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Effect of different acids surface treatments and thermocycling on shear bond strength of composite resin to feldspathic ceramic
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Background: the aim of this study was to evaluate the effect of different surface acids treatments (37%phospjoric acid, 5%hydrofluoric acid, 1.23 acidulated phosphate fluoride) of feldspathic ceramic VITA 3D MASTER , and the effect of thermocycling on shear bond strength using a ceramic repair kit (ivoclar/vivadent). Material and Methods: sixty Nickel-Chromium metal base plates were prepared(9mm diameter,3mm depth) using lost wax technique, 2mm thick layer of ceramic(VITA 3D MASTER) fused to metal plates, all specimens were embedded in acrylic resin blocks except their examined surfaces and divided into 3 main groups 20 specimens each, Grp A: treatment with 37%phosphoric acid for 2 mins, Grp B: etching with 5% hydrofluoric acid for 2mins, Grp C: etching with 1.23% acidulated phosphate fluoride for 10 mins; monobond-plus, heliobond, resin composite(Tetric EvoCeram) were applied to each specimen according to manufacturer's instruction using transparent split mold(5mm diameter, 4 mm height); specimens were stored in 37OC distilled water for 12 weeks, 10 specimens of each group were subjected to thermocycling between 5 oC and 55 o C for 800 cycles with 30s dwell time; shear bond strength was determined by a universal testing machine (instron 1122) at a cross head speed 0.5mm/min; One way ANOVA test, LSD test and student-t test were used to analyze shear bond strength. Results: Mean shear bond strength values for the tested groups were: A1= 11.65±0.68 Mpa, A2=10.88±0.58 Mpa, B1=17.93±0.41 Mpa, B2=17.42±0.35 Mpa, C1=15.17±0.61 Mpa, C2=14.51±0.48 Mpa ; one way ANOVA test showed highly significant difference among groups; LSD test revealed that the use of 5% HF for ceramic surface treatment(GB) was highly significant than the treatment with 37%PA(GA) or 1.23%APF(GC) respectively and the use of 1.23%APF(GC) was highly significant than the use of 37%PA(GA); Student t- test showed a significant difference between subgroups of the same group with and without thermocycling. Conclusion: ceramic surface treated with 5% HF acid for 2 mins recorded the highest shear bond strength, followed by surface treatment with 1.23% APF for 10 mins, most specimens treated with 5%HF showed cohesive failure with in ceramic while specimens treated with 1.23%AFP showed more (adhesive/cohesive) failure than adhesive or cohesive alone, and specimens treated with 37% PA showed nearly 50:50 adhesive and combination failure, thermocycling reduced the bond strength of each group significantly

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Publication Date
Sun May 01 2016
Journal Name
Journal Of Engineering
Production of Methyl Ester (Biodiesel) from Used Cooking Oils via Trans-esterification process
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Used cooking oil was undergoing trans-esterification reaction to produce biodiesel fuel. Method of production consisted of pretreatment steps, trans-esterification, separation, washing and drying. Trans-esterification of treated oils was studied at different operation conditions, the methanol to oil mole ratio were 6:1, 8:1, 10:1, and 12:1, at different temperature 30, 40, 50, and 60 º C, reaction time 40, 60, 80, and 120 minutes, amount of catalyst 0.5, 1, 1.5, and 2 wt.% based on oil and mixing speed 400 rpm. The maximum yield of biodiesel was 91.68 wt.% for treated oils obtained by trans-esterification reaction with 10:1 methanol to oil mole ratio, 60 º C reaction temperature, 80 minute reactio

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Publication Date
Wed Jun 01 2016
Journal Name
Journal Of Engineering
Accuracy Evaluation of Digital Elevation Model Created Using Handheld Global Positioning System Receivers
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This study aims to assess the accuracy of digital elevation model (DEM) created with utilization of handheld Global Positioning System (GPS) and comparing with Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), version 2. It is known that the quality of the DEM is affected by both of accuracy of elevation at each pixel (absolute accuracy) and accuracy of presented morphology (relative accuracy). The University of Baghdad, Al Jadriya campus was selected as a study area to create and analysis the resulting DEM. Additionally, Geographic Information System (GIS) was used to visualize, analyses and interpolate GPS track points (elevation data) of the study area. In this

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Publication Date
Thu May 18 2023
Journal Name
Journal Of Engineering
Place Identity in Defining Urban Space of Border Rivers in Historical City Centres
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In the city, building space could transform to be as place, because architecture does not include only traditional values such as housing, human protection, stability, etc, but could carry other dimensions beyond the housing or building occupancy or develop urban design. Rivers had vision in motion as a way to show dynamic processes in its flowing slowly, which are simply measured in time and the life of citizens. The research consider the river path in traditional cities as Alley connecting the spaces of the city ... old Baghdad was characterized by this property and it is look like Venice in the past, while traditional European cities were able to preserve this property till now, and capable to take transformation of the city with deve

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Publication Date
Sat Aug 01 2020
Journal Name
Journal Of Engineering
Experimental Evaluation of Evaporative Cooling for Enhancing Photovoltaic Panels Efficiency Using Underground Water
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This paper presents an experimental study of cooling photovoltaic (PV) panels using evaporative cooling. Underground (geothermal energy) water used to extract heat from it during cooling and cleaning of PV panels. An experimental test rig was constructed and tested under hot and dusty climate conditions in Baghdad. An active cooling system was used with auxiliary an underground water tank to provide cold water as a coolant over both PV surfaces to reduce its temperature. The cellulose pad has been arranged on the back surface and sprays cooling on the front side. Two identical PV panels modules used: without cooling and evaporative water cooling. The experiments are comprised of four cases: Case (I): backside cooling, Ca

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Corrosion Study of the Injection Equipments in Water in Al-Ahdeb Wells ‐Iraq
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Water injection equipments such as pipelines, which are used in the second recovery of oil in the Al-Ahdeb wells, suffer from the corrosion in water during maintaining vacuum deoxygenated tower that used to decrease concentration of the dissolved oxygen gas in the water from 6.2-9.1 ppm to o.5 ppm. This study involved calculation the corrosion rates of the internal surfaces of the
pipelines either during operation of the vacuum unit or when the tower out of operation. Finally, find the solution by one of the following suggestions. In the first suggestion removal of the dissolved O2 from water is achieved by increasing the dosage of the oxygen scavenger (sodium sulphite). The second suggestion involves removing the dissolved O2 from w

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Publication Date
Thu Dec 01 2022
Journal Name
Bulletin Of Electrical Engineering And Informatics
A model for incorporating suitable methods of usability evaluation into agile software development
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The challenge to incorporate usability evaluation values and practices into agile development process is not only persisting but also systemic. Notable contributions of researchers have attempted to isolate and close the gaps between both fields, with the aim of developing usable software. Due to the current absence of a reference model that specifies where and how usability activities need to be considered in the agile development process. This paper proposes a model for identifying appropriate usability evaluation methods alongside the agile development process. By using this model, the development team can apply usability evaluations at the right time at the right place to get the necessary feedback from the end-user. Verificatio

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Publication Date
Tue Dec 05 2023
Journal Name
Baghdad Science Journal
Antifungal Potential of Cladosporium sp. (Endophytic fungi) Associated with Olea europaea L. Leaves
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In the leaves of Olea europaea L. Olive trees an endophytic fungus was discovered. Cladosporium sp. was identified to be the fungus based on its morphological characteristics and nuclear ribosomal DNA ITS sequence analysis and was registered in NCBI as the Cladosporium genus has been registered under the number (0P939922.1) The species was not specified, and it was considered of unknown species after comparing it to global isolates. In comparison to olive leaf extract, Cladosporium sp. including total flavonoid, total phenolic, total terpenoid, and total saponins, Which were 121.9%, 198.1%, 89.13%, and 29.87 % respectively compared to its content in olive leaf extract, which was 61.54 %, 67.88 % , 17.1

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Publication Date
Wed Jan 01 2020
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees20
Opto- electrical properties of p-SnSe:S/N-Si heterojunction for solar cell application
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Publication Date
Sat Aug 01 2015
Journal Name
Journal Of Engineering
Analytical Approach for Load Capacity of Large Diameter Bored Piles Using Field Data
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An analytical approach based on field data was used to determine the strength capacity of large diameter bored type piles. Also the deformations and settlements were evaluated for both vertical and lateral loadings. The analytical predictions are compared to field data obtained from a proto-type test pile used at Tharthar –Tigris canal Bridge. They were found to be with acceptable agreement of 12% deviation.

               Following ASTM standards D1143M-07e1,2010, a test schedule of five loading cycles were proposed for vertical loads and series of cyclic loads to simulate horizontal loading .The load test results and analytical data of 1.95

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Publication Date
Wed Jul 05 2023
Journal Name
Chalcogenide Letters
Optimization physical properties of CdTe /Si solar cell devices fabricated by vacuum evaporation
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We investigated at the optical properties, structural makeup, and morphology of thin films of cadmium telluride (CdTe) with a thickness of 150 nm produced by thermal evaporation over glass. The X-ray diffraction study showed that the films had a crystalline composition, a cubic structure, and a preference for grain formation along the (111) crystallographic direction. The outcomes of the inquiry were used to determine these traits. With the use of thin films of CdTe that were doped with Ag at a concentration of 0.5%, the crystallization orientations of pure CdTe (23.58, 39.02, and 46.22) and CdTe:Ag were both determined by X-ray diffraction. orientations (23.72, 39.21, 46.40) For samples that were pure and those that were doped with

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