Vegetation vis-à-vis climate and glacier history during 12,400 to 5,400 yr BP from Dokriani valley,Garhwal Himalaya,India

Palynological analysis from a 10 m deep sediment profile from Dokriani valley, Garhwal Himalaya, provides temporal variation of vegetation vis-à-vis climate and glacier history of the region. This study reveals that between 12,406 and 10,633 cal yr BP vegetation was sparse when the climate was cool-dry and the glacier snout might had been located at lower elevations in comparison to its present position. Subsequently around 10,633 cal yr BP, an increase in the growth of diversified taxa close to the site, indicates the early Holocene climatic amelioration when glacier might have retreated at faster rate. Further, within Holocene some intermittent cool-dry episodes were recorded around 9,670 to 9,000 cal yr BP and 7,100 cal yr BP when glacier might have shown reduction in retreat rate or came to stagnation.     

Modern vegetational distribution and pollen dispersal study within Gangotri glacier valley, Garhwal Himalaya

Modern pollen-vegetation relationship has been analyzed in respect to vegetational distribution and pollen dispersal from sub-alpine and alpine ecological regimes within the higher reaches of the Gangotri glacier valley. The results in general cope with the local ecological conditions of the sites within the valley. Above the tree line limits, the pollen frequency of arboreal taxa is found lower than those of non-arboreal taxa. In contrast the pine-birch forest area at Chirbasa represented the frequency of arboreal pollen (AP) more than that of non-arboreal pollen (NAP) due to over representation of Pinus wallichiana (conifer). Pollen grains of extra-local arboreal elements, mostly conifers have also been recorded here with fair amount of temperate broad-leaved arboreal taxa viz. Quercus, Alnus, Corylus, Carpinus, Ulmus, Juglans etc. that have been transported by the upthermic winds from their growing limits at lower altitudes to the study sites at higher altitudes. Non-arboreal taxa viz. marshy/aquatic, steppe and of other herbaceaous taxa, represents the existing ecological regimes of their respective sites within the valley. Differential pollen preservation has been observed between the moss cushion and sediment samples from the same site that may be due to the direct exposure of moss cushions to air, thus showing more concentration of wind pollinated pollen-spores as compared to surface sediments.     

Oxidative Degradation of Orange II Dye in Water with Raw and Acid‐Treated ZnO,and MnO2

Commercial ZnO, MnO₂, and their acid‐treated forms were used as catalysts for oxidative degradation of Orange II dye in water. ZnO and MnO₂ were treated with 0.5, 0.75, or 1.0 N aqueous H₂SO₄. The acid treated oxides were found to be highly effective in bringing about degradation of Orange II in water. As much as 68.7% of the dye in an aqueous solution of 1 mg/L concentration could be degraded with untreated ZnO as the catalyst. The degradation increased to 79.5% with 1.0 N acid treated ZnO as the catalyst when the reaction was carried out at room temperature for 240 min. The catalytic activity was slightly affected by the solution pH in the range of 2.0–8.0. With MnO₂ as the catalyst, there was only 12.7% degradation of the dye, but this increased up to 100% when 0.5 N acid treated MnO₂ was used as the catalyst. It was found that a catalyst loading of 5.0 g/L of raw and acid‐treated ZnO and a loading of 0.5 g/L of raw and acid‐treated MnO₂ could bring about almost 100% degradation of Orange II in water in an interaction time of 240 min at room temperature.     

A note on the characters of some Lower Gondwana coals of West Siang district in the Arunachal Himalaya and their trace element content

Lower Gondwana coal from Garu-Gensi area in the West Siang district of Arunachal Pradesh in the Eastern Himalayas have been characterized with respect to their maceral constituents, mineral matter, ash composition, sulphurand trace-element contents. These are low-rank bituminous coals (V₀ = 0.64) and their vitrinite content is about 60%. A first hand data with respect to twenty one trace-elements are reported. Our data indicate that these Lower Gondwana coals of extra-peninsular region are richer in terms of their trace-element content when compared with their counter parts of peninsular India.     

Appraisal and mapping the spatial-temporal distribution of urban road traffic noise

The present study aims to compute the temporal and spatial distribution of road traffic induced noise pollution in an urban environment by monitoring and mapping. The study area was the entire Asansol city of West Bengal, India. A total of 35 locations were selected for collection of data, classified as industrial, commercial, residential, sensitive and mixed areas according to the national regulatory standards. Noise recordings were conducted during morning and night hours. Day time L_eq level ranged between 51.2 and 89.0 dB(A), whereas it ranged between 43.5 and 81.9 dB(A) during night. The average L_dn value was 73.28 ±8.51 dB(A) (Range: 55.1–87.3); The traffic noise index was 80.62 ± 15.88 dB(A) (Range: 49.4–115.8). The computed data were mapped by utilization of Geographic information system methodology that allowed the visualization and identification of the extent and distribution of sound pollution across the study area. This proves to be an ideal tool for carrying out noise impact assessments in urban settings. The study reveals that present noise level in all the locations exceeds the prescribed limit. Based on the finding, it can be mentioned that the population in this industrial town are exposed to significantly high noise level, which is caused mostly due to road traffic. The study reveals that vulnerable establishments like schools and hospitals are subjected to significantly high noise level throughout the day and immediate mitigatory measures are required to alleviate the problem.     

Assessment of heavy metal pollution in soils around a paper mill using metal fractionation and multivariate analysis

Effects of paper mill wastes on the status of soil copper (Cu), manganese (Mn) and zinc (Zn) in and around 16 sites near a paper mill in Assam, North East India (26°07.485′ to 26°07.915′ N latitude and 92°12.706′ to 92°15.065′ E longitude), have been investigated in the present study. The six-step sequential extraction techniques revealed that the water-soluble fraction had the least contribution (below detectable limit to 3.24 mg kg^?1 of Cu, 13.87 mg kg^?1 of Mn and 1.25 mg kg^?1 of Zn) towards soil contamination, irrespective of the metals evaluated. Chemical fractionation of Cu, Mn and Zn in majority of the sampling locations showed non-homogenous orders of contamination. Comparison of the magnitude of local and individual heavy metal contamination factors against global values showed that the places near the paper mill waste disposal site displayed higher potential risk from metal contamination. Furthermore, the mobility factor related to ecotoxicity of soil environment was found to be metal specific and depended not only on total metal concentration but also on the nature of metal in the order Mn > Cu > Zn.     

Developing a biosorbent from <Emphasis Type="Italic">Aegle Marmelos</Emphasis> leaves for removal of methylene blue from water

Dried, mature leaves of Aegle Marmelos tree were converted to a powder, which was used as a biosorbent for dyes in water with methylene blue as a case study. The biosorbent had a surface area of 52.63 mg/g, and FTIR spectra showed the presence of –COOH, –NH₂, –R–SC=O (thioester) and R1–S(=O, =O)-N(–R2, –R3) groups on the surface. The particles were found to be porous in nature from scanning electron micrographs, and EDX measurements showed the elements C, O, Na, Mg, K, Ca and Fe on the surface. Batch adsorption experiments showed that the adsorption of the dye was preferred at near-neutral conditions. Adsorption equilibrium was achieved in ~120 min with maximum dye uptake of 19.9 mg/g. Investigation into the kinetics of adsorption indicated that second-order kinetics gave the best fit to the experimental data, and a rate coefficient of 8.0 × 10^?2 to 32.3 × 10^?2 g mg^?1 min^?1 was obtained.     

Mass depletion from the nucleus of a disk galaxy and its effect on the outer structure of the galaxy

High-energy explosions in the nuclei of galaxies throw out large amount of gas with sufficiently large velocities. This high-velocity ejections of gas is observed in Seyfert galaxies and in many normal spiral galaxies. The ejected gas flows continuously in the outer region and builds the outer structure of the galaxy. The degree of influence of the outflowing gas on the outer structure depends on the energy released during the explosion and on the damping rate of flow. These two parameters may essentially determine the type of galaxy to be evolved to including the Hubble-type. The physical interpretation of some such observed phenomena has been achieved on the basis of the solution of gas dynamical equations with viscosity.     

Extended ring system of Uranus

Two photoelectric records of the occultation event on 10 March, 1977, obtained by two 102-cm-aperture telescopes, spaced 1500 km apart, are critically analysed and indications of a complex structure of distribution of occulting material surrounding the planet are obtained. The results confirm the existence of a very shallow broad ring system with local condensation lanes of narrow and intermediate widths. A system of numerous thin rings are also present around the planet in the equatorial plane.