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The Purpose of this research is to initiate the “Fourth Industrial Revolution” by using the Internet of things (IoT), which can be applied to flammable gas condition monitoring and detection of gas leakage and activate fire extinguisher in case of fire accidents. Liquefied petroleum gas (LPG) leakage and explosions cause many injuries and death each year. By developing an automated and remote LPG ppm condition monitoring and fire extinguisher activation system with the help of a cyber-physical system, the rate of accidents and injuries can be reduced to a significant amount.

The IoT enabled the sensors to transmit LPG concentration value reading to a mobile app or cloud server and control actuators by connecting all in the same network. In case of a fire accident, the solenoid valve automatically or can be activated by an android application manually, which will be pre-installed in mobile phones. Another advantage of this system is that the gas cylinder or flammable particle source can be closed by closing the solenoid valves attached to their outlets. The first challenge of Industry 4.0 is to develop a cyber-physical system where all physical entities can be monitored and controlled over the internet or another way remotely or from a single point.

This fire extinguisher system can be used everywhere and in all types of firefighting because all types of fire extinguishers are commercially available in cylinders where solenoid valves can be used instead of conventional valves. This system will reduce human effort in the fire safety system and reduce the number of losses owing to fire accidents by taking all actions automatically and from a safe distance. The reliability analysis of this system indicated that the working condition for the best outcome is 20–35°C and the baud rate of the controller should be 11.5 kHz.

The study of pieces of the literature summarizes that this work is unique in terms of the application of Industry 4.0 in the fire safety system and reliability analysis of this system helped to determine the operating condition for the best performance of this system. Some LPG condition monitoring system was developed using IoT before but had many limitations such as working capability during load shading or emergency cases.

The purpose of this paper is to study the sensitivity and selectivity properties of polyaniline/tantalum pentoxide (PANI/Ta₂O₅) composite to liquid petroleum gas (LPG).

Polyaniline/tantalum pentaoxide (PANI/Ta₂O₅) composites were synthesized by in situ chemical polymerization method using ammonium persulphate as an oxidizing agent. This is the novel polymerization process for the direct synthesis of emeraldine salt phase of the polymer. The composites were characterized by FTIR, XRD and SEM. Temperature dependence conductivity of the composites shows thermally activated behaviour. Sensitivity and selectivity of the composites are studied.

The PANI/ Ta₂O₅ composites of 20 wt% and 30 wt% are showing maximum change in resistance against time when compared to pure PANI and other polyaniline composites when exposed to LPG. The 20 wt % composites show maximum sensitivity of 83% to LPG. The selectivity studies reveals that LPG could be sensed better when compared to oxyacetylene and other test gases.

Selectivity studies have been carried out and the sensor proved to be better than metal oxides sensors.

The sensing material is of low cost.

To the best of the authors' knowledge, studies on Ta₂O₅‐based gas sensor have not been reported previously.

Low temperature co-fired ceramics (LTCC) technology-based micro-hotplates are of immense interest owing to their ruggedness, high temperature stability and reliability. The purpose of this paper is to study the role of thermal mass of LTCC-based micro-hotplates on the power consumption and temperature for gas-sensing applications.

The LTCC micro-hotplates with different thicknesses are designed and fabricated. The role of thermal mass on power consumption and temperature of these hotplates are simulated and experimentally studied. Also, a comparison study on the performance of LTCC and alumina-based hotplates of equivalent thickness is done. A thick film-sensing layer of tin oxide is coated on LTCC micro-hotplate and demonstrated for the sensing of commercial liquefied petroleum gas.

It is found from both simulation and experimental studies that the power consumption of LTCC hotplates was decreasing with the decrease in thermal mass to attain the same temperature. Also, the LTCC hotplates are less power-consuming than alumina-based one, owing to their superior thermal characteristics (low thermal conductivity, 3.3 W/ [m-K]).

This study will be beneficial for designing hotplates based on LTCC technology with low power consumption and better stability for gas-sensing applications.

The purpose of this paper is to fabricate an ethanol sensor which has bio-friendly and eco-friendly properties compared to the commercially available ethanol sensors.

This paper describes the construction of a highly sensitive ethanol sensor with low ppm level detection at room temperature by integrating three techniques. The first deals with the formation of organic/inorganic p-n heterojunction. Second, tuning of structural parameters such as length, diameter and density of Zinc Oxide (ZnO) nanostructure was achieved through introduction of the Fe dopant into a pure ZnO seed layer. Furthermore, ultra-violet (UV) light photoactivation approach was used for enhancing the sensing performance of the fabricated sensors. Four different sensors were fabricated by combing the above approaches. The structural, morphological, optical and material compositions were characterized using different characterization techniques. Sensing behavior of the fabricated sensors toward ethanol was experimented at room temperature with and without UV illumination combined with stability studies. It was observed that all the fabricated sensors showed enhanced sensing performance for 10 ppm of ethanol. In specific, FNZ (Fe-doped ZnO seeded Ni-doped Zn nanorods) sensor exhibited a higher response at 2.2 and 13.5 s for 5 ppm and 100 ppm of ethanol with UV light illumination at room temperature, respectively. The photoactivated FNZ sensor showed quick response and speedy recovery at 18 and 30 s, respectively, for 100 ppm ethanol.

In this study, the authors have experimentally analyzed the effect of Fe (in ZnO seed layer and ZnO NRs) and Ni (in ZnO NRs) dopants in the room temperature sensing performance (with and without UV light) of the fabricated ethanol sensors. Important sensing parameters like sensitivity, recovery and response time of all the fabricated sensors are reported.

The Fe doped ZnO seeded Ni doped Zn nanorods (FNZ sample) showed a higher response at 2.2 s and 13.5 s for very low 5 ppm and 10 ppm of ethanol at room temperature under UV light illumination when compared to the other fabricated sensors in this paper. Similarly, this sensor also had quick response (18 s) and speedy recovery (30 s) for 100 ppm ethanol.

This paper aims to study the various developments taking place in the field of gas sensors made from polyaniline (PANI) nanocomposites, which leads to the development of high-performance electrical and gas sensing materials operating at room temperature.

PANI/ferrite nanocomposites exhibit good electrical properties with lower dielectric losses. There are numerous reports on PANI and ferrite nanomaterial-based gas sensors which have good sensing response, feasible to operate at room temperature, requires less power and cost-effective.

This paper provides an overview of electrical and gas sensing properties of PANI/ferrite nanocomposites having improved selectivity, long-term stability and other sensing performance of sensors at room temperature.

The main purpose of this review paper is to focus on PANI/ferrite nanocomposite-based gas sensors operating at room temperature.

The purpose of this paper is to show how to obtain better response, selectivity and fast response and recovery from nanocrystalline ZnO‐based gas sensors as compared to conventional materials.

Nanocrystalline ZnO powders were prepared from the ultrasonic spray pyrolysis method. Aqueous solution of zinc acetate was atomized using ultrasonic atomizer. The aerosol generated was fed to the reaction furnace for pyrolysis. Nanocrystalline ZnO crystallites were collected using simple but novel trapping system. Thick film resistors of this powder were fabricated using screen printing technique.

As‐prepared powder was studied using X‐ray diffraction, transmission electron microscopy and scanning electron microscopy to know structure, size of nanocrystallites and microtopography, respectively. Absorption spectroscopy is used to determine the band gap energy. The gas‐sensing performance of this film was tested.

The sensor was found to be the most sensitive to NH₃. It gives better response, selectivity and fast response and recovery as compared to conventional materials‐based thick films.

Renewable energy alternatives and nanoscale materials have gained huge attention in recent years due to the problems associated with fossil fuels. The recyclable battery is one of the recent developments to address the energy requirement issues. In this work, the development of nanoscale materials is focused on using green synthesis methods to address the energy requirements of hybrid electric vehicles.

The current research focuses on developing metal oxide nanoscale materials (NANO-SMs). The Zno-Aloe vera NANO-SM is prepared using the green synthesis method. The developed nanoscale materials are characterized using analysis methods like FESEM, TEM, XRD and FTIR.

The average size of ZnO-Aloe vera mono-crystalline was recorded as 60–70 nm/Hexagonal shape. The nanoscale materials are used for the detection of LPG gases. The sensitivity observed was 48%. The response time and recovery time were recorded as 8–10 s and 230–250 s, respectively. The average size of SnO₂-green papaya leaves poly-crystalline was recorded as 10–20 nm/powder form.

Nanoscale materials are developed using green synthesis methods for hybrid vehicle applications. The nanoscale materials are used for the detection of harmful gases in hybrid vehicles.

Automatic robots can improve the efficiency of liquefied petroleum gas (LPG) tank inspection and maintenance, but it is difficult to achieve high-precision spatial positioning and navigation on tank surfaces. The purpose of this paper is to develop a spatial positioning robotic system for tank inspection. The robot can accurately identify and track weld paths. The positioning system can complete robot’s spatial positioning on tank surfaces.

A tank inspection robot with curvature-adaptive transmission mechanisms is designed in this study. A weld path recognition method based on deep learning is proposed to accurately identify and extract weld paths. Integrated multiple sensors, the positioning system is developed to improve the robot’s spatial positioning accuracy. Experiments are conducted on a cylindrical tank to test weld seam tracking accuracy and spatial positioning performance of the robotic system. The practicality of the robotic system is then verified in field tests.

The robot can accurately identify and track weld seams with a maximum drift angle of 4° and a maximum offset distance of ±30 mm. The positioning system has excellent positioning accuracy and stability. The maximum angle and height errors are 3° and 0.08 m, respectively.

The positioning system can improve the autonomous performance of inspection robots and solve the problems of weld path recognition and spatial positioning. Application of the robotic system can promote the automatic inspection and maintenance of LPG tanks.

Carbon dioxide (CO₂) has attracted special scientific interest over the last years mainly because of its relation to climate change and indoor air quality. Except for this, CO₂ can be used as an indicator of food freshness, patients’ clinical state and fire detection. Therefore, the accurate monitoring and controlling of CO₂ levels are imperative. The development of highly sensitive, selective and reliable sensors that can efficiently distinguish CO₂ in various conditions of temperature, humidity and other gases’ interference is the subject of intensive research with chemi-resistive zinc oxide (ZnO)-based sensors holding a privileged position. Several ZnO nanostructures have been used in sensing applications because of their versatile features. However, the deficient selectivity and long-term stability remain major concerns, especially when operating at room temperature. This study aims to encompass an extensive study of CO₂ chemi-resistive sensors based on ZnO, introducing the most significant advances of recent years and the best strategies for enhancing ZnO sensing properties.

An overview of the different ZnO nanostructures used for CO₂ sensing and their synthesis methods is presented, focusing on the parameters that highly affect the sensing mechanism and, thus, the performance of CO₂ sensors.

The selectivity and sensitivity of ZnO sensors can be enhanced by adjusting various parameters during their synthesis and by doping or treating ZnO with suitable materials.

This paper summarises the advances in the rapidly evolving field of CO₂ sensing by ZnO sensors and provides research directions for optimised sensors in the future.

Reviews the Transducers 2001/EUROSENSORS XV conferences that were held in Munich, 10‐14 June 2001. Microengineering figured prominently in the programme, almost half the sessions covering aspects of this subject, including power generation, packaging and wafer bonding, physical effects, machining and etching (also for high aspect ratio), micro‐thrusters, ‐jets, ‐pumps, ‐valves, ‐fluidics, ‐probes, optical 3D and RF MEMS, resonators, polymer based microsystems and commercialisation. Explicit sensor sessions included materials for gas sensing, chemical and gas sensors, biomedical systems, electrochemical sensors, inertial sensors, magnetic sensors, image, flow and thermal sensors. There were two sessions on actuators. Nano‐devices (physical in character) were covered in one session, though nanotechnology as such did not figure in the proceedings.