4,411 research outputs found

    (Anti-)chiral Superfield Approach to Nilpotent Symmetries: Self-Dual Chiral Bosonic Theory

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    We exploit the beauty and strength of the symmetry invariant restrictions on the (anti-)chiral superfields to derive the Becchi-Rouet-Stora-Tyutin (BRST), anti-BRST and (anti-)co-BRST symmetry transformations in the case of a two (1+1)-dimensional (2D) self-dual chiral bosonic field theory within the framework of augmented (anti-)chiral superfield formalism. Our 2D ordinary theory is generalized onto a (2, 2)-dimensional supermanifold which is parameterized by the superspace variable Z^M = (x^\mu, \theta, \bar\theta) where x^\mu (with \mu = 0, 1) are the ordinary 2D bosonic coordinates and (\theta,\, \bar\theta) are a pair of Grassmannian variables with their standard relationships: \theta^2 = {\bar\theta}^2 =0, \theta\,\bar\theta + \bar\theta\theta = 0. We impose the (anti-)BRST and (anti-)co-BRST invariant restrictions on the (anti-)chiral superfields (defined on the (anti-)chiral (2, 1)-dimensional super-submanifolds of the above general (2, 2)-dimensional supermanifold) to derive the above nilpotent symmetries. We do not exploit the mathematical strength of the (dual-)horizontality conditions anywhere in our present investigation. We also discuss the properties of nilpotency, absolute anticommutativity and (anti-)BRST and (anti-)co-BRST symmetry invariance of the Lagrangian density within the framework of our augmented (anti-)chiral superfield formalism. Our observation of the absolute anticommutativity property is a completely novel result in view of the fact that we have considered only the (anti-)chiral superfields in our present endeavor.Comment: LaTeX file, 20 pages, journal reference is give

    Manpower information

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    A description of the NAL nominal roll database (listing basic information about NAL employees) created using the Ingres relational database software. Using this database it is possible to provide a wide variety of reports about NAL staff, respond to a wide assortment of queries and undertake elementary statistical analysis to tabulate (and pictorially depict) the average age of NAL scientists, the future retirement pattern of NAL employees etc

    Thermodynamics of Massless Free Bosonic Higher Spin Fields

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    We have calculated the thermal partition function for the thermodynamical system of massless free bosonic higher spin fields (Fronsdal theory) by using Feynman path integral formalism. However, we have established a connection between the microscopic world (Quantum statistical) of the thermodynamical system of massless free bosonic HS fields to the thermodynamics of the macroscopic world its and also we have observed the duality between the thermodynamical system of massless free HS fields on dd-dimensional Minkowski spacetime and thermodynamical system of Klein-Gordon scalar fields on 4-dimensional Minkowski spacetime at the thermal equilibrium condition. The average energy of the canonical ensemble of the thermodynamical system of massless free bosonic HS fields is not in agreement with the equipartition theorem, hence it deviates from the classical behaviour of the system and it shows that the true signature of the quantum thermodynamical system.Comment: 7 pages, added one referenc

    Data-efficient Neuroevolution with Kernel-Based Surrogate Models

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    Surrogate-assistance approaches have long been used in computationally expensive domains to improve the data-efficiency of optimization algorithms. Neuroevolution, however, has so far resisted the application of these techniques because it requires the surrogate model to make fitness predictions based on variable topologies, instead of a vector of parameters. Our main insight is that we can sidestep this problem by using kernel-based surrogate models, which require only the definition of a distance measure between individuals. Our second insight is that the well-established Neuroevolution of Augmenting Topologies (NEAT) algorithm provides a computationally efficient distance measure between dissimilar networks in the form of "compatibility distance", initially designed to maintain topological diversity. Combining these two ideas, we introduce a surrogate-assisted neuroevolution algorithm that combines NEAT and a surrogate model built using a compatibility distance kernel. We demonstrate the data-efficiency of this new algorithm on the low dimensional cart-pole swing-up problem, as well as the higher dimensional half-cheetah running task. In both tasks the surrogate-assisted variant achieves the same or better results with several times fewer function evaluations as the original NEAT.Comment: In GECCO 201

    Application of Electro kinetic technique to remediate fly ash for its sustainable use

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    Fly ash is a by-product of coal combustion in thermal power plants which is classified as hazardous waste and a serious threat to environment. The study was conducted to determine the potential and examine the efficacy of electro kinetic technique (EKT) using variables like pH, total dissolved solids (TDS), e concentration of chlorides (Cl-), sodium (Na+),magnesium (Mg2+), potassium (K+), ammonia (NH3+) and calcium (Ca2+) on fly ash as a low-cost treatment for enhancing the use of fly ash in a more sustainable manner. The probability of removing heavy metals and chlorides from fly ash suspended in water using electro dialysis was studied as they are highly dependent on pH and conductivity of the fly ash. The voltage gradient and duration indicated significant effect in the change of pH values showing a range from 4.6 to 7.7 at cathode and anode respectively, while the Total dissolves solids (TDS) varying from 72.33±5.6 to 146±5.4 showed the enhanced availability of ions post electro dialysis. In terms of chlorides, Cl- the content was observed to be 265.06 mg/l which was high enough to cause corrosion problems in later stages of reuse of fly ash. The concentration of cations like Na+, K+, NH3+, Mg2+, Ca2+ were observed to be notably influenced by the duration of study and pH in electro dialysis. The experimental results of the study showed that the proposed technique based on the fundamentals of electro kinetics and dialysis could efficiently improve the remediation process which would remove metals by converting them to available form in fly ash

    Quality assessment of compost from Centralized windrow composter (CWC) and Source segregate automatic vessel composter (AVC) at Hyderabad city in India

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     Out of the millions of tons of Municipal Solid Waste (MSW) generated annually in India, only about 75-80% of the waste gets collected and out of this, only 22- 28% is processed and treated, and the remaining is deposited indiscriminately at dump yards. Hyderabad city generates around 5500MT of waste every day. And only 20% of the waste is used for composting using the windrow composting process. MSW composting is a rapidly growing method of solid waste management in Hyderabad and In-Vessel composting is the recent initiative by the Govt. of India to reduce the organic solid waste generated at the source. The present study was aimed to assess the degree of accumulation and contamination of the heavy metals in composts from Centralised Windrow Composter (CWC) and Source Segregated Accelerated Vessel Composter (AVC). Compost Samples from CWC and AVC were analysed for metals concentration using Energy Dispersive X-ray Fluorescence Spectrometers (ED-XRF). CWC samples were found with slightly high concentrations of heavy metals like Zinc (0.51 – 0.66%), Copper (0.36 – 0.45%), Nickel 0.03 – 0.05%), Iron (11.46 – 13.27%), and chromium (0.06 – 0.14%) compared to AVC. AVC samples contained high concentrations of Calcium (14.99 – 64.19%), Potassium (9.13 – 29.59%) and Phosphorous (1.55 – 3.43%) when compared to CWC. The current study does a comparative analysis on the process and nutrients available to assess the quality of the compost from both sources. Considering the above findings source segregated AVC seems to be a better composter than centralised CWC, as the concentrations of Ca, K, and P required by the plant were abundant in AVC. Also, considering the process aspect, there is always scope for cross-contamination if the waste is separated after treatment which is the case in CWC