Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. The material is far from ideal in fulfilling the mechanical requirements. Midline fracture; poor thermal conductivity and water sorption, are common problem in this material. The purpose of this study was to evaluate the effect of addition of surface treated Aluminum oxide nano fillers on some properties of heat cured (PMMA). Materials and methods: In addition to controlled group of heat cured PMMA the silanized (Al2O3) nanoparticles was added to PMMA powder by weight in three different percentages 1wt%, 2wt% and 3wt%, mixed by probe ultra-sonication machine. 200 specimens were constructed and divided into 5 groups according to the test (each group consist of 40 specimens) and each group was subdivided into 4 sub-groups. The tests conducted were thermal conductivity, thermal diffusivity, transverse strength, indentation hardness (shore D), surface roughness, water sorption and solubility. The results were statistically analyzed using ANOVA and Dunntt t-test. Results: A highly significant increase in transverse strength was observed with the addition of (Al2O3) nanoparticles to (PMMA) at the percentage of 1wt%, the value was 117.72 Mpa and significant increase at 2wt%; while a significant reduction occurred in transverse strength at the percentage of 3% the value was 90.110 Mpa. A significant increase in surface hardness and non significant differences in surface roughness were observed for all percentages. Conclusion: The addition of Al2O3 nanoparticles to acrylic resin improves the thermal properties and transverse strength of acrylic resin at the same time this addition decreases water sorption and solubility.
The social networking sites have brought about fundamental changes and a qualitative shift in the marketing industry and its strategies. The Iraqi ministries have used this site i.e. Facebook to spread and disseminate values in order to consolidate it in Iraqi society which has witnessed many changes in all aspects of life.
The researcher studies the pages of both ministries to know the values contained in the publications of the pages of these two ministries, the quality of grooming as well as the forms in which these values are marketed.
The researcher uses a survey method and content analysis for the publications of these two pages during the study period starting from January 1, 2
... Show MoreAllah legislated marriage and made it dwelling, fellowship and mercy between
the two couples, Prophet Moh'd (peace of Allah and blessing be upon him) ordered a
husband to look after his wife, treat her with full charity and make love with here
every kindly. On the other hand, he ordered a wife to obey her husband and respect
him deeply, nevertheless, some obstacles may sometimes be appeared within the life
of their marriage, this may be caused by either a husband or a wife. This problem is
called lifely disobedience (AL-Noshooz).
In the other words, this means that a wife begins to hate her husband, refuse his orders
and not obey him.
In brief, they hate each other which leads to some marks appear in their
m
Il semble que Khattabi était un linguiste, avec un endroit linguistique pour comprendre les textes de conversations et des mots étranges en particulier. Langue, et chacun avait ses arguments et ses preuves. Ses corrections incluaient la mélodie dans les mouvements, telle qu'une dilution plus serrée, la dilution de l'agitateur, le remplacement d'un autre mouvement, ou une autre rotation des mouvements, et le changement de structure morphologique du mot qui en résultait, ainsi que l'alerte sur les conséquences des lettres, Certaines de ces erreurs sont dues à la langue, et certaines sont considérées comme un type de déformation ou de fausse représentation connue de certains spécialistes, ce qui constitue un précédent louable
... Show MoreEvery researcher must say that the world in continually progress toward the best and that
the Arab and Islamic civilization had produced much of systems and virtuous educational
practices which raised from Islamic heritage. This nation was not isolated from external
world, but it was made a clear active for promote the banner of other nations which entered
under her influence to promote Islamic banner and Muslims. Consequently also Muslims are
affected and influenced, this resulted a clear impact in the civilization and educational
ideology especially in the contemporary teaching methods.
The effected of the long transmission line (TL) between the actuator and the hydraulic control valve sometimes essentials. The study is concerned with modeling the TL which carries the oil from the electro-hydraulic servovalve to the actuator. The pressure value inside the TL has been controlled by the electro-hydraulic servovalve as a voltage supplied to the servovalve amplifier. The flow rate through the TL has been simulated by using the lumped π element electrical analogy method for laminar flow. The control voltage supplied to servovalve can be achieved by the direct using of the voltage function generator or indirect C++ program connected to the DAP-view program built in the DAP-card data acqu
... Show MoreAlgae are photosynthetic microorganisms that play important role in aquatic ecosystems as they are the primary producers in aquatic food webs. Several groups of algae are capable of producing toxins that impact aquatic ecosystems, especially managed systems. Cyanobacteria are the most important algae in freshwaters, and many species produce cyanotoxins including hepatotoxins and neurotoxins. The potent cyano-neurotoxins β-N-methylamino-L-alanine (BMAA), 2, 4-diaminobutyric acid dihydrochloride (DABA), and anatoxin-a are especially critical with regards to public and animal health problems.
The: currency Auction is one of the monetary policy tools created after 2003, in order to keep pace with the changes that the monetary and financial policies will witness from financial openness and expectations of high levels of liquidity after international economic restrictions. It is necessary to re-evaluate the work of the currency Auction from time to time and observation its efficiency in adjustment the exchange rate And its reflection on the general level of prices as one of the objectives of its inception, and during the analytical aspect, it was confirmed that the currency Auction for selling the currency had a major role in adjustment the exchange rate and controlling inflation levels, due to the market’s dependence
... Show MoreThis paper is a review of the genus Sitta in Iraq, Five species of this genus are recognized
Sitta kurdistanica, S. neumayr, S. europaea, S.dresseri and S. tephronota. Geographical
distribution and systematic nots were given for separation and identification, also some notes
on nest building and nest sites of S. tephronota supporting by figures are presented.
The aim of this research is to employ the roundhouse strategy to study its impact on the students achievement of the 10th grade in physics and their core thinking. After the application of the research experience and gaining data, which was processed statistically using the statistical packages program (SPSS). The results of the researcher revealed the superiority of the students of the experimental group who studied using the roundhouse strategy on the students of the control group who studied the usual method in the achievement test. As results showed that there were statistically significant differences between the average scores of the experimental group and the average scores of the control group students in the core thinking test and
... Show MoreIlliteracy has spread in the last years, although it was eliminated in the 1980s. The return of illiteracy brings ignorance, illness, backwardness and regression among nations. It has taken many types, mainly alphabetical, scientific and computer illiteracy. Hence, the increasing nature of illiteracy has attracted the attention of governments and societies alike. This may touch the reality of societies starting with their youth unless those, who are in charge, will find workable solutions for the existing problems. The results of the study revealed that there is a real disaster awaiting the next generation after years of stray, and ignorance of the people in charge who are too engaged in getting their privileges to care about this proble
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