Background: This study was performed to determine the effect of aging of different types of composite material restorations on: Shear bond strength (SBS) to light cure and no mix chemical cure orthodontic adhesives with sapphire bracket and the debonding failure sites. Materials and methods: One hundred forty four composite disks were made from three different composite resin materials which are: 3M Filtek Z250, 3M filtek Z350 and 3M Valux plus, each group with (48) disks each, then according to the duration of storage each group was subdivided into two equal groups one of them stored for one day and the other was stored for one month, then each group was further subdivided into two equal subgroups with (12) disks each one bonded with light cure orthodontic adhesive and the other with no mix chemical cure adhesive. The sample was tested for bond strength using the universal testing machine and the Adhesive Remnant Index (ARI) was inspected under the stereomicroscope. Results: The results revealed that there was a highly significant difference among the three types of composite materials bonded with light cure orthodontic adhesive as showed by ANOVA test, while the T test showed that there was no significant difference between the two storage durations and also between the two orthodontic adhesives for both Filtek Z250 and Valux plus. Conclusions: The highest (SBS) values were obtained from Filtek Z350 samples than other two types of composite. All the samples stored for one day showed higher values of (SBS) than those stored for one month.
The objective of this work is to investigate the performance of a conventional three phase induction motor supplied by unbalanced voltages. An effort to study the motor steady state performance under this disturbance is introduced. Using per phase equivalent circuit analysis with the concept of symmetrical components approach, the steady state performance is theoretically calculated. Also, a model for the induction motor with the MATLAB/Simulink SPS tools has been implemented and steady state results were obtained. Both results are compared and show good correlation as well. The simulation model is introduced to support and enhance electrical engineers with a complete understanding for the steady state performance of a fully loaded induc
... Show MoreObjective(s): To determine the impact of instructional intervention program upon psychological health status for
women who undergo chemotherapy after mastectomy
Methodology: The sample consisted of (100) women, (50) considered as study group, and another (50) the control
group. A pre test was done for both groups (study and control), and then the study samples were exposed to an
instructional intervention and three-dimensional post tests and the length of time between each test 21 days in
the Institute and Hospital of Radiation and Nuclear Medicine. The questionnaire composed of three parts, first,
demographic information; include (age, educational level, type of family, occupation, marital status, and adequacy
of mo
This paper presents the first data for bremsstrahlung buildup factor (BBUF) produced by the complete absorption of Y-91 beta particles in different materials via the Monte Carlo simulation method. The bremsstrahlung buildup factors were computed for different thicknesses of water, concrete, aluminum, tin and lead. A single relation between the bremsstrahlung buildup factor BBUF with both the atomic number Z and thickness X of the shielding material has been suggested.
There is a great operational risk to control the day-to-day management in water treatment plants, so water companies are looking for solutions to predict how the treatment processes may be improved due to the increased pressure to remain competitive. This study focused on the mathematical modeling of water treatment processes with the primary motivation to provide tools that can be used to predict the performance of the treatment to enable better control of uncertainty and risk. This research included choosing the most important variables affecting quality standards using the correlation test. According to this test, it was found that the important parameters of raw water: Total Hardn
In this work, an explicit formula for a class of Bi-Bazilevic univalent functions involving differential operator is given, as well as the determination of upper bounds for the general Taylor-Maclaurin coefficient of a functions belong to this class, are established Faber polynomials are used as a coordinated system to study the geometry of the manifold of coefficients for these functions. Also determining bounds for the first two coefficients of such functions.
In certain cases, our initial estimates improve some of the coefficient bounds and link them to earlier thoughtful results that are published earlier.
4-methylaniline and its Schiff base derivative were intercalated into the Bentonite clay interlayers in a solid state reaction followed by a condensation reaction to produce two organo-clay composites. X-ray diffraction was used to identify the changes in basal spacing of montmorillonite layers which exhibited noticeable alteration before and after the formation of the composites. FT-IR spectra, on the other hand, were utilized for identifying the structural compositions of the prepared materials as well as the formation of the intercalated Schiff base derivative. The surface morphology of the composites was examined by Scanning Electron Microscopy SEM and Atomic Force Microscope AFM, which reflected some differences in the surface of prepa
... Show MoreThe main aim of this study was to molecular identification and determine the antagonistic impact of rhizosphere Trichoderma spp. against some phytopathogenic fungi, including (Magnaporthe grisea) pyricularia oryzae, Rhizoctonia solani and Macrophomina phasolina. Four Trichoderma isolates were isolated from rhizosphere soils of the different host plants in different locations of Egyptian governorates. The morphological characterization of isolated Trichoderma as well as using of (ITS1-5.8S-ITS2) ribosomal gene sequence acquisition and data analyses. By comparing the results of DNA sequences of ITS region, the fungi represented one isolate were positively identified as T. asperellum (1 isolate T1) and one as T. longibrachiatum (1 isolate T2)
... Show MoreThe plant occupied the largest area in the biosynthesis of silver nanoparticles, especially the medicinal plants, and it has shown great potential in biotechnology applications. In this study, green synthesis of silver nanoparticles from Moringa oleifera leaves extract and its antifungal and antitumor activities were investigated. The formation of silver nanoparticles was observed after 1 hour of preparation color changing. The ultraviolet and visible spectrum, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy techniques were used to characterize synthesis particles. Ultraviolet and visible spectroscopy showed a silver surface plasmon resonance band at 434
... Show MoreNear-ideal p-CdS/n-Si heterojunction band edge lineup has been investigated for the first time with aid of I-V and C-V measurements. The heterojunction was manufactured by deposition of CdS films prepared by chemical spray pyrolysis technique (CSP) on monocrystalline n-type silicon. The experimental data of the conduction band offset Ec and valence band offset Ec were compared with theoretical values. The band offset Ec=530meV and Ev=770meV obtained at 300K. The energy band diagram of p-CdS/n-Si HJ was constructed. C-V measurements depict that the junction was an abrupt type and the built-in voltage was determined from C-2-V plot