• Title/Summary/Keyword: H2S sensing

Search Result 213, Processing Time 1.729 seconds

An experimental study on the in-process measurement of case depth for LASER surface hardening process (레이저 표면경화 공정에서 경화층깊이의 실시간 측정을 위한 실험적 연구)

  • Woo, H.G.;Park, Y.J.;Han, Y.H.
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.10 no.2
    • /
    • pp.66-75
    • /
    • 1993
  • This paper proposes a monitoring method for nondestructive and in-process measurement of the case depth in LASER surface heat treatment process. The method is essentially an eddy-current method, and measures sensing coil's electrical impedance which varies with the changes of the material microstructure due to hardening. To investigate te validity of the proposed method a series of experiments were performed for various hardning depths. The results show that the relationship between the eddy- current sensor output and the changes in case depth is almost linear. This indicates that the eddy-current measuring method can be used as one of the possible monitoring method for mesauring the hardened depth in LASER heat treatment processes.

  • PDF

The Image Interpretation Module Development for an Urban Area

  • Kim, J.Y.;Chang, Y.H.;Chang, K.S.;Kang, H.G.;Kim, E.G.;Lee, I.C.;Kim, K.W.;Park, C.
    • Proceedings of the KSRS Conference
    • /
    • 2003.11a
    • /
    • pp.1183-1187
    • /
    • 2003
  • Five new satellite image interpretation modules are developed. The modules are for: 1) construction of a realistic color image, 2) feature recognition by intensity filtering, 3) removal of spurious spots by next -neighbor count comparison, 4) deviation-amplification filtering, and 5) feature recognition by spectral distribution pattern. The modules were applied to a set of IKONOS images of 8 x 8 km area of the city of Daejeon, Korea, to recognize the distribution of various features such as water resources, playgrounds, forests, etc.

  • PDF

Design and Implementation of Fire Management Components

  • Kim, K.S.;Park, J.H.;Lee, J.H.
    • Proceedings of the KSRS Conference
    • /
    • 2003.11a
    • /
    • pp.600-602
    • /
    • 2003
  • In Korea, fire is the second frequent disaster. A total of 32,966 fires were happened in 2002, and injured 2,235 people and damaged 12 million dollars. So, we developed several components related to fire in order to decrease these victims and the amount of damage and have applied those components to Daegu Fire Agency. In this paper, we describe the developing system. It consists of 5 major components: mobile fire facility management component, web service component, fire management component, fire server, and fire application. They were developed in object-oriented computing environment, ATL/COM and Visual C++. So, they have some advantages such as high reusability, full interoperability, and easy understanding.

  • PDF

Development and Evaluation of the Upper & Lower side Ondol System in Apartment Houses (공동주택의 윗목/아랫목 온돌 제어시스템 개발 및 평가)

  • Cho, D.W.;Yu, K.H.;Yu, J.Y.;Jung, H.K.;Kim, Y.H.;Kim, S.H.;U., M.;Yang, I.H.
    • Proceedings of the SAREK Conference
    • /
    • 2008.06a
    • /
    • pp.627-636
    • /
    • 2008
  • The purpose of this study is to develop the new korean district heating system for apartment houses. The upper & lower side ondol system with multi sensing control system was developed as a new korean district heating system and evaluated in 2 mock-up laboratories last winter. As a result of field measurement, when the load differences between perimeter zone and central zone are increased, the ondol system divided in the upper and lower side can be evaluated as the new ondol system with a capability for suppling proper heating energy for each zone. The user can have the freedom for changing an upper zone and a lower zone and controlling each temperature according to their needs.

  • PDF

A Study of Temperature Changes in the Dental Tissues Irradiated by $10.6{\mu}m$ Laser Beam ($CO_2$ 레이저 광의 조사조건에 따른 치아의 치수강내 온도상승에 관한 연구)

  • Ko, D. S.;Bak, Y. H.;Shin, S. H.;Eom, H. S.;Kim, U.;Lee, C. Y.
    • Korean Journal of Optics and Photonics
    • /
    • v.1 no.2
    • /
    • pp.210-216
    • /
    • 1990
  • This study was performed to obtain fundamental data on temperature increases in the dental tissues irradiated by IO.opm laser radiation. For this purpose a experimental facility was established. which was composed of a CO2 laser. a shutter unit and a temperature sensing device. The temperature changes in the pulp chamber of extracted molars. during and after the laser irradiation. were measured as function of laser power. the time of irradration and the thickness of the sample. An empirical formula for the maximum temperature increases, $\DeltaT_m$ was derived from the measured data as follows; $\DeltaT_m=\alphaP\Delta\tauexp(-\betad)$$ where P. $\Delta\tau$ and d are the laser power(W). irradiation time{sec) and the thickness(mm) between pulp chamber and occlusal surface. respectively. Also a theoretical calculation model based on simplified assumptions were established and the results from the calculation were compared with the measured temperature data. A fairly good agreement was obtained.obtained.

  • PDF

Sodium Salicylate Activates p38MAPK Though a Specific-Sensing Mechanism, Distinct from Pathways Used by Oxidative Stress, Heat Shock, and Hyperosmotic Stress

  • Kim, Jung-Mo;Oh, Su-Young;Kim, Min-Young;Seo, Myoung-Suk;Kang, Chi-Duk;Park, Hye-Gyeong;Kang, Ho-Sung
    • Biomedical Science Letters
    • /
    • v.9 no.4
    • /
    • pp.241-248
    • /
    • 2003
  • Sodium salicylate, a plant stress hormone that plays an important role(s) in defenses against pathogenic microbial and herbivore attack, has been shown to induce a variety of cell responses such as anti-inflammation, cell cycle arrest and apoptosis in animal cells. p38MAPK plays a critical role(s) in the cell regulation by sodium salicylate. However, the signal pathway for sodium salicylate-induced p38MAPK activation is yet unclear. In this study, we show that although sodium salicylate enhances reactive oxygen species (ROS) production, N-acetyl-L-cysteine, a general ROS scavenger, did not prevent sodium salicylate-induced p38MAPK, indicating ROS-independent activation of p38MAPK by sodium salicylate. Sodium salicylate-activated p38MAPK appeared to be very rapidly down-regulated 2 min after removal of sodium salicylate. Interestingly, sodium salicylate-pretreated cells remained fully responsive to re-induction of p38MAPK activity by a second sodium salicylate stimulation or by other stresses, $H_2O$$_2$ and methyl jasmonate (MeJA), thereby indicating that sodium salicylate does not exhibit both homologous and heterologous desensitization. In contrast, pre-exposure to MeJA, $H_2O$$_2$, heat shock, or hyperosmotic stress reduced the responsiveness to subsequent homologous stimulation. Sodium salicylate was able to activate p38MAPK in cells desensitized by other heterologous p38MAPK activators. These results indicate that there is a sensing mechanism highly specific to sodium salicylate for activation of p38MAPK, distinct trom pathways used by other stressors such as MeJA, $H_2O$$_2$ heat shock, and hyperosmotic stress.

  • PDF

Intercomparison of Shortwave Radiative Transfer Models for a Rayleigh Atmosphere (레일리 대기에서 단파 영역에서의 복사전달모델 결과들의 상호 비교)

  • Yoo, Jung-Moon;Jeong, Myeong-Jae;Lee, Kyu-Tae;Kim, Jhoon;Ho, Chang-Hoi;Ahn, Myoung-Hwan;Hur, Young-Min;Rhee, Ju-Eun;Yoo, Hye-Lim;Chung, Chu-Yong;Shin, In-Chul;Choi, Yong-Sang;Kim, Young Mi
    • Journal of the Korean earth science society
    • /
    • v.28 no.3
    • /
    • pp.298-310
    • /
    • 2007
  • Intercomparison between eight radiative transfer codes used for the studies of COMS (Communications, Ocean, and Meteorological Satellite) in Korea was performed under pure molecular, i.e., Rayleigh atmospheres in four shortwave fluxes: 1) direct solar irradiance at the surface, 2) diffuse irradiance at the surface, 3) diffuse upward flux at the surface, and 4) diffuse upward flux at the top of the atmosphere. The result (hereafter called the H15) from Halthore et al.'s study (2005) which intercompared and averaged 15 codes was used as a benchmark to examine the COMS models. Uncertainty of the seven COMS models except STREAMER was ${\pm}4%$ with respect to the H15, comparable with ${\pm}3%$ of Halthore et al.'s (2005). The uncertainty increased under a large $SZA=75^{\circ}$. The SBDART model generally agreed with the H15 better than the 6S model, but both models in the shortwave infrared region were equally good. The direct solar irradiance fluxes at the surface, computed by the SBDARTs of four different users, were different showing a relative error of 1.4% $(12.1Wm^{-2})$. This reason was partially due to differently installing the wavelength resolution in the flux integration. This study may be useful for selecting the optimum model in the shortwave region.

Fabrication and pH response characteristics of LAPS(Light addressable potentiometric sensor) with electrolyte/$Si_3N_4/SiO_2$/Si structure (Electrolyte/$Si_3N_4/SiO_2/Si$ 구조의 LAPS 제작 및 pH 응답특성)

  • Chang Su-Won;Koh Kwang-Nak;Kang Shin-Won
    • Journal of the Korean Electrochemical Society
    • /
    • v.1 no.1
    • /
    • pp.40-44
    • /
    • 1998
  • The LAPS device of fast response and high sensitivity, based on electrochemical potential difference, and its system were fabricated for the precise measurement of pH changes and its characteristic were investigated. The electrostatic variation characteristics of LAPS according to the pH changes and parameters in the device were verified through a simulation using LAPS equivalent circuit model. The LAPS device and its system were fabricated on the basis of the result of simulation. The fabricated LAPS system showed linear sensitivity (about 56 mV/pH within the range of pH 2 to pH 11. In order to overcome the defect of general urea sensor (especially slow response time), urease immobilized nitrocellulose membrane was attached on the LAPS and resulted in the very fast response time, 0.29 mV/sec, 0.86 mV/sec at urea concentration of $50{\mu}g/ml,\; 500{\mu}g/ml$, respectively. And also in order to measure the uranyl ion, the uranyl ion selective sensing membrane with calix[6]arene derivative was used and its sensitivity was 25mV/concentration decade in the wide uranyl ion concentration range of $10^{-11}M\;to\;10^{-4}M$.

Quasi-Solid-State Hybrid Electrolytes for Electrochemical Hydrogen Gas Sensor

  • Kim, Sang-Hyung;Han, Dong-Kwan;Hong, SeungBo;Jeong, Bo Ra;Park, Bok-Seong;Han, Sang-Do;Kim, Dong-Won
    • Journal of Electrochemical Science and Technology
    • /
    • v.10 no.3
    • /
    • pp.294-301
    • /
    • 2019
  • The quasi-solid-state hybrid electrolytes were synthesized by chemical cross-linking reaction of methacrylate-functionalized $SiO_2$ ($MA-SiO_2$) and tetra (ethylene glycol) diacrylate in aqueous electrolyte. A quasi-solid-state electrolyte synthesized by 6 wt.% $MA-SiO_2$ exhibited a high ionic conductivity of $177mS\;cm^{-1}$ at room temperature. The electrochemical $H_2$ sensor assembled with quasi-solid-state electrolyte showed relatively fast response and high sensitivity for hydrogen gas at ambient temperature, and exhibited better durability and stability than the liquid electrolyte-based sensor. The simple construction of the sensor and its sensing characteristics make the quasi-solid-state hydrogen sensor promising for practical application.

Study on Basic Properties of Single Crystalline ZnO Nanowire (단결정 산화아연 나노선의 기초 물성 연구)

  • Ra, H.W.;Khan, R.;Kim, J.T.;Yeo, C.H.;Im, Y.H.
    • Journal of the Korean Vacuum Society
    • /
    • v.18 no.4
    • /
    • pp.259-265
    • /
    • 2009
  • We fabricated the field effect transistor using single crystalline ZnO nanowires synthesized by a conventional thermal evaporation method and investigated their basic properties under the various conditions such as ultraviolet irradiation, reducing gas and electrolyte. The typical carrier concentration and mobility of the single crystalline ZnO nanowire with a diameter of 100 nm and length of 5 um were $1.30{\times}10^{18}cm^{-3}$ and $15.6cm^2V^{-1}s^{-1}$, respectively. The current of ZnO nanowire under ultraviolet irradiation significantly increased about 400 times higher as compared to in the darkness. In addition, the ZnO nanowire showed typical sensing characteristics for $H_2$ and CO due to well-known surface reactions and typical current-voltage characteristics under the 0.1 M NaCl electrolyte.