Objective. This study aimed to evaluate the orthodontic bond strength and enamel-preserving ability of a hydroxyapatite nanoparticles-containingself-etch system following exposure to various ageing methods. Materials and Methods. Hydroxyapatite nanoparticles (nHAp) were incorporated into an orthodontic self-etch primer (SEP, Transbond™ plus) in three different concentrations (5%, 7%, and 9% wt) and tested versus the plain SEP (control) for shear bond strength (SBS), adhesive remnant index (ARI) scores, and enamel damage in range-finding experiments using premolar teeth. The best-performing formulation was further exposed to the following four artificial ageing methods: initial debonding, 24 h water storage, one-month water storage, and one-month acid challenge. A field-emission scanning electron microscope (FE-SEM) was used to examine the integrity of debonded enamel surfaces and calcium-phosphates (CaPs) reprecipitation. Results. The best-performing formulation (7% nHAp-SEP) resulted in significantly lower SBS (
This paper is submitted as anew approach to simulate manufacturing control & planning system to define the problem of designing control system on the needs for materials.
Production planning & control is a total and complex operation, resides in the essence of manufacturing companies operations. The successful process of production planning and control systems is critical for the staying of manufacturing organizations in markets leading to the increasing consumer competition and which dominate most of manufacturing sectors because of the market oriented economy , thus , what has happened previously , that the companies possessed a great inventory of crude material, components, and groupings and they use in flexible techni
... Show MorePeriodontitis is a multifactorial chronic inflammatory disease that affects tooth-supporting soft/hard tissues of the dentition. The dental plaque biofilm is considered as a primary etiological factor in susceptible patients; however, other factors contribute to progression, such as diabetes and smoking. Current management utilizes mechanical biofilm removal as the gold standard of treatment. Antibacterial agents might be indicated in certain conditions as an adjunct to this mechanical approach. However, in view of the growing concern about bacterial resistance, alternative approaches have been investigated. Currently, a range of antimicrobial agents and protocols have been used in clinical management, but these remain largely non-v
... Show MoreThe study aimed to identify the treatment of the press image of the Great Return Marches in the French international news agency AFP by knowing the most important issues, their direction and the degree of interest in them. The study belongs to the descriptive research, and used the survey method, within the context of the content analysis method, and the researcher relied on the content analysis form tool and the interview tool to collect data. The study population is represented in the photos published by the French News Agency about the Great Return Marches during the period (end of March / 2018 until the end of November / 2019. The researcher chose an intentional sample using the Complete Census method. The study material represented
... Show Moreتهدف هذه الدراسة إلى بحث ظاهرة الاغتراب في رواية " ديك الفداء " لايلي عامير ، لأن هذه الظاهرة تبدو أكثر وضوحا في هذه الرواية ، وتمثل تیارا مسيطرة على معطياتها واتجاهاتها الفكرية والفنية، خاصة أن الكاتب استطاع أن يجسد هذه الظاهرة المحورية تجسيدا فنيا متميزا ، وكشف عن طبيعة العلاقة بين عالم الواقع وعالم الحلم لدى الشخصيات، وعما تتسم به من تناقض و تعارض وتصادم و شعور بالإحباط والضياع والاغتراب. وقد اشتملت ال
... Show MoreThe tagged research problem (the outputs of the written text in conceptual art) dealt with a comparative analytical study in the concept of conceptual art trends (land art - body art - art - language).
The study consisted of four chapters. The first chapter dealt with the theoretical framework, which was represented in presenting (the research problem), which raised the following question: What is the role of the written text in the transformations of the conceptual arts?
The first chapter included (the importance of research) and (research objectives) seeking to conduct comparative research in the written text within the trends of conceptual art as a moving phenomenon in art, and to reveal the variable written text in the
... Show MoreEcolinguistics is a twofold field in which ecology and language are its two major concerns. That is, this field is concerned with the way through which our thoughts, ideologies and the like influence the environment. The present study aims at analyzing (6) constructive and destructive environmental advertisements to find out how the techniques of erasure and salience operate in these types of advertisements. It studies the linguistic expressions that achieve these techniques in the constructive and destructive advertisements. The qualitative and quantitative methods are exploited in the current study. Analyzing (6) constructive and destructive environmental advertisements in accordance with Stibbe’s (2015) model of salience and erasure
... Show MoreBackground: Orthodontic therapy often causes external root resorption. Serum vitamin D (VD) level is important for tooth mineralization and bone remodeling. This study aimed to test the impact of vitamin D (VD) supplements on bone and root remodelling in a vitamin D (VD) deficient rat model following orthodontic retention. Methods and Material: 30 male Wistar rats were divided into three groups: a control group of 10 rats and two experimental groups of 10 rats each with vitamin D deficiency (VDD) induced by a VD-free diet for 21 days. And a third group with VD supplementAll groups received orthodontic active treatment using a modified orthodontic appliance that applied 50 gm of force for 14 days to move the maxillary right first mol
... Show MoreIraq has the distinction of being a great potential of non-renewable natural resources,
especially crude oil and natural gas. Since the discovery of crude oil at the beginning of the
twentieth century in Iraq. Although the different of investment types, it contributed to the oil
sector in the provision of financial resources to the state treasury , since that date until the
present time.
Search has been marked by division ((The foreign investment in the oil sector in Iraq after
2003)) into three sections. The first section included a brief history of the development of
Iraq's oil potential in terms of oil reserves, and oil fields, and the quantities of production and
export. The second section reviewed the investm
A Strength Pareto Evolutionary Algorithm 2 (SPEA 2) approach for solving the multi-objective Environmental / Economic Power Dispatch (EEPD) problem is presented in this paper. In the past fuel cost consumption minimization was the aim (a single objective function) of economic power dispatch problem. Since the clean air act amendments have been applied to reduce SO2 and NOX emissions from power plants, the utilities change their strategies in order to reduce pollution and atmospheric emission as well, adding emission minimization as other objective function made economic power dispatch (EPD) a multi-objective problem having conflicting objectives. SPEA2 is the improved version of SPEA with better fitness assignment, density estimation, an
... Show More