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.
Basic orientation is to look at identifying conceptual perspective to market self-research and descriptive, as has the marketing theme for the same attention in the practical side before endo scopic In recent years, is marketing an integrated and holistic included many areas not limited to the marketing of goods and services, and even included the marketing of religion, politics and individuals for themselves, as the awareness and concepts that seep into the soul of man from its inception until his arrival to the stage of owning a level of skills or expertise, scientific or all of those things degrees mixed with ambition and aspiration for self-realization takes way to search for opportunities or created, often observe individual
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In this study, the response and behavior of machine foundations resting on dry and saturated sand was investigated experimentally. A physical model was manufactured to simulate steady state harmonic load applied on a footing resting on sandy soil at different operating frequencies. Total of (84) physical models were performed. The parameters that were taken into consideration include loading frequency, size of footing and different soil conditions. The footing parameters are related to the size of the rectangular footing and depth of embedment. Two sizes of rectangular steel model footing were used. The footings were tested by changing all parameters at the surface and at 50 mm depth below model surface. Meanwhile, the investigated paramete
... Show MoreThe optical transmission and absorption spectra in UV-VIS were recorded in the wavelength range 350-800 nm for different glass compositions in the system: (CuO)x (PbO)50-x (Bi2O3)50 (x=2.5, 5.0, 7.5, 10.0, 12.5, 15.0, 20.0). Absorption coefficient {α (λ)}, optical energy gap (Eopt), refractive index (n), optical dielectric constant (ε`), Urbach energy (Ee), constant B and ratio of carrier concentration to the effective mass (N/m) have been reported. The effects of compositions of glasses on these parameters have been discussed. It has been indicated that a small compositional modification of the glasses lead to an important change in all the optical properties including non-linear behavior. The optical parameters were found to b
... Show MoreThe present study was undertaken to determine the species of tumbling flower beetles (Coleoptera, Mordellidae) found in Iraq. Specimens have been collected from different localities of Iraq since 1970. Results show that the tumbling flower beetles (Mordellidae) are represented with a total of 13 species belonging to four genera of three tribes, two of these species were described by Dr. Horak (1985,1990) as new species for Iraq Mediimorda maceki HoraK and Mordellistena bolognaHorak; two were previously reported Stenalia escherichi Schilsk and Mordellistena pumila (Gyllenhal) and ten are new records for Iraq. Stenalia araxicola Khnzorian, Stenalia brunneipennis Mulsant, Variimorda
... Show MoreThe purpose of this paper is to present an approach to compute accurately the distributions of the frictional heat generated, contact pressure and thermal stresses at any instant during the sliding period (heating phase) of the single-disc friction clutch system works in the dry condition and the complex interaction among them.
Numerical work was achieved using the developed elastic and thermal finite element models (axisymmetric models) to simulate the engagement of the single-disc friction clutch system.
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Objective:
This study aims to asses the patients' compliance with essential hypertension in respect to antihypertensive
medications, follow-up, dietary pattern and health habits, to identify the associated long-term complications, and
to find out the relationship between patient's compliance, and demographic characteristics such as age, gender,
level of education, and duration of disease.
Methodology:
A descriptive study was carried out in Nasiriyah Teaching Hospital to achieve presented objectives .
Results:
The results of the study revealed that there were a significant association between educational level and total
patient's compliance, a significant association was found between the duration of disease and
Drilling well design optimization reduces total Authorization for Expenditures (AFE) by decreasing well constructing time and expense. Well design is not a constant pattern during the life cycle of the field. It should be optimized by continuous improvements for all aspects of redesigning the well depending on the actual field conditions and problems. The core objective of this study is to deliver a general review of the well design optimization processes and the available studies and applications to employ the well design optimization to solve problems encountered with well design so that cost effectiveness and perfect drilling well performance are achievable. Well design optimization processes include unconventional design(slimhole) co
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Objective:
This study aims to asses the patients' compliance with essential hypertension in respect to antihypertensive
medications, follow-up, dietary pattern and health habits, to identify the associated long-term complications, and
to find out the relationship between patient's compliance, and demographic characteristics such as age, gender,
level of education, and duration of disease.
Methodology:
A descriptive study was carried out in Nasiriyah Teaching Hospital to achieve presented objectives .
Results:
The results of the study revealed that there were a significant association between educational level and total
patient's compliance, a significant association was found between the duration of disease and
In this paper a nonlinear adaptive control method is presented for a pH process, which is difficult to control due to the nonlinear and uncertainties. A theoretical and experimental investigation was conducted of the dynamic behavior of neutralization process in a continuous stirred tank reactor (CSTR). The process control was implemented using different control strategies, velocity form of PI control and nonlinear adaptive control. Through simulation studies it has been shown that the estimated parameters are in good agreement with the actual values and that the proposed adaptive controller has excellent tracking and regulation performance.