In the present work, the thermo-fluid characteristics of a heat exchanger formed of helical coiled tubes immersed in cold water are investigated experimentally. Two types of helical coiled tube are tested, a conventional vertical single helical coiled tube and a new triple vertical helical coiled tube in parallel connection called as meshed coils. The effect of hot water flow rates inside the tubes (ranges from 2.67 to 7.08 l/min), and its inlet temperatures (namely 50, 60, 70 and 80 °C) are investigated. The experimental results show that increasing the flow rate inside the meshed coils leads to decrease the temperature difference between inlet and outlet. An enhancement of heat transfer for meshed coils compared to single coil has been n

This paper proposed a new approach for an underwater visible light communication (UVLC) system using MIMO (2Tx/2Rx) technology. The BER performance, Q-factor, and data rate of the UVLC system are looked at in coastal waters of the Jerov type (J1C, J3C, J5C, J7C, and J9C). The applied system takes into account the angles ranging from 0 to 15° and 45°. The results indicated that 32-PPM outperformed other modulation techniques.

When the number of confirmed coronavirus disease cases rose in Iraq in the middle of February 2021, the Iraqi government performed a closure approach to constrain mobility and factory operations and enforce social distancing. In this research, the concentrations of air components (PM_2.5, PM₁₀, nitrogen dioxide (NO₂) and ozone (O₃)), which represent herein the degree of air quality index, were recorded, drawn and evaluated over central (Baghdad, the capital), northern (Kirkuk Province) and southern (Basra Province) Iraq before and during the closure. The experimental duration of this research was 6 months (from 1 January 2021 to 30 June 2021), which

Corona virus sickness has become a big public health issue in 2019. Because of its contact-transparent characteristics, it is rapidly spreading. The use of a face mask is among the most efficient methods for preventing the transmission of the Covid-19 virus. Wearing the face mask alone can cut the chance of catching the virus by over 70\%. Consequently, World Health Organization (WHO) advised wearing masks in crowded places as precautionary measures. Because of the incorrect use of facial masks, illnesses have spread rapidly in some locations. To solve this challenge, we needed a reliable mask monitoring system. Numerous government entities are attempting to make wearing a face mask mandatory; this process can be facilitated by using face m

Drought is a natural phenomenon in many arid, semi-arid, or wet regions. This showed that no region worldwide is excluded from the occurrence of drought. Extreme droughts were caused by global weather warming and climate change. Therefore, it is essential to review the studies conducted on drought to use the recommendations made by the researchers on drought.  The drought was classified into meteorological, agricultural, hydrological, and economic-social. In addition, researchers described the severity of the drought by using various indices which required different input data.  The indices used by various researchers were the Joint Deficit Index (JDI), Effective Drought Index (EDI), Streamflow Drought Index (SDI), Sta

Most of the Internet of Things (IoT), cell phones, and Radio Frequency Identification (RFID) applications need high speed in the execution and processing of data. this is done by reducing, system energy consumption, latency, throughput, and processing time. Thus, it will affect against security of such devices and may be attacked by malicious programs. Lightweight cryptographic algorithms are one of the most ideal methods Securing these IoT applications. Cryptography obfuscates and removes the ability to capture all key information patterns ensures that all data transfers occur Safe, accurate, verified, legal and undeniable.  Fortunately, various lightweight encryption algorithms could be used to increase defense against various at

This paper presents a complete design and implementation of a monitoring system for the operation of the three-phase induction motors. This system is built using a personal computer and  two types of sensors (current, vibration) to detect some of the mechanical faults that may occur in the motor. The study and examination of several types of faults including (ball bearing and shaft misalignment faults) have been done through the extraction of fault data by using fast Fourier transform (FFT) technique. Results showed that the motor current signature analysis (MCSA) technique, and measurement of vibration technique have high possibility in the detection and diagnosis of most mechanical faults with high accuracy. Subsequently, diagnosi

The study aims to measure the level of academic stress in the e-learning environment in three areas, students and their dealing with classmates, dealing with the professor and technical skills, and the nature and content of the curriculum among graduate students in the College of Education at King Khalid University during COVID-19 pandemic. This study was descriptive in nature (survey, comparative). The sample consisted of (512) male and female graduate students in the master's and doctoral programs. The Academic Stress Scale in the E-learning Environment designed by Amer (2021) was used. The results indicated a high level of academic stress among graduate students in the e-learning environment. The study also found that there were stati