A key characteristic of diesel engines is predicting the ignition delay period. This work predicts the ignition delay in diesel engines using combinations of ethanol/diesel fuel blend and pure diesel as fuel replacements. It provides an empirical formula for predicting delay periods.  A growing interest in alternative fuel blends, representing a substantial shift from the use of traditional diesel fuel, is reported. Modern study is focused on examining these combinations and how they might affect the dynamics of combustion in diesel engines. Experiments were carried out utilizing five different ethanol/diesel fuel blends, including pure diesel, with ethanol percentages varying from 5% to 20% in 5% quantities. Tests we

The study of surface hardness, wear resistance, adhesion strength, electrochemical corrosion resistance and thermal conductivity of coatings composed from sodium silicate was prepared using graphite micro-size particles and carbon nano particles as fillers respectively of concentration of (1-5%), for the purpose of covering and protecting the oil distillation towers. The results showed that the sodium silicate coating reinforced with carbon nano-powder has higher resistance to stitches, mechanical wear, adhesive and thermal conductivity than graphite/sodium silicate composite especially when the ratio 5% and 1%, the electrochemical corrosion test confirmed that the coating process of stainless steel 304 lead to increasin

This research investigates manganese (Mn) extraction from Electric Arc Furnace Steel Slag (EAFS) by using the Liquid-liquid extraction (LLE) method. The chemical analysis was done on the slag using X-ray fluorescence, X-ray diffraction, and atomic absorption spectroscopy. This work consisted of two parts: the first was an extensive study of the effect of variables that can affect the leaching process rate for Mn element from slag (reaction time, nitric acid concentration, solid to liquid ratio, and stirring speed), and the second part evaluates the extraction of Mn element from leached solution. The results showed the possibility of leaching  83.5 % of  Mn element from the slag at a temperature of 25°C, nitric acid co

Direct contact membrane distillation is an effective method for production of fresh water from saline water. In this study two samples were used as feed solutions; the first one was RO waste from Al-Hilla Coca-Cola Factory (TDS= 2382 mg/l) and the other was Haji Ali drainage water (TDS= 4127 mg/l). Polytetrafluoroethylene (PTFE) hydrophobic membrane supported with polypropylene (PP) was used as flat sheet form with plate and frame cell. Results proved that membrane distillation is an effective technique to produce fresh water with high quality from brine with low salinity content. With membrane area of 8x8 cm², the volume of treated water decreased from 34.97 ml at first half hour to 33.02 ml after 180 min of

In this paper, a robust adaptive sliding mode controller is designed for a mobile platform trajectory tracking.  The mobile platform is an example of a nonholonomic mechanical system. The presence of holonomic constraints reduces the number of degree of freedom that represents the system model, while the nonholonomic constraints reduce the differentiable degree of freedom. The mathematical model was derived here for the mobile platform, considering the existence of one holonomic and two nonholonomic constraints imposed on system dynamics. The partial feedback linearization method was used to get the input-output relation, where the output is the error functions between the position of a certain point on the platform

In this paper, the static analysis for finding the best location of boxes inside the composite wing-box structure has been performed. A software ANSYS (ver.11) was used to analyses the Aluminum wing to find the maximum stresses reached in. These results are used as a base for the composite wingbox to find the numbers of layers and location of the box beam and its dimensions so that the composite wingbox may carry the same loading conditions in the Aluminum wing. Analysis showed that a composite wingbox having two boxes is better than the single or triple boxes wing based on stress to weight ratio. Mass saving of (40%) had been achieved when composite wing-box is used instead of Aluminum wing.

Dissolution of gypsum rock in water is significant, which may result in hydrocarbon reservoir formation and evaporate deposits. However, the complexity of the gypsum dissolution process is still of interest because of its uncleanness that requires more critical analysis. The objectives of this experimental study are emphasis on the dissolution characteristics of gypsum rock under room temperature and by various types of water; namely: deionized, tap, fresh, acidic, well, and normal rainwatre. In addition, the influences of dissolution on gypsum rock's mechanical and physical characteristics. Gypsum rock was obtained from Agjalar area, in the southwest of Sulaymaniyah city, Northern Iraq. Experimental results show that we

The slurry infiltrated fiber concrete (SIFCON) is nowadays considered a special type of high fiber content concrete; it is high strength and high performance material. This paper investigates the effect of spread steel fiber into the slurry mortar on some properties of SIFCON. According to fiber distribution, two sets were used in this investigation. The first set consisted of randomly distributing fibers inside the slurry. The second set was by placing the fibers in an orderly manner inside the slurry. Crimped steel fibers with an aspect ratio of (60) were used. Two different volume fractions percentage of (7% and 9%) by volume of mold were used in both sets for this study. Also, a w/c ratio of (0.35) and superplasticiz

A load flow program is developed using MATLAB and based on the Newton–Raphson method,which shows very fast and efficient rate of convergence as well as computationally the proposed method is very efficient and it requires less computer memory through the use of sparsing method and other methods in programming to accelerate the run speed to be near the real time.
The designed program computes the voltage magnitudes and phase angles at each bus of the network under steady–state operating conditions. It also computes the power flow and power losses for all equipment, including transformers and transmission lines taking into consideration the effects of off–nominal, tap and phase shift transformers, generators, shunt capacitors, sh

An experimental and numerical study has been carried out to investigate the forced convection heat transfer by clean or dusty air in a two dimensional annulus enclosure filled with porous media (glass beads) between two vertical concentric cylinders. The outer cylinder is of (82 mm) outside diameters and the inner cylinder of (27 mm) outside diameter. Under steady state condition; the inner cylinder surface is maintained at a high temperature by applying a uniform heat flux and the outer cylinder surface at an ambient temperature. The investigation covered values of input power of (6.3, 4.884, 4.04 and 3.26 W), Reynolds number values of (300, 700, 1000, 1500, and 2000) and dust ratio values (density number N) of (2, 4, 6 and 8). A comput

The effect of the initial pressure upon the laminar flame speed, for a methane-air
mixtures, has been detected paractically, for a wide range of equivalence ratio.
In this work, a measurement system is designed in order to measure the laminar flame
speed using a constant volume method with a thermocouples technique. The laminar
burning velocity is measured, by using the density ratio method.
The comparison of the present work results and the previous ones show good
agreement between them. This indicates that the measurements and the calculations
employed in the present work are successful and precise.

An experimental and theoretical investigation of the effect of flow separation on the performance
of a cascade NACA 65_(12)10 axial compressor blade has been carried out. The experimental work
includes the fabrication of three blades from wood, each having a chord (100mm) but one of these blades having a span of (90mm) for smoke tunnel testing and the other two blades having a span of (380mm) for wind tunnel testing.The two blades were connected by suitable mechanism in order to be fixed in the wind tunnel protractor and rotated in the required stagger angle. The cascade was tested in an open type low-speed subsonic (Mach number=0.117) wind tunnel, for Reynolds number (Re=239605) based on maximum velocity (35 m/s) and airfoil c

Heat input due to the welding of mild steel pipe causes a temperature gradient in the parent metal. After welding and temperature cooling down, residual stresses appear around welding zone which reduces the weld strength. Residual stresses are a result of the temperature gradient and the dependency of material properties on the temperature, such as yield strength, elasticity modulus, and thermal expansion coefficient.
In this study, a typical flat joint of a single pass weld in a thin pipe was studied analytically and numerically. Analytical approach is performed by exploring a simple method to calculate the magnitude of residual stress in terms of the weld shrinkage behavior. Numerical analysis is performed by applying non-linear tra

The stresses and deflections in robot arm was analyzed using ANSYS software package. Industrial robot analyzed in this work consists of three arms that have 2-DOF. The analysis of each
arm had been made separately. The maximum stress and deflection have been analyzed for a static applied at one end of the arm while has the other end fixed. Links of various cross-sections having same masses, length, and material properties to make a choice of the shape that gives a high stiffness to weight ratio have been examined. After specifying the best section for the arms of the robot an optimization process began to determine the dimensions of the arms sections which give the least deformation this had been done by the aid of a program build u

The coupled treatment (conjugate numerical methodology) allows the simultaneous solution of the external flow (steady, two dimensional, compressible and turbulent flow) and conduction within the metal (steady, two dimensional) of gas turbine nozzle guide vane (with and without internal convection cooling). Validation of the developed conjugate capability is investigated in the present work.
The numerical results were compared with experimental results for steady, two dimensional, compressible and turbulent flow through the gas turbine nozzle cooling guide vane type (NASA-C3X), and the results were found to be in good agreement with experiments by )Hylton 1983).
The study shows that the (conjugate numerical methodology) gives good a

Thermohydraulic computer codes such as COBRA3C are now becoming in practical use as part of power plant licensing process. One of the areas of interest to reactor designer is the effect due to longterm operations and the changes that might occur either due to irradiation (burnup) effects or thermal stresses in the reactor. The present study is an attempt to predict coolant channel temperature profiles at the core End Of Life. In addition deeper insight is given to the individual single partial contribution to the changes in Begin Of Life and End Of Life profiles. The effects due to fuel swelling, rod bowing, and changes in physical properties are studied in details using COBRA3C code. The codes COBRA3C and the kinetic code AIREKMOD toget

The management of construction projects needs to complete the basics of system management and work. Starting from the idea and how to turn it into a full study and ended at the construction project completion arriving at the purpose prepared for it, so the projects need to control on its operation and integration system in order to succeed.

It is no secret for who concerned in construction projects field that the design stage is a very important stage in construction project because it determines the final features of the project through the requirements provided by the employer for the consultant to formulate it during this phase in the form of plans, drawings, and specifications, then translated on the ground as the shape of co

This study aims to suggest a technique for soil properties improvement of AL- Kadhimin shrine Minaret and to support the foundation, which has a tilt of roughly 80 cm from the vertical axis. The shrine of the AL- Kadhimin is made up of four minarets with two domes set in a large courtyard. The four minarets have skewed to varying degrees due to uncontrolled dewatering inside the shrine in recent years. However, the northeast minaret was the most inclined due to its proximity to the well placed inside shrine courtyard. When the well near the minaret is operated, the water level drops, increasing the effective stresses of the soil and causing differential settling of the minaret foundation. To maintain the minaret's foundation from potenti

This paper describes a comparison between beam-column junctions with and without construction joint, also, a parametric study deals with construction joint is presented by taking various conditions of the junction. These include the various positions of the construction joint, the axial load on the column, strength of concrete in the second cast and the amount of dowels crossing the joint. By developing a computer program which was originally written by Dr. Ihsan Al-Shaarbaf (1990), (P3DNFEA, program of three dimensional nonlinear finite element analysis), to consider the effect of construction joint depending on the fact that the shear force can be transmitted across the shear plane either by interlocking of the aggregate particles prot

Experiments were carried out to study the local and average heat transfer by natural convection in
a vertical concentric cylindrical annulus. The experimental setup consists of an annulus has a radius ratio of 0.555 and inner cylinder with a heated length 1.2m subjected to the constant heat flux while the outer cylinder is subjected to the ambient temperature. The investigation covers heat flux range from 58.2 W/m2 to 274.31 W/m2. Results show an increase in the natural convection as heat flux increases leads to an improve in the heat transfer process. An empirical equation of average Nusselt number as a function of Raylieh number was deduced

The behavior of prestressed concrete box-girder bridges has been studied under short term loading.
The 20-noded isoparametric three-dimensional brick elements have been used to model the concrete
in the box-girder with its two cantilever flanges. The reinforcing bars are idealized as axial
members embedded within the brick elements. The behavior of concrete in compression was
simulated by an elastic-plastic work hardening model followed by a perfectly plastic response,
which is terminated at the onset of crushing. In tension, a smeared crack model with fixed
orthogonal cracks is used with the inclusion of models for the retained post-cracking stress and
reduced shear modulus. The prestressing forces in the tendons ar

The need of higher powers in electrical drives has forced the researchers to develop new power source possibilities. Multilevel inverters have been presented as a cost effective solution for various high voltage and high power applications including power quality and motor drive problems. The traditional pulse width modulated (PWM) Inverter does not completely eliminate the unwanted
harmonics in the output waveform. Using the multilevel inverter as an alternative to traditional PWM inverters for electric motor drive applications is investigated. The concept of the Optimized Harmonic Elimination Stepped-Waveform (OHESW) technique for a multilevel inverter is presented. The effectiveness of this technique in minimizing the inverter swi

The present work studied the drop size distribution in the RTL contactor using two liquid-liquid systems, xylene-acetone-water and kerosene-acetone-water. Process variables studied were: rpm (10-50 min-1), continuous phase flow rate (4-12 l/h), dispersed phase flow rate (4-12 l/h), and concentration (0.1-0.5 mole/l). It was found that Sauter mean drop diameter (d32) decreased with increasing rpm and continuous phase flow rate, and decreasing dispersed phase flow rate and concentration. An empirical correlation, with a correlation coefficient equal to (92.6%), relating d32 with process variables was developed having the form:

Dr. Qahtan Al-Madfa’i’s architecture has been characterized by a particular characteristic that may be unique and extreme at the same time, that is the use of the distinctive three-dimensional structural coverings and the exploitation of structural construction to give an extra aesthetic touch to the composition of the building, to achieve the application of his universal ideas, which he strongly believed and defended.

      In the period of the marked urban decline that the country undergoes now, which urges us toward making a comparison between the beginning of the modern Iraqi architecture and its ascending path up to its peak and the periods of its decline until it reached a very

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Nowadays, the use of recycled waste construction materials instead of aggregates is becoming popular in construction owing to its environmental benefits. This paper presents an experimental and analytical campaign to study the behavior of axially loaded columns constructed from recycled aggregates. The latter was used instead of natural aggregates, and they were collected from the waste of previous concrete constructions. Different concrete mixtures made from varying amounts of recycled aggregates ranged from 0 to 50% of the total coarse aggregate were conducted to achieve 28 MPa. The effect of steel fibers is another investigated variable with volumes ranged from 0 to 2% concerning concrete’s mixture. The experimental

Nowadays, the power plant is changing the power industry from a centralized and vertically integrated form into regional, competitive and functionally separate units. This is done with the future aims of increasing efficiency by better management and better employment of existing equipment and lower price of electricity to all types of customers while retaining a reliable system. This research is aimed to solve the optimal power flow (OPF) problem. The OPF is used to minimize the total generations fuel cost function. Optimal power flow may be single objective or multi objective function. In this thesis, an attempt is made to minimize the objective function with keeping the voltages magnitudes of all load buses, real outp

In this research a local adsorbent was prepared from waste tires using two-step pyrolysis method. In the carbonization process, nitrogen gas flow rate was 0.2L/min at carbonization temperature of 500ºC for 1h. The char products were then preceded to the activation process at 850°C under carbon dioxide (CO2) activation flow rate of 0.6L/min for 3h. The activation method produced local adsorbent material with a surface area and total pore volume as high as 118.59m2 /g and 0.1467cm3/g, respectively. The produced . local adsorbent (activated carbon) was used for adsorption of lead from aqueous solution. The continuous fixed bed column experiments were conducted. The adsorption capacity performance of prepared activated carbons in this work

In this paper, the time-history responses of a square plan two-story reinforced concrete prototype building, considering the elastic and inelastic behavior of the materials, were studied numerically. ABAQUS software was used in three-dimensional (3D) nonlinear dynamic analysis to predict the inelastic response of the buildings. Concrete Damage Plasticity Model (CDPM) has been used to model the inelastic behavior of the reinforced concrete building under seismic excitation. The input data included geometric information, material properties, and the ground motion. The building structure was designed only for gravity load according to ACI 318 with

A Geographic Information System (GIS) is a computerized database management system for accumulating, storage, retrieval, analysis, and display spatial data. In general, GIS contains two broad categories of information, geo-referenced spatial data and attribute data. Geo-referenced spatial data define objects that have an orientation and relationship in two or three-dimensional space, while attribute data is qualitative data that can be counted for recording and analysis. The main aim of this research is to reveal the role of GIS technology in the enhancement of bridge maintenance management system components such as the output results, and make it more interpretable through dynamic colour coding and more sophisticated vi