Background: The desire for an attractive appearing fixed orthodontic appliance fueled the use of ceramic brackets and clear accessories. Elastics are one of the most versatile materials available to orthodontists so studying their effect on the esthetic appearance is important. This an in vivo study, conducted to evaluate the effect of exposing stretched clear elastomeric ligatures to the oral environment from four different companies (OrthoTechnology, Morelli, Ortho Organizer, and Ormco). Materials and Methods: A total of 240 elastomeric modules were examined, 60 modules from each brand. Each of the 60 patients enrolled in the study, received 4 elastomeric modules on the 4 lower incisors, one from each brand. The specimens were placed on the teeth for 1, 2 and 4 weeks. After removal each module was kept in a sealed plastic bag and prepared for imaging and color measurement. Color measurements were made before and after use of the specimens. Images were taken by a cellular attachable microscope connected to a mobile phone with special J-cam program and the color change was calculated according to CIE Labcolor spaces system by the Adobe Photoshop program. The resulting data were statistically analyzed using ANOVA, LSD and Chi square tests. Results: The results showed that, all the elastomeric ligatures discolored after use. The discoloration increased with an increased incubation period in the mouth reaching the peak at 4 weeks interval and the yellowness index was the mostly effected color component. Elastomeric ligatures from Morelli brand were the most prone to discoloration, while Ortho Organizers and Ormco ligatures were the least prone to discoloration with the presence of large individual variation. Conclusion: It is necessary to alert the patient about the color changes that the clear ligatures experienced and the staining effect of certain foods. The orthodontist should select brands that are more resistant to color changes.
To assess the biochemical, mechanical and structural characteristics of retained dentin after applying three novel bromelain‑contained chemomechanical caries removal (CMCR) formulations in comparison to the conventional excavation methods (hand and rotary) and a commercial papain‑contained gel (Brix 3000). Seventy‑two extracted permanent molars with natural occlusal carious lesions (score > 4 following the International Caries Detection and Assessment System (ICDAS‑II)) were randomly allocated into six groups (n = 12) according to the excavation methods: hand excavation, rotary excavation, Brix 3000, bromelain‑contained gel (F1), bromelain‑chloramine‑T (F2), and bromelain chlorhexidine gel (F3). The superficial and deepe
... Show MoreCu (In, Ga) Se2 (CIGS) nano ink were synthesized from molecular precursors of CuCl, In Cl3, GaCl3 and Se metal heated to 240 °C for 1 hour in N2-atmosphere to form CIGS nanocrystal ink, Thin films were deposited onto Au/soda-lime glass (SLG) substrates. This work focused on CIGS nanocrystals, including their synthesis and application as the active light absorber layer in photovoltaic devices (PVs). This approach, using spin-coating deposition of the CIGS light absorber layers (75 mg/ml and 150 nm thickness), without high temperature selenization, has enabled up to 1.398 % power conversion efficiency under AM 1.5 solar illumination. X-ray diffraction (XRD) studies show that the structural formation of CIGS chalcopyrite structure. The mo
... Show MoreThe present study investigates the realization and significance of textual themes in the organizational structure of M.A theses and Ph.D. dissertations, namely: the abstracts, introductions and conclusions, since in such parts the students depend on their own expressions, styles and constructions to express different viewpoints, plans, inferences, etc. The study also investigates the similarities and differences between M.A theses and Ph.D. dissertations concerning the use of textual themes;it sets out to conduct a detailed analysis of textual themes used in such texts. In conducting such an analysis, the study adopts Halliday's (1994) approach of textual themes. The results of such an analysis have clearly shown that, in spite of the di
... Show MoreThe Red Palm Weevil (RPW), Rhynchophorus ferrugineus (Olivier, 1790) is a devastating invasive pest of palm trees, invading the Iraqi date palm tree in 2015 for the first time in Safwan county, Basrah province. The Red Palm weevil has been categorized as a quarantine pest of date palm trees worldwide. In this study, a five years monitoring program has been achieved by scouting the invasive pest RPW population in Safwan county by using visual sampling and Pheromone baited traps.
The results indicated that the number of infested palms, increased from 12 trees in 2015 to 111 in 16 orchards in 2016. The number of the infested palms was minimized to 3 trees in the county in 2019 due to the management protocol of the Ministry of Agriculture
Chilled ceilings systems offer potential for overall capital savings. The main aim of the present research is to investigate the thermal performance of the indirect contact closed circuit cooling tower, ICCCCT used with chilled ceiling, to gain a deeper knowledge in this important field of engineering which has been traditionally used in various industrial & HVAC systems. To achieve this study, experimental work were implemented for the ICCCCT use with chilled ceiling. In this study the thermal performances of closed wet cooling tower use with chilled ceiling is experimentally and theoretically investigated. Different experimental tests were conducted by varying the controlling parameters to investigate their effects
... Show MorePurpose: As a result of the sudden and ill-considered trade openness of Iraq after 2003 to the countries of the world in general and the neighboring countries in particular, and in the absence of the necessary support for the national productive forces and the lack of effective standardization and quality control devices, this led to the exposure of most local products, especially agricultural ones, to decline and inability On the competition and thus dumping the Iraqi market, especially the agricultural products, with imported products, this study came to find out the effect that dumping has on the local production of chicken meat and the impact of that impact on the size of the food gap, and whether the results of the practica
... Show MoreOf the importance of the concept of ownership of real estate as the basic basis from which various projects are launched in various economic, tourism, and urban areas .... The need to research the diagnosis of real estate reality went astray in the difficulties, which played a decisive role in the process of urban development.
This leads us to the research problem of the difficulty of implementing urban development plans in many cases due to the absence of a clear methodology for organizing and modernizing the ownership of real estate and its coordination with the management of urban land and to achieve the objective
... Show MoreDue to the Geographical links, language is one of the multiple affects among Arabs and Turks. As the different studies demonstrate, Turkish contains many words derived from other languages, yet Arabic remains the language that has great affects on Turkish. Unlike Turkish language, Arabic is a derivative language that requires no suffixes. Thus, Arabic verbs are tuned into Turkish verbs by adding auxiliary verbs. The present study traces some of the Turkish compound words of Arabic roots with an explanation that shows the Auxiliary added to form the Turkish verb as found in the stories of Otman Chevek Sawy’s Like A voice in the Dark. The conclusion sums up the findings of the study illustrated by numbers.
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... Show MoreStudent performance may influence by several factors in all his study levels such as primary school, intermediate school and even in his college; some of these factors are psychological factors, social factors, and the factors which correlate with student environment.
In this paper we study some of these factors to discover their influence by using canonical correlation analysis to analyze the data. Many conclusions are discovered to help who focuses student performance or to make it pest in future.