Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Poisson

Numerically and Theoretically Studying of the Upper Composite Complete Prosthetic Denture

Sihama I. Salih; Jawad K. Oleiwi; Qahtan A. Hamad

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 1023-1037

The current study focused on the manufacturing and development properties of upper prosthesis complete denture from composite materials with the basis cold cured resin of poly methyl methacrylate as new fluid resin and reinforced materials by two different types of particles (nano-hydroxyapatite (nHA), micro zirconia (ZrO2)), that added with different volume fractions of (1%, 2% and 3%), and the different types of woven fibers (Glass fiber, Kevlar fiber), it were added with a fixed volume fraction of (5%) to PMMA composites.Specimens’ consist of a six groups where prepared by using (Hand Lay-Up) method from the composites materials and hybrid laminated composites materials. This research includes theoretical and numerical studies by using finite element method to confirming the experimental results of the effect of selected volume fractions of theseparticles and fibers on the (total deformation distribution, equivalent elastic strain and equivalent Von Mises stress) of the composite prosthetic dentures.
The theoretical part included calculations the values of theoretical safety factor and Poisson's ratio. While the numerical part based on finite element method (F.E.M), which was performed by using program (ANSYS-15) to analyze the prepared of denture composite materials and evaluate its characteristics which represent total deformation distribution, equivalent stress and equivalent elastic strain. This was performed by obtaining twenty one models for the PMMA composite dental prostheses which were treated as three dimension structure. The numerical results of the F.E.A showed coincided with some of the experimental results.

A Method For Detect Forgery from Images

Hanaa Mohsin Ahmed; Sabaa Rakan Salim

Engineering and Technology Journal, 2015, Volume 33, Issue 2, Pages 259-272

Due to the availability of many image editing and processing tools, it is possible to easily change the information represented by a digital paintings without leaving any obvious traces of tampering, which led to the problem of verification image. These issues of multimedia security have led to the development of several approaches to tampering detection. Digital image forensic is a branch that deals with the identity and authenticity of the images.
The proposed system is the Verification system for paintings. Where the Verification system used non-blind passive image forensic, and that it has been achieved by using fuzzy gradient based image reconstruction, which is able to detect all types of forgery (Splicing, Image Retouching, Geometrical Transformation, Copy Move Attack, other type) and also able to compute forgery ratio as percentage.
This methodology has its application in a context where the source image is available.The experimental results show that the algorithm can effectively locate the tampered area in multi block size 4X4 of any type, and using fuzzy process is obtained a good result to reduce time consuming for solving image reconstruction and also enhancement reconstruction image .

Mechanical Properties of High-Strength Fiber Reinforced Concrete

Zaid Muhammad Kani Al-Azzawi; Kaiss Sarsam

Engineering and Technology Journal, 2010, Volume 28, Issue 12, Pages 2442-2453

Experimental results of this work in addition to a wide range of data from previous work
were analyzed to study the mechanical properties and strength of high-strength concrete with and
without fibers. Different types of steel fibers (straight, hooked, duoform, crimped) with a volume
fraction ranging from 0 to 2 percent were studied. The concrete compressive strength ranged from 41
to 115 MPa. The influence of fiber on the compressive strength, axial strain, modulus of elasticity,
Poisson's ratio, modulus of rupture, and splitting tensile strength, were studied. In addition to that,
size effect of control specimens on high-strength fiber reinforced concrete materials, was observed.
The main conclusion indicates that high-strength concrete (HSC) properties, especially with fibers
are significantly different from normal-strength concrete (NSC).