Synthesis of zeolites from a lagoon ash

The amount of ash, and its hazardous impact on the environment, produced from the coal fired thermal power plants is continuously increasing. This poses a very challenging task of safe handling, proper disposal and utilisation of the ash. A very common method of disposal of the ash is the wet disposal, in a slurry form, in the lands nearby thermal power plants, known as lagoons. During the process of wet disposal, the ash interacts with water and looses its original physical as well as the chemical properties. The ash-water interaction may also lead to the formation of zeolites over a period of time, which may he used for various industrial applications. This paper deals with the effect of water interaction, and hence the formation of zeolite, on a typical Class 'F' lagoon ash, from India. (C) 2001 .

K x-ray satellite spectrum of Ca excited by photons

The K x-ray satellite spectrum of Ca excited by photons was studied using an LiF(200) plane crystal spectrometer. The satellite energies and their relative intensities were examined in the light of theoretical and experimental data available for electron and proton excitations. The energies were found to be in general agreement with the available data. However, the KL1/KL0 intensity ratio was found to be in agreement with that for electron excitation but not with that for proton excitation. (C) 1998 , Ltd

Accuracy assessment of MODIS/Terra snow cover product for parts of Indian Himalayas

Snow cover mapping is important for snow and glacier-related research. The spatial and temporal distribution of snow cover area is a fundamental input to the atmospheric models, snowmelt runoff models and climate models, as well as other applications. Daily snow cover maps from Moderate Resolution Imaging Spectroradiometer (MODIS) Terra satellite were retrieved for the period between 2004 and 2007, and pixels in these images were classified as cloud, snow or snow-free. These images have then been compared with ground snow depth (SD) measurements from the four observatories located at different parts of Himalayas. Comparison of snow maps with in situ data showed good agreement with overall accuracies in between 78.15 and 95.60%. When snow cover was less, MODIS data were found to be less accurate in mapping snow cover region. As the SD increases, the accuracy of MODIS snow cover maps also increases

A study of K x-ray hyper-satellites and KMM radiative Auger effect (RAE) of the elements 19 <= Z <= 25 by photon excitation

K x-ray emission spectra were generated by photon excitation to study the K alpha hyper-satellites, K beta L-1, K beta(5) satellites and KMM RAE structures of the elements 19 <= Z <= 25 using a wavelength dispersive spectrometer with LiF 200 and LiF 220 crystals. The Z-dependence of the energy shift and relative intensity of these lines with respect to the diagram lines were studied except in the case of KMM RAE constituent peaks, for which only energy shifts were examined. The measured energy shifts and relative intensities are compared with the available theoretical predictions. Three of the constituent peaks in the KMM RAE structure are assigned K-M1M2 (P-3), K-M1M2 (P-1) and K-M1M1 (S-1) transitions. Copyright (c) 2006 , Ltd