KUFA JOURNAL OF ENGINEERING

This work paid special attention on the laminar flame speed in a piloted methane-air in jet diffusion flame due to the strong nonlinearity of chemical reaction process where an extension for the unsteady laminar flamelet model is required. The purpose for doing that is set for two folds. The partial differential equations for solving the combustion model required the representation of laminar flame speed in it and the advanced combustion modeling which is promising step. The probability density function required the laminar flame speed to be modelled as a function in terms of the mixture fraction to perform the integration. The laminar flame speed model is discussed, and the results are compared with the experimental database with good accuracy. The model specifies the conditional laminar flame speed and the difference against the gas flow velocity.Â

The operation and structure of distribution system are changing with the integration of Distributed Generation (DG) units, where these units may have effect on power losses, stability, voltage profile, power quality and other quantities. Therefore the optimum location, size and number of DG units are necessary to avoid the negative impacts on electric power system. In this work, the Particle Swarm Optimization (PSO) technique is used to find the optimal number and locations of DG in order to minimize the active power losses. The thermal limit of transmission lines and transformers was studied to detect the lines or transformers which exceed the limit in order to process it. The voltage stability of distribution network has been investigated, using L index method.Â

The research presents a numerical study of the interaction between single cavity and adjacent pile in homogenous sandy soil by utilizing an efficient finite element formulation. A square cross sectionalconcrete pile, with (9) m length and (0.6) m width, hasbeen used. The interface layer between pile and surrounding soil was represented by thin layer element.The research results indicate that, in the direction perpendicular to the direction of applied load, where the ratio between the distance from the cavity to the pile and cavity length (measured in the same direction), is equal or more than (1.7)the effect of cavity can be neglected. While the values of the maximum bending moment decrease with increasing of the above mentioned ratio, and it became constant when the ratio ≥(2.0). The deformations around cavity increases with increasing lateral load and decreasing the above mentioned ratio, particularly in the nearest side of pile and these deformations are constant when the ratio ≥ (2.0).

No–fines concrete is obtained by omitting fine aggregate from the mix and the coarse aggregate particles are surrounded by a coating of cement paste.In the present work, well-graded coarse aggregate (20 mm maximum size) was used in preparing the mixes, instead of single sized coarse aggregate as recommended always for No –fines concrete. Concrete mixes with different aggregate /cement ratios were prepared to find an optimum mix giving the highest strength. The influence of aggregate /cement ratio on the unit weight, absorption and compressive strength were studied at different conditions of curing. It was found that the strength of No –fines concrete is lower than that of ordinary concrete. Also, this type of concrete behaves like the ordinary concrete relating to the growing of strength with the age.According to the properties investigated, No –fines concrete is sufficient enough to be used in different constructions, like low-rise buildings, pavements and other application.

In the UK, TRICS is a national trip generation databases and system. It is recommended to be used in quantifying traffic impacts of new residential developments. Thus, any enhancement in its methodology will positively influence the transport assessment process. This paper has three objectives; first, to examine the possibility of proposing new statistically-proven grouping for the TRICS residential land use subcategories. The second objective is to use the proposed grouping to construct parsimonious models for home-based trip production that can aid in quantifying traffic impact assessment. The third objective is to examine the validity of the developed models against two of the most internationally recognised trip information systems; the UK TRICS and the US ITE Trip Generation Manual. The statistical analysis ended up with new more accurate grouping where based on it eight trip production model were built. The developed models were found to be practical and rigorous.

In this study, a specified area of Al-Hussainia sector (which is the middle sector of Al-Dalmaj irrigation project in Kut city/ Iraq) has been selected tobe evaluated for its water suitability to irrigate cotton plant. The evaluation include: first Chemical evaluation of drainage water, second Analysis of drainage water by Aq.Qa software, and third computations of Leaching requirements for cotton crop.For the chemical evaluation the most important indicators for the salinity problem considered are (Electrical Conductivity, Total Dissolved Solids, Sodium Adsorption Ratio (SAR) and Sodium Content).The analysis of the hydrochemical results by Aq.Qa program shows that the internal consistency of the samples was acceptable.It is concluded that in the months July to October most of the measured concentrations of the tested elements were greater than the other four months because in hot weather the evaporation will increase which decrease thequantity of dissolved oxygen in water which cause the increase in concentrations of these elements. However the drainage water of Al-Hussainia sector can be used directly to irrigate cotton without reducing the yield with leaching requirement of 0.18 for location 1, leaching fraction of 0.17 needed for locations 2 and 6, while a leaching fraction of 0.16 should be provided for locations 3 ,4 ,and 5. However there is no need to mix the drainage water with fresh water.

This research presents a SHM (Structural Health Monitoring) techniques that are based on harmonic and transient analyses of cracked plate structure. Finite element models for the different cracked steel plate have been created by considering the length and the orientations of the crack, and a cantilever supported plates (parallel to the crack) are used.

The cracked structures are examined under harmonic concentrated lateral load. The frequency responses show that the lateral deflections of the crack plate decrease when increasing the crack length, whereas, the lateral deflections increase when increasing orientation angle until 90°. The models are also examined under the effect of transient concentrated lateral load. The time history responses show that the lateral deflections of the crack increase when increasing the crack length.

Finally, SHM analysis is applied in order to predict the early behaviour of the plates in accordance with the results above. The extrapolation for certain symbols of the results is performed to derive numerical formulas of the lateral deflections .The lateral deflection’s formula is used as a function for the half-crack length, however, there is a formula for each orientation angle.

In this paper, a system is established and designed for DC series motors torque measurement based on PLC (Programmable Logic Controller) techniques instead of using old traditional mechanical methods. The researchers tried to exploit the techniques available in PLC type LOGO! ® V6 to design the above mentioned system which measures the torque with a simple method. Measuring the torque in this system is based on two parts, the first part is to measure the supply voltage, current and speed of the DC series motor by Hall Effect sensors, then enters these values to the PLC. The second one is to calculate and process the torque of the motor depending on the mentioned above values by building a representative model based on mathematical equations representing the operation of the DC series motor. By comparing the results of both methods, it shows that the results are approximately the same but our system is much easier than the traditional systems. Our system contains a subsystem which enables the operator to monitor the mechanical output power and the percentage efficiency of the motor during its operation. To protect the operator and the motor from the risky situations of overload and over speed, which often happens when operating DC series motors, an overload and an over speed protections were included in our system.

In the modern construction practices, industrial wastes or by-products are largely used as raw materials in cement and concrete. It imparts positive environmental effect because the waste materials are not released to the environment; therefore, this research study was conducted to investigate the effects of used engine oil on properties of fresh and hardened concrete. The main variables included the type and dosage of admixture (commercially air entraining agent, used engine oil, and new engine oil), consistency, rate of slump loss, setting time and compressive and splitting tensile strength. Results showed that performance of used engine oil and the new engine oil mixes were similar. Results of this study also showed that used engine oil acted as a chemical plasticizer by improving the fluidity and the slump of the concrete mix. The used engine oil decreases the initial setting time and increases the consistency and rate of fluidity loss of ordinary Portland cement concrete. Effects of engine oil on the concrete compressive and splitting tensile strength were negative with respect to the control/reference mixes. However, engine oil concrete has a higher compressive and splitting tensile strength than the corresponding concrete mixes containing dosage of commercial air entraining agent.

In this research, a study was conducted experimentally to investigate the scour hole dimensions downstream the combined structures which consist of weir and gate. Twelve models have been designed and every model is formed from composite weir consists of two geometric shapes and three types of gates which are rectangular, semi-circular and triangular in shape, where multi factors were studied to find out the effect of changing geometry for both weir and gate, discharge flowing in the flume and particle size of bed material on the dimensions of scour hole. The experiments was conducted in a laboratory channel was constructed from blocks and concrete with length of 18 m, 1 m width and 1 m depth. The laboratory models were installed after 7 m from the main gate which is controlling the passage of water from the main reservoir into the flume.At the beginning, the calibration process was conducted to identify the actual discharge values that pass in the flume, then experiments were conducted to calculate the discharge coefficient for each model, which represents one of the studied factors within the dimensional analysis of the variables to derive the empirical formulas to calculate the dimensions of scour hole.Then the experiments were conducted in order to derive formulas to investigate the depth and length of the scour hole which formed in the sand floor spreading as a layer of 30 cm in thickness for a distance 4 m downstream combined structure. Two samples of sand were used in the experiments with different median size of particles ( d50), the first of 0.7 mm and the second of 1 mm.Using the dimensional analysis by π theorem and IBM SPSS 21 program, Four nonlinear relationships were derived to calculate the dimensionless scour depth (SD / d50) and another four nonlinear relationships calculates the dimensionless length of scour (SL / d50)depending on the laboratory results for each of the relative discharge (Qr), Froude number in terms of mean size of particle of bed material (Frd), non-dimensional difference head between upstream and downstream of combined structure (HD / d50), dimensionless distance between the lower edge of the weir and the upper edge of the gate (y3 / d50), dimensionless head over the crest of compound weir (h/d50) and the discharge coefficient (Cd), where the resulted determination coefficients (R2) from these relationships were good.

Strengthening and rehabilitation by confinement technique of reinforced concrete columns was investigated. The columns were confined by external steel collars. Behavior and failure load of columns were experimentally investigated. Results show thatConfinement in concrete column has improved its strength and ductility. Effect of confined area, size of collar and compressive strength of concrete on strengthening was investigated .Confined areahad significanteffect on the failure loadfor strengthened specimens and had more effective on the failure load for repaired specimens. The confinment hadclearer effect with low compressive strength of concrete.The result show an increase in ultimate axial load reach to (12.36 –56.04%)for strengthening columns and (47.5 –96.7%)for reaparingcolumns