Laser etching may be an alternative to acid etching of enamel and dentin. Several characteristics of irradiated dental hard tissues have been considered advantageous, microscopically rough surfaces without demineralization, open dentinal tubules without smear layer production and dentin surface sterilization. The aim of this study is to determine and compare histology the microleakage in class V cavity restored with a light cured composite after conditioning the samples(tooth surface) with 1-acid etching, 2-Q-switched Nd:YAG Laser etching and finally 3- acid and laser etching. Materials and methods: Twenty four non carious human extracted teeth were used in this study. The samples were equally grouped into four groups of six teeth each. A class V cavity was prepared. In group I, tooth surface was etched with a 37% phosphoric acid gel. In group II, the tooth surface was conditioned using a pulsed Nd:YAG Laser alone with a wavelength of 532 nm. The parameters were of pulse energy 60 mJ, pulse repetition rate 6Hz and energy density was 0.48 J/cm2. In group III, the tooth surface was treated with Nd: YAG Laser and then was etched with phosphoric acid. In group IV, the surface was treated with 37% phosphoric acid then irradiated with Nd: YAG Laser; with the same parameters and concentration mentioned in group I and II. The samples immersed in 1% basic fuschin dye to mimic the normal stains in oral cavity and the sections were examined by a stereomicroscope and the readings were scored. Results: The results showed that group IV, in which the surface was treated with 37% phosphoric acid and then irradiated with Nd: YAG Laser) recorded the least microleakage of the four groups, where group III, in which the tooth surface was treated with Nd: YAG Laser and then was etched with phosphoric acid)recorded reasonable results better than group I (group I tooth surface was etched with a 37% phosphoric acid gel) or group II , in which the tooth surface was conditioned using a pulsed Nd:YAG Laser alone) Conclusion: The use of Q-switched Nd:YAG laser in etching the tooth surface was so effective that it can be used in treating or conditioning the tooth surface to enhance bonding and the best parameters among the tested samples were pulse energy of 60mJ, pulse repetition rate of 6Hz and energy density 0.48 J/cm2.
دور شبكات التواصل الاجتماعي في ثورات الربيع العربي
(3)
The research aims to identify the educational values prevailing in the small kinetic games for the children of Riyadh, and to categorize the educational values of the kinetic games small children Riyadh. The research analyzed the content of a number of small kinetic games that included studied physical education at the two pre-kindergarten and stipulated by the Platform for kindergartens, which is being applied. The content analysis was used by analysts agreement with themselves over time (21) days. The agreement between the external researcher and analyst. The researcher used the Cooper to extract equation lab agreement between the researcher and the outside analyst, has reached agreement on determining factor idea and label values (0.8
... Show Moreان التعايش السلمي والوحدة الوطنية تربطهما علاقة وثيقة تعبر عن حاجة اجتماعية في أطار تطور مجتمعي للدولة العراقية، فقد شهد العراق بعد العام 2003 تحديا جديدا تمثل في تغليب الانتماءات الفرعية والطائفية والعرقية والدينية والمذهبية على الانتماء الوطني مما يؤدي الى بلورة وترسيخ عوامل الانقسام وتفتيت لمقومات الوحدة الاندماج الوطني ، لذلك تعد دعامة التعايش السلمي في المجتمعات ضرورة لازمة من اجل الحفاظ على كينونة
... Show MoreEach of the languages possesses a set of phenomena that researchers in its sciences should stop at to explain the secrets of this language, including the phenomenon of idiomatic expression. Perhaps this phenomenon may constitute an obstacle to non-native speakers of the language or even the native speakers themselves. The Arabic language is full of these expressions, Which needs us to dedicate its own studies to it so that we can collect it in a dictionary that includes and collects it with explanation and interpretation of its semantics
There is no doubt that the narrative form is a mixture of many elements that it
becomes so hard to differentiate between them. Thus, to differentiate between those
elements we must understand the job of every element; and that is the structure of narrative
form in the artistic frame of the old Arabic poem.
Poetry, as the readers confirm, is strongly related to a lot of arts. The rhetorical
form is related to the art of drawing and photography, the rhythm- the core of poetry- is
related to music, its structure to the art of architecture, its tension to drama as it consist of
internal conflict between its elements and ingredients, and the poetry has a narrative
element which relates it to the art of narration and it
كشفت دراسات ما بعد البنيوية والتطور الحاصل في الدراسات النقدية عن مقدار التداخل بين النصوص في انتاج الظواهر الادبية ، وخير ما يكشف هذا التداخل هو المنهج الذي يركز على دراسة التناص ولاسيما في النصوص التي تتشكل على وفق التناص الواعي الذي الذي يتألف من مجموعة نصوص ادبية يتفاعل فيها نص الكاتب مع نصوص اخرى.
This research deals with the idea of how the poetic reading can be a
rich field for producing the potential meanings in each text, through observing
the connection of the words and their link with other, thus composes, from the
collection of these interlaced meanings, what is called the poetic significant
(Symbolic) elaboration which deals with the reader of the text by regarding
him as a producer not as a consumer who can read a conscious reading, and
be diligent to solve the problem of the links of the relations among the
inspiring words because the language of poetry is an inspired language which
is capable of diversity and multiplicity of readings which is called the Symbolic
elaboration.
ارتبط الانسان بالطبيعة بأشكالها المختلفة ارتباطا وثيقا ، فهي تمثل الحاضنة له بمجالات حياته كلها، فما كان من الأدباء الا أن يجعلوها في كثير من الأحيان مادة لأدبهم وأرضية خصبة لنتاجهم، فتمظهرت بصورها المختلفة وحاجة الانسان لها وخيرها وشرها في الأدب على مدى التاريخ، والعرب شأنهم شأن غيرهم من الأمم فمنذ عصر ما قبل الاسلام كانت الطبيعة منفذا مهما وملجأ للشعراء في انتاج الأدب وابداعه وإلى يومنا هذا، ونحن إذ نتحد
... Show MoreIn this paper, a method for hiding cipher text in an image file is introduced . The
proposed method is to hide the cipher text message in the frequency domain of the image.
This method contained two phases: the first is embedding phase and the second is extraction
phase. In the embedding phase the image is transformed from time domain to frequency
domain using discrete wavelet decomposition technique (Haar). The text message encrypted
using RSA algorithm; then Least Significant Bit (LSB) algorithm used to hide secret message
in high frequency. The proposed method is tested in different images and showed success in
hiding information according to the Peak Signal to Noise Ratio (PSNR) measure of the the
original ima
This research paper sheds light on the stages of Atmospheric forecast in Iraq. It was found that atmospheric forecast in Iraq has passed through several successive and interrelated historical stages. Each stage is characterized by special methods of prediction that are different from other stages. The oldest stages used astronomy to forecasting cases of cold , heat, flood and drought