banner

A logarithmic formulation for anisotropic behavior characterization of bovine cortical bone tissue in long bones undergoing uniaxial compression at different speeds

The mechanical properties of bone tissues change significantly within the bone body, since it is considered as a heterogeneous material. The characterization of bone mechanical properties is necessary for many studies, such as in prosthesis design. An experimental uniaxial compression study is carried out in this work on bovine cortical bone tissue in long bones (femur and tibia) at several speeds to characterize its anisotropic behavior. Several samples from different regions are taken, and the result selection is carried out considering the worst situations and failure modes. When

Mechanical Design

UML Modeling of Online Public Bus Reservation System in Egypt

Designing a proper public transportation system is a main concern for many countries with large population size like Egypt. Therefore, the online based transportation business for individuals is highly growing in Egypt and the concept of online reservation in the transportation field has arisen. In this paper, a model in the analysis phase for an online public bus reservation system (OPBRS) is proposed. The system is large, complex and includes many interrelated functions. Therefore, the object-oriented modeling approach is chosen for developing the system by using the industry standard

Mechanical Design

Prediction of Internal Flow's Characteristics around Two Cylinders in Tandem using optimal T-S fuzzy

Laminar unsteady incompressible flow past two-cylinders in tandem is investigated numerically. The vortex shedding over the cylinders' arrangement is studied at various Reynolds numbers and blockage ratios while changing the distance between the two cylinders. The output from the numerical simulations is used to feed different regression methodologies to find the optimal approach for the proposed system modeling and identification. Artificial Neural Network (ANN) using Levenberg-Marquardt Algorithm (LM) training algorithm is used, as well as Takagi-Sugeno (T-S) fuzzy model are used and

Mechanical Design

Prediction of the Hitec Molten Salt Convective Heat Transfer Performance Using Artificial Neural Networks

Hitec molten salt is a ternary eutectic mixture salt that is used as an energy storage medium in concentrated solar power plants to improve the system performance and reduce the operational cost. Thus, the heat transfer performance represented in Nusselt number has been investigated numerically under different inlet temperature and velocity conditions with constant uniform side heat flux. Also, friction factor and mass flow rate are studied numerically. CFD input/output data with 40 studied cases are used as a training dataset of a 2-layer Neural Network for thermo-hydro fields’ accelerated

Mechanical Design

E-learning system model for university education using uml

High quality education should be the top priority for any nation seeking prosperity. This paper aims to present a conceptual model for e-learning system for developing countries. This is achieved adopting an object-oriented approach and Unified Modeling Language (UML). The functional and dynamic views of the system are presented and explained within this framework. The functional system includes Use Case diagrams and activity diagrams which are developed based on predefined functional requirements of the system. Furthermore, in the dynamic view of the system, interaction diagrams are developed

Mechanical Design

Effect of thickness and temperature on flexible organic P3HT:PCBM solar cell performance

A blend of poly 3-hexylthiophene (P3HT) and [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) is used as a photoactive layer for simulating a bulk heterojunction organic solar using general-purpose photovoltaic device model (GPVDM) software. The optical and electrical performance of the cell had been analyzed by changing the thickness of each layer and substrate material over a range of operating temperatures from -10 °C to - 40 °C. The flexible device exhibits higher PCE compared to a rigid device. The performance of the device was studied using transient simulation at different operating

Software and Communications
Mechanical Design

Enhancing barrier properties of chitosan extracted from shrimp shells as a sustainable material for active packaging using natural wastes

Due to the environmental concerns, much responsiveness has been paid to natural polymers and recycle wastes. Disposal of wastes like marine wastes and domestic wastes end up in landfills and open areas which cause environmental crisis. The development of biodegradable active packaging materials is one of the alternatives to reduce the using of synthetic petroleum-based plastics. Biodegradable films are made from biopolymers that were shown to have affinities in improving the shelf life of food product. © 2021 Nova Science Publishers, Inc.

Mechanical Design

Stabilized variational formulation of an oldroyd-B fluid flow equations on a Graphic Processing Unit (GPU) architecture

The governing equations of the flow of an oldroyd-B fluid are discretized using the finite element method. To overcome the convective nature of the momentum equation, the Galerkin/Least-Squares Finite Element Method (GLS/FEM) is used while the Discrete Elastic–Viscous Stress-Splitting (DEVSS) method is used to overcome the instability due to the absence of diffusion in the constitutive equations. The discretized equations are implemented on a hybrid system between the Graphics Processing Unit (GPU) architecture using Compute-Unified-Device-Architecture (CUDA) and a multi-core CPU. The

Mechanical Design

Efficient Finite Element Modeling of Complex HVAC Applications

A new Finite element model for HVAC applications is introduced. The model incorporates flow turbulence, buoyancy effects and unsteadiness. Also, the model accommodates complicated boundaries due to complex geometries and perforated tiles. Experimental validation is provided and extensive results for flow and temperature contours are presented. Temporal and spatial resolution prove that the model can capture important HVAC features as thermal comfort, buoyancy induced flow, complex boundaries. © 2020 IEEE.

Mechanical Design

Comparative Study of Nusselt Number Correlations for Hitec Molten Salt

Molten salt has been realized as a potential candidate as a clean non-pollutant heat transfer fluid for concentrated solar power plants because of its high heat capacity and broad ranges of operational temperatures. In this study, the Nusselt number of the commercially known Hitec molten salt is numerically assessed, using k-ϵ model turbulence model with non-equilibrium wall functions, for the ranges of 104-105 Reynolds number and 104-105 W/m2 uniform surface heat flux. Moreover, the present work is compared against previously published work with success. The proposed numerical model provides

Mechanical Design