KUFA JOURNAL OF ENGINEERING

In this paper, a mathematical model and simulation of flat plate solar collector are developed. The weather data, which used in the calculations of the performance of the collector, is for Mosul city. Detailed energy analyses were carriedout for evaluating the efficiency and useful heat gain of a typical flat plate solar collector under certain operation and design conditions. In this analysis, different fluids and different absorbing materials were used to indicate their effect on the performance of flat plate solar collector. Operating parameters, which considered as variables, are the mass flow rate, the inlet and the outlet temperature difference and the total solar radiation flux. The simulation program had written by using EES (Engineering Equation Solver) software program. The results of this analysis show that the copper and aluminum gives a good efficiency up to (0.6) with value (0.02) of collector performance coefficient whenwater as a working fluid, while the plain carbon steel gives efficiency (0.46)that stated previously because of low heat conductance . The results show also that the copper and the aluminum give the largest useful heat gain extracted from the collector as compared with plain carbon steel. It has been also show that the solar collector efficiency is higher in case of using water as working fluid than that of propylene glycol solution

A two-dimensional hydraulic flow model was developed using the SMS software (Surface Water Modeling System) to simulate the flow properties(thalweg line location) for meander in trapezoidal section channel, and its changes when a single emerge spur dike install at mid of the bend. The model was calibrated and verified through matching velocity profiles throughout the study reach.
Thalweg line location were found due to the variation of spur dike characteristic including 180 runs, included five different ratios of spur dike length to top channel width (L/Tw), five ratios of spur dike arm to its body length (l/L), and two spur arm`s direction for four different flow rates, as a result, through the flow configuration the new location of the thalweg in the bend channel after using the spur dike was about (44-71)%Tw which mainly affected by spur body length.

This paper deals with the attraction and repulsion properties of the magnetic field of permanent magnets in order to produce reciprocating motion in a member of magnetizing material.
The essential idea of this work have started by putting a string of eight magnets type (Nd Fe 35) spaced by equal spaces placed on the axis between two series of same magnet type each string consists of nine magnets pieces spaced apart vacuum. Series of internal and external were organized with different opposite polarity north and south that created a series of free movement of internal series between the two external strings.
First of all, designed magnetic motor rectal movement consisting of two fixed (for external strings) and one moving part (Series Interior) analysis was done and its operation was analyzed. In addition, equations that describe the magnetic field arising from the moving part were modified by using two-dimensional computer model. The (femm) program was used for modeling the distribution of density, and DS Solid Works program to study and calculate the magnetic flux density, field strength and torque generated.

Medical imaging is a process and technique used to create images to the human body or parts and function thereof for clinical purposes, to medical procedures seeking to reveal, diagnose or examine disease or medical science. In this paper we will explain three types of medical imaging techniques; Magnetic resonant Imaging (MRI), Positron Emission Tomography (PET) and Ultrasound (US) that are used in the breast cancer detection, then we will compare among them to know which one of this techniques are better to use in the detection of breast cancer by taking in the account all of the sensitivity, resolution, cost and side effect. The results show that superior of MRI against the both of PET and Ultrasound in the sensitivity and resolution, while the disadvantages of MRI techniques was the high cost and time required to get imaging.

Warm Mix Asphalt (WMA) is a technology that allows significant lowering of the mixing and compaction temperature of conventional Hot Mix Asphalt (HMA). This research presents the results of laboratory tests conducted to evaluate the properties and performance of warm mix asphalt. TheWMA has been prepared from two asphalt grades and one aggregate source with twoadditives (Aspha-min® and Sasobit®). The crumb rubber is also added to WMA which is prepared withAspha-min® and Sasobit® to evaluate effect of crumb rubber on WMA properties. The results of the study indicated that the two additives to the warm asphalt affected the mixture properties differently. When the mixture properties were compared, it was observed that Aspha-min® reduced the indirect tensile strength and resilient modulus values of the mixes, the two WMA additives increased the rut depths of the mixes, and both the additives reduced the tensile strength ratio of the mixes.WMA contains crumb rubber appears

This investigation is conducted to study the effect of addition of ceramic powder (CP) on drying shrinkage cracks and compressive strength of cement mortar. Steel molds having a trapezoidal section, and the end restrained at square shape used to study restrained drying shrinkage of cement mortar. Specimens of compressive strength, density, were cast. The admixture (CP) was used as addition with three levels of (2%, 4% and 8%) by weight of dry cement. All specimens were cured for (14 days). Average of six results was taken for any test of compressive strength and density. The experimental results showed that the adding of this admixture cause a delay in a formation of cracks predicted from a drying shrinkage, increase compressive strength at levels of (4%) of admixture and cause the decreasing in the density of cement mortar Specimens. The increment in compressive strength at level (4%) was (6.11%), but at level of (8%) it was decreased by (3.9%). The admixture has the visible effect in delay of the information of shrinkage cracks and decrease of its number.

A lot of harmonics exist inherently in the front end of 3-phase rectifier feeding Variable Frequency Drive (VFD) of 3-phase induction motor due to the nonlinearities behavior in such loads. The harmonics cause energy losses and deficiency to the overall system. The goal of this paper is to reduce the harmonics for a variable frequency drive by calculating the equivalent circuit of the 3-phase induction motor and identifying the parameters of a passive filter, which is connected to the input side for the rectifier from the VFD converter. The equivalent circuit for the 3-phase squirrel cage induction motor is achieved according to the results of laboratory tests. The concept of point of common coupling (PCC) is implied into the calculations of harmonics and power factor. The performance of the VFD described is simulated using Matlab /Simulink (2008).

Security of data transmission is one of the important factors in communication between two parties. Steganography is a part of image processing that applies to the principle that hidden data is concealed in such a way that a part from the two communicating parties knowledge the procedure of hiding method. In this paper, a steganography method using the video file as a cover is used to hide secret data video benefiting from the insignificancy exploited by the temporal DCT domain in the video cover. A two-dimensional transform is applied on the video footage; the coefficients in the transform domain between the frames are gathered into groups. Another DCT transform is applied on the one dimensional array of each group. The secret binary data are embedded using a dynamic insertion strategy. Experimental results showed that the algorithm produces a high quality stego-video whereas, the Peak signal to noise ratio is reached to 46 dB for particular parameters. The normalized correlation is in the range of (0.999-1) which means that stego-video is highly correlated to the cover video. This states that the algorithm is secure and does not arouse suspicions that secret data is concealed.

The present work investigates stress analysis and buckling analysis of cylindrical shell. It had been wide applications in the industry especially in mechanical and nuclear applications.. etc. The most common type of failure which may be happen in this type of structure was the buckling when was subjected to external hydrostatic pressure which represents the aim of this work. The buckling happen due to transfer major amount of strain energy into bending energy which leads to sudden failure in the structure. To avoid this type of failure the cylindrical shell must be stiffened by adding  stiffeners rings along the shell from internal or external surface. In this work two types of stiffeners existed, longitudinal and circumferential stiffeners based on the direction of the installation on the shell surface. In this work the critical pressure due to buckling was calculated numerically by using ANSYS15 for both stiffened and un-stiffened cylinder for various location and installing types, strengthening of the cylinder causes a significant increase in buckling pressures than non reinforced cylinder. Also the deflection for stiffened cylinder is function to mode shape and increasing with increasing the mode number because when the mode is increased, the strength of cylinder is increased and this leads to lower deflection. Also the stress analysis due to buckling for different depths of sea water was done to find the critical depth which may be the stresses exceeded the elastic limit. |And from stress analysis results, it is observed that there is not a huge difference in stresses between stiffened shell and un-stiffened shell in similar boundary and loading condition so the value of stresses in stiffened shell is a little lower compared to un-stiffened shell.

The research aim is to know the improvement extent of some mortar properties like compressive,tensile and flexural strength for the partial substitution of mortar cement by the natural pozzolanic materials of high activity as Nano metakaoline or rice husks ash at ratios of 2%, 3%, 4%, 5% and 6% of its cement weight. Research requirement are (205) samples, (25) samples for reference cement paste standard consistency with initial & final setting time and reference mortar compressive , tensile and flexural strength. (180) Samples are the mixed cement mortar samples for compressive , tensile and flexural strength as per the above substitution ratios for ages of (3) and (7) days. Results showed that the best substitution ratio by Nano metakaolineis(3%) of cement weight for the compressive strength was increased by (110.11%), tensile by (90.49%) and flexural strength by (85.59%) more than their reference mortar strength and the best substitution ratio by rice husks ash is(4%) of cement weight for the compressive strength was increasing by (83.34%) , tensile by (75.67%) and flexural strength by (66.53%) more than their reference mortar strength and the mortar has its good workability during the work.