S.I. Nadjafova, N.M. Ismailov
Abstract: Integral indicator of anthropogenic disturbed soils of Absheron peninsula is calculated, which allows to evaluate the potential of self-cleaning landscape. Integral indicator is calculated by the sum of the most important points of informative indicators of biological condition of soils: the enzymatic activity, the number of saprophytic and hydrocarbon oxidizing microorganisms, the ratio of the number of hydrocarbon oxidizing microorganisms to total population, phytotoxicity (seed germination). The indicators chosen for the following reasons: catalase and dehydrogenase – redox enzymes, they are most susceptible to contamination of soil by crude oil and petroleum products. The number of microorganisms characterizes the state of microorganisms in the soil and is an indicator of soil contamination. Phytotoxicity gives information about the soil condition and the conditions of the plant germination.
Keywords: Anthropogenic disturbance of the soil, integral index, degree of anthropogenic impact, bioparameters of soils, the potential of self-purification.
Pages: 143 – 150 | Full PDF Paper
Histopathological Alterations of Ptychadena mascariensis Exposed to Sub Lethal Concentrations of Crude Oil
Nafagha, Magdalene Okeh, Sikoki, Francis David and Georgewill, Onwunari Abraham
Abstract: Study on the impact of sub-lethal concentrations (0mg/L, 0.3gmg/L, 0.75mg/L, 1.5mg/L, 2.25mg/L and 3.0mg/L) of water-soluble fractions (WSFs) of crude oil on the toxic effects of WSF of crude oil on the histology of the skin, liver and heart of the frog Ptychadena mascariensis were carried out under laboratory conditions in the University of Port Harcourt, during a 12-week period of exposure in a renewal static bioassay system. At the end of the study, the skin, liver and heart of control frog retained their normal structural pattern. However, the cells of the skin, liver and heart frogs exposed to crude oil showed marked alterations. The skin showed massive fragmentation and dermal degradation. The liver exposed to WSF of crude oil showed mild to severe necrosis/degeneration of the hepatocytes, liver cells in disarray and distortion of cells, vacuolation, and hepatocellular foci. The tissues of the heart showed gradual increase in interstitial space and myocyte separation. The result of this study has shown that crude oil (WSF) is indeed toxic to frogs. The effect on P. mascariensis also indicated that this aquatic animal can serve as bio-indicator of crude oil contaminated fresh water bodies.
Keywords: Amphibians, bio-indicator, cardiomycetes, hepatocytes, Water soluble fractions.
Pages: 151 – 159 | Full PDF Paper
N. Kanodia and M. Kamil
Abstract: Properties of monolayers of Pluronic F127 at air/water interface have been investigated by using Langmuir trough method. Pluronic F127 is a triblock copolymer of poly(ethyleneoxide) (PEO groups)–poly(propylene oxide) (PO groups)–poly(ethylene oxide) (PEO groups). Surface pressure versus mean molecular area isotherms is studied. The isotherm of the monolayer showed the characteristics of a pancake-to-brush transition upon compression of the monolayer. The effect of adding surfactant (SDS) to polymer and the effect of increasing loading on polymer was also studied. The effect of repeated compression and expansion cycle (or hysteresis curve) is investigated to know about stability of the film formed. Static elasticity of monolayer gives information about molecular arrangement, phase structure and phase transition.
Keywords: Surface-pressure; mean molecular area isotherms; hysteresis; static elasticity.
Pages: 160 – 172 | Full PDF Paper