149 research outputs found

    Comparative Study of Various Metals in the Sewage Samples of Three Major Drains of the City-Patna, Bihar, India

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    Untreated sewage is a major water pollutant and widely used for irrigation in the agricultural fields of district Patna, Bihar, India. When sewage, containing heavy metals, irrigated into the agricultural fields, it enters into the human food chain by the process of bioaccumulation and biomagnification. In view of the above fact, the present study was conducted to determine the level of metals in the sewage samples of three major drains namely Mandiri, Rajapur and Pahari situated in the city Patna, Bihar, India, during March 2010 to February 2011. In comparison with other two drains, the metals were found in higher amount in the sewage of Pahari drain throughout the year

    Anomalies at finite density and chiral fermions

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    Using perturbation theory in the Euclidean (imaginary time) formalism as well as the non-perturbative Fujikawa method, we verify that the chiral anomaly equation remains unaffected in the presence of nonzero chemical potential, μ\mu. We extend our considerations to fermions with exact chiral symmetry on the lattice and discuss the consequences for the recent Bloch-Wettig proposal for the Dirac operator at finite chemical potential. We propose a new simpler method of incorporating μ\mu and compare it with the Bloch-Wettig idea.Comment: 12 pages, 3 figures,some typos corrected, a better proof for the \mu independence of anomaly is given in section IIB, v4: the published versio

    Critical review on arsenic: Its occurrence, contamination and remediation from water and soil

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    With the increasing pollution in today’s world, importance is being given to solve a problem and do it in a sustainable, eco-friendly manner. Arsenic is a class-1 carcinogen and also causes many other side effects to humans, plants and animals. The utilization of arsenic as wood preservatives, pesticides, or its historical overuse by some military units for rice killing operations has led to the increase in the toxic effects of arsenic like its carcinogenicity, decreased immune response etc. Although conventional methods like coagulation, lime softening, adsorption, membrane technology are effective, they have their disadvantages like additional waste generation, causing increased pollution and are expensive. The better alternative is phytoremediation. Appropriate plants like Brassica juncea, Hydrilla verticilata, Pteris vittata L., Vallisneria natans,  can be chosen based on the method of the remediation like phytoextraction, phytostabilization and phytofiltration or phytovoltalization. This review provides the list of a few plants which can be likely chosen for the purpose of both water and soil remediation. Advancements are occurring in bioremediation studies with the development of transgenic plants like transgenic tobacco, transgenic Arabidopsis thaliana for better phytoremediation.  Understanding the mechanism employed by the plant for its uptake/detoxification can aid in the enhancement of the process of remediation with the external supply of phosphorus. Along with this, the proper and safe disposal of plants is crucial for the remediation process. In addition, awareness of this solution to the general public is to be made for its effectiveness

    Phosphorus: A Boon or Curse for the Environment?

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    Phosphorus, a limiting nutrient of biosphere, exists as dissolved inorganic phosphorus (DIP), dissolved organic phosphorus (DOP), particulate inorganic phosphorus (PIP) and particulate organic phosphorus (POP) in water of soil as well as ponds, lakes, etc. The only available phosphorus for plants are DIP, while the other forms need to be converted to DIP by the decomposing microorganisms of the soil. The heavy metals (such as arsenic and chromium), which are the menace of both terrestrial and aquatic environment, are taken up by the plants and animals causing toxicity at physiological level. However, the metal (Cr and As) toxicity can be mitigated competitively by phosphorus, since the latter is a structural analogue. Since, phosphorus is an essential nutrient, plants prefer it over Cr or As. At the same time, if excess of phosphorus is applied in the soil in the form of fertilisers, it gets discharged into the water bodies (ponds, lakes, etc.) through agricultural runoff, causing eutrophication followed by harming the health of the water bodies. This can be further mitigated by employing the phenomenon of luxury uptake by the aquatic plants such as Pistia stratiotes

    Limnological studies on Different Ponds of Bihar, India: a Review

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    Pure water is essential for human survival. The availability of good quality water is an indispensable feature for preventing diseases and improving the quality of life. So, it is necessary to know about the different physicochemical parameters of water such as, temperature, electrical conductivity (EC), total suspended solid (TSS), total dissolved substance (TDS),turbidity, pH, alkalinity, hardness, chloride, sulphate, nitrate, fluoride, dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), nitrate and phosphate. Also Biological parameters such as planktons were examined. Results of the study indicated that the pond water of Bihar is slightly contaminated

    Towards QCD thermodynamics using exact chiral symmetry on lattice

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    The thermodynamics of massless ideal gas of overlap quarks has been investigated numerically for both zero and nonzero baryon chemical potential μ\mu. While the parameter M has been shown to be irrelevant in the continuum limit, it is shown numerically that the continuum limit can be reached with relatively coarser lattices for certain range of M. Numerical limitation of the existing method of introduction of chemical potential in the overlap formalism is discussed. We have also studied the energy density of free domain wall fermions in the absence of μ\mu and estimated the extent of lattice in the fifth dimension L5L_5 for which the overlap results are recovered. Interestingly, this value of L5L_5 is also minimum for the same range of M found in the overlap case.Comment: 5 pages, 4 figures, to appear in the proceedings of the 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions: Quark Matter 2008 (QM2008

    A primary study on the degradation of low-density polyethylene treated with select oxidizing agents and starch

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    Polyethylene has become an integral part of our contemporary lives. The neoteric versatile nature of polyethylene is used in constructing various applications. Out of the plastic waste discarded, 60% of the plastic waste enters landfills. The polyethylene discarded in the soil and water on exposure to the environment forms macroplastics (>2.5 cm), mesoplastics (5 mm - 2.5 cm) and microplastics (<5 mm). Microplastics in the water and soil are observed to have lethal and ecotoxicological effects on aquatic and terrestrial organisms. They enter the food chain and permeate into the food that one eats. In order to address this impending concern, the present study aimed to treat plastics to form a degradable, safe and earthy material. The dissolved polyethylene was treated with starch and was made to react with oxidizing agents such as hydrogen peroxide, nitric acid and acetic acid to lower its inert ability to withstand its degradation. The effect of starch and oxidizing agents on dissolved low density polyethylene was subsequently analysed. The analysis of treated polyethylene showed a decrease in its crystallinity percentage by 6.19 and an increase in its functional groups on reaction with solvent trichloroethylene made to react with starch and oxidizing agents. In the present research, tests were conducted to obtain the various methods that can be utilized to reverse the inert ability of polyethylene. The prevailing recycling model that uses antioxidation techniques is counterproductive since it was found that such techniques appeared to make the polyethylene more resistant to further degradation. In this study, the polyethylene was dissolved in the solvents, such as xylene and trichloroethylene, to make the polyethylene more susceptible to reactants and hence a viable model for treating polyethylene

    Generation of entangled channels for perfect teleportation channels using multi-electron quantum dots

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    In this work we have proposed a scheme for generating NN qubit entangled states which can teleport an unknown state perfectly. By switching on the exchange interaction (JJ) between the qubits one can get the desired states periodically. A multi electron quantum dot can be a possible realization for generating such NN qubit states with high fidelity. In the limit of NN \to \infty, there exists a unique time t=1Jcos1(1/8)t=\frac{1}{J}\cos^{-1}(-1/8) where the Hamiltonian dynamics gives the NN qubit state that can assist perfect teleportation. We have also discussed the effect of the nuclear spin environment on the fidelity of teleportation for a general NN qubit entangled channel.Comment: 6 pages, 3 figure

    Comparative study of phytoremediation of chromium contaminated soil by Amaranthus viridis in the presence of different chelating agents

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    Chromium is a harmful heavy metal to the environment due to the toxicity induced by it to plants and other living organisms. High concentration of Cr in soil poses severe toxicological problems ecosystem. Phytoremediation using different plants is an economical and environment-friendly method for removing Cr from soil. The addition of chelating agents augments the phytoextraction using plants.The present study aimed to augment the Cr phytoremediation capacity of Amaranthus virdis, a predominant plant species in the Cr-contaminated open dumpsites of Bangalore. . Phytoextraction of Cr by Amaranthus viridis was studied in the presence of different chelating agents viz. ethylenediaminetetraacetic acid (EDTA), citric acid (CA), growth promoting hormone- indoleacetic acid (IAA) and NPK fertiliser. A. viridis grown under different concentrations (5, 10 and 20 mg/Kg) of Cr were treated with 0.5g EDTA/Kg of soil, 0.5g CA/Kg of soil, 1mg IAA/Kg of soil and NPK (125 mg of nitrogen, 45 mg of phosphorous and 156 mg of potassium per Kg of soil). Results indicated that CA, at 10 mg/kg Cr supply, induced the highest uptake (up to 29.25 µg/plant). Furthermore, the study revealed that CA amendment induced maximum Cr uptake in A. viridis at all levels of Cr supply as compared to other amendments. This was due to the increased solubility of Cr in the presence of citric acid and the amelioration of oxidative stress due to Cr to plants by citric acid. This study inferred that the non-hyperaccumulating plant, A. virdis could be used as a phytoremediator for Cr in the presence of citric acid in the places where it is grown abundantly.   

    Effect of nickel uptake on selected growth parameters of Amaranthus viridis L.

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    Nickel is an essential element for normal physiological functions in plants. At higher doses (>50 mg/kg, as per WHO) it is toxic to plants and humans, which can bring about oxidative stress affecting the physiological functions of plants and is also considered carcinogenic to human beings. To manage nickel pollution in environment, proper chemical or phytoremediation techniques are required. In this regard nickel accumulator plants would offer a cost effective and environmental friendly phytoremediation method. In the present study, the nickel phyto-accumulation potential of Amaranthus viridis from soil was evaluated to check the tolerance level and the impact on selected morphological parameters like total biomass, plant height, root length and number of leaves. Nickel uptake by A. viridis was studied from Ni contaminated soil amended with20, 40, 60, 80 mg/Kg of Ni exposure under controlled conditions. Toxic effects and tolerance of the plant to toxic doses of nickel was evaluated by correlating the uptake per gram of biomass with various parameters of plant like its height, biomass, root length and, number of leaves.  Supply dependent maximum nickel uptake of 108 µg/gm and corresponding decrease in growth parameters were recorded up to 60 mg/Kg exposure. This study indicates the uptake of nickel by A. viridis increases with increase in supply up to 60mg/kg and beyond 60 mg/kg, the uptake decreases. The study also shows uptake of nickel per gram of biomass has a significant  negative correlation mainly with parameters like plant height (R= -0.71 at 0.05 level of significance) and total biomass (R = -0.83 at 0.05 level of significance) where as other parameters like length of root and number of leavers are not significantly affected (P>0.05) with uptake of nickel per gram of biomass
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