DIP coated thick films of ZNO and its ethanol sensing properties
10 Apr 2012-pp 1-5
TL;DR: In this article, the structural properties of ZnO gas-sensing films that were deposited on Aal 2 O 3 substrate were characterized using X-ray diffraction, scanning electron microscopy (SEM), and atomic microscopy.
Abstract: Recently, gas sensors based on the semiconducting metal-oxides such as ZnO have been found to be very useful for detecting ethanol vapor. Pure ZnO films have been investigated as sensors for ethanol. One of the requirements of the gas sensors is low power consumption, because the sensors need to work reliably and continuously. A low resistance material has lower driving power when it is used as a sensor. A significant resistance change can be obtained in the sensor, which results in a higher sensitivity. Several techniques have been used to prepare ZnO films, such as RF magnetron sputtering, chemical vapor deposition, sol-gel, and spray pyrolysis. In this study, ZnO film sensors deposited by dip coating method using copper as the electrode are reported. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Atomic microscopy were used to characterize the structural properties of ZnO gas-sensing films that were deposited on Aal 2 O 3 substrate. Zinc oxide nano particles have been paid more attention for their unique properties. Zinc oxide has been studied in many areas such as catalysts, optoelectronics and photochemistry in order to utilize its semiconductor characteristics. Zinc oxide can be used for gas sensing material, solar cell material, display screen, photocell electrode, and UV-light emitting diodes. Gas sensors pay more attention in these days.
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TL;DR: In this paper, an array of four thick film metal oxide semiconducting (MOS) sensors was fabricated, based on zinc oxide inks, using a commercially available screen printer, a 3 × 3 mm alumina substrate containing interdigitated electrodes and a platinum heater track.
Abstract: The illicit manufacture of drugs in the 21st century presents a danger to first responders, bystanders and the environment, making its detection important. Electronic noses based on metal oxide semiconducting (MOS) sensors present a potential technology to create devices for such purposes. An array of four thick film MOS gas sensors was fabricated, based on zinc oxide inks. Production took place using a commercially available screen printer, a 3 × 3 mm alumina substrate containing interdigitated electrodes and a platinum heater track. ZnO inks were modified using zeolite β, zeolite Y and mordenite admixtures. The sensors were exposed to four gases commonly found in the clandestine laboratory environment; these were nitrogen dioxide, ethanol, acetone and ammonia. Zeolite modification was found to increase the sensitivity of the sensor, compared to unmodified ZnO sensors, all of which showed strong responses to low ppm concentrations of acetone, ammonia and ethanol and to ppb concentrations of nitrogen dioxide. Machine learning techniques were incorporated to test the selectivity of the sensors. A high level of accuracy was achieved in determining the class of gas observed.
42 citations
TL;DR: In this article, a dip coated Mg-doped ZnO thin films were performed in temperature range of 150-400°C at different acetic acid vapor concentrations.
Abstract: Acetic acid vapor thin film gas sensor was developed by synthesizing Mg-doped ZnO nanoparticles using a low cost and facile sol–gel route and were characterized using field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and photoluminescence analysis. Morphological characterizations showed the formation of well-defined and highly crystalline ZnO nanoparticles on Si(100)/SiO2 substrate. Gas sensing characterization of dip coated Mg-doped ZnO thin films were performed in temperature range of 150–400 °C at different acetic acid vapor concentrations. At 300 °C, the sensitivity for pure ZnO, Zn0.98Mg0.02O and Zn0.94Mg0.06O samples at concentration of 200 ppm of acetic acid were 124, 78 and 67%, respectively. The highest sensitivity for Zn0.96Mg0.04O sample was 136% at the same vapor concentration and temperature. It showed a fast response time and recovery time (145 and 110 s, respectively).
35 citations
Journal Article•
TL;DR: In this paper, the authors carried out a quantitative approach in a questionnaire distribution across a given number of data collection respondents and has shown that financial crime and its success contribute directly to the financial performance of banks.
Abstract: A business associate in an organization may represent fraud as a series of disappointing business practices to help individuals. Therefore, it is an act to mask the other by covering real facts and presenting fake information and statements. Online manipulation is the biggest field that has been opened up. Online fraud has been more widespread as technical innovation coupled with internet penetration and resulting improvements have arisen. In terms of internet sales and valuation, e-commerce development is expressed. During the eight-year duration from 2008 to 2014, the overall volume of the trade rose from $268 billion to $ 1.5 trillion. The study carried out the quantitative approach in a questionnaire distribution across a given number of data collection respondents and has shown that financial crime and its success contribute directly. The findings indicated that the greater the fraud, the poorer the bank's performance, the more the online fraud appears to impact the financial performance of banks adversely.
Journal Article•
TL;DR: In this article, the authors examined the influence of organizational participation and encouragement in banks' work results and found a substantial level below 5% which indicates that the study variables are closely linked.
Abstract: All companies aspire to compete against their rivals, retain a strategic edge in the industry, gain the largest market share and be inspired to bring out their utmost to achieve their desired goals at work. Few businesses think they will gain growth and wealth by important assets for their workers. Unfortunately, most companies appear to exploit the dismissal of their workers and talented applicants. Recognizing the critical position of workers appears to have a major effect on operational performance as most companies aim to maintain staff by empowering and enhancing the working standards of their employees. Therefore, it is necessary to enforce certain techniques to retain high quality and ensure performance and efficiency. The research examined the influence of organizational participation and encouragement in banks' work results. A study of 100 participants was tested, and findings were evaluated using the chi-square analysis. The findings revealed a substantial level below 5% which indicates that the study variables are closely linked. The quantitative approach and qualitative framework have been used to analyze their perception of the effects of job retention on the success of workers. Approach a single case study for various branches by implementing a similar case study and addressing a larger number of samples. This allows the researcher to remove the survey challenge and hold evidence from a larger community with a deeper comprehension of the idea of encouragement and how it influences workers' output.
DOI•
07 Oct 2021TL;DR: In this article, a smart navigation system that can be mounted on a cap called "Smart Cap" is presented, which can help the deaf-blind community at large in navigation and movement from one place to another without human assistance.
Abstract: The bedrock and essence of any innovation are to make human life easier, and for people who are physically challenged, this world becomes a harsh place to live. Especially while considering those people who are both deaf and blind, this paper attempts to develop a smart navigation system that can be mounted on a cap called "Smart Cap", and this device will help the deaf-blind community at large in navigation and movement from one place to another without human assistance. This Smart Cap perceives the surrounding environment, also known as visible workspace, through a camera and identifies different objects/obstacles while simultaneously guiding proper navigation to the user through audio as well as sensory perception through smart vibrating bands (for deaf people), also the path planning and GPS plays an important role in defining a safe and secure route for the user. Raspberry Pi has acted as the backbone of this cap, analogue sensor such as Ultrasonic Sensor is used for obstacle detection, software technologies such as COCO database for storing images, YOLO for object detection, coding through Python using Libraries such as NUMPY& Open CV and last but not least GPS for real-time mapping and location of the user, all this cluster of technologies together makes this Smart Cap dependable.
References
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TL;DR: In this paper, the authors made measurements on galvanic cells involving solid electrolytes to obtain the standard molar free energy of formation of Ag-Te at elevated temperatures, and several phases of the system Ag−Te.
Abstract: Electromotive force measurements on galvanic cells involving solid electrolytes have been made in order to obtain the standard molar free energy of formation of , , , , , , and several phases of the system Ag‐Te at elevated temperatures.
529 citations
TL;DR: In this paper, the effects of UV light illumination on the performance of SnO 2 thin film gas sensors toward an oxidising gas of increasing interest due to environmental monitoring, like NO 2 are reported.
Abstract: A novel approach to operate semiconductor gas sensor at low temperatures avoiding the poisoning of the surface is described. The effects of UV light illumination on the performance of SnO 2 thin film gas sensors toward an oxidising gas of increasing interest due to environmental monitoring, like NO 2 are reported. The thin films gas sensors were prepared according to the rheotaxial growth and thermal oxidation (RGTO) technique with dc sputtering in Ar atmospheres. Results has shown that there is an enhancement of the performances with UV exposure: a decrease in the response and recovery time and no poisoning effect. This is promising for the development of a sensor for NO 2 working at room temperature.
248 citations
TL;DR: In this article, the relationship between gas sensing properties and film thickness was discussed on the basis of diffusivity and reactivity of the gases inside the oxide films, and it was found that the sensor response to H2 similarly decreased with an increase in film thickness.
Abstract: Thin film SnO2 sensors with various thicknesses were spin-coated from a hydrothermally treated SnO2 sol suspension. The FE-SEM observation revealed that the films prepared from the 1.8 wt.% SnO2 containing sol suspension had good uniformity packed with nano-crystalline SnO2 even after calcination at 600°C when its thickness was up to about 300 nm, though many cracks were observed for thicker films. The gas sensing characteristics to H2 and CO were evaluated as a function of film thickness (80–300 nm) in dry air. The electrical resistance of thin films decreased monotonically with increasing film thickness. It was found that the sensor response to H2 similarly decreased with an increase in film thickness, while the CO response was found to be almost independent of the film thickness. The relationship between gas sensing properties and film thickness was discussed on the basis of diffusivity and reactivity of the gases inside the oxide films.
196 citations
TL;DR: In this article, the electrical response of SnO 2 thin film as a function of thickness was studied in order to determine the optimum of this parameter to detect carbon monoxide, finding out that thickness around 200nm showed the highest response Structural characteristics of tin oxide such as grain size and net distortions were also analysed On the other hand, a study of two catalytic metals (Pt and Pd) and their influence on sensing parameters was also carried out Tests under controlled atmospheres and XPS analyses showed that the doping technique that provided a suitable quantity and doping profile of metal for CO
Abstract: In this work electrical response of SnO 2 thin film as a function of thickness was studied in order to determine the optimum of this parameter to detect carbon monoxide, finding out that thickness around 200 nm showed the highest response Structural characteristics of tin oxide such as grain size and net distortions were also analysed On the other hand, a study of two catalytic metals (Pt and Pd) and their influence on sensing parameters was also carried out Tests under controlled atmospheres and XPS analyses showed that the doping technique that provided a suitable quantity and doping profile of metal for CO detection was the so called “buried layer” when Pt was used as catalyst Therefore, a deeper study of the latter film was performed, in order to establish some of its electrical characteristics, moisture influence on response and long-term stability
86 citations
TL;DR: In this article, the structural and gas sensing properties of synthesized nanomaterials were studied by X-ray diffraction measurement (XRD) and transmission electron microscope (TEM) and the results revealed that the particle size is in the range of 30-35nm for Mn-Zn ferrite with good crystallinity.
74 citations