• Title/Summary/Keyword: $O_3$ sensitivity

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Effect of Mirror Misalignments on Optical Ray Path In a Ring Resonator

  • Lee, Dong-Chan;Lee, Jae-Cheul;Son, Seong-Hyun;Cho, Hyun-Ju
    • Journal of the Optical Society of Korea
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    • v.6 no.3
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    • pp.121-127
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    • 2002
  • The operating principal of a ring laser gyroscope depends on the phase difference for the counter-propagating waves within a closed path. The reflecting mirrors mounted on the monoblock form the traveling waves. The manufacturing accuracy of the monoblock influences the traveling path of ray, the sensitivity of laser resonator for misalignments, and diffraction losses. A 3 $\times$ 3 ray transfer matrix was derived for optical components with centering and squaring errors in a ring resonator. The matrix can be utilized to predict the optical ray paths on the basis of the manufacturing errors of the monoblock as well as the misalignment of mirrors. Then the distance and orientation (o. slope) at the arbitrary plane inside the resonator along the ideal optical path can be calculated from the chain multiplication of the ray transfer matrix for each optical component in one round trip. We also show that the counter-propagating rays In a ring resonator with errors does not coincide in each round trip, which results in gain difference between two beams, and how these errors can be adjusted through the alignment procedure. Finally this 3 $\times$ 3 ray matrix formalism can be used to calculate the beam size and its displacement from the optical axis and the deviation at the diaphragm.

A Study on the Sensitivity Analysis of Offshore wind farm Design (해상풍력발전 단지배치에 따른 민감도 분석에 관한 연구)

  • Kim, Do-Hyung;Jang, Eun-young;Kyong, Nam-Ho;Kim, Hong-Woo;Kim, Sung-Hwan;Kim, Chang-Suk
    • Journal of the Korean Solar Energy Society
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    • v.31 no.3
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    • pp.29-35
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    • 2011
  • This study draws economic expense factors according to the influence of generation resulted from slipstream and the arrangement of the complex when arranging and designing the complex for offshore windpower development as a model of 50MW offshore wind farm and conducts economics analysis. According to the result of the analysis, O (Optimize) arrangement was the one that has the highest generation for having the best windpower resources in terms of design and being least affected by slipstream; however, the arrangement requires expensive submarine cables and high installation cost. Therefore, according to the analysis of economics, it was thought that 50MW complex should have less economics as BC ratio 0.95 than the series arrangement of main wind direction and I+80 series arrangement would be rather more economical. This economics evaluation provides comparison according to the arrangement of the development complex considering the uncertainty of the electricity price and gross construction cost. And it is expected that the result of economics evaluation would greatly differ by installation capacity, and the reason is that the cost of electric infrastructure takes up a higher portion than the gross construction cost of the development complex. The only way to compensate this part is to make the windpower development complex larger. It seems that it will be necessary to enhance spot applicability to evaluate economics afterwards and pay consistent attention to and conduct follow-up research on the economics evaluation of the complex construction.

Study on Porous Silicon Sensors to Measure Low Alcohol Concentration (저농도 알코올 측정을 위한 다공질 실리콘 센서에 관한 연구)

  • Kim Seong-Jeen
    • Journal of the Korean Electrochemical Society
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    • v.2 no.3
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    • pp.130-133
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    • 1999
  • In this work, a capacitance-type alcohol gas sensor using porous silicon layer is developed to apply for breath alcohol measurement and its characteristics are estimated at room temperature. Current alcohol sensors using metal oxides such as tin-oxide are not only difficult to measure low alcohol concentration, but also should heat at $200\;to\;400^{\circ}C$ to improve the sensitivity. But the sensor using porous silicon layer has good sensitivity even at room temperature by very large effective surface area and suitable structure to fabricate integrated micro sensors. In the experiment, the capacitance was measured for the range of 0 to $0.5\%$ alcohol concentration with the interval of $0.05\%$, in which alcohol solution was kept at 25, 36, and $45^{\circ}C$ by a heater. As the result, good linearity was observed and the capacitance increased about 1.1, 2.6 and $4.6\%$ per the increment of $0.1\%$ alcohol concentration each temperature, respectively, at the frequency of 120 Hz.

The Rapid Diagnosis of $\beta$-Haemolitic Streptococcus sp. by Immunoperoxidase Method (면역효소항체법에 의한 $\beta$-용혈성 연쇄구균 Streptococcus sp.의 신속진단에 대하여)

  • Chun, Seh-Kyu;Choi, Dong-Lim;Park, Soo-Il
    • Journal of fish pathology
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    • v.1 no.2
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    • pp.103-110
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    • 1988
  • For the rapid diagnosis of bacterial diseases of cultured fishes, the immunoperoxidase method was applied to the detection of $\beta$-haemolitic Streptococcus sp. strain KST-2 isolated from tilapia(Oreochromis niloticus). The suitability of field analysis and the sensitivity of the immunoperoxidase method was compared with those of the counterimmunoelectrophoresis(CIE) and the immunodiffusion(ID). Results of testing cross-reactivity which did not indicate any cross reactivity with other fish pathogens, this method was specific to Streptococcus sp. The sensitivity of this method was $1{\times}10^3CFU/ml$ which was at least $10^2$times greater than the CIE and $10^4$times greater than the ID. The immunoperoxidase method was more suitable for field application and more sensitive than other diagnostic techniques tested on this study.

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NO Gas Sensing of ACFs Treated by E-beam Irradiation in H2O2 Solution (과산화수소 용액에 담지 된 활성탄소섬유의 전자선 조사에 따른 일산화질소 가스 감응)

  • LEE, SANGMIN;PARK, MI-SEON;JUNG, MIN-JUNG;LEE, YOUNG-SEAK
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.3
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    • pp.298-305
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    • 2016
  • In this study, we treated pitch-based activated carbon fibers (ACFs) in hydrogen peroxide using electron beam (E-beam) irradiation to improve nitrogen monoxide (NO) sensing ability as an electrode material of gas sensor. The specific surface area of ACFs treated by E-beam irradiation with 400 kGy increased from $885m^2/g$ (pristine) to $1160m^2/g$ without any changes in structural property and functional group. The increase in specific surface area of the E-beam irradiated ACFs enhanced NO gas sensing properties such as response time and sensitivity. When the ACFs irradiated with 400 kGy, response time was remarkably reduced from 360 s to 210 s and sensitivity was increased by 4.5%, compared to the pristine ACFs. These results demonstrate convincingly that surface modification of ACFs using E-beam in hydrogen peroxide solution can enhance textural properties of ACFs and NO gas sensing ability of gas sensor at room temperature.

Development of Humidity Sensor Based on Ceramic/Metal Halide Composite Films for Non-Contact Biological Signal Monitoring Applications (비접촉 생체신호 모니터링 응용을 위한 세라믹/메탈 할라이드 복합막 기반 습도센서 개발)

  • Park, Tae-Ung;Kim, Ik-Soo;Kim, Min-Ji;Park, Chulhwan;Seo, Eui-kyoung;Oh, Jong-Min
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.35 no.4
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    • pp.412-417
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    • 2022
  • Capacitive-type humidity sensors with a high sensitivity and fast response/recovery times have attracted a great attention in non-contact respiration biological signal monitoring applications. However, complicated fabrication processes involving high-temperature heat treatment for the hygroscopic film is essential in the conventional ceramic-based humidity sensors. In this study, a non-toxic ceramic/metal halide (BaTiO3(BT)/NaCl) humidity sensor was prepared at room temperature using a solvent-free aerosol deposition process (AD) without any additional process. Currently prepared BT/NaCl humidity sensor shows an excellent sensitivity (245 pF/RH%) and superior response/recovery times (3s/4s) due to the NaCl ionization effect resulting in an immense interfacial polarization. Furthermore, the non-contact respiration signal variation using the BT/NaCl sensor was determined to be over 700% by maintaining the distance of 20 cm between the individual and the sensor. Through the AD-fabricated sensor in this study, we expect to develop a non-contact biological signal monitoring system that can be applied to various fields such as respiratory disease detection and management, infant respiratory signal observation, and touchless skin moisture sensing button.

An Optical Intense 2D Electric Field Sensor Using a Single LiNO3 Crystal

  • Zhang, Yuanying;Zhang, Jiahong;Li, Yingna;Lei, Hongyi
    • Current Optics and Photonics
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    • v.6 no.2
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    • pp.183-190
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    • 2022
  • Based on the linear electro-optic (EO) effect of lithium niobite (LiNbO3, LN) crystal, an intense two-dimensional (2D) electric field sensor was analyzed, fabricated and experimentally demonstrated. The linear polarized light beam transmits along the optical axis (z-axis) of the LN crystal, and the polarization direction of the polarized light is 45° to the y-axis. The sensor can detect the intensity of a 2D electric field that is perpendicular to the z-axis. Experimental results demonstrated that the minimum detectable electric field of the sensor is 10.5 kV/m. The maximum detected electric field of the sensor is larger than 178.9 kV/m. The sensitivity of the sensor is 0.444 mV/(kV·m-1). The variation of the sensitivity is within ±0.16 dB when the sensor is rotated around a z-axis from 0° to 360°. The variation of the sensor output optical power is within ±1.4 dB during temperature change from 19 ℃ to 26 ℃ in a day (from 7:00 AM to 23:00 PM) and temperature change from 0 ℃ to 40 ℃ in a controllable temperature chamber. All theoretical and experimental results revealed that the fabricated sensor provides technology for the direct detection of intense 2D electric fields.

Characteristics of Yersinia enterocolitica Isolated from Foods (식품에서 분리한 Yersinia enterocolitica의 특성조사)

  • Lim, Soon-Young;Lee, Dong-Ha;Park, Sun-Hee;Park, Young-Sig;Yoon, Suk-Kwon;Kim, Chang-Min
    • Korean Journal of Food Science and Technology
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    • v.31 no.1
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    • pp.183-188
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    • 1999
  • The incidence of Yersinia enterocolitica in raw meat was determined over 10 month period. Y. enterocolitica was isolated from 8.5% of beef, 17.0% of pork and 25.6% of chicken. Overall prevalence of Y. enterocolitica in raw meat was 17.5%. Seasonal difference was observed in isolation rate in which pork and chicken samples collected in the second half of the year twice was more than that of the first half of the year. Serotypes of Y. enterocolitica isolates were O:5 (17.3%), O:8 (8.6%), O:3 (6.2%), O:1,2 (1.2%), and others. The antibiotics susceptibility tests showed Y. enterocolitica isolates were resistant to carbenicillin, ampicillin, erythromycin, penicillin and bacitracin. In contrast it showed sensitivity to polymyxin B, kanamycin, ciprofloxacin, gentamicin, trimethoprim/sulfamethoxazole, nalidixic acid, and tetracycline. PCR with specific primers derived from ail gene of Y. enterocolitica was applied to detect and confirm pathogenic Y. enterocolitica. About 10% of the isolated Y. enterocolitica proved to be pathogenic and most of them were found in pork. However, proper cooking and meat process can kill and remove all Y. enterocolitica in meat, because the organism is very sensitive to heat.

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A Study on the Feasibility of Lead(II) Iodide and Gd2O2S:Tb Overlapping Sensors in Gamma Source Conditions using FLUKA Simulation (FLUKA 전산 모사를 통한 감마선원 조건에서의 요오드화납(II)과 Gd2O2S:Tb가 결합된 센서의 적용가능성 연구)

  • Yang, Seung-Woo;Park, Yoon-Hee;Park, Ji-Koon;Heo, Ye-Ji
    • Journal of the Korean Society of Radiology
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    • v.16 no.4
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    • pp.381-386
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    • 2022
  • Non-Destruction Test (NDT) is a method to check internal defects without destroying the product. Among them, radiographic testing (RT) uses high-energy radiation, so it is very important to prevent radiation exposure of workers. Therefore, in this study, in this study, a radiation sensor structure that improves radiation detection performance compared to the existing PbI2 and can immediately detect accidents in RT was presented. For evaluation, the conversion efficiency was analyzed in the gamma ray source through FLUKA simulation. PbI2 with overlapping Gd2O2S:Tb presented in this study showed a higher radiation sensitivity from 1.22 to 3.22 times than that of non-overlapping PbI2. This indicates that the presented sensor is suitable for use as a radiation sensor for source detection in RT.

Sensitivity and Self-purification Function of Forest Ecosystem to Acid Precipitation (II) - Ion Balance in Vegetation and Soil Leachate - (산성우(酸性雨)에 대한 산림생태계(山林生態系)의 민감도(敏感度) 및 자정기능(自淨機能)(II) - 식생층(植生層)과 토양층(土壤層) 용탈(溶脫)이온 분석(分析)을 중심으로 -)

  • Chang, Kwan Soon;Lee, Soo Wook
    • Journal of Korean Society of Forest Science
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    • v.84 no.1
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    • pp.103-113
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    • 1995
  • To estimate buffer capacity and sensitivity of forest ecosystem to acid rain in Taejon, ionic components of throughfall, stemflow, soil leachate, and open rain in Pinus rigida and Quercus variabilis forest were analysed. The spatial sensitivity based on parent rock and forest type was given by IDRISI of GIS which created imagery conversion from soil and vegetation map. Parent rocks and soils were classified into acidic, sedimentary, metamorphic rock and then subdivided based on $SiO_2$ content. Average pH of vegetation leachate was higher in throughfall but lower in stemflow than open rain and higher in Quercus variabilis forest than in Pinus rigida forest. The flow of $SO{_4}^{2-}$, $NO_3{^-}$ and $Cl^-$ through vegetation leaching(throughfall plus stemflow) into soil were 7.2, 4.3, and 2.5 times, respectively, higher in Pinus rigida forest and 4.4, 2, and 2.5 times, respectively, higher in Quercus variabilis forest than in open field. But the concentration of exchangeable cations was 4.1 times higher in Pinus rigida forest and 4.6 times higher in Quercus variabilis forest than in open field. Average pH of soil leachate was lower than that of throughfall, but higher than that of stemflow. The concentration of exchangeable canons and $Al^{3+}$ in soil leachate were more in Pinus rigida forest than in Quercus variabilis forest and increase signficantly with the increase of acidic deposits. Pinus forest had more deposition and canopy interception of acidic pollutants and more nutrient loss than Quercus forest, and Quercus forest had more cation exchange and proton consumption and than consequently had less nutrient loss and better buffer capacity than Pinus forest. The 69% of forest soils was distributed on acidic rock, 25% of it on metamorphic rock, and 6% of it on intermediate and basic rock. Acidic rock residuals which had low very canon exchange capacity and high sensitivity to acid rain occupied a half of total forest land in Taejon area. Therefore forests in Taejon showed high vulnerability to acid rain and will receive much more stress with the increase of acid rain precursors.

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