Preferred Language
Articles
/
jbcd-943
The Influence of Different Fabrication Techniques and Preparation Designs on the Marginal Adaptation of Ceramic Veneers (An In vitro Comparative Study)
...Show More Authors

Background: Ceramic veneers represent the treatment of choice in minimally invasive esthetic dentistry; one of the critical factors in their long term success is marginal adaptation. The aim of the present study is to evaluate the marginal gap of ceramic veneers by using two different fabrication techniques and two different designs of preparation. Material and methods: A typodont maxillary central incisor used in the preparation from which metal dies were fabricated, which were in turn used to make forty stone dies. The dies divided into four experimental groups, each group had ten samples: A1: prepared with butt-joint incisal reduction and restored with IPS e.max CAD, A2: prepared with overlapped incisal reduction and restored with IPS e.max CAD. B1: prepared with butt-joint incisal reduction restored with IPS e.max press. B2: prepared with overlapped incisal reduction and restored with IPS e.max press. The marginal gap was measured with direct view technique using digital microscope at a magnification of 230x. Measurements were recorded for four surfaces for each sample and the maximum value was taken to represent that sample. Results: The data were analyzed with two-way ANOVA and independent samples t-tests. These tests revealed highly significant effects of both the preparation design and the technique of fabrication on the marginal gap (p=0.00), with CAD/CAM veneers, group A1 recorded the least marginal gap and pressing group, B2 showed the highest gap values. There was no significant effect of the interaction between the two parameters on the marginal gap. Conclusion: the CAD/CAM veneers with butt joint incisal reduction produced the most accurate margins while the least favorable combination was the pressable ceramic veneers with overlapped incisal reduction.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Jan 01 2014
Journal Name
Ibn Al- Haitham J. Fo R Pure & Appl. Sci
Multiple Mixing Ratios of Gamma Rays Reaction 32 70 70 33 Ge p n As (, ) γ Using a2-ratio Method.
...Show More Authors

The δ-mixing of γ-transitions in 70As populated in the 32 70 70 33 Ge p n As (, ) γ reaction is calculated in the present work by using the a2-ratio methods. In one work we applied this method for two cases, the first one is for pure transition and the sacend one is for non pure transition, We take into account the experimental a2-coefficient for previous works and δ -values for one transition only.The results obtained are, in general, in a good agreement within associated errors, with those reported previously , the discrepancies that occur are due to inaccuracies existing in the experimental data of the previous works.

Publication Date
Sun Sep 04 2016
Journal Name
Baghdad Science Journal
Degradation of Brilliant Green by Using a bentonite Clay- Based Fe Nano Composite Film as a Heterogeneous Photo- Fenton Catalyst.
...Show More Authors

This paper aims to study the chemical degradation of Brilliant Green in water via photo-Fenton (H2O2/Fe2+/UV) and Fenton (H2O2/Fe2+) reaction. Fe- B nano particles are applied as incrustation in the inner wall surface of reactor. The data form X- Ray diffraction (XRD) analysis that Fe- B nanocomposite catalyst consist mainly of SiO2 (quartz) and Fe2O3 (hematite) crystallites. B.G dye degradation is estimated to discover the catalytic action of Fe- B synthesized surface in the presence of UVC light and hydrogen peroxide. B.G dye solution with 10 ppm primary concentration is reduced by 99.9% under the later parameter 2ml H2O2, pH= 7, temperature =25°C within 10 min. It is clear that pH of the solution affects the photo- catalytic degradation

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Oct 30 2018
Journal Name
Acs Omega
Catalytic Hydrogenation of <i>p</i>-Chloronitrobenzene to <i>p</i>-Chloroaniline Mediated by γ-Mo<sub>2</sub>N
...Show More Authors

Promoting the production of industrially important aromatic chloroamines over transition-metal nitrides catalysts has emerged as a prominent theme in catalysis. This contribution provides an insight into the reduction mechanism of p-chloronitrobenzene (p-CNB) to p-chloroaniline (p-CAN) over the γ-Mo2N(111) surface by means of density functional theory calculations. The adsorption energies of various molecularly adsorbed modes of p-CNB were computed. Our findings display that, p-CNB prefers to be adsorbed over two distinct adsorption sites, namely, Mo-hollow face-centered cubic (fcc) and N-hollow hexagonal close-packed (hcp) sites with adsorption energies of −32.1 and −38.5 kcal/mol, respectively. We establish that the activation of nit

... Show More
View Publication
Scopus (14)
Crossref (15)
Scopus Clarivate Crossref
Publication Date
Mon Jun 05 2023
Journal Name
Al-khwarizmi Engineering Journal
Removal of Malachite Green from Aqueous Solution using Ficus Benjamina Activated Carbon-Nonmetal Oxide synthesized by pyro Carbonic Acid Microwave
...Show More Authors

Activated carbon derived from Ficus Binjamina agro-waste synthesized by pyro carbonic acid microwave method and treated with silicon oxide (SiO2) was used to enhance the adsorption capability of the malachite green (MG) dye. Three factors of concentration of dye, time of mixing, and the amount of activated carbon with four levels were used to investigate their effect on the MG removal efficiency. The results show that 0.4 g/L dosage, 80 mg/L dye concentration, and 40 min adsorption duration were found as an optimum conditions for 99.13% removal efficiency. The results also reveal that Freundlich isotherm and the pseudo-second-order kinetic models were the best models to describe the equilibrium adsorption data.

 

View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Wed Mar 30 2022
Journal Name
Iraqi Journal Of Science
1-D Simulation of Ultrafast-Pulsed Laser into Nano-Sized Multilayered Structure (Ni81Fe19/Cu/YIG/GGG) for Memory Device Applications
...Show More Authors

     Spintronic offers a solution by exploiting spin instead of electron charge since spin current propagation can occur in principle without dissipation. One of the applications involve within this project for storage media is heat-assisted magnetic recording (HAMR). The objective of this study is to simulate the behavior of thermal gradient to generate a pure spin current using an ultrafast femtosecond (fs) laser in a nano-sized  multilayered structure of (Al2O3/Ni81Fe19 (Py)/Cu/Y3Fe5O12 (YIG)/Gd3Ga5O12 (GGG)) at room temperature. A ferromagnetic/spacer/magnetic insulator nano-sized multilayered is the proposed structure f

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Using Activated Carbon developed from Iraqi Date Palm Seeds as Permeable Reactive Barrier for Remediation of Groundwater Contaminated with Copper
...Show More Authors

The possibility of using activated carbon developed from date palm seeds wastes as a permeable reactive barrier (PRB) to remove copper from polluted shallow groundwater was investigated. The activated carbon has been developed from date palm seeds by dehydrating methods using concentrated sulfuric acid. Batch tests were performed to characterize the equilibrium sorption properties of new activated carbon in copper-containing aqueous solutions, while the sandy soil (aquifer) was assumed to be inert. Under the studied conditions, the Langmuir isotherm model gives a better fit for the sorption data of copper by activated carbon than other models. At a pilot scale, One-dimensional column experiments were performed, and an integrated model ba

... Show More
View Publication Preview PDF
Publication Date
Thu Nov 02 2023
Journal Name
Journal Of Engineering
Optimum Reinforcement Depth Ratio for Sandy Soil Enhancement to Support Ring Footing Subjected to a Combination of Inclined-Eccentric Load
...Show More Authors

This work investigates the impacts of eccentric-inclined load on ring footing performance resting on treated and untreated weak sandy soil, and due to the reduction in the footing carrying capacity due to the combinations of eccentrically-inclined load, the geogrid was used as reinforcement material. Ring radius ratio and reinforcement depth ratio parameters were investigated. Test outcomes showed that the carrying capacity of the footing decreases with the increment in the eccentric-inclined load and footing radius ratio. Furthermore, footing tilt and horizontal displacement increase with increasing the eccentricity and inclination angle, respectively. At the same time, the increment in the horizontal displacement due t

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Dec 30 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Sy nthesis of Some New Schifrs-Bases Derived From 2-(4-m ethoxy phenyl)-5- (4-amino phenyl)-1,3,4-0xadiazole
...Show More Authors

A new compound  2-(4-methoxyphcnyl)-5-(4-aminophenyl)-1,3,4-

oxadiazole (VI) was prepared by intramol ecular condensation reaction followed  by elimination  of some simple  moieties such  as IhO  and HCI by using  POCI3 with acid hydrazide. A series of new Shiffs­

bases 2-(4-methoxyphenyl)-5-[4(4:alkoxybenzoyloxy) benzylidene amino phenyl] I,3,4-oxadia:t.ole (VII].was synthesized from treatment

of oxadiazole derivative [VI] with an appropriate  aromatic aldehyde

(IU). Struct\lfe of the resulting products have been ascertaim:d by their melting pointS, elemental analysis ( some of them) and spectral data.

 

View Publication Preview PDF
Publication Date
Fri Nov 24 2023
Journal Name
Iraqi Journal Of Science
Using Ultrasonic Technique to Measure Some Petrophysical Properties of Yamama Formation at Ratawi-7 Oil Well Core Samples, Southern Iraq
...Show More Authors

Twenty nine core samples were taken from Ratawi 7 Oil well according to the presence of oil in formation and availability of core samples. This well is located in the province of Basra/southern Iraq. The samples were collected from Yamama Formation. The core samples are taken from the well at different depths, ranging between (3663m-3676m). The range of Vp for these core samples is (668-4017 m/sec) and its average is (1779 m/sec), While the range of Vs is (291-1854 m/sec) and its average is (796 m/sec). In the current study the ultrasonic method is conducted to measure Vp, Vs as well as some petrophysical properties for core samples and some elastic moduli such as (Young's modulus, Bulk modulus, Shear modulus, Poisson's ratio and Lame's

... Show More
View Publication Preview PDF
Publication Date
Fri Feb 28 2020
Journal Name
Neuroquantology
Using X-Ray Films for Evaluation efficiency of Unsaturated Polyester Reinforced by Lead Oxide as Shielding for Medical X-ray Devices
...Show More Authors

The largest use of x-ray in medical by dentists, employers or persons that needed by patients with specific conditions, lead to higher exposure of x-ray that may cause many diseases. In the present work radiography films have been used in evaluating the efficiency of using unsaturated polyester polymer reinforced with lead oxide (PbO) as shield material for medical x-ray devices, many parameters studied like concentration and thickness that they are increasing the attenuation of x-ray in them. The results show that the attenuation of X-ray increasing with concentration of reinforced material and with thickness, and the optical density decreases with increasing concentration from 0% to 50%, we chose 30% as suitable concentration to increase

... Show More
View Publication
Scopus Crossref