Background: Porcelain veneers are under a great deal of stress which may lead to clinical failure as fracture or dettachment. This study examined whether different finishing lines and lingual shoulder preparations in the incisal area of the maxillary central incisor affect the bond of the porcelain veneers. Materials and methods: A two- dimensional finite element model was made. Location and magnitude of maximum Von Mises stresses were calculated in porcelain veneer. Six types of preparations were drawn as:incisal overlap of 0.5mm, 1mm and 1.5mm depth and lingual shoulder, and incisal overlap of 0.5mm, 1mm and 1.5mm depth without shoulder preparation. Results: Stress formation is maximum in the incisal edge region. All the lingual shoulder preparations presented better stress distribution than the non shoulder preparations Conclusion: Stress is distributed more evenly when the tested preparation possesses a good thickness of porcelain and the more the surface area with incisal overlap the less possibility of bond failure.
The analysis and efficiency of phenol extraction from the industrial water using different solvents, were investigated. To our knowledge, the experimental information available in the literature for liquid-liquid equilibria of ternary mixtures containing the pair phenol-water is limited. Therefore the purpose of the present investigation is to generate the data for the water-phenol with different solvents to aid the correlation of liquid-liquid equilibria, including phase diagrams, distribution coefficients of phenol, tie-lines data and selectivity of the solvents for the aqueous phenol system.
The ternary equilibrium diagrams and tie-lines
... Show More
(5)
(5)
In this paper different channel coding and interleaving schemes in DS/CDMA system over multipath fading channel were used. Two types of serially concatenated coding were presented. The first one composed of Reed-Solomon as outer code, convolutional code as inner code and the interleaver between the outer and inner codes and the second consist of convolutional code as outer code, interleaved in the middle and differential code as an inner code. Bit error rate performance of different schemes in multipath fading channel was analyzed and compared. Rack receiver was used in DS/CDMA receiver to combine multipath components in order to enhance the signal to noise ratio at the receiver.
The high viscosity of heavy oil is a crucial factor that strongly affects its up-stream recovering, down-stream surface transporting and refining processes. Economical methods for recovering the heavy oil and reducing is very important and related to capital and/or operating cost. This research studies the treatment of Iraqi heavy crude oil, which characterize with high viscosity and low API which makes transportation of heavy crude oil a difficult mission, needs for treatment to reduce viscosity for facilitating transportation and processing. Iraqi heavy crude oil was used Sharqi Baghdad, which obtained from Baghdad east oil fields with API 22.2º.Many kinds of additives were used to reduce the viscosity, experiments were performed o
... Show More
(4)
A simple, accurate and rapid method for separation and determination of most commonly usedinsecticides in Iraq [thiamethoxam (Thi), imidacloprid (Imi), indoxacarb (Ind), and abamectin (Aba)] ispresented. The separation was performed by gradient reversed-phase high performance liquidchromatography on a C18 stationary phase column. The method was developed and validated. The-1mobile phase was a mixture of acetonitrile and water using gradient flow. The flow rate was 1.0 mL min .The optimum temperature of separation was 25 ºC. The detection was performed at multiple wavelengths.The analysis time was up to 10.5 minutes with retention times of 3.221, 3.854, 6.385, and 9.452 min for-1the studied insecticides. The linearity was in the range of 0.
... Show More
(9)
(9)
The possible effects of COVID-19 vaccines on reproductive health and male fertility in particular have been discussed intensely by the scientific community and the public since their introduction during the pandemic. On news outlets and social media platforms, many claims have been raised regarding the deleterious effects of COVID-19 vaccines on sperm quality without scientific evidence. In response to this emerging conflict, we designed this study to evaluate and assess the effect of the Pfizer-BioNTech mRNA COVID-19 vaccine on male fertility represented by the semen analysis parameters.
... Show More
(18)
(16)
The purpose of this research is to design a list of the scientific and moral values that should be found in the content of the computer textbook for the second intermediate grade, as well as to analyze the content of the above- mentioned book by answering the following question:
What is the percentage of availability of scientific and moral values in the content of the computer textbook for Second Intermediate grade issued by the Iraqi Ministry of Education / the general directorate of the curriculum, for the academic year (2017-2018)?
In order to achieve the research objectives, the descriptive method (content analysis method) was adopted. The research community has been iden
... Show MoreThe tax system, like any other system, as a set of elements and parts that complement each other and are interrelated and interact to achieve specific goals, and is a natural reflection of the economic, social and political conditions prevailing in society, and therefore the objectives of tax policy formulated in line with the objectives of economic policy in general, which means that any change in economic policy clearly affects fiscal policy measures and fiscal policy in particular.
The problem of searching for the impact of foreign direct investment in the Iraqi tax system was focused on the study the of foreign direct investment and therole played in developing and improving the economic reality and its implicatio
... Show More
The research aims to measure the efficiency of health services Quality in the province of Karbala, using the Data Envelopment analysis Models in ( 2006). According to these models the degree of efficiency ranging between zero and unity. We estimate Scale efficiency for two types of orientation direction, which are input and output oriented direction.
The results showed, according Input-oriented efficiency that the levels of Scale efficiency on average is ( 0.975), in the province of Karbala. While the index of Output-oriented efficiency on average is (o.946).