Background: Incorporation of chemical additives has long been a technique used to improve properties of the gypsum products. The purpose of this work was to study the effects of adding a combination of gum Arabic and calcium hydroxide to a type III dental stone and type IV improved die stone with different proportion. The effect on water/powder ratio, and surface hardness was determined. Material and method: Both material stone and die stone were blended with two proportion of additives so that each material was mixed twice but with different proportion of gum Arabic (0.1% and 0.2%) and calcium hydroxide (0.5 % and 0.3%). Data for hardness were subjected to two-way analysis of variance. Results: The results revealed that the chemical additives were reduced the water requirements of gypsum products so that the reduction of water lead to increase the density of mixture that sets harder. For type III dental stone the additives significantly improved the surface hardness, while for type IV improved die stone the surface hardness was not enhanced except it was designed to be mixed at low water/powder ratio, and in some instances a reduction in hardness was observed, especially at the most reduced water / powder ratio (0.18).
This research was dealing with the aesthetic impact of encryption in form and content and aesthetic implications in the design of contemporary fabrics. That's where the design of the cloth is linked to the continuous development and continuous innovation and the pursuit of the all-new innovative designs and at the same time an unmarked Cryptographic with semantics and symbols reflect reality aesthetically pleasing and contains four chapters on the research :The first chapter discusses the research problem and its significance is the current quest ( encryption in form and content in contemporary designs fabrics and aesthetic implications ) in that it shows the importance of encryption in the design of fabrics and foundation design configu
... Show MoreThe surplus glycerol produced from biodiesel production process as a by-product with high quantity can be considered as a good source to prepare glycerol carbonate (GC) whereas with each 1000 kg from biodiesel obtains 100 kg from glycerol. Glycerol converted to glycerol carbonate over bio-char as a catalyst prepared by slow pyrolysis process under various temperatures from 400 ᴼC to 800 ᴼC. The char prepared at 700 ᴼC considered as a best one between the others which was manufactured to activate the transesterification reaction. GC have large scale of uses such as liquid membrane in gas separation, surfactants ,detergents , blowing agent , in plastics industry, in Pharmaceutical industry and electrolytes in lithium batteries.
... Show MoreThere are many methods of teaching foreign language to non-native speakers now therefore the discovery of new methods - which make students understand the language , vocabulary & saves them as soon as possible – becomes one of the most important duties of teachers and educators .
The personal experience shows that the teaching of the Russian language through memorizing Russian poetry is one of the fastest ways to master the language and know its rules and also improve the ability of translating vocabulary and being not able to save the Russian words only , but to make it complete too. Poetry is an article or text which loves by people and en
... Show MoreA new family of nematic liquid crystal dendrimers derived from 3,5-dihydroxybenzoic acid were synthesized. The synthesis of the dendrimers compounds shows the influence of the dendritic core on the mesomorphic properties. The liquid crystalline properties were studied by polarizing optical microscopy (POM) equipped with a hot stage, the structures of the synthesized compounds characterized using FTIR and 1HNMR spectroscopy.
In this paper we investigated some new properties of π-Armendariz rings and studied the relationships between π-Armendariz rings and central Armendariz rings, nil-Armendariz rings, semicommutative rings, skew Armendariz rings, α-compatible rings and others. We proved that if R is a central Armendariz, then R is π-Armendariz ring. Also we explained how skew Armendariz rings can be ?-Armendariz, for that we proved that if R is a skew Armendariz π-compatible ring, then R is π-Armendariz. Examples are given to illustrate the relations between concepts.
We dealt with the nature of the points under the influence of periodic function chaotic functions associated functions chaotic and sufficient conditions to be a very chaotic functions Palace
We introduce some new generalizations of some definitions which are, supra closure converge to a point, supra closure directed toward a set, almost supra converges to a set, almost supra cluster point, a set supra H-closed relative, supra closure continuous functions, supra weakly continuous functions, supra compact functions, supra rigid a set, almost supra closed functions and supra perfect functions. And we state and prove several results concerning it