• Title/Summary/Keyword: gas sensors

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Characterization and Photocatalytic effect of ZnO nanoparticles synthesized by spray-pyrolysis method

  • Lee, Sang-Duck;Nam, Sang-Hun;Kim, Myoung-Hwa;Lee, Kang-Suk;Kim, Young-Dok;Boo, Jin-Hyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.101-101
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    • 2010
  • ZnO shows a direct band gap of 3.37eV, large exciton binding energy (~60 meV), high oxidation ability, high sensitivity to many gases, and low cost, and it has been used in various applications such as transparent electrodes, light emitting diodes (LEDs), gas sensors and photocatalysts. Among these applications ZnO as photocatalyst has considerably attracted attention over the past few years because of its high activities in removing organic contaminants generated from industrial activities. In this research, ZnO nanoparticles were synthesized by spray-pyrolysis method using the zinc acetate dihydrate as starting material at synthesis temperature of $900^{\circ}C$ with concentration varied from 0.01 to 1.0M. The physical and chemical properties of the synthesized ZnO nanoparticles were examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transformation Infrared (FT-IR), and UV-vis spectroscopy. The Miller indices of XRD patterns indicate that the synthesized ZnO nanoparticles showed a hexagonal wurtzite structure. With increased precursor concentration, a primary, secondary particle sizes of ZnO nanoparticles increased by 0.8 to $1.5{\mu}m$ and 15 to 35nm, and their crystallinity was improved. Methyleneblue (MB) solution ($1{\mu}M$) as a test comtaminant was prepared for evaluating the photocatalytic activities of ZnO nanoparticles synthesized in different precursor concentration. The results show that the photocatalytic efficiency of ZnO nanoparticles was gradually enhanced by increased precursor concentration.

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Context-Aware System for Status Monitoring of Industrial Automation Equipment (산업 자동화 장비의 상태감시를 위한 상황인지 시스템)

  • Kim, Kyung-Nam;Jeon, Min-Ho;Kang, Chul-Gyu;Oh, Chang-Heon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.552-555
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    • 2010
  • In this paper, we propose a context-aware system using wireless multi sensor module to monitor the state for industrial factory environment. Wireless multi sensor module combines sensing values which are collected from each acceleration, pressure, temperature and gas sensors. Moreover, it delivers this data to server after being encoded by RS code. Thereafter, RS decoder decodes the values that are received from wireless multi sensor module and fixes errors which occur in wireless communication. Based on decoded data, context-aware algorithm sets critical range and compares it to the sensing values, if the sensing values are out of the range, an event occurs by the algorithm. At the same time, if there is another sensing value which is out of the range for standby time T seconds, the algorithm orders 3 steps-alarm to occur depending on each situation. Through this system, it becomes eventually possible to monitor machines' condition effectively. From the simulation, we confirm that this system is efficient to status monitoring of industrial automation equipment.

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A Study for Performance Estimation Standard and Standardization of u-IT Convergence Equipment (u-IT Convergence 기기의 성능평가기준과 표준화 연구)

  • Chun, Woo-Sung;Park, Dea-Woo;Lee, Sang-Ick;Kim, Eung-Sik;Kim, Hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.457-460
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    • 2009
  • u-IT Convergence appliances study and are developed in communication by development of u-IT technology, broadcasting, portal, contents, equipment and all fields of business such as solution. This treatise presents valuation basis of, economic performance, administration sex etc. by temperature, pressure, own, storehouse, gas, justice for humidity sensors and valuation basis that define u-IT Convergence, and sense information u-IT Convergence devices and terminal. Also, studied standardization standard of u-IT Convergence network appliance that follow in valuation basis for u-IT Convergence devices. Is going to contribute establish value as estimation product that equip stability and authoritativeness through correct certification assessment for technological development and appliances on Ubiquitous information-oriented society through this research and accomplish standardization.

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Design and performance study of fabry-perot filter based on DBR for a non-dispersive infrared carbon dioxide sensor (비분산적외선 CO2 센서를 위한 DBR기반의 패브리 페로-필터 설계 및 성능 연구)

  • Do, Nam Gon;Lee, Junyeop;Jung, Dong Geon;Kong, Seong Ho;Jung, Daewoong
    • Journal of Sensor Science and Technology
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    • v.30 no.4
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    • pp.250-254
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    • 2021
  • A highly sensitive and selective non-dispersive infrared (NDIR) carbon dioxide gas sensor requires achieving high transmittance and narrow full width at half maximum (FWHM), which depends on the interface of the optical filter for precise measurement of carbon dioxide concentration. This paper presents the design, simulation, and fabrication of a Fabry-Perot filter based on a distributed Bragg reflector (DBR) for a low-cost NDIR carbon dioxide sensor. The Fabry-Perot filter consists of upper and lower DBR pairs, which comprise multilayered stacks of alternating high- and low-index thin films, and a cavity layer for the resonance of incident light. As the number of DBR pairs inside the reflector increases, the FWHM of the transmitted light becomes narrower, but the transmittance of light decreases substantially. Therefore, it is essential to analyze the relationship between the FWHM and transmittance according to the number of DBR pairs. The DBR is made of silicon and silicon dioxide by RF magnetron sputtering on a glass wafer. After the optimal conditions based on simulation results were realized, the DBR exhibited a light transmittance of 38.5% at 4.26 ㎛ and an FWHM of 158 nm. The improved results substantiate the advantages of the low-cost and minimized process compared to expensive commercial filters.

Fabrication of surface-enhanced Raman scattering substrate using black silicon layer manufactured through reactive ion etching (RIE 공정으로 제조된 블랙 실리콘(Black Silicon) 층을 사용한 표면 증강 라만 산란 기판 제작)

  • Kim, Hyeong Ju;Kim, Bonghwan;Lee, Dongin;Lee, Bong-Hee;Cho, Chanseob
    • Journal of Sensor Science and Technology
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    • v.30 no.4
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    • pp.267-272
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    • 2021
  • In this study, Ag was deposited to investigate its applicability as a surface-enhanced Raman scattering substrate after forming a grass-type black silicon structure through maskless reactive ion etching. Grass-structured black silicon with heights of 2 - 7 ㎛ was formed at radio-frequency (RF) power of 150 - 170 W. The process pressure was 250 mTorr, the O2/SF6 gas ratio was 15/37.5, and the processing time was 10 - 20 min. When the processing time was increased by more than 20 min, the self-masking of SixOyFz did not occur, and the black silicon structure was therefore not formed. Raman response characteristics were measured based on the Ag thickness deposited on a black silicon substrate. As the Ag thickness increased, the characteristic peak intensity increased. When the Ag thickness deposited on the black silicon substrate increased from 40 to 80 nm, the Raman response intensity at a Raman wavelength of 1507 / cm increased from 8.2 × 103 to 25 × 103 cps. When the Ag thickness was 150 nm, the increase declined to 30 × 103 cps and showed a saturation tendency. When the RF power increased from 150 to 170 W, the response intensity at a 1507/cm Raman wavelength slightly increased from 30 × 103 to 33 × 103 cps. However, when the RF power was 200 W, the Raman response intensity decreased significantly to 6.2 × 103 cps.

Smart Safety Management System of Industrial Site using Zigbee Communication (Zigbee 통신을 활용한 산업현장의 스마트 안전관리 시스템)

  • Min, Ji-Hyeon;Jeong, Ga-Yeong;Ha, Hyun-Dong;Hwang, In-Tae;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.05a
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    • pp.546-549
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    • 2022
  • In recent years, to prevent the increase in accidents at industrial sites, various innovative technologies from the 4th industrial era have been incorporated into the construction administration to promote the advancement of safety management. As a result, smart safety management systems using intelligent monitoring that prevent and manage risks in industrial sites in real time are attracting attention. Smart safety management systems provide users with real-time, remote monitoring of factors such as noise, gas concentration fine dust concentration, building material quality, building tilt, and RFID-based worker access through sensors located everywhere. This paper presents a method for collecting and monitoring various data for smart safety management systems via Zigbee communication using Raspberry Pi.

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Fabrication and Evaluation of a Total Organic Carbon Analyzer Using Photocatalysis

  • Do Yeon Lee;Jeong Hee Shin;Jong-Hoo Paik
    • Journal of Sensor Science and Technology
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    • v.32 no.3
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    • pp.140-146
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    • 2023
  • Water quality is crucial for human health and the environment. Accurate measurement of the quantity of organic carbon in water is essential for water quality evaluation, identification of water pollution sources, and appropriate implementation of water treatment measures. Total organic carbon (TOC) analysis is an important tool for this purpose. Although other methods, such as chemical oxygen demand (COD) and biochemical oxygen demand (BOD) are also used to measure organic carbon in water, they have limitations that make TOC analysis a more favorable option in certain situations. For example, COD requires the use of toxic chemicals, and BOD is time-consuming and can produce inconsistent and unreliable results. In contrast, TOC analysis is rapid and reliable, providing accurate measurements of organic carbon content in water. However, common methods for TOC analysis can be complex and energy-intensive because of the use of high-temperature heaters for liquid-to-gas phase transitions and the use of acid, which present safety risks. This study focuses on a TOC analysis method using TiO2 photocatalysis, which has several advantages over conventional TOC analysis methods, including its low cost and easy maintenance. For TiO2, rutile and anatase powders are mixed with an inorganic binder and spray-coated onto a glass fiber substrate. The TiO2 powder and inorganic binder solutions are adjusted to optimize the photocatalytic reaction performance. The TiO2 photocatalysis method is a simple and low-power approach to TOC analysis, making it a promising alternative to commonly used TOC analysis methods. This study aims to contribute to the development of more efficient and cost-effective approaches for water quality analysis and management by exploring the effectiveness and reliability of the developed equipment.

Home IoT Sensor System for Prevent Safety Accidents in Single-person Household (1인 가구 안전사고 예방을 위한 Home IoT 센서 시스템)

  • Baek, Chang-Dae;Kim, Han-Ho;Cha, Hyun-Seok;Son, Hyeong-Min;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.05a
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    • pp.397-399
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    • 2021
  • The increase in single-person households and the development of Home IoT technology make it important to improve the convenience of the residential environment. In addition, the increase in indoor activities caused by COVID-19 calls for the development of products to make life more convenient for single-person households. This trend of increased indoor activity has made it easier to interact with the current residential environment than before, and as a result, the need to develop technology for Home IoT is emerging. Therefore, the Home IoT system will be developed to monitor the information needed to maintain an ideal indoor environment such as temperature, humidity, and fine dust. The system will also interact with users, and propose a system that improves safety in indoor activities by equipping the home with IoT sensors for preventing safety accidents such as gas leakage and fire.

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Development of unmanned hovercraft system for environmental monitoring (환경 모니터링을 위한 무인 호버크래프트 시스템 개발)

  • Sung-goo Yoo;Jin-Taek Lim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.2
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    • pp.525-530
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    • 2024
  • The need for an environmental monitoring system that obtains and provides environmental information in real time is increasing. In particular, in the case of water quality management in public waters, regular management must be conducted through manual and automatic measurement by law, and air pollution also requires regular measurement and management to reduce fine dust and exhaust gas in connection with the realization of carbon neutrality. In this study, we implemented a system that can measure and monitor water pollution and air pollution information in real time. A hovercraft capable of moving on land and water simultaneously was used as a measurement tool. Water quality measurement and air pollution measurement sensors were installed on the hovercraft body, and a communication module was installed to transmit the information to the monitoring system in real time. The structure of a hovercraft for environmental measurement was designed, and a LoRa module capable of low-power, long-distance communication was applied as a real-time information transmission communication module. The operational performance of the proposed system was confirmed through actual hardware implementation.

A Study on Energy Saving and Safety Improvement through IoT Sensor Monitoring in Smart Factory (스마트공장의 IoT 센서 모니터링을 통한 에너지절감 및 안전성 향상 연구)

  • Woohyoung Choi;Incheol Kang;Changsoo Kim
    • Journal of the Society of Disaster Information
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    • v.20 no.1
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    • pp.117-127
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    • 2024
  • Purpose: The purpose is to conduct basic research to save energy and improve the safety of manufacturing plant infrastructure by comprehensively monitoring energy management, temperature, humidity, dust and gas, air quality, and machine operation status in small and medium-sized manufacturing plants. Method: To this end, energy-related data and environmental information were collected in real time through digital power meters and IoT sensors, and research was conducted to disseminate and respond to situations for energy saving through monitoring and analysis based on the collected information. Result: We presented an application plan that takes into account energy management, cost reduction, and safety improvement, which are key indicators of ESG management activities. Conclusion: This study utilized various sensor devices and related devices in a smart factory as a practical case study in a company. Based on the information collected through research, a basic system for energy saving and safety improvement was presented.