adel Ahmed - Academia.edu (original) (raw)

Papers by adel Ahmed

2020 International Conference on Innovative Trends in Communication and Computer Engineering (ITCE), 2020

In this paper, development and experimental evaluations of high frequency transformer connected t... more In this paper, development and experimental evaluations of high frequency transformer connected to the full-bridge, phase-shift power converter are presented. This power converter is considered for power applications which have low input voltage and high current sources as a fuel cell generation system, telecommunication power plants, front stage of automotive AC power supplies and plasma generators. The main advantages of using this transformer in DC-DC converter are low size, low weight, low cost, and high performance. High-frequency transformer made of planar principle eliminates some shortcoming of old-fashioned wire wound and thus planar magnetics become increasingly popular in our life. The main constructor of planar transformer is PCB windings with core yield many advantages over the conventional magnetics. This paper discusses the effect of the magnetizing inductance of the planar transformer linked with DC-DC converter and distribution current in secondary windings. This power converter's operating principle is based on the quasi-resonant soft-switching circuit topology using high-frequency transformer parasitic parameters and lossless snubbing capacitors and its power is regulated using secondary-side phase-shifted controlled technology. Simulation and experimental testing of the performance of the proposed soft-switching DC-DC power converter using two new types of high-frequency transformers designed especially for this converter with different magnetizing inductances.

International Journal of Medical Science And Diagnosis Research, 2021

Thrombotic thrombocytopenic purpura is a medical emergency with varied clinical manifestations. T... more Thrombotic thrombocytopenic purpura is a medical emergency with varied clinical manifestations. TTP is a rare condition, but one that carries a high mortality. High index of suspicion with careful evaluation of thrombocytopenia and hemolytic anemia is of paramount importance. Symptoms result from microthrombi affecting microcirculation and can be varied depending on the organs involved. Laboratory parameters of microangiopathic hemolytic anemia i.e. schitocytosis and increased LDH and indirect hyperbilirubinemia support the diagnosis. Plasma exchange is the treatment of choice. Other modalities that may provide therapeutic benefit in cases of relapsing TTP or in patients with slow or partial response to plasma exchange include vincristine and rituximab. Splenectomy done in remission may decrease recurrence in patients with relapsing TTP.

Academy of Accounting and Financial Studies Journal, 2017

The adverse consequence of the on-going financial crisis has ignited interest into the relationsh... more The adverse consequence of the on-going financial crisis has ignited interest into the relationship and lack of communication between ethics and banking. However, already on the ethical banking horizon, the Islamic banking model (in theory) is in itself built upon the objective of pursing the benefit of society; rather than to solely profit maximise. However, Islamic banking is not free of its own critics. There are claims that the industry has ‘mimicked’ the conventional model; while marginalising their societal role. In addition, a few studies focused on Corporate Social Responsibility (CSR) disclosure practice of Islamic banks. The consensus has been that Islamic banks make minimal disclosure of CSR issues. Nevertheless, this is puzzling as Islamic banks are expected to fulfil their Social accountability and full disclosure expectations; as per the Sharia Law (Islamic law). Furthermore, rather than solely pursue profit maximisation, Islamic banks are expected to apply a moral fil...

mBio, 2020

The Phe43 cavity of HIV-1 envelope glycoproteins (Env) is an attractive druggable target. New pro... more The Phe43 cavity of HIV-1 envelope glycoproteins (Env) is an attractive druggable target. New promising compounds, including small CD4 mimetics (CD4mc), were shown to insert deeply into this cavity. Here, we identify a new network of residues that helps to shape this highly conserved CD4 binding pocket and characterize the structural determinants responsible for Env sensitivity to small CD4 mimetics.

International Journal of Energy Economics and Policy, 2019

The project financing of solar projects has been proven challenging given the relatively high cos... more The project financing of solar projects has been proven challenging given the relatively high costs (both for utility solar and rooftop solar) of solar projects, the uncertain life cycle for solar panels, and the lack of business models for financing in the private sector. Several governments have loan-financing programs available for solar-energy projects. The article describes the peculiarities of government policy in the solar energy field of countries that have already implemented large-scale projects for the construction of Solar powered satellite (SPS) (USA, China, India, EU) and countries that have just started to implement this option as an alternative energy into the country's overall energy system (Eastern Europe: Russia, Kazakhstan). This article is universal in nature. The data obtained and developments can be applied both in the local and international practice of managing an energy business operating in the field of alternative energy-the "solar" industry.

IET Information Security, 2019

In recent years, the web phishing attack has become one of the most serious web security problems... more In recent years, the web phishing attack has become one of the most serious web security problems, in which the phishers can steal significant financial information about the internet users to carry out financial thefts. Several blacklist-based conventional phishing website detection methods are used to predict the phishing websites. However, numerous phishing websites are not predicted precisely by these blacklist-based conventional methods since many new phishing websites are constantly developed and launched on the Web over time. In this study, hybrid intelligent phishing website prediction using deep neural networks (DNNs) with evolutionary algorithm-based feature selection and weighting methods are suggested to enhance the phishing website prediction. In the proposed hybrid intelligent phishing website prediction approaches, the most influential features and the optimal weights of website features are heuristically identified with the genetic algorithm (GA) to help in increasing the accuracy of phishing website prediction. Accordingly, the website features selected and weighted by the GA are utilised to train DNNs to accurately predict the phishing websites. The experimental results demonstrated that the proposed hybrid intelligent phishing website prediction approaches achieved significantly higher classification accuracy, sensitivity, specificity, and geometric mean in phishing website prediction compared to those proposed in other studies.

Zagazig University Medical Journal, 2019

Aim of the work: was to determine the level of IL-27 in patients with immune thrombocytopenia and... more Aim of the work: was to determine the level of IL-27 in patients with immune thrombocytopenia and its relationship to demographic,clinical and laboratory characteristics of patients as well as disease chronicity and response to treatment. Methods: A case control study carried out in Pediatric Hematology outpatient clinic , Zagazig University Hospitals. It included 80 subjects were divided into 4 group 1 included 20 patients with denovo ITP, group 2 included 20 patients with chronic ITP, group 3 included 20 patients with complete remission after 1st line therapy and group 4 (control group) included 20 healthy children as a control group. Results: there is significant difference regarding WBCs and Platelets, there was no significant difference in patients with ITP as regards hemoglobin level. ITP patients had significantly higher levels of IL-27 than controls. Patients with acute ITP had the highest levels of IL-27 among patient groups ,while, patients in remission had the lowest IL-27 levels among patient groups. There was significant relationship between 1st line therapy and serum IL-27 in patients with ITP. Patients who received IVIG and combined steroids and IVIG had significantly higher IL-27 levels than others. There was significant relationship between 2nd line therapy and serum IL-27 in patients with chronic ITP. Where patients who received Eltrombopag had significantly lower IL-27 levels than others. Conclusion: we propose that the using of IL-27 as a predictor for ITP occurrence and for responsiveness to treatment but this need to be confirmed in larger studies.

Benha Veterinary Medical Journal, 2016

This study was performed to investigate the effected of experimental work of intestinal surgery f... more This study was performed to investigate the effected of experimental work of intestinal surgery for removal caecum of rabbits on alanine amiotransferase (ALT), aspartate aminotransferase(AST), gamma glutamyletransferase (GGT), alkaline phosphatase (ALP), acid phosphotase (ACP), amylase, lipase, catalase (CAT), ceratine phosphokinase (CPK), lactate dehydrogenase (LDH) and cortisol hormone. Two groups of thirteen healthy female New Zland rabbits were used. The first one contained 15 rabbits and kept as control group. The second contain also 15 rabbits subjected to surgery for removal of caecum of rabbits. Blood sample were collected at 3, 6 and 9 days post-operative. The obtained result showed that the increase in serum ALT, AST, GGT, ALP, ACP, amylase, lipase, CAT, CPK, LDH and cortisol hormone were significant increase in experimental group compared with control group. From this result it could be concluded that the biochemical parameter affected with intestinal surgery for removal of rabbit's caecum.

Ceramics International, 2017

This work aims at obtaining aluminum titanate-based ceramics (Al 2 TiO 5 : AT) composites from in... more This work aims at obtaining aluminum titanate-based ceramics (Al 2 TiO 5 : AT) composites from industrial wastes. Al-sludge waste and rutile ore were used as rich sources of alumina and titania instead of pure materials. Sludge-(0-40 wt%) rutile mixtures were mixed, formed and fired at 1350°C for various times. Phase composition, microstructure, densification, mechanical and thermal behaviors of the obtained AT composites have been investigated. Complete conversion of the starting materials to AT with bulk density of 3.199 g/cm 3 , compressive strength and modulus of rupture of 326.425 MPa and 30.84 MPa, respectively and very low CTE (−0.927*10 −6 K −1) were achieved by firing the sludge-(30 wt%) rutile at 1350°C for 4 h. These results suggest that the obtained AT-ceramics from Al-sludge waste-rutile ore are a promising and an ecofriendly route.

International Journal of Power and Energy Conversion, 2017

This paper is aimed at implementation of a stand-alone residential photovoltaic (PV) system in As... more This paper is aimed at implementation of a stand-alone residential photovoltaic (PV) system in Assiut City, Egypt to feed different domestic loads at a home including lighting loads, washing machine, TV, refrigerator and computer up to 2 kW at 220 V during day and night hours. The system design is based on assessing the total electric power demand during day and night hours. The system has been implemented and the output voltage waveforms have been recorded for different load demand values. A complete harmonic analysis has been done with and without using the filter. The results show that the designed system succeeded in feeding the household appliances during day and night hours. With the use of LC filter, the inverter output voltage waveforms are close to be sinusoidal with THD values of 6.85% and 7.2% during day and night hours respectively, which match the IEEE standards limits for harmonic distortions.

Journal of environmental management, Jan 30, 2016

In this work, nanoscale single crystalline γ- and α-alumina powders have been successfully prepar... more In this work, nanoscale single crystalline γ- and α-alumina powders have been successfully prepared from aluminum foil waste precursor via co-precipitation method using NH4OH as a precipitant. The obtained gel after co-precipitation treatment, was calcined at different temperatures (500,700, 900, 1050, 1100, 1300 and 1500 °C) and the products were characterized by XRD, FTIR and HRTEM. The results revealed that nano-γ-Al2O3 was fully transformed to nanometer-sized α-Al2O3 (36-200 nm) after annealing at temperatures as low as 1100 °C.The thermally preheated powder at 500 °C was further pressed under 95 MPa by the uniaxial press and the obtained bodies were found to have98.82% of the theoretical density, 1.18% porosity and 708 MPa compressive strength, when sintered at temperatures as low as 1600 °C without using any sintering aid. These excellent results proved that this work will contribute to finding a commercial source for preparing sub 100 nm α-alumina through the secondary resour...

This paper is aimed at accurate estimation of the fault current at all Micro Grid (MG) buses duri... more This paper is aimed at accurate estimation of the fault current at all Micro Grid (MG) buses during grid-connected and islanding modes with different load types (dynamic or static). Following fault-current estimation, a design of an adaptive protection system is sought to protect the MG irrespective of the mode of operation or the type of load. The adaptive protection system has been designed using three calculation methods. The first method is the conventional method which depends on representing the power system by voltage source and Thevenin impedance. The second method depends on the IEC standard calculation method and its correction factors. The third method is a novel proposed method where all system real conditions have been taken into consideration. The proposed adaptive protection system is able to accurately estimate the value of fault currents in the MG and hence the relay tripping currents during any operating condition like grid connected mode, islanding mode, static lo...

Lecture Notes in Computer Science, 2006

This paper describes the GEOMI system, a visual analysis tool for the visualisation and analysis ... more This paper describes the GEOMI system, a visual analysis tool for the visualisation and analysis of large and complex networks. GEOMI provides a collection of network analysis methods, graph layout algorithms and several graph navigation and interaction methods. GEOMI is part of a new generation of visual analysis tools combining graph visualisation techniques with network analysis methods. GEOMI is available from http://www.cs.usyd.edu.au/ ∼ visual/valacon/geomi/.

IEEE Symposium on Information Visualization

Our visualisation of the IEEE InfoVis citation network is based on 3D graph visualisation techniq... more Our visualisation of the IEEE InfoVis citation network is based on 3D graph visualisation techniques. To make effective use of the third dimension we use a layered approach, constraining nodes to lie on parallel planes depending on parameters such as year of publication or link degree. Within the parallel planes nodes are arranged using a fast force-directed layout method. A number of clusters representing different research areas were identified using a self organising map approach.

Asia-Pacific Symposium on Visualisation 2007, APVIS 2007, Proceedings, 2007

In this paper, we present a case study for the visualisation and analysis of large and complex te... more In this paper, we present a case study for the visualisation and analysis of large and complex temporal multivariate networks derived from the Internet Movie DataBase (IMDB). Our approach is to integrate network analysis methods with visualisation in order to address scalability and complexity issues. In particular, we defined new analysis methods such as (p,q)-core and 4-ring to identify important dense subgraphs and short cycles from the huge bipartite graphs. We applied island analysis for a specific time slice in order to identify important and meaningful subgraphs. Further, a temporal Kevin Bacon graph and a temporal two mode network are extracted in order to provide insight and knowledge on the evolution.

2010 IEEE International Energy Conference, 2010

... Figure 3 shows the complete ramptime current control inverter and the switching signal genera... more ... Figure 3 shows the complete ramptime current control inverter and the switching signal generation. All details of ramptime implementation were reported before [14, 15]. ... [4] Eftichios Koutroulis, Kostas Kalaitzakis, " Design of a ... [10] Ion Boldea, "Variable speed generators", Book ...

MOJ Immunology, 2014

Type 1 Diabetes (T1D) is an autoimmune disease with both genetic and environmental components. Mo... more Type 1 Diabetes (T1D) is an autoimmune disease with both genetic and environmental components. More than 60 genes have been identified to affect the risk of T1D, with the HLA loci having the greatest impact on susceptibility. The association of T1D with alleles at HLA loci, especially the HLA class II genes DR and DQ, is well-established. However, other candidate genes may also have some significant impact on genetic susceptibility.

Medicine Science | International Medical Journal, 2015

Diarrhea is a common cause of death in developing countries and the second most common cause of i... more Diarrhea is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and electrolyte imbalances. Hence, the aim in the present study was to evaluate the effect of elemental zinc in treatment of diarrhea in children. 100 diarrheic patients (50 females) aged from 1-12 years old collected from the-clinics of pediatric department at Beni suef University Hospital, were divided into two equal groups. Group A received elemental Zinc in the form of Zinc Sulphate (10 mg elemental Zinc daily for infants and 20 mg for children) with the normal diarrhea treatment. Group B received the normal anti-diarrhea treatment only. There was no significant difference between the two groups regarding most of the parameters studied. However, the mean±SD recovery time in group A was significantly higher (p-value=0.019) than in group B. However, when antibiotic alone was used as anti-diarrheal treatment the recovery time in days in group A was less than in group B but with no significant difference. The expected beneficial efficacy of elemental Zinc in the form of Zinc Sulphate on the duration and severity of acute diarrhea was not observed. However, the study showed that Zinc may be effective in diarrhea due to bacterial infections.

Visual Information Communication, 2009

In this paper, we present new visual analysis methods for history of the FIFA World Cup competiti... more In this paper, we present new visual analysis methods for history of the FIFA World Cup competition data, a social network from Graph Drawing 2006 Competition. Our methods are based on the use of network analysis method, and new visualization methods for dynamic graphs with dynamic hierarchy and geographic clustering. More specifically, we derive a dynamic network with geographic clustering from the history of the FIFA World Cup competition data, based on who-beats-whom relationship. Combined with the centrality analysis (which defines dynamic hierarchy) and the use of the union of graphs (which determines the overall layout topology), we present three new visualization methods for dynamic graphs with dynamic hierarchy and geographic clustering: wheel layout, radial layout and hierarchical layout. Our experimental results show that our visual analysis methods can clearly reveal the overall winner of the World Cup competition history as well as the strong and weak countries. Further, one can analyze and compare the performance of each country for each year along the context with their overall performance. This enables to confirm the expected and discover the unexpected.