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CFD Application on Shell and Double Concentric Tube Heat Exchanger
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This work is concerned with the design and performance evaluation of a shell and double concentric tubes heat exchanger using Solid Works and ANSY (Computational Fluid Dynamics).

Computational fluid dynamics technique which is a computer-based analysis is used to simulate the heat exchanger involving fluid flow, heat transfer. CFD resolve the entire heat exchanger in discrete elements to find: (1) the temperature gradients, (2) pressure distribution, and (3) velocity vectors.  The RNG k-ε model of turbulence is used to determining the accurate results from CFD.

The heat exchanger design for this work consisted of a shell and eight double concentric tubes. The number of inlets are three and that of outlets are also three for all the fluids that pass through the heat exchanger.

A comparison was made for the numerical and experimental results and it was found that the percentage error for the hot oil outlet temperature was (6.8%) and the percentage error was (- 21%) for cold water outlet temperature.

 

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Publication Date
Thu Feb 07 2019
Journal Name
Journal Of The College Of Education For Women
Double Exile: Jean Rhys's Wide Sargasso Sea
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The problems of cultural displacement and a shaky sense of one's own identity
have been the main concern of the twentieth century Caribbean writer, Jean Rhys. As
a white Creole writer living in England, Rhys attempts to capture the ambivalence of
what it means to be caught between two cultures and never able to identify fully with
any one .Born to a Welsh father and a Creole(white West Indian) mother on the island
of Dominica in the West Indies, Jean Rhys was white but not English, West Indian but
not black. Her sense of belonging to the West Indies was necessarily charged with
awareness of being part of another culture. Thus, the ambiguity of being an
insider/outsider in both the metropolis, England, and the colo

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Publication Date
Mon Jun 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Effect of Adding Alcohols and Gas Velocity on Gas Hold up and Mass Transfer Coefficient in Bubble Columns with Draught Tube
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     The bubble columns are widely used as a two or three phase reactor in industrial chemical process such as absorption, biochemical reactions, coal liquefaction, etc. To design such a column, two main parameters should be taken in consideration, the gas hold-up (), and the liquid phase mass transfer coefficient KLa. The study includes the effect of gas velocity and the addition of alcohols on gas hold-up and mass transfer coefficient in bubble column with draught tube when the length of the column is 1.5m and the ratio of the draught tube diameter to the column diameter equals 0.5 and the air dispersion into the base of the draught tube using a multi hole tuyere is equivalent to a diameter of 0.15 mm and

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Publication Date
Mon Nov 11 2024
Journal Name
Jurnal Teknologi (sciences & Engineering)
THE EXTERNAL DRAFT TUBE GASLIFT BIOREACTOR: HYDRODYNAMIC CHARACTERISTICS AND PARAMETRIC OPTIMIZATION
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Gaslift reactors are employed in several bioapplications due to their characteristics of cost-effectiveness and high efficiency. However, the nutrient and thermal gradient is one of the obstacles that stand in the way of its widespread use in biological applications. The diagnosis, analysis, and tracking of fluid paths in external draft tube gaslift bioreactor-type are the main topics of the current study. Several parameters were considered to assess the mixing efficiency such as downcomer-to-rizer diameter ratio (Ded/Dr), the position of the diffuser to the height of bioreactor ratio (Pd/Lr), and gas bubble size (Db). The multiple regression of liquid velocity indicates the optimal setting: Ded/Dr is (0.5), Pd/Lr is (0.02), and Db

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Publication Date
Mon Nov 11 2024
Journal Name
Jurnal Teknologi (sciences & Engineering)
THE EXTERNAL DRAFT TUBE GASLIFT BIOREACTOR: HYDRODYNAMIC CHARACTERISTICS AND PARAMETRIC OPTIMIZATION
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Gaslift reactors are employed in several bioapplications due to their characteristics of cost-effectiveness and high efficiency. However, the nutrient and thermal gradient is one of the obstacles that stand in the way of its widespread use in biological applications. The diagnosis, analysis, and tracking of fluid paths in external draft tube gaslift bioreactor-type are the main topics of the current study. Several parameters were considered to assess the mixing efficiency such as downcomer-to-rizer diameter ratio (Ded/Dr), the position of the diffuser to the height of bioreactor ratio (Pd/Lr), and gas bubble size (Db). The multiple regression of liquid velocity indicates the optimal setting: Ded/Dr is (0.5), Pd/Lr is (0.02), and Db

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Publication Date
Thu Jul 01 2021
Journal Name
Journal Of Mechanical Engineering Research And Developments
Numerical Investigation of Natural Convection Heat Transfer in Partially Filled Porous Enclosure Subjected to Constant Heat
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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 respecti

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Publication Date
Sun Apr 02 2023
Journal Name
Journal Of Survey In Fisheries Sciences
Evaluation of the Serum Asprosin Levels in Patients with Double Diabetes
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Background : Double diabetes (DD) is the term used to describe situations in which a patient exhibits characteristics that are a combination of type 1 diabetes mellitus(T1DM) and type 2 Diabetes Mellitus (T2DM) a large epidemiological study found that 25.5% of people with T1D also had the metabolic syndrome. A new protein hormone called asprosin is predominantly released by white adipose tissue. It was initially discovered in 2016 . Asprosin is important diagnoses marker for insulin resistant in diabetes patients ,additionally is very important denotation about early diagnoses of type 2 diabetes. Objectives: The current study aims to find predictive significance of diagnosis a double diabetes by evaluating the asprosin in the blood serum of

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Publication Date
Thu Apr 13 2023
Journal Name
Journal Of Survey In Fisheries Sciences
The Elevation of Serum Subfatin Levels in Patients with Double Diabetes
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Background: Hybrid diabetes (or double diabetes, DD) occur when the patient which exhibits characteristics that combine type 1 diabetes (T1DM) and type 2 diabetes (T2DM). Formerly epidemiological studies found that quarter of people with T1D also had the metabolic syndrome. Subfatin, Also called cometin, it is a small (~27kDa) cytokine secreted by protein encoded by a gene called METRNL (simeler of meteorin). is much expressed in skin in the mucosal tissues and activated macrophages. Subfatin has also been described as a hormone that effected in some diseases such as metabolic diseases (including dyslipidemia), type 2 diabetes and obesity. Objectives: The current study objective is evaluating the subfatin in the blood serum of double diabet

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Publication Date
Tue May 23 2023
Journal Name
Journal Of Engineering
EXPERIMENTAL AND THEORETICAL STUDY OF TWO-PHASE HEAT PIPE
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In this study, thermal characteristics of a two-phase closed heat pipe were investigated experimentally and theoretically. A two-phase closed heat pipe (copper container, Fluorocarbon FC-72 (C6F14) working fluid) was fabricated to examine its performance under the effect of input heat flux range of 250–1253 W/m2 , 70% fill charge ratio and various tilt angles. The temperature distribution along the heat pipe, input heat to evaporator section, and output heat from condenser were monitored. A comprehensive mathematical model was developed to investigate the steadystate heat transfer performance of a two-phase closed heat pipe. A steady state analytical model, is presented to determine important parameters on the design of two-phase close

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Publication Date
Tue Dec 30 2014
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Heat Transfer Efficiency of Different Composite Insulators
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This research aims to investigate the thermal performance of different thermal composite insulators, wrapped around a closed-loop copper pipe (CLP). To achieve this aim a system was designed and manufactured. It is consisted of closed water tank insulated by Rock Wool, and supplied with two electric heaters, two thermostat, a flow meter, a water pump, digital temperature scales, and four series of (CLP).
Six insulators were prepared namely; composites of Impregnated Fiberglass with Elastoclad and foaming Rubber (FER), Impregnated Fiberglass with Elastoclad resin and Polymeric Membrane (FEM), Impregnated Fiberglass with Polyurethane thermoset resin and Foaming Rubber (FUR), Impregnated Fiberglass with Polyurethane thermoset resin and P

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Publication Date
Sun Jan 05 2014
Journal Name
Paripex - Indian Journal Of Research
Effect of heat treatment on the structural and optical properties of CuIn1-xGaxSe thin films
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The structural, optical properties of cupper indium gallium selenite (CuIn1-xGaxSe) have been studied. CuIn1-xGaxSe thin films for x=0.6 have been prepared by thermal evaporation technique, of 2000±20 nm thickness, with rate of deposition 2±0.1 nm/sec, on glass substrate at room temperature. Heat treatment has been carried out in the range (373-773) K for 1 hour. It demonstrated from the XRD method that all the as-deposited and annealed films have polycrystalline structure of multiphase. The optical measurement of the CIGS thin films conformed that they have, direct allowed energy gap equal to 1.7 eV. The values of some important optical parameters of the studied films such as (absorption coefficient, refractive index, extinction coeffici

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