Natural convection in a trapezoidal enclosure with partial heating from below and symmetrical cooling from the sides has been investigated numerically. The heating is simulated by a centrally located heat source on the bottom wall, and four different values of the dimensionless heat source length, 1/5, 2/5, 3/5, 4/5 are considered. The laminar flow field is analyzed numerically by solving the steady, two-dimensional incompressible Navier-Stokes and energy equations. The Cartesian velocity components and pressure on a collocated (non-staggered) grid are used as dependent variables in the momentum equations discretized by finite volume method; body fitted coordinates are used to represent the trapezoidal enclosure, and grid generation technique based on elliptic partial differential equations is employed. SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass. The range of Rayleigh number is (103≤ Ra ≤105) and Prandtl number is 0.7. The results show that the average Nusselt number increases with the increases of the source length.
The present research focuses on the study of the effect of mass transfer resistance on the rate of heat transfer in pool boiling. The nucleate pool boiling heat transfer coefficients for binary mixtures (ethanol-n-butanol, acetone-n-butanol, acetone-ethanol, hexane-benzene, hexane-heptane, and methanol-water) were measured at different concentrations of the more volatile components. The systems chosen covered a wide range of mixture behaviors.
The experimental set up for the present investigation includes electric heating element submerged in the test liquid mounted vertically. Thermocouple and a digital indictor measured the temperature of the heater surface. The actual heat transfer rate being obtained by multiplying the voltme
... Show MoreThe Research is interested in the detailed comparative study of certain selection of
Imam Alsamarqandi in some subjects of washing and touching the Gracious Quran.
The value of this study is that it is related to one aspect of the duties obliged on Muslim
like parity.
The study has tried to collect certain scholars’ opinions of eight doctrines with the
selection of Alsamarqandi to make a comp arson between them and to show how
Alsamarqandi is able to create legal laws from his sources to lead the researchers nto have
knowledge about the syllabi of the famous scientists.
Finally we ask God to bless to what is right and to accept this study and make it part of
our good deeds, Ameen.
The aim of this research is subjected to discover The Dictation mistakes which occur
widely in the Arabic Language written by Iraqi – News papers.
The research classified These Mistakes in Three groups as Follows:
1. The first group dealing with distinguishing between the Arabic – letter ) ا ( When Written
or ) أ ( at The beginning The word and as ) ئ ( which differ in meaning from each other .
2. The second group dealing with the writing of The Arabic ) ٙ( and as ) ٛ( at the end of The
word which differ in meaning from each other.
3. The Third group dealing with distinguishing in written The Arabic letter as ) ض( or as ) )ظ
which differ in meaning From each other.
4. The fourth group dealing with Th
The family Ormyridae has been very much neglected by workers and only two species has been recorded so far from Iraq. The present study, based mainly on my collection, deals with five species, of which one is new to science. The new species is described together with notes on locality data, host records, distribution and taxonomical remarks for all the species.
Nations are developed with education and knowledge that raise the status of society in its various segments, beyond that it leads to underdevelopment and deterioration in various sectors, whether economic, health, social, etc. If we considered the general name of The ministry of Education & Scientific Studies, then the second part seems to be not functioning, since scientific research has no material allocation and remains based on the material potential of the university professor. As for the first half of the topic, the reality of the situation reveals problems related to the Holy Trinity of Education which is (Professor - Student - the scientific method) where universities suffer at the present time from this problem, and
... Show MoreArtichoke (Cynara scolymus L.) is a nutritious vegetable that grown all over the world. It is a promising herbal plant, rich in bioactive components. It is considered as medicinal plant due to its nutritional and phytochemical composition, especially high proportion of phenolic compounds. The primary aim of this study was to achieve chemical profile analyses of artichoke for different phytochemcials, especially Scolymoside and Cynaroside. Methanolic crude was extracted from Artichoke leaves by rotary evaporator and separated by column chromatography. The fractions monitored by Thin Layer Chromatography (TLC), and identified in High-Pressure Liquid Chroma
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