bluuebunny/crossref_metadata_2025 huggingface dataset:
Nondestructive Inspection with Portable Ultrasonic Imaging System
Authors: Grills RH , Tsao MC
Published: December 2008

The device described herein is a microprocessor-controlled ultrasonic imaging system, the Ultra Image III, originally developed for the inspection of corrosion/erosion inside seawater pipelines. It has been used successfully for many other types of nondestructive testing (NDT) applications, including intergranular stress corrosion cracking detection in nuclear piping systems. It consists of four packages each with a weight of less than 13.6 kg (30 lb): the microprocessor, the dual-diskette drive, the ultrasonic pulser/receiver/gate package, and the display package that consists of an A-scan scope and a two-dimensional imaging scope. The scanner, equipped with pulse/echo or pitch/catch transducers, can function automatically or manually. Information for operational controls is input using a hand-held terminal that can be placed at remote distances from the test site. Output results are displayed in two-dimensional format in gray scale indicating the thickness of the pipe wall after corrosion/erosion effects. Test results are stored permanently on floppy diskettes for on-site overview and off-site detailed analysis.

The system is further equipped with a variety of software packages providing capabilities for a multicolor display of the size, configuration, and distributions of erosion patterns or flaw and crack orientations or both inside the tested material. The portability and versatility of the system is demonstrated with examples of different applications.
Detection of Intergranular Stress-Corrosion Cracking Using Automated Ultrasonic Techniques
Authors: Mikesell CR , Beller LS , Holm JA , Liu S-N
Published: December 2008

Intergranular stress-corrosion cracking (IGSCC), which has occurred in nuclear power plant piping systems, is detected ultrasonically. The principal problem is discrimination between the few acoustic reflections from flaws and the large number from geometry of the weld root and counterbore. This paper discusses two areas of recent work on the IGSCC problem: the development, fabrication, and initial testing of a miniature automated ultrasonic search head, and the detection and characterization of IGSCC using an imaging technique.

The search head contains a toroidal-axicon-lens system with folded acoustic optics. The resulting beam is remotely controlled to produce a small-diameter beam that is near parallel or defocused 2.5° or 5°. The transducer's linear and two angular motions and nearly all field operation steps are automated. This allows certified Level II inspectors, who are in short supply because of radiation “burnout,” to operate primarily from the radiationfree computer console area.

The imaging technique consists of comparing multiple images that present amplitude, position, and reflector “texture” information. The surface of IGSCC has small and highly irregular facets which scatter strongly in all azimuths at high frequencies. Other classes of targets have similarly distinctive characteristics.
An Eddy Current Technique to Estimate Dimensions of Crevice Corrosion Pits
Authors: Baron JA , Leemans DV , Dolbey MP
Published: December 2008

A model of an eddy current probe in the presence of an open defect, such as an elongated crevice corrosion pit, is developed. Assumptions are made in respect to field shape, field width, and lift-off function, which are then justified using experimental data. The technique generates estimates of both crevice depth and width without resorting to microminiature probes; other methods tend to generate a response to “volume lost” rather than the more important geometrical parameters. The model is tested against experimental data from artificial pits in a zirconium-niobium material in the range 50 to 800 μm deep, 500 to 2000 μm wide, and 5 to 20 mm long. The technique is also useful in assessing eddy current probe performance.
Sensing Probes and Instruments for Electrochemical and Electrical Resistance Corrosion Monitoring
Authors: Cooper GL
Published: December 2008

Corrosion monitoring in industrial environments is facilitated by using electrochemical or electrical resistance sensing probes and instruments. This paper describes their principles of operation and practical guidelines for successful implementation.
Electrochemical Techniques for Monitoring Corrosion Rates in Simulated Kraft White Liquors
Authors: Yeske RA
Published: December 2008

Corrosion severely damages carbon steel equipment exposed to alkaline sulfide liquors during kraft pulping operations. Studies have been conducted to determine whether linear polarization or electrical resistance methods could be used to monitor corrosion rates in kraft white liquors. Corrosion rates determined by these two methods have been compared with actual corrosion rates determined by weight loss. Linear polarization and electrical resistance methods both were found to provide accurate assessments of instantaneous corrosion rates, although errors in linear polarization results were observed when carbon steel was at passive potentials and liquor oxidation was possible. Empirical calibration of the linear polarization method is necessary for quantitative prediction of corrosion rates in kraft white liquors.
Mass Spectral Characterization of the Acid and Base Fractions from an Eastern and Western Shale Oil
Authors: Greenwood G
Published: December 2008

Detailed characterization of shale oils can provide invaluable information for refining into a saleable product. To provide this type of information, an acidic and a basic fraction were obtained from an eastern and western shale oil. The fractions were analyzed using 70-eV high-resolution electron impact and low resolution field ionization mass spectrometry. Comparison of the analytical data shows striking differences between the compositions of acids and bases for the eastern and western shale oils. The eastern shale acids are primarily benzoic acids and phenols, whereas, the western shale acids contain high concentrations of benzoic and long-chain carboxylic acids. Differences in the base fractions appear in the number of carbons exocyclic to the basic nucleus and in the size of the nitrogen containing nucleus with as many as six aromatic rings. In contrast, the western bases have a larger number of carbons exocyclic to a specific nucleus with the nucleus having fewer aromatic rings. The presence of these compound types has serious refining implications since their presence could complicate a simple hydrogenation/hydrogenolysis upgrading using present refinery technology.
Removal of Hydrogen Peroxide from Flat Packaging Material Used in Aseptic Packaging of Food
Authors: Stefanovic S , Dickerson RW
Published: December 2008

Hydrogen peroxide is used to sterilize packaging material intended for aseptic packaging. After sterilization is achieved, the hydrogen peroxide must be removed to satisfy the maximum permissible residual of 0.1 ppm, based on the contained volume of the aseptic package. A pilot plant scale system for sterilization of flat stock packaging material was used to identify some of the critical variables affecting removal of hydrogen peroxide. Flat stock material was exposed to hydrogen peroxide at 27 and 85°C at concentrations of 30 and 40% weight/weight. The sterilant was applied by immersion and misting. Hot sterile air at 66, 149, and 204°C was used to heat and remove the hydrogen peroxide. Immersion in hydrogen peroxide at 27°C, with a concentration of 30% weight/weight, and air drying at 149°C for 35 s, reduced the average residual for eight containers to 3.5 ppm. The lowest average residual (0.2 ppm) was observed when hydrogen peroxide was used at 27°C, with a concentration of 40% weight/weight, and drying air at 204°C was applied for 7 s. The critical variables were the effective temperature of the drying air, the temperature of the sterilant, and the residence time in the drying zone.
Isostatic and Quasi-Isostatic Methods for Determining the Permeability of Organic Vapors Through Barrier Membranes
Authors: Baner AL , Hernandez RJ , Jayaraman K , Giacin JR
Published: December 2008

Two test methods have been developed which provide quantitative and reliable values for the rate of diffusion of organic vapors through polymer membranes. Method I is based on a quasi-isostatic procedure and utilizes gas chromatography analysis for quantifying the amount of organic vapor that has permeated through the membrane. The permeability of a number of permeant/polymer membrane combinations was determined by this method, with studies being carried out at constant temperature and with varying permeant concentrations. The effect of permeant concentration on the permeability rate, P, permeability constant, ¯P, the apparent diffusion coefficient, Da, and the limiting diffusion coefficient, D0, was determined for the diffusion of toluene vapor through oriented polypropylene, Saran, and a Saran-coated oriented polypropylene structure.

Method II involved an isostatic procedure, in which a constant and low concentration of permeant is flowed through the upper cell chamber of a permeability cell. Simultaneously, nitrogen carrier gas (N2) of a known flow rate is continually passed through the lower cell chamber of the permeability cell and is conveyed to a gas chromatograph by means of a computer-aided gas sampling valve.

The methods developed allow determination of the diffusion of organic aroma constituents through barrier membranes under defined conditions including (1) temperature, (2) permeant concentration, (3) membrane thickness, (4) polymer morphology (percent crystallinity), and, (5) polymer thermal mechanical history (that is, degree orientation), and they will have significant utility in evaluating plastic packaging material for food packaging, particularly as plastics are showing increased usefulness as packaging for fresh and processed food products.
Psychometric Scaling of Gloss
Authors: O'Donnell FXD , Billmeyer FW
Published: December 2008

Visual observations on gloss have identified approximately six types of gloss. To study the interrelations among these a method for the multidimensional scaling of gloss was devised. Two sets of painted specimens were examined. The first set covered a wide range of gloss using specimens that were a single grey color. The second set covered a more restricted range of gloss but consisted of black, grey, and white specimens. The results for these particular specimens under the particular viewing and illuminating conditions described yielded unidimensional interval scales. These interval scales were then correlated with the instrumental measurements obtained from the specimens. Equations relating the visual data to the instrumental data were derived.
Measurement of Color on Foods: Some Experiences at INTI, Buenos Aires
Authors: Jungman D , Lozano RD , de Bellora CM
Published: December 2008

Among problems studied by the Optical Division of The National Institute of Industrial Technology (INTI) in Argentina are efforts related to the food industry. A review of the most relevant projects includes: basic research on non-enzimatic browning, corned-beef, sausage meat, fish, wheat products (semoline, semoline noodles, and flour), tomatoes, and products derived therefrom, apples, apple juice, and yerba maté (Ilex paraguariensis or Ilex theazans). Some discussion is given in each case.
Direct Metering of Pesticide Concentrations
Authors: Kuhlman DK , TenEyck G , Larson GH
Published: December 2008

A study was initiated to develop an automated injection system that would permit pesticide concentrate to be metered and mixed without the operator handling it manually or coming in contact with the chemical. A special jet nozzle assembly was designed that would allow the concentrate to be injected close to the discharge of the nozzle tip, and ensure good mixing of the concentrate with diluent for uniform deposition. This nozzle assembly allowed for a minimum of system concentration injection lag time in response to changes in ground speed. A complete spray system was then mounted on a Hesston 500 swather and field tested.
Understanding Volatilities of Forestry Spray Mixtures from Their Viscosities and Viscosity-Temperature Relationships
Authors: Sundaram A
Published: December 2008

A simple gravimetric method was developed to determine volatilities of spray mixtures and was compared with the droplet method. The method involved evaporation of a liquid film from a filter paper surface and provided greater precision than the droplet method. It also provided a greater sensitivity in identifying small differences in the volatilities of different spray mixtures. An indirect method was also investigated to provide an understanding of the volatilities of spray mixtures from their viscosities and viscosity-temperature relationships. The data indicated an inverse relationship between the viscosity of a spray mixture and its volatility. With respect to the viscosity-temperature relationships, most spray mixtures obeyed the Arrhenius equation for the viscous flow. The exponential relationship of viscosity with the reciprocal of temperature provided a good correlation. The intercept of the equation was directly related to volatility, and the slope was inversely related to volatility.
Theoretical Constraints and Precautions Using Light Scattering to Measure Drop Size Distributions
Authors: Dietrich VE
Published: December 2008

The structure and principles of the light scattering technique used to measure drop size distributions are briefly discussed. The sensitive nature of the optical system and the care required in adjustments are described. Comments on the detector and improvements in the later models are made. Suggestions for suitable equipment checks are offered. Calibration and sampling requirements are addressed. Lack of compatibility of models is explained.
Development of Instrumentation for Spray Drop Size Research
Authors: Simmons HC
Published: December 2008

The latest version of an optical, nonintrusive, imaging instrument for measuring drop sizes in sprays is briefly described. The range of drop sizes measurable is 6 to 1200 μm. The use of a laser allows the time exposure to be only 10 ns, which is suitable for fast-moving drops typically found with air-atomizing spray nozzles. References are given for a fuller description of the method and its advantages.
Oxidation Test Method Development by ASTM Subcommittee D02.09
Authors: Warne TM
Published: December 2008

ASTM Subcommittee D02.09 develops methods and equipment to measure thermal and oxidation stability of fuels, lubricating oils, and greases. This paper will outline the existing ASTM oxidation test methods available for petroleum products and briefly describe the status of new test method development underway. New oxidation tests will be described for gasoline, motor oils, turbine oils, hydraulic fluids, and gear lubricants.
Use of Titanium for Treatment of Toxic and Hazardous Wastes
Authors: Oettinger TP , Hoffman MC , Fontana MG
Published: December 2008

The application of titanium for treatment of hazardous and toxic wastes by wet air oxidation (WAO) is discussed. Process equipment utilized in 10.9 to 54.5 m3/day (2 to 10 gal/min) WAO units is illustrated. These systems typically operate at 250 to 300°C and 10.4 to 15.2 MPa (1500 to 2200 psig). Laboratory autoclave corrosion studies used to determine compatible materials of construction for WAO applications are described and results of these tests on representative wastes are presented. Results on titanium are compared with other candidate materials of construction.

Field experience obtained with Grade 2 titanium at a California Class I landfill site that uses WAO to detoxify hazardous wastes is presented. Results of autoclave corrosion tests, run on actual waste feed samples, are compared to in-line reactor specimens. Types of wastes treated and tested were those containing cyanides, phenols, sulfides, and pesticides.

Advantages of using Grade 12 titanium over Grade 2 for WAO toxic waste treatment are discussed. Some initial fabrication and forming problems encountered with Grade 12 are presented. The effects of surface conditions on successful forming and welding of Grade 12 were found to be significant. Adequate pickling of the starting base material was the most critical variable. The first toxic WAO unit constructed of Grade 12 titanium is illustrated, and a comparison of various fittings constructed of Grade 2 and Grade 12 is made.
Ti-3Al-2.5V for Seawater Piping Applications
Authors: Caplan IL
Published: December 2008

Copper-nickel alloys and steel are the materials most commonly used for piping applications in a seawater environment. For situations where reduced weight, increased flexibility, and excellent corrosion-erosion resistance are desired, titanium is an extremely attractive alternate material.

Commercially pure grades of titanium can be used for seawater piping, but are rather low in strength. However, by taking advantage of the high specific strength possible with alloys of titanium, substantial weight savings can be achieved.

Based upon screening studies, Ti-3Al-2.5V was selected for investigation as a candidate alloy for this application. Plate 25.4-mm (1-in.) thick, extruded from Ti-3Al-2.5V billet at a 10:1 reduction ratio, was used for heat treatment and property studies. In addition, double-vee butt weldments of this plate were prepared by the automatic cold-wire gas tungsten arc welding process. The results of mechanical property tests will be presented for both Ti-3Al-2.5V plate and weldments.

Results to date indicate that the Ti-3Al-2.5V alloy possesses a highly desirable suite of properties that make it a very attractive candidate for piping and machinery applications in the seawater environment.
Required Reliability of Reactive Metal Mill Products and Process Equipment
Authors: Smallwood RE
Published: December 2008

The process industry uses many different materials to construct its plants and equipment. The selection and use of these different materials of construction involves various compromises to achieve the corporate goal of a suitable return on investment. To achieve the required return on investment, the process plants must also achieve and maintain a high reliability. The personnel concerned with engineering, design, fabrication, operations, and maintenance practices must weigh various options afforded by different materials and select those materials and practices that provide the optimum economic benefit. Basic to material selection are the various standards and codes that define the materials available and how these materials are to be used. Since the reactive metals are now used within the process industry standards, such as those of ASTM, must reflect the process industry's need for reliable materials.
Ground-Water Monitoring Data Quality Objectives for Remedial Site Investigations
Authors: Evans RB
Published: December 2008

There is a need for a system of ground-water monitoring performance criteria (data quality objectives or DQO's), reference methods, equivalency testing protocols, and quality assurance procedures for ground-water monitoring in remedial site investigations. This framework should be related to relevant ambient concentration standards through data quality objectives which allow monitoring data to be compared to the ambient standards.
Document Control and Chain-of-Custody Considerations for the National Contract Laboratory Program
Authors: Laidlaw RH
Published: December 2008

The Environmental Protection Agency (EPA) Contract Laboratory Program (CLP) provides analytical services for investigations in support of the Superfund program. The work effort includes data generation used for preparation of enforcement cases. EPA has specified procedures for evidence handling that are used to enhance admissibility of data and to establish analytical integrity. The CLP has stringent requirements for document control and chain-of-custody and has established a system of audits to assure compliance with procedure.
Performance of USEPA Method for Analysis of 2,3,7,8-Tetrachloro-Dibenzo-p-Dioxin in Soils and Sediments by Contractor Laboratories
Authors: Garner FC , Homsher M , Pearson JG
Published: December 2008

The United States Environmental Protection Agency's superfund contractor laboratories use the method found in USEPA IFB WA84-A002 to analyze soil and sediment samples for the specific isomer 2,3,7,8-tetrachloro-dibenzo-p-dioxin. This method uses isotope dilution gas chromatography and mass spectrometry (GC/MS). The precision, accuracy, detection limit, isomer specificity, recovery, and other performance parameters are important in evaluating performance of laboratories and methods. The observed performance of this method in the production-line analysis of thousands of samples by eleven contractor laboratories is presented in this paper.
Semi-Volatile Organic Analytical Methods — General Description and Quality Control Considerations
Authors: Fisk JF
Published: December 2008

As a result of the enactment of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) in 1980, and the subsequent delegation of its authority by the President of the United States to the Administrator of the Environmental Protection Agency, the Contract Laboratory Program (CLP) has been developed to analyze “Superfund” samples in a broad-based manner in order to obtain the most information about them with a reasonable investment in time and money. The CLP uses gas chromatography/mass spectrometry (GC/MS) as its primary tool for analysis of samples for organic constituents. More explicitly, it employs solvent extraction techniques respectively appropriate for water and soil/sediment matrices prior to MS detection for semi-volatile compounds. An elaborate Quality Assurance/Quality Control (QA/QC) system is in place to guarantee that data generated by the CLP is of known quality and will hold up to the rigors of litigation, in addition to providing an ongoing monitoring of CLP laboratories QA/QC data in order to guarantee their successful performance.
Semi-Volatile Organic Analytical Methods Performance and Quality Control Considerations
Authors: Wolff JS , Homsher MT , Flotard RD , Pearson JG
Published: December 2008

The analysis of semi-volatile organic compounds in hazardous waste samples for the U. S. Environmental Protection Agency's Superfund Program is done by selected contractor laboratories using methods specified in the EPA Invitation for Bid document WA-85-J664. The Contract Laboratory Program maintains a data base containing information on precision and accuracy for matrix and surrogate spiking of samples. In addition, pre-award and quarterly blind quality assurance sample results yield data for precision and accuracy. The precision, expressed as relative standard deviation varies from 16% to 42% while the bias ranges from −59% to +12%.
Volatile Organic Analytical Methods Performance and Quality Control Considerations
Authors: Flotard RD , Homsher MT , Wolff JS , Moore JM
Published: December 2008

The analysis of volatile organic compounds in hazardous waste samples from the U.S. Environmental Protection Agency Superfund program is done by selected contractor laboratories using methods specified in the EPA Invitation to Bid document WA85-J664. Data for the precision and accuracy of the method is obtained from the quality assurance data in the Contract Laboratory Program database. Method precision is obtained from the results of matrix and surrogate spiking of the samples. Bias is obtained from the results of surrogate spiking, preaward samples, and quarterly blind quality assurance samples. The precision, expressed as relative standard deviation, varies from 8 to 16% while the bias varies from +6.5 to -46%.
Size-Dependent Sensitivity of Three Species of Stream Invertebrates to pH Depression
Authors: Allan JW , Burton TM
Published: December 2008

Three species of stream invertebrates, the caddis fly Lepidostoma liba (Ross), the isopod Asellus intermedius (Forbes), and the snail Physella heterostropha (Say), were found to be highly vulnerable to depression to pH 4.0 with 70% sulfuric acid (H2SO3) and 30% nitric acid (HNO3) from a control pH of 6.7 to 7.2. This vulnerability was directly correlated to size with smaller individuals being much less tolerant to pH 4 depression than were larger individuals. Smaller size classes, including egg masses of P. heterostropha, were totally eliminated by exposure to pH 4. Survival increased as initial body mass increased past a threshold size (0.5 mg dry weight per individual for A. intermedius, 0.6 mg for L. liba, and at a shell length of 4 mm for P. heterostropha). Depression of pH from 7 to 4 also depressed growth rates for A. intermedius, and L. liba. This experiment was conducted in recirculating laboratory streams operated near ambient temperatures at 8-week intervals throughout the year.
Buffering Capacity of Soft-Water Lake Sediments in Florida
Authors: Perry TE , Pollman CD , Brezonik PL
Published: December 2008

Fifty sediment cores from 13 soft-water lakes in north- and south-central Florida were collected to examine the role of surficial sediments in buffering lake water against changes in pH induced by additions of sulfuric acid (H2SO4). Intact cores were collected in duplicate from nearshore and pelagic locations to stimulate in situ lake sediment-water conditions. In addition, batch titrations of sediments treated with chloroform were performed in continuously shaken sediment-water slurries to evaluate ion exchange mechanisms and total mineralogical potential for acid neutralization.

Results from batch bottle experiments showed higher pH values in sediment-water slurries than corresponding lake water pH, suggesting that chemical processes in the sediments tend to counter inputs of acidity to the water column. The acid-neutralizing capacity (ANC) was moderately related to organic content; consequently, ANC was more pronounced in pelagic sediments, which typically accrete organic matter, than littoral sediments, which are more subject to wind-induced scour and resuspension and characteristically are impoverished in organic matter. Calculated areal buffering capacities from the batch studies ranged from 5.5 to 149 meq/m2/cm, indicating that sufficient buffering is available in 1 to 2 cm of sediment to neutralize annual proton loadings via ion exchange alone.

Significant neutralization of acid inputs also was observed in intact cores, and analysis of changes in cation chemistry in the overlying water of the cores suggests that microbially mediated sulfate reduction exceeded ion exchange as the principal alkalinity-producing mechanism. High rates of sulfate removal from the experimental cores support this conclusion; sulfate losses ranged from 32 to 94% in pelagic cores and 39 to 91% in littoral cores. Cores that received no acid showed losses of sulfate ranging from 55 to nearly 100% with concomitant increases in pH in the overyling water. Neutralization of added acid directly attributable to the sediments ranged from 31.8 to 101 meq/m2 over the 4-month duration of the study. Neutralization was independent of particle size distribution or sediment organic content.
A Simple Method to Measure pH Accurately in Acid Rain Samples
Authors: Boyle PF , Ross JW , Synnott JC , James CL
Published: December 2008

Conventional pH electrodes, which are designed to function in high-conductivity solutions, show slow and erratic response in pure water samples such as acid precipitation. Increasing conductivity without shifting pH solves the measurement problem. This method correctly measures pH in low conductivity solutions, using a Ross combination pH electrode, after the addition of a small amount of potassium chloride (KCl) solution to the sample. The Ross electrode, with its unique internal redox system, is chosen since it eliminates problems associated with temperature and because the precision and accuracy of data obtained in preliminary testing with it were comparable to those obtained with the standard hydrogen electrode. KCl addition to samples does not alter the pH significantly.
Alkali-Silica Reactivity: Effect of Alkali in Aggregate on Expansion
Authors: Stark D , Bhatty MSY
Published: December 2008

Tests were performed on samples of alkali-bearing aggregates to determine amounts of alkali that could be removed by leaching in Ca(OH)2 solution and water at 38°C (100°F) and 80°C (176°F). Additional tests were made on one reactive aggregate which was first subjected to leaching and then used to make mortar bars for testing in accordance with ASTM C 227. Leach periods of 7, 28, 90, and 180 days were used.

Results show that alkali present within concrete aggregate particles may participate in alkali-silica reactivity. Alkali levels much greater than those present in high-alkali cements can be leached from non-reactive as well as reactive aggregate materials. It is suggested that ion-exchange processes possibly augmented by partial dissolution of the aggregate, facilitate leaching of alkali.

Removal of alkali from aggregates, prior to their use in mortar bars, was shown to reduce expansions. Expansions were progressively reduced as greater amounts of alkali were leached from aggregates prior to their use with low- as well as high-alkali cements.

Applicability of these findings to concrete in service is discussed.
Influence of Cement Alkali Distribution on Expansion Due to Alkali-Silica Reaction
Authors: Struble L , Diamond S
Published: December 2008

In order to better understand the factors controlling alkali-silica reaction, a study was carried out to show if the distribution of alkalies among the cement minerals influences the expansion of mortar containing reactive aggregate. The approach was to determine the distribution of alkalies in four high-alkali portland cements, and to measure expansion of mortar bars prepared using these cements and reactive aggregates. In some cases, differences were observed in both the ultimate level and the early rate of expansion for cements differing in distribution of alkalies. The differences were substantial with opal as the reactive constituent. Cements richer in soluble alkali-sulfate phases appeared to show greater levels and rates of expansion. The results demonstrate that the specific distribution of alkalies among the cement minerals affects the expansion due to alkali-silica reaction.
Correlating Water-Soluble Alkalies to Total Alkalies in Cement—Considerations for Preventing Alkali-Silica Poputs on Slabs
Authors: Dobie TR
Published: December 2008

This paper reviews the problem of alkali-silica surface popouts on slabs in the north central United States and adjacent southern Canada. Based on the review, it is concluded that the popouts occur as a result of reaction of alkalies in the concrete with siliceous shale in the concrete sand. The reaction is caused by increased alkali concentration at the slab surface, which results when soluble alkalies are left behind by evaporating mixing water. The soluble alkalies in the cement, fly ash, aggregates, admixtures, and mixing water contribute to alkalies in solution. Weather conditions and placing and finishing methods are primarily responsible for concentration of water-soluble alkalies at the slab surface where the popouts occur.

The correlation between water-soluble alkalies and total alkalies is determined for a plant which produces cement that has several levels of alkali. The results indicate good correlation, but the benefit of reduction of total alkalies on resultant level of water-soluble alkalies does not appear significant compared to other factors which cause greatly increased alkali concentration at the slab surface.

Cements from other sources are also compared for correlation. The results indicate the portion of the total alkalies which is water-soluble varies widely from one cement plant to another and within the production from some plants.
Recent Developments in the Use of Fly Ash to Reduce Alkali-Aggregate Reaction
Authors: Smith RL , Raba CF
Published: December 2008

The alkali-aggregate reaction is receiving renewed attention for the following reasons:

1. Aggregates previously considered innocuous have shown expansions after several years.

2. The alkali content of portland cements has increased because of the process changes prompted by energy and environmental constraints.

3. The traditional use of fly ash to reduce the expansion from the alkali-aggregate reaction may not be beneficial if the fly ash has a low amorphous silica content and high alkali (particularly sodium) content.

The general mechanism for the alkali-silica reaction, the most common type of alkali-aggregate reaction, involves the attack of the reactive form of silica by the highly alkaline pore solutions to form a gel which imbibes water, creating internal stress and disruption of the concrete.

Factors affecting the alkali-aggregate reaction include the nature and amount of reactive aggregates, the alkali content of the cement and fly ash, the mix proportion, and the environment of the concrete.

With the increasing use of marginally reactive aggregates in combination with higher alkali cements and possibly fly ashes that will not deter the expansive reaction, it is very possible that concrete structures are being built today that in the years to come will begin to exhibit map cracking and eventually become unsafe.

Present test methods do not always predict when combinations of aggregate and cementitious materials will react to form expansive products. More research is needed on the long-term effects of high-alkali (particularly high-sodium) fly ash with a low amorphous silica content.
The Application of Compatibility Knowledge
Authors: Gilbertson JA
Published: December 2008

The author explains how experience and empirical rules are used in the design of equipment for use in oxygen-enriched atmospheres. Standard methods of testing materials are making the availability of consistent data more widespread. The lack of an agreed method of applying those data founded on theory and science impedes progress and is a barrier to educating newcomers.
Ignition of Metals and Alloys in Gaseous Oxygen by Frictional Heating
Authors: Benz FJ , Stoltzfus JM
Published: December 2008

The ignition of metals and alloys have been investigated by rotating the end of a hollow cylinder against an identical stationery cylinder on a common axis (frictional heating) in gaseous oxygen. A ranking criterion that measures the resistance of metals and alloys to ignition is discussed. It consists of the power per unit area required for ignition, conveniently expressed as the product of contact pressure P and average linear velocity ¯v. Data are presented that demonstrate that materials that are high in nickel and copper require greater Pv products for ignition (more resistant to ignition) than materials that are high in iron. Aluminum and titanium alloys are shown to require the lowest Pv products for ignition. The effects of varying surface velocity, contact pressure, coefficient of friction, and oxygen pressure on P¯v products required for ignition are discussed. The results indicate that P¯v product required for ignition increases as surface velocity increases, as contact pressure decreases, and as the coefficient of friction decreases. Increasing oxygen pressure will cause the P¯v product required for ignition to decrease at low pressures and increase at high pressures. In some cases, the relative ranking of materials based on P¯v products will also change as conditions are varied.

The data presented in this paper are from a development program to determine the merits of using such a dynamic test method for ranking materials for oxygen service. The results to date have indicated that more testing is required before this method can be made into a standard test. The data presented do show some of the major parameters affecting the ignition of materials when exposed to frictional heating. The repeatability of the data at any set of conditions have not been throughly investigated.
Ignition and Combustion Temperatures Determined by Laser Heating
Authors: Bransford JW
Published: December 2008

A laser heating technique and facility have been developed to study metal ignition and combustion in high-pressure oxygen. The ignition and combustion temperatures, estimates of oxidation rates, and ignition and combustion morphology can be determined. This facility and the laser heating techniques are described. Examples of the type of data obtained are presented and discussed. The ignition temperature curves for an aluminum alloy—Unified Numbering System (UNS) A96061, a stainless steel—UNS S30200, and two nickel alloys—UNS N07718 and N04400 are given.
The Flammability of Carbon Steel as Determined By Pressurized Oxygen Index Measurements
Authors: Benning MA , Werley BL
Published: December 2008

The ASTM oxygen index, a standard atmospheric pressure test for comparing the flammability of plastics, has been used in combination with other tests to evaluate the suitability of nonmetals for use in oxygen service. In 1983, this test was extended to allow measurements at pressures to 2 MPa (300 psig). This paper describes how the concept of a pressurized oxygen index test can be extended further to measure the flammability of metals and hence their suitability for use in oxygen service. An experimental program is described that measured oxygen indexes for carbon steel pipe (25 mm [1.0 in.] diameter by 4.8 mm [0.188 in.] wall) as a function of pressure to 20 MPa (3000 psig) at temperatures of about 300 and 355 K (80 and 180°F). Oxygen/nitrogen mixture velocities inside the pipe varied from 0.15 to 0.90 m/s (0.5 to 3 ft/s). An experimental system was developed, including the test specimen configuration and a thermite ignition pill for use in oxygen mixtures. Measured oxygen indexes were 81 mol% oxygen in nitrogen at 1.03 MPa (150 psi), 53 mol% at 6.9 MPa (1000 psi), and 51 mol% at 20.7 MPa (3000 psi). Additional tests demonstrated the effectiveness of Monel as a firebreak material and Buna N rubber as an ignition source for carbon steel.
Cleaning Methods and Procedures for Military Oxygen Equipment: Investigation Results
Authors: Schroll DW
Published: December 2008

Over the past several years a number of briefings have been given at the Oxygen Standardization Coordinating Group (OSCG) concerning cleaning methods and procedures for military oxygen equipment. Of particular concern has been the diversity of methods, cleaning compounds, and cleanliness criteria that exist in the military and industry in the manufacture, shipment, aircraft installation, and maintenance of military oxygen equipment. This will be discussed in some depth in this paper. The OSCG is an Army, Navy, and Air Force group that meets twice a year to discuss and coordinate changes to specification governing procurement of military oxygen equipment and related design and installation practices. Industry is also invited to attend and comment.
Threshold Sensitivities of Tests to Detect Oil Film Contamination in Oxygen Equipment
Authors: Gilbertson JA , Lowrie R
Published: December 2008

Equipment and components for use in an oxygen service are required to be “clean” or “free from oil,” as contamination by oil is believed to have been responsible for numerous incidents. In some specifications, cleanness is defined by stating the maximum allowable concentration in grams per square metre, but often the specification is qualitative. Four tests of cleanness are widely quoted; these are visual examination in white and in ultraviolet light, a wipe test, and a water break test. The threshold sensitivities of these four tests have been evaluated for six different hydrocarbon oils commonly used in the industry. The results of this limited project show that under the test conditions the order of increasing sensitivity was white light, ultraviolet (UV) light, modified wipe, and water break. Water break was 20 to 40 times more sensitive than the white light test. Considerable further investigation is recommended.
New Oil Detector System Enables Fully Instrumental Operation of Oxygen Reciprocating Compressors
Authors: Ernst P
Published: December 2008

This paper presents a new electronic oil detector system that guarantees a continuous monitoring of the function of the oil retention system of oxygen reciprocating compressors. As a measuring method the system uses the variation in the capacitance of a capacitor, as a result of absorption of oil by an absorbent element serving as a dielectric. Field experience shows that this system is a major step forward in safe, automatic, remote control of oxygen reciprocating compressors.
Quantitative Low-Tech Measurement of Fluid Nonvolatile Residue
Authors: Werley BL
Published: December 2008

A relatively simple and inexpensive mechanism is proposed for measuring the volume of fluid, nonvolatile residue (NVR) dissolved in dense solvents. The mechanism involves supporting the solvent/NVR with surface tension in an inverted transparent capillary tube and evaporating the solvent fraction to leave a continuous measurable column of NVR. The mechanism has been briefly tested on several hydrocarbon oils and has exhibited potential sensitivity over a range of at least 0.5 to 50 μL. The mechanism may be applicable to field measurement of oils extracted from surface films, porous insulations, and water. The mechanism is proposed as an embryonic basis for development into a potential ASTM standard.
Applied Fracture Mechanics for Assessing Defect Significance in a Crude Oil Pipeline
Authors: Christensen C , Hill RT
Published: December 2008

The integrity and service life of a pipeline will depend, to a large extent, on the fracture toughness properties and subcritical crack growth resistance of pipes with defects either inherently present or introduced during construction or service. Unstable fracture from crack like defects can occur if the fracture toughness of the line pipe material is inferior, whereas subcritical crack growth can occur under sustained load and cyclically varying loads (fatigue). Both of these subcritical growth mechanisms can be strongly influenced by the internal pipe environment (hydrogen sulfide, carbon dioxide) and external environment (corrosion, cathodic protection).

A case history of the application of fracture mechanics for evaluating the static fracture toughness and subcritical crack growth resistance of an external longitudinal weld toe crack is discussed.
Analysis of a compressor-Wheel Failure
Authors: Cipolla RC , Grover JL , Richman RH
Published: December 2008

Pieces of a burst compressor wheel from a large combustion turbine revealed severe segregation of alloying constituents and impurities, high densities of sulfide inclusions, and intergranular, oxide filled microcracks. Analysis of oxidation kinetics for AISI 4140 steel indicates, however, that the service environment could not have caused the observed scale thicknesses in the microcracks. One- and two-dimensional stress analyses confirm modest cyclic stresses and maximum stresses in the range of 531 to 683 MPa (77 to 99 ksi), not the 827 MPa (120 ksi) level implied by crack growth from 0.76 mm (0.03 in.) flaws. To account for the observed cyclic life of about 1500 cycles, the initial defects would have to be 8.6 mm (0.34 in.) to 16.8 mm (0.66 in.) long, according to fracture mechanics analyses performed by an influence function method. On the basis of all the results, it is concluded that small cracks were already in the wheel when it went into service.
Analysis of Two Metal-Forming Die Failures
Authors: Rich TP , Orbison JG
Published: December 2008

This case study presents the application of fracture mechanics to analyze the failures of two dies. One is the failure of a die used to swage fittings onto wire ropes. This failure is traced to very high stresses in the die cavity and relatively low fracture toughness; fatigue plays no role. In the second die, the failure is caused by the growth of a crack from the die cavity and is solely a fatigue problem. This die is used to mold gears in a powder metallurgy process.
Analysis of a Failed Saw Arbor
Authors: Clarke CK
Published: December 2008

Stress analyses incorporating stress concentration, fatigue, and fracture calculations should be an important aspect of failure analyses. The following description of a saw arbor failure provides a simple example of this necessity. The failure was a classical stepped shaft in bending fatigue failure. Stress concentration at the change in diameters was calculated to be a factor of five. However, stress calculations revealed normally expected stresses to be well below the endurance limit even with the stress concentration effects. Additional investigation revealed evidence for severe imbalance loads from one saw blade. It was hypothesized that some of the teeth from the carbide tipped saw had been knocked off, and the resulting imbalance loads were more than sufficient to initiate fatigue cracking.
Fatigue Crack Growth and Crack Arrest in the Nails Used for Intramedullary Fixation of Femur Fractures
Authors: Mattheck C , Kneifel B , Morawietz P
Published: December 2008

The fractures of large bones are often fixed by use of intramedullary nails. Sometimes these nails show cracks originating at the end of their slot and also at perforations which are necessary for the screws of interlocking nails. In this paper it is shown that notch stresses near these perforations are responsible for crack initiation. A fracture mechanical analysis is carried out in order to calculate the stress-intensity factor for such cracks under physiological loading. Fatigue considerations are presented, and conditions for crack arrest are shown. A new nail profile is proposed which reduces the notch stresses significantly.
OSHA's Hazard Communication Standard Falls Short
Authors: Mabry FM , Seminario MM , Barkman M
Published: December 2008

The focus of the “New Federalism” is supposed to be the return of regulation to state and local government. The Occupational Safety and Health Administration's (OSHA's) Hazard Communication Standard is a radical departure from the just-stated policy. The standard calls for preemption of state and local regulation in occupational settings. Also, regulation is limited to Standard Industrial Classification (SIC) Codes 20 through 39: the majority of workers therefore are not covered.

The standard is being challenged on legal grounds by the United Steelworkers of America and by state and other government entities who filed as intervenors. The trade secret claim provision is too broad and is without adjudicatory remedy for workers and representatives. The addendum outlines the court's decision in favor of the unions.
Training Programs: The Key Link to OSHA's Hazard Communication Standard
Authors: Capuano AA
Published: December 2008

The Occupational Safety and Health Administration (OSHA) Hazard Communication standard was developed to ensure that workers understand the hazards of substances in their workplace. The key to accomplishing this objective is through effective industrial training programs. Industry, while desiring performance language in OSHA standards, appears confused with the performance language of the Hazard Communication standard. Effective compliance can only be achieved through an understanding of the standard and the personality of one's company. Although many of the standard's requirements are unique, many other requirements have been performed for years by industry. The confusion performance language is creating has become a roadblock to effective compliance. A thorough analysis of the standard and company needs, coupled with a logical approach to compliance in a timely manner, is essential.
Legal Issues Related to the Hazard Communication Standard
Authors: Boccella CM
Published: December 2008

This paper will discuss several legal issues surrounding the promulgation of the OSHA hazard communication standard. The specific areas that are discussed are the litigation challenging the validity of the standard; the litigation on the preemptive effect of the standard on state right-to-know laws; the product liability concerns that are raised by the standard; and, the effect the standard will have on employee relations.