Testing the applicability of artificial intelligence techniques to the subject of erythemal ultraviolet solar radiation. Part two: an intelligent system based on multi-classifier technique

The problem we address here describes the on-going research effort that takes place to shed light on the applicability of using artificial intelligence techniques to predict the local noon erythemal UV irradiance in the plain areas of Egypt. In light of this fact, we use the bootstrap aggregating (bagging) algorithm to improve the prediction accuracy reported by a multi-layer perceptron (MLP) network. The results showed that, the overall prediction accuracy for the MLP network was only 80.9%. When bagging algorithm is used, the accuracy reached 94.8%; an improvement of about 13.9% was achieved. These improvements demonstrate the efficiency of the bagging procedure, and may be used as a promising tool at least for the plain areas of Egypt.     

Flash ignition and initiation of explosives-nanotubes mixture

Optical ignition and initiation of energetic materials could thus far be only accomplished through lasers, with specific characteristics of high power, pulse length, wavelength, and a small target area that greatly inhibit their applications. Here, we report that an ignition and an initiation process, further leading to actual detonation, does occur for energetic materials in lax contact with carbon nanotubes that are prone to opto-thermal activity via a conventional flashbulb. Our results show that, for the first time, optical initiation of energetic materials is possible on a large surface area and using ordinary light intensity of several W/cm2. The implication is that energetic materials mixed with optically active nanotubes could be new ideal candidates for safety apparatus, such as the firing of bolts on space shuttle rockets and aircraft exit doors.     

Transient fission and multiplicities

The de-excitation chain of the compound nucleus is treated, including the transient character of the fission process. The equations can handle all type of emission and take into account all the nuclei of the decay chain. The results show that the particles behave differently under the transient regime.     

Long-range electrostatic contributions to the many-body expansion of molecular potentials

A new approach is proposed to the introduction of long range electrostatic terms in the many-body expansion of the molecular potential. The method has been applied to the HO₂ and H₂F₂ potentials.     

Singular spectrum analysis based on the perturbation theory

Singular Spectrum Analysis (SSA) has been exploited in different applications. It is well known that perturbations from various sources can seriously degrade the performance of the methods and techniques. In this paper, we consider the SSA technique based on the perturbation theory and examine its performance in both reconstructing and forecasting noisy series. We also consider the sensitivity of the technique to different window lengths, noise levels and series lengths. To cover a broad application range, various simulated series, from dynamic to chaotic, are used to verify the proposed algorithm. We then evaluate the performance of the technique using two real well-known series, namely, monthly accidental deaths in the USA, and the daily closing prices of several stock market indices. The results are compared with several classical methods namely, Box–Jenkins SARIMA models, the ARAR algorithm, GARCH model and the Holt–Winter algorithm.     

Fabrication of a new multi-walled carbon nanotube paste electrode for stripping voltammetric determination of Ag(I)

A new modified carbon paste electrode based on multi-walled carbon nanotubes and a synthesized Schiff base of N,N'-bis(2-hydroxybenzylidene)-2,2'(aminophenylthio) ethane, acting as a chelating agent for Ag(I) ions, is described. The electroanalytical procedure for the determination of Ag(I) was comprised of two steps: the chemical accumulation of the analyte under open-circuit conditions followed by replacing the medium with a 0.1 M HCl solution where the accumulated Ag(I) was reduced for 20 s in -0.7 V. The potential was then scanned from -0.2 to +0.2 V to obtain the voltammetric peak. The effective parameters in the sensor response were examined. Under optimized operational conditions, a linear response range from 0.5-200 ng mL(-1) was obtained. The detection limit for silver determination was 0.092 ng mL(-1). For 7 successive determinations of 15.0 and 60.0 ng mL(-1) of Ag(I), relative standard deviations of 2.2% and 1.2% were obtained, respectively. The procedure was applied in determining Ag(I) in X-ray photographic films and water samples.     

Semi-exact solution for thermo-mechanical analysis of functionally graded elastic-strain hardening rotating disks

In this paper, distributions of stress and strain components of rotating disks with non-uniform thickness and material properties subjected to thermo-elasto-plastic loading are obtained by semi-exact method of Liao’s homotopy analysis method (HAM) and finite element method (FEM). The materials are assumed to be elastic-linear strain hardening and isotropic. The analysis of rotating disk is based on Von Mises’ yield criterion. A two dimensional plane stress analysis is used. The distribution of temperature is assumed to have power forms with the hotter point located at the outer surface of the disk. A mathematical technique of transformation has been proposed to solve the homotopy equations which are originally hard to be handled. The domain of the solution has been substituted by a new domain through which the unknown variable has been taken out from the argument of the function. This makes the solution much easier. A numerical solution of the governing differential equations is also presented based on the Runge–Kutta’s method. The results of three methods are presented and compared which shows good agreements. This verifies the implementation of the HAM and demonstrates its applicability to provide accurate solution for a very complicated case of strongly high nonlinear differential equations with no exact solution. It is important to notice that compared with other methods, HAM needs significant more computation time and computer hardware requirements which limit its application for those problems that other methods can easily handle them.     

On Strong (A)-Rings

In this paper, we introduce a strong property (A) as follows: A ring R is called satisfying strong property (A) if every finitely generated ideal of R which is generated by a finite number of zero-divisors elements of R, has a non zero annihilator. We study the transfer of property (A) and strong property (A) in trivial ring extensions and amalgamated duplication of a ring along an ideal. We also exhibit a class of rings which satisfy property (A) and do not satisfy strong property (A).