Comments on "Optimal Utilization of a Cognitive Shared Channel with a Rechargeable Primary Source Node"

Ahmed El Shafie,Ahmed Sultan Salem 한국통신학회 2015 Journal of communications and networks Vol.17 No.3

In a recent paper [1], the authors investigated the maximum stable throughput region of a network composed of a rechargeable primary user and a secondary user plugged to a reliable power supply. The authors studied the cases of an infinite and a finite energy queue at the primary transmitter. However, the results of the finite case are incorrect. We show that under the proposed energy queue model (a decoupled M/D/1 queueing system with Bernoulli arrivals and the consumption of one energy packet per time slot), the energy queue capacity does not affect the stability region of the network.

Evaluation of glycoproteins purified from adult and larval camel ticks (Hyalomma dromedarii) as a candidate vaccine

Amr E. El Hakim,Sobhy Abdel-Shafy,Amira M. K. Abouelella,Ragaa R. Hamed,Yasser E. Shahein 대한수의학회 2011 JOURNAL OF VETERINARY SCIENCE Vol.12 No.3

In order to identify antigens that can help prevent camel tick infestations, three major glycoproteins (GLPs) about 97, 66 and 40 kDa in size were purified from adult and larval Egyptian ticks, Hyalomma (H.) dromedarii, using a single-step purification method with Con-A sepharose. The purified GLPs were evaluated as vaccines against camel tick infestation in rabbits. The rabbits received three intramuscular inoculations of GLPs (20 μg/animal) on days 0, 14, and 28. In the immunoblot analysis, Sera from the immunized rabbits recognized the native GLPs and other proteins from larval and adult H. dromedarii ticks along with those from other tick species such as Rhipicephalus sanguineus but not Ornithodoros moubata. The effects of immunity induced by these GLPs were determined by exposing rabbits to adult H. dromedarii ticks. These results demonstrated that GLP immunization led to a slightly decreased reproductive index and significantly reduced rates of egg hatchability. These results demonstrated that immunization with the purified GLPs can provide protection against infestation by H. dromedarii and some other tick species. Further studies are needed to confirm the effectiveness of immunization with GLPs against other tick species.

Breakdown of passivation for zinc-antimony alloy in alkaline batteries verification; galvanostatic, impedance spectra, and charge-discharge techniques

Mahmoud Elrouby,Hoda Abd El-Shafy Shilkamy,Abd El-Rahman El-Sayed 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.3

The passivation of pure zinc surface can be considered a problem of Zn utilization as an anode in alkaline batteries due to its small capacity. Therefore, to improve the discharge capacity of the Zn anode, minor Sb alloying with Zn was investigated. The impact of trace Sb alloyed with Zn on the passivity and the breakdown of the colloidal passive film on the surface was studied in concentrated KOH solution utilizing galvanostatic, electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements at the passivated area. The galvanostatic data show that the required time of passivation (tpass.) is greater with increasing small Sb content in the alloy. The obtained results from electrochemical impedance spectroscopy (EIS) reveal that magnitudes of both resistivities of charge transfer (Rct.) and the impedance of Warburg (Zw) decrease, while the magnitude of capacitance of double layer (Cdl.) increases gradually with the increase in addition of small Sb to zinc metal. The evaluated data from the charging-discharging process show that the greatest value of potential height (ΔV) is for Zn-0.5%Sb alloy. Therefore, 0.5%Sb alloying with Zn can increase energy efficiency to a large extent than Zn and alloy II.

The temperature dependent electrical transport in biphenyl derivatives

M.M. Sallam,B.A. El-Sayed,A.A. Abdel-Shafi 한국물리학회 2006 Current Applied Physics Vol.6 No.1

The d.c. electrical conductivity measurements as a function of temperature of 4,4-dibromobiphenyl (DBrBP), 4,4-dichlorobiphe-nyl (DClBP) and 4,4-dimethoxybiphenyl (DMOBP) compounds have been carried out. The eects of conformational change withinskeleton of these compounds upon optical or thermal excitation (S1 S0 para substituents on the electrical conductivityhave been discussed. The conduction processes were interpreted in the light of their molecular spectroscopic data of the infrared,ultraviolet and emission spectra as a hopping processes. The semiconducting properties of the investigated compounds were arisingfrom electron-delocalization via intramolecular interaction ofp-electrons of (C@ C) bonds and electron-donating groups inparaincreases the possibility of electron-delocalization and the interaction ofp-electron system..

Potential role of microbial pathogens in control of red palm weevil (Rhynchophorus ferrugineus) ‐ A Review

Muhammad Yasin,Waqas Wakil,Hamadttu A.F. EL-SHAFIE,Geoffrey O. BEDFORD,Thomas A. Miller 한국곤충학회 2017 Entomological Research Vol.47 No.4

The invasive Red Palm Weevil (RPW), Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae), is one of the most destructive pests of ornamental and economically important palms globally. It has been found in 50 % of date‐growing and 15 % of coconut‐producing countries in the world. Synthetic organic insecticides have been the default method to combat this pest, but they are clearly inefficient due to the secretive nature of the insect and there is concern about non‐target effects from blanket spraying. For this reason, there is increasing interest in biological control methods such as the possible use of microbial entomopathogens, which might be incorporated into IPM approaches. In this review we summarize research work on microbial control agents, their effectiveness against RPW and their integration with other control measures.

Load-deflection analysis prediction of CFRP strengthened RC slab using RNN

Razavi, S.V.,Jumaat, Mohad Zamin,El-Shafie, Ahmed H.,Ronagh, Hamid Reza Techno-Press 2015 Advances in concrete construction Vol.3 No.2

In this paper, the load-deflection analysis of the Carbon Fiber Reinforced Polymer (CFRP) strengthened Reinforced Concrete (RC) slab using Recurrent Neural Network (RNN) is investigated. Six reinforced concrete slabs having dimension $1800{\times}400{\times}120mm$ with similar steel bar of 2T10 and strengthened using different length and width of CFRP were tested and compared with similar samples without CFRP. The experimental load-deflection results were normalized and then uploaded in MATLAB software. Loading, CFRP length and width were as neurons in input layer and mid-span deflection was as neuron in output layer. The network was generated using feed-forward network and a internal nonlinear condition space model to memorize the input data while training process. From 122 load-deflection data, 111 data utilized for network generation and 11 data for the network testing. The results of model on the testing stage showed that the generated RNN predicted the load-deflection analysis of the slabs in acceptable technique with a correlation of determination of 0.99. The ratio between predicted deflection by RNN and experimental output was in the range of 0.99 to 1.11.

Investigation of Meta-heuristics Algorithms in ANN Streamflow Forecasting

Yaxing Wei,Huzaifa Hashim,K. L. Chong,Y. F. Huang,Ali Najah Ahmed,Ahmed El-Shafie 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.5

The deterministic approach, which utilizes the gradient information in the search process, is prone to trapping at local minima, primarily due to the presence of saddle points and local minima in the non-convex objective function of an artificial neural network (ANN). This study investigated the efficacy of a hybrid model that adopted a meta-heuristic algorithm (MHA) as an optimizer to extend the training ANN method, from a gradient-based to a stochastic population-based approach for streamflow forecasting. In the latter, parameter tuning utilizing the design of experiment (DOE) technique, has become an integral element in the optimization process due to reliance on their parameters. For model convenience, a wavelet transform was employed to decompose the series into sub-series. The empirical studies of MHA performance showed that the hybrid MHA-ANN was superior for streamflow forecasting, especially with the firefly algorithm that had an average RMSE = 96.06, an improvement of approximately 17% over the gradient-based ANN (RMSE = 113.92). However, among the adopted MHAs, not all are compatible with optimizing the ANN for streamflow forecasting, thus requiring a thorough study as performance varies from case to case. Two additional statistical tests, such as the Kruskal-Wallis H test and the Mann-Whitney U test, further validated such disparity in the MHA's performance.

Optimization of Reservoir Operation using New Hybrid Algorithm

Zaher Mundher Yaseen,Hojat Karami,Mohammad Ehteram,Nuruol Syuhadaa Mohd,Sayed Farhad Mousavi,Lai Sai Hin,Ozgur Kisi,Saeed Farzin,김성원,Ahmed El-Shafie 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.11

Due to the scarcity of fresh water resources, exploiting dams’ reservoirs, based on their optimal operation, obviates construction of extra dams and high costs and satisfies downstream consumers’ water needs with high reliability. In this research, a new hybrid approach of Artificial Fish Swarm Algorithm (AFSA) and Particle Swarm Optimization Algorithm (PSOA) is used to optimize Karun-4 reservoir, increase energy production and minimize downstream water shortages. This Hybrid Algorithm (HA) brings about diversity of responses in PSOA, prevents entrapment of AFSA in local optimum traps and increases convergence speed and balances between the abilities to scan and make profit in the AFSA. This method was assessed based on reliability, vulnerability and resilience indices. In addition, based on a multi-criteria decision-making model, it was evaluated by comparing it with other evolutionary algorithms. To verify the HA, it was tested on few mathematical functions. Results indicated that the HA features performed higher reliability, lower vulnerability and resiliency, as compared with AFSA and PSOA. In addition, HA is ranked first according to the multi criteria decision making model. Further, among all the tested evolutionary methods, this new algorithm yielded the best answer for dam power plant’s objective function.