Tishreen University Journal -Engineering Sciences Series,

The role of compaction energy in increasing the bearing capacity of paving layers constructed from recycled materials from concrete demolition rubble

2024-02-05T19:20:33+00:00

In the last twenty years, the phenomenon of using recycled materials from demolition rubble (especially materials from the products of recycling concrete rubble) has spread in the construction of road paving layers, whether in flexible road pavement or solid pavement. The recycled aggregates from the products of concrete demolition may have geotechnical and engineering properties. Various, some of them limit their use in creating the base layer, including maximum dry density, relative bearing capacity, C.B.R, and Los Angeles wear. In our research, we tested the development of the maximum dry density and the bearing capacity of the C.B.R depending on the applied energy, which in turn gave good results, as the maximum dry density increased by 18% when a number of strokes of 65 were applied to each of the five layers forming the Proctor mold, which was offset by an increase in the relative bearing capacity. The C.B.R. by 23%. However, the maximum increase rates for these materials stopped increasing steadily with the number of blows (70-75) blows, meaning that the increase reached 5.7% for the maximum dry density and 82.1% for the relative bearing capacity of the C.B.R.

Phishing via instant messaging systems on social media sites using artificial intelligence techniques in the field of social engineering

2024-02-26T10:12:13+00:00

Phishing is an example of a very effective form of cybercrime that enables criminals to deceive users and steal sensitive data. With the increasing growth of Internet users, especially on social media platforms, the amount of publicly available personal information has increased dramatically, making these users more vulnerable to phishing attacks. This article provides a detailed explanation of the modern technical methods used in such attacks, especially the use of Natural Language Processing techniques for topic classification of social media posts to determine the victim’s area of interest and form the base for launching an attack that aims to steal victim’s sensitive data by sending a customized message according to His field of interest using instant messaging systems.

Study of turbulent rotational flows of the Rotor/Stator type in water machines: analysis and understanding of the physical properties.

2024-04-02T20:03:48+00:00

The study of rotational flows is considered one of the important research fields, as these direct flows between rotating and fixed disks are analyzed. These studies began as far back as 1951 by Batchlor, but recent studies have provided new and completely different approaches, opening up a wide field of scientific research in this field.

The importance of this study lies in the lack of integrated data to develop analytical models for flow equations in cavities subject to forced flow. This helps us to determine the forces acting on rotating discs in water machines and to understand the physical properties of flow outside the boundary layers For turbulent flow, studies have been directed towards evaluating the intensity of turbulence in the central core, and Reynolds components have been related to the characteristic non-dimensional values of the flow and the spatial coordinates radially and axially. The study was conducted using commercial software specialized in modeling fluid flow, and the experimental and analytical results were compared with references and previous studies.

These readings added to our understanding of the nature of the flow between the two boundary layers in this cavity, and led to radical modifications to the analytical laws based on the experimental approach. The study showed the importance of non-dimensional circumferential angular velocity in shaping the flow inside the cavity.

Development Of An Active Suspension System To Prevent Passenger Cars Rollover

2024-03-10T10:32:31+00:00

Rollover is one of the most dangerous maneuvers that a vehicle may undergo at driving , and the main cause of most traffic accidents deaths . Therefore, this study presents a developed model of Double A-Arms Suspension System , designed specifically to prevent the rollover of passenger cars during critical cornering maneuvers . The developed suspension system distinguishes by its ability to control of its roll center position , by controlling the inclination angles of the upper transverse arms , and its ability to provide an increase in the vehicle track width , during the control of roll center position .

A model of the developed suspension system was built within the MATLAB-Multibody modeling environment . All parameters of this model were set to be equivalent to the parameters of the “Double Wishbone Suspension” reference model, built for a traditional Double A-arms Suspension System in the same previous environment, and stored within the MATLAB example library. The reference and developed models were then tested under the same critical cornering maneuver conditions .

The developed model showed an ability to avoid rollover , unlike the reference model . The developed model also retained its ability to provide a good level of vibration dampening .

Developing A Methodology to Improve Tracking of Industrial Projects by Forecasting Earned Duration Index (EDI) Using Artificial Neural Networks (ANN)

2024-01-03T04:41:16+00:00

Construction enterprises produce a huge amount of operational data which are distributed among many databases, but these historical data are not collected and organized in the right way to support project tracking decisions effectively. Earned Duration Management (EDM) is one of the essential techniques in tracking construction project by using different indices to measure the progress and the performance of the project time schedule. The research aims to use artificial neural networks (ANN) to develop a model in order to predict the value of the earned duration index (EDI) at any period of the project using the historical data of company’s projects. The optimum design of the proposed forecasting module has been determined. The statistical parameters used to evaluate the accuracy of the proposed model were Root Mean Squared Error (RMSE) and Mean Absolute Error (MAE). The results of this research confirm the ability of artificial neural networks in predicting the value of earned duration index (EDI) at any period of the project life cycle ending up with satisfying results. The study recommends expanding the use of gene expression programming to improve the efficiency of the forecasting models for tracking indices of construction projects, which improve the tracking decisions in order to increase the economic performance of construction enterprises

Study of the change in the buckling modulus of jointed reinforced concrete spherical shells under the influence of dead and live loads

2024-04-30T08:15:04+00:00

shell spread widely, especially in public places and halls. In this research, we will study hemispherical domes made of reinforced concrete, which have a hinged support at the ends under the influence of buckling, in order to find out the relationship of the radius to thickness ratio to the buckling coefficient, which serves as a safety factor against buckling, as well as The radius-to-thickness ratio is related to the shape of the resulting buckling and the type of load applied. The study concluded that the dominant buckling shape is not related to the ratio of the shell’s radius to its thickness. This shape varies depending on the type of load overlay used, and the value of the buckling factor decreases with the increase in the ratio of the shell’s radius to its thickness. For the same thickness, the effective rate of implementation was determined to be between and that in order to increase the cross section, the value of the buckling factor decreases.

Study the influence of the brake flaps on the ship braking and maneuvering using CFD

2024-03-06T05:48:08+00:00

In this research, brake flaps were added to the hull of the KVLCC2 ship, and their effect on increasing the braking force of the ship was studied to reduce the large distances traveled by large ships during the stopping operation and before reaching the final stopping stage. This study used a Computational Fluid Dynamics (CFD) technique. The RANS equations and k-ω SST model were used to solve the Navier Stocks Equations. The program ANSYS was used in this research.

Initially, the numerical results were compared with the available experimental results. The agreement between both results was that good. After that, the calculations were made with one brake flab in several sites to the symmetrical part of the ship's hull, and then we added two flaps. The resistance and moments affecting the tanker during sailing were calculated at a straight course and different drift angles and speeds. The resistances and moments acting on the ship while sailing were calculated, and the results were studied and analyzed.

Evaluation of the Accuracy of the Two Kinematic Observing Methods in Global Navigation Satellite Systems Within Forests

2024-02-04T09:26:50+00:00

In order to manage natural resources and forests and demarcate their boundaries, Global Navigation Satellite Systems (GNSS) contribute to meeting a number of the needs of natural resources specialists, such as forest demarcation, positioning, and mapping, so its accuracy must be assessed. Therefore, the main objective of this research is to evaluate the accuracy of the two Kinematic observing methods in Global Navigation Satellite Systems (GNSS).

The first is the Post Processing Kinematic method (PPK), and the second is the method of Real Time Kinematic (RTK), by determining the perimeter and area of the forest, as well as the locations of the surrounding polygon points and the locations of the trees within it, with each of these two methods and comparing the results with the values resulting from observing in the traditional method (Total Station).

The results were presented in tables and charts, and indicated that the RTK method of locating polygon points surrounding the forest or its trees has better accuracy than the PPK method, but when calculating the area or perimeter, the accuracy of both methods is similar.

Novel system for human iris recognition depending on morphological operations and MLP classifiers

2024-05-25T09:27:11+00:00

This article suggested a novel system for human iris recognition, and created two algorithms for constrained iris images segmentation. We used Casia-Iris-Syn database Supplied by National Laboratory for Pattern Recognition , Institute of Automation , Chinese Academy of Sciences. K-fold cross validation method, morphological operations and multi-layer perceptron neural networks were used in this system. Two novel approaches has been proposed in the iris recognition system; the first was generated for iris image segmentation with an overall accuracy rate of (99.72%) for (10,000) iris images taken from the casia-iris-syn database, and the second was designed for feature extraction phase with average recognition rate of (99.78% for training patterns and 85.32% for testing patterns) using the same database. . We recommended the suggested method as an excellent system for human iris recognition.

Determining The Design Wind Speeds for Building Coastal Structures (Case Study Tartous City)

2024-04-02T08:35:46+00:00

Studying wind speed and its properties (speed-direction) is one of the most important considerations when designing the costal projects because of the direct relationship between a wind speed and a wave height as well as the importance on gettability wind power in electricity generating.

In this research hourly wind speed data and its direction that measured in Tartous meteorological station for 10 years are analyzed statistically by using Excel.

This study aimed to estimate wind speed at different return periods in Tartous city by using Weibull probability density function. The parameters of the Weibull distribution (k shape parameter- c scale parameter) are used for finding the wind speed at different return periods; These parameters are estimated by using three methods (maximum likelihood method-moment method-emprical method). These methods results have been compared with the provided data to find their accuracy based on root mean square errors (RMSE), the results showed that the best method of estimation was the maximum likelihood method.

The maximum Likelihood method showed that the maximum wind speed for 100 year return period is expected to be of the order of 25.3m/sec and 24.5 m/s from S and SW directions respectively

Improved aerodynamic design of small wind turbine blades

2023-10-24T21:04:35+00:00

The research aims to improve the aerodynamic design small Horizontal-Axis-Wind-Turbine blades to work at low wind speeds and at low flow of Reynolds number through testing the improvement method based on the use of two different airfoils along the length of the blade with the aim of increasing the capacity coefficient where the final shape of the improved blade is made of the two airfoils SD7062 and NACA23012.

In this research, we followed an analytical methodology based on modeling and simulation whereby an algorithm depends on the blade's element momentum theory BEMT was formed to extract the ideal aerodynamic parameters of the blades due to the design conditions.

At the beginning, two blades of each profile were designed separately based on the BEMT algorithm, and their performance was analyzed within the range of an assumed wind speed (7-4) V=m/s and the range of tip velocity ratio λ=[1-10], after that the two airfoils modified blade was designed and its performance was and its performance was analyzed at the same previous circumstance.

We performed an aerodynamic simulation of the enhanced two_ profiles blade in the ANSYS program using the CFD methodology depending on the possibility coefficient, the turbulence model (Shear Stress Transport) k-ω sst was selected.

The simulation results in MATLAB, ANSYS and QBLADE program showed that the capacity coefficient of the improved two airfoils blade was 0.42 at a wind speed of 7m/s and a tip speed ratio of λ = 7, while it was 0.38 for the turbine with the NACA23012 airfoil, and 0.35 for the turbine with the SD7062 airfoil, hence, the results of the modeling and simulation in the three programs were matched.