The current study presents an experimental investigation of heat transfer and flow characteristic for subcooled flow boiling of deionized water in the microchannel heat sink. The test section consisted of a single microchannel having 300μm wide nominal dimensions and 300μm height (hydraulic diameter of 300μm). The test section formed of oxygen-free copper with 72mm length and 12mm width. Experimental operation conditions spanned the heat flux (78-800) kW/m2, mass flux (1700 and 2100) kg/m2.s at 31˚C subcooled inlet temperature. The boiling heat transfer coefficient is measured and compared with existing correlations. Also, the experimental pressure drop is measured and compared with microscale pressure drop correlations. The results showed that higher mass flux leads to higher boiling heat transfer coefficient, and the dominant mechanism is convective boiling. Also, the experimental pressure drop decrease with increasing heat flux in a single-phase region while it increases in a two-phase region. Comparing the experimental results in the experimental condition range, showed that an existing correlation provides a satisfactory prediction of heat transfer coefficient and pressure drop.
There are a number of obstacles in the field of work of social workers that prevent them from performing their full role. Their tasks may sometimes be easy and manageable and at other times they may be difficult and complex, however professional roles are mostly the latter, contribute to the feeling of the inability to provide the work required at the level expected by others. In such cases, the relationship binding specialists to their work is affected negatively and this has devastating effects on the professional process as a whole, including their professional practice. This feeling of helplessness and depletion of energy and effort leads to a state of fatigue and emotional exhaustion that can be defined as job burnout, our study aims t
... Show MoreThe present paper is a qualitative descriptive study. It aims to examine the macro-cultural schemata addressing the concept of violence against women in Iraq from a cognitive linguistic point of view. To meet this objective, a number of Iraqi social caricatures have been selected from two popular and active Iraqi caricaturists, Odeh Al-Fahdawi and Nasser Ibrahim. The selection and the analysis of data have been achieved following the validity and reliability procedures and the ethical considerations. To meet this objective, Sharifian’s Model (2011) of Cultural Schemata has been adopted in data analysis. The study has concluded that the macro-cultural schemata regarding the concept of violence in the selected panels reveals that violenc
... Show MoreThe study of the dynamic behavior of packed distillation column was studied by frequency response analysis using Matlab program. A packed distillation column (80 mm diameter) (2000 mm height) filled with glass packing (Raschig Rings 10mm), packing height (1500 mm) has been modified for separation of methanol-water mixture (60 vol%). The column dynamic behavior was studied experimentally under different step changes in, feed rate (±30%), reflux rate (±22%), and reboiler heat duty (±150%), the top and bottom concentration of methanol were measured. A frequency response analysis for the above step response was carried out using Bode diagram, the log modulus and the phase angle were used to analyze the process model. A Matlab progra
... Show MoreThe study included gross morphology and pollen of plants – which collected during field trips , and dry ones for most specimen preserved with the Iraqi herbaria – related to the genus Lycopus L. , and to identify the unidentified species and rectify the error there in , so according to that the species L. europaeus L. only were specified for the genus . Through this work the varity L. europaeus var. glabrescens Schmidely were found at the first time , and suggested to record anew for Iraq . Pollen were of medium size, and had an ellipsoid shape in the equatorial view , and hexagonal in the polar view. The ecological and soil quality where these genus plants grows were specified , and were geographically distribut
... Show MoreThe present study is a linguistic study of comment clauses in the American Series „Friends‟ .Comment clauses refer to those clauses which comment on the content of the main clause or the attitude of the speaker towards the way of speaking .The problem of this study is to answer the following questions ; what types of comment clauses can be used in the face- to –face conversations , for what functions these comment clauses could be used , and how these comment clauses are used by the participants of these conversations . This study is a qualitative one . The study aims to investigate the types of comment clauses used in the American Series “Friends‟. The study also aims to investigate the pragmatic functions of these comment clause
... Show MoreThis study explores the semiotic aspects of American slang, specifically focusing on the phenomenon of reduplicative expressions in informal speech. Despite the extensive research on American slang, limited attention has been given to the cultural and mythical meanings embedded within reduplicative expressions. To address this gap, the study investigates how these expressions convey denotative, connotative, and mythical meanings within casual American discourse. The objectives of the study include: 1. To what extent does Barthes’ semiotic model hold potential for application in this study? 2. How are reduplicative slang expressions widely used in everyday American life? 3. To what extent do qualitative and quantitative methods hav
... Show MoreIdentity crisis is a dominant literary theme, especially in most Arab women writers’ works. However, it has not been given enough attention from a linguistic point of view. By so doing, the current study intends to fill this gap by analyzing the identity crisis from a pragma-stylistic perspective by examining the writer's style in three purposely selected extracts from Diana Abu-Jaber’s novel Origin (2007). The study aims to examine the identity crisis by using pragmatic and stylistic tools and to explore the effects of Abu-Jaber’s stylistic choices on the readers of her work. To conduct this study, an eclectic model comprising Searle’s speech acts (1979), Brown and Levinson's politeness theory (1987), Leech's model of figur
... Show MoreObjective: To conduct a standardized method for cavity preparation on the palatal surface of rat maxillary molars and to introduce a standardized method for tooth correct alignment within the specimen during the wax embedding procedure to better detect cavity position within the examined slides. Materials and methods: Six male Wistar rats, aged 4-6 weeks, were used. The maxillary molars of three animals were sectioned in the frontal plane to identify the thickness of hard tissue on the palatal surface of the first molar which was (250-300µm). The end-cutting bur (with a cutting head diameter of 0.2mm) was suitable for preparing a dentinal cavity (70-80µm) depth. Cavity preparation was then performed using the same bur on the tooth
... Show MoreObjective: To conduct a standardized method for cavity preparation on the palatal surface of rat maxillary molars and to introduce a standardized method for tooth correct alignment within the specimen during the wax embedding procedure to better detect cavity position within the examined slides. Materials and methods: Six male Wistar rats, aged 4-6 weeks, were used. The maxillary molars of three animals were sectioned in the frontal plane to identify the thickness of hard tissue on the palatal surface of the first molar which was (250-300µm). The end-cutting bur (with a cutting head diameter of 0.2mm) was suitable for preparing a dentinal cavity (70-80µm) depth. Cavity preparation was then performed using the same bur on the tooth surf
... Show MoreThe Rwandan author of comfort chests and verse pleasure of the most important historians of the Seljuks in the sixth century AH / twelfth century and belongs to the mostly ethnic scientists family has won favor with the Sultans of the Seljuks until he became the most famous Markhém is his main source of research sources with respect to the political and social history the Seljuks and the relationship of the Seljuk sultans of the Abbasid caliphs in Baghdad.
The book included the history of the Seljuks from the time of statehood in the fifth century AH / atheist century AD until the death of the Sultan Tgrl bin Arslan year 590 AH / 1193 AD and then shed Akhawarzmeyen, and touched the author at the end of the book in separate chapters t