A multi-variate heart disease optimization and recognition framework

Neural Computing and Applications - Cardiovascular diseases (CVD) are the most widely spread diseases all over the world among the common chronic diseases. CVD represents one of the main causes of...     

Study of heavy metal ion absorbance by amidoxime group introduced to cellulose‐graft‐polyacrylonitrile

Amidoximated grafted cellulose was obtained by reacting hydroxylamine and cellulose‐graft‐polyacrylonitrile (C‐g‐PAN), prepared by KMnO₄/citric acid redox system, and the resultant amidoximated grafted cellulose was characterized by scanning electron microscope (SEM), solid‐state NMR, FTIR, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and elemental analysis. The highest value of amidoxime content in the grafted sample was 2.42 mmol/g. The adsorption efficiencies of amidoximated grafted cellulose have been evaluated with studying different adsorption conditions. Amidoximated sample with amidoxime content 2.42 mmol/g showed high ability to adsorb the metal ions from the aqueous solutions as high as 1.7 mmol/g, 1.6 mmol/g, and 0.84 mmol/g for Co²⁺, Cu²⁺, Ni²⁺ ions, respectively, at the highest original metal ion concentration. These values are about three times larger than previous studies. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Study of dielectric properties of polypyrrole prepared using two different oxidizing agents

Polypyrrole samples that have been prepared in a conducting state by a chemical method using two different oxidizing agents, ferric chloride and potassium persulphate, in different concentrations have been transformed to a dielectric state by heating at 333 K for 7 days and then at 353 K for 4 days more. Then the frequency and temperature 32 dependence of the dielectric constant ε′, loss tangent tan δ and AC conductivity σ′ were investigated using a complex impedance technique. It has been found that the concentrations of the reactants used in the preparation have a noticeable effect on the dielectric properties. It has been concluded also that heating at constant temperature has enhanced the resistivity of the samples, which can be considered as a simple method of obtaining polypyrrole (PPy) in a dielectric state rather than more complex electrochemical methods which may be useful in some future applications such as the manufacture of supercapacitors. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99:3370–3379, 2006     

A DETAILED DESIGN OF A LAB-BUILT MODULATOR DRIVER FOR A MÖSSBAUER SPECTROMETER

The Doppler modulation system is a principal part of a Mössbauer spectrometer. It includes the Doppler modulator (velocity transducer) and a control system (the modulator driver) which consists of a function generator that produces a reference signal by which the vibrator can be controlled and the error correction circuit that corrects the motion of the vibrator according to the reference signal. The motion of the driver must be identical to the preferred wave shape for the operation of the spectrometer. The aim of the present article is to design and test a low cost lab-built modulator velocity driver for a Mössbauer spectrometer to be used in the constant acceleration (triangular) mode of operation, although it can be used in the other operational modes. A triangular wave is stored in RAM. The axis of the vibrator carries two coils, one for the driving signal and the other for the pickup signal which gives the shape of the motion of the driver (i.e., the actual motion of the source). The stored reference triangular wave is compared with the one from the pickup coil and the difference between them gives an error signal. The error signal will be zero if the motion of the vibrator is identical to that of the stored wave. This error signal is added to the driving pulse in a suitable phase and amplitude in order to obtain a source motion with minimized deviation from its correct value.     

Optimal Groundwater Management Using Genetic Algorithm in El-Farafra Oasis,Western Desert,Egypt

Groundwater is the unique source of fresh water in El-Farafra Oasis, western desert, Egypt. The increasing demand of groundwater in El-Farafra Oasis has resulted in an indiscriminate exploitation of this source causing environmental hazards such as decline of groundwater levels and well interference. In this paper, the study of these problems is conducted. The methodology introduced in this paper includes application of mathematical and Genetic Algorithm (GA) techniques. This situation has led to a growing realization that through good management, use of groundwater can be made more productive and sustainable. The proposed model of optimization is based on the combination of the MODFLOW with GA. The performance of the proposed model is tested on groundwater management problem (maximization of total pumping rate from an aquifer at steady-state). The results show that the GA solutions nearly agree with the solutions of other methods of previous works. Thus, it can be used to solve the management problems in groundwater. This model is used to develop the optimal pumping rate and number of wells in El-Farafra Oasis under different scenarios. The results show that under the current situation, the optimal pumping rate is 183023 m³/day. The second scenario assumes an increase of number of wells by 20%, the optimal rate reaches 220016 m³/day. The third scenario proposes pumping rate 254484 m³/day which equalizes an increase in the cultivated area by 4000 acres, the optimal rate reaches 258007 m³/day.     

Influence of relaying malicious node within cooperative sensing in cognitive radio network

Wireless Networks - Intending to enhance the utilization of the radio spectrum in cognitive radio without inflecting the primary user is a primary issue. Cooperative sensing techniques have been...     

An adaptive neuro-fuzzy sliding mode controller for MIMO systems with disturbance

This paper introduces the mathematical model of ammonia and urea reactors and suggested three methods for designing a special purpose controller. The first proposed method is Adaptive model predictive controller, the second is Adaptive Neural Network Model Predictive Control, and the third is Adaptive neuro-fuzzy sliding mode controller. These methods are applied to a multivariable nonlinear system as an ammonia–urea reactor system. The main target of these controllers is to achieve stabilization of the outlet concentration of ammonia and urea, a stable reaction rate, an increase in the conversion of carbon monoxide(CO) into carbon dioxide(CO_2) to reduce the pollution effect, and an increase in the ammonia and urea productions, keeping the NH_3/CO_2 ratio equal to 3 to reduce the unreacted CO_2 and NH_3, and the two reactors' temperature in the suitable operating ranges due to the change in reactor parameters or external disturbance. Simulation results of the three controllers are compared. Comparative analysis proves the effectiveness of the suggested Adaptive neurofuzzy sliding mode controller than the two other controllers according to external disturbance and the change of parameters. Moreover, the suggested methods when compared with other controllers in the literature show great success in overcoming the external disturbance and the change of parameters.     

Dynamic characteristics of combined conical-cylindrical shells

The truncated conical shape having a superimposed top cylindrical cap is widely used as a containment vessel for elevated water tanks. The evaluation of the wind and seismic responses of these tanks requires the knowledge of the dynamic characteristics of the vessels. This study reports the results of the first experimental and numerical investigation conducted to assess the dynamic behaviour of combined conical vessels. Shake table testing is conducted on a small-scale combined conical shell model. The tested specimen is then simulated numerically in a three-dimensional finite element analysis. The numerical model is validated through comparison with experimental results. An extensive parametric study is then conducted using the validated numerical model in order to determine the dynamic characteristics of full-scale combined conical vessels. Equations and charts describing the natural frequencies, the mode shapes and the generalized and effective masses of the vessels are obtained from this parametric study.