Eco-restoration of a high-sulphur coal mine overburden dumping site in northeast India: A case study

Eco-restoration of mine overburden (OB) or abandoned mine sites is a major environmental concern. In the present investigation, an integrated approach was used to rejuvenate a high-sulphur mine OB dumping site in the Tirap Collieries, Assam, India, which is situated in the Indo-Burma mega-biodiversity hotspot. A mine OB is devoid of true soil character with poor macro and micronutrient content and contains elevated concentrations of trace and heavy metals. Planting of herbs, shrubs, cover crops and tree species at close proximity leads to primary and secondary sere state succession within a period of 3 to 5 years. A variety of plant species were screened for potential use in restoration: herbs, including Sccharum spontaneum, Cymbopogon winterianus Jowitt (citronella), and Cymbopogon flexuosus (lemon grass) cover plants, including Mimosa strigillosa, M. striata, and M. pigra; shrubs, including Sesbania rostrata (dhaincha) and Cassia streata (cassia); and tree species, including Gmelina arborea (gomari) and Dalbergia sissoo (sissoo). Amendment with unmined soil and bio-organic matter was required for primary establishment of some plant species. Management of these plant species at the site will ensure long term sustainable eco-restoration of the coal mine-degraded land.     

Station factors of Khonsa and Yaongyimsen seismograph stations

Summary Body wave magnitudes of 384 and 440 teleseismic events in the distance range 9–100° are determined using short-period P-wave data obtained from the vertical component seismograms of Khonsa (Tirap district, Arunachal Pradesh) and Yaongyimsen (Mokukchung district, Nagaland) seismic stations. These magnitudes are compared with the corresponding body wave magnitudes reported by the National Earthquake Information Service of the United States Geological Survey. Average residuals for Khonsa and Yaongyimsen stations are found to be +0.09 and +0.48, respectively. It is observed that the average residuals (7) for both the stations decrease with respect to epicentral distance (), focal depth (h) and body wave magnitude (m_b). For the Khonsa station, the respective linear relations are: =0.12–1×10^–5 , M=0.22–7××10^–5 h, M=1.96–0.356m_b and similarly, for the Yaongyimsen station the relations are M=0.59–2×10^–5 , M=0.54–19×10^–5 h, M=2.56–0.391m_b. The nature of the variation of residuals is found to be nearly similar for both the stations.

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aum¶rt; uu m 384 u 440 muu u a amuu 9° – 100° u n¶rt; n mua mau a mau hna (a irap, Arunachal Pradesh) u Yaongyimsen (a Mokukchung, Nagaland). aum¶rt; auam mmmuu aum¶rt;au, nu m National Earthquake Information Service of United States Geological Survey. ¶rt;u amu ¶rt; mau Khonsa u Yaongyimsen a +0,09 u +0,48 mmm. aa, ¶rt;u u (M) ¶rt; u mau am amu m numa (),u aa (h) u aum¶rt; (m_b). mauu Khonsa mmmu u auumu ¶rt;u: M=0.12–1×10^–5 , M=0,22–7×10^–5 h, M=1,96–0,356m_b; ¶rt; mauu Yaongyimsen mmm M=0,56–2×10^–5 , M=0,54–19×10^–5 h, M=2,56–0,391m_b. m, m nu¶rt;a uu ¶rt; u mau nu ¶rt;uaa.

     

A radio study of the superwind galaxy NGC 1482

We present multifrequency radio continuum as well as H  i observations of the superwind galaxy NGC 1482, with both the Giant Metrewave Radio Telescope (GMRT) and the Very Large Array (VLA). This galaxy has a remarkable hourglass-shaped optical emission-line outflow as well as bipolar soft X-ray bubbles on opposite sides of the galactic disc. The low-frequency, lower-resolution radio observations show a smooth structure. From the non-thermal emission, we estimate the available energy in supernovae, and examine whether this would be adequate to drive the observed superwind outflow. The high-frequency, high-resolution radio image of the central starburst region located at the base of the superwind bi-cone shows one prominent peak and more extended emission with substructure. This image has been compared with the infrared, optical red continuum, Hα, and soft and hard X-ray images from Chandra to understand the nature and relationship of the various features seen at different wavelengths. The peak of the infrared emission is the only feature that is coincident with the prominent radio peak, and possibly defines the centre of the galaxy.
The H  i observations with the GMRT show two blobs of emission on opposite sides of the central region. These are rotating about the centre of the galaxy and are located at ∼2.4 kpc from it. In addition, these observations also reveal a multicomponent H  i absorption profile against the central region of the radio source, with a total width of ∼250 km s⁻¹. The extreme blue- and redshifted absorption components are at 1688 and 1942 km s⁻¹, respectively, while the peak absorption is at 1836 km s⁻¹. This is consistent with the heliocentric systemic velocity of  1850 ± 20 km s⁻¹  , estimated from a variety of observations. We discuss possible implications of these results.     

Crop yield estimation model for Iowa using remote sensing and surface parameters

Numerous efforts have been made to develop various indices using remote sensing data such as normalized difference vegetation index (NDVI), vegetation condition index (VCI) and temperature condition index (TCI) for mapping and monitoring of drought and assessment of vegetation health and productivity. NDVI, soil moisture, surface temperature and rainfall are valuable sources of information for the estimation and prediction of crop conditions. In the present paper, we have considered NDVI, soil moisture, surface temperature and rainfall data of Iowa state, US, for 19 years for crop yield assessment and prediction using piecewise linear regression method with breakpoint. Crop production environment consists of inherent sources of heterogeneity and their non-linear behavior. A non-linear Quasi-Newton multi-variate optimization method is utilized, which reasonably minimizes inconsistency and errors in yield prediction.     

Mineralogical and ash geochemical studies of coal-mine shale and its hydrocarbon potential: A case study of shale from Makum coalfield,Northeast India

The mineralogy and geochemical studies of the coal-mine shale collected from the Tirap opencast coal-mine (Makum coalfield, Northeast India) are reported in this paper. Thermo-chemical conversion (pyrolysis) of coal-mine shale has been studied to see its hydrocarbon potential. A combined approach using X-Ray diffraction (LTA-XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray spectrophotometer (EDS), X-ray fluorescence spectrometry (XRF), thermogravimetry-derivative and differential thermogravimetric (TG-DTG and DTA) analysis is made to obtain new information on the mineralogical and geochemical studies of a coal-mine shale (CMS) sample. Gas chromatography-mass spectrometry (GC-MS) analysis is performed to evaluate the quality of the liquid fraction (tar) obtained after pyrolysis at 600°C. The shale sample is dominated by quartz, clay minerals (kaolinite and illite), sulphate bearing phase like gypsum with minor proportion of anatase, probably as artifacts of the plasma-ashing process. GC-MS analysis illustrates the presence of highly oxygenated organic components (M.W. around 94-108) and high molecular weight (M.W. 256) cyclic sulphur (e.g. octathiocane with molecular formula S₈) compounds along with the complex N-containing organic sulphur compounds (M.W. around 255-486) in the tar produced.     

3C 459: a highly asymmetric radio galaxy with a starburst

Multifrequency radio observations of the radio galaxy 3C 459 using MERLIN, VLA and the EVN and an optical Hubble Space Telescope ( HST ) image using the F702W filter are presented. The galaxy has a very asymmetric radio structure, a high infrared luminosity and a young stellar population. The eastern component of the double-lobed structure is brighter, much closer to the nucleus and is significantly less polarized than the western one. This is consistent with the jet on the eastern side interacting with dense gas, which could be due to a merged companion or dense cloud of gas. The HST image of the galaxy presented here exhibits filamentary structures and is compared with the MERLIN 5-GHz radio map. EVN observations of the prominent central component, which has a steep radio spectrum, show a strongly curved structure suggesting a bent or helical radio jet. The radio structure of 3C 459 is compared with other highly asymmetric, Fanaroff–Riley II radio sources, which are also good candidates for studying jet–cloud interactions. Such sources are usually of small linear size and it is possible that the jets are interacting with clouds of infalling gas that fuel the radio source.