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Force decay of orthodontic elastomeric chains by using three different mechanisms simulating canine retraction
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Background: The ideal force-delivery system must: provide optimal tooth moving forces that elicit the desired effects, be comfortable and hygienic for the patient, require minimal operator manipulation and patient cooperation and provide rapid tooth movement with minimal mobility during orthodontic therapy, the elastomeric chains have the greatest potential to fulfill these requirements. Materials and Methods: This in vitro study was designed to determine the effect of three different mechanisms for canine retraction : (6-3 , 6-5-3 and chain loop ) on the load relaxation behavior of three types of elastomeric chains : (maximum clear , maximum silver and extreme silver) from the same company (Ortho Technology company) with two different brand configurations: closed loop and open (short filament) chains under effect of time at (zero time, 24hr., 7, 14 , 21 and 28 days) in artificial saliva. Results: Statistical analysis showed that there was a highly significant difference in the mean percentage force decay for the three different mechanisms (P? 0.001).For all the three types, the 6-3 mechanism had the smallest mean percentage force decay. There was a highly significant difference in the mean percentage force decay for the different types (P? 0.001). For all three mechanisms, extreme silver elastomeric chains had the smallest percentage force decay while maximum silver elastomeric chains had the highest percentage force decay. Conclusion: This study illustrated that for all the three types of elastomeric chains, the (6-3) mechanism had the smallest mean percentage force decay. This finding suggests that it may be most efficient to retract a canine utilizing elastomeric chain directly from the molar hook to the canine bracket. The chain loop mechanism may not be indicated for space closure in vivo due to the excessive physiological force values involved with this mechanism.

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Publication Date
Tue Jul 01 2008
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
DESCRIPTION OF THE THIRD INSTAR LARVA OF SARCOPHAGA AFRICA (= S. HAEMORRHOIDALIS) FALL. (DIPTERA: SARCOPHAGIDAE)
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Sarcophaga africa Fall. considered to be medical and veterinary importance, therefore, its third larval instar was described by digital camera under compound and dissecting microscope. This description includes spines type, shaped and cephalopharyngeal skeleton. Furthermore the anterior and posterior spiracles were also studied.

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Publication Date
Sun Sep 01 2019
Journal Name
Journal Of Physics: Conference Series
Seed weight effect on germination properties and seedling growth of some cultivars of lupine
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A laboratory experiment was carried out and repeated at field of College of Agricultural Engineering Sciences, University of Baghdad in 2017. First factor was three cultivars of lupine 'Giza-1', 'Giza-2' and 'Hamburg'. Second factor was three seed weights (lower weight, medium weight and higher weight) which was following the cultivars factor. Nested design was used. Results showed supremacy of 'Giza-1' cultivar significantly and gave higher germination ratio, radical length, seedling dry weight, seedling vigour index, field emergence ratio, plant height and number of leaves per plant. The treatment ('Giza-1'×higher seed weight) was supremacy significantly and gave higher germination ratio, radical length, plumule length, and seedling vigo

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Publication Date
Sat Jan 01 2011
Journal Name
Journal Of Engineering
PHYSICAL MODEL OF KEROSENE PLUME MIGRATION IN AN UNSATURATED ZONE OF THE SANDY SOIL
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Physical model tests were simulated non-aqueous phase liquid (NAPL) spill in two-dimensional
domain above the water table. Four laboratory experiments were carried out in the sand-filled
tank. The evolution of the plume was observed through the transparent side of this tank and the
contaminant front was traced at appropriate intervals. The materials used in these experiments
were Al-Najaf sand as a porous medium and kerosene as contaminant.
The results of the experiments showed that after kerosene spreading comes to a halt (ceased) in
the homogeneous sand, the bulk of this contaminant is contained within a pancake-shaped lens
situated on top of the capillary fringe.

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Publication Date
Wed May 31 2017
Journal Name
Journal Of Engineering
A Study of Parameters Affecting the Solvent Extraction-Flocculation Process of Used Lubricating Oil
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The aim of this study was to investigate the effect of operating variables on, the percentage of removed sludge (PSR) obtained during re-refining of 15W-40 Al-Durra spent lubricant by solvent extraction-flocculation treatment method. Binary solvents were used such as, Heavy Naphtha (H.N.): MEK (N:MEK), H.N. : n-Butanol (N:n-But), and H.N. : Iso-Butanol (N:Iso:But). The studied variables were mixing speed (300-900, rpm), mixing time (15-60, min), and operating  temperature (2540, oC). This study showed that the studied operating variables have effects where, increasing the mixing time up to 45 min for H.N.: MEK, H.N.: n-Butanol  and 30 min for H.N.: Iso-Butanol increased the PSR, after that percentage was decreased; increasing t

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Publication Date
Sat Mar 18 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Annealing on The Structural and Optical Properties of SnS Thin Films
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 Thin  films   of  pure   tin mono-sulfide  SnS with thicknesses of   (0.85) μm  were prepared by chemical spray  pyrolysis  technique  and  annealed for  two  hours with 673K.The effect of annealing on structural and optical properties for films prepared was  studied.  X-Ray   diffraction  analysis  showed   the  polycrystalline  with   orthorhombic structure.  It was  found  that   annealing process increased the intensity of diffraction peaks. Optical   properties  of  all  samples  were studied by  recording  the  absorption  and  transmission &nbsp

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Publication Date
Sun May 31 2009
Journal Name
Transition Metal Chemistry
Formation of polymeric chain assemblies of transition metal complexes with a multidentate Schiff-base
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The new multidentate Schiff-base (E)-6,6′-((1E,1′E)-(ethane-1,2-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-ylidene))bis(4-methyl-2-((E)(pyridine-2-ylmethylimino)methyl)phenol) H2L and its polymeric binuclear metal complexes with Cr(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) are reported. The reaction of 2,6-diformyl-4-methyl-phenol with ethylenediamine in mole ratios of 2:1 gave the precursor 3,3′-(1E,1′E)-(ethane-1,2-diylbis(azan-1-yl-1ylidene))bis(methan-1-yl-1-ylidene)bis(2-hydroxy-5-methylbenzaldehyde) W. Condensation of the precursor with 2-(amino-methyl)pyridine in mole ratios of 1:2 gave the new N6O2 multidentate Schiff-base ligand H2L. Upon complex formation, the ligand behaves as a dibasic oct

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Publication Date
Tue Jun 21 2022
Journal Name
Journal Of Planner And Development
Spatial analysis of primary and secondary education se rvices in the city of Ramadi
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The researchers aim of this research to analyze the reality of educational services in the city of Ramadi in order to reveal the efficiency of the spatial distribution of schools at the level of residential neighborhoods and the requirements of the population, based on the standards and indicators for this service.

The research problem related to the educational function of the city of Ramadi was formulated by asking about the efficiency of the spatial distribution of educational services and whether there is a balance in the distribution of schools to residential neighborhoods in a way that meets the requirements of the population, and in order to answer the research problem, the research hypothesis was formulated that there is

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Publication Date
Wed Aug 09 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Determination of Optimum Cultural Conditions for the Production of Cytosine Deaminase From Escherichia coli
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    The study involved isolation and characterization of E.coli from patient’s infected with diarrhea , in order to study the ability of the bacteria to produce cytosine deaminase (CD). Result showed eight isolates of E.coli which showed adifference in the production of (CD) and the isolate of E. coli E33 was the beast of its production of CD than the other’s and the value of the specific activity was 4.920  u/mg protein , when grown in the medium which contains 1% glycerol ,3% peptone as a source of Carbon and Nitrogen respectively with pH 8.   The optimum cultural condition‘s for the production of CD from E. coli E33 was studied the result‘s  showed that the isolate gave the

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Publication Date
Wed Jun 30 2021
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
RATE CONSTANT OF SOME AMINO DERIVATIVES DISSOCIATION: RATE CONSTANT OF SOME AMINO DERIVATIVES DISSOCIATION
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Amino glycoside derivation including, Neomycin, Streptomycin, Kanamycin and Gentamycin with special reagents, which  are  benzoylchloride; benzene sulfonyl chloride and phthalic anhydride were made to enhance Uv-detectability for HPLC analysis. But there are many problems facing pre column derivation and in order to solve this, the conductivity of antibiotic derivatives were used to calculate the dissociation constant and the hydrolysis rate which determined concern type reaction. In addition the  characteristics those controlling the hydrolysis of antibiotic-derivatives were investigated.

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Publication Date
Thu Dec 30 2010
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
DETERMINATION OF THE OPTIMUM OPERATING CONDITIONS IN THE GRANULATION OF GAMMA ALUMINA CATALYST SUPPORT
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Granulation Technique for Gamma Alumina Catalyst Support was employed in inclined disk granulator (IDG), rotary drum granulator (RD) and extrusion – spheronization equipments .Product with wide size range can be produced with only few parameters like rpm of equipment, ratio of binder and angle of inclination. The investigation was conducted for determination the optimum operating conditions in the three above different granulation equipments.
Results reveal that the optimum operating conditions to get maximum granulation occurred at ( speed: 31rpm , Inclination:420 , binder ratio:225,300% ) for the IDG,( speed: 68rpm , Inclination: 12.50 , binder ratio: 300% ) for the RD and ( speed:1200rpm , time of rotation: 1-2min )for the Caleva

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