• Title/Summary/Keyword: bleaching

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Changes in the Properties of Cotton Cellulose by Hydrogen Peroxide Bleaching (과산화수소 표백조건에 따른 면셀룰로오스의 특성 변화)

  • Heo, Yong-Dae;Sung, Yong Joo;Joung, Yang-Jin;Kim, Duk-Ki;Kim, Tae-Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.3
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    • pp.59-68
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    • 2013
  • The cotton contains various impurities such as protein, wax, pectins, coloring matter, even though cotton has been a major source of pure cellulose. The purification processes have been commonly applied to obtain the pure cellulose. However the excessive purification treatments could lead to the damage in the cellulose structure which could result in the degradation of cellulose and the limited application of cotton cellulose. In this study, the changes in cellulose structural properties such as crystallinity and DP(degree of polymerization) by the various conditions of the purification processes were investigated. The less toxic agents such as hydrogen peroxide and sodium silicate were applied for the purification treatment in this study. The increase in the process times, the temperature and the applied amount of chemical agents resulted in the more purified cellulose. The DP of cotton cellulose was increased at the first weak conditions by the reduction of small molecules such as pectin, wax, and so on. Especially the 2 % addition amount of $H_2O_2$ with $Na_2SiO_3$ resulted in the higher value in the DP and the brightness compared to the 1.5 % addition amount of $H_2O_2$. However, the 4 % addition amount of $H_2O_2$ with $Na_2SiO_3$ showed the decreased value because of excessive treatment. In case of the changes in the crystallinity (Gjk), the highest value of the crystallinity was obtained by the 2% addition amount of $H_2O_2$ on the cotton cellulose, which showed similar with the change in the DP.

Plasma Medicine: How can Nonthermal Atmospheric Plasma be Applied to Medicine? (플라즈마 메디신: 저온 상압 플라즈마는 어떻게 의학분야에 적용될 수 있는가?)

  • Park, Sang Rye;Hong, Jin Woo;Lee, Hae June;Kim, Gyoo Cheon
    • Journal of Life Science
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    • v.23 no.6
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    • pp.838-846
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    • 2013
  • As a forth state of material, plasma is ionized gas, which generates characteristically various reactive species. After late of $20^{th}$ century, plasma has been widely used in industry. After nonthermal atmospheric plasma was developed, it has been applied to biomedical fields. Nonthermal atmospheric plasma does not give thermal damages to human tissues, and it shows the high efficiency in cancer treatment, sterilization, tooth bleaching, coagulation, and wound healing. Because the application of plasma to biomedicine has been expanded through interdisciplinary studies, its value of high medical technology is increasing now. Since nonthermal atmospheric plasma was first applied to the mammalian cells and microorganisms, many valuable studies has been performed for about last 10 years, so that now the new research area called 'plasma medicine' has been formed. This article introduces the recent data resulted from plasma medicine and helps to understand the plasma medicine.

Improvement of the Thermostability of Xylanase from Thermobacillus composti through Site-Directed Mutagenesis

  • Tian, Yong-Sheng;Xu, Jing;Chen, Lei;Fu, Xiao-Yan;Peng, Ri-He;Yao, Quan-Hong
    • Journal of Microbiology and Biotechnology
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    • v.27 no.10
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    • pp.1783-1789
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    • 2017
  • Thermostability is an important property of xylanase because high temperature is required for its applications, such as wood pulp bleaching, baking, and animal feedstuff processing. In this study, XynB from Thermobacillus composti, a moderately thermophilic gram-negative bacterium, was modified via site-directed mutagenesis (based on its 3D structure) to obtain thermostable xylanase, and the properties of this enzyme were analyzed. Results revealed that the half-life of xylanase at $65^{\circ}C$ increased from 10 to 50 min after a disulfide bridge was introduced between the ${\alpha}$-helix and its adjacent ${\beta}$-sheet at S98 and N145. Further mutation at the side of A153E named XynB-CE in the C-terminal of this ${\alpha}$-helix enhanced the half-life of xylanase for 60 min at $65^{\circ}C$. Therefore, the mutant may be utilized for industrial applications.

Functional Ingredient and Their Some Variance in Amaranth and Quinoa (비름(Amaranth)과 명아주(Quinoa) 재배종의 기능성 물질과 변이)

  • Lee, Jae-Hak;Kim, Ki-Jun;Lee, Jung-Il;Lee, Seung-Tack;Ryu, Su-Noh
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.spc1
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    • pp.145-165
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    • 1996
  • Amaranth(Amaranthus spp. L.) and quinoa (Chenpodium quinoa Willd.) are old crops from South, Central America and Central Asia and their grains have been identified as very promising food crops because of their exceptional nutritive value. Squalene is an important ingredient in skin cosmetics and computer disc lubricants as well as bioactive materials such as inhibition of fungal and mammalian sterol biosynthesis, antitumor, anticancer, and immunomodulation. Amaranth has a component called squalene (2,6,10,15,19,23-hexamethyl-2,6,10,14,22-tetraco-sahexaene) about 1/300 of the seed and $5\~8\%$ of its seed oil. Oil and squalene content in amaranth seed were different for the species investigated. Squalene content in seed oil also increased by $15.5\%$ due to puffing and from 6.96 to $8.01\%$ by refining and bleaching. Saponin concentrations in quinoa seed ranged 0.01 to $5.6\%$. Saponins are located in the outer layers of quinoa grain. These layers include the perianth, pericarp, a seed coat layer, and a cuticle like structure. Oleanane-type triterpenes saponins are of great interest because of their diverse pharmacological properties, for instance, anti-inflammatory, antibiotic, contraceptive, and cholesterol-lowering effects. It is known that quinoa contains a number of structurally diverse saponins including the aglycones, oleanolic acid, hederagenin, and phytolaccagenic acid, which are new potential in gredient for pharmacological properties. It is likely that these saponin levels will be considerably affected by genetic, agronomic and environmental factors as well as by processing. With the current enhanced public interest in health and nutrition amaranth and quinoa will most likely remain in the immediate future within the realm of exotic health foods until such time as agricultural production meets the quantities and qualify required by industrial food manufacturers.

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Indoor and Outdoor Concentrations of Air Pollutants in Beauty Shops at kwangju Area

  • Son Bu-Soon;Song Mi-Ra;Yang Won-Ho;Park Jong-An
    • Journal of Environmental Science International
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    • v.15 no.2
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    • pp.101-106
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    • 2006
  • The work of hairdressers includes washing, coloring, bleaching, permanent waving, conditioning, and cutting hair. Hairdressers are subjected to a number of physical and toxicological hazards. The toxicological hazards are those resulting from exposure to a wide range of chemicals that are usually classified active processes. In this study, twenty beauty shops were selected to assess the exposure to indoor air pollutants such as VOCs and particulate matter $(PM_{10})$ during one month from September 1 to September 30, 2003. Indoor air quality of beauty shops might be worse by vehicle emissions because the beauty shops were generally located near roadways. Personal exposures to VOCs and $PM_{10}$ were related to indoor concentrations of beauty shops. According to the questionnaire, hairdressers complained of sore throat, eye irritation, and nervousness as physical symptoms. The measured mean concentrations of respiratory particulates were $30.5ng/m^3$ in indoor, $30.5ng/m^3$ in outdoor and $44.0ng/m^3$ on personal levels. The personal concentration was found higher than indoor and outdoor concentrations. The heavy metals mean concentrations were shown as indoor (Na>Zn>Cr), outdoor (Cr>Zn>Pb), and personal (Na>Cr>Zn) levels. Conclusively, customers as well as workers in the beauty shops might be highly exposed to air pollutants from indoor and outdoor sources. Therefore, proper management should be taken to improve the indoor air quality in beauty shops.

Biodiesel Refining and Glycerin Recovering Process of Transesterification from Tra Catfish Fat

  • Huong, Le Thi Thanh;Tan, Phan Minh;Hoa, Tran Thi Viet;Lee, Soo
    • Journal of the Korean Applied Science and Technology
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    • v.26 no.1
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    • pp.1-9
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    • 2009
  • Nowadays, Tra catfish fat is given attention as an appropriate material for biodiesel production in Vietnam. The aim of this work is to investigate the optimal conditions of refining biodiesel and recovering glycerin by the transesterification from Tra catfish fat using KOH catalyst. As our results, the yield of transesterification was achieved to 94.17% at $50^{\circ}C$ for 45 min with 6:1 molar ratio of methanol to fat in the presence of 0.8% KOH catalyst, and wherein the biodiesel was refined by washing with distilled water at $70^{\circ}C$ and dried in a microwave oven. The yield of raw glycerin recoveries from the transesterification process was 78.58%. The purity of raw glycerin was 84.14% by the conditions of neutralization state with $H_{3}PO_{4}$ solution (pH = 5), $70^{\circ}C$, and 60 min. Activated carbon (3.0 wt.%) was used for the bleaching process at $80^{\circ}C$ for 20 min. The biodiesel was obtained in accordance with for ASTM D 6751 (biodiesel standard). The ash and water of raw glycerins were 7.32 and 8.01%, respectively, and implied that the raw glycerin is very promising candidate to be used as a raw material for textile and cosmetic industries.

다채널 표면 플라즈몬 공명 영상장치를 이용한 자기조립 단분자막의 표면 분석

  • Pyo, Hyeon-Bong;Sin, Yong-Beom;Yun, Hyeon-Cheol
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.74-78
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    • 2003
  • Multi-channel images of 11-MUA and 11-MUOH self-assembled monolayers were obtained by using two-dimensional surface plasmon resonance (SPR) absorption. Patterning process was simplified by exploiting direct photo-oxidation of thiol bonding (photolysis) instead of conventional photolithography. Sharper images were resolved by using a white light source in combination with a narrow bandpass filter in the visible region, minimizing the diffraction patterns on the images. The line profile calibration of the image contrast caused by different resonance conditions at each points on the sensor surface (at a fixed incident angle) enables us to discriminate the monolayer thickness in sub-nanometer scale. Furthermore, there is no signal degradation such as photo bleaching or quenching which are common in the detection methods based on the fluorescence.

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Antioxidative Activity of Feral Haw (Crataegus pinnatifida BUNGE) Seed Extracts Using Various Solvents (자생 산사(Crataegus pinnatifida BUNGE)씨의 추출 용매에 따른 항산화 활성)

  • Kim, Min-A;Duan, Yishan;Seong, Jong-Hwan;Chung, Hun-Sik;Kim, Han-Soo
    • Korean journal of food and cookery science
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    • v.30 no.1
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    • pp.33-40
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    • 2014
  • The purpose of this study was to examine the antioxidative activity of feral haw (Crataegus pinnatifida BUNGE) seed extracts using 70% methanol, 70% ethanol, chloroform:methanol (CM, 2:1, v/v), n-butanol and ethyl acetate (EA). The total phenol content of the five extracts ranged from 37.29 mg/g to 55.53 mg/g. Moreover, the content was high in the 70% methanol and, 70% ethanol extracts, but low in the n-butanol extract. On the contrary, the total flavonoid content decreased in the order of n-butanol (2.93 mg/g), EA (2.67 mg/g), 70% methanol (1.00 mg/g), 70% ethanol (0.88 mg/g) and CM (0.67 mg/g) extracts. The $NO_2$ radical scavenging activity, antioxidant activity by ${\beta}$-carotene bleaching assay and, superoxide dismutase (SOD) like ability decreased in the order of 70% methanol, 70% ethanol, CM, EA and, n-butanol extracts; further, a similar tendency was also observed in the total phenol contents. Overall, these results indicated that the antioxidative activity of feral haw seeds was closely related to the total phenol and flavonoid contents. Therefore, haw seeds might be usefully applied to natural antioxidants as well as functional foods.

Effects of Oil Refining Processes on Oxidative Stability and Antioxidative Substances of Sesame Oil (정제공정이 참기름의 항산화 물질과 산화 안정성에 미치는 영향)

  • Han, Jin-Suk;Moon, Soo-Yeun;Ahn, Seung-Yo
    • Korean Journal of Food Science and Technology
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    • v.29 no.1
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    • pp.15-20
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    • 1997
  • Changes in antioxidative substances-sesamol, sesamin and sesamolin - and mineral contents of sesame oil during refining processes have been studied to investigate the oxidative stability of oils during the storage at $70^{\circ}C$. Fe, Cu, Mg and Zn were nearly removed from the oil by the degumming process. During storage, the changes of total volatile contents in crude and degummed sesame oil were not noticeable but those in alkali-refined and deodorized sesame oil were increased at early period of the storage. The increases of hexanal and pentanal were most noticeable and their concentration was increased markedly in alkali-refined, bleached and deodorized sesame oil at early period of the storage. During refining processes and storage, sesamin was relatively stable but the content of sesamolin was decreased. The content of sesamol was decreased until alkali-refining process but increased during a bleaching process. The content of sesamolin tended to decrease with increasing of sesamol during storage.

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Herbicidal Activity of New Rice Herbicide Pyrimisulfan+Mefenacet SC against Sulfonlurea-Resistant Sea Club Rush (Scirpus planiculmis) (설포닐우레아계 제초제 저항성 새섬매자기에 대한 신규 제초제 Pyrimisulfan+Mefenacet SC의 약제방제 효과)

  • Park, Min-Sik;Park, Yong-Seog;Kim, Sung-Min;Lee, Jeong-Deug
    • Korean Journal of Weed Science
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    • v.31 no.2
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    • pp.192-198
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    • 2011
  • This study was conducted to investigate the herbicidal activity against Scirpus planiculmis (SCPPL) which has been reported as resistant biotype on sulfonylurea (SU) herbicides at the west coast reclaimed area first and proliferated continuously at Hwasung and Pyeongtaek in Gyeonggi province, and some Chungnam province. In order to investigate resistance breakability against SCPPL, new rice herbicides containing tefuryltrione [p-hydrophenyl pyruvate dioxygenase (HPPD) inhibitor], pyrimisulfan and triafamone[actolactate synthethase (ALS) inhibitor] were tested. In both lab and field experiments, tefuryltrione GR, 4-HPPD inhibitor showed growth retardation with a bleaching on the young leaves of SCPPL at early time after treatment. However, it restored and regerminated with insufficient control effect. On the other hand, pyrimisulfan+mefenacet SC, triafamone+tefuryltrione GR, and ALS inhibitor showed excellent control effect on SU-resistant SCPPL with growth retardation and necrosis. In particular, pyrimisulfan+mefenacet SC showed excellent controlling effect on SU-resistant SCPPL in regional field experiments.