• Proceedings of the Korean Vacuum Society Conference
• /
• 2006.02a
• /
• pp.65-65
• /
• 2006

• Proceedings of the Korean Vacuum Society Conference
• /
• 2007.08a
• /
• pp.140-140
• /
• 2007

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2011.05a
• /
• pp.89-90
• /
• 2011

플라즈마 공정 중에 발생하는 플라즈마 누설은 챔버 압력의 변화를 초래하여 증착 또는 식각 중인 박막패턴을 손상시킨다. 따라서 플라즈마 누설을 실시간으로 탐지하는 것이 요구되며, 본 연구에서는 광방사분광기 (Optical emisison spectroscopy), 신경망, 그리고 제어차트를 결합한 플라즈마 누설의 인-시츄 탐지기술을 보고한다. 비교평가 결과 소수의 라디칼 정보를 감시하는 것보다 신경망 모델로부터의 예측정보를 이용할 때 보다 증진된 누설탐지 성능을 확인하였다.

• Journal of Pharmaceutical Investigation
• /
• v.17 no.4
• /
• pp.197-204
• /
• 1987

Novel pranoprofen algininate and lysinate salts were manufactured and their salt formation was confirmed by melting point, infrared spectroscopy, nuclear magnetic resornance spectroscopy, differential scanning calorimetry and powder X-ray diffractometry. The physical properties of pranoprofen lysinate and argininate salts were compared with those of pranoprofen through in vitro and in vivo tests. Solubility, $pK_a$ and lipid-water partition coefficient were measured through in vitro experiments, while antiinflammatory efficacy, analgesic effect, acute toxicity and in situ absorption were tested through in vivo experiments. The results obtained were as follows: 1) The solubilities of pranoprofen argininate and lysinate salts were increased markedly in pH 6.8 and pH 7.5 phosphate buffer solutions, comparing with that of pranoprofen itself. 2) $pK_a$ values of pranoprofen, pranoprofen argininate and lysinate salts were 6.34, 7.99 and 7.56 in carbon tetrachloride, and 5.86, 6.69 and 7.92 in chloroform, respectively by liquid-liquid partition method. 3) The lipid-water partition coefficients of pranoprofen argininate and lysinate salts were increased more than that of pranoprofen in carbon tetrachloride, chloroform, or benzene-pH 6.8 buffer system, but were nearly identical using pH 1.2 buffer as water phase. 4) Antiinflammatory effects of pranoprofen argininate and lysinate salts were remarkably increased and analgesic effects of the salts were as same as that of pranoprofen. 5) Pranoprofen argininate and lysinate salts were safer than pranoprofen itself in acute toxicity, and the in situ absorption rates of pranoprofen, pranoprofen argininate and lysinate salts were 0.392, 0.960 and $0.762\;hr^{-1}$, respectively according to the rat intestine recirculation experiment.

• Journal of the Korean Institute of Gas
• /
• v.27 no.1
• /
• pp.70-77
• /
• 2023

Air environment regulations have been strengthened due to increasing air pollutant emissions, the target of reducing emissions has increased and interest in gas measurement methods is also increasing. The sampling method is mainly used, but due to the spatial and temporal measurement limitations, the laser absorption spectroscopy which is a real-time and in-situ method is in the spotlight. In this study, we studied the wavelength modulation spectroscopy and described the calibration-free algorithm. The developed algorithm was modified to reflect 46 multi-absorption lines and was applied to light absorption signal analysis in visible and mid-infrared regions. In addition, the difference between the modulation parameters of laser was analyzed. As a result of reviewing the performance through O₂ and NO gas measurement experiments of various concentration conditions, the linearity was R²_O2=0.99999 and R²_NO=0.99967.

• Journal of the Korean Electrochemical Society
• /
• v.5 no.4
• /
• pp.221-225
• /
• 2002

Assisted by the highly sensitive confocal microprobe Raman spectrometer and proper surface roughening procedure, the Raman investigation on the adsorption and reaction of methanol was performed on Pt-Ru electrodes with different coverages. A detailed description of the roughening process of the Pt electrodes and the underpotential deposition of the Ru was given. Reasonably good Raman signal reflecting the metal-carbon vibration and CO vibration was detected. The appearance of vibrations of the Ru oxides, together with the existence of Ru-C, Pt-C and CO bands, clearly demonstrates the participation of the bi-functional mechanism during the oxidation process of methanol on Pt-Ru electrodes. The Pt-Ru electrode was found to have a higher catalytic activity over Pt electrodes. This preliminary study shows that electrochemical Raman spectroscopy can be applied to the study of rough electrode surface.

• Korean Journal of Remote Sensing
• /
• v.33 no.6_1
• /
• pp.981-992
• /
• 2017

We, for the first time, retrieved tropospheric nitrogen dioxide ($Trop.NO_2$) vertical column density (VCD) from ground-based instrument, Pandora, using the optical density fitting based on Differential Optical Absorption Spectroscopy (DOAS)in Seoul for the period from May 2014 to December 2014. The $Trop.NO_2$ VCDs retrieved from Pandora were compared with those obtained from Ozone Monitoring Instrument (OMI). A correlation coefficient (R) between those retrieved from Pandora and those obtained from OMI is 0.55. To compare with surface $NO_2$ VMRs obtained from in-situ, Trop. $NO_2$ VCDs retrieved from Pandora and those obtained from OMI are converted into $NO_2$ VMRs in boundary layer (BLH $NO_2$ VMRs) using data measured from Atmospheric Infrared Sounder (AIRS). Surface $NO_2$ VMRs obtained from in-situ range from 5.5 ppbv to 61.5 ppbv. BLH $NO_2$ VMRs retrieved from Pandora and OMI range from 2.1 ppbv to 44.2 ppbv and from 0.9 ppbv to 11.6 ppbv, respectively. The range of BLH $NO_2$ VMRs retrieved from OMI is narrower than that of BLH $NO_2$ VMRs retrieved from Pandora and surface $NO_2$ VMRs obtained from in-situ. There is a batter correlation between surface $NO_2$ VMRs obtained from in-situ and BLH $NO_2$ VMRs retrieved from Pandora (R= 0.50)than the correlation between surface $NO_2$ VMRs obtained from in-situ and BLH $NO_2$ VMRs retrieved from OMI (R = 0.36). This poor correlation is thought to be due to the lower near-surface sensitivity of the satellite-based instrument (OMI) than Pandora, the ground-based instrument.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.6
• /
• pp.1032-1041
• /
• 2010

The comparative influence of two nanoparticles [viz., superparamagnetic iron oxide nanoparticles (SPION) and nanobarium titanate (NBT)] upon the in vitro and in situ low-density polyethylene (LDPE) biodegradation efficiency of a potential polymer-degrading microbial consortium was studied. Supplementation of 0.01% concentration (w/v) of the nanoparticles in minimal broth significantly increased the bacterial growth, along with early onset of the exponential phase. Under in vitro conditions, ${\lambda}$-max shifts were quicker with nanoparticles and Fourier transform infrared spectroscopy (FTIR) illustrated significant changes in CH/$CH_2$ vibrations, along with introduction of hydroxyl residues in the polymer backbone. Moreover, simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) reported multiple-step decomposition of LDPE degraded in the presence of nanoparticles. These findings were supported by scanning electron micrographs (SEM), which revealed greater dissolution of the film surface in the presence of nanoparticles. Furthermore, progressive degradation of the film was greatly enhanced when it was incubated under soil conditions for 3 months with the nanoparticles. The study highlights the significance of bacteria-nanoparticle interactions, which can dramatically influence key metabolic processes like biodegradation. The authors also propose the exploration of nanoparticles to influence various other microbial processes for commercial viabilities.

• Smart Structures and Systems
• /
• v.8 no.5
• /
• pp.471-486
• /
• 2011

Various types of strain sensors have been developed and widely used in the field for monitoring the mechanical deformation of structures. However, conventional strain sensors are not suited for measuring large strains associated with impact damage and local crack propagation. In addition, strain sensors are resistive-type transducers, which mean that the sensors require an external electrical or power source. In this study, a gold nanoparticle (GNP)-based polymer composite is proposed for large strain sensing. Fabrication of the composites relies on a novel and simple in situ GNP reduction technique that is performed directly within the elastomeric poly(dimethyl siloxane) (PDMS) matrix. First, the reducing and stabilizing capacities of PDMS constituents and mixtures are evaluated via visual observation, ultraviolet-visible (UV-Vis) spectroscopy, and transmission electron microscopy. The large strain sensing capacity of the GNP-PDMS thin film is then validated by correlating changes in thin film optical properties (e.g., maximum UV-Vis light absorption) with applied tensile strains. Also, the composite's strain sensing performance (e.g., sensitivity and sensing range) is also characterized with respect to gold chloride concentrations within the PDMS mixture.

• Environmental Engineering Research
• /
• v.25 no.2
• /
• pp.238-242
• /
• 2020

Sediment microbial fuel cells (SMFCs) illustrated great potential for powering environmental sensors and bioremediation of sediments. In the present study, array anodes for SMFCs were fabricated with graphite rods as anode material and stainless steel plate as electric current collector to make it inconvenient to in situ settle down and not feasible for large-scale application. The results demonstrated that maximum power of 89.4 ㎼ was obtained from three graphite rods, twice of 43.3 ㎼ for two graphite rods. Electrochemical impedance spectroscopy revealed that three graphite rods resulted in anodic resistance of 61.2 Ω, relative to 76.0 Ω of two graphite rods. It was probably caused by the parallel connection of the graphite rods, as well as more biomass which could reduce the charge transfer resistance of the biofilm anode. The presently designed array configuration possesses the advantages of easy to enlarge the surface area, decrease in anodic resistance because of the parallel connection of each graphite rod, and convenience to berry into sediment by gravity. Therefore, the as prepared array node would be an effective method to fabricate large-scale SMFC and make it easy to in situ applicate in natural sediments.