Environmental Control Measures in Sponge Iron Industry with Particualr Reference to Tata Sponge Iron Limited

Direct reduced iron or sponge iron technology was developed as an alternate route for steel making and is considered as a clean technology. The waste generation and gas emissi-ons from this route of steel making are far less when comp-ared to the conventional blast furnace route. The paper details the efforts of Tata Sponge Iron Limited to make the process a clean technology without affecting its surroundings and natural resources

A Wave-function for Stringy Universes

We define a wave-function for string theory cosmological backgrounds. We give a prescription for computing its norm following an earlier analysis within general relativity. Under Euclidean continuation, the cosmologies we discuss in this paper are described in terms of compact parafermionic worldsheet systems. To define the wave-function we provide a T-fold description of the parafermionic conformal field theory, and of the corresponding string cosmology. In specific examples, we compute the norm of the wave-function and comment on its behavior as a function of moduli.Comment: 30 pages, 3 figures, v3: references adde

Is Brane Inflation Eternal?

In this paper, we show that eternal inflation of the random walk type is generically absent in the brane inflationary scenario. Depending on how the brane inflationary universe originated, eternal inflation of the false vacuum type is still quite possible. Since the inflaton is the position of the D3-brane relative to the anti-D3-brane inside the compactified bulk with finite size, its value is bounded. In DBI inflation, the warped space also restricts the amplitude of the scalar fluctuation. These upper bounds impose strong constraints on the possibility of eternal inflation. We find that eternal inflation due to the random walk of the inflaton field is absent in both the KKLMMT slow roll scenario and the DBI scenario. A more careful analysis for the slow-roll case is also presented using the Langevin equation, which gives very similar results. We discuss possible ways to obtain eternal inflation of the random walk type in brane inflation. In the multi-throat brane inflationary scenario, the branes may be generated by quantum tunneling and roll out the throat. Eternal inflation of the false vacuum type inevitably happens in this scenario due to the tunneling process. Since these scenarios have different cosmological predictions, more data from the cosmic microwave background radiation will hopefully select the specific scenario our universe has gone through.Comment: 32 pages; v2: references and comments adde

Cosmic String Cusps with Small-Scale Structure: Their Forms and Gravitational Waveforms

We present a method for the introduction of small-scale structure into strings constructed from products of rotation matrices. We use this method to illustrate a range of possibilities for the shape of cusps that depends on the properties of the small-scale structure. We further argue that the presence of structure at cusps under most circumstances leads to the formation of loops at the size of the smallest scales. On the other hand we show that the gravitational waveform of a cusp remains generally unchanged; the primary effect of small-scale structure is to smooth out the sharp waveform emitted in the direction of cusp motion.Comment: RevTeX, 8 pages. Replaced with version accepted for publication by PR

Cosmological Landscape From Nothing: Some Like It Hot

We suggest a novel picture of the quantum Universe -- its creation is described by the {\em density matrix} defined by the Euclidean path integral. This yields an ensemble of universes -- a cosmological landscape -- in a mixed state which is shown to be dynamically more preferable than the pure quantum state of the Hartle-Hawking type. The latter is dynamically suppressed by the infinitely large positive action of its instanton, generated by the conformal anomaly of quantum fields within the cosmological bootstrap (the self-consistent back reaction of hot matter). This bootstrap suggests a solution to the problem of boundedness of the on-shell cosmological action and eliminates the infrared catastrophe of small cosmological constant in Euclidean quantum gravity. The cosmological landscape turns out to be limited to a bounded range of the cosmological constant $\Lambda_{\rm min}\leq \Lambda \leq \Lambda_{\rm max}$. The domain $\Lambda<\Lambda_{\rm min}$ is ruled out by the back reaction effect which we analyze by solving effective Euclidean equations of motion. The upper cutoff is enforced by the quantum effects of vacuum energy and the conformal anomaly mediated by a special ghost-avoidance renormalization of the effective action. They establish a new quantum scale $\Lambda_{\rm max}$ which is determined by the coefficient of the topological Gauss-Bonnet term in the conformal anomaly. This scale is realized as the upper bound -- the limiting point of an infinite sequence of garland-type instantons which constitute the full cosmological landscape. The dependence of the cosmological constant range on particle phenomenology suggests a possible dynamical selection mechanism for the landscape of string vacua.Comment: Final version, to appear in JCA

Non-resonant microwave absorption studies of superconducting MgB_2

Non-resonant microwave absorption(NRMA) studies of superconducting MgB_2 at a frequency of 9.43 GHz in the field range -50 Gauss to 5000 Gauss are reported. The NRMA results indicate near absence of intergranular weak links. A linear temperature dependence of the lower critical field H_c1 is observed indicating a non s-wave superconductivity. However, the phase reversal of the NRMA signal which could suggest d-wave symmetry is also not observed.Comment: 8 pages, 2 figure

Geodesic motion in the space-time of a cosmic string

We study the geodesic equation in the space-time of an Abelian-Higgs string and discuss the motion of massless and massive test particles. The geodesics can be classified according to the particles energy, angular momentum and linear momentum along the string axis. We observe that bound orbits of massive particles are only possible if the Higgs boson mass is smaller than the gauge boson mass, while massless particles always move on escape orbits. Moreover, neither massive nor massless particles can ever reach the string axis for non-vanishing angular momentum. We also discuss the dependence of light deflection by a cosmic string as well as the perihelion shift of bound orbits of massive particles on the ratio between Higgs and gauge boson mass and the ratio between symmetry breaking scale and Planck mass, respectively.Comment: 20 pages including 14 figures; v2: references added, discussion on null geodesics extended, numerical results adde

Arsenic hyperaccumulation efficiency depends on time and tissue in Pteris vittata

The metalloid arsenic is a toxic environmental pollutant. Arsenic pollution becomes serious due to mining, mineral, smelting and tannery industry. Leaching of naturally occurring arsenic into drinking water aquifers, has been reported in many countries including India and Bangladesh. Available engineering methods for remediation is costly and difficult. Many plant species reported to accumulate arsenic. Pteris vittata has been reported as arsenic hyperaccumulator. An Indian eco-type of P. vittata has been used to study the arsenic accumulation. The plants were grown in arsenic containing soil along with soil without arsenic (control). The ferns were separated into two portions, i.e., above ground (fronds), stage specific as well as tissues from different position of pinnae and below ground (roots and rhizomes). Futher, it was also harvested at different time interval. Dried fern samples (0.1 g) were digested with mixture of concentrated nitric acid and perchloric acid. Heavy metal measurement in foliar and root samples was performed with ICP-OES. Tissue specific arsenic accumulation indicates that juvenile leaf contains highest arsenic than mature leaf. Middle pinnae of mature leaf show high arsenic content compared to upper and lower pinnae. Among the underground parts of the plant, rhizome contains high arsenic than roots. Further, time dependent arsenic accumulation study indicates that active accumulation of arsenic starts from day 7 to day 30 in leaf tissue, while in roots, day 3 to 7 show sudden increase and no much drastic change in accumulation from day 7 onwards

Large Angle CMB Fluctuations from Cosmic Strings with a Comological Constant

In this paper, we present results for large-angle CMB anisotropies generated from high resolution simulations of cosmic string networks in a range of flat FRW universes with a cosmological constant. Using an ensemble of all-sky maps, we compare with the COBE data to infer a normalization (or upper bound) on the string linear energy density $\mu$. For a flat matter-dominated model ($\Omega_{M}=1$) we find $G\mu/c^2 \approx 0.7\times 10^{-6}$, which is lower than previous constraints probably because of the more accurate inclusion of string small-scale structure. For a cosmological constant within an observationally acceptable range, we find a relatively weak dependence with $G\mu/c^2$ less than 10% higher.Comment: 5 pages, 5 figures; replaced with version to appear in Physical Review

Character Association and Path Analysis for Yield, Iron Content and Component Traits in Indigenous Rice Germplasm

Not AvailableRice is one of the major staple foods which contribute the energy source of nutrition. As variation in micronutrients is a major problem affecting the health of people, so selection for indigenous rice germplasm with higher micronutrient for iron and zinc is need of the hour. For selection of characters, character association and direct and indirect contribution of characters play an important role. The present investigation was conducted taking 94 germplasms using augmented design. Observations were recorded on 12 quantitative and 3 quality characters from five randomly selected plants in each genotype. The characters like days to 50 % flowering, days to maturity, plant height (cm), number of tiller per plant, panicle length (cm), number of grains per panicle, 1000-grain weight (g) yield per plant (g), harvest index (%), grain length (mm) grain width (mm), grain L/B ratio, amylose content, gelatinization temperature and iron content in brown rice (ppm) were taken and analyzed for character association and path analysis studies. The characters like 1000-grain weight, harvest index, grain length and grain breadth shown significant association with yield while there was negative association of harvest index with iron content of brown rice. Direct and indirect contributions also supported the character association in same manner. So, selection of 1000-grain weight, grain length and grain breadth are important characters to select plants for improvement of iron content in brown rice as well as yield.Not Availabl