GIS based spatial distribution mapping and suitability evaluation of groundwater quality for domestic and agricultural purpose in Kaithal district, Haryana state, India

Groundwater is a major resource for meeting huge domestic and agricultural requirements of Kaithal district in Haryana. Therefore, evaluation of its quality in terms of suitability for domestic and agricultural sectors is necessary for sustainable management of the resource. The present study has analyzed pre- and post-monsoon physico-chemical data of groundwater samples from bore wells spread over the entire district. Spatial distribution maps were generated for hydrogen ion concentration, total dissolved solids, total hardness, electrical conductivity, sodium adsorption ratio, residual sodium carbonate and percent sodium using the geographic information system. Furthermore, the study area was demarcated into different groundwater quality zones for domestic and agricultural use by applying various national and international standards. It was observed from the study that the groundwater was predominantly hard, alkaline and saline in nature. However, it was within safe limits for domestic use. Further, it was also experienced from the analysis that in about two-third parts of the district, groundwater was in desirable-to-permissible quality class for agricultural use but hazardous for soil as well as for crops in the remaining part. Also, a moderation in water quality was observed after the monsoon season, which can be attributed to a possible dilution due to groundwater recharge.     

Quasi-stellar objects and evolution of galaxies

In view of the striking similarities between Quasi-Stellar Objects on the one hand and the nuclei of N galaxies, Seyfert galaxies, radio galaxies and normal galaxies on the other, the possibility that QSOs might belong to an early phase in the evolutionary sequence of galaxies is explored. In this connection, considering the fact that nebulosities have been detected around five QSOs, the implications of the hypothesis that a QSO consists of a bright central object embedded in an extended nebulosity have been examined. In particular, the ratio a between the intensity of the bright central object and that of the surrounding nebulosity in the visual band of wavelengths has been calculated by the colour-given method for a sample of 81 QSOs with emission redshiftz0.76. This ratio a has been used to calculate the apparent visual magnitudem(V) and the absolute visual magnitudeM(V) of the bright central object (Nu) as well as that of the surounding nebulosity (Neb) of the QSOs in the sample and a criterion has been proposed as to the detectability of the surrounding nebulosities. Similar calculations have been made for N galaxies, Seyfert galaxies and normal galaxies. It is found that the values of log a, M(V) _Nu and M(V) _Neb for the four classes of extragalactic objects show a definite trend and suggest an evolutionary sequence: QSOsN galaxiesSeyfert galaxiesnormal galaxies.     

Measurement of Hubble constant: were differences in secondary distance indicators apparent as early as the HST Key Project?

Different measurements of the Hubble constant(H₀)are not consistent,and a tension between the CMB based methods and cosmic distance ladder based methods has been observed.Measurements from various distance based methods are also inconsistent.To aggravate the problem,the same cosmological probe(TypeⅠa SNe for instance)calibrated through different methods also provides different values of H₀.We compare various distance ladder based methods through the already available unique data obtained from the Hubble Space Telescope(HST).Our analysis is based on parametric(t-test)as well as non-parametric statistical methods such as the Mann-Whitney U test and Kolmogorov-Smirnov test.Our results show that different methods provide different values of H₀ and the differences are statistically significant.The biases in the calibration would not account for these differences as the data have been taken from a single telescope with a common calibration scheme.The unknown physical effects or issues with the empirical relations of distance measurement from different probes could give rise to these differences.     

Petrographic and depositional characteristics of Tadkeshwar lignite deposits (Cambay Basin), Gujarat

Tadkeshwar lignite deposits are one of the important Lower Tertiary lignite deposits of Cambay Basin, Gujarat. These lignites are rich in huminite macerals followed by liptinite and inertinite with moderate to high proportions of associated mineral matter. Under fluorescence mode these are found to be rich in liptinite macerals, in particular the liptodetrinite and resinite. The type of huminite suggests that the lignite is formed from mixed vegetal source, i.e. woody forest vegetation and herbs, shrubs. The composition of macerals indicates the deposition of lignite in sub-aqueous condition in wet-reducing environment with intermittent exposure and subsidence of the peat surface. The rank of the Main and the Leader seams, determined through reflectance measurement, indicate that the lignite is less mature. The considerable amount of perhydrous huminite may have contributed to the lower reflectance values in some of the samples. Low rank and appreciable amount of mineral matter make the lignite suitable for its utilization in thermal power plants, however when upgraded or mixed with better quality coals it can be used for other industries.     

Redshifts and the Hubble diagrams of Quasi-Stellar Objects

In order to investigate the nature of the redshifts of QSOs, Hubble diagrams have been plotted. First, [log (cz),m _v ] pairs have been plotted for a sample of 252 QSOs. This sample has been drawn from the recent catalogue (Burbidgeet al., 1977) of 633 QSOs after excluding those for which either the redshifts are uncertain or theV magnitudes are not known accurately. Before plotting,K-correction has been applied to theV magnitudes. A least-squares linear fit has been obtained for this plot and, as a result, we get a slope of 0.165±0.012 against 0.2 expected theoretically on the basis of the assumption that the QSOs are at cosmological distances implied by their redshifts. The discrepancy in the value of the slope has been attributed partly to the uncertainty in theK-correction and partly to the evolutionary effect. In order to eliminate the uncertainty due to theK-correction, [log (cz), logf(H)] pairs have been plotted for a sample of 52 QSOs and a least-squares linear fit has been obtained which has a slope of –0.497±0.076, in close agreement with the theoretically expected value of –0.5. This lends support to the hypothesis that the redshifts of the QSOs are cosmological in nature. Finally, the evolutionary effect has been examined, and we conclude that the QSOs do evolve in luminosity in course of time.     

Seismic quality factor observations for gas-hydrate-bearing sediments on the western margin of India

Any propagating wave undergoes attenuation, which is primarily governed by the physical properties of the medium, determined in terms of quality factor (Q). Research into the characteristics of both P- and S-wave Q with reference to gas-hydrates exploration remains in its infancy. Presence of gas-hydrates increases the Q, and this again depends on the nature of distribution and amount of hydrates within the sediments. Thus, estimation of Q provides useful input for both the detection and quantitative assessment of gas-hydrates. Here we propose a simple technique of deriving Q from prestack surface seismic reflection data based on the logarithm of spectral ratio (LSR), and apply the method to marine multi-channel seismic (MCS) data collected on the western margin of India where a bottom simulating reflector (BSR), which is a prime marker for gas-hydrates, has already been identified. The Q (256 ± 11) estimated over the region with a strong BSR is found to be more than double the Q (101 ± 9) derived for the region without any BSR or a weak BSR. The anomalously high Q with respect to the background can be used to detect gas-hydrates in areas where the BSR is not very clearly observed on seismic sections.