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 (
In this work, the effect of vortex shedding on the solar collector performance of the parabolic trough solar collector (PTSC) was estimated experimentally. The effect of structure oscillations due to wind vortex shedding on solar collector performance degradation was estimated. The performance of PTSC is evaluated by using the useful heat gain and the thermal instantaneous efficiency. Experimental work to simulate the vortex shedding excitation was done. The useful heat gain and the thermal efficiency of the parabolic trough collector were calculated from experimental measurements with and without vortex loading. The prototype of the collector was fabricated for this purpose. The effect of vortex shedding at different operation condition
... Show MoreJoseph Curtis wrote in his book (Introduction to Semiotics narrative and rhetoric) on the development of a semiotic project in exploring the meaning of communion. The book is rich in theoretical and analytical benefits both in the approach of texts and in the pursuit of letters in search of mechanisms of scriptural and scriptural generation and mechanics in narrative production, especially as the book offers exercises that help to assess the distance separating the narrative spread from the sin of the text, for the semiotics, Refers to the theoretical developments of the science of relations, through the combination of conventional definitions and the representative and comparative limitations, to provide an approach to the application o
... Show MoreThe analysis of detective novels has taken different aspects. The linguistic analysis of them, for example, has tackled the linguistic systems of morphology, phonology, syntax, semantics, and pragmatics. In line with the linguistic analysis, this study explores the various pragmatic and stylistic devices realized through detective novels for the purpose of misdirecting and deceiving the reader. The problem is that when readers try to reach to the truth, they face difficulties. They might not reach to the right solution or infer wrong conclusions because writers use some techniques to hide the truth and mislead them. This study aims at examining these techniques and devices; namely, Grice's Maxims and ambiguity as pragmatic devices on the
... Show MoreThe conjunctive ''and'' and its Arabic counterpart ''و'' are discourse markers that express certain meanings and presuppose the presence of other elements in discourse. They are indispensable aids to both the text writers and readers. The present study aims to show that such cohesive ties help the writer to organize his main argument and communicate his ideas vividly and smoothly. They also serve as explicit signals that help readers unfold text and follow its threads as realized in the progression of context. The researcher has utilized the Quirk Model of Semantic Implication for data analysis. A total of 42 (22 for English and 20 for Arabic) political texts selected from different elite newspapers in both Arabic and English for the analy
... Show MoreIdentity is an influential and flexible concept in social sciences and political studies. The basic sense of identity is looking for uniqueness. In one sense, it is a sign of identification with those we assume they are similar to us or at least in some significant ways they are so. Globalization, migration, modern technologies, media and political conflicts are argued to have a crucial effect on identity representation in terms of the political perspectives specifically in the United States of America. This paper endeavors to investigate how American politicians represent their identities in speeches delivered in different periods of time namely from 2015 to 2018 in terms of the pragmatic paradigm. Three randomly selected speeches by fa
... Show MoreDBN Rashid, International Journal of Innovation, Creativity and Change, 2020
The definition of "prostitute" and prostitution is a difficult one and a
question over which the legislators of many lands and nations differed. A
notable feature of prostitution is its epidemic increase at times of war,
revolution and armed commotion, on account of economic, social and
psychological factors generated by such conditions of mortal conflicts. Wars
invariably deprive young wives and lovers of their men folk, resulting in
financial , sexual and emotional frustrations . At no time is the natural
balance between the sexes more seriously disturbed than during wars, when
thousands of men are thrown into one sector of the country and hundreds of
towns and villages are left to women and children only. Lo
Background: The interest in herbal extracts as antimicrobial agents has increased over the past few years in endodontic therapy. Nasturtium officinale (watercress) is a promising plant with great medicinal values. This study aimed to investigate the antifungal activity of watercress oil in combination with calcium hydroxide against Candida albicans as intracanal medicament. Materials and Methods: Candida albicans was isolated from patients with necrotic root canal or failed root canal treatment. The sensitivity of Candida albicans to different concentrations of watercress oil extract was determined by using the agar well diffusion method in comparison with calcium hydroxide paste. The agar plate method was used to determine the minimum fung
... Show MoreBackground Psoriasis is one of the most prevalent chronic inflammatory skin conditions; its prevalence ranges from 1 to 3%. Tumor necrosis factor-alpha (TNF-α), a cytokine that enhances inflammation, is overexpressed in synovium and skin plaques in psoriasis. TNF-α plays a critical role in the pathogenesis of psoriasis. IL-10 is the most crucial cytokine for reducing excessive immune responses and decreasing pro-inflammatory reactions in all autoimmune disorders. Objective To evaluate the effect of Apremilast on ILـ10, TNFـα, and BMI in obese psoriatic patients. Methods Thirty patients included in this investigative study to measure the concentrations of TNFـα, ILـ10 and BMI, before and after receiving Apremilast. TNFـα and
... Show MoreThe importance of the study, which is how to use these exercises with the device in rehabilitating the flabby muscles after childbirth, which is a problem found in our society and in need of high education on it because the form of exercises does not need places designated for training such as halls or fitness halls, especially since the social woman has limited movement in which we see the responses Physiology in different ways, the woman’s body is not only subject to the day’s need for work or the need to complete hours of physical training, but she has feminist components that she must overcome, whether it is physiological or otherwise.The research sample was determined by the intentional method available from women whose age
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