Application of remote sensing technology for groundwater potential evaluation

With the help of the information drawn from a survey of India toposheet and by visual interpretation of satellite imagery of bands 2, 3 and 4, different thematic maps such as geomorphology and lineaments, drainage and land use, and land cover were prepared. These thematic maps have been superimposed and finally a groundwater potential zone map delineated on a survey of India toposheet. The whole block has been demarcated into 5 zones. Zones 1 and 2 are considered ideal groundwater potential areas, zone 3 is moderately ideal, and zones 4 and 5 are unfavourable for groundwater exploration. The validity of demarcation of the study area into different zones, as decided by remote sensing technology, has been justified by analysing the georesistivity sounding data of a number of places in this area. The net potential of the study area is estimated by GEC norm. It is observed that only 11.8% of annual utilisable groundwater is now used and there is vast scope of further exploitation of this resource.     

Preparation of Al--Al2O3 in-situ particle composites by addition of Fe2O3 particles to pure Al melt

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Reservoir Operation Modelling with Fuzzy Logic

In this article, a fuzzy rule based model is developed for the operation of a single purpose reservoir. The model operates on an 'if – then' principle, where the 'if' is a vector of fuzzy premises and the 'then' is a vector of fuzzy consequences. The steps involved in the development of the model include, construction of membership functions for the inflow, storage, demand and the release, formulation of fuzzyrules, implication and defuzzification. The methodology is illustrated through the case study of the Malaprabha irrigation reservoir in Karnataka, India. Reservoir storage, inflow, and demands are used as premises and the release as the consequence.Simulated reservoir operation with a steady state policy provides the knowledge base necessary for the formulation of the Fuzzy rules.     

Study of deuterium metal interaction by ion implantation

Dynamic and non-equilibrium effects involving interaction between deuterium and radiation produced defects were studied during deuterium implantation of Cu and Ti. The technique of neutron yield measurement during deuterium implantation was employed and theoretical analysis was made to study the dynamics. SIMS, GIXRD and SEM studies on deuterium implanted samples were employed to study the evolution of implanted deuterium profiles, structure of deuterides and surface topography respectively.     

Effect of copper and nickel coating on short steel fiber reinforcement on microstructure and mechanical properties of aluminium matrix composites

Commercially pure Al base short steel fiber reinforced composites were prepared by stir casting method and poured into a cast iron mould. Steel fibers were coated with copper and nickel by electroless deposition method. The density, hardness and strength of composites increased as compared to matrix alloy. The mechanical properties of these composites were measured and the results were correlated with the microstructure observation. It was found that copper-coated short steel fiber reinforced composites show considerable improvement in strength with good ductility because copper form a good interface between Al matrix and short steel fiber. Nickel-coated steel fiber reinforced composites showed improvement in strength to a lower extent possibly because of formation of intermetallic compound at the interface. The improvement in strength with uncoated fibers and nickel-coated fibers is on the lower side because of formation of brittle intermetallic compounds like Fe₂Al₅ and FeAl₃. Fracture surface of tensile specimen was examined under SEM, which revealed a ductile fracture. Copper coating on steel fiber improved the strength properties while retaining a high level of ductility due to better interface bonding.     

Thermal diffusivity, thermal conductivity, and specific heat of flax fiber–HDPE biocomposites at processing temperatures

There is increasing work on the use of flax fibers as reinforcement for manufacturing composites because of their lower cost and environmental benefit. During manufacturing of such natural fiber–plastic composites, heat transfer is involved, but information about the thermal conductivity and thermal diffusivity at the processing temperatures is not available. In this study, the thermal conductivity, thermal diffusivity, and specific heat of flax fiber–high density polyethylene (HDPE) biocomposites were determined in the temperature range of 170–200 °C. The fiber contents in biocomposites were 10%, 20%, and 30% by mass. Using the line-source technique, the instrumental setup was developed to measure the thermal conductivity of biocomposites. It was found that the thermal conductivity, thermal diffusivity, and specific heat decreased with increasing fiber content, but thermal conductivity and thermal diffusivity did not change significantly with temperature in the range studied. The specific heat of the biocomposites increased gradually with temperature.     

In vitro fibroblast response to ultra fine grained titanium produced by a severe plastic deformation process

The in vitro response of the mouse fibroblast cell line 3T3 on the surface of ultrafine grained titanium [produced by a severe plastic deformation (SPD) process] has been studied in this work. SPD Ti showed much higher strength than the coarse grained Ti and equivalent to that of Ti–6Al–4V alloy. Better cell proliferation was observed on SPD Ti compared to conventional Ti and Ti–6Al–4V alloy. This could be attributed to the increased surface free energy by reduction in the grain size and possibly the presence of a large number of nano size grooves at the triple point junctions in SPD Ti sample. There was no significant difference in the results of cytotoxicity tests of fine and coarse grained materials.     

Diffuse phase transition behavior of dysprosium doped barium titanate ceramic

The effect of dysprosium (Dy) doping on the structural and dielectric properties of barium titanate (BaTiO₃) ceramic has been studied. Dysprosium-doped barium titanate (BT) with general formula Ba_1-xDy_2x/3TiO₃ (x?=?0.0–0.1) is prepared through solid state reaction route. The XRD pattern reports the single phase tetragonal structure up to x?=?0.025 with space group of P4mm and a secondary phase is observed for higher concentration of Dy. The Raman study of Ba_1-xDy_2x/3TiO₃ (x?=?0.00, 0.01, 0.025) also reveals that the ceramic is showing tetragonal symmetry and with an increase in Dy doping the tetragonal phase is moving toward more symmetric phase i.e. cubic pm3m. The surface morphology of the sintered pellets shows a compact and homogeneous grain distribution with a decrease in grain size as the Dy content increases. The temperature and frequency dependency dielectric study of the ceramic compositions (x?=?0.00, 0.01, 0.025) are studied to show the effect of Dy ion on the A site of BaTiO₃ perovskite ceramic. The dielectric constant decreases with increase in Dy content. The dielectric diffusivity increases with increase in doping concentration. The P-E hysteresis loop confirms the ferroelectric behavior of the sample with decrease in remanent polarization and increase in coercive field.     

Effect of CH4/H2 plasma ratio on ultra-low friction of nano-crystalline diamond coating deposited by MPECVD technique

Nano-crystalline diamond coatings were deposited on the silicon substrate using Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD). Experiments were performed by varying the H₂ content in CH₄/H₂ plasma during synthesis. Raman spectral analysis revealed that with decrease in hydrogen content in the CH₄ plasma, the I_D/I_G ratio decreases with the formation of smaller crystallites. Such a film possesses a large grain boundary fraction containing hydrogenated amorphous carbon (a-C:H). During tribological test, sufficient amount of hydrogen present in the grain boundary passivates the dangling σ-bond causing ultra-low friction and extremely low wear evident by improvement in microstructure.