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Effect of Construction Joints on Performance of Reinforced Concrete Beams
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Construction joints are stopping places in the process of placing concrete, and they are required because in many structures it is impractical to place concrete in one continuous operation. The amount of concrete that can be placed at one time is governed by the batching and mixing capacity and by the strength of the formwork. A good construction joint should provide adequate flexural and shear continuity through the interface.

In this study, the effect of location of construction joints on the performance of reinforced concrete structural elements is experimentally investigated.

Nineteen beam specimens with dimensions of 200×200×950 mm were tested. The variables investigated are the location of the construction joints (at midspan or at third point of the specimens), type of construction joints (vertical, inclined, and key construction joints), and presence of stirrups at these joints. The specimens were tested using 1000 kN computer controlled versatile electronic testing machine. The specimens were positioned in the machine so that the deflection at center and\or at the location of construction joint was measured at each load step.

The results of the experimental program indicated that the best location of the construction joint is at the point of minimum shear. It was found that the use of vertical construction joint has little effect on the overall behavior of beam specimens (the percentage of reduction in ultimate load capacity is in the range of 0% - 5%).

While inclined construction joints results in a noticeable reduction in strength of beams relative to the strength of beam without construction joint the percentage of reduction in ultimate load capacity is in range of 8% - 20%.The presence of stirrups at the construction joints is an important variable, which affect the type of failure and load carrying capacity. It is found that adding of stirrups across the joint results in an increase in capacity in the range of (7%- 15%) and a decrease in deflection in the range of (20%- 48%).

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Publication Date
Mon Apr 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Doping Cu on the Structural and Optical Properties of (CdTe) Thin Films
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   In this research we studied  the structural and optical properties of (CdTe) thin films which have been prepared  by thermal evaporation deposition method on the glass substrate at R.T with thickness (450  25) nm., as  a function of doping  ratio with copper element  in (1,3,5) % rate .The structure  measurement  by X-ray diffraction (XRD) analyses shows that the single phase of (CdTe) with polycrystalline structure with a preferred orientation [111].   The optical  measurement shows that the (CdTe) films have a direct energy gap, and they decrease with the increase of doping ratio reaching to 5% . The optical constants are investigated and calculated, such as absorpti

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Publication Date
Sat Apr 30 2022
Journal Name
Sport Tk-revista Euroamericana De Ciencias Del Deporte
The effect of biomechanical feedback on the accuracy of the long serve in badminton
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The primary aim of the study was to find out the values of some biomechanical variables for the long serve skill in badminton and to identify the effect of biomechanical feedback on the performance of long serve. The present study had a single group, pre-post experimental study design. The research community was determined by the intentional method of one group with a pre-and post-test. The players of the Assyrian badminton club constituted the research community. A total of 12 players were present in the research community. The badminton players falling within the age group of 15-17 years for the season 2020-2021 were recruited as the participants for the study. A total of five players were selected as the participant

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Publication Date
Sun May 07 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Temperature On The Dispersability Of The Grafted Acrylic Acid Onto Alumina Particles
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 The ability of different alumina-grafted particles was examined for adsorption of phenol and p-chlorophenol under different conditions (i.e. concentrations and temperatures). Dispersion stability of alumina in liquid medium (water) was studied using settling under gravity technique. The result shows the settling initial rate of the alumina-grafted acrylic acid particles was faster than initial rate of settling when alumina-graft acrylic acid monomer adsorbed phenol and p-chlorophenol and vice versa to the alumina-graft poly(acrylic acid) polymer.

Thermodynamic parameters values (DG, DS, DH) were calculated for adsorption processes of phenol and p-chlorophenol adsorbed onto different surfaces. The

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Publication Date
Thu Dec 29 2016
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Soil Polluted with Crude Oil on Some Wood Properties of Casuarina equisetifolia
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    The current experiment was conducted to explore the effect of soil crude oil ( crude oil ) pollution on some wood properties of   Casuarina equisetifolia.      Four levels of pollution were applied on 40 (one-year) old seedlings . Measurements were taken by cutting the trees after two growth seasons from date of pollution .The studied Properties were fiber length, diameter, wall thickness, and specific gravity of external and internal wood.  Results showed an adverse effect of pollution on fiber diameter more than on fiber length. While wall thickness did not affect.  Fiber dimensions of external wood showed higher values  than that of internal one, especially for fiber

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Publication Date
Tue Jul 15 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of canal dryness and flaring on the accuracy of two electronic apex locators
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Background: This in vitro study evaluated the effect of canal dryness and flaring on the accuracy of two electronic apex locators for working length (WL) determination. Materials and methods: Sixty extracted teeth were used, after access opening was done, the occlusal surface was flattened to create stable reference point. The teeth were randomly divided into two equal main groups of flared and unflared group each one of 30 teeth. The flaring was done with Gates Glidden drills. The two main groups were further subdivided into two subgroups: dry canal and wet canal using 5.25% sodium hypochlorite groups, Electronic WL of each sample was determined using both Root ZX and i-Root apex locator. Consequently, histologic WL was determined by shav

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Publication Date
Sat Jan 01 2022
Journal Name
Euphrates Journal Of Agricultural Science
Effect of potassium fertilization levels and organic nutrient on growth and yield of cucumber
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Publication Date
Mon Feb 14 2022
Journal Name
Journal Of Educational And Psychological Researches
The Effect of S.N.I.P.S Strategy on the Achievement of Fifth Grade Students in Geography
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The present research aims at identifying the impact of S.N.I.P.S strategy on the achievement of fifth grade students in natural geography

For the purpose of verifying the objective of the research, the researcher put the following zero hypothesis: There is no statistically significant difference at the level of (0.05) between the mean score of experimental group who study according to the (S.N.I.P.S) strategy, and the mean score of control group who study according to the traditional method in the achievement test.

In order to verify the validity of this null hypothesis, the researcher adopted the experimental method. Two groups of (60) fifth grade literary students were collecte

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Publication Date
Sun Jun 04 2017
Journal Name
Baghdad Science Journal
Analysis and Study of the Effect of Atmospheric Turbulence on Laser weapon in Iraq
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One of the most important challenges facing the development of laser weapons is represented by the attenuation of the laser beam as it passed through the layers of atmosphere.This paper presents a theoretical study to simulate the effect of turbulence attenuation and calculates the decrease of laser power in Iraq. The refractive index structure C_n^2 is very important parameter to measure the strength of the atmospheric turbulence, which is affected by microclimate conditions, propagation path, season and time in the day. The results of measurements and predictions are based on the Kolmogorov turbulence theory. It was demonstrated by simulations that the laser weapons in Iraq were severely affected due to the large change in temperatures,

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Publication Date
Wed Dec 01 2021
Journal Name
Iraqi Journal Of Physics
Effect of Silver Nanoparticles on Fluorescence Intensity of Fluoreseina Dye Mixed in One Solution
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Metal enhanced fluorescence (MEF) is an unequaled phenomenon of metal nanoparticle surface plasmons, when light interacts with the metal nanostructures (silver nanoparticles) which result electromagnetic fields to promote the sensitivity of fluorescence. This work endeavor to study the influence of silver nanoparticles on fluorescence intensity of Fluoreseina dye by employment mixture solution with different mixing ratio. Silver nanoparticles had been manufactured by the chemical reduction method so that Ag NP layer coating had been done by hot rotation liquid method. The optical properties of the prepared samples (mixture solution of Fluoreseina dye solutions and colloidal solution with 5 minutes prepared of Ag NPs) tested by using UV-V

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Crossref
Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
Effect of sputtering power on optical Properties of RF sputtering deposited Ti6Al4V Thin Films
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Ti6Al4V thin film was prepared on glass substrate by RF
sputtering method. The effect of RF power on the optical properties
of the thin films has been investigated using UV-visible
Spectrophotometer. It's found that the absorbance and the extinction
coefficient (k) for deposited thin films increase with increasing
applied power, while another parameters such as dielectric constant
and refractive index decrease with increasing RF power.

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