Background: Impression materials, impression trays, and poured stone cast have been said to be the main source of cross infection between patients and dentists. However, it was observed that disinfection of the impression is not performed systematically in routine dental practice. Disinfection of alginates either by immersion or spray technique was found to cause dimensional inaccuracies, although with proper disinfection of alginates there were small dimensional changes. A variety of fluoride releasing products designed for topical use is currently available. Following their use, varied amount of fluoride is systemically absorbed depending on the fluoride concentration and the manner of its use. The objective of this study was to evaluate

     In this paper, a novel coronavirus (COVID-19) model is proposed and investigated. In fact, the pandemic spread through a close contact between infected people and other people but sometimes the infected people could show two cases; the first is symptomatic and the other is asymptomatic (carrier) as the source of the risk. The outbreak of Covid-19 virus is described by a mathematical model dividing the population into four classes. The first class represents the susceptible people who are unaware of the disease. The second class refers to the susceptible people who are aware of the epidemic by media coverage. The third class is the carrier individuals (asymptomatic) and the fourth class represents the infected ind

In this paper, we studied the effect of magnetic hydrodynamic (MHD) on accelerated flows of a viscoelastic fluid with the fractional Burgers’ model. The velocity field of the flow is described by a fractional partial differential equation of fractional order by using Fourier sine transform and Laplace transform, an exact solutions for the velocity distribution are obtained for the following two problems: flow induced by constantly accelerating plate, and flow induced by variable accelerated plate. These solutions, presented under integral and series forms in terms of the generalized Mittag-Leffler function, are presented as the sum of two terms. The first term, represent the velocity field corresponding to a Newtonian fluid, and the se

Density functional theory calculations are employed to investigate the impact of edifenphos molecule on the reactivity and electronic sensitivity of pure calcium oxide (CaO) nanocluster. The strong adsorption of edifenphos molecule on CaO nanocluster occurs by the sulfur head of the adsorbate, and the amount of the energy of this adsorption is around − 84.40 kcal/mol. The adsorption of edifenphos molecules results in a decrease in the values of Eg of CaO from 4.67 to 3.56 eV, as well as an increase in the electrical conductance. Moreover, the work function of CaO nanocluster is significantly affected, which changes the current of the field emission electron. Eventually, the recovery time is calculated around 99 ms at ambient temperature f

    The experiment was conducted at the Agricultural Research Office in Baghdad during July 2020 to test the ability of nanomaterials (ZnO and TiO₂) to inhibit  ochratoxin A, which is produced by a number of microbiology (fungi) including: Aspergillus ochraceus, A. niger, ,A. steynii, A. carbonarius,  Pencillume verrucosum and P. nordicum. The standard ochratoxin A, with known concentration, was treated with different concentrations of nanomaterials  (20, 40, 60, and 80 ppm) and two different particle sizes of nanoparticles approximately (15 nm) and (70 nm) for each (ZnO) and TiO₂; with 16 transactions. Through an examination of the HPLC, the results showed that all tra

This study investigates the influence of silver oxide (Ag2O) concentration on the optical characteristics of phosphate bioactive glasses (PBGs). PBGs have emerged as promising alternatives to conventional silicate glasses in the medical field due to their excellent bioactivity and chemical resistance. Samples with varying Ag2O concentrations (0, 0.25, 0.5, and 0.75g) were sintered at 780°C for 2 hrs in an electric furnace. The samples were subjected to Fourier transfer infrared spectroscopy (FTIR), ultraviolet-visible (UV-Vis) spectroscopy, and photoluminescence (PL) tests to assess their functional groups and optical properties. By analyzing the FTIR spectrum of phosphate bioactive glass containing different amounts of Ag2O, it is

Millions of pilgrims and visitors from numerous parts of the world flock to Karbala (one of the most prominent ideological and religious places in central Iraq) each year to visit the holy shrines in Karbala due to their sanctity. Many improvements have been made to the Two Holy Shrines (THS), the Shrines of Imam Husayn and Imam Abbas, and the area between them (ATHS), due to the high temperatures in this region and to improve pedestrian thermal comfort. Studies on improving outdoor thermal comfort in Karbala are scarce. Hence, this research aims to look into historical and current architectural changes and how they affect thermal comfort. On the hottest summer day, the ENVI-met software program was used to simulate the building des