Size distribution as a measure of dispersant performanceA paper submitted to the Journal of Environmental and Engineering Science.

2009 ◽  
Vol 36 (3) ◽  
pp. 540-549 ◽  
Author(s):  
Biplab Mukherjee ◽  
Brian A. Wrenn
Keyword(s):  
Size Distribution ◽  
Microscopic Examination ◽  
Uv Spectroscopy ◽  
Response Strategy ◽  
Distribution Data ◽  
Accurate Information ◽  
Volatile Components ◽  
Gravimetric Analysis ◽  
Dispersed Oil ◽  
Oil Spill Response

Study of the chemical dispersion of crude oil using size distribution methods can provide important information needed for oil-spill response strategy, which is lacking in the more commonly used mass–concentration methods. Therefore, identification of a reliable method or methods that can provide accurate information regarding droplet size and the mass of oil dispersed is necessary. This research compared four such methods. Gravimetric analysis of the oil mass dispersed was biased low due to loss of volatile components, whereas UV spectroscopy provided accurate results. Size–distribution data obtained using an optical particle counter (OPC) produced accurate estimates of oil mass dispersed, but microscopic examination produced inaccurate and poorly reproducible estimates. Although size–distribution metrics (e.g., estimates of the mean diameter of the size distribution) produced by the two methods were similar, microscopic examination gave unreliable estimates of the number concentration of dispersed oil droplets due to the relatively small number of observations relative to the OPC.

scholarly journals Next-Generation Smart Response Web (NG-SRW): An Operational Spatial Decision Support System for Maritime Oil Spill Emergency Response in the Gulf of Finland (Baltic Sea)

2021 ◽  
Vol 13 (12) ◽  
pp. 6585
Author(s):  
Mihhail Fetissov ◽  
Robert Aps ◽  
Floris Goerlandt ◽  
Holger Jänes ◽  
Jonne Kotta ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Oil Spill ◽  
Situational Awareness ◽  
Oil Spills ◽  
Relevant Information ◽  
Response Strategy ◽  
Spatial Decision Support System ◽  
Next Generation ◽  
Oil Spill Response ◽  
The Baltic

The Baltic Sea is a unique and sensitive brackish-water ecosystem vulnerable to damage from shipping activities. Despite high levels of maritime safety in the area, there is a continued risk of oil spills and associated harmful environmental impacts. Achieving common situational awareness between oil spill response decision makers and other actors, such as merchant vessel and Vessel Traffic Service center operators, is an important step to minimizing detrimental effects. This paper presents the Next-Generation Smart Response Web (NG-SRW), a web-based application to aid decision making concerning oil spill response. This tool aims to provide, dynamically and interactively, relevant information on oil spills. By integrating the analysis and visualization of dynamic spill features with the sensitivity of environmental elements and value of human uses, the benefits of potential response actions can be compared, helping to develop an appropriate response strategy. The oil spill process simulation enables the response authorities to judge better the complexity and dynamic behavior of the systems and processes behind the potential environmental impact assessment and thereby better control the oil combat action.

scholarly journals Atmospheric observations with E-band microwave links – challenges and opportunities

2020 ◽  
Author(s):  
Martin Fencl ◽  
Michal Dohnal ◽  
Pavel Valtr ◽  
Martin Grabner ◽  
Vojtěch Bareš
Keyword(s):  
Water Vapor ◽  
Size Distribution ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Distribution Data ◽  
Vapor Sensing ◽  
Challenges And Opportunities ◽  
Atmospheric Observations ◽  
Order Of Magnitude ◽  
Microwave Link

Abstract. Opportunistic sensing of rainfall and water vapor using commercial microwave links operated within cellular networks was conceived more than a decade ago. It has since been further investigated in numerous studies predominantly concentrating on the frequency region of 15–40 GHz. This manuscript provides the first evaluation of rainfall and water vapor sensing with microwave links operating at an E band (specifically, 71–76 GHz and 81–86 GHz), which are increasingly updating, and frequently replacing, older communication infrastructure. Attenuation-rainfall relations are investigated theoretically on drop size distribution data. Furthermore, quantitative rainfall estimates from six microwave links, operated within cellular backhaul, are compared with observed rainfall intensities. Finally, the capability to detect water vapor is demonstrated on the longest microwave link measuring 4.86 km in path length. The results show that E-band microwave links are by one order of magnitude more sensitive to rainfall than devices operating in the 15–40 GHz range and are thus able to observe even light rainfalls, a feat practically impossible to achieve previously. The E-band links are, however, substantially more affected by errors related to variable drop size distribution. Water vapor retrieval might be possible from long E band microwave links, nevertheless, the efficient separation of gaseous attenuation from other signal losses will be challenging in practice.

scholarly journals Evolution of Soot Particle Number, Mass and Size Distribution along the Exhaust Line of a Heavy-Duty Engine Fueled with Compressed Natural Gas

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3993
Author(s):  
Elia Distaso ◽  
Riccardo Amirante ◽  
Giuseppe Calò ◽  
Pietro De Palma ◽  
Paolo Tamburrano
Keyword(s):  
Particle Size ◽  
Natural Gas ◽  
Size Distribution ◽  
Soot Formation ◽  
Distribution Data ◽  
Exhaust Pipe ◽  
Heavy Duty ◽  
Compressed Natural Gas ◽  
Soot Particles ◽  
Exhaust Line

An experimental study has been conducted to provide a characterization of the transformations that particle size distributions and the number density of soot particles can encounter along the exhaust line of a modern EURO VI compliant heavy-duty engine, fueled with compressed natural gas. Being aware of the particles history in the exhausts can be of utmost importance to understand soot formation and oxidation dynamics, so that, new strategies for further reducing these emissions can be formulated and present and future regulations met. To this purpose, particle samples were collected from several points along the exhaust pipe, namely upstream and downstream of each device the exhaust gases interact with. The engine was turbocharged and equipped with a two-stage after-treatment system. The measurements were carried out in steady conditions while the engine operated in stoichiometric conditions. Particle emissions were measured using a fast-response particle size spectrometer (DMS500) so that size information was analyzed in the range between 5 and 1000 nm. Particle mass information was derived from size distribution data using a correlation available in the literature. The reported results provide more insight on the particle emission process related to natural gas engines and, in particular, point out the effects that the turbine and the after-treatment devices produce on soot particles. Furthermore, the reported observations suggest that soot particles might not derive only from the fuel, namely, external sources, such as lubricant oil, might have a relevant role in soot formation.

scholarly journals Modeling the facet growth rate dispersion of β l-glutamic acid—Combining single crystal experiments with nD particle size distribution data

2015 ◽  
Vol 133 ◽  
pp. 30-43 ◽  
Author(s):  
David R. Ochsenbein ◽  
Stefan Schorsch ◽  
Fabio Salvatori ◽  
Thomas Vetter ◽  
Manfred Morari ◽  
...  
Keyword(s):  
Growth Rate ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Glutamic Acid ◽  
Single Crystal ◽  
Size Distribution ◽  
Distribution Data ◽  
Facet Growth
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