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The Effect of Restriction Shape On Laminar Natural Convection Heat Transfer In A Vertical Circular Tube
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Natural convection heat transfer is experimentally investigated for laminar air flow in a vertical circular tube by using the boundary condition of constant wall heat flux in the ranges of (RaL) from (1.1*109) to (4.7*109). The experimental set-up was designed for determining the effect of different types of restrictions placed at entry of heated tube in bottom position, on the surface temperature distribution and on the local and average heat transfer coefficients. The apparatus was made with an electrically heated cylinder of a length (900mm) and diameter (30mm). The entry restrictions were included a circular tube of same diameter as the heated cylinder but with lengths of (60cm, 120cm), sharp-edge and bell-mouth. The surface temperature along the cylinder surface for same heat flux would be higher values for circular restriction with length of (120cm) and would be smaller values for bell-mouth restriction. The results show that the local Nusselt number (Nux) and average Nusselt numberare higher for bell-mouth restriction and smaller values for (120cm) restriction. For all entry shape restrictions, the results show that the Nusselt number values increases as the heat flux increases. From the present work an empirical correlations were obtained in a form of (Log) versus (Log) for each case investigated and obtained a general correlation for all cases which reveals the effect of restriction existence on the natural convection heat transfer process in a vertical circular tube.

 

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Publication Date
Mon Oct 05 2026
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of glass flakes reinforcement on the surface hardness and surface roughness of heat-cured poly (methyl methacrylate) denture base material
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Background: Heat-cured poly (methyl methacrylate) the principal material for the fabrication of denture base have a relatively poor mechanical properties. The aim of this study was to investigate the effect of glass flakes used as reinforcement on the surface hardness and surface roughness of the heat-processed acrylic resin material. Material and method: Glass flakes (product code: GF002) pretreated with silane coupling agent were added to Triplex® denture base powder using different concentrations. A total of 100 specimens of similar dimensions (65 x 10 x 2.5) mm were prepared, subdivided into 2 main groups of 50 specimens for each of the study tests. Ten specimens for the control group and 40 specimens for each of the experimental gro

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Publication Date
Tue May 01 2012
Journal Name
Iraqi Journal Of Physics
Detection of line shape parameters in normal and abnormal biological tissues
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Doppler broadening technique is suggested to monitor the development of tumours. It depends on the sensitivity of positronium (Ps) annihilation parameters to the sub- microstructural changes in biological tissues. This technique uses high resolution HpGe detector to measure the lineshape parameters (S and W) in normal mice's mammary tissues and adenocarcinoma mammary tissues as a function of tumour growth. The results demonstrate that the central parameter (S) decreases and the wing parameter (W) increases as the tumour grow. It is found that the S parameter changes considerably with the distribution of voids which are affected by the tumour development. Therefore the present technique can successfully be employed to monitor the developm

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Publication Date
Thu Jun 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
A Comparison of Vertical Marginal Fit of different Brands of Translucent Zirconia Crown Restorations
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Background: As the development of zirconia crown using CAD/CAM technology, the usage of full zirconia crown is gradually increased. The aim of this in-vitro study was to evaluate and contrast the vertical marginal fit of single all-ceramic translucent zirconia crowns constructed from different brands translucent zirconia blanks. Materials and Methods: An acrylic resin model of a left maxillary premolar was prepared all around the tooth with (1 mm) depth and 3D scanning to get fifteen STL files, then distributed into three groups (Imes-icor, Whitepeaks and Dental direct), 3D scanning and milling machine by Imes-icor CAD/CAM devise. Marginal gaps along vertical planes were measured at four indentations at the (mid mesial, mid distal, mid bucc

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Publication Date
Wed May 10 2023
Journal Name
Journal Of Engineering
DOUBLE DIFFUSIVE FREE CONVECTION IN A PACKED BED SQUARE ENCLOSURE BY USING LOCAL THERMAL NON-EQUILIBRIUM (LTNE) MODEL
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In the present study, free convection heat and mass transfer of fluid in a square packed bed enclosure is numerically investigated. For the considered geometrical shape, the left vertical wall of enclosure was assumed to be kept at high temperature and concentration while the opposite wall was kept at low temperature and concentration with insulating both the top and bottom walls of enclosure. The Brinkman– Forchheimer extended Darcy model was used to solve the momentum equations, while the energy equations for fluid and solid phases were solved by using the local thermal non-equilibrium (LTNE) model.Computations are performed for a range of the Darcy number from 10-5 to 10-1, the porosity from 0.5 to 0.9, and buoyancy ratio from -15 t

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Publication Date
Tue Jun 11 2002
Journal Name
Iraqi Journal Of Laser
Investigating the Effects of Carbon Dioxide Laser Fluence on Oral Soft Tissue
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This study investigates the surgical and thermal effects on oral soft tissues produced by CO2 laser emitting at 10.6 micrometers with three different fluences 490.79, 1226.99 and 1840.4 J/cm2. These effects are specifically; incision depth, incision width and the tissue damage width and depth. The results showed that increasing the fluence and /or the number of beam passes increase the average depths of ablation. Moreover, increasing the fluence and the number of beam passes increase the adjacent tissue damage in width and depth. Surgeons using CO2 laser should avoid multiple pulses of the laser beam over the same area, to avoid unintentional tissue damage.

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Publication Date
Sun Jan 02 2022
Journal Name
Journal Of The College Of Languages (jcl)
The Effect of Genderism on the Process and the Product of Translation
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    Many studies have been made and still concerning the field of translation. Since the mid-90's a considerable amount of researches has tackled the problem of gender and its effect on the process and the product of translation. Simon (1996, p 508) points out that when comparing women and men as translators and writers through history, women seem to be the weaker side. This paves the way to feminist movements which produce prominent studies concerning gender as a concept and translator's gender as practice on the quality and the accuracy of the translation.           

     Flotow (in Meschia, 2012, p 1-4) outlines several issues that can be

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
The effect of self management in the hardiness at work / study analytic in hospital Alshaheed Gaze Alharery
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The research is Concerned the Relationship between Self Management which is a modern administrative term and its dimensions "Self Control, Trust, and Conscientiousness" with the Hardiness and its dimensions "Challenge, Commitment, and Control". And the impact of the first variable on the second in The Hospital of Alshaheed Gaze Alharery.

The Questionnaire used and distributed on sample (60) Persons, contain from (40) Doctor, and (20) Employees from the total society (103).

The statistical methods have been used for testing the hypothesis is the mean, standard deviation correlation coefficient.

    The resea

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Publication Date
Thu May 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Restrained Edges Effect on the Dynamics of Thermoelastic Plates under Different End Conditions
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Frequency equations for rectangular plate model with and without the thermoelastic effect for the cases are: all edges are simply supported, all edges are clamped and two opposite edges are clamped others are simply supported.   These were obtained through direct method for simply supported ends using Hamilton’s principle with minimizing Ritz method to total energy (strain and kinetic) for the rest of the boundary conditions. The effect of restraining edges on the frequency and mode shape has been considered. Distributions temperatures have been considered as a uniform temperature the effect of developed thermal stresses due to restrictions of ends conditions on vibration characteristics   of a plate with different

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Publication Date
Sat Dec 31 2022
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
EFFECT OF Artemisia vulgaris L. AQUEOUS EXTRACT ON SOME GERMINATION PROPERTIES AND SEEDLING GROWTH OF LINSEED : EFFECT OF Artemisia vulgaris L. AQUEOUS EXTRACT ON SOME GERMINATION PROPERTIES AND SEEDLING GROWTH OF LINSEED
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ABSTRACT

            A laboratory experiment was carried out during winter season of 2021 in the Seed Technology Laboratory- College of Agricultural Engineering Sciences/ University of Baghdad, to find out the allopathic effects of aerobic and terrestrial aqueous extracts of Artemisia vulgaris L. on the seed germination and seedling growth of linseed. A factorial experiment according to a completely randomized design (CRD)at three replicates was used; the first factor in clouded type of aqueous extract for two plant parts which were aerobic (stems and leaves) and terrestrial (root and rhizomes), while the second factor included five concentrations

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Publication Date
Tue Jul 01 2025
Journal Name
Mastering The Minds Of Machines
The Impact of Transfer Learning and Pre-trained Models on Model Performance
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