An efficient application of fusion approach for hot spot detection with MODIS and PALSAR-1 data

Hot spot detection with satellite images, especially with synthetic aperture radar (SAR) images is still a challenging task. Several researchers have used TM/optical data for identification of hot spot but the use of SAR data is very limited for this type of application. The fusion of SAR data with TM/optical data may add additional information which in turn will lead for enhancement of detection capability of the hot spot. Therefore, this study explores the possibility of fusion of Moderate Resolution Imaging Spectroradiometer (MODIS) and Phased Array L-band Synthetic Aperture Radar (PALSAR) satellite images for the hot spot detection. Image fusion is emerging as a powerful tool where information of various sensors can be used for obtaining better results. For this purpose, vegetation greenness and roughness information which is obtained from MODIS and PALSAR satellite images, respectively, are used for fusion, and then, a contextual-based thresholding algorithm is applied to the fused image for hot spot detection. The proposed approach comprises of two steps: (1) application of genetic algorithm-based scheme for image fusion of MODIS and PALSAR satellite images, and (2) classification of the fused image as either hot spot or non-hot spot pixels by employing a contextual thresholding technique. The algorithm is tested over the Jharia Coal Field region of India, where hot spot is one of the major problems and it is observed that the proposed thresholding technique classifies the each pixel of the fused image into two categories: hot spot and non-hot spot and the proposed approach detects the hot spot with better accuracy and less false alarm.     

Behaviour of some intertidal molluscs exposed to water soluble fractions of diesel

The behaviour of three intertidal molluscs exposed to water soluble fractions of diesel were studied. The rate of crawling of Cerethidea fluviatilis decreased with an increase in concentration and the animals were completely immobilized at the highest dosage (50%). The burrowing ability of Katelysia opima was found to be suppressed in three different concentrations (25,50 and 75%). Smaller individuals (15–20 mm) appearing to be less sensitive than larger forms (20–25 mm). Byssal thread production in Perna viridis was significantly depressed in all concentrations, except the lowest doses of toxicant (5%), where slight stimulation was observed only with smaller sized individuals (20–30 mm).     

Identification of palaeochannels around Cauvery river near Talakad, Karnataka using remote sensing data

Visual interpretation of satellite images could help in the identification of present and past landforms. An attempt has been made to identify the palaeochannels of the Cauvery river in Karnataka state through visual interpretation of IRS-1C, LISS III False Colour Composites (FCC). In order to assess their inter-relationship with other hydrogeomorphic elements, various geomorphic units have been mapped. Major geomorphic units like alluvial plain, pediplain, valley fill. residual hill, ridges, meander scar, channel bars and water bodies have been demarcated. Considering the hydrogeomorphic setup of the palaeochannels. it is inferred that the disposition of palaeochannels of the area are controlled by the geology and structure and the prevailing geomorphic process.     

Evaluation of Electro-Oxidation of Textile Effluent Using Response Surface Methods

In the present investigation, treatment of textile effluent using an electrochemical technique was designed and analyzed using the Box-Behnken method. The influence of individual parameters on electro-oxidation of textile effluent has been critically examined using the response surface method (RSM), and a quadratic model for chemical oxygen demand (COD) reduction has been developed. It has been observed from the present analysis that the predicted values are in good agreement with experimental data with a correlation coefficient of 0.945.     

Environmental magnetic studies on surface sediments: a proxy for metal and hydrocarbon contamination

Visakhapatnam is one of the major port cities, and it is developed into a hub of many large- and medium-scale industries. Due to growing industrialization and urbanization, coast is vulnerable to both organic and inorganic micro-pollutants. Twenty-five surface sediments were collected along the Visakhapatnam coast for the measurement of texture size, petroleum hydrocarbons, trace metals and environmental magnetic parameters. The percentage of coarser particles was more in the northern region, whereas the percentage of fine particles was increased toward south. Elevated levels of petroleum hydrocarbons and trace metals were attributed due to marine and land-based sources, in particular, those were due to shipping activities, treated and partially treated sewage and industrial wastes. The concentrations of trace metals, petroleum hydrocarbons and magnetic minerals were decreased from nearshore to seaward. Our results revealed that the magnetic mineralogy is dominated by magnetite with a small proportion of hematite, and the grain size of magnetic minerals was in the range of pseudo-single domain to multidomain nature with detrital origin. From the principal component analysis, the magnetic concentration and mineralogy-dependent parameters co-vary with the heavy metal and PHC concentrations, suggesting that the inputs of magnetic minerals, petroleum hydrocarbons and heavy metals in the Visakhapatnam shelf sediments were derived from the same anthropogenic sources. Thus, the large magnetic dataset can be used to reduce the number of chemical analysis; hence, environmental magnetic parameters were used as a proxy for both organic and inorganic micro-pollutants.     

Sublethal effect of naphthalene on lipid peroxidation and antioxidant status in the edible marine crab Scylla serrata

The effect of naphthalene on lipid peroxidation and antioxidants status was studied in hepatopancreas, haemolymph and ovary of the Scylla serrata with reference to the active vitellogenic stage. There was an overall increase in lipid peroxidation activity in the tested samples. In contrast, the enzymatic (catalase, glutathione peroxidase, superoxide dismutase) and non-enzymatic antioxidants (vitamins C, E and glutathione) showed decreased activities for hepatopancreas, haemolymph and ovary.     

Initial results from the Madurai solar radio spectrograph

A new digital radio spectrograph, the Madurai Solar Radio Spectrograph (MSRS), has been constructed at Madurai Kamaraj University, Madurai, India, and is being operated at the Radio Astronomy Centre, Ooty in southern India to observe solar bursts in the frequency range 30–80 MHz. The operation of the new instrument is briefly described. Observations of solar bursts by this instrument and the results from the preliminary analysis are presented.