A random laser is a non-conventional laser whose feedback mechanism is based on dissorder-induced light. However, random lasers occur in gain media with numerous scatterers and produce coherent laser emission without any predesigned cavity. The generation of coherent emission from multiple scattering is quite general and its basic principles are shown here using sulforhodamine B-TiO suspensions system. These suspensions were pumped with 337.1 nm pulses from N2 laser and the spectral and temporal behavior of light emitted from the pumped surface was recorded. When we pump power above a certain threshold a dramatic narrowing of the emission line width and a shortening of the emitted pulses were observed. We have experimentally found that in a random laser based scattering, the threshold pumping density decreases with pump energy increased.
Die Tempusformen im Deutschen und Arabischen
L'ouverture des frontières et la mondialisation des échanges,comme les projets de l'intégration font de la connaissance de langue un enjeu essentiel ,professionnel et culturel,pour le citoyen de demain.
L'Irak est un pays Anglophone où domine l'anglais,le français est considérée comme deuxième langue étrangère en Irak.
Notre mini-mémoire se compose de deux parties.Dans la première partie nous essayons d'examiner la place du français en Irak qui nous dirige à savoir pourquoi on apprend le français en Irak et qui l'apprend?Est –ce qu'il y a une coopération française?
Dans la deuxième partie nous examinons les problèmes du français en Ir
... Show MoreRESUMEN:
Pretendemos hacer con este trabajo un breve recorrido sobre lo que han dicho algunos gramáticos de las construcciones condicionales, a la par señalaremos los criterios que los mismos establecen y siguen para diferenciar entre distintos tipos de estructuras condicionales o entre las construcciones que ellos entienden o consideran como tales y las que no, atendiendo fundamentalmente a dos criterios; formal y semántico-pragmático. El presente trabajo tiene como objetivo la clasificación y la descripción de las construcciones condicionales, demostrando que no todas las condicionales son hipotéticas ni todas las hipotéticas son condicionales.
Abstract
We intend to make this work
... Show Moreيعدّ مرقد السيدة نرجس كاحد المعالم القديمة المقدسة في العالم الإسلامي،
لابدّ من تسليط الضوء على شخصية السيدة نرجس عليها السلام
This research takes its significance by referring to the participation of Arab Muslims in the knowledge of the chemical heritage, including the new writings and additions to this science; and thus made the way easy directly or indirectly for Europeans in the scientific knowledge of chemical, Starting from Khalid bin Yazid until the death of the last scientists Muslims in this area .
Initiation in Islamic economy is the key for success and the way for advancement. It leads to the use of circumstances that through which the individual can achieve the accomplishments and gains. Once initiation spreads in the community, it will become a vivacious and that will lead to the development of its reality into the best. The Messenger (PBUH)( has encouraged imitation and the companionsshowed many imitations to deal with the economic issues that are vital to the stability of the peoples and communities and to achieve the necessary level of income and livelihood pursuant to what the Islamic economy has stipulated. Therefore, finding the ideal means to employ what Allah Almighty has endowed to humanity.
An experiment was carried out in the vegetables field of Horticulture Department / College of Agriculture / Baghdad University , for the three seasons : spring and Autumn of 2005 , and spring of 2007 , to study the type of gene action in some traits of yield and its components in summer squash crosses (4 x 3 = cross 1 , 3 x 7 = cross 2 , 3 x 4 = cross 3 , 3 x 5 = cross 4 , 5 x 1 = cross 5 , 5 x 2 = cross 6). The study followed generation mean analysis method which included to each cross (P1 , P2 , F1 , F2 , Bc1P1 , Bc1P2) , and those populations obtained by hybridization during the first and second seasons. Experimental comparison was performed in the second (Two crosses only) and third seasons , (four crosses) by using RCBD with three repl
... Show MoreIntroduction: This study was designed to examine the effects of addition of the combination of polymerized polymethyl methacrylate (PMMA) and zirconia (ZrO2) particles to heat cure PMMA resin on impact strength, surface hardness, and roughness. Methods: The 70% (w/w) of polymerized PMMA powder (particle size: 0.70mm) was mixed with 30% (w/w) of zirconia powder (ZrO2) (1mm) to produce PMMA-ZrO2 filler. Ninety acrylic specimens created were divided into three groups containing 0% wt (Control group), 2% wt, and 4% wt, PMMA-ZrO2 filler. Ten specimens were used for impact strength, surface hardness and roughness test, blindly. Data were analyzed via oneway ANOVA and the Tukey post hoc test using R 3.6.3. Results: There was statistically signific
... Show MoreBackground: Verrucous carcinoma (VSCC) is considered as a rare well differentiated carcinoma variant of SCC with no metastatic potential. The aim of this study is to evaluate the Immunohistochemical expression MMP-2, VEGF and D2-40 expression in OSCC and VSCC. Materials and methods: Thirty formalin fixed paraffin embedded tissue blocks of OSCC and another twelve VSCC were collected and Four micrometer thick sections were cut from each block and mounted on positively charged slides and stained immunohistochemically with monoclonal antibodies to MMP-2, VEGF and D2-40. Results: there is no statistical difference between SCC and VSCC regarding the immunoexpression of MMP-2 and VEGF. While the lymphatic vessels density were higher in SCC than V
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