Oil Spill Dispersant Effectiveness Protocol. I: Impact of Operational Variables

The current U.S. Environmental Protection Agency protocol for testing the effectiveness of dispersants, the swirling flask test, has been found to give widely varying results in the hands of different testing laboratories. The sources of the ambiguities in the test were determined by considering several options in a rigorous systematic fashion. Options considered were variability among three operators and the variability and limitations of three analytical instruments in establishing a calibration curve for oil/dispersant mixtures. Other options included flask type, impact of operational variables (rotational speed, mixing time, settling time, and oil:dispersant ratio), development of a revised procedure for dispersant effectiveness, reproducibility and repeatability of the revised procedure, and development of selection criteria for screening of dispersants. A redesign of the test flask, which is characterized by having baffles with a stopcock at the bottom for sample collection, was deemed necessary to accomplish reproducibility within operator and between operators. The results indicated that the baffled flask provided a total coefficient of variation (variations within operator and between operators) less than 11% compared to above 100% in some cases for the swirling flask.     

Evaluation of Mixing Energy in Laboratory Flasks Used for Dispersant Effectiveness Testing

The evaluation of dispersant effectiveness used for oil spills is commonly done using tests conducted in laboratory flasks. The success of a test relies on replication of the conditions at sea. We used a hot wire anemometer to characterize the turbulence characteristics in the swirling flask (SF) and the baffled flask (BF), the latter is being considered by the Environmental Protection Agency to replace the prior. We used the measurements to compute the velocity gradient, G and the energy dissipation rate per unit mass, ε. The study shows that the mixing in the BF is more uniformly distributed than that in the SF. Flask average energy dissipation rates in the SF were about 2 orders of magnitude smaller than those in the BF. The sizes of the microscales in the BF were found to be much smaller than that in the SF. Also, in the BF, the sizes of the microscales approached the size of oil droplets observed at sea (50–400?μm), which means that the turbulence in the BF closely resembles the turbulence occurring at sea during breaking waves. Hence, the BF is preferable for dispersant testing in the laboratory.     

Community patterns of psychiatric disorders after the Exxon Valdez oil spill

OBJECTIVE: This study examined the relationship between exposure to the Exxon Valdez oil spill and subsequent cleanup efforts and the prevalence of generalized anxiety disorder, posttraumatic stress disorder (PTSD), and depressive symptoms in 13 Alaska communities. METHOD: A community survey of 599 men and women was conducted approximately 1 year after the spill occurred. Questions from the National Institute of Mental Health Diagnostic Interview Schedule were used to assess symptoms of generalized anxiety disorder and PTSD. The Center for Epidemiologic Studies Depression (CES-D) Scale was used to assess levels of depressive symptoms. RESULTS: The post-spill (i.e., 1-year) prevalence of generalized anxiety disorder and PTSD for the study communities with all degrees of exposure was 20.2% and 9.4%, respectively. The prevalence of respondents with CES-D Scale scores above 16 and 18 was 16.6% and 14.2%, respectively. When compared with the unexposed group, members of the high-exposure group were 3.6 times as likely to have generalized anxiety disorder, 2.9 times as likely to have PTSD, 1.8 times as likely to have a CES-D Scale score of 16 and above, and 2.1 times as likely to have a CES-D Scale score of 18 and above. Women exposed to this event were particularly vulnerable to these conditions, and Alaska Natives were particularly vulnerable to depressive symptoms after the oil spill. CONCLUSIONS: The results suggest that the oil spill's impact on the psychosocial environment was as significant as its impact on the physical environment. The Exxon Valdez experience suggests a number of implications for the mental health needs of disaster victims, particularly in primary care settings.     

Bioremediation Kinetics of Crude Oil at 5°C

This bench scale experiment investigated the mineralization of crude oil at cold temperatures. Biodegradation rates of Alberta Sweet Mix crude oil at 5°C and at ambient temperatures (21°C) were compared. The experimental design consisted of 14 soil columns. Off-gas samples for each column were analyzed every second day using a gas chromatograph to determine CO2 production rates. The run lasted for 219 days, at which time the soil columns were sacrificed for analysis. Oil mineralization values were modeled by a number of methods, including CO2 production determination from GC measurements and gravimetrically determined hydrocarbon loss using soxhlet extraction. The results of the experiment suggested that temperature only affected the biodegradation rates of crude oil in the initial phase of the biodegradation process. After approximately 3 months, the degradation rates of crude oil at 5°C and 21°C were similar at about 11 mg hydrocarbon∕kg dry soil∕day. The conclusion of this study was that significant mineralization of Alberta Sweet Mix crude oil can occur at cold temperatures.     

A new statistical test for age-of-onset anticipation: application to bipolar disorder

Sixty 2nd, 5th, and 8th graders were interviewed on their moral and ecological reasoning about the 1990 Exxon Valdez oil spill that occurred in Prince William Sound, Alaska. Results showed that children understood that the oil spill negatively affected the local Alaskan shoreline, marine life, fishermen, recreationists, and the oil company. Children cared that harm occurred to the shoreline and marine life and conceived of both types of harm as violating a moral obligation. Fifth and 8th graders, compared with 2nd graders, used a greater proportion of anthropocentric reasoning (e.g., that nature ought to be protected to protect human welfare) and biocentric reasoning (e.g., that nature has intrinsic value, rights, or a teleology). Discussion focuses on how studying children's reasoning about nature not only extends the bounds of what counts as moral--to include a relationship with the natural world--but also provides a unique means by which to conduct basic research on children's moral development.     

Children's moral and ecological reasoning about the Prince William Sound oil spill.

Sixty 2nd, 5th, and 8th graders were interviewed on their moral and ecological reasoning about the 1990 Exxon Valdez oil spill that occurred in Prince William Sound, Alaska. Results showed that children understood that the oil spill negatively affected the local Alaskan shoreline, marine life, fishermen, recreationists, and the oil company. Children cared that harm occurred to the shoreline and marine life and conceived of both types of harm as violating a moral obligation. Fifth and 8th graders, compared with 2nd graders, used a greater proportion of anthropocentric reasoning (e.g., that nature ought to be protected to protect human welfare) and biocentric reasoning (e.g., that nature has intrinsic value, rights, or a teleology). Discussion focuses on how studying children's reasoning about nature not only extends the bounds of what counts as moral—to include a relationship with the natural world—but also provides a unique means by which to conduct basic research on children's moral development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

一种新型冶金能源—沥青浆体燃料的开发研究

本文介绍了两种最新研究开发的沥青浆体燃料及其物理特性和燃烧特性，试验表明它们可以在冶金工业炉窑上代油应用。     

Effects of Weathering on Treatment of Lead Contaminated Soils

Treatment of lead-contaminated material focuses on the reduction of leached lead concentrations in laboratory leaching tests. There has been little study on the chemical stability of treated materials after waste disposal. To investigate the effects of weathering on several solidification/stabilization chemistries, lead-contaminated soil was treated with various agents (cement, phosphates, dithiocarbamate, calcium hydroxide, calcium carbonate, and metallic iron) and subjected to natural weathering for one year. Lead concentrations and pH values in field percolates and leachates from toxicity characteristic leaching procedure (TCLP) and water leaching tests were used to evaluate changes in the treatment effectiveness. Weathering altered the treatment chemistry of several additives—alkaline additives were neutralized, while reduced additives were oxidized. Lead concentrations in field percolates from the untreated soil were around 1.0?mg/L, and did not vary over one year of weathering time. After one year of weathering, lead concentrations in field percolates from most samples were reduced to low levels (<0.15 mg/L). Weathering also affected lead concentrations in the TCLP and water leach test leachates from the treated wastes. Treated wastes in which the alkaline additives were neutralized or reduced additives oxidized gave higher TCLP lead concentrations after weathering than before, in contrast to the decreasing lead concentrations in the field percolates. Water leaching tests on the alkaline treated wastes had lower lead concentrations after weathering than before.     

Estimating the Oil Droplet Size Distributions in Deepwater Oil Spills

Oil released in a deepwater blowout breaks up into droplets. Hence, the time it takes for oil to reach the water surface, its location, and the size of the surface slick at a given time, are all affected by oil droplet sizes. Information on oil surfacing time, its location, and slick size are essential for emergency spill response as well as contingency planning. Despite the importance of the oil droplet size on oil fate in many oil spill problems, our ability to estimate oil droplet sizes has been poor. In this paper, methods are developed for a deepwater oil spill model to estimate the oil droplet size distribution generated due to an accidental release. Models for estimating oil droplet size distribution generated by a deepwater release are developed based on the maximum entropy formalism. The quality of results depends on the constraint equations used. The paper shows results using only the mass balance and specific surface area as constraint equations. The latter case showed markedly improved results. Model results for droplet size distribution are compared with limited experimental data.     

A test of the adaptive specialization hypothesis: Population differences in caching, memory, and the hippocampus in black-capped chickadees (Poecile atricapilla).

To test the hypothesis that accurate cache recovery is more critical for birds that live in harsh conditions where the food supply is limited and unpredictable, the authors compared food caching, memory, and the hippocampus of black-capped chickadees (Poecile atricapilla) from Alaska and Colorado. Under identical laboratory conditions, Alaska chickadees (a) cached significantly more food; (b) were more efficient at cache recovery; (c) performed more accurately on one-trial associative learning tasks in which birds had to rely on spatial memory, but did not differ when tested on a nonspatial version of this task; and (d) had significantly larger hippocampal volumes containing more neurons compared with Colorado chickadees. The results support the hypothesis that these population differences may reflect adaptations to a harsh environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermal Analysis of Cover Systems in Municipal Solid Waste Landfills

Cover temperature variations were determined at four municipal solid waste landfills located in different climatic regions in North America: Michigan, New Mexico, Alaska, and British Columbia. Cover temperatures varied seasonally similarly to air temperatures and demonstrated amplitude decrement and phase lag with depth. Elevated temperatures in the underlying wastes resulted in warmer temperatures and low frost penetration in the covers compared to surrounding subgrade soils. The ranges of measured temperatures decreased and average temperatures generally increased (approximately 2°C/m) with depth. The ranges of measured temperatures (Tmax?Tmin) were 18–30°C and 13–21°C and the average temperatures were 13–18°C and 14–23°C at 1 and 2?m depths, respectively. For soil and geosynthetic barrier materials around 1?m depth, the maximum and minimum temperatures were 22–25°C and 3–4°C, respectively. Frost depths were determined to be approximately 50% of those for soils at ambient conditions. The main direction of heat flow in the covers was upward (negative gradients). The cover gradients varied between ?18 and 14°C/m, with averages of ?7?to?1°C/m. The gradients for soil and geosynthetic barrier materials around 1?m depth varied between ?11 and 9°C/m with an average of ?2°C/m. Cover thawing n-factors ranged between 1.0 and 1.4 and the cover freezing n-factor was 0.6. Design charts and guidelines are provided for cover thermal analyses for variable climatic conditions.     

钛白粉生产中粗品对浆料粘度影响的研究

在保持浆料密度、脱盐水、分散剂加量、搅拌速度、搅拌时间等因素不变的条件下,进行了金红石型二氧化钛粗品的打浆实验。分别讨论了物料的pH值、磷、硫、钾、锌等微量元素百分含量以及金红石含量等因素对打浆后浆料粘度的影响。     

改性油页岩残渣对苯胺的吸附性能研究

为探讨油页岩矿山开采加工过程中产生的油页岩残渣环保利用的新途径,在油页岩残渣改性的基础上,研究了其对有机污染物苯胺的吸附作用。利用NaOH对油页岩残渣进行改性,设计正交试验优化了改性油页岩残渣吸附苯胺的最佳条件。其试验结果表明:在改性油页岩残渣粒径为0.01 mm、振荡速度为100 r/min、改性油页岩残渣用量为2 g/100 mL、温度10℃、pH7、吸附时间为40 min的最优化条件下,对初始质量浓度为20 mg/L苯胺的去除率可达83.92%。同时,绘制了改性油页岩残渣吸附苯胺的吸附等温性,其吸附过程与Langmuir和Freundlich吸附等温线拟合。     

Migration testing with olive oil in a microwave oven

A study was carried out to compare the overall migration from packaging materials into olive oil during heating in a microwave oven, and the overall migration from the same materials into olive oil but applying time and temperature conditions stipulated in the current EC and Dutch legislation on food packaging. Application of additional test conditions (e.g. 30 min and 1 h in combination with test temperatures exceeding 121 degrees C, and a test temperature of 130 degrees C) have demonstrated the need for extension of the test conditions mentioned in existing food packaging regulations to enable realistic migration testing of microwave packaging materials under conventional test conditions. It is concluded that the overall migration into olive oil from packaging materials intended for microwave oven use, including susceptor materials, can be judged on the basis of migration testing using conventional heating. For testing film or susceptor materials in a microwave oven by one-sided contact, a migration cell transparent to microwaves was developed and used up to 200 degrees C. In conventional high-temperature tests applying hot-filling of trays or migration cells, a temperature drop was observed, while handling oil at temperatures of 150 degrees-175 degrees C may be considered perilous. To prevent problems of this kind it is proposed to start migration tests at room temperature and to heat the simulant rapidly to the final test temperature. This procedure is comparable to migration tests carried out with aqueous food simulants at 121 degrees C in an autoclave.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cracking simulation for strained linepipes exposed to different heavy corrosion and pulsating load

Susceptibility of steel to cracking ‐either by contact with gas in wet H₂S environments or near neutral solutions‐ is a dominant factor for residual life of gas‐line pipes. Three different phenomena are concerned with cracking, namely hydrogen induced cracking (HIC), sulphide stress cracking (SSC) and stress orientated hydrogen induced cracking (SOHIC). Whereas laboratory test methods for HIC are established the situation is different in combination with stress. If the coating is damaged and a near neutral liquid medium is penetrating the pipe surface a strain induced crack might occur. This type of corrosion is named near neutral SCC (NNSCC). A qualified test method with simulated cyclic loading conditions was not available. A test stand including pulsating tension on a high level qualified for high strength steels, wet environments with pH‐values between 2.7 (sour gas) and 8,3 (synthetic seawater) and bubbling several gases such as H₂S, CO₂ or N₂ through the test solution with controlled room temperature was developed. The test‐method enables to qualify steels and pipes for line pipes in tests of short duration compared to lifecycles of line pipes.     

Human papillomavirus type 16 E6 protein up-regulates the expression of the high mobility group protein HMG-I(Y) gene in mouse 10T1/2 cells

Signs of acute respiratory distress were reported in moulting grey seals (Halichoerus grypus) hauled out on Lady's Holm, Shetland, following the Braer oil spill in January, 1993. Behavioural observations carried out between 16 January and 13 February 1993 showed that the proportion of animals exhibiting a discharge of nasal mucus was significantly higher than the proportion at a control site in the north (Papa Stour). The proportion of animals affected on Lady's Holm increased for up to one month following the spill. However, the time lag between exposure and peak response was approximately 30 days, longer than may be expected for an acute effect. The proportion of non-specific signs of respiratory distress in unexposed Shetland seals was assessed from observations made between 16 January and 25 January 1994. Symptoms similar to those seen in 1993 were also reported during this period, but the proportion of affected animals was higher in 1993. Symptoms were not observed at a grey seal moult site on the east coast of England in March 1993 and 1994. Grey seals moulting in Shetland during the time of the oil spill may have been acutely affected by exposure to hydrocarbons, but without sufficient baseline data on the occurrence of respiratory distress in grey seals it is difficult to determine the proportion attributable to other causes.     

Theoretical and Experimental Analysis of GFRP Bridge Deck under Temperature Gradient

The temperature difference between the top and bottom of a glass fiber reinforced polymer (GFRP) composite deck, ～ 65°C ( ～ 122°F), is nearly three times that of conventional concrete decks ～ 23°C ( ～ 41°F). Such a large temperature difference is attributed to the relatively lower thermal conductivity of GFRP material. In this study, laboratory tests were conducted on two GFRP bridge deck modules (10.2 and 20.3?cm deep decks) by heating and cooling the top surface of the GFRP deck, while maintaining ambient (room) temperature at the deck bottom. Deflections and strains were recorded on the deck under thermal loads. Theoretical results (using macro approach, Navier-Levy, and FEM) were compared with the laboratory test data. The test data indicated that the GFRP deck exhibited hogging under a positive temperature difference (i.e., Ttop>Tbottom, heating test; Ttop and Tbottom are temperatures at top and bottom of the deck, respectively) and sagging under a negative temperature difference (i.e., Ttop相似文献   

Hydrodynamic Modeling of Coastal LNG Cooling Water Discharge

The evaluation of the mixing zone for a proposed expansion to a liquefied natural gas facility on the northeast coast of the State of Qatar in support of an environmental impact assessment was performed using the Generalized Environmental Modeling System for Surface Waters (GEMSS). The circulating seawater at the facility absorbs heat during the liquefaction of natural gas, resulting in a maximum temperature rise of 10°C. The heated seawater is discharged through a long canal into the Arabian Gulf with minimum jet momentum. GEMSS was calibrated, verified, and then used to model the thermal plume for a proposed expansion of the facility. A probabilistic approach for defining the mixing zone using World Bank standards was developed. Model results show that the thermal plume is vertically stratified, with a relatively large surface area and a relatively small bottom contact area. The advantage of this design is that it maximizes heat exchange with the atmosphere by increasing the driving force and isolating the temperature increase from benthic organisms.     

Comparison of oil composition changes due to biodegradation and physical weathering in different oils

The well-characterized Alberta Sweet Mixed Blend oil and several other oils which are commonly transported in Canada were physically weathered and then incubated with a defined microbial inoculum. The purpose was to produce quantitative data on oil components and component groups which are more susceptible or resistant to biodegradation, and to determine how oils rank in relation to each other in terms of biodegradation potential. The biodegraded oils were characterized by quantitative determination of changes in important hydrocarbon groups including the total petroleum hydrocarbons, total saturates and aromatics, and also by quantitation of more than 100 individual target aliphatic, aromatic and biomarker components. The study reveals a pattern of distinct oil composition changes due to biodegradation, which is significantly different from the pattern due to physical or short-term weathering. It is important to be able to distinguish between these two forms of loss, so that loss due to weathering is not interpreted as loss due to biodegradation in the laboratory or in the field. Based on these findings, the oil composition changes due to biodegradation can be readily differentiated from those due to physical weathering. To rank the tested oils with respect to biodegradability, losses in total petroleum hydrocarbons and aromatics were used to calculate biodegradation potential indices, employing equations proposed by Environment Canada and the US National Oceanic and Atmospheric Administration. The different methods produced very similar biodegradation trends, confirming that patterns of oil biodegradability do exist.     

Bubble Sizes, Breakup, and Coalescence in Deepwater Gas/Oil Plumes

Bubble size distribution (BSD) plays a major role in transport and fate of gas or oil released in deepwater. However, no reliable method is available to estimate gas or oil BSD after a deepwater spill. Breakup and coalescence have been identified as key processes controlling BSDs in turbulent jets. The present work introduces bubble breakup and coalescence processes for deepwater gas or oil spill models. A population balance equation representing bubble volumes is used to model the evolution of bubble sizes caused by breakup and coalescence. Existing theories for bubble breakup and coalescence rates in bubble columns are adopted to deepwater plumes. The advantage of the present model is that the BSD is generated as a result of breakup and coalescence; and therefore, a predefined BSD is no longer necessary for simulations. The comparison of model-computed results with laboratory and field data shows a good agreement. Scenario simulations show that the seed diameter given to start computations affects only for a short distance from the release point. Simulations also show that bubble breakup and coalescence is important only during the early stages of the plume where turbulence is dominant. The importance of accounting for gas bubble breakup and coalescence in estimation of gas dissolution is also demonstrated.