bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved Test Procedure for Inorganic Particles in Fuel Oil
Authors: Vardi J , Siegmund CW
Published: December 2008

A new method for determining the concentration of inorganic particles in marine residual fuel oils has been developed. This method offers direct gravimetric measurement of abrasive particles present in the fuel, and, as such, the method is independent of the chemical composition of inorganic particles, including those of cracking catalysis. The method is a more meaningful tool in assessing wear potential in a diesel engine and its fuel handling system than the older aluminum analysis method.

In the new method, a centrifuge is employed to transfer the particles from the fuel to a nonfuel phase. During the transfer, the particles pass through an aqueous phase containing oxalic acid in which water soluble salts and rust particles are removed. The particles then are collected in a nonaqueous phase, heavier than water. Subsequently, the particles are transferred to a crucible where they are dried and ashed to remove carbonaceous material. The particles then are weighed to determine the amount of inorganic particles present.

An ASTM round robin was conducted to determine the precision of the new centrifuge method. Data obtained by seven laboratories on eight fuel samples were statistically analyzed to formulate a precision statement for the new method. At 150 ppm m/m inorganic particles content, repeatability is 24 ppm m/m, and reproducibility is 68 ppm m/m. This precision appears reasonable and compares well with the precision of other related ASTM methods such as Water and Sediment in Crude Oils and Fuel Oils by Centrifuge [D 1796-68 (1977)] and Particulate Contaminant in Aviation Turbine Fuels [D 2276-73 (1978)].
Controlling Compatibility of Residual Fuel Oils
Authors: Griffith MG , Siegmund CW
Published: December 2008

Residual fuel oils which contain thermally cracked residual components may become incompatible, especially when blended with distillate to make intermediate fuels. When this occurs, asphaltenes precipitate from the fuel and interfere with the proper operation of shipboard centrifuge and fuel handling systems. A study to determine the cause of incompatibility and how to avoid it revealed that asphaltene solubility in fuel oil could be described by general solubility relationships. From these relationships, factors were derived to characterize the relative solubility of the asphaltenes and the solvency of the nonasphaltene portions of the fuel. These factors can be determined by simple analytical procedures.

A semiempirical relationship has been developed between the factor for asphaltene solubility and that for nonasphaltene solvency that predicts whether any asphaltenes will precipitate as sediment, that is, whether a fuel will be compatible. Procedures also have been developed for blending these factors when two components are mixed. Thus, it is possible to predict whether a given blend of two fuel oils or of fuel oil and flux will be compatible based on the properties of the components and their ratio in the blend. This relationship has been used to ensure that fuel oil blends will not contain sediment, that these blends can be used to make sediment-free intermediate fuels, and that the fuels will not be incompatible with other fuels when they are commingled in storage.
Scaling Correlations of Flashover Experiments
Authors: Kanury AM
Published: December 2008

Preliminary scaling rules are synthesized to relate full-scale compartment fires with small-scale test fires; these rules then are applied to certain full- and quarter-scale model test data of the National Bureau of Standards, focusing on the issue of flashover as influenced by lintel height, initial burning item, and wall linings. The correlation attempt is only partially successful. Data of the tests in which flashover was deemed to have occurred within a finite time correlate in a reasonable fashion. However, test data in which flashover time is noted to be infinity do not obey the scaling hypothesis. The issue of whether or not flashover would occur under a set of prescribed conditions thus seems to be unsettled by this work. The similitude analysis presented here, however, appears to yield the rudiments of a framework within which a synthesis can be made of the experimental observations on the complex phenomenon of room-fire flashover.
Prediction of Upholstered Chair Heat Release Rates from Bench-Scale Measurements
Authors: Babrauskas V , Krasny JF
Published: December 2008

In an earlier study a full-scale furniture calorimeter was used to determine the heat release rates for upholstered chairs containing various construction materials. Samples of these same material combinations have now been tested in a bench-scale apparatus, the cone calorimeter. A correlation was established between bench-scale and full-scale data. Thus, it appears that prediction of flashover potential of a single upholstered item may be possible by using bench-scale results.
Control Safety Considerations for HVAC Smoke Management Techniques
Authors: Milewski L
Published: December 2008

The modern heating, ventilating, and air conditioning (HVAC) system has been designed efficiently for its specific function. Use of this system for smoke control stresses many of its components.

Central fans can be overloaded, outlet air terminals can hamper or obstruct efforts, and dangerous static pressures can be generated that can hold fire doors open or closed or blow out windows. Efforts to provide fresh air can cause freezing damage to critical central equipment.

This paper discusses the various problems without providing a specific course of action. The Summary is a checklist of considerations if the HVAC system is to be part of a smoke control system. The primary suggestion is that smoke control be part of the initial specifications to assure that certain safety factors are considered.

Specifications should consider: 1. Control fan load limiting controls. 2. Compressed air fuses to keep the system operating despite damaged lines. 3. Compressed air interlocks to abort smoke management efforts if all control fails. 4. A means to protect equipment from freeze damage in northern climates. 5. Positive position terminals, either fail open or fail closed depending on the concept selected. 6. Interlocks on self-contained terminals to drive open or closed. 7. Programmed control of terminals as opposed to “kill the main” approaches. 8. Matching pressurization areas to fan capacity. 9. Pressure testing of the system after completion, including fan load and forces on doors. 10. Possible use of dedicated fans on each floor (not part of the HVAC system) for pressurization and for exhaust.
The Human Aspects of Fires in Buildings—A Review of Research in the United Kingdom
Authors: Ramachandran G
Published: December 2008

Studies carried out by the Fire Research Station in the United Kingdom on human aspects of fires fall mainly into seven areas (indicated in the following paragraphs by italics).

Research on perception and acceptability of risk indicated that people have a fairly accurate perception of the relative severity of various hazards. They believe that most accidents are due to the faults of the victims, and they are unwilling to spend much money to reduce such hazards. On the other hand, many people do feel strongly about hazards which are outside their control. The assessment of monetary value placed on human life and the use of this value in fire protection economics are discussed with examples.

Research on human behavior in fires casts doubts on current behavioral assumptions and data which have implications for safe building evacuation. Information initially available to people regarding the possible existence of a fire and its size and location is often ambiguous and inadequate for taking appropriate action. People involved in fires rarely panic or behave entirely irrationally. This conclusion led to the current investigation on the nature and effective methods of presentation of appropriate information through microprocessor-controlled informative fire warning systems to ensure clear comprehension of alarm warnings and rapid and safe evacuation of the building. Research also has been carried out on methods of calculating the evacuation times of leaving buildings.

By investigating actual (serious) fires in domestic and group-residential buildings, Fire Research Station is studying people's environmental background, their actions prior to ignition, their involvement in ignition, their contribution to the fire's growth and spread, and their response to discovering the fire, fighting it, and escaping from it. A number of social and housing conditions affect the incidence of fires in dwellings: proportion of children in care, tenure (owner or tenant), and lack of amenities. Severe weather conditions during winter inflict greater loss of life among elderly females, especially those living alone.
Evaluation of Stripping Problems in Oregon
Authors: Takallou H , Hicks RG , Wilson JE
Published: December 2008

Before 1974, stripping in hot mix asphalt concrete was considered to be a relatively minor problem in Oregon. During the three-year period from 1974 to 1977, several problems were noted during and after construction of asphalt pavements. One of the major problems associated with asphalt pavements was its initial reduced resistance to raveling. This problem developed after the oil embargo in 1974. In recent years, problems with stripping and associated pavement deterioration have continued such that in 1983 amine-type antistrip agents were incorporated into over 20% of all projects constructed.

The state of Oregon's specification (before 1984) attempts to ensure good performance of asphalt mixtures against stripping. For example, the determining factor as to the suitability of a particular mixture against stripping has been American Association of State Highway and Transportation Officials (AASHTO) T-165, index of retained strength (IRS). If the IRS of a mix at the design asphalt content is below 70% with the asphalt and aggregate to be used in the paving, an antistrip agent is used to satisfy this requirement. A 70% minimum resilient modulus ratio after vacuum saturation and freeze-thaw conditioning is used to determine the suitability of a particular mixture against stripping.

This paper addresses the current problem of stripping in the state of Oregon. Field studies conducted in 1983 were designed to identify causes of recent raveling problems in central Oregon (high elevation and severe climate areas). The investigations involved field condition surveys and coring, reviewing project construction records, mix designs, and asphalt concrete test data (construction cores and compaction control test results), and numerous tests on cores obtained from the roadway.

From the information collected, several factors were found to be contributing to the observed raveling and recommendations made for correcting these deficiencies have been included in the 1984 specifications.
The Use of Water Immersion Tests in the Evaluation of the Effects of Water on Cold-Recycled Asphalt Mixtures
Authors: Tia M , Wood LE
Published: December 2008

The effectiveness of various immersion-mechanical tests in measuring the water susceptibility of cold-recycled asphalt mixtures was investigated. The immersion-mechanical tests involved subjecting compacted recycled asphalt mixtures to a 24-h water immersion process followed by mechanical tests. The various mechanical tests used in this study included the resilient modulus, Marshall stability, Hveem stabilometer S value, Hveem stabilometer R value, and Hveem cohesiometer tests. The test values obtained from the wet specimens were compared to the values obtained from the dry specimens, and the effectiveness of the test methods was evaluated.

The results of the study indicated that the resilient modulus, Marshall stability, Hveem S value, and Hveem cohesiometer tests were effective in measuring the changes in stiffness, stability, and cohesion of cold-recycled mixtures caused by water damage. The Hveem R-value test was not very sensitive in measuring the effect of water when a recycled mixture was relatively stable. However, the R-value test became very sensitive when a mixture was unstable, and thus it was very effective in determining the recycled mixtures that were highly water-susceptible. The water resistance of cold-recycled mixtures generally increased with curing time and compactive effort. The effects of the type of added virgin binder and the type of added virgin aggregate to the water resistance of cold-recycled asphalt mixtures were significant. The proper consideration of curing time, compactive effort, added virgin binder, and added virgin aggregate will help to attenuate the effect of water on cold recycled asphalt mixtures.
Crack Separation Energy Rates for Inclined Cracks in a Biaxial Stress Field of an Elastic-Plastic Material
Authors: Kfouri AP , Miller KJ
Published: December 2008

Elastic-plastic finite element analyses are described for plates containing inclined cracks and subjected to biaxial loads given by λ equal to σQ/σP where σP is the main principal tensile stress and σQ is the second in-plane principal stress. Three loading modes, λ equal to −0.5, −1, and 0.5 are considered and are compared also with previous results for the uniaxial mode λ = 0 and the equibiaxial mode λ = 1. Qualitative and quantitative information is presented on crack-tip opening displacements, on plastic strains and on maximum stresses near the crack tip. The analyses include calculations of J contour integrals and of crack separation energy rates GΔ for coplanar crack extension. Estimates of GΔ for nonplanar crack growth applicable to cases where the plastic flow is small are also made and used in conjunction with a fracture criterion based on maximum GΔ. The implications of these analyses for fatigue crack growth, in terms of plastic zone sizes, shapes, and orientation, are discussed with regard to (a) modes of cracking, (b) stress biaxiality, and (c) crack inclinations, and are then related to experimental results under mixed mode (I and II) loading conditions in stainless steel.
Biaxial/Torsional Fatigue of Turbine-Generator Rotor Steels
Authors: Williams RA , Placek RJ , Klufas O , Adams SL , Gonyea DC
Published: December 2008

This paper presents the results of a study to develop a methodology for predicting torsional fatigue damage to a turbine-generator rotor subjected to transient electrical disturbances. This methodology used torsional properties obtained from constant amplitude tests on 25.4-mm-diameter specimens. The predictions were verified with constant amplitude and variable amplitude tests of specimens up to 127 mm in diameter.

The constant amplitude tests gave the following results:

1. Fatigue reduction factors for notched specimens were readily estimated from Neuber's rule.

2. Size effect could be approximated by lowering the strain-life curve by a function of the diameter ratio.

3. Uniaxial and torsional fatigue properties and cyclic stress-strain properties correlated on octahedral shear stress and strain using a deformation theory of plasticity.

Variable amplitude loading tests indicated that range pair cycle counting technique and linear damage rule predicted fatigue lives within a factor of two of actual test results. In addition, the predicted lives were generally conservative.
A Criterion for Fully Reversed Out-of-Phase Torsion and Bending
Authors: Lee S-B
Published: December 2008

This paper presents a new design criterion for fully reversed out-of-phase torsion and bending fatigue. This criterion, similar in spirit to that proposed by Kanazawa, Miller, and Brown, is derived as an extension of Gough's ellipse quadrant.

Theories and tests under “in-phase” torsion and bending fatigue are briefly reviewed. A few commonly used fatigue theories for “out-of-phase” multiaxial loadings are critically evaluated. Tests were performed with cantilever type SM45C structural steel specimens under fully reversed out-of-phase combined torsion and bending loadings in the intermediate cycle regime. Available fatigue data under high-cycle out-of-phase torsion and bending are plotted on constant life diagrams calculated according to the new criterion.

For multiaxial out-of-phase loadings, generated by fully reversed combined torsion and bending, both the present test results and data in the literature are in good agreement with the new fatigue criterion. The criterion predicts fatigue life under fully reversed bending with out-of-phase or in-phase torsion at intermediate to high cycles.
Cyanophage Assay as a New Concept in the Study of Environmental Toxicity
Authors: Kraus MP
Published: December 2008

For over 15 years, a virus-based assay using a cyanophage/host system has been a reliable indicator of water quality in fresh and saline water, in sewage and water treatment, and in various lagooned agricultural and industrial wastes. More recently, this host/virus model has been used in the study of toxic effects and their mechanisms of action. To better comprehend specific effects at low doses, toxicants are observed during the infectious cycle. The success of this approach depends on the genetic distinctions by which one host differs from another in its sensitivity to certain cyanophages. Five cyanophages and eight hosts constitute the currently used system. A host/virus system carries the analysis into the realm of molecular biology whose vast store of genetic information on similar systems can contribute to the biological characterization of the blue-green algal system. Data acquired on formaldehyde, the s-triazine Actane, and the organophosphate pesticides Baytex and diazinon, indicate that the interaction of low doses of toxicant during the infectious cycle need not be a simple function of dose and imply that an LD50 (= median lethal dose) value, or the extrapolation of a laboratory-derived survival curve toward zero, may not be an accurate picture of environmental aquatic toxicity. In view of the current demand for in vitro screening methods, the economy and relative simplicity of the cyanophage approach is of considerable significance.
Factors Affecting Growth and Survival of the Asiatic Clam, Corbicula sp., under Controlled Laboratory Conditions
Authors: Dauble DD , Daly DS , Abernethy CS
Published: December 2008

Growth of Asiatic clams (Corbicula sp.) was determined in relation to food supply, water temperature, and clam size as an aid to researchers conducting chronic effects toxicity studies. Mean initial sizes (shell length) of clam groups were small (12 mm), medium (20 mm), and large (28 mm). Water temperatures for the two 84-day test series were 10, 20, and 30°C. Linear models provided good relationships (r2 > 0.90) between clam shell length, total weight, and wet/dry tissue weights. Clam growth was minimal during low phytoplankton densities (∼ 300 cells/mL), and all three size groups lost weight at 20 and 30°C. Mortality of small clams at 30°C was 100% after 71 days. At phytoplankton densities greater than 1000 cells/mL, overall differences in growth with respect to clam size and temperature were detectable at p > 0.01; growth of all clam groups was greatest at 30°C. Small clams exhibited the greatest absolute increase in mean shell length at all test temperatures and their weight gains were similar to those of medium and large clams. Clams in well water that were fed trout chow at 117 mg/mL dry weight had an estimated conversion efficiency of 2.0%. Use of individual marks and multivariate analysis techniques decreased sample size and test duration needed to detect differences in Corbicula growth.
Comparison of System Design and Reproducibility to Estimate Bioconcentration of Di-n-hexylphthalate by Daphnia magna
Authors: Gloss SP , Biddinger GR
Published: December 2008

Duplicated flow-through exposure systems consisting of two diluters, operated simultaneously, were used to compare the bioconcentration of 14C-di-n-hexylphthalate (14C-DHP) by Daphnia magna under single-species (modular) or multispecies (mixed) model formats proposed for use as microcosms to estimate bioconcentration.

Triplicate exposures of Daphnia in each diluter system were made under conditions which provided the following possible sources of DHP: (1) water only fed (Daphnia in mixed model fed unlabeled algae), (2) water only unfed, (3) water plus food (labeled algae), and (4) food only.

Water levels of 14C-DHP were maintained at approximately 0.22 μg/L. Algae (Selenastrum capricornutum), previously exposed in water with 0.08 µg/L 14C-DHP and used to feed Daphnia, contained approximately 0.11 µg 14C-DHP/g. Results at 24 h showed significantly (P < 0.05) higher accumulation of 14C-DHP in Daphnia exposed to the combination of contaminated food and water than any other treatment. Accumulation from exposures only to food was not different from controls. No differences were detected between the same treatments in the duplicate exposure systems. Coefficients of variation within a treatment combining replicates from both diluters (n ≥ 4) averaged 18% and ranged from 8 to 32%.

Exposures to 14C-DHP in water only (Daphnia fed) were conducted in a mixed model system wherein Daphnia were subjected to controlled predation by bluegill sunfish (Lepomis macrochirus). Results from the mixed model systems suggested that steady-state accumulation took longer than seven days to achieve. The measured bioconcentration factor (BCF) of 3250 for 14C-DHP in D. magna was similar to values reported for other phthalate esters in microcrustaceans.

Measured BCFs for the water only (48 h), food plus water (48 h), and the mixed model system (14 days) were 1066, 1486, and 3254, respectively. Calculated BCFs, using a first-order steady-state equilibrium model were 998, 1414, and 4655, respectively, for the same three treatments. All BCFs reported are for total 14C activity on a wet-weight basis.
Sediment Microbial Activity Tests for the Detection of Toxicant Impacts
Authors: Burton GA , Lanza GR
Published: December 2008

Sediments are a major factor influencing the fate and concentration of some toxicants. The use of sediment microbial activity in water quality assessment could enhance our ability to understand the impact of many toxicants. Sediments from six diverse lake sites were spiked with arsenic species, and effects on microbial activity were assessed with a test battery measuring dehydrogenase (TTC), acridine orange direct counts (AODC), formazan crystal production (INT), phosphatase, proteolysis, total direct counts (DC), direct viable counts (DVC), and total plate counts (TPC). Individual tests were modified for use in sediments. Oxygen, sediment age and volume, incubation time, diluent type, nutrient amendment, and agitation were studied as major variables.

Phosphatase and TTC activity were higher in microaerobic sediment microcosms. DVC accurately detected microbial activity in water but not in sediments. INT assays revealed that sediments contain higher percentages of dormant bacteria than overlying waters. Arsenic generally failed to suppress enzyme activity in nutrient-stimulated sediments. TTC, phosphatase, and INT activity showed variable responses to arsenic additions, depending on test conditions. Proteolysis was suppressed by arsenite under aerobic conditions after one month. Sediment bacterial isolates were not sensitive to arsenate, but they were very susceptible to arsenite. Important test modifications enabling accurate assessment with these assays include both sediment and nutrient concentrations, diluent type, and incubation condition.

The activity test sequence described here demonstrates the diversity of microbial community response to model toxicants. The use of several microbial activity tests best defines the degree of stimulation or inhibition in sediment toxicology. The diverse and complex nature of typical sediments requires careful pretesting before accurate activity assays can be run.
Using the Natural Detoxification Capacities of Marine Organisms to Assess Assimilative Capacity
Authors: Brown DA , Bay SM , Gossett RW
Published: December 2008

A test for determining the toxicity of contaminants in the environment is described, with a proposal that this test can be used to determine assimilative capacity for some contaminants. This test is based upon the observation that organisms have a measurable capacity to internally detoxify, and thereby safely assimilate, metal and organic contaminants. Toxic effects of contaminants appear to coincide with saturation of in vivo detoxification systems with metal or organic contaminants and appearance of these contaminants at intracellular sites of toxic action. A simple gel chromatography procedure has been devised to determine the intracellular partitioning of contaminants between an enzyme-containing (ENZ) pool which is a site of toxic action for both metals and organic compounds, a metallothionein-containing (MT) pool which is a site of detoxification for metals, and a glutathione-containing (GSH) pool which is a site of detoxification for organic compounds.

Several marine species including sea urchins, scorpion fish, croakers, and Dover sole were sampled from populations living near and away from a major California municipal wastewater outfall, and the partitioning of contaminants between intracellular pools was determined. Cadmium, copper, and zinc appeared to be successfully detoxified by the MT pool in all field-exposed organisms. Laboratory exposures were used to measure cadmium-detoxification capacity in tissues of scorpion fish; the relative sensitivity to cadmium was in the order: kidney > gills > intestine > liver. Oxygenated metabolites appeared to have exceeded the capacity of the GSH pool in field-exposed croakers and Dover sole, with fatty livers and fin erosion, respectively.

Therefore, at present levels of contamination of southern California coastal waters, the detoxification (assimilative) capacity of some marine organisms for certain trace metals does not appear to have been exceeded, whereas that for organic contaminants has.

Sediments and their associated microorganisms were also suggested to have a measurable capacity to detoxify contaminants by binding them so that they are not bioavailable or by degrading them to nontoxic forms.
A Model for Predicting the Influence of Suspended Sediments on the Bioavailability of Neutral Organic Chemicals in the Water Compartment
Authors: Staples CA , Dickson KL , Rodgers JH , Saleh FY
Published: December 2008

Site-specific water quality criteria may evolve from national water quality criteria based on site water characteristics. Suspended solids may be an important modifying parameter. A model is presented relating suspended solids characteristics (organic carbon content and suspended solids concentration) with a neutral organic chemical's sorption coefficient. Investigation of case studies with acenaphthene, dieldrin, and chrysene shows the dissolved and particulate-bound fractions (Cd and Cp) of total chemical concentration (Ct) to be dependent upon these factors. The model may be used to predict Cp and Cd in site waters. The model shows that chemicals with low Kp values in the presence of low suspended solids concentrations and organic matter are relatively unaffected by suspended solids. Conversely, chemicals with high Kp values, high suspended solids concentrations, and organic matter would be primarily sorbed to suspended solids.
Aquatic Safety Assessment of Chemicals Sorbed to Sediments
Authors: Adams WJ , Kimerle RA , Mosher RG
Published: December 2008

Chemical safety is assessed by the relationship of toxic effects to exposure concentrations, that is, by defining the margin of safety. To date, however, these principles have been applied only to organisms in the water column of aquatic ecosystems. A deficiency exists in our ability to understand the aquatic hazard of chemicals that are sorbed to sediment.

Studies to define the key route of exposure (interstitial water, water column water, sediment or food) were conducted with Kepone and the midge, Chironomus tentans, in partial life cycle static and flow-through tests. The endpoints measured were survival, growth, and bioaccumulation. Seven separate 14-day partial life cycle tests were conducted.

The no effect-effect concentrations for midges exposed to Kepone in the water were >5.4 <11.8 ppb. No effects were observed when the midges were fed food containing up to 17 900 ppb Kepone. In the sediment exposure studies, the no-effect concentrations varied from 3000 to 36 000 ppb depending upon the organic carbon content of the sediment. In all the sediment exposure studies, water column concentrations were below the water exposure chronic effect levels (11.8 ppb), and effects were observed only when the sediment interstitial column concentrations exceeded the 11.8 ppb water column exposure chronic effect level. Measured bioaccumulation factors for each study showed little variability when the midge tissue concentrations were divided by the sediment interstitial water concentrations. Calculations of the bioaccumulation factors based on water column concentrations or sediment concentrations were highly variable.

It can be concluded from our studies with Kepone and C. tentans that the key route of exposure is from the interstitial water and/or the water at the sediment/water interface. Toxic effects can be expected to occur in benthic invertebrates only if the chemical concentration is high enough in the sediments such that the equilibrium interstitial water concentration reached by desorption is equal to or higher than the concentration demonstrated to cause an effect in a water exposure test. Interpretation of aquatic hazard and calculation of safety factors for nonionic organic chemicals sorbed to sediments should be based on the concentration of the chemical in the sediment interstitial water, which is a function of the chemical's sediment partition coefficient (Kp), concentration of chemical on the sediment, and the organic carbon content of the sediment.
Fractography and Fracture Criteria of the Delamination Process
Authors: T Johannesson , M Blikstad
Published: December 2008

Angle-ply laminates of T300/1034 graphite/epoxy were loaded in tension. Prior to ultimate failure the interlaminar out-of-plane stresses cause edge delamination. The onset of delamination is determined by the strain energy release rate in the interlaminar region. Values of the critical strain energy release rate (Gc) for edge delamination calculated from the strain at delamination onset were fitted to a geometrical fracture criterion. It is seen that Gc increases with the KIII/KI ratio in the interlaminar region. The delamination fracture surfaces exhibit hackle formation, and the tilt of the hackles is characteristic of the interlaminar state of stress.
Thermographic Inspection of Carbon Epoxy Structures
Authors: Hillman DJ , Hillman RL
Published: December 2008

In-service damage to composite fighter aircraft structures is normally readily observed visually; often very serious damage can be identified as such by the visual observer. However, it is impossible to see whether or not nondestructive inspection (NDI) is warranted at sites consisting solely of surface scratches and dents because of the possibility of impact damage and other damages which appear superficial but may be significant. The tendency, therefore, has been to quantitatively inspect every dent and scratch observed on composite structures during field NDI to avoid overlooking a serious damage site. The purpose of the efforts reported in this paper is to eliminate this practice by providing a fast, inexpensive, large-area NDI tool capable of screening out superficial damage from serious damage.
Piezocone Penetration Testing in Soft Cohesive Soils
Authors: Tumay MT , Acar YB
Published: December 2008

The difficulty in obtaining samples for laboratory testing in very soft cohesive marine deposits necessitates the use of in-situ testing methods. Piezocone penetrometers that measure the tip resistance qc, sleeve friction fs, and the generated pore pressure u, are one of the most repeatible and reliable in-situ testing methods.

This study presents the experience obtained by the authors in analysis and evaluation of the soil characteristics with the use of piezocone penetrometers. Emphasis is given to the analysis of the penetration pore pressures.

Apart from the information obtained from the penetration pressures, their dissipation when the penetration is stopped gives valuable information on the time-deformation characteristics of the deposit. Upon the conclusions of theoretical and experimental studies, a practical method for determining in-situ coefficient of consolidation values is presented. While it is observed that the values obtained from penetration pore-pressure dissipations are generally greater than oedometer values, the present state of the art indicates that they better represent the in-situ behavior.
Pressure Release Disturbance in Simulated Marine Cores as Indicated by a Laboratory Gamma-Ray Densitometer
Authors: Chace AB
Published: December 2008

A gamma-ray density gage showed that under simulated marine conditions standard Ottawa sand decreased in bulk density as indicated by the closely related linear attenuation coefficient on release of 10.3-MPa (1500-psi) confining pressure. This simulated recovery of a marine core from a depth of 1050 m. Expansion of the sand samples in one holder continued an average of 17 h. Samples repressurized within 4 h regained their original density while those left unpressurized for over 5 h did not. Density variation in marine cores following retrieval is significant and results primarily from effervescence and expansion of gas bubbles.
The Phenomenon of Sample Tube Plugging
Authors: Holt JR , Ims BW
Published: December 2008

In order to overcome the limited recovered lengths and sample disturbance associated with driven sampling, long stroke hydraulic push or piston samplers have been developed for offshore operations in recent years. Use of such samplers, however, does not always result in recovered sample lengths consistent with the distance pushed. A detailed review of sample recovery for several offshore investigations has shown this phenomenon to be common to all soil types.

It is demonstrated that the recovered sample lengths can be predicted to a high degree of accuracy by comparing the friction resistance developed on the inside of the tubes with the soil bearing capacity as determined from cone penetrometer tests.

Implications of the findings are discussed with particular reference to sample disturbance.
Shear Strength Properties of Some Deep-Sea Pelagic Sediments
Authors: Noorany I
Published: December 2008

This paper describes the index and strength properties of a number of pelagic clayey silt and silty clay samples obtained from 14 locations in the ocean. The depth of the samples varied from a few centimetres to 55 m where water depths were more than 4000 m. The sediments were pelagic silts and clays of high plasticity with liquid limits as high as 227 and water contents as high as 388%. The vane shear strength varied from 5 to 13 kPa within the upper 60 cm of the soil profile and increased with depth. The su/σ′v ratios measured by laboratory vane shear test varied from 0.28 to 0.60 in the upper 25 m of sediment column, which appeared to be overconsolidated, and 0.22 in the deeper normally consolidated sediments. The corrected ratios measured by laboratory vane shear test varied from 0.28 to 0.60 in the upper 25 m of sediment column, which appeared to be overconsolidated, and 0.22 in the deeper normally consolidated sediments. The corrected su/σ′v values computed by the SHANSEP method varied from 0.34 for the deeper normally consolidated sediments to 1.1 for the near surface apparently overconsolidated sediments. The effective stress parameters were values computed by the SHANSEP method varied from 0.34 for the deeper normally consolidated sediments to 1.1 for the near surface apparently overconsolidated sediments. The effective stress parameters were c′ = 1 to 22 kPa and φ′ = 21° to 35°.
Toward a Unified Approach to Soil Property Characterization: In Situ Versus Laboratory
Authors: Chaney RC , Demars KR , Fang H-Y
Published: December 2008

This paper presents a review and analysis of a number of methods of correcting laboratory strength values to in-situ strengths. Methods presented are (1) utilization of an empirical correction factor, (2) use of an analytical model to extrapolate in-situ strength values from tests on disturbed laboratory samples, and (3) direct computation of strength values using residual pore-water pressures extrapolated from lab test data. Data indicate that the analytical and pore-water procedures are the most valid methodologies. The SHANSEP technique is discussed in relation to the analytical procedures.
Liquefaction Potential of Sediment in the Northern Bering Sea
Authors: Winters WJ
Published: December 2008

The liquefaction potential of sediment in Norton Sound and the northern Bering Sea was evaluated by estimating the liquefaction susceptibility of the material from in-situ and laboratory tests in terms of earthquake and wave loads required to liquefy the material, and then comparing estimated behavior with anticipated loadings caused by frequent storm waves in the relatively shallow water depths and infrequent earthquakes.

In-situ cone penetration tests (CPT) were performed at 13 stations. After the CPT data were transformed into equivalent standard penetration test (SPT) blow counts, analyses were performed that determined earthquake accelerations and sustained relative storm wave heights that would cause liquefaction.

Vibratory core samples, up to 6 m long, were obtained in silty sand grading to sandy silt near many of the CPT locations. Results of cyclic triaxial tests performed on those samples were used to calculate earthquake accelerations and sustained storm wave heights that would liquefy the sediment.

Liquefaction susceptibility estimates from laboratory tests typically were lower than those from in-situ tests; nevertheless, both approaches yielded the same conclusions for regional assessment of liquefaction potential. Wave and earthquake loadings are not strong enough to cause significant amounts of liquefaction in most areas.
A Bridge Site Investigation Using SPTs, MPMTs, and DMTs from Barges
Authors: Sonnenfeld SL , Schmertmann JH , Williams RC
Published: December 2008

The subsurface exploration from barges for the replacement of the Sunshine Skyway Bridge across Tampa Bay, FL, involved several relatively new field tests or new ways to use old tests. These included: (1) energy corrected standard penetration test (SPT) borings, (2) Menard pressuremeter tests (MPMTs), and (3) Marchetti dilatometer tests (DMT). This paper discusses the testing problems and shows how data from these tests compared with each other and some associated information obtained from laboratory tests.
A Laboratory Extraction Method to Simulate Codisposal of Solid Wastes in Municipal Waste Landfills
Authors: Francis CW , Maskarinec MP , Goyert JC
Published: December 2008

The objective of this research was to develop a laboratory extraction method for solid wastes that simulates concentrations of inorganic and organic constituents in leachates resulting from codisposal with municipal wastes in landfills. A scientific rationale and a data base are presented supporting the use of such an extraction method to characterize the potential hazards of leachates from a solid waste codisposed with municipal waste in a landfill containing about a 95:5 ratio of municipal and industrial waste, respectively. Two field lysimeters, each containing approximately 1.5 Mg of assorted municipal wastes, were used to generate a municipal waste leachate (MWL) that in turn was used to leach four industrial wastes under anoxic simulated codisposal conditions.

Leachates from the four industrial wastes were monitored for concentrations of inorganic and organic constituents over 79 days at a liquid/solid ratio of MWL and industrial waste of approximately 20:1, similar to the liquid/solid ratio currently being used in the extraction procedure to determine toxicity under the Resource Conservation and Recovery Act. Air-tight Tedlar® bags were used to collect leachate to avoid loss of volatile organic compounds and to maintain an anoxic environment. Data from the field lysimeter test facility were used to identify concentrations of “target” constituents (those constituents in the leachates of the industrial wastes that were observed at concentrations statistically higher than those observed in the control leachates). This data base was used as a model to evaluate several laboratory extraction methods that might be used to simulate the target concentrations.
Evaluation of Chemical and Biological Methods for the Identification of Mutagenic and Cytotoxic Hazardous Waste Samples
Authors: Andon B , Jackson M , Houk V , Claxton L
Published: December 2008

To assist in the development of methods for identifying potentially hazardous wastes, we have conducted studies on the extraction of toxicants from several solid waste samples. The extracts were tested for toxicity by the Chinese hamster ovary (CHO) cytotoxicity test and for mutagenic potential in the Salmonella histidine reversion assay. A new technique was also employed that measured the mutagenicity of neat waste samples by coupling thin layer chromatography (TLC) with the Salmonella histidine reversion assay.

The wastes selected for study were coke plant waste, herbicide manufacturing acetone-water effluent, and oil refining waste. Three extraction solvents—ethanol, dichloromethane (DCM), and dimethylsulfoxide (DMSO)—were chosen based on their solubility and compatibility with bioassay procedures. Each sample was divided into three parts and extracted with each of the three solvents separately.

All extracts were tested in the Salmonella assay at five dose levels with five Ames tester strains in the presence and in the absence of an exogenous metabolizing system. The DMSO and DCM extracts were utilized for CHO cytotoxicity evaluations. The three neat waste samples and two extracts were assayed by the Salmonella/TLC technique. In addition to the biological assessments, the gross chemical parameters for each sample were determined.

Results showed that coke plant waste and herbicide manufacturing acetone-water were mutagenic to S. typhimurium with the standard plate test. With the Salmonella/TLC technique, the coke plant waste was mutagenic and oil refining waste was both toxic and mutagenic. Oil refining waste was also toxic to CHO cells. Results of the gross chemistry determinations showed the three samples to have a wide range of solid content, total organic content, and extractables. Evaluation of the chemical extraction methods demonstrated few differences in extraction capabilities with respect to mutagenic activity.
Characterizing Petrochemical Wastes for Combustion
Authors: Lee K-C , Hansen JL , Whipple GM
Published: December 2008

Waste characterization is the first step for the design of an incinerator or for the prediction of a waste's combustion performance in an existing incinerator or other combustion device. Many petrochemical wastes are heterogeneous, so traditional analytical techniques that were developed to handle relatively pure or homogeneous coal or oil samples may not be efficacious. This paper will discuss the problems encountered in using traditional analytical techniques for waste characterization and some solutions to these problems. The analytical areas discussed include elemental composition, ash content, organic content, and metal content. A statistical analysis plan (not a sampling plan) is proposed for handling heterogeneous chemical waste.
Microcomputer Analysis of Laterally Loaded Piles
Authors: Sogge RL
Published: December 2008

The finite-element formulation is applied to the vertical beam-on-elastic foundation idealization of a laterally loaded pile system. This representation is such that any standard structural analysis program having beam members can be used. An example problem consisting of a laterally loaded pile in a nonhomogeneous soil is analyzed in detail. The simulation is conducted on a CP/M 64K random access memory (RAM) microcomputer. The soil strength properties are defined in terms of a net coefficient of subgrade reaction and represented by bar members. The input data file and the computer output are presented. The numerical analysis clearly demonstrates the influence of soil and structural stiffness on pile behavior and the ease of obtaining a solution, by use of a computer, when nonhomogeneous soil conditions exist.
Generalized Behavior of Laterally Loaded Vertical Piles
Authors: Gleser SM
Published: December 2008

A method previously presented by the author (in ASTM STP 154) is generalized to encompass soils having nonlinear p-y characteristics. This results in a method that can handle, but is not restricted to, pile-soil systems having (1) piles greater than 9 m (30 ft) in length having free, fixed, or partially fixed heads, and any cross-sectional shape and length relationship, for example, constant, tapered, or stepped, and of any materials or combination of materials; (2) soils of any variation with depth, whether homogeneous, stratified, or combinations thereof, and having p-y characteristics of any nature; (3) ability to qualitatively and quantitatively predict behavior and stresses under static, fluctuating, and repetitive lateral loadings, or where larger emergency loads can be interspersed between normal loads. Ways are suggested for dealing with each of these factors. In addition, a method is proposed for obtaining the effective soil constant at a given site for a range of lateral loads, using empirical test data from free-head piles of the same characteristics subjected to lateral loads. The method is validated by use on previously published data of a comprehensive series of tests on free-head piles by Assadeh and Davison (Journal of the Soil Mechanics and Foundation Division, Proceedings of the American Society of Civil Engineers, Vol. 96, No. SM5, Sept. 1970, pp. 1583–1603). Using the soil constants resulted in computed load-deflection curves closely approximating actual data. These constants are used in turn to compute the expected deflections and pile stress of those same piles under fixed-head conditions.

A serendipitous finding of the analysis was that there is a significant shape factor affecting the ability of piles to mobilize soil resistance to lateral loads, for example, under any given lateral load applied to free-head piles having approximately equal moments of inertia, those having circular cross sections were substantially more resistant to lateral movement than square or H-beam cross sections. This in turn significantly altered the effective soil modulus.

To determine the usefulness of the method in economic as well as structural design, an analysis was made of a built-up pile consisting of a 360-mm (14-in.) H-beam cut diagonally along its length and rewelded to form a tapered I beam 500 mm (20 in.) at the butt and 200 mm (8 in.) at the tip, with constant flanges. Although having the same weight as the basic H beam, the tapered pile was computed to have a lateral deflection under a load of 13 000 kg (30 000 lb), which is half of that of the basic beam under free-head conditions and 0.6 of that under fixed-head conditions.
Laterally Loaded Piles and the Pressuremeter: Comparison of Existing Methods
Authors: Briaud J-L , Smith T , Meyer B
Published: December 2008

The first part of this article deals with the determination of the critical depth Dc, below which the ground surface has little influence on the soil-structure interaction problem, and with the variation of soil resistance within that critical depth. A new approach is proposed to determine Dc using the relative rigidity of the pile with respect to the soil strength as measured by the pressuremeter limit pressure.

The second part of the article summarizes seven pressurementer methods to predict the lateral behavior of piles. Predictions by four of the methods are compared with the results of a full-scale load test. All methods predict the measured behavior with reasonable accuracy suggesting that the pressuremeter provides a sound testing base for the behavior prediction of laterally loaded piles.