In this investigation , borax (B) (additive I) and chlorinated paraffin (CP.) (additive II) ,were used as flame retardants for each of epoxy and unsaturated polyester resins in the weight ratios of 2,4,6, & 8% by preparing films of (130×130×3) mm dimensions. Also films of these resins with a mixture of [50%(B.)+50%(CP.)] (additive III) in the same weight ratios were prepared in order to study the synergistic effect of these additives on the flammability of the two resins . Three standard test methods were used to measure the flame retardation which are : 1-ASTM : D-2863 2-ASTM : D-635 3-ASTM : D-3014 The results obtained from these tests indicated that the additives (B),(CP.) and their mixture , gave a good effect as flame retardants for each epoxy and unsaturated polyester resins , but their synergistic effect was more effective than each of them alone. Finally , the compatibility between the additives and resins (which showed a clear effect on retardation) was also studied .
Objectives To quantify the reproducibility of the drill calibration process in dynamic navigation guided placement of dental implants and to identify the human factors that could affect the precision of this process in order to improve the overall implant placement accuracy. Methods A set of six drills and four implants were calibrated by three operators following the standard calibration process of NaviDent® (ClaroNav Inc.). The reproducibility of the position of each tip of a drill or implant was calculated in relation to the pre-planned implants’ entry and apex positions. Intra- and inter-operator reliabilities were reported. The effects of the drill length and shape on the reproducibility of the calibration process were also investig
... Show MoreMany people, especially among the youth or scholars, wonder about the position of Islam or the scholars of faith on the terminology used by scholars of theology in a certain period of time, and then circulated by people throughout the times and to the present day, such as the terms (the old, the maker, the updated, the cause and the cause) and so on, and this What I felt myself while teaching this subject from some of the students, some of whom consider it blasphemy, and some of them consider it an innovation of speech, and so there were many questions about this subject, which led me to write and research it, after relying on God Almighty, although the research is not long due to the nature of This topic on the one hand, and because I d
... Show MoreIraq enjoys many factors and ingredients that made it “affect and be affected at the same time” by the American-Iranian conflict from the “strategic geographical position” adjacent to Iran as an important point and that Iraq has been part of this conflict since the last period which witnessed the outbreak of the first Gulf War (1980-1988) because of border problems and a dispute over Shatt al-Arab, and what followed after that, specifically from 2003 when the United States of America and its allies occupied Iraq’s lands and made a political change by the destruction of its security and military institutions. It increased the importance of Iraq in being a subject of competition between the competing parties in exploiting the
... Show MoreTechnology is an important factor for achieving architecture as an impact and vulnerability. It represents one of the significant elements in creating the intellectual framework, as well as having its own intellectual breakdown, while values constitute the most important and obviously factor of the community's intellectual. Research aims was determined accordingly by: investigating the role and impact of values and their relationship to technology in architecture.
In this context, the research investigated values and technology in architecture, through discussing their aspects and dimensions in architecture. In the context of values, the research discussed their concept and the related ones to have a concrete def
... Show MoreIf the State attaches great importance to its foreign relations and intends to strengthen them in order to ensure the achievement of the highest national goals and interests. External relations between countries are one of the most prominent features of foreign policy, which depends on a combination of internal and external factors, the modern relations between Tunisia and Tunisia, which goes back to the pre-independence of Tunisia, when Iraq was a supporter of Tunisia's independence from France in the 1940s, Although these relations did not cause any disturbance by the two countries, but they remained weak relations did not develop in all areas except the sports and cultural field, which we will determine the reasons and the pos
... Show MoreInitially-produced isotopes during the course of the
Ensuring reliable data transmission in Network on Chip (NoC) is one of the most challenging tasks, especially in noisy environments. As crosstalk, interference, and radiation were increased with manufacturers' increasing tendency to reduce the area, increase the frequencies, and reduce the voltages. So many Error Control Codes (ECC) were proposed with different error detection and correction capacities and various degrees of complexity. Code with Crosstalk Avoidance and Error Correction (CCAEC) for network-on-chip interconnects uses simple parity check bits as the main technique to get high error correction capacity. Per this work, this coding scheme corrects up to 12 random errors, representing a high correction capac
... Show MoreThe study aims to demonstrate the importance of instructional methods in teaching Arabic language as a second language or teaching the Arabic language to non-native speakers. The study is in line with the tremendous development in the field of knowledge, especially in the field of technology and communication, and the emergence of many electronic media in education in general and language teaching in particular. It employs an image in teaching vocabulary and presenting the experience of the Arabic Language Institute for Non-Speakers-King Abdul-Aziz University. The study follows the descriptive approach to solve the problem represented by the lack of interest in the educational methods when teaching Arabic as a second language. Accordingl
... Show More