Model of spills and fires from LNG and oil tankers

A comprehensive model for predicting the dynamics of spills from LNG and oil product tankers is constructed from fluid mechanics principles and empirical properties of oil and LNG spills on water. The analysis utilizes the significant tanker hold and discharge flow area dimensions to specify the cargo liquid outflow history and the ensuing pool characteristics, including the establishment of a pool fire. The pool fire area, duration, and heat release rate are determined as functions of the tanker cargo variables. Examples of an LNG and gasoline spill show that for likely discharge flow areas these spills may be regarded as instantaneous, simplifying the evaluation of risk consequences.     

Numerical analysis of the process of heated oil evaporation from the emergency spill surface

A numerical investigation of the influence of wind velocity and spill thickness on the characteristics of heated oil evaporation from the emergency spill surface has been made. This paper presents the results of calculating the change with time in the mass of vapors in a cloud bounded by the concentration limits of flame propagation.     

Airborne mercury pollution from a large oil spill accident on the west coast of Korea

Atmospheric mercury pollution was recognized after a large oil spill on the west coast of Korea on 7 December 2007. In this study, the concentrations of gaseous elemental mercury (GEM: Hg(0)) in air were measured both shortly after the oil spill ( approximately 100h) and 1month after the accident near the accident site. When the Hg concentration levels were compared between two seashore sites and two parallel sites offshore, the values tend to decrease further offshore. The unusual rise in Hg concentration levels observed on the seashore area shortly after the accident (mean of 16.4+/-9.85ngm(-3)) dropped dramatically after 1month with active cleanup activities (2.99+/-1.40ngm(-3)). Because of the connection between crude oil and Hg (one of the major impurities), the unusual rise in the atmospheric Hg after the oil spill can be explained by the active evasion of Hg from the spilled crude oil. Although Hg levels determined a few days after the accident did not exceed the reference exposure limits (REL) proposed by several agencies, the early build-up of elemental mercury level due to the oil spill might have exerted certain impacts on the surrounding environments.     

SWOT analysis for safer carriage of bulk liquid chemicals in tankers

The application of strengths, weaknesses, opportunities and threats (SWOT) analysis to formulation of strategy concerned with the safe carriage of bulk liquid chemicals in maritime tankers was examined in this study. A qualitative investigation using SWOT analysis has been implemented successfully for ships that are designed to carry liquid chemicals in bulk. The originality of this study lies in the use of SWOT analysis as a management tool to formulate strategic action plans for ship management companies, ship masters and officers for the carriage of dangerous goods in bulk. With this transportation-based SWOT analysis, efforts were made to explore the ways and means of converting possible threats into opportunities, and changing weaknesses into strengths; and strategic plans of action were developed for safer tanker operation.     

CO2 mitigation potential from biodiesel of castor seed oil in Indian context

Biodiesel has become an interesting alternative to be used in diesel engine, because it has similar properties to the traditional fossil diesel fuel and may, thus, substitute conventional fuel with none or very minor engine modification. This article deals with alkaline transesterfication of castor oil and their properties for engine application. The purpose of the transesterfication process is to lower the viscosity of the oil from 226.82 cS to 8.50 cS ‘at’ 38°C. The flash point values of castor methyl esters are lower than that of castor oil. The density and gross calorific value of castor methyl ester are much closer to those of diesel. If 10% of total production of castor seed oil is transesterfied into biodiesel, then about 79,782 tones of CO₂ emission can be saved on annual basis. The CO₂ released during combustion of biodiesel can be recycled through next crop production, therefore, no additional burden on environment.     

Trials of bioremediation on a beach affected by the heavy oil spill of the Prestige

The objective of this study was to assess the efficiency of several bioremediation products in accelerating the in situ biodegradation of the heavy fuel oil spill of the Prestige. Trials of bioremediation were conducted in sand, rocks and granite tiles on the beach of Sorrizo (A Coruña, NW Spain) that was polluted by the spill. Neither the added microorganisms nor the nutrients significantly enhanced the degradation rate of the fuel oil in rocks, granite tiles or sand. PAH degradation up to 80% was determined in sand and tiles. In tiles the oxygen content of the residual oil increased from 1.6% up to 8% in 90 days, which could be explained by the accumulation of products coming from the partial oxidation of the hydrocarbons. Eighteen months after the spill, the rocks of the beach were still coated by a black layer of weathered fuel oil. For this reason an oleophilic product, sunflower biodiesel was tested on a rock. The application of biodiesel accelerated the gradually clean-up of the polluted surface and could also accelerate the degradation of the residual oil.     

Fractionalization of research impact reveals global trends in university collaboration

Scientometrics - The importance of collaborations between research institutions in producing highly-cited publications is well documented in the scientometric literature. To avoid a double-counting...     

In-depth analysis of the causal factors of incidents reported in the Greek petrochemical industry

This paper presents a statistical analysis of all reported incidents in the Greek petrochemical industry from 1997 to 2003. A comprehensive database has been developed to include industrial accidents (fires, explosions and substance releases), occupational accidents, incidents without significant consequences and near misses. The study concentrates on identifying and analyzing the causal factors related to different consequences of incidents, in particular, injury, absence from work and material damage. Methods of analysis include logistic regression with one of these consequences as dependent variable. The causal factors that are considered cover four major categories related to organizational issues, equipment malfunctions, human errors (of commission or omission) and external causes. Further analyses aim to confirm the value of recording near misses by comparing their causal factors with those of more serious incidents. The statistical analysis highlights the connection between the human factor and the underlying causes of accidents or incidents.     

Characteristics of the mobile field use system for the detoxification/incineration of residuals from oil and hazardous material spill clean-up operations

The Mobile ERIC is a complex thermal and chemical processing plant capable of detoxification of hazardous organic spills and contaminated debris at remote locations throughout the United States. It is designed to handle moderate spills in an efficient manner without undue restriction concerning the physical nature of the input wastes.     

In situ fastening graphene sheets into a polyurethane sponge for the highly efficient continuous cleanup of oil spills

Oil sorbents are an attractive option for oil-spill cleanup as they may be used for collection and complete removal of oil without adversely affecting the environment.However,traditional oil sorbents exhibit low oil/water separation efficiency and/or low oil-sorpfion capacity.In this study,an ultra-high performance graphene/polyurethane (PU) sponge has been successfully obtained by in situ polymerization in the presence of graphene dispersed in N-methylpyrrolidone (NMP).During polymerization,the NMP/graphene dispersion not only serves as a weak amine catalyst for the formation of the sponge,but promotes fixation of the graphene sheets in the framework of the PU sponge owing to the strong dipole interaction between NMP and graphene.The as-prepared graphene/PU sponge was used as an absorbing material for the continuous removal of oil from oil-spill water.The graphene/PU sponge can continuously and rapidly remove oils from immiscible oil/water mixtures in corrosive solutions,including strong acids and bases,hot water,and ice water,with an excellent separation efficiency of above 99.99％.In addition,the as-prepared graphene/PU sponge was effective in separating surfactant-stabilized emulsions with a high separation efficiency of ＞99.91％.     

Missing-data theory in the context of exploratory data analysis

This paper proposes a new method for exploratory analysis and the interpretation of latent structures. The approach is named missing-data methods for exploratory data analysis (MEDA). The MEDA approach can be applied in combination with several models, including Principal Components Analysis (PCA), Factor Analysis (FA) and Partial Least Squares (PLS). It can be seen as a substitute of rotation methods with better properties associated: it is more accurate than rotation methods in the detection of relationships between pairs of variables, it is robust to the overestimation of the number of PCs and it does not depend on the normalization of the loadings. MEDA is useful to infer the structure in the data and also to interpret the contribution of each latent variable. The interpretation of PLS models with MEDA, including variables selection, may be specially valuable for the chemometrics community. The use of MEDA with PCA and PLS models is demonstrated with several simulated and real examples.     

Simulation of the cumulative effects of chemical spills using a spatial-temporal dynamics analysis algorithm

Accidents in urban areas involving chemical spills demands development of not only feasible emergency strategies, but also a consistent framework to protect the environment and prevent accidents. This can be possible only by a sound understanding of the environmental impact of spills and their potential long-term effects. Furthermore, the impact assessment of chemical spills can not be done disregarding the spatial-temporal pattern of previous exposures reciprocally influenced by both chemical and environmental properties. In this context, this paper presents an analysis framework to quantify the cumulative effects of chemical spills at any given point of a certain area based on a "present" history of exposure coupled with chemical and environmental properties to predict possible scenarios of future exposure and estimate in advance potential alarming levels of pollution. In the present circumstances when increasing knowledge is required for an accurate prediction of spill migration through unsaturated soil, this paper proposes an algorithm capable of incorporating models of increasing complexities to simulate the single-spill events once new advancements in the field are taken. The algorithm developed is illustrated using a simple model with homogenous and steady-state conditions to simulate the single-spill events. A hypothetical case study was constructed to illustrate the analysis steps and the benefits of the algorithm.     

Models and model uncertainty in the context of risk analysis

This paper addresses the concept of model uncertainty within the context of risk analysis. Though model uncertainty is a topic widely discussed in the risk analysis literature, no consensus seems to exist on its meaning, how it should be measured, or its impact on the application of analysis results in decision processes. The purpose of this paper is to contribute to clarification. The first parts of the paper look into the contents of the two terms ‘model’ and ‘uncertainty’. On this platform it is discussed how focus on model uncertainty merely leads to muddling up the message of the analysis, if risk is interpreted as a true, inherent property of the system, to be estimated in the risk analysis. An alternative approach is to see the models as means for expressing uncertainty regarding the system performance. In this case, it is argued, the term ‘model uncertainty’ loses its meaning.     

Economic value of improved quantification in global sources and sinks of carbon dioxide

On average, about 45 per cent of global annual anthropogenic carbon dioxide (CO(2)) emissions remain in the atmosphere, while the remainder are taken up by carbon reservoirs on land and in the oceans-the CO(2) 'sinks'. As sink size and dynamics are highly variable in space and time, cross-verification of reported anthropogenic CO(2) emissions with atmospheric CO(2) measurements is challenging. Highly variable CO(2) sinks also limit the capability to detect anomolous changes in natural carbon reservoirs. This paper argues that significant uncertainty reduction in annual estimates of the global carbon balance could be achieved rapidly through coordinated up-scaling of existing methods, and that this uncertainty reduction would provide incentive for accurate reporting of CO(2) emissions at the country level. We estimate that if 5 per cent of global CO(2) emissions go unreported and undetected, the associated marginal economic impacts could reach approximately US$20 billion each year by 2050. The net present day value of these impacts aggregated until 2200, and discounted back to the present would have a mean value exceeding US$10 trillion. The costs of potential impacts of unreported emissions far outweigh the costs of enhancement of measurement infrastructure to reduce uncertainty in the global carbon balance.     

Detection-Identification of multiple unknown time-dependent point sources in a 2D transport equation: application to accidental pollution

We address the nonlinear inverse source problem of identifying multiple unknown time-dependent point sources occurring in a two-dimensional evolution advection–dispersion–reaction equation. Provided to be available within the monitored domain interfaces for recording the generated state and its flux crossing each suspected zone where a source could occur, we establish a constructive identifiability theorem based on an introduced dispersion-current function that yields uniqueness of the unknown elements defining all occurring sources. Then, the established theorem leads to develop a detection-identification method that goes throughout the monitored domain to detect in each suspected zone whether there exists or not an occurring source. Once a source is detected, the developed method determines lower and upper bounds of the mean value discharged by its unknown time-dependent intensity function. Thereafter, the method localizes the sought position of the detected source as the unique solution of an equation satisfied by the introduced dispersion-current function and identifies its unknown intensity function from solving an associated deconvolution problem. Ultimately, the unknown number of occurring sources is deduced as the sum of all detected-identified active sources. Some numerical experiments on a variant of the surface water BOD pollution model are presented.     

Evolution of hazardous material spills regulations in the United States

After seven years in the preparation stage, the U.S. Environmental Protection Agency published, on August 29, 1979, its hazardous substances regulation This paper reviews the basis of the regulations (the Federal Water Pollution Control Act), the various drafts issued and withdrawn by EPA, the philosop     

Evaluation of biodiesel as bioremediation agent for the treatment of the shore affected by the heavy oil spill of the Prestige

The efficiency of different bioremediation products (nutrients, microorganisms and biodiesel) was tested using tiles located in both the supra-littoral and intertidal zones of a beach that was affected by the heavy oil spill of the Prestige. Neither nutrients nor microorganisms meant an improvement with respect to the natural processes. The addition of biodiesel improved the appearance of the treated tiles and apparently accelerated the degradation of the aliphatic and aromatic fractions of the residual fuel oil. Nevertheless, PAHs degradation was similar and very high in all the treatments (80-85% after 60 days). On the other hand, the evolution with time of the amount of vanadium was similar to that of 17alpha(H),21beta(H)-hopane, so it was concluded that vanadium could also be used to estimate the extent of oil degradation in the field. These results also suggested that the residual fuel oil mineralization was very low throughout 1 year in all the treatments. Moreover, the increase of the oxygen content of the residual oil from around 1% till 4-8% indicated that the partial oxidation of hydrocarbons took place, and that the hydrocarbon oxidation products accumulated in the polar fractions. In general, the results pointed out that bioremediation techniques were not suitable for the recovery of shores affected by heavy oil spills.