This study evaluated the structural changes of enamel treated by the Regenerate system and carbon dioxide (CO2) laser against acid challenge. Thirty human enamel slabs were prepared and assigned into three groups: Group I: untreated (control); Group II: treated with the Regenerate system; and Group III exposed to CO2 laser. All specimens were subjected to an acid challenge (pH 4.5–7.0) for 14 days. Specimens were evaluated and compared at 120 points using five Raman microspectroscopic peaks; the phosphate vibrations ν1, ν2, ν3, and ν4 at 960, 433, 1029, and 579 cm−1, respectively, and the carbonate at 1070 cm−1, followed by Vickers microhardness test. The ratio of carbonate to phosphate was correlated to the equivalent microhardness numbers. The intensities of phosphate peaks ν1, ν2, and ν4 were reduced in all groups post-acid challenge, while the carbonate and ν3 were significantly increased (p < 0.000). Surfaces treated by Regenerate exhibited higher peak intensity of phosphate and carbonate before and after pH-cycling (p < 0.05). The mineral content in enamel had a direct effect on tissue microhardness, and the CO2-lased surfaces showed a reduced carbonate content and higher microhardness values. Both approaches induced surface changes that can protect enamel against acid challenge resulting in a significant benefit for dental healthcare.
A mathematical model was proposed to study the microkinetics of esterification reaction of oleic acid with ethanol over prepared HY zeolite catalyst. The catalyst was prepared from Iraqi kaolin source and its properties were characterized by different techniques. The esterification was done under different temperature (40 to 70˚C) with 6:1 for molar ratio of ethanol to oleic acid and 5 % catalyst loading.
The microkinetics study was done over two period of time each period was examined individually to calculate the reaction rate constant and activation energy. The impact of the mass transfer resistance to the reactant was also investigated; two different studies have been accomplished to do this purpose.
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... Show MoreDylan Thomas (1914-1953) is a modern poet belongs to the apocalyptic movement of the 1940's.This movement is influenced by the doctrines and techniques of surrealism.
Poetry for him should not be primarily concerned with man in society, but with the celebration of spiritual truth. It should bring to light the hidden causes, hence his personal interest is to strip darkness and explore the inward motives. To do this he uses a cluster of images: a constant building up and breaking down of images. His poetry depends on the romantic spontaneity, suggestiveness of the Symbolists and the the surrealists' mysterious liberation of the unconsciousness and
... Show MoreIn this review of literature, the light will be concentrated on the role of stem cells as an approach in periodontal regeneration.
Dylan Thomas (1914-1953) is a modern poet belongs to the apocalyptic movement of the 1940's.This movement is influenced by the doctrines and techniques of surrealism. Poetry for him should not be primarily concerned with man in society, but with the celebration of spiritual truth. It should bring to light the hidden causes, hence his personal interest is to strip darkness and explore the inward motives. To do this he uses a cluster of images: a constant building up and breaking down of images. His poetry depends on the romantic spontaneity, suggestiveness of the Symbolists and the the surrealists' mysterious liberation of the unconsciousness and the emotional involvement in the dynamics of life. In "Light Breaks
... Show MoreEmotions are part of the personality of the individual and affect many different aspects of the personality, and it is an important element of social and psychological adaptation, especially if it is within the limits of nature, and if the methods used to express them are appropriate and moderate.
Submission is one of the characteristics that express the way an individual relies upon in dealing with others and in dealing with matters of life. An individual who complies with instructions and orders and abides by them, and performs what is required of him without hesitation or delay. Adolescence is an important and accurate stage in the constructive development of an individual and in his psychological and social life.
The
... Show MoreMuseum education is of great importance to an appropriate representation of museums’ collections and exhibits, including traditional fashion. Therefore, museum educators/curators need to be equipped with the most essential skills in their profession in order to adequately present the museum’s history and holdings. This could be achieved through specialized training programs. However, Arab countries are still behind in terms of museum education. Therefore, this article aims to shed light on this issue by assessing the knowledge and skills possessed by museum educators/curators and how training programs could affect them
The marketing of banking service is considered to be one of the impotent fields which showed a universal inebriates . He research showed the comparison between the application of marketing in ideas and application for loot government and private Iraqi bank. The research comets of four parts; Mythology / the concept and the importance of Banking Marketing / Research applichlion/ Conelnion and recommendation.
This paper offers a postcolonial analysis of Sudanese author Tayeb Salih's novel Season of Migration to the North (1966), emphasizing the interplay between indigenous and colonial narratives. The analysis centers on the protagonist, Mustafa Sa'eed, who embodies its essence. The character of Mustafa Saeed represents the intricate interplay between colonial and indigenous elements. This research employs Edward Said's postcolonial concept, Contrapuntal Reading (1993), which underscores the interconnection of the histories of colonizers and the colonized through the portrayal of Mustafa Saeed's character, focusing on the mechanisms of colonial power, such as cultural hegemony, identity manipulation, and the resistance of the colonized.
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