KUFA JOURNAL OF ENGINEERING

Many researchers’ attention was drawn by the process of improving the characteristics and the performance of hot mix asphalt. In this research, Reed Plant Ash (RPA) and Reed Plant Powder (RPP) were used as a substance to optimize the characteristics of asphalt at (5, 10, 15, and 20) % by asphalt weight. The laboratory work included two parts to get the requirements of the research: the first part is the physical properties for pure and modified asphalt. The second part is the prepared specimen of HMA with pure and the best percent of modified asphalt according to the Marshall criteria using limestone dust at 7% as a filler to the surface layer. The study found that the HMA with modified asphalt by 10% RPP has more effects on its performance by improving the Marshal Stability, volumetric properties, tensile strength ratio, and retained Marshall Stability rather than control mix and HMA with modified asphalt by 15% RPA.

In this paper, the performance of the Multiple Input Multiple Output (MIMO) technique evaluated in term of Bit Error Rate (BER) with respect to Signal to Noise Ratio (SNR) by using Binary Phase Shift Keying (BPSK) modulation for two algorithms Maximum Likelihood (MLD) and Zero-Forcing (ZF) with different configurations of antennas array in Rayleigh and Additive White Gaussian Noise (AWGN) channels. The results were compared between them to determine which of the numbers antenna elements are suitable in the transmitter and receiver of each algorithm. The results of MLD offers a better configuration when 4×4 and 3×4 antennas array were used, while the ZF remains the same performance for the 2×2, 3×3 and 4×4 configurations. In different numbers of antennas, the best performance of ZF is got when the number of transmitter and receiver antennas are equal to 2×4 respectively. Also, the last one is better than the 4×4 and 3×4 configurations of MLD algorithm.

This comparison study focuses on the impacts of using nano-silica (nS) on chemical attack resistance of self-consolidating concrete (SCC) and its effectiveness in comparison to similar replacement levels of the more widely employed micro-silica (mS). Two types of cement were used to produce concrete mixes and three different percentages (3, 4.5, and 6 %) of nanosilica and microsilica were added as a replacement of cement by weight. Concrete specimens were cast and exposed to four harmful conditions including: sulfate solution, chloride solution and both of them for a period of up to 400 days. Based on the obtained results, replacement with colloidal nS proved to be significantly more effective in the chemical resistance than equivalent replacement of dry powder mS. The noticed improvements in chloride resistance and chloride penetration performance for concretes contained nS was correlated with the compressive strength results, which indicates for better pore structure characteristics. As expected, the improvement in the chemical resistance was more pronounced in concretes with cement type V.

Self compacting mortars (SCMs) plate specimens with dimension of (500×500×40) mm were cast with three-dimension (3D) textile glass fiber having three diverse thicknesses 6, 10, and 15mm to measure their punching strength. Plates with one and two layers of chicken wires, as well as micro steel fiber of 0.75 % volume fraction were tested under punching for comparison. Punching shear tests have been carried out by applying concentrated load with steel cylinder of 50mm diameter and 10 mm height. The mechanical behavior of SCMs plate was discussed in terms of observed behavior, ultimate load, load - deflection curves, and crack pattern. The results indicated an enhancement in the ultimate load at (28 and 90) day ages by about (7.82% and 24%), respectively. The maximum ultimate load was increased by about (58.4 and 54.1) % for plates reinforced by micro steel fiber at 28 and 90 days, respectively as compared with reference. The maximum deflection at the center of the Self-compact mortars plates for all tested plates was improved.

Resilient modulus for pavement layers is a key design parameter for pavement systems and permits for determination of how the pavement system will react to traffic loadings. It can be defined shortly as elastic modulus of a material under repeated loads. Several factors have effects on the elastic modulus of the layers of asphalt pavements. The indirect repeated axial load test was carried out by using the pneumatic repeated load system (PRLS) at Transportation Laboratory at Baghdad University to test seventy two cylindrical specimens prepared by the gyratory device. SPSS program was used to predict the resilient modulus model which contains many factors like asphalt content, asphalt viscosity, air voids, surface area, and temperature. Multiple linear regression is used to build the model of resilient modulus because it is a function of more than independent variables. F statistical significance value from the results of ANOVA table is smaller than 0.05 in the predicted model then the independent variables in the predicted model explain the variation in the resilient modulus variable. The coefficient of determination (R2) is 0.886 for the predicted model which is referred to a very good relation obtained. The predicted model shows that the modulus of resilience is highly affected by variation of temperature and moderately by viscosity of the asphalt whereas the stress level, types of filler, and the asphalt content have smaller effect on resilient modulus. The predicted model shows that there is a positive relationship among the resilient modulus and the two variables viscosity and the surface area whereas the three variables temperature, asphalt content, and air voids have inverse relationship with resilient modulus. Two asphalt types (40-50) and (60-70) from Dora refinery were used; the average value of resilient modulus corresponding to asphalt grade (40-50) is almost 21.331% times the value for asphalt grade (60-70). Three asphalt contents (optimum asphalt content, optimum asphalt content±0.5) were used; when the content of asphalt was increased from 4% to 4.5%, the average resilient modulus decreased by 2.923% whereas increasing the percent of asphalt content from 4.5 to 5 the average resilient modulus decreased by 1.737%. Two types of mineral fillers (cement and limestone) were used, and when cement was used as mineral filler, the average resilient modulus increased by 4.422% rather than using limestone as filler in the asphalt mixture. Three temperatures for test were used 10, 25, and 40 oC. The results showed that when temperature was increased from 10 to 25 ◦C, the average resilient modulus decreases by 65.738%; whereas when the test temperature was increased from 25 to 40 oC, the average resilient moduli decreased by 97.715%. The results also showed that the average resilient modulus increased by 9.69% when the stress level increased from 6.5 psi to 13 psi.

This paper utilizes a system identification to model EDM using Arduino and fuzzy controller. System identification is a useful tool for identifying the model depending on the input and output data of the controller. However, derivation of modeling process from first principles is often difficult due to its complexity. The proposed method is used for identifying the mathematical model of EDM from the real time experimental data from gather data from the systemy feeding the DC motor sine sweep or white noise inputs. The model identification of EDM servo system was conducted by using MATLAB/Simulink program and after that the obtained transfer function for the system. The proposed controller has been applied by using FLC .The results showed that the controller can work well with a quick response, no overshoot output and high control precision.

Recent years have witnessed emerging the cutting-edge method for point cloud creation using terrestrial laser scanner (TLS). The TLS manufacturers declare accuracies of their instruments up to the millimeter level. However, different constraints could degrade the accuracy of point cloud created by TLS. One of the obvious factors that may directly affect the accuracy of the results is a method of registration and georeferencing. In this paper, the indirect georeferencing using GNSS has been researched. The real time kinematic (RTK) technique has been suggested to measure GNSS points. The conducted test shows that average of 30 minutes data RTK-GNSS is enough to coincide with TLS data. Also, test reveals no improvements when adding more GNSS points. Nevertheless, there is an improvement in accuracy when more scans are conducted.

Permanent deformation (rutting) is considered one of the most important factors that reduces pavement life in roads network and highways in Iraq. In this paper, a laboratory investigation has been conducted to evaluate the effect of external factors on rutting of asphaltic mixture. The study was carried out using local materials for the surface layer. Three levels of temperature were examined namely, 40, 50, and 60 °C, in addition to three stresses intensities are 700N, 900N, and 1100N were investigated for wheel track test, and 10, 20, and 30 psi of repeated load were also tested. The results have cleared that the temperature and stress have a significant effect on the permanent deformation. Where mixtures resistance to rutting increases about 57.65% when temperature degree increases from 40 °C to 50 °C. Also, increasing load intensity from 700 to 900 N resulted in higher rutting values (about 40.75% increase has observed in term of WTT). Additionally, increasing temperature from 40 °C to 50 °C resulted in permanent strain and resilient strain increase by 84.49 % and 11.27 %, respectively. Also, increasing load intensity from 10 to 20 psi resulted in higher permanent strain and resilient strain values about 5.44 % and 27.94 %, respectively, for wearing layer. In term of uniaxial repeated load test, it has concluded that temperatures and stresses employed for design are relative high to reproduce the most unfavorable pavement conditions.

Finding a vacant parking space nowadays is time and fuel consuming. This problem may cause drivers to get frustrated and eventually improper parking will appear. The universities, in particular, are one of these places, which needs more attention for providing parking services. Therefore, this study has focused on finding the parking required for such facilities and the benefit of applying smart parking services there. The main campus of the University of Kufa has been evaluated by collecting parking data for both on-street and off-street parking. The results of field data show a clear lack of parking space for most of the faculties in the main campus. The required additional parking spaces are 260.This study has suggested using the smart parks. The model of smart park system has been introduced by this study as a solution to the parking problem, especially in the university and generally in other places. Arduino and ultrasonic sensors were used to detect the empty places in a park and display this status to the screen. The model has been applied at the park of College of Engineering with encouraging results.

A two modulation methods of the switching-capacitor inverter are proposed. The inverter output voltage is larger than the input voltage by connect switching-capacitor in series and in parallel respectively. The level output voltages are decided by number of the capacitor. Five capacitors are used to obtain eleven level in output voltage waveform. The proposed inverter is driven by the LS-PWM and LPS-PWM methods. The circuit configuration, states operation and simulation results by using MATLAB/SIMULINK are presented in this paper. The simulation results demonstrated best LPS-PWM method compared with LS-PWM in terms THD of output voltage.

This paper discussed the effect of welding variables on the heat-affected zone (HAZ) by using a tensile test of welded 10 mm thick low carbon steel AISI1010 commercial plate, which is welded using the Shielded Metal Arc Welding (SMAW) method. Different welding electrodes E6013 and E7018 were considered as welding parameters investigated. After that, the welded specimens were cut and machined to standard configurations for tensile test. The results showed that selecting different welding electrodes had a remarkable effect on the mechanical properties such as the ultimate tensile strength, elongation percentage, and yield strength of the welded specimens. The increment in the electrical current for each electrode in the welding processes led to decrease in yield strength and tensile strength. The initial decrease in tensile strength and yield strengths were observed. This behavior was attributed to the fact that different welding electrodes and increased the required electrical current to melting for the welding electrode, increased the electrical current led to increased heat input on heat affected zone (HAZ), then the observed change mechanical properties [which could create area for defect. The welding processes and tensile test at a room temperature was performed

Geopolymer concrete is still a new construction material in Iraq and needs tremendous research to get more information about the production technique. In this study, the foreign fly ash and local fly ash produced from Baghdad south gas power plant were used with good specifications to obtain geopolymer concrete. Also, the local attapulgite clay as a pozzolan material is used to investigate the possibility for production the geopolymer concrete. The experimental results showed that the method of curing of geopolymer concrete has a significant effect on the development of compressive strength. Water immersion curing is not recommended. The heat treatment method is the best due to accelerating the reactions and formation of geopolymer concrete. The attapulgite is the best suited locally for geopolymerization in terms of compressive strength and tensile strength.

Fine aggregate considered as the oldest building materials known by human, it's not inert substance, so that each of its physical and chemical properties need theoretical and laboratory studies, because, of its effect on the compressive strength and durability of concrete, one of the most important properties is the content of sulphate salts, which must be taken into account in all construction works. This research aims to conduct laboratory qualitative assessment of fine aggregate to demonstrate its suitability for construction work and quality assurance. Sampling of fine aggregate (sand) from four quarries in Al-Najaf Alashraf [(Syd Ali (S1), Wilaya Ali (S2), Syd Ahmed (S3) and Muhand Al-Khiat (S4)]. Some of physical tests (sieve analysis, deleterious materials (clay%), bulk density, specific gravity and absorption), chemical analysis for sulphate salts content, X-Ray technology for mineral composition as well as the compressive strength test were conducted on these samples. From the results of this research, its appear that Sample Wilaya Ali (S2) is the best for concrete works where the grading and sulphate salts content (SO3) is accepted by (IQS), and this sample gives accepted compressive strength. While Sample Syd Ali (S1) was the most fine with accepted sulphate salts content as compared with (IQS) which make it suitable for other construction works rather than concrete. Samples, Syd Ahmed (S3) and Muhand Al-Khiat (S4) are of high sulphate salts content (which cannot be treated) as compared with (IQS) which make them not compatible for concrete and other construction works.

At the high power switching circuit's applications, when the harmonic distortion is harmful, a multi-level diode clamped inverter is useful, especially when reduced total harmonic distortion and high power are desired. But when the levels get a rise, number of semiconductors are also rising, which leads to many problems such as increasing cost, losses, installation area, and total harmonic distortion. Many researchers have tried to find solutions to these problems. In this sense, this paper focuses on: a) build a new structure of five level diode clamped inverter. b) Increase the efficiency of the inverter by reducing the number of switches. c) Reduce the total harmonic distortion. The theoretical calculation and simulation results are performed for five level diode clamped inverter by MATLAB/ SIMULINK.

This paper deals with the investigation factors effecting core strength estimation by conducting an experimental study which included casting of six plain concrete beams. For each beam, 12 cubes were cast in addition to twenty-four core samples were extracted. The investigated factors involved the concrete compressive strength, concrete type, core extracting direction, core location, core depth in the beam, and the damage factor. It obtained results showed that the ratio of compressive strength in the vertical to horizontal cast direction is (1.075) and (1.080) for the traditional and superplasticizer concrete, respectively. Also, the depth factor of bottom to top zone strength in vertical cast direction is (1.110) and (1.066) for traditional concrete and the super plasticizer concrete respectively, while the location factor of center zone in vertical cast direction corresponding to (1.088) and (1.103). Finally, the damage factor is directly proportional with the concrete strength for both concrete types.

Wastewater effluent of plants is frequently disposed via injection wells or drain fields into the geological substrate near surface water streams. In this study, we evaluated and specified the relationships between the plants wastewater disposal flow, concentrations, and the disposal injection wells distances from surface water stream for minimum harmful pollutants transport to the stream. The study area was Basrah fertilizes plant near Shatt-Al-Basrah stream. A completed representation for the study area parameters data were done to simulate the aquifer, surface water, pollutants disposal, and flow-transport system for the current state and the proposed injection wells systems. The simulation and evaluation study showed that the current disposal system is harmful to the stream and the best disposal system for the wastewater plant was the injection wells. The study also revealed that the best distance for the proposed fertilizes plant disposal wells must be located not less than 480 m from the river with an injection rate not more than 3600 m3/day.

Overconsolidated soils are widely encountered in practice where settlement calculations are crucial. The recompression index (Cr) and the recompression ratio (Cr) are considered as one of the most important parameters used in settlement calculations. To achieve this purpose, expensive and time-consuming laboratory tests are usually conducted using undisturbed specimens to obtain the values of these parameters. Various equations derived from regression analysis were proposed to predict consolidation parameters from the physical properties of a soil. In this paper, however, an artificial neural network model (ANN) is proposed to predict Cr and Cr using natural water content, initial void ratio, total unit weight and effective overburden pressure. The proposed ANN model achieved good agreement with the results of one hundred seventy-nine standard one-dimensional consolidation tests collected from previous geotechnical investigations in Baghdad.

This study sheds light on measuring and calculating the average of noises pollution indications in An Najaf. The city has recently got growth in commercial and industrial activities as well as a significant increase in the number of vehicles. In addition, the use of diesel generators is due to electricity shortage for long periods. Noise quality assessment was studied in An Najaf City for five areas, i.e., educational, industrial, commercial, residential and quiet. The study has been conducted for five months starting in November 2016. Noise pollution indicators viz. L10, L50, L90, noise climate (N.C), equivalent continuous noise level (Leq) and noise pollution level (Lnp) were calculated for the above mentioned five areas. The results of this study showed that the highest value of (Leq), which is 108.44 dB, was in the industrial areas followed by 89.55 dB in the commercial areas, 87.1 dB in the educational areas, 80.4 dB in the quiet areas, and 69.05 dB in the residential areas. It has been noted that the highest values of Leq in all areas were higher than the permissible limit in the Iraqi standards, where the noise assessment study in this research revealed the disturbing situation of noise pollution in the city of Najaf.

The seepage phenomenon (uplift pressure - flow rate - exit gradient of hydraulic structures) is one of the main causes of failure or collapse of hydraulic structures, so it has been reduced using sheet piles under floor of hydraulic structures. In this study, effect of mutual interference piles were studied on seepage phenomenon by using finite elements program ANSYS. The results were verified with the practical results L-SAYED which given a good correlation. It was found that the use of the pile in the upstream reduced the uplift pressures by 8.36%, and the pile in the downstream increased it by 11.66%, the flow rate reduced by 66.8% and exit gradient of the hydraulic structures reduced by 28.28%.

In this study, the mixed convection heat transfer of the air inside a truncated cone enclosure with aspect ratio of (0.75, 1.75, 2, 2.45 and 2.65) with centered triangle obstacle height varying by (0, 2.5, 5, 7.5, 10, 12.5 and 20 cm) and the heated wall inclination angles of (20o, 30o, 40o, 50o, 60o), the Richardson number in the range of (7 to 11) was investigated numerically. The results are addressed to automotive a suggested solar container with titled solar collector. The heat transfer from the heat source (inclined solar collector) of the enclosure walls is investigated for mixed convection as interaction of the forced convection flow between the inlet and outlet port in the bottom wall. The parameters of heat source, Reynolds number, obstacle height, enclosure aspect ratio, and left and right walls titled angles are considered in this work. The numerical simulation of the problem is carried out using commercial CFD code. The results are given in terms of the streamlines, isothermal, and the enclosure Nusselt number that characterizes the heat transfer from the heat source and from the interior fluid to the enclosure walls, respectively. The results show that the interaction of the main flow and the flow at the heated walls and the buoyancy force at the heated walls increased by using a triangular obstacle and by increasing the obstacle heights, it increased by 20% when using obstacle at position of (h=5 cm). Also, it is found that the Nu increased with increasing Re and the wall heat flux. The Nu increased with increasing Ri in the case of using (h=0 and 5 cm) but it decreased slightly in the other cases and showed that the minimum value of Nu present at a heated wall inclination of θ=50o but the maximum value at θ=30o.