Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Stability


Improving The Stability of GRP Routing Protocol

Turkan A. Khaleel; Ahmed M. Fadhil; RanaKh.Sabri

Engineering and Technology Journal, 2016, Volume 34, Issue 6, Pages 1142-1149

More recent works aim at enhancing MANET performance, because of the multiple problems caused by the wireless transmission constraints. The problem that faces the routing protocol is to obtain the stable path with nodes movement. A route between a source to destination is called "stable" if it consists of mainly stable neighbors at each intermediate hops. In this paper, a Geographic Routing Protocol (GRP) algorithm was chosen as a MANET routing protocol to be modified for stability. A new protocol wasthen created called SGRP routing protocol which workslikethe GRP routing algorithm, but with some modification to obtain better link stability. The main objective of this research is to decrease the time delay caused by wireless network and enhance the network performance by selecting the best route in the set of available routes that will have the least distance and highest neighbor stability. The model for this research has been designed and simulated by using C/C++ language embedded in the OPNET Modeler 14.5 software package. The SGRP routing model has been compared with the original GRP protocol. Acceptable results have been obtained depending upon the performance of metrics (MANET delay, total packets dropped and Throughput). The average MANET Delay and total packets dropped during the use of SGRP have decreased, while the throughput was acceptable.

Experimental Stability and Thermal Characteristics Enhancement Analysis of Water Based Boehmite Nano fluid

Atia; Mohammed Hussein J. Al; Sarah A. Abed

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1193-1210

In this work attempt was made to formulate water based boehmite (AlOOH) nanofluid in one and two steps methods. Boehmite is the first born alumina phase as prepared by sol gel route using aluminum isopropoxide precursor, exhibit a combination of excellent consistency and dispersibility in water. Plain nanofluids containing boehmite at different concentrations were investigated for colloidal, suspensions and/or dispersions stability and thermal conductivity enhancement. X-ray diffraction analysis, laser diffraction particle size analysis, viscosity, thermal conductivity measurements, TG/DSC thermal analysis and sedimentation balance were used as characterization tools. The results show promising long-term fluid stability and thermal conductivity enhancement relative to starting based fluid following non-linear dependence on particles concentration. The maximum 2.7 times enhancement in thermal conductivity occurred at narrow boehmite concentration range as a result of achieving optimum nanoparticles aggregation level where neither the case of nanoparticles homogenous dispersion nor the case of fully aggregated clusters could retain these enhancements values. This far beyond behavior from Maxwell's model was explained on the basis of the known mechanisms of thermal conductivity enhancement of nanofluids.

Enhanced Aggregate-Asphalt Adhesion and Stability of Local Hot Mix Asphalt

Alaa H. Abed

Engineering and Technology Journal, 2011, Volume 29, Issue 10, Pages 2044-2059

A polymer modification is used to improve the fundamental properties of
asphalt binders as those properties relate to the performance of asphalt mixtures.Adhesion and cohesion are two important related properties of asphalt binders that can affect asphalt mixture performance. The first target of this study is to quantify
the effects of polymers on the adhesion and cohesion of the binders. Two types of stones are used in this study, limestone and sandstone. The pneumatic adhesion tensile tester (PATTI) is used to measure the pull-off tensile strength in Wisconsin University, it is found that the tensile strength between limestone and styrene butadiene styrene (SBS) polymer increase 26% to 55% as using 2% and 4% of SBS respectively, while increase 54% to 76% when use 2% and 3.5% of Functionalized Polyethylene (PE) polymer respectively. For sandstone, 2% and
4% of SBS causes increasing the strength 5% and 18% respectively, while these values becomes 29% and 51% for asphalt binder modified with 2% and 3.5% of PE respectively. The second objective of this paper is to find the effect of the fine aggregate and polymer on the stability of the local asphalt mixture. To achieve this target two
blends have been selected, the first blend is passing under restricted zone (Sshaped blend) and second blend passing through restricted zone (fine blend). The pressure distribution analyzer (PDA) which is developed to Gyratory Load-cell Plate assembly (GLPA) by asphalt research group in Wisconsin University to measure and evaluate the resistance of mixture to distortion, the (PDA) is placed
in the gyratory compactor mold and provide load measure which is recorded simultaneously with deflection, the vertical load and the eccentricity of the load are measured using three load cells placed at the edge of the plate, the measurements are used to calculate the resistive effort (w) as a function of number of gyrations. Functionalized polyethylene (PE) polymer and styrene-butadienestyrene
(SBS) are used to show effect of polymers on Construction Force Index
(CFI) which is related to the amount of the work done for rising density of the mix to 92%. The results indicated that CFI is reduced by about 68% as using 3.5% of PE, while it is reduced about 42% when using 4% of SBS which give good indication for contractors to use polymers for reducing cost. Resistive effort results show that fine blend has higher stability than coarse (S-shape) blend,all the tests of local asphalt binders are done in the University of Wisconsin-Madison- USA.

Convergence of The Discrete Classical Optimal Control Problem To The Continuous Classical Optimal Control Problem Including A Nonlinear Hyperbolic P.D. Equation

Jamil A. Ali Al-Hawasy

Engineering and Technology Journal, 2010, Volume 28, Issue 14, Pages 4687-4702

Our focus in this paper is to study the behaviour in the limit of the discrete classical optimal control problem including partial differential equations of nonlinear hyperbolic type. We study that the discrete state and its discrete derivative are stable in Hilbert spaces 1 H0(W) and L2(W) respectively. The discrete state equations containing discrete controls converge to the continuous state equations. The convergent of a subsequence of the sequence of discrete classical optimal for the discrete optimal control problem, to a continuous classical optimal control for the continuous optimal control problem is proved. Finally the necessary conditions for optimality of the discrete classical optimal control problem converge to the necessary conditions for optimality of the continuous optimal control problem, so as the minimum principle in blockwise form for optimality.