Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. The material is far from ideal in fulfilling the mechanical requirements. Midline fracture; poor thermal conductivity and water sorption, are common problem in this material. The purpose of this study was to evaluate the effect of addition of surface treated Aluminum oxide nano fillers on some properties of heat cured (PMMA). Materials and methods: In addition to controlled group of heat cured PMMA the silanized (Al2O3) nanoparticles was added to PMMA powder by weight in three different percentages 1wt%, 2wt% and 3wt%, mixed by probe ultra-sonication machine. 200 specimens were constructed and divided into 5 groups according to the test (each group consist of 40 specimens) and each group was subdivided into 4 sub-groups. The tests conducted were thermal conductivity, thermal diffusivity, transverse strength, indentation hardness (shore D), surface roughness, water sorption and solubility. The results were statistically analyzed using ANOVA and Dunntt t-test. Results: A highly significant increase in transverse strength was observed with the addition of (Al2O3) nanoparticles to (PMMA) at the percentage of 1wt%, the value was 117.72 Mpa and significant increase at 2wt%; while a significant reduction occurred in transverse strength at the percentage of 3% the value was 90.110 Mpa. A significant increase in surface hardness and non significant differences in surface roughness were observed for all percentages. Conclusion: The addition of Al2O3 nanoparticles to acrylic resin improves the thermal properties and transverse strength of acrylic resin at the same time this addition decreases water sorption and solubility.
Current research included preparation, characterization of some new chitosan- hydroxy benzaldehyde-Schiff bases with maleic anhydride. The present study aimed to the synthesis and characterization of novel chitosan Schiff base compounds using para- hydroxy benzaldeh and maleic anhydride. The derivative of the schiff-chitosan base, which is associated with different drugs, has been replaced with different amino and hydroxy drugs. The derivative is characterized by different analytical techniques. The results of FT-IR studies clearly indicate construction of the chief amine group in chitosan and the emergence of new bands that correspond to the association of maleic anhydride with the chitosan base. TGA, 1
... Show MoreField experiments were carried out for the autumn season 2022- 2021 in the field of College of Agricultural Engineering Sciences - University of Baghdad - Jadiriyah Complex –Station A- to study a combination of organic fertilizer (Vermicompost) and cow manure as well as a control treatment (soil only) intertwined with Spraying with silicon, calcium and distilled water (control) in the growth and production of three cultivars of beet (Cylindra, Dark Red, Red) within the design of Completely Randomized Block Design at three replications, The number of treatments was 9 for each replicate. The means were compared according to the least significant difference (L.S.D) at a probability lev
Electrochemical machining is one of the widely used non-conventional machining processes to machine complex and difficult shapes for electrically conducting materials, such as super alloys, Ti-alloys, alloy steel, tool steel and stainless steel. Use of optimal ECM process conditions can significantly reduce the ECM operating, tooling, and maintenance cost and can produce components with higher accuracy. This paper studies the effect of process parameters on surface roughness (Ra) and material removal rate (MRR), and the optimization of process conditions in ECM. Experiments were conducted based on Taguchi’s L9 orthogonal array (OA) with three process parameters viz. current, electrolyte concentration, and inter-electrode gap. Sig
... Show MoreThe parasite E.histolytica was first isolated from a stool sample, and then cultivated and maintained in vitro using Locke-egg medium (LEM) and Liver infusion agar medium (LIAM) . Then, the effect of some types of erythrocytes (human and sheep), on the growth and activity of the parasite in the two culture media was investigated. The parasite was able to ingest and lysis erythrocytes of human and sheep that were supplemented to the culture media and such manipulation was able to augment the reproduction rate of the cultivated E. histolytica, however, such consequence was media- and concentration-dependent. The reproduction rate was significantly increased (66.0, 57.5 and 58.6%, respectively) in LEM medium containing human erythrocytes ty
... Show MoreIn this report Silver doped Tin Sulfide (SnS) thin films with ratio of (0.03) were prepared using thermal evaporation with a vacuum of 4*10-6 mbar on glass with (400) nm thickness and the sample annealing with ( 573K ). The optical constants for the wavelengths in the range (300-900) nm and Hall effect for (SnS and SnS:3% Ag) films are investigated and calculated before and after annealing at 573 K. Transition metal doped SnS thin films the regular absorption 70% in the visible region, the doping level intensification the optical band gap values from 1.5- 2 eV. Silver doped tin sulfide (SnS) its direct optical band gap. Hall Effect results of (SnS and SnS:3% Ag) films show all films were (p-type) electrical conductivity with resistivity of
... Show MoreIn this research we prepared CdS thin films by Spray pyrolysis method on a glass substrates and we study its structural , optical , electrical properties .The result of (X-Ray ) diffraction showed that all thin films have a polycrystalline structure , The relation of the transmission as a function of wavelength for the CdS films had been studied , The investigated of direct energy gap of the CdS its value is (2.83 eV). In Hall effect measurement of the CdS we find the charge carriers is p – type and Hall coefficient 1157.33(cm3/c) ,Hall mobility 6.77(cm2/v.s)
Conducted the study of the experimental conditions of the interaction of glass the visual Alpmuth containing 15% Mall of zinc with phosphoric acid ????? various degrees of thermal and clip areas prone to interact different way turntable
The compound Fe0.5CoxMg0.95-xO where (x= 0.025, 0.05, 0.075, 0.1) was prepared via the sol-gel technique. The crystalline nature of magnesium oxide was studied by X-ray powder diffraction (XRD) analysis, and the size of the sample crystals, ranging between (16.91-19.62nm), increased, while the lattice constant within the band (0.5337-0.4738 nm) decreased with increasing the cobalt concentration. The morphology of the specimens was studied by scanning electron microscopy (SEM) which shows images forming spherical granules in addition to the presence of interconnected chips. The presence of the elements involved in the super
Naturally occurring radioactive materials (NORM) contaminated sites at Al-Rumaila Iraqi oil fields have been characterized as a part of soil remediation project. Activity of radium isotopes in contaminated soil have been determined using gamma spectrometer High Purity Germanium detector (HPGe) and found to be very high for Al-Markezia, Al-Qurainat degassing stations and storage area at Khadhir Almay region. The activity concentration of samples ranges from 6474.11±563.8 Bq/kg to 1232.5±60.9 Bq/kg with mean value of 3853.3 Bq/kg for 226Ra, 843.59±8.39 Bq/kg to 302.2±9.2 Bq/kg with mean value of 572.9 Bq/kg for 232Th and 294.31±18.56 Bq/kg to 156.64±18.1 Bq/kg with mean value of 225.5 for 40K. S
... Show More?Natural Occurrence of aflatoxin Bi and B2 was investigated monthly in paddy rice stored for duration of six months. Aflatoxin B| was detected at the beginning of storage. The concentration of aflatoxin Bi in paddy and polished rice was found to be (0.3 and ()) ppb respectively while aflatoxin B2 W'as not detected in both paddy and polished rice afler six months of storage, concentration of aflatoxin Bi ‘ ’ ' reached 3 ppb in paddy rice and 0.9 ppb in polished rice, while the study proved that the concentration of aflatoxin in paddy rice was higher than polished rice as a result of processing which reduce the toxin