1,527 research outputs found

    Suppressing Curvature Fluctuations in Dynamical Triangulations

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    We study numerically the dynamical triangulation formulation of two-dimensional quantum gravity using a restricted class of triangulation, so-called minimal triangulations, in which only vertices of coordination number 5, 6, and 7 are allowed. A real-space RG analysis shows that for pure gravity (central charge c = 0) this restriction does not affect the critical behavior of the model. Furthermore, we show that the critical behavior of an Ising model coupled to minimal dynamical triangulations (c = 1/2) is still governed by the KPZ-exponents.Comment: Talk presented at LATTICE96(gravity), 3 pages, LaTeX, espcrc2.sty, 1 figur

    Blocking of Dynamical Triangulations with Matter

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    We use the recently proposed node decimation algorithm for blocking dynamical geometries to investigate a class of models, with central charge greater than unity, coupled to 2D gravity. We demonstrate that the blocking preserves the fractal structure of the surfaces.Comment: Talk presented at LATTICE96(gravity), 3 pages, LaTeX, espcrc2.st

    Excitation sources of oscillations in solar coronal loops : a multi-wavelength analysis

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    An investigation into the excitation sources of oscillations detected in a coronal loop structure is carried out using the images obtained with Interface Region Imaging Spectrometer (IRIS) and the Atmospheric Imaging Assembly (AIA) instrument on board the Solar Dynamics Observatory (SDO). A loop structure in the active region AR 11967 on 2014 January 28, oscillating in the vicinity of a strong eruption and an M3.6 class flare site, is clearly noticeable in SDO/AIA 171 Å images. We study in detail, the oscillations with detected periods between 4 and 13 minutes and their connection in IRIS SJI 1330 Å and SDO/AIA 1700 Å images; both of these wavelengths sample the lower parts of the solar atmosphere. The simultaneous presence of many oscillations in the region of interest in all three wavelength passbands suggest that these oscillations were excited in the lower-chromosphere–photosphere plasma connected to the loop structure and then propagated at higher heights. We further investigate the Doppler velocity measurements from the spectrograph snapshots in IRIS C II 1336 Å, Si IV 1403 Å and Mg II k 2796 Å. These show signatures of upflows in the vicinity of the loop structure’s endpoints estimated from 171 Å images. We suggest that some of the oscillations observed in AIA 171 Å have been triggered by plasma ejections and perturbations seen in the lower layers of the solar atmosphere. Based on the estimated phase speeds, the oscillations are likely to be slow magnetoacoustic in nature

    Genetic modifications of horticultural plants by induced mutations and transgenic approach

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    Climate change has pressed the need to develop improved horticultural crop cultivars capable of tolerating extreme environmental conditions besides sustaining yield and quality. Induced mutations provide a viable option for the generation of a novel genetic variation. In horticultural crops, more than 800 mutant cultivars have so far been developed, and a majority of them are ornamentals followed by vegetables, fruits, decorative trees, berries, nuts, ornamentals and other plants. Transgenic technology has also led to the improvement of horticultural crops for plant type, fruit-shelf life, floral and quality assets besides resistance to biotic and abiotic stresses. Mutagenesis techniques have been integrated with in vitro culture and other molecular biology technologies, such as molecular markers and high-throughput mutation screening, thereby becoming more powerful and effective in crop breeding.Peer reviewe

    Magnetoroton instabilities and static susceptibilities in higher Landau levels

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    We present analytical results concerning the magneto-roton instability in higher Landau levels evaluated in the single mode approximation. The roton gap appears at a finite wave vector, which is approximately independent of the LL index n, in agreement with numerical calculations in the composite-fermion picture. However, a large maximum in the static susceptibility indicates a charge density modulation with wave vectors q0(n)1/2n+1q_0(n)\sim 1/\sqrt{2n+1}, as expected from Hartree-Fock predictions. We thus obtain a unified description of the leading charge instabilities in all LLs.Comment: 4 pages, 5 figure

    Effects of physiological doses of vitamin D sub(3) (Cholecalciferol) on induced molting and growth in giant freshwater prawn, Macrobrachium rosenbergii (de Man)

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    Effects of three different doses of vitamin D sub(3) on molting, growth, and calcium and phosphate composition of tissue and molt during the grow-out of the giant freshwater prawn Macrobrachium rosenbergii (average weight 10.56 ± 0.20 g), obtained from a grow-out pond, were studied. Intramuscular doses of vitamin D sub(3) (100, 500 and 2000 IU/kg body weight) were given on the 1st, 3rd, 5th, 7th, 9th, 11th, 13th, 15th, 20th, 25th and 30th days. All the experimental animals were fed with a basal diet containing fish meal, shrimp meal, wheat flour, groundnut de-oiled cake, soybean meal and wheat bran at 3% of the body weight. The numbers of molts were recorded as 20±0.50, 29±1.16, 51±1.87, and 30±1.60 in control, 100, 500 and 2000 IU/kg body weight physiological doses, respectively. Maximum growth was recorded in prawns given 500 IU/ kg dose. Survival was between 58.33 ± 9.13 and 77.77 ± 8.61%. The ash content and calcium level increased significantly (p0.05) in both tissue and molt at 500 and 2000 IU/kg doses. It was found that a higher physiological dose (2000 IU/kg) of vitamin D sub(3) increased the rate of mortality. Results have shown that vitamin D sub(3) has a positive impact on the growth and survival of M. rosenbergii and it interferes with the metabolism of Ca and P sub(i), in tissue, and alters molting frequency. Results on physiological dose suggest an alternative and effective dietary supplementation method of vitamin D sub(3) in the grow-out phase of M. rosenbergii

    Performance Investigation of Nylon-Kevlar Ringslot Parachute

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    Kevlar material is being used in parachute systems require high strength-to-weight ratios or becoming resistance to sustain high temperatures. However, Nylon-Kevlar parachutes are popular these days and are first preference of the parachute designers specially for recovery system of reentry vehicles. Tests of using Kevlar suspension lines, radials, vent and skirt re-enforcements, risers demonstrated that the Kevlar material can be used successfully in Ringslot parachute. The opening shock experienced by the parachute does not differ from all-Nylon parachutes. The parachute is much lighter and capable of withstanding higher load and therefore can be used for extraction or deceleration in recovery system of reentry vehicles. The design and performance of a hybrid Ringslot was investigated experimentally in sled test. The experimental method and performance data are described in this paper.Defence Science Journal, Vol. 64, No. 4, July 2014, pp. 406-410, DOI:http://dx.doi.org/10.14429/dsj.64.4950

    Unified description of floppy and rigid rotating Wigner molecules formed in quantum dots

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    Restoration of broken circular symmetry is used to explore the characteristics of the ground states and the excitation spectra of rotating Wigner molecules (RWM's) formed in two-dimensional parabolic N-electron quantum dots. In high magnetic fields, the RWM's are floppy rotors with the energies of the magic angular momentum (L) states obeying aL + b/L^{1/2}. Under such fields the ground-state energies (referenced to the kinetic energy in the lowest Landau level) approach the electrostatic energy of N point charges in the classical equilibrium molecular configuration. At zero field and strong interelectron repulsion, the RWM's behave like quasiclassical rigid rotors whose energies vary as L^2. The particular L-dependence in high B is inherent and natural to a floppy rotating WM, and it can be used as a crucial diagnostic tool for resolving the recently posed question whether the composite-fermion or the RWM picture is appropriate for QD's.Comment: 5 pages. Revtex4 with 3 EPS figures and 2 tables . For related papers, see http://www.prism.gatech.edu/~ph274c

    Invariance of Charge of Laughlin Quasiparticles

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    A Quantum Antidot electrometer has been used in the first direct observation of the fractionally quantized electric charge. In this paper we report experiments performed on the integer i = 1, 2 and fractional f = 1/3 quantum Hall plateaus extending over a filling factor range of at least 27%. We find the charge of the Laughlin quasiparticles to be invariantly e/3, with standard deviation of 1.2% and absolute accuracy of 4%, independent of filling, tunneling current, and temperature.Comment: 4 pages, 5 fig

    Safety considerations for hydrometallurgical metal recovery from lithium‐ion batteries

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    This paper presents a comprehensive overview of the critical process safety considerations inherent in hydrometallurgical metal recovery within the lithium-ion battery (LiB) recycling process. As hydrometallurgy application in LiB recycling is still in the early stages of development, it is crucial to identify the hazards and provide safety recommendations. Hazards related to hydrometallurgy are identified and categorized in process, toxic, fire, explosion, corrosion, environment, storage, and transport hazards. Risk reduction measures are suggested using the hierarchy of control methodology to eliminate and reduce risks to as low as reasonably practicable (ALARP), based on UK regulatory framework
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