Objective Advantageous properties of silicone elastomer made it one of the favorable materials in maxillofacial prosthesis construction, but these properties may change after months of usage or after pigments addition. This study aimed to define the optimum concentration for a mixture of two types of intrinsic pigments that added to VST-50 maxillofacial silicone material and study their effects on mechanical properties before and after artificial aging. Methods After the pilot study was conducted, 0.1% by weight of rayon flocking and 0. 2% by weight of burnt sienna intrinsic pigment concentration was selected because of improvement in tested mechanical properties of VST-50 maxillofacial silicone. A total of one hundred and eighty samples were prepared and divided into three equal test groups (tear strength, hardness and surface roughness), 60 samples were made for each test. Each test group includes 6 subgroups with 10 samples made for each one of them to test before and after (75 hours and 150 hours) of artificial aging. FTIR and XRD tests also were used in the study. Results The results show for pigmented samples before artificial aging that some mechanical properties had improved. After artificial aging, both periods resulted in non- significant decrease in tear strength while hardness and surface roughness had highly significantly increased. FTIR test and XRD test shows no chemical reaction between pigments and silicone. Conclusion The addition of intrinsic pigments had improved hardness and tear strength of maxillofacial silicone but after subjecting it to artificial aging, all of the tested properties had adversely affected.
The research article deals with the process of building or rebuilding the state in Iraq after 2003 in its various dimensions, in light of the vision and foundational procedures that were developed and supervised by the United States in cooperation with the new leaders of Iraq based on the mechanism of sectarianethnic representation, and diagnosing the imbalances that arose out of that vision and the accompanying procedures, which led to the emergence of new variables in the political process, especially in the post-ISIS* phase, which produced important challenges to the political system and the Iraqi state. The political dynamics and balances emerging after ISIS* represented at the same time opportunities and risks in the process of
... Show MorePregnancy-associated anemia is a widespread condition that can have varying impacts on both the mother and the developing fetus, depending on the level of hemoglobin in the mother’s blood and the stage of pregnancy at which the anemia occurs. In Iraq, 27% of all registered thalassemia cases are thalassemia minor. Pregnancy may aggravate mild undiagnosed thalassemia early in pregnancy. The objective of the study was to access the prevalence of undetected thalassemia minor in primigravida women who received prenatal care before 20 weeks and to compare the demographic and socioeconomic characteristic features between women with iron-deficiency anemia (IDA) and those without any anemia. A to
Abstrct The Turkish political system has undergone exceptional and unprecedented circumstances, represented by a series of security and political unrest that has cast its shadow over the Turkish state and regional and international challenges. It has never been a pretext or pretext for continuing the comprehensive reform process. The constitutional amendments of the 1982 Constitution, Justice and development, whether political, economic or social, is not a reaction to a difficult reality; it is a system of governance and a national option stemming from within. It promotes national unity and enshrines democracy and the concept of public rights and freedoms.
Gypsum is one of the important construction materials in Iraq in plastering surfaces and gypsum board , the ability of gypsum to give a comfortable an aesthetic ambiance as a construction material increase the need of gypsum , The particle size , total surface area and particle size distribution were factors affecting plaster properties used for construction properties . In this study gypsum paste was used with different mixing ratios of particle size and studied the physical properties of these types of pastes named (standard consistency ,setting time ,density) and compressive strength . The results showed that the water to gypsum ratio increased with increasing the fineness of the gypsum to (0.75%) and the setting time to the maxi
... Show MoreTo achieve sustainability in the field of civil engineering, there has become a great interest in developing reactive powder concrete RPC through the use of environmentally friendly materials to reduce the release of CO2 gas produced from cement factories as well as contribute to the recycling of industrial wastes that have a great impact on environmental pollution.
In this study, reactive powder concrete was prepared using total binder content of 800 kg/m3, water to binder ratio (0.275), and micro steel fibers 1% by volume of concrete. The experimental program included replacing fly ash with (8, 12, 16) % by cement weight to find the optimal ratio, which achieved the best mechanical proper
... Show MoreIn this research, a selection of some mineral water was selected on the basis of being the most marketed by the owners of shops in Najaf province, with six types, where daily samples of this water were taken by 50 ml for two months from (1/11/2018 -1/1/2019). The following ions concentrations were measured (Br-, Cl-, F-, NO3-, SO42-, Na+, K+, Ca2+, Mg2+), pH and the electrical conductivity were measured and the results were compared with the allowable rates according to the international organizations. It was noted that they conform to international and Iraqi standards.
The effect of solution heat treatment on the mechanical properties of Aluminum-Copper alloy. (2024-T3) by the rolling process is investigated. The solution heat treatment was implemented by heating the sheets to 480 C° and quenching them by water; then forming by rolling for many passes. And then natural aging is done for one month. Mechanical properties (tensile strength and hardness) are evaluated and the results are compared with the metal without treatment during the rolling process. ANSYS analysis is used to show the stresses distribution in the sheet during the rolling process. It has been seen that good mechanical properties are evident in the alloy without heat treatment due to the strain hardening and also the mechanical
... Show MoreIn this paper the definition of fuzzy anti-normed linear spaces and its basic properties are used to prove some properties of a finite dimensional fuzzy anti-normed linear space.