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Effect of optimal shot peening time on fatigue life for aluminum alloy 6061-T651
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The compressive residual stresses generated by shot peening, is increased in a direct proportional way with shot peening time (SPT). For each metal, there is an optimum shot peening time (O.S.T) which gives the optimum fatigue life. This paper experimentally studied to optimize shot peening time of aluminium alloy 6061-T651 as well as using of and analysis of variance (ANOVA).

Two types of fatigue test specimens’ configuration were used, one without notch (smooth) and the other with a notch radius (1,25mm), each type was shot peened at different time. The (O.S.T) was experimentally estimated  to be 8 minutes reaching the surface stresses at maximum peak of -184.94 MPa.

A response surface methodology (RSM) is presented to optimize the surface properties of fatigue life due to effect of two parameters (shot peening time and fatigue stresses). A statistical software was used to perform analysis of variance (ANOVA)  to predict the optimum shot peening time. The results were 8.007 minutes without notch and 7.53 minutes with notch. Two 2nd degree polynomials were obtained for the two studied cases with confidence level of 95%. Experimentally26.67% enhancement in fatigue life was obtained, but after using (RSM), the results gave 61% improvement, compared with ref. [2].

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Publication Date
Mon Jan 01 2024
Journal Name
Open Engineering
Effect of nano-TiO<sub>2</sub> on physical and rheological properties of asphalt cement
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Abstract<p>In recent years, nano-modified asphalt has gained significant attraction from researchers in the design of asphalt pavement fields. The recently discovered Titanium dioxide nanoparticles (TiO<sub>2</sub>) are among the most exciting and promising nanomaterials. This study examines the effect of 1, 3, 5, and 7% of nano-TiO<sub>2</sub> by weight of asphalt on some of its rheological and hardened properties. The experimental study included physical and rheological properties. The asphalt penetration, softening point, ductility, and rotational viscometer tests indicate that 5% nano-TiO<sub>2</sub> is the ideal amount to be added to bitumen as a modifier. The </p> ... Show More
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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
The effect of unsecured use of chemical pesticides on the environment and health in Iraq
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The wide use of pesticides in recent years leads to rapid distribution of these pollutants in the environment (air, water and soil).They were transported by means of air or water to biological ecosystems. They become more toxic through the processes of biological magnification while some of them persist for along period.The aim of this work is to show the negative effect that chemical pesticides causes, and in the same to show their side effect on the environment and health in Iraq. We could conclude that the bad use of these chemicals could cause an urgent impact now or in the future. Governmental offices dealing with these materials should take the right measures to minimize the danger and the misuse of these chemicals by seeking alternat

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Publication Date
Mon Mar 09 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of silica layer on bonding strength of thermoplastic nylon to cold cure acrylic resin
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Background: The combination of thermoplastic nylon resin materials and auto polymerizing resin is necessary in some situation for repair and adjustment. This study evaluated shear bond strength between thermoplastic nylon material (flexible) and auto polymerizing acrylic resin subjected to holes and silica coated layer. Materials and Method: Forty five (45) specimens were prepared from flexible acrylic bonded to auto-polymerizing acrylic resin and divided into three groups according to the surface treatments as follows: Group A: 15 specimens of flexible acrylic bonded with cold-cure acrylic by holes. Group B: 15 specimens of flexible acrylic bonded with cold-cure acrylic by silica coated layer. Group C: 15 specimens of flexible acrylic bon

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Publication Date
Tue Nov 14 2023
Journal Name
International Journal Of Dentistry
Antimicrobial Efficiency of Hypochlorous Acid and Its Effect on Some Properties of Alginate Impression Material
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Dental clinicians and professionals need an affordable, nontoxic, and effective disinfectant against infectious microorganisms when dealing with the contaminated dental impressions. This study evaluated the efficiency of hypochlorous acid (HOCl) as an antimicrobial disinfectant by spraying technique for the alginate impression materials, compared with sodium hypochlorite, and its effect on dimensional stability and reproduction of details. HOCl with a concentration of 200 ppm for 5 and 10 min was compared with the control group (no treatment) as a negative control and with sodium hypochlorite (% 0.5) as a positive control. Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa were selected to assess the antimicrobi

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Publication Date
Wed May 18 2016
Journal Name
مجلة كلية التربية الاساسية
Effect of citric and glutamic acids on physiological characteristics and yield of Vicia faba L.
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The field experiment was conducted in garden of Department of Biology, College of Education for Pure Sciences (Ibn- Al-Haitham), University of Baghdad during the season of growth (2014-2015). The experiment aimed to study the effect of citric acid with two concentration 10, 20 mg. L-1 and glutamic acid with two concentration 50, 100 mg. L-1 on growth and yield of broad bean (Vicia faba). The results were showed an increased in plant height, leaves number. Plant dry weight, chlorophyll content flowers number, absolute growth rate, crop growth rate, legume length and dry weight, legumes number, seed dry weight compared with control plants.

Publication Date
Fri Jan 11 2019
Journal Name
Iraqi Journal Of Physics
Effect of gamma irradiation and ZnO nano particles on the A.C electrical conductivity of polyaniline
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Conducting polyaniline / ZnO nano composites are synthesized
using a simplified cheap method with one step in –situ chemical
polymerization, and AC conductivity (σac) of the prepared samples is
studied in the range of frequency from 50 Hz to 15MHz.). The
presence of polarons in the conjugated polymer chain are responsible
for the ac conductivity is reliance on the frequency in these
composites. The effect of increasing the ZnO nano particle
concentration irradiation and gamma radiation on the electric
conductivity was analyzed. The result showed that the
nanocomposite prepared has the highest conductivity, from pure
polyaniline and the exponential factor S was found increasing with
ZnO content it was 0

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Publication Date
Tue Jan 18 2022
Journal Name
Heat Transfer
Effect of receiver geometry on the optical and thermal performance of a parabolic trough collector
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Abstract<p>In this study, the optical and thermal performance of a Parabolic Trough Collector PTC system is investigated theoretically. A series of numerical simulations and theoretical analysis has been conducted to investigate the effect of the receiver geometry and location relative to the focal line on its optical performance. The examined receiver geometries are circular, square, triangular, elliptical and a new design of circular‐ square named as channel receiver. The thermal performance of PTC is studied for different flow rates from (0.27 to 0.6 lpm) theoretically. Results showed that the best optical design is the channel receiver with an optical efficiency of 84% while the worst is the elliptical </p> ... Show More
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Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Study of annealing effect on some Optical Properties of CuIn(SexTe1-x)2 Thin Films
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The optical properties for the components CuIn(SexTe1-x)2 thin films with both values of selenium content (x) [0.4 and 0.6] are studied. The films have been prepared by the vacuum thermal evaporation method with thickness of (250±5nm) on glass substrates. From the transmittance and absorbance spectra within the range of wavelength (400-900)nm, we determined the forbidden optical energy gap (Egopt) and the constant (B). From the studyingthe relation between absorption coefficient (α) photon energy, we determined the tails width inside the energy gap.
The results showed that the optical transition is direct; we also found that the optical energy gap increases with annealing temperature and selenium content (x). However, the width of l

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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
On The Dynamical Behavior of a Prey-Predator Model With The Effect of Periodic Forcing
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The dynamical behavior of a two-dimensional continuous time dynamical system describing by a prey predator model is investigated. By means of constructing suitable Lyapunov functional, sufficient condition is derived for the global asymptotic stability of the positive equilibrium of the system. The Hopf bifurcation analysis is carried out. The numerical simulations are used to study the effect of periodic forcing in two different parameters. The results of simulations show that the model under the effects of periodic forcing in two different parameters, with or without phase difference, could exhibit chaotic dynamics for realistic and biologically feasible parametric values.

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Publication Date
Mon Mar 09 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of disinfectant agents on certain physical and mechanical properties of type IV dental stone
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Background: Dental stone casts come into contact with impression materials and becomes susceptible to cross contamination from saliva and blood. This study was done to evaluate the physical and mechanical properties of dental stone type IV after treatments with various disinfecting agents and regimes (methods). Materials and Methods: Type IV dental stone and different types of disinfecting agents were used and divided into seven groups: G1: dental stone without disinfection (control group), G2: dental stone mixed with silver nitrate powder 0.5% , G3: dental stone mixed with silver nitrate powder 1%, G4: dental stone mixed with copper sulfate powder 0.5%, G5: dental stone mixed with copper sulfate powder 1% ,G6: dental stone immersed in prop

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