTION AND IMPACT  

SciTech Connect

The properties of pentaamine (5-cyano-2H-tetrazolato-N2) cobalt (III) perchlorate (CP), which was first synthesized in 1968, continues to be of interest for predicting behavior in handling, shipping, aging, and thermal cook-off situations. We report coefficient of thermal expansion (CTE) values over four specific temperature ranges, decomposition kinetics using linear heating rates, and the reaction to three different types of stimuli: impact, spark, and friction. The CTE was measured using a Thermal Mechanical Analyzer (TMA) for samples that were uniaxially compressed at 10,000 psi and analyzed over a dynamic temperature range of -20 C to 70 C. Using differential scanning calorimetry, DSC, CP was decomposed at linear heating rates of 1, 3, and 7 C/min and the kinetic triplet calculated using the LLNL code Kinetics05. Values are also reported for spark, friction, and impact sensitivity.

Weese, R K; Burnham, A K; Fontes, A T

2005-03-30T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Solar heat collector  

SciTech Connect

An evacuated double-tubing solar heat collector is described comprising: an inner tube having an open end and a closed end; a selective absorption film applied over an exterior surface of the inner tube; an outer tube having an open end and a closed end; the inner tube being constructed to be received within the outer tube; and a substantially continuous annular coil spring ring being substantially found in cross section and of a predetermined thickness. The coil spring ring is disposed between and engages an interior surface of the outer tube and the exterior surface of the inner tube for spacing and resiliently supporting the inner tube relative to the outer tube. The ring is freely rotatably positioned to be moved axially along the length of the inner tube due only to frictional forces exerted on the coil spring. The coil spring ring is positioned on the inner tube at approximately a middle position along the length of the inner tube by being initially positioned on the inner tube adjacent to the closed end thereof and rotated upon itself axially along the inner tube only by frictional engagement with the interior surface of the outer tube as the inner tube is inserted into the open end of the outer tube and moved to a fully inserted position within the outer tube. The open end of the inner tube and the open end of the outer tube are fused to form a junction and hermetically sealed.

Takeuchi, H.; Mikiya, T.

1987-03-17T23:59:59.000Z

182

Friction in a Model of Hamiltonian Dynamics  

E-Print Network (OSTI)

We study the motion of a heavy tracer particle weakly coupled to a dense ideal Bose gas exhibiting Bose-Einstein condensation. In the so-called mean-field limit, the dynamics of this system approaches one determined by nonlinear Hamiltonian evolution equations describing a process of emission of Cerenkov radiation of sound waves into the Bose-Einstein condensate along the particle's trajectory. The emission of Cerenkov radiation results in a friction force with memory acting on the tracer particle and causing it to decelerate until it comes to rest.

Juerg Froehlich; Zhou Gang; Avy Soffer

2011-10-29T23:59:59.000Z

183

Casimir friction: Relative motion more generally  

E-Print Network (OSTI)

This paper extends our recent study on Casimir friction forces for dielectric plates moving parallel to each other [J. S. H{\\o}ye and I. Brevik, Eur. Phys. J. D {\\bf 68}, 61 (2014)], to the case where the plates are no longer restricted to rectilinear motion. Part of the mathematical formalism thereby becomes more cumbersome, but reduces in the end to the form that we could expect to be the natural one in advance. As an example, we calculate the Casimir torque on a planar disc rotating with constant angular velocity around its vertical symmetry axis next to another plate.

Johan S. Høye; Iver Brevik

2014-09-23T23:59:59.000Z

184

A Drucker-Prager model for elastic contact with friction; A Drucker-Prager model for elastic contact with friction.  

E-Print Network (OSTI)

?? In mumerical contact simulations with friction, the simple Coloumb law is usually employed. Standard plasticity models are difficult to use since the balance enforced… (more)

wu, yunxian

2011-01-01T23:59:59.000Z

185

Initial Development in Joining of ODS Alloys Using Friction Stir Welding  

SciTech Connect

Solid-state welding of oxide-dispersion-strengthened (ODS) alloy MA956 sheets using friction stir welding (FSW) was investigated. Butt weld was successfully produced. The weld and base metals were characterized using optical microscopy, scanning electronic microscopy, transmission electronic microscopy, and energy dispersion x-ray spectrum. Microhardness mapping was also conducted over the weld region. Analyses indicate that the distribution of the strengthening oxides was preserved in the weld. Decrease in microhardness of the weld was observed but was insignificant. The preliminary results seem to confirm the envisioned feasibility of FSW application to ODS alloy joining. For application to Gen IV nuclear reactor heat exchanger, further investigation is suggested.

Ren, Weiju [ORNL; Feng, Zhili [ORNL

2007-08-01T23:59:59.000Z

186

Global energy consumption due to friction in passenger cars  

Science Journals Connector (OSTI)

This study presents calculations on the global fuel energy consumption used to overcome friction in passenger cars in terms of friction in the engine, transmission, tires, and brakes. Friction in tribocontacts was estimated according to prevailing contact mechanisms such as elastohydrodynamic, hydrodynamic, mixed, and boundary lubrication. Coefficients of friction in the tribocontacts were estimated based on available information in the literature on the average passenger car in use today, a car with today’s advanced commercial tribological technology, a car with today’s best advanced technology based upon recent research and development, and a car with the best technology forecasted in the next 10 years. The following conclusions were reached: • In passenger cars, one-third of the fuel energy is used to overcome friction in the engine, transmission, tires, and brakes. The direct frictional losses, with braking friction excluded, are 28% of the fuel energy. In total, 21.5% of the fuel energy is used to move the car. • Worldwide, 208,000 million liters of fuel (gasoline and diesel) was used in 2009 to overcome friction in passenger cars. This equals 360 million tonne oil equivalent per year (Mtoe/a) or 7.3 million TJ/a. Reductions in frictional losses will lead to a threefold improvement in fuel economy as it will reduce both the exhaust and cooling losses also at the same ratio. • Globally, one passenger car uses on average of 340 l of fuel per year to overcome friction, which would cost 510 euros according to the average European gas price in 2011 and corresponds to an average driving distance of 13,000 km/a. • By taking advantage of new technology for friction reduction in passenger cars, friction losses could be reduced by 18% in the short term (5–10 years) and by 61% in the long term (15–25 years). This would equal worldwide economic savings of 174,000 million euros and 576,000 million euros, respectively; fuel savings of 117,000 million and 385,000 million liters, respectively; and CO2 emission reduction of 290 million and 960 million tonnes, respectively. • The friction-related energy losses in an electric car are estimated to be only about half those of an internal combustion passenger car. Potential actions to reduce friction in passenger cars include the use of advanced coatings and surface texturing technology on engine and transmission components, new low-viscosity and low-shear lubricants and additives, and tire designs that reduce rolling friction.

Kenneth Holmberg; Peter Andersson; Ali Erdemir

2012-01-01T23:59:59.000Z

187

FRICTION AND WEAR STUDY OF DISPERSED PHASE INTERMETALLIC COMPOUNDS IN FERROUS MATRICES  

E-Print Network (OSTI)

rights. .j . J LBL-5771 FRICTION AND WEAR STUDY OF DISPERSEDS. THESIS) i LBL-5771 FRICTION AND WEAR STUDY OF DISPERSEDWilman, "A Theory of Friction and Wear During the Abrasion

Riddle, R.A.

2010-01-01T23:59:59.000Z

188

Lubricant-Friendly, Superhard and Low-Friction Coatings by Design...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Lubricant-Friendly, Superhard and Low-Friction Coatings by Design Lubricant-Friendly, Superhard and Low-Friction Coatings by Design Superhard and low-friction coatings and surface...

189

Weak formulations and solution multiplicity of equilibrium configurations with Coulomb friction  

E-Print Network (OSTI)

Weak formulations and solution multiplicity of equilibrium configurations with Coulomb friction configurations of elastic struc- tures in contact with Coulomb friction. We obtain a variational formulation configurations with arbitrary small friction coefficients. We illustrate the result in two space dimensions

Bostan, Mihai

190

Turbulent heat transfer in a trapezoidal channel with transverse and v-shaped ribs on two opposite walls  

E-Print Network (OSTI)

This study investigates the turbulent heat transfer and friction in a trapezoidal channel with opposite walls roughened with transverse and v-shaped ribs. The roughened channel depicts the internal cooling passage of an aerofoil near the trailing...

Subramanian, Karthik

2006-04-12T23:59:59.000Z

191

Friction and the Inverted Pendulum Stabilization Problem Sue Ann Campbell  

E-Print Network (OSTI)

Friction and the Inverted Pendulum Stabilization Problem Sue Ann Campbell Department of Applied. Keywords: inverted pendulum, friction, feedback control, stability analysis. 1 #12;INTRODUCTION to be the cause of failure of a feedback controller to stabilize a three link inverted pendulum system [2

Campbell, Sue Ann

192

Certification of a weld produced by friction stir welding  

DOE Patents (OSTI)

Methods, devices, and systems for providing certification of friction stir welds are disclosed. A sensor is used to collect information related to a friction stir weld. Data from the sensor is compared to threshold values provided by an extrinsic standard setting organizations using a certification engine. The certification engine subsequently produces a report on the certification status of the weld.

Obaditch, Chris; Grant, Glenn J

2013-10-01T23:59:59.000Z

193

Role of Friction in Materials Selection for Automotive Applications  

SciTech Connect

This is an invited article for a special issue of the ASM International monthly magazine that concerns "Automotive Materials and Applications." The article itself overviews frictional considerations in material selection for automobiles. It discusses implications for energy efficiency (engine friction) and safety (brakes) among other topics.

Blau, Peter Julian [ORNL

2013-01-01T23:59:59.000Z

194

Quantized friction force: Lindbladian model satisfying Ehrenfest theorems  

E-Print Network (OSTI)

We construct a quantum counterpart of classical friction, a dissipative force acting against the direction of motion with the magnitude proportional to particle's velocity. In particular, a Lindblad master equation is derived satisfying the appropriate dynamical relations for observables (i.e., the Ehrenfest theorems). These findings significantly advance a long search for a universal valid Lindbladian model of quantum friction.

Denys I. Bondar; Renan Cabrera; Andre Campos; Herschel A. Rabitz

2014-12-05T23:59:59.000Z

195

Aspect ratio effect on heat transfer in rotating two-pass rectangular channels with smooth walls and ribbed walls  

E-Print Network (OSTI)

buoyancy parameter, (?? /? )xRo2(Rx/Dh) Dh hydraulic diameter de diameter of coolant exit hole e rib height f friction factor fo fully developed friction factor in non-rotating smooth tube h heat transfer coefficient H channel height k...) . N. K. Anand (Member) . D. L. O?Neal (Head of Department) May 2005 Major Subject: Mechanical Engineering iii ABSTRACT Aspect Ratio Effect on Heat Transfer in Rotating Two...

Fu, Wen-Lung

2005-08-29T23:59:59.000Z

196

E-Print Network 3.0 - asbestos-free friction lining Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

identification necessary. Off-line identification of friction is described by Armstrong 2... -feedback PD part and of an on-line friction compensation term, T f , which...

197

Ice friction: The effects of surface roughness, structure, and hydrophobicity  

SciTech Connect

The effect of surface roughness, structure, and hydrophobicity on ice friction is studied systematically over a wide range of temperature and sliding speeds using several metallic interfaces. Hydrophobicity in combination with controlled roughness at the nanoscale is achieved by femtosecond laser irradiation to mimic the lotus effect on the slider's surface. The controlled roughness significantly increases the coefficient of friction at low sliding speeds and temperatures well below the ice melting point. However, at temperatures close to the melting point and relatively higher speeds, roughness and hydrophobicity significantly decrease ice friction. This decrease in friction is mainly due to the suppression of capillary bridges in spite of the presence of surface asperities that facilitate their formation. Finally, grooves oriented in the sliding direction also significantly decrease friction in the low velocity range compared to scratches and grooves randomly distributed over a surface.

Kietzig, Anne-Marie; Hatzikiriakos, Savvas G.; Englezos, Peter [Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3 (Canada)

2009-07-15T23:59:59.000Z

198

ENERGY ABSORBER HEAT PUMP SYSTEM TO SUPPLEMENT HEAT RECOVERY SYSTEMS IN AN INDOOR SWIMMING POOL  

Science Journals Connector (OSTI)

ABSTRACT Compared with convontional indoor swimming pools with traditional plant engineering, the Schwalmtal indoor swimming pool has a final energy consumption of just 40%. This low consumption is achieved by improved insulation of the building's enveloping surface, through the operation of systems for the recovery of heat from drain water and waste air as well as by the operation of a heat pump system to gain ambient heat. The decentralised heat recovery systems met between 40 and 80% of the heat requirements in the supply areas where they were used. The electric heat pump system, which is operated in the bivalent mode in parallel to a heating boiler, could generate 75% of the heat provided by the central heating circuit to meet the residual heat requirements. The report illustrates the structure of the residual heat requirements of the central heating circuit. A description is given of the measured coefficients of performance of the brine/water heat pump connected by a brine circuit with two different energy absorber types - energy stack and energy roof. Finally, the ambient energy gained with the absorbers is broken down into the various kinds of heat gains from radiation, convection, condensation etc. KEYWORDS Energy absorber; energy stack; energy roof; heat pump; heat recovery systems; indoor swimming pool; energy engineering concept.

K. Leisen

1988-01-01T23:59:59.000Z

199

Evaluation of residual stress gradients in ductile cast iron using critical refracted longitudinal (Lcr) wave technique  

E-Print Network (OSTI)

improper or unnecessary heat-treatments extremely costly. Knowledge of the residual stress ipudient can make production of the component much more efficient and economicaL This knowledge could also be used to predict service life of components...

Pfluger, Ron Atlan

1995-01-01T23:59:59.000Z

200

Simulation of low energy muon frictional cooling  

Science Journals Connector (OSTI)

Frictional cooling is a proposed method of phase space reduction for a potential muon beam intended for collisions. The basic principle involves compensating for the muon energy loss in media by a constant electric field. The muons are in an energy regime below the ionization peak which for muons in helium is less than 10 keV . Electronic energy loss is treated as a continuous process and all individual nuclear scatters with scattering angles greater than 50 mrad are simulated as discrete processes. Other effects like the Barkas [W.H. Barkas, W. Birnbaum, F.M. Smith, Phys. Rev. 101 (1956) 778.] effect and Muonium formation are also included. The results of our simulations are summarized.

R. Galea; A. Caldwell; S. Schlenstedt; H. Abramowicz

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Creep motion of a model frictional system  

Science Journals Connector (OSTI)

We report on the dynamics of a model frictional system submitted to minute external perturbations. The system consists of a chain of sliders connected through elastic springs that rest on an incline. By introducing cyclic expansions and contractions of the springs we observe a reptation of the chain. We account for the average reptation velocity theoretically. The velocity of small systems exhibits a series of plateaus as a function of the incline angle. Due to elastic effects, there exists a critical amplitude below which the reptation is expected to cease. However, rather than a full stop of the creep, we observe in numerical simulations a transition between a continuous-creep and an irregular-creep regime when the critical amplitude is approached. The latter transition is reminiscent of the transition between the continuous and the irregular compaction of granular matter submitted to periodic temperature changes.

Baptiste Blanc; Luis A. Pugnaloni; Jean-Christophe Géminard

2011-12-27T23:59:59.000Z

202

Ellipticals and Bars: Central Masses and Friction  

E-Print Network (OSTI)

I give a very brief review of aspects of internal dynamics that affect the global shape of a galaxy, focusing on triaxiality, bars and warps. There is general agreement that large central masses can destroy triaxial shapes, but recent simulations of this process seem to suffer from numerical difficulties. Central black holes alone are probably not massive enough to destroy global triaxiality, but when augmented by star and gas concentrations in barred galaxies, the global shape may be affected. Even though we do not understand the origin of bars in galaxies, they are very useful as probes of the dark matter density of the inner halo. Finally, I note that dynamical friction acts to reduce a misalignment between the spin axes of the disk and halo, producing a nice warp in the outer disk which has many of the properties of observed galactic warps.

J. A. Sellwood

2001-07-18T23:59:59.000Z

203

Dynamical friction force exerted on spherical bodies  

E-Print Network (OSTI)

We present a rigorous calculation of the dynamical friction force exerted on a spherical massive perturber moving through an infinite homogenous system of field stars. By calculating the shape and mass of the polarization cloud induced by the perturber in the background system, which decelerates the motion of the perturber, we recover Chandrasekhar's drag force law with a modified Coulomb logarithm. As concrete examples we calculate the drag force exerted on a Plummer sphere or a sphere with the density distribution of a Hernquist profile. It is shown that the shape of the perturber affects only the exact form of the Coulomb logarithm. The latter converges on small scales, because encounters of the test and field stars with impact parameters less than the size of the massive perturber become inefficient. We confirm this way earlier results based on the impulse approximation of small angle scatterings.

O. Esquivel; B. Fuchs

2007-04-30T23:59:59.000Z

204

Some Hamiltonian Models of Friction II  

E-Print Network (OSTI)

In the present paper we consider the motion of a very heavy tracer particle in a medium of a very dense, non-interacting Bose gas. We prove that, in a certain mean-field limit, the tracer particle will be decelerated and come to rest somewhere in the medium. Friction is caused by emission of Cerenkov radiation of gapless modes into the gas. Mathematically, a system of semilinear integro-differential equations, introduced in [FSSG10], describing a tracer particle in a dispersive medium is investigated, and decay properties of the solution are proven. This work is an extension of [FGS10]; it is an extension because no weak coupling limit for the interaction between tracer particle and medium is assumed. The technical methods used are dispersive estimates and a contraction principle.

Daniel Egli; Gang Zhou

2011-08-29T23:59:59.000Z

205

High temperature low friction surface coating  

DOE Patents (OSTI)

A high temperature, low friction, flexible coating for metal surfaces which are subject to rubbing contact includes a mixture of three parts graphite and one part cadmium oxide, ball milled in water for four hours, then mixed with thirty percent by weight of sodium silicate in water solution and a few drops of wetting agent. The mixture is sprayed 12-15 microns thick onto an electro-etched metal surface and air dried for thirty minutes, then baked for two hours at 65.degree. C. to remove the water and wetting agent, and baked for an additional eight hours at about 150.degree. C. to produce the optimum bond with the metal surface. The coating is afterwards burnished to a thickness of about 7-10 microns.

Bhushan, Bharat (Watervliet, NY)

1980-01-01T23:59:59.000Z

206

PROPERTIES OF CP: COEFFICIENT OF THERMAL EXPANSION, DECOMPOSITION KINETICS, AND REACTION TO SPARK, FRICTION AND IMPACT  

SciTech Connect

The properties of pentaamine (5-cyano-2H-tetrazolato-N2) cobalt (III) perchlorate (CP), which was first synthesized in 1968, continues to be of interest for predicting behavior in handling, shipping, aging, and thermal cook-off situations. We report coefficient of thermal expansion (CTE) values over four specific temperature ranges, decomposition kinetics using linear and isothermal heating, and the reaction to three different types of stimuli: impact, spark, and friction. The CTE was measured using a Thermal Mechanical Analyzer (TMA) for samples that were uniaxially compressed at 10,000 psi and analyzed over a dynamic temperature range of -20 C to 70 C. Differential scanning calorimetry, DSC, was used to monitor CP decomposition at linear heating rates of 1-7 C min{sup -1} in perforated pans and of 0.1-1.0 C min{sup -1} in sealed pans. The kinetic triplet was calculated using the LLNL code Kinetics05, and predictions for 210 and 240 C are compared to isothermal thermogravimetric analysis (TGA) experiments. Values are also reported for spark, friction, and impact sensitivity.

Weese, R K; Burnham, A K

2005-09-28T23:59:59.000Z

207

Large scale inhomogeneity and local dynamical friction  

E-Print Network (OSTI)

We investigate the effect of a density gradient on Chandrasekhar's dynamical friction formula based on the method of 2-body encounters in the local approximation. We apply these generalizations to the orbit evolution of satellite galaxies in Dark Matter haloes. We find from the analysis that the main influence occurs through a position-dependent maximum impact parameter in the Coulomb logarithm, which is determined by the local scale-length of the density distribution. We also show that for eccentric orbits the explicit dependence of the Coulomb logarithm on position yields significant differences for the standard homogeneous force. Including the velocity dependence of the Coulomb logarithm yields ambigous results. The orbital fits in the first few periods are further improved, but the deviations at later times are much larger. The additional force induced by the density gradient, the inhomogeneous force, is not antiparallel to the satellite motion and can exceed 10% of the homogeneous friction force in magnitude. However, due to the symmetry properties of the inhomogeneous force, there is a deformation and no secular effect on the orbit at the first order. Therefore the inhomogeneous force can be safely neglected for the orbital evolution of satellite galaxies. For the homogeneous force we compare numerical N-body calculations with semi-analytical orbits to determine quantitatively the accuracy of the generalized formulae of the Coulomb logarithm in the Chandresekhar approach. With the local scale-length as the maximum impact parameter we find a significant improvement of the orbital fits and a better interpretation of the quantitative value of the Coulomb logarithm.

A. Just; J. Penarrubia

2004-10-29T23:59:59.000Z

208

Geothermal Heat Pumps- Heating Mode  

Energy.gov (U.S. Department of Energy (DOE))

In winter, fluid passing through this vertical, closed loop system is warmed by the heat of the earth; this heat is then transferred to the building.

209

Adaptive controller for regenerative and friction braking system  

DOE Patents (OSTI)

A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

Davis, Roy I. (Ypsilanti, MI)

1990-01-01T23:59:59.000Z

210

Power-law friction in closely-packed granular materials  

E-Print Network (OSTI)

In order to understand the nature of friction in closely-packed granular materials, a discrete element simulation on granular layers subjected to isobaric plain shear is performed. It is found that the friction coefficient increases as the power of the shear rate, the exponent of which does not depend on the material constants. Using a nondimensional parameter that is known as the inertial number, the power-law can be cast in a generalized form so that the friction coefficients at different confining pressures collapse on the same curve. We show that the volume fraction also obeys a power-law.

Takahiro Hatano

2006-12-14T23:59:59.000Z

211

Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater  

E-Print Network (OSTI)

. It is found that the integrated characteristics of heat transfer and flow friction increase with the hole's diameter at the same hole density (which is equal to the ratio of the hole's total area to the baffle's area), and the heat transfer rate increases...

Zheng, H.; Fan, X.; Li, A.

2006-01-01T23:59:59.000Z

212

The ground state problem for a quantum Hamiltonian model describing friction  

E-Print Network (OSTI)

The ground state problem for a quantum Hamiltonian model describing friction Laurent Bruneau friction introduced in [4]. This model consists of a particle which interacts with a bosonic reservoir is violated in the case of linear friction, but satis#28;ed when the friction force is proportional

213

Friction Observer and Compensation for Control of Robots with Joint Torque Measurement  

E-Print Network (OSTI)

Friction Observer and Compensation for Control of Robots with Joint Torque Measurement Luc Le Tien-- In this paper we introduce a friction observer for robots with joint torque sensing (in particular for the DLR. The observer output corresponds to the low-pass filtered friction torque. It is used for friction compensation

De Luca, Alessandro

214

Friction, Adhesion, and Deformation: Dynamic Measurements with the Atomic Force Phil Attard  

E-Print Network (OSTI)

Friction, Adhesion, and Deformation: Dynamic Measurements with the Atomic Force Microscope Phil. Adhesion Sci. Technol. 16, 753­791 (2002).) Running title: Friction, Adhesion, and Deformation Abstract for the friction force microscope, quantitative measurements of friction and the ef- fect of adhesion, measurement

Attard, Phil

215

Role of friction-induced torque in stick-slip motion J. Scheibert1,  

E-Print Network (OSTI)

Role of friction-induced torque in stick-slip motion J. Scheibert1, and D.K. Dysthe1 1 PGP describing the kinematics of the transition from static friction to stick-slip motion of a linear elastic the precursors to frictional sliding and the periodic stick- slip motion are controlled by the amount of friction

216

Demonstrations: blocks on planes, scales, to find coefficients of static and kinetic friction  

E-Print Network (OSTI)

Demonstrations: ·blocks on planes, scales, to find coefficients of static and kinetic friction Text: Fishbane 5-1, 5-2 Problems: 18, 21, 28, 30, 34 from Ch. 5 What's important: ·frictional forces ·coefficients of static and kinetic friction Friction Where objects move in contact with other objects, we know

Boal, David

217

Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction  

E-Print Network (OSTI)

Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction of microscopic friction. We will also present our investigation on the relative effectiveness of the use, it is possible to facilitate the refinement of students' ideas of microscopic friction. Keywords: friction

Zollman, Dean

218

Friction in (im-)miscible polymer brush systems and the role of transverse polymer-tilting  

E-Print Network (OSTI)

Friction in (im-)miscible polymer brush systems and the role of transverse polymer-tilting Sissi de preferred solvent, leading to low friction and low wear rates. Here, we demonstrate, using molecular systems also show smaller friction than miscible systems, although the friction reduction is less than

Mueser, Martin

219

Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction  

E-Print Network (OSTI)

Attractiveness of periodic orbits in parametrically forced systems with time- increasing friction with time-increasing friction Michele Bartuccelli,1,a) Jonathan Deane,1,b) and Guido Gentile2,c) 1 oscillator in the presence of friction, and study numerically how time-varying friction affects the dynamics

Bartuccelli, Michele

220

GENERALIZED NEWTON METHODS FOR THE 2DSIGNORINI CONTACT PROBLEM WITH FRICTION  

E-Print Network (OSTI)

GENERALIZED NEWTON METHODS FOR THE 2D­SIGNORINI CONTACT PROBLEM WITH FRICTION K. KUNISCH AND G. STADLER Abstract. The 2D­Signorini contact problem with Tresca and Coulomb friction is discussed in infinite-dimensional Hilbert spaces. First, the problem with given friction (Tresca friction) is considered

Kunisch, Karl

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Formation mechanism of linear friction welded Ti-6Al-4V alloy joint based on microstructure observation  

SciTech Connect

The microstructure of the linear friction welded Ti-6Al-4V titanium alloy joint was investigated by optical microscope, scanning electronic microscope and transmission electron microscope. Results show that the dynamic recovery and recrystallization resulting from the intensive plastic deformation and fast heating and cooling processes during linear friction welding account for the superfine {alpha} + {beta} grains in the weld center. Fine {alpha} grains distribute in the {beta} matrix or at the boundaries of {beta} grains. A mass of dislocations networks and metastructures present within the {alpha} and {beta} grains. - Research Highlights: {yields} TEM is employed in the analysis. {yields} The dynamic recovery is the main mechanism in thermal deformation of TC4. {yields} Superfine grains in the weld result from dynamic recovery and dynamic recrystallizaion, but the recrystallization is inadequate.

Ma Tiejun; Chen Tao, E-mail: ctwc-13@163.com; Li Wenya; Wang Shiwei; Yang Siqian

2011-01-15T23:59:59.000Z

222

Rolling friction for hard cylinder and sphere on viscoelastic solid  

E-Print Network (OSTI)

We calculate the friction force acting on a hard cylinder or spherical ball rolling on a flat surface of a viscoelastic solid. The rolling friction coefficient depends non-linearly on the normal load and the rolling velocity. For a cylinder rolling on a viscoelastic solid characterized by a single relaxation time Hunter has obtained an exact result for the rolling friction, and our result is in very good agreement with his result for this limiting case. The theoretical results are also in good agreement with experiments of Greenwood and Tabor. We suggest that measurements of rolling friction over a wide range of rolling velocities and temperatures may constitute an useful way to determine the viscoelastic modulus of rubber-like materials.

B. N. J. Persson

2010-08-26T23:59:59.000Z

223

A laboratory study of the friction behavior of granular materials  

E-Print Network (OSTI)

I report on laboratory experiments designed to investigate the microphysical processes that result in rate- and state-dependent friction behavior and experiments designed to match the boundary conditions used by numerical ...

Frye, Kevin M. (Kevin Michael), 1972-

2002-01-01T23:59:59.000Z

224

Friction Stir Spot Welding of Advanced High Strength Steels ...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. lm14grant.pdf More Documents & Publications Friction Stir Spot Welding of Advanced High...

225

Friction Modeling and Compensation for an Industrial Robot  

E-Print Network (OSTI)

Friction Modeling and Compensation for an Industrial Robot Stephen M. Phillips and Kevin R. Ballou it is assumed to be unpredictable or insignificant. In experiments on the PUMA 560 robot arm, Armstrong' dem

226

Friction optimisation and its effect on specific fuel consumption  

Science Journals Connector (OSTI)

As part of a complete-engine development project by Mahle, various optimisation measures were investigated on a modern baseline engine and analysed for their ability to improve the friction behavior of the engine

Dipl.-Ing. Jörg Rückauf; Dipl.-Ing. Boris Lerch

2009-07-01T23:59:59.000Z

227

On the friction coefficient of straight-chain aggregates  

E-Print Network (OSTI)

A methodology to calculate the friction coefficient of an aggregate in the continuum regime is proposed. The friction coefficient and the monomer shielding factors, aggregate-average or individual, are related to the molecule-aggregate collision rate that is obtained from the molecular diffusion equation with an absorbing boundary condition on the aggregate surface. Calculated friction coefficients of straight chains are in very good agreement with previous results, suggesting that the friction coefficients may be accurately calculated from the product of the collision rate and an average momentum transfer,the latter being independent of aggregate morphology. Langevin-dynamics simulations show that the diffusive motion of straight-chain aggregates may be described either by a monomer-dependent or an aggregate-average random force, if the shielding factors are appropriately chosen.

Lorenzo Isella; Yannis Drossinos

2010-07-16T23:59:59.000Z

228

Friction and Wear Enhancement of Titanium Alloy Engine Components...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

7-11, 2010 -- Washington D.C. pm007blau2010o.pdf More Documents & Publications Friction and Wear Enhancement of Titanium Alloy Engine Components Vehicle Technologies Office...

229

Friction anisotropy: A unique and intrinsic property of decagonal quasicrystals  

SciTech Connect

We show that friction anisotropy is an intrinsic property of the atomic structure of Al-Ni-Co decagonal quasicrystals and not only of clean and well-ordered surfaces that can be prepared in vacuum [J.Y. Park et al., Science309, 1354 (2005)]. Friction anisotropy is manifested in both nanometer-size contacts obtained with sharp atomic force microscope tips and macroscopic contacts produced in pin-on-disk tribometers. We show that the friction anisotropy, which is not observed when an amorphous oxide film covers the surface, is recovered when the film is removed due to wear. Equally important is the loss of the friction anisotropy when the quasicrystalline order is destroyed due to cumulative wear. These results reveal the intimate connection between the mechanical properties of these materials and their peculiar atomic structure.

Park, J. Y.; Ogletree, D.; Salmeron, M.

2008-05-01T23:59:59.000Z

230

Friction Stir Spot Welding of Advanced High Strength Steels ...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Steels (AHSS) Friction Stir Spot Welding of Advanced High Strength Steels (AHSS) Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on February...

231

Friction Stir and Ultrasonic Solid State Joining of Magnesium...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

and Ultrasonic Solid State Joining of Magnesium to Steel Friction Stir and Ultrasonic Solid State Joining of Magnesium to Steel 2012 DOE Hydrogen and Fuel Cells Program and Vehicle...

232

Rolling friction and energy dissipation in a spinning disc  

Science Journals Connector (OSTI)

...articles 1006 121 122 Rolling friction and energy dissipation in a spinning disc Daolin...disc, and consequently to quantify its energy. From our experimental observations...responsible for the dissipation of the energy. Furthermore, a mathematical model...

2014-01-01T23:59:59.000Z

233

Hanford Tank Waste Residuals  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Hanford Hanford Tank Waste Residuals DOE HLW Corporate Board November 6, 2008 Chris Kemp, DOE ORP Bill Hewitt, YAHSGS LLC Hanford Tanks & Tank Waste * Single-Shell Tanks (SSTs) - ~27 million gallons of waste* - 149 SSTs located in 12 SST Farms - Grouped into 7 Waste Management Areas (WMAs) for RCRA closure purposes: 200 West Area S/SX T TX/TY U 200 East Area A/AX B/BX/BY C * Double-Shell Tanks (DSTs) - ~26 million gallons of waste* - 28 DSTs located in 6 DST Farms (1 West/5 East) * 17 Misc Underground Storage Tanks (MUST) * 43 Inactive MUST (IMUST) 200 East Area A/AX B/BX/BY C * Volumes fluctuate as SST retrievals and 242-A Evaporator runs occur. Major Regulatory Drivers * Radioactive Tank Waste Materials - Atomic Energy Act - DOE M 435.1-1, Ch II, HLW - Other DOE Orders * Hazardous/Dangerous Tank Wastes - Hanford Federal Facility Agreement and Consent Order (TPA) - Retrieval/Closure under State's implementation

234

Small mass asymptotic for the motion with vanishing friction  

E-Print Network (OSTI)

We consider the small mass asymptotic (Smoluchowski-Kramers approximation) for the Langevin equation with a variable friction coefficient. The friction coefficient is assumed to be vanishing within certain region. We introduce a regularization for this problem and study the limiting motion for the 1-dimensional case and a multidimensional model problem. The limiting motion is a Markov process on a projected space. We specify the generator and boundary condition of this limiting Markov process and prove the convergence.

Mark Freidlin; Wenqing Hu; Alexander Wentzell

2012-01-05T23:59:59.000Z

235

Simple frictional analysis of helical buckling of tubing  

SciTech Connect

Previous analyses of helical buckling of tubing have not considered frictional forces. In this paper, differential equations are derived and solved for two simplified cases of interest: downward motion of the tubing-e.g., when buckling occurs during the landing of the tubing-and upward motion of the tubing-e.g., when buckling occurs as a result of thermal and differential pressure loading subsequent to landing. While somewhat more complicated than the conventional frictionless buckling equations, these solutions are still suitable for hand calculations. These solutions, however, do not represent general solutions to buckling with friction. Load reversals and lateral frictional forces add complications that would require computer analysis. Several examples are examined to evaluate the relative importance of friction, which has a significant impact on tubing length change for loaded cases. For instance, the choice of a conservative value for the friction coefficient may allow the solution of a difficult seal-design problem by reducing a large predicted length change. Friction also has an important effect on set-down loads. Frictionless buckling calculations do not give conservative results for this problem.

Mitchell, R.F.

1986-12-01T23:59:59.000Z

236

Bar-halo Friction in Galaxies I: Scaling Laws  

E-Print Network (OSTI)

It has been known for some time that rotating bars in galaxies slow due to dynamical friction against the halo. However, recent attempts to use this process to place constraints on the dark matter density in galaxies and possibly also to drive dark matter out of the center have been challenged. This paper uses simplified numerical experiments to clarify several aspects of the friction mechanism. I explicitly demonstrate the Chandrasekhar scaling of the friction force with bar mass, halo density, and halo velocity dispersion. I present direct evidence that exchanges between the bar and halo orbits at major resonances are responsible for friction and study both individual orbits and the net changes at these resonances. I also show that friction alters the phase space density of particles in the vicinity of a major resonance, which is the reason the magnitude of the friction force depends on the prior evolution. I demonstrate that bar slow down can be captured correctly in simulations having modest spatial resolution and practicable numbers of particles. Subsequent papers in this series delineate the dark matter density that can be tolerated in halos of different density profiles.

J. A. Sellwood

2004-07-26T23:59:59.000Z

237

The role of crystallography and nanostructures on metallic friction.  

SciTech Connect

In ductile metals, sliding contact is often accompanied by severe plastic deformation localized to a small volume of material adjacent to the wear surface. During the initial run-in period, hardness, grain structure and crystallographic texture of the surfaces that come into sliding contact undergo significant changes, culminating in the evolution of subsurface layers with their own characteristic features. Here, a brief overview of our ongoing research on the fundamental phenomena governing the friction-induced recrystallization in single crystal metals, and how these recrystallized structures with nanometer-size grains would in turn influence metallic friction will be presented. We have employed a novel combination of experimental tools (FIB, EBSD and TEM) and an analysis of the critical resolved shear stress (RSS) on the twelve slip systems of the FCC lattice to understand the evolution of these friction-induced structures in single crystal nickel. The later part of the talk deals with the mechanisms of friction in nanocrystalline Ni films. Analyses of friction-induced subsurfaces seem to confirm that the formation of stable ultrafine nanocrystalline layers with 2-10 nm grains changes the deformation mechanism from the traditional dislocation mediated one to that is predominantly controlled by grain boundaries, resulting in significant reductions in the coefficient friction.

Michael, Joseph Richard; Prasad, Somuri V.; Battaile, Corbett Chandler; Majumdar, Bhaskar Sinha (New Mexico Institute of Mining & Technology, Socorro, NM); Kotula, Paul Gabriel

2010-06-01T23:59:59.000Z

238

Bar-Halo Friction in Galaxies II: Metastability  

E-Print Network (OSTI)

It is well-established that strong bars rotating in dense halos generally slow down as they lose angular momentum to the halo through dynamical friction. Angular momentum exchanges between the bar and halo particles take place at resonances. While some particles gain and others lose, friction arises when there is an excess of gainers over losers. This imbalance results from the generally decreasing numbers of particles with increasing angular momentum, and friction can therefore be avoided if there is no gradient in the density of particles across the major resonances. Here we show that anomalously weak friction can occur for this reason if the pattern speed of the bar fluctuates upwards. After such an event, the density of resonant halo particles has a local inflexion created by the earlier exchanges, and bar slowdown can be delayed for a long period; we describe this as a metastable state. We show that this behavior in purely collisionless N-body simulations is far more likely to occur in methods with adaptive resolution. We also show that the phenomenon could arise in nature, since bar-driven gas inflow could easily raise the bar pattern speed enough to reach the metastable state. Finally, we demonstrate that mild external, or internal, perturbations quickly restore the usual frictional drag, and it is unlikely therefore that a strong bar in a galaxy having a dense halo could rotate for a long period without friction.

J. A. Sellwood; Victor P. Debattista

2005-11-05T23:59:59.000Z

239

The Equilibrium Tide Model for Tidal Friction  

Science Journals Connector (OSTI)

We derive from first principles the equations governing (a) the quadrupole tensor of a star distorted both by rotation and by the presence of a companion in a possibly eccentric orbit; (b) a functional form for the dissipative force of tidal friction, based on the concept that the rate of energy loss from a time-dependent tide should be a positive-definite function of the rate of change of the quadrupole tensor as seen in the frame that rotates with the star; and (c) the equations governing the rates of change of the magnitude and the direction of the stellar rotation, the orbital period and eccentricity, based on the concept of the Laplace-Runge-Lenz vector. Our analysis leads relatively simply to a closed set of equations, valid for arbitrary inclination of the stellar spin to the orbit. The results are equivalent to classical results based on the rather less clear principle that the tidal bulge lags behind the line of centers by some time determined by the rate of dissipation. Our analysis gives the effective lag time as a function of the dissipation rate and the quadrupole moment. We discuss briefly some possible applications of the formulation.

Peter P. Eggleton; Ludmila G. Kiseleva; Piet Hut

1998-01-01T23:59:59.000Z

240

Effect of temperature and arc discharge on friction and wear behaviours of carbon strip/copper contact wire in pantograph–catenary systems  

Science Journals Connector (OSTI)

A series of tests on friction and wear performance of pure copper rubbing against carbon strip under electric current have been carried out on a modified pin-on-disc friction and wear tester. The results indicate that there are temperature rise and arc discharge in the electrical sliding processes. The temperature rise of contact pairs and the intensity of arc discharge increase with the increasing of electric current. However, the friction coefficient increases firstly due to the accumulation of wear debris, and then decreases with the increasing of electric current due to the accumulation of electric heat and friction heat on contact interface. The increase in wear volume of the carbon strip is mainly caused by high temperature of contact pairs and arc discharge phenomenon. The test results also show that the wear volume of pin specimen with arc discharge is much greater than that without arc discharge under the same temperature. Therefore, the thermal wear due to high temperature has a distinct influence on the service life of pantograph contact strip and arc erosion even has more significant influence. Cooling measures should be applied in pantograph/catenary systems. Especially, off-line arc discharge of the contact couple should be suppressed to the maximum extent to extend the service life of pantograph contact strip.

T. Ding; G.X. Chen; J. Bu; W.H. Zhang

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Susanville District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

Susanville District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Susanville District Heating District Heating Low Temperature...

242

MECHANICAL PROPERTIES AND MICROSTRUCTURAL CHARACTERIZATION OF A MULTILAYERED MULTIPASS FRICTION STIR WELD IN STEEL  

SciTech Connect

Multilayered multipass friction stir welding (MM-FSW) makes it possible to use FSW to fabricate thick-section structures. In this work, MM-FSW was demonstrated on a high strength low alloy steel; ASTM A572 Grade 50. Three steel plates with thicknesses of 0.18", 0.18", 0.24" respectively were stacked and friction stir welded together to form a 0.6" thick welded structure. The welded plate was sectioned into rectangular bars transverse to the weld direction for tensile testing to evaluate mechanical properties. Digital image correlation (DIC) was employed to map the local strain fields during tensile testing. The initial failure was found to occur simultaneously at the bottom and middle layers away from the weld zone. The top layer failed last in the base metal. The failure locations were consistent among different samples tested. Also, Charpy V-notch impact tests were conducted for weld metal, heat affected zone, and the base metal at each layer as a function of temperature. The weld microstructures were characterized using optical and electron microscopy and micro-hardness mapping.

Lim, Yong Chae [ORNL; Sanderson, Samuel [MegaStir Technologies LLC; Mahoney, Murray [Consultant; Qiao, Dongxiao [ORNL; Wang, Yanli [ORNL; Zhang, Wei [ORNL; Feng, Zhili [ORNL

2013-01-01T23:59:59.000Z

243

Residual Strain Distribution in Bent Composite Boiler Tubes  

SciTech Connect

Kraft recovery boilers are typically constructed of carbon steel boiler tubes clad with a corrosion resistant layer, and these composite tubes are bent and welded together to form air port panels which enable the combustion air to enter the boiler. In this paper, the through-thickness residual strain in the carbon steel layer of non-heat-treated and heat-treated composite bent tubes were measured by neutron diffraction techniques and modeled by finite element modeling. The results can be used to optimize material selection and manufacturing processes to prevent stress corrosion and corrosion fatigue cracking in the boiler tubes.

Hubbard, Camden R [ORNL; Gorti, Sarma B [ORNL; Tang, Fei [ORNL

2006-01-01T23:59:59.000Z

244

Mechanical and metallurgical properties of MMC friction welds  

SciTech Connect

The mechanical and metallurgical properties of similar and dissimilar welds involving aluminum-based metal matrix composite (MMC) base material were investigated using factorial experimentation. The test materials comprised aluminum-based alloy 6061/Al{sub 2}O{sub 3} (W6A.10A-T6), aluminum Alloy 6061-T6 and AISI 304 stainless steel. Notch tensile strength increased when high friction pressures were employed during MMC/MMC, MMC/Alloy 6061, MMC/AISI 304 stainless steel and Alloy 6061/Alloy 6061 friction welding. In MMC/Alloy 6061 welds, notch tensile strength also increased when high forging pressures were employed. Applied oxide films on both the MMC and AISI stainless steel substrates had a markedly detrimental effect on dissimilar weld mechanical properties. The optimum notch tensile strength properties were produced when high friction pressure values were applied during dissimilar MMC/AISI 304 stainless steel welding. High friction pressure had two beneficial effects, i.e., it decreased the thickness of the FeAl{sub 3} intermetallic film and it promoted disruption and dispersal of oxide films at the joint interface. In direct contrast, the presence of thick anodized oxide films on the MMC substrate surface prior to friction welding had no observable influence on MMC/MMC weld mechanical properties.

Li, Z.; Maldonado, C.; North, T.H. [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science; Altshuller, B. [Alcan R and D Labs., Kingston, Ontario (Canada)

1997-09-01T23:59:59.000Z

245

Microwave calcination for plutonium immobilization and residue stabilization  

SciTech Connect

In the late 1980`s development was begun on a process using microwave energy to vitrify low level mixed waste sludge and transuranic mixed waste sludge generated in Building 374 at Rocky Flats. This process was shown to produce a dense, highly durable waste form. With the cessation of weapons production at Rocky Flats, the emphasis has changed from treatment of low level and TRU wastes to stabilizaiton of plutonium oxide and residues. This equipment is versatile and can be used as a heat source to calcine, react or vitrify many types of residues and oxides. It has natural economies in that it heats only the material to be treated, significantly reducing cycle times over conventional furnaces. It is inexpensive to operate in that most of the working components remain outside of any necessary contamination enclosure and therefore can easily be maintained. Limited testing has been successfully performed on cerium oxide (as a surrogate for plutonium oxide), surrogate electrorefining salts, surrogate residue sludge and residue ash. Future plans also include tests on ion exchange resins. In an attempt to further the usefullness of this technology, a mobile, self-contained microwave melting system is currently under development and expected to be operational at Rocky Flats Enviromental Technology Site by the 4th quarter of FY96.

Harris, M.J.; Rising, T.L.; Roushey, W.J.; Sprenger, G.S. [Kaiser-Hill Co., Golden, CO (United States)

1995-12-01T23:59:59.000Z

246

Temperature–friction characteristics of used lubricant from two-stroke cross-head marine diesel engines  

Science Journals Connector (OSTI)

It is now quite apparent that, in a two-stroke, cross-head marine diesel engine, the lubrication regime in the contact between piston ring and cylinder liner at the top dead centre (TDC) is of a boundary type. Therefore, the tribological performance of a system to simulate the real contact should be assessed under conditions closely resembling the operating engine environment. In the reality of engine operation, the lubricant is often contaminated by fuel and products of combustion, hence the need to study the temperature–friction characteristics of this actual lubricant under the conditions of boundary lubrication. In this paper, an oil taken from the drainage system of the engine was used. A five times heating and cooling test methodology was employed to assess tribological performance of a model contact lubricated with the actual oil. The model contact was formed by a pin sliding over a plate both made of materials used in two-stroke, cross-head marine diesel engines. Experiments showed that the general trend in temperature–friction characteristics of the used oil is similar to that of a new oil. However, the level of friction in the contact lubricated with an used oil is significantly higher than that for a new oil.

T.A Stolarski; Q Zhou

2002-01-01T23:59:59.000Z

247

Essential Substrate Residues for Action of Endopeptidases  

Science Journals Connector (OSTI)

Endopeptidases, which are influenced in their specificity primarily by basic residues of arginine or lysine are treated in seven sections, according to the position of the essential residue: ...

Prof. Dr. Borivoj Keil

1992-01-01T23:59:59.000Z

248

DISSOLUTION OF NEPTUNIUM OXIDE RESIDUES  

SciTech Connect

This report describes the development of a dissolution flowsheet for neptunium (Np) oxide (NpO{sub 2}) residues (i.e., various NpO{sub 2} sources, HB-Line glovebox sweepings, and Savannah River National Laboratory (SRNL) thermogravimetric analysis samples). Samples of each type of materials proposed for processing were dissolved in a closed laboratory apparatus and the rate and total quantity of off-gas were measured. Samples of the off-gas were also analyzed. The quantity and type of solids remaining (when visible) were determined after post-dissolution filtration of the solution. Recommended conditions for dissolution of the NpO{sub 2} residues are: Solution Matrix and Loading: {approx}50 g Np/L (750 g Np in 15 L of dissolver solution), using 8 M nitric acid (HNO{sub 3}), 0.025 M potassium fluoride (KF) at greater than 100 C for at least 3 hours. Off-gas: Analysis of the off-gas indicated nitric oxide (NO), nitrogen dioxide (NO{sub 2}) and nitrous oxide (N{sub 2}O) as the only identified components. No hydrogen (H{sub 2}) was detected. The molar ratio of off-gas produced per mole of Np dissolved ranged from 0.25 to 0.4 moles of gas per mole of Np dissolved. A peak off-gas rate of {approx}0.1 scfm/kg bulk oxide was observed. Residual Solids: Pure NpO{sub 2} dissolved with little or no residue with the proposed flowsheet but the NpCo and both sweepings samples left visible solid residue after dissolution. For the NpCo and Part II Sweepings samples the residue amounted to {approx}1% of the initial material, but for the Part I Sweepings sample, the residue amounted to {approx}8 % of the initial material. These residues contained primarily aluminum (Al) and silicon (Si) compounds that did not completely dissolve under the flowsheet conditions. The residues from both sweepings samples contained minor amounts of plutonium (Pu) particles. Overall, the undissolved Np and Pu particles in the residues were a very small fraction of the total solids.

Kyser, E

2009-01-12T23:59:59.000Z

249

Friction and Wear Behavior of Ultrahigh Molecular Weight Polyethylene as a Function of Crystallinity in the Presence of the  

E-Print Network (OSTI)

Friction and Wear Behavior of Ultrahigh Molecular Weight Polyethylene as a Function: In this study, the friction and wear behavior of ultrahigh molecular weight polyethylene (UHMWPE) were evaluated Words: ultrahigh molecular weight polyethylene (UHMWPE), crystallinity, friction, wear, phospholipid

Lin, Zhiqun

250

DHE (downhole heat exchangers). [Downhole Heat Exchangers (DHE)  

SciTech Connect

The use of downhole heat exchangers (DHE) for residential or commercial space and domestic water heating and other applications has several desirable features. Systems are nearly or completely passive -- that is, no or very little geothermal water or steam is produced from the well either reducing or completely eliminating surface environmental concerns and the need for disposal systems or injection wells. Initial cost of pumps and installation are eliminated or reduced along with pumping power costs and maintenance costs associated with pumping often corrosive geothermal fluids. Many residential and small commercial systems do not require circulating pumps because the density difference in the incoming and outgoing sides of the loop are sufficient to overcome circulating friction losses in the entire system. The major disadvantage of DHEs is their dependence on natural heat flow. In areas where geological conditions provide high permeability and a natural hydraulic gradient, DHEs can provide a substantial quantity of heat. A single 500-ft (152 m) well in Klamath Falls, Oregon, supplies over one megawatt thermal and output is apparently limited by the surface area of pipe that can be installed in the well bore. In contrast, DHEs used in conjunction with heat pumps may supply less than 8 KW from a well of similar depth. Here output is limited by conductive heat flow with perhaps a small contribution from convection near the well bore. The highest capacity DHE reported to date, in Turkey, supplies 6 MW thermal from an 820-ft (250 m) well. There were two main goals for this project. The first was to gather, disseminate and exchange internationally information on DHES. The second was to perform experiments that would provide insight into well bore/aquifer interaction and thereby provide more information on which to base DHE designs. 27 refs., 31 figs., 3 tabs.

Culver, G.

1990-11-01T23:59:59.000Z

251

Measurements of wall heat (mass) transfer for flow through blockages with round and square holes in a wide rectangular channel  

E-Print Network (OSTI)

COMMANDS . . APPENDIX C: UNCERTAINTY ANALYSIS . APPENDIX D: RAW DATA & RESULTS . . 71 . . . . 74 77 VITA. 134 vu1 LIST OF FIGURES Page Figurc 1 Internal and external cooling concepts used in modem gas turbine airfoils (Han et al. ). Figure 2... . . . . . . . . . . . . . . . . . . . . . . . . . 62 xt NOMENCLATURE A, flow cross-sectional area of test channel, m 2 surface area, m 2 D?hydraulic diameter of test channel, m friction factor f, reference friction factor for fully developed turbulent flow in smooth channel heat transfer...

Cervantes, Joel

2012-06-07T23:59:59.000Z

252

Frictional Cooling Scheme for Use in a Muon Collider  

SciTech Connect

The Muon Group at the MPI for Physics, Munich is investigating frictional cooling as a fast muon-beam emittance reduction scheme for a muon collider. A new simulation package, CoolSim, based on Geant4 has been developed for the simulation of low-energy beam cooling. New physics processes for low energy muons and protons have been implemented in the Geant4 framework. The group's Frictional Cooling Demonstration experiment aims to verify the principle of the cooling scheme. For this purpose, a 10-cm-long cooling cell has been constructed to test simulation of the energy loss and scattering mechanisms at low energy. This paper contains an introduction to a muon-collider frictional cooling scheme and the status of the demonstration experiment.

Greenwald, Daniel; Caldwell, Allen [Max-Planck-Insitut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Bao, Yu [Max-Planck-Insitut fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing (China)

2010-03-30T23:59:59.000Z

253

The Schroedinger equation with friction from the quantum trajectory perspective  

SciTech Connect

Similarity of equations of motion for the classical and quantum trajectories is used to introduce a friction term dependent on the wavefunction phase into the time-dependent Schroedinger equation. The term describes irreversible energy loss by the quantum system. The force of friction is proportional to the velocity of a quantum trajectory. The resulting Schroedinger equation is nonlinear, conserves wavefunction normalization, and evolves an arbitrary wavefunction into the ground state of the system (of appropriate symmetry if applicable). Decrease in energy is proportional to the average kinetic energy of the quantum trajectory ensemble. Dynamics in the high friction regime is suitable for simple models of reactions proceeding with energy transfer from the system to the environment. Examples of dynamics are given for single and symmetric and asymmetric double well potentials.

Garashchuk, Sophya; Dixit, Vaibhav; Gu Bing; Mazzuca, James [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208 (United States)

2013-02-07T23:59:59.000Z

254

Modeling of the moving induction heating used as secondary heat source in weld-based additive manufacturing  

Science Journals Connector (OSTI)

To combat thermal-induced problems such as residual stress, deformation, and crack, induction heating is introduced into weld-based additive manufacturing process as a controlled thermal intervention. To ... nume...

Xingwang Bai; Haiou Zhang; Guilan Wang

2014-10-01T23:59:59.000Z

255

Impurity gas effects on friction and wear of high-temperature materials for VHTRs  

SciTech Connect

Concentration being varied up to about10/sup 3/ PPM. developed at the Japan Atomic Energy Research Institute, reactor components, such as heat transfer tubes (Hastelloy-XR) of an intermediate heat exchanger, hot duct liners (Hastelloy-XR), core support plates (2 1/4 Cr-1 Mo steel), control rod sheaths (HastelloyXR), orifice devices (SUS 304), fuel blocks (graphite), and others, are exposed to helium gas coolant with a temperature of 1000/sup 0/C and a pressure of 4.1 MPa. The relative sliding movements of the structure, which are stimulated by flow-induced vibration, constraint force, and thermal expansion, might cause unfavorable friction and wear. Sliding wear tests were carried out on PGX graphite, 2 1/4 Cr-1 Mo steel, and heat- and corrosion-resistant Hastelloy-XR in 500 to 1000/sup 0/C. Environmental helium gas pressures of 0.2 and 4.1 MPa were chosen to compare the influence of the pressures. The effects of four different impurity gases (O/sub 2/, H/sub 2/, H/sub 2/O, and CH/sub 4/) on tribological behavior were studied, each gas Concentration being aried up to about10/sup 3/ PPM.

Kikuchi, K.; Kawaguchi, K.; Nemoto, M.; Sanokawa, K.; Watanabe, S.

1984-09-01T23:59:59.000Z

256

The Role of Sustainability Standards in the Energetic Use of Palm Oil Plantation Residues: Case Study of Cameroon  

Science Journals Connector (OSTI)

This chapter aims to discuss the sustainability aspects of using residual wood from plantations for the production of electricity and heat. ... There are continuous debates about the potential of biomass feedstoc...

Michael Schmidt; Berthold Hansmann; Pia Dewitz

2014-01-01T23:59:59.000Z

257

Effects of mechanical properties and surface friction on elasto-plastic sliding contact  

E-Print Network (OSTI)

Effects of mechanical properties and surface friction on elasto-plastic sliding contact S and many recent computational studies have established quantitative relationships between elasto-plastic systematically quantified the effect of the plastic deformation characteristics on the frictional sliding

Suresh, Subra

258

Experimental and Theoretical Investigation of Lubricant and Additive Effects on Engine Friction  

Energy.gov (U.S. Department of Energy (DOE))

Combining data from motored engine friction, a theoretical engine model, a line friction contact rig, and a fired engine can provide better insight to lube oil and additive performance.

259

Heat Stroke  

NLE Websites -- All DOE Office Websites (Extended Search)

stress, from exertion or hot environments, places stress, from exertion or hot environments, places workers at risk for illnesses such as heat stroke, heat exhaustion, or heat cramps. Heat Stroke A condition that occurs when the body becomes unable to control its temperature, and can cause death or permanent disability. Symptoms â–  High body temperature â–  Confusion â–  Loss of coordination â–  Hot, dry skin or profuse sweating â–  Throbbing headache â–  Seizures, coma First Aid â–  Request immediate medical assistance. â–  Move the worker to a cool, shaded area. â–  Remove excess clothing and apply cool water to their body. Heat Exhaustion The body's response to an excessive loss of water and salt, usually through sweating. Symptoms â–  Rapid heart beat â–  Heavy sweating â–  Extreme weakness or fatigue â– 

260

Lubricant-Friendly, Superhard and Low-Friction Coatings by Design  

Energy.gov (U.S. Department of Energy (DOE))

Superhard and low-friction coatings and surface treatments can help improve fuel economy and durability in engines.

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Wear 261 (2006) 410418 A low friction and ultra low wear rate PEEK/PTFE composite  

E-Print Network (OSTI)

Wear 261 (2006) 410­418 A low friction and ultra low wear rate PEEK/PTFE composite David L. Burris composite that exhibits low friction and ultra-low wear. It is hypothesized that a synergistic effect shuts down the dominant wear mechanism of each constituent. The friction coefficient and wear rate

Sawyer, Wallace

262

An accurate elasto-plastic frictional tangential forcedisplacement model for granular-flow  

E-Print Network (OSTI)

An accurate elasto-plastic frictional tangential force­displacement model for granular for both elastic and plastic deformations together with interfacial friction occurring in collisions of spherical particles. This elasto-plastic frictional TFD model, with its force-driven version presented in [L

Vu-Quoc, Loc

263

Friction and curvature judgement Chris Christou (1) and Alan Wing (2)  

E-Print Network (OSTI)

Friction and curvature judgement Chris Christou (1) and Alan Wing (2) (1) Optometry resistance to motion due to friction. This resistance creates a force vector which varies in direction with friction. But the vector also varies in direction with the curvature of the surface traversed by the finger

264

Friction experiments with elastography: the slow slip and the super-shear regimes  

E-Print Network (OSTI)

Friction experiments with elastography: the slow slip and the super-shear regimes S. Cathelinea , S technique derived from elastography, is used to follow the dynamic of the interface failure in a friction by Amontons in 1699 [1], the resistance to slip of an interface can be modeled by two main frictional states

Boyer, Edmond

265

M.-T. DO, P. MARSAC, Y. DELANNE Prediction of Tire/Wet Road Friction from  

E-Print Network (OSTI)

M.-T. DO, P. MARSAC, Y. DELANNE 1 Prediction of Tire/Wet Road Friction from Road Surface, validation of a contact model for the prediction of low-speed friction from road surface microtexture the friction ­ speed curve from road- and tire measurable parameters. The model development is briefly

Paris-Sud XI, Université de

266

ENSC 283: Friction and Minor Losses in Pipelines School of Engineering Science  

E-Print Network (OSTI)

ENSC 283: Friction and Minor Losses in Pipelines 1 School of Engineering Science Mechatronics), between which differential pressure up to a maximum of 200 mbar can be measured. #12;ENSC 283: Friction Figure 1- Components of experimental apparatus. #12;ENSC 283: Friction and Minor Losses in Pipelines 3

Bahrami, Majid

267

Dry friction between laser-patterned surfaces: Role of alignment, structural wavelength and  

E-Print Network (OSTI)

1 Dry friction between laser-patterned surfaces: Role of alignment, structural wavelength.gachot@mx.uni-saarland.de Abstract The ability to tune friction by tailoring surface topographies at micron length scales friction between laser-textured surfaces. Line-like laser patterns with varying structural wavelengths

Mueser, Martin

268

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results  

E-Print Network (OSTI)

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results C. Canudas dynamic friction force model for the longitudinal road/tire interaction for wheeled ground vehicles is val- idated via experiments with an actual passenger vehicle. Contrary to common static friction/slip maps

Tsiotras, Panagiotis

269

Collective friction coefficients in the relaxation time approximation F. A. Ivanyuk  

E-Print Network (OSTI)

Collective friction coefficients in the relaxation time approximation F. A. Ivanyuk Institute components of the friction coefficient for various single-particle potentials and have found that the nondiagonal component of the friction coefficient depends generally on the diffuseness of the potential

Pomorski, Krzysztof

270

Brownian dynamics algorithm for bead-rod semiflexible chain with anisotropic friction  

E-Print Network (OSTI)

Brownian dynamics algorithm for bead-rod semiflexible chain with anisotropic friction Alberto of semiflexible bead-rod chain with anisotropic friction can mimic closely the hydrodynamics of a slender filament dependent anisotropic bead friction coefficients. The algorithm is an extension of that given previously

Natelson, Douglas

271

Long Term Friction: from Stick-Slip to Stable Sliding1 Christophe Voisin1  

E-Print Network (OSTI)

1 Long Term Friction: from Stick-Slip to Stable Sliding1 Christophe Voisin1 , François Renard1 Abstract. We have devised an original laboratory experiment where we investigate6 the frictional behaviour, salt, an analogue for natural8 faults, allows for frictional processes plastic deformation and pressure

Paris-Sud XI, Université de

272

A parallel and multiscale strategy for the parametric study of transient dynamic problems with friction  

E-Print Network (OSTI)

with friction P.-A. Boucard1, D. Odi`evre1 and F. Gatuingt1 LMT-Cachan (ENS Cachan/CNRS/Universit´e Paris 6/PRES with friction. Our approach is based on the multiscale LATIN method with domain decomposition. This is a mixed; transient dynamics; domain decomposition; contact; friction; parallel processing 1. INTRODUCTION Modeling

273

Analysis of a unilateral contact problem taking into account adhesion and friction  

E-Print Network (OSTI)

Analysis of a unilateral contact problem taking into account adhesion and friction Elena Bonetti) adhesion and of the friction are taken into account. We describe the adhesion phenomenon in terms conditions, and friction by a nonlocal Coulomb law. All the constraints on the internal variables as well

Rossi, Riccarda

274

Noise and vibration for a self-excited mechanical system with friction  

E-Print Network (OSTI)

Noise and vibration for a self-excited mechanical system with friction K. Soobbarayen1,a , S. The contact is modelled by introducing several local contact elements at the friction interface and a cubic contact law is used to describe the contact force. The classical Coulomb law is applied to model friction

Boyer, Edmond

275

Creeping Friction Dynamics and Molecular Dissipation Mechanisms in Glassy Polymers Scott Sills and Rene M. Overney  

E-Print Network (OSTI)

Creeping Friction Dynamics and Molecular Dissipation Mechanisms in Glassy Polymers Scott Sills kinetic friction between an atomic force microscopy tip and a surface of amorphous glassy polystyrene has of the friction results using the method of reduced variables revealed the dissipative behavior as an activated

276

Long term friction: From stick-slip to stable sliding Christophe Voisin,1  

E-Print Network (OSTI)

Long term friction: From stick-slip to stable sliding Christophe Voisin,1 Franc¸ois Renard,1 July 2007. [1] We have devised an original laboratory experiment where we investigate the frictional properties, salt, an analogue for natural faults, allows for frictional processes plastic deformation

277

Analysis of a unilateral contact problem taking into account adhesion and friction  

E-Print Network (OSTI)

Analysis of a unilateral contact problem taking into account adhesion and friction Elena Bonetti) adhesion and of the friction are taken into account. We describe the adhesion phenomenon in terms conditions and the friction by a nonlocal Coulomb law. All the constraints on the internal variables as well

Rossi, Riccarda

278

Long Term Friction: from Stick-Slip to Stable Sliding Christophe Voisin1  

E-Print Network (OSTI)

1 Long Term Friction: from Stick-Slip to Stable Sliding Christophe Voisin1 , François Renard1 where we investigate the frictional behaviour of a single crystal salt slider over a large number for friction and plastic deformation and pressure solution creep to be efficient on the same timescale. During

Paris-Sud XI, Université de

279

Internal Friction Controls the Speed of Protein Folding from a Compact Configuration  

E-Print Network (OSTI)

Internal Friction Controls the Speed of Protein Folding from a Compact Configuration Suzette A is independent of the cosolutes used to adjust solvent friction. Therefore, interactions within the interior. Interestingly, we find a very strong temperature dependence in these "internal friction"-controlled dynamics

Roder, Heinrich

280

FRICTION AND THE INVERTED PENDULUM STABILIZATION PROBLEM Sue Ann Campbell Stephanie Crawford Kirsten Morris  

E-Print Network (OSTI)

FRICTION AND THE INVERTED PENDULUM STABILIZATION PROBLEM Sue Ann Campbell Stephanie Crawford of friction on the design and performance of feedback controllers that aim to stabilize the pendulum in the upright position. We show that a controller designed using a simple viscous friction model has poor

Morris, Kirsten

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Journal of Sound and Vibration (1997) 202(2), 203218 SEMI-ACTIVE CONTROL OF FRICTION  

E-Print Network (OSTI)

Journal of Sound and Vibration (1997) 202(2), 203­218 SEMI-ACTIVE CONTROL OF FRICTION DAMPERS P, U.S.A. (Received 22 January 1996, and in final form 21 October 1996) Semi-active control of friction dampers has been proposed to improve the energy dissipation characteristics of passive friction dampers

Dupont, Pierre

282

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Theoretical Advances  

E-Print Network (OSTI)

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Theoretical Advances C. Canudas we derive a new dynamic friction force model for the longitudinal road/tire interaction for wheeled-point friction problems, called the LuGre model [1]. By assuming a con- tact patch between the tire

Tsiotras, Panagiotis

283

Adaptive Friction Compensation for Servo J. Wang, S. S. Ge, and T. H. Lee  

E-Print Network (OSTI)

Adaptive Friction Compensation for Servo Mechanisms J. Wang, S. S. Ge, and T. H. Lee Department@nus.edu.sg Abstract Friction exists in all machines having relative motion, and plays an important role in many servo, accurate friction modeling and effective compensation techniques have to be investigated. In this chapter

Ge, Shuzhi Sam

284

Nonlinear friction of a damped dimer sliding on a periodic substrate S. Gonalves,1,2,  

E-Print Network (OSTI)

Nonlinear friction of a damped dimer sliding on a periodic substrate S. Gonçalves,1,2, * V. M, USA (Received 23 July 2004; published 12 November 2004) The nonlinear sliding friction of a dimer over that the friction force has an approximate v-3 depen- dence if the velocity is sufficiently large

Kenkre, V.M.

285

Passivity Analysis of a Motion Controller for Robot Manipulators with Dynamic Friction  

E-Print Network (OSTI)

Passivity Analysis of a Motion Controller for Robot Manipulators with Dynamic Friction Carlos the motion control in joint space of robot manipulators with friction described by the generalized LuGre friction model. The paper extends the nonadaptive ver- sion of the Slotine and Li's control system

Paris-Sud XI, Université de

286

DISPLAY OF FRICTION IN VIRTUAL ENVIRONMENTS BASED ON HUMAN FINGER PAD CHARACTERISTICS  

E-Print Network (OSTI)

DISPLAY OF FRICTION IN VIRTUAL ENVIRONMENTS BASED ON HUMAN FINGER PAD CHARACTERISTICS A. Nahvi, J City, UT 84112 ABSTRACT A friction display system is proposed for virtual environ- ments. Since a user the frictional properties of the human finger pad on 9 subjects by simultaneously recording force and movement

Hollerbach, John M.

287

ACC03-ASME0018 Controller Design for Flexible Systems with Friction  

E-Print Network (OSTI)

ACC03-ASME0018 Controller Design for Flexible Systems with Friction: Linear Programming Approach of friction is presented. A linear program- ming technique for finding an optimal control of linear flexible systems is extended to frictional systems. A floating oscillator is used in the development, where

Singh, Tarunraj

288

Friction, Frontogenesis, and the Stratification of the Surface Mixed Layer LEIF THOMAS*  

E-Print Network (OSTI)

Friction, Frontogenesis, and the Stratification of the Surface Mixed Layer LEIF THOMAS* Department restratification resulting from frontogenesis in regions of confluent flow. Frictional forces acting of friction versus frontogenesis in the restratification of the mixed layer and are tested using numerical

Thompson, Andrew

289

Internal friction in the ultrafast folding of the tryptophan cage q Linlin Qiu 1  

E-Print Network (OSTI)

Internal friction in the ultrafast folding of the tryptophan cage q Linlin Qiu 1 , Stephen J. Hagen is a diffusional process, and the speed of folding is controlled by the frictional forces that act important source of friction in folding reactions. By contrast, our studies of the folding dynamics

Hagen, Stephen J.

290

Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction  

E-Print Network (OSTI)

Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction-dimensional systems subject to a periodic force and study numer- ically how a time-varying friction affects oscillator in the presence of friction. We find that, if the damping coefficient increases in time up

291

Friction of a slider on a granular layer: Nonmonotonic thickness dependence and effect of boundary conditions  

E-Print Network (OSTI)

Friction of a slider on a granular layer: Nonmonotonic thickness dependence and effect of boundary the effective friction encountered by a mass sliding on a granular layer as a function of bed thickness and boundary roughness conditions. The observed friction has minima for a small number of layers before

Kudrolli, Arshad

292

Penetration rate prediction for percussive drilling via dry friction model  

E-Print Network (OSTI)

Penetration rate prediction for percussive drilling via dry friction model Anton M. Krivtsov a. Similarly, an increased weight on bit in downhole drilling does not improve the penetration rates when hard- tration rate is presented. The inherent nonlinearity of the discontinuous impact process is modelled

Krivtsov, Anton M.

293

TBM tunnel friction values for the Grizzly Powerhouse Project  

SciTech Connect

Tunnel boring machine (TBM) driven water conveyance tunnels are becoming increasingly more common. Despite advances in tunnel engineering and construction technology, hydraulic performance data for TBM driven tunnels remains relatively unavailable. At the Grizzly Powerhouse Project, the TBM driven water conveyance tunnel was designed using friction coefficients developed from a previous PG&E project. A range of coefficients were selected to bound the possible hydraulic performance variations of the water conveyance system. These friction coefficients, along with the water conveyance systems characteristics, and expected turbine characteristics, were used in a hydraulic transient analysis to determine the expected system pressure fluctuations, and surge chamber performance. During startup test data, these performance characteristics were measured to allow comparison to the original design assumptions. During construction of the tunnel, plaster casts were made of the actual excavated tunnel unlined and fiber reinforced shotcrete lined surfaces. These castings were used to measure absolute roughness of the surfaces so that a friction coefficient could be developed using the Moody diagram and compare them against the design values. This paper compares the assumed frictional coefficient with computed coefficients from headlosses measured during startup testing, and plaster cast measurement calculations. In addition, a comparison of coefficients will be presented for an other TBM driven water conveyance tunnel constructed in the 1980`s.

Stutsman, R.D. [Ensign & Buckley Consulting Engineers, Larkspur, CA (United States); Rothfuss, B.D. [Pacific Gas and Electric Co., San Francisco, CA (United States)

1995-12-31T23:59:59.000Z

294

Coupling Boltzmann and Navier-Stokes equations by friction  

SciTech Connect

The aim of this paper is to introduce and validate a coupled Navier-Stokes Boltzman approach for the calculation of hypersonic rarefied flows around maneuvering vehicles. The proposed strategy uses locally a kinetic model in the boundary layer coupled through wall friction forces to a global Navier-Stokes solver. Different numerical experiments illustrate the potentialities of the method. 29 refs., 24 figs.

Bourgat, J.F. [INRIA, Le Chesnay (France)] [INRIA, Le Chesnay (France); Le Tallec, P. [Universite Paris, Dauphine (France)] [Universite Paris, Dauphine (France); [INRIA, Le Chesnay (France); Tidriri, M.D. [ICASE, Hampton, VA (United States)] [ICASE, Hampton, VA (United States)

1996-09-01T23:59:59.000Z

295

The influence of internal friction on rotordynamic instability  

E-Print Network (OSTI)

Internal friction has been known to be a cause of whirl instability in built-up rotors since the early 1900's. This internal damping tends to make the rotor whirl at shaft speeds greater than a critical speed, the whirl speed usually being equal...

Srinivasan, Anand

2004-09-30T23:59:59.000Z

296

Page 1 of 40 Capital market frictions, Leasing and Investment  

E-Print Network (OSTI)

capital expenditures and reducing the sensitivity of investment expenditures to availability of internal be the only option. So, does leasing positively affect the capital expenditure of lessee firms? Does leasingPage 1 of 40 Capital market frictions, Leasing and Investment Vasantha Rao Chigurupati Ph

Saskatchewan, University of

297

Casimir Friction Force and Energy Dissipation for Moving Harmonic Oscillators  

E-Print Network (OSTI)

The Casimir friction problem for a pair of dielectric particles in relative motion is analyzed, utilizing a microscopic model in which we start from statistical mechanics for harmonically oscillating particles at finite temperature moving nonrelativistically with constant velocity. The use of statistical mechanics in this context has in our opinion some definite advantages, in comparison with the more conventional quantum electrodynamic description of media that involves the use of a refractive index. The statistical-mechanical description is physical and direct, and the oscillator model, in spite of its simplicity, is nevertheless able to elucidate the essentials of the Casimir friction. As is known, there are diverging opinions about this kind of friction in the literature. Our treatment elaborates upon, and extends, an earlier theory presented by us back in 1992. There we found a finite friction force at any finite temperature, whereas at zero temperature the model led to a zero force. As an additional development in the present paper we evaluate the energy dissipation making use of an exponential cutoff truncating the relative motion of the oscillators. For the dissipation we also establish a general expression that is not limited to the simple oscillator model.

Johan S. Høye; Iver Brevik

2010-01-14T23:59:59.000Z

298

Smoluchowski-Kramers approximation in the case of variable friction  

E-Print Network (OSTI)

We consider the small mass asymptotics (Smoluchowski-Kramers approximation) for the Langevin equation with a variable friction coefficient. The limit of the solution in the classical sense does not exist in this case. We study a modification of the Smoluchowski-Kramers approximation. Some applications of the Smoluchowski-Kramers approximation to problems with fast oscillating or discontinuous coefficients are considered.

Mark Freidlin; Wenqing Hu

2012-03-03T23:59:59.000Z

299

Finger pad friction and its role in grip and touch  

Science Journals Connector (OSTI)

...virtually all of their data correspond to a...increased with the load to a power in the range 0...strength and pressure data derived from experimental friction force data as a function of normal load using equations...2.4). The power-law parameters...

2013-01-01T23:59:59.000Z

300

Heat collector  

DOE Patents (OSTI)

A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

Merrigan, Michael A. (Santa Cruz, NM)

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Heat collector  

DOE Patents (OSTI)

A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

Merrigan, M.A.

1981-06-29T23:59:59.000Z

302

Experimental determination of residual stress by neutron diffraction in a boiling water reactor core shroud  

SciTech Connect

Residual strains in a 51 mm (2-inch) thick 304L stainless steel plate have been measured by neutron diffraction and interpreted in terms of residual stress. The plate, measuring (300 mm) in area, was removed from a 6m (20-ft.) diameter unirradiated boiling water reactor core shroud, and included a multiple-pass horizontal weld which joined two of the cylindrical shells which comprise the core shroud. Residual stress mapping was undertaken in the heat affected zone, concentrating on the outside half of the plate thickness. Variations in residual stresses with location appeared consistent with trends expected from finite element calculations, considering that a large fraction of the residual hoop stress was released upon removal of the plate from the core shroud cylinder.

Payzant, A.; Spooner, S.; Zhu, Xiaojing; Hubbard, C.R. [and others

1996-06-01T23:59:59.000Z

303

Variable enstrophy flux and energy spectrum in two-dimensional turbulence with Ekman friction  

E-Print Network (OSTI)

Experiments and numerical simulations reveal that in the forward cascade regime, the energy spectrum of two-dimensional turbulence with Ekman friction deviates from Kraichnan's prediction of $k^{-3}$ power spectrum. In this letter we explain this observation using an analytic model based on variable enstrophy flux arising due to Ekman friction. We derive an expression for the enstrophy flux which exhibits a logarithmic dependence in the inertial range for the Ekman-friction dominated flows. The energy spectrum obtained using this enstrophy flux shows a power law scaling for large Reynolds number and small Ekman friction, but has an exponential behaviour for large Ekman friction and relatively small Reynolds number.

Mahendra K. Verma

2012-03-23T23:59:59.000Z

304

nature physics | VOL 6 | MARCH 2010 | www.nature.com/naturephysics 155 How do you solve a problem like friction?  

E-Print Network (OSTI)

a problem like friction? I learned to respect friction, as a phenomenon with many nuances, when I friction between the ball and floor, work out, first, how far the ball goes before it is rolling. The first part, I quickly demonstrated, is easy. Assuming the force of sliding friction is independent

Loss, Daniel

305

Frictional melt pulses during a V1.1 Ma earthquake along the Alpine Fault, New Zealand  

E-Print Network (OSTI)

at which future catastrophic earth- quakes may originate. Our current understanding of frictional melting

306

Flow and Heat-Transfer Apparatus, Instrumentation and Data Acquisition Method  

E-Print Network (OSTI)

friction and convective heat transfer characteristics of nanofluids. Instead of a usual closed-loop system where pumps and after-cooling units are required, the developed apparatus utilizes nitrogen pressure-driven flow to test a single batch of fluid. This reduces the complexity of the system while improving its

Kostic, Milivoje M.

307

Microstructural characterization in dissimilar friction stir welding between 304 stainless steel and st37 steel  

SciTech Connect

In the present study, 3 mm-thick plates of 304 stainless steel and st37 steel were welded together by friction stir welding at a welding speed of 50 mm/min and tool rotational speed of 400 and 800 rpm. X-ray diffraction test was carried out to study the phases which might be formed in the welds. Metallographic examinations, and tensile and microhardness tests were used to analyze the microstructure and mechanical properties of the joint. Four different zones were found in the weld area except the base metals. In the stir zone of the 304 stainless steel, a refined grain structure with some features of dynamic recrystallization was evidenced. A thermomechanically-affected zone was characterized on the 304 steel side with features of dynamic recovery. In the other side of the stir zone, the hot deformation of the st37 steel in the austenite region produced small austenite grains and these grains transformed to fine ferrite and pearlite and some products of displacive transformations such as Widmanstatten ferrite and martensite by cooling the material after friction stir welding. The heat-affected zone in the st37 steel side showed partially and fully refined microstructures like fusion welding processes. The recrystallization in the 304 steel and the transformations in the st37 steel enhanced the hardness of the weld area and therefore, improved the tensile properties of the joint. - Highlights: Black-Right-Pointing-Pointer FSW produced sound welds between st37 low carbon steel and 304 stainless steel. Black-Right-Pointing-Pointer The SZ of the st37 steel contained some products of allotropic transformation. Black-Right-Pointing-Pointer The material in the SZ of the 304 steel showed features of dynamic recrystallization. Black-Right-Pointing-Pointer The finer microstructure in the SZ increased the hardness and tensile strength.

Jafarzadegan, M. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of) [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Feng, A.H. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China)] [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Abdollah-zadeh, A., E-mail: zadeh@modares.ac.ir [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Saeid, T. [Advanced Materials Research Center, Sahand University of Technology, P.O. Box: 51335-1996, Tabriz (Iran, Islamic Republic of)] [Advanced Materials Research Center, Sahand University of Technology, P.O. Box: 51335-1996, Tabriz (Iran, Islamic Republic of); Shen, J. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China)] [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Assadi, H. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of)] [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of)

2012-12-15T23:59:59.000Z

308

Heating System Specification Specification of Heating System  

E-Print Network (OSTI)

Appendix A Heating System Specification /* Specification of Heating System (loosely based */ requestHeat : Room ­? bool; 306 #12; APPENDIX A. HEATING SYSTEM SPECIFICATION 307 /* user inputs */ livingPattern : Room ­? behaviour; setTemp : Room ­? num; heatSwitchOn, heatSwitchOff, userReset : simple

Day, Nancy

309

Evaluation of residue drum storage safety risks  

SciTech Connect

A study was conducted to determine if any potential safety problems exist in the residue drum backlog at the Rocky Flats Plant. Plutonium residues stored in 55-gallon drums were packaged for short-term storage until the residues could be processed for plutonium recovery. These residues have now been determined by the Department of Energy to be waste materials, and the residues will remain in storage until plans for disposal of the material can be developed. The packaging configurations which were safe for short-term storage may not be safe for long-term storage. Interviews with Rocky Flats personnel involved with packaging the residues reveal that more than one packaging configuration was used for some of the residues. A tabulation of packaging configurations was developed based on the information obtained from the interviews. A number of potential safety problems were identified during this study, including hydrogen generation from some residues and residue packaging materials, contamination containment loss, metal residue packaging container corrosion, and pyrophoric plutonium compound formation. Risk factors were developed for evaluating the risk potential of the various residue categories, and the residues in storage at Rocky Flats were ranked by risk potential. Preliminary drum head space gas sampling studies have demonstrated the potential for formation of flammable hydrogen-oxygen mixtures in some residue drums.

Conner, W.V.

1994-06-17T23:59:59.000Z

310

Residue management at Rocky Flats  

SciTech Connect

Past plutonium production and manufacturing operations conducted at the Rocky Flats Environmental Technology Site (RFETS) produced a variety of plutonium-contaminated by-product materials. Residues are a category of these materials and were categorized as {open_quotes}materials in-process{close_quotes} to be recovered due to their inherent plutonium concentrations. In 1989 all RFETS plutonium production and manufacturing operations were curtailed. This report describes the management of plutonium bearing liquid and solid wastes.

Olencz, J.

1995-12-31T23:59:59.000Z

311

Transforms for prediction residuals in video coding  

E-Print Network (OSTI)

Typically the same transform, the 2-D Discrete Cosine Transform (DCT), is used to compress both image intensities in image coding and prediction residuals in video coding. Major prediction residuals include the motion ...

Kam??l?, Fatih

2010-01-01T23:59:59.000Z

312

Rack-and-pinion effects in molecular rolling friction  

E-Print Network (OSTI)

Rolling lubrication with spherical molecules working as 'nanobearings' has failed experimentally so far, without a full understanding of the physics involved and of the reasons why. Past model simulations and common sense have shown that molecules can only roll when they are not too closely packed to jam. The same type of model simulations now shows in addition that molecular rolling friction can develop deep minima once the molecule's peripheral 'pitch' can match the substrate periodicity, much as ordinary cogwheels do in a rack-and-pinion system. When the pinion-rack matching is bad, the driven molecular rolling becomes discontinuous and noisy, whence energy is dissipated and friction is large. This suggests experiments to be conducted by varying the rack-and-pinion matching. That could be pursued not only by changing molecules and substrates, but also by applying different sliding directions within the same system, or by applying pressure, to change the effective matching.

Oleg M. Braun; Erio Tosatti

2008-09-05T23:59:59.000Z

313

Wear and friction behavior of Zr implanted D3 steel  

SciTech Connect

Multicharged, pure, high current and pulsed ion beams of Zr have been extracted from a metal vapor vacuum arc (MEVVA) source and implanted into AISI D3 (C: 2-2,35%, Mn: 0,60%, Si: 0,60%, Cr: 11-13,50%, Ni: 0,30%, W: 1%, V: 1%) tool steel samples at the 3,6.1016, 5.1016 and 1.1017 ions/cm2 doses. The wear resistance and friction coefficient have been estimated using pin-on-disc wear tests. Implantation of Zr decreased the wear loss and friction coefficient. RBS, AES and SEM Microprobe analyses were used as a guide for explanation of implantation's effects.

Akbas, N.; Saklakoglu, I.E.; Monteiro, O.R.; Brown, I.G.

2001-08-23T23:59:59.000Z

314

Liquid friction on charged surfaces: from hydrodynamic slippage to electrokinetics  

E-Print Network (OSTI)

Hydrodynamic behavior at the vicinity of a confining wall is closely related to the friction properties of the liquid/solid interface. Here we consider, using Molecular Dynamics simulations, the electric contribution to friction for charged surfaces, and the induced modification of the hydrodynamic boundary condition at the confining boundary. The consequences of liquid slippage for electrokinetic phenomena, through the coupling between hydrodynamics and electrostatics within the electric double layer, are explored. Strong amplification of electro-osmotic effects is revealed, and the non-trivial effect of surface charge is discussed. This work allows to reconsider existing experimental data, concerning Zeta potentials of hydrophobic surfaces and suggest the possibility to generate ``giant'' electro-osmotic and electrophoretic effects, with direct applications in microfluidics.

Laurent Joly; Christophe Ybert; Emmanuel Trizac; Lyderic Bocquet

2006-07-19T23:59:59.000Z

315

Simple LMFBR axial-flow friction-factor correlation  

SciTech Connect

Complicated LMFBR axial lead-length averaged friction-factor correlations are reduced to an easy, ready-to-use function of bundle Reynolds number for wire-wrapped bundles. The function together with the power curves to calculate the associated constants are incorporated in a computer preprocessor, EZFRIC. The constants required for the calculation of the subchannels and bundle friction factors are derived and correlated into power curves of geometrical parameters. A computer program, FRIC, which can alternatively be used to accurately calculate these constants is also included. The accurate values of the constants and the corresponding values predicted by the power curves and percentage error of prediction are tabulated for a wide variety of geometries of interest.

Chan, Y.N.; Todreas, N.E.

1982-12-01T23:59:59.000Z

316

Friction and the oscillatory motion of granular flows  

E-Print Network (OSTI)

This contribution reports on numerical simulations of 2D granular flows on erodible beds. The broad aim is to investigate whether simple flows of model granular matter exhibits spontaneous oscillatory motion in generic flow conditions, and in this case, whether the frictional properties of the contacts between grains may affect the existence or the characteristics of this oscillatory motion. The analysis of different series of simulations show that the flow develops an oscillatory motion with a well-defined frequency which increases like the inverse of the velocity's square root. We show that the oscillation is essentially a surface phenomena. The amplitude of the oscillation is higher for lower volume fractions, and can thus be related to the flow velocity and grains friction properties. The study of the influence of the periodic geometry of the simulation cell shows no significant effect. These results are discussed in relation to sonic sands.

Lydie Staron

2012-11-26T23:59:59.000Z

317

Friction Properties of Molybdenum Alloyed Steel at Elevated Temperatures  

SciTech Connect

The high-temperature properties of steel surface can be improved by molybdenum surface alloying. Molybdenzing was carried out on carbon steel in the multi-function double glow plasma surface alloying furnace. The friction and wear tests were conducted on a high temperature ball-on-disk tribometer under the temperature of 25 deg. C{approx}600 deg. C. The contents of alloy element varied with alloyed layer were detected by SEM attached with EDS. The molybdenized layer is composed of the deposited layer and diffused layer. The micro-hardness of alloyed layer decreases from HV650 on the top layer to HV240. The friction coefficient of molybdenized layer decreases from 0.5{approx}0.6 to 0.2{approx}0.3 and wear rate decreases by 20% at elevated temperature after molybdenizing.

Li Jianliang; Xiong Dangsheng [Department of Material Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094 (China); Wu Hongyan [College of Math and Physics, Nanjing University of Information and Technology, Nanjing, 210044 (China)

2011-01-17T23:59:59.000Z

318

Friction vs Texture at the Approach of a Granular Avalanche  

E-Print Network (OSTI)

We perform a novel analysis of the granular texture of a granular bed close to stability limit. Our analysis is based on a unique criterion of friction mobilisation in a simulated two-dimensional packing. In this way, we recover the bimodal character of granular texture, and the coexistence of weak and strong phases in the sense of distinct contacts populations. Moreover, we show the existence of a well-defined subset of contacts within the weak contact network. These contacts are characterized by their important friction, and form a highly coherent population in terms of fabric. They play an antagonistic role with respect to force chains. We are thus able to discriminate between incoherent contacts and coherent contacts in the weak phase, and to specify the role that the latter plays in the destabilisation process.

Lydie Staron; Farhang Radjai

2005-05-04T23:59:59.000Z

319

Reducing Skin Friction and Heat Transfer over a Hypersonic Cruising Vehicle by Mass Injection.  

E-Print Network (OSTI)

??Demonstrating technologies for hypersonic aircraft that cruise at speeds greater than Mach 5 is one of the long-term visions of many agencies, like NASA. Reducing… (more)

Nozaki, Yoshifumi

2007-01-01T23:59:59.000Z

320

Determination of thermal conductivity and formation temperature from cooling history of friction-heated probes  

Science Journals Connector (OSTI)

......of geothermal gradient and thermal conductivity of rocks or sediments...the formation temperature and thermal conductivity. Ideally, to...measurements require extra battery power supply and an additional...cooling curve for deducing the thermal properties has been contemplated......

Tien-Chang Lee; A. D. Duchkov; S. G. Morozov

2003-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

A novel system to study wear, friction, and lubricants  

SciTech Connect

A novel enclosed (pressurized) multispecimen wear testing system was design and built to allow the fully computerized on-line measurement and control of friction, wear, and lubricants of different materials (metals, ceramics, composites, and plastics). This system is described in detail. The tribological parameters can be adjusted and controlled to reproduce the actual conditions that prevail in machine components. Several examples of the capabilities of the system are presented.

Maamouri, M.; Masson, J.F.; Marchand, N.J. (Ecole Polytechnique, Montreal, Quebec (Canada). Dept. de Metallurgie et de Genie des Materiaux)

1994-08-01T23:59:59.000Z

322

Solid Friction from stick-slip to pinning and aging  

E-Print Network (OSTI)

We review the present state of understanding of solid friction at low velocities and for systems with negligibly small wear effects. We first analyze in detail the behavior of friction at interfaces between wacroscopic hard rough solids, whose main dynamical features are well described by the Rice-Ruina rate and state dependent constitutive law. We show that it results from two combined effects : (i) the threshold rheology of nanometer-thick junctions jammed under confinement into a soft glassy structure (ii) geometric aging, i.e. slow growth of the real arrea of contact via asperity creep interrupted by sliding. Closer analysis leads to identifying a second aging-rejuvenation process, at work within the junctions themselves. We compare the effects of structural aging at such multicontact, very highly confined, interfaces with those met under different confinement levels, namely boundary lubricated contacts and extended adhesive interfaces involving soft materials (hydrogels, elastomers). This leads us to propose a classification of frictional junctions in terms of the relative importance of jamming and adsoprtion-induced metastability.

Tristan Baumberger; Christiane Caroli

2005-06-24T23:59:59.000Z

323

Hydrodynamics of rapidly rotating superfluid neutron stars with mutual friction  

E-Print Network (OSTI)

We study time evolutions of superfluid neutron stars, focussing on the nature of the oscillation spectrum, the effect of mutual friction force on the oscillations and the hydrodynamical spin-up phase of pulsar glitches. We linearise the dynamical equations of a Newtonian two-fluid model for rapidly rotating backgrounds. In the axisymmetric equilibrium configurations, the two fluid components corotate and are in beta-equilibrium. We use analytical equations of state that generate stratified and non-stratified stellar models, which enable us to study the coupling between the dynamical degrees of freedom of the system. By means of time evolutions of the linearised dynamical equations, we determine the spectrum of axisymmetric and non-axisymmetric oscillation modes, accounting for the contribution of the gravitational potential perturbations, i.e. without adopting the Cowling approximation. We study the mutual friction damping of the superfluid oscillations and consider the effects of the non-dissipative part of the mutual friction force on the mode frequencies. We also provide technical details and relevant tests for the hydrodynamical model of pulsar glitches discussed by Sidery, Passamonti and Andersson (2010). In particular, we describe the method used to generate the initial data that mimic the pre-glitch state, and derive the equations that are used to extract the gravitational-wave signal.

A. Passamonti; N. Andersson

2010-04-26T23:59:59.000Z

324

Liner surface improvements for low friction piston ring packs  

Science Journals Connector (OSTI)

The development of engine components in the automotive industry is governed by several constraints such as environmental legislation and customer expectations. About a half of the frictional losses in an internal combustion engine come from the interactions between the piston assembly and cylinder liner surface. The tribological considerations in the contact between the piston ring and cylinder liner have attracted much attention over the past few decades. Many non-conventional cylinder liner finishes have been, and are being, developed with the aim to reduce friction losses and oil consumption, but the effects of the surface finish on piston ring pack performance is not well understood. One way of reducing friction in the cylinder system is to reduce the tangential load from the piston ring pack, focusing on the oil control ring. However, the side-effect of this is a disappointingly increased oil consumption. In this study a number of different cylinder liner surface specifications were developed and implemented in test engines with the aim of maintaining the level for oil consumption when decreasing the tangential load for the piston ring pack. To improve our understanding of the result, the same surfaces were evaluated in elastic and elasto-plastic rough contact and hydrodynamic flow simulation models. It is shown that oil consumption is strongly related to surface texture on the cylinder liners and at lower speeds (900–1200 rpm), a 'rougher surface' with a high core (e.g. Sk) and valley roughness (e.g. Svk) results in higher oil consumption. At the medium speed range (1200–3600 rpm), oil consumption continues to dominate for the 'rough' surfaces but with a visible influence of a lower oil consumption for a decreased roughness within the 'rough' surface group. 'Smooth' surfaces with a 'smooth' core (Sk), irrespective of the valley component (Svk), show similar oil consumption. For engine speeds above 3600 rpms, an increase in plateau roughness results in higher oil consumption. Throughout the study, standard roughness parameters were computed to compare with the results from engine testing and simulation. Future work will be directed to continuous optimization between oil consumption and friction. Improving the understanding of the functional cylinder system surfaces' ability to form oil films in the cylinder system opens up opportunities, not only in reducing the tangential load of piston ring packs but also in optimizing oil viscosity in order to reduce friction.

C Anderberg; Z Dimkovski; B-G Rosén

2014-01-01T23:59:59.000Z

325

Process to recycle shredder residue  

DOE Patents (OSTI)

A system and process for recycling shredder residue, in which separating any polyurethane foam materials are first separated. Then separate a fines fraction of less than about 1/4 inch leaving a plastics-rich fraction. Thereafter, the plastics rich fraction is sequentially contacted with a series of solvents beginning with one or more of hexane or an alcohol to remove automotive fluids; acetone to remove ABS; one or more of EDC, THF or a ketone having a boiling point of not greater than about 125.degree. C. to remove PVC; and one or more of xylene or toluene to remove polypropylene and polyethylene. The solvents are recovered and recycled.

Jody, Bassam J. (Chicago, IL); Daniels, Edward J. (Oak Lawn, IL); Bonsignore, Patrick V. (Channahon, IL)

2001-01-01T23:59:59.000Z

326

Effects of Stone-Wales and vacancy defects in atomic-scale friction on defective graphite  

SciTech Connect

Graphite is an excellent solid lubricant for surface coating, but its performance is significantly weakened by the vacancy or Stone-Wales (SW) defect. This study uses molecular dynamics simulations to explore the frictional behavior of a diamond tip sliding over a graphite which contains a single defect or stacked defects. Our results suggest that the friction on defective graphite shows a strong dependence on defect location and type. The 5-7-7-5 structure of SW defect results in an effectively negative slope of friction. For defective graphite containing a defect in the surface, adding a single vacancy in the interior layer will decrease the friction coefficients, while setting a SW defect in the interior layer may increase the friction coefficients. Our obtained results may provide useful information for understanding the atomic-scale friction properties of defective graphite.

Sun, Xiao-Yu [Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072 (China); Key Laboratory of Hubei Province for Water Jet Theory and New Technology, Wuhan University, Wuhan 430072 (China); Wu, RunNi; Xia, Re [Key Laboratory of Hubei Province for Water Jet Theory and New Technology, Wuhan University, Wuhan 430072 (China); Chu, Xi-Hua; Xu, Yuan-Jie, E-mail: yj-xu@whu.edu.cn [Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072 (China)

2014-05-05T23:59:59.000Z

327

Geothermal district heating systems  

SciTech Connect

Ten district heating demonstration projects and their present status are described. The projects are Klamath County YMCA, Susanville District Heating, Klamath Falls District Heating, Reno Salem Plaza Condominium, El Centro Community Center Heating/Cooling, Haakon School and Business District Heating, St. Mary's Hospital, Diamond Ring Ranch, Pagosa Springs District Heating, and Boise District Heating.

Budney, G.S.; Childs, F.

1982-01-01T23:59:59.000Z

328

Water and Space Heating Heat Pumps  

E-Print Network (OSTI)

This paper discusses the design and operation of the Trane Weathertron III Heat Pump Water Heating System and includes a comparison of features and performance to other domestic water heating systems. Domestic water is generally provided through...

Kessler, A. F.

1985-01-01T23:59:59.000Z

329

LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES  

SciTech Connect

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston/ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and emissions. A detailed set of piston/ring dynamic and friction models have been developed and applied that illustrated the fundamental relationships between design parameters and friction losses. Various low-friction strategies and concepts have been explored, and engine experiments will validate these concepts. An iterative process of experimentation, simulation and analysis, will be followed with the goal of demonstrating a complete optimized low-friction engine system. As planned, MIT has developed guidelines for an initial set of low-friction piston-ring-pack designs. Current recommendations focus on subtle top-piston-ring and oil-control-ring characteristics. A full-scale Waukesha F18 engine has been installed at Colorado State University and testing of the baseline configuration is in progress. Components for the first design iteration are being procured. Subsequent work includes examining the friction and engine performance data and extending the analyses to other areas to evaluate opportunities for further friction improvement and the impact on oil consumption/emission and wear, towards demonstrating an optimized reduced-friction engine system.

Victor W. Wong; Tian Tian; Grant Smedley

2003-08-28T23:59:59.000Z

330

Flow frictional characteristics of microencapsulated phase change material suspensions flowing through rectangular minichannels  

Science Journals Connector (OSTI)

An experimental investigation was conducted on the laminar flow frictional characteristics of suspensions with microencapsulated phase change material (MEPCM) in water flowing through rectangular...

Yu Rao; Frank Dammel; Peter Stephan…

2006-08-01T23:59:59.000Z

331

E-Print Network 3.0 - apso skin friction Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

in Three-Dimensional Flows Summary: Abstract Recent improvements in three techniques for measuring skin friction in two- and three- dimensional... that the oil- film...

332

E-Print Network 3.0 - adhesive microstructure friction Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

at Berkeley Collection: Physics 20 How to get the yield locus of an adhesive powder from a single numerical experiment Summary: with experiments. The effect of friction...

333

a simple trolley-like model in the presence of a nonlinear friction and ...  

E-Print Network (OSTI)

expenditure, ?(x) is a twice smooth function describing the “friction” (media resistance) depending on the velocity. We assume that ?(0) = 0, ? (0) ? 0, and ? (x) ...

2013-04-19T23:59:59.000Z

334

Heat transfer and heat exchangers reference handbook  

SciTech Connect

The purpose of this handbook is to provide Rocky Flats personnel with an understanding of the basic concepts of heat transfer and the operation of heat exchangers.

Not Available

1991-01-15T23:59:59.000Z

335

Heating systems for heating subsurface formations  

DOE Patents (OSTI)

Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)

2011-04-26T23:59:59.000Z

336

Heat exchanger  

DOE Patents (OSTI)

A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

Brackenbury, Phillip J. (Richland, WA)

1986-01-01T23:59:59.000Z

337

Heat exchanger  

DOE Patents (OSTI)

A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

Brackenbury, P.J.

1983-12-08T23:59:59.000Z

338

Savannah River Tank Waste Residuals  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Savannah Savannah River Savannah River Tank Waste Residuals HLW Corporate Board November 6, 2008 1 November 6, 2008 Presentation By Sherri R. Ross Department of Energy Savannah River Operations Office The Issue * How clean is clean? * Ultimate Challenge - Justify highly radioactive radionuclides have been removed to the maximum extent practical? 2 removed to the maximum extent practical? - Building compelling regulatory documentation that will withstand intense scrutiny §3116 Requirements 1. Does not require disposal in deep geological repository 2. Highly radioactive radionuclides removed to the maximum extent practical 3. Meet the performance objectives in 10 CFR Part 3 3. Meet the performance objectives in 10 CFR Part 61, Subpart C 4. Waste disposed pursuant to a State-approved closure plan or permit Note: If it is anticipated that Class C disposal limits will be exceeded, additional

339

Friction stir welding tool and process for welding dissimilar materials  

DOE Patents (OSTI)

A friction stir welding tool and process for lap welding dissimilar materials are detailed. The invention includes a cutter scribe that penetrates and extrudes a first material of a lap weld stack to a preselected depth and further cuts a second material to provide a beneficial geometry defined by a plurality of mechanically interlocking features. The tool backfills the interlocking features generating a lap weld across the length of the interface between the dissimilar materials that enhances the shear strength of the lap weld.

Hovanski, Yuri; Grant, Glenn J; Jana, Saumyadeep; Mattlin, Karl F

2013-05-07T23:59:59.000Z

340

Curvature effect on tearing modes in presence of neoclassical friction  

SciTech Connect

Neoclassical physics (here associated to the poloidal variation of the magnetic field strength along field lines in a tokamak) is well known for driving self-generated plasma current and nonlinear magnetic islands associated to it in high performance, ITER relevant plasma discharges. It is demonstrated that the neoclassical friction between a magnetic perturbation and plasma flow already impacts magnetic islands in the linear regime, by inducing a weakening of curvature stabilization for tearing modes. This conclusion holds in particular for regimes where convection is influencing the pressure dynamics, as shown using a simple analytical model and confirmed in full Magneto-Hydro-Dynamics simulations.

Maget, Patrick; Mellet, Nicolas; Meshcheriakov, Dmytro; Garbet, Xavier [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France)] [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France); Lütjens, Hinrich [Centre de Physique Théorique, Ecole Polytechnique, CNRS (France)] [Centre de Physique Théorique, Ecole Polytechnique, CNRS (France)

2013-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Fluctuations in a kinetic transport model for quantum friction  

E-Print Network (OSTI)

We consider a linear Boltzmann equation that arises in a model for quantum friction. It describes a particle that is slowed down by the emission of bosons. We study the stochastic process generated by this Boltzmann equation and we show convergence of its spatial trajectory to a multiple of Brownian motion with exponential scaling. The asymptotic position of the particle is finite in mean, even though its absolute value is typically infinite. This is contrasted to an approximation that neglects the influence of fluctuations, where the mean asymptotic position is infinite.

Roland Bauerschmidt; Wojciech de Roeck; Jürg Fröhlich

2014-03-23T23:59:59.000Z

342

Radiative friction on an excited atom moving in vacuum  

E-Print Network (OSTI)

It is known that, when an excited atom spontaneously emits one photon, two effects are produced. First, the atom's internal and external states are entangled with the states of the emitted photon. Second, the atom receives a momentum transfered from the photon. In this work, the dynamics of such an atom in vacuum is studied. Through a specific calculation, it is demonstrated that these effects cause the atom to experience, on average, a friction force opposite to its initial velocity. Properties of the force are also discussed.

Wei Guo

2012-04-30T23:59:59.000Z

343

Residual Toxicities of Insecticides to Cotton Insects.  

E-Print Network (OSTI)

the effects of simulated wind and rain on the residues. Tempera- ture and humidity conditions incident to the holding period were sufficient to destroy most of the residual toxicity of this material. Effect of Simulated Wind Among the chlorinated... hydrocarbon insecticides, there was little difference between the effects of simu- lated wind and rain on residual toxicities. However, it is likely that under field conditions the effects of rain would be more noticeable. Simulated wind was less damaging...

Hightower, B. G.; Gaines, J. C.

1960-01-01T23:59:59.000Z

344

Friction Stir Spot Welding (FSSW) of Advanced High Strength Steel (AHSS)  

SciTech Connect

Friction stir spot welding (FSSW) is applied to join advanced high strength steels (AHSS): galvannealed dual phase 780 MPa steel (DP780GA), transformation induced plasticity 780 MPa steel (TRIP780), and hot-stamped boron steel (HSBS). A low-cost Si3N4 ceramic tool was developed and used for making welds in this study instead of polycrystalline cubic boron nitride (PCBN) material used in earlier studies. FSSW has the advantages of solid-state, low-temperature process, and the ability of joining dissimilar grade of steels and thicknesses. Two different tool shoulder geometries, concave with smooth surface and convex with spiral pattern, were used in the study. Welds were made by a 2-step displacement control process with weld time of 4, 6, and 10 seconds. Static tensile lap-shear strength achieved 16.4 kN for DP780GA-HSBS and 13.2kN for TRIP780-HSBS, above the spot weld strength requirements by AWS. Nugget pull-out was the failure mode of the joint. The joining mechanism was illustrated from the cross-section micrographs. Microhardness measurement showed hardening in the upper sheet steel (DP780GA or TRIP780) in the weld, but softening of HSBS in the heat-affect zone (HAZ). The study demonstrated the feasibility of making high-strength AHSS spot welds with low-cost tools.

Santella, M. L.; Hovanski, Yuri; Pan, Tsung-Yu

2012-04-16T23:59:59.000Z

345

Joint strength in high speed friction stir spot welded DP 980 steel  

SciTech Connect

High speed friction stir spot welding was applied to 1.2 mm thick DP 980 steel sheets under different welding conditions, using PCBN tools. The range of vertical feed rates used during welding was 2.5 mm – 102 mm per minute, while the range of spindle speeds was 2500 – 6000 rpm. Extended testing was carried out for five different sets of welding conditions, until tool failure. These welding conditions resulted in vertical welding loads of 3.6 – 8.2 kN and lap shear tension failure loads of 8.9 – 11.1 kN. PCBN tools were shown, in the best case, to provide lap shear tension fracture loads at or above 9 kN for 900 spot welds, after which tool failure caused a rapid drop in joint strength. Joint strength was shown to be strongly correlated to bond area, which was measured from weld cross sections. Failure modes of the tested joints were a function of bond area and softening that occurred in the heat-affected zone.

Saunders, Nathan; Miles, Michael; Hartman, Trent; Hovanski, Yuri; Hong, Sung Tae; Steel, Russell

2014-05-01T23:59:59.000Z

346

Microstructure characterization of the stir zone of submerged friction stir processed aluminum alloy 2219  

SciTech Connect

Aluminum alloy 2219-T6 was friction stir processed using a novel submerged processing technique to facilitate cooling. Processing was conducted at a constant tool traverse speed of 200 mm/min and spindle rotation speeds in the range from 600 to 800 rpm. The microstructural characteristics of the base metal and processed zone, including grain structure and precipitation behavior, were studied using optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Microhardness maps were constructed on polished cross sections of as-processed samples. The effect of tool rotation speed on the microstructure and hardness of the stir zone was investigated. The average grain size of the stir zone was much smaller than that of the base metal, but the hardness was also lower due to the formation of equilibrium ? precipitates from the base metal ?? precipitates. Stir zone hardness was found to decrease with increasing rotation speed (heat input). The effect of processing conditions on strength (hardness) was rationalized based on the competition between grain refinement strengthening and softening due to precipitate overaging. - Highlights: • SZ grain size (? 1 ?m) is reduced by over one order of magnitude relative to the BM. • Hardness in the SZ is lower than that of the precipitation strengthened BM. • Metastable ?? in the base metal transforms to equilibrium ? in the stir zone. • Softening in the SZ results from a decrease of precipitation strengthening.

Feng, Xiuli, E-mail: feng.97@osu.edu [Welding Engineering Program, Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43221 (United States); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Liu, Huijie, E-mail: liuhj@hit.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Lippold, John C., E-mail: lippold.1@osu.edu [Welding Engineering Program, Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43221 (United States)

2013-08-15T23:59:59.000Z

347

Residual Gas Mobility in Ormen Lange.  

E-Print Network (OSTI)

?? The topic of this report is "Mobility of Residual Gas in Ormen Lange" and it has been prepared as a part of the course… (more)

Undeland, Elisabeth

2012-01-01T23:59:59.000Z

348

,,,"Residual Fuel Oil(b)",,,," Alternative...  

U.S. Energy Information Administration (EIA) Indexed Site

Standard Errors for Table 10.5;" " Unit: Percents." ,,,"Residual Fuel Oil(b)",,,," Alternative Energy Sources(c)" ,,,"Coal Coke" "NAICS"," ","Total","...

349

Methods of separating particulate residue streams  

DOE Patents (OSTI)

A particulate residue separator and a method for separating a particulate residue stream may include an air plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams that are formed by the harvesting device and that travel, at least in part, along the air plenum and in a direction of the second, exhaust end; and a baffle assembly that is located in partially occluding relation relative to the air plenum and that substantially separates the first and second particulate residue air streams.

Hoskinson, Reed L. (Rigby, ID); Kenney, Kevin L. (Idaho Falls, ID); Wright, Christopher T. (Idaho Falls, ID); Hess, J. Richard (Idaho Falls, ID)

2011-04-05T23:59:59.000Z

350

Segmented heat exchanger  

DOE Patents (OSTI)

A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

Baldwin, Darryl Dean (Lafayette, IN); Willi, Martin Leo (Dunlap, IL); Fiveland, Scott Byron (Metamara, IL); Timmons, Kristine Ann (Chillicothe, IL)

2010-12-14T23:59:59.000Z

351

Micro-origin of Macro-strength: Friction  

E-Print Network (OSTI)

This paper presents an analytical study about the behavior of arbitrary shaped and sized non-cohesive two-dimensional granular materials. Several mechanical properties and relations are unraveled by connecting micro and macro scales in an explicit fashion that, at the same time, provides the basis of an analytical-theoretical framework for the development of new multi-scale techniques. Furthermore, the work herein presented is based on three main ideas that are developed and connected progressively; namely, the obtention of explicit expressions that enable us to relate micro-scale parameters, such as contact forces and fabric, to stress as a macro (continuum) physical property. Then, with these powerful tools, physical connections and relations between the mentioned micro-parameters and macro-constitutive parameters, in specific, Mohr-Coulomb's mobilized internal friction angle, are established. Finally, a non-linear optimization problem, which includes physical constraints at the contact point level, is proposed and solved in order to find the limit (maximum) internal friction angle in terms of the aforementioned micro-parameters. Thus, throughout this theoretical study, some important features about strength, anisotropy, contact buckling, and non-uniqueness of systems of contact forces are extracted, allowing us to have a deeper insight, as well as, a better understanding of the mechanical behavior of such complex-to-model materials.

Alex X. Jerves; José E. Andrade

2012-12-11T23:59:59.000Z

352

SECULAR DYNAMICAL ANTI-FRICTION IN GALACTIC NUCLEI  

SciTech Connect

We identify a gravitational-dynamical process in near-Keplerian potentials of galactic nuclei that occurs when an intermediate-mass black hole (IMBH) is migrating on an eccentric orbit through the stellar cluster towards the central supermassive black hole. We find that, apart from conventional dynamical friction, the IMBH experiences an often much stronger systematic torque due to the secular (i.e., orbit-averaged) interactions with the cluster's stars. The force which results in this torque is applied, counterintuitively, in the same direction as the IMBH's precession and we refer to its action as 'secular dynamical anti-friction' (SDAF). We argue that SDAF, and not the gravitational ejection of stars, is responsible for the IMBH's eccentricity increase seen in the initial stages of previous N-body simulations. Our numerical experiments, supported by qualitative arguments, demonstrate that (1) when the IMBH's precession direction is artificially reversed, the torque changes sign as well, which decreases the orbital eccentricity; (2) the rate of eccentricity growth is sensitive to the IMBH migration rate, with zero systematic eccentricity growth for an IMBH whose orbit is artificially prevented from inward migration; and (3) SDAF is the strongest when the central star cluster is rapidly rotating. This leads to eccentricity growth/decrease for the clusters rotating in the opposite/same direction relative to the IMBH's orbital motion.

Madigan, Ann-Marie; Levin, Yuri, E-mail: madigan@strw.leidenuniv.nl [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands)

2012-07-20T23:59:59.000Z

353

Department of Mechanical Engineering Fall 2011 Heavy Duty Diesel Engine Friction Reduction  

E-Print Network (OSTI)

PENNSTATE Department of Mechanical Engineering Fall 2011 Heavy Duty Diesel Engine Friction the friction losses of a heavy duty diesel engine. In addition, a tear down procedure needed to be created in order to guide the engine disassembly and testing. The overall goal was to improve fuel economy

Demirel, Melik C.

354

High-resolution friction force microscopy under electrochemical control Aleksander Labuda,1  

E-Print Network (OSTI)

High-resolution friction force microscopy under electrochemical control Aleksander Labuda,1 William and development of a friction force microscope for high-resolution studies in electrochemical environments in liquids. The noise of the system is analyzed based on a methodology for the quantification of all

Grütter, Peter

355

A phenomenological model to describe turbulent friction in permeable-wall flows  

E-Print Network (OSTI)

A phenomenological model to describe turbulent friction in permeable-wall flows C. Manes,1 L impermeable rough boundaries. A novel phenomenological model that describes such anomalous behavior), A phenomenological model to describe tur- bulent friction in permeable-wall flows, Geophys. Res. Lett., 39, L14403

Katul, Gabriel

356

Assessment of secondary crop residues. Final report  

SciTech Connect

This report is the first of three reports assessing the feasibility of converting secondary agricultural residues to energy in the form of either methane gas or ethyl alcohol. Secondary agricultural residues are defined in this study as those residues resulting from biomass processing to produce primary products; e.g., whey from cheese processing, vegetable processing wastes, residues from paper pulping, etc. This report summarizes the first two phases of this study, data compilation, and evaluation. Subsequent reports will analyze the technical and economic feasibility of converting these residues to energy and the implementability of this technology. The industries for which data has been compiled in this report include vegetable, fruit, seafood, meat, poultry, and dairy processing and the pulp, paper, and paperboard industry. The data collected include raw product input, final processed product output, residue types, and quantity, residue concentration, biodegradability, seasonality of production, and geographic distribution of processing facilities. In general, these industries produce a relatively solid residue ranging in total solids concentration from 10 to 50% and a dilute liquid residue with an organic content (measured as COD or BOD) ranging from a few hundred to a few thousand mg/l. Due to the significant quantities of residues generated in each of the industries, it appears that the potential exists for generating a substantial quantity of energy. For a particular industry this quantity of energy can range from only one percent upwards to nearly thirty-five percent of the total processing energy required. The total processing energy required for the industries included in this study is approximately 2.5 quads per year. The potential energy which can be generated from these industrial residues will be 0.05 to 0.10 quads per year or approximately 2 to 4 percent of the total demand.

Ashare, E.; Leuschner, A.P.; West, C.E.; Langton, B.

1981-03-01T23:59:59.000Z

357

Looping and reconfiguration dynamics of a flexible chain with internal friction  

E-Print Network (OSTI)

In recent past, experiments and simulations have suggested that apart from the solvent friction, friction arising from the protein itself plays an important role in protein folding by affecting the intra-chain loop formation dynamics. This friction is termed as internal friction in the literature. Using a flexible Gaussian chain with internal friction we analyze the intra- chain reconfiguration and loop formation times for all three topology classes namely end-to- end, end-to-interior and interior-to-interior. In a nutshell, bypassing expensive simulations we show how simple models like that of Rouse and Zimm can support the single molecule experiment and computer simulation results on intra-chain diffusion coefficients, looping time and even can predict the effects of tail length on the looping time.

Nairhita Samanta; Jayanta Ghosh; Rajarshi Chakrabarti

2014-04-09T23:59:59.000Z

358

Finite Element Analysis of the Amontons-Coulomb's Model using Local and Global Friction Tests  

SciTech Connect

In spite of the abundant number of experimental friction tests that have been reported, the contact with friction modeling persists to be one of the factors that determine the effectiveness of sheet metal forming simulation. This difficulty can be understood due to the nature of the friction phenomena, which comprises the interaction of different factors connected to both sheet and tools' surfaces. Although in finite element numerical simulations friction models are commonly applied at the local level, they normally rely on parameters identified based on global experimental tests results. The aim of this study is to analyze the applicability of the Amontons-Coulomb's friction coefficient identified using complementary tests: (i) load-scanning, at the local level and (ii) draw-bead, at the global level; to the numerical simulation of sheet metal forming processes.

Oliveira, M. C.; Menezes, L. F.; Ramalho, A. [CEMUC, Department of Mechanical Engineering, University of Coimbra, Polo II, Rua Luis Reis Santos, Pinhal de Marrocos, 3030-788 Coimbra (Portugal); Alves, J. L. [Department of Mechanical Engineering, University of Minho, Campus de Azurem, 4800-058, Guimaraes (Portugal)

2011-05-04T23:59:59.000Z

359

Predicting protein residue–residue contacts using deep networks and boosting  

Science Journals Connector (OSTI)

......structure prediction, protein residue-residue contacts...i.e. homologous proteins with known structure...train large boosted ensembles of DN classifiers achieving...advanced search of the Protein Data Bank filtering...contained fewer than 20% disordered residues (i.e. coordinates......

Jesse Eickholt; Jianlin Cheng

2012-12-01T23:59:59.000Z

360

Seismic Travel-Time Residuals and Plates  

Science Journals Connector (OSTI)

......United States, Canada and Greenland under the auspices of Project Vela Uniform (Long Range Seismic Measurements 1966). Arrival...1 that if we plot residuals on the focal sphere, we are at liberty to ascribe these residuals to source effects, receiver effects......

D. Davies; D. P. McKenzie

1969-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES  

SciTech Connect

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston and piston ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and wear. An iterative process of simulation, experimentation and analysis is being followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. To date, a detailed set of piston and piston-ring dynamic and friction models have been developed and applied that illustrate the fundamental relationships between design parameters and friction losses. Low friction ring designs have already been recommended in a previous phase, with full-scale engine validation partially completed. Current accomplishments include the addition of several additional power cylinder design areas to the overall system analysis. These include analyses of lubricant and cylinder surface finish and a parametric study of piston design. The Waukesha engine was found to be already well optimized in the areas of lubricant, surface skewness and honing cross-hatch angle, where friction reductions of 12% for lubricant, and 5% for surface characteristics, are projected. For the piston, a friction reduction of up to 50% may be possible by controlling waviness alone, while additional friction reductions are expected when other parameters are optimized. A total power cylinder friction reduction of 30-50% is expected, translating to an engine efficiency increase of two percentage points from its current baseline towards the goal of 50% efficiency. Key elements of the continuing work include further analysis and optimization of the engine piston design, in-engine testing of recommended lubricant and surface designs, design iteration and optimization of previously recommended technologies, and full-engine testing of a complete, optimized, low-friction power cylinder system.

Victor Wong; Tian Tian; Luke Moughon; Rosalind Takata; Jeffrey Jocsak

2005-09-30T23:59:59.000Z

362

Role of friction in pattern formation in oscillated granular layers Sung Joon Moon, # J. B. Swift, and Harry L. Swinney  

E-Print Network (OSTI)

Role of friction in pattern formation in oscillated granular layers Sung Joon Moon, # J. B. Swift grains. Our molecular dynamics simu­ lations reveal that friction is essential for realistic modeling at a container acceleration about 30% smaller than that observed in experiments and simulations with friction

Texas at Austin. University of

363

Friction anisotropy at Ni,,100...,,100... interfaces: Molecular dynamics studies Yue Qi and Yang-Tse Cheng  

E-Print Network (OSTI)

Friction anisotropy at Ni,,100...Ã?,,100... interfaces: Molecular dynamics studies Yue Qi and Yang of Technology, Pasadena, California, 91125 Received 8 March 2002; published 30 August 2002 The friction theories predict that most perfect clean incommensurate interfaces would produce no static friction

Goddard III, William A.

364

Friction-induced vibration of a lubricated mechanical system J-J. Sinou*, J. Cayer-Barrioz and H. Berro  

E-Print Network (OSTI)

1 Friction-induced vibration of a lubricated mechanical system J-J. Sinou*, J. Cayer-Barrioz and H that incorporates realistic laws of local friction issued from previous experimental results. The objective or by themselves, such as friction-induced vibrations. In all cases, these vibrations are hardly controllable

Paris-Sud XI, Université de

365

A LuGre Tire Friction Model with Exact Aggregate Dynamics Panagiotis Tsiotras, Efstathios Velenis and Michel Sorine  

E-Print Network (OSTI)

A LuGre Tire Friction Model with Exact Aggregate Dynamics Panagiotis Tsiotras, Efstathios Velenis and Michel Sorine Abstract-- The LuGre dynamic point contact friction model for the two-dimensional translation of a body on a surface has been used in the past to derive a model for the friction forces

Tsiotras, Panagiotis

366

Role of friction in pattern formation in oscillated granular layers Sung Joon Moon,* J. B. Swift, and Harry L. Swinney  

E-Print Network (OSTI)

Role of friction in pattern formation in oscillated granular layers Sung Joon Moon,* J. B. Swift as there are no elastic grains. Our molecular dynamics simulations reveal that friction is essential for realistic with friction. More importantly, even though square and hexagonal patterns form for a wide range

Texas at Austin. University of

367

Heat transfer and pressure drop for air flow through enhanced passages  

SciTech Connect

An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

Obot, N.T.; Esen, E.B.

1992-06-01T23:59:59.000Z

368

Heat transfer and pressure drop for air flow through enhanced passages. Final report  

SciTech Connect

An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

Obot, N.T.; Esen, E.B.

1992-06-01T23:59:59.000Z

369

Floatable solar heat modules  

SciTech Connect

A floating solar heat module for swimming pools comprises a solid surface for conducting heat from the sun's rays to the water and further includes a solid heat storage member for continual heating even during the night. A float is included to maintain the solar heat module on the surface of the pool. The solid heat storage medium is a rolled metal disk which is sandwiched between top and bottom heat conducting plates, the top plate receiving the heat of the sun's rays through a transparent top panel and the bottom plate transferring the heat conducted through the top plate and rolled disk to the water.

Ricks, J.W.

1981-09-29T23:59:59.000Z

370

Frictionally induced ignition processes in drop and skid tests  

SciTech Connect

The standard LANL/Pantex drop and skid tests rely on subjective assessment of reaction violence to quantify the response of the charge, and completely miss nonpropagating hot-spot ignition sites. Additionally, large variations in test results have been observed, which we propose is due to a misunderstanding of the basic physical processes that lead to threshold ignition in these tests. The tests have been redesigned to provide control of these mechanisms and to permit direct observation of hot spots at the impact site, allowing us to follow the progression of the outcome as the drop height and ignition source density are varied. The results confirm that frictional interactions between high-melting-point solids are the dominant ignition mechanism, not just at the threshold, but in fact at all realistic drop heights.

Dickson, Peter [Los Alamos National Laboratory; Parker, Gary [Los Alamos National Laboratory; Novak, Alan [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

371

The Impact of Organic Friction Modifiers on Engine Oil Tribofilms  

E-Print Network (OSTI)

Organic friction modifiers (OFMs) are important additives in the lubrication of machines and especially of car engines where performance improvements are constantly sought-after. Together with zinc dialkyldithiophosphates (ZDDPs) antiwear additives, OFMs have a predominant impact on the tribological behaviour of the lubricant. In the current study, the influence of OFMs on the generation, tribological properties and chemistry of ZDDP tribofilms has been investigated by combining tribological experiments (MTM) with in-situ film thickness measurements through optical interference imaging (SLIM), Alicona profilometry and X-ray photoelectron spectroscopy. OFMs and antiwear additives have been found to competitively react/adsorb on the rubbing ferrous substrates in a tribological contact. The formation and removal (through wear) of tribofilms are dynamic processes which result from the simultaneous interaction of these two additives with the surface of the wear track. By carefully selecting the chemistry of OFMs, ...

Ratoi, Monica; Alghawel, Husam; Suen, Yat Fan; Nelson, Kenneth

2013-01-01T23:59:59.000Z

372

Dynamical friction of radio galaxies in galaxy clusters  

E-Print Network (OSTI)

The distribution of luminous radio galaxies in galaxy clusters has been observed to be concentrated in the inner region. We consider the role of dynamical friction of massive galaxies ($M\\sim 10^{12.5}$ M$_{\\odot}$), assuming them to be hosts of luminous radio galaxies, and show that beginning with a Navarro-Frenk-White density profile of a cluster of mass $M_{cl}\\sim 10^{15}$ M$_{\\odot}$ of concentration $c\\sim 5$ and collapsing at $z\\sim 1$, the density profile of radio galaxies evolve to a profile of concentration $c \\sim 25$, as observed, in a time scale of $t\\sim 3\\hbox{--}5$ Gyr.

Biman B. Nath

2008-04-22T23:59:59.000Z

373

Lateral vibration effects in atomic-scale friction  

SciTech Connect

The influence of lateral vibrations on the stick-slip motion of a nanotip elastically pulled on a flat crystal surface is studied by atomic force microscopy measurements on a NaCl(001) surface in ultra-high vacuum. The slippage of the nanotip across the crystal lattice is anticipated at increasing driving amplitude, similarly to what is observed in presence of normal vibrations. This lowers the average friction force, as explained by the Prandtl-Tomlinson model with lateral vibrations superimposed at finite temperature. Nevertheless, the peak values of the lateral force, and the total energy losses, are expected to increase with the excitation amplitude, which may limit the practical relevance of this effect.

Roth, R. [Climate and Environment Physics, Physics Institute, University of Bern, Bern (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, Bern (Switzerland); Fajardo, O. Y.; Mazo, J. J. [Departamento de Física de la Materia Condensada and Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, 50009 Zaragoza (Spain); Meyer, E. [Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel (Switzerland); Gnecco, E. [Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, 28049 Madrid (Spain)

2014-02-24T23:59:59.000Z

374

Single-friction-surface triboelectric generator with human body conduit  

SciTech Connect

We present a transparent single-friction-surface triboelectric generator (STEG) employing human body as the conduit, making the applications of STEG in portable electronics much more practical and leading to a significant output improvement. The STEG with micro-patterned polydimethylsiloxane surface achieved an output voltage of over 200 V with a current density of 4.7 ?A/cm{sup 2}. With human body conduit, the output current increased by 39% and the amount of charge that transferred increased by 34% compared to the results with grounded electrode. A larger increment of 210% and 81% was obtained in the case of STEG with a large-size flat polyethylene terephthalate surface.

Meng, Bo; Cheng, Xiaoliang; Zhang, Xiaosheng; Han, Mengdi; Liu, Wen; Zhang, Haixia, E-mail: zhang-alice@pku.edu.cn [National Key Lab of Nano/Micro Fabrication Technology, Peking University, Beijing 100871 (China)] [National Key Lab of Nano/Micro Fabrication Technology, Peking University, Beijing 100871 (China)

2014-03-10T23:59:59.000Z

375

Surface energy budget over the South Pole and turbulent heat fluxes as a function of an empirical bulk Richardson number  

E-Print Network (OSTI)

Surface energy budget over the South Pole and turbulent heat fluxes as a function of an empirical in the monthly mean surface energy budget and to investigate the behavior of turbulent heat fluxes under stable and one as the residual of the surface energy budget (i.e., subsurface heat fluxes minus net radiation

Walden, Von P.

376

Mapping Residual Structure in Intrinsically Disordered Proteins at Residue Resolution Using Millisecond Hydrogen/Deuterium Exchange and Residue Averaging  

Science Journals Connector (OSTI)

Measurement of residual structure in intrinsically disordered proteins can provide insights into the mechanisms by which such proteins undergo coupled binding and folding. The present ... describes an approach to...

Theodore R. Keppel; David D. Weis

2014-12-01T23:59:59.000Z

377

Heat Pump for High School Heat Recovery  

E-Print Network (OSTI)

ICEBO2006, Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-12-1 Heat Pump for High School Bathroom Heat Recovery Kunrong Huang Hanqing Wang Xiangjiang Zhou Associate professor Professor Professor School...

Huang, K.; Wang, H.; Zhou, X.

2006-01-01T23:59:59.000Z

378

Pagosa Springs District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

Pagosa Springs District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Pagosa Springs District Heating District Heating Low...

379

Boise City Geothermal District Heating District Heating Low Temperatur...  

Open Energy Info (EERE)

Boise City Geothermal District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Boise City Geothermal District Heating District Heating...

380

San Bernardino District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

San Bernardino District Heating District Heating Low Temperature Geothermal Facility Facility San Bernardino District Heating Sector Geothermal energy Type District Heating...

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Kethcum District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

Kethcum District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Kethcum District Heating District Heating Low Temperature Geothermal...

382

Philip District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

Philip District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Philip District Heating District Heating Low Temperature Geothermal...

383

Midland District Heating District Heating Low Temperature Geothermal...  

Open Energy Info (EERE)

Midland District Heating District Heating Low Temperature Geothermal Facility Facility Midland District Heating Sector Geothermal energy Type District Heating Location Midland,...

384

Combined Heat and Power, Waste Heat, and District Energy | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Combined Heat and Power, Waste Heat, and District Energy Combined Heat and Power, Waste Heat, and District Energy Presentation-given at the Fall 2011 Federal Utility Partnership...

385

Waste Heat Management Options for Improving Industrial Process Heating Systems  

Energy.gov (U.S. Department of Energy (DOE))

This presentation covers typical sources of waste heat from process heating equipment, characteristics of waste heat streams, and options for recovery including Combined Heat and Power.

386

Guide to Geothermal Heat Pumps  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Geothermal Heat Pumps Work Using a heat exchanger, a geothermal heat pump can move heat from one space to another. In summer, the geothermal heat pump extracts heat from a building...

387

Woven heat exchanger  

DOE Patents (OSTI)

This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

Piscitella, R.R.

1984-07-16T23:59:59.000Z

388

Friction coefficients of sorghum grain on steel, teflon, and concrete surfaces  

E-Print Network (OSTI)

Friction Coefficients of Sorghum Grain on a Hot-rolled, 1010 Steel Surface at the Indicated Moisture Content and Time of Exposure to a 70oF and 80 Per Cent Relative Humidity Environment. . . 42 3 . Average Friction Coefficients of Sorghum Grain on a... at the Indicated Moisture Content and Time of Exposure to a 70 F and 55 Per Cent Relative Humidity Environment. 1 0. 5 20. Friction Data of Sorghum Grain on a I/16-inch Thick Teflon Sheet at the Indicated Moisture Content and Time of Exposure to a 70 F and 80...

Hossain, Quazi A

2012-06-07T23:59:59.000Z

389

Towards Intelligent District Heating.  

E-Print Network (OSTI)

??A district heating system consists of one or more production units supplying energy in the form of heated water through a distribution pipe network to… (more)

Johansson, Christian

2010-01-01T23:59:59.000Z

390

Total Space Heat-  

Annual Energy Outlook 2012 (EIA)

Buildings Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heat- ing Cool- ing Venti- lation Water Heat- ing Light- ing Cook- ing Refrig- eration...

391

ARM - Heat Index Calculations  

NLE Websites -- All DOE Office Websites (Extended Search)

FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Heat Index Calculations Heat Index is an index that combines air temperature and relative...

392

SAR impulse response with residual chirps.  

SciTech Connect

A Linear Frequency-Modulated (LFM) chirp is a function with unit amplitude and quadratic phase characteristic. In a focused Synthetic Aperture Radar (SAR) image, a residual chirp is undesired for targets of interest, as it coarsens the manifested resolution. However, for undesired spurious signals, a residual chirp is often advantageous because it spreads the energy and thereby diminishes its peak value. In either case, a good understanding of the effects of a residual LFM chirp on a SAR Impulse Response (IPR) is required to facilitate system analysis and design. This report presents an analysis of the effects of a residual chirp on the IPR. As reference, there is a rich body of publications on various aspects of LFM chirps. A quick search reveals a plethora of articles, going back to the early 1950s. We mention here purely as trivia one of the earlier analysis papers on this waveform by Klauder, et al.

Doerry, Armin Walter

2009-06-01T23:59:59.000Z

393

Mechanisms of hydrocracking of heavy oil residues  

Science Journals Connector (OSTI)

Based on research data, a technology of low-pressure residual fuel oil hydrocracking with a suspended catalyst has been developed. The process has been refined on a laboratory setup. The reaction kinetics has ...

Kh. I. Abad-zade; F. M. Velieva…

2009-07-01T23:59:59.000Z

394

Residual stress in nanocrystalline nickel tungsten electrodeposits  

E-Print Network (OSTI)

Characterizing the residual stress of thick nanocrystalline electrodeposits poses several unique challenges due to their fine grain structure, thickness distribution, and matte surface. We employ a three-dimensional ...

Ziebell, Tiffany D. (Tiffany Dawn)

2011-01-01T23:59:59.000Z

395

Friction Makes the World Go Round Even though there are many physical things that make everyday life possible, few are more important than  

E-Print Network (OSTI)

Friction Makes the World Go Round K.G. Rowe Even though there are many physical things that make everyday life possible, few are more important than friction. Friction allows us to walk, drive cars or drive on really slick ice--this would be the case in a world without friction. The Study of Tire Rubber

Roy, Subrata

396

Friction stir additive manufacturing for high structural performance through microstructural control in an Mg based WE43 alloy  

Science Journals Connector (OSTI)

Abstract Structural performance is a key challenge pertinent to additive manufacturing. A majority of the current techniques employed for metallic materials involve liquid–solid transformation and their performance is limited by solidification microstructures. Depending on the type of metallic alloy, this can be a serious impediment to structural properties. In this regard, solid-state additive manufacturing techniques have lagged behind. This study is focused on friction stir additive manufacturing (FSAM) as a potential technique to attain structurally efficient magnesium alloys. In this study, a multilayered stack of an Mg based WE43 alloy was built using FSAM at two different welding parameters. Formation of defects is sensitive to the heat input. In addition, dynamic recrystallization led to finer grain size (2–3 ?m). Such fine grain size coupled with desirable precipitate characteristics culminated in superior mechanical properties. Maximum hardness of 115 HV was obtained in as-fabricated state and increased to 135 HV after aging. These levels are similar to Al 2XXX alloys. In fact, in terms of strength, it translates to 400 MPa and 17% ductility and is significantly higher than the base material subjected to aging. Mechanical properties have been correlated with detailed microstructural observations. Texture is discussed for a higher heat input sample using orientation imaging microscopy.

S. Palanivel; P. Nelaturu; B. Glass; R.S. Mishra

2015-01-01T23:59:59.000Z

397

Microstructural Examination to Aid in Understanding Friction Bonding Fabrication Technique for Monolithic Nuclear Fuel  

SciTech Connect

Monolithic nuclear fuel is currently being developed for use in research reactors, and friction bonding (FB) is a technique being developed to help in this fuel’s fabrication. Since both FB and monolithic fuel are new concepts, research is needed to understand the impact of varying FB fabrication parameters on fuel plate characteristics. This thesis research provides insight into the FB process and its application to the monolithic fuel design by recognizing and understanding the microstructural effects of varying fabrication parameters (a) FB tool load, and (b) FB tool face alloy. These two fabrication parameters help drive material temperature during fabrication, and thus the material properties, bond strength, and possible formation of interface reaction layers. This study analyzed temperatures and tool loads measured during those FB processes and examined microstructural characteristics of materials and bonds in samples taken from the resulting fuel plates. This study shows that higher tool load increases aluminum plasticization and forging during FB, and that the tool face alloy helps determine the tool’s heat extraction efficacy. The study concludes that successful aluminum bonds can be attained in fuel plates using a wide range of FB tool loads. The range of tool loads yielding successful uranium-aluminum bonding was not established, but it was demonstrated that such bonding can be attained with FB tool load of 48,900 N (11,000 lbf) when using a FB tool faced with a tungsten alloy. This tool successfully performed FB, and with better results than tools faced with other materials. Results of this study correlate well with results reported for similar aluminum bonding techniques. This study’s results also provide support and validation for other nuclear fuel development studies and conclusions. Recommendations are offered for further research.

Karen L. Shropshire

2008-04-01T23:59:59.000Z

398

Simulation of tides, residual flow and energy budget in the Gulf of California  

Science Journals Connector (OSTI)

With the application of a two-dimensional nonlinear hydrodynamical-numerical semi-implicit model, the principal tides M2, S2, K2, N2, K1, P1 and O1 were studied. Energy budgets of the semi-diurnal M2 and S2 were calculated separately. The linear sum of these budgets was compared with the tidal energy budget obtained when these two tidal constituents interact. Since a quadratic form for the bottom friction was used, remarkable differences were found. The results show that in the area of the Colorado River delta, the dissipation of tidal energy is very strong. Intense tidal currents were observed in the same region and over the Salsipuedes Sill. Energy budgets calculated for forcing waves of different periods, but of the same amplitude, were used to estimate the principal periods of resonance. Although the topography of the Gulf is very complex, the model reproduced observed sea-surface elevation and current patterns. To study spring tide conditions, the above seven tidal constituents were simulated. Estimates of residual currents reveal the presence of several intense cyclonic and anticyclonic gyres. Over the Salsipuedes Sill, residual currents of the M2 tide reach values of more than 15 cm s?1. Horizontal distributions of dissipation rates of tidal energy and of kinetic energy were also obtained.

Noel Carbajal; Jan O. Backhaus

1998-01-01T23:59:59.000Z

399

ABSTRACT: Bioenergy Harvesting Technologies to Supply Crop Residues...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ABSTRACT: Bioenergy Harvesting Technologies to Supply Crop Residues In a Densified Large Square Bale Format ABSTRACT: Bioenergy Harvesting Technologies to Supply Crop Residues In a...

400

Experimental study of friction noise of dry contact under light load  

E-Print Network (OSTI)

musical instruments such as violins, guitars, sound radiated by glass when rubbing a moist finger, tyres on frictional sound may also be mentioned (Othman et al., 1990-1) and an original device for measuring

Le-Bot, Alain

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Friction of Steel Sliding Under Boundary Lubrication Regime in Commercial Gear Oils at Elevated Temperatures  

Energy.gov (U.S. Department of Energy (DOE))

This study was conducted to understand how to increase engine efficiency by reducing parasitic boundary regime friction losses and enable operation with lower viscosity oils while maintaining engine durability.

402

Forced Response Analysis of Integrally Bladed Disks with Friction Ring Dampers  

E-Print Network (OSTI)

is proposed. In numerical applications, a representative compressor blisk featuring several rings the wheel of blisks. These are held in contact with the blisk due to centrifugal loads and friction

Boyer, Edmond

403

Defining the role of elastic lubricants and micro textured surfaces in lubricated, sliding friction  

E-Print Network (OSTI)

Solutions for reducing friction in sliding, lubricated systems include modifying lubricant rheology using polymers and adding a micro-scale texture to the sliding surfaces, but the mechanism of how lubrication properties ...

Hupp, Sara J. (Sara Jean), 1979-

2008-01-01T23:59:59.000Z

404

In situ control of lubricant properties for reduction of power cylinder friction through thermal barrier coating  

E-Print Network (OSTI)

Lowering lubricant viscosity to reduce friction generally carries a side effect of increased metal-metal contact in mixed or boundary lubrication, for example near top ring reversal along the engine cylinder liner. A ...

Molewyk, Mark Allen

2014-01-01T23:59:59.000Z

405

Experimental investigation of energy dissipation behavior of the modified friction device  

E-Print Network (OSTI)

As building materials become stronger, dynamic design and structural control are effective means of improving serviceability in the future's ever lighter structures. The recently proposed modified friction device (MFD) ...

Zahner, Robert Marne

2011-01-01T23:59:59.000Z

406

Complex Non-Linear Modal Analysis for Mechanical Systems: Application to Turbomachinery Bladings With Friction  

E-Print Network (OSTI)

Complex Non-Linear Modal Analysis for Mechanical Systems: Application to Turbomachinery Bladings of a turbomachinery blade, with dry-friction interfaces is proposed. In the latter, an original framework

Paris-Sud XI, Université de

407

Micro and nano mechanics of materials response during instrumented frictional sliding  

E-Print Network (OSTI)

Over the past decade, many computational studies have explored the mechanics of instrumented normal indentation. In contrast, very few studies have investigated quantitative aspects of frictional sliding contact in the ...

Bellemare, Simon C. (Simon Claude)

2006-01-01T23:59:59.000Z

408

The Role of Friction Stir Welding in Nuclear Fuel Plate Fabrication  

SciTech Connect

The friction bonding process combines desirable attributes of both friction stir welding and friction stir processing. The development of the process is spurred on by the need to fabricate thin, high density, reduced enrichment fuel plates for nuclear research reactors. The work seeks to convert research and test reactors currently operating on highly enriched uranium fuel to operate on low enriched uranium fuel without significant loss in reactor performance, safety characteristics, or significant increase in cost. In doing so, the threat of global nuclear material proliferation will be reduced. Feasibility studies performed on the process show that this is a viable option for mass production of plate-type nuclear fuel. Adapting the friction stir weld process for nuclear fuel fabrication has resulted in the development of several unique ideas and observations. Preliminary results of this adaptation and process model development are discussed.

D Burkes; P Medvedev; M Chapple; A Amritkar; P Wells; I Charit

2009-02-01T23:59:59.000Z

409

Experimental and Theoretical Investigations of Lube Oil Performance and Engine Friction.  

E-Print Network (OSTI)

??The feasibility of using a motored small, single-cylinder 517 cc Hatz 1D50 diesel engine to evaluate lube oil performance and engine friction at conditions typical… (more)

Rohr, William Fredrick

2013-01-01T23:59:59.000Z

410

CONDENSATION/ADSORPTION AND EVACUATION OF RESIDUAL GASES IN THE SRF SYSTEM FOR THE CESR LUMINOSITY UPGRADE  

E-Print Network (OSTI)

cavity RBT transition HOM absorber FBT transition Nb waveguide Heat exchanger 270 l/s ion pump RF windowCONDENSATION/ADSORPTION AND EVACUATION OF RESIDUAL GASES IN THE SRF SYSTEM FOR THE CESR LUMINOSITY coupler performance in a superconducting RF system. It is there- fore important to understand condensation/adsorption

Geng, Rong-Li

411

Friction stir welding and processing of oxide dispersion strengthened (ODS) alloys  

DOE Patents (OSTI)

A method of welding including forming a filler material of a first oxide dispersoid metal, the first oxide dispersoid material having first strengthening particles that compensate for decreases in weld strength of friction stir welded oxide dispersoid metals; positioning the filler material between a first metal structure and a second metal structure each being comprised of at least a second oxide dispersoid metal; and friction welding the filler material, the first metal structure and the second metal structure to provide a weld.

Ren, Weiju

2014-11-11T23:59:59.000Z

412

Friction welded nonconsumable electrode assembly and use thereof for electrolytic production of metals and silicon  

DOE Patents (OSTI)

A nonconsumable electrode assembly suitable for use in the production of metal by electrolytic reduction of a metal compound dissolved in a molten salt, the assembly comprising a metal conductor and a ceramic electrode body connected by a friction weld between a portion of the body having a level of free metal or metal alloy sufficient to effect such a friction weld and a portion of the metal conductor.

Byrne, Stephen C. (Monroeville, PA); Ray, Siba P. (Pittsburgh, PA); Rapp, Robert A. (Columbus, OH)

1984-01-01T23:59:59.000Z

413

Stellite 6 Friction Changes Due to Aging and In-Service Testing  

SciTech Connect

For the past several years, researchers at the Idaho National Engineering and Environmental Laboratory, under the sponsorship of the U.S. Nuclear Regulatory Commission, have been investigating the ability of motor-operated valves to close or open when subjected to design basis flow and pressure loads. Part of this research addresses the friction that occurs at the interface between the valve disc and the valve body seats during operation of a gate valve. In most gate valves, these surfaces are hardfaced with Stellite 6, a cobalt-based alloy. The nuclear industry has developed methods to analytically predict the thrust needed to operate these valves at specific pressure conditions. To produce accurate valve thrust predictions; the analyst must have a reasonably accurate, though conservative, estimate of the coefficient of friction at the disc-to-seat interface. One of the questions that remains to be answered is whether, and to what extent, aging of the disc and seat surfaces affects the disc-to-seat coefficient of friction. Specifically, does the accumulation of a surface film due to aging of these surfaces increase the coefficient of friction and if so, how much? This paper presents results of specimen tests addressing this issue with emphasis on the following: • The change in the friction coefficient of Stellite 6 as it ages and whether the friction reaches a plateau. • The effect periodic gate valve cycling due to in-service testing has on the friction coefficient. • The results of an independent review of the test methods, processes, and the results of the research to date. • The status of ongoing aging and friction testing.

Watkins, John Clifford; DeWall, Kevin George

2001-07-01T23:59:59.000Z

414

Rotary magnetic heat pump  

DOE Patents (OSTI)

A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

Kirol, L.D.

1987-02-11T23:59:59.000Z

415

Electric force microscopy of semiconductors: Theory of cantilever frequency fluctuations and noncontact friction  

SciTech Connect

An electric force microscope employs a charged atomic force microscope probe in vacuum to measure fluctuating electric forces above the sample surface generated by dynamics of molecules and charge carriers. We present a theoretical description of two observables in electric force microscopy of a semiconductor: the spectral density of cantilever frequency fluctuations (jitter), which are associated with low-frequency dynamics in the sample, and the coefficient of noncontact friction, induced by higher-frequency motions. The treatment is classical-mechanical, based on linear response theory and classical electrodynamics of diffusing charges in a dielectric continuum. Calculations of frequency jitter explain the absence of contributions from carrier dynamics to previous measurements of an organic field effect transistor. Calculations of noncontact friction predict decreasing friction with increasing carrier density through the suppression of carrier density fluctuations by intercarrier Coulomb interactions. The predicted carrier density dependence of the friction coefficient is consistent with measurements of the dopant density dependence of noncontact friction over Si. Our calculations predict that in contrast to the measurement of cantilever frequency jitter, a noncontact friction measurement over an organic semiconductor could show appreciable contributions from charge carriers.

Lekkala, Swapna; Marohn, John A.; Loring, Roger F., E-mail: roger.loring@cornell.edu [Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853 (United States)

2013-11-14T23:59:59.000Z

416

Thulium-170 heat source  

SciTech Connect

An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

Walter, C.E.; Van Konynenburg, R.; VanSant, J.H.

1990-09-06T23:59:59.000Z

417

Thulium-170 heat source  

DOE Patents (OSTI)

An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

1992-01-01T23:59:59.000Z

418

Heat Treating Apparatus  

DOE Patents (OSTI)

Apparatus for heat treating a heat treatable material including a housing having an upper opening for receiving a heat treatable material at a first temperature, a lower opening, and a chamber therebetween for heating the heat treatable material to a second temperature higher than the first temperature as the heat treatable material moves through the chamber from the upper to the lower opening. A gas supply assembly is operatively engaged to the housing at the lower opening, and includes a source of gas, a gas delivery assembly for delivering the gas through a plurality of pathways into the housing in countercurrent flow to movement of the heat treatable material, whereby the heat treatable material passes through the lower opening at the second temperature, and a control assembly for controlling conditions within the chamber to enable the heat treatable material to reach the second temperature and pass through the lower opening at the second temperature as a heated material.

De Saro, Robert (Annandale, NJ); Bateman, Willis (Sutton Colfield, GB)

2002-09-10T23:59:59.000Z

419

Stabilization of Rocky Flats combustible residues contaminated with plutonium metal and organic solvents  

SciTech Connect

This report describes tests on a proposed flowsheet designed to stabilize combustible residues that were generated at the Rocky Flats Environmental Technology Site (RFETS) during the machining of plutonium metal. Combustible residues are essentially laboratory trash contaminated with halogenated organic solvents and plutonium metal. The proposed flowsheet, designed by RFETS, follows a glovebox procedure that includes (1) the sorting and shredding of materials, (2) a low temperature thermal desorption of solvents from the combustible materials, (3) an oxidation of plutonium metal with steam, and (4) packaging of the stabilized residues. The role of Los Alamos National Laboratory (LANL) in this study was to determine parameters for the low temperature thermal desorption and steam oxidation steps. Thermal desorption of carbon tetrachloride (CCl{sub 4}) was examined using a heated air stream on a Rocky Flats combustible residue surrogate contaminated with CCl{sub 4}. Three types of plutonium metal were oxidized with steam in a LANL glovebox to determine the effectiveness of this procedure for residue stabilization. The results from these LANL experiments are used to recommend parameters for the proposed RFETS stabilization flowsheet.

Bowen, S.M.; Cisneros, M.R.; Jacobson, L.L.; Schroeder, N.C.; Ames, R.L.

1998-09-30T23:59:59.000Z

420

Local origin of global contact numbers in frictional ellipsoid packings  

E-Print Network (OSTI)

In particulate soft matter systems the average number of contacts $Z$ of a particle is an important predictor of the mechanical properties of the system. Using X-ray tomography, we analyze packings of frictional, oblate ellipsoids of various aspect ratios $\\alpha$, prepared at different global volume fractions $\\phi_g$. We find that $Z$ is a monotonously increasing function of $\\phi_g$ for all $\\alpha$. We demonstrate that this functional dependence can be explained by a local analysis where each particle is described by its local volume fraction $\\phi_l$ computed from a Voronoi tessellation. $Z$ can be expressed as an integral over all values of $\\phi_l$: $Z(\\phi_g, \\alpha, X) = \\int Z_l (\\phi_l, \\alpha, X) \\; P(\\phi_l | \\phi_g) \\; d\\phi_l$. The local contact number function $ Z_l (\\phi_l, \\alpha, X)$ describes the relevant physics in term of locally defined variables only, including possible higher order corrections $X$. The conditional probability $P(\\phi_l | \\phi_g)$ to find a specific value of $\\phi_l$ given a global packing fraction $\\phi_g$ is independent of $\\alpha$ and $X$. An important step in defining $ Z_l (\\phi_l, \\alpha, X)$ is the determination of the local surface area fraction $\\psi_l$.

Fabian M. Schaller; Max Neudecker; Mohammad Saadatfar; Gary Delaney; Gerd E. Schröder-Turk; Matthias Schröter

2013-12-04T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Bar-Halo Friction in Galaxies III: Halo Density Changes  

E-Print Network (OSTI)

The predicted central densities of dark matter halos in LCDM models exceed those observed in some galaxies. Weinberg & Katz argue that angular momentum transfer from a rotating bar in the baryonic disk can lower the halo density, but they also contend that N-body simulations of this process will not reveal the true continuum result unless many more than the usual numbers of particles are employed. Adopting their simplified model of a rotating rigid bar in a live halo, I have been unable to find any evidence to support their contention. I find that both the angular momentum transferred and the halo density change are independent of the number of particles over the range usually employed up to that advocated by these authors. I show that my results do not depend on any numerical parameters, and that field methods perform equally with grid methods. I also identify the reasons that the required particle number suggested by Weinberg & Katz is excessive. I further show that when countervailing compression by baryonic settling is ignored, moderate bars can reduce the mean density of the inner halo by 20% - 30%. Long, massive, skinny bars can reduce the mean inner density by a factor ~10. The largest density reductions are achieved at the expense of removing most of the angular momentum likely to reside in the baryonic component. Compression of the halo by baryonic settling must reduce, and may even overwhelm, the density reduction achievable by bar friction.

J. A. Sellwood

2006-10-16T23:59:59.000Z

422

Thermoelectric heat exchange element  

DOE Patents (OSTI)

A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

Callas, James J. (Peoria, IL); Taher, Mahmoud A. (Peoria, IL)

2007-08-14T23:59:59.000Z

423

Disposal of Rocky Flats residues as waste  

SciTech Connect

Work is underway at the Rocky Flats Plant to evaluate alternatives for the removal of a large inventory of plutonium-contaminated residues from the plant. One alternative under consideration is to package the residues as transuranic wastes for ultimate shipment to the Waste Isolation Pilot Plant. Current waste acceptance criteria and transportation regulations require that approximately 1000 cubic yards of residues be repackaged to produce over 20,000 cubic yards of WIPP certified waste. The major regulatory drivers leading to this increase in waste volume are the fissile gram equivalent, surface radiation dose rate, and thermal power limits. In the interest of waste minimization, analyses have been conducted to determine, for each residue type, the controlling criterion leading to the volume increase, the impact of relaxing that criterion on subsequent waste volume, and the means by which rules changes may be implemented. The results of this study have identified the most appropriate changes to be proposed in regulatory requirements in order to minimize the costs of disposing of Rocky Flats residues as transuranic wastes.

Dustin, D.F.; Sendelweck, V.S. [EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant; Rivera, M.A. [Lamb Associates, Inc., Rockville, MD (United States)

1993-03-01T23:59:59.000Z

424

Disposal of Rocky Flats residues as waste  

SciTech Connect

Work is underway at the Rocky Flats Plant to evaluate alternatives for the removal of a large inventory of plutonium-contaminated residues from the plant. One alternative under consideration is to package the residues as transuranic wastes for ultimate shipment to the Waste Isolation Pilot Plant. Current waste acceptance criteria and transportation regulations require that approximately 1000 cubic yards of residues be repackaged to produce over 20,000 cubic yards of WIPP certified waste. The major regulatory drivers leading to this increase in waste volume are the fissile gram equivalent, surface radiation dose rate, and thermal power limits. In the interest of waste minimization, analyses have been conducted to determine, for each residue type, the controlling criterion leading to the volume increase, the impact of relaxing that criterion on subsequent waste volume, and the means by which rules changes may be implemented. The results of this study have identified the most appropriate changes to be proposed in regulatory requirements in order to minimize the costs of disposing of Rocky Flats residues as transuranic wastes.

Dustin, D.F.; Sendelweck, V.S. (EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant); Rivera, M.A. (Lamb Associates, Inc., Rockville, MD (United States))

1993-01-01T23:59:59.000Z

425

Heat Integrate Heat Engines in Process Plants  

E-Print Network (OSTI)

and refrigeration systems. In many instances these real heat engines may appear as a complex process consisting of flash vessels, heat exchangers, compressors, furnaces, etc. See Figure 18a, which shows a simplified diagram of a "steam Rankine cycle." How... and rejection profiles of the real machine. For example, the heat acceptance and re jection profiles for the steam Rankine cycle shown in Figure 18a have been drawn on T,H coordinates in Figure 18b. Thus providing we know the heat acceptance and rejection...

Hindmarsh, E.; Boland, D.; Townsend, D. W.

426

Assessment of dry residual biomass potential for use as alternative energy source in the party of General Pueyrredón, Argentina  

Science Journals Connector (OSTI)

Abstract The present article assesses the residual biomass availability and its energy potential in the Party of General Pueyrredón, a region located southeast of the province of Buenos Aires, Argentina. These were considered herbaceous and vegetable residues derived from the agricultural activity developed in the region, and forest residues resulting from the pruning of urban trees and garden maintenance. The estimates were based on statistical information of the 2011–2012 harvest and a series of parameters obtained from an extensive literature review. The calculations resulted in an availability of residual biomass of 204,536 t/year, implying an energy potential of 2605 TJ/year. If this biomass is used to generate electricity, it could supply 76,000 users from Mar del Plata city, the largest consumer center in the region. If the same available biomass is used for heat generation, 25,160 users could be supplied by the available residual biomass. The authors concluded that the residual biomass energy potential is significant in the studied region, but a more detailed study must be conducted to assess the techno-economic feasibility of using the available residual biomass as alternative energy source.

Justo José Roberts; Agnelo Marotta Cassula; Pedro Osvaldo Prado; Rubens Alves Dias; José Antonio Perrella Balestieri

2015-01-01T23:59:59.000Z

427

Condensation in horizontal heat exchanger tubes  

SciTech Connect

Many innovative reactor concepts for Generation III nuclear power plants use passive safety equipment for residual heat removal. These systems use two phase natural circulation. Heat transfer to the coolant results in a density difference providing the driving head for the required mass flow. By balancing the pressure drop the system finds its operational mode. Therefore the systems depend on a strong link between heat transfer and pressure drop determining the mass flow through the system. In order to be able to analyze these kind of systems with the help of state of the art computer codes the implemented numerical models for heat transfer, pressure drop or two phase flow structure must be able to predict the system performance in a wide parameter range. Goal of the program is to optimize the numerical models and therefore the performance of computer codes analyzing passive systems. Within the project the heat transfer capacity of a heat exchanger tube will be investigated. Therefore the tube will be equipped with detectors, both temperature and pressure, in several directions perpendicular to the tube axis to be able to resolve the angular heat transfer. In parallel the flow structure of a two phase flow inside and along the tube will be detected with the help of x-ray tomography. The water cooling outside of the tube will be realized by forced convection. It will be possible to combine the flow structure measurement with an angular resolved heat transfer for a wide parameter range. The test rig is set up at the TOPLFOW facility at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), so that it will be possible to vary the pressure between 5 and 70 bar. The steam mass content will be varied between 0 and 100 percent. The results will be compared to the large scaled Emergency Condenser Tests performed at the INKA test facility in Karlstein (Germany). The paper will explain the test setup and the status of the project will be presented. (authors)

Leyer, S.; Zacharias, T.; Maisberger, F.; Lamm, M. [AREVA NP GmbH, Paul-Gossen-Strasse 100, Erlangen, 91052 (Germany); Vallee, C.; Beyer, M.; Hampel, U. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Bautzner Landstrasse 400, Dresden, 01328 (Germany)

2012-07-01T23:59:59.000Z

428

DEVELOPMENT OF A SUPPLEMENTAL RESIDUAL CONTAMINATION GUIDELINE  

Office of Legacy Management (LM)

DEVELOPMENT OF A SUPPLEMENTAL RESIDUAL CONTAMINATION GUIDELINE DEVELOPMENT OF A SUPPLEMENTAL RESIDUAL CONTAMINATION GUIDELINE FOR THE NFSS CENTRAL DRAINAGE DITCH DECEMBER 1986 Prepared for UNITED STATES DEPARTMENT OF ENERGY OAK RIDGE OPERATIONS OFFICE Under Contract No. DE-AC05-81OR20722 By Bechtel National, Inc. Oak Ridge, Tennessee Bechtel Job No. 14501 I 1.0 INTRODUCTION AND SUMMARY 1.1 OBJECTIVE AND SCOPE The objective of this report is to describe the methodology used for establishing a supplemental residual contamination guideline for the NFSS vicinity property known as the Central Drainage Ditch (CDD). Supplemental guidelines may exceed authorized guidelines if the resultant dose will not exceed the DOE radiation protection standard of 100 mrem/yr (Ref. 1). This evaluation is based on realistic exposure pathways that were

429

Minimal Residual Disease in Chronic Myeloid Leukemia  

Science Journals Connector (OSTI)

...treatment with chemotherapy. In a hematologic complete remission, we know that a large portion of the leukemic cells remain out of sight. These cells, invisible to the microscopist, are the components of an important clinical problem termed "minimal residual disease." The concept of minimal residual disease... For many years hematologists have used the microscope to identify a complete remission of leukemia after treatment with chemotherapy. In a hematologic complete remission, we know that a large portion of the leukemic cells remain out of sight. These cells, ...

Löwenberg B.

2003-10-09T23:59:59.000Z

430

Heat transfer system  

DOE Patents (OSTI)

A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

McGuire, Joseph C. (Richland, WA)

1982-01-01T23:59:59.000Z

431

Wound tube heat exchanger  

DOE Patents (OSTI)

What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

432

Heat Exchangers for Solar Water Heating Systems | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems May 30, 2012 - 3:40pm Addthis Image of a heat exchanger. | Photo from iStockphoto.com Image of a heat exchanger. | Photo from iStockphoto.com Solar water heating systems use heat exchangers to transfer solar energy absorbed in solar collectors to the liquid or air used to heat water or a space. Heat exchangers can be made of steel, copper, bronze, stainless steel, aluminum, or cast iron. Solar heating systems usually use copper, because it is a good thermal conductor and has greater resistance to corrosion. Types of Heat Exchangers Solar water heating systems use three types of heat exchangers: Liquid-to-liquid A liquid-to-liquid heat exchanger uses a heat-transfer fluid that

433

LOW-ENGINE-FRICTION TECHNOLOGY FOR ADVANCED NATURAL-GAS RECIPROCATING ENGINES  

SciTech Connect

This program aims at improving the efficiency of advanced natural-gas reciprocating engines (ANGRE) by reducing piston/ring assembly friction without major adverse effects on engine performance, such as increased oil consumption and emissions. An iterative process of simulation, experimentation and analysis, are being followed towards achieving the goal of demonstrating a complete optimized low-friction engine system. To date, a detailed set of piston/ring dynamic and friction models have been developed and applied that illustrated the fundamental relationships between design parameters and friction losses. Various low-friction strategies and ring-design concepts have been explored, and engine experiments have been done on a full-scale Waukesha VGF F18 in-line 6 cylinder power generation engine rated at 370 kW at 1800 rpm. Current accomplishments include designing and testing ring-packs using a subtle top-compression-ring profile (skewed barrel design), lowering the tension of the oil-control ring, employing a negative twist to the scraper ring to control oil consumption. Initial test data indicate that piston ring-pack friction was reduced by 35% by lowering the oil-control ring tension alone, which corresponds to a 1.5% improvement in fuel efficiency. Although small in magnitude, this improvement represents a first step towards anticipated aggregate improvements from other strategies. Other ring-pack design strategies to lower friction have been identified, including reduced axial distance between the top two rings, tilted top-ring groove. Some of these configurations have been tested and some await further evaluation. Colorado State University performed the tests and Waukesha Engine Dresser, Inc. provided technical support. Key elements of the continuing work include optimizing the engine piston design, application of surface and material developments in conjunction with improved lubricant properties, system modeling and analysis, and continued technology demonstration in an actual full-sized reciprocating natural-gas engine.

Victor W. Wong; Tian Tian; Grant Smedley; Jeffrey Jocsak

2004-09-30T23:59:59.000Z

434

Measurement of local internal friction in metallic glasses  

SciTech Connect

Atomic force acoustic microscopy (AFAM), an advanced scanning probe microscopy technique, has been used to measure local elastic properties with a spatial resolution given by the tip-sample contact radius. AFAM is based on inducing out-of-plane vibrations in the specimen. The vibrations are sensed by the AFM cantilever from by the photodiode signal when its tip is in contact with the material under test. To measure local damping, the inverse quality factor Q{sup ?1} of the resonance curve is usually evaluated. Here, from the contact-resonance spectra obtained, we determine the real and imaginary part of the contact stiffness k* and from these two quantities the local damping factor Q{sub loc}{sup ?1} is obtained which is proportional to the imaginary part ? of the contact stiffness. The evaluation of the data is based on the cantilever's mass distribution with damped flexural modes and not on an effective point-mass approximation for the cantilever’s motion. The given equation is simple to use and has been employed to study the local Q{sub loc}{sup ?1} of amorphous PdCuSi metallic glass and its crystalline counterpart as a function of position of the AFM tip on the surface. The width of the distribution changes dramatically from the amorphous to the crystalline state as expected from the consequences of the potential-energy landscape picture. The center value of the distribution curve for Q{sub loc}{sup ?1} coincides very well with published data, based on global ultrasonic or internal friction measurements. This is compared to Q{sub loc}{sup ?1} measured in crystalline SrTiO{sub 3}, which exhibits a narrow distribution, as expected.

Wagner, H.; Büchsenschütz-Göbeler, M.; Luo, Y.; Samwer, K. [I. Physikalisches Institut, Georg-August Universität, Friedrich-Hund-Platz 1, D-37077 Göttingen (Germany); Kumar, A. [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Arnold, W., E-mail: w.arnold@mx.uni-saarland.de [I. Physikalisches Institut, Georg-August Universität, Friedrich-Hund-Platz 1, D-37077 Göttingen (Germany); Department of Materials and Materials Technology, Saarland University, Campus D 2.2, D-66123 Saarbrücken (Germany)

2014-04-07T23:59:59.000Z

435

Municipal water-based heat pump heating and/or cooling systems: Findings and recommendations. Final report  

SciTech Connect

The purpose of the present work was to determine if existing heat pump systems based on municipal water systems meet existing water quality standards, to analyze water that has passed through a heat pump or heat exchanger to determine if corrosion products can be detected, to determine residual chlorine levels in municipal waters on the inlet as well as the outlet side of such installations, to analyses for bacterial contaminants and/or regrowth due to the presence of a heat pump or heat exchanger, to develop and suggest criteria for system design and construction, to provide recommendations and specifications for material and fluid selection, and to develop model rules and regulations for the installation, operation, and monitoring of new and existing systems. In addition, the Washington State University (WSU) has evaluated availability of computer models that would allow for water system mapping, water quality modeling and system operation.

Bloomquist, R.G. [Washington, State Univ., Pullman, WA (United States); Wegman, S. [South Dakota Utilities Commission (United States)

1998-04-01T23:59:59.000Z

436

Vehicle Technologies Office Merit Review 2014: Friction Reduction through Surface Modification (Agreement ID:23284) Project ID:18518  

Energy.gov (U.S. Department of Energy (DOE))

Presentation given by Oak Ridge National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about friction...

437

Nanofriction Mechanisms Derived from the Dependence of Friction on Load and Sliding Velocity from Air to UHV on Hydrophilic Silicon  

Science Journals Connector (OSTI)

This paper examines friction as a function of the sliding velocity and applied normal load from air to UHV in a scanning force microscope (SFM)...

A. Opitz; S. I.-U. Ahmed; M. Scherge; J.A. Schaefer

2005-12-01T23:59:59.000Z

438

Chemical Stabilization of Hanford Tank Residual Waste  

SciTech Connect

Three different chemical treatment methods were tested for their ability to stabilize residual waste from Hanford tank C-202 for reducing contaminant release (Tc, Cr, and U in particular). The three treatment methods tested were lime addition [Ca(OH)2], an in-situ Ceramicrete waste form based on chemically bonded phosphate ceramics, and a ferrous iron/goethite treatment. These approaches rely on formation of insoluble forms of the contaminants of concern (lime addition and ceramicrete) and chemical reduction followed by co-precipitation (ferrous iron/goethite incorporation treatment). The results have demonstrated that release of the three most significant mobile contaminants of concern from tank residual wastes can be dramatically reduced after treatment compared to contact with simulated grout porewater without treatment. For uranium, all three treatments methods reduced the leachable uranium concentrations by well over three orders of magnitude. In the case of uranium and technetium, released concentrations were well below their respective MCLs for the wastes tested. For tank C-202 residual waste, chromium release concentrations were above the MCL but were considerably reduced relative to untreated tank waste. This innovative approach has the potential to revolutionize Hanford’s tank retrieval process, by allowing larger volumes of residual waste to be left in tanks while providing an acceptably low level of risk with respect to contaminant release that is protective of the environment and human health. Such an approach could enable DOE to realize significant cost savings through streamlined retrieval and closure operations.

Cantrell, Kirk J.; Um, Wooyong; Williams, Benjamin D.; Bowden, Mark E.; Gartman, Brandy N.; Lukens, Wayne W.; Buck, Edgar C.; Mausolf, Edward J.

2014-03-01T23:59:59.000Z

439

Automatic Methods for Predicting Functionally Important Residues  

E-Print Network (OSTI)

Pazos and Alfonso Valencia* Protein Design Group National Center for Biotechnology, Cantoblanco Madrid of protein families into subfamilies in the search for those positions that could have some functional families, testing the statistical meaning of the Tree-determinant residues predicted by three different

Pazos, Florencio

440

Residual Stresses in Weldments by Neutron Diffraction  

E-Print Network (OSTI)

Residual Stresses in Weldments by Neutron Diffraction Shanmukha Rao M, Jon James, Shirley Northover :- The neutron diffraction is determined from Bragg's law. When neutron propagate through crystal sample, Coherent, Incoherent and Absorption Scattering phenomena take place Weld MaterialsPlate materials Stress

Bandara, Arosha

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Specific Nucleoprotein Residues Affect Influenza Virus Morphology  

Science Journals Connector (OSTI)

...these residues to the crystal structure of NP, we...in the production of spherical virions, as indicated...WSN-AichiM1 virus. (A) Crystal structure of NP highlighting...M1 to form straight or bent elongated ribbons and...filamentous virions to spherical ones. We anticipate...

Kristy M. Bialas; Kendra A. Bussey; Raychel L. Stone; Toru Takimoto

2013-12-11T23:59:59.000Z

442

E-Print Network 3.0 - automotive shredder residue Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

residue Search Powered by Explorit Topic List Advanced Search Sample search results for: automotive shredder residue...

443

E-Print Network 3.0 - automotive shredder residues Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

residues Search Powered by Explorit Topic List Advanced Search Sample search results for: automotive shredder residues...

444

Geothermal Heat Pumps  

Energy.gov (U.S. Department of Energy (DOE))

The Geothermal Technologies Office focuses only on electricity generation. For additional information about geothermal heating and cooling and ground source heat pumps, please visit the U.S. Department of Energy (DOE)'s Buildings Technologies Office.

445

HEAT TRANSFER FLUIDS  

E-Print Network (OSTI)

The choice of heat transfer fluids has significant effects on the performance, cost, and reliability of solar thermal systems. In this chapter, we evaluate existing heat transfer fluids such as oils and molten salts based ...

Lenert, Andrej

2012-01-01T23:59:59.000Z

446

Residential heating oil price  

Annual Energy Outlook 2012 (EIA)

heating oil price decreases The average retail price for home heating oil fell 6.3 cents from a week ago to 2.91 per gallon. That's down 1.10 from a year ago, based on the...

447

Residential heating oil price  

U.S. Energy Information Administration (EIA) Indexed Site

heating oil price decreases The average retail price for home heating oil fell 7.5 cents from a week ago to 2.84 per gallon. That's down 1.22 from a year ago, based on the...

448

Residential heating oil price  

NLE Websites -- All DOE Office Websites (Extended Search)

heating oil price decreases The average retail price for home heating oil fell 7.6 cents from a week ago to 2.97 per gallon. That's down 1.05 from a year ago, based on the...

449

Residential heating oil price  

NLE Websites -- All DOE Office Websites (Extended Search)

heating oil price decreases The average retail price for home heating oil fell 3.6 cents from a week ago to 3.04 per gallon. That's down 99.4 cents from a year ago, based on the...

450

Characterization of contaminants in oil shale residuals and the potential for their management to meet environmental quality standards. Final report  

SciTech Connect

Some general aspects of various oil shale processes developed for scale-up to commercial size modular units are described. The overall magnitude of an envisioned commercial shale oil operation and the magnitude of resulting potentially polluting residues in particular solid residues from retorting oil shale and associated operations and wastewater from retort streams and other sources are considered. The potential problems ensuing from self-oxidation of stockpiles of oil shale and from residual carbonaceous retorted oil shale disposed above ground and/or from in situ retorting operations are examined. Some methods for managing self-heating processes are suggested. The most plausible method of avoiding potential self-heating for retorted oil shale is to oxidize as much as possible of the organic carbon present by utilizing a process that will produce low carbon or carbon-free retorted oil shale residues. In the case of unretorted oil shale, the dimensions and shapes of the stockpiles should be designed such that heat build-up is eliminated or kept to a minimum.

Schmidt-Collerus, J.J.

1984-02-01T23:59:59.000Z

451

MA HEAT Loan Overview  

Energy.gov (U.S. Department of Energy (DOE))

Presents information on the success of Massachusetts's HEAT loan offerings and how the financing tool is funded.

452

Ductless Heat Pumps  

NLE Websites -- All DOE Office Websites (Extended Search)

Water Heaters Showerheads Residential Weatherization Performance Tested Comfort Systems Ductless Heat Pumps New Construction Residential Marketing Toolkit Retail Sales...

453

Heat Pump Water Heaters  

NLE Websites -- All DOE Office Websites (Extended Search)

Water Heaters Showerheads Residential Weatherization Performance Tested Comfort Systems Ductless Heat Pumps New Construction Residential Marketing Toolkit Retail Sales...

454

Solar heat receiver  

DOE Patents (OSTI)

A receiver is described for converting solar energy to heat a gas to temperatures from 700 to 900/sup 0/C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.

Hunt, A.J.; Hansen, L.J.; Evans, D.B.

1982-09-29T23:59:59.000Z

455

Electric resistive space heating  

Science Journals Connector (OSTI)

The cost of heating residential buildings using electricity is compared to the cost employing gas or oil. (AIP)

David Bodansky

1985-01-01T23:59:59.000Z

456

Nondestructive, in-process inspection of inertia friction welding : an investigation into a new sensing technique.  

SciTech Connect

This paper investigates the capabilities of a new sensor for in-process monitoring of quality during friction welding. The non-contact sensor is composed of microphones that are mounted in an aluminum ring which surrounds the weld joint. The sensor collects the acoustical energy (in the form of sound pressure) that is emitted during the plastic deformation and phase transformations (if applicable) in friction welding processes. The focus in this preliminary investigation is to search for and identify features within the acoustical emission that are indicative of bond quality. Bar-to-bar inertia friction welding (one form of friction welding) of copper to 304L stainless steel is used in this proof-of-concept study. This material combination exhibits only marginal weldability and is ideally suited for validating the capabilities of this new sensing technique. A probabilistic neural network is employed in this work to analyze the acoustical emission's frequency spectrum in an attempt to classify acceptable, conditional, and unacceptable welds. Our preliminary findings indicate that quality-based process features do exist within the frequency spectrum of the acoustical signature. The results from this analysis are presented. Future work in improving the sensing and interpretation of the data is discussed in an effort to develop a robust method of quality-based, in-process monitoring of friction welds.

Hartman, D. A. (Daniel A.); Cola, M. J. (Mark J.); Dave, V. R. (Vivek R.); Dozhier, N. G. (Nathan G.); Carpenter, R. W. (Robert W.)

2002-01-01T23:59:59.000Z

457

Analysis of translational positioning of unit loads by directionally-oriented friction force fields  

Science Journals Connector (OSTI)

The objective of this study was numerical simulation and experimental examination of the process of translational positioning of a stream of unit loads (i.e. postal parcels) transported on conveyors. A system of two inversely-oriented fields of friction forces was used to perform the task of load positioning. In numerical investigations, one applied theoretical description of the positioning process based on the Karnopp's model of static friction and the dynamic friction model of LuGre. In the Karnopp's model, two classic friction coefficients were used (based on one or two parameters, respectively) and a nonlinear coefficient defined by a B-spline curve of third order (determined based on experimental results). The results of numerical investigation were verified by experiments, which consisted in translating the objects by a system of two inversely-driven belts. The analyses of numerical and experimental results indicated that the effectiveness of the positioning process is mostly influenced by nonlinearity of friction coefficient of the transported loads.

T. Piatkowski

2011-01-01T23:59:59.000Z

458

Special relativity as the limit of an Aristotelian universal friction theory under Reye's assumption  

E-Print Network (OSTI)

This work explores a classical mechanical theory under two further assumptions: (a) there is a universal dry friction force (Aristotelian mechanics), and (b) the variation of the mass of a body due to wear is proportional to the work done by the friction force on the body (Reye's hypothesis). It is shown that mass depends on velocity as in Special Relativity, and that the velocity is constant for a particular characteristic value. In the limit of vanishing friction the theory satisfies a relativity principle as bodies do not decelerate and, therefore, the absolute frame becomes unobservable. However, the limit theory is not Newtonian mechanics, with its Galilei group symmetry, but rather Special Relativity. This result suggests to regard Special Relativity as the limit of a theory presenting universal friction and exchange of mass-energy with a reservoir (vacuum). Thus, quite surprisingly, Special Relativity follows from the absolute space (ether) concept and could have been discovered following studies of Aristotelian mechanics and friction. We end the work confronting the full theory with observations. It predicts the Hubble law through tired light, and hence it is incompatible with supernova light curves unless both mechanisms of tired light (locally) and universe expansion (non-locally) are at work. It also nicely accounts for some challenging numerical coincidences involving phenomena under low acceleration.

E. Minguzzi

2014-11-28T23:59:59.000Z

459

Liquid heat capacity lasers  

DOE Patents (OSTI)

The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

Comaskey, Brian J. (Walnut Creek, CA); Scheibner, Karl F. (Tracy, CA); Ault, Earl R. (Livermore, CA)

2007-05-01T23:59:59.000Z

460

Heat Transfer Guest Editorial  

E-Print Network (OSTI)

Journal of Heat Transfer Guest Editorial We are indeed delighted in bringing out this special issue was showcased in diverse areas such as traditional heat and mass transfer, lab-on-chip, sensors, biomedical applica- tions, micromixers, fuel cells, and microdevices. Selected papers in the field of heat transfer

Kandlikar, Satish

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Acoustic Heating Peter Ulmschneider  

E-Print Network (OSTI)

Acoustic Heating Peter Ulmschneider lnstitut fiir Theoretische Astrophysik der Universitat waves are a viable and prevalent heating mechanism both in early- and in late-type stars. Acoustic heating appears to be a dominant mechanism for situations where magnetic fields are weak or absent

Ulmschneider, Peter

462

Ammoniated salt heat pump  

SciTech Connect

A thermochemical heat pump/energy storage system using liquid ammoniate salts is described. The system, which can be used for space heating or cooling, provides energy storage for both functions. The bulk of the energy is stored as chemical energy and thus can be stored indefinitely. The system is well suited to use with a solar energy source or industrial waste heat.

Haas, W.R.; Jaeger, F.J.; Giordano, T.J.

1981-01-01T23:59:59.000Z

463

Pioneering Heat Pump Project  

Energy.gov (U.S. Department of Energy (DOE))

Project objectives: To install and monitor an innovative WaterFurnace geothermal system that is technologically advanced and evolving; To generate hot water heating from a heat pump that uses non-ozone depleting refrigerant CO2. To demonstrate the energy efficiency of this system ground source heat pump system.

464

Home Heating | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Home Heating Everything you need to know about home heating, including how heating systems work, the different types on the market and proper maintenance. Read more Thermostats...

465

Water Heating | Department of Energy  

Energy Savers (EERE)

Energy Saver Water Heating Water Heating Infographic: Water Heaters 101 Infographic: Water Heaters 101 Everything you need to know about saving money on water heating costs....

466

Sodium Heat Engine Development Program  

SciTech Connect

The Sodium Heat Engine (SHE) is an efficient thermoelectric conversion device which directly generates electricity from a thermally regenerative electrochemical cell that relies on the unique conduction properties of {beta}{double prime}-alumina solid electrolyte (BASE). Laboratory models of a variety of SHE devices have demonstrated the feasibility and efficiency of the system, engineering development of large prototype devices has been slowed by a series of materials and fabrication problems. Failure of the electrolyte tubes has been a recurring problem and a number of possible causes have been postulated. To address these issues, a two-phase engineering development program was undertaken. This report summarizes the final results of the first phase of the program, which included extensive materials characterization activities, a study of applicable nondestructive evaluation methods, an investigation of possible stress states that would contribute to fracture, and certain operational issues associated with the electromagnetic pumps used in the SHE prototype. Mechanical and microstructural evaluation of commercially obtained BASE tubes revealed that they should be adequate for SHE applications and that sodium exposure produced no appreciable deleterious strength effects. Processing activities to produce a more uniform and smaller grain size for the BASE tubes were completed using isostatic pressing, extrusion, and slip casting. Green tubes were sintered by conventional and microwave plasma methods. Of particular interest is the residual stress state in the BASE tubes, and both analysis and nondestructive evaluation methods were employed to evaluate these stresses. X-ray and neutron diffraction experiments were performed to determine the bulk residual stresses in commercially fabricated BASE tubes; however, tube-to-tube variations and variations among the various methods employed did not allow formulation of a definitive definition of the as-fabricated stress state.

Singh, J.P.; Kupperman, D.S.; Majumdar, S.; Dorris, S.; Gopalsami, N.; Dieckman, S.L.; Jaross, R.A.; Johnson, D.L.; Gregar, J.S.; Poeppel, R.B.; Raptis, A.C.; Valentin, R.A.

1992-01-01T23:59:59.000Z

467

Friction and wear characteristics of ceramic nanocomposite coatings: Titanium carbide/amorphous hydrocarbon  

SciTech Connect

Friction and wear characteristics of titanium-containing amorphous hydrocarbon (Ti--C:H) coatings were measured during unlubricated sliding against WC--Co. These Ti--C:H coatings consist of nanocrystalline TiC clusters embedded in an amorphous hydrocarbon (a-C:H) matrix, i.e., they are TiC/a-C:H nanocomposites. The elastic modulus and hardness of the coatings exhibit smooth variations with increasing Ti composition. In contrast, a relatively abrupt transition occurs in the friction coefficient and wear rate of the coatings over a relatively narrow (20--30 at. %) Ti composition range. Our results reveal bimodal friction and wear behaviors for the TiC/a-C:H nanocomposites, a-C:H like at Ti compositions below 20%, and TiC like at Ti compositions above 30%. The two different wear mechanisms that operate as the volume fraction of nanocrystalline TiC clusters changes are discussed.

Cao, D. M.; Feng, B.; Meng, W. J.; Rehn, L. E.; Baldo, P. M.; Khonsari, M. M.

2001-07-16T23:59:59.000Z

468

Identification of Friction Parameters from the Inverse Analysis of a Direct Extrusion Test  

SciTech Connect

This work proposes to use a special upsetting test and an optimal direct extrusion one performed to identify the constitutive equation of the material behavior and the friction coefficients directly from the load-stroke curves. The proposed friction test has the advantage to permit to take into account contact phenomena corresponding to new specimen surfaces created during a real bulk cold forming process. A lot of numerical simulations are made with the commercial software FORGE2 in order to study the influence of some design and process parameters. Different friction laws will be identified starting from the classical Coulomb and Tresca ones. All the parameter identifications are made using the Inverse Analysis principle.

Adinel, Gavrus; Thien, Pham Duc [LGCGM Laboratory, EA 3913, INSA de RENNES, UEB, CS70839, F-35708, Rennes-Cedex 7 (France); Henri, Francillette [SCR/CM, UMR 6226, INSA de RENNES, UEB, CS70839, F-35708, Rennes-Cedex 7 (France)

2011-01-17T23:59:59.000Z

469

Interfacial Friction in Gas-Liquid Annular Flow: Analogies to Full and Transition Roughness  

SciTech Connect

New film thickness and pressure gradient data were obtained in a 5.08 by 101.6 mm duct for nitrogen and water in annular flow. Pressures of 3.4 and 17 atm and temperatures of 38 and 93 C were used to vary the gas density and liquid viscosity. These data are used to compute interfacial shear stresses and interfacial friction factors for comparison with several accepted literature correlations. These comparisons are reasonable for small values of the relative film thickness. However, the new data cover conditions not approached by the data used to construct those correlations. By combining the current data with the results of two other comprehensive modern experimental studies, a new correlation for the interfacial friction factor has been developed. This correlation adds elements of transition roughness to Wallis' fully-rough analogy to better predict interfacial friction factors over a wide range of gas Reynolds numbers and liquid film thicknesses.

Bauer, R.C.; Beus, S.G.; Fore, L.B.

1999-03-01T23:59:59.000Z

470

Temperature and water vapor pressure effects on the friction coefficient of hydrogenated diamondlike carbon films.  

SciTech Connect

Microtribological measurements of a hydrogenated diamondlike carbon film in controlled gaseous environments show that water vapor plays a significant role in the friction coefficient. These experiments reveal an initial high friction transient behavior that does not reoccur even after extended periods of exposure to low partial pressures of H{sub 2}O and O{sub 2}. Experiments varying both water vapor pressure and sample temperature show trends of a decreasing friction coefficient as a function of both the decreasing water vapor pressure and the increasing substrate temperature. Theses trends are examined with regard to first order gas-surface interactions. Model fits give activation energies on the order of 40 kJ/mol, which is consistent with water vapor desorption.

Dickrell, P. L.; Sawyer, W. G.; Eryilmaz, O. L.; Erdemir, A.; Energy Technology; Univ. of Florida

2009-07-01T23:59:59.000Z

471

Driven translocation of a polymer: role of pore friction and crowding  

E-Print Network (OSTI)

Force-driven translocation of a macromolecule through a nanopore is investigated by taking into account the monomer-pore friction as well as the "crowding" of monomers on the {\\it trans} - side of the membrane which counterbalance the driving force acting in the pore. The set of governing differential-algebraic equations for the translocation dynamics is derived and solved numerically. The analysis of this solution shows that the crowding of monomers on the trans side hardly affects the dynamics, but the monomer-pore friction can substantially slow down the translocation process. Moreover, the translocation exponent $\\alpha$ in the translocation time - vs. - chain length scaling law, $\\tau \\propto N^{\\alpha}$, becomes smaller when monomer-pore friction coefficient increases. This is most noticeable for relatively strong forces. Our findings may explain the variety of $\\alpha$ values which were found in experiments and computer simulations.

Johan L. A. Dubbeldam; V. G. Rostiashvili; T. A. Vilgis

2014-04-01T23:59:59.000Z

472

Residential Heating Oil Prices  

Gasoline and Diesel Fuel Update (EIA)

This chart highlights residential heating oil prices for the current and This chart highlights residential heating oil prices for the current and past heating season. As you can see, prices have started the heating season, about 40 to 50 cents per gallon higher than last year at this time. The data presented are from EIA's State Heating Oil and Propane Program. We normally collect and publish this data twice a month, but given the low stocks and high prices, we started tracking the prices weekly. These data will also be used to determine the price trigger mechanism for the Northeast Heating Oil Reserve. The data are published at a State and regional level on our web site. The slide is to give you some perspective of what is happening in these markets, since you probably will get a number of calls from local residents about their heating fuels bills

473

Active microchannel heat exchanger  

DOE Patents (OSTI)

The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

Tonkovich, Anna Lee Y. (Pasco, WA) [Pasco, WA; Roberts, Gary L. (West Richland, WA) [West Richland, WA; Call, Charles J. (Pasco, WA) [Pasco, WA; Wegeng, Robert S. (Richland, WA) [Richland, WA; Wang, Yong (Richland, WA) [Richland, WA

2001-01-01T23:59:59.000Z

474

Nanofluid heat capacities  

Science Journals Connector (OSTI)

Significant increases in the heat capacity of heat transfer fluids are needed not only to reduce the costs of liquid heating and cooling processes but also to bring clean energy producing technologies like concentrating solar power (CSP) to price parity with conventional energy generation. It has been postulated that nanofluids could have higher heat capacities than conventional fluids. In this work nano- and micron-sized particles were added to five base fluids (poly-? olefin mineral oil ethylene glycol a mixture of water and ethylene glycol and calcium nitrate tetrahydrate) and the resulting heat capacities were measured and compared with those of the neat base fluids and the weighted average of the heat capacities of the components. The particles used were inert metals and metal oxides that did not undergo any phase transitions over the temperature range studied. In the nanofluids studied here we found no increase in heat capacity upon the addition of the particles larger than the experimental error.

Anne K. Starace; Judith C. Gomez; Jun Wang; Sulolit Pradhan; Greg C. Glatzmaier

2011-01-01T23:59:59.000Z

475

A model for improvement of water heating heat exchanger designs for residential heat pump water heaters.  

E-Print Network (OSTI)

??Heat pump water heaters are a promising technology to reduce energy use and greenhouse gas emissions. A key component is the water heating heat exchanger.… (more)

Weerawoot, Arunwattana

2010-01-01T23:59:59.000Z

476

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP  

E-Print Network (OSTI)

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP W. D. C. Richards and W. L. Auxer General Electric Company Space Division King of Prussia, Pa. ABSTRACT A heat activated heat pump (HAHP for space heating since it directly utilizes the engine waste heat in addition to the energy obtained

Oak Ridge National Laboratory

477

Chapter 8 - Coal Combustion Residue Disposal Options  

Science Journals Connector (OSTI)

Abstract Coal combustion residues (CCRs) are presently regulated as solid waste (Subtitle D) under the Resource Conservation Recovery Act. Such classification promotes beneficial use by end-users i.e. mitigating excessive liability. According to the US Environmental Protection agency (USEPA), about 131 million tons of coal combustion residuals—including 71 million tons of fly ash, 20 million tons of bottom ash and boiler slag, and 40 million tons of flue gas desulfurization (FGD) material—were generated in the US in 2007. Of this, approximately 36% was disposed of in landfills, 21% was disposed of in surface impoundments, 38% was beneficially reused, and 5% was used as minefill. Stringent regulation, as Subtitle C (hazardous waste), would impose a perceived liability upon end-users; greatly reducing beneficial use opportunities. Mandatory use of synthetic liners—would not have prevented dike wall failure and fails to consider inherent engineering characteristics of CCRs.

Richard W. Goodwin

2014-01-01T23:59:59.000Z

478

Friction and wear tests on some coatings for a titanium riser  

SciTech Connect

Three types of coatings have been tested for their suitability for use on a titanium riser to be pulled through a `J` tube. The purpose of the coatings was to provide thermal insulation to the riser and galvanically isolate it from the steel `J` tube. The coatings tested were; polypropylene, polychloroprene and polychloroprene with PTFE overlay. The coatings were selected for their low friction, toughness and thermal insulation properties. The wear and friction coefficients of each coating has been measured in a test simulating the forces and environment which the riser would experience during the pull-in. All three coating performed satisfactorily.

Baxter, C.F. [Carl Baxter and Associates, East Horsley (United Kingdom); Lassen, S. [Inst. for Product Development, Lyngby (Denmark)

1995-12-31T23:59:59.000Z

479

Thermo-mechanical characterization of nano filled and fiber reinforced brake friction materials  

Science Journals Connector (OSTI)

Brake friction materials filled with multiwalled carbon nanotubes (MWCNT) and nanoclay have been fabricated and characterize for thermo-mechanical properties. Thermo gravimetric analysis (TGA) show that the stability of the friction composites increased with increase in MWCNT and nanoclay contents. Dynamic mechanical analysis (DMA) of the composite have been carried out to characterize the storage modulus (E?) loss modulus (E?) and damping factor (Tan ?) as a function of temperature. The storage and loss modulus show a maxima at lower content of MWCNT and nanoclay.

2013-01-01T23:59:59.000Z

480

Anomalous pinning behavior in an incommensurate two-chain model of friction  

Science Journals Connector (OSTI)

Pinning phenomena in an incommensurate two-chain model of friction are studied numerically. The pinning effect due to the breaking of analyticity exists in the present model. The pinning behavior is, however, quite different from that for the breaking of the analyticity state of the Frenkel-Kontorova model. When the elasticity of chains or the strength of interchain interaction is changed, pinning force and maximum static frictional force show anomalously complicated behavior accompanied by a successive phase transition and they vanish completely under certain conditions.

Takaaki Kawaguchi and Hiroshi Matsukawa

1998-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "residual heat friction" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


481

Casimir Friction in Terms of Moving Harmonic Oscillators: Equivalence Between Two Different Formulations  

E-Print Network (OSTI)

The Casimir friction problem can be dealt with in a simplified way by considering two harmonic oscillators moving with constant relative velocity. Recently we calculated the energy dissipation for such a case, [EPL {\\bf 91}, 60003 (2010); Europ. Phys. J. D {\\bf 61}, 335 (2011)]. A recent study of Barton [New J. Phys. {\\bf 12}, 113044 (2010)] seemingly leads to a different result for the dissipation. If such a discrepancy really were true, it would imply a delicate difficulty for the basic theory of Casimir friction. In the present note we show that the expressions for the dissipation are in fact physically equivalent, at T=0.

Johan S. Høye; Iver Brevik

2011-01-06T23:59:59.000Z

482

Friction as a probe of surface properties of a polymer glass  

E-Print Network (OSTI)

We probe the temperature dependence of friction at the interface between a glassy poly(methylmethacrylate) lens and a flat substrate coated with a methyl-terminated self-assembled monolayer. The monolayer exhibits density defects which act as pinning sites for the polymer chains. We show that the shear response of such an interface supports the existence, at the surface of the glassy polymer, of a nanometer-thick layer of mobile chains. Friction can be ascribed to the interplay between viscouslike dissipation in this layer and depinning of chains adsorbed on the substrate. We further show that the pinning dynamics is controlled by \\beta rotational motions localized at the interface.

Lionel Bureau

2007-07-12T23:59:59.000Z

483

The Rate-and State-Dependence of Sea Ice Friction Ben Lishman, Peter Sammonds, Daniel Feltham, and Alex Wilchinsky  

E-Print Network (OSTI)

for further work. 2. Experimental programme To produce a quantitative constitutive description of ice frictionPOAC09-66 The Rate- and State- Dependence of Sea Ice Friction Ben Lishman, Peter Sammonds, Daniel Feltham, and Alex Wilchinsky Rock and Ice Physics Laboratory, and Centre for Polar Observation

Feltham, Daniel

484

Department of Energy and Electrical Engineering Spring 2012 Heavy-Duty Diesel Engine Friction Reduction Testing and Analysis  

E-Print Network (OSTI)

PENNSTATE Department of Energy and Electrical Engineering Spring 2012 Heavy-Duty Diesel Engine and pumping frictional losses on Volvo-Mack's 11 liter Diesel Engine. Thermocouples and pressure transducers use this rig in the future to quantify frictional losses and improve on the efficiency of their diesel

Demirel, Melik C.

485

Friction Stir Welding of Mild Steel -Tool Durability and Steel Microstructure , H. K. D. H. Bhadeshia2  

E-Print Network (OSTI)

1" " Friction Stir Welding of Mild Steel - Tool Durability and Steel Microstructure A. De1 , H. K of steel, and extend the calculations to cover consequences on the microstructure of the steel while and the consequences on the physical metallurgy of the steel. Introduction Friction stir welding (FSW) of aluminium

Cambridge, University of

486

Friction and wear behavior of ultra-high molecular weight polyethylene as a function of polymer crystallinity  

E-Print Network (OSTI)

Friction and wear behavior of ultra-high molecular weight polyethylene as a function of polymer-grade ultra-high molecular weight polyethylene (UHMWPE) (GUR 1050 resin) were evaluated as a function replacements; Ultra-high molecular weight polyethylene (UHMWPE); Crystallinity; Friction; Wear 1. Introduction

Lin, Zhiqun

487

Influence of orographic and canopy conditions on friction velocities observed during frontal events using Doppler sodar observations  

SciTech Connect

Sodar friction velocities, obtained during frontal events traversing areas characterized by different orographic and canopy conditions (flat, bare ground, small hills and valleys with agricultural crops and trees, agricultural crops and forest on a flat ground, bare ground on the side of a mountain), are compared in order to identify the influence of topography on this parameter. For some case studies, sounding and sodar data are combined in order to provide a relation between the friction velocity and the low-level jet presence. For the cases analyzed in this paper, the following results are obtained: the frontal passage is associated with a decrease of the horizontal wind speed (about 50% in magnitude) in the surface layer, and an increase of the friction velocity before the frontal passage followed by a decrease just at the time of the frontal passage or with a little delay. Friction velocity is more intense in the cold side of the low-level jet and its maximum represents 2% of the low-level jet maximum magnitude. As it concerns the influence of the terrain conditions on friction velocity, mountain effects yield to more intense friction-velocity values and to a superposition of an oscillating behavior on the time variation of friction velocity, while forest effects induce a shift of the frontal signature on the time variation of friction velocity at higher height levels. 25 refs., 18 figs., 3 tabs.

Kotroni, V.; Amory-Mazaudier, C. (CRPE, Saint-Maur des Fosses (France))

1993-03-01T23:59:59.000Z

488

Thin layer chromatography residue applicator sampler  

DOE Patents (OSTI)

A thin layer chromatograph residue applicator sampler. The residue applicator sampler provides for rapid analysis of samples containing high explosives, chemical warfare, and other analyses of interest under field conditions. This satisfied the need for a field-deployable, small, hand-held, all-in-one device for efficient sampling, sample dissolution, and sample application to an analytical technique. The residue applicator sampler includes a sampling sponge that is resistant to most chemicals and is fastened via a plastic handle in a hermetically sealed tube containing a known amount of solvent. Upon use, the wetted sponge is removed from the sealed tube and used as a swiping device across an environmental sample. The sponge is then replaced in the hermetically sealed tube where the sample remains contained and dissolved in the solvent. A small pipette tip is removably contained in the hermetically sealed tube. The sponge is removed and placed into the pipette tip where a squeezing-out of the dissolved sample from the sponge into the pipette tip results in a droplet captured in a vial for later instrumental analysis, or applied directly to a thin layer chromatography plate for immediate analysis.

Nunes, Peter J. (Danville, CA); Kelly, Fredrick R. (Modesto, CA); Haas, Jeffrey S. (San Ramon, CA); Andresen, Brian D. (Livermore, CA)

2007-07-24T23:59:59.000Z

489

Heat pump system  

DOE Patents (OSTI)

An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

Swenson, Paul F. (Shaker Heights, OH); Moore, Paul B. (Fedhaven, FL)

1983-01-01T23:59:59.000Z

490

In-Situ Method for Treating Residual Sodium  

DOE Patents (OSTI)

A unique process for deactivating residual sodium in Liquid Metal Fast Breeder Reactor (LMFBR) systems which uses humidified (but not saturated) carbon dioxide at ambient temperature and pressure to convert residual sodium into solid sodium bicarbonate.

Sherman, Steven R.; Henslee, S. Paul

2005-07-19T23:59:59.000Z

491

In-situ method for treating residual sodium  

SciTech Connect

A unique process for deactivating residual sodium in Liquid Metal Fast Breeder Reactor (LMFBR) systems which uses humidified (but not saturated) carbon dioxide at ambient temperature and pressure to convert residual sodium into solid sodium bicarbonate.

Sherman, Steven R. (Idaho Falls, ID); Henslee, S. Paul (Idaho Falls, ID)

2005-07-19T23:59:59.000Z

492

A Practical Model for Mobile, Residual, and Entrapped NAPL in...  

NLE Websites -- All DOE Office Websites (Extended Search)

A Practical Model for Mobile, Residual, and Entrapped NAPL in Water-Wet Porous Media. A Practical Model for Mobile, Residual, and Entrapped NAPL in Water-Wet Porous Media....

493

Quantifying Residual Strains in Specimens Prepared by Additive Layer Manufacturing  

Science Journals Connector (OSTI)

Residual stresses and strains are prevalent in many components, especially those that are made using additive layer manufacturing. The residual strains are superposed onto any ... analysis may lead to inaccurate ...

A. N. Okioga; R. J. Greene; R. A. Tomlinson

2014-01-01T23:59:59.000Z

494

Testing regression models with residuals as data by Xia Hua.  

E-Print Network (OSTI)

Abstract In polynomial regression ... . In this thesis, I developed a residual based test, the turning point test for residuals, which tests the hypothesis that the kth order polynomial regression holds with ... while the ...

Hua, Xia, Ph. D. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

495

NEURAL NETWORK RESIDUAL STOCHASTIC COSIMULATION FOR ENVIRONMENTAL DATA ANALYSIS  

E-Print Network (OSTI)

on radioactive soil contamination from the Chernobyl fallout. Introduction The problem of analysing environmentalNEURAL NETWORK RESIDUAL STOCHASTIC COSIMULATION FOR ENVIRONMENTAL DATA ANALYSIS V. Demyanov, M original method of stochastic simulation of environmental data -- Neural Network Residual Sequential

496

1-D Transforms for the Motion Compensation Residual  

E-Print Network (OSTI)

Transforms used in image coding are also commonly used to compress prediction residuals in video coding. Prediction residuals have different spatial characteristics from images, and it is useful to develop transforms that ...

Kamisli, Fatih

497

Heat transfer and friction in a square channel with one-wall or two-wall rib turbulators  

E-Print Network (OSTI)

' 00 bfiikee ille All Lwu wells willi g~/gq () ~ Re = 80538. 1 0 + Re=30288. 5 Q 0 Re=14253. 2 Re=48848. 0 WHITE: SMOOTH SIDES V V Re=20187. 1 BLAQK: ROUGH SIDES 3 Z Z ! 2 @ 8 @ @ P. 0 2 4 6 8 10 12 14 16 18 20 X/0 I I'igure Is. Nussell...=60596. 1 P L Re=50610. 0 WHITE: SMOOTH SIDES 0 + Re=30357. 4 Q T Re=20413. 6 BLACK: ROUGH SIDES C' Q Re =14603. 9 D 3 Z Z v j 0 2 4 6 8 10 12 14 16 18 20 X/D tl II Figure 23. Nusselt number ratio distribution for 00' parallel broken ribs on one...

Huang, Jie Joy

2012-06-07T23:59:59.000Z

498

Policies supporting Heat Pump Technologies  

E-Print Network (OSTI)

Policies supporting Heat Pump Technologies in Canada IEA Heat Pump Workshop London, UK November 13 in the world, with an average of 16,995 kilowatt-hours per annum. #12;Canada's Context for Heat Pumps Impacts avenues: Ground source heat pumps for cold climates (heating and cooling) Reversible air source heat

Oak Ridge National Laboratory

499

Heat of combustion of retorted and burnt Colorado oil shale  

SciTech Connect

Heats of combustion were measured for 12 samples of retorted and 21 samples of burnt Colorado oil shale originating from raw shales with grades that ranged from 13 to 255 cm/sup 3/ of shale oil/kg of oil shale. For the retorted shales, the authors resolve the heat of combustion into exothermic contributions from combustion of carbon residue and iron sulfides and endothermic contributions from carbonate decomposition and glass formation. Eight samples reported in the literature were included in this analysis. Variations in the first three constituents account for over 99% of the variation in the heats of combustion. For the burnt shales, account must also be taken of the partial conversion of iron sulfides to sulfates. Equations are developed for calculating the heat of combustion of retorted and burnt oil shale with a standard error of about 60 J/g. 13 refs.

Burnham, A.K.; Crawford, P.C.; Carley, J.F.

1982-07-01T23:59:59.000Z

500

Heat of combustion of retorted and burnt Colorado oil shale  

SciTech Connect

Heats of combustion were measured for 12 samples of retorted and 21 samples of burnt Colorado oil shale originating from raw shales with grades that ranged from 13 to 255 cm/sup 3/ of shale oil/kg of oil shale. For the retorted shales, the heat of combustion was resolved into exothermic contributions from combustion of carbon residue and iron sulfides and endothermic contributions from carbonate decomposition and glass formation. Eight samples reported in the literature were included in this analysis. Variations in the first three constituents account for over 99% of the variation in the heats of combustion. For the burnt shales, account must also be taken of the partial conversion of iron sulfides to sulfates. Equations are developed for calculating the heat of combustion of retorted and burnt oil shale with a standard error of about 60 J/g.

Burnham, A.K.; Carley, J.F.; Crawford, P.C.

1982-07-01T23:59:59.000Z