A Comparative study of controllers for stabilizing a Rotary Inverted Pendulum

<p>This paper describes comparative study of various controllers on Rotary Inverted Pendulum (RIP). PID, LQR, FUZZY LOGIC and H∞ controllers are tried on RIP in MatLab Simulink. The same four controllers have been tested on test bed of RIP system the controllers are compared from various aspects. The controllers in simulink are compared with the controllers in real time.</p

Luminescence properties of K1/2Bi1/2TiO3:Pr3+ and Na1/2Bi1/2TiO3:Pr3+

International audienceThe luminescence properties of K1/2Bi1/2TiO3:Pr3+ and Na1/2Bi1/2TiO3:Pr3+ powders are investigated in the temperature range 10-600 K. The experimental data are interpreted on the basis of metal-to-metal charge transfer processes and by considering Bi3+-to-Pr3+ sensitization effects

Preparation, characterization and conductivity studies of NaAlSb(PO₄)₃ and HAlSb(PO₄)₃

347-354NaAlSb(PO4)3 and HAlSb(PO4)3 are prepared by solid-state and metathesis reactions respectively. They are characterized by powder XRD, IR and solid-state 31P-MAS NMR spectroscopy. These two compounds crystallize in the hexagonal NASICON structure with the space group of RC. Their infrared spectra exhibit characteristic vibrational bands of PO4 tetrahedra. The 31P-MAS NMR spectra of NaAlSb(PO4)3 and HAlSb(PO4)3 are characterized by a symmetric single peak around 9 ppm suggesting only one type of phosphorous in the hexagonal lattice. The activation energies for conduction and relaxation are more for NaAlSb(PO4)3 compared to the values of HAlSb(PO4)3. The isothermal conductivity of NaAlSb(PO4)3 i s higher than the conductivity of HAlSb(PO4)3. The imaginary parts of the impedance, (Z'') and electric modulus (M'') against log frequency show single peaks in both Z''  and M'' spectra

Low temperature preparation of NaTi2(PO4)(3) by sol-gel method

Bulk and nano sized rhombohcdral NaTi2(PO4)(3) belonging to NASICON family have been prepared by sol-gel method at low temperatures. The products are characterised by powder X-ray diffraction, Raman, SEM and TEM methods. The phase formation of NaTi2(PO4)(3) was started at 550 degrees C. The crystallite sizes of NaTi2(PO4)(3) prepared at 550 degrees C and 600 degrees C were found to be 35 nm and 37 nm respectively. The nano nature of the samples was confirmed from the line width of powder XRD and Raman lines. The Raman spectra are characterised by bands due to isolated phosphate groups and Ti-O vibrational modes. The morphology of nano crystallites was found to be irregular. The average particle size calculated from TEM was found to be 30 nnt and 35 nnt for the samples heated at 550 degrees C and 600 degrees C respectively. The high resolution TEm image clearly shows the lattice fringes corresponding to the rhombohedral lattice of NaTi2(PO4)(3)open

Synthesis, characterization and photocatalytic activity studies of tellurium containing defect pyrochlores, MSn_0.5Te_1.5O₆ (M = K, Ag, Cu_0.5 and Sn_0.5)

1174-1181Four new metal tin tellurites, MSn0.5Te1.5O6 (M = K, Ag, Cu0.5 and Sn0.5), have been synthesized by standard solid-state and facile ion exchange reactions and characterized by powder X-ray diffraction, FTIR, SEM-EDS and UV-vis diffuse reflectance spectroscopic techniques. All the compositions crystallize in cubic lattice with Fdmspace group, and are isomorphous with KTi0.5Te1.5O6. The photocatalytic activity of the as prepared materials for methylene blue and methyl violet degradation has been investigated under visible light irradiation. The AgSn0.5Te1.5O6 photocatalyst exhibits higher photocatalytic activity than MSn0.5Te1.5O6 (M = K, Cu0.5 and Sn0.5) for photodegradation of methylene blue and methyl violet. The higher photocatalytic performance of AgSn0.5Te1.5O6 is ascribed to its low band gap energy, which endows it with a very strong photooxidation ability to produce OH● and O2●- radicals as active species. The catalyst stability and mechanism of photocatalysis is also discussed

<span style="font-size:15.0pt;mso-bidi-font-size:16.0pt;mso-bidi-font-weight:bold" lang="EN-US">Effect of crystallite size on electron spin resonance of Gd³⁺ and luminescence of Eu³⁺ doped in La₆WO₁₂ </span>

204-208Nano-sized Eu3+ and Gd3+ doped lanthanum tungstates of composition La6-xLnxWO12 (Ln = Eu, Gd; 0 ≤ x ≤ 0.2) are prepared by sol-gel complexation method. These samples are characterized by powder X-ray diffraction (XRD). The average crystallite size is calculated from the XRD using Scherer’s equation. The electron spin resonance (ESR) spectrum of Gd3+ doped lanthanum tungstate (La6WO12) gives characteristic “U” type spectrum. The luminescence spectrum of Eu3+ doped La6WO12 gives characteristic 5D0→7Fn (n = 0 to 4) bands due to trivalent europium ions. The intensity of 5D0→7F2 transition decreases with increase in the sintering temperature due to depletion of surface Eu3+ ions. The intensity of 5D0→7F2 sintered at 700°C has highest intensity and may have laser applications