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Numerical Investigation of Natural Convection Heat Transfer in Partially Filled Porous Enclosure Subjected to Constant Heat

Steady natural convection in a square enclosure with wall length (L= 20 cm) partially filled by saturated porous medium with same fluid (lower layer) and air (upper layer) is investigated. The conceptual study of the achievements of the heat transfer is performed under effects of bottom heating by constant heat flux (q=150,300,450,600W/m2 ) for three heaters size (0.2,0.14,0.07)m with symmetrically cooling with constant temperature on two vertical walls and adiabatic top wall. The relevant filled studied parameters are four different porous medium heights (Hp=0.25L,0.5L, 0.75L, L), Darcey number (Da1) 3.025×10-8 and (Da2) 8.852×10-4 ) and Rayleigh number range (60.354 - 241.41), (1.304×106 – 5.2166×106 ) for Da1 and Da2 cases respectively. Numerically, COMSOL Multiphysics 5.5a® based on the Galerkin finite element method is used for solving the governing equations with depending Brinkman- Darcy extended mode for porous media region. The results show that, effects of increasing the Rayleigh number on the temperature profile besides the progressively increasing the average Nusselt number. Moreover, symmetrical distribution of local Nu along the bottom heated wall and it is be minimum at midpoint of bottom. Also, the heat transfer and fluid flow are affected by thickness of porous layer and are maximum at porous layer thickness (0.25L) which clearly observed with large heater size to be approximately (93%) for the average Nu. Generally, the heat transfer is enhanced for large Darcy number (8.852×10-4 ) and influenced by the convection regime improvement while it is mainly conduction mode for (Da1) for all Raleigh number with a little effect of convection when increase (Ra).

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Publication Date
Sun Apr 16 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Univariate and Multivariate Optimization of Spectrophotometric Determination of Europium (III) in Pure Form and Synthetic Sample

    Two different approaches, univariate and multivariate (simplex method), have been used to obtain the optimum conditions for the quantitative Spectrophotometric determination of Eu3+ using Solochrome violet RS (3-Hydroxy-4-(2-hydroxy phenyl azo) naphthalene -1sulfonic acid) (SVRS) as a chromogenic reagent. The investigation shows that Eu3+ ion forms a wine-red complex with SVRS in alkaline buffer solution having a maximum absorbance at 464 nm against reagent blank.       Calibration graphs obtained under univariate and simplex were found to be linear in the range of (0.30-8.0) µg/ml with detection limit 0.061µg/ml and molar absorptivity of 9877.66 L/mol.cm and (0.40-10.0)µg/ml with

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Publication Date
Wed May 31 2023
Journal Name
Russian Law Journal
LEGAL RULES GOVERNING THE DURATION OF THE CONTRACT IN ITS PERIOD OF FORMATION (COMPARATIVE LEGAL STUDY)

The duration of the contract is a legal term first provided for in French Amendment Decree No. 131/2016, and given the increasing importance of time in contracts, we have chosen to study the legal rules governing time at the formative stage by drawing on changes in French law compared to both Iraqi and Egyptian laws.

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Publication Date
Fri Mar 01 2013
Journal Name
International Journal Of Recent Research And Review
Influence of Discharge Pressure on the Plasma Parameter in a Planar Dc-Sputtering Discharge of Argon

Abstract- Plasma parameters in a planar dc-sputtering discharge in argon were measured by cylindrical electrostatic probe (Langmuir probe).Electron density, electron temperature, floating potential, and space potential were monitored as a function of working discharge pressure. Electrostatic probe and supporting circuit were described and used to plot the current – voltage characteristics. Plasma properties were inferred from the current-voltage characteristics of a single probe positioned at the inter-cathode space. Typical values are in the range of (10-16 -10-17) m-3 and (2.93 – 5.3) eV for the electron density and the electron temperature respectively.

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Publication Date
Sun Sep 05 2010
Journal Name
Baghdad Science Journal
Chemotherapy Effects on the Activities of Some Purine Metabolic Enzymes in Sera of Ovarian Cancer Patients

Adenosine deaminase (ADA; Ec: 3.5.4.4), 5´- Nucleotidase (5´– NT; Ec: 3.1.3.5), and AMP – amino hydrolase (AMP – deaminase AMPDA; Ec: 3.5.4.6) activities were measured in sera of ovarian cancer patients before surgery, and after chemotherapy. The results indicated that ADA specific activity increased significantly (P<0.05), while 5´-NT and AMPDA specific activity decreased significantly (P<0.05) in ovarian cancer patients before surgery in comparison with those of their corresponding control women and benign tumors groups. When the activities of these enzymes were measured after chemotherapy, a significant decrease (P<0.05) in ADA activity, and a significant increase (P<0.05) in 5´- NT and AMPDA activities w

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Publication Date
Sun Feb 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
The role of the integration of the knowledge economy and international accounting in achieving sustainable development

     The current environment is witnessing several developments as a result of the changes  taking place in all areas of economic, social , political and legal that led to the transformation of the industrial economy , which depends based on quantitative production to a knowledge economy which relies based on information and knowledge , as the central pillar of this economy during the trading  of  these information and knowledge between all individuals in general and decision makers , in particular, through information and communication technology of computers and the Internet to achieve sustainable human development in the social dimension.         &

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Publication Date
Wed Nov 24 2021
Journal Name
Iraqi Journal Of Science
Structural and Stratigraphic Study of Hartha Formation in the East Baghdad Oil Field, Central of Iraq.

Three-dimensional seismic reflection study was conducted for the Eastern
Baghdad oil field which is located in the middle part of Iraq within Al-Madaaen
province that belong to Baghdad governarate, South of Diyala River , this field
includes two southern parts (S1 and S2), the study area was about 781.905 km 2 for
the upper Cretaceous age, synthetic seismogram was generated from data of EB-5
and EB-1 wells. Saadi reflector was picked and identified to determine the Hartha
Formation. The seismic sections and time slice maps confirmed that the upper
Cretaceous age was affected by faults and the indicators of faults ended within
Hartha Formation and continue to the deeper formations with increasing intensity.
The

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Publication Date
Sun Jul 02 2023
Journal Name
Iraqi Journal Of Science
Determination of Uranium Concentration in Soil of Baghdad Governorate and its Effect on Mitotic Index Assay

The aim of this work is to determine the uranium concentration in soil samples
taken from the north, south, east, west and center of the city of Baghdad and
measure its impact on the rate of cell division for non-smokers peoples and living in
those areas and that between the ages 25-30 year.
The uranium concentration in the samples determined by using CR-39 track
detector . As calculated for the ten samples of each site when irradiated by thermal
neutrons from the (Am - Be) source with flux (5x 103 n S-1cm-2), the concentration
values were calculated by a comparison with standard geological samples. The
results indicate that the extent of the concentration of uranium in the soil north and
east of Baghdad was 12

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Publication Date
Thu Jun 15 2023
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of leukocytes cells types counts in blood from patients with different severities of periodontal diseases

Background: Periodontal diseases are inflammatory disorders caused by the accumulation of oral biofilm and the host response to this accumulation which characterized by exaggerated leukocytes and neutrophils attraction to the sites of inflammation by chemoattractants which are a very important part of the pathogenesis of periodontal diseases. This study aimed to determine and compare the clinical periodontal parameters and the leukocyte cell types in the peripheral blood between patients with gingivitis and periodontitis with different severities compared to healthy controls. Materials and methods: This study included 150 male subjects aged between 35-50 years. They were divided into three groups: gingivitis group (n=30), periodontitis p

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Publication Date
Sun Sep 06 2009
Journal Name
Baghdad Science Journal
Study of Malondialdehyde Levels in sera, RBCs and Tissues homogenate of Iraqi Women With Breast Tumors

Breast tumors patients generally have more oxidative stress than normal females. This was clear from a highly significant elevation (P<0.05) in malondialdehyde level in RBCs, serum and tissue of all patients groups with breast cancer as compared with control group. In this study we had found that free radicals in malignant breast tumors were higher than benign tumors, therefore the MDA might be used as a marker for prognosis of the disease.

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Publication Date
Mon Jan 02 2017
Journal Name
Al-academy
The signification levels of scenery in the Iraqi theatrical show (the play of alubah for example)

Signification with its different aspects constitutes various aesthetic pictures for human and nature creations over different periods of time. It was a focal around which logical thinking loops on the interpretation level of the signification movement according to its structural context expresses its hidden entities with which a human being deals according to two symmetrical levels while interpreting to attain meaning. Sense was the first passing window for the picture of signification which thought deals with. While trying to decode it and because art in general and theatre in particular are considered as the basis of creating signification through its visual and aural elements, so it was necessary to consider one of the elements of cre

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