bluuebunny/crossref_metadata_2025_split 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.
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.
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.
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.
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.
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.
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.
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.
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.
Hazards of Toxicity Information
Authors: Wiseman LM 
Published: December 2008

The Occupational Safety and Health Administration's (OSHA) Hazard Communication standard, state and local right-to-know laws, and a heightened public awareness of environmental issues have created new demands for information on the toxicological properties of chemicals and products. Several computer-searchable database producers have attempted to respond to these new demands by collecting and managing the growing amount of data and generally making it more easily and widely available.
Transforming this data into usable information presents some problems, especially since some of it may be of questionable quality or value. How do we increase our management's, our employees', and our customers' understanding of the true hazards associated with chemicals and products? What and how do we communicate to our various audiences—plant workers, health and safety professionals, management, marketing personnel, customers, and legislators? How do we ensure that we are providing information that is not only accurate and complete, but also usable and understandable? This paper presents one industrial organization's approach to the problems of handling toxicity information.
Celanese Corp. believes that information of the toxic properties of any chemical used in the company's processes or the toxicity of the company's final products is a basic component in the chemical's risk assessment. A Material Safety Data Sheet (MSDS) will effectively communicate accurate environmental, health, and safety information. Significant toxicological data will be communicated to employees, affected customers, regulatory authorities, and the public. The Toxicology Department has developed two documents, a Toxicity Summary and a Toxicity Evaluation, that can be used at the beginning of the communication process.
All those at Celanese involved in hazards communication share two ongoing responsibilities. One is for continuous analysis and verification of data on the toxic effects of chemicals. The second is to impart quality information to others—be it as an MSDS, a “Dear Customer” letter, or a briefing to employees—that will heighten their awareness and increase their understanding. It has been and will continue to be a learning process.
Using the Micro-CSIN Workstation to Provide Chemical Hazard Information
Authors: Hushon JM , Conry TJ 
Published: December 2008

Chemical hazards are of two basic types: emergency situations presenting imminent danger to humans or the environment and existing hazards such as dump sites or chemical storage areas. The information requirements and tools available for responding to these two types of hazards are different, and the Micro-CSIN Workstation developed by Bolt Beranek and Newman (BBN) under the sponsorship of the Council on Environmental Quality (CEQ), the Environmental Protection Agency (EPA), the National Library of Medicine (NLM), and the Centers for Disease Control (CDC), can respond to both.
Emergencies require rapid access to factual data. The Micro-CSIN Workstation permits rapid retrieval of factual data stored in three databases: Hazardous Substances Data Bank (NLM/TOXNET), Hazardline (OHS), and Ohmtads (CIS) according to a prestored, userspecified, retrieval profile. The data are then organized by subject area into a report. The Workstation also has the ability to rapidly retrieve chemical identification information.
In a nonemergency situation, it is possible to carry out a more thorough search of the literature. The Micro-CSIN Workstation makes use of a general bibliographic script to access and retrieve any of several hundred bibliographic databases available through Bibliographic Retrieval Systems (BRS), Chemical Abstracts Service (CAS), Dialog, NLM, and Systems Development Corp. (SDC). These more current and in-depth data can be used to supplement the chemical summary information.
For a company responding to the right-to-know laws, the chemical summaries are ideal, especially if supplemented by additional, more recently published results. One way of organizing right-to-know information is to organize all data into two computerized files using a database management software package. BBN uses RS/1, one of its software products. The two files cover (1) product-related information and (2) chemical-related information, and the files are cross-indexed. The structures of these files are presented along with a possible data management scheme for storing and manipulating local site data, material safety data sheets (MSDSs), chemical content information, and chemical-specific data needed to respond to the laws. It is in identifying and retrieving chemical-specific data that the Micro-CSIN Workstation technology is particularly valuable.