• Applied Biological Chemistry
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• 제32권1호
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• pp.1-7
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• 1989

Methyl linolenate를 자동산화반응(自動酸化反應)의 model 화합물(化合物)로 선정(選定)하여 실온(室溫)에서 90m1/min.의 air flow rate로 96시간(時間) 산화(酸化)시켰으며 여기서 얻어진 산화생성물(酸化生成物)을 TLC로 분리(分離)한 다음 각(各) 분획물(分劃物)을 ir, uv, nmr로 분석(分析)하였다. 분광기기분석(分光機器分析) 결과(結果)는 서로 일치(一致)하였으며 Rf. 0.28과 $0.15{\sim}0.10$의 화합물(化合物)들이 hydroperoxide와 cis, trans-substituted diene인 것으로 확인(確認)되었고 주(主)로 cis, transconjugated diene system과 약간(若干)의 trans, trans-configuration인 것으로 밝혀졌다. 특(特)히 $5.83{\sim}6.60ppm$에서 나타난 multiplet 부위(部位)는 산화생성물(酸化生成物)들의 화학구조(化學構造)를 결정(決定)함에 있어서 큰 도움을 줄 것으로 생각하기 때문에 앞으로 많은 연구(硏究)가 요망(要望)된다.

• 한국광학회지
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• 제14권6호
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• pp.594-599
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• 2003

1.6 $\mu\textrm{m}$ 파장대의 U밴드 광증폭기용 광섬유 소재인 Pr첨가 Ge-Sb-Se 계열 셀레나이드 유리의 굴절률을 분광타원법을 이용하여 결정하였다. 시료의 광물성을 조사하기 위해 투과 파장 영역에서의 타원 스펙트럼을 Sellmeier 분산관계식에 기반한 공기/미시 거칠기층/표면층/기층으로 구성된 4상계의 모델에 적용하여 굴절률과 분산계수 및 박막구조상수를 동시에 얻을 수 있었다. 디스크 형태로 가공된 각 시료의 양면을 대상으로 위치에 따라 수회 반복 측정을 통하여 시료의 표면 거칠기의 영향을 파악함으로써 조성 변화에 대한 굴절률 변화 양상을 보다 정확히 파악하였다. 시료의 표면 거칠기가 굴절률 측정치의 편차에 주된 영향을 미쳤으나 1 몰%에 해당하는 소량의 조성변화에 따른 굴절률 변화를 신뢰할 수 있는 수준으로 결정할 수 있었다. 실험적으로 결정된 조성변화와 굴절률과의 관계식은 단일모드의 셀레나이드 광섬유 제작에 있어 코어와 클래드의 조성을 결정하는데 직접적으로 활용될 수 있다.

• 천문학회지
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• 제55권2호
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• pp.23-36
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• 2022

We present a method to determine nitrogen abundance ratios with respect to iron ([N/Fe]) from molecular CN-band features observed in low-resolution (R ~ 2000) stellar spectra obtained by the Sloan Digital Sky Survey (SDSS) and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). Various tests are carried out to check the systematic and random errors of our technique, and the impact of signal-to-noise (S/N) ratios of stellar spectra on the determined [N/Fe]. We find that the uncertainty of our derived [N/Fe] is less than 0.3 dex for S/N ratios larger than 10 in the ranges T_eff = [4000, 6000] K, log g = [0.0, 3.5], [Fe/H] = [-3.0, 0.0], [C/Fe] = [-1.0, +4.5], and [N/Fe] = [-1.0, +4.5], the parameter space that we are interested in to identify N-enhanced stars in the Galactic halo. A star-by-star comparison with a sample of stars with [N/Fe] estimates available from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) also suggests a similar level of uncertainty in our measured [N/Fe], after removing its systematic error. Based on these results, we conclude that our method is able to reproduce [N/Fe] from low-resolution spectroscopic data, with an uncertainty sufficiently small to discover N-rich stars that presumably originated from disrupted Galactic globular clusters.

• International Journal of Computer Science & Network Security
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• 제23권3호
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• pp.193-202
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• 2023

Numerous articles under the study and the examination of heavy metals in human teeth have been published in recent years. The heavy metal poisoning is a widespread issue emerged in toxicology area these days. It has been discovered that long-term exposure to heavy metals typically present in traces, in our everyday meals, drinking water, and in the environment as pollution causes heavy metal poisoning in human beings. Industrial effluents, Coal and Oil, as well as a variety of consumer items, such as cosmetics, can all cause this type of exposure. Teeth, which are often thought of as exoskeleton parts, store heavy metals with a high affinity and represent long-term exposure information. In this study, we have chosen and examined the sections of dentine instead, then examined the entire tooth. We have combined the work done on the examination of heavy metals in human teeth using several instrumental approaches e.g. "Optical Spectroscopic Techniques" to detect elemental profile of human teeth in the current study.

• 분석과학
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• 제34권6호
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• pp.267-274
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• 2021

분광학적 검출에 의해 종말점을 확인하는 적정기(Spectrator; SPT)와 기존 적정기(automatic burette; ABT, autotitrator; ATT)를 사용한 분석 결과를 비교하기 위하여 동일한 시료에 대한 산-염기 적정 실험을 수행하였다. 각기 다른 적정장치를 사용하여 얻어진 측정값(종말점)의 직진성, 동등성, ANOVA, F-테스트, t-테스트 등을 통하여 차이점을 통계학 분석을 수행하였으며, 직진성에서 확인된 결정계수는 모두 0.999 이상이고 통계적으로 분석된 결과에 의하여 측정값에 차이가 없다는 귀무가설은 채택되었다. 새로운 실험방법에 대한 일치성을 확인하는 Bland-Altman 분석을 통하여 본 연구에서 사용한 적정장치에서 얻어진 측정값에서 불일치 양상이 확인되지 않았다.

• Near Infrared Analysis
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• 제2권1호
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• pp.43-53
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• 2001

A non-invasive spectroscopic method is presented for the measurement of pulmonary edema. Both early diagnosis and quantitative edema estimates were investigated. The spectroscopic determination of pulmonary edema involved the acquisition of diffuse reflectance spectra in the near-infrared (NIR) region with change in water concentration - water is the main constituent of edema fluid. Pulmonary edema was induced into the excised perfused lungs of seven animals by elevating the hydrostatic pressure. Estimates of edema were ascertained from a partial least squares regression of the measured spectral response. Actual edema was determined from the change (increase) in total lung weight. Estimates in relative lung weight increases due to in vitro edema were made with the near infrared spectra. The results revealed that fluid accumulation produced spectral changes in the O-H and C-H absorptions as well as scattering changes in the spectra. Histology of the lung was used to verify the presence or absence of interstitial and alveolar edema. Results demonstrated that near infrared spectroscopy might provide a new tool for clinical assessment of pulmonary edema.

• Journal of Photoscience
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• 제11권1호
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• pp.29-33
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• 2004

The mechanism of interaction of cyanocobalamin (CB) with bovine serum albumin (BSA) has been investigated by spectrofluorometric and circular dichroism methods. Association constant for the CB-BSA system showed that the interaction is non-covalent in nature. Binding studies in the presence of an hydrophobic probe, 8-anilino-l-naphthalene sulphonic acid, sodium salt (ANS) showed that there is hydrophobic interaction between CB and ANS and they do not share common sites in BSA. Stern-Volmer analysis of fluorescence quenching data showed that the fraction of fluorophore (protein) accessible to the quencher (CB) was close to unity indicating thereby that both tryptophan residues of BSA are involved in drug-protein interaction. The rate constant for quenching, greater than $10^{10}$ $M^{-1}$ $s^{-1}$, indicated that the drug binding site is in close proximity to tryptophan residue of BSA. Thermodynamic parameters obtained from data at different temperatures showed that the binding of CB to BSA involves hydrophobic bonds predominantly. Significant increase in concentration of free drug was observed for CB in presence of paracetamol. Circular dichroism studies revealed the change in helicity of BSA due to binding of CB to BSA.

• 천문학회보
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• 제40권1호
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• pp.72.3-72.3
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• 2015

We present the mid-infrared (MIR) luminosity function (LF) of local (z < 0.3) star forming (SF) galaxies based on the AKARI's NEP-Wide Survey data. We utilized a combination of the NEP-Wide point source catalogue containing a large number (114,000) of infrared (IR) sources distributed over the wide (5.4 sq. deg) field and spectroscopic redshift (z) data for 1790 selected targets obtained by optical follow-up surveys with MMT/Hectospec and WIYN/Hydra. The AKARI's continuous $2{\sim}24{\mu}m$ wavelength coverage and the spectroscopic redshifts for sample galaxies enable us to derive accurate spectral energy distributions (SEDs) in the mid-infrared. We carried out SED-fit analysis and employed 1/Vmax method to derive the mid-IR (e.g., $8{\mu}m$, $12{\mu}m$, and $15{\mu}m$ rest-frame) luminosity functions. Our results for local galaxies from the NEP region generally consistent with various previous works for other fields over wide luminosity ranges. The comparison with the results of the NEP-Deep data implies the luminosity evolution from higher redshifts towards the present epoch. We attempted to fit our derived LFs to the double power-laws and present the resulting power indices. We also examined the correlation between mid-IR luminosity and total IR luminosity.

• 응용통계연구
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• 제10권2호
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• pp.227-239
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• 1997

분광학분야에서 측정되는 자료는 여러 파장에서 측정된 스펙트럼 행렬과 이 스펙트럼을 통하여 알고자하는 어떤 반응치들의 행렬 또는 벡터로 주어진다. 이 경우 측정 자료에의 많은 잡음(noise)과 파장간의 상관관계가 내재한다. 부분최소제곱회귀 방법은 여러 개의 파장에서 측정된 자료를 모두 이용하는데 자료축약과정을 통하여 자료의 잡음 문제와 상관관계 문제를 해결하는 다변량통계방법이다. 본 연구에서는 이러한 자료에 적합한 부분최소제곱회귀의 이론을 알아보고 실제로 측정된 자료를 통하여 주어진 스펙트럼에 대한 반응치의 예측을 부분최소제곱회귀 방법을 이용하여 고찰하였다.

• 천문학논총
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• 제32권1호
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• pp.45-47
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• 2017

The Infrared Camera onboard the AKARI satellite carried out spectroscopic observations with a grism mode named NG, whose wavelength coverage was $2.5-5.0{\mu}m$. We reinvestigate the current flux calibration for the NG grism mode, with which calculated flux density implausibly decreases at $4.9{\mu}m$ especially for red objects due to the second-order light contamination. We perform a new spectral response calibration using blue and red standard objects simultaneously. New response curves which contain both the first-and second-order light are able to separate each contribution consistently and useful for studies of red objects such as CO ro-vibrational absorption in active galactic nuclei.