Background: Color stability of glass ionomers (GIs) could be affected by many factors such as pH and consumption of liquid medications like antibiotics. Most common antibiotics used during childhood are amoxicillin suspension (AM.S) and azithromycin suspension (AZ.S) which have acidic and basic pH respectively. Aim: to evaluate and compare the effect of AM.S and AZ.S on color stability of nano resin-modified GI. Methods: Thirty disc of nano resin-modified glass ionomer (2mm height x 4mm diameter) were divided into three groups (n=10 for each) and independently exposed to AM.S, AZ.S, and artificial saliva (A.S.). Color stability was evaluated in triplicate by VITA Easyshade® before and after three immersion protocols, repeated over a three-week duration with two-days intervals. In each protocol, samples were exposed for two minutes, three times daily for AM.S, once daily for AZ.S, and A.S. full day. GI discs rinsed off after each immersion and kept in artificial saliva until next immersion period. Results: One way ANOVA test and Post-hoc analysis of the changes in color space compartments of nano-resin modified GI samples demonstrated just a significant change (p˂0.05) in yellow-blue axis (Δb*) value after immersion in AM.S in comparison with A.S. Total Color change values (ΔE) of nano resin-modified glass ionomer samples also illustrated a significant effect (p˂0.05) between AM.S and A.S. only. The highest (ΔE) value was recorded for samples immersed in AM.S (ΔE =12.5) followed by AZ.S (ΔE=6.5) while the lowest was recorded for A.S. (ΔE=1.1). Conclusion: AM.S (the acidic medication) exhibited a higher staining effect to nano-resin modified GI samples when compared with AZ.S (the basic medication). Several factors such as low pH, more exposure time and coloring material of the immersion media added critical roles in coloring instability.
Willa Cather (1873-1947) sought to capture the gradation of human emotion through carefully selected descriptive and narrative touches and firmly controlled management of dramatic scenes, situations, dialogue, and point of view. Cather’s novels and stories drew increasingly upon her personal experiences and memories.
The old settlement of Virginia and the new lands of Nebraska formed the bedding ground for Willa Cather’s talents; so did the layers of memory she found across the North American continent, from New Mexico to Canada. She saw the full-blooded European immigrants, Czechs and Swedes, plowing the unbroken land, on the way up from peasants to proprietors.
 
... Show MoreThe aim of this study was to compare the effect of conventional implant site preparation technique and a combination of conventional/piezosurgery preparation on implant stability measured at different time intervals, insertion torque, and preparation time. A randomized controlled study was designed, it included 26 patients who received 54 dental implants randomly assigned to 2 groups; in the control group, implants were installed after conventional preparation with drills whereas the study group received implants after mixed conventional/piezosurgery preparation. The outcome variables included: implant stability measured immediately after implant insertion, at 8 weeks and 16 weeks postoperatively, insertion torque and preparation time. All
... Show MoreA variety of oxides were examined as additives to a V2O5/Al2O3 catalyst in order to enhance the catalytic performance for the vapor phase oxidation of toluene to benzoic acid. It was found that the modification with MoO3 greatly promoted the little reaction leading to improve catalyst performance in terms of toluene conversion and benzoic acid selectivity. The effect of catalyst surface area, catalyst promoters, reaction temperature, O2/toluene, steam/toluene, space velocity, and catalyst composition to catalyst performance were examined in order to increase the benzoic acid selectivity and yield.
Moisture induced damage in asphaltic pavement might be considered as a serious defect that contributed to growth other distresses such as permanent deformation and fatigue cracking. This paper work aimed through an experimental effort to assess the behaviour of asphaltic mixtures that fabricated by incorporating several dosages of carbon fiber in regard to the resistance potential of harmful effect of moisture in pavement. Laboratory tests were performed on specimens containing fiber with different lengths and contents. These tests are: Marshall Test, the indirect tensile test and the index of retained strength. The optimum asphalt contents were determined based on the Marshall method. The preparation of asphaltic mixtures involved
... Show MoreRutting is a predominant distress in asphalt pavements, particularly in hot climatic regions. This study systematically investigated the high-temperature performance of hot mix asphalt modified with five nanomaterials, namely, nano-silica (NS), nano-alumina (NA), nano-titanium (NT), nano-zinc (NZ), and carbon nanotubes (CNTs), under consistent laboratory conditions. Modification dosages were selected up to 10% for NS, NA, and NT, and up to 5% for NZ and CNTs. The experimental methodology comprised the following: (i) binder rheological characterization through rotational viscosity, G*/sinδ, and multiple stress creep recovery (MSCR) to quantify rutting susceptibility; (ii) chemical and microstructural assessments using Fourier transf
... Show MoreThis research studied the effect of magnetized water in concrete preparation and its effect on the presenting of cement in concrete mixtures also to find the ability of reducing the amount of cement in preparing one cubic meter, this is not exceed than 10% in one mixture , The experiments showed the preparation of standard cubes from the concrete which was used two kind of water magnetized water which was prepared by passing the tap water through the systems of different magnetic strength in terms of (6000,9000) Gauss and the ordinary water . The velocity of water through the magnetic field, which gives us the highest value for the compressive strength, was up to 1m/sec. to determine the best magnetic intensity, we examined The comp
... Show MoreThe modern teaching methods, and their importance in achieving the desired learning goals for the individual and the society, have been addressed, as it is necessary to develop the methods, ways and strategies used in the process of teaching the intermediate stages in the various fields in general and the field of physical education in particular, the importance of research is the effect of using the strategy of similarities in teaching some basic skills of basketball for students of the second intermediate. As for the problem of research, the researcher mentioned the lack of use of teachers’ strategy method similarities in the educational units because of its importance, and after study and analysis the researcher found it necessary to i
... Show MoreAmong the different passive techniques heat pipe heat exchanger (HPHE) seems to be the most effective one for energy saving in heating ventilation and air conditioning system (HVAC). The applications for nanofluids with high conductivity are favorable to increase the thermal performance in HPHE. Even though the nanofluid has the higher heat conduction coefficient that dispels more heat theoretically but the higher concentration will make clustering .Clustering is a problem that must be solved before nanofluids can be considered for long-term practical uses. Results showed that the maximum value of relative power is 0.13 mW at nanofluid compared with other concentrations due to the low density of nanofluid at this concentration. For highe
... Show MorePure nano Ferro fluid was synthesized by chemical co-precipitation method. The composite of polyaniline with nano sized Ferro fluid was prepared by In-situ–chemical oxidation polymerization method with ammonium per sulphate as an oxidant in aqueous hydrochloric acid under constant stirring at room temperature. The optical properties, absorption, transmission, optical energy gap (Eg) and optical constant refractive index (n) have been investigated. The value of the Eg decreased with increasing Ferro fluid concentration.