Preferred Language
Articles
/
joe-2040
Numerical Simulation of 3D- Flow Structure and Heat Transfer for Longitudinal Riblet Upstream of Leading Edge Endwall Junction of Nozzle Guide Vane
...Show More Authors

The simulation have been made for  3D flow structure and heat  transfer with and without

longitudinal riblet upstream of leading edge vane endwall junction of first stage nozzle guide vane .The research explores concept of weakening the secondary flows and reducing their harmful effects.Numerical investigation involved examination of the secondary flows ,velocity and heat transfer rates by solving the governing equations (continuity, Navier -stokes and energy equations ) using the known package FLUENT version (12.1).The governing equations were solved for three dimentional, turbulent flowe, incompressible with an appropriate turbulent model (k-ω,SST) .The numerical solution was carried out for 25 models of V-groove riblet with wide ranges of height (h) and space (s). The results indicated that, the riblet endwall junction was a powerful tool for controlling the flow structure, reducing secondary flow formation,and elimination the effect of heat transfer at leading edg and passage . The drag reduction produced by riblet was proportional with their height and space. V-groove riblet with dimension of (h=1.35mm and s=2.26mm) was found to be the most effective in reduction of drag (2.7%) and heat transfer (21%) so it was selected as an optimum dimension of riblet model. The results also showed that the drag reduction produced by riblet was proportional to their size. The riblet model had a great effect in elimination spanwise ,pitchwise velocities ,but strength the streamwise velocity .At leading edge ,the effect of secondary flow was extended up to 23% from span height and 35% upstream leading edge .The riblet model caused an increase in momentom at a region very close to leading edge and to move stagnation point very close to the leading edge.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Oct 01 2020
Journal Name
Biochem. Cell. Arch
NEW ORGANOTIN(IV) COMPLEXES DERIVED FROM 3,4-DIHYDROXYBENZALDEHYDEN(4)-ETHYL-3-SEMICARBAZONE LIGAND: SYNTHESIS, CHARACTERISATION AND BIOLOGICAL ACTIVITY
...Show More Authors

Two new organotin(IV) complexes Me2Snesc (C1) and Bu2Snesc (C2) have been synthesised from the reaction of the corresponding organotin(IV) chloride with the Schiff base ligand 3,4-dihydroxybenzaldehyde-4-ethylsemicarbazone (H2esc). The ligand was prepared in two steps. The first step includes the formation of 4-ethylsemicarbazide, which then reacted with 3,4-dihydroxybenzaldehyde to give the title ligand. Complex formation between the organotin(IV) moiety and the anionic form of 3,4-dihydroxybenzaldehy-4-ethylsemicarbazone occurred through the o-dihydroxy positions. The ligand and its complexes were characterised by elemental analysis, FT-IR and NMR (1H, 13C and 119Sn) spectroscopy. Accordingly, the complexes were proposed to have tetrahedr

... Show More
Scopus (3)
Scopus
Publication Date
Tue Jun 20 2023
Journal Name
Al-rafidain Journal Of Medical Sciences ( Issn 2789-3219 )
The PharmD Students’ Beliefs, Perceptions, and Challenges Regarding their First Year in the PharmD Program: A Qualitative Study
...Show More Authors

Background: The beliefs of pharmacy students in their curriculum may be critical to the success of medical education and the development of global health competences. Objective: To assess the beliefs, attitudes, and obstacles of PharmD students at the College of Pharmacy, University of Baghdad, during their first year in the newly adopted PharmD program. Method: In-depth qualitative interviews were conducted using flexible probing approaches. A sample of fourth-year PharmD students from the University of Baghdad's College of Pharmacy was selected using a purposive sampling method. The gathered data was analyzed using a thematic content analysis approach. Results: 40% of participants applied for the program because they believed it w

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Crossref
Publication Date
Sat Nov 05 2016
Journal Name
Research Journal Of Applied Sciences, Engineering And Technology
Image Compression Based on Cubic Bezier Interpolation, Wavelet Transform, Polynomial Approximation, Quadtree Coding and High Order Shift Encoding
...Show More Authors

In this study, an efficient compression system is introduced, it is based on using wavelet transform and two types of 3Dimension (3D) surface representations (i.e., Cubic Bezier Interpolation (CBI)) and 1 st order polynomial approximation. Each one is applied on different scales of the image; CBI is applied on the wide area of the image in order to prune the image components that show large scale variation, while the 1 st order polynomial is applied on the small area of residue component (i.e., after subtracting the cubic Bezier from the image) in order to prune the local smoothing components and getting better compression gain. Then, the produced cubic Bezier surface is subtracted from the image signal to get the residue component. Then, t

... Show More
View Publication
Crossref (2)
Crossref
Publication Date
Wed Jun 01 2022
Journal Name
Journal Of The College Of Languages (jcl)
Reduced and Citation Forms as Produced by Iraqi EFL University Students at Duhok University An Error Analytic Study
...Show More Authors

English is spoken by its native speakers in two different forms. Reduced form which marks the colloquial and rapid speech so that it is easily produced and a citation or unreduced form which is a characteristic of careful, emphasized and slow speech.

      This paper investigates Iraqi EFL university students’ production of the two forms mentioned above. The sample chosen includes twenty fourth year students, of which ten are males and the other ten are females from the Department of English of the College of Languages of the University of Duhok in Kurdistan Region of Iraq in the academic year 2020-2021.  The material tested is six connective words which represent the commonest ones in every-day co

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Sep 15 2019
Journal Name
Al-academy
Tourist Resting Units and their Design Methods in the Iraqi Marshlands: هدى محمود عمر -لقاء غازي حمد منصور
...Show More Authors

    The study dealt with the design of tourist resting units in the Iraqi Marshes in contemporary design methods while preserving the heritage. The first chapter contained the research problem which is the important event of the inclusion of the Marshes in the World Heritage List. This research is important because it aims to develop the tourist reality of the Marshlands. The second chapter dealt with three sections the first of which is tourism in the marsh environment, the second one dealt with the structure of tourist space and the third dealt with the design methods of the tourist resting units in the Iraqi marshes.

The most important results of the research are the following: the sample models have taken desig

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jul 01 2016
Journal Name
Arabian Journal Of Geosciences
Polymetallic sulfide ores hosted in Late Permian carbonate at the Alanish locality, northern Iraq: petrography and mineral chemistry
...Show More Authors

View Publication
Crossref (3)
Crossref
Publication Date
Wed Mar 15 2023
Journal Name
Journal Of Tikrit University For Humanities
The Egyptian-Chinese Consensus at the Bandung Conference and Its Impact on Strengthening Relations between Them in 1955
...Show More Authors

كان المؤتمر الآسيوي الأفريقي الأول الذي عُقد في مدينة باندونغ الاندونيسية عام 1955 هو المؤتمر هو الأول الذي اجتمعت فيه الدول الآسيوية والأفريقية بعد الحرب العالمية الثانية. كان مؤتمر باندونغ بمثابة نقطة الانطلاق نحو تأسيس حركة عدم الانحياز، والتي كانت مصر أحد أبرز أقطابها. شهد المؤتمر تقاربا في الآراء ووجهات النظر بين جمهورية مصر العربية وجمهورية الصين الشعبية، لا سيّما وإن الحكومة المصرية كانت قد تبنت س

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Dec 01 2019
Journal Name
Gene Reports
Hepatitis B virus genotypes among chronic hepatitis B patients from Baghdad, Iraq and their impact on liver function
...Show More Authors

Hepatitis B virus (HBV) infection is a significant global health problem. Populations of different ethnicities show great heterogeneity in HBV genotype frequency distributions. A cross-sectional study was conducted during June–October 2018 to determine frequency of HBV genotypes among chronic HBV patients from Baghdad, Iraq. The method of detection was nested polymerase chain reaction system. Further, the study assessed the impact of HBV genotypes on serum level of liver-function tests: total serum bilirubin, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase. Eighty chronic HBV patients were enrolled in the study. Six HBV genotypes were identified (A, B, C, D, E and F). The most frequently encountered genotypes

... Show More
Scopus (10)
Crossref (5)
Scopus Crossref
Publication Date
Wed Jan 01 2025
Journal Name
Advances In Animal And Veterinary Sciences
Exposure to Environmental Perfluorooctanoic Acid (PFOA) Induced Hepatocellular Apoptosis and Alteration in Serum Biomarkers in Diabetic Guinea Pigs
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Thu Oct 25 2018
Journal Name
Journal Of Optical Communications
320 Gbps Free Space Optic Communication System Deploying Ultra Dense Wavelength Division Multiplexing and Polarization Mode Division Multiplexing
...Show More Authors
Abstract<p>This work aims to investigate the integrated ultra-dense wavelength division multiplexing (UDWDM) and polarization division multiplexing (PDM) schemes incorporated in the free space optic (FSO) communication system. Erbium-doped fiber amplifiers (EDFAs) are used as post and pre-amplifiers in the proposed UDWDM–PDM–FSO system to boost the transmission power for increasing the distance. Thirty-two channels are transported over the FSO link to realize the total data transmission of 160 and 320 Gbps with 0.08 and 0.1 nm channel spacing, respectively. Results are also reported with non-return to zero modulation schemes. The performance of the proposed UDWDM–PDM–FSO transmission sys</p> ... Show More
View Publication
Scopus (8)
Crossref (7)
Scopus Crossref