The aim of this paper is to introduce and analyze chaotic and hyperchaotic conservative complex nonlinear systems. These systems appear in several branches of applied sciences. Lyapunov exponents are calculated to observe chaotic and hyperchaotic behaviors. The wide range of systems parameters at which chaotic and hyperchaotic solutions exist is calculated. The modules for complex variables are computed and plotted. The projections of chaotic and hyperchaotic solutions are shown in 3- spaces and 2-planes. The systems of this paper leave rooms for further studies in the near future, e.g. control and several types of synchronization of the solutions of these systems.

MHD mixed convection of Cu-water nanofluid in a two- sided lid -driven porous cavity with a partial slip is investigated

The effect of an inclined magnetic field on the mixed convection flow in a trapezoidal cavity is investicated

The aim of this paper is to introduce a generalized form of the Lorenz system with time delay. Instead of considering each state variable of the Lorenz system belonging to R, the paper considers two of them belonging to Rn. Hence the Lorenz system has (2n + 1) dimension. This system appears in several applied sciences such as engineering, physics and networks. The stability of the trivial and nontrivial fixed points and the existence of Hopf bifurcations are studied analytically. Using the normal form theory and center manifold argument, the direction and the stability of the bifurcating periodic solutions are determined. Finally, numerical simulations are calculated to confirm our theoretical results. The paper concludes that the dynamics of this system are rich. Additionally, the values of the delay parameter at which chaotic and hyperchaotic solutions exist for different values of n using Lyapunov exponents and Kolmogorov-Sinai entropy are calculated numerically.

The passivity theory is used to achieve projective synchronization in coupled partially linear complex-variable systems with known parameters. By using this theory, the control law is thus adopted to make state vectors asymptotically synchronized up to a desired scaling factor. This paper deals with sending different large messages which include image and voice signals. The theoretical foundation of the projective synchronization based on the passivity theory is exploited for application to secure communications. The numerical simulations of secure communication are used to send large message,an image and sound (voice) signal. The errors are controlled to zero that show the agreement between theoretical and numerical simulations results.

MHD mixed convection of localized heat source/ sink in a nanofluid- filled lid- driven square cavity with partial slip is investigated

Groundwater is a major water resource in Assiut governorate. Vulnerability assessment to delineate areas that are more susceptible to contamination from anthropogenic sources has become an important element for sensible water resources management and land use planning. Potential contamination of groundwater at any specified location depends upon several physical and environmental factors, such as depth to groundwater, soil type, groundwater recharge and of course aquifer composition. Few attempts have been made to assess the potential of groundwater contamination at the Nile Aquifer at Assiut governorate, however, these attempts focused on local, or site by site basis. This contribution aims at estimating a regional groundwater vulnerability assessment for the Nile Valley aquifer in Assiut governorate by applying DRASTIC model along with GIS (ArcMap 10.x) as an effective method for groundwater pollution risk assessment. The GIS technique has provided efficient environment for analyses and high capabilities of handling large spatial data and overlaying several thematic map layers. DRASTIC is an acronym for seven variables that control the groundwater contamination potential (Depth to water, net Recharge, Aquifer media, Soil media, Topography, Impact of the vadoze zone, and Conductivity of the aquifer) designed for characterizing the hydrogeological setting and evaluating aquifer vulnerability. This approach allowed investigating the potential of groundwater pollution on a regional scale of the study area. Using the variables given in the DRASTIC model, successive GIS-theme maps were developed describing the geometry of the area as well as the groundwater quality. These map layers were then combined in GIS to formulate the final groundwater pollution potential map. Some parts of the Nile Aquifer at Assiut governorate were dominated by “High” vulnerability classes, especially within the urban areas and settlements, while other parts were characterized by “Moderate” vulnerability classes. The elevated desert fringes of the study area obviously displayed “Low” aquifer vulnerability.

Groundwater resources in coastal aquifers constitute a main source of freshwater in many regions around the globe. This is typically true in arid and semi-arid regions where rainfall is scarce and infrequent and the surface water resources are almost absent. The consequences of climate changes and global warming on the freshwater in coastal aquifers have been investigated by several researchers over the last two decades. Due to the expected increase in the global temperature and the associated expansion of water in

Groundwater resources in coastal aquifers constitute a main source of freshwater in many regions around the globe. This is typically true in arid and semi-arid regions where rainfall is scarce and infrequent and the surface water resources are almost absent. The consequences of climate changes and global warming on the freshwater in coastal aquifers have been investigated by several researchers over the last two decades. Due to the expected increase in the global temperature and the associated expansion of water in

Understanding of the continuous dynamic relationship between water availability and land use /land cover change (LUCC) is an essential step in urban development planning. This is particularly crucial in dryland environments, where water and fertile soil are very limited and nonrenewable. Dakhla Oasis is located in the heart of the Western Desert of Egypt, 190 km to the west of Kharga Oasis, and is the oasis furthest from the main settlements of Egypt. Dakhla Oasis contains highly fertile lands and is rich in groundwater. It supports a relatively high population compared to Kharga Oasis with about 100,000 inhabitants. Groundwater is the only water source for irrigation and domestic use. The economy of Dakhla depends on several industries including agriculture, handicrafts and tourism. This paper presents the main results of an interdisciplinary research project in Dakhla Oasis with special emphasis on Rashda Village within the Oasis. The study is a model investigation of groundwater resources, land use/land cover and their link with demographic characteristics. One 1972 Landsat Multispectral Scanner System image, two 1984 Landsat Thematic Mapper images and Six 2011 SPOT4 satellite images were used for LUCC detection. In addition, a detailed database of groundwater extraction from 1960 to 2005 was available. Supervised image classification and visual interpretation were integrated to achieve more accurate LUCC maps. The results show that the study area has undergone very severe land cover changes with significant increases in urban settlements and in agricultural land. Local aquifer recharge and recovery fails to compensate for artificial groundwater extraction. The overall discharge increased between 1976 and 2006 by 54% to 62%, in different areas. This was associated with increases in population ranging from 8.5% to 150% in the same period. If extraction continues at current rates, pumping with current technology will become uneconomical in the next 90 years.