• Journal of Biosystems Engineering
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• 제39권3호
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• pp.215-226
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• 2014

Recently, spectroscopy has emerged as a potential tool for quality evaluation of numerous food and agricultural products because it provides information regarding both spectral distribution and image features of the sample (i.e., hyperspectral imaging). Spectroscopic techniques reveal hidden information regarding the sample and do so in a non-destructive manner. This review describes the various approaches of spectroscopic modalities, especially hyperspectroscopy and vibrational spectroscopies (i.e., Raman spectroscopy and Fourier transform near infrared spectroscopy) combined with chemometrics for the non-destructive assessment of contaminations and defects in agro-food products.

• Carbon letters
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• 제21권
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• pp.74-80
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• 2017

A highly facile and eco-friendly green synthesis of Annona squamosa (custard apple) leaf extract reduced graphene oxide (CRG) nanosheets was achieved by the reduction of graphene oxide (GO). The as-prepared CRG was characterized with X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-Vis), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopic techniques. Removal of oxygen containing moieties from the GO was confirmed by UV-Vis, FT-IR and XPS spectroscopic data. The XRD and Raman data further confirmed the formation of the CRG. TEM images showed the sheet structure of the synthesized CRG. These results show that the phytochemicals present in custard apple leaf extract act as excellent reducing agents. The CRG showed good dispersion in water.

• Natural Product Sciences
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• 제14권4호
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• pp.227-232
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• 2008

Phytochemical further investigation of the chloroform extract of the aerial parts of Crucianella maritima L. (Rubiaceae) growing in Egypt resulted in the isolation of a new anthraquinone; 3-formyl-1-hydroxy-2-methoxy anthraquinone (3) along with the four known compounds isolated for the first time from the genus Crucianella; alizarin-1-methyl ether (2), 1,4-dihydroxy-2-methoxy anthraquinone (5), 1, 3, 6-trihydroxy-2-methoxy anthraquinone (7) and the flavonol kaempferol (8), beside four known compounds previously isolated from the same plant. The structures of the isolated compounds were established based on different spectroscopic data including UV, IR, EIMS, 1D and 2D-NMR. Moreover, the antioxidant and antimicrobial activities of the isolated compounds were evaluated.

• Journal of Electrochemical Science and Technology
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• 제10권1호
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• pp.37-54
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• 2019

A new organic Schiff base compound N-benzylidene-2,5-dichloroaniline (BDC) was synthesized and the structure of the Schiff base is illuminated by some spectroscopic techniques. In addition, whether it is an applicable inhibitor in the industrial field was examined by conventional methods such as linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization for different concentrations. The BDC concentration and temperature effects were surveyed for elucidating the inhibitive mechanism. The BDC molecules are adsorbed to surface of mild steel via the Langmuir isotherm. Atomic force (AFM) and scanning electron microscope (SEM) techniques were utilized to give insight into surface characterization.

• 한국결정성장학회지
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• 제30권1호
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• pp.21-26
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• 2020

이 논문은 라이트박스의 주력 상품인 세 가지 색의 합성 다이아몬드의 분광학적 특성에 대해 분석한 결과이다. 드비어스의 브랜드인 라이트박스 주얼리는 2018년 9월부터 CVD 합성 다이아몬드를 판매하기 시작했다. 본 연구에서 검사된 샘플은 0.25 ct, 0.25 ct, 0.26 ct의 무색(H grade), 핑크, 청색의 합성 다이아몬드이며, 각 샘플의 테이블 중앙에는 라이트박스 로고가 레이저 각인되어 있었다. 분광학적 기법에 기초한 분석 결과, 무색 샘플은 결정성장 후 색 향상을 위한 고온고압 처리과정을 거치지 않았다. 핑크 샘플은 H3, 3H, 594 nm, NV, GR1의 광학 결함이 발견되었고, 이로 인해 결정성장 후 색 향상을 위해 조사와 열처리 과정을 거친 것으로 판단했다. 또한 블루 샘플은 열처리 과정 없이 조사만 되었음을 알 수 있었다.

• 천문학회지
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• 제54권2호
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• pp.49-60
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• 2021

Observations of line of sight (LOS) Doppler velocity and non-thermal line width in the off-limb solar corona are often used for investigating the Alfvén wave signatures in the corona. In this study, we compare LOS Doppler velocities and non-thermal line widths obtained simultaneously from two different instruments, Coronal Multichannel Polarimeter (CoMP) and Hinode/EUV Imaging Spectrometer (EIS), on various off-limb coronal regions: flaring and quiescent active regions, equatorial quiet region, and polar prominence and plume regions observed in 2012-2014. CoMP provides the polarization at the Fe xiii 10747 Å coronal forbidden lines which allows their spectral line intensity, LOS Doppler velocity, and line width to be measured with a low spectral resolution of 1.2 Å in 2-D off limb corona between 1.05 and 1.40 RSun, while Hinode/EIS gives us the EUV spectral information with a high spectral resolution (0.025 Å) in a limited field of view raster scan. In order to compare them, we make pseudo raster scan CoMP maps using information of each EIS scan slit time and position. We compare the CoMP and EIS spectroscopic maps by visual inspection, and examine their pixel to pixel correlations and percentages of pixel numbers satisfying the condition that the differences between CoMP and EIS spectroscopic quantities are within the EIS measurement accuracy: ±3 km s-1 for LOS Doppler velocity and ±9 km s-1 for non-thermal width. The main results are summarized as follows. By comparing CoMP and EIS Doppler velocity distributions, we find that they are consistent with each other overall in the active regions and equatorial quiet region (0.25 ≤ CC ≤ 0.7), while they are partially similar to each other in the overlying loops of prominences and near the bottom of the polar plume (0.02 ≤ CC ≤ 0.18). CoMP Doppler velocities are consistent with the EIS ones within the EIS measurement accuracy in most regions (≥ 87% of pixels) except for the polar region (45% of pixels). We find that CoMP and EIS non-thermal width distributions are similar overall in the active regions (0.06 ≤ CC ≤ 0.61), while they seem to be different in the others (-0.1 ≤ CC ≤ 0.00). CoMP non-thermal widths are similar to EIS ones within the EIS measurement accuracy in a quiescent active region (79% of pixels), while they do not match in the other regions (≤ 61% of pixels); the CoMP observations tend to underestimate the widths by about 20% to 40% compared to the EIS ones. Our results demonstrate that CoMP observations can provide reliable 2-D LOS Doppler velocity distributions on active regions and might provide their non-thermal width distributions.

• Archives of Pharmacal Research
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• 제20권4호
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• pp.338-341
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• 1997

Six substituted phenacyl derivatives of 4-hydroxypiperidine were prepared and their structures were confirmed through spectroscopic techniques. These newly synthesized derivatives were also screened for analgesic activity by chemical and thermal methods. Only halogenated phenacyl derivatives demonstrated more or less protection against acetic acid induced writhing in mice where as rest of three derivatives were found inactive when screened by this chemical method. Similarly all the six derivatives were proved inactive by tail flick test.

• Archives of Pharmacal Research
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• 제1권1호
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• pp.1-6
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• 1978

Rhodium (II) (isobutyrate)$_{4}L_2$, an antinumor drug, was shown to reactr with nucleic acid base derivatives, A, G, U and C in chloroform solution. When these derivatives were treated with one of novel metal compounds, rhodium carboxylate in chloroform solution, a fairly strong complex formation was observed by spectroscopic techniques. The characteristic of these complex was that binding occured at the two axial positions of rhodium (II) (isobutyrate)$_{4}L_2$ to the NH or )$NH_2$ group of the base in the ligands.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.388-388
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• 2010

Molybdenum oxide thin films were deposited on p-type Si(100) by an RF magnetron sputtering method. The physical and chemical properties of these films were studied with X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. The thickness of molybdenum oxide thin films was measured by spectroscopic ellipsometer (SE) and the thickness was about 200 nm. As the oxygen gas pressure increased, the thickness was decreased, the phases of the thin films were changed, and the amount of metallic Mo decreased but the contents of $Mo^{6+}$ species increases.

• Natural Product Sciences
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• 제4권3호
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• pp.148-152
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• 1998

The extract from the bulbs of Pancratium maritimum L. afforded 12 alkaloids belonging to the skeletally six different groups of the Amaryllidaceae alkaloids. In this paper, the isolation and identification of (-)-N-demethyl-galanthamine (1), (+)-tazettine (2) and (-)-2-O-demethylmontanine (3) are described. Their structures have been determined by using extensive spectroscopic techniques. This is the first report describing the occurrence of 1 and 3 in this plant.