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
Abstract
The basic orientation of the research is an attempting to apply the cost determining method according in the contract sector projects for Al- Iraq ceneral company, that this subject has a big value according to its modernity and its influence on the future and the eaning of the company.
The research aims to find out the effect of the method for determining cost based on the activity in determining the cost of the construction sector projects.The research was conducted in Iraq General Company for the implementation of irrigation projects. Bani search on three assumptions, the first is (that the application of the method for determining the cost on the basis of
... Show MoreHeavy metals concentration in the soils and sediments has increased worldwide during the last century as a result of the rapid increase in population which combined by an increase in human activity as agriculture, industrial and many other activities. Ten soil and three river sediment samples were collected from 10 main sampling stations at Shatt Al-Hilla River from Sada area to Dora Bridge in Babylon province. The chemical analysis of the sedimentation sample in the laboratory included pH calculation, electrical conductivity (EC) (Cation Exchange Capacity (CEC), organic matter (OM), and heavy metals as (Mn, Ni, Cr, Zn, Cu, Co, Pb, Cd, As and Fe). Indirect geochemical background (IGB) of heavy metal was calculated by the iterative
... Show MoreMoringa oleifera Lam. tree has often been considered a medicinal and economical plant for its nutritional and medicinal properties. This study is intended to use plant tissue culture and elicitation technologies to increase secondary metabolites in the callus cultures of the M. oleifera. Young nodal segments were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of plant growth regulators (PGRs). A combination of 1.5 mg/l NAA plus 0.5 mg/l TDZ resulted in a high callusing rate (70%) with the largest size. Various concentrations of Salicylic acid (SA) and Methyl jasmonate (MeJa) were individually added to the growth medium to evaluate their impact on the biomass of callus cul
... Show MoreThe present research aims to measure concentration of lead Pb214 in soil using remote sensing and GIS, associated radiological hazards in Baghdad, Iraq. Concentration of specific radioactivity of radioactive elements was measured and analyzed naturally and artificially in 48 soil samples for separate sites from Baghdad, Iraq using crystalline spectroscopy to detect germanium. The average radioactivity concentrations of lead were found, as it was found to have varying values from one site to another, as most of them exceeded the international permissible limit, as the highest concentration was recorded at 180 Bq in the sample H28 in Waziriyah district. Battery Lab (1), and the lowest concentration valu
... Show Moreتم في هذا البحث استخدام المحفز الجديد المصنع من تحميل دقائق البلاتين النانوية على سطح الصفائح النانوية للكرافين كمحفز ضوئي واختباره لدراسة التجزئة الضوئية لملوثات المياه وازالتها بشكل نهائي من مصادر المياه لما لها من تأثير سلبي على البيئة. حيث تم استخدام صبغة البروموفينول الأزرق كمثال على أحد الملوثات. في البدء تم التأكد من تحضير المحفز بالطريقة المستخدمة في طريقة العمل من خلال تشخيصه باستخدام عدد من ا
... Show MoreAs a result of changes in the chemical properties of the Shatt al-Arab River, especially in the last decade, as well as the lack of rainfall and the effect of seawater intrusion into the Shatt al-Arab, this study was conducted to investigate the possible changes in the water pipelines like corrosive and scaling which Shatt al-Arab River is the source of water supply for domestic use. Domestic water samples were collected from 10 various locations in Basrah to study the water's tendency to be corrosive or form scales along the pipelines. The Langelier Index, Ryznar Index, Larson-Skold Index, and Saturation Index were used to determine the corrosivity potential of water based on physical and chemical parameters. Most domestic wate
... Show MoreBackground: Lateral cephalometric radiography is commonly used as a standard tool in orthodontic assessment and treatment planning. This study aimed to determine the tongue and surrounding space area in a sample of Iraqi adults with class I dental and skeletal pattern. Materials and methods: The study included thirty healthy subjects (15 males and 15 females) with an age ranged between 23-34 years and class I dental and skeletal pattern with no history of any sleep related disorders. The assessed cephalometric measurement included length and height of the tongue and position of hyoid bone from cervical line. Descriptive statistics were obtained for the data. Genders difference was evaluated by independent sample t-test. Results: There wer
... Show MoreA total of 60 samples of drinking water filtrated by Reverser 0smosis Filtration System from April to October 2012, from different houses in Baghdad – Al Resafa, so as to identify the eggs and cysts of protozoa. Two methods applied direct smear and staining technique with zeal nelson stain, which appeared Tape warm eggs, Ascaris lumbrecoides eggs and oocyst of Cryptospordium sp. This study revealed that total contamination rate with intestinal parasites in tap water were 96.6% this high rate, refers to filtrate tap water by reverse osmosis system was useful to prevent or reduce the contamination of drinking water, in order to reduce risks to public health; So recommended to apply this method at water purification stations. Dis
... Show MoreThis work is devoted to the modeling of streamer discharge, propagation in liquid dielectrics (water) gap using the bubble theory. This of the electrical discharge (streamer) propagating within a dielectric liquid subjected to a divergent electric field, using finite element method (in two dimensions). Solution of Laplace's equation governs the voltage and electric field distributions within the configuration, the electrode configuration a point (pin) - plane configuration, the plasma channels were followed, step to step. The results show that, the electrical discharge (streamer) indicates the breakdown voltage required for a 3mm atmospheric pressure dielectric liquid gap as 13 kV. Also, the electric potential and field distributions sho
... Show MoreThe objective of the present study was to investigate the effect of body mass index (BMI) on semen parameters, level of sex hormone and sperm DNA integrity. Semen samples were collected from (85) infertile men and (40) healthy fertile men with range of age (38.191 ± 0.84) years during their attendance at High Institute of Infertility Diagnosis and ART, Al-Nahrain University from March to June 2016. Semen samples were obtained by masturbation after 72 hours of abstinence. Seminal fluid analyses included semen volume, sperm concentration, percent sperm motility, percent sperm morphology, and sperm chromatin integrity DNA fragmentation index (DFI]). Serum samples were collected from each subject for determination the level of Follicle Stim
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