20,399 research outputs found
Composition of primary cosmic rays near the knee
The size dependence of high energy muons and the size spectrum obtained in the air shower experiment suggest that the mean mass of cosmic rays remains nearly constant at approx 15 up to 5 x 1000,000 GeV and becomes one beyond. The composition model in which nuclei are removed spectrum steepens at 6.7 x 10 power GeV due to leakage from the galaxy, which explains the data which are consistent with data from other experiments
Understanding of the phase transformation from fullerite to amorphous carbon at the microscopic level
We have studied the shock-induced phase transition from fullerite to a dense
amorphous carbon phase by tight-binding molecular dynamics. For increasing
hydrostatic pressures P, the C60-cages are found to polymerise at P<10 GPa, to
break at P~40 GPa and to slowly collapse further at P>60 GPa. By contrast, in
the presence of additional shear stresses, the cages are destroyed at much
lower pressures (P<30 GPa). We explain this fact in terms of a continuum model,
the snap-through instability of a spherical shell. Surprisingly, the relaxed
high-density structures display no intermediate-range order.Comment: 5 pages, 3 figure
High-Yielding Multicut Coriander Variety, Arka Isha
Coriander (Coriandrum sativum L.) is one of the important leafy vegetables having a pleasant aroma. Very little research work has been done on improvement of leafy coriander and only a few local varieties, low-yielding and with low aroma, are available in the market. Research work at Indian Institute of Horticultural Research has resulted in development of a leafy coriander variety, Arka Isha, with a high yield potential and good aroma. It is a multicut variety where the plants are bushy, leaves are broad and leaf lobes are short, and the variety is late flowering. Yield is 3.74t ha-1 by pulling at 40 days after sowing, and 11.98t ha-1 by cutting. Leaves have 167.05mg 100g-1 of Vitamin C, with good aroma and keeping-quality
Vegetative propagation of Eucalyptus species through polyglobule
Macro-propagation of Eucalypyus species is possible on large scale through relatively cheaper technique with polyglobule than automatic and low cost chambers. Further it also gives an added advantage in controlling diseases and their spread as it is confined to the specific polyglobule. The spread of the humidity and temperature in the polyglobule are uniform unlike other large mist chambers
The eigenspectra of Indian musical drums
In a family of drums used in the Indian subcontinent, the circular drum head
is made of material of non-uniform density. Remarkably, and in contrast to a
circular membrane of uniform density, the low eigenmodes of the non-uniform
membrane are harmonic. In this work we model the drum head by a non-uniform
membrane whose density varies smoothly between two prescribed values. Using a
Fourier-Chebyshev spectral collocation method we obtain the eigenmodes and
eigenvalues of the drum head. For a suitable choice of parameters, which we
find by optimising a cost function, the eigenspectra obtained from our model
are in excellent agreement with experimental values. Our model and the
numerical method should find application in numerical sound synthesis
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