Scale effects in sliding friction: An experimental study (open access)

Scale effects in sliding friction: An experimental study

Solid friction is considered by some to be a fundamental property of two contacting materials, while others consider it to be a property of the larger tribosystem in which the materials are contained. A set of sliding friction experiments were designed to investigate the hypothesis that the unlubricated sliding friction between two materials is indeed a tribosystems-related property and that the relative influence of the materials properties or those of the machine on friction varies from one situation to another. Three tribometers were used: a friction microprobe (FMP), a typical laboratory-scale reciprocating pin-on-flat device, and a heavy-duty commercial wear tester. The slider material was stainless steel (AISI 440C) and the flat specimen material was an ordered alloy of Ni{sub 3}Al (IC-50). Sphere-on-flat geometry was used at ambient conditions and at normal forces ranging from 0.01 N to 100 N and average sliding velocities of 0.01 to 100.0 mm/s. The nominal, steady-state sliding friction coefficient tended to decrease with increases in normal force for each of the three tribometers, and the steady state value of sliding friction tended to increase as the mass of the machine increased. The variation of the friction force during sliding was also a characteristic of the …
Date: July 24, 1991
Creator: Blau, P.J.
Object Type: Article
System: The UNT Digital Library
Full-Scale Demonstration Low-NOx Cell Burner retrofit (open access)

Full-Scale Demonstration Low-NOx Cell Burner retrofit

The overall objective of the Full-Scale Low-NOx Cell (LNC) Burner Retrofit project is to demonstrate the cost-effective reduction of NOx generated by a large, base-loaded (70% capacity factor or greater), coal-fired utility boiler. Specific objectives include: at least 50% NOx reduction over standard two-nozzle cell burners, without degradation of boiler performance or life; acquire and evaluate emission and boiler performance data before and after the retrofit to determine NOx reduction and impact on overall boiler performance; and demonstrate that the LNC burner retrofits are the most cost-effective alternative to emerging, or commercially- available NOx control technology for units equipped with cell burners. The focus of this demonstration is to determine maximum NOx reduction capabilities without adversely impacting plant performance, operation and maintenance.
Date: May 24, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Theory-based transport simulations of TFTR L-mode temperature profiles (open access)

Theory-based transport simulations of TFTR L-mode temperature profiles

The temperature profiles from a selection of TFTR L-mode discharges are simulated with the 1-1/2-D BALDUR transport code using a combination of theoretically derived transport models, called the Multi-Mode Model. The present version of the Multi-Mode Model consists of effective thermal diffusivities resulting from trapped electron modes and ion temperature gradient ({eta}{sub i}) modes, which dominate in the core of the plasma, together with resistive ballooning modes, which dominate in the periphery. Within the context of this transport model and the TFTR simulations reported here, the scaling of confinement with heating power comes from the temperature dependence of the {eta}{sub i} and trapped electron modes, while the scaling with current comes mostly from resistive ballooning modes. 24 refs., 16 figs., 3 tabs.
Date: October 24, 1991
Creator: Bateman, G.
Object Type: Report
System: The UNT Digital Library
The effect of yield strength on side-bonding upset welds (open access)

The effect of yield strength on side-bonding upset welds

During the course of 9{degree} tapered side-bonding resistance upset weld development at Mound, various studies have been conducted to evaluate the effect of yield strength on welds in 304L stainless steel. The results of these studies have concluded that at high yield strengths there may be a minor reduction in the length of Class 2 or better bond. Satisfactory welds have been produced with materials having yield strengths ranging from 36.0 to 141.0 ksi. However, when body yield strengths exceed 80.0 ksi a minor decrease in bond lengths begins. A significant inverse relationship between stem yield strength and bond length was shown to exist. 8 refs., 9 figs., 10 tabs.
Date: September 24, 1991
Creator: Miller, R. G. & Perkins, M. A.
Object Type: Report
System: The UNT Digital Library
Theoretical studies on the electronic structure and properties of complex ceramic crystals and glasses (open access)

Theoretical studies on the electronic structure and properties of complex ceramic crystals and glasses

This progress report summarizes the accomplishment of the DOE-support research program at the University of Missouri-Kansas City for the period July 1, 1991--June 30, 1992. This is the second year of a three-year renewal. The major accomplishments for the year are: (a) Initiation of fundamental studies on the electronic properties of C{sub 60} and related crystals; (b) study of electronic structures and optical properties of several important ceramic crystals, especially on AlN, SiO{sub 2} and Al{sub 2}O{sub 3}; (c) first-principles calculation of total energies and structural phase transitions in oxides, nitrides, and borides; (d) theory of magnetism in Nd{sub 2}Fe{sub 14}B permanent magnetic alloy. The major focus for the next year's effort will be on the following areas: (1) Continuation of the fundamental studies on the buckminsterfullerene system with particular emphasis on the alkali-doped superconducting fullerides. (2) Fundamental studies on the structure and properties of Boron and B-related compounds. (3) Basic studies on the structural and electronic properties of metallic glasses with particular emphasis on the magnetic glasses. (4) Further development of the first-principles OLCAO method for applications to super-complex systems.
Date: January 24, 1991
Creator: Ching, Wai-Yim.
Object Type: Report
System: The UNT Digital Library
SPH (smoothed particle hydrodynamics) simulations of hypervelocity impacts (open access)

SPH (smoothed particle hydrodynamics) simulations of hypervelocity impacts

The smoothed particle hydrodynamics (SPH) method has been used to simulate several cases of hypervelocity impact in an exploratory study to determine the suitability of the method for such problems. The calculations compare favorably with experimental results and with other numerical simulations. We discuss the requirements that must be satisfied for SPH to produce accurate simulations of such problems. 18 refs., 9 figs.
Date: January 24, 1991
Creator: Cloutman, L.D.
Object Type: Report
System: The UNT Digital Library
Optical and environmentally protective coatings for potassium dihydrogen phosphate (KDP) harmonic converter crystals (open access)

Optical and environmentally protective coatings for potassium dihydrogen phosphate (KDP) harmonic converter crystals

Potassium dihydrogen phosphate (KDP) crystals have been used as harmonic converters on the Nova laser at LLNL for over six years. All crystals were coated with a single layer, quarterwave AR coating of porous silica with a refractive index of 1.22. This was prepared by a sol-gel process and was applied from a colloidal suspension by spin coating at room temperature. A few crystals were also coated with a methyl silicone coating prior to the application of the AR coating for environmental protection. The initial optical performance of all crystals was very good but there has been some deterioration over the years because of environmental and laser damage degradation. The deterioration in the silicone samples was, however, much less than the others. We are now in the process of replacing all ten KDP arrays with new crystals and will apply the silicone undercoat to all samples. Recently we have been evaluating a new perfluorinated organic polymer coating which has a refractive index of 1.29. This material is soluble in fluorinated solvents and can be applied by dip coating from solution at room temperature. We hope that this can provide environmental protection when applied to KDP and also act as an …
Date: June 24, 1991
Creator: Thomas, I. M.
Object Type: Article
System: The UNT Digital Library
Oxidation of Coal and Coal Pyrite Mechanisms and Influence on Surface Characteristics (open access)

Oxidation of Coal and Coal Pyrite Mechanisms and Influence on Surface Characteristics

The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical coal cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the fourth quarter, characterization and oxidation tests were done on Upper Freeport coal from the Troutville {number sign}2 Mine, Clearfield County, Pennsylvania. In addition, standard test methods for characterizing pyrite-bearing materials were studied. 3 figs., 2 tabs.
Date: September 24, 1991
Creator: Doyle, F. M.
Object Type: Report
System: The UNT Digital Library
Fundamental studies of catalytic processing of synthetic liquids. Quarterly progress report, April 1, 1991--June 30, 1991 (open access)

Fundamental studies of catalytic processing of synthetic liquids. Quarterly progress report, April 1, 1991--June 30, 1991

This project revolves around understanding the fundamental processes involved in the catalytic removal of harmful oxygenated organics present in coal liquids. We are modelling the complex type of sulfided Mo catalyst proposed for these reactions with simple single crystal surfaces. These display a controlled range and number of reaction sites and can be extensively characterized by surface science techniques. We then investigate the reaction pathways for representative simple oxygenates upon these surfaces. In order to better understand the nature of the active surface in these experiments we have recorded low energy diffraction (LEED) data from the p(2 {times} 2) structure formed by sulfur on Mo(110). We have compiled a large number of intensity-voltage (IV) curves and have started the process of solving the surface structure using the new Tensor LEED method. Our previous work has shown that an important component of furan reactions on sulfided Mo surfaces are dehydrogenation reactions of adsorbed hydrocarbon fragments. The desorption of hydrogen occurs in several steps and is strongly influenced by the amounts of sulfur and carbon on the surface. In order to understand this complex behavior during this period we commenced a series of adsorption/desorption experiments for hydrogen (deuterium) on Mo(110). These experiments …
Date: June 24, 1991
Creator: Watson, P. R.
Object Type: Report
System: The UNT Digital Library
Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 January 1991--31 March 1991 (open access)

Development of improved iron Fischer-Tropsch catalysts. Quarterly technical progress report, 1 January 1991--31 March 1991

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.
Date: April 24, 1991
Creator: Bukur, D. B.
Object Type: Report
System: The UNT Digital Library
Pipe Cleaning Operating Procedures (open access)

Pipe Cleaning Operating Procedures

This cleaning procedure outlines the steps involved in cleaning the high purity argon lines associated with the DO calorimeters. The procedure is broken down into 7 cycles: system setup, initial flush, wash, first rinse, second rinse, final rinse and drying. The system setup involves preparing the pump cart, line to be cleaned, distilled water, and interconnecting hoses and fittings. The initial flush is an off-line flush of the pump cart and its plumbing in order to preclude contaminating the line. The wash cycle circulates the detergent solution (Micro) at 180 degrees Fahrenheit through the line to be cleaned. The first rinse is then intended to rid the line of the majority of detergent and only needs to run for 30 minutes and at ambient temperature. The second rinse (if necessary) should eliminate the remaining soap residue. The final rinse is then intended to be a check that there is no remaining soap or other foreign particles in the line, particularly metal 'chips.' The final rinse should be run at 180 degrees Fahrenheit for at least 90 minutes. The filters should be changed after each cycle, paying particular attention to the wash cycle and the final rinse cycle return filters. These …
Date: January 24, 1991
Creator: Clark, D. & Wu, J.
Object Type: Report
System: The UNT Digital Library
D0 Experimental Area Emergency Backup Power and Generator Test (open access)

D0 Experimental Area Emergency Backup Power and Generator Test

The DO experimental area has a generator designated as emergency power. This generator provides power for critical loads and starts automatically upon loss of commercial power. This note concerns the testing of this generator. A list of loads is attached to this note. One of the loads on the emergency power grid is a 10KVA Uninterruptable Power Supply(UPS). The UPS powers the cryogenic controls and Oxygen deficiency hazard equipment(ODH) and has a minimum rating of 20 minutes while on its batteries(to cover the transfer time to/from the emergency generator). Jan 23,1991 at 1640 hrs this system was tested under the supervision of the Terry Ross, Marv Johnson, Dan Markley, Kelly Dixon, and John Urbin. The power feeder to the emergency power grid at DO was disconnected. The generator responded immediately and was supplying power to the emergency power grid in less than 10 seconds. During the 10 seconds that there was no power on the emergency grid the UPS switched on its inverter and provided uninterrupted power to the cryogenic control system and the ODH system. All of the motorized equipment shut off instrument air compressor, vacuum pumps 1 and 2, insulating vacuum blower, glycol cooling pumps, cooling tower fan, …
Date: January 24, 1991
Creator: Markley, D.
Object Type: Report
System: The UNT Digital Library
Final design review of boron carbide safety rod (open access)

Final design review of boron carbide safety rod

The object of this paper discusses the design review of the boron carbide safety rod for the Westinghouse Savannah River Company. This paper reviewed information presented by personnel of the Savannah River Laboratory (SRL) Equipment Engineering Section, SRL Materials Technology Section and Reactor Materials Engineering and Technology. From this report, views, opinions and recommendations were made on the safety rod from materials testing to production.
Date: September 24, 1991
Creator: Lutz, R. N.
Object Type: Report
System: The UNT Digital Library
BPM System Improvements (open access)

BPM System Improvements

During the accelerator studies period of 12/90 through 1/91 the Accumulator BPM system was investigated in some detail in an effort to improve its reliability and accuracy in making closed orbit measurements. The motivation for this is to try and improve the beam energy resolution for E760. The relativistic {beta} of the {bar p} is given by {beta} = f{sub R}L/c where f{sub R} is the revolution frequency, L is the orbit length ({approx} 474050mm), and c is the speed of light. Hence, the error in {beta} is given by d{beta}/{beta} = df{sub R}/f{sub R} + dL/L. Since df{sub R}/f{sub R} is {approx} 2 x 10{sup -7}, the main contribution to the error comes from dL. During the E760 run of 5/90 to 9/90 dL was estimated to be {approx} 1mm. It is thought that this can be reduced to {approx} .25mm with proper use of the present BPM system. L is given by L = L{sub 0} + {delta}L where L{sub 0} is the accurately known orbit length of a reference orbit (extracted from an energy scan of the J/{Psi} or {Psi}{prime}), and {delta}L is the difference orbit between the current orbit and the reference orbit. SL is calculated …
Date: April 24, 1991
Creator: Church, M.
Object Type: Report
System: The UNT Digital Library
High speed data transmission for the SSC solenoidal detector (open access)

High speed data transmission for the SSC solenoidal detector

High speed data transmission using fiber optics for the Superconducting Super Collider solenoidal detector has been studied. The solenoidal detector system will consist of nine subsystems involving more than a total 10{sup 7} channels of readout electronics. Consequently, a new high performance data acquisition system, incorporating high-speed optical fiber networks, will be required to process this large quantity of data. 15 refs., 3 figs., 1 tab.
Date: April 24, 1991
Creator: Leskovar, B.
Object Type: Article
System: The UNT Digital Library
Development of improved iron Fischer-Tropsch catalysts (open access)

Development of improved iron Fischer-Tropsch catalysts

The objective of proposed research is development of catalysts with enhanced slurry phase activity and better selectivity to fuel range products, through a more detailed understanding and systematic studies of the effects of pretreatment procedures and promoters/binders (silica) on catalyst performance.
Date: April 24, 1991
Creator: Bukur, D.B.
Object Type: Report
System: The UNT Digital Library
Theoretical studies on the electronic structure and properties of complex ceramic crystals and glasses. Annual progress report, July 1, 1991--June 30, 1992 (open access)

Theoretical studies on the electronic structure and properties of complex ceramic crystals and glasses. Annual progress report, July 1, 1991--June 30, 1992

This progress report summarizes the accomplishment of the DOE-support research program at the University of Missouri-Kansas City for the period July 1, 1991--June 30, 1992. This is the second year of a three-year renewal. The major accomplishments for the year are: (a) Initiation of fundamental studies on the electronic properties of C{sub 60} and related crystals; (b) study of electronic structures and optical properties of several important ceramic crystals, especially on AlN, SiO{sub 2} and Al{sub 2}O{sub 3}; (c) first-principles calculation of total energies and structural phase transitions in oxides, nitrides, and borides; (d) theory of magnetism in Nd{sub 2}Fe{sub 14}B permanent magnetic alloy. The major focus for the next year`s effort will be on the following areas: (1) Continuation of the fundamental studies on the buckminsterfullerene system with particular emphasis on the alkali-doped superconducting fullerides. (2) Fundamental studies on the structure and properties of Boron and B-related compounds. (3) Basic studies on the structural and electronic properties of metallic glasses with particular emphasis on the magnetic glasses. (4) Further development of the first-principles OLCAO method for applications to super-complex systems.
Date: January 24, 1991
Creator: Ching, Wai-Yim
Object Type: Report
System: The UNT Digital Library
Final design review of boron carbide safety rod (open access)

Final design review of boron carbide safety rod

The object of this paper discusses the design review of the boron carbide safety rod for the Westinghouse Savannah River Company. This paper reviewed information presented by personnel of the Savannah River Laboratory (SRL) Equipment Engineering Section, SRL Materials Technology Section and Reactor Materials Engineering and Technology. From this report, views, opinions and recommendations were made on the safety rod from materials testing to production.
Date: September 24, 1991
Creator: Lutz, R. N.
Object Type: Report
System: The UNT Digital Library
ANS-8. 23: Criticality accident emergency planning and response (open access)

ANS-8. 23: Criticality accident emergency planning and response

A study group has been formed under the auspices of ANS-8 to examine the need for a standard on nuclear criticality accident emergency planning and response. This standard would be ANS-8.23. ANSI/ANS-8.19-1984, Administrative Practices for Nuclear Criticality Safety, provides some guidance on the subject in Section 10 titled -- Planned Response to Nuclear Criticality Accidents. However, the study group has formed a consensus that Section 10 is inadequate in that technical guidance in addition to administrative guidance is needed. The group believes that a new standard which specifically addresses emergency planning and response to a perceived criticality accident is needed. Plans for underway to request the study group be designated a writing group to create a draft of such a new standard. The proposed standard will divide responsibility between management and technical staff. Generally, management will be charged with providing the necessary elements of emergency planning such as a criticality detection and alarm system, training, safe evacuation routes and assembly areas, a system for timely accountability of personnel, and an effective emergency response organization. The technical staff, on the other hand, will be made responsible for establishing specific items such as safe and clearly posted evacuation evacuation routes and dose …
Date: June 24, 1991
Creator: Pruvost, Norman L.
Object Type: Article
System: The UNT Digital Library
Pulsed power supply for three APS septum magnets (open access)

Pulsed power supply for three APS septum magnets

Three septum magnets will be operated at a repetition-rate of 2 Hz. Two of the septum magnets are identical and operate at the same values; these are the synchrotron extraction and the storage ring injection magnets. They are transformer septum magnets, with a primary inductance of 23 {mu}H and resistance of 6.3 m{Omega}, and must be pulsed at a 2 Hz rate to extract beam from the synchrotron and inject beam into the storage ring at 7.7 GeV. The third septum magnet is used to inject electrons into the synchrotron at 650 MeV or positrons at 450 MeV. It is also a transformer septum magnet, with a primary inductance of 21 {mu}H and resistance of 6.7 m{Omega}, and must be pulsed at a 2 Hz rate. A design study was performed of the power supply proposed in the APS Title I design. This supply produces a pulse that is approximately a half-sine-wave with a base width of approximately 1/3 ms; its peakcurrent is adjustable from 470 A to 4.7 kA and is repeatable within {plus_minus}0.05%. The septum steel is reset by a half-sine pulse of reverse polarity a few milliseconds after the forward current pulse. No beam is present during …
Date: March 24, 1991
Creator: McGhee, D. G.
Object Type: Report
System: The UNT Digital Library
Winter Fuels Report: Week Ending October 18, 1991. [Contains Glossary] (open access)

Winter Fuels Report: Week Ending October 18, 1991. [Contains Glossary]

This report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and State and local governments on the following topics: distillate fuel oil net production, imports and stocks for all Petroleum Administration for Defense Districts (PADD) and product supplied on a US level; propane net production, imports and stocks for PADD's, 1, 2, and 3; natural gas supply and disposition and underground storage for the United States and consumption for all PADD's; residential and wholesale pricing data for propane and heating oil for those States participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the United States and selected cities; and US total heating degree-days by city. 37 figs., 13 tabs.
Date: October 24, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library