In this study, the effects of blending the un-branched acrylate polymer known as Poly (n-decyl acrylate), and the branched acrylate polymer known as Poly (iso-octyl acrylate), on the viscosity index (VI), and the pour point of the Iraqi base stocks 40, and 60 respectively, were investigated. Toluene was used as a carrier solvent for both polymer types. The improvement level of oils (VI, & pour point) gained by blending the oil with the acrylate derived polymers was compared with the values of (VI, and pour point) gained by blending the oil with a commercial viscosity index, and pour point improver. The commercial lubricant additive was purchased and used by Al-Daura Refineries. It consisted of an un-known olefin copolymer dissolved in an un-known carrier solvent. All polyacrylate derivatives and the commercial lubricant additive named HITEC5748 were blended with each type of oil in weight percentage of (2, 4, 6, 8, & 10) wt. %. The result of the study was that the improvement in the viscosity index and the pour point of both base stock types was higher when using the polyacrylate derivatives than when using the commercial olefin copolymer additive.
The basic concepts of some near open subgraphs, near rough, near exact and near fuzzy graphs are introduced and sufficiently illustrated. The Gm-closure space induced by closure operators is used to generalize the basic rough graph concepts. We introduce the near exactness and near roughness by applying the near concepts to make more accuracy for definability of graphs. We give a new definition for a membership function to find near interior, near boundary and near exterior vertices. Moreover, proved results, examples and counter examples are provided. The Gm-closure structure which suggested in this paper opens up the way for applying rich amount of topological facts and methods in the process of granular computing.
T he article deals with the linguistic, cultural, sociolinguistic, functional and stylistic characteristics of the translation of gluttonic discourse text structures within the framework of the Arabic-Russian combination, as well as with the difficulties encountered in interpretation and translation and related to different conditions under which speech is generated in Arabic and Russian-speaking areas.
The current research aims to highlight the role of social networking sites in the dissemination of scientific knowledge and the importance of their use by researchers, and the researcher relied on the descriptive approach and the survey method. Among the data collection tools are the questionnaire and paper and electronic sources. Among the most important results that the research came out with: The number of the subscribers’ sites was (14) sites, and the most used social sites for receiving and Disseminating Scientific knowledge are: Facebook, Telegram, WhatsApp, Viber, Messenger and YouTube. All respondents receive tacit knowledge (Exchange of Messages and News) through social networking sites, and few of them do not receive explicit kn
... Show MoreThe (Richard Wagner) of cultural figures rare collected between philosophy and literature and the arts to reach the concept of the artwork destruction (Gesamtkunstwerk), who called for by the movement romantic, he is a thinker, and composer renewed, and playwright, designer and architect of a special kind.Able ( Wagner ) that translates his thoughts technical and design in the field of opera and disclose those ideas models actual dealt joints essential this art heritage, which was developed and laid his modern rules approach by achieving his dream creates theater ideal, which was held in the city ( Bayreuth) in ( Bavaria ), one of the German Federal States .The study reviews the ideas of Wagner and their sources, which have had an import
... Show MoreThe objective of this study was to investigate the levels of depression, anxiety, and stress among dentists during covid-19 lockdown and to investigate the relationship between stress and each mental health state.
A cross-sectional survey on 269 dentists was conducted using DASS-21 and PHQ-9 questionnaires. Bivariate and multivariate models were constructed and the odds ratio (OR) was calculated to assess the strength of the association between an independent categorical variable and the outcome.
Being unsatisfied with the job was as
The rotor dynamics generally deals with vibration of rotating structures. For designing rotors of a high speeds, basically its important to take into account the rotor dynamics characteristics. The modeling features for rotor and bearings support flexibility are described in this paper, by taking these characteristics of rotor dynamics features into standard Finite Element Approach (FEA) model. Transient and harmonic analysis procedures have been found by ANSYS, the idea has been presented to deal with critical speed calculation. This papers shows how elements BEAM188 and COMBI214 are used to represent the shaft and bearings, the dynamic stiffness and damping coefficients of journal bearings as a matrices have been found
... Show MoreThe current research deals with practical studies that explain to the Iraqi consumer multiple instances about the phenomenon of water hammer which occur in the water pipeline operating with pressure. It concern a practical study of the characteristics of this phenomenon and economically harmful to the consumer the same time. Multiple pipe fittings are used aimed to reduce this phenomenon and its work as alternatives to the manufactured arresters that used to avoid water hammer in the sanitary installations, while the consumer did not have any knowledge as to the non-traded for many reasons, including the water pressure decreases in the networks and the use of consumer pumps to draw water directly from the network. Study found a numbe
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