Consequence modelling,vulnerability assessment and fuzzy fault tree analysis of hazardous storages in an industrial area

The hazards associated with major accident hazard (MAH) industries are fire, explosion and toxic gas releases. Of these, toxic gas release is the worst as it has the potential to cause extensive fatalities. Qualitative and quantitative hazard analyses are essential for the identitication and quantification of the hazards associated with chemical industries. This research work presents the results of a consequence analysis carried out to assess the damage potential of the hazardous material storages in an industrial area of central Kerala, India. A survey carried out in the major accident hazard (MAH) units in the industrial belt revealed that the major hazardous chemicals stored by the various industrial units are ammonia, chlorine, benzene, naphtha, cyclohexane, cyclohexanone and LPG. The damage potential of the above chemicals is assessed using consequence modelling. Modelling of pool fires for naphtha, cyclohexane, cyclohexanone, benzene and ammonia are carried out using TNO model. Vapor cloud explosion (VCE) modelling of LPG, cyclohexane and benzene are carried out using TNT equivalent model. Boiling liquid expanding vapor explosion (BLEVE) modelling of LPG is also carried out. Dispersion modelling of toxic chemicals like chlorine, ammonia and benzene is carried out using the ALOHA air quality model. Threat zones for different hazardous storages are estimated based on the consequence modelling. The distance covered by the threat zone was found to be maximum for chlorine release from a chlor-alkali industry located in the area. The results of consequence modelling are useful for the estimation of individual risk and societal risk in the above industrial area.Vulnerability assessment is carried out using probit functions for toxic, thermal and pressure loads. Individual and societal risks are also estimated at different locations. Mapping of threat zones due to different incident outcome cases from different MAH industries is done with the help of Are GIS.Fault Tree Analysis (FTA) is an established technique for hazard evaluation. This technique has the advantage of being both qualitative and quantitative, if the probabilities and frequencies of the basic events are known. However it is often difficult to estimate precisely the failure probability of the components due to insufficient data or vague characteristics of the basic event. It has been reported that availability of the failure probability data pertaining to local conditions is surprisingly limited in India. This thesis outlines the generation of failure probability values of the basic events that lead to the release of chlorine from the storage and filling facility of a major chlor-alkali industry located in the area using expert elicitation and proven fuzzy logic. Sensitivity analysis has been done to evaluate the percentage contribution of each basic event that could lead to chlorine release. Two dimensional fuzzy fault tree analysis (TDFFTA) has been proposed for balancing the hesitation factor invo1ved in expert elicitation .

Studies on the effect of toxic heavy metal mercury on the physiology and biochemistry of an estuarine crab Scylla serrata (Forskal)

This thesis Entitled studies on the effect of toxic heavy metal mercury on the physiology and biochemistry of an estuarine crab scylla serrata (Forskal). Evaluate the toxicity of three sub lethal concentrations of mercury, viz., 0.009 mg/l, 0.02 mg/1, and 0.04 mg/l on the mud crab, Scylla serrata through bioaccumulation, and depuration studies. To characterize the biochemical responses to the sub-lethal stress of mercury in chelate muscles, abdominal muscles, hepatopancreas and gills. To study the activity pattern of acid and alkaline phosphatases in mercury-exposed crabs. To evaluate the induced changes in these tissues through histopathological studies,The Cochin backwaters is one of the most productive and biologically active backwater systems, and is the habitat of varieties of fishes, mollusks, and crustaceans, though this water body also receives tons of effluents from factories located on the banks of the river, Periyar.To study the activity levels of acid and alkaline phosphatases in crabs, at three time periods, exposed to three sub lethal concentration of mercury,

Studies on the toxic effects of somepesticides on the fish etroplus maculatus

The present study involved investigation of the lethal and sublethal effects of three pesticides individually. The pesticides are the commercial formulations of DDT (organochlorine).Dime— cron (organophosphate) and Gramoxone (paraquat dichloride).Aspects like individual toxicity, modulations in the activities of some selected enzymes, consequent to exposure to sub lethal levels of pesticides, sub lethal effects onperipheral haematology and alterations caused on the tissue architecture of brain, gills and liver, have been documented. Attempts have been made to analyse the impact of pesticides, added at realistic Levels to the experimental media, on the life and activity of Etroplus maculatus

Combined toxic effects of oil and pesticides on selected marine invertebrates

In recent years, pollution in general and sea water pollution in particular, has become an important topic for national and international considerations. Because of its impact on society, marine pollution has attracted great attention from politicians, administrators, natural scientists and technologists all over the world. To save our environment from further deterioration, it is essential to have an assessment of this problem This thesis involves investigation of the lethal and sub lethal effects of four pesticides and two petroleum oil, individually and in combinations on two commercially important bivalves. Among the four pesticides used two are organophosphates and the other two are organochlorines. Synthetic Pesticides, especially organophosphates and organochlorines have become increasingly important additions to chemical wastes polluting natural aquatic Communities special attention is given in the present investigation to delineate the combined toxic effect of oil and pesticides. The results are presented under different sections to make the presentation meaningful.

Effect of some toxic metals on selected phytoplankton of Kerala water

The extraction and use of metals has been the mainstay for the sustained development and progress of a nation. Metals, though fairly stable in the natural environment are found in trace quantities in water bodies. Attention has therefore been focused to identify the metals that impair the water quality. In the last few decades the concern about the fate of these metals in the aquatic system has been gaining momentum, particularly in the industrial belts. The disasters caused by metal poisoning in recent times have prompted an indepth study of the interaction of metals with aquatic biota. Kerala, basically an agriculture oriented state has witnessed the upsurgence of various industries as a part of the nationwide economic development programme. Cochin has been identified as the industrial capital of the state.The present study is an attempt towards a better understanding of the metal-phytoplankton interactions with special reference to the physiological changes in the species. various parameters such as temperature, salinity, pH, nutrients, number of cells, photosynthetic pigments, carbohydrates, protein and lipid are studied to highlight the complexity of metal..phytoplankton interaction

Studies on the toxic effects of selected heavy metals in the freshwater mussel lamellidens corrianus (lea)

Industrialisation affects air, water, and soil. Industrial effluents which enter the aquatic environment either by direct disposal or through run off, affect living organisms at morphological and physiological levels. In any living tissue toxic materials exert their effects first at molecular and biochemical levels (Robbins and Angell, 1976). Most of the industrial effluents contain elevated concentrations of organic and inorganic chemicals capable of eliciting stimulatory or inhibitory effects on the metabolism of aquatic organisms. Heavy metals form an important group of environmental pollutants. Effects of pollution on the aquatic environment by heavy metals have received considerable attention in recent years due to their toxicity even at very low levels, persistence in the environment, and chances of getting biomagnified. A pollutant that does not affect a particular process under normal unstressed condition may affect the ability of the animal to adjust to changing environmental conditions which ultimately decrease its chances of survival (Thurberg et al., 1973

Toxic Metal Distribution in the Core Sediment of Cochin Estuarine System (CES)

This article present the result from a study of two sediment cores collected from the environmentally distinct zones of CES. Accumulation status of five toxic metals: Cadmium (Cd), Chromium (Cr), Cobalt (Co), Copper (Cu) and Lead (Pb) were analyzed. Besides texture and CHNS were determined to understand the composition of the sediment. Enrichment Factor (EF) and Anthropogenic Factor (AF) were used to differentiate the typical metal sources. Metal enrichment in the cores revealed heavy load at the northern (NS1 ) region compared with the southern zone (SS1). Elevation of metal content in core NS1 showed the industrial input. Statistical analyses were employed to understand the origin of metals in the sediment samples. Principal Component Analysis (PCA) distinguishes the two zones with different metal accumulation capacity: highest at NS1 and lowest at SS1. Correlation analysis revealed positive significant relation only in core NS1, adhering to the exposition of the intensified industrial pollution

An??lisis bibliom??trico sobre evaluaci??n de programas y comunidades terap??uticas para la rehabilitaci??n de toxic??manos

Analizar el estado de la cuesti??n sobre trabajos que se han realizado para evaluar programas y comunidades terap??uticas orientadas a la rehabilitaci??n de toxic??manos. Consulta de 7 bases de datos que facilitaron el acceso a 14 revistas, en su mayor??a estadounidenses. En total, se consultan 166 registros referidos al objeto de estudio. Se parte de una fundamentaci??n te??rica y metodol??gica sobre estudios bibliom??tricos y de una b??squeda de referencias bibliogr??ficas sobre evaluaci??n de programas y comunidades terap??uticas para la rehabilitaci??n de toxic??manos en las bases de datos pertinentes. Seguidamente se hace un an??lisis de documentos en el cual se identifican diversas variables: a) Referentes a los datos propios del documento (autor, a??o, t??tulo...); b) Referentes a la estructura interna del documento (tipo de evaluaci??n, finalidad, dise??o, muestra...); c) Referentes a los resultados y/o conclusiones obtenidas (puntos fuertes y d??biles, recomendaciones...). Adem??s de ello, se tienen en consideraci??n indicadores de productividad e indicadores de colaboraci??n. Se ha utilizado una parrilla de an??lisis construida 'ad-hoc' y tambi??n una serie de indicadores bibliom??tricos. Esta parrilla est?? estructurada en tres unidades de an??lisis compuestas por un n??mero determinado de variables. La codificaci??n de la informaci??n de tipo cuantitativo se hace a trav??s del programa inform??tico SPSS, el cual permite obtener estad??sticos de cada variable. El an??lisis cualitativo se realiza mediante el procedimeitno de an??lisis de contenido. Destacan, entre otras: a) La mayor??a de los trabajos analizados est??n realizados en colaboraci??n; b) La producci??n de trabajos desde 1984 hasta 1997 permanece uniforme, en 1998 se observa un punto de inflexi??n que corresponde con un aumento de los trabajos publicados y que dura hasta 2004; c) La mayor??a de los trabajos son realizados en USA debido a la mayor tradici??n evaluadora que existe en ese pa??s y el mayor n??mero de recursos existentes para financiar y publicar las evaluaciones realizadas; d) El tipo de documento m??s utilizado es el art??culo de revista; e) La mayor parte de los trabajos est??n realizados en contexto p??blico y con financiaci??n de la administraci??n; f) Todos los trabajos revisados contemplan una revisi??n bibliogr??fica; g) La mayor parte de los trabajos se refieren a la teor??a o modelo de evaluaci??n del que parten de un modo impl??cito; h) El tipo de evaluaci??n m??s empleada es la 'sumativa, expost, externa'; i) La finalidad de la mayor??a de los trabajos es 'verificar', tanto si se cumplen los objetivos planteados por el programa evaluado, como si se cumplen las hip??tesis de evaluaci??n planteadas que hacen referencia a alg??n resultado deseado; j) La metodolog??a empleada en los dise??os es en su mayor parte cuasiexperimental; k) El sistema de control m??s utilizado es el control reflexivo, es decir, menciones sobre un mismo grupo; l) Las t??cnicas e instrumentos de recogida de informaci??n m??s utilizados son los cuantitativos; m) El tama??o de la muestra elegido suele ser grande siendo el tipo de muestreo m??s com??n el 'no probabil??stico'; n) Las evaluaciones se dirigen a los usuarios de los programas y comunidades terap??uticas.

Numerical comparison between Maxwell stress method and equivalent multipole approach for calculation of the dielectrophoretic force in octupolar cell traps

This work presents detailed numerical calculations of the dielectrophoretic force in octupolar traps designed for single-cell trapping. A trap with eight planar electrodes is studied for spherical and ellipsoidal particles using an indirect implementation of the boundary element method (BEM). Multipolar approximations of orders one to three are compared with the full Maxwell stress tensor (MST) calculation of the electrical force on spherical particles. Ellipsoidal particles are also studied, but in their case only the dipolar approximation is available for comparison with the MST solution. The results show that the full MST calculation is only required in the study of non-spherical particles.

Workshop 1 p16 Toxic Mentors table

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Evaluation of the Toxic Effect from Eupatorium Microphyllum L.F. (Asteraceae) Extracts on Aedes Aegypti Larvae (Diptera: Culicidae) in Laboratory Conditions

In the present work the toxic activity of extracts of Eupatorium microphyllum L.F. was evaluated on 4th instar larvae of the mosquito Aedes aegypti (Linneaus), under laboratory conditions. Aqueous extracts were utilized in concentrations of 500 mg L-1, 1,500 mg L-1 and 2,500 mg L-1 and acetone in concentrations of 10 mg L-1, 20 mg L-1, 30 mg L-1, 40 mg L-1and 50 mg L-1. The bioassays were carried out for triplicate each one with 20 larvae, exposed for 24 hours to 150 mL of solution. In all the bioassays were employed control groups. In the evaluation of the acetone extracts, a negative control was employed to avoid that the mortality of the larvae to occur on account of the solvent. The Aqueous extracts showed low moderate action in the mortality of larvae, less than 20%. On the contrary, the action of the acetone extracts was observed to 10 and 20 mg L-1with 15% of mortality, while to 30 and 40 mg L-1 were registered 22 to 38% of mortality. However, to 50 mg L-1 the mortality was of 95.4% with highly significant statistical results. The concentrations of the acetone extracts showed to be the most efficient for the control of the mosquitoes selected. Both types of extracts showed toxic effect in larvae of A. aegypti, nevertheless, greater effect in the acetone extracts was observed relating to the aqueous extracts of E. microphyllum, which constitutes a viable alternative in the search of new larvicides from composed natural.