Background: Coated archwires have been introduced to improve esthetics during orthodontic treatment. Theaim of the present study was to evaluate and compare the load–deflection characteristics and force levels of six brands of coated nickel titanium orthodontic archwires using palatal and gingival deflection. Materials and methods: Ten round wires (0.016 inch) and ten rectangular wires (0.019x0.025 inch) were obtained from each of six brands (G&H, Opal, Ortho Technology, Dany, Hubit and Astar Companies). The load-deflection properties of these archwires were evaluated by the modified bending test usinga readymade dental arch model in both palatal and gingival directions at 37°C temperature using a universal material testing machine. Forces generated at maximum loading of 2mm and at unloading of 1.5mm were measured. Results: All the wires showed hysteresis and significant differences in their load deflection curves, but these differences were more evident in round wires than in rectangular wires where G&H wires showed the widest loading- unloading deflection curves. The maximum loading force of round wires in gingival deflection were higher than by palatal deflection. The force decline during unloading (plateau gap) ranged between 18 to 34% for round wires and 17 to 37% for rectangular wires. Conclusion: Coated epoxy wires (G&H, Opal, Astar and Ortho Technology) produced lower forces compared to polymer (Dany) and Teflon (Hubit) coated round and rectangular archwire.
The vortex rate sensor is a fluidic gyroscope with no moving parts and can be used in very difficult
conditions like radiation, high temperature and noise with minimum cost of manufacturing and
maintenance. A vortex rate sensor made of wood has been designed and manufactured to study
theoretically and experimentally its static performance .A rig has been built to carry out the study,
the test carried out with three different air flow rates (100, 150, and 200 l/min).The results show that
the relation between the differential pressure taken from the sensor pickoff points and the angular
velocity of the sensor was linear.The present work involved theoretical and experimental study of
vortex rate sensor static characteri
The vortex rate sensor is a fluidic gyroscope with no moving parts and can be used in very difficult conditions like radiation, high temperature and noise with minimum cost of manufacturing and maintenance. A vortex rate sensor made of wood has been designed and manufactured to study theoretically and experimentally its static performance .A rig has been built to carry out the study,
the test carried out with three different air flow rates (100, 150, and 200 l/min).The results show that the relation between the differential pressure taken from the sensor pickoff points and the angular velocity of the sensor was linear.The present work involved theoretical and experimental study of vortex rate sensor static characteristics .Vortex rat
In this work, the linear properties of Vitamin D3-5000IU soft gel were investigated by measuring its absorption and fluorescence spectra. It was observed that there was a shift towards longer wavelength within limits (75 nm), with quantitative efficiency equal to (33.58%). The values of absorbance were used to calculate the extinction coefficient, optical refractive index, optical conductivity and optical dielectric constant values.
The non-linear properties of Vitamin D3-5000IU soft gel was also studied using the Z-Scan technique by using Neodymium-doped Yttrium Garnet (Nd: YAG) continuous laser (CW) emitting in &n
... Show MoreA progressive increase in the desire for environmentally friendly lubricants by users and strict government regulations for the use of these lubricants has provided an opportunity to use plant oils as biodegradable lubricants, therefore vegetable oils have been investigated to replace oil lubricants because of their maintaining the conditions of nature (environment) properties. In this paper, the influences of the blending ratio of mustard seeds oil with commercial mineral oil (SAE40) on the tribological characteristics were investigated and compared with mineral oil using the four-ball tribotester. Mustard seeds oil was blended with mineral oil at a volumetric ratio ranging from 22.5 to 90%. All experimental works were
... Show MoreCorrosion inhibiting admixtures are unique among other methods to protect reinforced concrete from corrosion damage. In this study, the effect of furfural on the fresh and hardened properties of concrete mixes of 35 and 45 MPa compressive strengths as well as the corrosion inhibition of furfural was evaluated. Furfural was added at different dosages (1, 2 and 3% by weight of cement) with and without superplasticizer (HRWR). Different electrochemical measurements were performed (Half-cell potential, Tafel plot and linear polarization resistance). Electrochemical measurements confirmed that furfural dramatically reduces the rate of corrosion; the inhibition efficiencies were 62.7 and 63.8 % due to 3% furfural addition to 35 and 45MPa-concr
... Show MoreBackground: With the start of the current century, increased the interest in the role of the adipose tissue derived substances that named adipokines in the inflammatory diseases of the human being including the inflammatory periodontal disease, but scientific evidences were not clearly demonstrate the association between these adipokines and periodontal pathologies. Materials and Methods: Forty two subjects male only with normal body mass index were selected for the study with an age ranged (30-39 years). Samples were divided into three groups of 14 subjects in each group based on clinical periodontal parameters; clinically healthy gingiva (group I), gingivitis group (group II) and chronic periodontitis patients group (group III), from whom
... Show MoreHashimoto Thyroiditis (HT) is the most common autoimmune thyroid disease and the commonest cause ofhypothyroidism. C-reactive protein (CRP) is synthesized in hepatocyte in response to autoimmune disorders;strongly induced by IL-6. This study aimed to estimate serum IL-6 and CRP levels in autoimmune and non-autoimmune hypothyroidism. The present study included 60 Iraqi female hypothyroid patients divided to 30autoimmune and 30 non-autoimmune, with age ranged between 24-50 years and 30 healthy controls withage ranged between 27-52 years. Serum samples were collected from study groups. The levels of thyroidhormones (TSH, T4 and T3) were determined by using automated Chemiluminescence Immunoassay (CLIA)analysis system. Detection the levels of t
... Show MoreThis study describe the effect of temperature on the optical
properties of nickel(ii) phthalocyanine tetrasulfonic acid tetrasodium
salt (NiPcTs) organic thin films which are prepared by spin coating
on indium tin oxide (ITO-glass). The optical absorption spectra of
these thin films are measured. Present studies reveal that the optical
band gap energies of NiPcTs thin films are dependent on the
annealing temperatures. The optical band gap decreases with increase
in annealing temperature, then increased when the temperature rising
to 473K. To enhance the results of Uv-Vis measurements and get
more accurate values of optical energy gaps; the Photoluminescence
spectra of as-deposited and annealed NiPcTs thin fi
Study was done in the period between (2015–2017) in biology department in college of Education for pure science/Ibn Al-Haitham at Baghdad University and in Pathology department/college of medicine at Al-Nahrain University. The study was retrospectively designed. The clinicopathological parameters were obtained from patients’ admission case sheets and pathology reports (age, gender). The presents study included 120 patients having thyroid nodules, classified according to results of histopathology into 4 groups, 30 patients within each; the first group included patients with follicular adenoma, the second group included patients with follicular carcinoma, the third group included patients with follicular variant of papillary carcinoma (FV
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