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Search Results: 1 - 10 of 463883 matches for " Esam A. Ismail "
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Impact of Surface Water and Groundwater Pollutions on Irrigated Soil, El Minia Province, Northern Upper Egypt  [PDF]
Rafat Zaki, Esam A. Ismail, Wagih S. Mohamed, Ali Kamel Ali
Journal of Water Resource and Protection (JWARP) , 2015, DOI: 10.4236/jwarp.2015.717120
Abstract: Current research has been focused on heavy metals pollution in surface water and groundwater and effect on irrigated soil from El Minia Province, north Upper Egypt. Concentration of heavy metals (e.g., As, Co, Hg, Ni, Se, Cd and Cr) in surface water, groundwater and irrigated soil samples is most significantly affected by leachate of many pollutants as the factories, agricultural activities, urban and natural processes. Microbiological parameters and microscopic investigations are revealed that some localities are common by micro-organisms, which are unsuitable for drinking waters.
Land Use and Land Cover Changes of West Tahta Region, Sohag Governorate, Upper Egypt  [PDF]
Ismail Esam, Faid Abdalla, Niesner Erich
Journal of Geographic Information System (JGIS) , 2012, DOI: 10.4236/jgis.2012.46053
Abstract: Due to the growing of population in Egypt during the last few decades, great changes in agricultural area, and urbanization of Egypt art occurred. In this study we utilized the available record of multitemporal Land sat Thematic Mapper (Tm) and Egyptsat image to produce land cover/land use map of the area between 1987 and 2009. Also we used the post-classification change detection analysis to detect the change in the agriculture, urban areas and the change in the River Nile during the period between 1987 and 2009. The post-classification change detection analysis shows that agriculture development increased by 1785.96 Hectare through the study period with average annual rate of land reclamation 81.18 Hectare/year. While the urban area increased by 2231.24 Hectare with average annual rate 101.42 Hectare/ year the increase of the urbanization and the growth occurring through encroachment into the farmer old cultivated lands. The change in the River Nile is not so much is reached to 138.32 hectare in the study period with average annual rate 6.29 Hectare/year. The result of this study show that, the accuracy are quantify with the land cover changes and also delineate their spatial patterns, which display the efficiency of land sat in evaluating landscape dynamics over a particular time span. This data are very useful for natural resources management.
Comparison of the Groundwater Quality in the West Tahta Area, Upper Egypt in 1989 and 2011  [PDF]
Ismail Esam, Faid Abdalla, Niesner Erich, Mauritsch Hermann
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.311162
Abstract: Egypt is characterized by arid climate with rare rainfall that means surface water. The River Nile is the main source of water supply. The study area is located in Upper Egypt in the western desert. The area under investigation is subjected to intensive development in the last twenty years, clearly seen in the change of the agriculture and urban areas. The rapid increase of the population in Egypt especially in the upper part leads to an increasing demand for houses on the old cultivated land lead to the migration towards the desert and reclaimed new areas. These new reclaimed areas are depending on the ground water. The extensive use of groundwater and increasing fertilizing system leads to the change of the water table, characterization and quality. In this study we use the analysis of 30 groundwater samples collected and analyzed in 1989 and 28 groundwater samples collected and analyzed in 2011 from the same area to identify the change in the quality of the ground water. According the hydrogeologic data which were collected from the study area in 1989 and 2011 we found a changing water table decreasing, from 1 to 48 m in 1989 and 5 to 60 m in 2011. The water level is decreasing in the same direction towards the River Nile. The sufficient recharge and leaching and dissolution of the aquifer materials due to extensive use lead to increase in TDS which reaching to 4453 ppm in 2011. The water type in the 1989 samples is mainly NaHCO3 and in 2011 samples Na2SO4. Grid classification shows that the water samples collected in 1989 are mainly sodium bicarbonate and sodium chloride extending to sodium sulphate while the water samples collected in 2011 are mainly sodium sulphate and sodium chloride. Most of the 1989 groundwater samples are suitable for drinking purposes while majority of the 2011 groundwater samples are not suitable due to high salinity.
Groundwater Management in the Esna City, Upper Egypt: An Application of Remote Sensing and Numerical Modeling  [PDF]
Manal Abdel Monem, Abdalla Faid, Esam Ismail, Matthias Sch?niger
Natural Resources (NR) , 2014, DOI: 10.4236/nr.2014.512063
Abstract: The major issues concerning water development and management include water conservation and the efficiency of water use, cost recovery, social and environmental factors. So continuous monitoring is essential to evaluate the reclamation impacts on the groundwater potentiality such as Esna Area. The main objective of this work is to determine the new development areas in Esna during the period from 1984 to 2011 using remote sensing technique. The impacts of the present and future development have been evaluated by using the two-dimensional numerical groundwater flow Simulation Package (visual modflow 4.2). The package is used to construct and calibrate a numerical model that can be used to simulate the response of the aquifer in the study area under implementing different management alternatives in the form of changes in piezometric levels and salinity. From land use maps of the study area in the year 2011, a lot of changes in development areas especially out the border of the old land were observed. The change in land reclaimed area was estimated with 44% in the period from year 1984 to 2011. This development accompanied with draw down about 2.5 meters through this period of time. The authors recommend applying different kinds of change detection technique on the study area. Comparing between results, continuous monitoring of the development area is highly recommended.
Turbo Decoder for Low-Power Ultrawideband Communication Systems
Esam A. Obiedat,Lei Cao
International Journal of Digital Multimedia Broadcasting , 2008, DOI: 10.1155/2008/897069
Abstract: A new method to reduce the computational complexity of the turbo decoding in ultrawideband (UWB) orthogonal frequency division multiplexing (OFDM) system is proposed. Existing stopping techniques for turbo decoding process using constrained decoding assume fixed signal-to-noise ratio (SNR) for all the OFDM symbol bits so they fail to yield an acceptable bit-error rate (BER) performance in multicarrier systems. In this paper, we propose a bit-level stopping technique for turbo decoding process based on the constrained decoding method. In this technique, we combine the cyclic redundancy check (CRC) with an adaptive threshold on the log likelihood ratio (LLR) on each subcarrier to detect for convergence. The threshold is adaptive in the sense that the threshold on the LLR of a bit is determined by the average SNR of the OFDM symbol and the channel gain of the transmission subcarrier. Results show that when the channel state information (CSI) is used to determine the threshold on LLR, the stopping technique can reduce the computational complexity by about 0.5–2.5 equivalent iterations compared to GENIE turbo without degradation in the BER performance.
Surface investigation of chitosan film with fatty acid monolayers
Esam A. El-hefian
Maejo International Journal of Science and Technology , 2009,
Abstract: The surface pressure- molecular area ( -A) isotherm curves of two fatty acids of different chain lengths, i.e. stearic (C18) and arachidic (C20) acids, were obtained by using Langmuir-Blodgett (LB) technique. Results showed clear isotherm plots with limiting mean molecular area around 21 2 for both acids. However, the monolayer was found to collapse at higher than 33 mN m-1 and 21 mN m-1 for stearic acid and arachidic acid respectively. The effect of Langmuir-Blodgett monolayers of the acids was investigated by atomic force microscopy (AFM). Chitosan film, before and after dipping in water, was also studied by means of AFM so that it could be used for comparison. It was found that the surface of chitosan was more homogeneous and smoother after dipping in water. In addition, more homogeneous surfaces were achieved after transferring a layer of the fatty acid onto the substrate.
Characterisation of chitosan solubilised in aqueous formic and acetic acids
Esam A. El-hefian
Maejo International Journal of Science and Technology , 2009,
Abstract: The intrinsic viscosity of chitosan (MW 7.9 x 105 g mol-1) having a high degree of deacetylation and solubilised in aqueous formic and acetic acids was determined at room temperature. Contact angle and conductivity of the chitosan solutions were also studied. The values of critical coagulation concentration (CCC) were then obtained from the plots of contact angle or conductivity versus concentration.
Effects of temperature, shearing time and rate of shear on the viscosity of chitosan/agar-blend solutions
Esam A. El-hefian
Maejo International Journal of Science and Technology , 2010,
Abstract: In this study, a number of aqueous solutions of chitosan/agar blends (with chitosan as the major component) were prepared. The effects of temperature, shear rate and shearing time on the rheological property, i.e. the apparent viscosity, were investigated for the blend solutions. Results show that a non-Newtonian behaviour was pronounced at temperatures from 20oC to 50oC for all solutions and that a decrease in viscosity with increasing temperature was also observed. It was also found that all the blend solutions obeyed the Arrhenius equation to different degrees. In addition, shearing time independence was found to occur at a low shear rate only for pure chitosan solution. However, the shearing time independence slowly shifted to occur at higher shear rate with increasing agar content.
Rheological study of chitosan and its blends: An overview
Esam A. El-hefian
Maejo International Journal of Science and Technology , 2010,
Abstract: Chitosan, a modified natural carbohydrate polymer derived from carapaces of crabs and shrimps, has received a great deal of attention for its applications in diverse fields owing to its biodegradability, biocompatibility, non-toxicity and anti-bacterial property. The wide-ranging applications involve a broad spectrum of characterisation techniques and rheology represents one technique of growing importance in this field. This paper is an attempt to review the latest development in the rheology of chitosan, either on its own or associated with other materials, including the parameters that strongly influence its rheological behaviour such as concentration, pH and temperature.
Secure Hop-by-Hop Aggregation of End-to-End Concealed Data in Wireless Sensor Networks
Esam Mlaih,Salah A. Aly
Mathematics , 2008,
Abstract: In-network data aggregation is an essential technique in mission critical wireless sensor networks (WSNs) for achieving effective transmission and hence better power conservation. Common security protocols for aggregated WSNs are either hop-by-hop or end-to-end, each of which has its own encryption schemes considering different security primitives. End-to-end encrypted data aggregation protocols introduce maximum data secrecy with in-efficient data aggregation and more vulnerability to active attacks, while hop-by-hop data aggregation protocols introduce maximum data integrity with efficient data aggregation and more vulnerability to passive attacks. In this paper, we propose a secure aggregation protocol for aggregated WSNs deployed in hostile environments in which dual attack modes are present. Our proposed protocol is a blend of flexible data aggregation as in hop-by-hop protocols and optimal data confidentiality as in end-to-end protocols. Our protocol introduces an efficient O(1) heuristic for checking data integrity along with cost-effective heuristic-based divide and conquer attestation process which is $O(\ln{n})$ in average -O(n) in the worst scenario- for further verification of aggregated results.
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