Petroleum exploration potential of Tamtsag Basin

The Tamtsag Basin is located in the extreme eastern portion of the Mongolia. The Basin and its counterpart in China (the Hailar Basin) are united a whole basin on the structural setting. In recent years, the Tamtsag Basin attracts more and more attention with the important exploration discovered in the 19th block by SOCO and in Hailar Basin of China. This paper discusses the exploration potential of Tamtsag Basin from the viewpoint of petroleum geology.     

A study on quality of aquatic environment in Tumen River Area

After the survey of pollution sources, a study on surface water quality assessment and forecast is given by means of grey system method, fuzzy mathematical method and multiple-index method. Based on it, aquatic environment quality features, treatment measures and environmental strategies of the area are proposed. The quality of aquatic environment of 5 rivers in the Tumen River area is studied. The results show that the pollution of surface water is serious; water quality of most rivers is between grade IV and V except the Hunchun River, being higher than grade IV standard; pollution levels of most rivers have been basically controlled except the of Burhatong River, which is deteriorating gradually. Pollutants of the rivers are comparatively regular, mainly are SS, COD, BOD, AR-OH, NH₃-N. The main pollution trades are chemical fibre industry, pulp and paper making industry and mining industry. If the growth rate of gross industrial product is higher than 25 percent under the encouraging-model of regional exploitation, the pollutants’ load will overtake the bearing capacity of aquatic environment. Thus some protection program against pollution must be worked out in order to achieve the harmonious development of economy society and environment. A project from “Studies on Earlier Stage of Regional Development” of the Chinese Academy of Sciences     

Search for groups of extragalactic radio sources

We explore the possibility of searching for groups of radio sources from the FIRST catalog on angular scales 1′–5′. We developed an efficient method of searching for such groups that takes into account the need for combining the components of extended sources represented in the catalog by separate objects. We found 31 groups of radio sources with angular sizes <5′ that contain no fewer than five sources with flux densities ≥3 mJy. This number is at least triple the expected number of such groups for a random Poisson distribution of radio sources in the sky. The prospects for using groups of radio sources to detect and study distant systems of galaxies are discussed.     

RXTE observations of the transient sources IGR J17091-3624 and IGR J18539+0727

We present the results of our analysis of the RXTE observations for two transient sources, IGR J17091-3624 and IGR J18539+0727, in April 2003. The derived energy spectra of the sources and the power-density spectra of their light curves make it possible to classify them as low/hard-state X-ray binaries. The parameters of the power spectrum for IGR J18539+0727 lead us to tentatively conclude that the compact object in this binary is a black hole.     

The Expansion of the Distance Between Two Arbitrary Gravitating Points as Applied to Specific Models of Celestial Bodies

For the complete system of biharmonic functions a suitable representation in spheroidal coordinates is found. It is used for expanding the distance between two arbitrary gravitating points and its inverse quantity in appropriate series. Such expansions can be of interest and useful in a number of problems of celestial mechanics and stellar dynamics.     

CORROSION AND ADHERENCE AT SEA OIL-PLATFORM

Measurements of the adhesive corrosion and protective potentials of 3 Bohai Sea oilplatforms under different cathodic protection showed corrosion still occurred on these platforms undertheir designed protective potentials. Preliminary conclusions from indoor experiments on the relation betweenadhesive corrosion and cathodic protection showed adhering organisms caused the corrosion onthese platforms.     

Hard X-ray spectrum of Mkn 421 during the active phase

Spectral measurement of Mkn 421 were made in the hard X-ray energy band of 20–200 keV using a high sensitivity, large area scintillation counter telescope on November 21, 2000 and these coincided with the onset of an active X-ray phase as seen in the ASM counting rates on board RXTE. The observed spectrum can not be fitted to a single power law similar to the PDS data of BeppoSAX. The data can be fitted both by a two component power-law function or a combination of an exponential function with a power law component at the high energies above 80 keV. We identify these components with those arising from the synchrotron self compton and the high energy power-law tail arising from the upgrading of the thermal photons due to multiple Compton scattering a la Cyg X-1. A comparison with the earlier data clearly suggests a spectral variability in the hard X-ray spectrum of the source. We propose a continuously flaring geometry for the source as the underlying mechanism for energy release.     

Migration of the Ganga river and its implication on hydro-geological potential of Varanasi area, U.P., India

Borehole data reveals that during Late Quaternary, the Ganga river was non-existent in its present location near Varanasi. Instead, it was flowing further south towards peripheral craton. Himalayan derived grey micaceous sands were being carried by southward flowing rivers beyond the present day water divide of Ganga and mixed with pink arkosic sand brought by northward flowing peninsular rivers. Subsequently, the Ganga shifted to its present position and got incised. Near Varanasi, the Ganga river is flowing along a NW-SE tectonic lineament. The migration of Ganga river is believed to have been in response to basin expansion caused due to Himalayan tectonics during Middle Pleistocene times. Multi-storied sand bodies generated as a result of channel migration provide excellent aquifers confined by a thick zone of muddy sediments near the surface. Good quality potable water is available at various levels below about 70 m depth in sandy aquifers. Craton derived gravelly coarse-to-medium grained sand forms the main aquifer zones of tens of meter thickness with enormous yield. In contrast, the shallow aquifers made up of recycled interfluve silt and sandy silt occur under unconfined conditions and show water-level fluctuation of a few meters during pre-and post-monsoon periods.     

Deciphering potential groundwater zone in hard rock through the application of GIS

Remote Sensing and Geographic Information System has become one of the leading tools in the field of hydrogeological science, which helps in assessing, monitoring and conserving groundwater resources. It allows manipulation and analysis of individual layer of spatial data. It is used for analysing and modelling the interrelationship between the layers. This paper mainly deals with the integrated approach of Remote Sensing and geographical information system (GIS) to delineate groundwater potential zones in hard rock terrain. The remotely sensed data at the scale of 1:50,000 and topographical information from available maps, have been used for the preparation of ground water prospective map by integrating geology, geomorphology, slope, drainage-density and lineaments map of the study area. Further, the data on yield of aquifer, as observed from existing bore wells in the area, has been used to validate the groundwater potential map. The final result depicts the favourable prospective zones in the study area and can be helpful in better planning and management of groundwater resources especially in hard rock terrains.