870 research outputs found

    Assessment of Water Quality Around Mine Sites

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    One of the major impacts of mining processes is the contamination of water bodies through mine water drainage, leakage of water exposed to minerals, water from soil heaps, acid mine drainage and mine water rebound. Water is the most important element of eco-system and it is thus imperative to determine and mitigate the effects of mining operation on the same. Also, contaminated water has adverse physiological effects on human being and other animals. For this, it is important to identify the critical parameters in the water sample which is the scope of the study. Sampling, Water quality parameters and their tests: Samples were collected from different mines including both coal and metal mines spread over northern and western Odisha such as samples from Ib Valley coal mines of MCL, discharge of iron mines from Chhattisgarh and Koira region and were analysed through a series of experiments following standard procedure. The concentration of various physical, chemical, metallic and organic parameters were found which included determination of turbidity, conductivity, solids, iron, chromium content, pH, hardness, ammonia, nitrate, sulphate, phenol, fluoride, phosphate and organic parameters of importance such as Dissolved oxygen, Bio-chemical Oxygen Demand and Chemical Oxygen Demand. Results and Discussions: The results indicated that discharge of iron mine, Chhattisgarh, exceeds the contamination limits for physical and metal parameters but is within limits for others. Samples from the coal mining areas are having elevated concentrations of physical, chemical and organic parameters, such as solid content, turbidity and dissolved oxygen. Samples from metal mining region of Koira showed higher iron content and other nutrients. The results were quantified to determine the degree of contamination. The values of degree of contamination (Cd) are given in the table-1. The Cd values indicate that the water samples from coal mines, iron mines of Chhattisgarh, Barsuan and Bandhal from Koira region are heavily polluted. Sl no Sample Id Degree of Contamination 1 Coal mine main sump discharge, MCL, Ib Valley 39.76 2 Iron mines, Chhattisgarh 93.4 3 Coal mine, MCL, North Central Ib Valley 4.85 4 Nallah nearby Iron mines, Barsuan area 6.253 5 Nallah in between two iron mines -4.766 6 Origin of a nallah near iron mine -4.1726 7 Nallah Adjacent to Manganese and Iron Mines 38.84 8 Post mine stream (Mn and Fe mines) of nallah -1.784 9 Nallah, 100 mtrs from the Iron Mine -2.7 10 Nallah flowing downhill from a Fe Mine -2.3

    Long-range angular correlations on the near and away side in p–Pb collisions at

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    Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

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    We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

    Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

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    Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

    Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

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    Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

    Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

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    Pseudorapidity and transverse-momentum distributions of charged particles in proton-proton collisions at root s=13 TeV

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    The pseudorapidity (eta) and transverse-momentum (p(T)) distributions of charged particles produced in proton-proton collisions are measured at the centre-of-mass energy root s = 13 TeV. The pseudorapidity distribution in vertical bar eta vertical bar <1.8 is reported for inelastic events and for events with at least one charged particle in vertical bar eta vertical bar <1. The pseudorapidity density of charged particles produced in the pseudorapidity region vertical bar eta vertical bar <0.5 is 5.31 +/- 0.18 and 6.46 +/- 0.19 for the two event classes, respectively. The transverse-momentum distribution of charged particles is measured in the range 0.15 <p(T) <20 GeV/c and vertical bar eta vertical bar <0.8 for events with at least one charged particle in vertical bar eta vertical bar <1. The evolution of the transverse momentum spectra of charged particles is also investigated as a function of event multiplicity. The results are compared with calculations from PYTHIA and EPOS Monte Carlo generators. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

    Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb-Pb collisions at root s(NN)=2.76TeV

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    The elliptic flow, v(2), of muons from heavy-flavour hadron decays at forward rapidity (2.5 <y <4) is measured in Pb-Pb collisions at root s(NN)= 2.76TeVwith the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee-Yang zeros methods are used. The dependence of the v(2) of muons from heavy-flavour hadron decays on the collision centrality, in the range 0-40%, and on transverse momentum, p(T), is studied in the interval 3 <p(T)<10 GeV/c. A positive v(2) is observed with the scalar product and two-particle Q cumulants in semi-central collisions (10-20% and 20-40% centrality classes) for the p(T) interval from 3 to about 5GeV/c with a significance larger than 3 sigma, based on the combination of statistical and systematic uncertainties. The v(2) magnitude tends to decrease towards more central collisions and with increasing pT. It becomes compatible with zero in the interval 6 <p(T)<10 GeV/c. The results are compared to models describing the interaction of heavy quarks and open heavy-flavour hadrons with the high-density medium formed in high-energy heavy-ion collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

    Underlying Event measurements in pp collisions at s=0.9 \sqrt {s} = 0.9 and 7 TeV with the ALICE experiment at the LHC

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    Depth-resolved abundance and diversity of arsenite-oxidizing bacteria in the groundwater of Beimen, a blackfoot disease endemic area of southwestern Taiwan

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    The role of arsenite oxidizers in natural attenuation of arsenic pollution necessitates studies on their abundance and diversity in arsenic-contaminated aquifers. In this study, most probable number-polymerase chain reaction (MPN-PCR) and denaturing gradient gel electrophoresis (DGGE) was applied to monitor depth-wise abundance and diversity of aerobic arsenite oxidizers in arsenic-enriched groundwater of Beimen, southwestern Taiwan. The results revealed that the abundance of arsenite oxidizers ranged from 0.04 to 0.22, and the lowest ratio was observed in the most arsenic-enriched and comparatively more reduced groundwater (depth 200m) of Beimen 1. The highest ratio was observed in the less arsenic-enriched and less reduced groundwater (depth 60m) of Beimen 2B. DGGE profiles showed a shift in diversity of arsenite oxidizers, consisting of members of the Betaproteobacteria (61%), Alphaproteobacteria (28%) and Gammaproteobacteria (11%), depending on mainly arsenic concentration and redox level in groundwater. Groundwater with the lowest arsenic and highest dissolved oxygen at Beimen 2B harbored 78% of the arsenite oxidizers communities, while groundwater with the highest arsenic and lowest dissolved oxygen at Beimen 1 and Beimen-Jinhu harbored 17 and 22% of arsenite oxidizers communities, respectively. Pseudomonas sp. was found only in groundwater containing high arsenic at Beimen 1 and Beimen-Jinhu, while arsenite oxidizers belonging to Alpha- and Betaproteobacteria were dominated in groundwater containing low arsenic
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