• Title/Summary/Keyword: Photo-Activity

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Antioxidant Activity and Standardization of Extraction Solvents of SJ004 (SJ004의 추출용매별 항산화 활성 및 표준화 연구)

  • Lee, Dae-Yeon;Jo, Ju-Hwi;Kim, Wan-Su;Lee, Ho-Sung;Yi, Young-Woo;Park, Sang-In;An, Keon-Sang;Lee, In-Hee
    • Journal of Korean Medicine Rehabilitation
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    • v.30 no.2
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    • pp.67-75
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    • 2020
  • Objectives SJ004 is a natural herbal medicine that contains Acyranthes japonica Nakai and Eucommia ulmoides Oliver traditionally used for joint and spinal diseases. This study aimed to establish an efficient method of extracting SJ004 to standardize using the yield, high-performance liquid chromatography (HPLC), and antioxidant assay. Methods SJ004 was extracted with distilled water, 70% and 100% of ethyl alcohol (EtOH). The method validation of 20-hydroxyecdysone and pinoresinol diglucoside was determined by HPLC-photo diode array and the content of SJ004 was calculated. The antioxidant activity of each extract was compared and measured using total flavonoids, total phenolic compounds, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ferric reducing antioxidant power according to the standard protocol. Results The yield was highest in pure water extract and lowest in 100% EtOH. But, the content of marker compounds indicating 20-hydroxyecdysone and pinoresinol diglucoside was highest in 100% EtOH extract. In the physiological activity measurement using antioxidant activity, 100% ethanol extract was highest. The limit of detection indicating 20-hydroxyecdysone and pinoresinol diglucoside were analyzed 0.33 ㎍/mL, 0.1616 ㎍/mL, and the limit of quantification were analyzed 1.01 ㎍/mL and 0.49 ㎍/mL respectively. Conclusions The experimental results showed that the extraction conditions have a significant effect on content of marker compounds and antioxidant activity. As a result of method validation, SJ004 was standardized by 20-hydroxyecdysone and pinoresinol diglucoside.

Photosynthesis, Chlorophyll Contents and Leaf Characteristics of Illicium anisatum under Different Shading Treatments (비음처리에 따른 붓순나무의 광합성, 엽록소 함량 및 엽 특성)

  • Son, Seog-Gu;Han, Jin-Gyu;Kim, Chan-Soo;Hwang, Suk-In;Jeong, Jin-Heon;Lee, Sung-Gie
    • Journal of Environmental Science International
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    • v.16 no.11
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    • pp.1313-1318
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    • 2007
  • Illicium anisatum was bred under four different light intensity. Those condition were full sunlight(PPFD $1600{\mu} mol\;m^{-2}s^{-1}$), 30% treatment(PPFD $400{\mu} mol\;m^{-2}s^{-1}$), 50% treatment(PPFD $250{\mu} mol\;m^{-2}s^{-1}$) and 70% treatment(PPFD $100{\mu} mol\;m^{-2}s^{-1}$), respectively. Chlorophyll a and b were increased according to decrease of light intensity. Thirty percent and 50% treatment had not significant different in chlorophyll a and b. Thirty percent treatment was shown the best photosynthetic activity through invested photosynthetic rate, intercellular $CO_2$ concentration and water use efficiency. Photosynthetic activity trend of 50% treatment was similar to 30% treatment. Seventy percent treatment was shown the best photosynthetic activity at low light intensity but that was decreased to lower value than 30% and 50% treatment under high intensity. Control, bred full sunlight, was shown the worst photosynthetic activity at measured all light intensity. That result could imply that was caused by photo-inhibition because of long term exposed of shade tolerant plant at high light intensity. Leaf characteristics had not significant different in leaf length, width and area but leaf dry weight had similar trend to photosynthetic activity.

Antimicrobial Activity of Water-soluble Extract from Artemisia princeps var. orientalis (Artemisia princeps var. orientalis 수용성 추출물의 항균효과)

  • Cho, Hwa-Young;Yoon, Sung-Yong;Park, Jeong-Jin;Yun, Kung-Won;Park, Jong-Moon
    • KSBB Journal
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    • v.21 no.2
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    • pp.129-132
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    • 2006
  • The importance of natural preservative has increased in recent years. The natural preservatives have been used in the field of foods, cosmetics and pharmacology. In the present work Artemisia sp., well recognized for their effect of antimicrobial activity, were extracted by methanol and water sequentially for selecting only water-soluble compounds that can be used as additives in food and cosmetics. Antimicrobial activities of water extracts from stem and leaf of Artemisia princeps var. orientalis were investigated by the disc diffusion method. Two gram positive bacteria(Staphylococcus aureus and Bacillus subtilis) and three gram negative bacteria(Escherichia coil, Agrobacterium tumefaciens and Pseudomonas putida) were used for antimicrobial activity studies. The water-soluble compounds from methanol extract showed higher antimicrobial activity than only water extract to these bacteria. Comparative evaluation of water-soluble metabolite profiles with caffeic acid that is known as an antimicrobial compound from Artemisia sp. was performed by high performance liquid chromatography with photo-diode array detection.

Preparation of AgCl/Ag3PO4/Diatomite Composite by Microemulsion Method for Rapid Photo-Degradation of Rhodamine B with Stability under Visible Light

  • Zhu, Hai-Tao;Ren, Qi-Fang;Jin, Zhen;Ding, Yi;Liu, Xin-Yu;Ni, Xi-Hui;Han, Meng-Li;Ma, Shi-Yu;Ye, Qing;Oh, Won-Chun
    • Korean Journal of Materials Research
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    • v.30 no.8
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    • pp.383-392
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    • 2020
  • In this paper, AgCl/Ag3PO4/diatomite photocatalyst is successfully synthesized by microemulsion method and anion in situ substitution method. X-ray diffraction (XRD), photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV-Vis) are used to study the structural and physicochemical characteristics of the AgCl/Ag3PO4/diatomite composite. Using rhodamine B (RhB) as a simulated pollutant, the photocatalytic activity and stability of the AgCl/Ag3PO4/diatomite composite under visible light are evaluated. In the AgCl/Ag3PO4/diatomite visible light system, RhB is nearly 100 % degraded within 15 minutes. And, after five cycles of operation, the photocatalytic activity of AgCl/Ag3PO4/diatomite remains at 95 % of the original level, much higher than that of pure Ag3PO4 (40 %). In addition, the mechanism of enhanced catalytic performance is discussed. The high photocatalytic performance of AgCl/Ag3PO4/diatomite composites can be attributed to the synergistic effect of Ag3PO4, diatomite and AgCl nanoparticles. Free radical trapping experiments are used to show that holes and oxygen are the main active species. This material can quickly react with dye molecules adsorbed on the surface of diatomite to degrade RhB dye to CO2 and H2O. Even more remarkably, AgCl/Ag3PO4/diatomite can maintain above 95 % photo-degradation activity after five cycles.

Effects of Calcination Temperature on Ti02 Photocatalytic Activities (TiO2 광촉매 활성에서 소성온도의 영향)

  • Kim Seung-Min;Yun Tae-Kwan;Hong Dae-Ii
    • Journal of Environmental Science International
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    • v.14 no.9
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    • pp.889-896
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    • 2005
  • The nanosized $TiO_2$ photocatalysts were prepared by the hydrolysis of $TiCl_4$ and calcined at different temperatures. The resulting materials were characterized by TGA, DSC, XRD, and TEM testing techniques. XRD, TEM, and BET measurements indicated that the particle size of $TiO_2$ was increased with rise of calcination temperature and surface area was decreased with rise of it. The prepared $TiO_2$ photocatalysts were used for the photocatalytic degradation of congo red. The effects of calcination temperature, $TiO_2$ loading, the initial concentration of congo red, and usage frequencies were investigated and the rate constants were determined by regressing the experimental data. Calcination is an effective treatment to increase the photo activity of nanosized $TiO_2$ photocatalysts resulting from the improvement of crystallinity. The optimum calcination temperature of the catalyst for the efficient degradation of congo red was found to be $400^{\cric}C$. The rate constant was decreased with increase in the initial concentration of congo red and increased with increase in the $TiO_2$ loading. In the case of $TiO_2$ photocatalysts, the photocatalytic activity wasn't greatly affected by the usage frequencies.

Effect of ACF and WO3 from ACF/WO3/TiO2 Composite Catalysts on the Photocatalytic Degradation of MO Under Visible Light

  • Meng, Ze-Da;Song, Da-Ye;Zhu, Lei;Park, Chong-Yeon;Choi, Jong-Geun;Oh, Won-Chun
    • Journal of the Korean Ceramic Society
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    • v.48 no.4
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    • pp.282-287
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    • 2011
  • ACF and $WO_3$ modified $TiO_2$ composites (ACF/$WO_3$/$TiO_2$) were prepared using a sol-gel method. The composites were characterized by Brunauer.Emmett.Teller (BET) surface area measurements, X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis and scanning electron microscope (SEM) analysis. A methyl orange (MO) solution under visible light irradiation was used to determine the photocatalytic activity. The degradation of the MO was determined using UV/Vis spectrophotometry. An increase in photocatalytic activity was observed and attributed to an increase of the photo-absorption effect by the $WO_3$ and the cooperative effect of the ACF.

Photodecomposition of Different Organic Dyes Using Fe-CNT/TiO2 Composites under UV and Visible Light

  • Zhang, Kan;Meng, Ze-Da;Oh, Won-Chun
    • Journal of the Korean Ceramic Society
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    • v.47 no.2
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    • pp.169-176
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    • 2010
  • The Fe-treated CNT/$TiO_2$ photocatalysts mixed with anatase and rutile phase have been developed for the decomposition of non-biodegradable different organic dyes like methylene blue (MB), rhodamine B (Rh.B), and methyl orange (MO) in two conditions as ultraviolet and visible light respectively. The results indicate that all the Fe-CNT/$TiO_2$ composites proved to be more efficient photocatalysts since degradation of MB at higher reaction rates, tthe decomposition rate of different dyes increases with an increase of $Fe^{3+}$ concentration in composites the highest rate of decomposition of different dyes was noted under UV irradiation. These results can indicate that the large CNT network is facilitate the electron transfer and strongly adsorb dye molecules on the texted photocatalysts, iron is reactive in the photo-Fenton process resulting in high production of OH radicals and also high activity of the photocatalyst. And Fe particles can generate more photoinduced electrons to conduction band of $TiO_2$ under visible light irradiation. The composites of Fe-CNT/$TiO_2$ photocatalysts synthesized by a sol-gel method were characterized by BET, TEM, SEM, XRD and EDX.

Performance Test of $TiO_2$ Catalyst in VOCs Photocatalytic Degradation (VOCs 광촉매 분해용 $TiO_2$촉매제조 및 성능평가)

  • Lee Seung-Bum;Lee Jae-Dong;Park Yoon-Shin
    • Journal of environmental and Sanitary engineering
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    • v.20 no.4 s.58
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    • pp.45-50
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    • 2005
  • Titania gel formations were prepared by sol-gel method using titanium(IV) chloride $(TiCl_4)$, and its characteristics were analyzed by varying the $epoxide/TiCl_4$ ratio and the amount of water In the end, titania $(TiO_2)$ aerogel were prepared using supercritical drying process. VOCs such as benzene, toluene, and m-xylene (BTX) were oxidized using prepared titania aerogel and commercially available $TiO_2$, and its performance was compared. The surface area, pore volume, and average pore diameter of 1,2-epoxybutane are significantly smaller than the propylene oxide. And the titania aerogels with 6 moi of epoxides have high surface areas, pore volumes, and average pore diameters. As a result of photo-oxidation, conversion of benzene was reached about $70\%$, and other reactants were reached about $60\%$ similarly. The conversion of BTX was increased as inlet concentration decreased. The reactivity of titania calcined at $600^{\circ}C$ was greater than $400^{\circ}C$ and $800^{\circ}C$. Water is required as a reactants for the oxidation of VOCs, and the continuous consumption of hydroxyl radicals required replenishments to maintain catalyst activity. The activity ratio increased with increasing reaction time when enough amount of water was present in the reactor.

Properties and Photocatalytic Activity of Pitch-binded ACF/TiO2Composites

  • Oh, Won-Chun;Jung, Ah-Reum
    • Journal of the Korean Ceramic Society
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    • v.45 no.3
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    • pp.150-156
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    • 2008
  • Pitch-binded activated carbon fiber(ACF)/$TiO_2$ composite photocatalysts were prepared by Carbon Tetra Chloride (CTC) solvent mixing method with different mixing ratios of anatase to ACF. The result of the textural surface properties demonstrated that there is a slight increase in the Brunauer, Emmett and Teller (BET) surface area of composites with an increase of the amount of ACF. The surfaces structure morphologies of the composites were observed using an Scanning Electron Microscope (SEM). In the XRD patterns for all ACF/$TiO_2$ composites, the diffraction peaks showed the formation of anatase crystallites. The EDX spectra showed the presence of C, O and Si with strong Ti peaks. Most of these samples were richer in carbon and major Ti metal than any other elements. From the photo-decomposition results, the excellent activity of the ACF/$TiO_2$ composites between c/$c_0$ for methylene blue and UV irradiation time could be attributed to both the effects of the photocatalysis of the supported $TiO_2$ and adsorptivity of activated carbon fiber and another carbon derived from pitch.

Bridging the Age-Related Communication Gap: An Encounter Between Senior Citizens and Communication Students Towards Social Integration

  • Bantugan, Brian Saludes;Bantugan, Fe C.;Urbano, Ricardo C.
    • Asian Journal for Public Opinion Research
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    • v.5 no.2
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    • pp.84-103
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    • 2018
  • This paper is built upon an attempt to answer the question: "What can be done to facilitate social integration between the elderly of Bagac, Bataan and the communication students of St. Paul University Manila?" The research was designed as a qualitative inquiry that involved an outreach activity by 24 dominantly female students of Development Communication to the senior citizens of Bagac, Bataan (Philippines) and a reflection period involving the students. The students were tasked to pay special attention to the digital engagements and/or disengagements of the elderly to allow them to learn more about the difficulties and potential of using social media in development-related projects involving senior citizens. The actual two-hour encounter involved socialization between the elderly and the students. The students, prior to the encounter, were tasked to generate the funds, use them to acquire and prepare the gifts, develop the program during the actual encounter based on research-based guidelines, and photo document the entire activity. They were given guide questions for reflections a week after. The reflections were thematically analyzed and revealed that in order to facilitate greater social integration between the elderly and the communication students. The university should address the health and digital aversion issues that intensify the sense of isolation of the elderly experience daily. This can be done by enhancing the communication skills of the communication students in 16 areas.