[en] The Rihand reservoir bordering Uttar Pradesh's Mirzapur district and neighbouring Madhya Pradesh's Sidhi district, is the country's largest man made lake; over 50 km long. Giant power plants are coming around the lake: to generate a mammoth 20,000 MW of electricity. India has large coal reserves for generation of energy. The fly ash fallout rates in the vicinity of Rihand reservoir were measured in terms of kg/km²/month for a duration of one year (1987) and was recorded to be from 120.50 to 1548.28 t/km²/month. The concentration of some toxic metals (zinc, cobalt, copper, lead, nickel) was determined by AAS-method in a number of fly ash samples collected at selected sites in the vicinity of the congregation of number of power plants at Rihand reservoir. These metals were found in soil samples collected from different depths. Their concentrations were determined in soil samples collected from contamination free areas. The salient findings with regards to the toxic metals permeabilities in the soil horizon in the vicinity of the thermal power plants in Rihand reservoir are discussed. (author)

[en] The effect of alloying elements silicon and manganese in plain carbon steels are studied using Moessbauer effect technique and known microscopic information. It is found that for low carbon concentrations the alloying elements essentially go into the substitutional sites of the iron lattice, but as carbon concentration increases these elements form carbides besides occupying substitutional positions. (author)

[en] The effect of annealing on the structure changes of natural goethite and bog iron ore is studied by the Moessbauer effect. Infrared and differential thermal analyses are also carried out. It is observed that both, goethite and bog iron ore contain iron as α-FeOOH. The temperature of transformation of α-FeOOH to α-Fe₂O₃ is found to be about 400⁰C. Goethite exhibits superparamagnetism and the crystallization is not completed while bog iron ore is of the hard type of the lake ore deposits. (author)

[en] The effects of cold work and low-temperature sensitization heat treatment of non-sensitized austenitic stainless steels have been investigated and related to the cracking in nuclear power reactors. Types 304, 304L and 304LN developed martensite after 15% cold working. Heat treatment of these cold worked steels at 500 deg. C led to sensitization of grain boundaries and the matrix and a desensitization effect was seen in 11 days due to fast diffusion rate of chromium in martensite. Types 316L and 316LN did not develop martensite upon cold rolling due to its chemical composition suppressing the martensite transformation (due to deformation) temperature, hence these were not sensitized at 500 deg. C. The sensitization of the martensite phase was always accompanied by a hump in the reactivation current peak in the double loop electrochemical potentiokinetic reactivation test, thus providing a test to detect such sensitization. It was shown that bending does not produce martensite and therefore, is a better method to simulate weld heat affected zone. Bending and heating at 500 deg. C for 11 days led to fresh precipitation due to increased retained strain and desensitization of 304LN due to faster diffusion rate of chromium along dislocations. The as received or solution annealed 304 and 304LN with 0.15% nitrogen showed increased sensitization after heat treatment at 500 deg. C, indicating the presence of carbides/nitrides

[en] Radiation measurements were made in coal and fly ash samples from Savannah Electric ampersand Power Company (SEPCO) plant on the Savannah River and the soil core samples from three sites along the flow gradient of Savannah State University Campus Creek. The objective of this study was to determine the magnitude of natural radiation due to radon and potassium in the Savannah area and possible effect of external factors such as the operations at Savannah River Site (SRS). The instrument used for this purpose was Geiger Counter Model 500 (Tennelec/Nucleus, Inc.) which was standardized with known samples of Sr-90 (0.1 μCi t_1/2 = 28.6 yrs., beta radiation) and Co-60 (1.0 μCi t_1/2 = 5.27 yrs., gamma radiation). Beta and gamma radiations in the samples were differentiated with the help of polyethylene and lead absorbers. Results showed quite low radioactivity in bituminous coal from SEPCO plant and it reduced by a factor of 0.5 and 0.25 in fly ash and weathered fly ash, respectively. Radioactivity of soil samples was slightly greater in the top soil (0-3 cm) of two sites and it decreased markedly with depth (20 cm). Site III soil samples containing lime shells had a negligible radioactivity because carbonate rocks developed from calcareous skeletal matter have low radioactivity from their beginning. Radioactivity appeared to be mainly associated with the fine textured top soil of two sites (high clay content) and it exhibited very little leaching downward into lower layers. Clay particles with greater radioactivity, are formed from the decomposition of feldspars and micas which contain a large fraction of earth's potassium fraction. Measurements with the use of absorbers indicated that the observed radiation in all the samples was mainly due to the gamma rays. A comparison with the radioactivity in coal dust and fly ash samples from SRS revealed that the Savannah samples contained extremely low radiation, which may be due only to the natural sources

[en] Crystal field parameters for ErGaG and Er³⁺ YAlG are used to compute the temperature dependence of Schottky specific heat, paramagnetic susceptibility, magnetic anisotropy, sup(μ)eff and quadrupole splitting in the range 10-400 K. The hyperfine interaction parameters A and B for ¹⁶¹⁶⁶Er and ¹⁶⁷Er in both the systems are also obtained and in turn used to estimate the nuclear specific heat contribution. The studied parameters compare well with the available experimental results. (author)

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[en] The objective of this study was to determine the feasibility of coal fly ash-amended composts for use as an alternate manure for agricultural crops. Home-made organic composts was mixed in various proportions with fine fly ash collected from Savannah River Site, and allowed to decompose for two weeks while the mixture was kept wet. Water extracts from the amended composts were analyzed for selected major and trace elements. These amended composts were mixed with sifted sandy loam soil in a predetermined optimum ratio of 1:3 and used to grow corn and sorghum plants. It was shown that fly ash additions to home-made compost facilitated efficient plant utilization of nutrients when 20-40% fly ash in compost was applied to the soil. The maximum dry shoot yields correlated with the higher concentrations of K, Ca and N and lower concentrations of B in the amended compost treatment

[en] Moessbauer effect spectroscopy has been used to analyse various corrosion products formed on steels corroded in the presence of reinforced cement and concrete (rcc). The various products formed were assigned on the basis of their internal magnetic field, quadrupole interaction and isomer shift values. The chemical and structural analyses of steels and concretes were performed to supplement the results. A heavily corroded steel bar was also studied and the possible reasons of accelerated corrosion have been discussed. Further, it was found that steels having more cementite end up with the corrosion product Fe₃O₄, while others with β FeOOH only. (auth.)