Applied Science Private University

About: Applied Science Private University is a education organization based out in Amman, Jordan. It is known for research contribution in the topics: Population & Catalysis. The organization has 4124 authors who have published 5299 publications receiving 116167 citations.

Thermal stability of hydroxyapatite whiskers derived from the hydrolysis of α-TCP

Abstract: Figure 2 SEM micrographs of sample: (a) A, (b) B, (c) C and (d) D. Whisker shaped hydroxyapatite (Ca10(PO4)6(OH)2, HAp) is a promising candidate material for reinforcing ceramic or polymer matrices to be used in the biomedical and dental fields [1]. Various techniques for preparation of whiskerlike or fibrous HAp have been reported [2–6]. Among these, the hydrolysis of α-Ca3(PO4)2 (α-TCP) under controlled processing conditions (aqueous pH, temperature and time) is often adopted to generate a whisher shaped form of HAp [2, 3]. Several authors [7–10] have reported on the thermal stability of synthetic HAp but the results are not generally coincident. It is suggested that the reason for this that the thermal decomposition of HAp is inherently dependent on the crystallinity, stoichiometry and atmosphere conditions prevailing during the reactions

First Passage Probability for Nonlinear Oscillators

Abstract: An approximate method of calculating the probability that a nonlinear oscillator will fail within a specified interval of time is developed, where failure is assumed to occur at the instant the response amplitude first exceeds a critical level. It is shown for oscillators driven by white noise that the energy envelope of the response process is well represented as a one-dimensional Markov process. From the appropriate Fokker-Planck equation of this process simple differential equations for the moments of the time to failure are derived, and integrated numerically in certain cases. In the case of an oscillator with linear damping but a nonlinear spring of the power law type, a complete analytical solution is found in terms of hypergeometric functions. A comparison with digital simulation results indicates that the proposed theory yields a lower bound from the mean time to failure which is close when the damping is very light.