Poly vinyl alcohol has been studied for its ability to form crystallites by using annealing method. Semicrystalline films of poly vinyl alcohol (PVA) were prepared by casting 11.5 wt. % and 13 wt. % PVA aqueous solution onto glass slides at annealing temperature range 90 -120°C and duration time 15- 60 minute. This allowed the macromolecules to form crystallites, small regions of folded and compacted chains separated by amorphous regions where single PVA chain may pass through several of these crystallites. Degree of crystallinity of PVA films (hydrogels) was determined by method of density; on the other hand the swelling behavior was conducted by the determination of water uptake, wet degree of crystallinity, gel fraction and solubility. The results of PVA films showed that water uptake decreased with increasing temperature, time of annealing and PVA concentration, while degree of crystallinity increased, and gel fraction and solubility decreased with increasing temperature and time of annealing. The maximum dry and wet degree of crystallinity was 64% and 36% respectively at 120°C and 60 min.
RHS Nasser, NHY Al-Afoun, SPECIALUSIS UGDYMAS, 2022
چکیده
کشورعراق مرزهای زمینی ایران دارد که علاوه بر این ، مشترکات وروابط متعدد اقتصادی ،سیاسی، فرهنگی ودينى ميان هر دو ملت می باشند . عراق بعلت موقعیت جغرافیایی ونزدیکی به ایران سهم بیشتری برای ورود واژه های فارسی به لهجه ی خود داشت ، علاوه بر این رویدادهای سیاسی متقابل قدیم و جدید میان دو کشور سبب ورود بسیاری از لغات فارسی به لهجه ی عراقی شد که کاربرد این لغات هم اکنون در لهجه ی عراقی آشکار است ، ای
... Show More Educational services in Iraq face many problems that have reduced the efficiency of the educational process, as a result of the difficult conditions experienced by educational services in Iraq. This led to the accumulation of these problems and their exacerbation significantly over the years, as there was no fundamental solution to these problems. The study proposes a planning method for managing the educational system in Iraq, especially for the primary and secondary levels, where these negative phenomena are very prominent, especially the deficit in school buildings and the phenomenon of overcrowding in classrooms. &am
... Show Morepaid recent developments in the information and communications technology and the accompanying developments in the global market to pay particular accounting information users to demand more sophistication in terms of corporate financial reporting systems, which led to the emergence of a new type of reporting (financial reporting in real time). where is the information and communications technology mainstay Nations for the development and progress, thanks to the development of technology that have made the transmission of information easily conducted and high speed to all who need it, communication is instantaneous and the flow of information via the internet dramatically exceeded the border temporal and spatial anywhere in the w
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The organization and coordination of any communication is based on the system of turn-taking which refers to the process by which a participant in a conversation takes the role of speaker. The progression of any conversation is achieved by the change of roles between speaker and hearer which, in its turn, represents the heart of the turn-taking system. The turn-taking system is not a random process but it is a highly organized process governed by a set of rules. Thus, this system has certain features and rules which exist in any English communicative process. These rules, if applied by speakers, help to achieve successful exchange of turns in any conversation. This paper attempts to present full exposition of the concepts of conversation
... Show MoreThe aim of the research was designing a nutritional program with amino acids well as designing exercises for muscular strength training for youth female badminton players. In addition to that the researcher aimed at identifying the effect of amino acid accompanied with muscular training on some physiological indicators in youth female badminton players. The researcher used the experimental method. The subjects were (7) youth female badminton players from the Armenian badminton club. Many physiological tests were conducted including PWC170 and Vo2Max. The data was collected and treated using proper statistical operations to conclude that amino acid accompanied with muscular ability training have a positive effect on some physiological indica
... Show MoreBackground: This in vitro study was carried out to evaluate the effect of various endodontic irrigants (sodium hypochlorite, ethylene diaminetetracetic acid and normal saline) on sealing ability of (Biodentine, mineral trioxide aggregate, and amalgam) used to repair furcal perforations. Material and methods: One hundred and twenty extracted human molars with divergent roots were used in this study. A standard root canal access cavity was prepared in each tooth and furcal perforation was made and was standardized by using k file size 100 instrument to get a perforation of (1.32mm) in diameter .The teeth were randomly divided in to three groups of 40 teeth according to the type of material used to repair the perforations (Group A: The furcal
... Show MoreBackground: Alginate impression material is the irreversible hydrocolloid material that is widely used in dentistry. The contact time between alginate and gypsum cast could have a detrimental effect on the properties of the gypsum cast. The objective of this study is to evaluate the impact of various contact time intervals of Alginate impressions & type III dental stone on surface properties of stone cast. Materials and Methods: Time intervals tested were 1hour, 6 hours and 9 hours. Surface properties of stone cast evaluated were surface detail reproduction, hardness and roughness. Surface detail reproduction was determined using cylindrical brass test block in accordance with ISO 1563. Surface roughness was measured by profilometer
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The summary:
This research paper presents a standard economic study. This study aims to build an economic standard form of the investment effect in Human Capital on Economic Growth in Algeria. The study showed that there is an inverse relationship between the investment and human capital. This is expressed by expending on education and economic growth. This contradicts with the economic theory. Such matter could be explained by that expending on education does not contribute in the economic growth. This refers to that the education sector result does not employee or save jobs. Thus, it does not contribute in growth; in addition, the Algerian economy depends on petrol in the first class. This means the ab
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