Objective: Evaluate the effects of different storage periods on flexural strength (FS) and degree of conversion (DC) of Bis-Acryl composite and Urethane dimethacrylate provisional restorative materials. Material and Methods: A total of 60 specimens were prepared from four temporary crown materials commercially available and assigned to four tested groups (n = 15 for each group): Prevision Temp, B&E CROWN, Primma Art, and Charm Temp groups. The specimens were stored in artificial saliva, and the FS was tested after 24 h, 7 d, and 14 d. A standard three-point bending test was conducted using a universal testing machine. Additionally, the DC was determined using a Fourier transform infrared spectroscopy (FTIR) device. The data were analyzed statistically using two- way ANOVA, Tukey`s HSD post-hoc test, and the Bonferroni test, all at a 5% significance level. For each group, a paired samples test was applied to compare the DC of the immediate and 24 h samples. Results: The highest FS value was found for the Prevision Temp material, while the Charm Temp material showed the lowest FS, with no statistically significant difference between the mean values of the groups at 24 h; while there were significant differences at 7d and 14 d of storage. However, within each group, the aging had no significant impact on the FS, except for an increase in the FS of the B&E CROWN group after 14 d. Prevision Temp also had the highest mean DC value. At each time interval, significant differences were recorded. Moreover, within each group of material, aging significantly increased the DC, except for the Primma Art. Conclusion: Bis-acryl composite resin materials exhibited higher flexural strength compared to traditional methyl methacrylate resin during the 14 d investigation period. Aging in artificial saliva did not significantly affect the mechanical performance of the tested materials. Materials with higher DC values showed greater flexural strength; where the Prevision Temp showed higher FS and DC values than the other tested materials.
In this paper, numerical and experimental studies on the elastic behavior of glass fiber reinforced polymer (GFRP) with stiffeners in the GFRP section's web (to prevent local buckling) are presented. The GFRP profiles were connected to the concrete deck slab by shear connectors. Two full-scale simply supported composite beams (with and without stiffeners) were tested under impact load (three-point load) to assess its structural response. The results proved that the maximum impact force, maximum deflection, damping time, and damping ratio of the composite beam were affected by the GFRP stiffeners. The experimental results indicated that the damping ratio and deflection were diminished compare
... Show MoreThis research examines the future of television work in light of the challenges posed by artificial intelligence (AI). The study aims to explore the impact of AI on the form and content of television messages and identify areas where AI can be employed in television production. This study adopts a future-oriented exploratory approach, utilizing survey methodology. As the research focuses on foresight, the researcher gathers the opinions of AI experts and media specialists through in-depth interviews to obtain data and insights. The researcher selected 30 experts, with 15 experts in AI and 15 experts in media. The study reveals several findings, including the potential use of machine learning, deep learning, and na
... Show MoreIn this study, silver-tungsten oxide core–shell nanoparticles (Ag–WO3 NPs) were synthesized by pulsed laser ablation in liquid employing a (1.06 µm) Q-switched Nd:YAG laser, at different Ag colloidal concentration environment (different core concentration). The produced Ag–WO3 core–shell NPs were subjected to characterization using UV–visible spectrophotometry, X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive spectroscopy, electrical analysis, and photoluminescence PL. The UV–visible spectra exhibited distinct absorption peaks at around 200 and 405 nm, which attributed to the occurrence of surface Plasmon reson
The current study was carried out to find out the relationship between the Above-Ground Biomass and the spectral vegetative indices (Normalized Difference Vegetation Index, Soil Adjusted Vegetation Index, Difference Vegetation Index) (NDVI, SAVI, DVI) for soils with different salinity levels. Al Salamiyat Project was chosen as a study area located at an altitude of 34 m above sea level and within the geographical coordinates (E 44°.09´13.65´´ N 33°.25´ 07.87´´ and E 44°.17´ 46.03´´ N 33°.2l´40.72´´), with a total area of 14265 Dunum. Surface and subsurface soil samples were chosen from the study area and according to the previously defined salinity units, except for th
The research aims to shed light on the role of artificial intelligence in achieving Ambidexterity performance, as banks work to take advantage of modern technologies, artificial intelligence is an innovation that is expected to have a long-term impact, as well as banks can improve the quality of their services and analyze data to ensure that customers' future needs are understood. . The Bank of Baghdad and the Middle East Bank were chosen as a community for the study because they had a role in the economic development of the country as well as their active role in the banking market. A sample of department managers was highlighted in collecting data and extracting results based on the checklist, which is the main tool for the stu
... Show MoreThis research prepared polymer blend contains from epoxy resin (Ep) and polyurethane
)Pu) as a matrix material of percentage (90 %) from epoxy and ) 10 (% polyurethane and
reinforced by PVC fibers and aluminum fibers two dimension knitted mat with fractional
volume(15 %), and study impact strength before and after reinforcing at temperatures of
(20,40,60(
o
CØŒand the results have shown that the reinforcing matrix materials by fibers
increased impact strength values that rise from(3.387kJ/m2) to (151.62kJ/m2) of composite
material (Ep+Pu+PVC(and thus ) Ep+Pu+PVC+Al.F) at last (Ep+Pu+Al.F (. following
composite material so that temperatures increase led to rise impact strength values except the
polymer
يسعى البحث إلى الاهتمام بإحدى الوظائف المهمة في إدارة الموارد البشرية وهي تقويم الأداء التي تواجه مجموعة من الانتقادات والآراء السلبية، اذ ظهر في الأّونة الأخيرة أنموذج جديد يمكن إن يتجاوز تلك السلبيات وهو أنموذج التغذية العكسية المتعدد المصادر درجة .وقد حاول الباحثان توظيف هذا المفهوم في اثنتين من المنظمات العامة العراقية هما (دائرة كهرباء الوسط) التابعة لوزارة الكهرباء
و (دائرة الماء والمجاري) ال
Artificial Neural Network (ANN) is widely used in many complex applications. Artificial neural network is a statistical intelligent technique resembling the characteristic of the human neural network. The prediction of time series from the important topics in statistical sciences to assist administrations in the planning and make the accurate decisions, so the aim of this study is to analysis the monthly hypertension in Kalar for the period (January 2011- June 2018) by applying an autoregressive –integrated- moving average model and artificial neural networks and choose the best and most efficient model for patients with hypertension in Kalar through the comparison between neural networks and Box- Je
... Show MoreThe research work covers a study of the possibility of producing porous ceramic bodies
as a thermal insulators by adding fired Dechla kaolinite (grog)to the same non burned
kaolinite.
Different weight percentage ranged between (0,15,25,35and40)from grog and sawdust
passed through mesh 50 to Deuchla-clay kaolinit.Cylindrical shape samples (30mm diameter
and 30mm height) were prepared by the semi-dry methed,moulding pressure was 50 N/mm
2
.
After drying at 110
o
c,the samples were burnet in the furnace at temperatures
900,950,1000,1050,and 1100
o
c. The sawdust burnt out and leaves air spaces which contribute
to the high thermal insulation value.
The fired samples were investigated to de