Frictional resistance occurs whenever sliding happens, negatively impacting treatment outcomes and duration. It is a clinical challenge and must be dealt with efficiently to achieve the best orthodontic results. Aims of this study: compare and evaluate the static frictional forces under the wet condition to mimic the oral environment produced by using a polycrystalline ceramic bracket, monocrystalline ceramic bracket, 0.014 of an inch nickel-titanium (Rhodium coated archwires, and ilusio aesthetic archwires), and 0.019 x 0.025 of an inch stainless steel (Rhodium coated archwires, and ilusio aesthetic archwires). Ninety-six aesthetic brackets (48 monocrystalline and 48 polycrystalline brackets) were used and stored in different incubation media (distilled water and acid challenge); each 16 bracket-archwire combinations were tested 6 times by Instron testing machine under wet conditions. Polycrystalline ceramic brackets combined with 0.014-inch NiTi rhodiumcoated archwires produced significantly low mean static frictional force in an acidic environment. Furthermore, no significant mean static frictional forces difference between monocrystalline and polycrystalline ceramic brackets if combined with 0.014 of an inch NiTi ilusio or 0.019 x 0.025 of an inch SS rhodium coated archwires. Conclusion: Coupling polycrystalline ceramic brackets with 0.014 of an inch NiTi rhodium coated rather than ilusio archwires in an acidic environment is advisable. At the same time, it is wise to combine with polycrystalline ceramic brackets the 0.019 x 0.025 of an inch SS ilusio archwires in distilled water rather than to combine with monocrystalline brackets
Comparative morphological study has been treated for two species of the genus Chaenorhinum (D.C.) Richb., These species were: 1. Chaenorhinum calycinum 2. Chaenorhinum rubrifolium (Robill. & cast. Ex Lam. & DC.) Fourr. The genus belong to the family Scorphulariaceae. Morphological characters has been studies for: root, stem, leaves, flowers (calyx, corolla, androcium including filaments and anthers, gynocium including ovary, style and stigma), fruits and seeds also has been characterized. Key for there two species presented using some quantitative characters. Other characters like shape of fruits and seeds were used too, and they were of a useful taxonomic value
As performers in a social world, we communicate with other people by sharing information on many different levels. Each utterance includes linguistic information and conveys much information about the speaker’s identity. Variation in voice quality indexes information about the speaker and marks the speaker’s identity as a unique individual. The present study aims to validate the belief that each individual has an inalienable voice print that can’t be imitated. The study verifies that, even the more similar personality between two individuals, or the close position in society the variance is voice quality. The acoustic analysis is performed via analysing the acoustic parameters namely: the fundamental frequency, amplitude, inten
... Show MoreContamination of surface and groundwater with excessive concentrations of fluoride is of significant health hazard. Adsorption of fluoride onto waste materials of no economic value could be a potential approach for the treatment of fluoride-bearing water. This experimental and modeling study was devoted to investigate for the first the fluoride removal using unmodified waste granular brick (WGB) in a fixed bed running in continuous mode. Characterization of WGB was carried out by FT-IR, SEM, and EDX analysis. The batch mode experiments showed that they were affected by several parameters including contact time, initial pH, and sorbent dosage. The best values of these parameters that provided maximum removal percent (82%) with the in
... Show MoreThe present study deals with the morphological and histological aspects of the forebrain(Cerebrum) in the Columba livia domestica (Gmelin, 1789) to identify the histoarchitecture of its layers. This bird' has a large head found as perpendicular to the longitudinal axis. The morphological results reveal that for brain (Cerebrum) pear shaped, its outer surface is smooth without folds or deep grooves. Cerebrum is made up of two regions, the Pallium and the Subpallium. The Cerebral cortex includes four layers of hyperpallium (Wulst) , Dorsolateral corticoid area (CDL), Hippocampus, Piriform cortex. The internal cortex of cerebrum consists of Dorsal Ventricle ridge which includes the mesopallium, nidopallium, and archospallium. All these reg
... Show MoreComparative morphological study has been treated for two species of the genus Chaenorhinum (D.C.) Richb., These species were: 1. Chaenorhinum calycinum 2. Chaenorhinum rubrifolium (Robill. & cast. Ex Lam. & DC.) Fourr. The genus belong to the family Scorphulariaceae. Morphological characters has been studies for: root, stem, leaves, flowers (calyx, corolla, androcium including filaments and anthers, gynocium including ovary, style and stigma), fruits and seeds also has been characterized. Key for there two species presented using some quantitative characters. Other characters like shape of fruits and seeds were used too, and they were of a useful taxonomic value
Background: Diabetes mellitus (DM) could be regarded as a set of chronic metabolic disorders which have a common aspect of hyperglycemia. The resistance in the peripheral actions of insulin or impaired insulin secretion could be the reason hepcidin which is a peptide hormone derived from liver, in systemic iron homeostasis is an essential regulator, and its lopsided production participates in the pathogenesis of iron disorders in spectrum. Osteoporosis often accompanies many diseases like ß-thalassemia, hemochromatosis, sickle liver diseases, cell disease and hemosiderosis featured by iron overload, evidences suggest that Iron overload and iron deficiency are suggested by evidences that they affect bone in a negative way, acting
... Show MoreThe principal concern of this study is Disjunct and Conjunct adverbials in the
English language. The study sets out to explore and clarify the types, nature and
structure of disjuncts and conjuncts. It also aims at testing student's performance to
evaluate the use and usage of the disjuncts and conjuncts in their written performance.
Two tests, accordingly, were given to some fifty students of at the Dept. of English, at
the college of languages (third and fourth stages) in the University of Sulaimani. The
hypothesis that the study was based on are those students use disjuncts and conjuncts
hardly enough in their writings and when doing so, they generally tend to stick only to
the most commonly used and familiar o
Background: Restoration of the gingival margin of Class II cavities with composite resin continues to be problematic, especially where no enamel exists for bonding to the gingival margin. The aim of study is to evaluate the marginal leakage at enamel and cementum margin of class II MOD cavities using amalgam restoration and modern composite restorations Filtek™ P90, Filtek™ Z250 XT (Nano Hybrid Universal Restorative) and SDR bulk fill with different restoratives techniques. Materials and method: Eighty sound maxillary first premolar teeth were collected and divided into two main groups, enamel group and cementum group (40 teeth) for each group. The enamel group was prepared with standardized Class II MOD cavity with gingival margin (1 m
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