Objective. This study aimed to evaluate the orthodontic bond strength and enamel-preserving ability of a hydroxyapatite nanoparticles-containingself-etch system following exposure to various ageing methods. Materials and Methods. Hydroxyapatite nanoparticles (nHAp) were incorporated into an orthodontic self-etch primer (SEP, Transbond™ plus) in three different concentrations (5%, 7%, and 9% wt) and tested versus the plain SEP (control) for shear bond strength (SBS), adhesive remnant index (ARI) scores, and enamel damage in range-finding experiments using premolar teeth. The best-performing formulation was further exposed to the following four artificial ageing methods: initial debonding, 24 h water storage, one-month water stora

     The reliability of hybrid systems is important in modern technology, specifically in engineering and industrial fields; it is an indicator of the machine's efficiency and ability to operate without interruption for an extended period of time. It also allows for the evaluation of machines and equipment for planning and future development. This study looked at reliability of hybrid (parallel series) systems with asymmetric components using exponential and Pareto distributions. Several simulation experiments were performed to estimate the reliability function of these systems using the Maximum Likelihood method  and the Standard Bayes method  with a quadratic loss (QL) function and two priors: non-informative (Jeffery) and inform

The Frequency-hopping Spread Spectrum (FHSS) systems and techniques are using in military and civilianradar recently and in the communication system for securing the information on wireless communications link channels, for example in the Wi-Fi 8.02.X IEEE using multiple number bandwidth and frequencies in the wireless channel in order to hopping on them for increasing the security level during the broadcast, but nowadays FHSS problem, which is, any Smart Software Defined Radio (S-SDR) can easily detect a wireless signal at the transmitter and the receiver for the hopping sequence in both of these, then duplicate this sequence in order to hack the signal on both transmitter and receiver messages using the order of the se

This paper deals with the description of the system of formation and derivation of words in the Russian language. In this work, we will present recent trends in the study of the Russian language that deal with vocabulary formation. The lexical system of the Russian language is associated with a common (or opposite) meaning; similar (or opposite) in stylistic characteristics; united by a common type of word formation; related to a common descent and belonging to a vocabulary of much or little use, etc. The results of the most prominent linguists and specialists who dealt with this topic will be presented, in addition to presenting their different views on word formation. The words of the Russian language consist of mor vimat that participate

The research aims to; identify the management of conflict as perceived by secondary school managers toward the directors of directorates of education in wassat province, identify functional performance as perceived by secondary school managers toward the directors of directorates of education in wassat province. Besides, explore the relationship between Conflict management and functional performance among the directors of directorates of education in wassat province. A descriptive approach deemed more appropriate with study design. As a tool to collect the data of current research, the author used a questionnaire. Spss tools were used for data analysis

This study aimed to study the inhibition activity of purified bacteriocin produced from the local isolation Lactococcuslactis ssp. lactis against pathogenic bacteria species isolated from clinical samples in some hospitals Baghdad city. Screening of L. lactis ssp. Lactis and isolated from the intestines fish and raw milk was performed in well diffusion method. The results showed that L. lactis ssp. lactis (Lc4) was the most efficient isolate in producing the bacteriocin as well observed inhibitory activity the increased that companied with the concentration, the concentration of the twice filtrate was better in obtaining higher inhibition diameters compared to the one-fold concentration. The concentrate

The present study is undertaken to evaluate the effects of hypothyroidism induced by carbimazol in male rat reproductive system. Rats were treated with carbimazol (80 and 160 mg/kg body weight) daily for two, four, six, and eight weeks, while control rats were given distilled water orally. The results of these experiments are: 1-Treatment with carbimazol produced increase in body weight of treated animals. This increase was not statistically significant even at high concentrations. 2-Decrease in testicular weight  was observed during all administration points. This decrease was aggravated proportional to duration and dose (p≤0.001). 3-Results of most intervals showed significant decrease in epididymal-head weight, while no sig