bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Implications of Poor Bridge Surface Performance
Authors: Yanev BS 
Published: March 2009

There are approximately 2,100 bridges in the Metropolitan area of New York City; 842 of the bridges, counting over 4,500 spans, are the responsibility of the City administration. According to New York State inspection records, 56% of these bridges are rated less than 4.5 on a 7 grade system. This is regarded by the New York City Department of Transportation (NYC DOT) Bridge Bureau as an indication of the need for structural repair of some magnitude. In the situation involving 42% of the City's bridges, a ten-year, $3.5 billion program envisions complete rehabilitation. A recent NYC DOT study examined the remaining 58% of the bridges and concluded that considerable structural repairs are necessary in order to avoid the need for premature rebuilding of that portion as well.
A further step is the identification of structural components requiring repair or replacement, and the optimal frequency of such measures. A program for component rehabilitation is expected as a result of this study. The elimination of certain problem-prone structural components from future design can be considered as well. Ultimately, schedules for timely repairs can be generated in order to extend the useful life of a bridge. This is viewed as a supplement to the New York City Preventive Maintenance Program which is already applied to bridges in good condition. The following structural components emerge as the primary sources of problems on most of the bridges:
Joints—Approximately 90% of the structural deterioration is concentrated in the vicinity of joints and is precipitated by joint failure. Experience suggests that “the only good joint is no joint.” Yet joints are inevitable and their maintenance while still in serviceable condition is vital to the structure as well as to traffic.
Drainage—More than 60% of the bridge drainage systems are rated “not functioning as designed.” This results in saturating bridge decks and the entire superstructures with water and de-icing salt, causing rapid corrosion.
Wearing Surface—Deck—The deck and wearing surface, frequently monolithic in recent years, are the first to suffer from the malfunctioning of the above components. Further, they are subjected to the increasingly severe dynamic loadings due to the growing volume and weight of traffic.
The consequences to the bridge structure are grave. Concrete piers crack, spall and fail due to the dynamic loadings. Steel members crack under the combined effect of fatigue and corrosion. In all of these cases, problems originate at the roadway surface and rapidly propagate throughout the structure. The progress of this path of rapid deterioration is traced for several bridge types frequently encountered in New York. Measures used with limited success in mitigating the surface and structural deficiencies are described.
Cleaning Aluminum Heat Pipe Casings with Replacements for Ozone-Depleting Chemicals
Authors: Meyers B 
Published: March 2009

The internal cleanliness of heat pipe casings used in spacecraft thermal control systems must meet strict non-volatile residue (NVR) and particulate requirements. Presently, Trichloroethane (TCA) is used in the precleaning of heat pipes and 1,1,2 trichloro 1,2,2 Trifluoroethane (CFC-113) is used for precision cleaning. TCA removes oils and other organic contaminants while CFC-113 removes particles and fibers.
A new process was developed and tested for heat pipe casing cleaning using replacements for TCA and CFC-113 which meets NVR and particulate cleanliness requirements. An alkaline cleaner was used instead of TCA for precleaning and deionized water (DI) with a nitrogen gas aeration was used instead of CFC-113 for precision cleaning.
The new process was tested on five heat pipe casings and four of these met the cleanliness requirements of MIL-STD-1246B, level 250D. The five casings were subjected to life tests. After five months, all of the casings have acceptable levels of non-condensable gas (NCG). Solvent extraction (NVR), particulate counts and suface analysis alone do not provide adequate confidence that the heat pipes will perform as intended. A heat pipe's performance is degraded when NCG forms within the pipe. This phenomenon can only be assessed by life testing which involves charging the heat pipe with ammonia and periodically determining the NCG level.
Evaluation of Plasma Cleaning, an Environmentally Friendly Process, for Removing Lubricants from Metallic Surfaces
Authors: Paciej R , Jansen F , Krommenhoek S 
Published: March 2009

The effectiveness of plasma cleaning as a substitute for CFCs was compared to two alternative methods, CO2 snow and detergent cleaning. The proposed ASTM G XYZ standard test coupon described in “Standard Practice for Preparation of Contaminated Test Coupons for the Evaluation of Cleaning Agents for Use in Oxygen-Enriched Systems and Components” was used to compare all three cleaning methods. The cleaning experiments employed two different hydrocarbon oils, Precision-D and 3-in-1, which were applied to the test coupons by either dipping the coupons into a lubricant and solvent mixture or spraying the mixture onto the coupons. Also, three different test coupons were chosen for the experiments: AL3003 (aluminum), C1018 (carbon-steel), and CDA706 (brass alloy).
Plasma, CO2 snow, and detergent cleaning were demonstrated to be effective in removing oil contamination from metallic surfaces. CO2 snow and detergent cleaning methods are most beneficial in removing gross oil contamination from rough surfaces. Plasma cleaning which can also be used to remove gross oil contamination is recommended over the other methods when oil contamination must be reduced to very low levels.
A Selection and Evaluation Protocol for Alternatives to Halogenated Hydrocarbon Solvents for Oxygen Cleaning Applications
Authors: Million JF , McIlroy K , Zawierucha R 
Published: March 2009

Components and systems for gaseous or liquid oxygen service must be cleaned to eliminate the presence of reactive contaminants. Halogenated solvents such as 1,1,1 trichloroethane have been commonly used as preferred cleaning agents for oxygen systems; however, due to environmental and safety concerns, suitable alternatives are needed.
A substantial amount of work has been done on alternatives by various groups. However, many of these alternatives have limitations which should be identified via standardized comparative tests to identify potential problem areas. Furthermore, guidance on the use of standard tests is required.
It is believed that there is a need to establish a standard protocol for comparative testing of environmentally acceptable Chlorofluorocarbon (CFC) alternatives. A Task Force within the ASTM G-4 Committee has been addressing this matter since January, 1992.
This paper discusses issues critical to such a protocol. In addition, it presents an interim protocol suitable for dialogue between the developers of alternatives to CFC cleaning agents and users of equipment in oxygen enriched atmospheres.
Friction Characteristics of Plastic Plain Bearings at Low Velocity
Authors: Budinski KG 
Published: March 2009

A study was conducted to compare the friction characteristics of ball bushings and plastic plain bearings for a low-speed mechanical drive. The goal was freedom from stick-slip behavior.
Laboratory tests were conducted to measure the static and kinetic coefficient of friction of 12 bushing/shaft couples. The test results indicated that the most consistent friction characteristics were obtained with bushings made from oil-impregnated ultrahigh molecular weight polyethylene sliding on a hardened steel shaft with a surface roughness of 0.2μm Ra. The variability of the friction force is proposed as the parameter to be measured when freedom from stick-slip behavior is the system goal.
Comparison of Laboratory Abrasion Tests and Field Tests of Materials Used in Tillage Equipment
Authors: Swanson PA 
Published: March 2009

In agricultural equipment used for tillage, abrasion by hard particles is a major mode of wear. Field tests and customer surveys of equipment usage can provide valuable data on the rate of wear of different soil working tools. However, it is usually very time consuming and costly to gather this type of information. While field testing will continue to play an important role in the evaluation of agricultural equipment durability, the use of laboratory tests that adequately simulate the wear modes occurring in the field can significantly reduce the amount of field testing required to evaluate wear of tillage tools. In this review, important criteria for determining the degree to which laboratory tests simulate the wear occurring in field tests or service will be presented. These include not only a comparison of the wear rate and relative wear resistance determined from laboratory and field tests, but also a comparison of the worn surfaces to identify the wear mechanisms that are active.
Widely used abrasion tests, including the ASTM G65 Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Wheel Apparatus and the G105 Standard Test Method for Conducting Wet Sand/Rubber Wheel Abrasion Tests will be reviewed, and their ability to simulate the wear that occurs in tillage operations will be examined. Examples will be provided that highlight the strengths and weaknesses of these laboratory tests in ranking the abrasion resistance of materials used in soil working tools. A major limitation of all of these tests is their inability to simulate wear that occurs under the combined action of soil abrasion and repeated impacts by rocks. Difficulties associated with the gathering of quantitative field data needed to carry out the comparison of laboratory and field test results will also be discussed.
Laboratory Wear Tests for Qualifying Automotive Air-Conditioning Lubricants for Use with Refrigerant HFC-134a
Authors: Tseregounis SI , Spearot JA , Rounds FG , Baker JA , Serrianne BC 
Published: March 2009

Three laboratory, block-on-ring wear tests were developed to evaluate potential lubricants for automotive air-conditioning (AC) compressors designed to use the alternative refrigerant HFC-134a. The tests were conducted in a pressurized refrigerant atmosphere using stepwise increasing loads. The three tests utilized steel rings and steel, brass, and aluminum blocks, respectively. Using multiple-variable, regression analyses, results from the three laboratory wear tests were used to explain wear phenomena occurring in a variable displacement AC compressor.
Correlations of the laboratory wear test data with data from compressor tests indicated that an optimized compressor lubricant should minimize aluminum and brass wear and maximize steel seizure loads. A variety of additives were evaluated using the three wear tests. Many additives were identified which could increase the seizure load and reduce steel wear. Several additives were capable of reducing brass wear relative to the base fluid in which they were blended. No additives were found to reduce the galling and wear of aluminum. Residual Clcontaining impurities in the HFC-134a refrigerant can increase the load at which seizure occurs in steel-on-steel wear tests.
Prediction of the Thermal Performance of Single and Multi-Airspace Reflective Insulation Materials
Authors: Desjarlais AO , Yarbrough DW 
Published: March 2009

A recent test program to determine the thermal performance of reflective thermal insulation materials and systems was carried out on behalf of the Department of Energy. This program indicated that the thermal performance of multi-airspace reflective cavities (multi-layer reflective insulations) could not be accurately predicted by a one-dimensional analysis applied in combination with the thermal performance data for single airspaces.
A new correlation has been developed in an effort to improve the accuracy of predicted R-values for multi-airspace reflective systems. This correlation is described and compared to the thermal test data generated by the recent test program.
Generally good agreement between calculated and measured R-Values is achieved for single airspaces. However, calculated values for multiple airspaces are up to 60 percent greater than the measured values. This disagreement indicates that the commercial multifoil product that was tested may not achieve the idealized one-dimensional heat flow that is true of the correlation.
Thermal Measurement of In-Situ and Thin-Specimen Aging of Experimental Polyisocyanurate Roof Insulation Foamed with Alternative Blowing Agents
Authors: Christian JE , Courville GE , Graves RS , Linkous RL , McElroy DL , Weaver FJ , Yarbrough DW 
Published: March 2009

This paper reports apparent thermal conductivity (k) values from field and laboratory aging tests on a set of industry-produced, experimental polyisocyanurate (PIR) laminated boardstock foamed with hydrochlorofluorocarbons (HCFCs) as alternatives to chlorofluorocarbons (CFCs). The PIR boards were blown with five gases: CFC-11, HCFC-123, HCFC-141b, and 50/50 and 65/35 blends of HCFC-123/ HCFC-141b.
The k-values were determined at mean temperatures from 0 to 50°C (30 to 120°F) using techniques that meet ASTM C 1114 (Thin Heater Apparatus) and ASTM C 518 (Heat Flow Meter Apparatus) test methods. Results on laminate boards with facers provide an independent laboratory check on the increase in k observed for field exposure in the ORNL Roof Thermal Research Apparatus (RTRA). The observed laboratory increase in k was between 8% and 11% for all three blowing agent foams for a 240 day field exposure in the RTRA.
A thin-specimen aging procedure established the long-term thermal resistance of gas-filled foams. Thin specimens were planed from the industry-produced boardstock foams and aged at 24 and 65°C for up to 300 days.
An exponential dependency of k with the quantity (diffusion coefficient X time)½/thickness, provided effective diffusion coefficients for air components into the foams and blowing agent out of the foams. The foams blown with alternative blowing agents exhibited k-values 8 to 16% (average 12.7%) above CFC-11 foams under similar conditions.
Field exposures were conducted on specimens under single ply EPDM membranes in the RTRA for over 400 days. Hourly averages of panel temperature and heat flux were analyzed to obtain k as a function of mean temperature on a week by week basis. The k-values derived from the field data provided effective diffusion coefficients for air components in the foam, which were greater than those obtained from the thin-specimen aging procedure at 24°C by 20 to 70%, but were less than the 65°C aging values by 20 to 80%.
The relative performance of test specimens of HCFC-141b under a black and under a white membrane is reported. The field data suggests that the percent increase in k over that of the foam blown with CFC-11 is, after one year of aging, 4.3% for HCFC-123 and 10.2% for HCFC-141b. This leads to the same ordering of foams as derived from the thin-specimen analysis.
Some Factors Affecting the Long-Term Thermal Insulating Performance of Extruded Polystyrene Foams
Authors: Booth JR 
Published: March 2009

The long-term thermal performance of insulation products is important to ensure their suitability in applications where product life can be fifty years or more. Actual measurements of foams aged under conditions of use are helpful but can only be gathered in real time. While necessary to assure the validity of model predictions, such measurements do not allow early determination of the future performance of new systems. With the need for all users of CFCs to find alternatives, the question of how to ensure long-term thermal performance takes on immediate significance. In this paper we describe some work done in our laboratory to assure the long-term thermal performance of STYROFOAM* brand insulation foam.
The use of bundles of thin-sliced foam samples provides a technique for accelerating foam aging. Aging curves relating bundle k-factor to a scaled age consolidates the data for measurement of the slope of k-factor with scaled age. This slope can be employed to evaluate the effective diffusion coefficients of candidate CFC replacements in polystyrene foams. The ratio of effective diffusion coefficient to film diffusion coefficient yields insight concerning the cell structure of the foam.
CFC Blowing Agents Substitutes — A Status Report
Authors: Zwolinski LM , Knopeck GM , Shankland IR 
Published: March 2009

Rapidly moving events at the national and global levels mean a virtual elimination of chlorofluorocarbons (CFC) as insulation foam blowing agents by the year 2000. There have been a number of more environmentally acceptable substitutes proposed for CFCs. As replacements for CFC-11, HCFC-123 and 141b have received most attention, while HCFC-22 and HFC-134a have been considered as CFC-12 substitutes.
This paper reports on the progress made to critically evaluate these substitute materials in rigid polyurethane and polyisocyanurate insulating foams. The processing, industrial hygiene, and final foam performance of the substitutes are emphasized. The path to commercialization of HCFC-141b is presented in some detail.
Normalization: An Experimental Method for Developing J-R Curves
Authors: Zhou Z , Lee K , Herrera R , Landes JD 
Published: March 2009

The method of normalization has been used to develop J-R curves for metallic materials based only on analysis of load and displacement pairs in a ductile fracture test record. This method eliminates the need for crack length monitoring equipment. It not only provides a method for more easily conducting and evaluating J-R curve tests; but it could be useful for tests conducted under special conditions such as under dynamic loading, in restructive facilities such as a hot cell, or even in a facility with limited instrumentation.
The method uses a normalized deformation curve which has a functional relationship resembling a power law in the beginning and a straight line later. A functional form is proposed to fit this material deformation pattern. This form was used along with the load versus displacement records to evaluate J-R curves for many materials. The results showed that the new method was a more accurate and versatile one for the assessment of the J-R curve. Compared with previous application of this method, the accuracy is remarkably improved in the beginning stages of the J-R curve where a JIc point is determined. The JIc point was analyzed on more than 60 specimens and found to be consistent with methods used in the ASTM test standards.
Fracture Toughness and Fatigue Crack Initiation Tests of Welded Precipitation-Hardening Stainless Steel
Authors: Underwood JH , Farrara RA , O'Hara GP , Zalinka JJ , Senick JR 
Published: March 2009

An analysis is described of a welded stainless steel box beam that experienced a structural failure during fatigue testing. Cracks initiated at notches caused by partial penetration welds and grew to a length of several centimetres in about 1000 load cycles.
The objective here is to describe the characterization of fracture toughness and fatigue crack initiation for the precipitation-hardening stainless steels used for the welds and parent plate of the beam. Three-point bend specimens were used to measure both fatigue crack initiation life and the J-integral fracture toughness of the parent plate and weld metal in various conditions. The notch fatigue analysis method of Barsom and Rolfe was used to analyze the crack initiation test results. The crack was grown further, side notches were added, and JIc tests were performed using ASTM Test Method for JIc, a Measure of Fracture Toughness (E 813-87) with a modified load-line-displacement unloading-compliance procedure to measure crack growth.
Conclusions drawn from the work include the following: (a) JIc can be accurately determined with a three-point bend test using load-line displacement to measure crack growth by unloading compliance (An accurate expression for a/W in terms of load-line displacement was developed.); and (b) fatigue crack initiation life and JIc fracture toughness of stainless steels in various conditions were characterized. The welded and aged condition, with no intermediate solution treatment, showed unstable, cleavage-type fracture and resulted in a low JIc value and a short initiation life.
Key-Curve Analysis of Linde 80 Welds
Authors: Yoon KK , Van Der Sluys WA , Lowe AL 
Published: March 2009

Some reactor vessel weldments have relatively high copper contents that, when exposed to neutron irradiation, cause reductions in fracture toughness in the Charpy upper-shelf energy temperature region. To address this concern, a large number of both unirradiated and irradiated compact specimens were tested and the resulting J-resistance curves were generated. Key curves were developed from the load displacement records of single-specimen unloading compliance test data for magnesium-molybdenum-nickel/Linde 80 submerged-arc weld metals to study various aspects of toughness data behavior. In this paper, only a number of representative compact specimen tests are analyzed using the Herrera and Landes individual specimen key-curve approach to compare specimen size, temperature, and irradiation effects as part of a J-resistance model development effort for the Linde 80 class of weld metals.
The results of this study indicate (1) that the key-curve method works when applied to the Linde 80 type weld metals, (2) that a power law representation of the key curve provides a means to extract the Ramberg-Osgood exponent from the key curve if there are no available tensile data for the weld metal, and (3) that the irradiated specimens from both power reactors and a test reactor do not exhibit significant differences in comparable key-curve characteristics.
Observations in Conducting J-R Curve Tests on Nuclear Piping Materials
Authors: Marschall CW , Landow MP 
Published: March 2009

This paper describes some of Battelle's experiences in developing J-R data for nuclear piping materials. Compact specimens were machined from both carbon steel and stainless steel pipe and subjected to testing at elevated temperatures, similar to temperatures encountered in nuclear reactor coolant piping. In many cases, the specimens displayed toughness levels above those considered valid by ASTM standard methods of testing. Furthermore, cracks were grown by about 50% of the original ligament, well in excess of the 10% limit imposed by ASTM Test Method for Determining J-R Curves (E 1152-87).
Topics discussed in the paper include: (1) monitoring crack extension using the direct-current electric potential method, (2) specimen thickness changes ahead of the growing crack, (3) observations of fracture appearance and crack growth direction in ferritic versus austenitic steels, (4) observations of ductile-crack jumps in carbon steels tested at 288°C (550°F), (5) unusual effects of partial unloadings in testing carbon steels at 288°C (550°F), and (6) difficulties with certain ASTM definitions in testing highly ductile materials.