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Effect of Using Combined Square Nozzle & winglet with Helical Tape on Thermal Characteristics in Tube Heat Exchanger

Influence of combined square nozzle with helical tape inserted in a constant heat flux tube on heat transfer enhancement for turbulent airflow for Reynolds number ranging from 7000 to 14500 were investigated experimentally. Three different pitch ratios for square nozzle (PR = 5.8, 7.7 and 11.6) according to three different numbers of square nozzle (N = 3, 4 and 5) and constant pitch ratios for helical tape were used. The results observed that the Nusselt number and friction factor for combination with winglets were found to be up to 33.8 % and 21.4 %, respectively higher than nozzle alone for pitch ratio PR=5.8. The maximum value of thermal performance for using combination with winglets was about 1.351 for pitch ratio= 5.8. Nusselt number and friction factor correlations from experimental data were developed for turbulent flow.

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Publication Date
Wed Jun 30 2010
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Study on Vanadium Recovery from Spent Catalyst Used in the Manufacture of Sulfuric Acid

Spent catalysts for sulfuric acid production have large amount of vanadium and due to environmental authority it is required to reduce the vanadium contain of the spent catalyst. Experimental investigation was conducted to study the vanadium recovery from spent catalyst via leaching process using sodium hydroxide to study the effect of process variables (temperatures, sodium hydroxide molarities, leaching time and particle size) on vanadium recovery. The effect of process variables (temperature, particle size,molarities of sodium hydroxide and leaching time) on the percentages of vanadium recovery were investigated and discussed .It was found that the percentage of vanadium recovery increased with increasing temperature up to 100 , incre

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Publication Date
Sat Dec 01 2018
Journal Name
Proceedings Of International Structural Engineering And Construction
ON THE REDUCTION OF PRESTRESSING FORCE NEAR SUPPORTS IN PARTIALLY PRESTRESSED CONCRETE FLEXURAL MEMBERS

Straight tendons in pretensioned members can cause high-tensile stresses in the concrete extreme fibers at end sections because of the absence of the bending stresses due to self-weight and superimposed loads and the dominance of the moment due to prestressing force alone. Accordingly, the concrete tensile stresses at the ends of a member prestressed with straight tendons may limit the service load capacity of the member. It is therefore important to establish limiting zone in the concrete section within which the prestressing force can be applied without causing tension in the extreme concrete fibers. Two practical methods are available to reduce the stresses at the end sections due to the prestressing force. The first method based

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Publication Date
Mon Jun 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Kinetic Study on Catalytic Wet Air Oxidation of Phenol in a Trickle Bed Reactor

Kinetics study on the phenol oxidation by catalytic wet air oxidation (CWAO) using CuO.NiO/Al2O3 as heterogeneous catalyst is presented. 4 g/l phenol solution of pH 7.3 was oxidized in a trickle bed reactor with gas flow rate of 80% stochiometric excess (S.E).. In order to verify the proposed kinetics, a series of CWAO experimental tests were done at two temperatures (140 and 160° C), oxygen partial pressures (9 and 12 bar), and weight hourly space velocity (WHSV) (1, 1.5, 2, 2.5, and 3 h-1). According to Power Law, the reaction orders are found to be approximately 1 and 0.5 with respect to phenol concentration and oxygen solubility, respectively. These values favorably compare with those cited in the literature for intrinsic kinetics,

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Publication Date
Sat Jan 20 2024
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Seasonal Variations Of Attached Cyanophyceae Algae on Cocreate Brideges In Tigress Rivere From Baghdad

The attached Cyanophyta community is a model for monitoring aquatic systems and interpreting environmental change in aquatic systems. The present study aims to conduct a seasonal study on Cyanophyta attached to the concrete abutments of three bridges (Al-Jadriya Bridge, Bab Al-Moadam Bridge, and Al-Muthanna Bridge) in the Tigris River within the city of Baghdad, central Iraq (from October 2021 to June 2022). The study included the quality of Cyanophyta and, the eleven environmental parameters (water temperature, electric conductivity, salinity, pH, total alkalinity, Calcium, Magnesium, dissolved oxygen, total dissolved solids, total phosphorus, and total nitrogen). Monthly samples were taken from the water under each bridge from three sa

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Publication Date
Wed Jan 01 2020
Journal Name
Indian Journal Of Ecology
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Publication Date
Thu Mar 15 2018
Journal Name
Journal Of Baghdad College Of Dentistry
The Impact of Mother-Infant Bonding on Periodontal Health Status in the Postpartum Period

Background: Mother-infant bonding is an important psychological step postpartum and disturbed relationship may carry dramatic consequences as a psychological disorder which may affect the periodontal health of the mother. The aim of the present study was to assess the effect of the postpartum Mother-infant bonding on their periodontal condition. Materials and Methods: Mothers in the postpartum period with age range 20-35 years were subjected to postpartum Bonding Questionnaire (PBQ). Periodontal health status was assessed by measuring probing pocket depth and clinical attachment level. Results: The mean values of both probing pocket depth (PPD) and clinical attachment loss (CAL) were higher among disordered mothers than mothers with normal

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Publication Date
Sun Nov 12 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Environmental Effects of Lower Zab Tributary on Benthic Invertebrates Species Diversity in Tigris River

Benthic   invertebrates'   diversity   and    some  physical    a:1d

chemical characteristics in Lower Zab tributary and Tigris River were studied.  Month l y samples  were col l ected  from  November  2001 to October 2002.

The rt:sLllts of the present study showed  the turbidity iu Tigris river

before the confluence to be higher (34.4 NTU) compared to the other stations.  Mean salinity was greater in Lower Zab tributary (0.33 %) compared to that in the river.  Lower Zab tJibutary and Tigris River were good in Oxygen content, and a high dissolved oxygen value was recorded (7.9 mg/L) in Lower Zab tributary.

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Publication Date
Fri Jul 08 2022
Journal Name
Innovation Of Businesses, And Digitalization During Covid-19 Pandemic
The Impact of Political Stability and Macroeconomic Variables on Foreign Direct Investment in Turkey

Foreign direct investment (FDI) is one of the most practical types of foreign investment. FDI contributes to job creation, foreign exchange earnings and national income escalation, improving semi-skill and skilled labor. Based on our knowledge, this paper is the first study attempting to investigate the effect of political stability on the FDI in Turkey using an econometric approach. Achieving this objective, a co-integration analysis was conducted between the FDI and its determinants in the short-run and long-run including “macroeconomic indicators” and “Political Stability (PS)” in Turkey. Using annual data from 1974 to 2017 via Auto-Regressive Distributed Lag (ARDL) model. The results confirm the positive correlation betwe

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Publication Date
Tue Oct 01 2024
Journal Name
Separation And Purification Technology
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Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Science
Laser-Induced Breakdown Spectroscopy for Determination of Toxic Metals in Fertilizers: emphasis on Lead

    The present work aims to evaluate the content of some toxic metals in chemical and organic fertilizers purchased from local markets in Baghdad, Iraq. The analysis was performed by laser-induced breakdown spectroscopy (LIBS) system. The emission spectral lines of lead (Pb), chromium (Cr), cadmium (Cd) and cobalt (Co) have been recorded to determine the best peak representing each element according to the NIST database. The validity of the LIBS procedure was checked by cross-validating the obtained results using atomic absorption spectroscopy (AAS) with a maximum relative error of 5.3%. Moreover, for qualitative analysis, Pb I 296.64 nm emission line was determined to be superior for the evaluation of lead content in terms of three

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