Tikrit Journal of Engineering Sciences

This paper contains the results of CBR tests that performed on compacted samples of real dune sand (cohesionless sand grains) and pseudo dune sand which is a mixture of sand sized aggregate of clay and silt. The effect of compaction and soaking on the bearing values are included in this research. The results indicated that the compacted real dune sands have high strength and low sensitivity to soaking. The 5 mm penetration of CBR of this soil is higher than that of 2.5 mm. On the other hand, the loss of strength due to soaking can be quite considerable in compacted pseudo dune sands. The CBR values obtained at 2.5 mm and 5 mm penetration are approximately equal in pseudo dune sands.

In this paper, Artificial Neural Networks (ANN), which are known for their ability to model nonlinear systems, provide accurate approximations of system behavior and are typically much more computationally efficient than phenomenological models are used to predict the etchant copper concentration in the electrolytic cell in terms of electric potential, operating time, temperature of the electrolytic cell , ratio of surface area of poles per unit volume of solution and the distance between poles. In this paper 350 sets of data are used to trained and test the network.. The best results were achieved using a model based on a feedforword Artificial Neural Network (ANN) with one hidden layer and fifteen neurons in the hidden layer gives a very close prediction of the copper concentration in the electrolytic cell.

High octane blend base gasoline stocks are reformulated from 30% LSRN, 45% Reformate and 25% Powerformate on volume basis. ASTM standard and IROX 2000 analysis are performed to test blend stocks sample. Different additive types are used to improve octane number. These additives are tetraethyl lead, methylcyclopentadienyl manganese tricarbonyl; methyl alcohol, ethyl alcohol, iso-propanol, n-butanol, sec-butanol, tertiary butyl alcohol, tert-amyl alcohol, active amyl alcohol, iso-pentyl alcohol, isobutyl carbinol, benzol ,telone, xylene, amino benzene, N-N-dimethyl aniline, dimethyl ketone, and ethyl methyl ketone. Comparison is made between significant individual RON gains measured by standard CFR test-engine. The results indicated that the combined iso-propanol, oxinol (50/50 blend of methanol and TBA), aniline, and xylene with hydrocarbons fraction content in the gasoline base pool is better to ensure high RON. The results showed that a mixture of 20/54/10/16 of blend aniline/ iso-propanol/ oxinol/ xylene respectively, led to an increase in RON of gasoline blend pool from 84.5 to 96 RON, or 11.5% RON gain.

Four major anions (nitrate, phosphate, sulfate and chloride) are measured in Tigris river at Mosul in six locations since Sept.2005 to June 2006. The same 4 anions are measured previously by researches or thesis, so their results are added to the former one for comparison. The variation of flow is also reported for the whole period in order to study the concentration-flow relationship. The nitrate and phosphate concentrations are increasing with the river flow increase and decreasing with its decrease for most periods, (reaching up to1.05mg/l at June for nitrate and 0.482mg/l at April for phosphate) .The lowest concentrations are observed (as low as 0.285 mg/l at Dec. for nitrate and 0.07mg/l at Jan for phosphate). Sulfate and chloride concentration are varying oppositely to the river flow for most periods, both showing their peaks at Jan. and their lowest at June (reaching up to 170 mg/l for sulfate, and 33.4 mg/l for chloride) while the minimum values are 68mg/l for sulfate, and 15.6 mg/l for chloride. The data of the previous years are not complete and data for only 8 years are available. It indicates that the anions concentrations variation corresponding to the river flow is similar to that of the studied years. However the data with equal flow rate only are used for comparison purposes to achieve correct results. All of the studied anions are increasing since 1982-2006 in different percentages except the phosphate. The 4 major anions are lower than the standards and MCL for the recent and previous studies.

The aim of this research is to build a ciphering system by using genetic neural network technique to protect data against unauthorized access to the data being transferred. The encryption data includes three stages: first Stage :- Using the genetic algorithm to train backpropagation neural network for obtaining weights. Second Stage:- Encryption data by using the weights obtained from first backpropagation layer and consider its weights as a encrypted key. third Stage:- Decryption data by using the weights obtained from second backpropagation layer and consider its weights as a decrypted key. This system is similar to coding asymmetric, and have the ability of coding a group of data such as:- pictures, waves and texts.

Nonlinear finite element analyses is carried out using the ANSYS11 program to predict the ultimate load for two different types of reinforced concrete continuous two-span deep beams. Results of comparing analytical with experimental data demonstrates the accuracy of the program. The effects of longitudinal reinforcement and web openings are studied and showed that the longitudinal reinforcement at top and middle region has little effect on the ultimate load, and the effect of web opening location has great effect on the ultimate load especially when the load path passes through the openings centerline. Web opening location also has great effect on values and distribution of shear and normal stresses especially at opening region.

Differential Pulse Code Modulation (DPCM) is one of the predictive coding techniques. The number of previous pixels employed in the estimate operation is referred to as the order of the predictor. Predictor using one pixel for estimation is called “first order predictor”. A “second order predictor” utilizes two pixels and an “nth order predictor” would employ n previous pixels. From the results computed in this work, by testing the prediction mean square error (MSE) using different numbers of previous picture elements. The results show that the MSE decreases significantly by using up to three pixels, and further decreases of MSE are rather small by using more than three pixels that means the performance improvement becomes negligible and only a marginal gain beyond a third-order predictor can be achieved. That means, Peak Signal to Noise Ratio (PSNR) increases significantly by increasing the predictor order, the performance improvement becomes negligible beyond third order predictor.

HYSYS process simulator is used for the analysis of existing HF stripping column in LAB plant (Arab Detergent Company, Baiji-Iraq). Simulated column performance and profiles curves are constructed. The variables considered are the thermodynamic model option, bottom temperature, feed temperature, and column profiles for the temperature, vapor flow rate, liquid flow rate and composition. The five thermodynamic models options used (Margules, UNIQUAC, van laar, Antoine, and Zudkevitch-Joffee), affecting the results within (0.1-58%) variation for the most cases. The simulated results show that about 4% of paraffin (C10 & C11) presents at the top stream, which may cause a problem in the LAB production plant. The major variations were noticed for the total top vapor flow rate with bottom temperature and with feed composition. The column profiles maintain fairly constants from tray 5 to tray 18. The study gives evidence about a successful simulation with HYSYS because the results correspond with the real plant operation data.

Wastewater of hospitals creates serious environmental problems since it may contain viruses, poisonous medical materials and heavy materials. Thus, extensive care should be given for such wastes before disposing to surface water or city sanitary network. In this research, a detailed investigation for the wastewater discharged from different departments of Al-Nu’uman general hospital has been performed during the period February – June, 2005. It is found that wastewater discharge from that hospital is 0.76 m3/(day.bed) which is very close to the Iraqi and International health regulations. This research program includes measurements of different wastewater characteristics including BOD = 180 mg/l , COD = 474 mg /l, PO4= = 15 mg/l , SO4= = 108 mg/l , SS = 1979 mg/l , pH = 7.5 , average Temperature of ( 23° C ). The results of this work indicated that the range of Al-Nu’uman general hospital wastewater characteristics fall within the general limits of hospital wastewater characteristics.

The aim of this research is invention probabilistic approach to analyze the recession curve for mean monthly inflows to lakes of Dokan dam at Lesser Zab river and Derbendikan dam at the Diyalah river by dividing the recession curve to many class interval and finding the mathematical equations which controls each class interval by using finite mathematics, and using Markov chain to calculated the transition probability matrix for the classes intervals. A computer program in Visual basic language with visual application interface in Excel software which be developed to generate recession curve. The results indicated that recession curve consist of five class intervals and each class interval have a power regression equation, the statistical analysis indicated a good confidence to use a computer program to generate the recession curve because that average of relative percentage error wasn’t greater than 8 % for Dokan dam and 9% for Derbendikan dam.