16,627 research outputs found

    Study of Broadside Linear Array Antenna with Different Spacing and Number of Elements

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    A uniform linear antenna array has all its elements placed along a straight line with same spacing between them. This paper presents the comparative study of the consequences of different spacing and number of elements in terms of array factor, antenna directivity and half power beam-width (HPBW) for Broadside array. The results were obtained through the antenna parameters algorithm and simulations were done with MATLAB. The algorithm has been designed to operate with random number of elements with specific spacing. Output was studied with 2, 10, 40, 70 and 100 numbers of elements having speciļ¬c spacing. The particular spacings are 0.1Ī», 0.25Ī», 0.5Ī» and 0.75Ī». With the increase of number of elements and spacing between them, the directivity and array factor increases

    Universal Scaling Property of System Approaching Equilibrium

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    In this Letter we show that the diffusion kinetics of kinetic energy among the atoms in non- equilibrium crystalline systems follows universal scaling relation and obey Levy-walk properties. This scaling relation is found to be valid for systems no matter how far they are driven out of equilibrium.Comment: 6 pages, 4 figure

    Empirical modelling and simulation of transmission loss between wireless sensor nodes in gas turbine engines

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    Transmission loss measurements between a grid of hypothetical WSN node locations on the surface of a gas turbine engine are reported for eight frequencies at 1 GHz intervals in the frequency range 3.0 to 11.0 GHz. An empirical transmission loss model is derived from the measurements. The model is incorporated into an existing system channel model implemented using Simulink as part of a wider project concerning the development of WSNs for the testing and condition monitoring of gas turbine engines

    Acceleration and Deceleration in Curvature Induced Phantom Model of the Late and Future Universe, Cosmic Collapse as Well as its Quantum Escape

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    Here, cosmology of the late and future universe is obtained from f(R)f(R)-gravity with non-linear curvature terms R2R^2 and R3R^3 (RR being the Ricci scalar curvature). It is different from f(R)f(R)-dark enrgy models, where non-linear curvature terms are taken as gravitational alternative of dark energy. In the present model, neither linear nor no-linear curvature terms are taken as dark energy. Rather, dark energy terms are induced by curvature terms in the Friedmann equation derived from f(R)f(R)-gravitational equations. It has advantage over f(R)f(R)- dark energy models in the sense that the present model satisfies WMAP results and expands as āˆ¼t2/3\sim t^{2/3} during matter-dominance. So, it does not have problems due to which f(R)f(R)-dark energy models are criticized. Curvature-induced dark energy, obtained here, mimics phantom. Different phases of this model, including acceleration and deceleration during phantom phase, are investigated here.It is found that expansion of the universe will stop at the age (3.87t0+694.4kyr)(3.87 t_0 + 694.4 {\rm kyr}) (t0t_0 being the present age of the universe) and after this epoch, it will contract and collapse by the time (336.87t0+694.4kyr)(336.87 t_0 + 694.4 {\rm kyr}). Further,it is shown that universe will escape predicted collapse (obtained using classical mechanics) on making quantum gravity corrections relevant near collapse time due to extremely high energy density and large curvature analogous to the state of very early universe. Interestingly, cosmological constant is also induced here, which is very small in classical domain, but very high in quantum domain.Comment: 33 page

    Anopheline fauna of parts of Tirap district, Arunachal Pradesh with reference to malaria transmission

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    In a survey on the anopheline fauna in highly malaria endemic areas of the Tirap district of Arunachal Pradesh, 7476 anophelines belonging to 17 species were collected, including seven species of anophelines which are recognized malaria vectors in India. Anopheles tessellatus and A. jamesii were recorded for the first time in this area. The parasitological survey revealed that the area was endemic for malaria particularly P. falciparum. the slide positivity rate and slide falciparum rate being 25.63 and 19.21 per cent respectively. On dissection of 10 anopheies species, malarial infection was detected in two viz., A. minimus and A. dirus
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