bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmaceutical Product Placement: Simply Script or Prescription for Trouble?
Authors: Ta Sony , Frosch Dominick L.
Published: April 2008

Pharmaceutical product placements integrate brands into story lines and may be an evolution in the industry's focus on direct-to-consumer advertising. Although it is still uncommon, the potential for such marketing is present and warrants attention. Medications have a unique status as a product category, and policies need to be tailored accordingly.
Environment-Assisted Intergranular Cracking: Factors that Promote Crack Path Connectivity
Authors: Scully JR
Published: April 2008

Environment-assisted intergranular cracking occurs in many polycrystalline materials as a result segregation of impurities to grain boundaries, precipitation of second phases and solute depletion at grain boundaries, or precipitate free zone (PFZ) formation. The presence of a specific environment and sustained tensile stress can render a material susceptible if the required grain boundary metallurgical conditions exist. Models have been developed to describe conditions for intergranular cracking. Such models are usually based on either dissolution-controlled intergranular cracking or hydrogen embrittlement along grain boundary paths. Currently, these models rely on average descriptions of grain boundary segregation level, solute depletion, and PFZ character. However, solute depletion, segregation, and PFZ character can vary from grain boundary to boundary depending on boundary energy, crystallographic mis-orientation, and other factors. The propagation of an continuous intergranular crack through a component requires a high population of such highly susceptible grains, favorable geometrical grain facet orientation relative to direction of uniaxial tensile stress, or high hydrostatic tensile stress to overcome unfavorable geometric grain facet orientation. Statistical theories of fracture and bond percolation provide methods to quantify whether a critical population of susceptible grains is necessary to provoke extensive intergranular cracking. These theories provide insight into whether or not a well-connected intergranular crack can propagate through a structure. Two examples explore the existence of a bond percolation threshold in two substantially different systems that exhibit intergranular cracking by either anodic dissolution or hydrogen embrittlement.
Micromechanical Modeling of Hydrogen Transport—A Review
Authors: Sofronis P , Taha A
Published: April 2008

Reviewing the mechanical aspects of stress corrosion cracking and hydrogen embrittlement almost 25 years ago, Rice [1, 2] indicated that an accurate analysis of hydrogen transport as affected by local stresses and strains is of primary importance toward understanding the conditions under which the mechanisms causing hydrogen embrittlement operate [3]. In 1980, Hirth in a review article [4] made it clear that trapping of hydrogen is a very important part of hydrogen embrittlement, and its significance lies behind the embrittling mechanisms. The purpose of this study is to review the models of hydrogen transport in non-hydride forming systems, and draw conclusions as regards to the hydrogen degradation effect. It should be pointed out that this review does not aim at identifying and quoting the entire literature on the subject, which is voluminous. In fact, there is a number of recent articles devoted on various specific issues of hydrogen transport, and related issues of trapping [5–12]. Rather, the effort will be directed toward providing the status of our current understanding of hydrogen transport, and in particular how solid mechanics methodology can help in this direction.
An Analysis of Baffle/Former Bolt Cracking in French PWRs
Authors: Scott PM , Meunier MC , Deydier D , Silvestre S , Trenty A
Published: April 2008

Irradiation-assisted stress corrosion cracking (IASCC) has been observed in various highly irradiated, stainless steel core components of both Boiling Water and Pressurized Water nuclear reactors. This phenomenon is believed to be responsible for cracking detected by ultrasonic nondestructive examination of some Type 316L stainless steel baffle/former bolts in six first generation CP0 series PWRs operating in France. Similar bolt failures in PWR core structures have been confirmed more recently in other countries. This paper describes a statistical analysis of the French observations. The objective was to determine whether any of the known fabrication and operating characteristics of the baffle/former bolts could be identified as having an important influence on the extent of bolt cracking. This information has been used to aid decisions concerning inspection frequency, possible replacement of cracked bolts, and selection of more resistant materials.
Considerations in Using Laboratory Test Data as an Indicator of Field Performance: Stress Corrosion Cracking
Authors: Jones RH
Published: April 2008

Correlations between laboratory stress corrosion test data and field performance and data are done for the express purpose of demonstrating the validity of the laboratory data for use in component design and performance. Improved component performance and life-prediction is the primary goal of developing correlations between the laboratory and field performance. It is not sufficient to merely obtain data from a standard test and assume this will suffice. The purpose of this paper is to summarize the role of standardized tests, specialized tests, full-size component tests, the impact of the quality of field data, inability to match field conditions in the laboratory, and role of modeling in developing a high confidence laboratory-field correlation.
Influence of Surface Films and Adsorption of Chloride Ions on SCC of Austenitic Stainless Steels in 0.75M HCl at Room Temperature
Authors: Chou PH , Etien R , Devine TM
Published: April 2008

In situ surface enhanced Raman spectroscopy (SERS) was used to investigate the surface films that form on 304 and 316L stainless steels in a number of acidic solutions that either cause stress corrosion cracking (SCC) at room temperature (O.75M HCl) or do not cause SCC at room temperature (0.75M NaCl (pH3), 0.74M H2SO4, 0.87M HC1O4 and 0.75M HBr). The results indicate the same film forms on the steels in all solutions except 1M NaCl (pH3). Hence, while a specific surface film may be necessary for SCC, it is not sufficient to cause SCC of tensile stressed stainless steels. It was also determined that adsorption of chloride ions on stainless steel in 0.75M HCl does not occur in the range of potentials in which SCC occurs. Hence, the role of chloride in causing SCC of stainless steels in acidic solutions at room temperature is not associated with either the formation of specific surface films or adsorption of chloride ions.
Toward A More Rational Taxonomy For Environmentally Induced Cracking
Authors: Ellis PF , Munson RE , Cameron J.
Published: April 2008

An improved taxonomy (systematic nomenclature) is proposed for environmentally induced cracking in aqueous systems. This improved taxonomy reduces the number of named environmentally induced cracking phenomena from more than 25 to just 7, and places these in relationship to each other, to cracking phenomena that are independent of environmental factors, and to corrosion processes that are independent of stress.

This improved taxonomy is designed to reduce the confusion inherent in the current post hoc nomenclature and to facilitate predictive or anticipatory consideration for the potential for cracking phenomena in materials, equipment, and structures.
Environmentally Assisted Cracking of Cold Drawn Eutectoid Steel for Civil Engineering Structures
Authors: Toribio J , Ovejero E
Published: April 2008

The paper analyzes the environmentally assisted cracking behaviour of eutectoid steels with different degrees of cold drawing subjected to electrochemical conditions promoting localized anodic dissolution. The experimental results showed a progressively anisotropic behaviour as the degree of cold drawing increases, with an evolution in the fracture type from Mode I (isotropic behaviour in slightly drawn steels) to mixed mode propagation (strongly anisotropic behaviour in heavily drawn steels). The fractographic analysis revealed changes in the microscopic topography depending on the fracture propagation mode. The phenomenon of crack tip blunting by selective dissolution in the near-tip area is discussed and the blunting effect increases with the degree of cold drawing. Attention is also paid to the possibility of evolution from smooth blunting to cornered blunting associated with shear at the crack tip vertices, so the markedly oriented pearlitic microstructure favours cornered blunting in the most heavily drawn steels.
Importance of Ionic Composition of Reconstituted Laboratory Test Water in Interpreting Metal Toxicity Test Results
Authors: Welsh PG , Chapman GA , Hansen JA , Lipton J
Published: April 2008

We compare the ionic composition of ASTM reconstituted water with surface waters of the United States. The relative concentrations of major cations in surface waters are variable: Ca:Mg molar ratios range from 0.3 to 12.9, and Na:K molar ratios range from 1.4 to 600. However, the relative concentrations of these cations in ASTM reconstituted water are constant: the Ca:Mg molar ratio is 0.7 and the Na:K molar ratio is 21.3. Recent research has demonstrated that Ca is more important than Mg in modifying metal toxicity to salmonids. Hence, differences in the relative concentrations of these cations between surface waters and ASTM reconstituted waters may bias metal toxicity results. We also evaluate the potential for Na to modify Cu toxicity in salmonids. Sodium concentrations as high as 32.S mg/L did not influence Cu toxicity. These results indicate that ASTM reconstituted water may not be appropriate for metal toxicity tests.
Ability of the Quinones Arising from the UV Irradiation of Anthracene to Induce 7-Ethoxyresorufin-O-Deethylase Activity in a Trout Liver Cell Line
Authors: Schirmer K , Joyce EM , Dixon DG , Greenberg BM , Bols NC
Published: April 2008

Quinone derivatives of the polycyclic aromatic hydrocarbon, anthracene, were investigated for their ability to induce 7-ethoxyresorufin-O-deethylase (EROD) activity in a cell line from rainbow trout liver, RTL-W1. Of the 11 anthracene quinones tested, five were capable of inducing EROD activity. From most to the least potent, the order of induction potency, based on EC50 values, was 2,6-dihydroxyanthraquinone = 1,2,4trihydroxyanthraquinone < 1,2-dihydroxyanthraquinone = 1,3-dihydroxyanthraquinone = 2-hydroxyanthraquinone. The 1,2,10-trihydroxylated anthracene also induced EROD activity whereas anthraquinone did not, indicating that the quinone structure alone was not adequate for EROD induction to occur. The current results show that UV irradiation of an AhR-inactive PAH, such as anthracene, can yield derivatives that are AhR active and induce EROD activity in fish cells and presumably in fish. Thus, responses mediated by the AhR and/or P4501A should be considered in the environmental risk assessment of UV/PAH interactions.
Harmonization of Plant Toxicity Tests
Authors: Petrie RC
Published: April 2008

The Environmental Protection Agency (EPA) Office of Pesticide Programs (OPP) is participating in Organization For Economic Cooperation and Development (OECD) workgroups to update OECD guidelines number 201 (aquatic algal toxicity), number 208 (terrestrial plant toxicity), and to develop a new yet unnumbered guideline for the aquatic macrophyte Lemna spp. The EPA participants have presented the 850 series EPA guidelines and existing American Society for Testing and Materials (ASTM) guidelines to the OECD workgroups for their consideration. Under the existing North Atlantic Free Trade Agreement (NAFTA), the EPA is harmonizing plant toxicity tests and nontarget plant risk assessment methods with the Pest Management Regulatory Agency (PMRA), Canada. A pesticide regulatory workshop was recently held at the EPA to share information with Mexican government pesticide regulators. The OECD guidelines are focusing on pesticide and toxic substances, whereas NAFTA harmonization efforts to date are primarily for methods used to evaluate pesticides. While some of the plant tests are similar for toxic substances and pesticides, statutes and risk assessment methods are different.
Monitoring Polycyclic Aromatic Hydrocarbon (PAH) Bioavailability Near Offshore Produced Water Discharges
Authors: Neff JM , Sauer TC , Hart AD
Published: April 2008

Produced water is the largest volume waste associated with production of oil and gas on offshore platforms. Produced water that meets effluent limitations for total oil and grease contains low concentrations of petroleum hydrocarbons, low molecular weight organic acids, and several metals. The U.S. EPA has expressed concern that some of these chemicals could be bioaccumulated to potentially toxic concentrations by marine organisms in the receiving waters of offshore produced water discharges. This paper presents the results of an intensive monitoring study to determine if marine animals bioaccumulate polycyclic aromatic hydrocarbons (PAHs) from produced water discharges to offshore waters of the Gulf of Mexico.

Two platform pairs, each consisting of a produced water-discharging platform and a nearby non-discharging reference platform were selected for monitoring in offshore waters (90 to 260 m depth) of the northern Gulf of Mexico. Produced water, ambient sea water, two species of bivalve mollusks, and several species of fish were collected from each platform pair. Forty PAH analytes, including parent and alkyl PAHs, were analyzed in all samples.

The two discharging platforms discharged an average of 1.75 million L/d and 1.13 million L/d of produced water containing 30 to 43 μg/L (ppb) and 24 to 51 μg/L of PAHs, respectively. More than 90 percent of the PAHs were naphthalene and alkylnaphthalenes. The two bivalves, jewel boxes and thorny oysters, collected from legs of the platforms, contained up to 800 ng/g dry wt (ppb) total PAHs in their soft tissues. Muscle tissues of fish collected from the platform pairs contained <1 to 120 ng/g dry wt total PAHs. The dominant PAHs in the bivalve tissues were alkylnaphthalenes, fluorenes, phenanthrenes, and dibenzothiophenes, all characteristic of a petroleum source. A few individual PAHs were present at a significantly higher concentration in tissues of thorny oysters, but not jewel boxes, from one of the produced water-discharging platforms than from the paired reference platform. The relative concentrations of different PAHs in oysters was different than that in the produced water. The evidence for bioaccumulation of PAHs from produced water by shellfish was considered weak and inconclusive, because bioaccumulation of petroleum-derived PAHs was demonstrated in only one instance, and the source(s) of the PAHs was unclear. Concentrations of individual PAHs in fish muscle were low. Higher concentrations of individual PAHs were detected with similar frequency in fish from the reference and discharging platforms. Thus, the fish were not bioaccumulating PAHs from the produced water discharges. Bivalves are more suitable than fish for monitoring bioaccumulation of petroleum hydrocarbons near offshore produced water discharges.
Differential Display Polymerase Chain Reaction and Gene Expression in Copper-ExposedDaphnia magna
Authors: Diener LC , Dixon DG , Greenberg BM , Schulte PM
Published: April 2008

Contamination of aquatic systems by metals and polycyclic aromatic hydrocarbons (PAHs) is a prevalent environmental problem. These contaminants are known to impact populations, organismal health, and survival negatively. Most of the organism and ecosystem level changes are a consequence of underlying molecular and subcellular damage. Therefore, molecular bioindicators are likely to be a sensitive tool for environmental assessment. We have demonstrated that both copper and phenanthrenequinone (PHEQ) alter protein expression in Daphnia magna. To investigate altered gene expression in Daphnia magna exposed to copper, PHEQ, and other contaminants, a technique based on the differential display polymerase chain reaction (ddPCR) is being developed for D. magna. This technique promises numerous applications as it permits a survey of the genes being expressed in any given organism. Furthermore, ddPCR allows one to monitor the changes in gene expression that result from any toxicant exposure. This paper reviews the applications of ddPCR and describes our development of ddPCR as a bioindicator of gene expression in D. magna in response to toxicant exposure. This is the first step in the development of a novel gene fingerprinting technique that can be applied to any compound and organism of interest.
Metal LC50s of a Soil Nematode Compared to Published Earthworm Data
Authors: Boyd WA , Stringer VA , Williams PL
Published: April 2008

A comparison of the acute LC50s for five metals between the standard test organism Eisenia fetida and the soil nematode Caenorhabditis elegans was made. Although the test with C. elegans is shorter (24 h vs. 2 wks) and uses less soil or testing medium (2.33 g vs. 200 g dry weight) than that for E. fetida, LC50s were comparable for the earthworm and nematode. The current study further investigated similarities by extending the exposure time to 48 h. Comparisons were made to 24-h C. elegans data, published E. fetida data, and U.S. Environmental Protection Agency (EPA) allowable concentrations. The nitrate salts of Pb, Ni, Cd, Zn, and Cu were used to generate LC50s. Two naturally occurring soils in Georgia were chosen to compare different soil properties on the metals' toxicity. Tifton soil was sampled from the southern region of Georgia and is characterized by relatively high sand and low clay and soil organic matter (SOM) contents. Cecil soil, in contrast, is found in the Piedmont region of Georgia and is characterized by relatively high amounts of clay and SOM. As anticipated, extending the exposure time to 48 h significantly increased the toxicity (i.e. decreased the LC50s) of the metals compared to published 24-h C. elegans data. Physical-chemical properties of soils are known to affect the binding of polyvalent metals and thus the bioavailability and toxicity of these metals. Increasing clay and SOM contents allow for an increased capacity to bind metals. For this reason, LC50s were higher in Cecil than in Tifton soil. Because tests using C. elegans are rapid, reliable, and generate data comparable to that of the earthworm, we suggest further studies that may lead to the standardization of the nematode for use as a soil toxicity-testing organism.
Laboratory and Field Approaches to Characterize the Soil Ecotoxicology of Polynitro Explosives
Authors: Sunahara GI , Robidoux PY , Lachance B , Renoux AY , Gong P , Rocheleau S , Dodard SG , Sarrazin M , Hawari J , Thiboutot S , Ampleman G
Published: April 2008

Nitro-aromatic and heterocyclic compounds such as 2,4,6-trinitrotoluene (TNT), l,3,5-trinitro-l,3,5-triazacyclohexane (RDX), 1,3,5,7-tetranitro-l,3,5,7-tetrazacyclooctane (HMX), have been identified worldwide in soil and groundwater, at sites related to military activities. Among these chemicals, the toxicology of TNT is better known; however, gaps of knowledge still exist. We characterized the soil ecotoxicology of these energetic polynitro substances and their degradation products. The toxicities of these chemicals on microbial, plants, and invertebrate (oligochaete) species, and to cultured mammalian cell systems were examined using spiked and field soil samples. A sensitivity distribution ranking the responses of species was assembled for establishing soil benchmarks for explosives such as TNT. Preliminary field studies were also carried out using earthworm mesocosms. These approaches will increase the toxicological understanding of energetic compounds and our ability to detect exposure/toxicities of these substances in the field, and aid in establishing environmentally acceptable criteria, which are of great interest to land managers.
Synergistic Toxicity of a Mixture of 1,2-dihydroxyanthraquinone and Copper on the Aquatic Plant Lemna gibba
Authors: Babu TS , Tripuranthakam S , Greenberg BM
Published: April 2008

Polycyclic aromatic hydrocarbons (PAHs) and metals are toxic to animals, plants and microorganisms. Both these groups of contaminants coexist in the industrialized environments. Therefore, it is important to study the mixture toxicity of such pollutants on biological systems. In the present study, we have used the aquatic higher plant Lemna gibba as a test organism to study the mixture toxicity of an oxy-PAH 1,2-dihydroxyanthraquinone (1,2-dhATQ), and the metal copper. 3 μ,Ml,2-dhATQ inhibited photosynthetic electron transport downstream of photosystem II at the cytochrome b6/f complex. Such an inhibition results in the alteration of the redox status of the chloroplast to a reduced state because the plastoquinone pool goes to a net reduced state. Under such circumstances, when 4 μM CuSO4 was administered to L. gibba, there was a synergistic inhibition of growth and protein expression. We infer from these results that the synergistic toxicity caused by the mixture of 1,2-dhATQ plus CuSO4 is due to the catalytic transfer of electrons by Cu2+ from the reduced plastoquinone pool to O2. Such a mediation of electrons leads to the generation of reactive oxygen species, which could cause greater toxicity of 1,2-dhATQ.

Polycyclic aromatic hydrocarbons (PAHs) and metals are common contaminants in industrialized environments. Both these groups of chemicals are highly toxic to a variety of biological organisms (Martineau et al. 1994, McConkey et al. 1997, Wetzel and Werner 1995). In addition to their direct effects on biological systems, most PAHs have been shown to undergo photomodification under sunlight and they have an increased toxicity following photomodification (Arfsten et al. 1996, Huang et al. 1997b).
Development of a Method to Estimate the Mass and Toxic Bioavailabilities of Pentachlorophenol during its Transport through Saturated Porous Media
Authors: Dudal Y , Deschênes L
Published: April 2008

Bioavailability of organic contaminants in soil has recently been a focus of interest but a lack of knowledge of its behavior during contaminant transport through saturated porous media, such as aquifers, is observed. This research presents a method, based on a generally accepted definition of bioavailability, that quantifies mass and toxic bioavailabilities of organic contaminants during their transport in terms of bioavailability rates. Elutions of pentachlorophenol (PCP) were performed using inoculated laboratory columns at two different pore-water velocities and on two different media. Both PCP and the toxic response (Microtox) were monitored at the exit of the columns for quantification of the rates. Results show that the non-dimensional mass bioavailability rate decreased with increasing pore-water velocity (from 0.52 to 0.15) and with increasing retention (from 0.15 to 0.02). The non-dimensional toxic bioavailability rate decreased with increasing retention (from 0.59 to 0.22). Results indicate that this method shows a potential for quantifying contaminant bioavailability according to both outcomes: biodegradation and toxicity.
The Effect of Fluid Properties on the Spray Quality from a Flat Fan Nozzle
Authors: Dexter RW
Published: April 2008

The quality of sprays from a flat fan nozzle (8002) is demonstrated for water-based fluids of three types: surfactant solutions, dispersions and polymer solutions. The characteristics of these sprays are contrasted with the very different behavior of sprays formed from emulsions. The effects of concentration and oil droplet size of emulsions on the spray droplet size distribution and spray pattern are presented and discussed. Separate measurements of the spray angle, sheet breakup length, droplet size distribution and spray pattern along the fan width and thickness, using photography and a patternation method, are reported. These data and images from high speed photography of the break-up region of the spray show that emulsions cause premature disruption of the spray sheet, shifting the distribution of droplet sizes to larger values. Data from sprays of various emulsions support the hypothesis that disruption is the result of the presence of hydrophobic regions formed by the rapid stretching of the surface of the hydrophobic liquid droplets. Some advantages of emulsions over water-soluble polymers for spray drift control are presented.
Correlation Between Formulation Properties and Safety Measures for a Dry Product Mixing and Milling Facility
Authors: Klusacek H
Published: April 2008

In the Bayer Crop Protection business group, we have developed a procedure to decide whether or not a mixing and milling facility is suitable to produce dry crop protection products in a safe manner.

Materials handled in such a facility may be combustible or thermally instable. The following hazards may exist: • A dust explosion may occur if a dust/air mixture is within explosion limits and an ignition source is present. • A dust/liquid aerosol hybrid mixture may be formed if flammable liquids are present. • An exothermal decomposition may occur generating pressure. Quick decomposition may lead to a heat explosion or the products of the decomposition may include flammable gases that eventually ignite and burn or explode.

Consequently, the following must be avoided to insure safety: • The start of decomposition reaction. • The explosion of a dust, gas or hybrid aerosol of flammable liquids and solids

The components and the formulated product need to be examined to determine under which conditions decomposition or explosion may occur.

A base set of material safety data is established following the German Guideline Test Methods to Determine the Safety Characteristics of Dusts (VDI 2263 Part 1).

Test methods are used to describe the undisturbed powder with respect to: • Flammability • Burning Behavior • Exothermic Decomposition • Deflagration • Impact Sensitivity

Additional test methods are used to describe the aerosolized powder • Dust Explosiveness • Minimum Ignition Energy

In a decision chart basic questions are answered with the help of these safety data to decide if a hazard is present during unit operations and which safeguards have to be taken. Additionally, one is able to decide whether or not a given facility is suitable to handle a specific product in a safe manner.
Matricap® Systems: Factors Affecting Pesticide Delivery and Targeting
Authors: Levy R , Nichols MA , Opp WR
Published: April 2008

Matricap® controlled-delivery technology is based on the use of one or more nonpolymer coatings composed of fatty acids, fatty alcohols or esters of these products including salts (e.g., plasticizers), with or without one or more polymer binders, agglomerating agents or additional formulation aids to regulate the release rate and release profile of bioactive agents from solid carrier matrices. Specific gravity, solubility, hydrolysis, and biodegradation interactions of the coating(s), carrier, and bioactive agent in an admixture were utilized to design specific compositions for aquatic or terrestrial pest-management applications. If the formulation components were properly matched, a composition could deliver a bioactive agent to specific surface and/or subsurface areas of an aquatic or terrestrial habitat to target the orientation and/or feeding patterns of pest populations for prolonged periods.

Controlled delivery of insect growth regulators, microbial larvicides, and central nervous system inhibitors used to control mosquito larvae in surface or subsurface areas of a water column were shown to be functions of the type, concentration and/or number of coatings incorporated into a composition. Slight variations in the ratio of two or three fatty acid, fatty alcohol and/or fatty acid ester coatings in a coating complex were observed to significantly increase or decrease the duration of delivery from a solid matrix as well as alter the controlled-release profile and positional distribution of a bioactive agent in an aquatic habitat. The rate and duration of controlled delivery of an insect growth regulator used to control German cockroaches were dependent on the type and concentration of fatty acid ester(s), polymers, and bait complex utilized to fabricate coated, extruded, or continuous film bait stations.
A Novel Nozzle-Adjuvant System for Low Volume Pesticide Application for Agriculture and Forestry
Authors: Sexton F , Johnson R , McMullan PM
Published: April 2008

Minimizing off-target drift of pesticides while optimizing spray efficacy is the desired goal for pesticide applicators. However, these two factors often offset one another; i.e., a reduction in drift potential may reduce efficacy. A unique nozzle-adjuvant system that has minimal driftable fraction at reduced spray volumes using invert emulsion technology was evaluated. Research was conducted to evaluate the effectiveness of several different agrichemicals at several different volumes using this nozzle-adjuvant system. Results indicated that spray volume for glyphosate-isopropylamine and glufosinate-ammonium could be substantially reduced when using the invert emulsion nozzle. Further, three common cotton defoliation products were as effective at 47 L/ha spray volume using the new spraying system compared with conventional application at 95 L/ha. In forestry site preparation research, several commonly used site preparation treatments were more effective at 47 L/ha spray volume using the invert emulsion technology than at 95 L/ha using AccuFlo nozzles.
Turbine Oil Quality and Field Application Requirements
Authors: Swift ST , Butler KD , Dewald W
Published: April 2008

Power generation and other types of industrial turbines have always required the use of high quality lubricants. This paper will discuss the evolution of turbine oil formulation technology, and the use of different quality products in different applications. The original “R&O” type circulating oils, which are suitable for use in many hydraulic and steam turbine systems, have a long and successful history. Next came high performance products, designed for increased operating life. Finally, products have been introduced recently that provide the high stability needed for systems which operate under severe conditions of thermal stress, such as may occur in certain gas turbine operations.

Selecting a suitable turbine oil requires meeting the application requirements of equipment and service environment, while balancing initial and life cycle cost considerations and oil performance history. Field experience with different types of equipment and different turbine oil types will be described, with examples of situations where each oil type has performed successfully. Experience with field performance problem-solving will also be addressed, such as a gas turbine filter plugging problem which was resolved by selecting the appropriate turbine lubricant.

Turbine equipment manufacturers generally specify the properties and performance requirements of turbine oils according to the type and severity of operation. Standardized laboratory tests provide an indicator of an oil's performance, although such performance needs to be confirmed by field experience. New testing tools are needed which will better correlate to the performance requirements of new generation equipment.
Performance Advantages of Turbine Oils Formulated with Group II Base Oils
Authors: Okazaki ME , Militante SE
Published: April 2008

Formulation of high-quality turbine oils with API Group II base oils provides finished turbine oils with numerous performance advantages. When blended with the proper additives, these high-purity base oils provide turbine oils with outstanding oxidation stability, lower sludging tendencies, and improved water separability properties. The exceptional feature of these Group II finished products is their outstanding oxidation stability. The outstanding oxidation stability of the Group II lubricants is due not only to the high-purity base oils, but also to the carefully chosen additive package. The inherent sludging tendency of turbine oils is reduced when changing from Group I to Group II oils. Also, the water separability of these oils is improved when making the same change. Data which highlight these striking performance differences between Group I and Group II finished turbine oils and field test data will be shown.
Antioxidant Analysis for Monitoring Remaining Useful Life of Turbine Fluids
Authors: Ameye J , Kauffman RE
Published: April 2008

In this study we measured the remaining useful life of a wide range of turbine lubricants by detecting directly the remaining activity and performance of phenolic and amine antioxidants, known as primary antioxidants. We applied a patented (linear) voltammetric technique. First we evaluated the accuracy of the voltammetric response (vs. weight %) for phenolic (BHT) and amine (PANA) types of antioxidants. The next step of the program included antioxidant performance testing using laboratory oxidation tests. The voltammetric test data were then correlated with other widely used analytical methods (RBOT, FTIR, and DSC). These tests enabled us to understand the performance of mixed antioxidant systems and their importance in the remaining useful life of the new generation of turbine lubricants.

Finally and in order to understand the chemical role of antioxidants in real life conditions we monitored several industrial steam and gas turbine lubricants (N. America and Europe) with voltammetric analyses to observe the antioxidants' depletion trends. Voltammetric analysis correlated well with the RBOT (as per ASTM D-2272), and standard physico-chemical analysis methods (TAN, viscosity, color,...). These results show that antioxidant monitoring adds valuable information to RBOT and DSC measurements for the new type of turbine lubricants. This will allow the user to enhance the management of the oil on-site; to detect abnormal equipment/usage and consequently to improve the planning of maintenance actions resulting in a more efficient oil management.
Isocyanate Measurement Methods - ISO Standardization
Authors: Brown RH
Published: April 2008

Historically, a large number of alternative methods have been devised for the measurement of airborne isocyanates. Nearly all these methods rely on the derivatization of the reactive isocyanate groups to products that can be analyzed, usually by some form of chromatography. The choice of an ideal method relies partly on the requirements of the regulatory authorities, but there are also technical considerations concerning the validity and reliability of the various methods and the cost and availability of instrumentation. It would be comforting if we had a consistent body of advice from the regulatory authorities concerned. However, NIOSH (USA) recommends three methods, OSHA (USA) recommends two methods, ASTM (USA) recommends three methods, NIWL (Sweden) recommends one method and the HSE (UK) recommends two methods. All of these methods are different, with the exception of the l-(2-methoxyphenyl)piperazine (2-MP) and the l-(2-pyridyl)piperazine (2-PP) methods, which appear twice.

Can the International Standardization Organization help? Actually, ISO is preparing four technical specifications. First, it is preparing a method based on the 2- MP reagent (ISO/FDIS 16207). Second, it is preparing a method based on the 9-(l- methyl-anthracenyl)piperazine reagent (New Work Item). Two further methods, based on the dibutylamine method and the Iso-Chek™ method have been agreed as potential new work items but have not been balloted yet. So many alternative methods would seem inconsistent with the ISO objective of variety reduction. The reason is that, in addition to having different areas of application, all existing methods have some disadvantages. Thus, a fifth (guidance) standard is being developed which will explain in more detail the advantages and disadvantages of each method and it is hoped, will point to the development of a genuinely universal method.
Laboratory Comparison of Sampling Methods for Reactive Isocyanate Vapors and Aerosols
Authors: Rando RJ , Poovey HG , Mokadam DR
Published: April 2008

Three methods for quantifying test atmospheres of TDI, MDI, and their respective pre-polymers were compared in the laboratory: the modified OSHA 42 sampler, Tulane dichotomous sampler, and the ISO-CHEK™. Grouped samples (both 15-minute and 3-hour sampling periods) were collected from test atmospheres of the monomers ranging from approximately 2 to 20 ppb and of the pre-polymers ranging from 32.2 to 344.2 μg isocyanate/m3. In these tests, the Tulane sampler consistently yielded the highest results and accurately speciated the isocyanate into vapor and aerosol fractions. The OSHA sampler agreed with the Tulane sampler for MDI but reported lower concentrations of TDI. The ISO-CHEK™ consistently yielded the lowest results for isocyanate monomer and exhibited the highest variability, but it agreed with the Tulane sampler for short-term measurements of isocyanate pre-polymer. While not suitable for personal monitoring, overall the Tulane dichotomous sampler appears to be the most reliable of the devices for either short- or long-term sampling of reactive isocyanate vapors and aerosols.
Work-Related Asthma from Exposure to Isocyanate Levels Below the Michigan OSHA Permissible Exposure Limit
Authors: Reilly MJ , Rosenman KD , Peck JH
Published: April 2008

This paper examines the characteristics of 261 work-related asthma (WRA) cases exposed to isocyanates reported to an occupational disease surveillance system in Michigan from 1988–1998, and reviews Michigan Occupational Safety and Health Act (OSHA) inspections at 42 of the facilities where they worked. After October of 1993 when the Michigan OSHA program implemented a newer sampling methodology for isocyanates, 42 inspections were conducted in relation to the WRA cases reported. Samples for isocyanates were not collected in one facility. Isocyanate air levels at 40 of the 41 companies where measurements were taken revealed exposures <0.005 parts per million (ppm), as a time-weighted average (TWA). Sampling for isocyanates at one company revealed a level of 0.005 ppm for TDI (TWA).

At 36 of the 42 inspections, similarly exposed co-workers as the index cases completed a breathing symptom questionnaire. Although non-significant, companies were more likely to have co-workers indicate breathing symptoms where the index case reported exposure to one or more isocyanate spills (11 of 13 companies with spills vs. 15 of 23 companies without spills; OR 2.93, 95% CL 0.43-34), and a higher average percent of symptomatic co-workers compared to the companies where the index case reported no spills (23% vs. 16%; OR 1.42, 95% CL 0.99-2.03). Again, although non-significant, there were more MDI-using companies in which at least one co-worker reported breathing problems than TDI or HDI-users (83% vs. 67% vs. 56%; chi-square 2.49, p=0.29). MDI-using companies had a higher average percentage of symptomatic coworkers than TDI-users and HDI-users (23% vs. 15% vs. 14%; chi-square 9.92, p=0.007).

Michigan workers are exposed to isocyanates below permissible exposure limits yet continue to develop WRA. Spills may account for some but not all of these cases. Despite the lower volatility of MDI, co-workers with exposure to MDI were more likely to have respiratory symptoms than co-workers exposed to TDI or HDI. The majority of these 42 isocyanate-using companies (72%) had no medical surveillance program to monitor for worker sensitization. Compliance with OSHA laws, or “being within permissible exposure limits” will not guarantee the prevention of WRA. Effective engineering controls, established spill clean-up procedures, a comprehensive hazard communication program, and a medical surveillance program to identify newly sensitized workers for prompt removal from exposure may help to prevent isocyanate-induced WRA. Further work is needed to determine the relative effectiveness of each of these components in preventing isocyanate-exposed workers from developing asthma.
Isocyanate Exposures in the United Kingdom
Authors: McAlinden JJ
Published: April 2008

Isocyanates are asthmagens and most studies of occupational exposures to isocyanates have concentrated on inhalation of the vapor or aerosol. However, exposure may also occur through skin contact with the aerosol or during the handling of liquid isocyanates. Prolonged contact may lead to irritation or contact dermatitis.

Isocyanates are not produced in the United Kingdom (UK). UK industry, however, currently imports between 90000 and 100000 tonnes of isocyanate per year. Isocyanates are widely used in the UK for the manufacture of flexible and rigid foams, fibers, coatings such as paints and varnishes, and elastomers. The UK industry occupational population potentially exposed to isocyanates is about 25000 workers and the overall use of isocyanates by UK industry is increasing slowly.

Traditionally, the occupational group considered to be most at risk from isocyanate induced occupational asthma is spray painters in the motor vehicle repair industry. Because of this, HSE has undertaken campaigns, targeted specifically at the motor vehicle repair industry, to identify how, why and for how long workers are exposed to isocyanates. The findings are discussed in this paper.

The distribution of cases of occupational asthma throughout UK industry by occupation and agent as reported to two UK occupational health databases over the last ten years are also discussed in this paper. Findings are then compared against industry's own occupational health data and sector population breakdowns. Consideration is also given to whether an underlying UK trend of increasing non- occupational asthmas could also influence the reporting of work-related cases.
Field Evaluation of a Gravimetric Sampling Method as a Screening Tool for the Monitoring of Airborne Isocyanates in Paint-Spray Operations
Authors: Norton WW , Dharmarajan V
Published: April 2008

The industrial applications of polyurethane coatings have been steadily growing. The reaction of polyisocyanates to polyols is the basis for all polyurethane coatings. The Oregon State OSHA PEL for HDI-polyisocyanates is 0.5 mg/m3 8-hour TWA and 1.0 mg/m3 ceiling. The recommended impinger sampling method for HDI-polyisocyanates is cumbersome and potentially hazardous.

Previous comparisons of impinger versus filter sampling in paint spray environments have shown that the filters can underestimate the polyisocyanate concentration. However, a recent NIOSH study concluded that an upper limit for the isocyanate concentrations in a paint-spray environment could be measured/calculated by a gravimetric method.

In this study, a PVC-filter gravimetric method was compared to an impinger-sampling method for measuring isocyanate concentrations during spray painting of automobiles. Seven side-by-side impinger and gravimetric sample sets were collected inside a custom-made chamber from a 2-gal plastic bottle. Each set consisting of four impingers and four filter cassettes with the same inlet orientation was mounted symmetrically inside the chamber. Tygon® tubing passing through the base connected the samplers to battery-operated pumps outside. Additionally, a vacuum pump connected to five holes at the base permitted the paint spray to be drawn into the chamber at isokinetic velocity.

Gravimetric samples were weighed with a precision analytical balance. Impinger samples were analyzed for isocyanates by a standard HPLC/UV method. The gravimetric weights were converted to isocyanate weights using a factor based on the paint formulation. The average isocyanate concentrations in mg/m3 by the two methods were statistically compared. The average ratio of gravimetric measurements to impinger measurements was 1.06 ± 0.15 % for n = 6 (total 48 samples). The gravimetric isocyanate concentrations are the theoretical maximums for the paint atmosphere sampled, whereas, the impinger isocyanate concentrations are the true in-situ values. The predictable correlation between the two methods suggests that the gravimetric method could serve as a screening tool for monitoring isocyanates in validated paint atmospheres.
Use of Air-Purifying Respirators for Substances with Limited or Poor Warning Properties
Authors: Corbitt SM , Heger EA , Sarvadi DG
Published: April 2008

In 1998, the Occupational Safety and Health Administration (OSHA) updated its general industry respiratory protection standard, 29 CF.R. § 1910.134. The use of airpurifying respirators (APR) was affected by a significant policy change that requires employers to provide respirators equipped with a NIOSH certified end-of-service-life indicator (ESLI) for the expected contaminant, or to implement a change schedule for canisters and cartridges based on objective data showing that the cartridges are effective in preventing exposure to the contaminant, and have an adequate service life.

However, questions continue to be raised about the permissibility of using APR in certain industrial applications where workers may be exposed above allowable limits to substances with poor warning properties. This paper outlines some of the important considerations such as: what data are necessary to demonstrate that the respirator cartridge/filter is quantitatively effective at removing the contaminant of interest, and what data are needed to demonstrate that employee exposures to a contaminant are within the range that the respirator can effectively remove it from the inhaled air stream. These considerations must be taken into account to assure that APR are properly selected and used to provide protection against substances with poor warning properties. Methylenediphenyl diisocyanate (MDI) and polymeric products made from MDI will be used as an example in this discussion.
On The Reasons That Make Bench Tests Unrealiable
Authors: Mizuhara K , Tomimoto M
Published: April 2008

It is well known that the wear rates of materials evaluated in bench testers are fairly reproducible. However, the performance of the materials obtained in bench tests and practical uses were sometimes completely different from each other. This paper discusses the reasons for such discrepancies observed in hydraulic pump testing in terms of the test conditions and the response of the fluid to them. By analyzing the test condition that reproduced the pump wear in bench tests, it is suggested that at lower temperatures and pressures, the behavior of the fluid at higher temperatures and pressures could be reproduced. Then it is concluded that applying the estimated load and sliding velocities in actual pump to bench tests that use different contact configuration may cause the erratic results. It is also concluded that estimating the phenomena governing the performance in an actual pump is one of the keys to conducting useful bench tests.

The factors that affect the test results and the usefulness and limits of the bench tests are also discussed.
Use of Bench Tests to Evaluate Water-Glycol Hydraulic Fluid Lubrication
Authors: Totten GE , Bishop RJ , Xie L
Published: April 2008

The anti-wear lubrication performance of a series of hydraulic fluids was determined using various bench wear tests including: Four-Ball, Pin-on-V-Block Falex Wear Test, Timken Block-on-Ring, a recently developed cyclic contact stress (3-vane-on-ring) test and the ASTM D-2882 Vickers V-104C vane pump test. These bench tests were selected since they are used in the fluid power industry for fluid selection, qualification and performance troubleshooting. The results of this work showed that none of the bench tests evaluated provided any correlation with the wear rates obtained with the ASTM D-2882 pump test. Bench wear test correlations are possible only if the conditions of the wear test, such as wear contact geometry, loading, speeds, and materials reasonably model the specific wear contact of interest in the hydraulic pump. Even then, the general reliability of the bench testing conditions should first be validated by hydraulic pump testing.