The main target of this paper is to determine the optimum time for preventive maintenance on machines. Tow methods has been implemented estimating the optimum time duration for preventive maintenance . the first techniques use scheduling depending on data concerning the machine maintenance cost and halted cost from the production reach to the optimum time for maintenance which reflect the minimum cost. Where as the second techniques depends on reability function to estimate the optimum duration time which reflect the minimum cost. The tow techniques above by which we count on in fixing the preventive maintenance both give same result . we also prove that the scheduling method best than the reability function .

In this paper, a discretization of a three-dimensional fractional-order prey-predator model has been investigated with Holling type III functional response. All its fixed points are determined; also, their local stability is investigated. We extend the discretized system to an optimal control problem to get the optimal harvesting amount. For this, the discrete-time Pontryagin’s maximum principle is used. Finally, numerical simulation results are given to confirm the theoretical outputs as well as to solve the optimality problem.

In present work the effort has been put in finding the most suitable color model for the application of information hiding in color images. We test the most commonly used color models; RGB, YIQ, YUV, YCbCr1 and YCbCr2. The same procedures of embedding, detection and evaluation were applied to find which color model is most appropriate for information hiding. The new in this work, we take into consideration the value of errors that generated during transformations among color models. The results show YUV and YIQ color models are the best for information hiding in color images.

An Optimal Algorithm for HTML Page Building Process

The current study aimed to standardize the multi-position suicidal tendency scale MAST in the Saudi environment as well as to assess suicidal tendencies in adolescents. Moreover, the study aimed to test the psychometric characteristics of the scale among a sample of (490) high school and undergraduate students, in the adolescence who ranging in age from (16-21) years. The scale demonstrated satisfactory internal consistency in terms of validity and reliability tests. as the results showed of exploratory factor analysis to the four dimensions of suicidal tendencies loading on two factors that accommodate 74.60% of the overall variance of the scale (1) the attitude toward life,  and absorbs 43, 20% of the total variance of the scale,

In this research is estimated the function of reliability dynamic of multi state systems  and their compounds and for three types of systems (serial, parallel, 2-out-of-3) and about two states (Failure and repair) depending on calculating the structur function allow to describing the behavior of

The effect of solution heat treatment on the mechanical properties of Aluminum-Copper alloy. (2024-T3) by the rolling process is investigated. The solution heat treatment was implemented by heating the sheets to 480 C° and quenching them by water; then forming by rolling for many passes. And then natural aging is done for one month. Mechanical properties (tensile strength and hardness) are evaluated and the results are compared with the metal without treatment during the rolling process. ANSYS analysis is used to show the stresses distribution in the sheet during the rolling process.  It has been seen that good mechanical properties are evident in the alloy without heat treatment due to the strain hardening and also the mechanical

Purpose To extract the lower anterior teeth, the oral surgeon needs to anesthetize the pulpal tissue of the accused tooth and the surrounding tissues. The lingual nerve innervates the lingual soft tissue to the lower teeth, this nerve usually anesthetized alongside the inferior alveolar nerve by a block technique. However, the lingual tissue of the lower anterior teeth usually anesthetized by either infiltration or periodontal ligament injection (PDL) techniques. This study was intended to compare between these two techniques. Methods Forty-eight teeth were extracted from 24 patients. Non-adjacent two lower anterior teeth in the same patient were selected. The lingual soft tissue in one of them was anesthetized by PDL injection technique wh