Background: The success and maintenance of indirect dental restorations is closely related to the marginal accuracy, which is affected by many factors like preparation design, using of different fabrication techniques, and the time of taking final impression and pouring it. The purpose of this in vitro study was to evaluate the effect of different pouring time of conventional impression on the vertical marginal gap of full contour zirconia crowns in comparison with digital impression technique. Materials and Methods: Forty sound recently extracted human permanent maxillary first premolar teeth of comparable size and shape were collected. Standardized preparation of all teeth samples were carried out to receive full contour zirconia crown re

Flat-plate collector considers most common types of collectors, for ease of manufacturing and low price compared with other collectors. The main aim of the present work is to increase the efficiency of the collector, which can be achieved by improving the heat transfer and minimize heat loss experimentally. Five types of solar air collectors have been tested, which conventional channel with a smooth absorber plate (model I), dual channel with a smooth absorber plate (model II), dual channel with perforating “V” corrugated absorber plate (model III), dual channel with internal attached wire mesh (model Ⅳ), and dual channel with absorber sheet of transparent honeycomb, (model Ⅴ). The dual channel collector used for

Background: Porcelain veneers are under a great deal of stress which may lead to clinical failure as fracture or dettachment. This study examined whether different finishing lines and lingual shoulder preparations in the incisal area of the maxillary central incisor affect the bond of the porcelain veneers. Materials and methods: A two- dimensional finite element model was made. Location and magnitude of maximum Von Mises stresses were calculated in porcelain veneer. Six types of preparations were drawn as:incisal overlap of 0.5mm, 1mm and 1.5mm depth and lingual shoulder, and incisal overlap of 0.5mm, 1mm and 1.5mm depth without shoulder preparation. Results: Stress formation is maximum in the incisal edge region. All the lingual shoulder

Reduction has been linked visually in art since man began making functional and aesthetic forms, and this beginning can be identified with cave paintings. Reduction is one of the clearest indications of intellectual presence in aesthetic experience. Modernism was greatly supported by the great transformations that the intellectual movement witnessed in the world in general and in Europe in particular. There, and their transfer of European artistic experiences, and the reflection of this influence in their aesthetic sculptures, and for this reason the researchers find that the study of the aesthetic references of the reductive forms in the Iraqi sculptural experience represents a great importance in the study of the history of contem

The aesthetic dimension in popular subjects is one of the important topics in the history and culture of peoples, as it is the vessel from which their faith, traditions, original values, language, ideas, practices and way of life are derived, which expresses their culture and national identity, and it is the bridge of communication between generations throughout the ages.

It is one of the main pillars in the process of development and development, and popular subjects have special images related to real daily life, and they are the best source for man to narrate through him in his portrayal of daily life in general, and for the artist in particular, who is part of this daily life and its vocabulary, as he interacts with it so that

Reduction has been linked visually in art since man began making functional and aesthetic forms, and this beginning can be identified with cave paintings. Reduction is one of the clearest indications of intellectual presence in aesthetic experience. Modernism was greatly supported by the great transformations that the intellectual movement witnessed in the world in general and in Europe in particular. There, and their transfer of European artistic experiences, and the reflection of this influence in their aesthetic sculptures, and for this reason the researchers find that the study of the aesthetic references of the reductive forms in the Iraqi sculptural experience represents a great importance in the study of the history of contemporar

The artistic signature of calligraphers has been regarded as a significant aspect of Arabic calligraphy since its inception. As the art form evolved and acquired an aesthetic dimension, the artistic signature became an integral part of this dimension. The calligrapher failed to include his name on the frames, a practice that has become customary among calligraphers nowadays. This tradition allowed to trace the evolution of Arabic calligraphy and identify certain gaps in the calligraphy composition. Additionally, the inclusion of calligrapher's name contributes to the achievement of visual balance within the calligraphy composition, signifying consistency or formal separation. The current study concentrated to investigate the aesthet

The architecture of the richly decorated mosques demonstrated that the Islamic culture is one of the most significant and greatest civilizations in the history of humanity. The plant decorative units are one of the key areas in which the Muslim artist excelled. As a result, he created various plant forms that he took from nature, which led him to invent the arabesque art consisting of plant motifs with curved and rounded lines or wrapped between them. These shapes with curved borders include leaves, twigs, and flowers. Buildings and artefacts from the nineteenth century AD have this shape. they achieved their objectives during the twelfth and thirteenth centuries. There was another kind of vegetable decorative unit, made up of stems and

Organic Permeable Base Transistors (OPBTs) reach a very high transit frequency and large on-state currents. However, for a later commercial application of this technology, a high operational stability is essential as well. Here, the stability of OPBTs during continuous cycling and during base bias stress is discussed. It is observed that the threshold voltage of these transistors shifts toward more positive base voltages if stressed by applying a constant potential to the base electrode for prolonged times. With the help of a 2D device simulation, it is proposed that the observed instabilities are due to charges that are trapped on top of an oxide layer formed around the base electrode. These charges are thermally released after rem