Abd El-Hameed Fayed A.,Banha University
Clinical Ophthalmology | Year: 2017
Purpose: To assess the changes in the contractility of the ciliary muscle in eyes with presbyopia before and after phacoemulsification and intracapsular lens implantation using ultrasound biomicroscopy (UBM). Patients and methods: This prospective study included 50 eyes of 30 consecutive subjects operated at the Department of Ophthalmology. Patients with any ocular disorder affecting visual acuity, corneal surface irregularities, had posterior capsular perforation or intensive postoperative corneal edema, or were <35 years of age, were excluded. A clear corneal phacoemulsification and posterior chamber intraocular lens were implanted. UBM was performed with and without instilling 2% pilocarpine. Ciliary body axial length (CBAXL), anterior chamber depth, and angle were measured before and 1 month after surgery. Results: The CBAXL showed a greater contractile shortening (P<0.5), with centripetal, contractile shift of ciliary muscle mass. Conclusion: After phacoemulsification and intracapsular lens implantation, ultrasonic biomicroscopy showed significant centripetal movement of the ciliary body compared with that before surgery. This shows that a lenticular sclerotic component may influence both lens movement and the contractility of the ciliary muscle and is believed to be related to the presbyopia. © 2017 Fayed.
Ahmed F.S.,Banha University |
Shafy M.,NCNSRC |
Abd El-megeed A.A.,National Institute for Standards of Egypt |
Materials and Design | Year: 2012
Seals made of acrylonitrile-butadiene rubber (NBR) are one of the classified seals used in nuclear facilities. But at high irradiation doses the physical and mechanical properties of NBR are adversely affected due to the degradation induced by radiation and hence affect the sealing performance reducing their service life. In order to improve the NBR sealing performance, antioxidants can be added to the NBR compounds. N-N-substituted p-phenylene diamines (PPDs) antioxidants are selected to improve the resistance of NBR seals against gamma irradiation up to 5. MGy. The effect of addition of different PPDs on the mechanical and physical properties of the NBR seals is investigated. Three types of antioxidants which are N-isopropyl-N'-phenyl-p-phenylene diamine (IPPD), phenyl B-naphthylamine (PBN), and N-(1,3-dimethylbutyl)-N-phenyl-p-phenylene diamine (6PPD) are chosen. The physical and mechanical properties of these NBR compounds were evaluated by measuring crosslinking density, the tensile strength, and the percentage of elongation as well as hardness and abrasion resistance. The results of the present study show that the addition of 6PPD as a candidate antioxidant to NBR seal material gives the best physical and mechanical performance compared to the other studied antioxidants. © 2011 Elsevier Ltd.
Khedr A.M.,Zagazig University |
Osamy W.,Banha University
Journal of Parallel and Distributed Computing | Year: 2011
Target tracking is an important sensing application of wireless sensor networks. In these networks, energy, computing power, and communication bandwidth are scarce. We have considered a random heterogeneous wireless sensor network, which has several powerful nodes for data aggregation/relay and large number of energy-constrained sensor nodes that are deployed randomly to cover a given target area. In this paper, a cooperative approach to detect and monitor the path of a moving object using a minimum subset of nodes while maintaining coverage and network connectivity is proposed. It is tested extensively in a simulation environment and compared with other existing methods. The results of our experiments clearly indicate the benefits of our new approach in terms of energy consumption. © 2011 Elsevier Inc. All rights reserved.
Khedr A.M.,University of Sharjah |
Osamy W.,Banha University
Information Sciences | Year: 2011
Many applications of wireless sensor networks (WSNs) require the tracking and the surveillance of target objects. The information to be gathered about the target may be related to only a particular monitored sub-area. Therefore, it is desirable to direct queries only to the nodes monitoring this particular area and for energy saving reasons, only the queried nodes should respond. In this paper, we introduce two new efficient distributed algorithms for finding the minimum number of connected perimeter sensor nodes that are sufficient to cover the perimeter of queried region, where the union of their sensing regions covers the perimeter of queried area. The simulation results show that our proposed algorithms achieve significant reduction in communication load, while preserving full perimeter coverage. © 2011 Elsevier Inc. All rights reserved.
Shaidan N.H.,Petronas University of Technology |
Eldemerdash U.,Petronas University of Technology |
Awad S.,Banha University
Journal of the Taiwan Institute of Chemical Engineers | Year: 2012
Ion exchange represents an efficient technique for removing of heavy metals from wastewater effluents. Limited number of studies focuses on fixed bed performance for metal removal. In this study, the removal of Ni 2+ from synthetic wastewater using a strong acidic cation exchange resin in a fixed bed columns was investigated. The experiments were conducted at different pH (3-7) and initial heavy metal concentrations (1.8, 2.8 and 3.8g Ni/L). Investigation of the regeneration effect on the resin was conducted. The removal efficiency and rate of removal are shown on the breakthrough curves and the kinetic study of the process was determined. The Thomas model was applied to follow the exchange dynamics, the results from experimental work were compared to those using Thomas model, it is shown that the calculated breakthrough curves agreed well with the measured ones. The metal level in the treated wastewater was examined using the atomic absorption spectrophotometer to show that the Ni 2+ concentration complies with the standard environmental regulations limits. © 2011 Taiwan Institute of Chemical Engineers.
Ghoneim N.H.,Cairo University |
Abdel-Moein K.A.,Cairo University |
Saeed H.,Banha University
Parasitology Research | Year: 2012
Giardiasis is a re-emerging infectious disease of worldwide significance caused by Giardia duodenalis. This study investigated the occurrence of zoonotic G. duodenalis assemblages in fish to explore the possible role of fish in the epidemiology of human giardiasis. For this purpose, 92 fish (Tilapia nilotica and Mugil cephalus) collected from (fish farms and Nile River) at different governorates in Egypt were examined for the presence of G. duodenalis in their feces by using enzyme linked immunosorbent assay, then positive fecal samples were tested by duplex PCR for identification of triose phosphate isomerase (tpi) gene specific for zoonotic assemblages A and B. The overall prevalence of G. duodenalis in the examined fish was 3.3%, while the detection rates among the examined fish species were 2.9% and 4.2% for T. nilotica and M. cephalus, respectively. G. duodenalis was detected in the feces of both farmed and wild fish whereas all isolates were genotyped as assemblage A. In conclusion, the occurrence of zoonotic G. duodenalis assemblage A in the examined fish species at two different aquatic environments underlines the possibility of fish to be an additional reservoir for zoonotic G. duodenalis assemblages that contributes in the contamination of water with this pathogen and thus the role of fish in the epidemiology of human giardiasis cannot be ruled out. © Springer-Verlag 2011.
Omara F.A.,Cairo University |
Arafa M.M.,Banha University
Journal of Parallel and Distributed Computing | Year: 2010
The scheduling and mapping of the precedence-constrained task graph to processors is considered to be the most crucial NP-complete problem in parallel and distributed computing systems. Several genetic algorithms have been developed to solve this problem. A common feature in most of them has been the use of chromosomal representation for a schedule. However, these algorithms are monolithic, as they attempt to scan the entire solution space without considering how to reduce the complexity of the optimization process. In this paper, two genetic algorithms have been developed and implemented. Our developed algorithms are genetic algorithms with some heuristic principles that have been added to improve the performance. According to the first developed genetic algorithm, two fitness functions have been applied one after the other. The first fitness function is concerned with minimizing the total execution time (schedule length), and the second one is concerned with the load balance satisfaction. The second developed genetic algorithm is based on a task duplication technique to overcome the communication overhead. Our proposed algorithms have been implemented and evaluated using benchmarks. According to the evolved results, it has been found that our algorithms always outperform the traditional algorithms. © 2009 Elsevier Inc. All rights reserved.
Ali S.A.,Banha University
Aquacultural Engineering | Year: 2013
Micro-screen rotating drum filters are an alternative to sand filtration especially when excessive waste water is a concern. The filtering process of drum screen filters is very simple, yet very efficient and reliable due to their overall design and operation. Drum filters are designed with few moving parts to ensure a long life with low operating/maintenance costs.Micro-screening essentially captures particles on a screen fabric while letting the water pass. This paper describes a design of two an industrial-scale drum screen filters driven by undershot wheel and its performance installed in recirculating aquaculture system culturing tilapia at El-Nenaeia fish farm. These filters are consisted of a woven metal mesh of 100μm. The design criteria for solids loading rate in the influent water is 10kgm-2min-1.The results indicate that the design parameters of the filter such as surface are and rotation speed were affected by the water flow rate, where the surface area and drum speed ranged from 1.58 to 27.87m2, and 1.05 to 8.40, respectively. The results also indicated that the efficiency of filter decreased during the first two months compared to the last two months of fish growth period, with an average 34.22±8.85% during the first 60 days and an average 52.41±16.77% during the last period. Using water wheels for driving the screen filter is very important in saving energy, where the filter with such dimensions needs 1.0hp for driving it, which represents 18.0kW daily. © 2012 Elsevier B.V..
El-Bashir S.M.,King Saud University |
El-Bashir S.M.,Banha University
Journal of Luminescence | Year: 2012
This work concerning the photophysical properties of fluorescent nanohybrid films based on poly(methylmethacrylate) (PMMA) doped with coumarin dyestuff and entrapped with different concentrations of hydrophilic nanosilica. Spectroscopic tools were applied in order to determine the optimum concentration of nanosilica for the best optical properties for a matrix used as fluorescent solar concentrator. The optical constants and photoluminescence spectra of fluorescent nanohybrid films showed an enhancement of the photon trapping efficiency and matrix stability by increasing the concentration of SiO 2 nanoparticles. © 2012 Elsevier B.V.
Khedr A.M.,University of Sharjah |
Khedr A.M.,Zagazig University |
Osamy W.,Banha University
Information Sciences | Year: 2013
Wireless sensor networks are composed of a large number of tiny sensors that have limited resources and yet must form a connected network. The main challenge in the design of sensor networks is the limited battery power of the sensors and the difficulty of replacing and/or recharging these batteries due to the nature of the monitored field. Thus, it is necessary that the sensors be densely deployed and energy-efficient protocols be designed to maximize the network lifetime while meeting the specific application requirements in terms of coverage and connectivity. Given a query over a sensor network the minimum connected sensor cover problem is to select a minimum, or nearly minimum, set of sensors such that the selected sensors cover the query region and form a connected network. In this paper, we propose a new distributed algorithm to find the minimum connected cover of the queried region for heterogeneous sensors, each with arbitrary sensing and transmission radii and different energy levels. Each sensor node in the network determines whether to sense the queried region according to its minimum-weight coverage cost. We provide performance metrics to analyze the performance of our approach and the simulation results show that our approach clearly improves the network lifetime over existing algorithms. © 2012 Elsevier Inc. All rights reserved.