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Frequency Domain Analysis for Geometric Nonlinear Seismic Response of Tall Reinforced Concrete Buildings
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This paper aims to study the second-order geometric nonlinearity effects of P-Delta on the dynamic response of tall reinforced concrete buildings due to a wide range of earthquake ground motion forces, including minor earthquake up to moderate and strong earthquakes. The frequency domain dynamic analysis procedure was used for response assessment. Reinforced concrete building models with different heights up to 50 stories were analyzed. The finite element software ETABS (version 16.0.3) was used to analyze reinforced concrete building models.

The study reveals that the percentage increase in buildings' sway and drift due to P-Delta effects are nearly constant for specific building height irrespective of the seismic design category assigned to the building. Generally, increase in building lateral displacement and story drift due to P-Delta effects for all seismic design categories is less than 2% for 10 story buildings, whereas this increase for 20 stories or taller buildings is significant with a maximum value around 16% for 50 story building. As for column forces, the study shows that, generally, columns bending moment increases and shear force decreases when P-Delta effects accounted for. In conclusion, the study recommended that the effects of P-Delta need to be addressed for all SDCs allowed by ASCE7-10 and the most important factor to abandonment P-Delta effects is the building height limit.

 

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Publication Date
Mon Aug 01 2022
Journal Name
Journal Of Engineering
Dynamic Behavior of Machine Foundations on layered sandy soil under Seismic Loadings
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In this paper, a dynamic investigation is done for strip, rectangular and square machine foundation at the top surface of two-layer dry sand with various states (i.e., loose on medium sand and dense on medium sand). The dynamic investigation is performed numerically using finite element programming, PLAXIS 3D. The soil is expected as a versatile totally plastic material that complies with the Mohr-Coulomb yield criterion. A harmonic load is applied at the base with an amplitude of 6 kPa at a frequency of (2 and 6) Hz, and seismic is applied with acceleration – time input of earthquake hit Halabjah city north of Iraq. A parametric study is done to evaluate the influence of changing L/B ratio (Length=12,6,3 m and width=3 m), type of sand

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Publication Date
Sun Nov 01 2015
Journal Name
Journal Of Engineering
Greening Existing Buildings in Contemporary Iraqi Urban Reality/ Virtual Model
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The approach of greening existing buildings, is an urgent necessity, because the greening operation provides the speed and optimal efficiency in the environmental performance, as well as keeping up with the global green architecture revolution. Therefore, greening existing buildings in Iraq is important for trends towards renewable energies, because of what the country went through economic conditions and crises and wars which kept the country away from what took place globally in this issue. The research problem is: insufficient knowledge about the importance and the mechanism of the greening of existing buildings, including its environmental and economic dimensions, by rationalization of energy consumption and preservi

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Publication Date
Wed Apr 01 2009
Journal Name
6th.engineering Conference/college Of Eng. /university Of Baghdad
Comparison between analytical solution and experimental results for reinforced loose sand
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Presents here in the results of comparison between the theoretical equation stated by Huang and Menq and laboratory model tests used to study the bearing capacity of square footing on geogrid-reinforced loose sand by performing model tests. The effects of several parameters were studied in order to study the general behavior of improving the soil by using the geogrid. These parameters include depth of first layer of reinforcement, vertical spacing of reinforcement layers, number of reinforcement layers and types of reinforcement layers The results show that the theoretical equation can be used to estimate the bearing capacity of loose sand.

Publication Date
Tue Dec 01 2020
Journal Name
Iraqi Journal Of Physics
Comparative study of the linear and nonlinear optical properties for different Iraqi heavy and light crude oils
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Iraqi oil crudes have some of the physical and chemical characteristics that distinguish it from other types of oil crudes in the world. Some of these features such us molecular composition, rheological, viscosity and emulsions are studied carefully by researchers. In this work, a comparative study of the linear and the non-linear optical properties for typical heavy and light crude oils of Iraqi origin was studied utilizing Z-scan technique. The He -Ne laser of wavelength 632.8 nm had been used for this purpose. These samples were collected from Basra and Kut oil fields. The values of the non-linear refractive index (n2), non-linear absorption coefficient (β), and third-order electrical susceptibility (χ3) were e

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Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of Multistage and Numerical Discretization Methods for Estimating Parameters in Nonlinear Linear Ordinary Differential Equations Models.
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Many of the dynamic processes in different sciences are described by models of differential equations. These models explain the change in the behavior of the studied process over time by linking the behavior of the process under study with its derivatives. These models often contain constant and time-varying parameters that vary according to the nature of the process under study in this We will estimate the constant and time-varying parameters in a sequential method in several stages. In the first stage, the state variables and their derivatives are estimated in the method of penalized splines(p- splines) . In the second stage we use pseudo lest square to estimate constant parameters, For the third stage, the rem

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Publication Date
Sun Dec 05 2010
Journal Name
Baghdad Science Journal
Stability of Nonlinear Systems of Fractional Order Differential Equations
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In this paper, a sufficient condition for stability of a system of nonlinear multi-fractional order differential equations on a finite time interval with an illustrative example, has been presented to demonstrate our result. Also, an idea to extend our result on such system on an infinite time interval is suggested.

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Publication Date
Thu Aug 15 2024
Journal Name
Journal Of Ethnicity In Substance Abuse
Knowledge, attitude, and frequency of hookah smoking among medical students
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Publication Date
Thu Mar 30 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Frequency of Antineutrophil Cytoplasmic Antibodies (ANCA) in Some Autoimmune Diseases
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Anti-Neutrophil Cytoplasmic Antibodies (ANCA) are a heterogeneous group of autoantibodies with a broad spectrum of clinically associated diseases. The diagnostic value is established for Proteinase 3 (PR3)-ANCA as well as Myeloperoxidase (MPO)-ANCA. To estimate the frequency of anti-neutrophile cytoplasmic antibodies (ANCA) in sera from a group of Iraqi patients with some autoimmune diseases compared with a healthy control group. Serum samples were collected from one hundred patient, 47 males and 53 females; with age range of 16-70 years; 20 specimens from patients with systemic lupus erythematosus (SLE), 30 from patients with ulcerative colitis (UC), and 50 from patients with rheumatoid arthritis (RA). A group of 40 apparently healthy b

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Publication Date
Sat Dec 30 2017
Journal Name
Al-khwarizmi Engineering Journal
Design & Implementation of High Switching & Low Phase Noise Frequency Synthesizer
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This research  describes the design & implementation of frequency synthesizer using single loop Phase lock loop with the following specifications: Frequency range (1.5 – 2.75) GHz,Step size (1 MHz), Switching time 36.4 µs, & phase noise @10 kHz = -92dBc & spurious -100 dBc

  The development in I.C. technology provide the simplicity in the design of frequency synthesizer because it implements the phase frequency detector(PFD) , prescalar &  reference divider in single chip. Therefore our system consists of  a single chip contains (low phase noise PFD, charge pump, prescalar  & reference divider), voltage controlled oscillator , loop filter & reference oscillator. The single chip

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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
Effect of frequency Chirp on the black and gray solitions
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the behavior of the first-order black and gray solitons propagtedin optical fiber in the presence of frequency chirp is studied analytically and numerically results show that phase profile of black solitons changes abruptly

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