The presentwork is a theoretical study in the field of charged particle optics. It concentrates on the design of electrostatic enzil lens for focusing charge particles beams, using inverse method in designingthe electrostatic lens. The paraxial ray equation was solved to obtain the trajectory of the particles, the optical properties such as the focal length and spherical and chromatic aberration coefficients were determined. The shape of the electrode of the electrostatic lens were determined by solving poison equation and the results showed low values of spherical and chromatic aberrations, which are considered as good criteria for good design.
The professional skepticism is one of the fundamental concepts necessary for practicing the audit profession, without which the auditor can not reach a reasonable assurance as to the correctness of the evidence and the information obtained by the auditing department. The auditor's possession of the characteristics of professional skepticism and his practice of professional skepticism during the audit process lead to an increase The quality of audit and thus raise the confidence of the financial community in the audit profession again after the exposure of several crises led to the loss of financial society confidence in the audit profession.
The aim of the study is to measure the impact of professional sk
... Show MorePortland cement is considered the most involved product in environmental pollution. It is responsible for about 10% of global CO2 emissions [1]. Limestone dust is a by-product of limestone plants and it is produced in thousands of tons annually as waste material. To fulfill sustainability requirements, concrete production is recommended to reduce Portland cement usage with the use of alternative or waste materials. The production of sustainable high strength concrete by using nanomaterials is one of the aims of this study. Limestone dust in 12, 16, and 20% by weight of cement replaced cement in this study. The study was divided into two parts: the first was devoted to the investigation of the best percentage of replacement of waste
... Show MoreThe present studies are focused on the modification of the properties of epoxy resin with different additives namely aluminum, copper by preparing of composites systems with percentage (20%, 40% and 50%) of the above additives. The experimental results show that the D.C of conductivity on wt% filler content at ( 293-413 ) K electrical conductivity of all above composites increased with temperature for composites with filler contact and find the excellent electrical conductivity of copper and lie between (2.6*10-10 - 2.1*10-10)?.cm . The activation energy of the electrical conductivity is determined and found to decrease with increasing the filler concentration.
Three different distribution modules of silicon solar cells in a panel are used in this study . Each module consists of five identical circular silicon solar cells of radius (5cm) and then the total panel areas are identical. The five solar cells are arranged in the panel in different shapes: circular, triangular and rectangular .The efficiency for these three panel distribution are measured indoor and outdoor. The results show that the efficiency is a function of the cells distribution.
Waste is the most common phenomenon in the educational systems. Such a waste should reduce its efficiency and weaken its productivity which is best represented by failing and dropouts .thus resources meant to develop the educational institutions quality and quantity–wise would be wasted .in other words the return of the investments allotted to develop the educational system would fall short of the aims . The consequences would worst in the primary learning field. The research has three chapters: The first chapter is about significance of the research and its aims in addition to a review of literature. The second chapter is about the concept of dropping out of schools in the primary learning sector plus a history of the phenomenon .Thir
... Show MoreTrading global discourse topic as one of the other entrances to world peace, and the most important reasons for co-existence of intellectual and lumpy, and there Important issue related to a fundamental issue of the other cases are denied and the exclusion of others, Trading global discourse topic as one of the other entrances to world peace, and the most important reasons for co-existence of intellectual and lumpy, and there Important issue related to a fundamental issue of the other cases are denied and the exclusion of others, The stories of the prophets and their people the position of calling them and thought the new Massadik it. have found through research that there are two types of methods in the exclusion are as follows:
... Show MoreThis research in the philosophy of ethics, we have written under the title (Sensory And Mental Dialogue In The Philosophy Of Ethics -Criticism And Analysis-). Consists of three sections; first: talked dealt within the second part; we writhe about controversial consepts of sensory and mental. Then we about the concept of common philosophical doctrines, either in the third section we talked about the concept of the mind doctrines that secured sence mainly studies in philosophy. The purpose for which our finding in this research is to show that undeniable sense or exceeded in any doctrine of mentale doctrines, just as the mind can not be bypassed or undeniable doctrines sensory ... So as to complete the theory that we have in our thesis to
... Show MoreThe theme of unity of the topics that figured prominently Quran, cited preachers and scholars verses function on the unity and sense, to lift the nation from Hdtha, saved from the crisis, in an attempt to reunite and heal the rift, and re nation to unity and strength, and conduct on the path religion True, The Quran the unit is the Constitution of the Islamic nation and a safety valve, a strong rope of God. The following us in our research and Rod talk about it lonely in the Quran, and the statement of some form, and means its findings, including: (obey Allah and His Messenger, and referring to the Quran and Sunnah, and talk by saying better, reform between the brothers, call wisdom and good advice, etc.. ..), as Pena main obstacles and
... Show MoreCams are considered as one of the most important mechanical components that depends the contact action to do its job and suffer a lot of with drawbacks to be predicted and overcame in the design process. this work aims to investigate the induced cam contact and the maximum shear stress energy or (von misses) stresses during the course of action analytically using Hertz contact stress equation and the principal stress formulations to find the maximum stress value and its position beneath the contacting surfaces. The experimental investigation adopted two dimensions photoelastic technique to analyze cam stresses under a plane polarized light. The problem has been numerically simulated using Ansys software version 15 as FE
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