Background/: Buccal tubes are orthodontic attachments used on the posterior teeth instead of bands, so it is important to focus on the effect of their properties on orthodontic treatment. The aims of the present in vitro study are to evaluate and compare the buccal tube front and back openings dimensions and the torsional play angle of six different brands. Materials and Methods: The samples consisted of Single bondable, non-convertible first molar buccal tubes from six brands supplied from six companies (Dentaurum, Forestadent, Ormco, 3M, American Orthodontic, A-Star). Regarding tube opening dimension, ten buccal tubes of each brand were examined by an optical microscope. Each tube was fixed during examination using synthetic mud and oriented for observation of the front and back slot openings. A picture was taken for both tube openings and the result appeared on the computer's screen where width and height measurements were made. While regarding torsional play angle, ten buccal tubes of each brand were used. Each tube was fixed on a metal block attached to a surveyor base. Then an L-shaped wire was inserted inside the front opening of the tube. Two photographs were taken, one with the wire in free fall position and the other with the wire elevated by a 10g weight with the same angle of shooting as the first photograph. Later, the two images were superimposed in Adobe Photoshop program, and an electronic MB-ruler Software was used to calculate the angle which represents the torsional play within each tube. The data were then statistically analyzed using ANOVA and LSD tests. Results: There are marked differences between measured tube dimensions and the manufacturer stated dimensions with the front tube openings being generally larger than the back opening dimensions. Furthermore, the torsional play angle was highest in A-Star and smallest in Ormco's tubes. This angle was significantly correlated to the height of the tube front opening. Conclusion: It can be concluded that tube dimension varies among different companies and effect greatly torsional play angle.
Gelatin is a valuable substance that is known to have a complex 3D structure, but it has limited adsorption efficiency, which limit its application at physiological temperature. In this paper, gelatin was improved by the addition of glutaraldehyde (GTA) to enhance its ability to adsorb dye in aqueous solution. The adsorption experiments were conducted under different conditions, such as the amount of adsorbent, the concentration of the dye, and the temperature. The study found that the qe by GTA-GE (4.978 to 23.056 mg/g) and GE (4.8 to 21.333 mg/g) increased with the increase of initial dye concentrations but decreased with the amount of adsorbent. The parameters at equilibrium were at a pH of 4 and a dose of adsorbent of 100 mg in
... Show MoreThis study explores the theory of Ecofeminism ,which elucidates how capitalism and patriarchal society treat women and nature. Moreover, it studies the effects of gender categories to show how social norms unfairly control women and the environment. This study explores how Tess Onwueme's Then She Said it dramatizes the combined tyranny of nature and women. It emphasizes the devastation caused by oil firms colluding with local authorities to exploit both. The playwright examines the historical oppression of Delta women and the environmental damage they endure, using dramatic visuals and dialogue to illustrate the harsh realities of pollution and poverty. This study examines the contradiction between the prosperity of oil companies and the po
... Show MoreMetal oxide nanoparticles, including iron oxide, are highly considered as one of the most important species of nanomaterials in a varied range of applications due to their optical, magnetic, and electrical properties. Iron oxides are common compounds, extensive in nature, and easily synthesized in the laboratory. In this paper, iron oxide nanoparticles were prepared by co-precipitation of (Fe+2) and (Fe+3) ions, using iron (II and III) sulfate as precursor material and NH4OH solution as solvent at 90°C. After the synthesis of iron oxide particles, it was characterized using X-ray diffraction (XRD), infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). These tests confirmed the obtaining o
... Show MoreThis paper demonstrates the spatial response uniformity (SRU) of two types of heterojunctions (CdS, PbS /Si) laser detectors. The spatial response nonuniformity of these heterojunctions is not significant and it is negligible in comparison with p+- n silicon photodiode. Experimental results show that the uniformity of CdS /Si is better than that of PbS /Si heterojunction
The synthesis, characterization and liquid crystalline properties of N4,N40 -bis((1 H-benzo[d]imidazol-2- yl)methyl)-3,30 -dimethyl-[1,10 -biphenyl]-4,40 -diamine and of their corresponding Mn(II), Fe(II), Ni (II), Cu(II), and Zn(II) complexes are described. The ligand and complexes have been characterized by elemental analysis, magnetic susceptibility measurements (meff), conductometric measurements and Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (1 H NMR), (13C-NMR) and UV–Vis spectroscopy. Spectral investigations suggested octahedral coordination geometrical arrangement for M(II) complexes. The phase transition temperatures were detected by differential scanning calorimetry (DSC) analysis and the phases are confirmed
... Show MoreOxidative stress is oxidative damage caused by free radicals and reactive oxygen species (ROS). These ROS can cause oxidative damage to cellular components, including membrane lipids, receptors, enzymes, proteins, and nucleic acids. It would eventually lead to cell apoptosis and the appearance of certain pathological conditions. This work investigates the antioxidant potentials of chamomile extract in vitro by evaluating the extract activity to scavenge 2,2-Diphenyl-1-picrylhydrazyl (DPPH), also in vivo by investigating its effects on oxidative stress-induced rats by assessing the total oxidant status (TOS) and total antioxidant capacity in the radiation exposed rats with and without the treatment with chamomile extract. The results
... Show MoreThe knowledge related with lexical items can be realized as including relations of meaning a cross words. Words that share a similarity of meaning are called to be synonymous, and words that share a contrary of meaning are called to be antonymous. Both of them are universal linguistic phenomenon that exist in terms of linguistic system of every language. The present study aims at finding out areas of difficulty that Iraqi EFL learners encounter in the use of synonymy and antonymy, both on the recognition and production levels. Also tries to detect the main reasons behind such difficulties. A diagnostic test of two parts, namely, recognition and production, is designed. The test is built to include two linguistic phenomenon which are: synony
... Show More