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Effect of modified nanohydroxyapatite fillers addition on some properties of heat cured acrylic denture base materials
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Background: Poly (methylmethacrylate) is not ideal in every aspect and has disadvantages such as insufficient surface hardness, increase water sorption and poor impact resistance and the latter being the primary cause of fracture of denture base resins. The aim of this study was to evaluate the effect of addition of silanized nano- hydroxyapatite (HA) on some properties of heat cured acrylic denture base material. Materials and methods: HA nano particles were first silanized with MPS (tri methacryloxypropyletrimethoxy silane coupling agent) then ultrasonicated with methylmethacrylate (monomer) to disperse agglomerated nano particles and mixed with polymer. 2% by wt of HA nano particles was selected as the best concentration that added to the denture base material according to the pilot study.(100) specimens were prepared by conventional water bath processing technique and divided to two groups: 50 specimens for control group or 0% HA and 50 for experimental group or 2% HA then each group was subdivided to five groups with 10 specimens for each test: impact strength, transverse strength, surface hardness, surface roughness, water sorption and water solubility. Results: highly significant increase in impact strength and surface hardness after addition of 2% HA nano particles but not significant decrease in water sorption whereas solubility was significantly decreased. Surface roughness was significantly increased as compared with control group but remained within the acceptable limit less than 2m. HA nanoparticles addition highly decreased the transverse strength value. Conclusion The addition of 2% HA nano particles considerably improved the impact strength, surface hardness and had positive effect on water sorption and solubility. Whereas the same concentration tend to highly decreased transverse strength and increase surface roughness.

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Publication Date
Fri Sep 30 2022
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Adsorption Isotherms and Isosteric Heat of Adsorption of Metal Organic Frameworks as Gas Storage for Liquefied Petroleum Gas Vehicle in Iraq
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   This research provides a novel technique for using metal organic frameworks (HKUST-1) as a gas storage system for liquefied petroleum gas (LPG) in Iraqi vehicles to avoid the drawbacks of the currently employed method of LPG gas storage. A low-cost adsorbent called HKUST-1 was prepared and characterized in this research to investigate its ability for propane storage at different temperatures (25, 30, 35, and 40 oC) and pressures of (1-7) bar. HKUST-1 was made using a hydrothermal method and characterized using powder X-ray diffraction, BET surface area, scanning electron microscopic (SEM), and Fourier Transforms infrared spectroscopy (FTIR). The HKUST-1 was produced using a hydrothermal technique and possesses a high crys

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Publication Date
Sat Oct 01 2011
Journal Name
Journal Of Engineering
DEVELOPING LAMINAR MIXED CONVECTION HEAT TRANSFER THROUGH VERTICAL CONCENTRIC ANNULI WITH ADIABATIC INNER CYLINDER
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Theoretical and experimental investigations have been carried out on developing laminar
combined free and forced convection heat transfer in a vertical concentric annulus with uniformly
heated outer cylinder (constant heat flux) and adiabatic inner cylinder for both aiding and opposing
flows. The theoretical investigation involved a mathematical modeling and numerical solution for
two dimensional, symmetric, simultaneously developing laminar air flows was achieved. The
governing equations of motion (continuity, momentum and energy) are solved by using implicit
finite difference method and the Gauss elimination technique. The theoretical work covers heat flux
range from (200 to 1500) W/m2, Re range from 400 to 2000 an

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Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
MIXED CONVECTIVE AND RADIATIVE HEAT TRANSFER IN A HORIZONTAL CONCENTRIC AND ECCENTRIC CYLINDRICAL ANNULI
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A numerical investigation has been performed to study the effect of eccentricity on unsteady state, laminar aiding mixed convection in a horizontal concentric and eccentric cylindrical annulus. The outer cylinder was kept at a constant temperature
while the inner cylinder was heated with constant heat flux. The study involved numerical solution of transient momentum (Navier-Stokes) and energy equation using finite difference method (FDM), where the body fitted coordinate system (BFC) was
used to generate the grid mesh for computational plane. The governing equations were transformed to the vorticity-stream function formula as for momentum equations and to the temperature and stream function for energy equation.
A computer progra

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Publication Date
Tue May 16 2023
Journal Name
Journal Of Engineering
Experimental Investigation Utilizing Thermal Image Technique to the Heat Transfer Enhancement Using Oscillated Fins
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Heat transfer around a flat plate fin integrated with piezoelectric actuator used as oscillated fin in laminar flow has been studied experimentally utilizing thermal image camera. This study is performed
for fixed and oscillated single and triple fins. Different substrate-fin models have been tested, using fins of (35mm and 50mm) height, two sets of triple fins of (3mm and 6mm) spacing and three frequencies
applied to piezoelectric actuator (5, 30 and 50HZ). All tests are carried out for (0.5 m/s and 3m/s) in subsonic open type wind tunnel to evaluate temperature distribution, local and average Nusselt number (Nu) along the fin. It is observed, that the heat transfer enhancement with oscillation is significant compared to without o

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Publication Date
Mon Nov 01 2021
Journal Name
Energies
Solidification Enhancement in a Triple-Tube Latent Heat Energy Storage System Using Twisted Fins
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This work evaluates the influence of combining twisted fins in a triple-tube heat exchanger utilised for latent heat thermal energy storage (LHTES) in three-dimensional numerical simulation and comparing the outcome with the cases of the straight fins and no fins. The phase change material (PCM) is in the annulus between the inner and the outer tube, these tubes include a cold fluid that flows in the counter current path, to solidify the PCM and release the heat storage energy. The performance of the unit was assessed based on the liquid fraction and temperature profiles as well as solidification and the energy storage rate. This study aims to find suitable and efficient fins number and the optimum values of the Re and the inlet tem

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Publication Date
Thu Jul 06 2017
Journal Name
Al-mustansiriyah Journal Of Science
Physiological and histological effects of (zinc and iron) oxide nanoparticles on some fertility parameters in female mice
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Nowadays nanoparticles have widespread application in various industriesbecause of their special and unique features, there are many studies in sideeffects of nanomaterial. This study done by 40 white female mice withevery other day intraperitoneally injection of low and high doses of both ofZnO kg of body weight) and FeOnanoparticles (5 and 40 mg/kg). After a 15 days period, the mice weresacrificed and blood samples were collected for hormone analysis, andtissue samples for morphometric studies.Statistical Analysis shows significant differences in LH, Estrogen,Progesterone hormone levels between groups, while there are insignificantdifferences in Follicle stimulating hormone (FSH) level between thegroups compared with its level in

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Publication Date
Tue Dec 31 2024
Journal Name
مـجـلــة الـدراســات التربــويــة والعـلـمـيــة - كلـيــة الـتــربـيــة - الجــامـعـة العـراقـيــة ال
Synthesis, Characterization and Studies on Thermal, Antioxidant, Docking and Biological of New Ligands with Some Metal Complexes
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Publication Date
Mon Dec 21 2020
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
SEASONAL FLUCTUATION OF STINK BUG MUSTHA SPINULOSA (LEFEBVRE, 1831) (HEMIPTERA, PENTATOMIDAE) ON SOME TREES IN ERBIL CITY
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Phytophagous stink bugs (Hemiptera, Pentatomidae) are economically important insect pests of fruit, vegetable, nut and field crops. This study was carried out during the season of 2013 in orchards within Erbil city, to follow the stink bug Mustha spinulosa (Lefebvre, 1831) seasonal fluctuation on some fruit trees: olive, plum, apricot, pear, apple and almond.
The stink bug reaches its maximum abundance throughout the second week of August (38.2/tree) coinciding with mean temperature and relative humidity of 33.40C and 28.14% respectively, and the highest total mean of the number of the insect was recorded on the olive trees (181.8/tree). The study reveals that the stink bug attacked 22 trees (fruit and forest) while it has not atta

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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Academic research the impact of organizational culture on the performance of the internal – study in government institutions- analysis study on some government institutions in state of Qatar
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This study was aimed to explore the impact of social concepts about tribe, clan and women, on internal audit performance. These concepts are considered to be components of the organizational culture and performance of internal audit practice, with respect to the individual and collective performance within the institution. The study, furthermore, was intended to investigate and understand the role of the organizational culture of the tribal, clan and women components with regard to their role in society, in Qatar.

To achieve these objectives, the researcher followed the descriptive analytical approach, using a questionnaire directed to experts and staff working in the banking sector, with the view to test

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Publication Date
Fri Dec 31 2021
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
STUDY OF THE EFFECT OF CHITOSAN EXTRACTED FROM THE MUSHROOM ON THE EXPERIMENTALLY INDUCED HYPERLIPIDEMIA IN MALE RABBITS: STUDY OF THE EFFECT OF CHITOSAN EXTRACTED FROM THE MUSHROOM ON THE EXPERIMENTALLY INDUCED HYPERLIPIDEMIA IN MALE RABBITS
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The present study aimed to identify the therapeutic evaluation of chitosan extracted from the fungus cushroom and pure chitosan on glucose and lipid profile in the blood of 35 male rabbits with hyperlipidemia induced experimentally by cholesterol. The tests included estimation of glucose levels, total cholesterol, triglycerides, high-density lipoproteins, low-density lipoproteins, and very low-density lipoproteins. hyperlipidemia was induced in the male rabbits used in the study which was administered orally with cholesterol 150mg/kg body weight for a week. rabbits were divided into seven groups: control, cholesterol, pure chitosan, mushroom chitosan, cholesterol and pure chitosan, cholesterol and mushroom chitosan and cholestero

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