bluuebunny/crossref_metadata_2025 huggingface dataset:
Historic Waste-Site Use and Geotechnical Characterization—Data Sources and Data Utility
Authors: Elifrits CD , Hatheway AW
Published: February 2009

Uncontrolled waste sites seldom have a record of the events that occurred prior to, during, and after disposal of waste at the site. There are sources of remote sensor data that can be interpreted to provide a temporal record of site history and geotechnical information. Evaluation of the information contained in these sources and merging of these data sets requires consideration of the capability of remote sensing methods for recording appropriate and needed information and the corresponding map and other graphical means used to present the information. Research at the University of Missouri—Rolla (UMR) has led to development of a system of historic data source identification, assessment of the usefulness of the available data, and merging of these sets of interpreted, temporal data with appropriate map bases at scales and levels of detail that meet requirements for remedial investigations and feasibility studies. Additional specific topics which the UMR system has addressed are scales, resolution, and enlargements of photos and maps. The historic site-use characterization system makes full use of available data: U.S. Geological Survey mapping photography, U.S. Department of Agriculture's Agricultural Stabilization and Conservation Service and Soil Conservation Service aerial photography, U.S. Environmental Protection Agency environmental monitoring systems data, and aerial photography from local and regional agencies and contractors.
Geotechnical Applications of Three New U.S. Government Remote Sensing Programs
Authors: Molnia BF
Published: February 2009

Although not primarily designed to collect geotechnical information, three U.S. Government remote sensing programs are providing significant new data of substantial geotechnical value. The programs are the National High-Altitude Photography (NHAP) Program and the Side-Looking Airborne Radar (SLAR) Program, both administered by the U.S. Geological Survey's (USGS) National Mapping Division, and the National Aeronautics and Space Administration's (NASA) Shuttle Imaging Radar (SIR) Program. NHAP and SLAR data collection are parts of the USGS's continuing efforts to provide coverage of the United States for mapping and geological interpretation. SIR data were collected by NASA from the Shuttle in 1981 and 1984 on two experimental missions designed to further our understanding of the radar signatures of geological features. Collectively, these data represent a new and powerful tool for use by practitioners to provide new insights into qualitative geotechnical evaluations. Among the many uses of these data are regional structural interpretation, delineation of drainage characteristics, evaluation of surface wetness characteristics, and assessment of rock and soil surface texture and grain size. Use of these data can assist in the preparation of inexpensive regional analyses that can be used for the planning and execution of detailed site-specific studies.
An Approach to the Updating of a Data Base for a Geographic Information System: Land Use and Land Cover Data
Authors: Lin H
Published: February 2009

One of the keys to the effectiveness of a geographic information system (GIS) is up-to-date data in its data base. Land-use and land-cover data are important data in a current GIS in China. The land-use and land-cover conditions often change, because they are easily affected by changes in natural conditions and the activities of human beings. Space-borne remote sensing—because of its periodicity, speed, scanning scope, and the lower cost of obtaining the synthetic information—is becoming the main data source for updating land-use and land-cover data in the GIS data base. The crux of the updating procedure is to link the remote sensing system and the GIS by means of a digital image processing system. Accuracy in locating and classifying is considered the crucial problem in image processing. A remote sensing image is a model of a region which has been compressed in spatial dimensions and synthesized with its essential factors on the surface. Thus, the information from the images evidently has a regional geographic pattern. The GIS has the basic data and the analysis software for the registration and analysis of the spatial information from remote sensing and other sources. The GIS can be considered the basis of digital image processing and map automation.
Overview of Remote Data Transmission Systems
Authors: Paulson RW
Published: February 2009

During the last decade, electronics, communications, and satellite technologies have greatly enhanced the collection and communication of environmental data from remote locations. While numerous environmental data collection agencies have begun to employ remote telemetry systems operationally, hydrologic data collection agencies have made the greatest transition to these technologies. The U.S. Soil Conservation Service has established a remote communications network with over 500 hydrologic sites, using a communications technique known as “meteorburst,” which relies on ionized micrometeor trails in the atmosphere to reflect radio messages between a hydrologic station and an interrogation site. Most major agencies collecting hydrologic data in the United States and Canada rely on satellite communications to collect data directly from approximately 3000 remote locations and to provide the data in real time to central data processing and dissemination facilities. Elements of remote data transmission systems are discussed, and major operators and users of such systems are identified.
Criteria for the Selection of Remote Data Telemetry Methods for Geotechnical Applications
Authors: Chedsey GL
Published: February 2009

The field of geotechnical monitoring has just within the last decade entered the age of automatic and remote data telemetry. Civil engineers, especially geotechnical engineers, have just recently opened the door to allow communication lines, telephone modems, radio links, and satellites to convey monitoring data automatically from the field to the office. The initial projects involving instrumentation automation and data telemetry were used for either very remote areas or very large projects. However, monitoring data can now be automatically gathered at the site and transmitted to a central location easily, efficiently, and economically, for projects of any size.

This paper details the types of automation and data acquisition used by Geotechnical Engineering and Mining Services (GEMS) to monitor conventional geotechnical instruments; for example, pneumatic and vibrating wire piezometers, thermistors, stream and reservoir level sensors, and others. Instrument data acquisition systems are of paramount importance to monitoring systems because they must accurately monitor the instrument and store the data. Equipment details, including electronics, are addressed.

The paper compares the four types of data transmission: telephone, radio [both ultrahigh-frequency (UHF) and very-high-frequency (VHF)], communication line, and satellite. Guidelines for the use of each type of data telemetry are given, and the relative advantages and disadvantages of each method are explained. The focal point of the paper is a table that summarizes the following items for each of the four telemetry methods: (a) best application, for example, the optimum number and types of sensors; (b) transmission range/rate and times per day; (c) accessibility; (d) reliability; and (e) relative cost.

In addition, applications are shown in which multiple types of data transmission methods are applicable. Case histories of recent projects involving geotechnical instrument automation and data acquisition with data telemetry also are given.
Corrosion Studies in Complex Environments
Authors: Koch GH , Spangler MJ , Thompson NG
Published: February 2009

Corrosion studies have typically been performed in relatively simple environments where variations in corrosion behavior are determined as functions of one variable at a time. However, the desire to more closely simulate actual service environments requires more complex test environments. To study the effects of environmental variables on the corrosion behavior of materials, a statistical approach is highly desirable. In this paper, a sequential experimental design approach for complex experimental environments will be described. Examples are given where this approach is used to study the effect of solution variables in complex environments on the electrochemical parameters for different alloys.
Testing Methods for Indoor and Outdoor Atmospheric Corrosion
Authors: Fiaud C
Published: February 2009

Simulation tests for indoor and outdoor atmospheric corrosion appear essential to reliably predict the behavior of designs and materials in operating environments. Chamber tests are preferentially conducted for indoor corrosion. Some results are given concerning the sulfidation of copper and silver by H2S (hydrogen sulfide) in the presence of additives such as NO2 (nitrogen dioxide) or Cl2 (chlorine molecule). It is shown that chemical reactions between gases are responsible for the acceleration of the rate of sulfidation of metals. Comparison with onsite measurements shows that several classes of test severities must be defined. In studying outdoor atmospheric corrosion, attention is presently focused on the use of electrochemical sensors, which allow the determination of times of wetness and corrosion rates. Chamber tests may be used in some special cases. An example is given for the behavior of metallic materials exposed to corrosion under storage conditions. The combination of chamber and electrochemical tests has led to some understanding of the mechanism of formation and spread of corrosion products for an Fe-Ni alloy. The alloy has a behavior intermediate between that of an active (iron-like) material and a self-passivated (stainless steel-like) one, depending on the aeration conditions of the surface.
The Use of Synthetic or Natural Seawater in Studies of the Corrosion of Copper Alloys
Authors: Castle JE , Chamberlain AHL , Garner B , Parvizi MS , Aladjem A
Published: February 2009

The inorganic components of seawater are well known and easily simulated by mixtures of the appropriate salts. The adoption of such mixes has the advantage that the buffering ability of seawater is simulated to some extent but leaves open the question of the role of the organic component of seawater, which is not simulated in any of the normal recipes available. It is always open to the experimenter to avoid the problem of simulating seawater by carrying out the test exposures in the sea itself. However seawater has such a variability that any exposure site or time of year will be inadequate in some unknown regard.

This paper describes our experience in holding water in the laboratory and of work relating to the influence of organic natural products on the corrosion of Kunife 10 (alloy CA706, 10Ni1.5FeCu alloy). To attempt to create a “modus operandi” for waters containing organic species, it is essential to first envisage their possible actions, for example, chelating action, inhibition, stimulation of transport, a reduction in ionic activity in solution leading to a change in the Pourbaix diagram, modification of crystal habits, or the formation of weak boundary layers. These aspects will be discussed in the paper.

A detailed study of the micro-organisms, which develop in tanks containing seawater over the period of their use as a stock of test medium and of the concomitent changes in water chemistry, has been made and will be reported. A more direct method of examining the effect of the organic component is to remove it from the water in order that it may be added back to synthetic mixes or used to augment the seawater itself. A system, which permits the removal and retention of high molecular weight compounds, will be described.

It is concluded that the organic material may have less influence on the corrosion of the Kunife alloy than on some other systems but that the techniques established to deal with organic components of seawater have been successful. In particular an influence of organic molecules on the cathodic process at low oxygen levels has been demonstrated.
The Effect of Dissolved Copper on the Erosion-Corrosion of Copper Alloys in Flowing ASTM Seawater
Authors: Cheung WK , Thomas JGN
Published: February 2009

Erosion-corrosion experiments have been carried out on tubular copper alloys in ASTM artificial seawater, using two recirculating flow systems. The results showed that the order of resistance to erosion-corrosion of the alloys was correct, but the values of the critical breakaway flow velocities were considerably greater than those reported for once-through seawater cooling systems in practice. Analysis of the recirculating seawater showed that because of the high initial corrosion rates of the copper alloys, the concentration of dissolved metal ions increased rapidly to significant values, and supersaturation of copper ions was occurring. A technique has now been developed to remove dissolved copper and other heavy metal ions from the recirculating seawater in the flow systems by passage through a suitably prepared chelating ion-exchange resin. Under these conditions, the corrosion rates of tubes of 90/10 copper-nickel were considerably higher than those obtained previously in the presence of dissolved copper ions.
The Electrochemistry of Steel Corrosion in Concrete Compared to Its Response in Pore Solution
Authors: Dawson JL , Langford PE
Published: February 2009

Corrosion control of steel reinforcement relies on the maintenance of the high alkalinity of the hydrated cement especially in the presence of chloride ions. The present paper also indicates the adverse effect that chloride contamination of the initial mix can have on the permeability of the matrix to oxygen diffusion.

Data obtained on steel specimens embedded in ordinary portland cement paste prepared with varying additions of sodium chloride are presented. Potentiodynamic polarization curves obtained after 400-days exposure in a controlled humidity environment are compared to curves from steel immersed in extracted pore solutions. Pore solution measurements are shown to provide analogous information to embedded steel samples on the anodic and passivation processes. However, pore solution experiments do not simulate the influence of the matrix in controlling diffusion and resistivity, which influence the long-term durability and macro-cell development.
Materials Performance for Residential High Efficiency Condensing Furnaces
Authors: Hindin B , Agrawal AK
Published: February 2009

In high efficiency furnaces, the condensate that is produced from the flue gas contains trace amounts of such contaminants as SOx=, Cl− (chloride ions), NO3− (nitrate ion), NO2− (nitrate ion), F− (fluoride ions), and organic acids. The condensate after concentration by reevaporation becomes very corrosive to the heat exchanger materials. An electrochemical investigation has been conducted using 316L as a reference alloy and synthetic condensates to identify the environmental factors most significant in corrosion. The condensates were formulated using a statistical experimental design approach. Through a regression analysis of the results, chloride and temperature were identified as the most damaging factors. Investigation of several other alloys in an aggressive condensate showed that their corrosion performance was dependent upon their Cr and Mo contents. Subsequently, a large number of alloys were evaluated in a gas-fired furnace by exposing them to chloride-spiked condensates under alternate wetting and drying conditions for 90 days. The alloys included austenitic, ferritic, and duplex stainless steels, and also a few aluminum, copper, and nickel-based alloys. Most of the alloys performed well in the condensate having 26 ppm Cl−; a few of the alloys did well in 200 ppm Cl−, but at 1000 ppm Cl− only those alloys which had high Cr and Mo contents survived.
Composite Interlaminar Fracture Toughness: Three-Dimensional Finite-Element Modeling for Mixed Mode I, II, and Fracture
Authors: Murthy PLN , Chamis CC
Published: February 2009

A computational method/procedure is described which can be used to simulate individual- and mixed-mode interlaminar fracture progression in fiber composite laminates. Different combinations of Modes I, II, and III fracture are simulated by varying the crack location through the specimen thickness and by selecting appropriate unsymmetric laminate configurations. The contribution of each fracture mode to strain energy release rate is determined by the local crack closure methods, while the mixed mode is determined by global variables. The strain energy release rates are plotted versus extending crack length, where slow crack growth, stable crack growth, and rapid crack growth regions are easily identified. Graphical results are presented to illustrate the effectiveness and versatility of the computational simulation for (1) evaluating mixed-mode interlaminar fracture, (2) for identifying respective dominant parameters, and (3) for selecting possible simple test methods.
Sublaminate- or Ply-Level Analysis of Composites and Strain Energy Release Rates of End-Notch and Mixed-Mode Fracture Specimens
Authors: Valisetty RR , Chamis CC
Published: February 2009

A computational procedure is described for the sublaminate- or ply-level analysis of composite structures. This procedure is useful to obtain stresses in regions affected by delaminations, transverse cracks, and discontinuities related to material properties, geometry, and loads. In this analysis, attention is focused on those layers or groups of layers (sublaminates) which are immediately affected by flaws. These layers are analyzed as if they were homogeneous bodies in equilibrium in isolation from the rest of the laminate. The theoretical model used for the analysis of individual layers allows the relevant stresses and displacements near discontinuities to be represented in the form of pure decay type solutions. As a result, the exponential-precision-related problems that are inherent to sublaminate- or ply-level analysis are removed. This allows sublaminate analysis of laminates without any restriction on the maximum number of layers, delaminations, transverse cracks, and other types of discontinuities. In conjunction with the strain energy release rate (SERR) concept and composite micromechanics, this computational procedure is used to model select cases of end-notch and mixed-mode fracture specimens. The computed stresses are in good agreement with those from a three-dimensional finite-element analysis. The SERRs also compare well with limited experimental data.
Interlaminar Fracture Analysis of Composite Laminates Under Bending and Combined Bending and Extension
Authors: Armanios EA , Rehfield LW
Published: February 2009

Interlaminar fracture or delamination is a primary damage mode in laminated composites. It is caused by high interlaminar stresses which are produced by local stress raisers such as holes, free edges, ply drops, and other defects and discontinuities which may be manufacturing related or service induced. Delaminations alter internal load paths and usually contribute to the ultimate failure of the structure.

The present work is concerned with the development of a simple analytical model which permits the rapidly varying interlaminar stresses and energy release rate to be estimated by elementary means. Extensive numerical computations are avoided, and the results are obtained in closed form. The model is applied to the edge delamination specimen subjected to uniform bending and combined bending and extension loadings. Interlaminar stresses, total energy release rate, and energy release rate components are estimated.
Effect of Adhesive Layers on Impact Damage in Composite Laminates
Authors: Sun CT , Rechak S
Published: February 2009

Adhesive layers were included along the interfaces of a baseline graphite/epoxy [05/905/05] laminate for impact study. Impacted specimens were sectioned longitudinally and transversely for observation of the damage modes. The existence of adhesive layers resulted in the following effects: delamination was effectively suppressed up to very high impact velocities; matrix cracking in the upper lamina was greatly reduced; and the contact area appreciably increased thereby reducing the stress concentration effect. An apparent disadvantage in using adhesive layers was found; that is, the bending crack in the bottom lamina which could branch out into delamination cracks when adhesive layers were absent tended to penetrate the middle lamina and break fibers.
The Sandwich Column as a Compressive Characterization Specimen for Thin Laminates
Authors: Lagace PA , Vizzini AJ
Published: February 2009

A study was conducted to evaluate the reliability of a sandwich column specimen for uniaxial compressive tests. Both stress-strain and failure behavior were observed, and comparisons were made with predictions from existing techniques. The properties of the aluminum honeycomb core were also measured and included in the analysis to show its limited effects on the overall behavior of the specimen. Control tests were performed on specimens with aluminum facesheets to further quantify the effect of the honeycomb core on the overall behavior of the structure. The main battery of tests was conducted with graphite/epoxy facesheets of [θ12], [±θ/o]s, and [0/±θ]s configurations. The general excellent correlations between the observed moduli and Poisson's ratios and predicted values indicate that the specimen provides true stress-strain behavior. Moreover, consistent failure modes within the test section including both in-plane failure and ply buckling or delamination failure followed by in-plane failure indicate that the specimen is valid for failure behavior data.
Instability-Related Delamination Growth in Thermoset and Thermoplastic Composites
Authors: Rothschilds RJ , Gillespie JW , Carlsson LA
Published: February 2009

Mixed-mode crack propagation in compressively loaded thermoset and thermoplastic composite columns with an imbedded through-width delamination (ITWD) is investigated. Beam theory is used to analyze the geometrically nonlinear load-deformation relationship of the delaminated subregion. The beam-theory model incorporated the effects of elastic restraint at the ends of the delaminated subregion. The elastic restraint model (ERM), combined with existing finite-element modeling of the crack-tip region yields expressions for the Mode I and Mode II components of the strain energy release rate GI and GII to predict the critical load at the onset of delamination growth. Experimental data were generated for geometries yielding a wide range of GI/GII ratios at the onset of crack growth. A linear mixed-mode crack growth criterion (GI/GIc + GII/GIIc = 1) in conjunction with the ERM provides good agreement between predicted and measured critical loads for both materials studied.
Growth of Elliptic Delaminations in Laminates Under Cyclic Transverse Shear Stresses
Authors: Chatterjee SN , Ramnath V , Dick WA , Chen YZ
Published: February 2009

Models for predicting growth of delaminations in laminated composites under fatigue loading are needed for development of different types of criteria, namely, (1) design criteria for damage tolerance and durability of composite components, (2) accept/reject criteria for manufactured parts, and (3) repair/replace decision making for components damaged in service. For this reason, various studies have been and are being conducted to study one-dimensional growth of delaminations in coupons or beam specimens for obtaining semi-empirical growth laws. In this study, two-dimensional growth patterns of single as well as multiple delaminations (through the thickness of the laminate) under mixed-mode loading conditions are predicted using such a growth law, and the results are compared with data from a series of test specimens. The growth law is obtained from measured growths of the major axis of implanted (double-layer trifluoroethylene resin sealed at edges) elliptic delaminations in the midplane of 76-mm-wide (04/±452)s4 AS-1/3501 plates loaded in three-point bending reported in a previous study.
Viscoelastic/Damage Modeling of Filament-Wound Cylindrical Pressure Vessels
Authors: Prater JL , Hackett RM
Published: February 2009

A simulation model of the viscoelastic/damage response of a filament-wound cylindrical pressure vessel to proof-test loading is developed. The matrix material of the composite system is assumed to be linearly viscoelastic. A damage model based upon a quadratic relationship between the transverse modulus and maximum circumferential strain is proposed. The resulting nonlinear model is solved by an iterative routine based upon a reduced stiffness. The elastic-viscoelastic correspondence principle is used to produce, in the Laplace domain, an associated elastic solution for the maximum circumferential strain which is inverted by the method of collocation to yield a time-dependent solution for each iteration. A numerical example is included to demonstrate the application of the simulation model.
Residual Stress and Strength Loss in Filament-Wound Composites
Authors: Knight CE
Published: February 2009

Filament-wound composites are fabricated using an initial stress in the filament strand called the “winding tension.” This initial stress will interact structurally with the winding form and each of the wound layers incrementally as the fabrication process proceeds. The interactions will result in a variable residual stress distribution or possibly in total tension loss in some of the wound layers. Total tension loss before cure of the resin matrix produces strength loss in the affected layers and the whole structure.

An incremental construction procedure has been implemented into a finite element computer program for analysis of the winding process. The method involves switching “on” element stiffnesses in the finite element model as construction proceeds. The initial stress in the element being switched on due to winding tension is converted to nodal loads and applied to the currently existing structure. If any layer loses all its initial stress, then its material stiffness is reduced (assuming the uncured composite cannot carry fiber direction compressive loads). The incremental addition of element stiffnesses and modification of material properties make the analysis incrementally nonlinear.

An analytical and experimental study was conducted on a series of cylinders. The parameters investigated include winding mandrels of aluminum or plastic, two uniform winding tension levels, and two final composite thicknesses all using a Kevlar/epoxy composite. Two aluminum mandrel thicknesses were used to vary the mandrel stiffness, with the plastic mandrel serving as a very low stiffness mandrel. Residual stress distributions were predicted for all the wound parts, and these were used to calculate the mandrel strain during construction which was compared with measured response of strain gages on the mandrel. Correlations were very good. Tension loss in the inner layers was seen in two cases; these were for the highest winding tension and largest final composite thickness wound on the thin aluminum mandrel and wound on the plastic mandrel.

The study shows results of modeling the fabrication process and the consequence of fabrication parameter choices. Situations were produced which show strength loss in Kevlar/epoxy composites. It is therefore necessary to include fabrication engineering as part of the design of filament-wound structures.
Mechanical Behavior of Braided Composite Materials
Authors: Simonds RA , Stinchcomb W , Jones RM
Published: February 2009

Graphite/epoxy composite material specimens manufactured with AS-4 fiber and 3501 matrix in a 3-D braiding process were subjected to tension, compression, impact, and cyclic loading. The type of braiding utilized for the specimens results in a material that is not subject to delamination as experienced by laminated composites. Further, braiding has potential for the direct creation of structural shapes such as I-beams or stiffened panels which can be manufactured as one piece rather than being assembled from several laminated elements. The specimens employed in this study, however, were more familiar straight-sided coupon shapes. Tension test results indicate a tensile strength of 1280 MN/m2 (186 ksi) and a tensile Young's modulus of 106 GN/m2 (15.3 Msi). The compression strength is 447 MN/m2 (64.8 ksi) and the compressive Young's modulus is similar to that for tension. A series of impact tests was performed on the material to determine the threshold of detectable impact damage. An energy of 5.4 J (4 ft·lb) was found to produce damage that was detectable by both radiography and by ultrasonic C-scanning. Fatigue tests were run on the material at a stress ratio of −1 to determine the fatigue life of the braided composite. Specimens fatigued at 290 MN/m2 (±42 ksi) had nominal lives of 20 000 cycles. Reducing the fatigue stress to ±(40 ksi) 276 MN/m2 extended the life to 80 000 cycles. Lower stresses produced longer lives. In addition, compression, and fatigue tests were run on specimens that had been subjected to the 5.4-J (4-ft·lbs) impact test. There was virtually no change in compressive strength and fatigue life compared to specimens without the prior impact loading. Thus, impact loading has little, if any, effect on the mechanical behavior of the braided composites included in this study. In conclusion, braided composites have potential to solve many of the shortcomings of more conventional laminated composite materials.
New Automation Tools for the Metals Analysis Laboratory
Authors: Owens GD , Hammons JL , Franklin LC , Pekel DB
Published: February 2009

New tools are available to the chemist for use in automation and data management. These include intelligent instruments and commercially available software packages. These two components may be used as a foundation for assembling an automated analysis system. This allows the amount of custom software required to be kept to a minimum. We have used this strategy to assemble an automated metals analysis system. The system consists of a Mettler AE 163 balance, a Perkin-Elmer model 3030B atomic absorption spectrophotometer and an IBM PC/AT. The SYMPHONY software package provides a spreadsheet for calculations and a word processor for report generation. The link between the instruments and SYMPHONY is formed by two instrument control and data acquisition programs written in BASIC. Use of this system has resulted in the removal of potential errors due to manual data transcription and calculation, as well as time savings in analysis.
Local Area Networking in the Analytical Laboratory
Authors: Kunz FW , Cole GS
Published: February 2009

The use of dedicated or shared computers or both for analytical instrument control, data accumulation, data reduction, and data reporting is now commonplace in most well-equipped laboratories. This paper details a local area network (LAN) concept for an analytical laboratory which improves the use of computers as well as reduces computing costs. Various instruments, including X-ray diffraction, X-ray fluorescence, electron microprobe, and surface spectroscopy equipment are connected to our LAN for file transfer and remote terminal logins.

There is also an increasing demand for filing data, monitoring quality assurance, and generating composite management reports accumulated from these various analytical instruments; this can be accomplished by accessing an electronic laboratory notebook system.
Development of an Integrated Company-Wide On-Line Laboratory Data System
Authors: Brinegar J , Kunish R , Pawlowski J
Published: February 2009

Howmet Turbine Components Corporation has developed an integrated, computer-based system for the submittal, tracking, storage, disposition, reporting, and analysis of laboratory samples and data (chemical analyses and mechanical testing results). The system comprises four application modules: (1) On-line computer application programs control submitting, tracking, verifying, and reporting of test results; (2) a computer automated data collection from laboratory instruments and transmits results to the mainframe computer; (3) a purchased data base management system stores data and allows user-defined data retrievals; and (4) data analysis software provides statistical analysis and graphic representation of the data. The computerized laboratory system has contributed to more efficient laboratory work, higher productivity of divisional personnel, and more effective data evaluation. This contributes to the production of higher quality parts on a competitive cost basis.
Evaluation of Repellent Seed Treatments and Effects on Early Corn Performance
Authors: Koehler AE , Johnson RJ , Burnside OC , Lowry SR
Published: February 2009

A combination of field, field enclosure, and germination chamber studies was used to evaluate the effects of methiocarb [3,5-dimethyl-4-(methylthio)phenol methylcarbamate] and thiram (tetramethylthiuram disulfide) repellent seed treatments on early corn performance. The thiram treatments used (0.08, 0.4, 0.8, 0.5, 1.25, and 2.5% active ingredient by corn seed weight) had negligible effects on germination/emergence time or on corn plant heights. The thiram treatments never reduced stand counts in comparison to controls, but apparently increased stand counts in some trials, particularly under wet conditions. The methiocarb treatments evaluated (0.5, 1.25, 2.5, and 5.0% active ingredient by corn seed weight) had only occasional effects on early corn performance. However, certain methiocarb treatments advanced or retarded germination in some trials and increased plant heights in three trials. Methiocarb treatment did not affect corn stand counts in most trials, but increased or reduced stand counts in some. The reduced stand counts appear related to wet conditions and possibly to other field effects. The techniques used have application in studies of both plant and rodent responses to seed-treatment repellents.
A Test Method That Evaluates Avian Perch Repellents
Authors: Scott EJ , Schafer EW
Published: February 2009

A cage design and test method that evaluates the efficacy of tactile avian perch repellents in the laboratory is described. Pigeons, starlings, and house sparrows were tested. Efficacy was demonstrated by a chi-square analysis of the time spent on perches by pigeons and starlings. Activity of individual birds exposed to three to five perches over a 2 to 4-h period was monitored. Pressure-sensitive microswitches were used to monitor activity, while counter and event recorders registered the number of landings and total time spent on each perch. Closed-circuit TV provided a visual record of bird activity without human disturbance. Examples of tests run with four avian perch repellents and pigeons demonstrated the differences in bird response and efficacy of the four products.
Correlation of Two Census Methods (Food Consumption and Gnawing Evidence) for Assessing Norway Rat Populations
Authors: Yo S-P , Marsh RE , Salmon TP
Published: February 2009

Two population census methods (relative indexes), food consumption and gnawing evidence on wooden stakes, were compared in a large 32 by 32-m outdoor enclosure of wild free-living Norway rats (Rattus norvegicus). Wooden survey-type stakes were driven partway into the ground with a portion left projecting above ground as a gnawing surface. Gnawing frequency was measured on a yes-or-no basis at each stake laid out in a 9 by 9 grid pattern. The food consumption census method employed paraffinized food blocks with consumption measured by weight. It was found that both census methods reflect population changes, and a relatively good correlation could be made in relation to the predetermined size of the rat population and subsequent changes. The correlation between the two census methods themselves was significant although not highly so (r = 0.453, P < 0.001), which is not entirely surprising since the two methods measured totally different factors. The data were analyzed using a three-dimensional frequency distribution method. To further assess the two methods, a nonparametric technique was also used to measure space utilization (area occupied by rats) in the outdoor enclosure. The space utilization pattern obtained by the gnawing index was substantially similar to the space utilization pattern indicated by the food consumption index.
Efficacy Determinations of Rodenticide Use and Trapping for Reduction of Coconut Loss in the Philippines
Authors: Milan PP , Jackson WB
Published: February 2009

Trapping and anticoagulant baiting to reduce rodent populations in coconut plantations—and consequently to reduce crop losses—were evaluated in Leyte (Central Philippines). Activity indices (trap success and tracking board utilization) were used to reference rodent populations (largely Rattus rattus mindanensis). Relative numbers of rodent-damaged, fallen coconuts were used to assess control efficacy.

Both anticoagulant baiting (ground, trunk, crown) and snap trapping (ground and crown) reduced numbers of rodents and fallen and damaged coconuts. Crown baiting was the most effective in reducing rat numbers and thus damage, and it also provided the most favorable cost/benefit ratio. Marking of rodents with metallic flakes contained in bait showed vertical movements in coconut trees as well as movements from croplands into coconut plantations at times of harvest and field preparation.
Tetracyclines as Fluorescent Bone Markers in Cotton and Roof Rats
Authors: Lefebvre LW , Pendergast JF , Decker DG
Published: February 2009

Three tetracycline compounds, demeclocycline hydrochloride (DMCH), tetracycline hydrochloride (TCH), and chlortetracycline hydrochloride (CTH), were administered by gavage and tested as fluorescent bone markers for adult cotton (Sigmodon hispidus) and roof (Rattus rattus) rats. Probit and logistic regression models did not fit the data well; a more extensive test, with more widely spaced doses and additional low doses, may improve fit. TCH and CTH, which are considerably less expensive than DMCH, appeared to be similar to DMCH in marking roof rats at higher doses (72, 108, and 162 mg/kg) but not at low doses (32 and 48 mg/kg). Cotton rat mandibles were not as distinctly marked as those of roof rats by any of the compounds. Only at high doses (162 and 243 mg/kg) of DMCH or TCH were more than 50% of cotton rats scored as marked by both evaluators. The dose-response test results support field evidence that DMCH is not an effective marker for cotton rats. Neither TCH or CTH appear to be better candidates than DMCH as markers for cotton rats.
Retention of Physiological Marks by Coyotes Ingesting Baits Containing Iophenoxic Acid, Mirex, and Rhodamine B
Authors: Knowlton FF , Savarie PJ , Wahlgren CE , Hayes DJ
Published: February 2009

Pen-reared coyotes (Canis latrans) voluntarily ingested small tallow baits containing 10 or 15 mg of iophenoxic acid, 100-mg mirex, and 150-mg rhodamine B. One week after treatment with 10 and 15-mg iophenoxic acid, mean serum iodine was elevated from pretreatment levels of less than 5 µg/100 mL to 175 and 324 µg/100 mL, respectively. Serum iodine levels declined to about 25 µg/100 mL after four months, but were still fivefold higher than controls. Coyotes that ate baits containing 100-mg mirex averaged 0.34-ppm mirex in serum one week later levels declined to 0.15 ppm after four months. Serum samples obtained 2 and 24 h after death contained higher concentrations of iodine and mirex than samples obtained immediately before death. Although some back guard hairs of coyotes fed 150-mg rhodamine B showed distinct fluorescent bands, rhodamine B did not appear to provide a dependable mark because all guard hairs were not marked.
Test Methods for Steel Foothold Traps: Criteria and Performance Standards
Authors: Linhart SB , Linscombe RG
Published: February 2009

Controversy over the continued use of steel traps for capturing wildlife has increased in recent years. Despite the great number of different types of traps and their widespread application for harvesting fur, controlling wildlife damage, and carrying out other wildlife management objectives, few tests of performance have been conducted and no standard test methods have been published. This paper lists and describes some of the physical criteria and laboratory and field tests needed to determine performance, including efficiency, selectivity, and injury sustained by captured animals.
Galvanic Corrosion Prediction and Experiments Assisted by Numerical Analysis
Authors: Fu JW
Published: February 2009

Principles used in the finite element modeling and boundary element modeling methods are explained in this paper. These methods are useful to corrosion engineers in analyzing corrosion cell current distributions. The paper begins with a description of how the current distribution phenomenon is represented by mathematical equations and how these equations can be solved using numerical calculations. A one-dimensional corrosion cell is used to demonstrate the methods. Later, the procedures used in the numerical modeling methods are described. Suggestions are given to corrosion engineers who are interested in using numerical modeling to analyze their corrosion problems. An example of the numerical analysis of galvanic corrosion is given. Factors affecting the accuracy of these methods are discussed.
Computer Modelling of Galvanic Corrosion
Authors: Adey RA , Niku SM
Published: February 2009

The computer simulation of galvanic corrosion systems has been shown to provide accurate information that can be used to improve design and avoid costly failure. The systems capability to model any general geometry coupled with the ability to accept a wide variety of forms of polarization data enables its effective use in a wide variety of marine and industrial applications. A number of cathodic protection applications are presented as a special case of galvanic corrosion.
Comparisons of Localized Ionic Currents as Measured from 1-D and 3-D Vibrating Probes with Finite-Element Predictions for an Iron-Copper Galvanic Couple
Authors: Kasper RG , Crowe CR
Published: February 2009

The ionic current density in the near-field of a corroding iron-copper galvanic couple was measured, and the results were compared with the predictions of a finite- element model, which calculates near-field potential and current density distributions. All three components of the ionic current density vector were measured using a three-dimensional vibrating microprobe. The calculated current densities were based on the measured polarization curves of the individual constituent materials forming the couple. Agreement between the predicted and measured results was excellent. Agreement between one-dimensional ionic current density distributions from previous work was also excellent.
Prediction of Tube-Tubesheet Galvanic Corrosion Using Finite Element and Wagner Number Analyses
Authors: Scully JR , Hack HP
Published: February 2009

Galvanic corrosion predictions for heat exchanger tube/tubesheet galvanic couples are presented and discussed. The predictions were performed using finite element analysis using two programs, WECAN and MARC, and by Wagner number analysis under conditions of secondary and tertiary current distribution. Long-term electrochemical potentiostatic polarization data generated over 120 days in natural seawater were used to account for time effects. Results of the predictions are presented in the form of potential and galvanic current density as a function of distance from the tubesheet along the tube axis.

Seawater exposures of some tube/tubesheet material combinations were performed to compare with the predictions. These exposures used segmented tubes connected in series through the use of zero resistance ammeters. Material combinations exposed included a Monel Alloy 400 tubesheet coupled to a 90-10 copper-nickel tube, a 90-10 copper-nickel tube coupled to a zinc anode at the position of the tubesheet, and a nickel-aluminum-bronze tubesheet coupled to an Alloy 625 tube. Tube/tubesheet data obtained from the literature were also compared to predictions.

This study is directed towards determining not only the degree of accuracy of the predictions from the finite element and Wagner number analysis techniques, but also the sensitivity of the analyses to small changes in the electrochemical data used to obtain the predictions. The feasibility of these two analysis techniques for accurate qualitative as well as quantitative galvanic corrosion prediction for the tube/tubesheet configuration is discussed.
Integration of Galvanic Corrosion Control Technology into Design
Authors: Jenkins JF
Published: February 2009

Corrosion and design are synergistic. Design affects the type and amount of corrosion that is likely to occur, and corrosion affects the functionality of a given design. As galvanic corrosion can result in rapid localized attack, its effects are often severe.

The general relationship between open circuit potential, polarization, electrolyte resistivity, area ratio, and galvanic corrosion is well understood by corrosion engineers but is often not considered during design. Control of galvanic corrosion is most often accomplished by identifying probable sites for galvanic attack and either eliminating the possibility of galvanic corrosion through elimination of the dissimilar metals or by other means.

Where atmospheric exposure is encountered, mitigation of galvanic effects can be accomplished by eliminating design features that trap and hold moisture, the use of sealants, or the use of welded versus bolted joints. The selection of fastener materials must also consider galvanic compatibility.

In applications where the surfaces subject to galvanic attack are submerged, electrical isolation of dissimilar metals, control of the relative anodic and cathodic areas, the use of protective coatings, and the application of cathodic protection should be considered.

The technology to control galvanic corrosion is well known to corrosion engineers but is often not considered during the design process. It is the responsibility of corrosion engineers to insure that corrosion control technology is incorporated into the design process. This may be achieved either by education of design engineers regarding galvanic corrosion or by the inclusion of a corrosion engineer in the design team.
Controlling Galvanic Corrosion in Soils with Cathodic Protection
Authors: Turner JM
Published: February 2009

Galvanic corrosion of buried external metallic surfaces can be controlled and mitigated by proper design, installation, and maintenance of the cathodic protection system. The design criteria typically used by corrosion engineers have been well documented and are supported by successful field applications. Design considerations discussed include selecting the appropriate type of cathodic protection system, electrolyte resistivity, coating quality, and types of anodes available.
The Effect of Soil Resistivity and Soil Temperature on the Corrosion of Galvanically Coupled Metals in Soil
Authors: Escalante E
Published: February 2009

Galvanic corrosion current measurements carried out on stressed Type 301 stainless steel coupled to zinc at six underground test sites over a period of four years indicate that the galvanic current is controlled by soil resistivity or oxygen availability in the soil. In well aerated soils, resistivity plays a dominant role, but in poorly aerated soils, oxygen controls the corrosion process. Furthermore, at a certain depth, approximately 1 m, soil resistivity is strongly influenced by soil temperature and only slightly affected by soil moisture. Finally, Type 301 stainless steel in a half-hard or full-hard condition is susceptible to hydrogen embrittlement failure in soil when exposed to potentials capable of causing hydrogen evolution.