Journal of Techniques

Trial mixes were made to study and define the best mix design method applied to local aggregate (Gravel and sand obtained from the area located between Al-Rasheediah and Al-Danadan place in Mosul city). Test results indicated that :
(a) Generally , when the discussing the results with relation to mix proportions and different levels of workability , the Building Research Establishment method (British method) recorded an increase in the workability and compressive strength rather than the American Concrete Institute (ACI) method using the local aggregate located at the assigned region above , the percentages of increasing in these properties are shown in the following table :

Workability levels Slump test (%) Compressive Strength (%)
(Low) , Slump = (3-5) cm. 28.03 12.07
(Medium) , Slump = (8-10) cm. 14.40 10.48
(High) , Slump = (15-80) cm. 21.40 12.10
Averages 21.27 % 11.55 %

(b) It is possible to make another comparison , for a given water/cement ratio , the Building Research Establishment method (British method) gives a workability higher than that obtained by the American Concrete Institute (ACI) method , and for the same water/cement ratio the (ACI) method gives a compressive strength higher than that obtained by the (British method).
(c) The Building Research Establishment method (British method) is more practical and applicable than the American Concrete Institute (ACI) method because it takes into account type of cement , type of aggregates as well as other characteristics (especially particle shape).

The present study comprises experimental tests to determine the mechanical and thermal properties of concrete and thermal insulating material mixture. The work was carried out in two stages , at first stage five concrete blocks with dimensions of (300mm x 300 mm x 50mm) were molded containing grains of corks with volumetric percentage of insulation of (15%,20%,25%,30%,35%). Then the thermal conductivity of the specimens has been tested at different temperatures. At the same time five standard cubes with dimensions (150mm x 150mm x 150mm) have been molded from the same previous mixtures, and the compressive strength test was done for each sample. The previous work-steps have been repeated for the second stage associated with the addition of asbestos grains to concrete as insulating material instead of cork. The results of thermal conductivity were shown in curves at different temperatures and volumetric percentages, and were statistically processed using (SPSS, version 15) program, then the following relationships has been established:
k = 0.555 + 0.007 Tav - 1.532 Ø (for concrete blocks which contains cork)
k = 0.565 + 0.011 Tav - 1.021 Ø (for concrete blocks which contains asbestos)
The values of the thermal conductivity of the blocks that contains cork were ranged between (0.22-0.65)W/m.oC, those values were less than the others which contains same percentage volume of asbestos under the same tests conditions, which ranged between (0.44-0.9)W/m.oC. The results of compressive strength of the concrete cubes have been shown as curves, it shows that the values for the specimens which contain cork were ranged between (12-32) N/mm2, which are less in values than those of the equivalent specimens which contain asbestos in which the values ranged between (25-40) N/mm2.

In Babylon factory, the percentage of defective units in production of medical syringes very high that is very high because the dimensions of products are not conforming for specified specifications and increasing demand on products. Thus, manager of the factory asked analyses of process of production to determinate percentage of scrap and rework because of the external diameter of the gasket piston is less than lower specification limit and reworks due to the external diameter greater than upper specification limit, and the cost of it due to scrap or rework are high and causing confusion at next assembly operations where the cost of scrap is equal to cost of rework.
The research aims to study the external diameter of the gasket piston because of an increasing diameter of gasket from specification which results an increasing in applied pressure on hup cylinder which results difficult in moving of piston while decreasing the diameter from specification does not seal of preventive process flow of liquid causes of entering air and easy of piston motion. The search dealt calculating of control limits for and found that process in control and follows normal curve. Thus, the process capability is calculating and percentage determinating of rework and scrap and studding to modify the mean and variability of process an selecting the best solution. An effects appear the solution for modifying the variability of process from(0.03) to (0.02) is the best solution because that solution will reduce the percentage of defective production from to and the percentage of rework will reduce to zero without that is effecting upon mean of process.

Slag is an industrial disposal which considered as a secondary product of pig- iron . these disposal will cause a severe harm to the environment in case of not get rid of it . In the practical part of our research slag has been added to the concrete mix in two ways , first by using it to replace as cement by weight as a substitutions of cement in different percent ( 10 , 20 , 30 , 40 ) % , second by using the slag instead of apart of sand in the same percent as mentioned in first . In addition to first and second above super plasticizer ( melment L10) has been added as percent of (5.5% ) from cement use in the mixture .
The result shows improvement in all concrete specimens for the added percentage of the slag as replacement materials and the addition of super plasticizer ( melment L10) in the production of concrete with high workability and improvement in its properties such as the initial surface absorption , total absorption and porosity relative with the reference mix. The use slag of ( 10,20) % as addition material instead of part of sand showed slightly improvement in the properties , but the addition of ( 30,40)% produced low concrete workability and as a result increasment of initial surface absorption , total absorption and porosity

The strain path for sheet metal may be changed during forming , this may be affect the forming limit curve (FLC) . In this work the FLC before and after prestraining was determined for aluminum alloy (2024 T3) to study the effect of this type of prestraining and in different values on the FLC. This alloy was chosen because it is used widely , specially in aircraft structures. It was shown that the using of The equibiaxial stretching (in the first stage), reduces the forming limit curve at all strain paths (in the second stage) . It was noted that, the major strain at Forming Limit Level, when prestrains in equibiaxial stretching path direction is used was lowered at the three levels of prestrain (0.3, 0.5 and 0.07) .

This research is aimed to use Pareto chart in determining variation reasons result from casting (Al – 4.6 %Cu) alloy. Several molds were used in casting the alloy mentioned above to find out the effect of cooling rates on the resulted defect percentage. Microstructure tests showed that casting in air–cooled non isolated permanent mold gives the minimum percentage of defects (4.323%) while the percentage was (37.062 %) when furnace-cooled mold was used.

In this study a practical attempt is performed to produce a binder material of an expansion nature from the locally available materials in Iraq .The material is produced by mixing a limited portions of pure gypsum with cement to achieve the required expansion . Two types of locally produced cements are used , Ordinary Portland Cement ( O.P.C. ) and Sulphate Resisting Portland Cement
( S.R.P.C. ) of Al- Kufa and Karbala factories respectively. A technical gypsum is used throughout this work . Cement is added with three different levels ( 5,10 and 15 )% from the dry weight of gypsum . Fresh mixture is tested for its spread ability , setting time , as well as small joists of ( 25 * 25* 250 ) mm size, are tested to investigate their soundness using autoclave method . Cubes of (50) mm size in addition to prisms of ( 40 * 40 * 160 ) mm are cast to measure their compressive strength and linear expansion respectively , in the hardened state of this mixture .Results indicated that , the material produced from the locally available materials was satisfactory for strength and durability required. The architectural presentation is fair to be used in cracks repair . The results showed that : 1.The produced material was workable in its fresh state and hard enough to resist loads as well as preventing moisture in its hardened state .2. The linear expansion of the produced material at ( 28 ) days age was about ( 100 and 75 ) % compared with the reference expansion at ( 2 hrs ) age by using (O.P.C.) and (S.R.P.C.) addition respectively, which was less than that of pure plaster by about ( 250 )% .3. The compressive strength is higher than that of pure gypsum which was about ( 150% ) more for ( 10 % and 15% ) addition of (O.P.C.) and (S.R.P.C.) respectively at the age of ( 7 )days .4.The autoclave expansion was about ( 1% ) as a maximum in the addition of ( 15% ) of (O.P.C. ) state.

This research is focused on the development of new method for applying the solid wastes (sacks) from high volume, low cost, renewable fiber sources as reinforcing material for blend consists of epoxy resin as the matrix-binder at fixed weight and different weights of polyvinyl formal (PVF) as additive resin. The experimental results of sacks were compared with commercial carbon fibers to improve the mechanical and thermal properties of prepared (epoxy-PVF) blend.
Several experiments were carried out to investigate the optimum operating conditions (mixing speed and mixing time) for the preparation of (epoxy-PVF) blend at room temperature to achieve an optimum performance. The optimum mixing speed and time were 700 rpm and 15 minutes respectively.
The optimum weighted ratios of prepared blend were characterized by the hardness, impact strength, bending distortion, bending deflection and thermal conductivity properties for the nonreinforced samples with sacks and carbon fibers that found (0.21, 0.10, 0.16, 0.16 and 0.10 weight of PVF in (g)/weight of epoxy in (g) as w/w) for each property respectively. These ratios showed the best chemical bonding forces between epoxy and PVF resins. The maximum values of hardness and impact strength properties for nonreinforced samples occurred at the optimum weighted ratios of prepared blend were found 82shore and 2.15J/cm2 respectively. While the minimum bending deflection and thermal conductivity values of nonreinforced samples occurred at the optimum weighted ratios of prepared blend were found 16mm and 0.01159W/cm.oC respectively.
Experimental results showed that reinforced samples with sacks and carbon fibers leading to enhancement in the mechanical and thermal properties and clearly improvement when compared to the nonreinforced samples. The improvement of reinforced samples with sacks for mechanical and thermal properties was predominant compared to the commercial carbon fibers.
Keywords: epoxy, polyvinyl formal, sacks, carbon fibers and thermo-mechanical properties.

Hyrogeologic study of Hillah City which is located in the western side of Babil Province is made. The study is focused to the strategic effects of Al Uhudia Stream on the groundwater system of Al Hillah City. It flows from the north toward the south of the city with length of 11km and difference in levels of 3m between the (intake and tail) U.S and D.S of the stream. The existence of the stream causes at least approximately a reduction in water table levels of 0.5m overall the study area with continuous dewatering process as well. In summary, the role of the stream serves as a dewatering system of underlying layer and as irrigation stream to irrigate the fields at the tail. The existence of the stream with its shoulders will provides a pleasant view to the city, if a good touristic planning is developed

The material under investigation is Sialon matrix reinforced with TiN. The Percentage of TiN is changed until maximum density is achieved. TiN is added to improve hardness, fracture toughness and density

effect of non-standard atmospheric behaviors such as; change in temperature, change in air pressure, humidity and difference in elevation on measuring distances by using electronic distance measurement instruments such as total station. Then by using meteorological data sheets of Baghdad city (2007), we can derive a model and design it by a computer program and another program (Mat lab 6.5) to calculate the amount of correction on measured distances under these circumstances.
The research concludes that the change in the length of measured distance is neglected when measuring short distances but that change increases when the change in temperature, humidity, air pressure and the height above sea level are increased more than the circumstances at which the instrument was made (standard condition ) ,as shown in the instrument guide (user manual ).

This investigation aim to study the effect of sisal fiber addition on the different properties of concrete, also to study the use of the Iraqi bauxite for the first time in Iraq as a pozzolanic material. Sisal fiber was used at three percentages of total mix volume (0.5%, 1.0% and 1.5%), Iraqi bauxite was used in three percentages (10%, 20% and 30%) as a partial replacement by weight of cement. This paper studied the effect of Sisal fiber and the Iraqi Bauxite on the mechanical properties which represented by the compressive strength, flexural strength, splitting strength, impact resistance for tiles, also the ultrasonic pulse velocity test which is one of the non-destructive testes, the pH level and water absorptions has been done.
The results from this study showing that the concrete reinforced with sisal fiber and using Iraqi bauxite exhibited improvement in flexural strength and splitting tensile strength while a small reduction in compressive strength was reported. The results showed also improvement in the impact resistance. Adding of sisal fiber made a reduction in the ultrasonic pulse velocity. The results showed that this kind of concrete reported a reduction in water absorption in comparative with reference concrete reinforced with fibers only. The use of bauxite as a partial replacement of cement reduced the alkalinity of concrete reinforced with fiber and that would improve its durability. From the results of this investigation, found that concrete reinforced with 1.0% of sisal fiber give the best results and using Iraqi Bauxite with 20% as a partial replacement by weight of cement enhanced the properties of reinforced concrete with sisal fiber.

This research deals with constructing and implementing voltage source inverter to control voltage at any frequency. The microcontroller 89c51 is used by pulse width modulation (PWM) generating different pulses in the duty cycle at any frequency. The voltage applied to an induction motor is varied by using a single phase, 400 HZ, voltage source inverter. The microcontroller is programmed to generate a train of pulses with different duty cycles at constant frequency 400 HZ. The range of duty cycle is from 0% - 60% at 5% resolution.
The inverter receives the DC signal from the rectifier and converts it to AC power to feed the motor. MOSFETS are used as inverter power switches which are controlled by pulses calculated and generated by the microcontroller. Voltage inverter is represented by computer simulation applying orcad 9.2 program. The system is applied practically by implemting the design

The acute toxicity effect of benzene on the survival of two Shatt Al - Arab river snails species ( Lymnaea auricularia and Theodoxus jordani ) was tested . The two species were subjected to several concentrations of benzene . The tests were performed for 48 and 96 hours , into renewal toxicity test system , under the laboratory conditions . The median lethal concentration ( LC50 ) values indicated that the snail L . auricularia was more sensitive to benzene than the snail T . jordani

The objectives of this research is to predict the values of the (head, efficiency, pressure and velocity)of the three dimensional flow inside impeller and volute by using computational fluid dynamics technique CFD commercial code (CFX-TASCflow V. 2.12). The governing equations are continuity and three dimensional Navier-Stokes equations. These equations are discretized by finite volume method and solved by SIMPLE logarithm.
The observed data for pump are collected from Al-Karama Company. The predicted results of the performance characteristics curves are validated with the observed results. The validations are properly predicted at design and below the design flow rate, but above the design flow rate; the prediction starts to deviate and over at off-design conditions. The recirculation zone appears at the diffuser near the tongue at off-design conditions. The mean square error (MSE) is used to evaluate the deviation between predicted and observed results. The maximum deviation between predicted and observed results is equal to 5%. The results demonstrate the capability of the software package to calculate the performance characteristics for centrifugal pump with a volute

Computational studies with the factors affecting the steric energies of Diels-Alder
addition and their correlation with the relevant physical properties of the product and
reactant molecules were investigated. A single and multi – parametric linear regression
analysis was applied with the rate constant as dependent and independent variables.
One of the reactant (Dien or Dienophile) of four series was kept constant and the other
reactants were varied. The products and reactants were influenced by all the molecular
properties with different extent and different direction for these four serious of
reactions. These properties included the total steric energy=E stretching +E bending +E
torsion +E over lap +Evdw+E dipole-dipole. The polarity and the values of steric
energies were increased due to high electrostatic repulsion power of Dienophile malic
unhydride and hexachlorocyclopent-1-ene for series (i) and (ii) respectively. While the
rate constants of tetracyanoethylene were increased with decreasing electrons affinity in
series (iii) , and the low steric energies of anthracen in series (iv) as determined using
MM2 program and this was due to its coplanarity

The water – soluble fractions (WSF ) of gas oil ( refined product ) , Gar ( heavy ) and Nahran – Umar ( light ) crude oils were tested for their acute toxicity . Four animals species ( Lymnaea auricularia , Thiodoxus jordani , Corbicula fluminalis and Corbicula fluminea ) from Shatt Al – Arab river were exposed to series concentrations of oils water - soluble fractions . The tests were carried out for 96 hours , into renewal toxicity system , under the laboratory conditions . In the terms of median lethal concentration ( LC50 ) , the order of test sensitivity was L. auricularia , T. jordani , C . fluminalis and C . fluminea . The water - soluble fractions of gas oil were the most toxic to test animals than water - soluble fractions of crude oils . The water - soluble fractions of light crude oil were more toxic than those of the heave one

A digital subscriber line (DSL) technology provides transport of high-bit rate digital information over telephone lines. This high-speed digital transmission requires advanced signal processing to overcome transmission impairments resulting from: crosstalk noise from the signals present on the other wires in the same binder, radio noise and impulse noise. Impulse noise (IN) is nonstationary crosstalk from temporary electromagnetic events in the vicinity of phone lines. The effects are temporary and typically at much lower frequencies with higher power level and reduces the system performance if cannot be overcome to it.
In this paper we focus on this effect on ADSL system for two channels (fast channel and interleaved channel).After that we study the performance of the system by calculating the probability of error (Pe) with and without impulse noise for two channels and comparing between them.
The system was simulated by using MATLAB simulation tools, from the simulation results the Pe was found 6.4449x10-6 and 7.3472x10-5 for fast channel with the effect of AWGN disturbance and IN disturbance respectively at 26dB energy signal to noise ratio (Es/No) whereas the Pe was found 6.1242x10-6 for interleaved channel with the effect of AWGN disturbance and IN disturbance at 26dB energy signal to noise ratio (Es/No).Within the paper an overview is provided about the major building block of the simulator and some analysis results are present by depending on MATLAB simulink tools.

Implementing digital filters mathematically, and verifying their functions, is an easy task with the help of many available CAD software such as MATLAB. But implementing hardware digital filters with fixed function IC’s and verifying their function is a difficult task particularly for under graduate students in electrical and electronic engineering. However, with the emerging of Programmable Logic Devices (PLD’s), and Field Programmable Gate Array (FPGA) devices, implementing hardware digital filters became an easy task. This paper shows how a programmable hardware first order filters can be implemented, synthesized, and simulated using (MAX+PLUS II, ver.10) development software. MATLAB filter design tool were used to determine the filter coefficients, and then these coefficients are fed to the PLD inputs, to get the desired filter specifications. The response of the implemented filter in the PLD device has been verified by comparing it to the response of MATLAB filter of the same ty

In this study, novolac resin is used as a matrix in the composite which reinforced with some ceramic particles such as alumina, silica, and, limestone as paint. Novolac -alumina (N-A), novolac- silica (N-S), and novolac-limestone (N-L) composites contain (10-30) wt% reinforcing materials .The composites exhibit the mechanical properties like adhesion, impact and hardness better than the mechanical properties of novolac resin.

In this study ,an experimental investigation is carried out to compare the initial surface absorption (ISA ) as well as compressive strength between self compacting concrete ( S.C.C) and ordinary concrete . Two series of mixes were cast , one belonged to ordinary concrete while the second was for ( S.C.C ). Additives included in these mixes were limestone dust and Super plasticizer of retarding effect called ( Glenium 51 ) with a ratio by weight of cement of ( 2 % ).The tests performed on the fresh state of both types of concrete were , slump , slump flow , T 50 cm , U – box flow , flow time of V funnel, as well as , flow time of V funnel at T = 5 sec . In the hardened state , initial surface absorption , and compressive strength were measured for both types of concrete.Results indicated Slump flow of S.C.C was about ( 8 ) times more than that of conventional concrete , while ISA of S.C.C was about ( 5 ) times less than that of conventional concrete . S.C.C . Compressive strength of S.C.C was about (25 % ) higher than that of conventional at age ( 28 ) days , but at age of (14) days , both types of concrete showed same compressive strength .

The Inverted pendulum (IP) is a very popular plant for testing dynamics and control of highly non – linear plants. In the inverted pendulum control problem, the aim is to move the cart to the desired position and to balance a pendulum without the pendulum falling.
The goal of this paper is to design a robust Fuzzy Logic Controller (FLC) which is capable of driving the cart of the Inverted Pendulum to the desired position and balancing the ball around zero angles with respect to the vertical plane.
To accomplish this task several steps are passed through. First, a state - space model of the Inverted Pendulum has been analyzed and then builds using Simulink Software Package. Next, design of the FLC is performed using Fuzzy Inference System (FIS) within Matlab software package. Robustness of the designed control system has been tested for the response to different types of command signals and disturbance rejection points of view.
Simulation results show that the suggested FLC is robust against different environments conditions.

Two-dimensions flow over single circular cylinder in inside convergent-divergent channel are investigated. Considerations is given to the effect of Reynolds number,
(Re), peak of convergent-divergent channel, (a), and the length of base of peak, (b), on heat transfer and flow phenomena. A finite volume procedure on non-orthogonal collocated grid on SIMPLE algorithm was used to solve the conservation equations (mass, momentum and energy) with constant heat flux under laminar fully developed flow conditions.
Comparisons with the cylinder in straight channel, in the same flow rate and heat transfer conditions, have been performed. Heat transfer from cylinder in convergent-divergent channel is found to be always larger than the value characteristic of a cylinder in straight channel, also pressure drop performance increases. The results show that the maximum of heat transfer be at (a/H= 0.53, b/H= 0.46).

Direct Sequence Code Division Multiple Access (DS-CDMA) communication system have attracted considerable attention for third-generation (3G) mobile system .They have the ability to suppress a wide variety of interfering signals including Narrow-Band (NB) ,Multiple Access interference (MAI) and Multipath Interference (MPI).
Multipath effects are one of the major factors that limit system performance depending on the channel characteristics, in this paper the three paths effect was taken on DS-CDMA for ten users transmitted as baseband binary phase shift keying(BPSK) and the system assume synchronized.
Five users have maximal-linear code (127bits) and five users have gold code (127bits) in order to measure the difference between them, the code rate 8.125 MHz for each user with data rate 64Kb/s and the system was designed and simulated by using MATLAB-simulink version (6.5).
The probability of error (BER) was calculated for different cases of signal to noise ratio (Eb/No),the BER for maximal-linear code was 7.18x10-3for where as for gold code was 4.375x10-4 at Eb/No equal -2dB under three paths effect .

In many instances, the mathematical model of the plant is simply unknown or ill-defined, leading to greater complexities in the design of the control system. It has been proved that intelligent control systems give a better performance in such cases. In this paper two controllers are integrated to obtain the new intelligent controller .The conventional (proportional- Integral- derivate ) controller is integrated with intelligent controller ,Fuzzy logic Controller to control two complex plants. Two plants(Automatic Voltage Regulator (AVR),& DC Motor)are taken in this paper and the simulation has been performed using MA TLAB program. Determinately the idea for the proposed method in this paper depends on study the behavior of PID controller on-line then the PID parameters are adjusted by new rule base table for fuzzy controller which govern the output response for the system .During PID studying properties, there are some important relations between time response parameter and PID parameters such as: IF steady state error (ess) high THEN increases the Integral constant (KI.), IF rise time (tr) high THEN increase the proportional constant (Kp), IF overshot(O.S) high THEN increase the derivate constant (Kd), and so on to fill the rule base table, therefore a new rule base table is obtained with a good response for the systems