Background: The buckling load as well as the natural frequency under axial load for non-prismatic beam is a changeling problem. Determination of buckling load, natural frequency, and elastic deflection is very important in civil applications. The current paper used both perturbation method (PM), analytic method, and differential quadrature method (DQM), numerical method, to find buckling load and natural frequency with different end supports. The deflection of the beam resting on an elastic foundation under transverse distributed and axial loads is also obtained. Both PM and DQM are used for

Water waves propagation over submerged obstacles is considered. The problem serves as an efficient model for modeling breakwaters. A numerical wave tank is developed to simulate the induced flow field. The model is based on multiphase viscous flow assumptions. Computations are performed adopting clustered grids and suitable initial and boundary conditions. The results are verified using the flow field particle image velocimetry (PIV) measurements. Spatial and temporal resolutions are validated. Complex flow phenomena occurring due to the presence of the relatively large sized obstacle are

The unsteady flow field variations between healthy and diseased three-dimensional rigid posterior cerebral artery are numerically investigated. The Computational hemodynamic simulations have been known to provide valuable clinical information to researchers and surgeons that proved to be crucial for the assessment of medical risks, pre-surgical conditioning and treatment planning. The wall shear stress (WSS) and wall pressure are the most important hemodynamic variables, and both are used to give accurate description about the health status of the artery. The results showed that at the

Unmanned Aerial Vehicles (UAVs) are increasingly being used in many challenging and diversified applications. These applications belong to the civilian and the military fields. To name a few; infrastructure inspection, traffic patrolling, remote sensing, mapping, surveillance, rescuing humans and animals, environment monitoring, and Intelligence, Surveillance, Target Acquisition, and Reconnaissance (ISTAR) operations. However, the use of UAVs in these applications needs a substantial level of autonomy. In other words, UAVs should have the ability to accomplish planned missions in unexpected

This paper proposes a technique based on a MAT-LAB code capable of getting an optimized preliminary design of an efficient low-speed compressor qualified for laboratory experiments with relatively low cost. The code was made to design five repeated compressor stages on two steps conducted iteratively, namely 'mean line and radial design' to determine the optimum compressor geometry and then the 'off-design' to test the stability of the design in other working conditions. The optimization tool minimizes a flexible cost function which can be changed if needed to get different designs. A certain

In this paper, we characterize the asymmetric total degrees of freedom (DoF) of a multiple-input multiple-output (MIMO) 3-way channel. Each node has a separate-antenna full-duplex MIMO transceiver with a different number of antennas, where each antenna can be configured for either signal transmission or reception. Each node has two unicast messages to be delivered to the two other nodes. We first derive upper bounds on the total DoF of the system. Cut-set bounds in conjunction with genie-aided bounds are derived to characterize the achievable total DoF. Afterwards, we analytically derive the

The widespread usage of wireless local area networks and mobile devices has fostered the interest in localization systems for wireless environments. The majority of research in the context of wirelessbased localization systems has focused on device-based active localization, in which a device is attached to tracked entities. Recently, device-free passive localization (DfP) has been proposed where the tracked entity is neither required to carry devices nor participate actively in the localization process. DfP systems are based on the fact that RF signals are affected by the presence of people

Soil contamination with petroleum products and/or waste are a problem that can be detected nearby industrial areas and other amenities that include underground leaking tanks or pipelines. The negative effect of oil contamination on the soil properties is significant and can completely alter the strength as well as the serviceability limit states of the bearing stratum. In this study, Diesel was mixed with cohesionless soils using four different mixing percentages, starting with 5% up to 13.5% by weight, to cover a wide range of contamination ratios. The effects of contamination on the soil

Expanded polystyrene (EPS) has long been used to reduce stresses acting on buried structures. In this study, the efficiency of utilising EPS in reducing vertical stresses acting on cut-and-cover tunnels was investigated. To gauge this, short- and long-term shear strength parameters of EPS with densities of 25, 30, and 35 kg/m3 were determined. Interface friction of EPS with various materials was measured considering the use of geotextile as a protective cover for EPS. Laboratory testing included unconfined compression, creep strain based on time-temperature-stress superposition, and modified

Recently, the construction of water structures and seepage reduction are critical issues. This importance was induced due to the required specifications for the desired type of concrete. Mechanical strength and permeability are the two major parameters in achieving the design mix efficiently. This study investigates the effect of different types of admixures on the performance of concrete. The performance of concrete was evaluated using the mechanical strength and permeability tests. The concrete mixes admixtures include A retarder (Sika R2004 type G), water proofing material (addicrete DM2)