Denture bases are fabricated routinely using Poly(methyl methacrylate) (PMMA) acrylic resin. Yet, it is commonly known for its major drawbacks such as insufficient strength and ductility. The purpose of this study was to improve the performance of PMMA acrylic resin as a denture base material by reinforcement with surface treated lithium disilicate glass ceramic powder. The ceramic powder was prepared by grinding and sieving IPS e.max CAD MT blocks. Then, the powder was surface treated with an organosilane coupling agent (TMSPM) and added to PMMA in amount of 1%, 3%, 5% and 7% by weight. Characterizations of the powder was done by particle size analysis, XRD and FTIR. Transverse strength, Impact strength, Shore D hardness and surface roughness were tested for the prepared composites and neat PMMA. Particle size analysis showed that the average particle diameter was 1.46 µm. XRD confirmed the microstructure of IPS e.max CAD MT. FTIR showed the presence of TMSPM functional groups in the powder after treatment and there was a chemical interaction between the treated powder and the PMMA after the addition. One-way ANOVA and Tukey’s HSD test showed that there was a highly significant increase (P < 0.01) in transverse strength, impact strength and hardness with non-significant increase in roughness for 1% group. The mean values of 1% group were 67.3 MPa for transverse strength, 5.21 kJ/m2 for impact strength, 89.8 for Shore D hardness and 1.22 µm for surface roughness. While for control group, mean values were 59.3 MPa for transverse strength, 3.74 kJ/m2 for impact strength, 87.1 for Shore D hardness and 1.1 µm for surface roughness. However, with higher amounts of powder, there was a highly significant decrease in transverse strength and increase in roughness which was considered undesirable. In conclusion, reinforcing PMMA denture base material with 1% lithium disilicate glass ceramic powder may have the potential for enhancing the clinical performance of this material.
Photonic Crystal Fiber Interferometers (PCFIs) are widely used for sensing applications. This work presents the fabrication and study the characterization of a relative humidity sensor based on a polymer-infiltrated photonic crystal fiber that operates in a Mach- Zehnder Interferometer (MZI) reflection mode. The fabrication of the sensor only involves splicing and cleaving Photonic Crystal Fiber (PCF) with Single Mode Fiber (SMF). A stub of (LMA-10) PCF spliced to SMF (Corning-28). In the splice regions. The PCFI sensor operation based on the adsorption and desorption of water vapour at the silica-air interface within the PCF. The sensor shows a high sensitivity to RH variations from (27% RH - 95% RH), with a change in its reflected powe
... Show MoreThe modified Hummers method was applied to prepare graphene oxide (GO) from the graphite powder. Tin oxide nanoparticles with different loading (10-20 wt.%) supported on reduced graphene oxide were synthesized to evaluate the oxidative desulfurization efficiency. The catalyst was synthesized by the incipient wetness impregnation (IWI) technique. Different analysis methods like FT-IR, XRD, FESEM, AFM, and Brunauer-Emmett-Teller (BET) were utilized to characterize graphene oxide and catalysts. The XRD analysis showed that the average crystal size of graphene oxide was 6.05 nm. In addition, the FESEM results showed high metal oxide dispersions on the rGO. The EDX analysis shows the weight ratio of Sn is close to its theoretical weight.
... Show MoreThe current study aimed to determine the morphometric and meristic characteristics of the North African catfish Clarias gariepinus (Burchell, 1822). Six specimens of C. gariepinus were collected from the Tigris River, in central Iraq. This study is considered the confirmation first record of this species in Iraq, and the second documentation of this exotic fish. The present species is characterized by a very long dorsal fin, a rounded caudal fin and four pairs of barbels.
Spectrophotometric method was developed for the determination of copper(II) ion. Synthesized (2,2[O-Tolidine-4,4-bis azo]bis[4,5-diphenyl imidazole]) (MBBAI) was used as chromogenic reagent at pH=5. Various factors affecting complex formation, such as, pH effect, reagent concentration, time effect and temperature effect, have been considered and studied. Under optimum conditions concentration ranged from (5.00-80.00) µg/mL of copper(II) obeyed Beer`s Low. Maximum absorption of the complex was 409nm with molar absorpitivity 0.127x104 L mol-1 cm-1. Limit of detection(LOD) and Limit of quantification were 1.924 and 6.42 μg/mL, respectively.
... Show MoreA simple, low cost and rapid flow injection turbidimetric method was developed and validated for mebeverine hydrochloride (MBH) determination in pharmaceutical preparations. The developed method is based on forming of a white, turbid ion-pair product as a result of a reaction between the MBH and sodium persulfate in a closed flow injection system where the sodium persulfate is used as precipitation reagent. The turbidity of the formed complex was measured at the detection angle of 180° (attenuated detection) using NAG dual&Solo (0-180°) detector which contained dual detections zones (i.e., measuring cells 1 & 2). The increase in the turbidity of the complex was directly proportional to the increase of the MBH concentration
... Show MoreMost of the literature on the management and application terkzat waved the last period on large organizations was the negligence of knowledge management in small organizations where research aims to find out knowleddge management, small projects In oxygen Ahli plant in Iraq, and the fact the role of knowledge management in small projects from the standpoint of employees in order to achieve this used production method results. The results showed that knowledge management has a role in the high level of productivity during the years 2010-2013. The results showed that knowledge management has a role in the high level of productivity during the years 2
... Show MoreThis study aims to know how and what is the media processing presented by the television talk shows for the religious extremism topics in terms of topics, hosted personalities, and ways to address this global phenomenon.
The study is based on descriptive research, and the researcher used the analytical-survey method, analyzing the episodes of (Awkar Al Dhalam) T.V Show which was presented on Al-Iraqiya News Channel, and (Islam Hur) T.V Show which was presented on Al-Hurra in 2019 with 25 episodes from each Show, The sample and research community was chosen with the intent to cover the research problem and its
The study reached several conclusions, including:
- The various dialogs in the episo
Аннотация
В статье считается национально-культурная специфика и языковое изменчивость выражения заключений в художественном тексте. В настоящее время в изучении художественного текста существует множество взаимодополняющих подходов и концепций, которые способствуют лучшему пониманию его языковых и культурных аспектов. Художественный текст как «воспроизведение» и от
... Show Moreאורי-צבי גרינברג, אחד המשוררים היהודים הבולטים במאה ה-20, ולפי מבקרים רבים, היה גרינברג מהמשוררים החלוצים בתקופה שמלאה בחדשנות ובתנודת האירועים הפוליטיים והביטחוניים, באירופה ובמזרח התיכון. גרינברג יליד גליציה ב-1894, גדל במשפחה חסידית, הוא הגר פלסטינה ב-1923, ומשנה ההיא גרינברג נצל את עצמו לעבודה הספרותית והפוליטית ביחד. הוא תרם להקמתם של כתבי-עת והעתונים וכתב יצירות ספרותיות רבות, רובן היו שירים בעלי
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