Background: The PMMA polymer denture base materials are low in thermal and strength properties. The aim of the study was to investigate the change in glass transition temperature, E-Moudulus and coefficient of thermal expansion of acrylic denture base material by addition of Al2O3, TiO2 and SiO2nano-fillers in 5% by weight. Materials and methods: The type of polymerization is free radical bulk polymerization. one hundred twenty (120) specimens were prepared , the specimens were divided into four groups according to the material had been added (one control and three for Al2O3, TiO2 and SiO2nanocomposite) each group was subdivided in to three groups according to the test had been done on it, the degree of transition (Tg) was measured by The differential scanning calorimeter (DSC), E-Modulus and coefficient of thermal expansion and contraction was measured by Thermo Mechanical Analyzer (TMA) .Each sample was tested at different temperatures (30,40,50,60,70C°). Results: Highly significant decrease in coefficient thermal expansion and contraction and in E-Modulus occurred in acrylic incorporated with Al2O3, TiO2 and SiO2 nano-fillers in 5% by weight when compared to control group. For glass transition temperature a significant increase had occurred with the addition of nanofillers at 5% when compared to control group. Conclusion: The results showed that the polymer nanocomposites possess material properties different from that of unmodified PMMA, nanocomposite has thermal and mechanical stability more than heat neat PMMA.
Natural fibers and particles reinforced composites are being broadly used due to their bio and specific properties such as low density and easy to machine and production with low cost. In this work, water absorption and mechanical properties such as tensile strength, flexural strength and impact strength of recycled jute fibers reinforced epoxy resin were enhanced by treating these fibers with alkaline solution. The recycled jute fibers were treated with different concentration of (NaOH) solution at (25 0C) for a period of (24) hours. From the obtained results, it was found that all these properties are improved when fibers treated with (7.5wt% NaOH) related to untreated fibers. Conversely, the mentioned properties of composit
... Show MoreA paraffin wax and copper foam matrix were used as a thermal energy storage material in the double passes air solar chimney (SC) collector to get ventilation effect through daytime and after sunset. Air SC collector was installed in the south wall of an insulated test room and tested with different working angles (30o, 45o and 60o). Different SC types were used; single pass, double passes flat plate collector and double pass thermal energy storage box collector (TESB). A computational model based on the finite volume method for transient tw dimensional domains was carried out to describe the heat transfer and storage in the thermal energy storage material of collector. Also, equivalent specific heat metho
... Show MoreThe objective of the research is to measure the impact of social responsibility on the financial performance of the National Bank of Iraq for the period from 2014 to 2016 (3 years) through discussing and analyzing the level of practice of the Bank of Baghdad for social responsibility and the impact on their financial performance during the period. To measure the independent variable (CSR), the researcher used the CSR Disclosure Index and relied on the ROA as an indicator to measure the dependent variable (financial performance). The results of the research showed the main hypothesis of the research, which states that the social responsibility of the banks has no significant impact on the financial performance. In relation to the disclosu
... Show MoreThe study aimed at ideutifying the impact of scieutific skills in strategy and liabits of mind amony stueuts in tenth grade . The study demanded to choose a sampie that coutaiun (42) student of the fourth grade of the secondary school who were dirided into tow groups , the first is experimental studied according to scieutific skill strategy , and the other controlling , studied according to the usualway . An achievement test has been taken that adopted staudard for mind skills as research tools that are applid after ascertaining sincerity proved at the end of the experiment .The study has reached to the conclusion that there are statistically significant differnces in farour of the experiment group in both
... Show MoreThe zirconia ceramic restoration (ZCR) is used as substitutes for the metal-ceramic restoration. Clinical studies demonstrating of ZCRs showed a high fracture incidence of veneering layer than metal-ceramic restorations. This attributed to the low bond strength of zirconia to veneering ceramic as a result of lacking of glass content in its matrix. Surface treatment was proposed to improve the bonding strength between zirconia and veneering ceramic. Several studies revealed that some treatment such as airborne particle abrasion (APA) is responsible for generating chipping of veneering ceramic. The study aimed to develop a new zirconia coatings to increase bonding strength between zirconia substrate and veneering porcelain. Three groups of 15
... Show MoreBackground: Radiation therapy reported to be an effective in palliating pain. Objective: To describe roles of palliative radiotherapy in controlling pain in metastatic cancerous patients, and evaluation of radio-therapy doses in pain management. Methods: A prospective observational study carried out at the Baghdad Radiotherapy and Nuclear Medicine Center/Baghdad Medical City Complex, Baghdad, Iraq, from 1st of December 2018 to 30th of May 2019. 88 Patients, were included. Patients were assessed before applying radiotherapy, and at the end of treatment. Pain scoring used from 0 to 10. Kaplan Meier survival curve used. Result: The mean±SD of age was 55.44±11.1 years, and the most frequent age group was 41-50years as 37(42.1%). Breas
... Show MoreResearch seeks to test the impact of the dimensions of mindfulness on organizational Innovation, proposed in the light of the review literature on two variables of the research, which referred in General to the dynamic relationship between them, as result of weakness of mindfulness as one important factor driving the diversity of innovation and time, ways to sustain and preserve and then support innovations made by creators, weakness in the overall level of organizational Innovation, this represents the problem research, data collection over designing identification, distributed to sample Formed from (30) head Department at a number of colleges of the University of Baghdad, results confirms the validity of resea
... Show MoreThe purpose of the research is to identify the social capital of the Municipality of Samawah Municipality by defining the level of its three dimensions (the structural dimension, the relational dimension and the cognitive dimension) and identifying the appropriate means that contribute to increasing the structural empowerment of the workers in the Municipality of Samawah. Between the social capital and the structural empowerment of the workers. From the perspective of social capital, the researchers examined the correlation and the effect of dimensions (structural, relational, cognitive) on the structural empowerment of the workers and with data collected from a sample of (168) Samawah, which is part of the Ministry of Constructi
... Show MoreAbstractoEl presente estudio tiene como objetivo realizar un análisis comparativo entre dos obras literarias destacadas: “El amor en los tiempos del cólera” del célebre escritor Gabriel García Márquez y la novela “Los jardines del presidente” del escritor iraquí Mohsen al-Ramli. Estas dos novelas, escritas en diferentes contextos culturales y geográficos, comparten una serie de elementos contextuales y narrativos que nos invitan a explorar sus similitudes y diferencias.Principalmente, ambas obras pertenecen al género del realismo y se sumergen en las circunstancias y experiencias de sus personajes en sociedades oscuras dominadas por la opresión, la guerra y las tradiciones impuestas. Los autores ofrecen una perspectiva crí
... Show MoreThe importance of websites appears as a modern tool that helps people connect with each other and exchange information rapidly. An increase number of new websites have been created in public or private spheres, which benefit individuals and society as a whole. This research aims to design a website specialized in marketing sustainable fashion that meets the needs of the Saudi market. It followed a descriptive and analytical approach. A survey has been conducted on a random sample of e-marketing users. The sample number is 101 users. The study resulted in: Determining the effectiveness of e-marketing, studying consumer purchasing tendencies, and designing a website for sustainable fashion based on the survey’s results. The study recomme
... Show More