Preferred Language
Articles
/
aRb9oIsBVTCNdQwC-9XF
Modifications of Polymers through the Addition of Ultraviolet Absorbers to Reduce the Aging Effect of Accelerated and Natural Irradiation
...Show More Authors

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.

Scopus Clarivate Crossref
View Publication
Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Integrating the role of internal and external audit to ensure the success of the assessment methodSelf-General Authority of Taxation
...Show More Authors

المقدمة

تتعامل الجهات الضريبية في مختلف دول العالم بأساليب عديدة لجباية الضرائب من المكلفين بغض النظر عن فئات وأصناف هؤلاء المكلفين،وفي العراق تم اعتماد العديد من الأساليب لجباية الضرائب على امتداد المدد الزمنية المتعاقبة،وكان لأسلوب التقدير الذاتي وهو أحد تلك الأساليب مجالاً للتطبيق خلال مدة زمنية معينة،حيث جرى تطبيق هذا الأسلوب على وحدات اقتصادية معينة، وبالرغم من المساوئ التي قد ترافق تطبيق

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Feb 01 2023
Journal Name
Journal Of Engineering
Effect of the Proposed Outlets on the Hydrodynamic Behavior and Water Quality of the South-West Part of the Al Hammar Marsh
...Show More Authors

The current study aims to find a new plan to manage the water quality of the western part of the Hammar Marsh to reduce the salts that cause problems for the marshes and preserve their environmental life by isolating the southwestern part of the Hammar Marsh by closing the outlet under the railway embankment. The outlet is discharging saline water to the east-western part of Al Hammar Marsh. After isolating the southwestern part of the marsh, a new outlet is proposed. The impact of the flow hydrodynamics on improving the water quality was simulated using the SMS model. The hydrodynamics and water quality simulation models for the marsh are : a hydrodynamic model and average depth (SMS RMA2) and a two-dimensional water quality model (SMS

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
The Effect of Different Types of Aggregate and Additives on the Properties of Self-Compacting Lightweight Concrete
...Show More Authors

The major aim of this research is study the effect of the type of lightweight aggregate (Porcelinite and Thermostone), type and ratio of the pozzolanic material(SF and HRM) and the use of different ratios of w/cm ratio(0.32 and 0.35) on the properties of SCLWC in the fresh and hardened state. SF and HRM are used in three percentage 5%,10%, and 15% as a partial replacement by weight of
cement for all types of SCLWC. The requirements of self-compatibility for SCC are fulfilled by using the high performance superplasticizer (G51) at 1.2liter per 100 kg of cement. The values of air dry density and compressive strength at age of 28 days within the limits of structural lightweight concrete. The air dry density and compressive strength at a

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Tue May 28 2024
Journal Name
Journal Of Optics
Study of the optical properties of aluminum films and the effect of current frequency on plasma parameters
...Show More Authors

View Publication
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Sat Feb 02 2019
Journal Name
Journal Of The College Of Education For Women
The Effect of Arab Environment on the Artist's Works August Renoir: The Effect of Arab Environment on the Artist's Works August Renoir
...Show More Authors

Abstract:
This study is considerated one of many Studies above the standing of
the Islamic Arab nation which was chosen by God from other nations all over
the world . Some of these nations used to come to the Arab nation to take
whatever useful for them from the beginning of history till now . The
researcher deals in this study with a French artist who is well-know as
August Renoir . He traveled to Algeria and lived there . He was
influenced by the Islamic culture.
The study include. from chapter . chapter one deals with the framework of
programming (out line ) . Chapter two deals with the theoretical framework .
It includes five sections. Deals with the Islamic drawings(Arabesque) . section
three deals w

... Show More
View Publication Preview PDF
Publication Date
Fri Sep 01 2023
Journal Name
Materials Letters
Facile construction of g-C3N4/MnWO4/NiS heterostructures for photocatalytic degradation of organic contaminates under visible light irradiation
...Show More Authors

View Publication
Scopus (46)
Crossref (40)
Scopus Clarivate Crossref
Publication Date
Tue Feb 28 2023
Journal Name
Egyptian Journal Of Chemistry
Application of UV-A light Operating Photoreactor for Green Degradation of Direct Blue 15 through the Photo-Fenton-like process: Effects and Box-Behnken Optimization
...Show More Authors

View Publication
Scopus (3)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Sun Oct 07 2012
Journal Name
Journal Of Educational And Psychological Researches
The Effect of KWL Strategy on the Achievement of the Students of the fourth class literary in the subject of History and the Development of Cognitive Thinking skills
...Show More Authors

Whereas conventional methods of teaching history do not meet the sometimes purpose has suggested some educators strategies modern help to improve the level of students in the education process through activating prior knowledge and employed in positions of current learning, and focus attention on the points and the outstanding elements of the content and practice techniques Calendar criticof ideas and meanings and mental and linguistic activities used to verify the extent of reaching understanding.                                       &n

... Show More
View Publication Preview PDF
Publication Date
Wed Mar 01 2023
Journal Name
Accounting And Financial Sciences Journal
The Extent to which the Quality of Accounting Information Systems Contributes to Reducing Material
...Show More Authors

This research dealt with shedding light on the nature of material misrepresentations, in addition to knowing the extent to which the quality of accounting information systems contributes to reducing material misrepresentations On the theoretical side, a number of sources were relied upon in dealing with the research problem and presentation of the topic, while in the practical side, it was relied on the questionnaire form, where the research sample was (accountants and auditors), where 50 forms were distributed and 50 were received, and the data was analyzed and hypotheses tested through the program Statistical spss to show the relationship between the variables. The research reached a number of conclusions, the most important of which is t

... Show More
View Publication
Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
Effect of frequency Chirp on the black and gray solitions
...Show More Authors

the behavior of the first-order black and gray solitons propagtedin optical fiber in the presence of frequency chirp is studied analytically and numerically results show that phase profile of black solitons changes abruptly

View Publication Preview PDF