This aim of this study is to assess the Tigris River sediments and utilize them as a new abrasive for the preparation of polished surface of magnetite ore to be studied under reflected light ore microscope. Such polishing process was tested using 250, 125, 71, 45, 25 and 18μm grain sizes of the river sediments. For the completion of the polishing and to obtain a glossy perfect polished surface, the 7 and 2.5 μm sized standard diamond pastes were used. After each polishing stage, the reflectance and roughness of these surfaces were measured as an evaluation step for the polishing efficiency. The reflectance values (R%) of the magnetite surface were found to be reversely proportioned to the abrasive grain size; while the surface roughness values (Ra) showed positive relationship with the grain size. The polished surface showed gradual improvement with decreasing grain size of the abrasive. The reflectance increased at a rate of 0, 0, 0.3, 1.2, 2.5, 3.7, 9.3, 20% with reducing grain sizes from 250, 125, 70, 45, 25, 18, 7 and 2.5 µm; at the same time, the roughness reduced at a rate of 72.2, 51.8, 23.7, 17.2, 10.9, 7.5, 6, 3.8 with reducing grain size. The 18 µm abrasive grain size of river sediments was found to be the best. Buffing by 2.5 µm diamond paste as the last stage, improved the polishing efficiency and resulted in 20% reflectance. Based on the obtained results, the Tigris sediments can be considered as fine-grained granules with the ability of preparing a flat, homogeneous surface with little roughness and reasonable degree of reflectivity.
Measurements of radon gas concentrations were carried out for 12 soil samples at 3 sampling depths (surface, 5 cm and 10 cm) collected from (4) locations in south Baghdad suburbs (Bu'aitha) using solid state nuclear track detector CR-39 and sealed can technique. Radon concentrations for surface samples were ranged from 402.2 to 1538.4 Bq.m-3 with an average 994.4 Bq.m-3. Whereas, radon concentration was ranged from 813.1to 2050.4 Bq.m-3 and from 1309.8 to 4626. 1Bq.m-3 with an average values of 1359.8 Bq.m-3 and 2338.3 Bq.m-3 for 5 cm and 10 cm depths respectively. Maximum radon level was found at the location near to the river (site S4) while the minimum radon level was f
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This paper aims to prove an existence theorem for Voltera-type equation in a generalized G- metric space, called the -metric space, where the fixed-point theorem in - metric space is discussed and its application. First, a new contraction of Hardy-Rogess type is presented and also then fixed point theorem is established for these contractions in the setup of -metric spaces. As application, an existence result for Voltera integral equation is obtained.
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This work presents the modeling of the electrical response of monocrystalline photovoltaic module by using five parameters model based on manufacture data-sheet of a solar module that measured in stander test conditions (STC) at radiation 1000W/m² and cell temperature 25 . The model takes into account the series and parallel (shunt) resistance of the module. This paper considers the details of Matlab modeling of the solar module by a developed Simulink model using the basic equations, the first approach was to estimate the parameters: photocurrent Iph, saturation current Is, shunt resistance Rsh, series resistance Rs, ideality factor A at stander test condition (STC) by an ite
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This research was conducted to investigate the water quality of the lesser Zab
river, to evaluate the water suitability for agricultural usings and report the effect of
human activities on this water. Samples were collected along the river stream
starting from Dukan area till the convergence with Tigris River. All the tests were
conducted at the labs of Environmental sciences and Technology College /
University of Mosul and Erbil water project/Erbil city.
The results of using Piper diagram showed that the water is alkine, due to the effect of the origional rock's components of that area on the water quality. While the using of Stiff diagram elucidate that the water samples contain ions belong to the area of the lesser Z
Background. Endodontic infections caused by remaining biofilm following disinfection with chemical fluids encourage secondary bacterial infection; hence, employing laser pulses to activate the fluids is advised to improve microbial biofilm clearance. This study investigated the performance of Er,Cr:YSGG laser in photon-induced photoacoustic streaming (PIPS) agitation of 5.25% sodium hypochlorite (NaOCl) to enhance the removal of mature Enterococcus faecalis (E. faecalis) biofilms in complex root canal systems. Methods. The mesial roots of the lower first and second molars were separated and inoculated with E. faecalis bacteria for 30 days. The roots were irrigated with 5.25% NaOCl, some of them were agitated with passive ultrasonic
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The rising temperatures are the most significant aspect in the period of climate variability. In this study PRECIS model data and observed data are used for assessing the temperature change scenarios of Sindh province during the first half of the present century. Observed data from various meteorological stations of Sindh are the primary source for temperature change detection. The current scenario (1961–1990) and future one (2010-2050) are acted by the PRECIS Regional Climate Model at a spatial resolution of 25 * 25 km. Regional Climate Model (RCM) can yield reasonably suitable projections to be used in the climate - scenario. The main objective of the study is to prepare maps. The simulated temperature as obtained from climate model-
... Show MoreBackground: Adjustment of any premature occlusal contact of any zirconia restoration requires its polishing or glazing in order to restore the smoothness of the restoration. The objective of this in vitro study was to evaluate the effects of different polishing systems and glazing on the surface roughness of full-contour zirconia. Material and methods: Forty disks (diameter: 8 mm, thickness: 6.4 mm) were prepared from pre-sintered full-contoured zirconia block; they were colored and sintered in a high-temperature furnace at 1500ËšC for 8 hours. The specimens were then leveled and finished using grinding and polishing machine and adjusted using diamond disk. The specimens were then randomly divided into four groups (n=10), group I involves
... Show MoreThis study was conducted to evaluate the effect of discharge of water purification plants ,on the purity of Tigris River water in Baghdad city. The two studied plants were involved in the study : Sharq –Dijla and Al-Karama water purification plants. The study was attempted to focus on probable pollutants. Chemical, physical tests were accomplished on water samples collected from four sites with fact of three replicates for each sample of each site of the river and the plant : before, after, inside the plants and at the pipe. This study started from October 2012 to September 2013. In case of heavy metals Results showed that the highest level of aluminum was 1.08 ppm during (December-January) at Sharq-Dijla plants, while the lowest level
... Show MoreOne of the most important methodologies in operations research (OR) is the linear programming problem (LPP). Many real-world problems can be turned into linear programming models (LPM), making this model an essential tool for today's financial, hotel, and industrial applications, among others. Fuzzy linear programming (FLP) issues are important in fuzzy modeling because they can express uncertainty in the real world. There are several ways to tackle fuzzy linear programming problems now available. An efficient method for FLP has been proposed in this research to find the best answer. This method is simple in structure and is based on crisp linear programming. To solve the fuzzy linear programming problem (FLPP), a new ranking function (R
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