Background: The demand for better esthetic during orthodontic treatment has increased nowadays, so orthodontists starting using esthetic arch wires, brackets and ligatures.Tooth colored brackets were introduced in different types of materials. Sapphire ceramic brackets are one type of esthetic brackets and their color stability remains the main concern for the clinicians and patients at the same time. The present study design to evaluate the effect of three different staining materials (pepsi, black tea and cigarette smoke) on the stainability of sapphire ceramic brackets bonded with three types of light cure orthodontic adhesives which include: Resilience, Enlight and Transbond. Materials and Methods: The sample consisted of three hundred sixty sapphire brackets. The brackets were divided according to bonding materials into three groups each group consist of one hundred twenty brackets, then each subgroup farther subdivided into four groups according to the material they were immersed (distilled water, black tea, Pepsi and cigarette smoke) with thirty brackets each, then Each group with ten brackets farther subdivided according to time interval of immersion in each media into three groups one day, seven days and fourteen days at 37°C in the incubator.A UV-Visible spectrophotometer (Shimadzu, UV -1800) was used to perform a light absorption test. Results: ANOVA and LSD post Hoc tests were used to identify the significant effects of the staining materials at a significance level P ≤ 0.05.It was found that the immersion time gradually influenced the color stability of the adhesive materials with sapphire brackets with the highest activity observed at fourteen days interval. The brackets bonded with Resilience light cure adhesive are the most type affected by staining materials, then followed by the brackets bonded with Transbond and finally the brackets bonded with Enlight light cure adhesive. For the staining materials it was found that the cigarette smoke is the most powerful staining material, followed by tea and finally pepsi. Conclusions: From the above result we can conclude that the type of adhesive must take in consideration when the esthetic brackets have been used.
Doctrinal responses
On the fabrications of succor
Tamimi
This paper is devoted to the analysis of nonlinear singular boundary value problems for ordinary differential equations with a singularity of the different kind. We propose semi - analytic technique using two point osculatory interpolation to construct polynomial solution, and discussion behavior of the solution in the neighborhood of the singular points and its numerical approximation. Two examples are presented to demonstrate the applicability and efficiency of the methods. Finally, we discuss behavior of the solution in the neighborhood of the singularity point which appears to perform satisfactorily for singular problems.
The present study including determined pathological changes in Barbus sharpeyi, as
well as description behavior and growth of bunni fish by used 180 fingerlings, Fish
were distributed randomly upon four treatments in addition to control group. First
treatment (T1) contained cadmium 0.093mg/L with changing water and added cadmium
continuously, the second treatment (T2) contained cadmium 0.093mg/L with changing
water without adding cadmium, third treatment (T3) contained cadmium 0.046mg/L
with changing water and adding cadmium continuously, fourth treatment (T4) contained
cadmium 0.046mg/L with changing water without adding cadmium. In order to estimate
LC50 used 120 fingerlings of fish B. sharpeyi, were exposed to
In this paper we present the theoretical foundation of forward error analysis of numerical algorithms under;• Approximations in "built-in" functions.• Rounding errors in arithmetic floating-point operations.• Perturbations of data.The error analysis is based on linearization method. The fundamental tools of the forward error analysis are system of linear absolute and relative a prior and a posteriori error equations and associated condition numbers constituting optimal of possible cumulative round – off errors. The condition numbers enable simple general, quantitative bounds definitions of numerical stability. The theoretical results have been applied a Gaussian elimination, and have proved to be very effective means of both a prior
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Obviously, within the years 2004, 2005, 2006, several infection cases of damping – off ,leaves ,flowers ,buds and petioles blight ,stem canker ,crown rot have seen on (Gerbera jamesonii) plants in nurseries and appears dirty white(brown) color mold at the first and then convert to gray color on the foliage. The studying is carried out in two locations in Baghdad city which are Palestine Street (Al-Khirat, Al-Zina nurseries) and Zaiyuna (Zainab, Zaiyuna, Baghdad nurseries). The isolation and diagnosis were identified the causal pathogen was Botrytis cinerea.The pathogenicity test was carried out with positive results were positive resulted. The infections percentage on gerbera plants ranged in the studied nu
... Show MoreThe aim of this investigation is to present the idea of SAH – ideal , closed SAH – ideal and closed SAH – ideal with respect to an element , and s- of BH – algebra .
We detail and show theorems which regulate the relationship between these ideas and provide some examples in BH – algebra .
Let R be a prime ring and δ a right (σ,τ)-derivation on R. In the present paper we will prove the following results:
First, suppose that R is a prime ring and I a non-zero ideal of R if δ acts as a homomorphism on I then δ=0 on R, and if δ acts an anti- homomorphism on I then either δ=0 on R or R is commutative.
Second, suppose that R is 2-torsion-free prime ring and J a non-zero Jordan ideal and a subring of R, if δ acts as a homomorphism on J then δ=0 on J, and if δ acts an anti- homomorphism on J then either δ=0 on J or J
Z(R).
This paper devoted to the analysis of regular singular initial value problems for ordinary differential equations with a singularity of the first kind , we propose semi - analytic technique using two point osculatory interpolation to construct polynomial solution, and discussion behavior of the solution in the neighborhood of the regular singular points and its numerical approximation, two examples are presented to demonstrate the applicability and efficiency of the methods. Finally , we discuss behavior of the solution in the neighborhood of the singularity point which appears to perform satisfactorily for singular problems.
Antimagic labeling of a graph with vertices and edges is assigned the labels for its edges by some integers from the set , such that no two edges received the same label, and the weights of vertices of a graph are pairwise distinct. Where the vertex-weights of a vertex under this labeling is the sum of labels of all edges incident to this vertex, in this paper, we deal with the problem of finding vertex antimagic edge labeling for some special families of graphs called strong face graphs. We prove that vertex antimagic, edge labeling for strong face ladder graph , strong face wheel graph , strong face fan graph , strong face prism graph and finally strong face friendship graph .
يسعى هذا البحث الى تقديم اطار عملي ونظري حول موضوع "تأثير الاقتصاد المنزلي في تعزيز الاداء العالي" وتم اختبار مخطط الدراسة الفرضي في القطاع التعليمي الحكومي في محافظة البصرة ,ويتضمن عدد من تشكيلات الجامعة التقنية الجنوبية. واستخدمت الاستبانة والمقابلة الشخصية كأسلوب لجمع البيانات للدراسة وكان حجم العينة114 موظف. وقد استخدمت عدد من الاساليب الاحصائية لاختبار فرضيات الدراسة. واظهرت النتائج بأن هناك تأثير ايج
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