Background: White spot lesions (WSLs) are subsurface enamel demineralization manifested as white opacities which had an esthetic problem. The purpose of this in-vitro study was to evaluate the lesion depth improvement of WSLs following application of fluoride varnish, tooth mousse and resin infiltration (ICON). Materials and methods: Artificial WSLs were created on 120 premolar teeth using demineralization solution with pH (4-4.5). Samples randomly allocated into four groups; fluoride varnish, tooth mousse, ICON and untreated group. Groups were discolored in Cola and orange juice for 24 hours. Teeth were ground sectioned by longitudinal cutting then these sections examined and photographed under stereomicroscope at 12X magnification then an

Iraqi EFL students face difficulties in writing composition, especially academic writing, which affects negatively their exam results. This study has been conducted in the Department of English at College of Education for Women, University of Baghdad, in order to identify first year EFL students’ incompetence in writing. This may enhance their achievement by some weekly writing activities. It deals with Iraqi EFL students’ difficulties in writing paragraphs such as descriptive, process, opinion, and factual paragraphs. The study aims to identify these difficulties and to suggest suitable solutions for them. The researcher perceives that it is necessary to enhance students’ skills in writing because it i

In this manuscript divide into two parts the first experimental and the second theoretical. The experimental part of polyvinyl chloride (PVC) can be used with aluminum (30%). Nanomaterials are synthesized by a laser pulse melting solution by ethanol. The effect of laser on the structural, morphological, optical, and electrical properties of nanoparticles (PVC) was examined by UV spectroscopy, x-ray diffraction (XRD), electron microscopy (TEM). The theoretical part of the DFT can be used to approximate the generalized gradient of the Perdew, Burke, and Ernzerhof (PBE) / 6-31G (d) groups, which were created using additional Gaussian 09 software through Gaussian 5.08. To build PVC nanocrystal pure which chemical formula [(C2H3Cl)n] and build (

Research aims to develop a novel technique for segmental beam fabrication using plain concrete blocks and externally bonded Carbon Fiber Reinforced Polymers Laminates (CFRP) as a main flexural reinforcement. Six beams designed an experimentally tested under two-point loadings. Several parameters included in the fabrication of segmental beam studied such as; bonding length of carbon fiber reinforced polymers, the surface-to-surface condition of concrete segments, interface condition of the bonding surface, and thickness of epoxy resin layers. Test results of the segmental beams specimens compared with that gained from testing reinforced concrete beam have similar dimensions for validations. The results show the effectiven

This work provides an analysis of the thermal flow and behavior of the (load-free) refrigerator compartment. The main goal was to compare the thermal behavior inside the refrigerator cavity to the freezer door (home refrigerator) effect and install a fan on the freezer door while neglecting the heat transmitted by thermal radiation. Moreover, the velocity distribution, temperature, and velocity path lines are theoretically studied. This was observed without affecting the shelves inside the cabinet and the egg and butter places on the refrigerator door as they were removed and the aluminum door replaced with a glass door. This study aims to expand our knowledge about the temperature and flow fields of this refrigerator mo

 

Experimental work has been performed on three capillary tubes of different lengths and diameters using R-12 and R-134a. The test also studies the effect of discharge and speed of evaporator fan. The results clearly showed that refrigerant type and discharge significantly influence the temperature drop across the capillary tube. While the speed of evaporator fan has small effect. Experimental results showed that the temperature gradient for the two refrigerants are the same, but after approximatly one meter the temperature gradient of R-134a  is steeper than R-12.

 

Carbonate matrix stimulation technology has progressed tremendously in the last decade through creative laboratory research and novel fluid advancements. Still, existing methods for optimizing the stimulation of wells in vast carbonate reservoirs are inadequate. Consequently, oil and gas wells are stimulated routinely to expand production and maximize recovery. Matrix acidizing is extensively used because of its low cost and ability to restore the original productivity of damaged wells and provide additional production capacity. The Ahdeb oil field lacks studies in matrix acidizing; therefore, this work provided new information on limestone acidizing in the Mishrif reservoir. Moreover, several reports have been issued on the difficulties en

    In this work, an experimental study has been done to expect the heat characteristics and performance of the forced-convection from a heated horizontal rectangular fins array to air inside a rectangular cross-section duct. Three several configurations of rectangular fins array have been employed. One configuration without notches and perforations (solid) and two configurations with combination of rectangular-notches and circular-perforations for two various area removal percentages from fins namely 18% notches-9% perforations and 9% notches-18% perforations are utilized.  The rectangular fins dimensions and fins number are kept constant. The fins array is heated electrically from the base

Characteristic of money laundering phenomenon is a compound and complex nature like the style of regular crimes . These operations are planned and excuted with those who have high quality experiences to hide the evidences of their deeds so They ask the help of financials ,economicals and legists to plan for money laundering. Banks are important and suitable places for illegal circulation of money because of the different types of accounts , rapidity and overlap which emphasis of its main duty to dislocate illegal money which comes from illegal sources without adding legal characteristic to it . Here we should explain the important role of banks in striving the phenomenon –Bank should try to show and analyze inward proced