• Journal of Sensor Science and Technology
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• v.24 no.2
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• pp.96-100
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• 2015

In the present study, we developed a real-time radiation-monitoring sensor for an underwater radiation-monitoring system and evaluated its effectiveness using reference radiation sources. The monitoring sensor was designed and miniaturized using a silicon photomultiplier (SiPM) and a cerium-doped-gadolinium-aluminum-gallium-garnet (Ce:GAGG) scintillator, and an underwater wireless monitoring system was implemented by employing a remote Bluetooth communication module. An acrylic water tank and reference radiation sources ($^{137}Cs$, $^{90}Sr$) were used to evaluate the effectiveness of the monitoring sensor. The underwater monitoring sensor's detection response and efficiency for gamma rays and beta particles as well as the linearity of the response according to the gammaray intensity were verified through an evaluation. This evaluation is expected to contribute to the development of base technology for an underwater radiation-monitoring system.

• Journal of Digital Contents Society
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• v.16 no.1
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• pp.97-104
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• 2015

The conventional 1 Hall sensor-type water gauge has some defects that it can not detect counterflow and low-speed flow of water, and it also generates power consumption during even sleep mode. In this paper, a low-power consumption wireless digital remote water gauge with a counterflow detection capability is proposed. The proposed water gauge detects the direction and amount of water flow by using the three Hall sensors placed at $120^{\circ}$ intervals with 8-year national standard life durability. The water gauge with three Hall sensors works without error regardless of water speed does not generate power dissipation during sleep mode by presented reading algorithm for bew water gauge. The proposed water gauge is designed to send its ID, current time and counting value to repeater or central control center with specified frequency by RF Module.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.63-69
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• 2020

The rapid development in modern industrialization pollutant the water and atmospheric air across the globe that have a major impact on the human and livings health. In worldwide, every country government increasing the importance to improve the outdoor air pollution monitoring and control to provide quality of life and prevent the citizens and livings life from hazard disease. We proposed the environmental dust level detection method for outdoor facilities using sensor fusion technology to measure precise micro-dust level and monitor in realtime. In this proposed approach use the camera sensor and commercial dust level sensor data to predict the micro-dust level with data fusion method. The camera sensor based dust level detection uses the optical flow based machine learning method to detect the dust level and then fused with commercial dust level sensor data to predict the precise micro-dust level of the outdoor facilities and send the dust level informations to the outdoor air pollution monitoring system. The proposed method implemented on raspberry pi based open-source hardware with Internet-of-Things (IoT) framework and evaluated the performance of the system in realtime. The experimental results confirm that the proposed micro-dust level detection is precise and reliable in sensing the air dust and pollution, which helps to indicate the change in the air pollution more precisely than the commercial sensor based method in some extent.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.6-6
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• 2018

• Journal of Electrochemical Science and Technology
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• v.1 no.2
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• pp.121-126
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• 2010

An amperometric ascorbic acid selective sensor utilizing the transfer reaction of proton liberated from the dissociation of ascorbic acid in aqueous solution across an elliptic micro-hole water/organic gel interface is demonstrated. This redox inactive sensing platform offers an alternative way for the detection of ascorbic acid to avoid a fouling effect which is one of the major concerns in redox based sensing systems. The detection principle is simply measuring the current change with respect to the assisted transfer of protons by a proton selective ionophore (e.g., ETH 1778) across the micro-hole interface between the water and the polyvinylchloride-2-nitrophenyloctylether gel phase. The assisted transfer reaction of protons generated from ascorbic acid across the polarized micro-hole interface was first characterized using cyclic voltammetry. An improved sensitivity for the quantitative analysis of ascorbic acid was achieved using differential pulse stripping voltammetry with a linear response ranging from 1 to $100\;{\mu}M$ concentrations of ascorbic acid. As a demonstration, the developed sensor was applied for analyzing the content of vitamin-C in different types of commercial pharmaceutical tablets and syrups, and a satisfactory recovery from these samples were also obtained.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.253-261
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• 2016

A variety of methods for detecting the location of an underground water pipeline are being used across the world; the current main methods used in South Korea, however, have the problems of low precision and efficiency and the limitations in actual application. On this, this study developed locator capable of detecting the location of a water pipe by the use of an IMU sensor, and technology for using the extended karman filter to correct error in location detection and to plot the location on the coordinate system. This study carried out a tract test and a road test as basic experiments to measure the performance of the developed technology and equipment. As a result of the straight line, circular and ellipse track tests, the 1750 IMU sensor showed the average error of 0.08-0.11%; and thus it was found that the developed locator can detect a location precisely. As a result of the 859.6-m road test, it was found that the error was 0.31 m in case the moving rate of the sensor was 0.3-0.6 m/s; and thus it was judged that the equipment developed by this study can be applied to long-distance water pipes of over 1 km sufficiently. It is planned to evaluate its field applicability in the future through an actual pipe network pilot test, and it is expected that locator capable of detecting the location of a water pipe more precisely will be developed through research for the enhancement of accuracy in the algorithm of location detection.

• Membrane Journal
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• v.31 no.4
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• pp.241-252
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• 2021

Rapid industrialization with growing population leads to environmental water pollution. Demand in generation of clean water from waste water is ever increasing by scarcity of rain water due to change in weather pattern. Colorimetric detection of heavy metal present in clean water is very simple and effective technique. In this review membrane based colorimetric detection of mercury (II) ions are discussed in details. Membrane such as cellulose, polycaprolactone, chitosan, polysulfone etc., are used as support for metal ion detection. Nanofiber based materials have wide range of applications in energy, environment and biomedical research. Membranes made up of nanofiber consist up plenty of functional groups available in the polymer along with large surface area and high porosity. As a result, it is easy for surface modification and grafting of ligand on the fiber surface enhanced nanoparticles attachment.

• Corrosion Science and Technology
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• v.10 no.4
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• pp.151-155
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• 2011

The iron oxide particles could be resulted from the corrosion of the circulating water system of a power plant. Because it may be one of the trouble materials which affect the power generation efficiency due to the deposition on steam generator tube and turbine blade, the continuous observation of its concentration is very important. The laser induced break-down detection (LIBD) technology was applied to monitor continuously the concentration of corrosion products with the detection limit of ppb level. The measurement system consists of a Nd:YAG pulsed laser, a polarizing beam splitter, a flow-type sample cell, an acoustic emission sensor, a high speed data acquisition board, a personal computer, etc.. The performance test results confirmed that this technology can be effective to monitor the corrosion product concentration of the circulating water system of a power plant.

• Smart Structures and Systems
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• v.20 no.1
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• pp.75-83
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• 2017

Effectively monitoring the concrete cracks is an urgent question to be solved in the structural safety monitoring while cracks in hydraulic concrete structures are ubiquitous. In this paper, two experiments are designed based on the measuring principle of Pulse-Pre pump Brillouin Optical Time Domain Analysis (PPP-BOTDA) utilizing Brillouin optical fiber sensor to monitor concrete cracks. More specifically, "V" shaped optical fiber sensor is proposed to determine the position of the initial crack and the experiment illustrates that the concrete crack position can be located by the mutation position of optical fiber strain. Further, Brillouin distributed optical fiber sensor and preinstall cracks are set at different angles and loads until the optical fiber is fractured. Through the monitoring data, it can be concluded that the variation law of optical fiber strain can basically reflect the propagation trend of the cracks in hydraulic concrete structures.

• BioChip Journal
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• v.12 no.4
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• pp.326-331
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• 2018

Contamination by pesticides is an everincreasing problem associated with fields of environmental management and healthcare. Accordingly, appropriate treatments are in demand. Pesticide detection methods have been researched extensively, aimed at making the detection convenient, fast, cost-effective, and easy to use. Among the various detecting strategies, paper-based assay is potent for real-time pesticide sensing due to its unique advantages including disposability, light weight, and low cost. In this study, a paper-based sensor for chlorpyrifos, an organophosphate pesticide, has been developed by layering three sheets of patterned plates. In colorimetric quantification of pesticides, the blue color produced by the interaction between acetylcholinesterase and indoxyl acetate is inhibited by the pesticide molecules present in the sample solutions. With the optimized paper-based sensor, the pesticide is sensitively detected (limit of detection =8.60 ppm) within 5min. Furthermore, the shelf life of the device is enhanced to 14 days after from the fabrication, by treating trehalose solution onto the deposited reagents. We expect the paper-based device to be utilized as a first-screening analytic device for water quality monitoring and food analysis.