Journal of Engineering and Sustainable Development (JEASD)

An Intermittent Cycle Extended Aeration System (ICEAS) offers advantages for treating sewage; such as easy operation, process flexibility, and low capital cost. The laboratory bench scale experiments were carried out treating domestic wastewater of Basrah City in fabricated ICEAS reactor of 72 L working volume. The domestic wastewater has the following characteristics (average values) pH= 7.5, Biochemical Oxygen Demand BOD= 200 mg/L, Chemical Oxygen Demand COD= 410 mg/L, Total Phosphorus TP= 7 mg/L, Total Suspended Solid TSS= 272. The aim of this research was to evaluate performance of the ICEAS system for treating domestic wastewater. Experimental results showed that the efficiency of ICEAS reactor to remove COD, Ammonia, TN, and TP were 91%, 83%, 60%, and 72%, while SBR efficiency were 87%, 81%, 58%, 69%, respectively. So, removal efficiency of ICEAS reactor was slightly higher than SBR. Comparison the effluent quality of ICEAS reactor with WHO, European and China discharge standards into surface waters were explained that COD concentration (37 mg/L) was meet to all standards (including Iraqi standard), while Ammonia NH3-N (7.87 mg/L), Total Nitrogen TN (17.16 mg/L) and TP (2.84 mg/L) were to European and China but not meet to WHO standard with slightly differences.

The paper aims to make the coordinates obtained from global positioning systems compatible with local maps in Iraq for mobile locations . Therefore , number of control points have been selected in the study area . Both geographic and map projection coordinates are measured using mobile geopositions based on Universal Transverse Mercator ( UTM ) projection and World Geodetic System ( WGS 1984 ) datum . The measured geographic coordinates are transformed to map projection in Iraq using geographic information system ( GIS ) depending on Clarke 1880 ellipsoid . ArcGIS model builder is designed to implement coordinates transformation . Field calculator scripts are written by Python programming language . Differences between the measured and transformed coordinates are determined . The results show that the differences in northing coordinates are about ( 278.6 m ) and the percentage of difference to this value is ( 0.6 % ) , while the differences in easting coordinates reach to ( − 287.6 m ) with its percentage of difference equals to ( 0.4 % ) in the study area . It is concluded that positions discrepancies should be considered in map production and updating for engineering works .

A broad-crested weir has been considered the most hydraulic structures which was used in open channels for flow measurement and to control the water surface levels due to its simplicity. Both experimental and numerical models were conducted on a broad crested weir and stepped weir with a rounded corner. In this study, FLUENT software as a type of Computational Fluid Dynamics (CFD) model, represented as a numerical model in order to simulate flow over weirs that govern by Reynold averaged Navier Stoke equation and their results were compared with experimental results. The structured mesh with high concentration near the wall regions was employed in the numerical model. The volume of fluid (VOF) method with four turbulence models of Standard k–ε, RNG k–ε, Realizable k–ε and Standard k–ω are applied to estimate the free surface profile. The result showed that the flow over weirs is turbulent and the characteristics of free surface were complex and often difficult to be predicted. Also, the comparison of water surface profile between experimental value and numerical results obtained from the turbulent models showed that the standard k–ε model has the best similarity and standard k–ω model has the minimum similarity with experimental value.

This study is concerned with the effect of curing methods and early curing on the some properties of high performance lightweight concrete HPLWC that exposed to effects of hot dry weather conditions to improve the performance of concrete structures. The experimental work was carried out during Iraqi summer season at 12:00 pm. with average temperature 55°C and relative humidity RH 13% under actual atmospheric condition by used fixed mix proportions for preparing and casting specimens and applying different curing methods represented by water curing (WC) for 13 day, water based curing compound (WBC), and bitumen based curing compound (BBC), as well as curing specimens by burlap covering with sprinkling water 3 times a day(BWS) after (5:00, and 8:00,24:00)h. from casting for 13 day, and air curing(AC). The effect of selected curing methods on the properties of HPLWC was evaluated by measuring compressive and splitting tensile strength, modulus of rupture, static and dynamic modulus of elasticity and pulse velocity. The results show that the best performance with regard to the 28 day strength and later ages was in specimens cured by applying WBC followed WC, and then BWS, and less order BBC and in the decreasing order specimens of AC. The results display that early curing after (5:00, and 8:00) h. from casting does not improve concrete properties comparative to that cured after 24 h.

The present work represent an experimental study to verify the transient heat transfer characteristics of a target plate under air impingement from different orifice sizes (D=5, 10, 15 and 20mm), with orifice to plate distance ratio (H/D=2, 4, 6 and 8). Air jet velocities is varied in the range (Uj=18-40m/s) representing (Re=7100-11900). The heat transfer coefficient on the target plate are calculated on the basis of two dimensional infinite case. The local variation of Nusselt number in the transient period is measured. The values are compared to that at the steady state condition. Results show that the Nusselt values are maximum at state of impingement process and decays with time on proceeding of the cooling process and also with space reaching the plate edge.

The characteristics of organic soil are low permeability, low shear strength and high compressibility, therefore organic soil has to be improved before any engineering works can commence. In this study dry kaolinite is used as a clay minerals and fresh reed as an organic material for different percentages (0%, 2%, 5%, 8%, 12% and 20%) by dry weight. Lime is used as a treatment material of different percentages (0%, 3%, 6%and 9%) by dry weight. The experimental work included a series of compaction and compressibility tests conducted on 48 samples. The effect of addition of lime on compressibility characteristics of non-decomposed and decomposed model organic soil was studied. The results showed that the compressibility characteristics [compression index, rebound index, coefficient of consolidation and coefficient of secondary compression] are increased with increased organic content for decomposed and non-decomposed samples. The use of lime has improved the compressibility characteristics of organic soil.

The work describes a research study the creep behavior of a gypsiferous soil, the soil used throughout this study was taken from location of Tikrit University site in Salah El-Deen City in Iraq. The soil was clayey sand and classified as (SC) according USCS with a gypsum content of (48.92%). The mineralogical and chemical properties of the soils were determined. The Odometer test was used throughout the test programs. A series of double and single oedometer tests for a long period time were performed in this work . The results indicate that the soil is of low compressibility when loaded under drying condition for both 1day and 64 day respectively while high compressibility it can be noticed for wet soil sample under the same loading period. The collapse potential increases with logarithm of time noticed for 200 kPa stress (8.17% at 1day to 16.17% at 64 days) and (12.2% at 1 day to 14.7% at 64 day) for 1600 kPa stress. The results showed that the increases in collapse potential with the increasing applied stress for the samples loading for 1 and 64 day, also it can be observed high decrease in collapse potential (21.2 % to 14.7 %) after 800 kPa stress for 64 day loading sample. Also the results show nonlinear relations between the creep rate and logarithm of time, the creep rate decrease about (4.4% and 2.5 %) from 1day to 64 day for 200 and 1600 kPa stress respectively.

In this paper, a single phase quasi-Z-source inverter with maximum power point tracking (MPPT) is proposed for photovoltaic (PV) system. A boost DC-DC converter is used to implement the MPPT algorithm for tracking the maximum power from a PV panel. Perturb& Observe (P&O) method is used as a maximum power point tracker due to its simplicity. The suggested quasi-Z-source inverter employs the quasi-Z-source network and only two active switches to achieve the same output as the traditional voltage-fed full bridge inverter does. The proposed quasi-Z-source inverter has small size, lower cost and high efficiency since no any transformer is used (the input dc source and the output ac voltages share the same ground). Nonlinear sinusoidal pulse width modulation (SPWM) is used to produce sinusoidal inverter output voltage .Power simulation (PSIM) program is used for simulation and the obtained results show the validity of the proposed DC-AC conversion system.

The creep of clayey subgrade soils is understood to be a process of deformation progressing in time under a constant stress and temperature. Owing to the creep of subgrade layer, stress redistribution occurs with a subsequent drop of the strength, and hence decreases in the value of the safety factor of the pavement structure. In addition, the seasonal variation in temperature in the subgrade layer tends to change throughout the pavement's life. The influence of temperature on the behavior and properties of subgrade soils influences pavement performance, and distress of pavement structures. Experimental investigation of creep in a clayey subgrade layer under constant stress, with consideration of variation of temperature and dry density is a very difficult task. Therefore, despite of urgency of the problem, little has been published on this matter. Therefore it is important to investigate, and study effects of combined temperature and creep characteristics of the response of subgrade pavement layer performance by using oedometer apparatus to analysis creep behavior of pavement layers under effect of different temperatures. Based on the results of this study it is concluded that, the increase in the temperature from 20 oC to 70oC causes an increase of (52, 55.9 and 56.1%) in the creep strain of the seventh day from applying load for soil sample, asphalt sample and combined sample, respectively.

: In this work, A STATCOM of 12-pulse two levels is used to regulate the bus voltage at specific bus bar under many cases of abnormal conditions like load and source disturbances. The proposed system consists of a single machine, transmission line and load. The compensation process are performed and compared between the two suggested control methods, first, the conventional control by using PI controller only which is used to improve the voltage profile. Second, the adapting controller uses self-tuning fuzzy PI controller for improving the voltage profile. At the time of disturbance gets occurrence, the PI controller must change its parameters to recover the voltage profile into the stable state at the disturbance moment. The simulation results show the improvements of voltage profile for both two types and then compare them. The improvement of voltage profile using adaptation method is less over shoot and attains a steady state faster than the conventional PI when the system is subjected under many disturbances. The results of the harmonic effect show low values of total harmonic distortion (THD) of supply voltage and current. Moreover, it is acceptable with IEEE standards because a new technique of Sinusoidal Pulse Width Modulation (SPWM) is used.

The increasing of road material demand particularly on mineral filler and additives has been followed-up by finding the new alternative materials. Local materials such as Portland cement, and lime may potentially use to substitute current need. Therefore, it is essential to study the performance and durability of these materials in HMA mixture. To find the durability index, the specimens are immersed around 0 (unconditioned) to 14 days at 60ºC and tested by using Marshall and ITS tests. Based on Marshall test, the index values for mixes variations; DCF, DPC, DL, DPF, and DC are found to be; 42.965%, 36.59%, 36.582%, 35.68%, and 33.42%, respectively.

This paper presents the results of an experimental investigation for heat transfer and pressure drop characteristics in a square duct inserted with angle-ribbed straight diagonal tape. The straight tape used in the current study inserted in diagonal side of 44 mm hydraulic diameter square test section duct has uniform heat-fluxed walls. Different angled ribs were repeatedly placed at similar locations on both opposite sides of the inserted tape. The investigation covers a range of Reynolds numbers from (3400 to 20,800) according to hydraulic diameter and air is employed as working fluid. For studying the heat transfer dependency on ribs inclination angle, six different inclination angles (α) of 10°, 20°, 30°, 45°, 60°, 90° are examined at constant value for both rib blockage ratio (BR) and pitch spacing ratio (PR) of 0.2 and 1 respectively. The angle-ribbed diagonal tape generate a pair of longitudinal vortex flow through the heated duct and it is apparent that these vortices helps to induce impingement flows on the duct walls leading to drastic increase in heat transfer rate over the duct. The experimental results showed that the insertion of ribbed diagonal tape leads to a significant increase in Nu and f over smooth duct with no tape. Ribs at α= 45° provides higher heat transfer and friction losses as compared with other angles about (77.78, 98.42)% respectively more than smooth duct while ribs at 10° provides higher thermal enhancement factor (TEF) by about 1.297 at lower Re.

Lime concrete shall be prepared by mixing coarse aggregate and lime mortar in the specified proportions with required quantity of water. Lime has been used as a cementing material since times immemorial. The influence of hydrated lime Ca(OH)2 on the 7, 28 and 56 days compressive and splitting tensile strength also 28 day density tests were investigated. Results indicated that all mixes specimens exhibited continuous strength gain. The defects in lime concrete, particularly its slow setting compared with that of cement concrete could be got rid of by adding to it a definite proportion of cement. Result showed that the 28 – day compressive strength of lime concert mix was 4.8MPa, while the 28 day compressive strength of cement concerte mix was 28.7mpa with the same mix proportion. At 28days of curing, the percentage increase in compressive strength of lime- cement concerte mix relative to lime concerte mix was 70%. Lime concrete have some advantageous properties e.g., good workability and plasticity, lime is cheaper too and is locally available.

This study investigates the effect of using olive oil on the pollutants emissions in the continuous combustion chamber. The bio-fuels used are mixtures of olive oil with two types of hydrocarbon fuels (gas oil and kerosene). The pollutants measured include carbon monoxide CO, unburned hydrocarbon UHC, soot and nitrogen oxide NOx .It is found that all pollutants have less percent emissions when using olive oil blended with percent addition of 5%, 10%, and 15%. The reduction in emission with olive oil blends is due to the existence of oxygen O2 in the chemical structure of the olive oil which is sufficient to achieve the complete combustion. The test was conducted through the range of equivalence ratio between (0.85-1.7). Results showed that olive oil blends with gas oil brings about 45.63% reduction in UHC and 36.48% soot, while CO 32.24% and NOx showed only about 39.54% reduction from that of pure gas oil. Whilst, blends with kerosene, showed a reduction of about 48.92% in UHC and 42.13% soot, while for CO and NOx the reduction was 37.41% and 42.85% respectively compared with those of pure kerosene emission.

Friction stir welding was used widely in joining of dissimilar Aluminum alloys joints which used in aerospace applications due to high specific strength and superior corrosion resistance. Aluminum alloys 5052 H34 and 7075 T6 was successfully welded at tool rotation speed (400) rpm and travel speed (187) mm/min with using adjustable scrolled pin tool. Corrosion behavior of this joint was investigated using potentiostat in two medias “0.5% HCl, 0.5% NaOH” to show the polarization resistance and calculate the corrosion rate from data of “Tafel extrapolation method”. The microstructures of different zones of FSW joint have been investigated. Cyclic polarizations were done to measure the resistance of specimens to pitting corrosion. From the results obtained, it has been shown that best corrosion resistance of welded joint was noticed in 0.5% NaOH comparing with 0.5% HCl. The corrosion rate of FSW welded joint was higher than base alloys in 0.5% NaOH, while it's lower than base alloys in 0.5% HCl. The Base metal alloys susceptible to pitting corrosion while friction stir welded joint exhibit good general and pitting corrosion resistance in NaOH and HCl media.

Last few years interesting in, recycled coarse aggregate (derived from old concrete) was increased in pavement construction. This type of aggregate has good results approximately and economically from natural coarse aggregate results. In this research Kaolin was used as a filler material addition in percentages (0, 5, 10, 15, and 20%) by weight of cement to know the effect of that type of filler material on asphalt mixture. The values show that the flow of asphalt mixture is between (2-5) mm, this is more accepted with recycled aggregate than the natural aggregate especially of mix (0 and 5%) of adding Kaolin. Also, the use of recycled aggregates gives values of stability of asphalt mixture more than the natural aggregates.

This paper presents an experimental method using (TPBT) Three Point Bending Test to identify fracture parameters and performance of concrete rigid pavements such as (KI, KIC, J-Integral and GF). To achieve these objectives and to conduct the experimental part of this study, two concrete mixtures developed (Mix No.1 and Mix No.2) from local available materials are used which include: Iraqi Portland cement (Tasloja) resistant to sulphates, coarse aggregate gradation with a maximum sizes of (25) mm for Mix No.1 according to AASHTO M 43, Size No. 67grade type and maximum size of (19) mm, river sand as a fine aggregate, and water.12 concrete beam specimens are subjected to two loading rates (0.45kN/s and 0.75kN/s) to reflect the interaction with different traffic loading and different crack depths (0,15%,30%) of specimen depths are used to simulate the initial crack depth in rigid pavement. Experimental results show that, the maximum loading for fracture increased with the increased in loading rate for (Mix No.1) and (Mix No.2). The deflection for No.1 presents higher deflection results than Mix No.2 and these results give an indication that (Mix No.1) is more flexible than Mix No.2 under different loading rates and other conditions. The results show that, maximum load at failure and deflection decrease with the increase in notch depth.