Abstract: Objectives: To investigate the effect of temperature elevation on the bonding strength of resin cement to the zirconia ceramic using fractional CO2 laser. Background: Fractional CO2 laser is an effective surface treatment of zirconia ceramic, as it increases the bonding strength of zirconia to resin cement. Methods: Thirty sintered zirconia discs (10 mm diameter, 2 mm thickness) were prepared and divided to three groups (N=10) and five diffident pulse durations were used in each group (0.1, 0.5, 1, 5 and 10 ms). Group A was treated with 10 W power setting, group B with 20 W and group C with 30 W. During laser irradiation, temperature elevation measurement was recorded for each specimen. Luting cement was bonded to the treated zirconia surfaces and cured for 30 seconds. Shear bond strength was evaluated by a testing machine (universal) with bond failure mode determination. Results: The lowest temperature elevation measurement of the irradiated specimen which gave maximum shear bond strength was about 1.6±0.3 Ċ higher than ambient room temperature (27±0.2 ºC). Apparent micromechanical irregularities were seen in the treated samples and cracks formation with increased pulse duration and power setting were also observed. Conclusions: The temperature elevation is a vital factor in the surface roughness of zirconia ceramic with fractional CO2 laser irradiation and the lowest temperature elevation at best shear bond strength of zirconia ceramic to the resin cement is satisfied with the shorter pulse duration of 0.1 millisecond.
Most cultivars of sorghum have low field emergence as common problem. Three experiments were carried out at Agriculture College, Baghdad University. First experiment was conducted in laboratory according to Complete Randomized Design (CRD) with four replicates. Second and third experiments were conducted at field according to Randomized Complete Block Design (RCBD) during the spring and the fall seasons of 2015, respectively, with four replicates for each one. Same two factors were studied at each experiment. First factor was seed priming by seed soaking for 10 hours in distilled water, solvents of GA3, KCl and thiamine (300, 40 and 30 mg*L-1, respectively) and non-primed seed. Second factor was three cultivars of sorghum (Inqath, Kafier an
... Show MoreThe present study was carried out on forty eight epididymis of sexually mature dogs to elucidate light microscope features and the presence of testosterone receptors inside epididymis in different seasons. Twenty four dogs aged 3 years were used during the periods from 1/2/2015-1/2/2016. The epididymis were carefully dissected from the testis after orchidectomy operations and fixed, dehydrated, clarified and embedded in paraffin. Sections were stained with hematoxylin and eosin and periodic acid schiff. As well as, paraffin embedded cytoimmunochemistry technique was used for detection of testosterone receptors. Muscular coats showed no significant differences during different seasons or among segments. Epithelial heigh
... Show MoreSpeech encryption approaches are used to prevent eavesdropping, tracking, and other security concerns in speech communication. In this paper, a new cryptography algorithm is proposed to encrypt digital speech files. Initially, the digital speech files are rearranged as a cubic model with six sides to scatter speech data. Furthermore, each side is encrypted by random keys that are created by using two chaotic maps (Hénon and Gingerbread chaotic maps). Encryption for each side of the cube is achieved, using the based map vector that is generated randomly by using a simple random function. Map vector that consists of six bits, each bit refers to one of the specific chaotic maps that generate a random key to encrypt each face of the cube. R
... Show MoreIn this paper an accurate Indian handwritten digits recognition system is
proposed. The system used three proposed method for extracting the most effecting
features to represent the characteristic of each digit. Discrete Wavelet Transform
(DWT) at level one and Fast Cosine Transform (FCT) is used for features extraction
from the thinned image. Besides that, the system used a standard database which is
ADBase database for evaluation. The extracted features were classified with KNearest
Neighbor (KNN) classifier based on cityblock distance function and the
experimental results show that the proposed system achieved 98.2% recognition
rate.
The purpose of this study is to determine the useful of Schiff bases derivatives containing (oxazepine, tetrazole) rings with biological activity which can be used as drug and antimicrobial, the present work is started from [Binary (2,5(4,'4-diaminophenyl) – 1,3,4 – oxadiazole]. A variety of Schiff bases and heterocyclic (oxazepine, tetrazole) have been synthesis, and confirm that structures by physical properties , FTIR , 1H-NMR, 13C-NMR, elemental analysis, [Microbial study against three type of bacteria (staphylococcus aurea and klebsiella pneumonia) and (Canadida albncans) fungi].All analyzation performed in center of consulatation University of Jordan.
Television plays an important role in health education development of the consumer, where the health programs offered by satellite channels offering a variety of subjects that deal with human health in general, as do people with some misconceptions health practices either due to lack of awareness or a low level of culture they have is one of the problems that require a search, so the research aims to clarify what the TV play in health education to the consumer through a content analysis of health issues covered by the television health programs and identify health issues positive and negative in everyday human life, it has been identified green apple program Broadcast of the channel mbc1 as a model for health programs offered by the Arab
... Show MoreThe aim of this study to investigate the microbial load and type of preservative for the types of yogurt available in the Iraqi market to ensure the safety of food provided to the consumer and protect through examining the types of yogurt from harmful bacteria as well as to contain ratios acceptable to yeasts and molds is to find out by comparing models curd careless Iraqi standard quality(ISQ) and see how they conform to these specifications have been collecting 12 brands of yoghurt types it was been (Kala, Activia 1, Activia 2, Mazia, Shelan, Aib, Mersin, Morsi, Al-Safi, Zabady, Zakho, Arbil). Bacteriological tests were conducted on samples of yogurt (total bacterial count, coliform count, counting yeasts and molds). The results showed
... Show MoreThis research aims to modify the components of stainless steel alloy by the method of surface engineering through the single diffusion coating technique in order to obtain new alloys with high efficiency in resisting harsh environmental conditions. Steam a mixture of sodium chloride ( ) and sodium sulfate ( ) at a temperature of 900 and then compare it with the base alloy. The results showed that the alloys produced in this way are very efficient. The results showed that the aluminum coating showed high efficiency in resisting oxidation and provided better protection for a longer time compared to the uncoated alloy due to the oxide crust layer formed with high adhesion as well as the aluminum-rich phases, whether the phase
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