Samarra Journal of Engineering Science and Research

Dams are among the most crucial hydraulic structures that play a fundamental role in flood control, hydroelectricity power generation, and various other purposes for which dams are constructed, In recent decades, simulation models have significantly facilitated understanding dam performance under multiple conditions and predicting potential catastrophes in emergency situations such as dam failure and extreme floods, many dams face the risk of slope failure due to water pressure or foundation soil conditions upon which the dam is constructed, Therefore, this research paper presents studies that have addressed dam simulation models, taking into consideration various operational and flood conditions, Additionally, it examines studies concerning dam slope failures, their most significant impacts and the methodologies for building these simulation models.

Today the NOMA has exponential growth in the use of Optical Visible Light Communication (OVLC) due to good features such as high spectral efficiency, low BER, and flexibility. Moreover, it creates a huge demand for electronic devices with high-speed processing and data rates, which leads to more FPGA power consumption. Therefore; it is a big challenge for scientists and researchers today to recover this problem by reducing the FPGA power and size of the devices. The subject matter of this article is producing an algorithm model to reduce the power consumption of (Field Programmable Gate Array) FPGA used in the design of the Non-Orthogonal Multiple Access (NOMA) techniques applied in (OVLC) systems combined with a blue laser. However, The power consumption comes from Complex Digital Signal Processing (DSP) due to mathematical operations such as addition and multiplication which consume more FPGA power when compared with other parts of NOMA. The multiplication operation consumes more FPGA power than the additional operation. The article's goal is to propose low FPGA power consumption algorithms called recursive IFFT/FFT which reduce the FPGA power consumption by more than 45% compared with the model without the proposed algorithm using AMD Xilinx Kintex-7 with high-speed analogue card.

This study investigates the effects of delay time in cold joints on the structural behavior of reinforced concrete (RC) beams and cubes with varying compressive strengths of 30 MPa and 50 MPa. The selected delay times (0, 60, and 180 minutes) were chosen to study their effect on shear strength and bond performance in the critical regions containing a cold joint.The shear strength at the critical regions that containa cold joint was investigated in the beam without shear reinforcement tested under a four-point load. For the cubes, the bonding strength in the cold joint was indirectly investigated using the bi-surface shear test. Experimental results detected that cold joints significantly influence shear strength and failure modes, specifically forlonger delay times. Beams without stirrups dominantly failed in shear, with diagonal cracks initiating near the support, while delay times exacerbated the weakening of bonds, altering stress distribution and crack patterns. Similarly, cubes subjected to bi-shear stress demonstrated varied failure modes, transitioning from cohesive to adhesive and mixed failures depending on the delay time and compressive strength. A higher compressive strength of 50 MPa enhanced the overall shear capacity compared to 30 MPa; however, it also contributed to increased brittleness in failure modes. The findings emphasize that the interaction between delay times and compressive strength plays acrucial role in influencing the bonding characteristics and shear behavior of concrete elements containing cold joints.

The rapid escalation in plastic production and consumption has resulted in a substantial increase in plastic waste, presenting serious environmental issues. In recent years, researchers have explored the possibility of using recycled plastic as an alternative aggregate in high-strength concrete, aiming to mitigate plastic waste and improve sustainability in construction practices. This study reviews the effects of incorporating recycled Plastic Aggregates (PA) on the properties of high-strength concrete. The review examines the effect of PA on concrete's physical, mechanical, and durability characteristics, highlighting both the potential benefits, such as enhanced energy absorption and sulfuric acid resistance, as well as limitations, including reduction incompressive strength. Current research indicates that despite changes in mechanical properties, concrete with recycled PA remains viable for many engineering applications. The findings confirm the need for further investigation into pre-treatment methods to optimize plastic aggregate performance, contributing to sustainable waste management and eco-friendly construction solutions.