A Review of the Relationship Between the Characteristics of Spilled Oil and Dispersant Effectiveness

2008 ◽  
pp. 87-87-7 ◽  
Author(s):  
GP Canevari
Keyword(s):  
Dispersant Effectiveness ◽  
The Relationship ◽  
Spilled Oil

scholarly journals Evaluating Surface Washing Agent Performance

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Robert Grosser ◽  
Robyn Conmy ◽  
Devi Sundaravadivelu ◽  
Andrea Burkes ◽  
Edith Holder ◽  
...  
Keyword(s):  
Oil Spill ◽  
Mechanism Of Action ◽  
Total Mass ◽  
Substrate Surface ◽  
General Rule ◽  
Oil Slick ◽  
Primary Mechanism ◽  
Dispersant Effectiveness ◽  
The Relationship ◽  
Spilled Oil

Surface washing agents (SWAs) can be used to enhance removal of spilled oil from shoreline surfaces and structures. There are two classes of SWA products, “lift and float” products which remove the oil from the surfaces to create an oil slick which can be recovered mechanically and “lift and disperse” products which emulsify and disperse the oil into the water column, which are more difficult to remove mechanically. Therefore, information regarding the ability of a product to lift oil from a surface and its mechanism of action once the oil has been removed is important for oil spill responders. The SWA effectiveness (SWAE) of 15 products (conducted and reported blind) listed on the NCP Product Schedule was evaluated by applying oil to a sand substrate, allowing time for the oil to adhere to the substrate, treating with SWA, and washing with artificial seawater to release any oil that has been lifted from the substrate surface. The efficiency of SWAs is calculated based on the mass of oil remaining on the substrate relative to the total mass of oil applied. The Dispersant Effectiveness (DE) of SWA products was determined using the Baffled Flask Test and was used to sort products based on their mechanism of action (“lift and disperse” rather than “lift and float”). Using a sand basket approach, the amount of oil remaining in sand varied from 10 to 95% for the various products tested, where a lower percent signifies a better SWA. The DE varied between 8 and 81%. Though previous studies have concluded that good SWAs are poor dispersants and vice versa, the results from this study demonstrate that this is not a general rule. A stoplight decision framework was developed that considers the relationship between DE and SWAE, and serves to identify products whose primary mechanism is “lift and disperse” rather than “lift and float.” Results suggest that regardless of which test is used to evaluate SWAs, coupling findings with DE can provide useful information for decisions during response operations.

scholarly journals Estimation of the Mechanical Recovery Potential of Spilled Oil at Sea Considering the Spatial Thickness Distribution

2020 ◽  
Vol 8 (5) ◽  
pp. 362
Author(s):  
Yunseon Choe ◽  
Hyeonuk Kim ◽  
Cheol Huh ◽  
Choong-Ki Kim ◽  
Meang-Ik Cho ◽  
...  
Keyword(s):  
Thickness Distribution ◽  
Estimation Methods ◽  
Residual Oil ◽  
Recovery Model ◽  
Recovery Potential ◽  
Response Planning ◽  
Planning Models ◽  
The Relationship ◽  
Spilled Oil ◽  
Mechanical Recovery

Recovery modeling and countermeasures for oil spilled at sea have been extensively researched, but research remains insufficient on recovery potential estimation methods. It is required to access the mechanical recovery potential by considering the relationship between oil behavior, environmental conditions, and the performance of clean-up activities. Two response-planning models were developed in this study. One is a spatially uniform recovery model for estimating recovery potential that reflects weathering, oil properties, and equipment efficiency. The other is a spatially nonuniform recovery model that considers not only the above characteristics but also local thickness reduction by skimming. A comparison between the two models and an analysis of their effects on response was carried out through the calculation using an accident scenario. It is possible to analyze the effect of the thin slicks, natural dissipation, and the quantification of deployable skimming systems with the spatially nonuniform recovery model. Finally, we analyzed interrelationships among residual oil volume on the sea, response time, and the number of skimming systems.

scholarly journals Are Oil Spills Enhancing Outbreaks of Red Tides in the Chinese Coastal Waters from 1973-2017?

2021 ◽  
Author(s):  
xin LIU ◽  
chunchang zhang ◽  
ruiying geng ◽  
xin lv
Keyword(s):  
Oil Spill ◽  
Coastal Waters ◽  
Oil Spills ◽  
Red Tide ◽  
Contingency Management ◽  
Coastal Region ◽  
Red Tides ◽  
The Relationship ◽  
Spilled Oil ◽  
Shed Light

Abstract Between 1973–2017, evidences of red-tide outbreaks and oil spill accidents in the Chinese coastal waters were collected. Statistical analysis and multiple regression models were used to determine the relationship between the red tide and the oil spill. Major findings reveal that, (1) the frequency of red tides positively correlates to the number of oil spills and the volume of oil spilled as well; (2) The higher percentage of small spills (< 7 tonnes) are more likely to enhance the outbreaks of red tides; (3) More severe oil spill with penalty recorded implies a higher possibility to trigger the red tide afterwards. Therefore, oil spill contingency management aiming at preventing oil spills and mitigating spill effect could be of benefit to decrease the frequency of red tides as well. For example, it is suggested to carry out physical combat instead of chemical dispersants to remove the spilled oil in the shallow coastal areas for reducing the outbreak risk of red tides after the oil spill. The findings from this study shed light on the preventative management of red tides occurrence in the Chinese coastal waters and the similar coastal region elsewhere.

THE EFFECTIVENESS OF DISPERSANTS: VARIATION WITH ENERGY

1993 ◽  
Vol 1993 (1) ◽  
pp. 567-574 ◽  
Author(s):  
M. F. Fingas ◽  
D. A. Kyle ◽  
J. B. Holmes ◽  
E. J. Tennyson
Keyword(s):  
Water Column ◽  
Rotational Speed ◽  
Chemical Dispersion ◽  
Mixing Energy ◽  
Oil Dispersant ◽  
The Stability ◽  
Dispersant Effectiveness ◽  
Relationship Of ◽  
The Relationship ◽  
Oil Type

ABSTRACT A study of the relationship of dispersant effectiveness and mixing energy was performed. Energy was varied by changing the rotational speed of a specially designed apparatus. The effects of dispersant type and oil type were also measured. The stability of the resulting emulsions was gauged by measuring the amount of oil that remained in the water column over time. The findings are that each oil-dispersant combination shows a unique threshold or onset of dispersion. The effectiveness goes up linearly with energy, expressed as flask rotational speed. Natural dispersion was also measured and shows behavior similar to that of chemical dispersion, except that the thresholds occur at a higher energy and effectiveness rises more slowly with increasing energy. Effectiveness (defined as the percentage of oil in the water column) rises rapidly to 80 to 90 percent with increasing energy for light oils treated with chemical dispersants. Heavier oils will disperse, but to lesser effectiveness values.

RESEARCH AND DEVELOPMENT IN THE INSTITUTE OF OCEAN ENVIRONMENTAL TECHNOLOGY

1983 ◽  
Vol 1983 (1) ◽  
pp. 95-103
Author(s):  
Atsuo Yazaki
Keyword(s):  
Research And Development ◽  
Oil Recovery ◽  
Sea Water ◽  
Water Channel ◽  
Environmental Technology ◽  
Circulating Water ◽  
Oil Boom ◽  
Relationship Of ◽  
The Relationship ◽  
Spilled Oil

ABSTRACT This paper presents a summary of research and development projects at the Institute of Ocean Environmental Technology. First, projects in the field of oil boom and skimmer development are described. Oil containment performance for each of four new oil booms, and the oil recovery rate for each of seven new oil recovery devices and a new oil recovery ship are explained. Next, as typical examples of research projects concerning ocean and marine environmental problems, summaries of the following themes are presented: (a) oil spreading on the water surface, (b) the mechanism of oil leakage from a flat plate barrier, (c) oil slick behavior around a moving catamaran skimmer, (d) a law of similarity for the performance of oil recovery equipment, (e) evaporation of gasoline under various conditions, (f) the relationship of spilled oil and dissolved oxygen in sea water, (g) the effectiveness of chemical dispersants for spilled gasoline, (h) the generation of transient waves in a circulating water channel, and (i) experiments with a wave energy absorber.

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

Tinkering with cognitive gadgets: Cultural evolutionary psychology meets active inference

2019 ◽  
Vol 42 ◽  
Author(s):  
Paul Benjamin Badcock ◽  
Axel Constant ◽  
Maxwell James Désormeau Ramstead
Keyword(s):  
Evolutionary Psychology ◽  
Research Program ◽  
Active Inference ◽  
Innovative Research ◽  
Cognitive Faculties ◽  
Cultural Evolutionary ◽  
The Relationship

Abstract Cognitive Gadgets offers a new, convincing perspective on the origins of our distinctive cognitive faculties, coupled with a clear, innovative research program. Although we broadly endorse Heyes’ ideas, we raise some concerns about her characterisation of evolutionary psychology and the relationship between biology and culture, before discussing the potential fruits of examining cognitive gadgets through the lens of active inference.

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 260-261
Author(s):  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Particle Flux ◽  
Unit Area ◽  
Signal To Noise ◽  
Resolution Image ◽  
High Resolution Image ◽  
Pass Through ◽  
Counting Statistics ◽  
The Relationship ◽  
Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

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