• Title/Summary/Keyword: Reaction monitoring

Search Result 585, Processing Time 0.024 seconds

Cure Monitoring for Prototyping of Reaction Injection Molding (RIM 시작공정을 위한 경화 모니터링)

  • 권재욱;이대길
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2001.04a
    • /
    • pp.32-36
    • /
    • 2001
  • Recently, reaction injection molding has been used broadly for rapid prototyping, because of its convenience and versatility. Since the properties of molded products are dependent on the process variables and the production is very short(less than 2minutes), the control of process variables is important. Generally, the two significant process variables are degree of cure and temperature of the reactants. In this paper, the relation between the degree of cure and the temperature of reactants was investigated to find the optimal curing condition of reaction injection molding for rapid prototyping. The degree of cure during reaction injection molding was measured by the Lacomtech sensor and dielectrometry equipment employing Wheatstone bridge type circuit.

  • PDF

Nurses' Monitoring Practice for Adverse Drug Reactions (약물 유해 반응에 대한 간호사의 모니터링 실천에 관한 연구)

  • Kim, Hyun-Jin;Lee, Seon-Hye
    • Journal of Korean Academy of Nursing Administration
    • /
    • v.22 no.1
    • /
    • pp.91-98
    • /
    • 2016
  • Purpose: The aim of this study was to identify the relationship between nurses' knowledge of adverse drug reactions (ADR), attitudes, and monitoring practices and to establish an effective ADR reporting system and provide baseline data for its activation. Methods: The participants in this study were chosen by convenience sampling and included 182 nurses working at major general hospitals that operate a Regional Drug Safety Center. Data were collected from June 1 to 12, 2015 and analyzed using Cronbach's ${\alpha}$, descriptive statistics, independent t-test, one way ANOVA, Pearson correlation coefficient and stepwise regression with the SPSS program. Results: The nurses' average score for knowledge was 7.62 points, for attitude, 41.04 points and for monitoring practices, 34.22 points. ADR monitoring practices positively correlated with knowledge (r=.19, p=.011), attitude (r=.41, p<.001), drug performance competency (r=.54, p<.001), and drug education satisfaction (r=.54, p<.001). Drug performance competency, drug education satisfaction, and attitudes explained 42.0% of the ADR monitoring practices (Adj $R^2=.42$, F=43.95, p<.001). Conclusion: In order to facilitate and encourage nurses' voluntary monitoring practice of ADR, efforts must be made to create positive attitudes toward ADR, and to increase drug performance competency and drug education satisfaction.

Estimation of reaction forces at the seabed anchor of the submerged floating tunnel using structural pattern recognition

  • Seongi Min;Kiwon Jeong;Yunwoo Lee;Donghwi Jung;Seungjun Kim
    • Computers and Concrete
    • /
    • v.31 no.5
    • /
    • pp.405-417
    • /
    • 2023
  • The submerged floating tunnel (SFT) is tethered by mooring lines anchored to the seabed, therefore, the structural integrity of the anchor should be sensitively managed. Despite their importance, reaction forces cannot be simply measured by attaching sensors or load cells because of the structural and environmental characteristics of the submerged structure. Therefore, we propose an effective method for estimating the reaction forces at the seabed anchor of a submerged floating tunnel using a structural pattern model. First, a structural pattern model is established to use the correlation between tunnel motion and anchor reactions via a deep learning algorithm. Once the pattern model is established, it is directly used to estimate the reaction forces by inputting the tunnel motion data, which can be directly measured inside the tunnel. Because the sequential characteristics of responses in the time domain should be considered, the long short-term memory (LSTM) algorithm is mainly used to recognize structural behavioral patterns. Using hydrodynamics-based simulations, big data on the structural behavior of the SFT under various waves were generated, and the prepared datasets were used to validate the proposed method. The simulation-based validation results clearly show that the proposed method can precisely estimate time-series reactions using only acceleration data. In addition to real-time structural health monitoring, the proposed method can be useful for forensics when an unexpected accident or failure is related to the seabed anchors of the SFT.

Intepretation of Faradaic Impedance for Corrosion Monitoring

  • Itagaki, M.;Taya, A.;Imamura, M.;Saruwatari, R.;Watanabe, K.
    • Corrosion Science and Technology
    • /
    • v.3 no.1
    • /
    • pp.1-5
    • /
    • 2004
  • A polarization resistance is generally used to estimate the corrosion rate in the corrosion monitoring by an electrochemical impedance method. When the Faradaic impedance has a time constant due to the reaction intermediate, the electrochemical impedance describes more than one loop on the complex plane. For example, the electrochemical impedance of iron in acidic solution shows capacitive and inductive loops on the complex plane. In this case, the charge transfer resistance and the polarization resistance are determined at middle and low frequency ranges, respectively. Which should be selected for corrosion resistance in corrosion monitoring, the charge transfer resistance or the polarization resistance'? In the present paper, the above-mentioned question is examined theoretically and experimentally.

Gas Chromatography/Mass Spectrometry and Gas Chromatography/Tandem Mass Spectrometry of some s-Triazine Pesticides

  • Kim, Yoo-Joong;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
    • /
    • v.10 no.2
    • /
    • pp.196-200
    • /
    • 1989
  • Some s-triazine herbicides, namely simazine, atrazine, and propazine present as trace components in a complex mixture were analyzed by GC/MS and GC/MS/MS methods. Even though monitoring the molecular ions was the best in terms of sensitivity, adequate analysis could not be done when interfering species were present. When doubly charged ions which appeared at characteristic m/z values were monitored, chromatograms were rather free from interference. More importantly, selected reaction monitoring was found to provide a selective means of detection with general applicability.

Liquid Phase Oxidation of Xylenes: Effects of Water Concentration and Alkali Metals

  • Jhung, Sung-Hwa;Lee, Ki-Hwa;Park, Youn-Seok
    • Bulletin of the Korean Chemical Society
    • /
    • v.23 no.1
    • /
    • pp.59-64
    • /
    • 2002
  • A facile and precise batch oxidation reaction system allows continuous monitoring of the oxidation rate and cumulated oxygen conversion of xylenes, and the side reactions to carbon monoxide and carbon dioxide may also be studied. The oxidation reaction can be analyzed precisely with the rate and amount of oxygen consumed. The reaction reveals that 4-carboxybenzaldehyde is an unstable intermediate of p-xylene oxidation as the reaction proceeds instantaneously from p-toluic acid to TPA (terephthalic acid). The alkali metals accelerate oxidation, even though they retard the reaction initially. The oxidation rate increases with decreasing water concentration. However, in the later part of reaction, the reactivity decreases a bit if the water concentration is very low. This retarding effect of water can be overcome partly by the addition of potassium. The oxidation of o-xylene, compared with the oxidation of p-xylene and m-xylene, proceeds quite fast initially, however, the oxidation rate of xylene isomers in the later stage of reaction is in the order of p-xylene > mxylene > o-xylene.

A Numerical Study on NOx Emission of the Swirl Premixed burner for Several Chemical Reaction Mechanisms (스월 예혼합 버너의 화학반응식에 따른 NOx 특성에 대한 수치적 연구)

  • Cho, Cheonhyeon;Baek, Gwangmin;Sohn, Chae Hoon;Cho, Ju Hyung;Kim, Han Seok
    • 한국연소학회:학술대회논문집
    • /
    • 2012.11a
    • /
    • pp.133-135
    • /
    • 2012
  • This study presents the prediction of NOx and mixing characteristics with several chemical reaction mechanisms of methane in EV burner of double cone. Experimental results are compared with numerical results for validation. Mixing characteristics are analyzed at monitoring points based on the modified unmixedness. The mixing characteristics were improved in a certain case, the lance injection case. In 1-step reaction case, inside of the cone, flame was formed and lots of NOx was generated because the fuel injected from the lance was overestimated. In 2-step reaction case, numerical results showed a good agreement with experimental results in a qualitative manner.

  • PDF