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Shell and Double Concentric Tube Heat Exchanger Calculations and Analysis
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This study concerns a new type of heat exchangers, which is that of shell-and-double concentric tube heat exchangers. The case studies include both design calculations and performance calculations.

       The new heat exchanger design was conducted according to Kern method. The volumetric flow rates were 3.6 m3/h and 7.63 m3/h for the hot oil and water respectively. The experimental parameters studied were: temperature, flow rate of hot oil, flow rate of cold water and pressure drop.

A comparison was made for the theoretical and experimental results and it was found that the percentage error for the hot oil outlet temperature was (- 1.6%). The percentage errors for the pressure drop in the shell and in the concentric tubes were (17.2%) and (- 39%) respectively. For cold water outlet temperature, the percentage error was (- 3.3%), while it was (18%) considering the pressure drop in the annulus formed. The percentage error for the total power consumed was (-10.8%).

A theoretical comparison was made between the new design and the conventional heat exchanger from the point of view of, length, mass, pressure drop and total power consumed.

 

 

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Publication Date
Sun Dec 07 2014
Journal Name
Baghdad Science Journal
Synthesis, Characterization and Stability Study of V(IV), Zr(IV), Rh(III), Pd(II), Cd(II) and Hg(II) Complexes with Pyrazol Derivative
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In this work lactone (1) was prepared from the reaction of p-nitro phenyl hydrazine with ethylacetoacetate, which upon treatment with benzoyl chloride afforded the lactame (2). The reaction of (2) with 2-amino phenol produced a new Schiff base (L) in good yield. Complexes of V(IV), Zr(IV), Rh(III), Pd(II), Cd(II) and Hg(II) with the new Schiff base (L) have been prepared. The compounds (1, 2) were characterized by FT-IR and UV spectroscopy, as well as characterizing ligand (L) by the same techniques with elemental analysis (C.H.N) and (1H-NMR). The prepared complexes were identified and their structural geometries were suggested by using elemental analysis (C.H.N), flame atomic absorption technique, FT-IR and UV-Vis spectroscopy, in additio

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
PAPR Reduction of OFDM Signals Using Clipping and Coding
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The problem of the high peak to average ratio (PAPR) in OFDM signals is investigated with a brief presentation of the various methods used to reduce the PAPR with special attention to the clipping method. An alternative approach of clipping is presented, where the clipping is performed right after the IFFT stage unlike the conventional clipping that is performed in the power amplifier stage, which causes undesirable out of signal band spectral growth. In the proposed method, there is clipping of samples not clipping of wave, therefore, the spectral distortion is avoided. Coding is required to correct the errors introduced by the clipping and the overall system is tested for two types of modulations, the QPSK as a constant amplitude modul

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Crossref
Publication Date
Mon Feb 13 2023
Journal Name
Journal Of Educational And Psychological Researches
Evaluation of Activities and Evaluation Questions Implied in the Content of the Computer Textbook for the Fifth Preparatory Grade According to Creative Thinking and Developing Suggestions
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The current research aims to evaluate the activities and evaluation questions implied in the content of the computer textbook for the fifth preparatory grade according to the creative thinking and developing suggestions through answering the following question: what is the percentage of creative thinking skills in the content of the computer textbook for the fifth Preparatory grade students issued by the Iraqi Ministry of Education/ Directorate General of the curriculum in the academic year (2019-2020)? The researchers followed the descriptive-analytical approach.  The research community was determined by the content of the computer textbook for the fifth preparatory grade. As for the research sample, it was limited to all activitie

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Publication Date
Thu Oct 01 2009
Journal Name
Journal
Female pattern alopecia and lipoproteins
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S Khalifa E, N Adil A, S Husam Ali, H Nibras A…, 2009

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Publication Date
Fri Jul 01 2011
Journal Name
Alustath
Pun in English and Arabic
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Publication Date
Wed Sep 15 2021
Journal Name
Journal Of Baghdad College Of Dentistry
Diet and orthodontics- A review
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During the course of fixed orthodontic therapy, patients should be instructed to eat specific food stuffs and beverages in order to maintain good health for the dentition and supporting structures and prevent frequent attachment debonding that prolong the treatment duration. After searching and collecting articles from 1930 till July 2021, the current review was prepared to emphasize various types of foods that should be taken during the course of fixed orthodontic therapy and to explain the effect of various food stuffs and beverages on the growth and development of craniofacial structures, tooth surfaces, root resorption, tooth movement, retention and stability after orthodontic treatment and the effect on the components of fixed ortho

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Scopus (6)
Crossref (5)
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Publication Date
Thu May 31 2018
Journal Name
الاستاذ للعلوم الانسانية والاجتماعية
Tolerance between Christianity and Islam
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The Christian religion came in love and co-existence with all human beings, united in the minds of its people, including the great creation to form a strong unit of high ethics that contributes to the unity among the members of society and coexistence in security, peace and love of harmony.

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Publication Date
Mon Aug 01 2022
Journal Name
Baghdad Science Journal
Semihollow-Lifting Modules and Projectivity
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Throughout this paper, T is a ring with identity and F is a unitary left module over T. This paper study the relation between semihollow-lifting modules and semiprojective covers. proposition 5 shows that If T is semihollow-lifting, then every semilocal T-module has semiprojective cover. Also, give a condition under which a quotient of a semihollow-lifting module having a semiprojective cover. proposition 2 shows that if K is a projective module. K is semihollow-lifting if and only if For every submodule A of K with K/( A) is hollow, then K/( A) has a semiprojective cover.

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Scopus (2)
Scopus Clarivate Crossref
Publication Date
Thu Oct 01 2009
Journal Name
Iraqi Postgraduate Medical Journal
Femal pattern alopecia and lipoproteins
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KE Sharquie, AA Noaimi, HA Salman, NA Hindy, Iraqi Postgraduate Medical Journal, 2009 - Cited by 1

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Publication Date
Mon Jan 01 2024
Journal Name
Fifth International Conference On Applied Sciences: Icas2023
Ejectivity and goldie-extending modules
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