In this study, generation of elliptical gears with different teeth profiles of crowned involute, double circular arc (DCA), and combined (crowned involute with DCA) has been developed. The resulting mathematical equations have been computerized and feed to CNC end mill machine to manufacture elliptical gear models with different profiles. These models are investigated in plane polariscope to show the resulting stresses under certain load. Comparison of photo-elastic stress results shows that combined elliptical gears with DCA side as a loaded side have a minimum resulting contact stress with a reduction percentage of 40% compare with contact stresses in counterpart elliptical gear of involute profile (which is commonly u

In this paper we present the theoretical foundation of forward error analysis of numerical algorithms under;• Approximations in "built-in" functions.• Rounding errors in arithmetic floating-point operations.• Perturbations of data.The error analysis is based on linearization method. The fundamental tools of the forward error analysis are system of linear absolute and relative a prior and a posteriori error equations and associated condition numbers constituting optimal of possible cumulative round – off errors. The condition numbers enable simple general, quantitative bounds definitions of numerical stability. The theoretical results have been applied a Gaussian elimination, and have proved to be very effective means of both a prior

one of the most important consequences of climate change is the rise in sea levels, which leads to the drowning of some low-lying island states, which leads to them losing the elements of statehood and thus affecting their status as a state, this resulted in several proposals made by the jurisprudence of international law to solve this issue, perhaps the most important of which is the idea of the government in exile, and the proposal to continue recognition of submerged countries, in a way that makes it possible to talk about a new concept of states represented by deterritorialized states, all of which are ultimately proposals that contain great difficulties that hinder their implementation in reality.

     In this research, silver nanoparticles (AgNPs) were manufactured using aqueous extract of mushroom Pleurotus ostreatus. Anticancer potential of AgNPs was investigated versus human breast cancer cell line (MCF-7). Cytotoxic response was assessed by MTT assay. AgNPs showed inhibition effect at the following concentrations 12.5, 25, 50, 100 and 200 µg/ml versus MCF-7 cell line, and all treatments had a positive result. The MCF-7 cells were inhibited up to 85.14 % at the concentration 200 μg/ml of AgNPs which reduced cells viability to 14.86%, while 12.5 μg/ml of AgNPs caused 24.23% cells inhibition with reduction of cells viability to 75.77%.

After the persistence of the British policy of oppression and control over the American colonies and the attempts to obliterate the identity of their inhabitants, the colonies worked on moving forward towards achieving independence, and Virginia was the first to initiate the development of the new government frameworks, through George Mason in drafting the Virginia Bill of Rights in 1776, which expressed the philosophy of the era Enlightenment and independent revolutionary thought, which called for equality and natural rights for individuals and the need for a free popular government that works for the common good.

       Atorvastatin have problem of very slightly aqueous solubility (0.1-1 mg/ml). Nano-suspension is used to enhance it’s of solubility and dissolution profile. The aim of this study is to formulate Atorvastatin as a nano-suspension to enhance its solubility due to increased surface area of exposed for dissolution medium, according to Noyes-Whitney equation.

        Thirty one formulae were prepared to evaluate the effect of ; Type of polymer, polymer: drug ratio, speed of homogenization, temperature of preparation and inclusion of co-stabilizer in addition to the primary one; using solvent-anti-solvent precipitation method under high power of ultra-sonication.

استخلص عامل التلزن من E. faecalis EM1 بعد تكسير الخلايا بعدة طرق واختيار الطريقة التي تعطي اعلى قيمة تلزن والترسيب بالكحول الاثيلي , واجري فحص التلزن وقياسه للمستخلص  مع انواع من البكتريا السالبة لملون غرام تضمنت     Escherichia coli  و Klebsiella  pneumoniae  و Serratia

     Islamic manuscripts are considered an identity for the civilizational, cognitive and cultural development of nations and the Islamic world as a whole, and to identify this identity

Evaluation is one of the most important elements of  teaching process. The recent trends in evaluation and educational reform movements have called for using alternative evaluation, which focuses on performance evaluation. Authentic assessment is usually described as formative, in which students participate in their acquisition, in addition to the fact that students are productive and active, which is reflected in the students' achievement and skill level. The study aims to reveal the degree of knowledge and use of alternative assessment tools by primary school teachers in Gaza -Palestine. To meet the objective of the study, the researchers used the descriptive-analytical method and the questioner as a study tool. The study sample c