Background: Mouthwashes used widely as ancillary to mechanical oral hygiene methods. Little information provided about the effect of mouthwashes on ions released from orthodontic brackets. Therefore, the present study has been established to evaluate the effect of different mouthwashes on the corrosion resistance and the biocompatibility of two brands of brackets. Materials and Methods: Eighty premolar stainless steel brackets were used (40 brackets from each brand). They were subdivided into four subgroups (n=10) according to immersion media (deionized distilled water, Corsodyl, Listerine and Silca herb mouthwashes). Each bracket was stored in a closely packed glass tube filled with 15ml of the immersion media and incubated for 45 days at 37ºC. Then chromium, nickel, copper and manganese ions release were measured using Atomic absorption spectrophotometer, while iron ions release were measured by using Iron kit and spectrophotometer. For statistical analysis, t-test, analysis of variance (ANOVA) and least significant difference (LSD) were used. Results: The results revealed that the ions released from Dentaurum brackets were significantly higher than that from OrthoTechnology brackets in all type of immersion media except for Chromium ions in Corsodyl mouthwash. The release of copper and chromium ions was significantly higher in Listerine and Corsodyl mouthwashes than in deionized distilled water being related to the pH of the immersion media. While, the release of iron, nickel and manganese ions in the three mouthwashes was comparable to that in deionized distilled water. Conclusions: The amounts of released ions were below toxic levels and did not exceed the daily dietary intake, but it may be recommended to avoid prolonged use of Listerine and Corsodyl mouthwashes in patients allergic to chromium.
The purpose of this research was to evaluate rice husk functionalized with Mg-Fe-layered double hydroxide (RH-Mg/Fe-LDH) as an adsorbent for the removal of meropenem antibiotic (MA) from an aqueous solution. Several batch experiments were undertaken using various conditions. Based on the results, the optimal Mg/Fe-LDH adsorbent with a pH of 9 and an M2+/M3+ ratio of 0.5 was associated with the lowest particle size (specifically. 11.1 nm). The Langmuir and Freundlich models were consistent with the experimental isotherm data (R2 was 0.984 and 0.993, respectively), and MA’s highest equilibrium adsorption capacity was 43.3 mg/g. Additionally, the second-order model was consistent with the adsorption kinetic results.
Abstract
Multivariate GARCH Models take several forms , the most important DCC dynamic conditional correlation, and CCC constant conditional correlation , The Purpose of this research is the Comparison for both Models.Using three financial time series which is a series of daily Iraqi dinar exchange rate indollar, Global daily Oil price in dollar and Global daily gold price in dollarfor the period from 01/01/2014 till 01/01/2016, Where it has been transferred to the three time series returns to get the Stationarity, some tests were conducted including Ljung-Box , JarqueBera , Multivariate ARCH to Returns Series and Residuals Series for both models In Comparison
... Show MoreLiquid-crystalline organic semiconductors exhibit unique properties that make them highly interesting for organic optoelectronic applications. Their optical and electrical anisotropies and the possibility to control the alignment of the liquid-crystalline semiconductor allow not only to optimize charge carrier transport, but to tune the optical property of organic thin-film devices as well. In this study, the molecular orientation in a liquid-crystalline semiconductor film is tuned by a novel blading process as well as by different annealing protocols. The altered alignment is verified by cross-polarized optical microscopy and spectroscopic ellipsometry. It is shown that a change in alignment of the
Second language learner may commit many mistakes in the process of second language learning. Throughout the Error Analysis Theory, the present study discusses the problems faced by second language learners whose Kurdish is their native language. At the very stages of language learning, second language learners will recognize the errors committed, yet they would not identify the type, the stage and error type shift in the process of language learning. Depending on their educational background of English as basic module, English department students at the university stage would make phonological, morphological, syntactic, semantic and lexical as well as speech errors. The main cause behind such errors goes back to the cultural differences
... Show MoreThis work represents study the rock facies and flow unit classification for the Mishrif carbonate reservoir in Buzurgan oil Field, which located n the south eastern Iraq, using wire line logs, core samples and petrophysical data (log porosity and core permeability). Hydraulic flow units were identified using flow zone indicator approach and assessed within each rock type to reach better understanding of the controlling role of pore types and geometry in reservoir quality variations. Additionally, distribution of sedimentary facies and Rock Fabric Number along with porosity and permeability was analyzed in three wells (BU-1, BU-2, and BU-3). The interactive Petrophysics - IP software is used to assess the rock fabric number, flow zon
... Show MoreThe research aims to identify small and medium enterprises in accounting thought in terms of definition and concept, and this international financial reporting standard for small and medium-sized enterprises (SMEs) in the theoretical aspect. As for the practical aspect, the small and medium-sized enterprises standard has been applied to the financial statements of the company in question, the preparation of the opening entry on the date of the transition, the requirements of measurement and the accounting disclosure on the date following the application of the standard, and the preparation of the company's financial statements and the accompanying explanations according to the standard of small and medium-sized enterprises. The r
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