• Title/Summary/Keyword: environmental instrumentation

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Measurement Uncertainty of Nitrous Oxide Concentrations from a Upland Soil Measured by an Automated Open Closed Chamber Method (밭토양에서 폐쇄형 자동 챔버법으로 측정한 아산화질소 농도에 대한 측정 불확도)

  • Ju, Ok Jung;Kang, Namgoo;Lim, Gap June
    • Korean Journal of Environmental Agriculture
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    • v.39 no.3
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    • pp.237-245
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    • 2020
  • BACKGROUND: The closed chamber method is the most commonly used for measuring greenhouse gas emissions from upland fields. This method has the advantages of being simple, easily available and economical. However, uncertainty estimation is essential for accurate assessment of greenhouse gas emissions and verification of emission reductions. The nitrous oxide emissions from upland field is very important for the nitrogen budget in the agriculture sectors. Although assessment of uncertainty components affecting nitrous oxide emission from upland field is necessary to take account of dispersion characteristics, research on these uncertainty components is very rare to date. This study aims at elucidation of influencing factors on measurement uncertainty of nitrous oxide concentrations measured by an automated open closed chamber method from upland field. METHODS AND RESULTS: The nitrous oxide sampling system is located in the upland field in Gyeonggi-do Agricultural Research and Extension Services (37°13'22"N, 127°02'22"E). The primary measurement uncertainty components influencing nitrous oxide concentrations (influencing factors) investigated in this research are repeatability, reproducibility and calibration in the aspects of nitrous oxide sampling and analytical instrumentation. The magnitudes of the relative standard uncertainty of each influencing factor are quantified and compared. CONCLUSION: Results of this study show what influencing factors are more important in determination of nitrous oxide concentrations measured using the automated open closed chambers located in the monitoring site. Quantifying the measurement uncertainty of the nitrous oxide concentrations in this study would contribute to improving measurement quality of nitrous oxide fluxes.

Efficiency to Discovery Transgenic Loci in GM Rice Using Next Generation Sequencing Whole Genome Re-sequencing

  • Park, Doori;Kim, Dongin;Jang, Green;Lim, Jongsung;Shin, Yun-Ji;Kim, Jina;Seo, Mi-Seong;Park, Su-Hyun;Kim, Ju-Kon;Kwon, Tae-Ho;Choi, Ik-Young
    • Genomics & Informatics
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    • v.13 no.3
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    • pp.81-85
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    • 2015
  • Molecular characterization technology in genetically modified organisms, in addition to how transgenic biotechnologies are developed now require full transparency to assess the risk to living modified and non-modified organisms. Next generation sequencing (NGS) methodology is suggested as an effective means in genome characterization and detection of transgenic insertion locations. In the present study, we applied NGS to insert transgenic loci, specifically the epidermal growth factor (EGF) in genetically modified rice cells. A total of 29.3 Gb (${\sim}72{\times}coverage$) was sequenced with a $2{\times}150bp$ paired end method by Illumina HiSeq2500, which was consecutively mapped to the rice genome and T-vector sequence. The compatible pairs of reads were successfully mapped to 10 loci on the rice chromosome and vector sequences were validated to the insertion location by polymerase chain reaction (PCR) amplification. The EGF transgenic site was confirmed only on chromosome 4 by PCR. Results of this study demonstrated the success of NGS data to characterize the rice genome. Bioinformatics analyses must be developed in association with NGS data to identify highly accurate transgenic sites.

Instrumentation on structural health monitoring systems to real world structures

  • Teng, Jun;Lu, Wei;Wen, Runfa;Zhang, Ting
    • Smart Structures and Systems
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    • v.15 no.1
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    • pp.151-167
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    • 2015
  • Instrumentation on structural health monitoring system imposes critical issues for applying the structural monitoring system to real world structures, for which not only on the configuration and geometry, but also aesthetics on the system to be monitored should be considered. To illustrate this point, two real world structural health monitoring systems, the structural health monitoring system of Shenzhen Vanke Center and the structural health monitoring system of Shenzhen Bay Stadium in China, are presented in the paper. The instrumentation on structural health monitoring systems of real world structures is addressed by providing the description of the structure, the purpose of the structural health monitoring system implementation, as well as details of the system integration including the installations on the sensors and acquisition equipment and so on. In addition, an intelligent algorithm on stress identification using measurements from multi-region is presented in the paper. The stress identification method is deployed using the fuzzy pattern recognition and Dempster-Shafer evidence theory, where the measurements of limited strain sensors arranged on structure are the input data of the method. As results, at the critical parts of the structure, the stress distribution evaluated from the measurements has shown close correlation to the numerical simulation results on the steel roof of the Beijing National Aquatics Center in China. The research work in this paper can provide a reference for the design and implementation of both real world structural health monitoring systems and intelligent algorithm to identify stress distribution effectively.

A Study of Changes in the Water Quality of Agricultural Reservoirs due to Drought (가뭄으로 인한 농업용 저수지의 수질 변화 연구)

  • Cho, SungHyen;Hwang, Soonho;Lee, Dongguen;Lee, Guntaek;Choi, Jung-Hoon
    • Journal of the Korean earth science society
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    • v.43 no.1
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    • pp.110-118
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    • 2022
  • Frequent drought damage has resulted in the polarization of water resources. In Korea, local periodic abnormal droughts continued to occur between 2011 and 2017, resulting in decreased water storage rates of small-scale reservoirs designed with a frequency of 10-year droughts. This decrease can degrade water quality and limit the use of already secured quantities. Therefore, to prepare for and overcome drought, quality management and recalculation of drought frequency are required. This study estimates the potential pollutants causing quality changes in the reservoir. In addition, it reviews the decrease in storage and consequent changes in the quality of a reservoir during drought.

Effects of Atmospheric Ozone on the Rice Blast Pathogen Pyricularia grisea

  • Hur, Jae-Seoun;Kim, Ki-Woo;Kim, Pan-Gi;Yun, Sung-Chul;Park, Eun-Woo
    • The Plant Pathology Journal
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    • v.16 no.1
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    • pp.19-24
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    • 2000
  • The direct effects of acute $\textrm{O}_3$ on the growth, sporulation and infection of Pyricularia grisea, rece blast pathogen, were investigated to understand the interactions between ozone and the pathogen. Acute exposure of 200 nl $\textrm{l}^{-1}$ ozone for 8 h significantly reduced conidia germination on water atar. Ozone exposure of 200 nl $\textrm{l}^{-1}$ for 8h per day for 5 days had no effect on increase in colony diameter, but severely damaged actively growing aerial mycelia. However, the damage to mycalia was recovered during the following 16 h exposure of unpolluted air. Conidial production was also stimulated by the acute ozone exposure for 5 days. The conidia exposed to the acute ozone for 5 days normally germinates but slightly reduce appressoria formation on rice leaf. However, the conidia produced by artificial stimulation under the same ozone concentration for 10 days showed significant reduction in appressorea for mation on a hydrophobic film. This study suggests that the acute ozone could ingibit appressoria formation as well as vegetative growth of the pathogen, resulting in decrease in rece blast development in the field during summer when high ozone episodes could occur occasionally.

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Inter-laboratory Comparison of Stable Carbon and Nitrogen Isotopic Composition Data Using Elemental Analyzer-isotope Ratio Mass Spectrometers

  • Kim, Jung-Hyun;Kang, Sujin;Bong, Yeon-Sik;Park, Kwangkyu;Kang, Tae-Woo;Park, Yong-Se;Kim, Dahae;Choi, Seunghyun;Joo, Young Ji;Choi, Bohyung;Nam, Seung-Il;Lee, Sang-Mo;Shin, Kyung-Hoon
    • Journal of Environmental Analysis, Health and Toxicology
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    • v.21 no.4
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    • pp.229-236
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    • 2018
  • In this study, inter-laboratory comparison was done using elemental analyzer-isotope ratio mass spectrometers (EA-IRMSs) to determine carbon and nitrogen contents as well as stable carbon and nitrogen isotopic compositions (${\delta}^{13}C$ and ${\delta}^{15}N$) of five environmental samples containing lake and marine sediments, higher plant leaves, and fish muscle, and one organic analytical standard (Protein (Casein) Standard OAS). Five national laboratories participated in this comparison study, and each laboratory analyzed all five samples and the analytical standard. Results showed that variations in total organic carbon (TOC) and total nitrogen (TN) contents as well as ${\delta}^{13}C_{TOC}$ and ${\delta}^{15}N_{TN}$ values among the laboratories were large compared to the analytical uncertainties. The results highlighted the inhomogeneity of the test samples and thus, the need to select suitable standard reference materials for future inter-laboratory studies. Further inter-laboratory comparison exercises could promote good measurement practices in the acquisition of stable carbon and nitrogen isotopic composition data.