bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Mechanical Characterization of Fiber Filled Unsaturated Polyester Composites
Authors: Collister J , Gruskiewicz M
Published: March 2009

Dynamic mechanical testing was used to qualitatively study the effects of various constituents of sheet molding compound (SMC) and bulk molding compound (BMC) materials, including unsaturated polyester resin, a chemical thickener (magnesium oxide), a filler (calcium carbonate), and glass fibers. Tests were designed to evaluate the influence of each constituent as it was added to the overall composition. The parameters tested were elastic shear modulus, viscous shear modulus, and complex viscosity as functions of frequency for non-cross-linked materials, and elastic shear modulus, viscous shear modulus, and damping as functions of temperature for cross-linked materials. The chemical thickener was observed to change the molecular weight of the polyester resin, as indicated by the appearance of a rubbery plateau in the viscoelastic spectrum, while cross-linking, filler, and glass fibers were observed to contribute heavily to the elastic shear modulus and temperature sensitivity.
Occurrence of Fretting in Practice and Its Simulation in the Laboratory
Authors: Waterhouse RB
Published: March 2009

Fretting arises in practice where a structure or multicomponent system involving contacting surfaces experiences vibration. Examples are the false brinelling of wheel bearings when automobiles are transported by road or the damage which can arise in gun mountings on military vechicles. Fretting also occurs when one of the members of a contact is subjected to cyclic stressing, as in the contact region between the hub and wheel seat of a wheel-on-axle or flywheel-on-shaft assembly. In attempting to simulate fretting situations in the laboratory, attention must be given to the contact configuration, the mode of exciting oscillatory slip, the control and measurement of the amplitude of slip, alignment and application of the normal load, and control of the environment. Finally, the resultant damage must be assessed and the method used should take into account not only the material removed from the surfaces but the material transferred between the surfaces as well as surface deformation and cracks, which in practice could have a profound influence on the life of the component.
Effect of Ion Implantation on Fretting Fatigue in Ti-6Al-4V Alloy
Authors: Vardiman RG , Creighton D , Salivar G , Effatian A , Rath BB
Published: March 2009

The effect of fretting on the fatigue life of titanium alloys is known to be severely deleterious. A preliminary study shows ion implantation to hold great promise for improving the fretting fatigue life in Ti-6Al-4V alloy.

Carbon implanted at 75 keV to a dose of 2 × 1017 atoms/cm2 gives a peak concentration of 30 atomic percent at a depth of approximately 1700 Å. Incoherent particles of titanium carbide averaging 100 Å in size were found by transmission electron microscopy. Fatigue specimens were subjected to fretting on one surface at a normal stress of 20.7 MPa. A significant improvement in lifetime was found. No difference in the mode of failure was observed between the implanted and the unimplanted specimens.
Chemistry and Materials in Geothermal Systems
Authors: Miller RL
Published: March 2009

The development of a geothermal fluid is traced, from its origin as meteoric water precipitating on the earth's surface, as it flows through the soils and rocks of geological formations, to the point where it returns to the surface as a hot spring, geyser, well, or other form. Water of magmatic origin is also included. The tendency of these hydrothermal fluids to form scale by precipitation of a portion of their dissolved solids is noted. A discussion is presented of types of information required for materials selection for energy systems utilizing geothermal fluids, including pH, temperature, the speciation of the particular geothermal fluid (especially its chloride, sulfide, and carbon dioxide content), and various types of corrosive attack on common materials. Specific examples of responses of materials to geothermal fluids are given.
Material Selection Guidelines for Geothermal Power Systems—An Overview
Authors: Conover M , Ellis P , Curzon A
Published: March 2009

Perhaps the most important difference between traditional electric power generation and geothermal power generation is the potentially severe corrosion of metals caused by the use of the geothermal fluids. The object of this overview is to present the principal results of work conducted for the U.S. Department of Energy under Contract EG-77-C-04-3904. Process streams are identified by the presentation of nine geothermal power cycles applicable to four types of liquid-dominated geothermal resources found in the United States. Of the many constituents in geothermal fluids, seven key chemical species are identified that account for most corrosion phenomena in geothermal power systems. These species are: oxygen, hydrogen sulfide, carbon dioxide, ammonia, chloride, sulfate, and hydrogen ion concentrations. Based on analyses of actual geothermal materials test data and test methods, the performance of metals in geothermal fluid, steam, and condensate is presented for carbon and stainless steels, titanium, nickel, copper, and many other alloys. The applicability of new nonmetallic materials in geothermal systems is also addressed. Finally, the similarities and differences between seawater and geothermal corrosion phenomena are discussed.
Surface Corrosion of Metals in Geothermal Fluids at Broadlands, New Zealand
Authors: Braithwaite WR , Lichti KA
Published: March 2009

Corrosion studies of metallic construction materials for a geothermal power plant at Broadlands, New Zealand, are described. Surface corrosion investigations on 36 materials in seven geothermal media, using the ASTM coupon method, have been initiated, and results for selected materials are presented in a logarithmic graphical form. The observed corrosion characteristics are discussed in terms of corrosion product composition and stability and theoretical film-formation mechanisms.
Corrosion in Geothermal Brines of the Salton Sea Known Geothermal Resource Area
Authors: Cramer SD , Carter JP
Published: March 2009

Corrosion research is being conducted by the Bureau of Mines, U.S. Department of the Interior, to determine suitable construction materials for geothermal resource recovery plants. High chromium-molybdenum iron-base alloys, nickel-base and titanium-base alloys, and a titanium-zirconium-molybdenum alloy (TZM) exhibited good resistance to general, crevice, pitting, and weld corrosion and stress corrosion cracking in laboratory tests in deaerated brines of the Salton Sea known geothermal resource area (KGRA) type at 232°C and in brine containing dissolved carbon dioxide and methane. Only titanium-base alloys were resistant to corrosion in oxygenated Salton Sea KGRA-type brine. Copper adversely affected the resistance to general corrosion of low-alloy steels in deaerated brine, whereas chromium, nickel, silicon, and titanium improved it. Carbon steel, Type 4130 steel, and Types 410 and 430 stainless steels exhibited poor corrosion resistance in field tests in five brine and steam process streams produced from geothermal well Magmamax No. 1. These alloys were highly susceptible to pitting and crevice corrosion. General corrosion rates were high for the carbon and Type 4130 steels.
Round-Robin Evaluation of Methods for Analysis of Geothermal Brine
Authors: Watson JC
Published: March 2009

Geothermal liquid and gas analysis provides necessary information for evaluating corrosion and scaling, optimizing power plant design, assessing environmental impacts, and ensuring compliance with legal requirements. A basic problem with geothermal analysis is a lack of standardization of analytical methods.

In 1976, Pacific Northwest Laboratory (PNL), operated by Battelle Memorial Institute for the U.S. Department of Energy, initiated a program under the U.S. Department of Energy-Division of Geothermal Energy (DOE-DGE) to determine the state of the art of methods of analysis for geothermal fluids. Following the issuance in 1976 of a comment manual [1]2 of literature-abstracted methods, an organizational meeting held in early 1977 led to the formulation of a round-robin field testing program. Attendees representing two government agencies, four government-funded laboratories, five private laboratories, and three industrial concerns agreed on 40 parameters to be evaluated. Two round-robins were conducted with approximately 20 laboratories participating in the analysis: the first sample collection, at the U.S. Bureau of Reclamation site in East Mesa, Calif., involved the evaluation of a low-solids (0.4 percent by weight) brine, while the second, conducted at the Geothermal Loop Experimental Facility (GLEF) of the San Diego Gas and Electric Co., Niland, Calif., involved a high-solids (24 percent by weight) brine.

Statistical analysis of the data from these tests shows that the greatest range of results was obtained for the species silver, aluminum, antimony, fluoride, bromide, iodide, phosphate (PO4), and total hydrogen sulfide (H2S). In addition, the constituents rubidium, copper, manganese, lead, and zinc showed a high degree of variability for the brine with low total dissolved solids (TDS). Barium, bicarbonate (HCO3), boron, potassium, sulfate (SO4), arsenic, and total carbon dioxide (CO2) were more difficult to analyze in the higher TDS brine than in the lower one.
Utilitarian Benefits of Magnitude Estimation Scaling for Testing Product Acceptability
Authors: Moskowitz HR
Published: March 2009

This paper contrasts magnitude estimation (ratio) scaling and 9-point category scaling (hedonic scale) in terms of ability to detect differences in products and ability to illustrate the relation between product acceptance and formula ingredient level. Magnitude estimation shows more differences among products. Furthermore, magnitude estimation better reveals the relation between acceptance and ingredient level, making it easier for a product formulator to see how rapidly acceptance changes when the formulation is not at its optimum level.
Evaluating the Effect of Residual Stresses on Notched Fatigue Resistance
Authors: Reemsnyder HS
Published: March 2009

Many current fatigue design criteria for structural details present allowable stress ranges for specified design lives but neglect mean and residual stresses. The paper reviews published test results and shows that residual stresses and concomitant mean stresses can have a significant influence on fatigue resistance in certain cases. The beneficial effects of compressive residual stresses due to shot-peening are well-known. For example, shot-peening of non-load-carrying fillet-welded carbon steel and butt-welded constructional alloy steel has increased the fatigue strengths at two million cycles by 20 to 40 percent. Also, the fatigue resistance of weldments can be influenced significantly by the presence of residual stresses, provided the stress ratio is equal to or less than zero and the lives are greater than one million cycles. The fatigue strength of transverse butt welds with reinforcement intact at two million cycles has been increased by 12 percent and 24 to 33 percent for stress ratios of, respectively, 0 and −1 through thermal stress relief. Such improvement has also been shown for longitudinal non-load-carrying fillet welds (for example, attachments, gussets, etc.) where the increases in fatigue strength at two million cycles due to thermal stress relief for stress ratios of 0, −1, and −4 were, respectively, 15, 57, and 168 percent.

The paper presents an extension of the local-strain fatigue life initiation model to accommodate residual and mean stresses. The model is based upon the stress-strain function of Smith, Watson, and Topper and includes iterative solutions for Kσ and 2Nf. Changes in residual stresses due to cyclic loading and fatigue lives of notches at nonzero mean stresses are predicted and compared with experimental results. Also, further extensions of the model to accommodate plane strain—that is, thickness effects—and surface roughness are discussed.
Effect of Residual Stresses on Fatigue Crack Growth Rates in Weldments of Aluminum Alloy 5456 Plate
Authors: Nordmark GE , Mueller LN , Kelsey RA
Published: March 2009

Rates of fatigue crack propagation were determined for CT specimens taken from the weld metal, heat-affected zone, and base metal of an Alcoa 649A Process 5556 butt weld in a 51-mm (2-in.)-thick 5456-H117 plate. Crack-opening displacement measurements were taken during the fatigue crack propagation tests so that the effects of crack-opening loads and residual stresses could be determined. The use of the concept of Elber's effective stress intensity range, based on the measurements of crack-opening loads, indicates that the crack propagation rates are equivalent in the weld metal, heat-affected zone, and base metal. Furthermore, the effect of stress ratio also can be correlated using the effective stress intensity range concept.
Residual Stress and Stress Interaction in Fatigue Testing of Welded Joints
Authors: Berge S , Eide OI
Published: March 2009

Longitudinal non-load-carrying fillet welds in a structural steel were tested in axial tension. In constant-amplitude loading, the stress range approach was verified. In variable-amplitude block loading, stress interaction effects were observed. In general, interaction effects were beneficial or, in one case, only slightly detrimental to the fatigue life as compared to the Miner Palmgren summation index. For R = 0, interaction caused a significant delay in crack growth as compared to constant-amplitude loading, particularly with small cycles in the load spectrum. For R = −1, delay effects were small, and dependent on the sequence of peak/trough in each load cycle. Stress-relieved, as compared to as-welded specimens, exhibited a larger delay at R = 0, and a slight acceleration of crack growth at R = −1. Increasing the mean stress from 0 to 25 MPa gave only small changes, as did randomization of the block sequence.
Effects of Multiple Shot-Peening/Cadmium-Plating Cycles on High-Strength Steel
Authors: Kohls JB , Cammett JT , Gunderson AW
Published: March 2009

A study was made of the effects of multiple shot-peening and cadmium plating operations on high-strength AISI 4340 steel used in aircraft landing-gear applications. No detrimental effects were observed on surface microstructure and tensile properties or on fatigue and unnotched stress corrosion resistance in high-humidity air. An apparent degradation in stress corrosion life of fatigue precracked specimens was observed after four and five peening and plating operations.
A Driving Rain Index for Masonry Walls
Authors: Grimm CT
Published: March 2009

The British have developed and the Canadians have subsequently adopted a driving rain index that is here applied as a criterion to define the severity of exposure of masonry walls to water permeation. Recommendations are made for minimum thicknesses of several masonry materials in walls with and without coatings and furring in five geographical regions of the United States.
Initial Effects of Clear Coatings on Water Permeance of Masonry
Authors: Brown RH
Published: March 2009

The results of water permeance tests on twelve walls before and after coating with a proprietary clear water repellant are reported. Half of the single-wythe walls were brick; and other half, normal-weight concrete masonry units. Half of the walls used masonry cement mortar; the other half, portland cement-lime mortar. Comparison of results revealed a significant reduction in the amount of leakage, an increase in the amount of time required to achieve maximum rate of leakage, and a decrease in the percentage of damp area as a result of the application of the coating. The walls will be retested after six months of outdoor exposure.
Controlling Aggregate Properties for Compliance with Statistical Specifications
Authors: Molnar JT
Published: March 2009

The author outlines aggregate process control procedures applicable to both single-plant and multiple-plant operations. The elements in establishing a control program covered here include: the basic plan, the selection and training of technicians, the sampling locations, and rapid testing and reporting methods. The main benefit of an effective control program is that it minimizes the chance of incurring penalties in the form of price reductions when the aggregate is used in products which fail to conform to the requirements of statistical or end-result specifications. Other benefits are also discussed.
Evaluation of the Resistance of Type 316 Stainless Steel Against Progressive Deformation
Authors: Pellissier-Tanon A , Bernard JL , Amzallag C , Rabbe P
Published: March 2009

An experimental program has been conducted on Type 316 stainless steel uniaxial specimens to determine the main characteristics of their behavior under repeated loading. The cyclic stress-strain curve measured under constant repeated load, without high preloads, is independent of the level of the mean stress. Two different behaviors with respect to the occurrence of progressive deformation have been observed: (1) at room temperature, progressive deformation occurs when the maximum value of the tensile stress exceeds a critical value, and (2) at 320°C and for loading with temperature cycling between ambient temperature and 320°C, progressive deformation occurs when the amplitude of stress exceeds a critical value.

These results show that Section III of the ASME Code, which limits the range of variation of the primary plus secondary stress intensity to the value of 3 Sm, gives an effective guarantee against progressive deformation for operating conditions in the range of 20 to 320°C. It is recalled that the absence of progressive deformation is a necessary condition for the validity of conventional low-cycle fatigue analysis.
Economics of Using Incinerator Residue as a Highway Construction Material
Authors: Patankar U , Taylor MR , Ormsby WC
Published: March 2009

The technology for the use of residue from municipal incinerators in highway construction has been developed over a number of years in conjunction with studies performed for the Federal Highway Administration's Materials Division. This study focuses on an evaluation of the economic factors influencing the use of incinerator residue in bituminous highway construction. Five Standard Metropolitan Statistical Areas (SMSA) (Chicago, Ill.; Harrisburg, Pa.; Miami, Fla.; New York, N.Y., and Washington, D.C.) were chosen to evaluate the economic factors that weigh on the greater use of residue in highway construction. The residue was evaluated for use as subbase material and in bituminous base. A cost analysis model was developed to determine economic feasibility that has broad application for other substitute aggregate economic analysis. The results of this study show that incinerator residue would prove competitive with virgin aggregate in highway construction in three of the five metropolitan areas studied. Projections can therefore be made that it is likely that incinerator residue would be economically feasible in other urbanized SMSAs having municipal incinerators.
Potential for Asphalt Stabilized Sand Bases in Texas
Authors: Little DN , Button JW , Epps JA
Published: March 2009

Depletion of high quality aggregate sources in concert with inflated transportation costs has created a need for utilization of locally available aggregate sources as base materials. Many state specifications, developed only for asphalt concrete surface courses, preclude the use of low quality aggregates that may be suitable for bases in properly designed pavement systems. Paving mixtures containing poorly graded sands from Texas and asphalt cement or emulsified asphalt are evaluated using results from two laboratory tests: (1) resistance to lateral flow (R-value) before and after moisture treatment, and (2) diametral resilient modulus. Ranges of resilient moduli that have provided successful pavements in Texas are presented. Moduli determined in the laboratory have been correlated to moduli collected in the field by in situ deflection testing.
Use of Geotextiles to Extend Aggregate Resources
Authors: Robnett QL , Lai JS
Published: March 2009

The use of an interlayer of geotextiles or fabrics was found to allow a substantial reduction in the aggregate layer thickness required to provide a given level of performance formance for aggregate-surfaced roads over soft soil deposits. Experimental results were used to derive equations that relate key performance parameters for aggregate-soil systems containing Typar 3401 fabric. Numerous laboratory and field studies concerning the use of fabric to reinforce aggregate layers were cited. Various design methods for specific commercial product lines and two general design methods were used to illustrate typical ranges in aggregate savings that may be effected by use of fabric.
General, Localized, and Stress-Corrosion Resistance of a Series of Copper Alloys in Natural Atmospheres
Authors: Castillo AP , Popplewell JM
Published: March 2009

The general, localized, and stress-corrosion performance of a series of copper-base alloys exposed to marine, urban-industrial, and heavy-industrial environments is described after up to 12 years' exposure. The effect of alloying additions, test environment, and test parameters are reported versus corrosion susceptibility.
Atmospheric Corrosion Tests of Copper and Copper Alloys in Sweden—16-Year Results
Authors: Holm R , Mattsson E
Published: March 2009

In 1958, exposure tests were started in rural, marine, and urban atmospheres in Sweden, covering 36 copper alloys in sheet or rod form. Test results after two and seven years' exposure have been reported earlier. this is the concluding report of the tests as completed after 16 years' exposure.

Greenish coatings had developed on most of the materials after six to seven years at the urban and marine sites. At the rural site, however, no distinct green coating had developed on any material after 16 years, only different shades of black or brown. The amount of patina retained increased substantially from 7 to 16 years of exposure. The patina was found to be more protective in the marine and rural atmospheres than in the urban one. The patina was also examined by X-ray analysis and scanning electron microscopy-EDX.

The average penetration (determined gravimetrically) during 16 years of exposure had stabilized at the following levels:

0.3 to 0.5 µm/year in rural atmosphere

0.5 to 0.9 µm/year in marine atmosphere

0.9 to 1.3 µm/year in urban atmosphere

The dezincification rate of brass had decreased somewhat during the period from 7 to 16 years. It was highest for brasses with an (α + β)-phase structure, the maximum dezincification depth measured metallographically after 16 years being 90 to 215 µm, the loss in ultimate tensile strength 5 to 15 percent and the reduction in elongation up to 30 percent.
Use of Grass Shrimp in Toxicity Tests
Authors: Buikema AL , Niederlehner BR , Cairns J
Published: March 2009

The literature pertaining to the use of grass shrimp in toxicity testing is reviewed. Information on the life history, species differences, collection, culture, handling, effects of toxicants, standard methods for toxicity testing, and potential problems in experimental design is presented. Suggestions for future research are made.
Assessing the Risk of Fires Systemically
Authors: Rowe WD
Published: March 2009

The risks of fire, from either natural or man-made causes, can never be completely eliminated. The objective of control of risk from fires is to reduce the probability and consequences of events leading to fires to a level where the residual risks are commensurate with the benefits of society's undertakings. Involuntary and inequitably distributed risks must be considered as well as voluntary ones.

On a systemic level, the causes of fires may be identified and the risk of their occurrence estimated. This need not be done in detail, but major contributors to accidental and purposeful fires can be identified, especially in buildings. A second step is addressing control through prevention and mitigation during and after occurrence. The cost-effectiveness of the risk reduction of these approaches provides a first-level ordering of where to apply resources. The ability to implement such control actions realistically through standards, inspections, building codes, and so on, provides a means for reordering priorities.

The impact of acceptable levels of risk, established by societal requirements through the voluntary standard-setting process, is also addressed. Both acceptance and achievement standards are discussed.
Structural Properties of Timber Pile
Authors: Armstrong RM
Published: March 2009

Results of test programs with short pile sections and small clear specimens are reviewed to evaluate the influence of imperfections and preservative treatment on the strength properties of timber piles. Reduction factors developed from this review, available information on natural wood strength variations, and available information on the influence of load duration are used to evaluate the structural capacity of embedded timber piles under axial loading. Indicated allowable axial unit stresses for treated timber piles range from 3.8 MPa (550 psi) to 6.4 MPa (925 psi), depending on the extent of knots and treatment conditioning that are permitted in current (1978) timber pile standards.
Influence of Codes and Standards on the Use of Steel Piles
Authors: Dismuke TD
Published: March 2009

A brief review and evaluation of the provisions of existing codes and standards regarding steel piles is presented. The reasoning behind the current proposal for an allowable bearing load of 50 percent of the steel yield strength is presented.

The use of existing codes and standards to provide adequate guidance for preventing foundation failures is questioned. Codes based on load factor concepts and improved field inspection are thought to be necessary.
Static and Cyclic Axial Load Tests on a Fully Instrumented Pile
Authors: Lu TD , Fischer JA , Miller VG
Published: March 2009

The results of static and cyclic axial pile load tests performed on a fully instrumented steel H-pile driven into a glacial till deposit are presented.

Cyclic loads were applied through a hydraulic system interfaced with an automated electronic-electromechanical closed loop servo system to achieve a controlled load intensity to the pile in a specific shape (sinusoidal) at specific frequency (0.1 Hz). The load-deflection, load transfer, and configuration of the pile during pile driving and after each load increment was measured through an instrumentation system that consisted of load cells, deflectometers, strain gages, accelerometers, and inclinometers.

Data obtained in this investigation indicated that:

1. Axial deformation of the pile remained essentially constant prior to and after cyclic axial load application. The behavior of the pile was essentially elastic during cyclic load application.

2. Within the scope of testing performed, cyclic vertical load increments do not effect the load carrying capacity or load transfer characteristics of the pile.

3. Load transfer characteristics varied with the magnitude of applied axial load. The ratio of point bearing resistance to the applied load increased with the applied load. However, the rate of increase generally decreases with increasing applied load.
Field Tests on Vertical Piles Under Static and Cyclic Horizontal Loading in Overconsolidated Clay
Authors: Price G
Published: March 2009

This paper describes experiments that provided information on the behavior of vertical tubular steel piles under horizontal working loads in London clay. Four aspects of piled foundation behavior were examined:

1. The effect of static and cyclic horizontal working loads on the behavior of a single pile.

2. The magnitude of the induced movements in unloaded piles at three and six pile diameter spacings from a horizontally or vertically loaded pile.

3. The stiffness of a single pile loaded horizontally compared with the stiffness of a row of three piles loaded horizontally at right angles to the row.

4. The effect of a cap on the behavior of a row of three piles loaded vertically and horizontally (at right angles to the row).

The main conclusions drawn are:

1. Low levels of cyclic horizontal loading cause small adverse changes in the behavior of vertical piles.

2. The interaction between piles under horizontal load is considerably less than under vertical load.

3. Conclusion 2 is substantiated by the observations that the stiffness of three piles in a row is approximately three times the stiffness of a single pile under horizontal loads.

4. A cap significantly reduces the horizontal movements under load but has little effect on the vertical behavior of the piles.

5. The experimental techniques used enabled small changes in the pile-soil behavior to be successfully monitored.
A Simple Approach to Pile Design and the Evaluation of Pile Tests
Authors: Randolph MF , Wroth CP
Published: March 2009

In the past, the design of a pile in a given soil against undue settlement has entailed lengthy numerical analysis for a variety of pile geometries. Similarly the back analysis of load tests on piles has usually been accomplished by repeated analysis with differing soil stiffness profiles in order to arrive at the profile which gives best agreement with the measured results. The recent development of an approximate closed form solution for the problem of a vertically loaded pile has enabled these two processes to be considerably simplified.

The present paper takes the solution as developed and extends it to the case of piles bearing on a stiffer stratum of soil. The solution may then be used both for the design of single piles and also for the back analysis of pile tests. For given soil conditions, it is possible to draw up design charts showing how the settlement of a pile may vary with load level and pile geometry. This process is demonstrated for some typical soil conditions. For evaluating load tests, the closed form solution may be manipulated to give an immediate estimate of the average soil stiffness down the pile for the case of tests on uninstrumented piles. If additional information (such as the settlement of the pile base) is available, it is possible to obtain an estimate of the soil stiffness profile down the length of the pile without recourse to a computer. Examples of some actual pile tests are given.
Atmospheric Monitoring for Hydrogen Sulfide by Photorateometric Analysis
Authors: Kimbell CL
Published: March 2009

A new method for analysis of the hydrogen sulfide (H2S) content of the atmosphere is by photorateometric measurement. This detection method consists of a surface chemically treated with lead acetate enclosed in the chamber. Reaction with H2S causes a color change. A photocell response is produced by “rate of change” electronics, the output of which is proportional to the first derivative of the photocell output. This first derivative signal is a measure of H2S concentration. An output linear with concentration is obtained. A range of measurement may be obtained in parts per million (ppm) and parts per billion (ppb) with extreme accuracy. Response time using the rateometric technique is sufficiently fast to allow plume characterization using surface vehicle or aircraft mounted analyzers.
Damage Mechanism and Life Prediction of Graphite/Epoxy Composites
Authors: Badaliance R , Dill HD
Published: March 2009

This paper describes observation of fatigue damage mechanism in composites subjected to compression dominated fatigue loading, formulation of a damageindicating parameter based on the intralaminar microcracking of the resin, and its application in conjunction with a linear fatigue damage model to predict spectrum life of graphite/epoxy composite laminates.
Taint Threshold of Diphenyl Oxide in Rainbow Trout
Authors: Branson DR , Blau GE , Alexander HC , Peters TL
Published: March 2009

Rainbow trout were exposed continuously for seven days to sublethal concentrations of diphenyl oxide (DPO) in water. The trout flesh was then analyzed for taste and DPO concentrations. The following conclusions were based on the experimental results:

1. Trout flesh containing 7.5 ± 1.2 μg/g DPO was identified by a panel as characterizing the breakpoint between tainted and untainted taste. Trout exposed continuously to 16 μg/litre of DPO in the water for one week show flesh concentrations of DPO that correspond to this fish-taint threshold.

2. The DPO concentrations in trout flesh increased 1.75 times after baking. This phenomenon could be due to water loss and to possible transfer of DPO from the skin to the flesh during baking. Cooked trout flesh containing 13 ± 2 μg/g DPO were at the fish-taint threshold.

3. A statistically significant correlation was obtained between fish-taint scores and the DPO concentration in flesh, which permits the prediction of fish taint to be made from a given DPO residue in fish.

4. Statistical analysis of the taste data indicated that neither taste fatigue nor taster experience was a factor in this study.

5. This study illustrates that taint in fish can be one of the more sensitive water quality criteria for some chemicals.
Value of Chemical Fractionation for Identifying the Toxic Components of Complex Aqueous Effluents
Authors: Parkhurst BR , Gehrs CW , Rubin IB
Published: March 2009

Chemical fractionation can be used to separate complex aqueous effluents into several less complex fractions, and this technique has been combined with mutagenesis testing to provide an effective means of screening the potential health hazards of products and of aqueous effluents. The purpose of this study was to evaluate the applicability of combining chemical fractionation with acute toxicity testing as a method of identifying and quantitatively assessing those components of a synthetic fuel process effluent that are toxic to aquatic biota.

A representative synthetic fuel effluent was fractionated into three organic fractions (acid, base, and neutral) and an inorganic fraction. The original effluent, the fractions, and a reconstituted effluent were tested for acute toxicity to Daphnia magna.

The results demonstrated that (1) the neutral fraction was the most toxic; (2) the acid and neutral fractions contributed the most toxicity, 51.3 and 41.9 percent, respectively, to the toxicity of the whole effluent; (3) the toxicities of the four fractions were additive; and (4) the fractionation process did not significantly alter the toxicity of the effluent. Possible applications of this approach, as well as its limitations, are discussed.
Bioconcentration and Metabolism of Linear Alkylbenzene Sulfonate by Daphnids and Fathead Minnows
Authors: Comotto RM , Kimerle RA , Swisher RD
Published: March 2009

The bioconcentration potential of the anionic surfactant linear alkylbenzene sulfonate (LAS) was studied using daphnids (Daphnia magna) and fathead minnows (Pimephales promelas) in studies extending up to 50 days. Uptake in the test organisms, as measured by 14C activity, was a function of chain length and exposure concentration. In whole organisms, the dry weight bioconcentration factors (BCF) were 500 to 4000 for daphnids and 200 to 2000 for fathead minnows. In fish tissues, the greatest 14C activity occurred in the gall bladder, the BCFs ranging from 20 000 to 70 000, while the least occurred in the muscle, the BCFs remaining in the range of 100 to 400. In depuration studies, greater than 85 percent of the 14C content was cleared from all tissues within three to four days, with nearly 100 percent clearance within ten days.

The results of desulfonation/gas chromatography analyses of tissues suggested that the fathead minnows metabolised LAS, and the daphnids did not. Substantial portions of the 14C content in the tissues of fathead minnows were not present as LAS, but presumably were present as metabolites (30 to 50 percent in muscle tissue, and 97 percent or more in the case of the gall bladder). A comparison of the uptake of 14C from tagged LAS with that from tagged taurocholic acid (TCA), a naturally occurring bile surfactant, gave somewhat contrasting uptake patterns in fathead minnows. The 14C-LAS activity reached a steady state in tissues within three days, while the 14C-TCA activity continued to accumulate in tissues throughout the exposure period.

It can be concluded from these LAS and TCA bioconcentration studies that surfactant materials may, in general, show similar patterns of uptake, site of deposition, metabolism, and depuration. From the present studies and from previously reported toxicity and microbial biodegradation studies, it can be further concluded that under environmental conditions there is little likelihood that LAS bioconcentration creates a hazard to aquatic ecosystems.
Exposure Assessment: A Key Issue in Aquatic Toxicology
Authors: Sanders WM
Published: March 2009

Environmental exposure assessment, an intermediate step in risk analysis, ties projected volumes of toxic materials entering the environment to specific environmental effects. Thus, prediction of the environmental fate and distribution of a toxic compound is an integral part of any hierarchical scheme of risk analysis.

Environmental exposure assessment is a new and emerging science, and, although some processes have not been adequately characterized, tests for the most significant ones (volatilization, hydrolysis, oxidation, etc.) are available. Both screening tests and detailed protocols are presently available for determining the process kinetics for selected chemicals exposed to differing environmental conditions. Preliminary exposure assessments can be made from the screening data if the following rate processes are estimated: microbial degradation, chemical transformation, photolysis, hydrolysis, ionization, and partitioning. Because these processes can act either synergistically or competitively, depending upon the chemical structure of the material and the conditions of the environment, great care must be taken to conduct the tests in sequential order.

The greatest unrealized potential for exposure assessment lies in the use of mathematical modeling techniques. When environmental exposure models are coupled with environmental effects models, powerful tools for risk assessment emerge. Such sophisticated models need to be refined and verified, however, before risk analysis becomes accurate and cost-effective.
Effects of Calcium and Sediment Concentrations on the Release of Metals and Nutrients from Dredge Spoil Dispersions
Authors: Snitz FL , Weber WJ , Barney JL , Posner JC
Published: March 2009

Sediment from the lower Cuyahoga River (5.8 river km from the mouth at Lake Erie) was dispersed in reactors containing simulated lake water constituted to have pH, dissolved oxygen (DO), alkalinity, and hardness values typical of Great Lakes Waters. The parameters of pH and DO were maintained constant during the course of the experiments, while calcium and sediment dispersion concentrations were systematically varied. The calcium ranged from 5 to 120 mg/litre and the sediment from 0.5 to 50 g(dry)/litre.

The materials investigated for release from the sediment dispersions included magnesium, cadmium, copper, lead, zinc, iron, manganese, chromium, arsenic, total dissolved phosphate as PO4, and total Kjeldahl nitrogen. In general, the extent of release was inversely related to the calcium and sediment concentrations. Significantly, the unit release of metals and nutrients in oxygenated waters increased two to five-fold with each order-of-magnitude decrease in sediment dispersion concentration.

The methods of the research bear upon the development of procedures for evaluating the potential impact of dredging operations on water quality. The results of this investigation show that the amounts of dredge spoil constituents released into solution can be comparable in magnitude to those of dissolved mineral species in rivers and outfalls.
The Influence of Four Exclusion Cylinder Designs on Alfalfa Growth
Authors: Sauer WC
Published: March 2009

Four exclusion cylinder designs were tested to determine the impact of a cylinder enclosure on the production of the enclosed alfalfa. The designs of the 1.07-m (42-in.) diameter cylinders can be described as follows: (a) 0.9-m (3 ft) high, 25.4-mm (1-in.) mesh welded wire with open top; (b) 0.9-m (3-ft) high, 25.4-mm (1-in.) mesh welded wile with 25.4-mm (1-in.) mesh top; (c) 0.9-m (3-ft) high, 6.35- mm (0.25-in.) mesh hardware cloth with open top; and (d) 0.46-m (18-in.) high, 25.4-mm (1-in.) mesh welded wire with 25.4-mm (1-in.) mesh top. The cylinders were placed in ground-squirrel-free alfalfa fields for various time intervals from mid-March to mid-June 1976 and 1977. The sample unit included vegetation within a cylinder and comparable area(s) of vegetation within 1.5 to 3m (5 to 10 ft) from each cylinder, each clipped at ground level. Dry weights were taken of each sample to estimate the hay production. None of the cylinder designs except the 6.35-mm (0.25-in.) mesh caused significant growth change in the enclosed alfalfa. This design resulted in a 15 percent reduction in forage production. No significant small herbivore population was determined by visual observation or feeding activity at feeding census stations.
Evaluation of Deer Damage to Hay in Southern Wisconsin
Authors: Mullen CA , Rongstad OJ
Published: March 2009

This study evaluated the spotlight method of assessing hay losses due to deer (Odocoileus virginianus) grazing. This method uses the mean number of deer feeding in a field per night, an estimated daily consumption of 1.36 kg per deer, and the length of the growing season in days to calculate the total losses for a field. The authors counted deer on 22 different hay fields to obtain variability in deer use. The number of deer in a field on any particular night was extremely variable. This variability required over 100 nightly counts in order to have a mean estimate within 0.5 deer. Exclosures were set up on two study plots to determine the differences in yield between grazed and ungrazed hay. There was a significant reduction in yield in all three cuttings of both study plots. The damage was only to the alfalfa portion of the hay. Grazing on the first hay crop had a carry-over effect on subsequent crops. Based on deer counts on the study plots and the reduction in yield between the exclosure and unprotected areas, the reduction in yield per night of deer use ranged from 1 to 31 kg for the three cuttings on the two study plots. The authors recommend that the spotlight method for assessing deer damage to hay be abandoned because of the time required to develop a reliable estimate of deer use and because of the variability of the hay's response to grazing.
Two-Choice Preference Testing of Taste Repellency in Quelea quelea
Authors: Bullard RW , Shumake SA
Published: March 2009

A three method laboratory preference testing program has been developed for evaluating candidate taste repellents on quelea (Quelea quelea). In all three methods, the birds are first adapted to the test conditions and food types and then offered a choice between the control food and one test food; preference is measured as proportion of total food consumed. A four-day individual cage test has been satisfactory for evaluating quelea response to 15 bird-resistant sorghum varieties. To avoid preference biases due to visible differences in shape, size, and color between the control and test foods, the foods were pelleted, and the birds were adapted to feed in neardarkness during the tests. A similar test, using surface-coated millet has been used to evaluate the repellency of constituents extracted from bird-resistant sorghums. In these cage tests, the repellents are ranked primarily by t test results. In the third method, a six-day enclosure test designed to simulate field conditions, five birds in a 2.5 by 2.4 by 2.2-m screened enclosure were offered a choice between tannin-coated and control sorghum heads. Preference was measured by analysis of variance. In general, experience indicates that, if precautions are taken to reduce stress and minimize extraneous factors, such as visual cues, adequate separations can be made among the test repellents with quite simple testing regimes.
Design to Cope with Incipient Fires
Authors: Bryan JL
Published: March 2009

The focus of this paper is directed to incipient fires in residential occupancies due to the magnitude of the problem in this occupancy and the availability of data concern with the definition of the fire occurrence in the occupancy. Variables of concern to the designer are identified and discussed relative to the prevention of the ignition and propagation of the incipient fire, for example, flame spread, smoke propagation, rate of heat release and the geometric configuration of interior finish materials and furnishings. The availability and suitability of smoke detection devices and systems to react to the incipient fire are considered relative to the potential savings in human fatalities, injuries, and financial loss. The ultimate control system in the form of the residential automatic sprinkler system are examined with the recent design advances in these systems.
Quantitative and Qualitative Analysis of Purgeable Organics by High-Resolution Gas Chromatography and Flame Ionization Detection
Authors: Dowty BJ , Antoine SR , Laseter JL
Published: March 2009

Recently, interest has been shown in the use of a purge and trap technique for the analysis of low molecular weight Environmental Protection Agency priority pollutants. A procedure for analysis of halogen and nonhalogen priority pollutants in a single analysis in the less than microgram per litre (part per billion) concentration range is described. This is achieved by use of either high-resolution glass or steel gas chromatography capillary columns. Percent recoveries for various compounds ranged from 51 to 100 percent. Percent standard deviations as well as lower limits of detection for each compound investigated are reported. Problems encountered in the coupling of a commercially available purging and trapping device to glass capillary columns are described and solutions presented.
Identification of Organic Components in Aqueous Effluents from Energy-Related Processes
Authors: Pellizzari ED , Castillo NP , Willis S , Smith D , Bursey JT
Published: March 2009

The qualitative and quantitative comparison in seven aqueous samples from four different energy-related operations were determined. Striking differences were observed in both the types and quantities of individual organics in samples from coal and oil shale processes. High-resolution gas chromatography coupled with mass spectrometry and Fourier transform infrared spectroscopy was required to provide sufficient separation and molecular characteristics for identification of each organic substituent. These instrumental processes must be computerized to allow for fast data reduction.

A greater amount and diversity of nitrogen-containing compounds were found in samples from in situ oil shale processing. Few qualitative differences were apparent among samples from in situ and low-Btu coal gasification.