Abstract : Silicone elastomer is widely used as the material of choice for fabricating maxillofacial prosthesis. However, silicone properties are far from ideal; low tear strength, low tensile strength and insufficient elasticity are the most undesirable properties. The purpose of this study was to evaluate the effect of addition of nano SiO2filler on tear strength, tensile strength, elongation at break, hardness and color of Cosmesil M-511 HTV maxillofacial silicone elastomer. Nano SiO2was added to the silicone base in concentrations of 4%, 5% and 6% by weight. Silicone with 0% nano filler served as a control. Tear test was done according to ISO 34-1. Tensile and elongation test was done according to ISO 37. Shore A hardness test was done according to ISO 7619. Visual color measurement test was done according to ASTM D1535. Scanning electron microscope was used to assess the efficiency of dispersing method. FTIR test was conducted to evaluate the interaction of nano SiO2with the silicone. Statistical analysis was done using one-way ANOVA and Fisher’s LSD test. SEM showed well dispersion of nano filler within the silicone matrix. FTIR indicated that nano SiO2interacted with the PDMS through its surface hydroxyl group. All nano SiO2concentration groups showed a highly significant increase in tear strength, tensile strength and elongation at break compared to the control group. The 5% group showed the highest mean values among other groups. Shore A hardness showed a highly significant increase with all nano SiO2concentrations with the increase being directly proportional to filler concentration increase. Spectrophotometer results showed a highly significant decrease in translucency of the material with all nano filler concentrations but this decrease in translucency was visually demonstrated as slight increase in color intensity. Reinforcement of M-511 silicone with 5% nano SiO2significantly improves all mechanical properties tested with a slight change of color seen visually.
The most used material in the world after water is concrete, which depends mainly on its manufacture of cement leading to the emission of carbon dioxide (CO2), flying dust, and other greenhouse gasses (GHGs) resulting in pollution of the atmosphere. The emission of CO2 from cement production is approximately 5% of the global anthropogenic CO2. This research focuses on investigating the amount of CO2 emission from the Iraqi General Cement Company plants includes the cement factories of Kirkuk, Al-Qa’em, Fallujah, and Kubaisa, using the GHGs Protocol Measures Program (specifically cement based-method).
Ethanol as a solvent, a precursor of titanium isopropoxide and a stabilizer of either hydrochloric acid or ammonium hydroxide was used to prepare a titanium dioxide aqueous solution. The aqueous solutions with different values of pH and the morphology of the resultant reaction of the nanoparticles of titanium dioxide were investigated. The X-ray diffraction showed that at low temperatures and with acidic solutions, rutile structures are more favorable to grow on titanium dioxide synthesized, while at low and average temperatures and with base solutions, anatase phase is more pronounced. The crystalline form and the re-confirmation of the crystallite size growth were observed by the scanning electron microscopy. The atomi
... Show MoreEthanol as a solvent, a precursor of titanium isopropoxide and a stabilizer of either hydrochloric acid or ammonium hydroxide was used to prepare a titanium dioxide aqueous solution. The aqueous solutions with different values of pH and the morphology of the resultant reaction of the nanoparticles of titanium dioxide were investigated. The X-ray diffraction showed that at low temperatures and with acidic solutions, rutile structures are more favorable to grow on titanium dioxide synthesized, while at low and average temperatures and with base solutions, anatase phase is more pronounced. The crystalline form and the re-confirmation of the crystallite size growth were observed by the scanning electron microscopy. The atomic force micr
... Show MoreThis study was aimed to investigat integrated system for in vitro growth of paulownia plants by assessing the efficacy of chlorine dioxide (ClO2) as an alternative to autoclave in sterilizing culture medium. Therefore, this study was devised to compare autoclave sterilization at three different times (5, 10, and 15) minutes and three different concentrations of ClO2 (0, 0.4, 0,8, 1) mg/L. The results showed that, compared with (0.4) mg/L concentration, concentrations of (0.8 and 1) mg/L are more effective at sterilizing the culture medium. ClO2 sterilization improved individual single node growth more than autoclave sterilization. Since ClO2 is non-toxic, it could be used as a safe alternative to autoclave when propagating paulown
... Show MoreAutorías: Ghassan Adeeb Abdulhasan, Talib Faisal Shnawa, Yasir Wajih Qaddoori. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 6, 2022. Artículo de Revista en Dialnet.
جريت دراسة مختبرية لمعرفة تأثير الزيت الطيار لقشور ثمار نبات النارنج الصفرC. aurantium تجاه النمو السطحي للفطريات Penicillium expansum، Aspergillus flavus و Fusarium oxysporum ، أظهرت نتائج الفعالية التثبيطية للزيت الطيار تأثيراً معنويا متفاوتاً في الفطريات المشمولة بالدراسة، إذ كان الزيت الطيار أكثر تأثيرأَ في الفطر P. expansum تلاه الفطر A. flavus ،في حين كان الفطر oxysporum F.أقل حساسية تجاه الزيت الطيار. بصورة عامة اظهر الزيت الطيار تأثيرا تثبيطيا
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