Tikrit Journal of Engineering Sciences

In the present study two convective types of solar dryers were investigated and tested under the Iraqi climate conditions. The first is called indirect type which consists of solar collector and drying chamber and the second type is a direct solar dryers. A drying equation based on a thin layer-drying function has been introduced to simulate the change of moisture content of crops with time taking into account the effect of flow rate of air, drying temperature, humidity ratio, initial and final moisture contents, and crops distribution on the drying rate and can be used for different crops. The dryers were tested using potato, fruit, any vegetables and other kinds of green leaves under typical condition of Iraqi weather. Good agreement has been obtained between the present results and the available published measurements. The study indicates that the indirect solar dryer gives definite performance advantage compared with the direct solar dryer.

The hydro engineering characteristics of Al-Ajeej basin which was located within south Sinjar plain north west Iraq was analyzed to predict the possibility of surface runoff harvesting during rainfall season in the upstream sites in this basin using watershed modeling system (WMS). The hydrological feasibility of constructing small dam on Al-Ajeej valley with some preliminary design calculations were presented. The best optimum dam site was selected to be located (3.95) km downstream the confluence of Al-Badee branch with Al-Ajeej valley (35 46 6 Latitude and Longitude 41 36 11) having a catchment's area of (3043)km2. The proposed dam height was (12.5) meter with a dam length of (1277)m, while the normal storage volume of the reservoir is (38.8) million m3. Construction a dams in such sites characterized by water shortage during all around the year will give an aid in the sustainable development of such area by increasing the cultivation lands, the agricultural products and also modify the income of the villagers living in this area leading to prevent them leaving their lands to other places.

Voltage stability is indeed a dynamic problem. Dynamic analysis is important for
better understanding of voltage instability process. In this work an analysis for voltage
stability from bifurcation and voltage collapse point of view based on a center
manifold voltage collapse model. A static and dynamic load models were used to
explain voltage collapse. The basic equations of simple power system and load are
used to demonstrate voltage collapse dynamics and bifurcation theory. These
equations are also developed in a manner, which is suitable for the Matlab-Simulink
application. Detection of voltage collapse before it reaches the critical collapse point
was obtained in simulation results.

Color is a perceived phenomenon and not a physical dimension like length or
temperature, although the electromagnetic radiation of the visible wavelength spectrum is measurable as a physical quantity. A suitable form of representation must be found for storing, displaying, and processing color images. This representation must be well suited to the mathematical demands of a color image processing algorithm, to the technical conditions of a camera, printer, or television, and to human color perception as well. These various demands cannot be met equally well simultaneously. For this reason, differing representations are used in color image processing according to the processing goal. Color spaces indicate color coordinate systems in which the image values of a color image are represented. The standard color system, established by the International Lighting Commission CIE (Commission Internationale de I ’Eclairage), will be described. This system represents the international reference system of color measurement. The contribution deals with the Matlab application used for television and color spaces analysis. All of the color spaces can be derived from the RGB information supplied by devices such as cameras and scanners. There is a list of common color spaces. The application allows selection of input color image, direct and backward transformation into the selected space including CIE diagram picture analysis and NTSC system. The additional functions of this research are evaluation of histogram of colors. The Color Spaces application outputs are introduced on various test pictures.

The present study deals with the use of artificial neural networks ANN in predicting the ultimate load capacity of reinforced concrete beams. The data is collected from the numerical solution by finite element method of the simply supported beams with various properties, under the action of two point loads, symmetrically with the center. The data were arranged in a format such that input parameters cover the geometrical, reinforcements ratio and properties of beams and the corresponding output is the ultimate (failure) load.
Results were compared with the available methods in the literature. It was found that the average ratio of numerical solution (finite element) to predicted failure loads of beams was 1.018 for neural network, and 1.21 for limit state theory. It is clear that neural network provides an efficient alternative method in predicting the ultimate load capacity for R.C. beams.

This study aims of predication Power Duration Curves(PDC) resulting from the
optimal operation of the multi reservoirs system which comprises the reservoirs of
Bakhma dam,Dokan dam and Makhool dam for the division of years over 30
years.Discrete Differential Dynamic Programming(DDDP) has been employed to find
the optimal operation of the said reservoirs.
PDC representing the relationship between the generated hydroelectric power and
percentage of operation time equaled or exceeded . The importance of these curves lies
in knowing the volume of electric power available for that percentage of operation time.
The results have shown that the sum of yearly hydroelectric power for average Release
and for the single operation was 5410,1604,2929(Mw)for the reservoirs of Bakhma,
Dokan, Makhool dams, which resulted from the application of independent DDDP
technology. Also, the hydroelectric power whose generation can be guranteed for 90%
of the time is 344.91,107.7,188.15 (Mw) for the single operation and
309.1,134.08,140.7 (Mw) for the operation as a one system for the reservoirs of
Bakhma, Dokan, and Makhool dams respectively.

In this research an attempt is made on the ability of aerobic treatment of synthetic solutions containing lead and chromium using effective microorganisms within the reactor. To achieve the desired objectives of the research, synthetic aqueous solutions of lead and chromium was used in the concentration of chromium and lead ions of 5, 10,50 and 100 mg / l .The work was done at constant pH equal to 4.5 and temperature of 30 ± 1 º C. Effective microorganisms solutions was added to the reactor at Vol.% of 1/50 ,1/100 ,1/500 and 1/1000, with retention time was 24 hours to measure the heavy metals concentration the atomic absorption device was used. The experimental results showed that each 1mg / l of lead and chromium ions need 24 mg of effective microorganisms to achieve removal of 92.0% and 82.60% for lead and chromium respectively. Increasing the concentration of effective microorganisms increases the surface of adsorption and thus increasing the removal efficiency. It is found that the microorganisms activity occur in the first five hours of processing and about 94% of adsorption capacity of biomass will take place. It is also found the selectivity of microorganisms to lead ions is higher than for chromium ions.

The effect of the value of running capacitor on the performance of a single-phase
induction motor is studied through the evaluation of the efficiency, power factor and
vibration of the machine for different values of this capacitor choosing unsuitable value of
the running capacitor worsen the performance of the motor and it may even damage the
motor as a consequence of increasing auxiliary winding current.
In this research, a computer program has been developed for finding an optimum
running capacitor for the induction motor.
Experimental results has been obtained in the laboratory and compared with the
computer results for validation. The effect of the running capacitor on motor vibration has
also been obtained and measured. Although this study was performed on a certain twophase
induction motor, the same developed computer program may be used to obtain the
optimum value of the running capacitor for any single phase IM of known parameters.

In this research an experimental laboratory pilot plant was used to assess the ability of the integrated fixed film activated sludge (IFAS) process to upgrade the hydraulic capacity of the ordinary activated sludge units. The experimental plant consisted of three basins, which were designed to work simultaneously under the same operating conditions. The second and third basins were developed to work on the suggested process by adding a fixed media to these reactors in such way so that the specific area in the second basin was 18.72 m2/m3 and in the third 37.44 m2/m3. The experimental program was divided into five stages so that, the applied discharges in the second, third, fourth and fifth stages were 150%, 200%, 250% and 300% of the discharge in the first stage respectively. The result of the experimental work showed that the (IFAS) process can effectively upgrade the capacity and performance of the ordinary activated sludge process. In the second basin, the discharge was increased to about 125 % of its original value without reduction in the organic removal efficiency while, in the third basin the load increased to 150 % of its original value and also no reduction in the removal efficiency was observed. The settling characteristics of the activated sludge also improved and filamentous growth became very limited.

Laboratory tests and analysis results for materials chosen from al-Adhaim site
indicate that either suitable according to American Standards for use as clays
quarries for filling ,dams ,dykes and embankments or unsuitable for one or more
reasons . Treatments take place ,according to type of problems for example
physical problem , as excess in silt and sand particles percentages , also decrease
in clays particles percentage ,vice versa. In addition to physical foul, many
treatments can be done , chemical problems such as excess in gypsum content,
total dissolved salts and organic materials according to British Standards. In
addition to chemical foul, by grass, plants roots , treatments done which can be
done according to the causes of these problems.

In this research the hydraulic characteristics of sharp crested weirs with semi- circular shape were studied, the study was depended on the dimensional analysis which confirmed by experimental work. The dimensional analysis results demonstrate that the effective parameters on the discharge of flow over this type of weir are the ratio of water height above the weir crest to the radius of this weir (H/R) and the ratio of water height above the weir crest to the height of the crest (H/P). Experimental tests were carried out on (16) models of weirs with Semi-circle shape where the radius of cutting was change four times (R=5, 10, 15, 20 cm) and for any radius the height of the crest was change four times (P= 30, 25, 20, 15 cm). The results show a great influence of the parameter (H/R) on flow parameter (Q2/gH5) while the effect of the parameter (H/P) is limited. Depending on non-dimensional parameters and experimental results, the statistics program (SPSS) were used to create empirical equation for measuring the discharge over the sharp crested weirs with semi-circular shape. The results of the equation show a very good agreement with the experimental result for determine the discharge with knowing the depth of water over the weir (H) , radius of cutting of the weir (R) and height of the crest (P). Also the equation shows a great influence of the radius (R) and limited influence of the height (P) on the discharge over this type of weirs.

A study of the degree of acidity for the precipitation in four different sites in Tikrit city was done for the period from 1-February to 1-April/2007 which is the period of rains in this year.
Chemical tests included (pH) as the direct indicator of the degree of acidity ,and the concentration of sulphates (SO4-2 ) and nitrates ( NO3- ) as indirect indicator.
The (pH) range was (5.56-6.4) which indicates the presence of acid rain in the area under study . (SO4-2 ) concentrations range was (88-223)mg/l while ( NO3- ) concentrations range was (80-170)mg/l.
The wind velocity ,temperature, and humidity during the sample collection period ranged (2.25-4)m/s, (1-26)0C, (22%-90%) respectively.