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Institution

Nahrain University

EducationBaghdad, Iraq
About: Nahrain University is a education organization based out in Baghdad, Iraq. It is known for research contribution in the topics: Laser & Vinyl chloride. The organization has 1496 authors who have published 2051 publications receiving 12145 citations. The organization is also known as: Al-Nahrain University & Saddam University.


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Journal ArticleDOI
TL;DR: Almost all synthetic polymers require stabilization against adverse environmental effects, and two aspects of degradation are of particular importance: Storage conditions, and Addition of appropriate stabilizers.
Abstract: Exposure to ultraviolet (UV) radiation may cause the significant degradation of many materials. UV radiation causes photooxidative degradation which results in breaking of the polymer chains, produces free radical and reduces the molecular weight, causing deterioration of mechanical properties and leading to useless materials, after an unpredictable time. Polystyrene (PS), one of the most important material in the modern plastic industry, has been used all over the world, due to its excellent physical properties and low-cost. When polystyrene is subjected to UV irradiation in the presence of air, it undergoes a rapid yellowing and a gradual embrittlement. The mechanism of PS photolysis in the solid state (film) depends on the mobility of free radicals in the polymer matrix and their bimolecular recombination. Free hydrogen radicals diffuse very easily through the polymer matrix and combine in pairs or abstract hydrogen atoms from polymer molecule. Phenyl radical has limited mobility. They may abstract hydrogen from the near surrounding or combine with a polymer radical or with hydrogen radicals. Almost all synthetic polymers require stabilization against adverse environmental effects. It is necessary to find a means to reduce or prevent damage induced by environmental components such as heat, light or oxygen. The photostabilization of polymers may be achieved in many ways. The following stabilizing systems have been developed, which depend on the action of stabilizer: (1) light screeners, (2) UV absorbers, (3) excited-state quenchers, (4) peroxide decomposers, and (5) free radical scavengers; of these, it is generally believed that excited-state quenchers, peroxide decomposers, and free radical scavengers are the most effective. Research into degradation and ageing of polymers is extremely intensive and new materials are being synthesized with a pre-programmed lifetime. New stabilizers are becoming commercially available although their modes of action are sometimes not thoroughly elucidated. They target the many possible ways of polymer degradation: thermolysis, thermooxidation, photolysis, photooxidation, radiolysis etc. With the goal to increase lifetime of a particular polymeric material, two aspects of degradation are of particular importance: Storage conditions, and Addition of appropriate stabilizers. A profound knowledge of degradation mechanisms is needed to achieve the goal.

809 citations

Journal ArticleDOI
TL;DR: This study has reviewed the available literature and recently published data related to bio-based raw materials and the chemical modifications of raw materials, and analyzed the impacts and benefits of the use of bio- based raw materials as functional fluids or biolubricants.
Abstract: The depletion of the world's crude oil reserve, increasing crude oil prices, and issues related to conservation have brought about renewed interest in the use of bio-based materials. Emphasis on the development of renewable, biodegradable, and environmentally friendly industrial fluids, such as lubricants, has resulted in the widespread use of natural oils and fats for non-edible purposes. In this study, we have reviewed the available literature and recently published data related to bio-based raw materials and the chemical modifications of raw materials. Additionally, we have analyzed the impacts and benefits of the use of bio-based raw materials as functional fluids or biolubricants. The term biolubricants applies to all lubricants, which are both rapidly biodegradable and non-toxic to humans and other living organisms, especially in aquatic environments. Biodegradability provides an indication of the persistence of the substance in the environment and is the yardstick for assessing the eco-friendliness of substances. Scientists are discovering economical and safe ways to improve the properties of biolubricants, such as increasing their poor oxidative stability and decreasing high pour points. “Green” biolubricants must be used for all applications where there is an environmental risk.

268 citations

Journal ArticleDOI
TL;DR: In this article, the addition of a simple amide to AlCl3 causes the formation of a liquid of the form [AlCl2·nAmide]-AlCl4−, which is a suitable medium for the acetylation of ferrocene and the electrodeposition of aluminium.

187 citations

Journal ArticleDOI
TL;DR: A blockchain-based data sharing system is proposed to tackle the issue of privacy of patients, which employs immutability and autonomy properties of the blockchain to sufficiently resolve challenges associated with access control and handle sensitive data.

170 citations

Journal ArticleDOI
TL;DR: A total of five new metal complex derivatives of 2N-salicylidene-5-(p-nitro phenyl)-1,3,4-thiadiazole, HL with the metal ions Vo(II), Co(II, Rh(III), Pd(II) and Au(III) have been successfully prepared in alcoholic medium as discussed by the authors.

165 citations


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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20239
202235
2021326
2020379
2019267
2018253