This study explains the design of a single-plate clutch using experimental measurements. The ratios of materials used to make the samples were 34g of Kevlar fiber (aramid 49 type), 150g of epoxy-type Sikadur-52, 10g of iron powder, and 10g of graphite powder. The three different sample types were made as laminates and cut using water cutter machinery according to the ASTM standard for each test. The following procedures were taken: The prepared mold was created first. Epoxy and the hardener were mixed in a 2:1 ratio. After that, the mixture was stirred well for a sufficient period of time. Then a quantity of the epoxy mixture was placed in the mold, and Kevlar fibers were placed in layers. The following ratios were used to create three samples: Sample 1 (34 g of Kevlar fiber, 150 g of epoxy), Sample 2 (34 g of Kevlar fiber, 150 g of epoxy, 10 g Fe), and Sample 3: Kevlar fiber (34 g), graphite (10 g), epoxy (150 g), and iron (10 g). The following facts have been found: When Kevlar fiber (aramid 49 type) was used at a weight of 34g for all samples, the best performance was achieved by hybrid composite sample3, which has the highest values (modulus of elasticity and higher wear resistance) in comparison to the other two composite samples (sample2 and sample1). In comparison to composite sample 1, the hybrid composite samples 2, and 3 have the highest value. (Tests for hardness).

The influence of friction pressure on welding quality when friction stud welding 1017 low carbon steel with AISI 304 austenitic stainless steel is investigated in this study. friction stud welding is employed in industrial applications instead of conventional welding processes Due to the friction welding process didn't need to reach the melting point of welded metals. Welding is performed on these dissimilar metals by utilizing a lathe machine with a load cell connected to a weight indicator and a manufacturing grip to fasten the plate at a rotating speed of 1600 RPM, a friction time of 20 seconds, and a friction pressure of (15, 20, and 25) MPa. After the welding procedure is completed, the specimens are subjected to tensile, torque, and hardness tests to evaluate the welding quality. In addition, optical microscope research was carried out to determine the microstructural aspects. The effect of friction pressure on welding quality was investigated based on the information generated from the results. The increase of friction pressure during the process from 15 MPa to 25 MPa leads to an increasing ultimate tensile strength from 203 MPa to 210 MPa approximately. Also, the torque values raised from 179 N.m to 198 N.m in the same case.

For several decades, calcium chloride has been widely used as a cheap and effective accelerator. Calcium chloride is remarkably decreasing the initial and final setting times of concrete. It is mainly used at low-temperature concreting because it allows for earlier finishing and reduces the effects of water freezing inside fresh concrete. The use of calcium chloride in reinforced concrete has been decreased after identifying its effect on reinforcement corrosion. However, calcium chloride is still widely used in ordinary concrete and some reinforced concrete in specific proportions. This paper reviews the most important mechanical and chemical effects of calcium chloride on concrete mixtures, its effects on reinforcement corrosion, the conditions of its use, and its mechanism of action. This review study highlights the need for a detailed study to verify calcium chloride’s exact role in reinforcement corrosion and the maximum permissible limits for its use in reinforced concrete. In addition, there is a need to study the compatibility of calcium chloride with other concrete admixtures.

This paper investigates a simple mathematical model for a water level system, which consists of a DC motor (water pump), and a Speed to Height transformation block, that relates the speed of the motor, to the height of the water level. The input signal is the applied voltage to the armature of the DC motor, while the output signal is the rotational speed of the shaft. A simple modified model-free adaptive controller is suggested, to control the level of water, by adjusting the rate of the incoming water flow to the container, by changing the speed of the water pump, that fills the container. The suggested controller consists of a conventional model free adaptive controller, combined with the proportional integral derivative controller. The parameters of the controller are tuned using two methods. The overall controlled water level system is simulated through MATLAB R2015a software. The results show the efficiency of the suggested controller, when compared to the tuned PID and the MFAC, due to its least fluctuation peak, fast response with a small settling time, and zero steady-state error.

This research was conducted to verify the removal efficiency of cadmium ions from an aqueous solution using a low-cost natural adsorbent. Rosemary plant was used in a batch system, and to understand this process more, several factors were investigated as follows: pH, contact time, initial metal ions concentration, amount of adsorbent material, and agitation speed. All experiments were carried out at room temperature. Whereas, the results showed the optimal value of removal was 83% for cadmium onto rosemary plant, under optimum operating conditions: pH 5, the adsorbent material dosage 2 g/100 ml, contact time 60 min, the metal concentration 10 mg/L, and agitation speed 250 rpm. The Freundlich adsorption isotherm model fits the equilibrium adsorption data for Cd⁺²better than the Langmuir model. This study found that the rosemary plant as a cost-effective and locally adsorbent for removing Cd⁺²from polluted water is efficient. Thus, it is possible to use the rosemary plant as a low-cost material to be used to adsorb heavy metals from wastewater.

The problem of computing the set of prime implicants to represent a Boolean function is a classical problem that is still considered a running problem for research because all known approaches have limitations. The article reviews existing methods for computing prime implicants and highlights their limitations, particularly for multi-output functions and limited scalability due to the growth in memory required to complete the computation. Then it proposes a recursive ternary-based minimization algorithm to compute the prime implicants of multi-output Boolean functions. The algorithm is based on the concept of Programmable Logic Array (PLA) tables, which provide a structured and efficient representation of Boolean functions. The algorithm takes advantage of the ternary logic system to efficiently compute the prime implicants while maintaining scalability for large and complex functions, which has significant implications for digital circuit design and optimization.

Soil contamination produced by improper management of various petroleum and industrial products causes potential risks to the environment and soil engineering properties. Such contamination causes environmental deterioration and adversely affects soil engineering performance, altering almost all geotechnical properties. Several remediation techniques have been proposed to decontaminate the polluted soils. Choosing the best technique depends on both the energy consumption during operation and the treatment efficiency. The lack of a universally appropriate treatment method and the unavoidable expansion of contaminated land have justified the sake of reviewing the behavior of contaminated soils to develop both environmentally and geotechnically suitable soils for construction projects. The present paper reviewed some soil contamination sources’ backgrounds, effects, and remediation methods. Soils influenced by petroleum hydrocarbons and industrial effluents were evaluated. According to the reviewed studies, contaminants are evidenced to have a negative impact on soils' geotechnical characteristics by increasing settlement and swelling, reducing shear strength, and decreasing permeability. The need to restore the engineering characteristics of soils suggest the necessity to use remediation or stabilization technique. The electrochemical method, bioremediation, and stabilizing by additives are revealed to be efficient in improving the engineering properties and performance of contaminated soils.

The control of (PMSM) is the subject of this study and the torque ripple reduction in (PMSM) is the main goal of this work. Torque and flux are controlled using a predictive model and Vector Control. Because it is commonly employed in regulating electric motors. Space vector control and predictive control are two (PMSM) control approaches used in this study. Predictive control was determined to be more effective in terms of response and action after a Matlab simulation of the two approaches. MPC covers all potential switching states that decrease actual torque and flux ripples as well as Total Harmonic Distortion. The benefits of MPC include simple principles, an easy-to-use console, and the ability to implement limits quickly. However, there are some drawbacks to this technique, including the requirement for bigger accounts and faster machines. The fundamental principles of the control techniques discussed are provided A (PMSM) powered by a two-level power converter is then used to simulate the control approaches. Their performance in comparison is based on the obtained results.

With the rapid development of wireless communication, 5G is gradually growing into a large-scale basic Internet that supports various industries in the whole society. The substantial expansion of its service scope poses many challenges for the underlying technology, especially for the crucial component of the physical Layer-Orthogonal Frequency Division Multiplexing (OFDM). Recently, Neural Networks (NNs) have attracted extensive attention due to their excellent performance in computing vision and natural language processing. Its strong universality also provides new development space for traditional communications. This manuscript conducts an in-depth study on channel estimation for OFDM systems and explores the possible application of a Generalized Regression Neural Network (GRNN) to estimate the Channel Impulse Response (CIR) attenuated by AWGN and Rayleigh fading system. Moreover, three traditional channel estimation algorithms, i.e., LS, MMSE, and LMMSE, are derived by mathematics. In addition, this thesis illustrates several typical neural networks in detail, including their internal structure, parameter updating process, and related optimization algorithms.

Investigating important challenges to eliminate crude oil fouling in pipelines needs to be studied thoroughly. According to environmental and economic issues, fouling in pipelines increases the price of crude oil. According to chemical and environmental experts, the loss in heat required additional energy to compensate which meant higher fuel consumption and more carbon emissions into the atmosphere. The increase in fluid flow rate combined with a constant drop in pressure is dangerous for pipelines. In addition, the Iraqi crude oils block refinery preheat trains because they contain very little asphaltene. The fouling of a variety of these crude oils and their blends is examined in this paper. Fouling may be caused by four major processes: solid particles, corrosion, sedimentation, and chemical reaction.