Background: The treatment of dental tissues proceeding to adhesive procedures is a crucial step in the bonding protocol and decides the clinical success ofrestorations. This study was conducted in vitro, with the aim of evaluating thenanoleakage on the interface between the adhesive system and the dentine treated by five surface modalities using scanning electron microscopy and energydispersiveX-ray spectrometry. Materials and methods: Twenty five extracted premolars teeth were selected in the study. Standardized class V cavities were prepared on the buccal and lingual surfaces then the teeth divided into five main groups of (5 teeth in each group n=10) according to the type of dentine surface treatment that was used: Group (A): dentine was conditioning with Er, Cr: YSGG laser. Group (B): dentine was conditioning with (Er, Cr: YSGG laser + acid). Group (C): dentine was conditioning with (acid + Er, Cr: YSGG laser). Group (D): dentine was conditioning with acid etch. Group (E): dentine was conditioning with acid + 10% sodium hypochlorite. For All the teeth SBMP adhesive were used and restored with Z250 composite restoration then all specimens were subjected to thermocycling 500 cycles, at 5° to 55 °C. The teeth were soaked in silver nitrate suspension. Then the teeth sectioned bucco-lingually across the centre of the restorations. The specimens were characterized using scanning electron microscopy and the amount of nanoleakage was measured by EDX spectro-analysis to identify the existence of metallic silver particles. Results: Data were analysed statistically by one way ANOVA test and (LSD) Tests. The results showed that there were statistically highly significant differences among all groups of the present study.The resultshowed that the acid and laser (group III) exhibited the lowest mean value of nanoleakage at around (6.14 %), whereas the highest mean value of nanoleakage (12.83 %) was determined by the only acid (group IV). Conclusions: Treating the acid etched dentine with Er: Cr: YSGG laser showed promising results as it exhibits lowest amount of nanoleakage of the adhesive bonding system.
This paper reports an experimental study regarding the influence of vertical oscillations on the natural convection heat transfer from a vertical channel. An experimental set-up was constructed and calibrated; the vertical channel was tested in atmosphere at 25o
C. The channel-to-ambient temperature difference was varied with the power supply to the electrical heater ranging between
15W to 70W divided into five levels. Data sets were measured under different operating condition from a test rig under six vibrating velocities (VVs) levels ranging from (5-30 m/s) in addition to the stationary state. The results show that the maximum heat transfer enhancement factor (E) occurs at Rayleigh number (Ra=2.328×103 ) and vibrational Reynol
This paper presents a method to organize memory chips when they are used to build memory systems that have word size wider than 8-bit. Most memory chips have 8-bit word size. When the memory system has to be built from several memory chips of various sizes, this method gives all possible organizations of these chips in the memory system. This paper also suggests a precise definition of the term “memory bank” that is usually used in memory systems. Finally, an illustrative design problem was taken to illustrate the presented method practically
Fine aggregates used for concrete works in Sulaymaniyah city frequently fail to meet the standard requirements for gradation and fineness modulus in cement concrete. This paper aims to critically evaluate gradation, fineness modulus, and clay contents of various natural sands produced and used for concrete work in the region. Sixteen field sand samples were collected from various sites in Darbandikhan (5 samples), Qalat Dizah (5 samples), Koysinjaq (5 samples), and Piramagroon (1 sample) confirming to ASTM D75. The field samples were parted into test specimens based on ASTM C702. Then, sieve analysis was carried out on the oven-dry test specimens in compliance with ASTM C136. The test results of fine aggregates wer
... Show MoreBackground: Indeterminate colitis (IC), a term
originated by pathologists to characterize confounding
histopathlogic appearance of resected mucosa, has
become catch phrase for cases in which diagnostic
criteria at all levels elude classification as Crohn's
disease (CD) or ulcerative colitis (UC).
OBJECTIVES: evaluate the prevalence of pANCA
expression in the sera and its isotypes.
Patients and methods: PATIENTS GROUP
consisted of 60 patients (40 males and 20 females)
with indeterminate colitis and their age range was (19-
84 years). CONTROL GROUP consisted of 30 (15
males and 15 females) healthy volunteers and their
age range was (20- 66 years).
Antineutrophil cytoplasmic ( pANCA and cANCA)
te
Tira is a custom known to the Arabs since the pre-Islamic era. in the occurrence of good or evil. And from the pessimism: that the Arabs in the pre-Islamic era depended on birds, so if one of them went out for a matter, If he sees a bird flying to the right, he will believe in him and go on his journey and his need. The research aims to introduce Imam Al-Manawi and explain his saying in Al-Tira through his book Fayd Al-Qadeer.
The advancements in horizontal drilling combined with hydraulic fracturing have been historically proven as the most viable technologies in the exploitation of unconventional resources (e.g., shale and tight gas reservoirs). However, the number of fractures, well timing, and arrangement pattern can have a significant impact on the project economy. Therefore, such design and operating parameters need to be efficiently optimized for obtaining the best production performance from unconventional gas reservoirs. In this study, the process of selecting the optimal number of fractures was conducted on a section of a tight gas reservoir model (based on data from the Whicher Range (WR) tight gas field in Western Australia). Then, the optimal number
... Show MoreThe experimental and theoretical methods were studied for inhibition of the corrosion titanium in HCl by using neomycin sulfate drug. The results of neomycin sulfate drug had good corrosion protection for titanium in hydrochloric acid and the inhibition efficiency (%IE) increasing with increasing concentration of drug because the neomycin sulfate drug had adsorption from acid solution on surface of titanium metal. The program of hyperchem-8.07 was used for theoretical study of the drug by molecular mechanics and semi-empirical calculations. Quantum chemical was studied drug absorption and electron transferred from the drug to the Titanium metal, also inhibition potentials of drug attachment with the (LUMO-HOMO) energy gap,
... Show MoreVisualization of subsurface geology is mainly considered as the framework of the required structure to provide distribution of petrophysical properties. The geological model helps to understand the behavior of the fluid flow in the porous media that is affected by heterogeneity of the reservoir and helps in calculating the initial oil in place as well as selecting accurate new well location. In this study, a geological model is built for Qaiyarah field, tertiary reservoir, relying on well data from 48 wells, including the location of wells, formation tops and contour map. The structural model is constructed for the tertiary reservoir, which is an asymmetrical anticline consisting of two domes separated by a saddle. It is found that
... Show MoreThis paper is concerned with the blow-up solutions of a system of two reaction-diffusion equations coupled in both equations and boundary conditions. In order to understand how the reaction terms and the boundary terms affect the blow-up properties, the lower and upper blow-up rate estimates are derived. Moreover, the blow-up set under some restricted assumptions is studied.
It has aimed by this research at presenting new interpretations to diversification phenomenon and its possible effects on firm value. These interpretations are culminated by the disclosure of the distinct role of resource-based view in the study of relationship between diversification strategy and firm value. The study has conducted on a sample consisted of the largest American companies listed in Fortune 500 along with seven years period
(2005-2011). This first local attempt, which has based on panel dat--a analysis for interpreting an expected variance of firm value due to diversification strategy, may helps with a clear vision to solve the contradiction and confusion surrounded the true linkages between t