Background: The ideal force-delivery system must: provide optimal tooth moving forces that elicit the desired effects, be comfortable and hygienic for the patient, require minimal operator manipulation and patient cooperation and provide rapid tooth movement with minimal mobility during orthodontic therapy, the elastomeric chains have the greatest potential to fulfill these requirements. Materials and Methods: This in vitro study was designed to determine the effect of three different mechanisms for canine retraction : (6-3 , 6-5-3 and chain loop ) on the load relaxation behavior of three types of elastomeric chains : (maximum clear , maximum silver and extreme silver) from the same company (Ortho Technology company) with two different bran

An oil spillage has been a great threat to human life in parts of Koya district, especially through the contamination of domestic water. An attempt was made to find and map the extent of pollution in the area. According to a field survey, more than 17 springs and 34 hand-dug and artesian wells have been contaminated with crude oil. The contamination was recorded recently after loading began of tens of oil tankers in the Taq-Taq oil field, and as a result hundred barrels of oil have spilled into the creeks and soil daily. Hence, 2D resistivity imaging was adopted via four laid-out traverses running normal to the strike of the outcrops. A Wenner-Schlumberger array configuration was used to achieve both vertical and lateral resistivity dist

Background: This study aimed to compare the mechanical properties between four groups of newly fabricated combination wires according to their method of union, according to the gauges of wires and a comparison were made between them and their originals. Materials and method: A total of 60 stainless steel combination wires were fabricated , divided into four groups according to gauge of wires and their method of union, each of them with 15 samples, the groups were welded (0.016x0.022-0.016 and 0.016x0.022-0.018) and soldered (0.016x0.022-0.016 and 0.016x0.022-0.018), samples were made according to certain parameters which were : for the welded samples: length,weight, duration of pulsation and size of copper electrode tips used; for the sold

The pollution of aquatic ecosystems with toxic heavy metals is representing a major environmental issue, as a result of releasing these metals to ecological ambient without treatment, leading to their persistence and non-biodegradation in the environment. Various traditional methods are utilized as an attempt to remove heavy metals from waste water but still without making any actual progress. This study hypothesizes that Eichhornia crassipes (water hyacinth) dried leaves powder is potential in removing some of these heavy metals (HM), including lead, copper, cadmium and chrome from aqueous solutions via biosorption influenced by some variable experimental factors. This aim was approached by using two different experimental conditions: (

     The bound radial wave functions of Cosh potential which are the solutions to the radial part of Schrodinger equation are solved numerically and used to compute the size radii; i.e., the root-mean square proton, neutron, charge and matter radii, ground density distributions and elastic electron scattering charge form factors for nitrogen isotopes ^{14,16,18,20,22}N. The parameters of such potential for the isotopes under study have been opted so as to regenerate the experimental last single nucleon binding energies on Fermi's level and available experimental size radii as well.

Background: Consideration of mandibular third molar is important from orthodontic perspective due to several factors such as, lower anterior arch crowding, relapse in lower anterior region, interference with uprighting of mandibular first and second molars during anchorage preparation and molar distalization. The aims of this study were to assess of gender differences in the mandibular third molar position and compare and evaluate whether there is any differences in the results provided by CT scan and lateral reconstructed radiograph. Materials and Methods: The sample of present study consisted of 39 patients (18 males and 21 females) with age range 11-15 years. CT images for patients who were attending at Al Suwayra General Hospital/the C

Aspergillus niger is one of the most important filamentous fungi that used in the fermentation industry. Aspergillus niger isolate was cultured on potato-dextrose agar (PDA) for activation, and the optimum conditions for xylanase production from this local isolate were studied by solid state fermentation, using a medium composed of wheat bran moisten with corn steep liquor at ratio 1:0.5 (v:w) at initial pH 5.5, inoc-ulated with 1.6 × 106 spores/ml, and incubated at 30ᵒC for 5 days.

 Two series of Schiff Bases [VI]n and thiazolidin-4-one derivatives[VII]n were synthesized by many steps starting from cyclization of 4- hydroxyacetophenon with thiourea in iodine to yield 1,3-thiazole compound which was reacted with pentoxy bromide in anhydrous potassium carbonate to converted compound[II] and this reacted with Phenol to yield azo compound[III]. The azo compound reacted with ethyl chloro acetate in basic medium to get a new easter compound[IV]  which is converted to their acid hydrazid[V]. The later compound condensation with n-alkoxy benzaldehyde to give new Schiff bases[VI]n . Imine group undergoes addition cyclization with thioglycolic acid to get thiazolidinone compounds[VII]n .Also, two new series of Schi

In this study the Bauxite has been activated and used to prepare two complexes: Bauxite - urea and Bauxite - melamine, these complexes were merged and polymerized with formaldehyde to prepare the complex Bauxite polymer - urea - melamine - formaldehyde (modified Bauxite). In the Bauxite-urea complex XRD results indicate that the urea molecules penetrate among the layers of the crystal plane (110) of the Gibbsite mineral while in the Bauxite-melamine the interaction was at the outer surface of the Bauxite forming minerals because the relatively large volume of the melamine molecule. FT-IR results show the interaction of these two bases with Bauxite was mainly based on the hydrogen bonding and in less extent on the coordination between N l