The photooxidative degradation process of plastics caused by ultraviolet irradiation leads to bond breaking, crosslinking, the elimination of volatiles, formation of free radicals, and decreases in weight and molecular weight. Photodegradation deteriorates both the mechanical and physical properties of plastics and affects their predicted life use, in particular for applications in harsh environments. Plastics have many benefits, while on the other hand, they have numerous disadvantages, such as photodegradation and photooxidation in harsh environments and the release of toxic substances due to the leaching of some components, which have a negative effect on living organisms. Therefore, attention is paid to the design and use of safe, plastic, ultraviolet stabilizers that do not pose a danger to the environment if released. Plastic ultraviolet photostabilizers act as efficient light screeners (absorbers or pigments), excited-state deactivators (quenchers), hydroperoxide decomposers, and radical scavengers. Ultraviolet absorbers are cheap to produce, can be used in low concentrations, mix well with polymers to produce a homogenous matrix, and do not alter the color of polymers. Recently, polyphosphates, Schiff bases, and organometallic complexes were synthesized and used as potential ultraviolet absorbers for polymeric materials. They reduced the damage caused by accelerated and natural ultraviolet aging, which was confirmed by inspecting the surface morphology of irradiated polymeric films. For example, atomic force microscopy revealed that the roughness factor of polymers’ irradiated surfaces was improved significantly in the presence of ultraviolet absorbers. In addition, the investigation of the surface of irradiated polymers using scanning electron microscopy showed a high degree of homogeneity and the appearance of pores that were different in size and shape. The current work surveys for the first time the use of newly synthesized, ultraviolet absorbers as additives to enhance the photostability of polymeric materials and, in particular, polyvinyl chloride and polystyrene, based mainly on our own recent work in the field.
The study aims to design an electronic puppet educational theater by Camtasia studio and identify the effectiveness in learning some of the artistic gymnastics skills for first grade, the research curriculum is experimental by designing two equal groups, and the research sample first grade students are distributed among 4 grade, and by the pumpkin determines two divisions (15 from each) representing the experimental group and control group, the main experiment conducted for 8 weeks by two educational units per week after which the post-tests were conducted, SPSS was used to process the results, and it was found that the electronic puppet educational theater contributed by making the learning process enjoyable and interesting and meeting the
... Show MoreThe interest in pre-service teacher training has become influential in teaching English as a foreign language, and the purpose of this training course is to prepare qualified teachers to teach effectively through the application of this technique by undergraduate students. This research aims to find out the effect of using the seven principles of good practice as a teaching technique on the fourth stage student-teachers’ performance at the College of Education for Women/University of Baghdad, during the academic year 2017-2018. The sample includes (60) students selected according to the stratified sampling method. The observational checklist used by the department to assess the student teachers’ performance during the practicum perio
... Show MoreIn The Name of Allah Most Gracious Most Merciful
The fundamentals of jurisprudence have a great role in facilitating the ways to know the Shari’a rulings for everything that takes place between people in terms of relationships, and the actions that are issued by them, because without it, the sources from which the rulings were taken are not known, and the methods used by the imams of ijtihad in taking these rulings from those sources are not understood. The foundations on which they followed in the interpretation of texts and its rules, and Muslim scholars in different eras celebrated this science and gave it great care: with what they wrote in it from the works of different directions, but of course the complexity printed many
... Show Moreدر قرآن کريم آياتي وجود دارد که يک يا چند بار به صورت کاملا مشابه در يک سوره و يا چند سوره، تکرار شده است. يکي از مسائل مهم در ترجمه قرآن کريم، ترجمه اينگونه آيات است، از آنجا که مشابه بودن اين آيات از روي حکمت الهي است، مترجمان نيز بايد در ترجمه خود اين مسأله را رعايت کرده و براي آيات مشابه ترجمهاييکسان ارائه کنند. از طرفي ممکن است تفاوت در ترجمه، مفهوم آيه را نيز تحت تأثير قرار دهد و براييک آيه مشابه دو مفهوم
... Show MoreCan not reach a comprehensive concept for interior design through the use of Harmonization term according transformations experienced by the terms of the variables associated with the backlog of cultures that characterize concepts according to the nature of the users of the spaces in the design output, which necessitates the meaning of the combination of knowledge, art, science, such as the type of perceptions design the Harmonization cognitive science with art to create products of the use of design configurations that help the designer to put such a product within the reality and like the fact that reliable, as well as the rational knowledge tend somehow to the objective specifically in facilitating the substance subject to perceptible
... Show MoreThe impact of applying the K-W-L self-scheduling technique on first-year intermediate students' learning of basic volleyball skills, Ayad Ali Hussein*, Israa Fouad Salih
Objectives: The study aimed to evaluate health behavior, evaluate Health Action Process Approach, determine the effectiveness of the Health Action Process Approach based the application of program on students’ engaging in regular physical exercise.
Methodology: The research design for this study was a quasi-experimental. The study sample included high school male students, the final sample size was(160 ) Non-probability sampling (convenience sample) are chosen, (80) students study group and (80) students control group.
Results: The results show there was no statistically significant difference in the HAPA constructs among family's socioeconomic class groups and less tha
... Show MoreThe use of the Iraqi song in the symphony orchestra is one of the pioneering and important works, which carries with it an artistic value of aesthetic specificity in how to use the Iraqi singing heritage. The research aimed to identify the employment of the song (Foug Al-Nakhl) and its works within the Iraqi national symphony orchestra music by the author Hans Count Momer whose works still have a great influence on the authors of the Iraqi orchestra. The researcher presented a brief introduction to the Iraqi Symphony Orchestra, a brief introduction about the author, and the trends of world music towards heritage. He also talked about musical composition, research procedures and tools, and applying the tool to the selected sample (F
... Show MoreThis study was prepared to investigate the performance and behavior of concrete thrust blocks supporting pipe fittings. In the water distribution networks, it is always necessary to change the path of the pipes at different degrees or to create new branches. In these regions, an unbalanced force called the thrust force is generated. In order to counter this force, these regions are supported with concrete blocks. In this article, the system components (soil, pipe with its bend and thrust blocks) have been numerically modeled and simulated by the ABAQUS CAE/2019 software program in order to study the behavior and stability of the thrust block with different burial conditions (several b