• Title/Summary/Keyword: UV absorbance

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Qualitative Analysis by Derivative Spectrophotometry (II) - Computer-assisted spectral analysis using derivative spectra and Root Mean of Squares of differences -

  • Park, Man-Ki;Park, Jeong-Hill;Cho, Jung-Hwan
    • Archives of Pharmacal Research
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    • v.12 no.4
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    • pp.289-294
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    • 1989
  • A computer program which can differentiate compounds whose absorbance spectra are very similar was developed. The program. [SPECMAN PLUS], written in Pascal provides automated spectral comparison techniques, utilizing the values of Root Mean of Squares (RMS) of differences. This comparison routine of the program can deal with spectra of compounds different concentrations and different spectral recording resolutions. In addition, the program was designed applicable to any spectral data of digital form. The program was applied to the UV spectra of 13 pencillins and 5 cephalosporins, whose absorbance spectra are so similar. As a result, all compounds examined could be differentiated from each other.

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Dyeing Properties of Morus alba L. Fruit Powder on the Silk Fabric (오디 분말을 이용한 견직물의 염색성)

  • Bai, Sang-Kyoung
    • Fashion & Textile Research Journal
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    • v.10 no.5
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    • pp.779-783
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    • 2008
  • The main colorant of Morus alba L. fruit is anthocyanin which is a kind of flavonoid group. In this article, the dyeing properties of colorant extracted from Morus alba L. fruit were investigated on some silk fabrics. The results were as follows: The maximum absorbance of Morus alba L. fruit showed at 284 nm, and 516 nm by UV-VIS spectrophotometer. The dye adsorption increased according as dye concentration. The optimal dyeing temperature was $60^{\circ}C$ and the dye equilibrium was reached 40 minutes after dyeing. The highest K/S value of the colorant obtained at bath ratio 40:1. The effect of pH of dye solution showed higher K/S value at acidic than alkaline condition. Almost Mordants except pre-Fe and Sn did not significantly increased dye adsorption. The pre mordanted silk fabrics showed RP, P, and post mordanted ones showed PB, GY. The color fastnesses to light, washing, and perspiration were modified at pre-Sn mordanted samples.

Studies on the Natural Dyes(12) -Dyeing Properties of Amur Cork Tree Colors for Silk- (천연염료에 관한 연구(12) -황벽 색소의 견섬유에 대한 염색성-)

  • 조경래;강미정
    • Textile Coloration and Finishing
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    • v.12 no.4
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    • pp.239-247
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    • 2000
  • The coloring matter was extracted from the heartwood of Amur cork tree by distilled water. Change of UV-Visible spectra of coloring matter solution by extraction condition and stability for irradiation were determined, and the effect of repeated dyeing with condition of dyebath and mordanting method on shade depth and lightfastness were also investigated. The results are as follows : 1) Absorbance of Amur cork tree extract increased with the lapse of extraction time. λmax of color solution extracted from Amur cork tree was found at 420, 333, and 262nm. 2) Absorbance of Amur cork tree extract decreased remarkably after 2hr irradiation. 3) The K/S of silk fabrics increased with the increase of dyeing temperature, time, amounts of Amur cork tree for extraction, and pH of color solution. 4) K/S of silk fabrics dyed by repeated dyeing method was affected by pH and concentration of color solution. 5) Lightfastness of silk twice dyed with Amur cork tree extract after pre-mordanted by 8%(o.w.f) chromium acetate was moderately improved.

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Influences of Environmental Conditions and Refractory Organic Matters on Organic Carbon Oxidation Rates Measured by a High Temperature Combustion and a UV-sulfate Methods (다양한 환경요인과 난분해성 유기물에 따른 고온산화 및 UV산화방식 총 유기탄소 산화율 변화)

  • Jung, Heon-Jae;Lee, Bo-Mi;Lee, Keun-Heon;Shin, Hyun-Sang;Hur, Jin
    • Journal of Korean Society on Water Environment
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    • v.32 no.1
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    • pp.98-107
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    • 2016
  • This study examined the effects of environmental conditions and the presence of refractory organic matter on oxidation rates of total organic carbon (TOC) measurements based on high temperature combustion and ultraviolet-sulfate methods. Spectroscopic indices for prediction of oxidation rates were also explored using the UV spectra and fluorescence excitation-emission matrix (EEM) of humic acids. Furthermore, optimum TOC instrument conditions were suggested by comparing oxidation rates of a standard TOC material under various conditions. Environmental conditions included salts, reduced ions, and suspended solids. Salts had the greatest influence on oxidation rates in the UV-sulfate method. However, no effect was detected in the high temperature combustion method. The UV-sulfate method showed lower humic substance oxidation rates, refractory natural organic matter, compared to the other methods. TOC oxidation rates for the UV-sulfate method were negatively correlated with higher specific-UV absorbance, humification index, and humic-like EEM peak intensities, suggesting that these spectroscopic indices could be used to predict TOC oxidation rates. TOC signals from instruments using the UV-sulfate method increased with increasing chamber temperature and increasing UV exposure durations. Signals were more sensitive to the former condition, suggesting that chamber temperature is important for improving the TOC oxidation rates of refractory organic matter.

Influence of UV-B Radiation on Photosynthesis, Growth and Pigmentation of Chondrus ocellatus (Rhodophyta) from Shallow Water

  • Taejun Han;Han, Young-Seok;Cho, Man-Gee;Park, Jin-Hee;Goo, Jae-Gun;Kang, Sung-Ho
    • Korean Journal of Environmental Biology
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    • v.21 no.4
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    • pp.368-376
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    • 2003
  • The UV-B sensitivity was tested for the intertidal species Chondrus ocellatus from Korea, by measuring photosynthesis estimated as effective quantum yield ($\Phi_{PSII}$) of photosystem II (PS II), growth and content and composition of photosynthetic pigments and UV-absorbing pigments (UVAPs). The $$\Phi_{PSII}$ of the alga decreased with increasing time of exposure to UV-B radiation, followed by fast and nearly full recovery indicating dynamic photoinhibiton. Fresh weight-based growth and pigment contents of C. ocellatus were not seriously affected by UV-B radiation. A single broad peak at 327 nm was obtained from methanol extracts of C. ocellatus, and the absorbance peak increased with increasing UV. The single peak was resolved into three peaks (311, 330 and 336 nm) by the fourth -derivative, and quantitative change in response to UV-B radiation occurred only at 330 nm. High performance liquid chromatography (HPLC) analysis of purified extracts indicated that three MAAs (mycosporine-like amino acids) are present, asterina 330, palythine and shinorine. Field observations during three growing months showed that C. ocellatus exhibit the highest amount of UVAPs in May followed by July and little trace in September, coinciding with the species' phenology. In an ecological context, dynamic photoinhibition as well as accumulation of UVAPs may enable the shallow water red alga C. ocellatus to be well adapted to high UV-B environments.

Photosynthetic Response and Protective Regulation To Ultraviolet-B Radiation In Green Pepper (Capsicum annuum L.)Leaves

  • Kim, Dae-Whan;Jun, Sung-Soo;Hong, Young-Nam
    • Journal of Photoscience
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    • v.8 no.1
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    • pp.1-7
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    • 2001
  • The deteriorative effect of ultraviolet-B(UV-B) radiation on photosynthesis was assessed by the simultaneous measurement of O$_2$ evolution and chlorophyll(Chl) fluorescence in green pepper. UV-B was given at the intensity of 1 W$.$m$\^$-2/, a dosage often encountered in urban area of Seoul in Korea, to detached leaves. Both Pmax and quantum yield of O$_2$ evolution was rapidly decreased, in a parallel phase, with increasing time of UV-B treatment. Chl fluorescence parameters were also significantly affected. Fo was increased while both Fm and Fv were decreased. Photochemical efficiency of PSII(Fv/Fm) was also declined, although to a lesser extent than Pmax. Both qP and NPQ were decreased similarly with increasing time of UV-B treatment. However, PS I remained stable. The addition of lincomycin prior to UV-B treatment accelerated the decline in Fv/Fm to some extent, suggesting that D1 protein turnover may play a role in overcoming the harmful effect of UV-B. The amount of photosynthetic pigments was less affected than photosynthetic response in showing decline in Chl a and carotenoids after 24 h-treatment. Presumptive flavonoid contents, measured by changes in absorbance at 270 nm , 300 nm and 330nm, were all increased by roughly 50% after 8 h-treatment. Among antioxidant enzymes, activities of catalase and peroxidase were steadily increased until 12h of UV-B treatment whereas ascorbate perxidase, dehydroascorvate reductase and glutathione reductase did not show any significant change. The results indicate that deteriorative effect of UV-B on photosynthesis precedes the protection exerted by pigment synthesis and antioxidant enzymes.

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Changes in Spectroscopic Characteristics and Pyrene Binding Reactivities of Dissolved Organic Matters By Biodegradation (생분해에 의한 용존 자연유기물질 분광특성 및 Pyrene 결합반응성 변화)

  • Park, Min-Hye;Hur, Jin
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.9
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    • pp.893-899
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    • 2008
  • Changes in spectroscopic characteristics and pyrene binding coefficients of terrestrial dissolved organic matters(DOM) were investigated during microbial incubation. The incubation studies were conducted for 21 days using a leaf litter DOM and a soilderived DOM with an inoculum from a river. The dissolved organic carbon(DOC), the specific UV absorbance(SUVA), the synchronous fluorescence spectra, and the pyrene organic carbon-normalized binding coefficient(K$_{oc}$) of the DOM were measured at the incubation days of 0, 3, 7, 14 and 21. After the 21-day incubation, DOC were reduced to 61% and 51% of the original concentrations of the litter DOM and the soil-derived DOM, respectively. Comparison of the spectroscopic characteristics before and after the incubation revealed that the SUVA, the fulvic-like fluorescence(FLF), the humic-like fluorescence(HLF) of the different DOM were enhanced by the incubation whereas the protein-like fluorescence(PLF) was reduced. This indicates that more aromatic and humic-like compounds were enriched during the biodegradation process while biodegradable and weak carbon structures were depleted. Irrespective of the DOM sources, SUVA values showed a positive relationship with pyrene K$_{oc}$ with a correlation coefficient of 0.97. The FLF and HLF also exhibited good correlations with K$_{oc}$ values although different regression equations were obtained from the different DOM. Our results suggest that the selected spectroscopic characteristics could be good estimation indices for the changes of the binding reactivity of DOM for hydrophobic organic contaminants during biodegradation process.

Emulsification of Natural Sunscreen with Green Tea Extract : Optimization Using CCD-RSM (녹차추출물이 함유된 천연 자외선차단 크림의 제조: CCD-RSM을 이용한 최적화)

  • Lee, Seung Bum;Zuo, Chengliang;Xu, Yang;Hong, In Kwon
    • Applied Chemistry for Engineering
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    • v.31 no.5
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    • pp.532-538
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    • 2020
  • In this study, emulsification process were conducted to manufacture the natural sunscreen from raw materials such as shea butter, olive emulsifier wax, and green tea extract. The emulsification was optimized by using the central composite design model-response surface methodology (CCD-RSM) where the response values were established as the mean droplet size (MDS) and emulsion stability index (ESI) after 7 days in addition to UV absorbance at 300nm. The amount of emulsifier and additives and emulsification time were established as operating variables and the optimal conditions of sunscreen emulsification were accepted as 3.70, 2.47 wt.%, and 15.42 min, respectively according to the result of CCD-RSM. On the other hand, the response values were estimated as 1173.80 nm and 99.56% for MDS and ESI, respectively, after 7 days, in addition to UV absorbance at 300 nm (2.47). The average error from actual experiments was a low level as about 3.0 ± 1.5%, which is mainly due to the fact that the optimization using CCD-RSM applied in this study was in the relatively high significant level.

SPECTROPHOTOMETRIC EVALUATION OF SEALING EFFECTS OF SEVERAL ROOT-END FILLING MATERIALS (분광광도법을 사용한 수종 역충전재의 근단부 폐쇄효과에 관한 연구)

  • Yi, Jin-Gyu;Park, Sang-Jin;Choi, Kyung-Kyu;Choi, Gi-Woon
    • Restorative Dentistry and Endodontics
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    • v.28 no.6
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    • pp.449-456
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    • 2003
  • The purpose of this study is to evaluate the sealing effect of several root-end filling materials using spectrophotometric analysis. 180 single root teeth with one canal were instrumented and canal filled. Root resected and root end preparation was made. Teeth were randomly classified to S experimental group(MTA, EBA, IRM, TCP, ZOE) and 1 control group according to root-end filling material MTA group used PRO ROOT MT A, EBA group used Super EBA. TCP group used NEW APATITE LINER TYPE II main component of which is ${\alpha}-tricalcium$ phosphate (TCP). According to manufacture's instruction experimental material was mixed and retrfilled. After 2% methylene blue solution penetration absorbance for each test sample was measured with spectrophotometer (JASCO UV-530, Japan). The mean absorbance of control and experimental group was as follows; MTA: 0.092, IRM: 0.226, Super EBA: 0.255, ZOE: 0.374, Control: 0.425, TCP: 0.501 and the result analyzed by Turkey test at P=0.05 level. Conclusions of this study are as follows; 1. The absorbance increase in following sequence MTA, IRM, Super EBA, ZOE, Control. TCP. 2. MTA showed the least leakage but was not significant with IRM or Super EBA and was significant with control or TCP(p<0.05). 3. TCP had the most leakage and was not significant with control group.

Color Characteristics of Korean Traditional Soy Sauces Prepared Under Different Processing Conditions (제조조건에 따른 한국전통간장의 색 특성에 관한 연구)

  • 전민선;손경희;채선희;박현경;전형주
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.31 no.1
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    • pp.32-38
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    • 2002
  • The characteristics of blown color of Korean traditional soy sauces under different processing conditions were investigated in this research. As for meju type, traditional and modified mejus were used. The samples were produced from four levels of aging time. 0 day, 60 days, 120 days and 180 days in both clay jar and glass jar. Color intensity of soy sauce was probed with different mothods. In terms of colorcharacteristics, the absorbance at 420 nm seemed to reflect the brown color intensity of soy sauces. UV-VIS spectra of the soy sauce with traditional meiu revealed that the absorbance at 235 nm was produced during the soaking period whereas that at 410 nm was created during the aging process and only round in the spectra of soy sauce aged for 180 days. As for the soy sauce with modified meiu, the maximum absorbance was focused at 235 nm which were prepared during soaking period.