• 제목/요약/키워드: bleaching

검색결과 615건 처리시간 0.029초

Antioxidant activity of sesame cake extracts obtaining using various ethanol extraction conditions

  • Lee, Kyoung Ah;Min, Keun Young;Lee, Na-Kyoung;Chang, Kyung Hoon;Cho, Seong Jun;Chung, Won Dae;Paik, Hyun-Dong
    • 한국식품과학회지
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    • 제49권3호
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    • pp.338-342
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    • 2017
  • The antioxidant activities of sesame cake extracts prepared using ethanol and hot water were evaluated. Seventy percent-ethanol extracts yielded the highest total phenolic (96.56 mg/g extract) and flavonoid (8.35 mg/g extract) contents. In the ${\beta}$-carotene bleaching and ferric thiocyanate test, 30%-, 50%-, and 70%-ethanol extracts exhibited higher antioxidant activity than that exhibited by 90%-ethanol extracts. However, 90%-ethanol extracts showed greater antioxidant activities in phenyl-2-picryl-hydrazyl free radical scavenging test and thiobarbituric acid test using corn oil. The antioxidant activities of sesame cake extracts did not correlate with the total phenolic and flavonoid contents; however, the results suggest that oxidative stability may be improved by sesame cake extracts.

The Middle Lamella Remainders on the Surface of Various Mechanical Pulp Fibres

  • Li, Kecheng;Tan, Xuequan;Yan, Dongbo
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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    • pp.51-59
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    • 2006
  • The surface of various mechanical pulp fibres including thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), and alkaline peroxide mechanical pulp (APMP) fibres, were characterized using SEM, AFM, and XPS. With SEM and AFM, middle lamella material was observed to be non-fibrillar, patch-like, while fibre secondary wall was observed to have a microfibrillar structure. It was found that after the first-stage refiner, lignin-rich middle lamella remainders are present on the fibre surface of all three pulps, although most of the fibre surfaces expose microfibrillar structure. After the final-stage refining, large amounts of granules are present on the TMP fibre surface. In contrast, most middle lamella remainders remain on the surface of CTMP fibres after final stage refining and even after peroxide bleaching. XPS results have confirmed that the non-fibrillar surface material is the lignin-rich middle lamella remainder., and the remainders of middle lamella contribute to the high surface lignin concentration.

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Dentinal Tubules Occluding Effect Using Nonthermal Atmospheric Plasma

  • Lee, Chang Han;Kim, Young Min;Kim, Gyoo Cheon;Kim, Shin
    • International Journal of Oral Biology
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    • 제43권2호
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    • pp.83-91
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    • 2018
  • Nonthermal atmospheric plasma has been studied for its many biomedical effects, such as tooth bleaching, wound healing, and coagulation. In this study, the effects of dentinal tubules occlusion were investigated using fluoride-carboxymethyl cellulose (F-CMC) gel, nano-sized hydroxyapatite (n-HA), and nonthermal atmospheric plasma. Human dentin specimens were divided to 5 groups (group C, HA, HAF, HAP, and HAFP). Group HA was treated with n-HA, group HAF was treated with n-HA after a F-CMC gel application, group HAP was treated with n-HA after a plasma treatment and group HAFP was treated with n-HA after a plasma and F-CMC gel treatment. The occlusion of dentinal tubules was investigated using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS), which shows Ca/P ratio. In the EDS results, a higher Ca/P ratio was shown in the groups including n-HA than in the control group. The specimens of group HAP and HAFP had a higher Ca/P ratio in retentivity. In the SEM results, there was not a significant difference in the amount of times applied. Therefore, this study suggests F-CMC gel and n-HA treatment using nonthermal atmospheric plasma will be a new treatment method for decreasing hypersensitivity.

Initial Risk Assessment of Benzoyl Peroxide in OECD High Production Volume Chemical Program

  • Heekyung Bae;Kim, Su-Hyon;Kim, Mi-Kyoung;Sanghwan Song;Hyunju Koo;Lee, Moon-Soon;Jeon, Seong-Hwan;Na, Jin-Gyun;Park, Kwangsik
    • 한국환경독성학회:학술대회논문집
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    • 한국환경독성학회 2003년도 추계국제학술대회
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    • pp.160-161
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    • 2003
  • In Korea, 1, 357 tonnes of benzoyl peroxide was produced as a white granule with purities ranging 22 to 95% in 2001. 75% of benzoyl peroxide is mainly used in the manufacture of expandable styrene polymer and other resins as initiators of polymerization and also been used in the treatment of acne vulgaris and the medical product contains mainly 5 to 10% of it. A very small portion of benzoyl Peroxide is used as flour bleaching agent, Potential human exposure from workplaces is expected to be negligible because this chemical is produced in closed system in only one company in Korea and when a production facility monitors its workplace for the worker exposure annually, the concentration of airborne aerosols at the personal sampling has been less than 1mg/㎥.

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Reactive Dyeing of Bio Pretreated Cotton Knitted Fabrics

  • Ayoub, Alvira;Ali, Iftikhar;Son, Eun Jong;Jeong, Sung Hoon
    • 한국염색가공학회지
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    • 제26권4호
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    • pp.283-289
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    • 2014
  • This study describes the feasibility and optimization of reactive dyeing on bio treated cotton knitted fabrics. For this, cotton knitted fabrics distinctly with two different enzymes, alkaline Pectinases(Scourzyme $L^{(R)}$) and Pectate lyases(Bactosol Co. ip $liquor^{(R)}$). In this way by increasing the concentration and processing temperature, the access of enzymes towards the fatty and waxy substrate was found to be accelerated. To achieve higher absorbency and whiteness index, a series of experiments was carried out to assure that Pectate lyases enzymes possesses high access towards the fats and waxes at high temperature. To this end, cotton knitted fabrics was dyed without oxidative bleaching step. The Pectate lyases scoured and dyed fabrics showed less color difference when 2% dye shade is used. The fabrics pre-scoured with Pectate lyases showed good the light and washing fastness properties, compared to the conventional and Pectinases dyed fabrics. However pectinases enzymes showed lower activity at high temperature, caused poor wettability and whiteness index of fabrics. The improvement of the accessibility of enzyme to the pectin at higher temperature Pectate lyases treatment before dyeing was found to be useful for subsequent pectin degradation in cotton knitted fabrics.

알칼리성 $100^{\circ}C$에서 화학적 산소요구량 신속정량법 (A Rapid COD Test Procedure for Alkaline Permanganate Value Determination)

  • 채명준;이수영;김영경
    • 분석과학
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    • 제8권2호
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    • pp.167-170
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    • 1995
  • 염소이온의 유무 및 양에 상관없이 적용할수 있는 알칼리성 과망간산 산화제에 의한 화학적 산소요구량을 신속하게 정량하는 실험절차를 개발하였다. 끓는 물에서 닫힌 환류 90초 동안이면 충분하였다. 시료량 5mL, 최종 부피 10mL일 때 NaOH는 1%, $KMnO_4$ 농도는 0.6mM이 최적 용액 조건이었다. 한 차례의 실험(시료 5~6개)에 걸리는 시간은 5분 이내였다.

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닥 펄프 제조공정 자동화에 따른 단위공정 폐수의 특성 (Characteristics of wastewater from unit systems of automative process for manufacture of paper mulberry pulp fibers)

  • 황지현;황성준;김형진
    • 펄프종이기술
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    • 제47권3호
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    • pp.55-62
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    • 2015
  • Paper mulberry fibers have been used as fibrous raw materials for manufacturing traditional handmade paper, hanji for a long time. Compared to wood pulp fibers, pulp fibers from mulberry bast tissue have some benefits in physical and chemical properties due to their high D.P (degree of polymerization), M.W (molecule weight) and long fiber length. Specially, Korean handmade hanji shows outstanding characteristics in mechanical tensile strength, folding endurance, flexibility and long sustainable conservation properties. Therefore, hanji is widely applied to daily supplies, hygienic goods, medical supplies, clothing industries and so on. Recently, the potential demand of mulberry pulp fibers is more and more increased on the strength of high application fields. This study was focused on the possibility of wastewater recycling in unit operation systems for the development of automated mass production line. The properties and environmental loads of wastewater from debarking, cooking, bleaching and screening process were analyzed by means of COD, conductivity, turbidity and solid materials. The wastewater from debarking and cooking process was comparatively high in pollution load, and would be treated by additional approaches of chemico-physical method.

$Gei^3ta^1$ in Taiwan Mandarin--- A Particular Construction

  • Lee, Chia-Chun
    • 한국언어정보학회:학술대회논문집
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    • 한국언어정보학회 2007년도 정기학술대회
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    • pp.268-274
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    • 2007
  • The present paper investigates a particular structure in Taiwan Mandarin, "(NP) + (intensifier) + $gei^3ta^1$ "give him/it"+ adjective" in terms of construction grammar. The structure is mostly observed in utterances of younger generation. Though it is not regarded as a grammatical or standard structure, it is still a register of language. The structure lays emphasis on speaker's attitude toward an undesired, unpleasant event. In most cases, the attitude tends to be negative. The events or propositions must have existed or been completed. The adjectives compatible with this structure belong to category of higher degree. The grammatical usage illustrates semantic bleaching of $gei^3ta^1$. And the changes from giving to a grammatical particle denoting subjective belief is a kind of subjectification. Moreover, $ta^1$ could refer to events or situation expressed by a more complicated grammatical structure, or denotes nothing as a dummy word. Though many previous studies paid attention to the newly developed structure resulted from language contact, the adequate account was not provided. It is hoped through this investigation, we will get a better understanding of this particular structure.

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Distal Demonstrative Hitlo in Taiwanese Southern Min

  • Zhao, Yi-jing
    • 한국언어정보학회:학술대회논문집
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    • 한국언어정보학회 2007년도 정기학술대회
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    • pp.522-530
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    • 2007
  • This article investigates the use of distal demonstrative Hitlo in Taiwanese Southern Min (TSM) from a discourse-pragmatic perspective. The analysis is based on a 5-hour corpus of spoken data, including daily conversations, radio interviews, TV drama series, and some random examples. A total of 172 tokens of Hitlos are identified in the data. They can be divided into six categories according to their functions: firstly, exophoric usage, those Hitlos which refer to an object non-linguistically which can be identified in the immediate situation; secondly, endophoric usage, those which refer to an element textually; thirdly, referent introducing function, those which can be used to introduce a new but identifiable referent into the conversation (the referent usually has topical importance); fourthly, hedging expression, those which serve as a marker of imprecision; fifthly, a condition introducing marker, those which function as an indicator of the coming of a conditional sentence; finally, pause fillers, those which help speakers to manage speech turn or indicate the mental states In addition, an interactive function which Hitlo is found to serve will be discussed. Moreover, a grammaticalizational process involving semantic bleaching which Hitlo is probably undergoing is revealed in general. Finally, a filled demonstrative principle, stating that it may be a universal phenomenon to use demonstratives as filled pause will be proposed.

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Electrochromic 막의 특성과 물질이동 방지막의 효과에 대한 연구

  • 황하룡;백지흠;허증수;이대식;이덕동;임정옥;장동식
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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    • pp.66-66
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    • 2000
  • Electrochromism이란 기전력 방향에 의한 가역적으로 색이 변하는 현상을 말하며, 열린 회로 기억성을 가지며 소비전력이 적고, 우수한 착색 효율을 갖는 등 여러 가지 유용성 때문에 디스플레이 및 전기적 착색 유리창에의 기술적 적용 가능성을 보이고 있다. 본 연구에서는 가장 우수한 일렉트로크로믹 특성을 내는 것으로 알려진 WO3 박막과 대향 전극으로 V2O5 박막을 사용하였다. 이들 박막은 알칼리 이온 주입물질이며, coloration.bleaching상태에서 광학 밀도가 크고, 내구성이 좋으며, 작은 비용으로 재료를 사용할 수 있다. 그리고 더 우수한 장점으로 부각되는 대면적의 코팅의 매력적인 기술인 졸겔법으로 제조 가능한 특성을 가지고 있다. 졸겔법 및 진공증착법으로 박막을 제조하고, 박막산화 및 수명저하 등의 위험이 적은 리튬이온을 이용하여 소자를 제작한 후 일렉트로크로믹 특성을 조사하고, 우수한 소자의 제조조건을 얻고자 하였다. 측정결과 졸겔법으로 제조된 WO3 박막과 V2O5 박막을 수증기 분위기에서 50$0^{\circ}C$로 1시간 열처리한 경우 가장 우수한 투과 변화율을 나타내었다. 정상전압인 2 volt보다 높은 3 volt로 cyclic voltamogram을 측정하는 과정에서 정.역방향 동작을 거듭할수록 peak이 크게 감소하는 현상을 발견하였으며, 양이온의 흐름에 의해 물질의 이동이 발생할 것이라는 판단아래 Auger depth profile을 측정한 결과 WO3막의 텅스텐과 ITO막의 인듐이 상호 확산하는 것을 관찰할 수 있었다. 이를 방지하기 위해 수백 의 텅스텐 박막을 WO3 막 위에 증착한 후 cyclic voltamogram과 Auger depth profile을 측정한 결과, cyclic voltamogram의 peak의 감소량이 1/10이하로 감호하였으며, 리튬이온의 흐름에 의한 인듐과 텅스텐의 이동을 효과적으로 방지할 수 있었다. 따라서 텅스텐 확산방지막의 삽입이 소자의 수명을 향상시킬 수 있는 효과적인 방법이라고 사료된다.

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