In this paper, a dual port high gain hybrid (silicon graphene) antenna is designed and investigated. Some of the important qualities of the proposed radiating structure include the following: (1) XGBoost and Random Forest-based machine learning (ML) techniques are applied to predict the reflection coefficient (|S11|) features of the designed radiator to reduce the simulation time; (2) the use of a cross slot provides the circularly polarized waves between 4.92 and 5.38 THz; (3) a 1 ∗ 2 array structure produces the high gain, i.e., 10.0 dBi within the operating frequency range; and (4) the opposite orientation of the aperture provides a polarization diversity concept, which, in turn, improves the isolation level to more than 30 dB. After comparing the results obtained from CST and HFSS, as well as those predicted from the ML algorithm, it is confirmed that the designed radiator operates from 4.71 to 5.85 THz. The good value of far-field and diversity parameters affirms the fitness of the designed radiator for wireless power transfer in the THz regime.

Temperature measurement and transmission of a signal safely to the control room for further processing is important for the process industry. In this paper, a modified head-mounted temperature measurement system using a thermocouple with opto-isolation has been developed. Here, the thermocouple is connected to the terminals, mounted on the ceramic base in the head of the thermo-well. It consists of two signal conditioners for thermocouple and AD590, both signal conditioning outputs applied to a summer circuit. The output of the summer circuit which is in the range of 1.73-3.43V, adjusted by a signal conditioning circuit, is applied to the middle electrode of Mach-Zehnder interferometer (MZI). MZI produces normalized optical signals according to the variations in temperature. These optical signals are then transmitted to the control room safely in the inflammable process industry. The transmitted signals are demodulated in the control room and then sent to the PC through an Opto-isolator circuit and DAS card. The necessary theory as well as mathematical equation has been derived. The experimental and simulation results are reported here.

The liquid level measurement and transmission of signal safely up to the control room for further processing is important for the process industry. In this article, an electronic float and a signal conditioning circuit have been used for measuring the height of the liquid level in terms of electrical signals. An electrooptic amplitude modulator has been used to change an electrical signal matching to the liquid level information into an optical signal. Mach-Zehnder interferometer (MZI) has been used as an amplitude modulator. The optical signals contain information of the height of the liquid and transmit safely up to the remote location such as control room in the inflammable process industry. The optical signal is converted to electrical signal in the remote location by the demodulation technique and then sent to an opto-isolator circuit followed by the PC through a data acquisition system (DAS) card. The signal is sent to PC for further processing in the process industry. The necessary theoretical and mathematical equation has been derived for understanding the operation of the system. The simulation and experiment results are presented in this present article.

It is extremely important to accurately measure the liquid level as a process variable of a storage tank used by any plant. The transmitted electrical signal from a liquid level transducer or any other transducer to a remote indicator or controller may sometimes suffer from the measurement error due to its contamination with noise signal. This may be easily avoided by using modern optical fiber communication technique wherein we see the production of optical signal from the transducer output and its noise free communication through fiber-optic cable. In thie present paper, an opto-electronic liquid level transmission technique has been proposed for liquid which is conducting in nature and generally, collected in a storage tank. The electronic part of the transmitter unit consists of a modified capacitive transducer with a signal conditioner unit which produces an electrical DC output voltage which is linearly related with the level of the conducting liquid in the storage tank. This DC voltage is transformed into an optical signal with the help of Mach–Zehnder Interferometer (MZI) based electro- optic converter. Generated Optical signal may be dispatched to any location which is remote in nature by using fiber optic cable. Thus, various types of measurement error observed in the conventional capacitive level transmitter are minimized by using the proposed system. In the preset paper, a prototype model of the proposed system has been designed and developed to test its functionality. A good linear characteristic of the normalized optical output in support of the derived equations is observed.

A PC based cost effective electro-optic type flow measurement technique is designed and developed. The anemometric principle i.e. the effect of heat loss on a heating element due to flowing fluid is utilized for the measurement of flow rate of liquid in the process industry. A constant voltage p-n junction diode is used as a basic sensing element and the output of the sensing element is amplified and conditioned with the help of the instrumentation amplifier and signal conditioning circuit. Transmission of electrical signals in remote locations suffers from measurement errors due to electromagnetic induction effect, stray capacitance effect etc. The transmission of electrical signal is also not safe for the industries where an inflammable area is present between fields to remote locations and optical transmission is preferred in such areas. To overcome these, an electro-optical system has been developed. The process variable is first sensed electrically. This electrical signal of the transducer is converted into an optical signal using an electro-optic amplitude modulator and then it is transmitted in the form of an optical signal from field to control room through inflammable areas. The modulated signals are demodulated in the control room or remote location and then send to the PC through an optoisolator circuit and DAS card. The experiment has been performed and the theory as well as the mathematical equation has been derived to explain the operation of the proposed system. The overall PC based flow indicator system is also found to have linear characteristics with very good repeatability within tolerable percentage error.The experimental result is reported in the paper.

Design and analysis of Quadrifilar helical antenna are presented in this paper. The proposed antenna is designed for Cube-Sats in the low earth and medium earth orbits. It is a combination of four helical antennas, each separated by 90?, and excited separately at the feeding point. The antenna is designed for operation at 4.5 GHz with an impedance bandwidth of 11.11 %. Design of the antenna is done in two steps. The first step being the design of a ground plane, which can make the antenna operate at 4.5 GHz. The second step is to analyze the antenna?s performance for different helix angles using the best ground plane dimensions obtained in the first step. The gain versus frequency curve has been obtained and the designed antenna is having a gain of more than 4 dB at the resonant frequency of 4.5 GHz.

In this study, an improved inductive pickup coil and an electro-optic type displacement transmitter has been proposed. A modified differential inductance bridge network has been used to generate electrical signals and Mach–Zehnder interferometer (MZI) converts an electrical signal into an optical signal. The sensitivity of the sensor part of the transducer is very good because of two parallel magnetic paths for the inductive pickup. The theoretical equations explaining the operation of the transducer are derived. The proposed transducer is tested experimentally to obtain the static characteristics. The characteristics of the MZI-based displacement transmitter have been observed by using PC-based Opt wave Opti-BPM.v.9 simulation software in the linear zone. The experimental and simulated results are reported in this study. Very good linear characteristics of the transducer with adjustable sensitivity have been observed. The transmitter output in the form of normalised intensity of light is also found to be linearly related with displacement. The theoretical equations derived in this are found to support the experimental characteristics to a very good extent.

A simple, low cost liquid level measurement technique for all types of liquids has been proposed in this study. A force resistive sensor has been used to sense the height of liquid level in a storage tank. The force resistive sensor gives the information of the height of liquid level in terms of resistance. The resistance of the sensor corresponding to the height of liquid level is converted into a voltage signal with the help of a resistance to voltage converter. The resistance-to-voltage converter output has been passed through signal conditioning circuit and voltage-to-current converter to transmit the signal to a remote location like a control room. The theoretical equations explaining the operation of the force resistive sensor for the liquid level have been derived. The whole unit has been designed, fabricated and its function has been studied experimentally. The experimental results are reported in this study. A very good linear characteristic of the proposed transmitter has been observed with very good repeatability and with a very small uncertainty of measurement.

The rotameter, the widely used flow meter, is generally used as a local indicator. Therefore, for industrial use, some necessary technique is required to transmit float displacement to remote location. Direct transmission of electrical signal through connecting wires is generally prohibited in an inflammable region. In this paper, an electro-optic system is developed using a modified inductive-type rotameter, which produces an electrical signal according to float movement of the rotameter. The electrical signal is then converted into an optical signal using the Mach-Zhender interferometer. Necessary equations along with the developed theory of operation are presented in this paper. An experiment is performed on the proposed transmitter and the experimental and simulation results are reported in this paper. Very good linearity and repeatability with a very small uncertainty in the measurement of the transducer characteristic have been observed. The graphical abstract is shown.

Measurement of liquid level in a storage tank using float is one of the important, simplest and cheapest method. However, the main drawback of this sensor is its inability to transmit the reading. Costlier and complicated designs are developed to transmit the float position to a remote station like control room. Direct transmission of electrical signal through connecting wires is generally prohibited in the inflammable region. In this paper, a very simple electro-optic system has been developed to transmit the electrical signal output of the transducer to a remote location using Mach-Zehnder interferometer. The necessary equations describing the principle of operation of the proposed transmitter are derived and presented in this paper. The operation of the transmitter is experimentally tested, and the experimental results are reported in this paper. A very good linearity and repeatability of the transducer and transmitter characteristics have been observed.

A new optical type pressure sensing system is proposed in this paper. Bellows, an elastic type sensing element is used to indicate the pressure in the form of displacement of bellows element. For automated process industries, the signal is required to be send to a remote location like control room. In order to send the mechanical movement of bellow corresponding to the applied pressure, to a control room the signal is to be converted in the form of electrical, pneumatic or optical signal. For inflammable industries optical signal transmission is preferred. In this work the displacement of bellow element is first converted into an electrical signal using hall probe sensor then it is converted into an optical signal using (MZI) Mach-Zehnder Interferometer. The proposed sensing system is designed and its theory of operation is developed. The experiment was done on the proposed system and the experimental characteristic shows very good linearity with excellent repeatability.

A rotameter is a variable area type flow sensor. It is generally used as a local indicator and display unit. Hence, a special technique is needed to transmit and to display the reading of a rotameter at a remote distance. In this paper, an improved inductance bridge-type technique has been developed to convert the float movement of the rotameter into an electrical current signal, which can be transmitted to a remote indicator. A straight ferromagnetic wire attached to the float of the rotameter acts as a sensing element of the proposed rotameter transducer. The movement of the wire as a result of fluid flow variations inside an inductive pickup coil changes the self-inductance of the coil with the changes in flow rate. An improved inductance bridge network has been used to measure the self-inductance of the coil. It has been observed that the variation of the self-inductance of the pickup coil as well as the variation of the transducer and transmitter outputs with flow rate has a very good linearity and repeatability. The necessary theoretical equations, along with the experimental results, are reported in this paper.

The capacitive sensors are used in a variety of industrial and automotive application. A capacitive sensor converts a change in position, or properties of dielectric material into an electrical signal. These properties of capacitor can be used to measure the liquid level in storage tanks. The various aspects and configurations of capacitive liquid level measurement have been described. Here, review is also done on the several types of liquid level measurement techniques using capacitive sensor, for conducting and non-conducting liquid.

Rotameter is one type of the variable area flow meter in which the height of the float is linearly related to the flow rate of liquid. It is generally used for measurement of flow rate of liquid and for display. The Rotameter gives the information about flow rate locally. In this paper an attempt has been made to transmit the information to a remote receiver. Float variation according to flow rate has been converted to an electrical voltage signal, the voltage signal amplified and transmitted to remote indicator. For generation of voltage a non-magnetic straight thin cylindrical rod has been taken whose one end is connected to float of Rotameter and the other end connects with the core of an LVDT. When float varied according to the flow rate of the liquid then core of LVDT also varied and generated voltage. It has been observed that movement of float as well as core and variation of LVDT output voltage has good linearity and repeatability. The necessary theoretical equations, along with the experimental results, are reported and compared in this paper.

Model Predictive Control (MPC) is used mainly for specific handling of constraints. MPC is implemented mainly by microprocessors. So, before implementation it is converted to discrete time. This paper presents about the design of dynamic linear controller for a binary distillation column. The design is based on MPC, which is based on prediction of control variable. We have used Wood and Berry 2×2 function for the distillation column. Firstly, we have implemented an ideal MPC by taking unit step input. Secondly, we have implemented general MPC for binary distillation column by taking the unit step input with and without disturbance. We have analyzed the manipulated and controlled variables for the distillation column using MPC. We have also find how to remove the ringing effect in manipulated variables for MPC.

Model Predictive Control (MPC) is used mainly for specific handling of constraints. This paper presents about the design of dynamic linear controller for a binary distillation column. The design is based on MPC, which is based on prediction of control variable. We have used Ogunnaike and ray 3×3 process and Doukas and Luyben 4×4 for the distillation column. We have implemented manipulated and controlled variable for 3×3 process using MPC. We have also analyzed the manipulated and controlled variables for 4×4 process using MPC.