Retarding of Precipitation Hardening of Al-Cu Alloy by Cadimium Addition
Sabreen
Ali
author
Alaa
A. Atiyah
author
Amin
D. Thamir
author
text
article
2013
eng
The aim of the present work is to prepare a set of Al-Cu alloys with slow precipitation hardening by aging. Present work results can be utilized during the importing or exporting of such alloys at solution treatment conditions. In order to establish this aim, a set of Al-4%Cu alloys have been prepared in the laboratory to investigate the effect of Cd-addition with the percentage varied from (0.1, 0.3 and 0.5) weight percentage. The prepared alloys with different Cd additions were subjected to a natural aging up to 60 days after solution treatment. As a result, the alloys showed an obvious retarding in the aging kinetics as the percentage of Cdadditions increasing. This retarding was found to be due to the trapping of the vacancies that resulted during the quenching step that resulted in delays of Gunier- Preston zones precipitation. SEM has been used in monitoring of microstructure as well as optical microscopy
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
2997
3006
https://etj.uotechnology.edu.iq/article_83384_c88ae142146ac550df4afbab1b7b1c98.pdf
dx.doi.org/10.30684/etj.31.16A.1
Modeling and Simulation of the Cogeneration Plant Equipped with Back-Pressure Turbine Operates at Various Control Programs of Exit Steam Temperature
Moayed
Razoki Hasan
author
Mohammed
Jasim Salih
author
text
article
2013
eng
Cogeneration represents one of the main ways for increasing the efficiency of primary energy use. This paper deals with a theoretical analysis of cogeneration plants equipped with various back-pressure turbines type R. These plants are studied during their operation with conventional method (water injection) and the suggested method (sliding live steam temperature) to regulate steam temperature supplied to the industrial consumers. A computer program had been written to work under MathCad software to simulate cogeneration plant with each back-pressure turbine under design and off design conditions. The performance of the different schemes is analysed in view of the first and second laws. In this analysis entropy method (second law) in addition to more conventional energy analysis (first law), are employed to evaluate overall and component efficiencies, fuel consumption and to identify the thermodynamic losses. The results show that, using the suggested method leads to increase the overall efficiency of the cogeneration plant for all types of back-pressure turbine and can reduce the fuel consumption. Finally, the results show that increasing back-pressure leads to improve the performance of cogeneration plant regardless of the method used.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3007
3034
https://etj.uotechnology.edu.iq/article_83385_8c1e74be7e8f0a322f85315054c42153.pdf
dx.doi.org/10.30684/etj.31.16A.2
Characterization of Niti Super Elasticity Shape Memory Alloys
Rasha
Ali Hussein
author
Emad
S. Al-Hassani
author
Sahib
M. Al-Saffar
author
text
article
2013
eng
Ni-Ti samples were prepared by powder metallurgy. The prepared samples were master samples M1 (55% Ni- 45%Ti) and M2 (56% Ni- 44%Ti). The additive percentage of Ta was 5%, 7% and 9% to master sample M1 and M2, while Nb addition was 1%, 2% and 4% to M1 and M2. The pressure of pressing was 800 Mpa. The samples were sintered at 950 °C for a time of 9 hr. Samples were then examined by using SEM technique, XRD, DSC, Vickers hardness. The porosity was measured according to Archimedes method. Scanning electronic microscopy images showed that most prepared samples have porosity, which in turn imparts decreasing microhardness values across the surface. Better increase of microhardness values is found in M2+5%Ta. Scanning electron microscopy indicated also the best martensitic structure in M1+4% Nb and M2+4%Nb. X-ray diffraction observations indicated that NiTi, Ni3Ti and NiTi2 phases exist in all samples. NiTi phase is playing a dramatic role in enhancing shape memory effect and superelasticity. DSC results show that transformation temperatures range in (46-134°C). This indicates that all samples at room temperature have one phase which is martensite.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3035
3051
https://etj.uotechnology.edu.iq/article_83386_c4915d6aae45cf2f8d15b9c6df420b71.pdf
dx.doi.org/10.30684/etj.31.16A.3
Deformation Characteristics of Base and Subbase Layers under Monotonic & Cyclic Loading
Omar
Abbas AL-Azzawi
author
Namir.
K.S. AL-Saoudi
author
Falah
Hassan Rahil
author
text
article
2013
eng
Base and Subbase layers are considered as the platform for distributing the different applied stresses in flexible pavements. The two layers must provide sufficient strength to resist any excessive generated deformation to achieve this goal, proper compaction machinery is essential to reach the required degree of compaction. The present paper investigates the influence of degree of compaction of the base and Subbase layers on the generated deformation under the action of both monotonic and cyclic loadings. Model tests were performed by compacting beds of base and Subbase layers to relative densities of 65%,77% and 88%, inside steel container of dimensions 1000mm*750mm*750mm. The final thicknesses of the base and Subbase layers were 150mm and 350mm respectively. A circular model footing of diameter 175mm: equivalent to 24194 mm tire contact area is placed on the base layer and subjected to a series of monotonic and cyclic loadings. The results of monotonic tests revealed an increase of 71% and 107% in the carrying capacity when the relative density increased from 65% to 77% and from 65% to 88% respectively. The cyclic tests revealed a substantial increase in the number of cycles at any stress level as the relative density increases from 65% to 77% and from 65% to 88%.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3052
3060
https://etj.uotechnology.edu.iq/article_83387_bfa66fb9b599610968800ece8169ffa2.pdf
dx.doi.org/10.30684/etj.31.16A.4
Preparation and Characterization of Porous Anodic Alumina membrane
Ahmed.
A. Hashoosh
author
Kahtan.
K. Al-Khazraji
author
Ahmed.
A. Moosa
author
text
article
2013
eng
Porous Anodic Alumina (PAA) was prepared by two-step anodization on both sides of an aluminium foil. The anodization carried out at anodizing temperature 17oC using oxalic acid as an anodizing electrolyte. The (PAA) template was characterized with optical microscope and SEM. The optical microscope image showed two (PAA) layers after the dissolution of the residual aluminium. The average pore diameter was found to be (75) nm. The average interpore distance of (PAA) prepared was found to be (99) nm. The thickness of (PAA) was found to be (59.5) μm.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3061
3066
https://etj.uotechnology.edu.iq/article_83388_9732260b84316d2222189275c9682448.pdf
dx.doi.org/10.30684/etj.31.16A.5
Optimal Sizing of Photovoltaic Irrigation Water Pumping System in Samara
Ali
H. Al-Hamdani
author
Majed
Hassan
author
Roshen
Tariq Ahmad
author
text
article
2013
eng
Water pumping from wells and rivers for irrigation is a well established procedure on many farms in Iraq and is practical on various levels around the world. Typical irrigation systems consume a great amount of conventional energy through the use of electric motors and generators powered by fuel. The overall objective of this research was to determine the feasibility of using photovoltaic (PV) modules to power a water pump for a small-scale irrigation system in the North-West of Iraq (Samara). The study involved field observations, simulations of global solar radiation and PV electrical output. Field observations involved an installation of 24-monocrystaline silicon PV modules as shown in figure (1). This system was installed to give maximum power equal to (1960 watt) with maximum open circuit voltage (Voc = 175 volts) and maximum short circuit ( Isc= 14 Amp ). This module was connected to the pump via a charge controller and AC inverter. The parameters monitored were voltage, current, back-of-panel temperature, pressure, and flow. These observed parameters were used to determine PV electrical output and volume of water pumped. Site latitude, elevation, and panel tilt were applied to the solar radiation and PV electrical output models. PV electrical output and volume of water pumped were monitored between January 2000 and December 2000. As expected, an increase in power causes an increase in the volume of water pumped.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3067
3077
https://etj.uotechnology.edu.iq/article_83389_01c5c63a4abb7aa10ad13ed2c2f2c214.pdf
dx.doi.org/10.30684/etj.31.16A.6
Carbon Nanotube Prepared by Pulse Laser Ablation of Graphite Target in Iso-Propanol Solution
Khawla
S. khashan
author
Mayyadah
H. Mohsin
author
text
article
2013
eng
In this work carbon nanotube was synthesis by pulse laser ablation of graphite target in Iso-propanol solution. Fourier Transform Infrared Spectroscopy (FTIR), UV-Visible Spectrophotometer and Transmission Electron Microscopy (TEM) were used to study chemical bonding, optical absorption, particle size, structure and morphology of the carbon nanotube. The FTIR absorption peak at 2335.6, 1647.1 cm-1& 1269.1 cm-1 stretching vibration bond, it is inferred that the C ≡ C , C = C and C-C, respectively. Bonds suggests the formation carbon nanoparticles suspend in this solvent, UV absorption peaks coincide with the electronic transitions corresponding to linear hydrogen – capped polyyne (Cn+1H2), polyynes are important precursor molecular components in the formation of carbon nanotubes. The TEM show the aggregation of the carbon nanoparticles with size ranges from (1.66 to 41.6 nm), the structure and morphology of the CNT’s with diameter at range 11.1 – 46.15 nm and length at range 261.1 - 592.3 nm.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3078
3089
https://etj.uotechnology.edu.iq/article_83390_88ab6b5f2cf14060650262cba80834c2.pdf
dx.doi.org/10.30684/etj.31.16A.7
Mechanical Properties of Reactive Powder Concrete (RPC) with Various Steel Fiber and Silica Fume Contents
Lubna
S. Danha
author
Wasan
Ismail Khalil
author
Hisham
M. Al-Hassani
author
text
article
2013
eng
An experimental work was carried out to investigate some mechanical properties of Reactive Powder Concrete (RPC) which are particularly required as input data for structural design. These properties include compressive strength, tensile strength (direct, splitting and flexural), flexural toughness, load-deflection capacity and static modulus of elasticity. The effects of three variable parameters on these properties were carefully studied which are, the silica fume content SF (0%, 10%, 15%, 20%, 25%, and 30%) as a partial replacement by weight of cement, hooked macro steel fibers volume fraction Vf (0%, 1%, 2% and 3%) and superplasticizertype(Sikament®-163N and PC200).The diameter of the steel fiber is 0.5mm and its length is 30mm with aspect ratio 60.The experimental results showed that as the silica fume content (SF) increases from 0% to 30% the compressive strength significantly increases, while the increase in tensile strength is relatively lower. The inclusion of steel fibers leads to a considerable increase intensile strength, while the addition of steel fibers causes a slight increase in compressive strength of RPC as fiber volume fraction increases from 0% to 3%.The increase in the steel fibers volume fraction and silica fume content improved the loaddeflection behavior and consequently gave higher ductility and fracture toughness of RPC.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3090
3108
https://etj.uotechnology.edu.iq/article_83391_3797e53b4b6fb47340ed37c23c2ecf1c.pdf
dx.doi.org/10.30684/etj.31.16A.8
The Effect of Operating Factors on the Pollutants Emission from a Constant Pressure Burner
Abdul
Al-Kadhim M. Hasan
author
Abdul
Sattar Jawad M.Hasan
author
Riyadh
Salman Radhi
author
text
article
2013
eng
This paper presents the effect of varying operating conditions on pollutants emission (carbon monoxide [CO], unburned hydrocarbon [UHC], and Soot) from constant pressure burner. In this research a liquid fuel used are gas oil and kerosene .The operating conditions which taken in account are atomization pressure, inlet air temperature, equivalence ratio, as well as type of fuel. It is found that the Carbon monoxide and Unburned hydrocarbon are inversely proportional to inlet air temperature with maximum decrease of (95%, 43%) respectively. In contrast, soot is directly proportional to inlet air temperature as the maximum increase in soot emission is 170%. Carbon monoxide , Unburned hydrocarbon , and Soot are inversely proportional to Atomization pressure as the maximum decrease in Carbon monoxide , Unburned hydrocarbon, and soot emissions are (56.5%, 37.4%, 76%) respectively. The relation between Carbon monoxide, Unburned hydrocarbon, and soot with equivalence ratio is directly proportional as maximum increase in Carbon monoxide, and Unburned hydrocarbon emissions are (130%, 81 %,) respectively, while soot emissions is 190 %. Emissions from a constant pressure burner depend on the physical and chemical properties of fuel used, such as (viscosity, surface tension, volatility, the ratio of hydrogen atoms number to carbon atoms number (H/C), and lower heating value). it is found that the maximum increase in Carbon monoxide, Unburned hydrocarbon, soot emissions from gas oil are generally higher than those from kerosene fuel by (72%,17.5%,38%) respectively`.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3109
3124
https://etj.uotechnology.edu.iq/article_83392_f91b01323edbdebc99e21cbcb8d43442.pdf
dx.doi.org/10.30684/etj.31.16A.9
Soil Site Investigations Using 2D Resistivity Imaging Technique
Hussein
H. Karim
author
Mohammed
A. Al-Neami
author
Wisam
M. Y. Mohammad
author
text
article
2013
eng
The use of 2D Electrical Resistivity Imaging (ERI) technique in combination with geotechnical and geological data allow the determination of the lithological composition and detailed internal architecture of the subsurface and understanding the characterisation and description of the geology of the site. This study is aimed to evaluate the use of 2D ERI for the detection and characterisation of heterogeneities in subsurface soil. The survey was conducted using a Wenner-Schlumberger and Wenner configurations along thirteen ERI parallel profiles which have been investigated in the project of Al-Obaidi Electrical Transformation Station site to find the resistivity and depth of soil horizons with their lithological description. Analysis of imaging sections shows that Wenner-Schlumberger sections are with higher resolving power than Wenner sections in both horizontal and vertical variations in resistivity reflecting more pronounced soil horizons with depth, where Wenner sections are limited to the upper soil layers. Resisitvity values in the imaging sections indicate that the stratigraphy of the study area is mostly of clayey soil. 4 to 7 distinct geoelectric layers generally identify the subsurface down to depth of about 20 m. High resistivity values in the top soil, medium-high resistivity values representing the upper soil layers, while lower reistivity values are indicated for the lowerest layers. The resistivity values are inversely proportional to many soil properties such as fine content (clay and silt), salt content (sulphate and gypsum content) for saturated conditions, water content, plasticity index (P.I) and void ratio particularly for saturated condition. The resistivity values are directly proportional to sand content, void ratio, salt contents for dry condition. The integrated use of ERI technique and conventional site investigation has led to a far better understanding of the site than could have been achieved using site investigation methods alone.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3125
3146
https://etj.uotechnology.edu.iq/article_83393_002daf44e42f1f47d121a378b88267c6.pdf
dx.doi.org/10.30684/etj.31.16A.10
Prediction and Investigation Particulate Fillers (Aluminum &Alumina) Effect on the Thermal Conductivity of Polymeric Matrix Composite (Polyester)
Hasan
A .Alasady
author
Ibtihal
Al-Namie
author
Ahmed
A.M
author
text
article
2013
eng
The main objective of this paper is to study the thermal conductivity of composite materials and the parameters affecting it, then to determining the validity of the best theoretical model matching with experimental results and to predict thermal conductivity of any composite materials with different particle size. Alumina& aluminum filled thermoset polyester composites are investigated in this study, and their thermal conductivity will be the central focus. Aluminum particle, alumina particle and aluminum fiber (5wt % to 45wt %) were added to polyester matrixes. It was found that both fillers and fiber positively effect on the thermal conductivity of the composite. By using visual basic program, the results show there are three different theoretical models (Maxwell Equation, Lord Rayleigh Equation &Lewis and Nielsen Equation) valid to predict the effective thermal conductivity for reinforced the polyester by Al and Al2O3 powder until 35wt% and 45wt% respectively. In addition, the rule of mixture model is good to predict the effective thermal conductivity (for aluminum fiber parallel with polyester matrix).
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3147
3158
https://etj.uotechnology.edu.iq/article_83394_45dce31afba2660b15560e0f5a4da6a7.pdf
dx.doi.org/10.30684/etj.31.16A.11
Corrosion Behaviour of Aluminium Alloy 7020-T6 welded Joint in Sea Water at Different Variables
Huda
Mohammed Abdulaziz
author
text
article
2013
eng
were welded by using inert gas metal arc welding method (MIG)to obtain butt joint with geometry of single V at 45⁰with two pass. The joints were tested by X-ray radiography and faulty pieces were excluded.and the indefectible joints were subjected to stress relief heat treatment including heating the joint to evaluating temperature 100 C⁰for one hour and air cooling.Optical microscopy with camera was used to observe the welded joint microstructure.Micro hardness test were carried out using Vickers instrument to measure the hardness of the welded joint. Corrosion behavior of welded jointspecimens in 3.5% NaCl solution at different media velocity (1, 2, 3) m/min and temperature of (25, 50, 75) ⁰ C for each velocitywas examined using Tafelpolarization measurements. It is determined byopen circuit potential (OCP) after that the cell’s current is changed due to the increasing in potentialby ±100mV to calculate corrosion current then corrosion rate. The results show that the corrosion rate is increased with increasing solution temperature. This is because of the prevention of oxygen from dissolving in water, while the corrosion rate decreases with increasing velocity of sea water since the movement of the liquid prevents the formation of deposits and ions gathering on cathode pole where corrosion can easily develop. when comparing corrosion rate between the welded and unwelded samples, the welded samples gives more corrosion rate value since the cycle of heating and cooling that occurs during the welding process affects the microstructure of welds.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3158
3185
https://etj.uotechnology.edu.iq/article_83395_31015e3a0f8a4524c7eac2f9854daf1f.pdf
dx.doi.org/10.30684/etj.31.16A.12
Insertion of Rotational Effects to the Calculation of J-Integrals Using Finite and Boundary Element Methods
Ameen
Ahmed Nassar
author
text
article
2013
eng
The calculation of J-integrals for cases with rotational effects using the finite or boundary elements needs special treatment. In this work, an attempt is made to derive the J-integral expressions for cases with rotational loading conditions. New useful ideas for reducing domain integrals to boundary integrals and improving the accuracy of J-integrals are developed. The new ideas are implemented in finite and boundary element programs which were developed and validated in this work by taking a case study of central-cracked rotating disc with known analytical solution. The results of the developed programs show good agreements with the analytical solution.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3186
3193
https://etj.uotechnology.edu.iq/article_83396_2abadc45e293722a21d499a92bec66ca.pdf
dx.doi.org/10.30684/etj.31.16A.13
Fabrication of Tio2 and V2o5 Thin Films by Powder Coating Technique
Mohammed
S. Hamza
author
Alaa
Aladdin
author
Shatha
Kazem
author
text
article
2013
eng
Titanium dioxide (TiO2) and vanadium oxide (V2O5) in different mixing percentage (100, 50, 0)% from them powders as thin film on substrate of glass .the coating thickness was ( 0.37 ±0.03 μm ). Thin films were inspection by microphotographs with scanning electron microscopy (SEM) and x-ray diffraction (XRD). The results showed that thin films was prepared crystalline and also the compound (tio2, v2o5), and the structure was regular and smooth.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3194
3202
https://etj.uotechnology.edu.iq/article_83397_19e0ddd4dcc7224bad574ccb86ef57cf.pdf
dx.doi.org/10.30684/etj.31.16A.14
Flutter Estimation for Low Speed Aircraft Wing Using Fully Coupled Fluid – Structure Interaction
Mauwafak
Ali Tewfik
author
Mohammed
Idris Abu-Tabikh
author
Hayder
Sabah Abd Al-Amir
author
text
article
2013
eng
The aero elastic responses and the flutter condition of 3-D flexible aircraft wing were estimated by developed fully coupled fluid-structure interaction approach. The actual wing in this approach was represented by an equivalent plate .Equivalent plate model (structure model) based on assumed mode method was then combined with unsteady panel-discrete vortex method (aerodynamic model) to build relatively simple aeroelastic model. This model could be used for estimation of flutter condition of moderate to high aspect ratio and low sweep wings of aircraft flight at low subsonic speeds. The obtained results from the present model are able to prediction the flutter condition of the actual wing at different angles of attack. The increasing in the angle of attack leads to reduce flutter speed and flutter frequency.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
31
v.
16
no.
2013
3203
3215
https://etj.uotechnology.edu.iq/article_83400_54f577196d950387c20efa71ce3206ad.pdf
dx.doi.org/10.30684/etj.31.16A.15