Naseer Sabri

Toward Optical Sensors: Review and Applications

Recent advances in fiber optics (FOs) and the numerous advantages of light over electronic systems have boosted the utility and demand for optical sensors in various military, industry and social fields. Environmental and atmospheric monitoring, earth and space sciences, industrial chemical processing and biotechnology, law enforcement, digital imaging, scanning, and printing are exemplars of them. The ubiquity of photonic technologies could drive down prices which reduced the cost of optical fibers and lasers. Fiber optic sensors (FOSs) offer a wide spectrum of advantages over traditional sensing systems, such as small size and longer lifetime. Immunity to electromagnetic interference, amenability to multiplexing, and high sensitivity make FOs the sensor technology of choice in several fields, including the healthcare and aerospace sectors. FOSs show reliable and rigid sensing tasks over conventional electrical and electronic sensors. This paper presents an executive review of optical fiber sensors and the most beneficial applications.

Path Loss Analysis of WSN Wave Propagation in Vegetation

Deployment of a successful wireless sensor network requires precise prediction models that provide a reliable communication links of wireless nodes. Prediction models fused with foliage models provide sensible parameters of wireless nodes separation distance, antenna height, and power transmission which affect the reliability and communication coverage of a network. This paper review the line of sight and the two ray propagation models combined with the most known foliage models that cover the propagation of wireless communications in vegetative environments, using IEEE 802.15.4 standard. Simulation of models is presented and the impacts of the communication parameters, environment and vegetation have been reported.

Wireless Sensor Network Wave Propagation in Vegetation

The Wireless Sensor Network (WSN) total path losses of a greenhouse based on the two popular empirical vegetation attenuation models are used to predict the connectivity and the maximum coverage of wireless nodes within the communication path. The foliage imposed effect on the propagating waves is examined, simulated and the total path losses concluded as a function of antenna height and a separation distance of WSN nodes in a field of various densities of vegetation inside a greenhouse. The implemented library of foliage propagation model can be embedded easily with other WSN simulator platforms. The best antennas height based on greenhouse environment and total path loss is shown to be with the 3.5 m and 1 m height for transceivers of main and end nodes, where less total path loss is obtained and perfect connectivity of (100 %) when used with MED vegetation models for all vegetation depths, less than 50 m, while ITU model shows perfect connectivity for same height combination but with less foliage depth of 40 m while it shows 88 % connectivity for higher foliage depth than 40 m.

Fiber Optic Sensors: Short Review and Applications

An extensive review of optical fiber sensors and the most beneficial applications is presented in this chapter. Although electrical sensing technologies have been successfully deployed in countless applications, the introduction of optical sensing, engineers and scientists can now perform measurements that were previously impractical or, in some cases, impossible with conventional electrical sensors. At present, many real-world applications already use both approaches to combine both benefits. The inherent advantages of fiber optic sensors such as lightweight, small size, passive, low attenuation, immunity to electromagnetic interference (EMI), wide bandwidth and environmental ruggedness were heavily used to offset their major disadvantages of high cost. Thus Fiber optic sensors (FOSs) have boosted the utility and demand for optical sensors in various military, industry and social fields. FOSs show reliable and rigid sensing tasks over conventional electrical and electronic sensors.

Optimization of Power Consumption for Centrifugation Process Based on Attenuation Measurements

The main objective of this research is to produce a mathematical model that allows decreasing the electrical power consumption of centrifugation process based on attenuation measurements. The centrifugation time for desired separation efficiency may be measured to determine the power consumed of laboratory centrifuge device. The power consumption is one of several parameters that affect the system reliability and productivity. Attenuation measurements of wave propagated through blood sample during centrifugation process were used indirectly to measure the power consumption of device. A mathematical model for power consumption was derived and used to modify the speed profile of centrifuge controller. The power consumption model derived based on attenuation measurements has successfully save the power consumption of centrifugation process keeping high separation efficiency. 18kW.h monthly for 100 daily time device operation had been saved using the proposed model.

Reduction of Power Consumption for Centrifugation Process Using Separation Efficiency Model

The power consumption, capacity, speed of rotation, separation precision and the centrifugation time are essential technical parameters of the centrifuge device, and hence their reliability may affect the system reliability and productivity. The modified period of velocity profile model (spinning period) which leads to decreasing the power consumption of laboratory centrifuge devices is derived. Based on the centrifugation time model, a fuzzy controller is proposed for the laboratory centrifuge device. The proposed controller design will produce high reliability by selecting various separation efficiencies, evaluating the separation efficiency period precisely, and reduction of separation power consumption. Based on the derived model, a low-cost controller modification leads to a shorter blood test time and lower power consumption while improving the separation efficiency to greater than 95 %.

A Wide Range Measurement and Disclosure of Ultrasonic Attenuation for Very Low Concentrations of Solid in Liquids Using Exponential Pulser Technique

The low solid concentrations in solutions are discovered and measured based on measurement the attenuation that occurs with a wave propagating through a fluid. Currently methods (Pitch-Catch, Pulse-echo and Immersion method) have some of weak points related with range of detection and power consumption, therefore, to increase the measuring range to include the detection of very low concentrations in solution as well as not relying on the material that the container is made of, a new technique for the pulser was designed to overcome the disadvantages of the three currently methods. This technique has been thoroughly applied to dispensing with the use of a container or reflector with a high reflection coefficient and Expanding the measuring range to include very low concentrations. The new technique demonstrates the system’s ability to distinguish the presence of particles in a fluid at a concentration lower than 10 %, which is below the limit of detection of the current method with the same device settings.

A New Ultrasound Pulser Technique for Wide Range Measurements

The objective of this research was to design and implement a new ultrasonic pulse-power-decay technique that transmits multiple ultrasound pulses through slurry to determine the lowest concentration that can provide an accurate attenuation measurement. A wide measurement range is obtained using the pulsed-power-decay transmission technique, and regardless of the material used to construct the container. A signal in the receiver transducer provides the attenuation measurements, for each echo, a fast Fourier transform (FFT) of the appropriate signal was obtained and compared with the water signals to yield the attenuation as a function of frequency. The data show the feasibility of measuring a kaolin concentration of 5% wt. When using a commercial pulser with the same device setting, no detectable echo was observed. Therefore, new technique measurements may prove useful in detecting solid content in liquid. This study demonstrated that the proposed pulsed-power transmission technique is promising for evaluating low concentrations of solids in fluids and for measuring sedimentation in solid-liquid systems.

Wireless sensor network wave propagation in vegetation: Review and simulation

Radio wave propagation through foliage medium induces an additional excess loss on the propagating components such as direct wave and reflected waves. Therefore to provide reliable and to enhance network coverage of wireless Sensor Actor Network (WSAN) a precise study and modeling of these effects must overcome with adequate prediction of the propagation loss of the WSAN signals. In this paper, the foliage imposed effect on the propagating waves is examined and the losses(dB) are concluded as a function of antenna height and the separation distance of wireless nodes in a field of various dense of foliage. Small distance low height, near ground, vegetated radio-wave propagation, the propagation loss is modeled by an integration of the foliage imposed effect and the effect from the radio wave reflections from the ground.