Background: Calcium hydroxide and calcium-silicate materials used as direct pulp capping materials. The aims of this in vitro study is to compare among these materials in, the calcium ion release and pH change in soaking water after immersion of materials’ specimens in deionized water. Also Solubility and water sorption of materials’ specimens measured after soaking time. Calcium-silicate materials used were Biodentine, TheraCal and MTA Plus. Materials and methods: Four materials used in this study; Urbical lining (as control group), Biodentine, TheraCal and MTA Plus. Ten discs fabricated from each tested material, by using plastic moulds of 9 mm diameter and 1 mm thickness. Each specimen was immersed in 10 ml of deionized water and stored at 37ºC using incubator for 3 hr, 24hr, 14 days and 30 days as a sequence. The amount of calcium ion (Ca+2) released in soaking water was measured in each tube using atomic absorption spectrophotometer. Also pH analysis for soaking water measured by using pH meter. For solubility and water sorption measurement, the specimen (n=10) weighed with precision weighing scale before immersion in deionzed water to determine the initial Weight (W1) and immediately after weighing immersed in 10 mL of deionized water at 37 °C for 1 week using an incubator, then removed and weighing again (W2). The samples blotted dry using filter paper and dehydrated in an oven at 37 °C for 24 hr. and weighed again (W3). Then percentage of solubility and water sorption were determined. Data obtained were analyzed using one-way ANOVA and Tukey tests at 0.05 significant levels. Results: Statistical analysis showed highly significant differences (P<0. 05) among tested materials and in all tests (Ca+2 release, pH change, solubility and water sorption). Biodentine showed higher calcium ion released at four soaking time (3 hr, 24hr, 14 days and 30 days), with non significant difference with TheraCal and highly significant difference with MTA Plus and control group at 24 hr. immersion time; While MTA Plus showed non significant difference with control group at 24 hr. Less amount of calcium released was in control group. All tested materials induced alkalization of the soaking water that decreased with time. Means of solubility and water sorption showed that MTA Plus and biodentine had higher solubility in comparison with control group, while TheraCal showed less solubility than control group. The results of water sorption showed that less sorption percentage occurred in control group in comparison with other groups. Conclusion: calcium-silicate materials released more Ca+2 with time than calcium hydroxide. TheraCal showed less solubility and higher water sorption in comparison with control group. Biodentine and MTA Plus showed higher solubility and water sorption in comparison with TheraCal and control group.
Rapid worldwide urbanization and drastic population growth have increased the demand for new road construction, which will cause a substantial amount of natural resources such as aggregates to be consumed. The use of recycled concrete aggregate could be one of the possible ways to offset the aggregate shortage problem and reduce environmental pollution. This paper reports an experimental study of unbound granular material using recycled concrete aggregate for pavement subbase construction. Five percentages of recycled concrete aggregate obtained from two different sources with an originally designed compressive strength of 20–30 MPa as well as 31–40 MPa at three particle size levels, i.e., coarse, fine, and extra fine, were test
... Show MoreIn this study, a preliminary economic feasibility study of the project of wind power at the site of Al-Shehabi (Wasit-Iraq) was conducted using measured wind data at altitudes of 10, 30, 50 and 52 m per 10 minutes. For the purpose of comparison, data from NASA were used at the same location at 50 m height. The lowest unit cost of electricity from wind energy was found to be 0.028 $/Kwh and 0.0399 $/Kwh by using the standard methodologies of Levelized Cost of Energy (LCOE) equation and Net Present Value (NPV) procedure, respectively. Furthermore, RETScreen software was used to perform the economic prefeasibility study of a proposed wind farm. The study concludes that this site is economically feasible if a wind fa
... Show MoreMedia writing is accuracy writing. Clarity and concision are its predominant features. It is a writing that goes straight to the essence because it has no time to waste. Furthermore, it must be as accurate as scientific writing. It is destined for the average reader and has to be understood by everyone. However, it can be as elegant as literary writing. The variety in its forms of expression does not prevent media writing from having its own amplitude.
In short, this study is a practical approach that aims at studying different kinds of writing styles and identifying the specificity of media writing using some patterns and examples
In this paper, we have derived Bayesian estimation for the parameters and reliability function of Perks distribution based on two different loss functions, Lindley’s approximation has been used to obtain those values. It is assumed that the parameter behaves as a random variable have a Gumbell Type P prior with non-informative is used. And after the derivation of mathematical formulas of those estimations, the simulation method was used for comparison depending on mean square error (MSE) values and integrated mean absolute percentage error (IMAPE) values respectively. Among of conclusion that have been reached, it is observed that, the LE-NR estimate introduced the best perform for estimating the parameter λ.
The settlement evaluation for the jet grouted columns (JGC) in soft soils is a problematic matter, because it is influenced by the number of aspects such as soil type, effect mixture between soil and grouting materials, nozzle energy, jet grouting, water flow rate, rotation and lifting speed. Most methods of design the jet-grouting column based on experience. In this study, a prototype single and group jet grouting models (single, 1*2, and 2*2) with the total length and diameter were (2000 and 150 mm) respectively and clear spacing (3D) has been constructed in soft clay and subjected to vertical axial loads. Furthermore, different theoretical methods have been used for the estimation
Nations are developed with education and knowledge that raise the status of society in its various segments, beyond that it leads to underdevelopment and deterioration in various sectors, whether economic, health, social, etc. If we considered the general name of The ministry of Education & Scientific Studies, then the second part seems to be not functioning, since scientific research has no material allocation and remains based on the material potential of the university professor. As for the first half of the topic, the reality of the situation reveals problems related to the Holy Trinity of Education which is (Professor - Student - the scientific method) where universities suffer at the present time from this problem, and
... Show MoreNew mode for the on-line determination of oxonium ion in different strong acids using CFIA via the use of homemade linear array Ayah 5Sx4-ST- 5D solar CFI analyser
Surface drip irrigation is one of the most conservative irrigation techniques that help control providing water directly on the soil through the emitters. It can supply fertilizer and providing water directly to plant roots by drippers. One of the essential needs for trickle irrigation nowadays is to obtain more knowledge about the moisture pattern under the trickling source for various types of soil with various discharge levels with trickle irrigation. Simulation numerical using HYDRUS-2D software, version 2.04 was used to estimate an equation for the wetted area from a single surface drip irrigation in unsaturated soil is taking into account water uptake by roots. In this paper, using two soil types were used, namely
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