• Journal of Biomedical Engineering Research
• /
• v.30 no.6
• /
• pp.461-468
• /
• 2009

Magnetic resonance electrical impedance tomography (MREIT) enables us to perform high-resolution conductivity imaging of an electrically conducting object. Injecting low-frequency current through a pair of surface electrodes, we measure an induced magnetic flux density using an MRI scanner and this requires a sophisticated MR phase imaging method. Applying a conductivity image reconstruction algorithm to measured magnetic flux density data subject to multiple injection currents, we can produce multi-slice cross-sectional conductivity images. When there exists a local region of fat, the well-known chemical shift phenomenon produces misalignments of pixels in MR images. This may result in artifacts in magnetic flux density image and consequently in conductivity image. In this paper, we investigate chemical shift artifact correction in MREIT based on the well-known three-point Dixon technique. The major difference is in the fact that we must focus on the phase image in MREIT. Using three Dixon data sets, we explain how to calculate a magnetic flux density image without chemical shift artifact. We test the correction method through imaging experiments of a cheese phantom and postmortem canine head. Experimental results clearly show that the method effectively eliminates artifacts related with the chemical shift phenomenon in a reconstructed conductivity image.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.16 no.1
• /
• pp.47-63
• /
• 1990

Image analyser was used to understand the condition of skin surface and to evaluate the efficacy of cosmetic treatment. It was unsatisfactory to analyse skin surface structure although several methods using image analyser had been presented. We developed the new system composed of image analyser and Tandem Scanning Reflected Light Microscope (TSRLM) having the remarkable optical sectioning property as image input device. By using this new system, we quantitatively measured the change of skin surface, the depth and width of furrow in micron unit, resulted by cosmetic treatments. And also three dimensional image of skin was reconstructed with serial sectioned images, which were captured through TSRLM, for better understanding of the effect of cosmetic treatment. It was found that skin relief was more easily understood and the change of skin surface caused by cosmetic treatment was more accurately measured by using this system. In addition, we was also aware of the possibility of in vivo direct measurement of skin furrow without replica. It was conceivable that our system could be applicable for study of cosmetic effects further.

• Korean Chemical Engineering Research
• /
• v.61 no.2
• /
• pp.247-257
• /
• 2023

Precise counting of cell number stands in important position within clinical and research laboratories. Conventional methods such as hemocytometer, migration/invasion assay, or automated cell counters have limited in analytical time, cost, and accuracy., which needs an alternative way with time-efficient in-situ approach to broaden the application avenue. Here, we present simple coding-based cell counting method using image analysis tool, freely available image software (ImageJ). Firstly, we encapsulated RFP-expressing bacteria in a droplet using microfluidic device and automatically performed fluorescence image-based analysis for the quantification of cell numbers. Also, time-lapse images were captured for tracking the change of cell numbers in a droplet containing different concentrations of antibiotics. This study confirms that our approach is approximately 15 times faster and provides more accurate number of cells in a droplet than the external analysis program method. We envision that it can be used to the development of high-throughput image-based cell counting analysis.

• Journal of environmental and Sanitary engineering
• /
• v.20 no.3 s.57
• /
• pp.17-26
• /
• 2005

Many researches were focused on the data which obtained from chemical bulk analysis. It is difficult to evaluate source contribution by wet type chemical bulk analysis. In this study, we have reviewed the characterization of individual particle for source identification. We analyzed by SEM/EDX methods. We have obtained average geometric particle diameter measured by optical diameter which were resulted from SEM/EDX image scan, representative physical diameter of individual particle was $3.38\;{\mu}m\;in\;A,\;3.67\;{\mu}m\;in\;B$. In the result of image analysis at each spots particles, both samples non-sphere shapes, C-rich particles. In consequence of chemical analysis of individual particle, each sampling sites some elements.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.867-870
• /
• 2007

In order to solve image sticking phenomena, the gas-phase and liquid-phase interfacial reactions of photosensitive polyimide can annihilate photoreactive carbon-carbon double bonds, which remain after photo-alignment process. The annihilation processes dramatically affect residual DC and photochemical reorientation of photoactive functional groups.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.1135-1142
• /
• 2010

A series of N(2)-benzothiazolyl substituted tetrahydroindazoles has been synthesized via cyclic ${\beta}$ keto esters. Optimum reaction condition was found as acidic toluene and effect of higher acidity towards substituted hydrazines in situ was described. Synthesized compounds have been achieved as single isomer and characterized by using 1D and 2D NMR spectral reports. Antimicrobial screening was carried out for the synthesized compounds along with a series of N(2)-pyridyl tetrahydroindazoles.1 The results of the in vitro antimicrobial screening studies revealed that compounds 13, 16 against Staphylococcus aureus, 11 against Escherichia coli, 10-12, 16 against Pseudomonas aeruginosa and 12 against Klebsiella pneumoniae recorded almost two-fold better activity compared to the standard drug used.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.1
• /
• pp.81-84
• /
• 2007

Ab initio periodic Hartree-Fock calculations with the full potential and minimum basis set are applied to interpretation of scanning tunneling microscope (STM) and atomic force microscope (AFM) images on 1TVTe2. Our results show that the simulated STM image shows asymmetry while the simulated AFM image shows the circular electron densities at the bright spots without asymmetry of electron density to agree with the experimental AFM image. The bright spots of both the STM and AFM images of VTe2 are associated with the surface Te atoms, while the patterns of bright spots of STM and AFM images are different.

• Membrane Journal
• /
• v.21 no.2
• /
• pp.171-176
• /
• 2011

Membrane fouling is formed due to pore blocking and cake formation by suspended material or contaminant in the membrane boundary layer. Membrane fouling is main obstacle for the wider application of industrial water treatment. The objective of this paper is to study the direct monitoring technique for the measuring the membrane fouling in real time. We investigated the extracted image of R, G, and B by visible light irradiation of 360 nm wavelength to measure the membrane fouling in real time by transparent foulant. The intensity of B of 400~499 nm wavelength range was stronger than that of R and G. The fluorescence image extraction analysis appeared to be a very attractive technique for monitoring the membrane fouling in real time.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.10
• /
• pp.1120-1122
• /
• 2001

• Journal of the Korean Magnetic Resonance Society
• /
• v.4 no.1
• /
• pp.64-73
• /
• 2000

There are several methods to achieve selective NMR image of differing chemical species with the three most popular methods of Dixon's, CHESS, and SECSI. A major problem common to all chemical shift imaging methods is the uniformity of the static magnetic field and distortions introduced when RF coils are loaded with a conducting specimen. Without magnetic field shimming, these methods cannot be used to acquire selectively image protons in fat and water which are separated by approximately 3.0ppm. Experiments with a phantom, with linewidths of 2.5 to 3.5ppm, were quantitatively evaluated for the three methods and a new chemical shift imaging method. In this study the new chemical shift imaging method (modified CHESS+SECSI technique) which included a selective saturation and refocusing pulse, was developed to determine the ratios of water and fat in different samples.