• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.12
• /
• pp.5931-5936
• /
• 2012

This study was to evaluate the clinical usefulness of the PRESS technique based on the correlation between PRESS technique and biopsy results by applying 3.0T high magnetic field MRS technique for evaluation of non-alcoholic fatty liver disease patients. This experiment were carried out using a 3.0T magnetic resonance imaging equipment. The part data of each spectrum is taken by peak area integration. The part data of resonance peak was used to calculate relative ratio. MR spectral peak in patients with non-alcoholic fatty liver disease is from 0.9 to 1.6 ppm. According to MRS method study result, Patients with NAFLD were obtained with 94% sensitivity and 80% specificity(p=0.000). When compared to normal based on MRS and Biopsy results was valid correlation(r=0.79, p=0.04). Results for NAFLD(r=0.89, p=0.002) also showed a correlation. Therefore, PRESS technique to evaluate patients with non-alcoholic fatty liver disease, the distribution difference between normal liver and fatty liver part is significantly distinguished. Biopsy and MRS fatty liver peak ratio(%) proves high lipid over grade(r = 0.7).

• Journal of the Korean Magnetics Society
• /
• v.14 no.6
• /
• pp.228-231
• /
• 2004

We have studied local magnetization reversal and magnetic properties induced by Laser annealing method in the strip-patterned Ta/NiFe/FeMn/Ta and Ta/NiFe/FeMn/NiFe/Ta multilayers fabricated by ion-beam deposition. The films were exposed to the emission of the DPSS (Diode Pumped Solid State, Nd:YAG) laser under 600 G. The laser beam intensity increased up to 440 mW. When the laser illuminated the patterned film with the power of above 200 m W, the intensity of MR peak located in +87 Oe shrunk. A new MR peak was generated at -63 Oe. When the laser power is 400 mW, the location of positive MR peak(H$\sub$ex/) was changed slightly from +87 Oe to +76 Oe, and the MR ratio was decreased from 0.9% to 0.1 %. On the other hand, the new (negative) MR peak shifted from -63 Oe to -80 Oe, with the MR ratio increased up to 0.3%. As the illuminated area expanded, the intensity of opposite MR peak increased and it of negative MR peak decreased. This proved that the local reversal of exchange biasing should be realized by laser annealing.

• Analytical Science and Technology
• /
• v.19 no.6
• /
• pp.512-518
• /
• 2006

The evidence containing some kind of petroleum at the fire spot was analyzed by gas chromatography to identify a fire's sources. To extract some petroleum from fire evidence, 10.0 mL of n-hexane was added in this solution, and it was shaken for 30 minutes. To identify a kind of petroleum in fire evidence, the prepared n-hexane solution was injected and analyzed in the gas chromatograph. The chromatogram of sample was different from those of thinner and gasoline that have low boiling point, and shown different peak pattern to heating and boiler oils. But it was similar to the chromatogram of diesel oil. After small amount of diesel oil was added to the sample, the area of characteristic peaks was increased more than those of raw sample. From the results, the kind of petroleum in the fire evidence was diesel oil.

• Progress in Medical Physics
• /
• v.17 no.3
• /
• pp.159-166
• /
• 2006

The nonlinearity of hemodynamic response in the somatosensory cortex was investigated with vibrotactile stimulation. The stimuli consisted of a train of 25 Hz, each tasting five different duration periods, 2 s, 4 s, 8 s 12 s, or 16 s with 20 sec periods of no vibration in a pseudo-random order. In order to understand the linearity on the change of stimulus duration for somatosensory cortex, two different tests- checking the linearity of system and finding the impulse response function from gamma-variate function were applied to analyze the hemodynamic response functions. They have produced nearly same results. The BOLD response in the somatosensory cortex Is nonlinear for stimuli of less than 8 seconds, but nearly linear for stimuli greater than 8 seconds. The amplitude, area, TTP, and FWHM as functions of the stimulus duration were calculated and showed a significant downward trend with Increasing stimulus duration for the amplitude and the area. It supports the ranges of nonlinearity are less than 8 seconds.

• Korean Chemical Engineering Research
• /
• v.55 no.3
• /
• pp.401-408
• /
• 2017

In preparation of self-repairing polymer-modified waterproofing asphalt-montmorillonite (MMT) composite, silylation-modification characteristics of cation ($Na^+$) exchanged K-10 (Na-MMT-K) using 3-aminopropyltriethoxysilane (APS) were studied and the optimal conditions of its silylation-modification process were proposed by use of the results of XRD analysis on silylation-modified Na-MMT-K (S-Na-MMT-K) under various conditions. According to XRD results, it was confirmed that peaks of Na-MMT-K were simultaneously consistent with those of K-10 and natural or Ca-MMT modified Na-MMT. Similarly, S-Na-MMT-K was observed to have two basal spacings ($d_{001}$), among which the area-ratio of a secondary (001) peak ($2{\theta}=3.9{\sim}4.2^{\circ}$) to a primary (001) peak ($2{\theta}{\sim}8.838^{\circ}$) was suggested to be a criterion to represent a degree of APS silylation-modification. Then, the optimal conditions on APS-stirring period prior to APS-MMT reaction, APS-MMT reaction period, APS concentration and reaction temperature at the highest area-ratio were turned out to be 20 min, 2~3 hr, 7.5 w/v% and $50^{\circ}C$, respectively.

• Proceedings of the KSMRM Conference
• /
• 2001.11a
• /
• pp.173-173
• /
• 2001

목적： 1.5T 생체용 자기공명영상기기를 이용한 수소자기공명분광법으로 용액 내 물질의 정량분석에 대한 가능성을 알아보고자 하였다. 대상 및 방법： 0.01％에서 50％까지의 여러 농도를 갖는 포도당+증류수 혼합액의 모델용액을 만들어 생체용 자기공명영상기기와 시험관 nuclear magnetic resonance (NMR) 분광기에서 각각 수소 자기공명분광법을 시행하여 스펙트럼을 얻었다. 또한 12명의 당뇨환자에서 방광내의 소변에 대해 생체용 자기공명영상기기에서 스펙트럼을 얻고 소변을 추출하여 시험관 NMR 분광기에서 수소자기공명분광법을 시행하였다 각각의 방법으로 얻은 스펙트럼 상에서 포도당 농도에 따른 포도당/물 피크의 면적 비의 변화를 구하였고, 통계처리는 상관분석과 단순선형회귀분석을 시행하였고 회귀식을 산출하였다. 또한 생체용 자기공명영상기기를 이용하여 얻은 결과가 객관적인지 알아보기 위해 시험관 NMR 분광기에서 얻은 결과와의 상관관계를 분석하였다.

• Journal of the Korean Institute of Gas
• /
• v.4 no.2 s.10
• /
• pp.27-32
• /
• 2000

In this study, $Mn_3O_4$ was synthesized by the different equivalent ratios using solution of $MnCL_2 {\cdot} 4H_2O$ and NaOH. We have investigated the crystal structure and surface area by XRD, BET Method, studied on the decompositon and adsorption of carbon dioxide with synthesized $Mn_3O_4$. As the results, we surveyed that main peak was $Mn_3O_4$, some Peaks were $MnO_2$ and $Mn_5O_8$ The specific surface area was ranged from $13.92m^2/g$ to $32.33m^2/g$. The decomposition of $CO_2$ was observed by the differential equivalent ratios at $450^{\circ}C$. $CO_2$ was well decomposed at equivalent ratio of 0.75. The amount of chemisorption of $CO_2$ was ranged from 2.885 to 19.628cc/g. Optimal equivalent ratio was 1.00 for the chemisorption of $CO_2$.

• Analytical Science and Technology
• /
• v.29 no.6
• /
• pp.283-292
• /
• 2016

Conventional fingerprint powders used during crime scene investigations pose potential health hazards. Thus, multiple natural replacement powders, including squid ink powder, indigo and rice powder were used to develop (visualize) latent fingerprints on non-porous surfaces (e.g., glass, plastic and tile). Fingerprints developed using the natural powders were compared using the Automatic Fingerprint Identification System (AFIS) with those developed with traditional black powder. The peak areas of ridges were also compared using densitometric image analyses. Collectively, objective and quantitative evaluation methods were developed. The effectiveness of natural powders varied depending on the surface but, in general, squid ink powder performed well on most surfaces. Indigo powder performed well on tile surfaces, while rice powder performed well on glass surfaces. Plastic was the most difficult surface from which to develop fingerprints. Image analysis using Field Emission Scanning Electron Microscopy (SEM) demonstrated the importance of the size and shape of natural powder particles to properly adhere to the ridges. Although densitometric image analyses did not correlate the number of minutiae and ridge peak areas, an unbiased, objective evaluation method would be possible using image analyses with a reference image. Additional experimentation will yield safe and cost-effective natural powders with which adequate fingerprint development can be performed.

• Applied Chemistry for Engineering
• /
• v.10 no.6
• /
• pp.876-880
• /
• 1999

The surfactant self-diffusion coefficients of mixed micellar solutions of ionic and nonionic surfactants have been measured by the NMR pulsed field gradient spin echo(FT-PGSE) method. In addition, the line widths of $^1H$ NMR signal have been monitored. The system investgated are $C_{12}EO_5/SDS/D_2O$, $C_{12}EO_5/DTAC/D_2O$, and $C_{12}EO_8/SDS/D_2O$. In the sample series, the molar ratios of $D_2O$ to surfactant(ionic+nonionic) were kept constant while the surfactant mixing ratio was varied. For the $C_{12}EO_5$ system, the surfactant self-diffusion coefficient indicates minimum when the surfactant mixing ratio is about 20% ionic surfactant. The observed decrease in self-diffusion coefficients as nonionic surfactant was replaced by ionic surfactant is interpreted to mainly be due to an increased micelle-micelle repulsion. The increase in self-diffusion coefficients occurring at higher fraction of ionic surfactant is shown to be due to a decrease in micelle size. For the $C_{12}EO_8$ system, the effect of the surfactant mixing ratio is much weaker which can be understood by considering the molecular geometry and large headgroup area. The proton NMR line widths correlate well with the self-diffusion coefficients and broadening of the alkyl chain methylene signals is found when the self-diffusion coefficients is low.

• The Korean Journal of Food And Nutrition
• /
• v.15 no.4
• /
• pp.331-336
• /
• 2002

Conformation of soymilk protein was examined to obtain basic information for improved calcium intolerence of soymilk protein partially hydrolyzed with protease. Surface hydrophobicities of three proteins showed the order of SMP(soymilk protein) < SPI(soy protein isolate) < PT-SMP(protease treated soymilk protein). Total thiol group contents of SMP and PT-SMP were similar but larger than that of SPI. Reducing rate of disulfide bond in PT-SMP after 2-mercaptoethanol treatment was laster than that in SMP. And so, this result indicates that PT-SMP may be less compacting due to protease treatement. From circular dichroism result, PT-SMP showed different pattern from SMP and SPI suggesting change of secondary structure by hydrolysis. And analysis of heat denaturating property by DSC showed that denaturation enthalpy of three proteins were all small. Especially enthalpy of PT-SMP was least, and this result suggested that PT-SMP was denatured easily by heating due to less compacting structure.