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Study of Gamma — irradiation effects on the Polymethylmethacrylate (PMMA) Using (PAL) Method
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Gamma - irradiation effect on polymethylmethacrylate (PMMA) samples has been studied using Positron Annihilation Lifetime (PAL) method. The orthopositronium (o-Ps) lifetime τ3, hence the o-ps parameters, the volume hole size (Vh) and the free volume fraction (Ꞙh) in the irradiated samples were measured as a function of gamma-irradiation dose up to 28.05 kGy. It has been shown that τ 3, Vh, and Ꞙh, are increasing in general with increasing gamma-dose, to reach a maximum percentage increment of 22.42% in τ3, 60% in Vh and 29.5% in Ꞙh, at. 2.55 kGy, whereas τ2 reaches maximum increment of 119. 7% at 7.65 kGy. The results suggest that gamma-irradiation induces structure changes in PMAM, causing degradation in the main chains, and the presence of oxygen Causes reduction in the amorphous regions ; oxygen and the peroxy radicals form cross-linking at reactive sites between neighboring chains, giving a net reduction of the degradation yield.

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Publication Date
Mon Dec 03 2018
Journal Name
Journal Of Engineering
Studying the Effects of Different Polymers on Rheological Properties of Water Base Muds
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This research is focusing on finding more effective polymers that leads to enhance the rheological properties of Water Base Muds. The experiments are done for different types of mud for all substances which are Polyacrylamide, Xanthan gum, CMC (Carboxyl Methyl Cellulose). This study shows the effect of add polymer to red bentonite mud, effect of add polymer to Iraqi bentonite mud, the effect of add bentonite to polymer mud. The mud properties of Iraqi bentonite blank are enhanced after adding the polymers to the blank mix, CMC gives the highest value of plastic viscosity and Gel strength than others; X-anthan gives the highest value of yield point and gel strength than others. For the red bentonite mud, Polyacrylamide has the highes

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Publication Date
Sun Jun 05 2011
Journal Name
Baghdad Science Journal
Toxicity effects of some heavy metals on the growth of alga Scenedesmus dimorphus
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The toxicity effect of some heavy metals (Lead, Cadmium, Copper, and Zinc) on the growth of alga Scenedesmus dimorphus which belongs to the Division of Chlorophyta was studied and depended on the total cell number . The growth rate and doubling time were also calculated accordingly in present of absent of the the heavy metals . There were differences in toxic effects of the metals (p<0.05) . The growth was decreased gradually with alga when exposured to Lead at 15,20 and 25 mg/l in comparison with the control , mean while 30 mg/l caused an acute decrease in growth . Treating the alga with 0.05,0.1,0.5 mg/l concentration of Cadmium the number of cells decreased while at 1 mg/l the effect was more pronounced . As for Copper the conc

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Publication Date
Sat Feb 13 2021
Journal Name
Journal Of Lasers In Medical Sciences
Effects of Different Laser Treatments on Some Properties of the Zirconia-Porcelain Interface
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Introduction: This study was performed to compare the effect of Fractional CO2 laser or Q switched Nd:YAG laser of surface treatment on the shear bond strength of zirconia-porcelain interface. Methods: Fractional CO2 laser at 30 W, 2 ms, time interval 1 ms, distance between spots 0.3 mm, and number of scans is (4) or Q switched Nd:YAG laser at 30 J/mm2 and 10 Hz were used to assess the shear bond strength of zirconia to porcelain. Pre-sintered zirconia specimens were divided into three groups (n = 10) according to the surface treatment technique used: (a) untreated (Control) group; (b) CO2 group; (c) Nd:YAG group. All samples were then sintered and veneered with porcelain according to the manufacturer’s instructions. Surface morph

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Publication Date
Mon Dec 03 2018
Journal Name
Journal Of Engineering
Studying the Effects of Different Polymers on Rheological Properties of Water Base Muds
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This research is focusing on finding more effective polymers that leads to enhance the rheological properties of Water Base Muds. The experiments are done for different types of mud for all substances which are Polyacrylamide, Xanthan gum, CMC (Carboxyl Methyl Cellulose). This study shows the effect of add polymer to red bentonite mud, effect of add polymer to Iraqi bentonite mud, the effect of add bentonite to polymer mud. The mud properties of Iraqi bentonite blank are enhanced after adding the polymers to the blank mix, CMC gives the highest value of plastic viscosity and Gel strength than others; X-anthan gives the highest value of yield point and gel strength than others. For the red bentonite mud, Polyacrylamide ha

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Publication Date
Thu Feb 01 2018
Journal Name
European Journal Of Drug Metabolism And Pharmacokinetics
Effects of Human Sulfotransferase 2A1 Genetic Polymorphisms 3 on the Sulfation of Tibolone
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Publication Date
Mon Dec 22 2025
Journal Name
Sciences Journal Of Physical Education
Using two types of electronic questions by applying the Quiz Creator program in the method of guided discovery and its effect on learning and maintaining a motor chain on the throat
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Publication Date
Mon Feb 18 2019
Journal Name
Iraqi Journal Of Physics
Studying the spectral properties of thin films of rhodamine (6G) dyes doped polymer (PMMA) dissolved in chloroform
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              In the present work, poly methyl methacrylate (PMMA) doped with Rhodamine 6G was prepared. The spectral properties (absorption and fluorescence) of the films were studied at different concentrations (1x10-5, 2x10-5, 5x10-5, 7x10-5, and 1x10-4mol/l). The investigated samples were made in the form of thin films. This was achieved by dissolving a certain weight of PMMA in a fixed volume of chloroform, composite films was with thickness (25.8μm) at room temperature. The achieved results were pointed out that absorption and fluorescence spectra have taken a wide spectral rang so when increased the concentratio

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Publication Date
Mon Feb 04 2019
Journal Name
Iraqi Journal Of Physics
Nonlinear optical properties of synthesized porous nanostructures PMMA via template-directed methods
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Colloidal crystals (opals) made of close-packed polymethylmethacrylate (PMMA) were fabricated and grown by Template-Directed methods to obtain porous materials with well-ordered periodicity and interconnected pore systems to manufacture photonic crystals. Opals were made from aqueous suspensions of monodisperse PMMA spheres with diameters between 280 and 415 nm. SEM confirmed the PMMA spheres crystallized uniformly in a face-centered cubic (FCC) array. Optical properties of synthesized pores PMMA were characterized by UV–Visible spectroscopy. It shows that the colloidal crystals possess pseudo photonic band gaps in the visible region. A combination of Bragg’s law of diffraction and Snell’s law of refraction were used to calculate t

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Publication Date
Sun Mar 05 2017
Journal Name
Baghdad Science Journal
Study the Effects of Olive Leaves Extracts in the activity of the enzyme GOT and their Biological Activities
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The olive tree, has been used it is important plant for the time being some of their parts on a large scale in the treatment of gastrointestinal disorders and stimulate circulation . Moreover, it is used as antibacterial material and also to address some of the respiratory system, diabetes, food preservation osteoporosis. This study involved the collection of olive leaves from different areas in Baghdad / Iraq. These leaves have been harvested, wash it, then dried and crushed, where the study aimed to identify the active ingredients and chemical elements in the olive leaf as well as its effect on the action of GOT enzyme .The study showed that the aqueous extracts (cold and hot) of the olive leaves powder are acidic in nature pH values

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Publication Date
Sun Feb 03 2019
Journal Name
Iraqi Journal Of Physics
Thickness and gamma-ray effect on physical properties of CdO thin films grown by pulsed laser deposition
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Polycrystalline Cadmium Oxide (CdO) thin films were prepared
using pulsed laser deposition onto glass substrates at room
temperature with different thicknesses of (300, 350 and 400)nm,
these films were irradiated with cesium-137(Cs-137) radiation. The
thickness and irradiation effects on structural and optical properties
were studied. It is observed by XRD results that films are
polycrystalline before and after irradiation, with cubic structure and
show preferential growth along (111) and (200) directions. The
crystallite sizes increases with increasing of thickness, and decreases
with gamma radiation, which are found to be within the range
(23.84-4.52) nm and (41.44-4.974)nm before and after irradiation for

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