Time Of Spill Research Articles

Revisiting the quantum field theory of neutrino oscillations in vacuum

We consider neutrino oscillations in vacuum in the framework of quantum field theory in which neutrino production and detection processes are part of a single Feynman diagram and the corresponding cross section is computed in the standard way, i.e. with final states represented by plane waves. We use assumptions which are realized in actual experiments and concentrate on the detection process. Moreover, we also allow for a finite time interval of length τ during which the detector records neutrino events. In this context we are motivated by accelerator-neutrino oscillation experiments where data taking is synchronized in time with the proton spill time of the accelerator. Given the final momenta and the direction of neutrino propagation, we find that in the oscillation amplitude—for all practical purposes—the neutrino energy Q is fixed, apart from an interval of order 2πℏ/τ around a mean energy this is an expression of energy non-conservation or the time-energy uncertainty relation in the detection process due to . We derive in excellent approximation that in the amplitude the oscillation effect originates from massive neutrinos with the same energy , i.e. oscillations take place in space without any decoherece effect, while the remaining integration over Q in the interval of order 2πℏ/τ around results in a time-correlation function expressing the time delay between neutrino production and detection.

Exposure to Oil and Hypoxia Results in Alterations of Immune Transcriptional Patterns in Developing Sheepshead Minnows (Cyprinodon variegatus)

The area and timing of the Deepwater Horizon oil spill highlight the need to study oil and hypoxia exposure in early life stage fishes. Though critical to health, little research has targeted the effect of oil and hypoxia exposure on developing immune systems. To this end, we exposed sheepshead minnows (Cyprinodon variegatus) at three early life stages: embryonic; post-hatch; and post-larval, to a high energy water accommodated fraction (HEWAF) of oil, hypoxia, or both for 48 hours. We performed RNAseq to understand how exposures alter expression of immune transcripts and pathways. Under control conditions, the embryonic to post-hatch comparison (first transition) had a greater number of significantly regulated immune pathways than the second transition (post-hatch to post-larval). The addition of oil had little effect in the first transition, however, hypoxia elicited changes in cellular and humoral immune responses. In the second transition, oil exposure significantly altered many immune pathways (43), and while hypoxia altered few pathways, it did induce a unique signature of generally suppressing immune pathways. These data suggest that timing of exposure to oil and/or hypoxia matters, and underscores the need to further investigate the impacts of multiple stressors on immune system development in early life stage fishes.

Risk of oil contamination of fish eggs and larvae under different oceanic and weather conditions

Abstract An oil drift model is applied to determine the spread of oil spills from different locations along ship lanes off southern Norway every month for 20 years. These results are combined with results from an egg- and larvae drift model for Atlantic cod (Gadus morhua) to determine their risk of being impacted by oil. The number of eggs and larvae exposed to oil contamination is connected to environmental conditions. The highest risk of overlap between an oil spill and cod in early life stages occurs during March and April when the eggs and larvae concentrations are highest. Spills off the west coast pose a greater risk because of the ship lanes’ proximity to the spawning grounds, but there is large interannual variability. For some spill locations the interannual variability can be explained by variability in wind and ocean currents. Simultaneously occurring onshore transports lead to a high-risk situation because both oil and larvae are concentrated towards the coast. This study demonstrates how results from oil drift and biological models can be combined to estimate the risks of oil contamination for marine organisms, based on the location and timing of the oil spill, weather/ocean conditions, and knowledge of the organisms’ life cycle.

Measuring the Impact of Traceability Information on Oyster Consumer Behavior Following a Contamination Event

AbstractWe fuse and jointly estimate revealed and stated preference data over the BP Deepwater Horizon oil spill time horizon to analyze the potential for a new seafood traceability system to mitig...

Assessing relative potential economic impacts of an oil spill on commercial fisheries in the Great Australian Bight using a Bayesian Belief Network framework

Review based experiences of oil-spill induced impacts on fisheries were used to develop a Bayesian Belief Network (BBN) to evaluate the potential economic consequences of a (hypothetical) oil spill in the Great Australian Bight, an area currently being explored by several major international oil companies. The model differs from most previous BBN analyses in that it also considers the relatively short term economic impacts of such a spill, encompassing market and fisher behaviour, as well as impacts on the stocks affected directly by the spill. The results suggest that impacts vary depending on the characteristics of the fishery (i.e. main species, location etc.) and the timing and extent of the oil spill, but market, management and fisher behavioural responses (and their ability to respond) were found to have the greatest impact on the final economic outcomes.

Generation of red drum (Sciaenops ocellatus) hematology Reference Intervals with a focus on identified outliers.

The Deepwater Horizon (DWH) oil spill in 2010 released millions of barrels of crude oil into the northern Gulf of Mexico, exposing numerous species of animals to the toxic components of oil. A comprehensive assessment of morbidity and mortality caused by DWH oil exposure was undertaken by the DWH Natural Resource Damage Trustees to characterize ecosystem damages. This study aimed to characterize normal hematologic RIs in red drum fish with blood cell descriptions, and to demonstrate the importance of identifying and removing outliers when generating RI. Two years after the oil spill, 57 adult, red drum fish of mixed sexes were caught along the eastern Louisiana coastline. Eight different sites were chosen to catch the fish; 6 sites were contaminated with oil, and 2 sites were not contaminated at the time of the oil spill. Hematologic RIs were generated from heparinized whole blood samples of healthy red drum as determined by gross examination and histopathologic examination. Two methods were used to detect hematologic effects likely caused by oil contamination. Red drum PCVs (RI 42-62%) were higher than previously reported in cold water and bottom-dwelling fish species, while absolute WBC counts (RI 2.9-8.7 ×109 /L) were comparable to WBC counts previously reported in other fish species with heterophil and lymphocyte absolute concentrations frequently being equivalent. Anemic animals (PCV<42%) were only identified in oil-contaminated sites. RIs in many wild fish species are lacking, and therefore, this study provides valuable baseline data on healthy red drum fish. The outliers assessed using ASVCP RI guidelines can provide valuable clinical information regarding individuals in population health assessments, which may be more sensitive for the detection of abnormalities than for population statistics comparing the mean. The importance of removing outliers and rerunning RI statistics is highlighted by this field example.

Estimating oil pollution risk in environmentally sensitive areas of petrochemical terminals based on a stochastic numerical simulation

This paper presents a method based on the oceanic current model and the oil spill model to evaluate the pollution risk of sensitive resources when oil spills occur. Moreover, this study proposes a novel impact index based on the risk theory to improve the risk assessment accuracy. The impact probability and the first impact time of the oil spill are calculated through a stochastic numerical simulation. The risk assessment content is enriched by establishing an impact model that considers the impact of sensitive index and spillage. Finally, the risk score of sensitive resources in an oil spill accident is visualized for formulating a scientific and effective protection priority order in a contamination response strategy. This study focuses on integrating every possible impact factor that plays a role in risk assessment and helps to provide a better theoretical support for protecting sensitive resources.

An analysis of beam parameters on proton-acoustic waves through an analytic approach

It has been reported that acoustic waves are generated when a high-energy pulsed proton beam is deposited in a small volume within tissue. One possible application of proton-induced acoustics is to get real-time feedback for intra-treatment adjustments by monitoring such acoustic waves. A high spatial resolution in ultrasound imaging may reduce proton range uncertainty. Thus, it is crucial to understand the dependence of the acoustic waves on the proton beam characteristics. In this manuscript, firstly, an analytic solution for the proton-induced acoustic wave is presented to reveal the dependence of the signal on the beam parameters; then it is combined with an analytic approximation of the Bragg curve. The influence of the beam energy, pulse duration and beam diameter variation on the acoustic waveform are investigated. Further analysis is performed regarding the Fourier decomposition of the proton-acoustic signals. Our results show that the smaller spill time of the proton beam upsurges the amplitude of the acoustic wave for a constant number of protons, which is hence beneficial for dose monitoring. The increase in the energy of each individual proton in the beam leads to the spatial broadening of the Bragg curve, which also yields acoustic waves of greater amplitude. The pulse duration and the beam width of the proton beam do not affect the central frequency of the acoustic wave, but they change the amplitude of the spectral components.

Effect of atmospheric and sea stability on liquefied natural gas (LNG) dispersion: Implications to Australian LNG marine transport

Increasing demand for natural gas as a fuel source has led to increasing marine transport of liquefied natural gas (LNG) that is flammable and makes LNG tankers a potential terrorist target. This study utilises CFD simulation coupled with wave modelling for investigating the effect of atmospheric and sea (sea waves in particular) stability on LNG pool formation and dispersion process. Pasquill stability was used to determine the stability classes for each of the scenarios and cases studied. The importance of modelling the roll and pitch of LNG carriers was investigated; with sloshing leading to an increase of up to 31% on tank wall pressure and an increase of 100s on spill time. Analyses also show that as stability increases, LNG pool radius also increase; and a larger pool radius was indicative of a lower evaporation rate. The increasing stability (more stable conditions) was shown to have little effect on the earlier growth of the LNG pool and the temporal evolution of evaporation rate (0–50s); once the discharge of LNG form the tanker starts decreasing, the effect of increasing stability in each case, starts becoming visible (∼50 and onwards). The results showed that stability effects induced by the sea waves were noted to have a greater impact on the whole spill and dispersion process. Overall the increasing stability conditions led to 8% increase in downwind dispersion of the vapour cloud, 11% increase in the crosswind dispersion and 19% decrease in vertical dispersion. Finally the implications of this study to Australian LNG export was investigated, from which it was concluded that LNG exports during winter can lead to the least affected areas compared to that in summer. In order to mitigate LNG spill hazards from an LNG carrier, the areas of focus should be on travel routes in close proximity to islands; and following an LNG spill, stopping the LNG carrier would minimise the hazard zone.

Post-deepwater horizon blowout seafood consumption patterns and community-specific levels of concern for selected chemicals among children in Mobile County, Alabama.

The goal of the study was to characterize risk pertaining to seafood consumption patterns following the Deepwater Horizon oil spill, among school children (K to 4th grade) residing in close proximity to the Gulf of Mexico in Mobile County, Alabama. Responses on seafood consumption pattern including the type of seafood and intake rate during the pre and post oil spill periods, from parents of 55 school children from three schools located <20mile radius from the Gulf of Mexico shoreline (coastal group) were compared with those from parents of 55 children from three schools located ≥20miles away from the shoreline (inland group). We also estimated levels of concern (LOCs) in seafood for selected chemicals found in crude oil including heavy metals, and polycyclic aromatic hydrocarbons (PAH), and dioctyl sodium sulfosuccinate (DOSS), the primary compound in dispersants. The coastal group ate more seafood consisting primarily of crustaceans (62% vs. 42%, p=0.04) and fin fish (78% vs. 58%, p=0.02) from the Gulf of Mexico compared to the inland group, while the inland group ate more fin fish not found in the Gulf of Mexico (62% vs. 33%, p<0.01). In the post-oil spill time period, both groups substantially reduced their consumption of sea food. On average, the coastal group ate ≥2 seafood meals per week, while the inland group ate ≤1 meal per week; these frequency patterns persisted in the post oil-spill period. Comparison of the estimated LOCs with contaminant levels detected in the seafood tested by the Food and Drug Administration and National Oceanic and Atmospheric Administration, post-oil spill, found that the levels of PAHs, arsenic, and DOSS in seafood were 1-2 orders of magnitude below the LOCs calculated in our study. Levels of methyl mercury (MeHg) in the seafood tested pre- and post- oil spill were higher than the estimated LOCs suggesting presence of higher levels of MeHg in seafood independent of the oil spill. In sum, the study found higher than average seafood consumption among children along the Mobile coastal area when compared to the inland children and the National Health and Nutrition Examination Survey (NHANES) estimates. Risk characterization based on the LOCs indicated no increase in risk of exposure despite higher seafood consumption rates among the study population compared to the general population.

An investigation into the factors influencing the detectability of oil spills using spectral indices in an oil-polluted environment

ABSTRACTThe aim of this article is to investigate and test the influence of oil spill volume and time gap (number of days between oil spill events and image acquisition date) on normalized difference vegetation index (NDVI) and normalized difference water index (NDWI). This was carried out to determine the effect of these factors on vegetation condition affected by the oil spill. Based on regression analysis, it was shown that increase in the volume of oil spill resulted in increased deterioration of vegetation condition (estimated using NDVI and NDWI) in the study site. The study also tested how the length of time gap between the oil spill and image acquisition date influences the detectability of impacts of oil spill on vegetation. The results showed that the length of time between image acquisition and oil spill influenced the detectability of impacts of oil spill on vegetation condition. The longer the time between the date of image acquisition and the oil spill event, the lower the detectability of impacts of oil spill on vegetation condition. The NDVI seemed to produce better results than the NDWI. In conclusion, time and volume of oil spill can be important factors influencing the detection of pollution using vegetation indices (VIs) in an oil-polluted environment.

Measuring the Impact of the BPDeepwater HorizonOil Spill on Consumer Behavior

We exploit the timing of the BP Deep-water Horizon oil spill to develop a unique dataset of oyster consumer actual and anticipated behavior immediately prior to and following the event. A revealed and stated preference model allows both short- and longer-term responses to the spill to be investigated. Findings indicate that the BP spill had a negative impact on oyster demand in terms of short-run actual behavior, although spill effects show signs of dissipating several months following the spill. By accounting for unobserved heterogeneity in the sample, findings further indicate that short- and longer-term spill responses differ across consumer groups.

Effect of Mahua Biodiesel Blends on the Combustion Characteristics of Direct Injection CI Engine at Various Compression Ratios

In the current study, combustion characteristics were evaluated using mahua biodiesel blends at different compression ratios on a direct injection CI engine. Non edible mahua oil was transesterified into biodiesel by two stage technique. Combustion parameters were evaluated for B5, B10 and B20 blends of mahua biodiesel with diesel and they were compared with straight diesel at compression ratios of 16, 17 and 18.Compression ratio was varied without altering the combustion chamber geometry and the static spill timing was set to 23° bTDC. Parameters like In cylinder pressure, heat release rate, rate of pressure rise and cumulative heat release were evaluated in this study at 100% engine loading conditions. Higher peak cylinder pressure and heat release was observed at higher compression ratios. The ignition delay of the blends were slightly higher compared to diesel at all CR tested. Peak cylinder pressure of the blends was slightly higher at CR 18. The ignition delay was also observed to be lower at higher compression ratio. The peak pressure was observed closer to TDC at higher compression ratios for all fuels tested.

Phytoplankton and the Macondo oil spill: A comparison of the 2010 phytoplankton assemblage to baseline conditions on the Louisiana shelf

The Macondo oil spill was likely the largest oil spill to ever occur in United States territorial waters. We report herein our findings comparing the available baseline phytoplankton data from coastal waters west of the Mississippi River, and samples collected monthly from the same sampling stations, during and after the oil spill (May–October, 2010). Our results indicate that overall, the phytoplankton abundance was 85% lower in 2010 versus the baseline, and that the species composition of the phytoplankton community moved towards diatoms and cyanobacteria and away from ciliates and phytoflagellates. The results of this study reaffirm the view that phytoplankton responses will vary by the seasonal timing of the oil spill and the specific composition of the spilled oil. The trophic impacts of the purported lower abundance of phytoplankton in 2010 coupled with the observed assemblage shift remain unknown.

Oil Spill Modeling Aiming at the Protection of Ports and Coastal Areas

Oil spill models are used worldwide to provide preventive measures in assessing risks of actual and potential damage to natural resources from spills, and also in assisting coastal facilities and local authorities in their strategic development of oil spill mitigation planning and response. Numerous oil spill simulation models exist in the bibliography. They vary in complexity, applicability to location and ease of use. A synoptic presentation of the types of oil slick models internationally applied in operational mode is done, focusing on the model developed by Aristotle University of Thessaloniki. The current study elaborates on that oil slick numerical model which simulates the transport and weathering (due to a number of physicochemical processes evolving with time) of an oil spill that accidentally occurred in a coastal area, coupled with a 3D hydrodynamic model. The model is applied in a semi-confined water body, namely Thermaikos Gulf, in N. Greece, which contains the Port of Thessaloniki, a potential source of accidentally spilled oil. Findings of the present study highlight the existing experience on the subject and denote the applicability of such models in either tracing the source of a spill or in predicting its path and spread, thus proving their value in real-time crisis management.

Understanding the Causes of Spills From the Supply and Handling of Chemicals at Resource Construction Sites: A Case Study

An intermediate bulk container (IBC) was punctured during its handling, releasing a refined oil product onto land at a large construction site in an environmentally sensitive region of Australia. Understanding and controlling the risks from fuel, oil, and chemical spills on the current project was of critical importance as part of the project's overall approval, and ongoing compliance depended on the project committing to minimizing all chemical and petroleum hydrocarbon spills on the site. The telehandler (forklift) did not pierce the plastic of the IBC directly (as was expected to be the case) but rather one of the tynes caught on the underside of the metal base plate (pallet belly plate), despite numerous controls being in place at the time of spill (to limit the risks of damaging the IBC), revealing a previously unreported mechanism for a fluid spill from handling of petroleum hydrocarbons and related chemicals. The investigation team used a root cause analysis (RCA) technique, based on the fishbone (Ishikawa) diagram, which was undertaken with 12 expert contributors (from the project) to identify the underlying cause: The inspection process was inadequate. This study is a companion to the article published in Winter 2014 in Remediation (Guerin, 2014) covering multiple causes of spills from plant and equipment commonly used on construction and remediation projects. ©2015 Wiley Periodicals, Inc.

SU‐E‐T‐755: Timing Characteristics of Proton and Carbon Ion Treatments Using a Synchrotron and Modulated Scanning

Purpose:The time required to deliver a treatment impacts not only the number of patients that can be treated each day but also the accuracy of delivery due to potential movements of patient tissues. Both macroscopic and microscopic timing characteristics of a beam delivery system were studied to examine their impacts on patient treatments.Methods:35 patients were treated during a clinical trial to demonstrate safety and efficacy of a Siemens Iontris system prior to receiving approval from the Chinese Food and Drug Administration. The system has a variable cycle time and can provide proton beams from 48 to 221 MeV/n and carbon ions from 86 to 430 MeV/n. A modulated scanning beam delivery technique is used where the beam remains stationary at each spot aiming location and is not turned off while the spot quickly moves from one aiming location to the next. The treatment log files for 28 of the trial patients were analyzed to determine several timing characteristics.Results:The average portal time per target dose was 172.5 s/Gy for protons and 150.7 s/Gy for carbon ions. The maximum delivery time for any portal was less than 300 s. The average dwell time per spot was 12 ms for protons and 3.0 ms for carbon ions. The number of aiming positions per energy layer varied from 1 to 258 for protons and 1 to 621 for carbon ions. The average spill time and cycle time per energy layer were 1.20 and 2.68 s for protons and 0.95 and 4.73 s for carbon ions respectively. For 3 of the patients, the beam was gated on and off to reduce the effects of respiration.Conclusion:For a typical target volume of 153 cc as used in this clinical trial, the portal delivery times were acceptable.

An investigation into the cause of loss of containment from the supply of mini-bulk lubricants

An Intermediate Bulk Container (IBC) was punctured during its handling, releasing oil onto soil at an environmentally-sensitive region of Australia. The telehandler did not pierce the plastic of the IBC directly (as was expected) but rather one of the tynes had caught on the underside of the metal base plate, despite numerous controls being in place at time of spill, revealing a previously unreported mechanism for a fluid spill from handling of petroleum hydrocarbons. The diverse investigation team used a root cause analysis (RCA) technique to identify the underlying cause: the inspection process was inadequate with contributing factors of not using a spotter and design of IBC did not anticipate conditions. Engineering controls were put in place as part of the change management process to help prevent spills from occurring from piercing from telehandler tynes on the current project site.

Initial community and environment determine the response of bacterial communities to dispersant and oil contamination

Bioremediation of seawater by natural bacterial communities is one potential response to coastal oil spills, but the success of the approach may vary, depending on geographical location, oil composition and the timing of spill. The short term response of coastal bacteria to dispersant, oil and dispersed oil was characterized using 16S rRNA gene tags in two mesocosm experiments conducted two months apart. Despite differences in the amount of oil-derived alkanes across the treatments and experiments, increases in the contributions of hydrocarbon degrading taxa and decreases in common estuarine bacteria were observed in response to dispersant and/or oil. Between the two experiments, the direction and rates of changes in particulate alkane concentrations differed, as did the magnitude of the bacterial response to oil and/or dispersant. Together, our data underscore large variability in bacterial responses to hydrocarbon pollutants, implying that bioremediation success varies with starting biological and environmental conditions.

Proton beam characterization by proton-induced acoustic emission: simulation studies

Due to their Bragg peak, proton beams are capable of delivering a targeted dose of radiation to a narrow volume, but range uncertainties currently limit their accuracy. One promising beam characterization technique, protoacoustic range verification, measures the acoustic emission generated by the proton beam. We simulated the pressure waves generated by proton radiation passing through water. We observed that the proton-induced acoustic signal consists of two peaks, labeled α and γ, with two originating sources. The α acoustic peak is generated by the pre-Bragg peak heated region whereas the source of the γ acoustic peak is the proton Bragg peak. The arrival time of the α and γ peaks at a transducer reveals the distance from the beam propagation axis and Bragg peak center, respectively. The maximum pressure is not observed directly above the Bragg peak due to interference of the acoustic signals. Range verification based on the arrival times is shown to be more effective than determining the Bragg peak position based on pressure amplitudes. The temporal width of the α and γ peaks are linearly proportional to the beam diameter and Bragg peak width, respectively. The temporal separation between compression and rarefaction peaks is proportional to the spill time width. The pressure wave expected from a spread out Bragg peak dose is characterized. The simulations also show that acoustic monitoring can verify the proton beam dose distribution and range by characterizing the Bragg peak position to within ~1 mm.