An investigation was conducted effect of addition co- solvent on solvent extraction process for two types of a lubricating oil fraction (spindle) and (SAE-30) obtained from vacuum distillation unit of lube oil plant of Daura Refinery. In this study two types of co-solvents ( formamide and N-methyl, 2, pyrrolidone) were blended with furfural to extract aromatic hydrocarbons which are the undesirable materials in raw lubricating oil, in order to improve the viscosity index, viscosity and yield of produced lubricating oil. The studied operating condition are extraction temperature range from 70 to 110 °C for formamide and 80 to 120 °C for N-methyl, 2, pyrrolidone, solvent to oil ratio range from 1:1 to 2:1 (wt./wt.) for furfural with formamide extraction and 1:1 to 3:1 (wt./wt.) for furfural with NMP extraction. The results of the investigation show that the viscosity index of lubricating oil fraction increases while viscosity and percentage yield of raffinate decreases with increasing extraction temperature, the solvent to oil ratio and co-solvent to furfural ratio. For formamide the best temperature were 90 °C, furfural to co-solvent ratio (60:40) and solvent to lube oil ratio (1.5:1) to get best value of viscosity index 102, viscosity 3.01 cst and 69.23 % yield. While for NMP co-solvent 110 °C extraction temperature, (2:1) solvent to lube oil ratio and (60:40) furfural to co-solvent ratio, to produce lube oil with 96 viscosity index, 9.10 cst viscosity and 68.50 yield.
ABSTRACT Purpose: the aim of this in vitro study was to compare the marginal gap and internal fitness between single crowns and the crowns within three-unit bridges of zirconium fabricated by CAD-CAM system. Materials and methods: A standard model from ivoclar company was used as a pattern to simulate three-units bridge (upper first molar and upper first premolar) as abutments used to fabricate stone models, eight single crowns for premolar and eight of three units bridges. Crowns and bridges fabricated by CAD-CAM system were cemented on their respective stone models then sectioned at the mid-point buccolingaully and misiodistaly and examined under stereomicroscope. Result: the marginal gap in premolar crowns and premolar within bridge we
... Show MoreBackground: With the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.The present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (Hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). Materials and Methods: The samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). They were divided as the following: group I (control): the porcelain surface left u
... Show MoreThe study area is located in Al-Anbar Governorate, western Iraq. The climatic data were collected from Al-Ramadi Meteorological Station for the period 1990 to 2020 and used to assess the climatic condition of the study area. The total annual rainfall, relative humidity, monthly average temperature, evaporation, wind speed and sunshine duration are 108 mm, 52.7 %, 22.6˚C, 2814.3 mm, 2.2 m/s and 8.8 h/day, respectively. The climate of the study area is described as an arid to sub arid and relatively hot in summer and cold with low rain in winter. During the data used, the highest potential evapotranspiration was 217.1 mm in July, while the lowest value was 10.7 mm in January, with a total amount of 1170.07 mm. The highest and l
... Show MoreThis research provides a study of the virtual museums features and characteristics and contributes to the recognition of the diversity of visual presentation methods, as the virtual museums give the act of participation and visual communication with programs at an open time, so that it would contribute to reflection, thinking and recording notes, developing the actual and innovative skills through seeing the environments. The study has been divided into two sections the first one is virtual museum techniques. The techniques were studied to reach the public and are used remotely by the services of personal computers or smart phones being virtual libraries that store images and information that was formed and built in a digital way and how
... Show MoreIn this paper the research introduces a new definition of a fuzzy normed space then the related concepts such as fuzzy continuous, convergence of sequence of fuzzy points and Cauchy sequence of fuzzy points are discussed in details.
The study aimed to build a suggested conception for employing gamification in teaching the general education curricula. Using the analytical method of the previous analytical studies in Teaching, which agreed with the determinants of the analysis of 20 studies from 2014 to 2019, they come on order: points, badges, leaderboards, and then levels. The four most commonly used theories are the theory of self-determination, flow theory, the theory of planned behavior and social theory. In addition, the researcher identified the most commonly used models in gamification, respectively: the ARCS model and the user-based design model. Based on the results of the analysis and using the descriptive approach, the researcher presented a practical perc
... Show MoreIn this research note approximately prime submodules is defined as a new generalization of prime submodules of unitary modules over a commutative ring with identity. A proper submodule of an -module is called an approximaitly prime submodule of (for short app-prime submodule), if when ever , where , , implies that either or . So, an ideal of a ring is called app-prime ideal of if is an app-prime submodule of -module . Several basic properties, characterizations and examples of approximaitly prime submodules were given. Furthermore, the definition of approximaitly prime radical of submodules of modules were introduced, and some of it is properties were established.
Derivative spectrophotometry is one of the analytical chemistry techniques used
in the analysis and determination of chemicals and pharmaceuticals. This method is
characterized by simplicity, sensitivity and speed. Derivative of Spectra conducted
in several ways, including optical, electronic and mathematical. This operation
usually be done within spectrophotometer. The paper is based on form of a new
program. The program construction is written in Visual Basic language within
Microsoft Excel. The program is able to transform the first, second, third and fourth
derivatives of data and the return of these derivatives to zero order (normal plot).
The program was applied on experimental (trial) and reals values of su
يهدف البحث الحالي إلى اختبار العلاقة بين نوعية حياة العمل والإبداع التنظيمي في ديوان وزارة التخطيط ، ولبلوغ الهدف المذكور وبناء على معطيات البحث الاستطلاعي للباحث بني ألانموذج الفرضي للبحث الذي ضم المتغير المستقل والمعتمد، واعتماداً على حركية الأنموذج صيغت فرضيتان، ولاختبار صحة الفرضيات وجمع المعلومات من عينة البحث البالغة (100) مدير يمثلون مرك
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