Background: Polymethylmethacrylate (PMMA) has relatively unsatisfactory mechanical properties such as low flexural strength and impact strength also dimensional instability. Material and method: Zirconium silicate nanoparticles were coated with a layer of trimethoxysilylpropylmethacrylate (TMSPM) before sonication in monomer (MMA) with the percentages 1% and 1.5% by weight then mixed with powder using conventional procedure, (150) samples were prepared and divided into three groups, each group consisted of (50) samples, the first group prepared from PMMA without addition (control), another group with the addition of 1% wt Zrsio4 nanoparticles (experimental) and the third one with 1.5% wt Zrsio4 nanoparticles (experimental). Each group was divided into 5 sub-groups according to the test performed. The tests conducted impact strength, transverse strength, indentation hardness (shore D), surface roughness, water sorption and solubility. The size, shape and distribution of nanofiller were estimated using scanning electron microscope (SEM) .The results were statistically analyzed using ANOVA and LSD test. Result: Highly significant increase in impact strength, transverse strength and surface hardness occurred with the incorporation of 1.5% wt Zirconium silicate nanofiller but non-significant increase in impact strength, significant increase in transverse strength and highly significant increase in surface hardness occurred with the incorporation of 1% wt Zrsio4 nanofiller. Non-significant increase in surface roughness with both 1% and 1.5% wt Zrsio4 . Highly significant decrease in water sorption and solubility with 1.5% wt Zrsio4 nanofiller and non-significant decrease in water sorption and solubility with 1% wt Zrsio4 compared with control group. Conclusion: The maximum increase in impact strength, transverse strength, and surface hardness was observed in denture base nano composite containing 1.5% Zrsio4. In addition, highly significant decrease in water sorption and solubility and non-significant increase in surface roughness was also noticed.
Heat exchanger is an important device in the industry for cooling or heating process. To increase the efficiency of heat exchanger, nanofluids are used to enhance the convective heat . transfer relative to the base fluid. - Al2O3/water nanofluid is used as cold stream in the shell and double concentric tube heat exchanger counter current to the hot stream basis oil. These nanoparticles were of particle size of 40 nm and it was mixed with a base fluid (water) at volume
concentrations of 0.002% and 0.004%. The results showed that each of Nusselt number and overall heat transfer coefficient increased as nanofluid concentrations increased. The pressure drop of nanofluid increased slightly than the base fluid because
Background: Wounds are any disruption to the normal anatomic structure of tissue which leads to the loss of epithelial continuity with or without a loss of underlying connective tissue, as well as the anatomic and functional integrity of the living tissue . Wound healing is a complex process with overlapping phases haemostasis, inflammation, proliferation and maturation/matrix Remodeling. Each phase of wound healing requires different management strategies, and inappropriate treatment can delay wound healing. The aim of wound treatment is a rapid wound closure and re-establish tissue function,chia seeds oil are widely used herbal medicines because of their anti-inflammatory and antioxidant capacity as they considerd agood source of polyunsa
... Show MoreThe effect of cognitive trips via the Internet (web quest) accompanying practical lessons in learning some basic handball skills for female students
The aim of the research is to identify the cognitive method (rigidity flexibility) of third-stage students in the collage of Physical Education and Sports Sciences at The University of Baghdad, as well as to recognize the impact of using the McCarthy model in learning some of skills in gymnastics, as well as to identify the best groups in learning skills, the experimental curriculum was used to design equal groups with pre test and post test and the research community was identified by third-stage students in academic year (2020-2021), the subject was randomly selected two divisions after which the measure of cognitive method was distributed to the sample, so the subject (32) students were distributed in four groups, and which the pre te
... Show MorePseudomonas aeruginosa gram-negative, bacilli and facultative aerobic, P. aeruginosa cause cystic fibrosis patients, wounds, burns, and immunodeficienct patients, that have many virulence factors such as pyocyanin , cytotoxic ,biofilm formation and motility, Eighty-eight isolates belonging to P. aeruginosa were collected including the 66 clinical isolates obtained from different hospitals in Baghdad and were from different sources and 22 environmental isolates from previous studies of soil near oil fields. Microscopical and cultural characteristics were studied and diagnosed using biochemical tests, VITEC device, their ability to adhere to non-living (Polystyrene), living cell line (A549) and cytotoxicity of bacterial filtrate
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The study evaluated the effect of adding quercetin to some characteristics of the sperm of the ram. This study was conducted in the animal field, Department of Animal Production, College of Agricultural Engineering Science, University of Baghdad for the period 5/12/2021 to 20/2/2022. In this experiment, 3 rams were used at the age of 2-2.5 years and weighed 50-55 kg. The semen was collected early in the morning and once a week and the semen was pooled to remove the individual differences. The treatments were divided: quercetin-free control group, treatment T1 (3 µL/mL quercetin), T2 treatment (6 µL/mL quercetin), T3 treatment (9 µL/mL quercetin). The result of the study showed
... Show MoreThe exchange rate is of great importance at the global and local levels alike, as this importance increases with the increasing rates of development of economic relations between countries of the world due to openness and integration into the global economy, expressed by the expansion of the volume of trade and financial relations between countries. The Central Bank of Iraq has set the need to stabilize this price as a goal to reduce inflation rates and reduce them to the internationally accepted rates by using the foreign currency sale window to achieve a balance between the forces of supply and demand for foreign currency and to preserve the value of the Iraqi dinar. The research concluded that the central bank was It has a maj
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