bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Studies on Oil Spill Dispersants
Authors: Fingas MF , Dufort VM , Hughes KA , Bobra MA , Duggan LV 
Published: December 2008

Laboratory tests of oil spill dispersant effectiveness are used around the world to select dispersants for application to specific oils. These tests are presumed, by some, to represent real sea conditions and to provide the user with a result that is representative if not identical to a real dispersant application at sea. A number of tests have been developed over the years. At this time, the two most widely used tests are the Mackay test, otherwise known as the Mackay-Nadeau-Steelman (MNS) test, and the Labofina test, otherwise known as the Warren Springs or rotating flask test. The Mackay test employs a high velocity air stream to energize 6 L of water, whereas the Labofina test uses rotation of a separatory funnel with 250 mL of water. Both tests apply a large amount of energy to the oil/water system.
This paper compares test results from these apparatus with those from two lesser known devices, the oscillating hoop and the swirling flask. Both devices are relatively new, and protocols for their use have not been finalized. The oscillating hoop apparatus uses a hoop which is moved up and down at the water surface. The concentric waves serve both to energize the oil in the hoop and to contain it. Thirty-five litres of water are used in this test. The swirling flask test makes use of a 125-mL Erlenmeyer flask. The flask is rotated using a standard chemical/biological shaker to produce a swirling motion in the contents.
The results obtained using all 4 apparatus with a number of oils and dispersants are presented. A total of 121 oil/dispersant combinations were tested in the 4 apparatus.
The correlation of numeric values between the Mackay, Labofina, oscillating hoop, and swirling flask is low. The correlation of effectiveness ranking is also poor. An oil that disperses more readily than another, according to one test, is less readily dispersable according to one or more of the other tests. Similarly, a dispersant that is more effective by one test is less effective by another. The results from the oscillating hoop correlate poorly with all other test results.
Specific tests were also conducted to ascertain the effect of settling or rising time (the time the oil-in-water mixture is allowed to sit unagitated before a sample is taken). Longer settling times alter the oscillating hoop test results dramatically, improve the correlation for results with different apparatus, and enhance correlation with physical data such as viscosity. Differences in the effectiveness results are still apparent.
Results show that all the high energy tests (the Mackay, the Labofina and the oscillating hoop) produce unique dispersant effectiveness results and those correlate poorly with the physical properties of the oil.
Design and Evaluation of a Large Boat-Mounted Dispersant Spraying System and Its Integration with Other Application Equipment
Authors: Onstad LA , Lindblom GP 
Published: December 2008

Oil spill response groups have recognized that it is essential to have the ability to apply dispersants properly when they are needed. Some of these organizations have developed unique application equipment as part of their total capability. Two California industry cooperatives have designed dispersant spray systems that are attached to existing advancing recovery devices, thus providing the largest spray systems yet developed for any surface vessels.
Detailed calibration of the systems has been done and has provided tables and charts which can be used by both management and operators for direction of dispersant application programs. Close control of dispersant dosage is a requirement for successful dispersant application and also for accurate documentation for regulatory authorities. The calibration work reported here has also shown the variability that can be found in very similar systems and indicated the need for careful evaluation of educator performance, as well as the value of use of accurate metering pumps for dispersant, whether used diluted or undiluted.
Gas Chromatography/Mass Spectrometry Analysis of n-Alkylbenzothiophenes Identified in Arabian Heavy Asphaltenes, Pyrolysis Oil
Authors: Gallegos EJ 
Published: December 2008

Present concepts hold that the genesis of organic sulfur compounds is due mainly to secondary processes. The secondary process is a chemical reaction of oil with sulfur or sulfur species to give nonthiophenic sulfides and thiols first, then benzothiophenes, and ultimately stable dibenzothiophenes. This work describes the pyrolysis gas chromatography/mass spectrometry (GC/MS) identification of a homologous series of n-alkylbenzothiophenes extending from C10 to C30 in Arabian Heavy asphaltenes. Within each homolog there are at least 22 isomers. The mass spectra of these isomers typically show relatively intense molecular ions with base peaks at m/z 147, 161, or 175.
The striking similarity of the fragmentation profiles of the homologous benzothiophenes and homologous n-alkylbenzenes also present in the sample strongly suggests that the benzothiophenes are generated directly from the reaction of the alkylbenzenes with sulfur species. Reflux experiments with known alkylbenzenes and elemental sulfur produced an abundance of thiophene derivatives including benzothiophenes.
An Expert Program for the Interpretation of Gas Chromatography/Mass Spectrometry Data on Fossil Fuel Distillates
Authors: Aczel T , Colgrove SG , Le L 
Published: December 2008

An expert system has been developed for the interpretation of the gas chromatography/mass spectrometry (GC/MS) spectra of fossil fuel distillates. The approach extends the scope of commercially available data systems by using interpretation rules generally carried out by a skilled professional expert. The rules and procedures incorporated in the program deconvolute unresolved peaks, set acceptability limits for the identifications provided by commercial data systems, and identify components that the commercial data systems fail to identify, or identify incorrectly, at least as to compound class and carbon number.
Need for such an approach stems from the inability of commercial data systems to deal adequately with complex hydrocarbon mixtures. The spectral matching algorithms used by these systems do not consider spectra/structure correlations and fail when GC/MS peaks are unresolved or pure compound spectra are not available for comparison or both. These conditions occur in the majority of cases with boiling range above 149°C (300°F). The expert program discussed in the paper obviates these difficulties. It results in 90 to 95% correct identifications, 99% plus on a concentration basis, and it saves 20 to 30 h of skilled time per sample.
Background and Development of ASTM D 4378: Practice for In-Service Monitoring of Mineral Turbine Oils for Steam and Gas Turbines
Authors: Roberton RS 
Published: December 2008

Several years ago a study group was set up at ASTM (American Society for Testing and Materials) under Subcommittee C (Turbine Oils) of Committee D-2 on Petroleum Products and Lubricants to develop a standard for in-service monitoring of steam and gas turbine oils. The study group included well qualified and experienced representatives from turbine equipment builders, oil producers, the power generation industry, and consultants among its members. The objective was achieved and an ASTM standard D 4378, entitled “Practice for In-Service Monitoring of Mineral Turbine Oils for Steam and Gas Turbines” was issued as a single standard in 1984 and is now included in the Annual Book of ASTM Standards. In developing the standard, it was recognized that turbine oils are unique lubricants requiring the highest degree of oxidation stability and resistance to sludge formation and are expected to give years of service. Also, the high cost of oil changes and unplanned shutdowns had to be balanced against the cost of laboratory manpower and equipment for analytical testing.
This paper covers the results of an initial study of monitoring practices within the power generation industry and discusses in some detail why some methods in use for many years are of doubtful significance and should be eliminated. It also describes the development of sampling and testing schedules. To follow the oxidative degeneration of the oil, the well-established TAN (Total Acid Number) test is retained and used in conjunction with the Rotary Bomb Oxidation Test, (RBOT) (D 2272) to provide a much more reliable indication of remaining service life. Other properties of the oil which must be retained in service are discussed, and major significance has also been given to the interpretation of test data and appropriate action steps.
The technical merit of D 4378 and its acceptance by the international community is confirmed by the fact that it has been used by a joint working group of ISO (International Standards Organization) and IEC (International Electrotechnical Commission) as a basis for an international maintenance and use guide.
A Supplier's Approach to Turbine Oil Monitoring
Authors: Trabert GR , Schreuders GJ 
Published: December 2008

To ensure the successful operation of a turbine circulating oil system, the turbine manufacturer, the turbine operator, and the lubricant supplier must cooperate by furnishing their technical expertise.
Examples of turbine oil problems show that effective sampling procedures and monitoring of turbine oils is required to assure a long service life. ASTM Practice for In-Service Monitoring of Mineral Turbine Oils for Steam and Gas Turbines (D 4378) is an excellent guide to accomplish this.
The Reliable Control of Oil Quality in Japanese Turbine Units
Authors: Ohgake R , Sunami M , Yoshida T , Watanabe H 
Published: December 2008

The reliable operation of Japanese steam, gas, and water power turbines using a newly developed trouble-resistant oil in association with a successful maintenance service system is discussed.
A classic steam turbine oil formula containing a phenolic oxidation inhibitor and a succinic acid-type rust inhibitor made from low-aromatic base stock has been used for trouble-free maintenance. In Japan, the oil supplier and the user jointly administer quality control programs for turbine oils. The accumulated data of the oil supplier are utilized for estimating the optimum oil makeup for individual turbines. Since the installation of several computerized systems responsible for maintaining the quality of steam turbine oil in 165 power stations, the remaining life of the oil has been maintained over the warning limit by estimating the optimum oil's makeup.
Remote control systems have been employed at many small hydroelectric power plants in Japan to save manpower. Such modernization has brought about an additional lubrication problem—severe valve sticking. More than 100 water turbine generators have suffered from this problem since around 1965. Maintenance-free type oil was required for these units. A new-type turbine oil for which a sludge dispersant is employed has solved this valve-sticking problem. The evaluation method and in-service performance are provided.
The largest combined-cycle power station in the world (output 2000 MW) was recently installed at Futsu Power Station of the Tokyo Electric Co. (in 1985). The lubrication of 14 heavy duty gas turbines (GE9001E, 113 MW) is performed by a new high-temperature gas turbine oil. This oil has done well, providing more than 8000 trouble-free hours of lubrication. The oil quality monitor and control systems are discussed.
Fatigue Crack Growth Under Combined Mode I and Mode II Loading
Authors: Stanzl ES , Czegley M , Mayer HR , Tschegg EK 
Published: December 2008

The influence of static Mode I and static Mode II loading on Mode I fatigue crack growth has been studied with 12 weight % chromium steel.
Static Mode I was superimposed as a tensile load on fatigue-loading with mean stress equal to zero, thus resulting in R-values of - 1, - 0.33, 0, +0.25, and +0.5. For these values, fatigue-crack growth curves were determined in the threshold regime with crack growth rates typically between 3 × 10-13 and 5 × 10-9 m/cycle.
In addition, a constant static Mode II load was superimposed on the same above-mentioned Mode I load. The resulting crack growth rates were found to vary systematically with crack length and load ratio. For R-ratios ⩽ 0 enhanced fatigue crack growth rates were observed at crack lengths up to a defined value. After a certain crack length was attained, slightly reduced crack growth rates were detected. For high R-ratios, long as well as short fatigue cracks grew slower than under pure Mode I fatigue loading. The results are discussed in light of the crack closure phenomenon and the fracture morphology, which was studied in a scanning electron microscope (SEM).
In the Appendix, a basic procedure for determining stress-intensity values for high-frequency (21 kHz) fatigue loading is given in comparison with conventional loading.
A Finite-Element Investigation of Viscoplastic-Induced Closure of Short Cracks at High Temperatures
Authors: Palazotto A , Bednarz E 
Published: December 2008

The authors have developed a finite-element program with constant-strain capabilities that can handle cyclic loading. The constitutive relation is considered to be elastic-viscoplastic incorporating the Bodner-Partom flow rule. Incalloy 718 is the alloy considered at a temperature of 670°C. The computer algorithms are discussed for consideration of crack closure and extension.
The program is applied to a single-edge-cracked specimen with an initial crack length of 25 μm acting under a load distribution of 90% of the yield stress for the material considered. A plane-stress finite element is used to evaluate the effect of an R-value equal to 0.1, considering frequencies of 0.01 and 1.0 Hz. The crack is allowed to grow to a final length of 46 μm. The plastic zone in front of the crack tip is approximately equal to the initial crack length, yielding conditions associated with short cracks.
The results indicate the effect viscoplasticity plays when considering and comparing two separate frequencies. A plastic wake, due to crack closure, develops behind the propagating crack and increases for the lower frequency. In order to realistically predict plasticity-induced closure, one must mathematically allow the crack to grow. Stress and strain fields in front of the crack show a noticeable change with time due to the viscoplastic effect.
Influence of Cathodic Charging on the Tensile and Fracture Properties of Three High-Strength Steels
Authors: Tremblay V , Nguyen-Duy P , Dickson JI 
Published: December 2008

The influence of cathodic charging in sulfuric acid solution on mechanical properties of AISI 4340, AISI 300M, and AMS 6340 steels was studied for different tempering temperatures. Cathodic charging decreased the tensile elongation, the reduction in area, and the ultimate tensile stress as a result of hydrogen-induced surface cracks having brittle features, which then transformed into cracks propagating by microvoid nucleation and coalescence along planes of maximum shear stress.
The curves of the J-integral as a function of the crack advance Δa presented a change in slope at a small Δa value. For the lower tempering temperatures, this Δa value was relatively large and similar to that required to obtain a single crack propagating across the thickness. Cathodic charging decreased JIc as a result of bands of brittle cracking near each lateral surface and of facilitated initiation of cracking, in an alternating fashion along planes of maximum shear stress.
Fracture Behavior of Compacted Fine-Grained Soils
Authors: Fang H-Y , Mikroudis GK , Pamukcu S 
Published: December 2008

Existing cracks, when triggered to advance, often contribute to the progressive failure mechanism and erosion of slopes, embankments, excavations, river banks, and other earthen structures of compacted fine-grained soils. To assess the effect of existing cracks on these earth structures it is necessary to quantitatively measure the magnitude of load necessary to advance the crack to failure. This load has been defined as the fracture load of soils in previous investigations.
This study reports the results of an experimental procedure used to measure the fracture load and its variation with precrack length and also evaluate the load deflection relations for compacted clays and marine clays. A simple procedure, based on concepts of linear elastic fracture mechanics (LEFM) theory, was utilized. Soil specimens were prepared and tests were conducted according to ASTM Method E 399. Fracture load and fracture toughness were evaluated. Results indicate that reasonable estimations of fracture load in clay soils could be made using the fundamentals of LEFM theory, which constitutes the basis of the fracture toughness analysis.
Oxidation and Deuterium Uptake of Zr-2.5Nb Pressure Tubes in CANDU-PHW Reactors
Authors: Urbanic VF , Warr BD , Manolescu A , Chow CK , Shanahan MW 
Published: December 2008

Oxidation and deuterium uptake in Zr-2.5Nb pressure tubes are being monitored by destructive examination of tubes removed from commercial Canadian Deuterium Uranium Pressurized Heavy-Water (CANDU-PHW) stations and by analyses of microsamples, obtained in-situ, from the inside surface of tubes in the reactor. Unlike Zircaloy-2, there is no evidence for any acceleration in the oxidation rate for exposures up to about 4500 effective full power days. Changes towards a more equilibrium microstructure during irradiation may be partly responsible for maintaining the low oxidation rate, since thermal aging treatments, producing similar microstructural changes in initially cold worked tubes, were found to improve out-reactor corrosion resistance in 589 K water.
With one exception, the deuterium uptake in Zr-2.5Nb tubes has been remarkably low and no greater than 3-mg/kg deuterium per year (0.39 mg/dm2 hydrogen per year). The exception is the most recent surveillance tube removed from Pickering (NGS) Unit 3, which had a deuterium content near the outlet end about five times higher than that seen in the previous tube examined. Current investigations suggest that most of the uptake in that tube may have come from the gas annulus surrounding the tube where deuterium exists as an impurity, and oxidation has been insufficient to maintain a protective oxide film.
Results from weight gain measurements, chemical analyses, metallography, scanning electron microscopy, and transmission electron microscopy of irradiated pressure tubes and of small coupons exposed out reactor are presented and discussed with respect to the observed corrosion and hydriding behavior of CANDU-PHW pressure tubes.
Diffusion of 3D Transition Elements in α-Zr and Zirconium Alloys
Authors: Hood GM , Schultz RJ 
Published: December 2008

Measurements of tracer diffusion coefficients D of Fe-59, Ni-63 and Cr-51, in zirconium single crystals and of Fe-59 in some zirconium alloys have been made. The single crystal measurements were made in directions both parallel Dǁ and perpendicular D⊥ to the c axis of the specimens; results for nickel were obtained at 1025, 883, and 674 K and for iron at 674 K. The low temperature diffusion profiles are generally complex and indicate the probable operation of more than one diffusion process. The diffusion behavior of nickel in zirconium seems to parallel that of iron, for which more data are available and, probably, that of cobalt; at high temperatures, the effective activation energy for diffusion hD is approximately 0.6 eV, while at lower temperatures, a value closer to 2.0 eV seems more appropriate. The diffusion profiles indicate that Dǁ D⊥ at all temperatures, though there is a tendency for the anisotropy to diminish as the temperature decreases. The high-temperature results, associated with intrinsic behavior, conform to previously developed, diffusion parameter/atomsize correlations. The lower temperature data are probably symptomatic of complexing and precipitation effects. Chromium diffusion measurements have been made at 887, 977, and 1114 K. The diffusion profiles are generally well-behaved, and D(T) obeys the customary Arrhenius law D = D° exp (-hD/kT) with values of 2.4 × 10-6 2and 9.5 × 10-6 m2s for D°(ǁ) and D°(⊥), respectively, and 1.39 and 1.61 eV for the corresponding hDǁand h°⊥ parameters. The chromium D values are in general agreement with some earlier data; Dǁ is from 2.6 to 5.2 D⊥, and the ratio increases with decreasing temperature.
In addition to the above, measurements of iron diffusion in Zircaloy-2 and Zr-2.5wt% Nb have been made at 893 and 1122 K. The diffusion profiles are reasonably well behaved; the associated Ds are from 20 to 100 times lower than corresponding D(Fe) values for nominally pure single crystal α-Zr; the alloy D(Fe) results are very similar to previous, corresponding D(Ni) data for these alloys. Isolated diffusion measurements have also been made on a Zr-1.08 at% Sn alloy, at 1121 K, and on single crystals of Zr-0.1 at% Fe, at 1054 K. The values of Dǁ|, D⊥, and the associated ratio, Dǁ/D⊥, for the Zr(Fe) alloy are all somewhat lower than the corresponding data for iron diffusion in pure α-Zr. In addition, the Zr(Fe) alloy showed remarkable compositional variations; some comment on this behavior is made.
Determining Delivery Rates of Push-Type Granular Product Spreaders
Authors: Birthisel TD 
Published: December 2008

A method for and the equipment needed for calibrating delivery rates of push-type granular product spreaders are discussed.
This method has proven to be suitable for use by product and equipment manufacturers in determining specific product spreader settings for the full range of push-type spreaders and for some small tractor-pulled models.
Experience over a wide range of materials and conditions has provided numerous insights into some underlying principles and problem areas. These are treated briefly and include the following: (a) the need for proper metering orifice calibration, (b) variation between individual spreaders of the same model and manufacturer, (c) flow variations in relation to the hopper-fill level, (d) the nonlinear relationship between the flow and the spreader setting scale, (e) problems due to spreader wear, (f) variation due to the product repose angle, and (g) variation due to particle size changes in the product.
The SAR Number for Slurry Abrasion Resistance
Authors: Miller JE 
Published: December 2008

With the use of the Miller Number for slurry abrasivity and its usefulness in the slurry pumping industry in predicting pump wear, it became obvious that the same test could be run in “reverse” to determine the effect of a “standard” slurry on a candidate material, thereby giving a relative measure of how a particular material would perform. In fact, about half of the 20 Miller machines in existence throughout the world are used specifically for wear or abrasion-resistance tests.
In this presentation the machine will be briefly described along with the basic procedure for determining SAR (slurry abrasion resistance) as derived from the Miller Number procedure.