Background: Prophylaxis methods are used to mechanically remove plaque and stain from tooth surfaces; such methods give rise to loss of superficial structure and roughen the surface of composites as a result of their abrasive action. This study was done to assess the effect of three polishing systems on surface texture of new anterior composites after storage in artificial saliva. Materials and methods: A total of 40 Giomer and Tetric®N-Ceram composite discs of 12 mm internal diameter and 3mm height were prepared using a specially designed cylindrical mold and were stored in artificial saliva for one month and then samples were divided into four groups according to surface treatment: Group A (control group):10 specimens received no surfa

The calibration of the three meter Baghdad University Radio Telescope (BURT) has been performed using two types of calibrations: Antenna Position calibration, and Detector calibration. The sun is used as a reference source to calibrate the telescope. The antenna position Azimuth (Az), and Elevation (El) are calibrate according to sun's azimuth and elevation in the date (11/10/2017; at time 10:19 AM). A calibration report is designed to illustrate the calibration parameters for each specific date and time. The detector calibration is representing a study for power spectrum response for the sun according to radio telescope frequency band (1.3 GHz – 1.5 GHz) with central frequency (1.42 GHz). Drift Scan function in the telescope's softwar

Ultrasonic pulse echo measurements on porous alumina as ceramic

material with porosities ranging from (20-40)% showed effect of volume

fraction of porosity on both thermal and elastic properties. A quadratic relationships, by using a least squares method, is deduced for the dependence of the shear velocity, longitudinal velocity, shear modulus, Young's modulus,  bulk  modulus, Poisson 's ratio, Debye temperature, specific heat, and thermal conductivity on the total  porosity. By these relationships,  the  thermal  and  elastic  properties  results  of  pore-free alumina  were  calculated.  The  elastic  properties  results  of  

Microbial Desalination Cell (MDC) is capable of desalinating seawater, producing electrical power and treating wastewater. Previously, chemical cathodes were used, which were application restrictions due to operational expenses are quite high, low levels of long-term viability and high toxicity. A pure oxygen cathode was using, external resistance 50 and 150 k Ω were studied with two concentrations of NaCl in the desalination chamber 15-25 g/L which represents the concentration of brackish water and sea water. The highest energy productivity was obtained, which amounted to 44 and 46 mW/m³, and the maximum limit for desalination of saline water was (31% and 26%) for each of 25 g / L and 15 g / L, respectively, when using an ex

The study of vegetative change of cities is one of the most important studies related to human life because of its direct correlation with the temporal conditions that occur. These include the economic problems that force people to move and look for job opportunities in the city, which leads to an increase in the population density of cities, especially for cities with an important economic and administrative location as in the capital city of Baghdad. In this study, the effect of the increasing in population density was analyzed on the urban planning of Baghdad city. The decreasing in vegetation was due to the increasing of urban areas on the outskirts of the city, which led to an increase in its area. Moreover, urban cities increased t

In this article our goal is mixing ARMA models with EGARCH models and composing a mixed model ARMA(R,M)-EGARCH(Q,P) with two steps, the first step includes modeling the data series by using EGARCH model alone interspersed with steps of detecting the heteroscedasticity effect and estimating  the model's parameters and check the adequacy of the model. Also we are predicting the conditional variance and verifying it's convergence to the unconditional variance value. The second step includes mixing ARMA with EGARCH and using the mixed (composite) model in modeling time series data and predict future values then asses the prediction ability of the proposed model by using prediction error criterions.

The process of evaluating data (age and the gender structure) is one of the important factors that help any country to draw plans and programs for the future. Discussed the errors in population data for the census of Iraqi population of 1997. targeted correct and revised to serve the purposes of planning. which will be smoothing the population databy using nonparametric regression estimator (Nadaraya-Watson estimator) This estimator depends on bandwidth (h) which can be calculate it by two ways of using Bayesian method, the first when observations distribution is Lognormal Kernel and the second is when observations distribution is Normal Kernel

Background: The quantity and the quality of available bone, influence the clinical success of dental implants surgery. Cone beam Computed tomography is an established method for acquiring bone images before performing dental implant. Cone beam computed tomography is an essential tool for treatment planning and post-surgical procedure monitoring, by providing highly accurate 3-D images of the patient's anatomy from a single, low-radiation scan which yields high resolution images with favorable accuracy. The aim of study is the Measurement of alveolar bone (height and buccolingual width) and density in the mandible among Iraqi adult subject using CBCT for assessment of dental implant site dimensions. Material and method: The study sample in

An electrical survey was carried out by using 2D imaging technique at (15)
station. The study area is located southern Al-Shihaby area, south-east of Wasit
governorate, Eastern Iraq. The numbers of the employed electrodes were (120) and
the (a) spacing equal to (10m), and the total length of survey line is (1200m). The
inverse models of 2D imaging showed one Quaternary aquifer located in the
Quaternary deposits which comprises in alluvial fan and wind deposits of
(Pleistocene – Holocene) ages. Layers of aquifer consist of gravel and sand with
little silt. Low resistivity values reflected the presence of clay layers, and increasing
salinity of water gradually with the depth. The aquifer occurs at minimum depth