509 research outputs found
Design and Simulation of Blending Function for Landing Phase of a UAV
This paper aims to achieve the autonomous landing of unmanned air vehicle (UAV). Itmainly deals with glide path design, flare path design, design of blending function, andinterfacing the glide and flare paths with the blending function. During transition from glideslope to flare path, a UAV will tend to the unstable region. In a manned aircraft, the pilotcontrols the unstability that occurs during the change of phase from glide slope to flare, butwhich is impossible in UAV till now. A blending function has been formulated for use in a UAVto overcome this unstability during transition. This simulation is done with the Matlab Simulinkand the results are reported
Vibrational spectroscopic investigations, DFT computations, nonlinear optical and other molecular properties of 3-bromo-5-fluorobenzonitrile
The FTIR and FT-Raman spectra of 3-bromo-5-fluorobenzonitrile (BFBN) have been recorded in the regions 4000-400 cm-1 and 3500-400 cm-1, respectively. Utilizing the observed FT-Raman and FTIR data, a complete vibrational assignment and analysis of the fundamental modes of the compound have been carried out and subsequently confirmed by total energy distribution (TEDs). In the calculations performed to determine the optimum molecular geometry, harmonic vibrational frequencies, infrared intensities and Raman scattering activities, the density functional theory (DFT/B3LYP) method with 6-31+G(d,p) and 6-311++G(d,p) basis sets has been used. The results have been compared with the experimental values. The difference between the observed and scaled wavenumber values of most of the vibrational modes is very small. The NLO properties such as polarizability and first hyperpolarizability of the molecule have been calculated. The effects of frontier orbitals, HOMO and LUMO and the transition of electron density transfer have been discussed. The UV-Vis spectrum has been done which confirms the charge transfer of BFBN. The chemical interpretation of hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis
Synchronization transition in coupled time-delay electronic circuits with a threshthreshold non-linearity
Experimental observations of typical kinds of synchronization transitions are reported in unidirectionally coupled time-delay electronic circuits with a threshold nonlinearity and two time delays, namely feedback delay T1 and coupling delay T2. We have observed transitions from anticipatory to lag via complete synchronization and their inverse counterparts with excitatory and inhibitory couplings, respectively, as a function of the coupling delay T2. The anticipating and lag times depend on the difference between the feedback and the coupling delays. A single stability condition for all the different types of synchronization is found to be valid as the stability condition is independent of both the delays. Further, the existence of different kinds of synchronizations observed experimentally is corroborated by numerical simulations and from the changes in the Lyapunov exponents of the coupled time-delay systems
Enhancement of yield in nutmeg (Myristica fragrans Houtt.) through pruning
Enhancement of yield in nutmeg (Myristica fragrans Houtt.) through pruning
 
Painlev{\'e} singularity structure analysis of three component Gross-Pitaevskii type equations
In this paper, we have studied the integrability nature of a system of three
coupled Gross-Pitaevskii type nonlinear evolution equations arising in the
context of spinor Bose-Einstein condensates by applying the Painlev\'e
singularity structure analysis. We show that only for two sets of parametric
choices, corresponding to the known integrable cases, the system passes the
Painlev\'e test.Comment: 17 pages. Accepted in Journal of Mathematical Physic
Collision of Multimode Dromions and a Firewall in the Two Component Long Wave Short Wave Resonance Interaction Equation
In this paper, we investigate the two component long wave short wave
resonance interaction (2CLSRI) equation and show that it admits the Painleve
property. We then suitably exploit the recently developed truncated Painleve
approach to generate exponentially localized solutions for the short wave
components and while the long wave L admits line soliton
only. The exponentially localized solutions driving the short waves
and in the y direction are endowed with different energies
(intensities) and are called "multimode dromions". We also observe that the
multimode dromions suffer intramodal inelastic collision while the existence of
a firewall across the modes prevents the switching of energy between the modes.Comment: published in J. Phys. A: Math. Theor. 42, 10200
On the microstructure and tensile behaviour of nanostructured NiTi alloy produced by electroplastic rolling
Electroplastic rolling was employed to produce nanostructured (NS), near-equiatomic NiTi alloy from a coarse grained NiTi nugget (ingot), which was produced using vacuum induction melting, followed by quenching in water from a temperature of 800°C. The microstructure of NS NiTi was characterized using X-ray Diffraction (XRD) and transmission electron microscopy (TEM). XRD analysis revealed that the NS NiTi is predominantly martensitic at room temperature, with less than ≈10 % of the austenite phase. The NS NiTi alloy has an average grain size of ≈36 nm. TEM investigation confirmed the presence of grains that are less than 10 nm in size and no amorphous zones were detected. The NS martensitic NiTi alloy specimens were tested in tension at two different strain rates (10−2 and 10−1 s−1). In contrast to a stress-strain profile expected in a martensitic NiTi alloy, the stress-strain curves show conventional tensile behaviour. The observed UTS was high, around ≈1800 MPa, with a less than usual elongation to failure of ≈6 %. The presence of dimples on the fracture surfaces can be seen in scanning electron microscopy (SEM) images, which is indicative of ductile fracture. The role of grain size in the observed deformation and fracture features is also discussed
Design and Evaluation of Portable Manually Operated Spawn Spreading Machine for Oyster Mushroom (Pleurotus florida) Cultivation
Oyster mushroom (Pleurotus florida) is gaining demand owing to its benefits and taste. But, the prevailing manual method of cultivation is compromised with limited spawn spreading capacity and high chance of contamination which could be overcome by use of a spawn spreading machine. Currently no such machine is available which has prompted us to develop the same. The benefaction of the developed machine to the farmers is lightweight, portable, autoclavable, affordable, uncomplicated design, unskilled person can operate and minimize contamination chance that leads to increase in yield of mushroom. It constitutes the main frame, truncated conical hopper and ball valve metering mechanism. The machine evaluated in the lab shown that a highest spawn spreading capacity of 288 bags/h as compared to manual spreading operation of 110 bags/h for rice straw substrate at spawning rate of 50 g. In this context, the result clearly indicate that, the spawn spreading machine is very cost effective, save time and reduce labour requirement as compared to manual operation
Geometric effects on T-breaking in p+ip and d+id superconductors
Superconducting order parameters that change phase around the Fermi surface
modify Josephson tunneling behavior, as in the phase-sensitive measurements
that confirmed order in the cuprates. This paper studies Josephson coupling
when the individual grains break time-reversal symmetry; the specific cases
considered are and , which may appear in SrRuO and
NaCoO(HO) respectively. -breaking order parameters
lead to frustrating phases when not all grains have the same sign of
time-reversal symmetry breaking, and the effects of these frustrating phases
depend sensitively on geometry for 2D arrays of coupled grains. These systems
can show perfect superconducting order with or without macroscopic
-breaking. The honeycomb lattice of superconducting grains has a
superconducting phase with no spontaneous breaking of but instead power-law
correlations. The superconducting transition in this case is driven by binding
of fractional vortices, and the zero-temperature criticality realizes a
generalization of Baxter's three-color model.Comment: 8 page
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