bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relation of CO2 Concentration to Office Building Ventilation
Authors: Persily A , Dols WS
Published: March 2009

Tracer gas techniques have been used to study air exchange in mechanically ventilated office buildings for many years. The analysis of the concentration of carbon dioxide (CO2) generated by building occupants has been suggested as an alternate means of evaluating building air exchange and ventilation system performance. Various techniques for CO2 analysis have been proposed. These include measuring the decay rate of CO2 concentration after the occupants leave the building, analyzing real-time CO2 concentration data in conjunction with a CO2 mass balance equation, and using instantaneous CO2 concentration readings to directly determine air exchange rates. Local CO2 concentrations have also been suggested as a means of evaluating ventilation effectiveness. These techniques require specific assumptions and unique conditions in order to yield reliable information on building air exchange characteristics, and these requirements may not always be met in office buildings.

This paper examines the relationship between CO2 concentration and building air exchange. A dataset of simultaneously measured air exchange rates, based on sulfur hexafluoride (SF6) decay, and CO2 concentrations obtained in three office buildings is employed to examine this relationship. The results indicate that CO2 decay rates can provide reliable estimates of building air exchange rates, but that there may be significant error associated with the use of instantaneous concentrations to determine air exchange rates.
Air Leakage Tests of Manufactured Housing in the Northwest United States
Authors: Ek CW , Onisko SA , Gregg GO
Published: March 2009

Recently installed HUD-code manufactured housing in the Pacific Northwest region of the United States has been tested for air leakage characteristics. The tests were done to establish a database of air leakage under current manufacturing and installation practice. Test results will help establish the potential for future energy savings through air leakage control programs when applied to manufactured housing.

Average leakage rates for double-wide manufactured homes were found to be 8.40 air changes per hour (ACH) at 50 Pa pressure differential and are predicted by the LBL model to be 0.50 ACH under natural atmospheric conditions. These averages are based on 93 homes tested for air leakage with the blower-door or fan depressurization technique. The estimated coefficient of variation (COV) of the 50 Pa leakage rate was 0.23. Nineteen different manufacturer's homes were tested.

Twelve of the leakiest homes were “house doctored” for air leakage control. These homes averaged 11.75 ACH at 50 Pa before house doctoring, and 9.34 ACH after the retrofit work. The homes improved an average of 19.5%. The retrofit job took 3.5 h per home, with an average expenditure (including labor) of $200 (U.S.).
Measurement of Airtightness, Air Infiltration, and Indoor Air Quality in Ten Detached Houses in Sendai, Japan
Authors: Yoshino H , Nagatomo M , Yamamoto Y , Matsumoto H , Utsumi Y
Published: March 2009

Airtightness, indoor air quality, and air infiltration were measured in ten occupied, detached, two-story houses of wooden construction in the winter of 1986–87. The floor area of the houses was 120 to 160 m2. The houses had various types of heating systems. Seven of the houses had exhaust fan units for ventilating living rooms with air-to-air heat exchangers. Airtightness was measured by the fan pressurization method. Equivalent leakage area per floor area was 1.9 to 5.7 cm2/m2. The concentrations of CO2, NO2, and suspended particles were measured. CO2 and NO2 concentrations in the houses where unvented oil heaters were used were higher than in the other houses. The airtightness and indoor air quality measured during this period were compared with measured results obtained for 13 detached houses during the winter of 1984–5. Air infiltration was measured by the concentration decay method using SF6 as a tracer gas and was compared with the calculated value on the basis of equivalent leakage area.
Comparison of Different Methods for Airtightness and Air Change Rate Determination
Authors: Nantka MB
Published: March 2009

The problems of air change and airtightness in buildings are not sufficiently recognized in Poland, which results in the lack of precisely defined standards for building design. This paper discusses the correlation between airtightness and air change rates and presents measured and calculated air change rates with and without different sources of airflows in occupied houses. It discusses also the influence of pressure differences that were measured on the air change. The results of tests can be used to verify present standards in the field of airtightness and air change rates and give the basis for further testing of these processes.
Geotechnical Engineering for Ocean Waste Disposal: An Introduction
Authors: Lee HJ , Demars KR , Chaney RC
Published: March 2009

As members of multidisciplinary teams, geotechnical engineers apply quantitative knowledge about the behavior of earth materials toward designing systems for disposing of wastes in the oceans and monitoring waste disposal sites. In dredge material disposal, geotechnical engineers assist in selecting disposal equipment, predict stable characteristics of dredge mounds, design mound caps, and predict erodibility of the material. In canister disposal, geotechnical engineers assist in specifying canister configurations, predict penetration depths into the seafloor, and predict and monitor canister performance following emplacement. With sewage outfalls, geotechnical engineers design foundation and anchor elements, estimate scour potential around the outfalls, and determine the stability of deposits made up of discharged material. With landfills, geotechnical engineers evaluate the stability and erodibility of margins and estimate settlement and cracking of the landfill mass. Geotechnical engineers also consider the influence that pollutants have on the engineering behavior of marine sediment and the extent to which changes in behavior affect the performance of structures founded on the sediment. In each of these roles, careful application of geotechnical engineering principles can contribute toward more efficient and environmentally safe waste disposal operations.
Ocean Disposal of Particulate Wastes: Practices, Properties, and Processes
Authors: Bohlen WF
Published: March 2009

In the United States, the ocean serves as a receiving area for a variety of particulate wastes including dredged materials, sewage sludge, construction debris, and selected industrial residue. By mass, dredged materials dominate this waste stream. These sediments are removed using mechanical or hydraulic techniques and deposited at near-shore sites in water depths ranging from 20 to 100 m. Methods developed over the past ten years permit accurate placement of the dredged sediments at the disposal areas and the formation of coherent mounds of material. The degree of heterogeneity characterizing these mounds complicates sampling intended to detail short- and long-term environmental effects associated with material placement. This variability requires care in survey design and execution beyond that routinely used. In particular, surveys intended to complement quantitative evaluation of mass and material transport from the disposal mounds require an increased understanding of the geotechnical properties of the deposit over spatial scales ranging from millimetres to hundreds of metres and temporal scales from minutes to months. Measurements would place primary emphasis on the characteristics governing mound consolidation, the migration of interstitial waters and associated contaminants, and the factors affecting the physical stability of the deposit.

Acquisition of data adequate to detail these characteristics requires the development of a new generation of geotechnical sensors able to provide high resolution in situ measurements over extended periods of time and modification of survey procedures to encourage use of the sensors and incorporation of the resulting data within interdisciplinary studies. Such modification appears essential within efforts to develop the quantitative predictive methods required for the future management of oceanic waste disposal areas.
Effects of Ocean Disposal of Wastes on Properties of Marine Sediments
Authors: Pamukcu S , Tuncan A , Fang H-Y
Published: March 2009

Ocean disposal of waste products exerts significant influence on physical properties of marine sediments. Little has been done to assess some of the long-term implications of ocean dumping or spilling of chemical compounds on the depositional and physical properties of sediments. In this research the effects of three such materials on depositional characteristics, microstructure, and some index properties of laboratory prepared marine clays were studied.

The contaminants used were fly ash, activated sewage sludge, and fuel oil. The clay samples were kaolinite, illite, and a mixture called “marine clay,” which consisted of illite, kaolinite, chlorite, and Ca-montmorillonite. The test setup consisted of rectangular settling columns with four sampling ports along one side. Clay soil was premixed with a designated amount of contaminant and transformed into slurry using distilled water. The slurries were then transferred into the settling columns, mixed thoroughly with more distilled water, and allowed to settle in a water column approximately 0.5 m high. Time-settlement, time-concentration, and concentration-depth curves were generated for various mixtures of clay and contaminant. At the completion of the sedimentation, core specimens were taken for index property and pH measurements and samples for scanning electron microscope analysis.

The effect of chemicals on the sedimentation trend, index properties, and the microstructure was evaluated based on phenomena such as flocculation, agglomeration, dispersion, and electrostatic forces between particles. The hypotheses were supported by the sedimentation data and the observations of some microstructure features.
Geotechnical Properties and Processes of Deep Ocean Sediments as Related to Disposal of Toxic Wastes—An Overview
Authors: Silva AJ
Published: March 2009

The geologic stability, beneficial sediment properties, and remoteness of some deep ocean regimes provide alternatives to land-based options for disposal of toxic wastes. A brief discussion of the various geologic regimes, sediment types, and physiochemical properties is presented. An overview of various emplacement methods, natural seabed processes, geotechnical data acquisition and testing systems, and pertinent geotechnical considerations is also presented. For buried containerized hazardous substances, the sediment forms the geologic barrier between the waste and the biosphere. Geotechnical parameters such as shear strength, permeability, and the sediment-waste package interactions need to be considered. For solid high-level nuclear wastes, the effects of high-induced temperatures and radiation are important. In addition to downslope sediment processes, erosion, and faulting, it is important to assess the state of stresses within the sediment mass with particular concern for possible excess pore pressures. These and other related effects need to be incorporated in analytical waste migration models. Other aspects such as in situ testing and monitoring, laboratory physical modeling, and field experiments are discussed.
Subseabed Disposal Project Experiment: Piezometer Probe Measurement Technology
Authors: Bennett RH , Burns JT , Li H , Walter D , Valent PJ , Percival CM , Lipkin J
Published: March 2009

Deep-ocean piezometer probes were developed and extensively tested in the laboratory, hyperbaric chamber, and the Pacific Ocean Basin environment at ambient pressures of 1 to 545 atm. The probes are small diameter (8 mm) and utilize single sensor differential transducers to measure very slight changes in excess pore-water pressure caused by induced mechanical and thermal stresses in the surrounding sediment. Pore pressure increases can cause time-dependent changes in the physical and mechanical properties of the sediment and thus affect the integrity of the sediment's “isolation” capacity. A unique system design, which exposes the transducers' external and internal (line pressure) components to ambient hydrostatic pressures, permits the measurement of extremely small pressure changes with high sensitivity and precision. The pressure sensors exhibited excellent sensitivity and stability during deep-ocean simulated laboratory tests and in-situ systems performance tests.

Simulation tests were performed with piezometers inserted in reconstituted illitic marine clay for a period of 30 days. Two deep-ocean deployments were conducted in 5500-m water depths off the Pacific Ocean Basin in red clay deposits. Small differential excess pore pressures were generated in response to both mechanically and thermally generated forcing functions. Ambient pressure changes of less than 0.14 kPa (0.02 psi) were measured with precision at total hydrostatic pressure of 545 atm.

In addition to the measurement of ambient and dynamic pore pressure, the piezometer insertion and dissipation data can be used to effectively derive the sediment shear strength and permeability. These are critical parameters in the geotechnical assessment of geological formations considered for subseabed waste disposal sites.
In-Situ Pore-Pressure Measurements for a Detailed Geotechnical Assessment of Marine Sediments: State of the Art
Authors: Schultheiss PJ
Published: March 2009

The purpose of sampling and geotechnical testing of marine sediments is to ascertain and predict their in-situ properties. For many applications, limitations in accuracy imposed by the sampling and testing procedures may not be critical. However, for the safe disposal of some toxic wastes, there is a requirement for higher degrees of precision and reliability in the determination of some pertinent parameter. For waste products that are to be buried in marine sediments, and where the sediments themselves provide a geologic barrier to the release of waste products into the oceans, it is essential to determine accurately the flow regime of the natural pore waters. Furthermore, it may be desirable to monitor any changes that occur in the flow regime after emplacement. In-situ measurement of pore-water pressure and permeability is possibly the simplest, most reliable, and perhaps the most accurate technique for determining the rate of pore-water advection in marine sediments.

Experience of developing the techniques required to make these measurements and in interpreting the data has been gained in one area of the North Atlantic Ocean (Madeira abyssal plain) for the feasibility study into the disposal of high-level radioactive wastes and in other areas for different applications. Over 40 deployments have been made using pop-up pore-pressure instruments (PUPPIs) over the past few years to depths of up to 6 m below the seabed in water depths greater than 5000 m. PUPPIs have a resolution as low as 15 Pa, are calibrated in-situ at the end of each deployment, and can be deployed in water depths of up to 6000 m for periods of up to a year. Ambient differential pore pressures are measured at the end of each deployment after the insertion pressure has fully decayed (this may take several days depending on the sediment type). Permeability values are obtained using the hydrostatic tidal cycle. Natural pore-water advection rates are determined using these in-situ values assuming Darcian flow. Depending on the permeability, the resolution can be as low as 1 mm/year.

In addition to determining pore-water flow rates, the PUPPIs provide other pertinent geotechnical information. For example, the ambient pore-pressure measurements enable the effective stress profile to be calculated from sediment density core data; hence the consolidation state of the sediments can be determined. The maximum insertion pressure is indicative of the shear strength, and the horizontal coefficient of consolidation can be obtained from the pressure decay curve.

Apart from the geotechnical site assessment aspects of pore-pressure measurements, the PUPPIs can be used for short and long-term monitoring of changes that may occur either naturally or artificially as a direct result of the waste emplacement.
Subseabed Disposal Project Experiment: Pore Water Pressure Response to Piezometer and Canister Insertion
Authors: Valent PJ , Burns JT , Walter DJ , Li H , Bennett RH
Published: March 2009

Induced excess pore water pressures resulting from the insertion of piezometer probes of 8-mm (0.31-in.) diameter and a simulated waste canister of 102-mm (4.0-in.) diameter and the dissipation of these excess pressures were measured during deep-ocean component tests of the In Situ Heat Transfer Experiment (ISHTE). The sediment at the Pacific test site 1100 km north of Oahu, Hawaii, is an illitic clay.

Insertion-induced excess pore pressures were found to agree well with those predicted by models. Several aspects of the induced excess pressure dissipation were evaluated including the effects of probe and heater diameter, distal excess pore pressure response, and the synergistic excess pore pressure response from multiple insertions. The dissipation of induced excess pressures measured at each piezometer is predicted well by theory. The same analytical models predict the excess pore pressure history measured at the piezometers in response to the waste canister insertion. Present models were evaluated that predict insertion excess pressures and their dissipation rate at the probe surface and at distal, far field, points.
Pore Pressure Response to Probe Insertion and Thermal Gradient: ISIMU-II
Authors: Riggins M , Valent PJ
Published: March 2009

The ISIMU-II experiment was designed to assess the pore pressure response during piezometer and heater probe insertion and the subsequent excess pore pressure behavior as a result of a thermal field within the sediment. The dissipation of the excess pore pressures generated during probe insertion was predicted using an exponentially decreasing function which incorporates a smear factor to account for sediment remolding next to the piezometer wall. An analytical model to describe concurrently the rise in excess pore pressures as a result of sediment heating and the radial dissipation of the resulting pore pressures into the surrounding sediment is described and applied to the experimental data.
Thermal Aspects of the Subseabed Disposal of High-Level Radioactive Waste
Authors: Hickox CE , Percival CM , Olson LO
Published: March 2009

The results of studies that address thermal aspects of the subseabed disposal of high-level radioactive waste are summarized. A mathematical model is proposed for the description of thermal transport from a discrete source of heat in a fluid-saturated seabed sediment. For model parameters typical of those associated with subseabed disposal, it is demonstrated that thermally induced convection is relatively weak, and consequently, the thermal field is established primarily by conduction. However, the weak convective motion is of importance to the transport of radionuclides that may inadvertently be released into the sediment. Numerical predictions of thermal effects are presented for a reference emplacement geometry. The validity of the modeling approach was verified experimentally in a laboratory scale simulation. An initial deployment of a large-scale thermal experiment during an oceanographic expedition provided in-situ measurements of sediment thermal conductivity, which is an important parameter in the modeling. Based on the collective results of our studies, a clearer understanding of the thermal aspects of subseabed waste disposal has emerged.
A Geotechnical Investigation of a Deep Ocean Site
Authors: Freeman TJ , Schüttenhelm RTE
Published: March 2009

A site investigation in deep water often relies solely on laboratory tests to evaluate the geotechnical properties of the sediments. This imposes two fundamental limitations on the investigation: (1) the maximum depth to which the properties can be profiled and (2) the uncertainty of sample disturbance and de-pressurization effects on the measured data. This paper uses results from investigations performed in a water depth of 5.4 km at an abyssal plain site, Great Meteor East (GME), to illustrate how ambiguities can arise in laboratory measurements of strength, and discusses how a simple in-situ test, the expendable “penetrator,” can be used to corroborate the laboratory data.

Despite the layered nature of the sediments at GME, both laboratory and penetrator data indicate the overall trend to be a linear increase of strength with depth. However, triaxial tests where the sample was consolidated back to the estimated in-situ stress σ'ν indicate a strength gradient 70% greater than that determined from quick undrained (UU) tests; normalized data from tests performed at higher consolidation pressures show better agreement with the UU data. Odometer test results show little evidence of over-consolidation or cementation in the sediments, suggesting sample disturbance to be the most likely explanation of the discrepant triaxial strengths.

The results of some 14 penetrator tests allow the sediment strength profile to be extrapolated to a depth of 58 m. Tests performed up to 60 km apart yielded similar resistance profiles, and the inferred strength gradient agrees broadly with that based on the UU data. It is concluded that the sediments at GME are normally consolidated, unindurated, and not fundamentally different to other soft cohesive deposits found on land or in shallow water.
Using RS-170 Video Images for Quantitative Image Analysis
Authors: Russ JC
Published: March 2009

With the advent of image analysis systems based on personal computers with standard video interface cards (popularly known as frame grabbers), and the availability of inexpensive video cameras that can be routinely connected to light and electron microscopes (as well as others), consideration must be given to dealing with the particular characteristics and defects of the standard RS-170 signals for quantitative image analysis purposes. Some of these problems should be taken into consideration in selecting hardware, while others are amenable to subsequent correction by appropriate image processing. This paper outlines the major problems and limitations.
Applications of Pc-Based Digital Imaging for Storing Microscopy Images on Optical Disks
Authors: Schleitweiler PM , Ransick MH
Published: March 2009

Advances in video technology and digital imaging have resulted in the ability to produce an image in a high quality digital format. Images that are created and viewed in a digital format can not only be quantitatively measured but can also be stored to disk for later examination. Write-once read many (WORM) optical disks are excellent media for archiving digital images. Several applications are discussed. All of the applications use a PC-based system for storing and recalling images on optical disks. These applications include metallographs, specialized microscopes, and scanning electron microscopes.
Image Processing of X-Ray Radiographs for NDE
Authors: Basart JP
Published: March 2009

Available image processing techniques can meet many of the needs for processing radiographs of materials. Low-contrast noisy images of materials can be processed by a sequence of operations which enhance signals that are otherwise barely discernible by eye. Trends in the background intensity can be removed, noise can be filtered, and the signal can be enhanced. Automatic feature extraction can then be applied. Computer requirements vary considerably with the sophistication of the process. More sophisticated techniques, which often are superior in performance, may require more computer time and memory.
Scanning Acoustic Microscopy for Grain Structure Studies
Authors: Adler L , Nagy PB
Published: March 2009

The main focus of this presentation is to describe the use of a new ultrasonic device, the Scanning Acoustic Microscope (SAM), for grain structural studies. The acoustic microscope, which uses ultrasonic waves which cover a frequency range from 20 MHz to 2 GHz, is a novel ultrasonic imaging technique and produces images comparable to the optical microscope. The significance of the acoustic microscope does not lie in its resolution alone. There are several advantages to using acoustic waves for producing images, e.g. ultrasonic waves penetrate materials that are opaque to optical waves, the distinctive origin of the contrast in the mechanical properties allows one to obtain quantitative information about grain structures, boundary imperfections, etc. Several examples of SAM applications will be presented. Advantages and disadvantages of the contrast mechanism inherent with the scanning acoustic microscope will be discussed.
Development of a Computer Vision Methodology for the Analysis of Surface Deformations in Magnified Images
Authors: Sutton MA , Chae TL , Turner JL , Bruck HA
Published: March 2009

An optical system, similar in concept to a telecentric lens system, has been developed to decouple in-plane surface deformations from out-of-plane motions for magnified images of a specimen under loading. The key parameters of the optical system were identified and rigorous testing of a prototype system was completed. The range in system parameters that can be used to eliminate the effect of out-of-plane motion (ΔSo) when ΔSo is less than a pre-specified magnitude (β) was experimentally quantified. Using the test results, an optical system was designed, built and successfully tested.

Images of two test specimens at various loads are obtained at magnifications ranging from 2X to 6X, after testing was performed to ensure that the specimens do not move out-of-plane more than β during the loading history. First, images of a specimen undergoing uniaxial loading are acquired. Next, images of a single edge cracked specimen under load are obtained. For both specimens, the in-plane surface displacement field is determined by using digital image correlation of image subsets. Displacement gradients on the surface are computed after smoothing the displacement data. It is shown that the optical system developed in this work can be combined with a digital correlation method to accurately quantify in-plane surface deformations independent of the out-of-plane motion for magnifications up to 6X. Similar considerations will allow one to use the methodology with larger or smaller magnification factors.
Improved Method for E1122 Image Analysis Nonmetallic Inclusion Ratings
Authors: Forget C
Published: March 2009

The assessment of nonmetallic inclusions in steels according to the JK classification scheme of ASTM E45 using the E1122 image analysis method has presented several problems for instrument manufacturers. The major problems encountered are: discrimination of inclusion types, speed of analysis; and relating the measurement data to other methods, such as JIS G0555 and DIN 55602, as well as the new E1245 stereological method. A new technique has been developed for such ratings where the characteristics of every inclusion (type, length, width and position) are recorded in computer memory. Sulfides and oxides are first distinguished with the results stored in two different files as each field is scanned. Measurements and calculations are only performed at the end of the multiple field run over the prescribed specimen area. Advantages of this approach are numerous. Because every inclusion's position is mapped in a giant matrix, algorithms can be written and applied to separate oxide types according to their spatial distribution and shape. For instance, B-type (aluminate) stringers can be easily differentiated from C-type (silicate) stringers because B-types will generally begin and end with individual particles. Therefore, even if an agglomerated B-type stringer has the appearance of a C-type stringer, which would confuse most image analyzers (due to the continuity of touching particles within the stringer), this additional condition to the algorithm would properly classify such a stringer. Working with the stored inclusion information also allows for complete reconstruction of B- or C-type stringers that are separated by less than the 127 μm spacing (per ASTM E45 and E1122) even if the total stringer length exceeds the standard ASTM field size. Thus, “oversize” stringers that extend beyond the frame borders will be correctly sized. Another advantage of the new approach is that, regardless of the magnification used to detect the inclusions and store the data, the rating is always performed using the required 0.5 mm2 field area. Thus, this method permits used of a higher magnification which may be required to properly detect and classify inclusions in steels with low inclusion contents, such as bearing steels. Finally, because all detected inclusions are re-mapped on the screen at the end of the analysis, the inclusions can be subjected to other measurements, not required by E45 or E1122, such as those required by other standards. The end of analysis map can also be subjected to additional processing for evaluation of clustering or banding tendencies.
Homogeneity Test of Continuously Cast Copper Alloy Strip Structure
Authors: Horálek V , Klofáč J
Published: March 2009

Continuously cast copper alloy strips nave their own typical structure formed by columnar crystals that grow from the heat-removal walls of the mould towards each other until they impinge and create the so called “dividing area”. A new homogeneity test of such a structure is presented. It is based on the intraclass correlation coefficient.
A Carbide Rating System for P/M T-15 Tool Steel
Authors: Green DR
Published: March 2009

High speed tool steels contain substantial amounts of carbon and carbide formers. The resulting carbides provide high hot hardness, but they also make the high speed steels difficult to form by hot working or by grinding. The benefits and difficulties of the high speed steels are both extreme in T-15, since it is one of the most highly alloyed of the high speed steels. T-15 is therefore a prime candidate for powder metallurgy techniques, because the fine, uniformly distributed carbides provided by the process greatly improve workability and grindability with no sacrifice in hot hardness. One commercial method for consolidating powder is the Consolidation by Atmospheric Pressure (CAP) process. The CAP process requires high sintering temperatures which produce a variety of carbide sizes in the finished product. A useful rating of carbide sizes was obtained from semi-automatic image analysis of T-15. Carbide ratings can be roughly correlated to grindability. Use of this rating system facilitated the determination and adjustment of necessary processing parameters to consistently produce a superior material.
Quantification of Iron Ore Sinter Structure by Optical Image Analysis
Authors: Jenkins BM , Lovel RR , Thurlby JA
Published: March 2009

Iron ore sinter has a multiphase heterogeneous structure containing numerous defects. This structure determines certain properties which influence the performance of sinter in blast furnace solid and softening zones. The relationships between these properties and the sinter production parameters are not understood fully, hence, the first step taken towards improving sinter performance involves characterizing the sinter structure accurately. For this reason, a new technique using automated optical image analysis has been developed to identify sinter phases and categorize sinter structure types. Structure descriptors include measures of phase abundance, calcium ferrite morphology and hematite morphology. This paper describes the analyser, results and applications. Specialized sampling and specimen preparation techniques are also described.
Application of Fractographic Measurements to Modelling of Hydrogen Stress Cracking
Authors: Jenkins BM , Cherry BW
Published: March 2009

Macroscopic measurements of fracture surfaces were found to be vital for the development of a model of hydrogen stress cracking (HSC). This type of cracking can occur in buried natural gas pipelines exposed to aggressive external environments in which cathodic protection reactions can produce damaging hydrogen. The model, which is based on a 3-stage crack growth mechanism, allows crack initiation conditions and times-to-failure to be predicted. It was developed with results of laboratory tests on X60 steel and 3-stage crack growth data obtained from the examination of resultant fracture surfaces. These examinations involved analysis of scanning electron and optical microscope images which enabled the maximum stress intensity factors to be calculated for each stage of crack growth. This paper describes the fractography methods and possible applications for a HSC model.
Treatment of Reversed Sigmoidal Curves for Fractal Analysis
Authors: Underwood EE
Published: March 2009

A modified fractal equation is proposed for the irregular profiles obtained from metal fracture surfaces. Experimental results do not conform to the self-similitude postulate of Mandelbrot. Instead a reversed sigmoidal curve is obtained in the fractal plot. A new procedure is developed whereby a linear fractal plot and a constant fractal dimension are obtained. A parallel fractal equation is provided for rough, irregular surfaces. The details of the new analyses are presented in depth, emphasizing the assumptions and advantages underlying the adopted procedure.
Power Plant Water Chemistry Research at EPRI in the 1990's
Authors: Passell TO , Dooley RB
Published: March 2009

The objective of plant water chemistry research at EPRI will continue to be the reduction of component damage by corrosive attack by the water and steam coolants. New chemistries will be evolutionary from the present practices by improving our surveillance of impurities, finding new additives to control pH and oxidizing power, and developing improved water treatment methods. Surveillance of the state of the coolant on-line as contrasted with existing grab sampling at infrequent intervals will require improved probes for such purposes. It is likely that different chemistries will be needed for different piping metallurgies, though the current common ones are not seriously different except for those with and without copper alloys. Improved guidelines for chemistry practices and limits are expected to be needed, but a number of those now in place should require little change.
Development of an On-Line Expert System: Cycle Chemistry and Demineralizer Operation Advisor
Authors: Sopocy DM , Montanus JA , Jonas O , Rice JK , Agogino A , Dooley B , Divakaruni SM
Published: March 2009

An on-line expert system for fossil fuel power plants, the Cycle Chemistry and Demineralizer Operation Advisor (CYCLEXPRTtm/DEMINXPRTtm), is being developed as an Electric Power Research Institute (EPRI) project. This expert system will assist plant operating personnel in the identification of trends and interpretation of plant chemistry data from both on-line analyzers and laboratory analyses in the context of plant physical conditions and operation. CYCLEXPRT/DEMINXPRT will operate on a microcomputer and will interface with existing plant instrumentation, data acquisition, and/or monitoring systems, which presents a variety of design challenges. Several significant features of this expert system are discussed in this paper, including the design of a modular expert system architecture, design of a consistent user interface, development of a standard specification for information transfer, and application of sensor validation techniques.

A critical element of this expert system is the validation of sensor information. The importance of QA/QC measures in the interpretation of plant chemistry data is being illustrated dramatically in EPRI Research Project 2712-3, “Monitoring Cycle Water Chemistry at Fossil Plants.” The techniques developed and refined in this research project are being applied in CYCLEXPRT/DEMINXPRT.
Monitoring Water: The Legal Perspective
Authors: Koorse SJ
Published: March 2009

Monitoring data influence a wide variety of important regulatory decisions. Most notably, regulatory agencies rely on monitoring data to develop and determine compliance with the environmental standards they have been mandated to enforce. Decisions made in reliance on such data often bear important consequences, including capital investment for treatment equipment, monetary penalties for noncompliance, and even imprisonment. This paper traces the source and evolution of the extensive monitoring requirements that the regulated community will face in the 1990s, and examines the legal concerns associated with the integrity of the resulting data.
Special Studies at the Los Angeles Department of Water and Power to Address New EPA Regulations
Authors: Ng HH , White BN , Busatto MJF , Shovlin MG , Heumann DW
Published: March 2009

Special studies have been undertaken at the Los Angeles Department of Water and Power in response to new EPA drinking water regulations. A remote electro-optical sensor (REOS) system permits early detection of algal blooms by continuously monitoring photosynthetic rates and other parameters in a distribution reservoir. A fish monitoring system utilizes abnormal reactions of fish as an early warning system of accidental or intentional contamination. No significant levels of byproducts were found in the use of Advanced Oxidation Processes (AOP), ozone and hydrogen peroxide, to remove trichloroethylene and tetrachloroethylene from contaminated groundwater supplies. Finally, corrosion studies show that the effectiveness of some treatment chemicals is highly dependent upon the dosage of the chemical used.
Futuristic Approaches to Environmental Analysis and Monitoring for Pollution Prevention and Control
Authors: Martin-Goldberg M , Raymer JH , Voyksner RD , Pellizzari ED
Published: March 2009

Several selected analytical technologies are examined which hold potential promise of providing new capabilities for environmental analysis and monitoring in pollution prevention and control. Among these are supercritical fluids, ion trap mass spectrometry (MS), liquid Chromatographic interfaces for MS, laser enhanced spectroscopy, electrochemical methods, and a few hybrid techniques. Brief descriptions of the principle of the technique and example applications are discussed.
Present Practice and Future Prospects for Field Gas Chromatography
Authors: Spittler TM
Published: March 2009

The past five years have seen a significant emphasis on the use of chemical instrumentation to perform rapid assessment and accurate analysis in the field. This trend began with gas chromatography and has grown rapidly with the introduction of new instruments with remarkable sensitivity and versatility. Coupled with a renewed interest in simple techniques like headspace analysis for volatiles and rapid extraction procedures for nonvolatiles, field gas chromatography is proving to be invaluable in field investigations.

There are several features which make an instrument suitable for field use. Among the key factors are ruggedness and simplicity of design, reliability and versatility. A few of the most versatile and sensitive instruments will be discussed here and some of the most practical applications will be discussed. Finally, reference will be made to one of the most important problems facing the environmental community today, protection of drinking water supplies. Because of their unique sensitivity, field chromatographs show great promise in enabling an analyst to cost-effectively and rapidly assess the condition of potable groundwater before contamination has progressed to the point of rendering it unfit for consumption.
Evaluation of the Hanby Field Test Kit for Detection of Aromatics in Water
Authors: Rhodes IAL , Claybon RW , Wisniewski HL , Calkin AL , Leon JA , Hewitt RW
Published: March 2009

Ground water sampling and analysis are large efforts in terms of manpower and cost. The primary water contaminants from petroleum sources are the aromatic constituents due to their solubility in water. A commercially available field test kit (Hanby Analytical Laboratories, Inc.) was evaluated for application of on-site detection of low level contamination of water by aromatics. The results obtained using this kit are compared with those obtained in the laboratory using gas chromatographic methods.
Relation Between the National Handbook of Recommended Methods for Water Data Acquisition and ASTM Standards
Authors: Glysson GD , Skinner JV
Published: March 2009

In the late 1950's, intense demands for water and growing concerns about declines in the quality of water generated the need for more water-resources data. About thirty Federal agencies, hundreds of State, county and local agencies, and many private organizations had been collecting water data. However, because of differences in procedures and equipment, many of the data bases were incompatible. In 1964, as a step toward establishing more uniformity, the Bureau of the Budget (now the Office of Management and Budget, OMB) issued “Circular A-67” which presented guidelines for collecting water data and also served as a catalyst for creating the Office of Water Data Coordination (OWDC) within the U.S. Geological Survey. As one of its early actions, OWDC gathered representatives from private enterprises, educational institutions, technical societies and government agencies to form two advisory committees. Work groups from these committees then wrote a manual entitled, “The National Handbook of Recommended Methods for Water Data Acquisition.” Nationally accepted methods were cited for measuring, sampling, and analyzing water and for processing hydrologic data. The methods included the collection of data on water in aquifers, rivers, lakes, reservoirs, estuaries, and the atmosphere. The long-range plan was to periodically update the manual by adding new water-data methods as they were developed.

This paper discusses past, present, and future aspects of the relation between methods in the National Handbook and standards published by ASTM (American Society for Testing and Materials) Committee D-19 on Water's Subcommittee D-19.07 on Sediment, Geomorphology, and Open Channel Flow. The discussion also covers historical aspects of standards-development work jointly conducted by OWDC and ASTM.
The Application of Ion Exchange to Meet the Many Challenges to Produce an Improved Grade of Pure Water in the 90'S
Authors: McGarvey FX
Published: March 2009

The term “pure water” has a constantly changing meaning. Over the years ion exchange has played an important role in these changes. The first large scale production of 18- megohm-cm water became possible through the use of the mixed bed ion exchange process. In a sense, this was the start of pure and ultrapure waters.

Ion exchange processes will continue to play an important role in the evolution of new water grades. Ion chromatography has shown the way to measure concentrations of dissolved substances in the part per trillion (ppt) range, and new plant specifications are being measured at the ppt level, and this will result in future environmental standards.

In the future ion exchange technology will continue to lead the way, resulting in materials and processes which will accomplish the new requirements. Ion exchange resins, having low leachables, are being developed so that total organic carbon (TOC) levels can be achieved in pure water. Selective ion exchange materials with chelating functionality are appearing. These, coupled with stable conventional ion exchange resin, will help to solve waste problems resulting from toxic and radioactive substances.
Usage of Chemicals in Offshore Oil and Gas Production
Authors: Hudgins CM
Published: March 2009

This paper reviews the chemicals used to help control many operating problems encountered in U.S. offshore oil and gas production. The discussions covers the production treating chemicals, gas processing chemicals, and stimulation and workover chemicals. A brief discussion of each chemical group presents its purpose, solubility properties, primary generic chemical types, and typical use concentrations. Acute aquatic toxicity and solubility information provided by the chemical suppliers is presented for the production treating chemicals, including biocides, scale and corrosion inhibitors, emulsion breakers, etc. Aquatic toxicity data for the gas processing chemicals (methanol, glycols) was primarily obtained from the literature.

A portion of these chemicals will dissolve in the produced water, with the remainder going with the oil. Most of the water produced with oil and gas in offshore operations in the U.S. is treated to remove dispersed oil and grease, then discharged to the sea. The discussion on environmental aspects summarizes information on the aquatic toxicity, solubility, and typical treatment and discharge concentrations for chemicals used for each purpose. Actual environmental impact must include site specific factors, such as water depth, current, temperature, etc., which are outside the scope of this paper.
Monitoring Water Quality in Thermal Power Systems
Authors: Rice JK
Published: March 2009

There is a definite need for standardized practices in determining measurements of continous instruments, in both fossil and nuclear plants. Due to the national guidelines being implemented, and the increase of continuous instruments now available, statistically-based performance information analogous to that of grab samples is urgently needed. Interplant (inter-instrument) precision and bias is also essential for substantial comparisons between a plant's measurements and the standard recommended by the guideline. Above all, there is a critical need for a dedication to achieving measurements of known and controlled quality of cycle chemistry parameters.
New Technology for Protozoology: Immunofluorescence and Gene Probe Technology for Detection of Parasites
Authors: Rose JB
Published: March 2009

The development of methods to detect Giardia cysts and Cryptosporidium oocysts in water began concurrently with the investigation of the first documented outbreaks of waterborne giardiasis in 1965 and Cryptosporidiosis in 1985. The use of immunofluorescence techniques has greatly enhanced the ability to detect cysts and oocysts in environmental waters. Although immunofluorescence is being rapidly adapted for protozoan analysis of water there are a number of major limitations. These include background fluorescence, particularly due to algae, the time required to examine each sample microscopically and the inability to determine viability of the cyst or oocyst. Recently gene probe technology has emerged as a potential solution to some of these concerns. A cDNA probe to ribosomal RNA for Giardia has been used to rapidly screen for cysts in water samples. The sensitivity has approached the detection of 1 cyst in five ml of concentrate.
Emerging Techniques in Pollution Control
Authors: Levin MA
Published: March 2009

Observing the short history of molecular biology it is clear that the emergence of new techniques has transformed how one approaches and thinks about specific problems, both fundamental and applied, and that the infrastructure of the biotechnology industry provides impetus for new techniques to rapidly reach the marketplace and become readily available. The use of the ELISA technique and the polymerase chain reaction are examples of techniques that developed from laboratory study to a full fledged commercialized product within three years.

This paper surveys developments in the industry that may impact assay techniques and monitoring methods used in environmental situations and water analysis.