Preferred Language
Articles
/
jbcd-533
Effects of three different types of intracoronal bleaching agents on shear bond strength of stainless steel and sapphire brackets bonded to endodontically treated teeth (An in vitro study)
...Show More Authors

Background: evaluate the effects of three different intracoronal bleaching agents on the shear bond strengths (SBS) and failure site of stainless steel and monocrystalline (sapphire) orthodontic brackets bonded to endodontically treated teeth using light cured orthodontic adhesive in vitro. Materials and methods: Eighty extracted sound human upper first premolars were selected, endondontically treated and randomly divided equally (according to the type of the brackets used) into two main groups (n = 40 per group). Each main group were subdivided (according to the bleaching agent used) into four subgroups 10 teeth each; as following : control (un bleached) group, hydrogen peroxide group (Hp) 35%, carbamide peroxide group (CP) 37% group and sodium perborate (SP) group . The bleaching process was applied three times (4 days intervals) sequentially and the bleached teeth were stored in artificial saliva four weeks before bonding. Orthodontic brackets were bonded with a light cure composite resin and cured with LED light. After passing 24 hours of bonding procedure, the brackets were debonded by a Tinius-Olsen universal testing machine, to measure the shear bond strength. After debonding, each bracket base and the corresponding tooth surface were examined using a stereomicroscope and their Adhesive Remnant Index (ARI) was recorded. Results: The ANOVA test showed that the SBS of stainless brackets was significantly reduced by intracorornal bleaching agents. Furthermore, LSD showed no significant difference in SBS between the three types of bleaching agents used in stainless steel group. Whilst for sapphire group, the results The ANOVA test showed no significant difference in SBS between the bleached groups and the control group. Chi-square comparison no significant difference in failure site between bleached and control groups in both brackets types used. Conclusion: The effect of intracoronal bleaching on SBS was reduced SBS of stainless steel and not for sapphire. However, the intracoronal bleaching had no effect on the failure site of orthodontic brackets used.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jan 03 2021
Journal Name
Al-qadisiyah Journal For Engineering Sciences
Bearing Capacity of Square Footing Resting on Layered Soil
...Show More Authors

The bearing capacity of layered soil studies was carried out with various approaches such as experimental, theoretical, numerical, and combination of them. This work is focused on the settlement and bearing capacity of shallow foundations subjected to the vertical load placed on the surface of layered soils. The experimental part was performed by manufacturing soil cubic container (570 mm x 570 mm x 570 mm).  A model square footing of width 60 mm was placed at the surface of the soil bed. The relative density of sand was constant at 60%, and the clay was prepared with a density of 19.2 (kN/m3) and water content of 14.6%. PLAXIS 3D FEM was used to simulate the experimental tests and performing a parametric study. The results showed

... Show More
View Publication
Crossref (3)
Crossref
Publication Date
Fri Jan 01 2016
Journal Name
Journal Of The College Of Languages (jcl)
Some Reflections on the Semantic Changes of Neos Creativity
...Show More Authors

Various semantic innovations and expansions have been tackled as factors and sources of neos.  A variety of internal (linguistic) and external (extra-linguistic) motives and motifs leads to the appearance of new terms causing such changes in the political language.  Some statesmen are productive in introducing new terms and creative in manipulating expressions and meanings.

      New words are nonces that get metaphorical expansion for quadrilateral motivations resting on extra meaning innovation, new terms at the semantic expansions to be honed as neos.  In tracing the phases of the semantic processes of neos and hulks, lexical and semantic changes might be of widening or narrowing of refe

... Show More
View Publication Preview PDF
Publication Date
Fri Oct 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The Impact Of Entrepreneurial Leadership On Organizational Crisis Management
...Show More Authors

The current research aims to test the relationship of the entrepreneurial leadership and its factors (strategic factors, communication factors, personal factors, motivational factors) in managing the organizational crisis and its stages (detection of warning signs, readiness and prevention, containment of damages, restoration of activity, learning) among a sample of companies of the Ministry Water resources (Al-Fao State Company for the implementation of irrigation projects, Al-Rafidain Company for the implementation of dams, Iraq Company for the implementation of irrigation projects), as well as standing at the level of interest of the research companies in the search variables and their factors and stages, there is no doubt tha

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Oct 01 2018
Journal Name
Iraqi Journal Of Physics
The effect of gold nanoparticles on WO3 thin film
...Show More Authors

Chemical spray pyrolysis technique was used at substrate temperature 250 ˚C with annealing temperature at 400 ˚C (for 1hour) to deposition tungsten oxide thin film with different doping concentration of Au nanoparticle (0, 10, 20, 30 and 40)% wt. on glass substrate with thickness about 100 nm. The structural, optical properties were investigated. The X-ray diffraction shows that the films at substrate temperature (250 ˚C) was amorphous while at annealing temperature have a polycrystalline structure with the preferred orientation of (200), all the samples have a hexagonal structure for WO3 and Au gold nanoparticles have a cubic structure. Atomic force microscopy (AFM) was used to characterize the morphology of the films. The optical pr

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
BEARING CAPACITY OF SHALLOW FOOTINGS RESTING ON DUNE SAND
...Show More Authors

As a result of the growth of economic, demographic and building activities in Iraq, that necessitates carrying out geotechnical investigations for the dune sand to study behavior of footings resting on these soils. To determine these properties and to assess the suitability of these materials for resting shallow foundation on it, an extensive laboratory testing program was carried out. Chemical tests were carried out to evaluate any possible effects of the mineralogical composition of the soil on behavior of foundation rested on dune sands.
Collapse tests were also conducted to trace any collapse potential. Loading tests were carried out for optimum water content and different shapes of footing. Loading test recommends manufacturing o

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Tue Aug 15 2023
Journal Name
Journal Of Economics And Administrative Sciences
The Influence of Customer Knowledge Management on Sustainable Promotion
...Show More Authors

This research has investigated the effect of the customer knowledge management CKM in sustainable promotion SP. The research conducted a quantitative method on a sample of employees in the Al-Furat State Company for Chemical Industries affiliated / the Ministry of Industry and Minerals in Iraq. The research’s problem presented a set of questions, one of the most important was (is there a relation and impact between the dimensions of customer knowledge management and sustainable promotion). The aim of the research is to identify the extent to which customer knowledge management activities are applied in understudy organization. This research adopted the questionnaire as a main instrument to collect information from (140) participants in

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Sep 01 2022
Journal Name
Iraqi Journal Of Physics
The Effect of Power on Inductively Coupled Plasma Parameters
...Show More Authors

In this work, we studied the effect of power variation ​​on inductively coupled plasma parameters using numerical simulation. Different values ​​were used for input power (750 W-1500 W), gas temperature 300K, gas pressure (0.02torr),         5 tourns of the copper coil and the plasma was produced at radio frequency (RF) 13.56 MHZ on the coil above the quartz chamber. For the previous purpose, a computer simulation in two dimensions axisymmetric, based on finite element method, was implemented for argon plasma. Based on the results we were able to obtain plasma with a higher density, which was represented by obtaining the plasma parameters (electron density, electric potential, total power, number density of argon ions, el

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Mon Sep 30 2019
Journal Name
College Of Islamic Sciences
Loqmania commandments in the Koran And its impact in the refinement of the doctrine and morals emerging
...Show More Authors

Luqman's story stated that human instinct, if I was brought up properly, reaches wisdom and inflicts the right to everything. It is to go to worship God and adhere to the satisfaction of morals and high morals that are ordered to meet among human beings in this life, because this worship educates in the soul the most beautiful morals needed by human beings of honesty, honesty and modesty, and the work of good and virtues, and distancing the soul from evil and vices.

View Publication Preview PDF
Publication Date
Mon Feb 25 2019
Journal Name
Oriental Journal Of Chemistry
Viscosity and Density Studies of Drugs in Aqueous Solution and in Aqueous Threonine Solution at 298.15 K
...Show More Authors

View Publication
Crossref (2)
Crossref
Publication Date
Fri Nov 30 2018
Journal Name
Oriental Journal Of Chemistry
Viscosity and Density Studies of Drugs in Aqueous Solution and in Aqueous Threonine Solution at 298.15 K
...Show More Authors

Viscosities (η) and densities (ρ) of atenolol and propranolol hydrochloride in water and in concentrations (0.05 M) and (0.1 M) aqueous solution of threonine have been used to reform different important thermodynamic parameters like apparent molal volumes fv partial molal volumes at infinite dilution fvo , transfer volume fvo (tr), the slop Sv , Gibbs free energy of activation for viscous flow of solution ΔG*1,2 and the B-coefficient have been calculated using Jones-Dole equation. These thermodynamic parameters have been predicted in terms of solute-solute and solute-solvent interaction.