STRUCTURE AND ROTATION OF THE SOLAR INTERIOR: INITIAL RESULTS FROM THE MDI MEDIUM-L PROGRAM

The medium-l program of the Michelson Doppler Imager instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to 300. The data for the program are partly processed on board because only about 3% of MDI observations can be transmitted continuously to the ground. The on-board data processing, the main component of which is Gaussian-weighted binning, has been optimized to reduce the negative influence of spatial aliasing of the high-degree oscillation modes. The data processing is completed in a data analysis pipeline at the SOI Stanford Support Center to determine the mean multiplet frequencies and splitting coefficients. The initial results show that the noise in the medium-l oscillation power spectrum is substantially lower than in ground-based measurements. This enables us to detect lower amplitude modes and, thus, to extend the range of measured mode frequencies. This is important for inferring the Sun's internal structure and rotation. The MDI observations also reveal the asymmetry of oscillation spectral lines. The line asymmetries agree with the theory of mode excitation by acoustic sources localized in the upper convective boundary layer. The sound-speed profile inferred from the mean frequencies gives evidence for a sharp variation at the edge of the energy-generating core. The results also confirm the previous finding by the GONG (Gough et al., 1996) that, in a thin layer just beneath the convection zone, helium appears to be less abundant than predicted by theory. Inverting the multiplet frequency splittings from MDI, we detect significant rotational shear in this thin layer. This layer is likely to be the place where the solar dynamo operates. In order to understand how the Sun works, it is extremely important to observe the evolution of this transition layer throughout the 11-year activity cycle.     

Database management and analysis for CAPE project using remote sensing and GIS

The present study attempts to conceptualise an approach to integrate the remotely sensed and spatial?n-spatial data generated over the years under Crop Acreage and Production Estimation (CAPE) project through GIS for their easy retrieval and comparison; and to develop a program in dBASE to calculate crop acreage using non-spatial attributes imported from GIS. The “Crop Information System” thus developed would help the planners in analysis/comparison of the database related to crops over the years.     

Spherules from the Late Cretaceous Phosphorite of the Fatehgarh Formation, Barmer Basin, India

A first report of discovery of spherules, glassy balls, highly magnetic fine dust and microbracciated matrix in the Fatehgarh Formation of Barmer Basin, Rajasthan, India is being presented in this paper. The Fatehgarh Formation is a mixed siliciclastic, carbonate and phosphorite formation of Cretaceous age in the Barmer Basin that comprises sediments of Middle Jurassic to Lower Eocene age. The phosphorite zone in the Fatehgarh Formation is 8 metre-thick zone that comprises phosphatic sandstone, bone bed, bedded phosphorite and phosphatic and non phosphatic gastropod beds. The spherules occur in a thin phosphatic-clay mud and silt band of bone bed, which also yielded a very rich and diverse microvertebrate assemblage with a dominant Late Cretaceous (Maastrichtian) form of Igdabatis along with forms comprising of Semionodontid, Lapisosteum and Enchodontid. The end Cretaceous is marked for a mass extinction of numerous species including dinosaurs. An extraterrestrial impact is interpreted as the reason for this mass extinction. Whether these spherules are related to the volcanic source or K/T Boundary impact ejecta found at Caribbean and Gulf of Mexico region needs detailed chemical and age characterization for which study is in progress.     

Biotransformation of amide using Bacillus sp.: isolation strategy, strain characteristics and enzyme immobilization

Amidase hydrolases/acyltransferases are of considerable industrial interest due to potential applications in the production of useful hydroxamic acids. The test strain, capable of acetamide degradation, was isolated by an enrichment technique with acetamide as sole source of nitrogen. Based on morphology, physiological tests and biochemical tests, this isolate was identified as Bacillus sp. and on the basis of 16S Ribosomal ribonucleic acid sequence, a phylogenetic tree was drawn and was identified as Bacillus megaterium. Resting cells containing active acyltransferase enzyme were prepared and immobilized in the gel beads of sodium alginate, agar, polyacrylamide and polyvinyl alcohol?Calginate. The beads were tested for acyltransferase using Iron (III) chloride reagents at 55°C and were found to be affected by substrate concentration, type of buffer, buffer pH and reaction temperature. These factors were optimized using sodium alginate immobilized beads. This study proved useful in understanding the technique of immobilization of acyltransferase enzyme, its operational stability and its importance in the synthesis of hydroxamic acid.     

Feasibility study of waste (d) potential: co-digestion of organic wastes,synergistic effect and kinetics of biogas production

The present study investigated the synergistic effect of co-digesting food and green waste from institute campus for enhanced biogas production in different ratios in batch tests (37 ± 1 °C, 90 rpm, 45 days). The results showed that blending improved the biogas production significantly, with highest biogas yield (660 ± 24 mL g^?1 volatile solids) that was achieved at 75:25 of food and green waste ratio on volatile solids basis. The yield was 1.7- and 1.9-fold higher than the mono-digestion of food and green waste (370 ± 34; 342 ± 36 mL g^?1 volatile solids), respectively. The increase in biogas production may be attributed to optimum carbon to nitrogen ratio resulting in higher yield. The addition of TiO₂ nanoparticles showed virtually no effect on biogas production. Characterization was carried out to gain an insight of feedstocks. Modified Gompertz and logistics models were applied for kinetic study of biogas production where modified Gompertz model showed goodness of fit (R ² = 0.9978) with the experimental results.     

Hydrochemical characterization and suitability assessment of groundwater in Baga–Calangute stretch of Goa,India

The present study is the first attempt to determine the suitability of groundwater for drinking and irrigation in the Baga–Calangute stretch of Goa. The suitability of groundwater for potable use was assessed by comparing observed values against standards prescribed by the Bureau of Indian Standards, and the quality was classified based on the Weighted Arithmetic Water Quality Index. Most of the groundwater samples (90%) were found to be suitable for drinking except for hardness, chlorides, and nitrates. The percent sodium (%Na), residual sodium carbonate, soluble sodium percentage, sodium adsorption ratio, Kelly’s ratio, and Permeability Index were found to be within the prescribed limits for irrigation purposes. The major mechanism controlling groundwater chemistry, i.e., rock–water interaction, was also studied, and it was found that silicate weathering plays a major role in the dissolution of minerals. Based on the hydrochemical characterization, the water was observed to be of the Ca–Na–SO₄ composition type except for one sample which was of the Na–Cl composition type. Classification of the meteoric genesis suggested that the groundwater in surficial aquifers in the region had a deep meteoric percolation, and its chemistry is regulated by rock–water interaction.     

Copper isotope fractionation in the Meiduk porphyry copper deposit,Northwest of Kerman Cenozoic magmatic arc,Iran

The Meiduk deposit possesses three different Cu reservoirs each with a unique Cu isotope signature. δ⁶⁵Cu for the leached cap minerals ranges from ?2.5 to +0.49‰ to ?0.45 to +0.3‰ for hypogene minerals and from +1.3 to +4.4‰ for supergene enrichment minerals. Oxidation of hypogene sulphides and effective trapping of copper (from solutions derived from the leached cap) in the supergene enrichment zone caused this relationship. A systematic pattern of low Cu isotope values close to the surface and higher isotope values with depth reveals a palaeo‐fluid pathway in the northwest–southeast direction over the deposit. Thus, the copper isotope data from leached cap and enrichment minerals can be used to monitor copper migration during supergene weathering at the Meiduk deposit.     

Rain rate measurements over global oceans from IRS-P4 MSMR

In this paper rain estimation capability of MSMR is explored. MSMR brightness temperature data of six channels corresponding to three frequencies of 10, 18 and 21 GHz are colocated with the TRMM Microwave Imager (TMI) derived rain rates to find a new empirical algorithm for rain rate by multiple regression. Multiple correlation analysis involving various combinations of channels in linear and non-linear forms and rain rate from TMI is carried out, and thus the best possible algorithm for rain rate measurement was identified which involved V and H polarized brightness temperature measurements at 10 and 18 GHz channels. This algorithm explained about 82 per cent correlation (r) with rain rate, and 1.61 mm h^-1 of error of estimation. Further, this algorithm is used for generating global average rain rate map for two contrasting months of August (2000) and January (2001) of northern and southern hemispheric summers, respectively. MSMR derived monthly averaged rain rates are compared with similar estimates from TRMM Precipitation Radar (PR), and it was found that MSMR derived rain rates match well, quantitatively and qualitatively, with that from PR.     

Discovery of animal eggs and embryos from the Ediacaran (Terminal Proterozoic) Chambaghat Formation,Krol Group,Himachal Lesser Himalaya

The globular to suboval microfossils with distinctively ornamented outer coverings interpreted as animal eggs and embryos have been discovered from the black phosphatic chert lentils of the Ediacaran (Terminal Proterozoic) Chambaghat Formation (Krol sandstone), Krol Group, Himachal Lesser Himalaya, India. Similar animal eggs and embryos have earlier been recorded only from the phosphorites of the uppermost Neoproterozoic Doushantuo Formation (Ca. 570±20 Ma) exposed at Weng’an, South China. Present record of eggs and embryos is comparable with extant eggs and embryos of cnidarians and bilaterians like molluscs, annelids and arthropods. The eggs and embryos from the Terminal Proterozoic rocks of India are the only one recorded from the equivalent stratigraphic horizon outside China. This discovery of eggs and embryos adds to the understanding the evolutionary trends in the Proterozoic metazoan life.