Weqar Ahmad Siddiqui

Morphological and biochemical changes in Azadirachta indica from coal combustion fly ash dumping site from a thermal power plant in Delhi, India

The foliar and biochemical traits of Azadirachta indica A. Juss from fly ash (FA) dumping site in Badarpur thermal power plant (BTPP) New Delhi, India was studied. Three different experimental sites were selected at different distances from the thermal power plant. Ambient suspended particulate matter (SPM) and plant responses such as leaf pigments (chlorophyll a, chlorophyll b, and carotenoids), total chlorophyll, net photosynthetic rate, stomatal index (SI), stomatal conductance (SC), intercellular carbon dioxide concentration [CO2]i, net photosynthetic rate (NPR), nitrogen, nitrate, nitrate reductase activity, proline, protein, reducing sugar and sulphur content were measured. Considerable reduction in pigments (chlorophyll a, chlorophyll b and carotenoids), and total chlorophyll was observed at fly ash dumping site. Fly ash stress revealed the inhibitory effect on Nitrate reductase activity (NRA), Nitrate, soluble protein, and reducing sugar content, whereas stimulatory effect was found for the stomatal index, nitrogen, proline, antioxidants and sulphur content in the leaves. Under fly ash stress, stomatal conductance was low, leading to declining in photosynthetic rate and increase in the internal CO2 concentration of leaf. Single leaf area (SLA), leaf length and leaf width also showed a declining trend from control to the polluted site. Antioxidant enzymes increased in leaves reflecting stress and extenuation of reactive oxygen species (ROS).

EFFECT OF SINTERING TEMPERATURE ON THE STRUCTURAL AND DIELECTRIC PROPERTIES OF ZINC CADMIUM FERRITES PREPARED BY EGG-WHITE TECHNIQUE

The effect of cadmium substitution and sintering temperature on the microstructure and dielectric properties of nano ZnCdxFe2-xO4 ferrites (x=0.0, 0.05, 0.1, 0.2, 0.3 and 0.5) has been investigated and prepared by egg-white technique. Electrical conductivity and dielectric measurements have been analysed in the frequency range from 100 Hz to 10 MHz. The variation of the real (e′) and imaginary (e″) part of dielectric constant, AC conductivity (σAC) and loss tangent (tan δ) with frequency has been studied. It follows the Maxwell–Wagner model based on the interfacial polarization in consonance with the Koops phenomenological theory. It is found that the permittivity of ZnCdxFe2-xO4 ferrites improved and shows a maximum value (~9 × 103) at 100 Hz for the x=0.1 sample.

Impact of Di-Methyl Ether (DME) As anAdditive Fuel for Compression IgnitionEngine in Reduction of Urban Air Pollution

With ever growing concerns on environmental pollution, energy security and future oil supplies, the global community is seeking nonpetroleum based alternative fuels to increase the efficiency of energy use. Di-methyl ether (DME) can be used as a clean, high-efficiency compression ignition (CI) engine fuel with reduced NOx, SOx, and particulate matter. DME‟s diesel engine-compatible properties are its high cetane number and low auto-ignition temperature. However, physical properties of DME (viz. lower viscosity, lubricity, combustion enthalpy and boiling point)demands modifications to diesel engine internal structures and components.The technology with pure DME as an alternative fuel for CI engine and vehicle is still under development stage. However, if DME is used as an additive fuel with diesel, the relative “goodness” of each fuel might be utilized. This paper analyses the potential benefit of blending DME in diesel fuel in reduction of urban air pollution.

A Calix (4)Arene Based Chemosensor For Recognition Of Cu 2+ Ion.

A novel calix(4)arene based chemosensor having two schiffs base units has been designed, synthesized and characterized by NMR and ESI-MS analysis. It is found to exhibit excellent selectivity for Cu 2+ over a wide range of alkali, alkaline earth and other transition metal ions in acetonitrile solution. Its metal binding affinity and binding constant studies revealed a 1:1 binding stocheometry of the ligand with Cu 2+ ion.