1,258 research outputs found

    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

    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

    Off-Diagonal Long Range Order and Scaling in a Disordered Quantum Hall System

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    We have numerically studied the bosonic off-diagonal long range order, introduced by Read to describe the ordering in ideal quantum Hall states, for noninteracting electrons in random potentials confined to the lowest Landau level. We find that it also describes the ordering in disordered quantum Hall states: the proposed order parameter vanishes in the disordered (σxy=0\sigma_{xy}=0) phase and increases continuously from zero in the ordered (σxy=e2/h\sigma_{xy}=e^2/h) phase. We study the scaling of the order parameter and find that it is consistent with that of the one-electron Green's function.Comment: 10 pages and 4 figures, Revtex v3.0, UIUC preprint P-94-03-02

    Exotic Quantum Order in Low-Dimensional Systems

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    Strongly correlated quantum systems in low dimensions often exhibit novel quantum ordering. This ordering is sometimes hidden and can be revealed only by examining new `dual' types of correlations. Such ordering leads to novel collective modes and fractional quantum numbers. Examples will be presented from quantum spin chains and the quantum Hall effect.Comment: To appear in Solid State Communications, Proceedings of Symposium on the Advancing Frontiers in Condensed Matter Science. 12pages +6 PS figure
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