Tikrit Journal of Engineering Sciences

Solid waste management operations are collecting, transportation, and disposal of residential, commercial, institutional, construction, demolition, and wide street areas; the result of the daily activity of humans needs to be properly managed. Iraq faces many problems associated with its unregulated solid waste systems. First, however, this study examined the reality of solid waste management in Iraq and ways to develop it. The total number of participants in this research was 326 participants .The data collected in February and March 2021, interview methodology and questionnaire which used, and the analysis software used for this research is IBM SPSS version 23; the two methodologies were used and combined to reach the largest possible amount of qualitative and quantitative information that may be absent from the researcher and to reach good results and outputs for the research, for reasons including obtaining more and deeper information to reach the largest segment of society and to achieve the goals of the thesis and obtain good results by integrating the two methodologies. The study concluded by analyzing the data, The municipality’s weak role and the lack of regular timetables in organizing waste collection and transportation operations, and 64% agreed that there are not sorting of waste from the source; also, the lack of cooperation and coordination between the public and the municipality, 39% agreed that most municipalities do not have healthy and environmentally safe landfills for waste disposal, 33% strongly agreed that there are no appropriate policies and laws that enhance the effectiveness of solid waste management, 49% strongly agreed that residents are ready to sort the waste in the designated place in case the municipality provides the containers, 53% agreed that residents are willing to pay for collecting waste from their homes or stores. After analyzing the study results, Iraq needs stations for sorting and transporting waste and stations for recycling plastic, paper and metals. Also, there is a need for sanitary landfills compatible with environmental conditions, and the municipality should play a greater role and give the private sector a greater role in the solid waste management process and overcome obstacles that hinder the work of investment companies, in addition to raising community awareness through holding educational workshops. For example, in schools and universities to spread environmental awareness in the community.

Concrete elements under high-speed projectiles effect has an increasing interest recently. Understanding to what extent the concrete can resists the effect of projectiles, very necessary in design structures in order to save the occupants. The objective of this study is to develop improved numerical model for predicting dynamic response of RC slabs under HSP attack. The present study presents a total of 12 concrete slabs casted and tested under plain and steel reinforcement. Parameters investigated were slab thickness, (50 mm, 100 mm, and 150 mm) and projectile type. Dynamic simulation was performed also and the results obtained have been discussed and compared with experimental response. Generally, it was concluded that penetration depth was controlled by target thickness regardless the steel reinforcement. Good alignment achieved between numerical and experimental date with respect to penetration depth and crater vale.

This research is devoted to investigating experimentally the punching shear strength of reactive powder concrete slabs under monotonic loading. All slabs have the same flexural reinforcement and same dimensions (1000mm length,600mm width,50mm thickness). The experimental program includes casting and testing of sixteen slabs tested under monotonic loading. The major parameters adopted in the current research include the shape of column (circle, square), column size (twocolumn sizes), number of columns (one, two), and the distance between two columns (3d,5d,7d). Results showed that, the slabs with circular column sections have slightly higher ultimate load than those with square column sections. An increasing column area increases the load of punching shear failure. It was found that the ultimate failure load for slabs with two columns is greater than the slabs with one column. Related to the effect of distance between the two columns for monotonic, it was found that the slabs maximum load reaches the maximum value at distance between the two columns equal to(7d) for a circular section with a diameter of 85mm and 113mm and square section with dimensions of (100*100)mm. While the maximum failure load reaches the maximum value when the distance between two columns (d) for a square section with the dimension of (75*75)mm. Related to the crack patterns, it was noticed that for slabs with larger columns sections with the distance between columns equal to 7d, the failure zone extended (in a large direction) to the slab sides.

Rainwater harvesting and flood prevention in cities are significant urban hydrological concerns. The use of porous pavement is one of the most effective solutions to handle this matter. Thus, this study aims to develop Porous Interlocking Concrete Pavement (PICP) using recycled aggregate from concrete waste. This porous pavement, then later, can be utilized in low traffic areas and parking lots to harvest water by infiltration and reduce surface runoff. First, the physical properties of the porous concrete blocks, such as density (unit weight), absorption, coefficient of permeability, and porosity, were studied. Also, the mechanical properties of concrete mixtures like compressive strength and flexural strength were tested. This study used two types of PICP, the first one with ordinary coarse aggregate (P1) and the second with recycled crushed concrete coarse aggregate (P2), and then compared their performance to the conventional concrete pavement blocks used the two types of coarse aggregate (R1 and R2). The results show that the unit weight (density) of porous types was reduced by 25% and 26%, and the total porosity increases by around 2.4 times and 18 times respectively, as compared to conventional concrete pavement types. However, the compressive strength and flexural strength of porous concrete types decreased by (55% and 71%), respectively, compared to conventional types. Overall, the infiltration test results showed that the infiltrated water through porous concrete increased by about 83% in comparison to conventional concrete. From the results, utilizing porous concrete pavement can be considered a promising material in terms of water harvesting and decreasing rainwater flooding. Additionally, using recycled concrete can bring economical and environmental benefits.

The present work depends on the previous energy and exergy analysis study for a steam cycle of North Refineries Company (NRC)/Baiji, Iraq, which was conducted at real and rated operating loads. After the results of that study are presented, this current study is conducted and aimed to
produce the engineering solutions for improving the cycle performance through studying the operational choices that are actually available in the plant as investigating the effect of increasing the air mass flow rate in the main condenser of the cycle. The calculations were done by using the
MATLAB program. The results showed that increasing the air mass flow rate or increasing the number of fans in service from 8 to 14 fans will reduce the energy losses in the main condenser and in the cycle. The energy loss reduction can be enhanced in the improvement of the energy
efficiency by raising it from 30.11 % to 48.61 % at real load and from 33.49% to 48.93 % at rated load. On the other hand, the exergy analysis showed that the exergy destructions for the main condenser and for the cycle would decrease if the number of fans increased. This decreasing of exergy destruction in the main condenser will raise the exergy efficiency from 21.95 to 27.06 % at real load and from 21.18 % to 25.45 % at rated load.

Buses of General Company for Passenger Transport was the primary mode for public transportation in Baghdad City. This system suffers from many problems, part of which were related to bus routes, while the other part was related to the bus and its operators. These problems have a direct effect on the users of public transport buses. The objective of this study was to assess the performance of eight public transport bus routes which they represented by the Al-Tahrir bus network and adopting the level of the transit service method. Seven transit performance measures were selected in this study, such as bus travel time, hours of service during the day, service frequency (headway), total delay on the route, running speed of the bus, bus occupancy, and capacity of the route. The results of this study showed that bus routes No. (72, 36, 13, 114, 11, 30, 37, and 9) were operating at overall Level of Transit Service LOTS (D, E, E, E, E, D, E, and E) respectively, whereas the bus network (Al-Tahrir bus network) was operating at overall LOTS (E); therefore, the performance of Al-Tahrir bus network was not acceptable, and improvements were needed to increase the level of transit service of this network.

Textile Reinforced Concrete (TRC) can be used as independent structural elements due to its high loading capacity and proper to product light weight and thin walled structural elements. In this
study, the bending behavior of TRC plates that reinforced with dry carbon fiber textile and exposed to high temperatures was experimentally studied under 4-points bending loading. The
examined parameters were; (a) number of textile fiber reinforcements layers 1, 2 and 3 layers; (b) level of high temperatures 20°C, 200°C, 300°C, and 400°C. Firstly, the mechanical properties of the cementitious matrix and the tensile properties of TRC coupons at each predefined temperature were evaluated. The results showed that the ultimate tensile stress of the TRC coupons did not affect up to 200°C, however, a significant reduction observed at 300°C and 400°C by 19% and 24%
respectively. Regarding the compressive strength and flexural strength of the cementitious matrix, the degradation was not severe until 200°C, while it became critical at 400 °C (23% and
22% respectively). The result of the bending of TRC plates showed that doubling and tripling textile fiber reinforcements layers improved the flexural loading. In general, increasing the level of temperatures resulted in decrease in the flexural capacity of TRC plates. The highest decrease recorded for the specimen reinforced with 1-layer of carbon fiber textile subjected to 400 °C and was 33%.

Textile-Reinforced Cement (TRC) was used in structural retrofitting and strengthening existing structures. While at present, recent studies have turned around using TRC as an independent structural element. This research presented an experimental study on the flexural behavior of TRC plates. Several parameters were taken into account, specifically, (a) the number layer of textile fiber materials (1, 2, and 3); (b) the configuration of the reinforcement (together or interface); (c) thickness of TRC plate (50, 70) mm. This study included preparing and testing twelve specimens; two specimens were un-reinforced, whereas the rest ten specimens were reinforced by dry carbon fiber textile. The results found that increasing the number of layers for both reinforcement configurations led to increased flexural capacity. Increasing the thickness of the plate has a negative effect on the flexural capacity for both reinforcement configurations. Finally, the interface reinforcement configuration with thickness 50 mm or 70 mm had higher flexural capacity than the specimens with together reinforcement configuration.

This study deals with the application of geographical information system (GIS) datasets and methods to assess the landslide susceptibility in Wadi Hujran. The area has a rocky terrain and belongs to the Shaqlawa district of the Kurdistan Region of Iraq. The region is placed towards the Northeast side of Erbil city. The region covers an area of 18.56 Km2 (1856.1 ha) and consists of rough broken and stones. The watershed area is surrounded by North latitudes 36° 21' 53.514" to 36° 17' 49.7796" and East longitudes 44° 17' 5.658" to 44° 20' 9.06". Three factors, namely the morphometric, geological, and environmental, were used to prepare the landslide susceptibility index. The study made use of AHP method and prepared a landslide susceptibility map. Data related to geology, topography, hydrology, rainfall, and land use were used to prepare the map. Physical and statistical methods were used to validate the map. A heuristic approach was incorporated to produce the final susceptibility map. ArcGIS software was used to generate the landslide zones. A total of five landslide zones were generated, which varied from very low landslide zones (80.5) to very high landslide zone (84.5). The zones also included low landslide zone (1262.2), moderate landslide zone (1505.9), and high landslide zone (566.8), and the ratio of consistency in the present study was 0.06 AHP less than 1, and all the five zones in the study were compiled landslide zonation estimated.

The recycling of waste requires large areas; besides recycling wastes to their origin is often economically and environmentally costly. Glass is considered as a solid waste that is difficult to dispose of; it doesn't degrade nor burn. Since glass is a silicic substance with similar properties to aggregates, it can be recycled in asphalt mixtures. This research aims to determine optimum binder content (OBC) of conventional hot asphalt mixture (HMA), (control mixture), and investigate the effect of crushed glass waste (CGW), on its properties. In this work, several percentages of CGW (10%, 15%, 20%, and 25%) have been used as a partial substitution for the weight of fraction size 2.36-0.075mm of natural aggregate to prepare glass-contained asphalt mixtures and compare their properties with the control mixture. Mix design by Marshall method was used, and the properties according to Iraqi standards (SORB/R9,2003), for binder layer, were found, as well as conducting of Retained Marshall stability (RMS), indirect tensile strength (IDT), and tensile strength ratio (TSR), tests on mixtures, as performance tests. The results showed that the OBC of the control mixture was 5% wt., and the Marshall stability and flow values of glass-contained asphalt mixtures were oscillating around the values of the control mixture. The air voids, voids in mineral aggregate, and bulk density were reduced regularly as CGW increased. Also, it was observed from the results that the glass-contained mixtures have good performance properties. However, all results conformed to the standards (SORB/R9, 2003). So, the incorporation of CGW in HMA for the binder layer is feasible.

The future wireless communication requires a reliable transmission at high data rates, so the transmission over frequency-selective fading Multiple-Input–Multiple-Output MIMO channels become interesting since the capacity of "MIMO" channels expressions enormous gains above that of their essential single-input–single-output "SISO" channels. This paper examines the performance of the Low Complexity Zero Forcing "LCZF" equalizer for both systems single-input–single-output-Orthogonal Frequency Division Multiplexing" SISO-OFDM" and spatially multiplexed-Multiple-Input–Multiple-Output "SM-MIMO-OFDM" with different "QAM" modulations. It is exploring a new algorithm to improve the performance of the "BER", spectral efficiency, and power efficiency and to reduce the complexity of the "RF" communication system under the effect of the Additive White Gaussian Noise "AWGN" and multipath fading channel. It is also improves an efficient channel by developing a Low Complexity Zero Forcing "LCZF" equalizer for both "SISO-OFDM" and "SM-MIMO-OFDM" wireless Communication systems. This is done by proposing a new algorithm at the receiver side to covert the Linear Convolution in to Cyclic Convolution by adding Zero Padding "ZP" to the channel impulse response in such a way to be the same length to the transmitted signal in the time domain which is of length N, where N is the length of "IFFT".

Submerged Groynes are low profile linear structures that are generally located on the outside bank to form Groynes fields and prevent the erosion of stream banks by redirecting high-velocity flow away from the bank. This research was studied in detail through two major stages. The first stage of the study is based on laboratory experiments to measure the development of local scour around L-shape submerged Groyne with the time, and special attention is given to the effects of different hydraulic and geometric parameters on local scour. Also; maps were drawn showing contour lines that represented the bed levels for maximum scour depth after reaching the equilibrium case. The result showed that a decrease in the scour depth ratio due to the increasing submerged ratio, and the number of Groynes. While the scour hole geometry will increase with the Froude number, flow intensity, and the spacing between Groynes, the decreasing percentage in the scour hole was measured to be about (4.3) % and (4.4) % for decreasing the spacing between Groynes from (2Lg) to (1.5Lg). Besides, it was range about (11.1) % and (14.0) % when reducing the spacing from (1.5Lg) to (Lg) under the same value of maximum Froude number. The second stage of the study is based on experimental results. A new formula was developed by using statistical analysis and it was found that a good determination coefficient.