Tikrit Journal of Engineering Sciences

Measurements of metrological data of maximum, minimum ambient temperature, humidity and sunshine duration for a period of 23 years during the period of 1977-2000, at Tikrit (34. 35°N, 43.37°E), TuzKurmato (34.88°N, 44.64°E), and Kirkuk (35.30°N, 44. 21°E) were used to establish an Angstrom type correlation equations for direct global solar radiation. The diffuse radiation was estimated by using Klien and Page Models. This calculation appears to be sufficient to discriminate each station from the others due to it’s local characteristic of the sites. The overall results shown for TuzKurmato, the received radiation on the plane surface is higher than Tikrit and Kirkuk while the diffuse radiation reversely behaved as for Tiktit is the highest. The developed model can be used for estimating global solar radiation on horizontal surfaces. The monthly average total solar radiation was estimated. The value of correlation coefficient (r) and value of Root Mean Square Error (RMSE), Mean Bias Error (MBE) and Mean Percentage Error (MPE) were determined for each equation

This study aims to demonstrate the effects of geogrid reinforcement on the bearing capacity of strip footing under eccentric loading. Numerical analysis using finite element program called (PLAXIS 2D Professional v.8.2) are presented. The effect of each of the depth ratio of the topmost layer of geogrid (u/B), the vertical distance ratio between consecutive layers (h/B), number of geogrid layers (N), and the effective depth ratio of reinforcement (d/B) on the bearing capacity were studied, where (B) is the footing width. Also, the combined effect of load eccentricity ratio (e/B), depth of embedment ratio of footing ( f D /B) and the angle of internal friction ( ) on the ultimate bearing capacity were investigated.

The main objectives of this research were to study and analyses oily wastewater characteristics originating from old-processing plant of North Oil Company and to find a suitable and simple method to treat the waste so it can be disposed off safely.
The work consists of two stages; the first was the study of oily wastewater characteristics and its negative impacts. The results indicated that oil and grease were the most dominant pollutant with concentration range between 1069 – 3269.3 mg/l that must be removed; other pollutants were found to be within Iraqi and EPA standards. The next stage was the use of these characteristics to choose the proper technology to treat that wastewater. This stage was divided into two stages: the first stage was a jar tests to find the optimum doses of alum, lime and powdered activated carbon (PAC). The second stage was the treatment by a batch pilot plant constructed for this purpose employing the optimum doses as determined from the first stage to treat the waste using a flotation unit followed by a filtration-adsorption unit. The removal efficiencies of flotation unit for oil and grease, COD, and T.S.S found to be 0.9789, 0.974, and 0.9933, respectively, while the removal efficiency for T.D.S was very low 0.0293. From filtration – adsorption column the removal efficiencies of oil and grease, T.D.S, COD, and T.S.S were found to be 0.9486, 0.8908, 0.6870, and 0.7815, respectively. The overall removal efficiencies of pilot plant were 0.9986, 0.8939, 0.9921, and 0.9950, respectively. The results indicated that this type of treatment was the simplest and most effective method that can be used to treat produced oily wastewater before disposal.

This research deals with the field investigations and construction properties for using limestone as a lightweight course aggregate in concrete mixture in stead of normal coarse aggregate. Concrete cubes samples have been prepared with dimensions of 150*150*150 mm according to ASTM. For these samples the normal coarse aggregate was replaced by 100% coarse crushed limestone. Three types of limestone which were used (Al-Sinea, Makhool and Himreen), it was found that the Al-Sinea type of limestone gave a good combination (fcu =32.11MPa without admixtures).
The obtained results showed a suitable reduction in dead loads of structural elements and cost. Accordingly, the usage of limestone will improve the structural applications and concrete mix properties to attain economic viability. These above results make limestone as a good alternative of normal coarse aggregate.

The diesel engine is the most efficient prime mover commonly available today. Diesel engines move a large portion of the world’s goods, power much of the world’s equipment, and generate electricity more economically than any other device in their size range. But the diesel is one of the largest contributors to environmental pollution problems worldwide, and will remain so, with large increases expected in vehicle population.
This experimental study has been conducted with direct injection diesel engine and particulate matters (PM) concentrations were measured at variable operating variables. The results show that PM concentrations influence by changing equivalence ratio, load, engine speed and injection timing.

Increasing on gaseous fuels as clean, economical and abundant fuels encourages the search for optimum conditions of gas-fueled internal combustion engines. This paper presents the experimental results on the lean operational limits of Recardo E6 engine using gasoline, LPG, NG and hydrogen as fuels. The first appearance of almost motoring cycle was used to define the engine lean limit after the fuel flow was reduced gradually. The effects of compression ratio, engine speed and spark timing on the engine operational limits are presented and discussed in detailed. Increasing compression ratio (CR) extend the lean limits, this appears obviously with hydrogen, which has a wide range of equivalence ratios, while for hydrocarbon fuel octane number affect gasoline, so it can' t work above CR=9:1, and for LPG it reaches CR=12:1, NG reaches CR=15:1 at lean limit operation. Movement from low speeds to medium speeds extended lean misfire limits, while moving from medium to high speeds contracted the lean misfiring limits. NOx, CO and UBHC concentrations increased with CR increase for all fuels, while CO2 concentrations reduced with this increment. NOx concentration increased for medium speeds and reduced for high speeds, but the resulted concentrations were inconcedrable for these lean limits. CO and CO2 increased with engine speed increase, while UBHC reduced with this increment. The hydrogen engine runs with zero CO, CO2 and UNHC concentrations, and altra low levels of NOx concentrations at studied lean misfire limits.

Level of posted highway traffic signs (HTSs) comprehension by drivers is used to investigate the effectiveness of the posted HTSs in Iraq. Twenty four HTSs, different characteristics of drivers, and survey with questions of short answer and multiple-choice is selected for this aim. The study results show that there is an increase in the driver comprehension process of HTSs with the increasing of his level of education, level of urbanization of his residence and driving daily practice. Inverse relation occurred with the increasing of driver number of accidents. The results of this research show that it is very important to modify some of the HTSs so as to be easy for comprehending by making it more legible and more appropriateness, also it is recommended to educate drivers to raise there ability to understand the meanings of all the HTSs.

This work presents the design and implementation of a versatile digital overcurrent (O/C) relay using a single microprocessor. The relay is implemented by a combination of a look-up table and a counter. The software development and hardware testing are done using a microcomputer module based on a 8-bit microprocessor. The digital processing of measured currents enables a separate setting of operating values selection of all types of inverse or constant time characteristics overcurrent protection. This protection provides reasonably fast tripping, even at terminal close to the power source were the most serve faults can occur excluding the transient condition. So this method has an excellent compromise between accuracy hardware and speed.

The resistance of asphaltic concrete to cracking is dependent upon its tensile strength and flexibility characteristics. Also the low tensile strength has recognized as a major contributor to other performance problems.
The fatigue life of mixtures decreases exponentially with decreasing of tensile strength. This trend is justified by the loss in stiffness and thereby initiating cracks and stripping.
The main objective of this research is intended to study the effect of different variables related with the used materials and the external conditions on the tensile strength and predict a model of indirect tensile strength in asphalt concrete paving materials under the local prevailing conditions and investigate the effect of percent of additives of (Polyestrene resins and Hydrated Lime) to enhance the resistance ability of asphalt concrete mixture against distresses.
The main affected factors; soaking, asphalt content, compaction, aggregate maximum size and temperature, influence on the indirect tensile strength and presented through a statistics analysis model for tensile strength in asphalt mixture.

In the beginning of the International Style receding, at the modernism stage breeches, and the post-modern start, in the last quarter of the previous century, when Architects and Thinkers called to return to heritage and historical worth, to obtain the architectural identity, the Architects and Thinkers of Arab and Muslims got back inducing the ancient architectural heritage of towns and buildings, to reveal the Arabic and Islamic identity.
The Urban Fabric of these ancient towns was, as a result, one of the most important pedestals of deep-seated characters of the Islamic and Arabic identity, through its organic pattern, co-operative condensed fabric, close bendy lanes, and closed courtyards. But the structural analyses of the ancient urban fabric, in this paper,clarified some facts, the Condense Fabric and the closed courtyards were a synchronic solution of the climatic circumstances, fitting the synchronous technical evolution, the Organic Pattern of the Urban Fabric was a reflection of the absence or weakness of the central authority, that couldn’t make initial planning of towns and sectors.
This research approves an Islamic doctrine for urban fabric, deeply different of the current in the previous studies.

The rapid urban growth has lead to an urgent need to increase residential buildings in such a way that requires quick execution of such buildings. The appearance of modern materials such as reinforced concrete has helped in getting fast-constructed houses of a westerly pattern such that excluding the inherited styles that are in harmony with severe environment like that of the Middle East. This has resulted in a modern pattern of buildings lacks the microclimate which was enjoyed by the traditional pattern and which have provided the inhabitant with a relative thermal comfort.
This research try to compare different microclimates due to the variation of open architectural spaces patterns in the residential units (traditional ones) represented by (the courtyards and Iwan) and the modem one represented by the space of (garages and terraces) in Summer in Mosul city.
The results showed that the traditional open spaces are the nearest to the thermal comfort zone, although both of them don't represent the ideal state of human comfort in this period of Summer.

Survey and sampling collections on municipal solid waste (MSW) composition and generation rate of Mosul city was conducted for more than six months with daily repetition .The results revealed the variation of solid waste components with the domination of food and organic waste. Other components as paper, glass, plastic, metal, tin can, textiles and wood were clearly shown. Also small percentages of rubber, leathern materials, trimming and others were founded also.
The percentages of different solid waste components with those dominated in the 1988 were made. The apparent differences were attributed to changes ofconsumption style and living of Iraqi families. Organic matter which constituted (68.17%) can be using to produce soil conditioners. Recycled and reused matters comprised (20.0%) could also be advantageously used. The remaining small percentages which amounted (11.83%) could be sent to landfill.
Statistical analyses were done to represent the scatter of each component about the mean value.
The daily per capita generation rate of solid waste in the city as pure residential generation amounted to (0.305 Kg/capita per day). The Gross generation of various types of solid waste was calculated as (0.61 Kg/capita per day). Some mathematical relations were used to forecast the future generation rate and composition of the city solid waste.

The objective of this research is to evaluate Method of Line (MOL) used for solution of water flow equations through porous media using MATLAB package functions for solution of ordinary differential equations ODE,s , instead of writing long programs codes. sink & source term to MOL model were included. Then Comparing MOL model with another model that uses finite element method in solving water flow equations(FEM) in one dimensional flow using computer program code in FORTRAN. Two cases were examined for evaluation and comparison of these two models. Firstly, infiltration phenomena using sandy soil was studied with the same parameter for both models. Results show that there is a divergence between the two models along time of 60 minutes of infiltration. Changes of moisture content with soil depth were sharp with FEM model. Second case, data of the volume of water content for wheat field where used taking irrigation and evaporation into account, along the growth period of wheat crop and different depths up to 100 cm. Results show that output of FEM model has high degree of agreement with the measured data for all depths and along all period of growth. Data given by MOL model were less in values than measured data for all depths and along all period of wheat growth time.

A robotic system for the disabled who needs supports at meal is proposed. A feature of this system is that the robotic aid system can communicate with the operator using the speech recognition and speech synthesis functions. Another feature is that the robotic aid system uses an image processing, and by doing this the system can recognize the environmental situations of the dishes, cups and so on. Due to this image processing function, the operator does not need to specify the position and the posture of the dishes and target objects. Furthermore, combination communication between speech and image processing will enables a friendly man-machine to communicate with each other, since speech and visual information are essential in the human communication.

The feasibility of using combination of effective microorganism (EM1) and conventional chemical conditioner was evaluated in this study to assess and discern the dewatering properties of the secondary sludge that produced from wastewater treatment plant of the medical assembly in Mosul city 9Conventional coagulants such as lime, Alum, and ferrous sulfate, six doses for each coagulant type i9e)5 - 30()10 - 60 (and (25 -
150mg/l ( respectively, were used in the sludge conditioning processes for enhancement of the sludge dewatering capacity 9The characteristics of conditioned sludge, such as specific resistance of filtration (SRF( were determined at each dose9Experimental results indicated that effective microorganism seeds have a passive effect on SRF value which was about )% 7194(and (%75(in lime and ferrous sulfate respectively9While in Alum conditioning process a significant effect on SRF reduction was accomplished which was about %)-4799( and ( - % 3298( for effective microorganism and Alum dose increments respectively 9The best Alum dosage, for minimum SRF 0998348×10 12 m /kg, was 60 mg/l at 1 % of effective microorganism 9