Background:The demand for esthetic orthodontic appliances is increasing so that the esthetic orthodontic archwires were introduced. This in vitro study was designed to evaluate the surface roughness offiber-reinforced polymer composite (FRPC) archwires compared to coated nickel-titanium (NiTi) archwires immersed in artificial saliva. Materials and Methods:Three types of esthetic orthodontic archwires were used: FRPC (Dentaurum), Teflon coated NiTi (Dentaurum) and epoxy coated NiTi (Orthotechnology). They were round (0.018 inch) in cross section and cut into pieces of 15 mm in length.Forty pieces from each type were divided into four groups; one group was left at a dry condition and the other three groups were immersed in artificial saliva (pH=6.75 ± 0.015) at 37ºC for 1, 14 and 28 days intervals. The AFM was used to evaluatesurface analysis of all samples.ANOVA, Kruskal-Wallis, LSD and Mann-Whitney U tests were used to identify and localize the source of differences among the groups. Results:At each immersion period, FRPC wires exhibited the highest Ra among the study groups, except at 28 days immersion period where the Teflon coatings were the roughest. On the other hand, the least rough surfaces were the epoxy coatings when compared to analogous esthetic archwires, except at 1 day immersion period where the Teflon coatings had the least roughness. However, statistically non-significant differences were found between Teflon and epoxy at the dry condition and the 1 day immersion. Conclusions:The epoxy coated archwires are the best and the most appropriate esthetic orthodontic alignment archwires in term of the least surface roughness initially and over the course of study period.
Abstract
The research aims to verify the dimensions of tax justice that exist in Iraq, and to determine their impact on tax compliance. Through a revised model of tax justice based on the literature of tax justice according to the classification of the studies of (Saad, 2009), (Wenzel, 2002), by using a questionnaire as an experimental measurement tool designed to be in line with perceptions of tax justice in Iraq. To define the dimensions of tax justice (the independent variable) with eight dimensions (Distributive justice, Exchange justice, Vertical justice, Horizontal justice, Retributive justice,
... Show MoreThe rotation effect upon Morse potential had been studied and the values of the effective potential in potential curves had been calculated for electronic states (X2?+g , B ?u ) K2 molecule. The calculation had been computed for rotational quantum number (J = 5). Also, drawing potential curves for these systems had been done using Herzberg and Gaydon equations. It was found that the values of the dissociation energy which resulting from using Herzberg equation greater than that of Gaydon equation. Besides, it was found that the rotation effect for (X and B) electronic states in Morse potential is very small and in this case may negligible.
The main aim of the current research is to focus the light on some bacterial contamination on cracked eggshell and egg content plus studying the sensitivity of these bacterial isolates to antibiotics. For this purpose, a total of 50 eggs were collected from the markets in Baghdad city (Iraq) and examined for bacterial isolation from cracked eggshells and from the egg contents. The bacterial isolates were cultured and purified then transferred to a specific media to study its sensitivity against antibiotics. The results revealed that bacteria isolated from both cracked eggshells (46%) and egg contents (44%). The bacteria isolated include E. coli, Staphylococcus, Enterococcus faecalis, Enterobacter and Pseudomonas. The results of antibiotic s
... Show MoreMolecular interactions between 2-isopropenylnaphthalene-methacrylic acid (IPNMA) block copolymer( as a model for water- soluble polymer) and methanol at several temperatures were studied using fluorescence techniques , Fluorescence spectrum for (IPNMA) exhibits two emission bands at around 342 nm and 387 nm corresponding to the monomer and the excimer bands , respectively .The fluorescence spectra of dilute solution of (IPNMA) in methanol were recorded in temperature range of 8- 45?C . Plot of the excimer to monomer intensity ratio Ie/Im versus temperature was obtained, which shows double lines with positive slopes crossing at 25?C , the increasing of slope value above this temperature is s
... Show MoreBreast tumor patients generally have more oxidative stress than normal females. This was clear from significant decrease (P<0.05) in tissue GSSG-Red activity. The study had found that free radicals in malignant breast tumors were higher than benign tumors, therefore the GSH- Red might be used as markers for prognosis of the disease. Results of molecular characterization show optimum enzyme concentration substrate conc., optimum pH, temperature & time & effect of some (chemotherapies in constant conectrations) for GSSG-Red activity.
BN Rashid, Social Sciences, 2022
The majority of Iraqi translator-student have problems at two main levels: the conceptual level and the productive level. From different perspectives, such problems are either related to ‘language’ or to ‘cognition’. This binary view is an indication to the implicit and interchangeable relationship between language and cognition. The relationship between cognition language and translator starts with the first language and its effect on the Iraqi translators. Identifying the effect is the aim of the present study. It is hypothesized that Iraqi students are negatively influenced by the problems and weaknesses of first language schema. This reflects the major claim and later concludes that first language instruction in the Iraq
... Show MoreThe objective of this study was to evaluate the alteration in levels of gonado trophins hormones i.e.,Leutizing (LH),Follicular(FSH) in sera of patients with thyroid disorders and molecular binding study of (LH ,FSH) with their antibodies The study was conducted at the specialized center for endocrinology and diabetes from January / 2009 to March / 2010.Two hundreds and twenty three Iraqi subjects, 109 patients with thyroid disorders at age range between (40-50) years and 114 healthy individuals as control group were included in this study.The majority of patients were female with hyperthyroidism and (49.54 % ) were at age range between(40 - 50) years. The levels of hormones(LH,FSH.tri iodothyronine(T3).thyroxine(T4), thy
... Show MoreIn the present research we the study the deposition of radioactive elements naturally and particularly radioactive radon gas in parts of the body of organisms which are of direct relevance to human life in the city of Baghdad as the samples which were collected from the bones and skin of some kinds of birds and chicken based on the principle that radioactive elements are concentrated always on the bones. We use of this as the exercise detector impact nuclear (CR-39), using the technology Cylindrical diffusion , the results indicated that the largest concentration of radon found in the bone bird Seagull tapered as it was (625 ± 37) Bq.cm-3, and less concentration of radon gas in the chicken bones of Al-kafeel as it was (105 ± 10) Bq.c
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