Journal of Engineering

The study explores the capabilities of a smart antenna array known as the Switched Active Switched Parasitic Antenna (SASPA) to create a directive and electronically steerable radiation pattern. The SASPA array consists of antenna elements that can switch between active and parasitic states using P-Intrinsic-N (PIN) diodes. This allows for a directional radiation pattern with high gain and a small beamwidth, achieved with only one active element at a time. By sequentially changing the parasitic state to the active state for all elements, the directed radiation pattern can be easily rotated. The study uses a uniform circular array (UCA) structure to achieve symmetrical radiation patterns and full coverage of the entire azimuth plane. Additionally, a novel method for reducing the mutual coupling effect in SASPA arrays is proposed, which helps control some parameters of the generated radiation pattern. The simulated results show that an N-element SASPA-UCA produces N-symmetrical, switchable, and steerable radiation patterns with high gain, small beamwidth, and a high Front-to-Back (F/B) ratio. Further improvements in these parameters can be achieved by increasing the number of elements in the array.

Electronic Health Record (EHR) systems are used as an efficient and effective method of exchanging patients’ health information with doctors and other key stakeholders in the health sector to obtain improved patient treatment decisions and diagnoses. As a result, questions regarding the security of sensitive user data are highlighted. To encourage people to move their sensitive health records to cloud networks, a secure authentication and access control mechanism that protects users’ data should be established. Furthermore, authentication and access control schemes are essential in the protection of health data, as numerous responsibilities exist to ensure security and privacy in a network. So, the main goal of our suggested solution is to maintain a secure authentication and access control mechanism for health cloud data. Thus, in this work, Security Secret Key Provider (SSKP) phase is proposed for the E-healthcare-based cloud that consists of two parts. The first is an authentication scheme that is Security Secret Key (SSK) and the second is a modular access control mechanism. We explain the methodology of the proposed approach through appropriate evaluation results, which improves system security and performance by minimizing the time spent to get authentication and access the data. Simulation results indicate that our approach is significantly more effective than existing research.

This work investigates experimentally the effect of using a skirt with a square foundation of 100 mm width resting on dry gypseous soil (i.e., loose soil with 33% relative density), and subjected to an inclined load. Previous works did not study the use square skirted foundation rested on gypseous soil and subjected to inclined load. The investigated soil was brought from Tikrit city with 59% gypsum content. Standard physical and chemical tests on selected soil were carried out. Model laboratory tests were carried out to determine the effect of using a skirt with a square foundation on the load-settlement behavior of gypseous soil and subjected to inclined load with various Skirt depth (Ds) to foundation width (B) ratio Ds/B (0,0.5,1, and1.5). The results show that using a skirt with a square foundation improves load-carrying capacity and reduces settlement of foundation rested on loose gypseous soil and the amount of improvement increase with increasing skirt depth to foundation width Ds/B. Bearing capacity improved by about (193) %, and Settlement ratio (Sᵣ) reduced from (1) % for square foundation without a skirt to (0.14) at Ds/B, equal to 1.5 at θ =0° with the y-axis (Where θ is the inclination angle of the applied load); and bearing capacity improved by about (162) % for the square skirted foundation with Ds/B, equal to 1.5 and θ =15° with the y-axis.

This paper demonstrates the construction, designing, analysis, and control strategies for fully tracking concentrated solar thermal by using programmable logic control in the city of Erbil, Iraq. This work used the parabolic dish as a concentrated solar thermal. At the focal point, the collected form of energy is used for heating water in the receiver, analyzing this prototype in real-time with two different shapes of the receiver and comparing the results. For tracking the parabolic dish, four light-dependent resistors are used to detect the sun's position in the sky so that the tracking system follows it to make the beam radiation perpendicular to the collector surface all of the time during the day for maximum solar power energy. This work discusses the essential stages of a two-axis prototype; implementation, solar-location strategy, the analysis in terms of theory, structural design, and material. The two-axis prototype is implemented with the help of programmable logic control - Siemens (S7-1200) as a control unit. This study results show that a parabolic dish tracker with a cylindrical conical receiver obtains 15.25% improved efficiency in comparison to the cylindrical receiver. According to the testing results of the prototype design, both shapes of the receiver are convenient for steam production.

The ability to produce load-bearing masonry units adopting ACI 211.1 mix design using (1: 3.2:2.5) as (cement: fine aggregate: coarse aggregate) with slump range (25-50mm) which can conform (dimension, absorption, and compressive strength) within IQS 1077/1987 requirements type A was our main goal of the study. The ability to use low cement content (300 kg/m3) to handle our market price products since the most consumption in wall construction for low-cost buildings was encouraging. The use of (10 and 20%) of LECA as partial volume replacement of coarse aggregate to reduce the huge weight of masonry blocks can also be recommended. The types of production of the load-bearing masonry units were A and B for (10 and 20%), respectively. Finally, the use of the spray curing method was the more suitable simulation of reality and easier for factory producers, taking into consideration that the increasing curing time from 14 days (recommended in IQS 1077/1987) to 28 days may be led to conversation masonry type from B to A as in R20%-300.

A roundabout is a highway engineering concept meant to calm traffic, increase safety, reduce stop-and-go travel, reduce accidents and congestion, and decrease traffic delays. It is circular and facilitates one-way traffic flow around a central point. The first part of this study evaluated the principles and methods used to compare the capacity methods of roundabouts with different traffic conditions and geometric configurations. These methods include gap acceptance, empirical, and simulation software methods. The present aim is to compare different roundabout capacity models for acceptable capacity predictions for single-lane and multi-lane roundabouts. Previous studies such as RODEL, SIDRA, Swiss, HCM6, and IRC overestimate capacity, while the GHCM method underestimates it. Each VISSIM and SIDRA predicted higher capacity than HCM2010, Paramics, and Simtrafic capacity methods. Generally, the precise prediction of capacity value depends on the circulating flow, exiting traffic flow, driver behavior, and geometric variations. Also, a comparison between seventeen methods was made using virtual data. For a single-lane roundabout, Girabase and Swiss models estimated higher capacity values when compared with other models, while HCM 2010 estimated lower capacity. The Shamueli’s model provides an estimate of capacity about the same as the lower bound of the HCM 2000 model. Brilon’s model estimated lower capacity values for a multi-lane roundabout compared with other methods. At low circulating flow, the Girabase model estimated a higher capacity value, while with the increasing circulating flow, the FHWA2000 estimated a higher capacity than the Girabase model. Also, there is a bit of a difference between SIDRA 5 and 8.0. There is a small interval between models that are implemented in a single-lane roundabout. Therefore, the models are better at predicting the capacity of a single lane than they are at predicting the capacity of multiple lanes.

When a vehicle is left parked in the sun for an extended period, the gathered heat causes damage to several interiors within the cabin and causes discomfort for people and animals left inside the car. In the present work, the effect of the orientation of a parked white minibus on temperature distribution and cooling load calculation is studied experimentally in an open environment. Two different cases were studied facing south and facing east. For several hours, the temperature inside the car cabin had been monitored and measured at five separate locations. The cooling load calculations are carried out based on the experimental measurements. The results show that the overheating of parked cars always happens as a result of the radiation load especially when a car has a large surface glass area. Also, the ambient load is directly proportional to the ambient temperature, and the total load related directly to radiation load reaches the maximum value of 2358.1 W at 3:00 pm for 1st case and 2118.3 W at 11:00 am for 2nd case which shows an increase of 11.32 %. Thus, these results emphasized the fact that the orientation of the parked car may considerably affect the temperature distribution and the cooling load of the car cabin. Also, the study may be considered an essential step in designing any assisted ventilation or auxiliary air conditioning system that may enhance the car cabin conditions even while the car’s engine was off (parked automobile).

Accurate computation of the roughness coefficient is important in the studies of open channel flow. To measure and identify the hydraulic characteristics of the flow system, the model simulation is necessary to study and get the results of the hydraulic properties to specify Manning coefficient of the Euphrates River. In this study, the reach is extended along the Euphrates River from Haditha Dam to Ramadi Barrage with a distance of 169km. The HEC-RAS model was implemented to simulate the flow within the study reach. The geometry of the river was represented by more than two hundred cross-sections surveyed in 2013 and 2021. The model was calibrated using some observed discharges at the Heet gage station for records of the last five years. The Model was validated using five sets of observed water levels in different cases of manning coefficient in the model. The Root Mean Square Error (RMSE) was used for comparison of the model results. Results of the model showed that the roughness coefficient value for this reach is 0.026 for the river bed and 0.030 for the River bank. These values gave the best coincidence between the simulated and observed values of water levels.

In this study, the hydromorphodynamic simulation of a stretch of the Euphrates River was conducted. The stretch of the Euphrates River extended from Haditha dam to the city of Heet in Al-Anbar Governorate and it is estimated to be 124.4 km. Samples were taken from 3 sites along the banks of the river stretch using sampling equipment. The samples were taken to the laboratory for grain size analysis where the median size (D50) and sediment load were determined. The hydromorphodynamic simulation was conducted using the NACY 2DH solver of the iRIC model. The model was calibrated using the Manning roughness, sediment load, and median particle size and the validation process showed that the error between the simulation and the recorded data was minimal. After calibration, three different scenarios were considered and the scenarios were based on different river discharges (low, average, and flood discharge). Four statistical indices were used to check the predicted values of the velocities and water depth in various sections of the Euphrates River section at the city of Heet and these indices were Mean Absolute Deviation (MAD), Mean Square Error (MSE), Root MSE (RMSE), and the Mean Absolute Percentage Error (MAPE). For velocity, values of the above indices for the first scenario were found to be 0.19, 0.046, 0.21, and 0.17 respectively. However, for water depth, values for the above statistical indices were found to be 0.07, 0.01, 0.01, and 0.13 respectively. The values confirmed the accuracy of the prediction of model iRIC Nacy2DH.

The use of recycled aggregates from construction and demolition waste (CDW) can preserve natural aggregate resources, reduce the demand for landfill, and contribute to a sustainable built environment. Concrete demolition waste has been proven to be an excellent source of aggregates for new concrete production. At a technical, economic, and environmental level, roller compacted concrete (RCC) applications benefit various civil construction projects. RCC is a homogenous mixture that is best described as a zero-slump concrete placed with compacting equipment, used in storage areas, dams, and most often as a basis for rigid pavements. The mix must be sufficiently dry to support the weight of vibratory machinery while still being sufficiently moist to allow paste binder dispersion throughout the mass for efficient compaction. Limited studies into the use of RCC with fine recycled aggregate not from pavements are figured. This study aims to see how well-recycled concrete aggregates (RCA) perform in RCC mixtures. Also, how well waste concrete could be used as a fine and coarse aggregate substitute in roller-compacted concrete pavement mixes, to create a good concrete mix in both wet and firm phases. The test results of mechanical properties showed 10% RCA is similar to those in the reference mix in the compressive strength, a 100% RCA ratio reduces compressive strength by almost 30%. Comparing Reference mix and Recycled concrete by 30% replacement, the compressive strength drops by just 6% when the RCA ratio is 30%.

Soil improvement has developed as a realistic solution for enhancing soil properties so that structures can be constructed to meet project engineering requirements due to the limited availability of construction land in urban centers. The jet grouting method for soil improvement is a novel geotechnical alternative for problematic soils for which conventional foundation designs cannot provide acceptable and lasting solutions. The paper's methodology was based on constructing pile models using a low-pressure injection laboratory setup built and made locally to simulate the operation of field equipment. The setup design was based on previous research that systematically conducted unconfined compression testing (U.C.Ts.). The soil improvement techniques were investigated by injecting a low-pressure mixture of water and ordinary Portland cement (O.P.C.) with (0.8, 1, and 1.3) W/C ratios. The study revealed the relationship between pile model samples (U.C.Ts.) and W/C ratios. It also showed that the pile model samples' (U.C.Ts.) result decreased from 14 to 12 to 10 MPa, respectively, with an increase in W/C ratios from 0.8 to 1 and 1.3, respectively. Furthermore, the stiffness characteristics of a jet grouting column were calculated based on Mohr's Circles theory, and numerous theoretical approaches obtained the consequences of tensile strength.

This study aims to assess the water quality index (WQI) according to the Canadian Council of Ministers of the Environment's Water Quality Index method (CCME WQI). Four locations (measurement stations) are selected along the Tigris River, in Iraq. Two of them are located in the north near Mosul City, (Mosul Dam and Mosul city), and the other two are located in the south near Al-Amarah city, (Ali Garbi and Al-Amarah). The water data collected is for the period 2011 to 2013, including eleven water quality parameters. These are magnesium (Mg +2), calcium (Ca 2+), potassium (K +), sodium (Na +), sulfate (SO 42-), chloride (Cl -), nitrate (NO 3-), bicarbonate (HCO 3-), total dissolved solids (TDS), electric conductivity (EC), and (biochemical oxygen demand BOD 5). Results show that the water quality in Mosul city ranged from (83-94) in the two stations, while it has a range of (52-59) in Al-Amarah city for the two sites as well. According to WHO standards, these ranges indicate that the river waterfalls in a good level in Mosul city, while it belongs to the marginal category for Al-Amarah city. This is expected due to the disposal of many pollution sources along the distance from north to south downstream the river, therefore these pollution sources must be controlled.