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alkej-127
Experimental and Numerical Study of Crack Effect on Frequency of Simple Supported Beam
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In this research the natural frequency of a cracked simple supported beam (the crack is in many places and in different depths) is investigated analytically, experimentally and numerically by ANSYS program, and the results are compared. The beam is made of iron with dimensions of L*W*H= (0.84*0.02* 0.02m), and density = 7680kg/m3, E=200Gpa. A comparison made between analytical results from ANSYS with experimental results, where the biggest error percentage is about (7.2 %) in crack position (42 cm) and (6 mm) depth. Between Rayleigh method with experimental results the biggest error percentage is about (6.4 %) for the same crack position and depth. From the error percentages it could be concluded that the Rayleigh method gives close results to experimental than ANSYS. Also it is found that the frequency of beam when the crack is in the middle position is less than the frequency with crack near the end position.

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Publication Date
Fri Jan 01 2021
Journal Name
المجلة العراقية لدراسات الصحراء
Effect of water requirements on the cultivation of vegetable crops ( Analytical study agricultural geography
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The effect of water requirements in the cultivation and production of some vegetable crops (summer and winter) was studied in order to determine the importance of water during the different stages of growth in order to carry out the vital processes, as most of the physiological processes within plants in general are affected directly or indirectly by the presence of water, and the research has reached To the fact that moderate soil moisture is important in the germination of crops, as its decrease negatively affects the failure to germination, the failure to elongate peacocks, or the production of incomplete fruits. As for the increase of that moisture, it causes great damage to the vegetable crops, such as their exposure to diseases and pe

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Publication Date
Thu May 18 2023
Journal Name
Journal Of Engineering
Theoritical and Experimental Investigation of the Dynamical Behaviour of Complex Configuration Rotors
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The present work considers an alternative solution for a complex configuration of rotor discs by applying Galerkin Method. The theoretical model consists of elastic shaft carrying number of discs and supported on number of journal bearings. The equation of motion was discretized to finite degree of freedom in terms of the system generalized coordinates. The various effects of the dynamical forces and moments arising from the bearing, discs and shaft were included. Rayleigh beam model is used for analyzing the shaft while the discs are considered rigid . The validity and convergence of the present analysis was carefully checked by comparing with the Finite Element solution. An example of rotor consists of three different size discs and su

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Publication Date
Wed Dec 12 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Relationship between General and Spinal Anesthesia and Its Impact upon Breast Feeding: Comparative Study
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Objective: To identified the relationship between general and spinal Anesthesia upon breastfeeding and (demographic &reproductive) : Comparative Study. Methodology: The present study employs a descriptive comparative design held at the labor and delivery room , operational room for cesarean section and maternity word in maternity department at Al Emamain Al Kadhamain Medical City in Baghdad city. Data collection was initiated on 2nd January to end of March /2014. Purposive sample consisted of (150) mother and her neonate, The study sample divided into three groups:(50) under general anesthesia , (50) under

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Publication Date
Mon Dec 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Experimental Investigation of Using Evaporative Air Cooler for Winter Air-Conditioning in Baghdad
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This paper presents an efficient methodology to design modified evaporative air-cooler for winter air-conditioning in Baghdad city as well as using it for summer air-conditioning by adding a heating process after the humidification process. laboratory tests were performed on a direct evaporative cooler (DEC) followed by passing the air on hot water through heat exchanger placed in the coolers air duct exit. The tests were conducted on the 2nd of December /2011 when the ambient temperature was 8.1°C and the relative humidity was  (68%). The air flow rate is assumed to vary between 0.069 to 0.209 kg/s with constant water flow rate of 0.03 kg/s in the heat exchanger. The performance is reported in terms of effectiveness of DEC, satura

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Publication Date
Mon Jul 10 2023
Journal Name
Journal Of Engineering
Experimental Study of Pre-Cast Reinforced Concrete Deep Beams (Hallow Core section) Retrofitting with Carbon Fiber Reinforced Polymer (CFRP)
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Experimental programs based test results has been used as a means to find out the response of individual elements of structure. In the present study involves investigated behavior of five reinforced concrete deep beams of dimension (length 1200 x height 300 x width150mm) under two points concentrated load with shear span to depth ratio of (1.52), four of these beams with hallow core and
retrofit with carbon fiber reinforced polymer CFRP (with single or double or sides Strips). Two shapes of hallow are investigated (circle and square section) to evaluated the response of beams in case experimental behavior. Test on simply supported beam was performed in the laboratory & loaddeflection, strain of concrete data and crack pattern of

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Publication Date
Sun Nov 19 2017
Journal Name
Iraqi Journal Of Laser
Effects of Diode Laser 940 nm with and without 5 % Sodium Fluoride White Varnish with Tri-calcium Phosphate on Dentin Permeability (In vitro study)
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It is found that hypersensitive teeth have a larger number and wider patent tubules than those of non-sensitive teeth. Objective: The aim of this study is to compare between the effects of diode laser at different power densities, with and without sodium fluoride on the sealing of exposed dentinal tubules and dentin permeability. Materials and methods: 118 teeth were used. Samples were divided into three major groups. The first consisted of 100 teeth used for permeability test. The second consisted of 16 teeth for measuring external surface temperature elevation while irradiation. The third, in turn, consisted of one pair of teeth observed under SEM for dentine surface morphology analysis. Results: For dentin permeability measurement, th

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Publication Date
Mon Jan 30 2023
Journal Name
Iraqi Journal Of Science
Study the Effect of Oxygen on Coronene Electronic and Spectroscopic Properties via the Density Functional Theory (DFT)
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    The electronic properties (such as energy gap HOMO levels. LUMO levels, density of state and density of bonds in addition to spectroscopic properties like IR spectra, Raman spectra, force constant and reduced masses as a function of frequency) of coronene C24 and reduced graphene oxide C24OX , where x=1-5, were studied.. The  methodology employed was  Density Functional Theory (DFT) with Hybrid function B3LYP and 6-311G** basis sets. The energy gap was calculated for C24 to be 3.5 eV and for C24Ox was from 0.89 to 1.6862 eV  for x=1-5 ,respectively.   These energy gaps values are comparable to the measured gap of Graphene (1-2.2 eV). The spectroscopic properties were  compared with experimental measurements, specificall

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Publication Date
Thu Dec 01 2022
Journal Name
Iraqi Journal Of Physics
Investigation of Radio Frequency Signal Propagation of Wireless Services in Oyo, Oyo State, South Western Nigeria
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This study reported the investigation of the Radio Frequency (RF) signal propagation of Global System for Mobile Communications (GSM) coverage in Emmanuel Alayande College of Education (EACOED), Oyo, Oyo State, Nigeria. The study aims at amplifying the quality of service and augment end users' sensitivity of the wireless services operation. The drive test method is adopted with estimation of coverage level and received signal strength. The Network Cell Info Lite application installed in three INFINIX GSM mobile phones was employed to take the measurement of the signal strength received from the transmitting stations of different mobile networks. The results of the study revealed that MTN has the maximum signal strength with a mean value

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Publication Date
Sun Jun 16 2019
Journal Name
Al–bahith Al–a'alami
Academic Trends of Paper Press in Comparison with Internet Press A Field Study on Professors o College of Media at University of Baghdad
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This search seeks to know the trends of academics in the field of Press and audio, video and read press about paper press compared with continued development and widespread deployment of web journalism. This research belongs to descriptive studies which depends on sample survey approach adopted by five-meter design measuring trends. It contains 28 items having applied honesty and reliability transaction and the scale form is distributed to the sample studied of about 110 professors and then the researcher collects them and then applying the appropriate statistical program to get the results. This search seeks to know the trends of academics in the field of Press and audio, video and read press about paper press compared with continu

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Crossref
Publication Date
Sun Mar 31 2019
Journal Name
Association Of Arab Universities Journal Of Engineering Sciences
Behavior of Plain Concrete Beam Analyzed Using Extended Finite Element Method
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In this study, plain concrete simply supported beams subjected to two points loading were analyzed for the flexure. The numerical model of the beam was constructed in the meso-scale representation of concrete as a two phasic material (aggregate, and mortar). The fracture process of the concrete beams under loading was investigated in the laboratory as well as by the numerical models. The Extended Finite Element Method (XFEM) was employed for the treatment of the discontinuities that appeared during the fracture process in concrete. Finite element method with the feature standard/explicitlywas utilized for the numerical analysis. Aggregate particles were assumedof elliptic shape. Other properties such as grading and sizes of the aggr

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