An Outage Probability in Cooperative MIMO Under Slow Fading Channel

Slow fading channel one of the most important channels which appears widely in cellular mobile system. Although, it has several problems such as bad effects of fading which cause an attenuation to the signal. This paper presents a new scheme in cooperative communication system under slow fading channel to enhance and increase the quality of communication systems performance. This new scheme is called a cooperative multiple input–multiple output Antenna. The main idea of this scheme depends on transmitting multi copy of message via tow paths. Its' performance has compared with MIMO technique in term of outage probability. Thus, the negative effects of fading are mitigated and the outage probability is enhanced. Furthermore, the reliability in communication system under slow fading channel has improved

Smart monitoring system of Najran dam

Najran city faces the flood situation every year due to intensive rain and climatic disturbances. Flooding also causes loss of money, along with loss of life and property and the destruction of agriculture and livestock. Thus, this project proposes a conceptual framework with three main phases: monitoring the water level inside the dam and level in water stream before and after the dam, controlling the opening and closing of the dam gate and measuring the water pressure at the dam barrier. In the case of high water level dam is monitored through water sensors placed at the top of the dam and then these sensors give a reference to the stepper motor and the flow of the stepper motor is controlled by the dam gate. The experimental results shows that the proposed system has the capability to reliably tackle the flood water. It can accurately measure the water level and control the gate of dam as soon as the level of the water reaches to danger level and water pressure at the barrier is measured by the sensor. The developed real-time monitoring system in Najran dam will help authorities to take preventive actions to deal with flood disaster

One-Dimensional Phononic Crystals: A Simplified Platform for Effective Detection of Heavy Metals in Water with High Sensitivity

Recently, the pollution of fresh water with heavy metals due to technological and industrial breakthroughs has reached record levels. Therefore, monitoring these metals in fresh water has become essentially urgent. Meanwhile, the conventional periodic one-dimensional phononic crystals can provide a novel platform for detecting the pollution of heavy metals in fresh water with high sensitivity. A simplified design of a defective, one-dimensional phononic crystals (1D-PnC) structure is introduced in this paper. The sensor is designed from a lead-epoxy multilayer with a central defect layer filled with an aqueous solution from cadmium bromide (CdBr2). The formation of a resonant peak through the transmittance spectrum is highly expected. This study primarily aims to monitor and detect the concentration of cadmium bromide in pure water based on shifting the position of this resonant peak. Notably, any change in cadmium bromide concentration can affect the acoustic properties of cadmium bromide directly. The transfer matrix method has been used to calculate the transmission spectra of the incident acoustic wave. The numerical findings are mainly based on the optimization of the cadmium bromide layer thickness, lead layer thickness, epoxy layer thickness, and the number of periods to investigate the most optimum sensor performance. The introduced sensor in this study has provided a remarkably high sensitivity (S = 1904.25 Hz) within a concentration range of (0–10,000 ppm). The proposed sensor provides a quality factor (QF), a resolution, and a figure of merit of 1398.51752, 48,875,750 Hz, and 4.12088 × 10−5 (/ppm), respectively. Accordingly, this sensor can be a potentially robust base for a promising platform to detect small concentrations of heavy metal ions in fresh water

Optical Detection of Fat Concentration in Milk Using MXene-Based Surface Plasmon Resonance Structure

MXene (Ti3C2Tx) has emerged very recently as an interacting material for surface plasmon resonance (SPR) configuration. It was discovered that Ti3C2Tx can facilitate the adsorption of biomolecules due to its higher binding energies, stronger interaction between matter and light, and larger surface area. In this work, a two-dimensional Ti3C2Tx and silicon layer-based SPR refractometric sensor is proposed for the sensitive and fast detection of milk fat concentration due to the high significance of this issue to people all over the world. The proposed SPR structure employs BK7 (BK7 is a designation for the most common Borosilicate Crown glass used for a variety of applications in the visible range) as a coupling prism and silver as a metal layer. The layer thicknesses and the number of Ti3C2Tx sheets are optimized for the highest performance. The highest reached sensitivity is 350 deg./RIU with 50 nm silver and 4 nm silicon with a monolayer of Ti3C2Tx, which is ultra-high sensitivity compared to the latest work that utilizes SPR configuration. The proposed SPR-based sensor’s ultra-high sensitivity makes it more attractive for usage in a variety of biosensing applications

Omega-shaped tag antenna with inductively-coupled feeding using U-shaped stepped-impedance resonators for RFID applications

This study proposes a new omega-shaped tag antenna with inductively-coupled feeding (ICF) using U-shaped stepped- impedance resonators (SIRs). It aims at improving the performance of the tag antennas for Radio Frequency Identification (RFID) applications. The radiating body of the antenna is fed using two mirroring symmetrical U-shaped SIRs. This antenna is a simpler alternative for the existing antennas that match the impedance of the antenna to the chip impedance effectively applying varied reinforcement of the equivalent inductance of the radiating structure. In addition to the use of an omega-shaped structure, the proposed feeding technique boosts performance of the antenna impedance, dimensions, and peak gain. The measured size of the antenna was 50×55.55×1.6 mm3. It attains a peak gain of 1.8 dBi and radiation efficiency higher than 85% at its operating frequency. The experimental results revealed that this tag antenna has the characteristic of good impedance matching within the frequency range of 900-940 MHz, corresponding to a better power reflection coefficient of -3 dB. Comparison between the measured and simulated results verified that the proposed feeding method is capable to improve overall performance of RFID tag antennas

A promising ultra-sensitive CO2 sensor at varying concentrations and temperatures based on Fano resonance phenomenon in different 1D phononic crystal designs

Abstract Detecting of the levels of greenhouse gases in the air with high precision and low cost is a very urgent demand for environmental protection. Phononic crystals (PnCs) represent a novel sensor technology, particularly for high-performance sensing applications. This study has been conducted by using two PnC designs (periodic and quasi-periodic) to detect the CO2 pollution in the surrounding air through a wide range of concentrations (0–100%) and temperatures (0–180 °C). The detection process is physically dependent on the displacement of Fano resonance modes. The performance of the sensor is demonstrated for the periodic and Fibonacci quasi-periodic (S3 and S4 sequences) structures. In this regard, the numerical findings revealed that the periodic PnC provides a better performance than the quasi-periodic one with a sensitivity of 31.5 MHz, the quality factor (Q), along with a figure of merit (FOM) of 280 and 95, respectively. In addition, the temperature effects on the Fano resonance mode position were examined. The results showed a pronounced temperature sensitivity with a value of 13.4 MHz/°C through a temperature range of 0–60 °C. The transfer matrix approach has been utilized for modeling the acoustic wave propagation through each PnC design. Accordingly, the proposed sensor has the potential to be implemented in many industrial and biomedical applications as it can be used as a monitor for other greenhouse gases