structural properties and chemical composition change the photocatalytic activity in tio2-sio2 nanopowder composite. the sio2-tio2 nanostructure is synthesized based on sol–gel method. the nanoparticles are characterized by x-ray fluorescents (xrf), x- ray diffraction (xrd), tunneling electron microscopy (tem), field emission scanning electron microscopy (fe-sem), uv-vis. spectrophotometer and ...

the current study presents a new analytical method for buckling analysis of rectangular and annular beams made up of functionally graded materials with constant thickness and poisson’s ratio. the boundary conditions of the beam are assumed to be simply supported and clamped. the stability equations were obtained by using conservation of energy. the critical buckling load and first mode shape we...

the current study presents a new analytical method for buckling analysis of circular plates with constant thickness and poisson’s ratio, made of functionally graded material subjected to radial load. governing equations are based on energy method for thin plates. the boundary conditions of the plate are assumed to be simply supported and clamped. the stability equations were obtained by using c...

the dependence on ionic strength of protonation of l-aspartic acid and its complexation withdioxouranium(vi) is reported in sodium perchlorate solution as a background salt. the measurementshave been performed at 25 ± 0.1 °c and various ionic strengths in the range 0.1 to 1.0 mol dm-3, using acombination of potentiometric and spectrophotometric techniques. the overall analysis of the present an...

the complexation of sodium molybdate with para-sulfonatocalix [4] arene was studied in thetemperature range from 20 to 40 °c and ph = 5.8 by spectroscopic method in water solution. thestability constants of complexes were calculated by the multiwavelength analysis of spectral datausing squad program. the equilibrium constant, spectroscopic data, molar absorptivities andconcentrations of all spe...

based on the {s+, i-} pathway, the concentration of surfactant and surface charge density of silanolate groups control the phase transition from lamellar, to hexagonal through cubic form. the high surface charge density of silanolate groups was observed for the lamellar phase. with decrease of molar concentration of surfactant on the gel, the yield of reaction decreases and the stability of mes...

An important consideration in control issues is control of nonlinear systems. Sliding control is among those nonlinear controllers that can control the system desirably in the presence of unstructured uncertainties of carelessness in specifying parameters of the system. In sliding control, also called Variable Structure Control, the main objectives of the controller &#10are achieved by introduc...

An important consideration in control issues is control of nonlinear systems. Sliding control is among those nonlinear controllers that can control the system desirably in the presence of unstructured uncertainties of carelessness in specifying parameters of the system. In sliding control, also called Variable Structure Control, the main objectives of the controller are achieved by introducin...