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The Effect of Air Gap Width (S) and the Ratio (P1/D2) on .Minimum Projector Focal Length (Fp)min for the Double Pole-Piece Lens- at Costant Excitation (NI)
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The  spherical  double pole-piece  electron  lens i§ depend  on some

fact0rs : the-  minimum va}ue-of projector  fo·cal  length (Fp)i:J,Iill  â€¢  the

maximum value of  magnetic flux density (Bm) , the total  hal[ width

,(W)  o'f asyriunetrical   clln'e  of  magnetic field  distribution  [because there are differe_nt values of bore diameter  (D1) • i.                                               the ratio (D)D2) with different values] and the air gap width (S) between tlw iron poles The rat'io (S!Om) is used to represent' this type of lenses and depend  as

a primary factor to desi:gn the lenses . Therefore the effect of  air gap width and; the ratid (D1 /Dx) on the varia_ble-above , especially  (Fp)mili Wi;is studied to obtain  the mos-t favorable design  â€¢. highest  fje)d of view (r) and magnification  (M) of doublet projeetor tens although, the

requirtXI projector lens is about (M=JOO x) .!ll All calculat.ic;ms done by

the finite  element  method  sugges-ted by (Munro, l973)  C2-l   , which is a numerical  method  used to find the magnetic field in electron lenses .

 

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Publication Date
Thu Jun 08 2023
Journal Name
Iraqi Journal Of Laser
PDF The effect of nanoelectrodes number and length on enhancing the THz photomixer performance
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Abstract: Despite the distinct features of the continuous wave (CW) Terahertz (THz) emitter using photomixing technique, it suffers from the relatively low radiation output power. Therefore, one of effective ways to improve the photomixer emitter performance was using nanodimensions electrodes inside the optical active region of the device. Due to the nanodimension sizes and good electrical conductivity of silver nanowires (Ag-NWs), they have been exploited as THz emitter electrodes. The excited surface plasmon polariton waves (SPPs) on the surface of nanowire enhances the incident excitation signal. Therefore, the photomixer based Ag-NW compared to conventional one significantly exhibits higher THz output signal. In thi

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Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Laser
Propanol Vapor Sensor Utilizing Air-Gap as Sensing Part of the Mach-Zehnder Interferometer
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The purpose of this study is to demonstrate a simple high sensitivity vapor sensor for propanol ((CH3)2CHOH). A free space gap was employed in two arms of a Mach-Zehnder interferometer to serve as the sensing mechanism by adding propanol volume (0.2, 0.4, 0.6, 0.8, and 1) ml and to set the phase reference with a physical spacing of (0.5, 1, 1.5, and 2) mm. The propagation constant of transmitted light in the Mach-Zehnder interferometer’s gap changes due to the small variation in the refractive index inside sensing arm that will further shift the optical phase of the signal. Experimental results indicated that the highest sensitivity of propanol was about 0.0275 nm/ml in different liquid volume while highest phase shift was 0.182×103 i

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
The Effective Width in Composite Steel Concrete Beams at Ultimate Loads
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A composite section is made up of a concrete slab attached to a steel beam by means of shear connectors. Under positive and negative bending moment, part of the slab will act as a flange of the beam, resisting the longitudinal compression or tension force. When the spacing between girders becomes large, it is evident that the simple beam theory does not strictly apply because the longitudinal stress in the flange will vary with distance from the girder web, the flange being more highly stressed over the web than in the extremities. This phenomenon is termed "shear lag". In this paper, a nonlinear three-dimensional finite element analysis is employed to evaluate and determine the actual effective slab width of the composite steel-concrete

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Publication Date
Sat Jul 22 2023
Journal Name
Journal Of Engineering
Effect of Transverse Base Width Restraint on the Cracking Behavior of Massive Concrete
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The effect of considering the third dimension in mass concrete members on its cracking behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in
addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method. The finite element method was also implemented in the structural analysis adopting the concept of initial strain problem. Drying shrinkage volume changes were calculated using the procedure sug

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Publication Date
Fri Sep 01 2006
Journal Name
Journal Of Engineering
Effect of Transverse Base Width Restraint on the Cracking Behavior of Massive Concrete
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The effect of considering the third dimension in mass concrete members on its cracking behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method. The finite element method was also implemented in the structural analysis adopting the concept of initial strain problem. Drying shrinkage volume changes were calculated using the procedure suggested

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Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Engineering
Analytical and Experimental Investigation for the Effect of Air Injection Angle on the Performance of Airlift Pump
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The effect of air injection angle on the performance of airlift pump used for water pumping has been studied analytically and experimentally. An airlift pump of dimensions 42mm diameter and 2200 mm length with conventional and modified air injection device was considered. A modification on conventional injection device (normal air-jacket type) was carried out by changing injection angle from 90  (for conventional) to 45  and 22.5  (for modified). Continuity and one-dimensional momentum balance for the flow field with basic principle of two-phase flow and expressions of slip ratio and friction factor as function of flow rates were formulated. The analytical and experimental investigations were carried out f

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Publication Date
Thu Mar 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
The relationship between the gap of knowledge and the strategic performance gap
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Address the intellectual controversy nature of the gap of knowledge and the strategic performance gap. The researcher start off from this intellectual controversy to seek to test the nature of the relationship and impact between them across a sample of (61) academics in the colleges of business and economics at the universities in Baghdad ,as the more specialized in the fields of knowledge and the strategic performance, The researcher is attain to the existence of relationship and impact of knowledge gap in strategic performance gap, the research included four axes first went to the methodology and second to theoretical frame and the third to view and analyze the results and test hypotheses while the fourth was devoted to the con

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Publication Date
Thu Jun 01 2023
Journal Name
Baghdad Science Journal
Design and study the effect of inner bore diameter on the magnetic and optical properties of the unipolar lens
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    Many designs have been suggested for unipolar magnetic lenses based on changing the width of the inner bore and fixing the other geometrical parameters of the lens to improve the performance of unipolar magnetic lenses. The investigation of a study of each design included the calculation of its axial magnetic field the magnetization of the lens in addition to the magnetic flux density using the Finite Element Method (FEM) the Magnetic Electron Lenses Operation (MELOP) program version 1 at three different values of current density (6,4,2 A/mm2). As a result, the clearest values and behaviors were obtained at current density (2 A/mm2). it was found that the best magnetizing properties, the high

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The effect of the dimensions of the strategic lens on achieving tax pioneer performance: Practical research in the General Authority for Taxes
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The aim of the research is to shed light on the dimensions of the strategic lens and its impact on achieving the pioneer tax performance and represented by the dimensions (strategic direction, growth, pilot indicator, renewal and modernization, efficiency and effectiveness) in the General Tax Authority. The questionnaire was adopted as a tool to collect data and information from the adult sample They are (91) who are on the site (Assistant Director General, Head of Division, First Division Deputy, Second Division Deputy, Division Officer, Division Officer Associate) The statistical program (SPSS) has been used to calculate (the mean, the standard deviation, the correlation coefficient, the difference coefficient, the F test, the

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Publication Date
Sat Jan 01 2022
Journal Name
Aip Conference Proceedings
The effect of different flooding ratio on Al-Shuwaija marsh
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In this research, the effect of changing the flood level of Al-Shuwaija marsh was studied using the geographic information systems, specifically the QGIS program, and the STRM digital elevation model with a spatial analysis accuracy of 28 meters, was used to study the marsh. The hydraulic factors that characterize the marsh and affecting on the flooding such as the ranks of the water channels feeding the marsh and the degree of slope and flat areas in it are studied. The area of immersion water, the mean depth, and the accumulated water volume are calculated for each immersion level, thereby, this study finds the safe immersion level for this marsh was determined.

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