Studying Land Use Travel Demand Interaction Using 3S Technology for Tiruchirappalli City

This paper gives an overview of a major application of modern geospatial tools such as remote sensing, GIS and GPS, i.e., 3S technology in estimating travel demand along Indian roads by considering the study area, Tiruchirappalli urban city in Tamil Nadu. In the study, an attempt was made to estimate travel demand based on the current land-use classification as the pattern of travel depends on the type of land use activity in a zone. IRS high resolution image Cartosat-1 of year 2009 was used to extract the land-use information required. The travel demand model developed was validated with the field obtained OD-matrix to understand the accuracy of the method considered.     

Seasonal variations in the sediment biogenic properties of a tropical mangrove environment,southwest coast of India

Temporal and spatial changes in the sediment properties of a mangrove ecosystem (Cochin, southwest coast India) are presented. The region was freshwater dominated during monsoon (June–September) and seawater dominated during other two seasons. The system remained eutrophic due to the high inputs of organic matter (OM) during most part of the year. The organic-rich sediments accumulated high amount of carbohydrates (22% of OM) and proteins (11% of OM) during non-monsoon months as compared to coastal environments. Principal component analysis showed that the biochemical properties are uniformly influenced by seasonal and spatial variations. Higher concentrations of sediment protein over carbohydrate indicate an efficient mineralization leading to the non-availability of aged OM in the system. The dominance of these labile components is generally indicative of the eutrophic condition of the system.     

Nonlinear electrodynamics in f(T) gravity and generalized second law of thermodynamics

In this paper, we study the nonlinear electrodynamics in the framework of f(T) gravity for FRW universe along with dust matter, magnetic and torsion contributions. We evaluate the equation of state and deceleration parameters to explore the accelerated expansion of the universe. The validity of generalized second law of thermodynamics for Hubble and event horizons is also investigated in this scenario. For this purpose, we assume polelike and power-law forms of scale factor and construct f(T) models. The graphical behavior of the cosmological parameters versus smaller values of redshift z represent the accelerated expansion of the universe. It turns out that the generalized second law of thermodynamics holds for all values of z with Hubble and event horizons in polelike scale factor whereas for power-law form, it holds in a specific range of z for both horizons.     

Intercomparison of Air–Sea Interface Fluxes over the Yellow Sea and Korea Strait: Impact of Tsushima Warm Current

Surface-layer meteorological observations obtained from oceanic buoys over the Korean Strait and the Yellow Sea are used to estimate surface-layer turbulent fluxes of heat, moisture and momentum over the East-Asian Marginal Seas. Special emphasis is paid towards explanation of the impact of the Tsushima warm current flowing through the Korean Strait on air–sea interface fluxes. During the active phase of the Tsushima warm current, when the difference in sea surface temperature and air temperature becomes as large as 8°C, the sensible heat flux increases to a value of about 135 W m⁻², while the latent heat flux is around 200 W m⁻². The study attempts to broaden our understanding on the air-sea interaction processes over the Yellow Sea and Korean Strait.     

Quasi-static Planar Deformation in a Medium Composed of Elastic and Thermoelastic Solid Half Spaces Due to Seismic Sources in an Elastic Solid

A two-dimensional problem of quasi static deformation of a medium consisting of an elastic half space in welded contact with thermoelastic half space, caused due to seismic sources, is studied. Source is considered to be in the elastic half space. The basic equations, governed by the coupled theory of thermoelasticity, are used to model for thermoelastic half space. The analytical expressions for displacements, strain and stresses in the two half spaces are obtained first for line source and then for dip slip fault. The results for two particular cases, adiabatic conditions and isothermal conditions, are also obtained. Numerical results for displacements, stresses and temperature distribution have also been computed and are shown.     

X-ray characterization of thin foil gold mirrors of a soft X-ray telescope for ASTROSAT

X-ray reflectivity measurements were performed on several thin foil gold mirrors fabricated in TIFR for a Soft X-ray Imaging Telescope. The mirrors were made from thin aluminum foils with a reflecting layer of sputtered gold transferred from a smooth glass mandrel using an epoxy. X-ray reflectivity measurements were performed on a sample of randomly selected mirrors using CuK _α (8.05 keV), CrK _α (5.41 keV) X-rays and also at several energies in the energy range of 155–300 eV using the synchrotron source Indus-1. It was found that the roughness of the low-density top gold layer as obtained from the fitting of X-ray reflectivity data for CuK _α radiation is relatively more as compared to that obtained from the CrK _α radiation. This indicates that in the mirrors made by this process, the upper surfaces are smoother as compared to the deeper layers. It was also observed that the critical angle almost vanishes in the very low energy range of 290–300 eV due to strong absorption effects of the low density material sitting on top of these mirrors. Due to this absorption effect, efficiency of these mirrors reduces in this energy range. This is first time that reflectivity measurements are being reported for very soft X-rays (≤ 300 eV) for mirrors made for any X-ray astronomy mission.     

Feeder and post Deccan Trap dyke activities in the northern slope of the Satpura Mountain: Evidence from new 40Ar-39Ar ages

We present new 40Ar-39 Ar plagioclase crystallization ages from the dykes exposed at the northern slope of the Satpura Mountain range near Betul-Jabalpur-Pachmarhi area,~800 km NE of the Western Ghats escarpment.Among the two plateau ages,the first age of 66.56±0.42 Ma from a dyke near Mohpani village represents its crystallization age which is either slightly older or contemporaneous with the nearby Mandla lava flows(63-65 Ma).We suggest that the Mohpani dyke might be one of the feeders for the surrounding lava flows as these lavas are significantly younger than the majority of the main Deccan lavas of the Western Ghats(66.38-65.54 Ma).The second age of 56.95±1.08 Ma comes from a younger dyke near Olini village which cuts across the lava flows of the area.The age correlates well with the Mandla lavas which are chemically similar to the uppermost Poladpur,Ambenali and Mahabaleshwar Formation lavas of SW Deccan.Our study shows that the dyke activities occurred in two phases,with the second one representing the terminal stage.     

Evaluation of atmospheric corrections on hyperspectral data with special reference to mineral mapping

Hyperspectral images have wide applications in the fields of geology, mineral exploration, agriculture, forestry and environmental studies etc. due to their narrow band width with numerous channels. However, these images commonly suffer from atmospheric effects, thereby limiting their use. In such a situation, atmospheric correction becomes a necessary pre-requisite for any further processing and accurate interpretation of spectra of different surface materials/objects. In the present study, two very advance atmospheric approaches i.e. QUAC and FLAASH have been applied on the hyperspectral remote sensing imagery. The spectra of vegetation, man-made structure and different minerals from the Gadag area of Karnataka, were extracted from the raw image and also from the QUAC and FLAASH corrected images. These spectra were compared among themselves and also with the existing USGS and JHU spectral library. FLAASH is rigorous atmospheric algorithm and requires various parameters to perform but it has capability to compensate the effects of atmospheric absorption. These absorption curves in any spectra play an important role in identification of the compositions. Therefore, the presence of unwanted absorption features can lead to wrong interpretation and identification of mineral composition. FLAASH also has an advantage of spectral polishing which provides smooth spectral curves which helps in accurate identification of composition of minerals. Therefore, this study recommends that FLAASH is better than QUAC for atmospheric correction and correct interpretation and identification of composition of any object or minerals.     

Evaluation of the Comparative Toxicity of Thiotox,Dichlorvos and Carbofuran to Two Fresh Water Teleosts Ophiocephalus punctatus and Mystus Vittatus

The present study was undertaken to evaluate the comparative toxicity of Thiotox (Endosulfan) (an organochlorine), Dichlorvos (DDVP) (an organophosphorus) and Carbofuran (a carbamate) so as to determine the TL 50 values, acute toxicity ranges, relative toxicities, relative susceptibility, safe concentrations, regression equations, heterogeneity factor and 95% confidence limits for the period of 24, 48, 72 and 96 h, taking two fresh water teleosts, Mystus vittatus and Ophiocephalus punctatus as test animals. From the relative toxicity of these pesticides it is evident that thiotox was the most toxic and dichlorvos the least toxic one, while the toxicity of carbofuran was in between these two extremes for both the fishes. On the basis of relative susceptibility, Mystus vittatus was found to be more susceptible than Ophiocephalus punctatus for thiotox, dichlorvos and carbofuran, respectively. The safe concentrations were computed for all the three pesticides taking different application factors, so as to avoid the long term water pollution by these pesticides.