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CFRP Strengthening of RC Beams with Multiple Openings Subjected to Static and Impact Loads
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The provision of openings in serviceable reinforced concrete beams may result in a substantial decline in the beam's capacity and integrity, indicating the necessity of opening strengthening. The present study investigates the experimental response of reinforced concrete T-beams with multiple web-strengthened openings disposed in shear span to static and impact loads. Fourteen RC T-beams were tested in two groups, each of seven beams. The first group was tested under static loading up to failure, while the second group was tested under repeated impact loading until the width of shear cracks reached 0.3 mm. The residual static strengths of the beams subjected to impact loading were then determined. The test variables considered were: number of web openings, the method used to strengthen the member at openings and the height of drop during impact tests. All beams were simply supported with load applied at mid – span. Static results indicated that T-beams with four and six un-strengthened web circular openings whose diameter is 48% of the web depth have strength capacities less than those without openings by 30% and 41%, respectively. However, strengthening of webs results in an increase in the strength capacities ranging between 27% and 92%, depending on the type of strengthening. Impact results indicated that the beam with four openings did not show a remarkable increase in the maximum mid-span deflection compared with the solid beam, while that with six openings showed an increase in the maximum mid-span deflections by about 75% greater than the maximum mid-span deflection of the solid beam. Strengthening of specimens could overcome the increase in deflections.

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Publication Date
Sun Dec 06 2015
Journal Name
Baghdad Science Journal
Generated and shifted of Ion beams By Electrostatic Lenses (Einzel lens)
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In this paper, the path of the extracted and focused ions by the electrostatic lense having three electrodes of the same size and shape have been studied. However, the first and third electrodes had a different potential from the second electrode and the distance between any three electrodes was (d).The beams of the charged particles were controlled by using electrostatic fields which are used for accelerating and focusing. This paper focuses also on the effect of electrodes potentials on ion beam focusing. It is found that the best focusing was achieved when the values of the potential of the first and third electrode are equal to half of the value of the second electrode. Concerning transmiting and acumulating the ions beams, the study sh

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Publication Date
Thu Sep 01 2022
Journal Name
Engineering Structures
Mesoscale analysis of Fiber-Reinforced concrete beams
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Publication Date
Sat Apr 07 2018
Journal Name
Civil Engineering Journal
Behavior of Precast Prestressed Concrete Segmental Beams
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The structural behavior of Segmental Precast Post-tensioned Reinforced Concrete (SPPRC) beams largely depends on the behavior of the joints that connect between the segments. In this research, series of static tests were carried out to investigate the behavior of full-scale SPPRC beams with different types of epoxy-glued joint configurations; multi-key joint, single key, and plain key joint. The reference specimen was monolithically casted beam and the other specimens were segmental beams with five segments for each one. The general theme from the experimental results reflects an approximate similarity in the behavior of the four beams with slight differences. Due to the high tensile strength of the used epoxy in comparison to concr

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Publication Date
Thu Dec 01 2022
Journal Name
Civil And Environmental Engineering
Enhancing the Structural Analysis of Rc Piled - Raft Foundation by Actual Behaviour of Supporting Piles
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Abstract<p>This paper presents a numerical analysis of the piled-raft foundation (PRF) based on the actual behavior of supporting piles. The raft was modeled as a thin plate, while the piles were modeled as springs in different ways. This research also aims to propose an analytical model of piles based on actual behavior at fieldwork. The results proved that the structural behavior of raft member can be improved through utilizing the actual behavior of supporting piles. When the piles were modeled as non-linear stiffness springs, settlements and bending stresses of raft foundation were reduce marginally as compared with those obtained from piles with linear stiffness springs.</p>
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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Engineering
Evaluation The Performance Geodetic of the Receivers Using Static Positioning Technique
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Global Navigation Satellite System (GNSS) is considered to be one of the most crucial tools for different applications, i.e. transportation, geographic information systems, mobile satellite communications, and others. Without a doubt, the GNSS has been widely employed for different scientific applications, such as land surveying, mapping, and precise monitoring for huge structures, etc. Thus, an intense competitive has appeared between companies which produce geodetic GNSS hardware devices to meet all the requirements of GNSS communities. This study aims to assess the performance of different GNSS receivers to provide reliable positions. In this study, three different receivers, which are produced by different manufactur

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Publication Date
Mon Jan 30 2023
Journal Name
Iraqi Journal Of Science
Periodic Solutions For Nonlinear Systems of Multiple Integro-differential Equations that Contain Symmetric Matrices with Impulsive Actions
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This paper examines a new nonlinear system of multiple integro-differential equations containing symmetric matrices with impulsive actions. The numerical-analytic method of ordinary differential equations and Banach fixed point theorem are used to study the existence, uniqueness and stability of periodic solutions of impulsive integro-differential equations with piecewise continuous functions. This study is based on the Hölder condition in which the ordering ,  and  are real numbers between 0 and 1.

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Publication Date
Fri Aug 13 2021
Journal Name
Journal Européen Des Systèmes Automatisés
Proxy-based sliding mode vibration control with an adaptive approximation compensator for euler-bernoulli smart beams
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Proxy-based sliding mode control PSMC is an improved version of PID control that combines the features of PID and sliding mode control SMC with continuously dynamic behaviour. However, the stability of the control architecture maybe not well addressed. Consequently, this work is focused on modification of the original version of the proxy-based sliding mode control PSMC by adding an adaptive approximation compensator AAC term for vibration control of an Euler-Bernoulli beam. The role of the AAC term is to compensate for unmodelled dynamics and make the stability proof more easily. The stability of the proposed control algorithm is systematically proved using Lyapunov theory. Multi-modal equation of motion is derived using the Galerkin metho

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Publication Date
Tue Aug 03 2021
Journal Name
Key Engineering Materials
A Comparison Study between Asymmetrical Castellated Steel Beams Encased by Reactive Powder Concrete with Laced Reinforcement
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The main objectives of this study are to study the enhancement of the load-carrying capacity of Asymmetrical castellated beams with encasement the beams by Reactive Powder Concrete (RPC) and lacing reinforcement, the effect of the gap between top and bottom parts of Asymmetrical castellated steel beam at web post, and serviceability of the confined Asymmetrical castellated steel. This study presents two concentrated loads test results for four specimens Asymmetrical castellated beams section encasement by Reactive powder concrete (RPC) with laced reinforcement. The encasement of the Asymmetrical castellated steel beam consists of, flanges unstiffened element height was filled with RPC for each side and laced reinforced which are use

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Publication Date
Tue May 11 2021
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Paediatric multiple sclerosis: a case report of missed and dismissed diagnosis
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Multiple Sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system (CNS). Up to 10 % of MS patients have onset in paediatric age group. Although the clinical profile of MS appears similar to that seen in adults, several features may differ and specific issues arise in children. Here, we reported a 12-year old girl who presented with 3-year history of episodes of seizures and facial nerve palsy and finally fatigue and cognitive impairment were noted and interfered with her academic performance. Because of the presumed atypical clinical presentations, the diagnosis was missed then dismissed despite neuroimaging features and CSF immunological findings that were highly suggestive of MS. Later, evolution of the

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Publication Date
Tue Feb 28 2023
Journal Name
Iraqi Journal Of Science
On the Existence and Oscillatory Solutions of Multiple Delay Differential Equation
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    In this paper, we introduce new conditions to prove that the existence and boundedness of the solution by convergent sequences and convergent series. The theorem of Krasnoselskii, Lebesgue’s dominated convergence theorem and fixed point theorem are used to get some sufficient conditions for the existence of solutions. Furthermore, we get sufficient conditions to guarantee the oscillatory property for all solutions in this class of equations. An illustrative example is included as an application to the main results.

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