Most dental works require a diagnostic impression; alginate is contemplated as the most popular material used for this purpose. Titanium dioxide nanoparticles show evidence of antimicrobial activity in the recent era, for this purpose, this study aimed to evaluate the effect of adding Titanium dioxide nanoparticles on antimicrobial activity and surface detail reproduction of alginate impression material. Materials and methods: Titanium dioxide nanoparticles (purity = 99%, size= 20nm) was added to alginate at three different concentrations (2%, 3% and 5%). 84 samples were prepared in total. Samples were tested for antimicrobial activity using a disc diffusion test, and surface detail reproduction was done using (ISO 21563:2021). One-way ANOVA and independent sample t-test were used for data analysis through SPSS software. Results: for the antimicrobial test, inhibition zones for Streptococcus mutans and Candida albicans showed significant changes concerning the alteration in Titanium dioxide nanoparticle concentrations. The inhibition zone significantly increased with an increase in the percentage of Titanium dioxide nanoparticles. The mean of the inhibition zone for S. mutans was superior to C. albicans and the difference was statistically significant. Regarding surface detail reproduction, the control group, 2% and 3% groups manifested very similar results, only the group to which 5% of Titanium dioxide nanoparticles were added showed a decline in detail reproduction when compared to the other three groups. Conclusion: Within the limitation of this study, we can conclude that the antimicrobial activity against S mutans and C. albicans were significantly increased in modified groups, and this escalation was directly linked to the increase in Titanium dioxide nanoparticles concentration. In contrast, the surface detail reproduction was decreased when adding 5% Titanium dioxide nanoparticles to alginate.
Low- and medium-carbon structural steel components face random vibration and dynamic loads (like earthquakes) in many applications. Thus a modification to improve their mechanical properties, essentially damping properties, is required. The present study focuses on improving and developing these properties, significantly dampening properties, without losing the other mechanical properties. The specimens used in the present study are structural steel ribbed bar ISO 6935 subjected to heating temperatures of (850, 950, and 1050) ˚C, and cooling schemes of annealing, normalizing, sand, and quenching was selected. The damping properties of the specimens were measured experimentally with the area under the curve for the loadi
... Show MoreIn this paper the effect of thermal annealing on the structural and optical properties of Antimony Selenide (Sb2Se3) is investigated. Sb2Se3 powder is evaporated on clean amorphous glass substrates at room temperature under high vacuum pressure (4.5×10-6 mbar) to form thin films. The structural investigation was done with the aid of X-ray diffraction (XRD) and atomic force microscopy (AFM). The amorphous to polycrystalline transformation of these thin films was shown by X-ray diffraction analysis after thermal annealing. These films' morphology is explained. (UV-Vis ) spectra in ranges from 300 to 1100 nm was used to examine the optical properties of the films .The absorption coefficient and optical energy gap of the investigated films are
... Show MoreThe study aims to investigate the relationship between the gender diversity of board director, the accounting conservatism and firm value in Iraqi firms. The sample was represented by 30 Iraqi firms listed on the Iraqi market over the period 2017. The research was based on the main hypothesis that gender diversity has a positive relationship with conservatism and firm value, that conservatism as an intermediate variable will enhance the positive relationship between gender diversity and firm value. The study reached results that support the research hypotheses. The appointment of females to the board helps improve the provision of conservative accounting information and avoids overstate when reporting earnings. Based on these res
... Show MoreThe toxicity of insecticide dichlorvos (90%) was tested in ovaries of mosquito fish using three sublethal concentrations (0.3, 0.6, 0.8 µg/L) and studied their effects on the means of body and ovary weights, gonadosomatic index, ovum size and ova number. Results showed that there was a significant (P<0.05) decrease in body and ovary weights, ovum size and ova count. However, there was no significant (P<0.05) difference in gonadosomatic index in treated groups with the three concentrations of dichlorvos compared with the control group. This study was added evidence on the ovular toxicity of dichlorvos concerning its effect on fish production as well as reduction in the means of productive offspring and their survival.
CdS and CdTe thin films were thermally deposited onto glass substrate. The CdCl2 layer was deposited onto CdS surface. These followed by annealing for different duration times to modify the surface and interface of the junction. The diffraction patterns showed that the intensity of the peaks increased with the CdCl2/annealed treatment, and the grain sizes are increased after CdCl2/annealed treatment
This study presents a comprehensive set of laboratory works for the examined soil layers extracted from Baghdad city (specifically from Alkadhimya, Alaitaifiya, and Alhurriya) to illustrate their engineering properties. The researchers have adopted the unified soil classification system for soil classification purposes. Also, the direct shear test was performed for soil samples with various degrees of saturation (0%, 25%, 50%, 75%, and 100%). The test results have shown a significant reduction in cohesion property with higher moisture content within soil samples. Also, a noticeable reduction in angle of internal friction value has occurred with such changes. Furthermore, it has been found that the bearing capacity of unsaturated soi
... Show MoreThis study was aimed to reduce the amount of the sprayed solution lost during trees spraying. At the same time, the concentration of the sprayed solution on the target (tree or bush) must be ensured and to find the best combination of treatments. Two factors controls the spraying process: (i) spraying speed (1.2 km/h, 2.4 km/h, 3.6 km/h), and (ii) the type of sensor. The test results showed a significant loss reduction percentage. It reached (6.05%, 5.39% and 2.05%) at the speed (1.2 km/h, 2.4 km/h, 3.6 km/h), respectively. It was noticed that when the speed becomes higher the loss becomes less accordingly. The interaction between the 3.6 km/h speed and the type of Ultrasonic sensor led to a decrease in the percentage of the spray
... Show MoreIn this research the effect of cooling rate and mold type on mechanical properties of the eutectic
and hypoeutectic (Al-Si) alloys has been studied. The alloys used in this research work were (Al- 12.6%Si
alloy) and (Al- 7%Si alloy).The two alloys have been melted and poured in two types of molds with
different cooling rates. One of them was a sand mold and the other was metal mold. Mechanical tests
(hardness, tensile test and impact test) were carried out on the specimens. Also the metallographic
examination was performed.
It has been found that the values of hardness for the alloys(Al-12.6%Si and Al-7%Si) which poured in
metal mold is greater than the values of hardness for the same alloy when it poured in a heated