bluuebunny/crossref_metadata_2025 huggingface dataset:
A Test System for Computer Controlled Thermomechanical Fatigue Testing
Authors: Jones WB , Schmale DT , Bourcier RJ
Published: March 2009

This paper describes a computer controlled testing system that is capable of performing complex thermomechanical fatigue tests. Three different tests have been developed: 1. High temperature compression (HTC) tests in which the gage length of the specimen is held at constant length and the mechanical strain is totally imposed by the triangular temperature cycle. 2. High temperature tension (HTT) tests in which the mechanically imposed length change is exactly double the thermally induced length change. 3. Multiple isothermal deformation (MID) tests for which the deformations occur isothermally and the temperature is changed every half cycle while maintaining constant mechanical strain.
Dedicated Microprocessor-Based Controller for Fatigue Testing
Authors: Sunder R , Venkatesh CS
Published: March 2009

The Intelligent Mechanical Test Controller (IMTC) was developed to provide programmable control of servohydraulic loadframes. It includes hardware for control waveform generation, multichannel data acquisition, feedback selection and servoloop control. Software fused into the system handles arbitrary waveform generation, peak monitoring with interlocks, data processing by way of least square correlation of one channel versus another, and continuous machine status update and display. A Mechanical Test Language (MTL) was created and its interpreter fused into the IMTC to enable local as well as remote programming of mechanical tests. Data transfers are implemented in user definable engineering units. Use of the IMTC does not require additional realtime hardware or system software on most host computers.
A Semiautomated Computer-Interactive Dynamic Impact Testing System
Authors: Alexander DJ , Nanstad RK , Corwin WR , Hutton JT
Published: March 2009

A computer-assisted semiautomated system has been developed for testing a variety of specimen types under dynamic impact conditions. The primary use of this system is for the testing of Charpy specimens. Full-, half-, and third-size specimens have been tested, both in the laboratory and remotely in a hot cell for irradiated specimens. Specimens are loaded into a transfer device that moves the specimen into a chamber, where a hot air gun is used to heat the specimen, or cold nitrogen gas is used for cooling, as required. The specimen is then quickly transferred from the furnace to the anvils and then broken. This system incorporates an instrumented tup to determine the change in voltage during the fracture process. These data are analyzed by the computer system after the test is complete. The voltage-time trace is recorded with a digital oscilloscope, transferred to the computer, and analyzed. The analysis program incorporates several unique features. It interacts with the operator and identifies the maximum voltage during the test, the amount of rapid fracture during the test (if any), and the end of the fracture process. The program then calculates the area to maximum voltage and the total area under the voltage-time curve. The data acquisition and analysis part of the system can be also used to conduct other dynamic testing. Dynamic tear and precracked specimens can be tested with an instrumented tup and analyzed in a similar manner.
Use of Computer Systems in High-Temperature Crack Growth Studies
Authors: Earthman JC
Published: March 2009

Computer-based systems have been used in experimental studies of high-temperature crack growth in oxygen-free high conductivity (OFHC) copper, copper with 1% antimony (Sb) by weight and 12Cr-1Mo-V steel. The testing machines employed for these studies were automated using computer feedback control techniques enabling the computer to regulate the applied load during the experiment. Crack length data were continually acquired by the computer during the experiments enabling it to control the value of a given loading parameter such as the stress intensity factor, K, or the J-integral rate parameter, C*. By holding a given parameter constant as the crack extends, investigators were able to determine whether the relationship between a particular loading parameter and the crack growth rate is unique. The results of the automated tests have also made it possible to further the understanding of the interaction between crack tip damage and the stresses that drive the crack growth process.
A Data Acquisition and Control Program for Axial-Torsional Fatigue Testing
Authors: Kalluri S , Bonacuse PJ
Published: March 2009

A computer program was developed for data acquisition and control of axial-torsional fatigue experiments at NASA-Lewis Research Center. The multitasked, interrupt-driven program was written in PASCAL and assembler. This program is capable of dual-channel control and six-channel data acquisition. It can be utilized to perform in-phase and out-of-phase axial-torsional isothermal fatigue or deformation experiments. The program was successfully used to conduct in-phase axial-torsional fatigue experiments on 304 stainless steel at room temperature and on Hastelloy X at 800°C. This paper describes the details of the software and gives some of the results generated to date.
Vibro Replacement - Design Criteria and Quality Control
Authors: Priebe HJ
Published: March 2009

Stone Columns are applied to improve cohesive soils. Although the equipment and procedure are the same as for the vibro compaction of non-cohesive soils, the inherent principles with regard to the improvement are completely different. The fact that the effects of both techniques overlap each other must not lead to wrong design criteria and/or wrong interpretations of the results.

Stone Columns are not independent structural members like piles. Theoretical approaches for the design are facilitated if the improvement is related to the conditions of the surrounding soil. However, approximations are indispensable, especially with regard to the interpretation of load tests which are the only reliable method of in-situ testing.
Specifications for Constructing and Load Testing Stone Columns in Clays
Authors: Stark TD , Yacyshyn BM
Published: March 2009

The purpose of this paper is to provide guidelines for writing a performance specification for the construction and load testing of stone columns in cohesive soils. Specifications from five different sources, three specialty contractors and two agencies, were studied to develop the guidelines described herein. The two primary components of a performance specification are the performance criteria for the stone column foundation and the load testing procedures used to verify that the desired ground improvement has been achieved.
Slide Correction by Stone Columns
Authors: Goughnour RR , Sung JT , Ramsey JS
Published: March 2009

A review of design procedures for slope stabilization by stone columns is given. Stone column design and construction is reviewed for three projects where natural slopes were stabilized by stone columns. Stone column construction was achieved by the wet vibro-replacement method, a dry preaugering technique, and the dry, bottom-feed method. Instrumentation is described and performance of the stone columns on these projects is reviewed. Slope movement has stopped completely in all cases.
Design and Installation of Stone Columns at Naval Air Station
Authors: Hayden RF , Welch CM
Published: March 2009

Stone columns were used to increase bearing capacity, reduce settlement, and mitigate liquefaction potential for one- to four-story structures on a housing project at Fallon Naval Air Station, Fallon, Nevada. Eighteen field plate load tests were used to measure load versus settlement characteristics of the stone columns. Standard penetration test borings and cone penetrometer measurements in the improved soils at various distances from the columns were also used to evaluate load tests and to predict building foundation performance.
The Use, Testing and Performance of Vibrated Stone Columns in the United Kingdom
Authors: Watts KS , Charles JA
Published: March 2009

Vibrated stone column ground improvement techniques are being used extensively for low rise housing and light industrial units in the United Kingdom. Much of the work is on filled sites. There is a need for simple and inexpensive forms of testing. The advantages and limitations of different types of in situ tests are considered. A brief account is given of field studies to evaluate the effectiveness of vibrated stone columns at two sites with different ground conditions.
Seismic Testing Methods for Evaluation of Deep Foundation Improvement by Compaction Grouting
Authors: Byle MJ , Blakita PM , Winter E
Published: March 2009

Improvement of subsurface soils by the injection of grout inclusions, termed compaction grouting, has been used since the mid 1950's. For improvement verification, past practice has generally been to test the compaction grouted area with SPT or CPT methods. However, since these procedures test only a single point: too little testing may not accurately represent the non-homogeneous nature of the improved soils while testing in sufficient numbers for accurate statistical evaluation may be uneconomic. An alternative to these methods is direct transmission seismic testing. This technique is particularly well suited to evaluate inclusion-improved soils since the seismic velocity is measured throughout the zone of improvement. To date, little information has been published on this method. The purpose of this paper, therefore, is to demonstrate the use of seismic test procedures, to evaluate data accumulated from two test sites and to present recommended guidelines for the use of these methods.
Vibratory Deep Compaction of Underwater Fill
Authors: Castelli RJ
Published: March 2009

A case history is presented describing the use of vibratory deep compaction of underwater fill placed behind an anchored steel sheet pile bulkhead. The project included extensive testing to evaluate a variety of compaction equipment, procedures and backfill materials. Quality control tests, including static cone penetration tests, standard penetration tests, and settlement measurements were performed to verify compliance with specified compaction criteria and to assess the impact of deep compaction on the bulkhead structure. The successful completion of this project illustrates the effectiveness of vibratory deep compaction for marine applications.
Volumetric Leak Detection — A Systems Perspective
Authors: Rogers WF
Published: March 2009

Volumetric testing of USTs has grown exponentially in recent years, stimulated by regulation and by increasing business sensitivity to potential liabilities from leaking tanks. This paper attempts to lay an intellectual groundwork for discussion of such systems and focuses on the objectives of leak detection and the role of measurement precision. The important methodological issues of identifying and discriminating among sources of apparent volume changes which are not related to leakage, and the analysis and interpretation of test results will also be addressed.
Error Sources in Automatic Tank Gauging System
Authors: Fleischer DW
Published: March 2009

There are several sources of error which an automatic tank gauging system must overcome in order to accurately detect and measure a liquid leak from an underground storage tank. Some of these sources are: liquid temperature change measurement inaccuracies, tank chart errors, liquid temperature coefficient of expansion inaccuracies, absolute and differential liquid level measurement inaccuracies, liquid evaporation, tank thermal expansion, liquid expansion in tank piping, vapor pockets, tank deformation and groundwater pressure. This paper describes the occurrence and impact of these errors.
Location of Leaks in Pressurized Petroleum Pipelines by Means of Passive-Acoustic Sensing Methods
Authors: Eckert EG , Maresca JW , Hillger RW , Yezzi JJ
Published: March 2009

Experiments were conducted on the underground pipeline at the EPA's UST Test Apparatus in which three acoustic sensors separated by a maximum distance of 38 m (125 ft) were used to monitor signals produced by 11.4-, 5.7-, and 3.8-L/h (3.0-, 1.5-, and 1.0-gal/h) leaks in the wall of a 5-cm-diameter pressurized petroleum pipeline. The range of line pressures and hole diameters used in the experiments were 70 to 140 kPa (10 to 20 psi), and 0.4 to 0.7 mm (0.015 to 0.030 in.), respectively. Application of a leak location algorithm based upon the technique of coherence function analysis resulted in mean differences of approximately 10 cm between predicted and actual leak locations. Standard deviations of the location estimates were approximately 30 cm.

Spectra computed from leak-on and leak-off time series indicate that the majority of acoustic energy received in the far field of the leak is concentrated in a frequency band from 1 to 4 kHz. The strength of the signal within this band was found to be proportional to the leak flow rate and line pressure. Energy propagation from leak to sensor was observed via three types of wave motion: longitudinal waves in the product, and longitudinal and transverse waves in the steel. The similarity between the measured wave speed and the nominal speed of sound in gasoline suggests that longitudinal waves in the product dominate the spectrum of received acoustic energy. The effects of multiple-mode wave propagation and the reflection of acoustic signals within the pipeline were observed as non-random fluctuations in the measured phase difference between sensor pairs.
Analysis of UST Leak Vapor Diffusion and Liquid Build-Up
Authors: Schreiber RP , Rosenberg MS
Published: March 2009

The need for improved leak detection and corrective action has prompted research into the movement of hydrocarbon vapors from leaking underground storage tanks (USTs) as well as the build-up of liquid hydrocarbon on the water table. This research has included the development of two evaluation techniques, one for simulating vapor diffusion from an UST leak and another for simulating the mounding of leaked hydrocarbon liquid. Both techniques are designed to produce approximate estimates of hydrocarbon movement and build-up, and as such are intended to be used in the early stages of site remediation planning and monitoring. The result of the research is a set of response curves and analytical techniques that can be used in designing monitoring systems and in performing site clean-ups.
Evaluation of Metal Oxide Semiconductor and Polymer Adsorption Gas Sensors as Applied to Underground Storage Tank Leak Detection
Authors: Portnoff MA , Grace R , Guzman AM , Hibner J
Published: March 2009

Gas sensor properties are measured with the purpose of comparing two sensor technologies used for underground storage tank leak detection. Metal Oxide Semiconductor (MOS) and the Polymer Adsorption (PA) gas sensors were tested in simulated underground storage tank environments using the Carnegie Mellon Research Institute (CMRI) automated gas testing facilities. This automated system was used to monitor the response of the sensors while dynamically exposing them to various mixtures of methane, butane and xylene. The sensors were also tested to determine the effects of humidity on their responses. Sensor responses were characterized by sensitivity, selectivity, and speed of response and recovery to the test environments. The test results are presented as a list of sensor specifications to allow the potential end user a direct comparison of these two different types of sensors.
Fiber Optic Chemical Sensors — An Overveiw
Authors: Grey AE , Partin JK
Published: March 2009

In a span of approximately 20 years, fiber optic sensing has grown from a laboratory oddity to a viable analytical field technigue for the detection and monitoring of a wide variety of analytes. One of the reasons for this rapid growth is the range of technigues that can be used for the detection of species. These include changes in absorption, reflection, refraction, phase, polarization, and fluorescence. In general, any chemical or physical reaction that will perturb the light transmission through the optical fiber can be used as the basis for a fiber optic detector. Examples of fiber optic chemical sensors are presented and their advantages over conventional devices are discussed.
New Vapor Method Detects and Locates Leaks from Pipelines
Authors: Martin MV
Published: March 2009

This paper covers a new process that detects and locates leaks from pipelines using a patented sensor tube. The sensor tube is laid parallel to a gas or liquid pipeline to monitor for vapors from a release. The sensor tube membrane has a high permeability for vapor absorption and diffusion. A vacuum is pulled on the sensor tube with cycle time dependent on the vapor pressure of the leaking substance, distance the sensor tube is placed from the leak source, and the type, compaction, and moisture content of the soil. Vapors that have diffused into the sensor tube are transported to a pump/detection unit that monitors for an increase of vapor concentration along the length of the sensor tube. The system monitors for increases in vapors concentration over the background vapors present in the soil and around the pipe. The vapors are transported at a flow controlled rate allowing leak location to be calculated. Examples of actual applications and installation techniques are provided. The paper concludes with a summary of a third party protocol developed to evaluate this techniques capability.
Evaluation of Pipeline Leak Detection Systems
Authors: Glauz WD , Flora JD , Hennon GJ
Published: March 2009

Leaking underground storage tank systems present an environmental concern and a potential health hazard. It is well known that leaks in the piping associated with these systems account for a sizeable fraction of the leaks. EPA has established performance standards for pipeline leak detection systems, and published a document presenting test protocols for evaluating these systems against the standards. This paper discusses a number of facets and important features of evaluating such systems, and presents results from tests of several systems. The importance of temperature differences between the ground and the product in the line is shown both in theory and with test data. The impact of the amount of soil moisture present is addressed, along with the effect of frozen soil. These features are addressed both for line tightness test systems, which must detect leaks of 0.10 gal/h (0.38 L/h) at 150% of normal line pressure, or 0.20 gal/h (0.76 L/h) at normal line pressure, and for automatic line leak detectors that must detect leaks of 3 gal/h (11 L/h) at 10 psi (69 kPa) within an hour of the occurrence of the leak. This paper also addresses some statistical aspects of the evaluation of these systems. Reasons for keeping the evaluation process “blind” to the evaluated company are given, along with methods for assuring that the tests are blind. Most importantly, a test procedure is presented for evaluating systems that report a flow rate (not just a pass/fail decision) that is much more efficient than the procedure presented in the EPA protocol, and is just as stringent.
Risk Assessment to an Integrated Planning Model for UST Programs
Authors: Ferguson KW
Published: March 2009

The U.S. Postal Service maintains the largest civilian fleet in the United States totalling approximately 180,000 vehicles. To support the fleets daily energy requirements, the Postal Service also operates one of the largest networks of underground storage tanks nearly 7,500 nationwide. A program to apply risk assessment to planning, budget development and other management actions was implemented during September, 1989. Working closely with a consultant, the postal service developed regulatory and environmental risk criteria and weighting factors for a ranking model. The primary objective was to identify relative risks for each underground tank at individual facilities. Relative risks at each facility were determined central to prioritizing scheduled improvements to the tank network. The survey was conducted on 302 underground tanks in the Northeast Region of the United States. An environmental and regulatory risk score was computed for each UST. By ranking the tanks according to their risk score, tanks were classified into management action categories including, but not limited to, underground tank testing, retrofit, repair, replacement and closure.
Use of On-Site Soil Vapor Analysis in UST Site Assessments: A Summary of Results at 635 Sites
Authors: Golding RD , Wichman TA
Published: March 2009

Over six hundred sites in the state of Iowa were evaluated for hydrocarbon contamination associated with underground storage and delivery systems. Driven probe technology was used to obtain the soil vapor samples which where analyzed on-site using a field mobilized, laboratory grade gas chromatograph. A hydrocarbon concentration of 1000 (μg/l in the soil gas had been established as an action level for state assisted cleanup. This action level proved to be conservative. Approximately 72% of the sites were at or above this action level. The pattern of hydrocarbon distribution was found to be affected by three physical site properties. As was expected, concentration readings increased with depth and as groundwater was approached. Higher readings were obtained under pavement vs under unpaved areas. High hydrocarbon concentrations were not a reliable indicator of leakage. Of the sites which passed a tightness test, hydrocarbon concentrations in the soil gas approached saturation at 70% of the sites. However, low hydrocarbon concentration was a better indication of system tightness. Only 8% of the sites with low levels of hydrocarbons failed a system tightness test. Relative soil permeability remained fairly constant down to approximately 7 feet (2.1 meters) where it began to increase due to the proximity to groundwater in the capillary fringe.
Pyrethroid Microemulsions
Authors: Rebmann V , Fiquet L
Published: March 2009

A system containing a polyarylphenolethoxylate as the nonionic surfactant, and a calcium dodecylbenzenesulfonate in alcohol as the anionic surfactant and co-surfactant respectively, was used to study microemulsions of Permethrin and Cypermethrin (common insecticides of the important Pyrethroids class).

The influence of co-surfactant chain length was investigated employing phase diagrams. The results obtained with this pseudo-quaternary system of technical products are compared with those found for more basic systems and theoretical studies predicting a strong influence of slight co-surfactant chain length reduction.

Besides providing a good understanding of the phase behavior, phase diagrams offer a complete picture of the different microemulsions likely to be formulated with the described system, thus offering a large choice of formulations meeting specific application requirements. An example of such an approach is given, with the optimization of both 10 and 25 % Permethrin microemulsions.
Formulation Test Methods and Statistical Experimental Design
Authors: Becher DZ
Published: March 2009

The opportunity presented by the need for a dry formulation for field testing an experimental herbicide was used to evaluate the utility of statistical experimental design in the development of such formulations. This method has the potential to significantly reduce the number of experimental formulations required to discover the best composition. The wetting time, settling, and redispersion were used to evaluate the formulations.

A number of different statistical models were tested and the results compared. It was found that while a complete cubic model gave the most accurate predictions a quadratic model was adequate for most purposes. It was found that the ability to accurately and reproducibly measure the effect of composition on formulation performance is the limiting factor in the utility of this method. The need for better test methods for dry formulations was evident.
Effect of Surfactant Type and Order of Addition on Droplet Size and Dynamic Interfacial Properties
Authors: Berger PD , Berger CH
Published: March 2009

A model system containing a nonionic surfactant (nonylphenol + 9.5EO) and an anionic surfactant (Sodium C14-16 alpha-olefin Sulfonate) was used to study the effect of surfactants on droplet size and dynamic interfacial tension. BLANDOL™ (white mineral oil) was selected as the oil phase and the dynamic interfacial tension of the two surfactants at various concentrations, temperatures and in the presence of electrolyte was measured. The effect of using the surfactants separately and together was also measured. In addition, the effect of adding the surfactant to the oil phase and the water phase to the oil phase was determined.

The implications of the results are discussed with respect to emulsion stability, demulsification, spray drying, spray drift control, wetting and spreading.
Effect of Drift Retardant Chemicals on Spray Drift, Droplet Size and Spray Pattern
Authors: Ozkan HE , Reichard DL , Zhu H , Ackerman KD
Published: March 2009

Specific objectives of this study were to determine the effects of various drift retardant chemicals (Direct, Driftgard, Formula 358, Nalco-trol, and Target) on droplet size, spray pattern, and spray drift reduction. The results of this study indicated that, at recommended rates, Nalco-trol provided the largest increase in volume median diameters of the sprays followed by Direct, Target, Driftgard, and Formula 358. In general all drift retardants created patterns with greater volume toward the center than that of water only. Cumulative deposits beyond 0.5 m downwind increased for all drift retardants when the wind velocity was increased from 2.0 to 4.0 m/s. The least amount of downwind deposit beyond 0.5 m at 4.0 m/s was with Nalco-trol followed by Target, Driftgard, Direct and Formula 358. In general, a comparison of the spray deposits from mixtures containing drift retardants on horizontal targets and vertical strings indicated that Nalco-trol and Target were the most effective in reducing spray drift followed by Direct, Driftgard, and Formula 358.
Physico-Chemical Properties, In-Flight Evaporation and Spread of Spray Droplets Containing Pesticide Adjuvants
Authors: Hall FR , Thacker JRM , Downer RA
Published: March 2009

In-flight evaporation, droplet spread on water sensitive paper, equilibrium surface tension, and dynamic surface tension were measured for each of 12 adjuvants mixed with water. The correlation between the physico-chemical properties and droplet spread was determined. The results indicated that the adjuvants had significant and varied effects upon the parameters that were measured. Speculative rankings were derived for (A) evaporation rates and (B) spreading potentials. The rankings were compared with manufacturer's claims for the adjuvants and the results are discussed in terms of the benefits to be derived from using these products in pesticide applications.
Rain-Fastness of

Bacillus Thuringiensis

Deposits on Conifer Foliage
Authors: Sundaram A , Leung JW , Devisetty BN
Published: March 2009

Eight oil-based and four aqueous experimental formulations of Bacillus thuringiensis var. kurstaki, were sprayed in a laboratory chamber over potted seedlings of white spruce and balsam fir. Foliar deposits were assessed before and after 3 mm rain with a rainfall intensity of 5 mm/h, using a force-feeding bioassay (FFB) method of foliar extracts on the spruce budworm larvae. In addition, a total protein assay (TPA) method was used to compare the two sets of results.

The FFB method showed that formulations that provided high deposits (IU/cm2) on foliage, showed some residual activity after the rainfall, whereas formulations that provided low deposits showed no activity after the rain. This trend was observed regardless of the formulation type, oil-based or aqueous. The TPA method was more sensitive than the FFB method because with all formulations, some protein deposits (ng/cm2) remained on foliage after the rain. In general, the oil-based formulations showed greater rainfastness than the aqueous formulations, a finding that was not as evident in the FFB method. The differences in the two sets of data were due to the fact that the FFB method depended on the biological response of an insect, thus resulting in high variability in deposits, whereas the TPA method provided a direct estimation of protein deposits that were less variable.
A Simulation Model of the Dose Transfer of Foliar Applied Insecticides
Authors: Taylor RAJ , Chapple AC , Hall FR
Published: March 2009

The inefficiency of pesticide application has become a serious economic and environmental problem. Improving application efficiency requires a better understanding of the application process. The transfer of dose from spray tank to pest target involves a large set of physical and biological factors. Investigating such a complex system experimentally is extremely laborious and costly. A model is described that allows investigation of the biological consequences of altering the application parameters for foliar applied insecticides (in this case, the bacterial insecticide Bacillus thuringiensis var. Kurstaki when used against the diamondback moth (Plutella xylostella L.) with cabbage as the substrate). Parameters input into the model include the frequency distribution of droplet size, spatial distribution of the deposit, the subsequent degradation of the deposit by environmental factors, and toxicological effects against the target pest. Possible applications of the model are discussed, as are some preliminary results.
Measurement of Spray Distribution Uniformity for Agricultural Nozzles Using Spectral Analysis
Authors: Wang L , Zhang N , Slocombe JW , Kuhlman DK
Published: March 2009

A laboratory sampling procedure was developed to measure spray distribution uniformity of nozzles used for agricultural chemical applications. A fast Fourier transformation (FFT) algorithm was used to obtain Fourier spectra of spray pattern profiles. A model of the degree of nonuniformity (DNU) was established based on the spectral analysis. The DNU model used a concept of weighted alternating-current components (WAC) to describe the variations of the profiles. Laboratory data were used to compare the DNU model with the traditionally used coefficient of variation (CV) model in detecting profile fluctuation patterns and in determining the nonuniformity. It was found that the DNU model could provide quantitative judgements in cases where the CV model was unable to detect differences in spray distribution uniformity.
Use of Intelimer® Microcapsules to Control the Release of Agricultural Products and Reduce Leaching
Authors: Meyers PA , Greene CL , Springer JT
Published: March 2009

Landec Corporation has developed a family of polymers (Intelimer®) with unique properties that are currently being used in the microencapsulation of agricultural pesticides. Landec is developing uses for its proprietary polymers, which have a temperature switch built into them. Below the switch temperature the polymers have a very low permeability to the diffusion of active ingredients and above the switch they are quite permeable. This property allows the preparation of capsule suspensions (CS) that release active ingredients in response to small changes in temperature. Many different classes of pesticides including an acetanilide (alachlor) and a sulfonyl urea herbicide have been encapsulated.

Soil temperature initiates many biological processes. If the delivery of the pesticide coincides with these processes, the most effective control of the pest will occur. In application practices where the pesticide is applied before planting, degradation processes deplete the pesticide, necessitating the need for a larger amount of pesticide to be applied, to give a particular window of control (10 days to 45 days). The use of temperature activated release of pesticides may be the most cost effective use of a pesticide. The soil can be treated prior to planting, but release of the pesticide will not occur until the appropriate temperature is reached. Microcapsules utilizing this release mechanism offer many advantages over conventional formulations, such as a reduction in leaching, protection from environmental degradation and reduced application rates.

In column leaching and field trial studies, CS's of a sulfonyl urea and an acetanilide controlled migration of the active within the top 5 or 7.5 centimeters of soil, while wettable granules and wettable powders had 3 to 8 times further migration in the soil. Test results illustrate that CS's can significantly decrease groundwater leaching potential of herbicides. A temperature-activated “on/off” response in biological control was observed in temperature controlled growth chamber studies.
New Manufacturing Processes for Making WDG Pesticides
Authors: Gerety PJ
Published: March 2009

This paper is a review, based on practical experience, of existing and new processes for making water-dispersable granules (WDGs) from pesticide technicals. The conventional process for making WDG pesticides is pan agglomeration. This process has disadvantages, however, which the new processes may overcome. The disadvantages include difficulty in limiting worker exposure to the pesticide involved, dealing with water-soluble and low-melting technicals, reducing to the absolute minimum dust generation during product handling, and so forth.

The new processes discussed are low pressure extrusion, dry compaction / granulation, spray-dryer agglomeration, and fluid bed agglomeration. Also discussed are ways to treat low-melting technicals to improve stability during milling and storage. The paper also discusses certain formulation elements, including surfactants, carriers, and disintegrants, which have been found to be particularly suitable for the new agglomeration processes.
Fleet Test Correlations of Original Equipment Coolant Pump Failures and Engine Coolant Formulations
Authors: Burns JM
Published: March 2009

Automobile coolant pump failures can be minimized by choosing an engine coolant formulation that has a relatively insignificant effect on the seal as well as the other materials used in the construction of the pumps. A fleet test involving 203 1990 Ford Crown Victoria taxi cabs provided data demonstrating that the number of pump failures experienced by the group of taxis employing a unique experimental coolant free of most traditional corrosion inhibitors was much lower than the number experienced by any of the other four test groups employing different, more traditional, formulation variations.

Sixty to eighty-five percent of the original equipment coolant pumps on the four groups of vehicles employing the more traditional coolant formulations had to be replaced during the test period, which nominally covered the vehicles' first 160 000 km. Only 15% of the original coolant pumps installed on the experimental coolant test group required replacement.
An Investigation of Carboxylic Acids as Corrosion Inhibitors in Engine Coolant
Authors: Mercer WC
Published: March 2009

The ability of carboxylic acids to inhibit corrosion in automotive cooling systems was first reported more than 40 years ago. Aromatic carboxylic acids, such as benzoic acid and its derivatives, have been extensively studied and are used in Europe as corrosion inhibitors in commercial coolants. There are few studies of corrosion inhibition by aliphatic carboxylic acids in the open literature. Aliphatic dibasic acids, such as 1,10-decanedioic, and aliphatic monobasic acids, such as octanoic, have recently been proposed as inhibitors in automotive coolant formulations. To date, ASTM performance test data have not been available.

This paper presents a comparison of the performance of selected carboxylic acid coolants with each other and with a traditional North American coolant in laboratory and fleet tests. Protection of cooling system metals, inhibitor depletion, and mixed coolant effects were investigated.
Corrosion Testing for Aluminum Alloy Selection in Automotive Radiators
Authors: Beal RE , El-Bourini R
Published: March 2009

Durability of aluminum alloy automotive radiators in service depends on the alloy selected and the expected engine coolant environment. The challenge is to find testing methods that correlate with service experiences that allow for comparative evaluation of competing materials without resort to long-term vehicle exposure at initial selection stages. Design, manufacture, and processing affect radiator performance and must be taken into account in corrosion testing. Aluminum alloys AA3003 and AA7072 are used to illustrate the test program.

Electrochemical corrosion test methods were used for screening purposes in alloy selection and corrosion test environment studies. A simulated service test method is used with selected corrosion media to provide accelerated corrosion data in full sized radiators. The importance of relating corrosion test media to ultimate engine coolant use and abuse is covered. Methods have been correlated with field tests to prove the approach used.
Phosphate-Molybdate Supplement Coolant Additives for Heavy Duty Diesel Engines
Authors: Hudgens RD
Published: March 2009

Supplemental coolant additives (SCAs) are commonly used in heavy duty diesel service. The SCA boosts the performance of the typical antifreeze coolant and replaces additives lost to depletion and coolant dilution.

In the early 1970s chromate based SCA's were phased out because of chromate's toxicity and adverse environmental impact. Borate-nitrite based SCAs replaced the chromates and are widely used today.

This paper describes the development of a third generation phosphate-molybdate additive package. Relative to the borate-nitrite SCAs, the phosphate-molybdate supplemental coolant additive gives better overall aluminum protection. Furthermore if overtreated, it is less likely to cause solder bloom, silicate gelation, and water pump leakage.
Test Strips for Rapid On-Site Analysis of Engine Coolants
Authors: Hemmes PR , Kreiser TH , Valle S , Hercamp RD
Published: March 2009

This paper reviews the use of test strips for measuring the composition of engine coolants. The tests described include test strips for freezepoint, cylinder lining cavitation corrosion protection, reserve alkalinity, pH, chloride, and mercaptobenzothiazole.

Freezepoint strips work with reasonable accuracy with both ethylene glycol and propylene gly col based coolants. They will also work with mixtures of the two. The strips are shown to work with coolants containing phosphates, borates, or benzoates. Data show that good results can be obtained with new users so that training is minimized.

Strips for liner cavitation protection are described. Good results were obtained with visually read strips for nitrite in the range of 200 to 4000 ppm and for molybdate in the range of 75 to 1500 ppm. A hand-held reflectance meter to read these strips is described. Precision and accuracy data are given. The strips are not sensitive to glycol concentration.

Data are presented for the accuracy of test strips for reserve alkalinity and pH. Test strips for mercaptobenzothiazole are described. A description is also provided of a prototype test for chloride levels in used coolants where the makeup water may have contained salts. In all cases, test strips were found to be accurate, easy-to-use, inexpensive devices useful for routine field monitoring of coolants.
Characterization of Used Engine Coolant by Statistical Analysis
Authors: Woodward SM , Gershun AV
Published: March 2009

Since the 1950s, the most common choice of engine coolant has been a 50:50 mixture of ethylene glycol and water, with the ethylene glycol containing selected corrosion inhibitors and other additives such as nitrates, silicates, borates, phosphates, tolyltriazole (TTZ), mercaptobenzothiazole (MET), antifoam, molybdates, silicones, dye, surfactant, and alkalinity builder. Manufacturers in Europe and Asia use a different corrosion inhibition technology than those used in North America.

The function of the engine coolant is simple, to remove the heat from the engine and to protect the engine from corrosion and pitting of the metal surfaces. As the coolant accumulates miles or hours in a vehicle cooling system, it develops many different types of problems. With time, the inhibitors deplete, the ethylene glycol degrades, the pH of the coolant solution decreases, and corrosion starts to take place. Silicates can combine with excessive levels of magnesium or calcium, thus losing their ability to protect aluminum; MBT is easily oxidized and results in loss of copper protection; and phosphates can combine with calcium and magnesium to form an insoluble sediment.

A consequence of this chemistry is that the coolant that comes out of an automobile after time and use can be significantly different than what went into it. With the increased emphasis placed on proper waste disposal and recycling of used coolant, it is important to understand what is coming out of the car.

During 1989 and 1990, a statistically valid survey and characterization of used engine coolant was taken from commercial automotive service centers. The purpose of the survey was to characterize the condition of a typical used engine coolant. The samples were evaluated for suspended matter, and analyzed for pH, reserve alkalinity (RA), percent ethylene glycol (EG), diethylene glycol (DEG), propylene glycol (PG); the presence of degradation acids (acetate, glycolate, formate, and ethylenediaminetetraacetate [EDTA]); the level of inhibitors (nitrites, nitrates, TTZ, MET, benzotriazole [BZT], benzoate), oil, chloride, fluoride, sulfate concentrations, and 14 other elements (Al, B, Ca, Cu, Fe, K, Mg, Mo, Na, P, Pb, Si, Sn, Zn) in their soluble and insoluble forms. The samples were also tested following U.S. Environmental Protection Agency (EPA) guidelines to determine if the engine coolant would be considered a hazardous waste.

This paper presents the findings of this survey and shows the variation in the condition of engine coolant taken from automobiles at the time the average consumer decides to change the fluid.
Heavy Duty Diesel Engine Coolants: Technology Update
Authors: Kelley FA
Published: March 2009

A summary of current heavy duty engine coolant technology is provided which includes a description of heavy duty engines and applications, current problems and concerns which face the industry, industry standard specifications and test methods which are under development to address the concerns, and future directions for the technology. The special needs of heavy duty engines dictate that engine coolant formulations be developed and made available that are tailored to these engines. Efforts to improve fuel economy and durability while reducing emissions and noise will have an important impact on the application of engine coolant technology to heavy duty diesel engines in the future.
Hydroxylapatite Powders for Implant Coatings
Authors: Tofe AJ , Brewster GA , Bowerman MA , Myers RN , Hurson SM
Published: March 2009

Dense, porous, resorbable and nonresorbable are all too familiar terms associated with hydroxylapatite (HA) bone grafting materials. While each of the above have their clinical applicability in osseous oral rehabilitation, the HA powder characteristics that ensure optimal plasma spray coatings to implants are distinctly different.

The powder's calcium phosphate phases, the density of the powder, the particle size of the powder and the particle shape and subsequent flow characteristics all can impact upon the quality of the final HA coating. These physical properties coupled to controlling the melt of the powder surface are shown to be related to the quality of HA coatings on implants with respect to crystallinity and bonding strengths. While multiple parameters are important in plasma spraying, control of the powder is the first step toward high-quality coatings.
Techniques for the Characterization and Quality Control of Hydroxyapatite Raw Materials and Coatings
Authors: Flohr KW
Published: March 2009

The chemical laboratory at a commercial coating company is responsible for characterizing and testing the quality of hydroxyapatite (HA) for both incoming raw material and the applied coatings prior to acceptance of a manufactured lot. Quality control tests of the raw material include measurement of crystallinity of the HA using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopic (FTIR) methods and chemical analysis of the HA for the proper calcium to phosphorus ratio and for the presence of impurities. The finished coatings undergo all the same tests as the raw material plus an evaluation of adhesion.

Evaluated raw materials have varied widely in composition and properties. Chemical compositions ranged from stoichiometric HA to tricalcium phosphate. Impurities ranged from a probably biologically insignificant presence of magnesium to the presence of over four weight percent of toxic barium and included up to 10 weight percent soluble calcium carbonate. The crystallinity varied from greater than 90% to less than 5%. Variations in crystallinity, the presence of calcium oxide and calcium carbonate, and substitutions of cations other than calcium have the potential of causing variations in the final coating. The reported crystallinity variation was between two different lots from the same supplier. Therefore, it is necessary to continue Quality Control (QC) testing, even for previously approved vendors. The samples with high levels of barium were submitted for use as a less expensive source of HA. This indicates the need to examine carefully all sources of raw materials.

Since the coating used by our company on implants is applied in an inert gas plasma arc, no introduction of foreign cations occurs. However, changes in crystallinity and the transformation from HA to other calcium phosphatephases can occur. The early detection of such changes allows for rapid correction of operator parameters.

In the process of testing HA, a variety of techniques have been developed which may be of general use in the field of HA studies. These include a rapid screening for the presence of carbonate by use of an FTIR, examination of the presence of gross levels of contaminants and simultaneous measurement of grain size and shape by use of a scanning electron microscope with an energy dispersive spectrometer, and working methods to determine the concentration of foreign cations using an atomic absorption spectrophotometer. Additionally, the use of a common vocabulary for HA properties and standardized methods will allow comparison of coatings, not of sales hype.
Nondestructive Characterization of Hydroxylapatite Coated Dental Implants by XRD Method
Authors: Keller L , Rey-Fessler P
Published: March 2009

For the nondestructive characterization of HA deposited onto dental implants by plasma spraying, the incident beam path of a θ: 2θ X-ray powder diffractometer has been modified with parallel beam optics. The diffractometer is equipped with a dedicated sample stage to accommodate single cylindrical specimens with a diameter of 3.5mm to 4mm. The peak resolution of the instrument equals that of a standard Bragg-Brentano diffractometer. Nondestructive probing of implants with smooth and threaded surfaces will identify the phases present and reveal the presence of grain texture. From observations of noncrystalline scatter and line broadening it appears that the 2-phase concept (matrix = amorphous fraction + crystalline fraction) for crystallinity is inadequate. Both, “perfect” crystalline and “imperfect” crystalline HA are contained in the crystalline fraction of a plasma sprayed HA coating.