Background: Heat-cured poly (methyl methacrylate) the principal material for the fabrication of denture base have a relatively poor mechanical properties. The aim of this study was to investigate the effect of glass flakes used as reinforcement on the surface hardness and surface roughness of the heat-processed acrylic resin material. Material and method: Glass flakes (product code: GF002) pretreated with silane coupling agent were added to Triplex® denture base powder using different concentrations. A total of 100 specimens of similar dimensions (65 x 10 x 2.5) mm were prepared, subdivided into 2 main groups of 50 specimens for each of the study tests. Ten specimens for the control group and 40 specimens for each of the experimental groups (2%, 3%, 5%, and 7%) glass flakes content. The surface hardness was evaluated using the Shore D hardness test, while the surface roughness was evaluated using a profilometer device that detect the geometry of the specimen unpolished surface. Results were analyzed using the Wilcoxon rank sum test and the 1-way analysis of variance, (P-value 0.05). Results: The surface hardness tended to increase significantly p˂ 0.05 with the increasing flakes concentration, as an increase of 5.12% was recorded in surface hardness for the highest loading level; while the roughness showed a significant increase that remained within the tolerable range –less than 2µm– (significant bacterial colonization would occur if the surface roughness is more than 2µm). Conclusion: The addition of glass flakes to heat-cured poly(methyl methacrylate) enhanced the hardness of the material, the improvement was statistically significant for the higher glass flakes concentrations (5% and7%), while for the surface roughness there were a constant increase in roughness along with the increasing glass flakes content
Abstract
In the present work, thermal diffusivity and heat capacity measurements have been investigated in temperature range between RT and 1473 K for different duplex stainless steel supplied by Outokumpu Stainless AB, Sweden. The purpose of this study is to get a reliable thermophysical data of these alloys and to study the effect of microstructure on the thermal diffusivity and heat capacity value. Results show the ferrite content in the duplex stainless steel increased with temperature at equilibrium state. On the other hand, ferrite content increased with increasing Cr/Ni ratio and there is no significant effect of ferrite content on the thermal diffusivity value at room temperature. Furthermore, the heat capacity of all sam
... Show MoreWorld statistics proved that the most of work dangerous accidents, which causes death, are occurred in the construction works. These accidents related to many causes such as loss of workers experience and ignoring rules of safety requirements, especially young workers. Due to the risk of accidents that may occur in the site of work, the idea of this study crystallized to show the relationship between the age of worker and number of injuries and accidents, to identify the causes of these injuries, and to put the appropriate solutions to avoid or reduce the risk of work injuries. Also, the research shows the main principles of safety requirements to forming a clear picture about the subject of the study. A questioner form was prepared to c
... Show MoreThermal conductivity measurement was done for specimens of Polystyrene/ titanium dioxide, Polycarbonate/ titanium dioxide and Polymethylmetha acrylate/ titanium dioxide composites for weight ratio of 1.9/ 0.1 and 1.8/ 0.2 wt% for different thickness of the samples. The experimental results show that the thermal conductivity is increased with the increasing of thickness of layers and with the weight ratio of TiO2
This experiment was carried out in one of the fields (A) affiliated to the College of Agricultural Engineering Sciences / University of Baghdad, for the spring season 2021, On hybrid tomato plants (Mayai Mayai) to test flower viability, using two factors, the first was three levels of irrigation interval (2, 4, 6) days, and the second factor three concentrations of compound Nano fertilizer with concentrations (0, 1.5, 2.5) gm liter-1, so that the number of treatments is 9 treatments and three replications, the number of experimental units is 27 experimental units distributed randomly according to the random drawing method to ensure reducing experimental error and obtaining the most accurate results. A factorial experiment 3 x 3 x 3 was carr
... Show MoreImage processing applications are currently spreading rapidly in industrial agriculture. The process of sorting agricultural fruits according to their color comes first among many studies conducted in industrial agriculture. Therefore, it is necessary to conduct a study by developing an agricultural crop separator with a low economic cost, however automatically works to increase the effectiveness and efficiency in sorting agricultural crops. In this study, colored pepper fruits were sorted using a Pixy2 camera on the basis of algorithm image analysis, and by using a TCS3200 color sensor on the basis of analyzing the outer surface of the pepper fruits, thus This separation process is done by specifying the pepper according to the color of it
... Show MoreThe electrical properties of polycrystalline cadmium telluride thin films of different thickness (200,300,400)nm deposited by thermal evaporation onto glass substrates at room temperature and treated at different annealing temperature (373, 423, 473) K are reported. Conductivity measurements have been showed that the conductivity increases from 5.69X10-5 to 0.0011, 0.0001 (?.cm)-1 when the film thickness and annealing temperature increase respectively. This increasing in ?d.c due to increasing the carrier concentration which result from the excess free Te in these films.