• 제목/요약/키워드: Free carbon

검색결과 951건 처리시간 0.034초

HyRAM+를 이용한 수소 누출 시뮬레이터 구현 (Inplementation of a Hydrogen Leakage Simulator with HyRAM+)

  • 황성호
    • 문화기술의 융합
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    • 제10권1호
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    • pp.551-557
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    • 2024
  • 수소는 청정, 무탄소, 고에너지등 다양한 특징을 가진 재생에너지원으로 국제적으로 '미래에너지'로 인정받고 있다. 수소에너지 산업의 급속한 발전과 더불어 수소 수요를 충족시키기 위하여 더 많은 수소 인프라가 필요한 실정이다. 그러나 수소 인프라 사고가 빈번한 발생함으로 인해, 수소산업 발전에 걸림돌이 되고 있다. 미국 Sandia National Laboratories에서 개발한 HyRAM+는 수소충전소를 포함한 다양한 저장 응용 분야에 대한 수소 안전 평가와 관련된 데이터와 방법을 통합하는 소프트웨어 툴킷이다. HyRAM+의 물리 모드는 수소충전소 컴포넌트에 따라 수소누출 결과를 모사하여 가스 플룸 분산, 제트 프레임 온도와 궤적 그리고 복사 열속 등을 그래프로 나타낸다. 본 논문에서는 강원도 삼척시에 있는 수소충전소를 대상으로하여 HyRAM+ 소프트웨어를 이용하여 수소 누출 데이터를 추출하였다. HyRAM+에서 추출한 데이터를 이용하여 수소 누출(Leakage) 발생 시뮬레이터를 개발하였다. 데이터베이스와 그라파나(Grafana)를 이용하여 시뮬레이터에서 발생한 데이터를 보여주는 대쉬보드(Dashboard)로 구현하였다.

The Trend of Cigarette Design and Tobacco Flavor System Development

  • Wu, Jimmy Z.
    • 한국연초학회지
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    • 제24권1호
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    • pp.67-73
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    • 2002
  • In light of addressing consumer health concern, coping with anti-tobacco movement, and promoting new product, tobacco industry is actively pursuing to make a new generation of cigarettes with low tar and nicotine deliveries, and less harmful substances. Low tar and low nicotine cigarettes increases their market shares dramatically world wide, especially in KT&G, multinational tobacco companies, EU countries, even in China regulated by CNTC to set up yearly target to lower tar and nicotine deliveries. On the other hand, to design a new cigarette with reduced harmful substances begins to gain speed. The "modified Hoffmann list" publishes thirty plus substances in tobacco leaf and main smoke stream, which is the prime suspect causing health problems. Various ways and means are developed to reduce such components including new tobacco breeds, new curing method, tobacco leaf treatment before processing, selected filtration system, innovated casing system to reduce free radicals, as well as some non conventional cigarette products. In TSRC held this year, the main topic is related to reduce tobacco specific nitrosamines in tobacco leaf. The new generation of cigarette is in the horizon. It still needs a lot help to produce commercial products with satisfied taste and aroma characters. The flavor industry is not regulated by many governments demanding which ingredients might or might not be for tobacco use. However, most of the cigarette companies self impose a list of ingredients to guide flavor suppliers to design flavors. Unfortunately, the number of ingredients in those lists is getting shorter every year. It is understandable that the health is not the only reason. Some cigarette companies are playing safe to protect the company from potential lawsuit, while others are just copying from their competitors. Moreover, it is obvious that it needs more assistance from casings and flavors to design new generation of cigarettes with missing certain flavor components in tobacco leaf and main smoke stream. These flavor components are either non-existed or at lower level at new form of cured tobacco leaf or filtered in the main smoke stream along with reduced harmful substances. The use of carbon filters and other selected filtration system poses another tough task for flavor system design. Specific flavor components are missing from the smoke analysis data, which brings a notion of "carbon taste" and "dryness" of mouth feel. It is ever more demanded by cigarette industry to flavor suppliers to produce flavors as body enhancer, tobacco notes, salivating agents, harshness reducer, and various of aromatic notes provided they are safe to use. Another trend is that water based flavor or flavor with reduced ethanol as solvent is gaining popularity. It is preferred by some cigarette companies that the flavor is compounded with all natural ingredients or all ingredients should he GMO free. The new generation of cigarettes demands many ways of new thinking process. It is also vital for tobacco industry. It reflects the real needs for the consumers that the cigarette product should be safe to use as well as bearing the taste and aroma characters smokers always enjoyed. An effective tobacco flavor system is definitely a part of the equation. The global trend of tobacco industry is like trends of any other industries lead by consumer needs, benefited with new technology availability, affected by the global economy, and subjected for various rules and regulations. Anti-tobacco organizations and media exceptionally scrutinize cigarette, as a legal commercial product. Cigarette is probably the most studied commercial product for its composition, structure, deliveries, effects, as well as its new developmental trend. Therefore, any new trend of cigarette development would be within these boundaries. This paper is trying to point out what it would be like for tobacco industry in the next few yews and what concerns the tobacco industry. It focuses mostly on the efforts to produce safer cigarettes. It is such a vital task for the tobacco industry and its affiliate industries such as cigarette papers, filters, flavors, and other materials. The facts and knowledge presented in this paper might be well known for the public. Some of the comments and predictions are very much personal opinion for a further discussion.

폐콘크리트 미분말 치환율에 따른 이산화탄소 반응경화 시멘트의 광물상 분석 (Mineralogical Analysis of Calcium Silicate Cement according to the Mixing Rate of Waste Concrete Powder)

  • 이향선;송훈
    • 한국건축시공학회지
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    • 제24권2호
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    • pp.181-191
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    • 2024
  • 석회석은 시멘트의 주원료로써 90% 이상을 사용하고 있으며, 고온 소성 과정에서 및 석회석의 탈탄산 반응으로 많은 양의 CO2를 배출한다. 이에 석회석 사용량 저감을 위해 원료를 대체할 수 있는 부산물에 관한 연구들이 진행 중이다. 또한 광물 탄산화는 기체인 CO2를 탄산염 광물로 전환하는 기술로 산업시설에서 배출되는 CO2를 포집하여 광물로 저장 및 자원화할 수 있다. 한편, 건설폐기물은 계속적으로 증가하는 추세로, 폐콘크리트는 많은 부분을 차지하고 있다. 폐콘크리트는 파쇄 및 분쇄를 통해 순환골재로써 활용되고 있으나 이때 발생하는 폐콘크리트 미분말은 유효하게 재이용 되지 못하고 대부분 폐기 또는 매립되는 실정이다. 이에 본 연구에서는 폐콘크리트를 석회석 대체재로써 활용하여 광물 탄산화 기술을 적용할 수 있는 이산화탄소 반응경화 시멘트 제조 가능성을 확인하고자 한다. 폐콘크리트 미분말 치환율 및 이산화탄소 반응 경화 시멘트의 주요 광물이 생성되는 조건인 SiO2/(CaO+SiO2) 몰비에 따른 광물 분석 결과, 폐콘크리트 미분말 치환율과 SiO2/(CaO+SiO2) 몰비가 높을수록 주요 광물인 Pseudowollastonite와 Rankinite 생성량이 증가하였다. 또한 세 가지 SiO2/(CaO+SiO2) 몰비에서 공통적으로 폐콘크리트 미분말을 50% 치환한 경우 Gehlenite가 생성되었으며, 생성량 또한 유사하였다. 이는 콘크리트 미분말에 함유하고 있는 Al2O3 성분이 CaO와 SiO2와 반응하여 Gehlenite가 합성된 것으로 판단된다. Gehlenite의 경우 Pseudowollastonite와 Rankinite와 같이 광물 탄산화를 통해 탄산염 광물인 CaCO3를 생성하는 산화물로써 이는 Al2O3가 함유된 산업부산물을 원료로 사용하는 경우 이산화탄소 반응경화 시멘트의 광물로써 활용이 가능할 것으로 기대한다.

Chlorella sp. KR-1 열분해에 의한 지질 회수 및 열분해 오일 특성 분석 (Recovery of Lipids from Chlorella sp. KR-1 via Pyrolysis and Characteristics of the Pyrolysis Oil)

  • 이호세;전상구;오유관;김광호;정수현;나정걸;여상도
    • Korean Chemical Engineering Research
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    • 제50권4호
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    • pp.672-677
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    • 2012
  • Chlorella sp. KR-1 바이오매스에 대한 열분해를 통하여 세포 내 지질을 회수하였다. 중성지질 함량이 10.8%와 36.5%인 두 종류의 KR-1 샘플에 대하여 $600^{\circ}C$에서 열분해를 수행함으로써 지질 함량이 열분해 오일 수율 및 품질 등 반응 특성에 미치는 영향을 살펴보았다. 열분해 결과, 중성지질 함량이 높아 C/H 비가 낮은 샘플이 열분해 전환율 및 오일 수율이 높았다. 저분자량의 유기산, 케톤, 알데히드, 알콜은 두 시료의 열분해에서 모두 발생하였으나 중성지질 함량이 높은 미세조류의 경우 palmitic acid와 oleic acid를 비롯한 유리 지방산의 함량이 높은 대신 질소 함유 유기화합물의 함량은 상대적으로 적었다. 미세조류 열분해 오일은 두 개의 층으로 분리되는데 상부의 경질 분획은 지질 분해에 의하여, 하부의 중질 분획은 당류나 단백질의 분해에 의하여 생성된 것으로 판단되었다. 상부의 경질 분획에는 중성지질의 분해 산물인 유리지방산 이외에 직쇄형 알칸도 상당 부분 포함되어 있었으며 이는 미세조류 열분해시 열분해와 함께 탈카르복실 반응을 비롯한 탈산소 반응이 동시에 일어났기 때문이다. GC 분석을 통하여 생성된 열분해 오일의 품질을 조사하고 지질 추출 방법으로서의 열분해 공정을 평가하였다. 중성지질 함량이 36.5%인 KR-1 샘플의 경우 열분해 수율이 56.9%이며 이 중 경질분획은 68.2%로서 경질분획 만의 수율은 38.8%였다. 또한, 경질분획의 80% 이상이 유리지방산과 순수 탄화수소로 구성되어있어 열분해를 통하여 대부분의 지질을 회수할 수 있음을 확인하였다.

Agar를 분해하는 swarming 박테리아 균주의 특성과 동정 (Characterization and Identification of an Agar-Degrading Motile Bacteria Strain)

  • 강성완;유아영;유종언;강호영
    • 생명과학회지
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    • 제22권2호
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    • pp.259-265
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    • 2012
  • 환경에서 분리된 CK214 균주는 1.5% (w/v) agar가 포함되어 있는 LB 평판배지에서 빠르게 이동하는 특징을 가지며, agar 고체평판배지 위의 CK214 균주의 집락 주위로 움푹한 투명환이 관찰되었다. 이 균주는 단일 탄소원으로 agar만이 첨가된 최소 배지에서 잘 자랐으며, DNS 법을 이용하여 CK214 균주의 외부추출성분이 agar 분해활성을 가진다는 것을 확인하였다. CK214 균주는 다양한 농도의 agar (0.5, 1.0, 1.5 2.0% w/v)가 포함된 고체평판 배지에서 swarming 운동을 하였다. CK214 균주를 동정하기 위해 그람염색과 현미경 관찰, 생화학적 분석(API), 16S rRNA 염기서열분석에 기초한 계통발생학적 분석을 수행하였다. 이를 통해 CK214 균주는 그람 양성의 간균으로, Paenibacillus 속에 포함되었으며 Paenibacillus lactis MB 2035와 가장 가까운 연관성을 보이는 것을 확인할 수 있었다. 또한 CK214 균주는 agar 고체표면에서 주모성의 편모를 형성하는 것을 투과 전자 현미경(TEM)을 통해 관찰하였다. CK214 균주의 agarase 활성과 운동성의 연관성에 관한 앞으로의 연구를 위해 transposon random mutagenesis에 의한 agar 분해활성 결손 돌연변이주를 구축하였다.

Experimental and numerical disbond localization analyses of a notched plate repaired with a CFRP patch

  • Abderahmane, Sahli;Mokhtar, Bouziane M.;Smail, Benbarek;Wayne, Steven F.;Zhang, Liang;Belabbes, Bachir Bouiadjra;Boualem, Serier
    • Structural Engineering and Mechanics
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    • 제63권3호
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    • pp.361-370
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    • 2017
  • Through the use of finite element analysis and acoustic emission techniques we have evaluated the interfacial failure of a carbon fiber reinforced polymer (CFRP) repair patch on a notched aluminum substrate. The repair of cracks is a very common and widely used practice in the aeronautics field to extend the life of cracked sheet metal panels. The process consists of adhesively bonding a patch that encompasses the notched site to provide additional strength, thereby increasing life and avoiding costly replacements. The mechanical strength of the bonded joint relies mainly on the bonding of the adhesive to the plate and patch stiffness. Stress concentrations at crack tips promote disbonding of the composite patch from the substrate, consequently reducing the bonded area, which makes this a critical aspect of repair effectiveness. In this paper we examine patch disbonding by calculating the influence of notch tip stress on disbond area and verify computational results with acoustic emission (AE) measurements obtained from specimens subjected to uniaxial tension. The FE results showed that disbonding first occurs between the patch and the substrate close to free edge of the patch followed by failure around the tip of the notch, both highest stress regions. Experimental results revealed that cement adhesion at the aluminum interface was the limiting factor in patch performance. The patch did not appear to strengthen the aluminum substrate when measured by stress-strain due to early stage disbonding. Analysis of the AE signals provided insight to the disbond locations and progression at the metal-adhesive interface. Crack growth from the notch in the aluminum was not observed until the stress reached a critical level, an instant before final fracture, which was unaffected by the patch due to early stage disbonding. The FE model was further utilized to study the effects of patch fiber orientation and increased adhesive strength. The model revealed that the effectiveness of patch repairs is strongly dependent upon the combined interactions of adhesive bond strength and fiber orientation.

표고균사체 발효하수오 배양적 특성 및 이화학적 성분 (Chemical compositions of fermented Polygonum multiflorum Thunberg. root by Lentinula edodes (Berk.) Pegler mycelials cultivation)

  • 오준석;홍재희;박태영;김경제;진성우;반승언;고영우;정상욱;임승빈;서경순
    • 한국버섯학회지
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    • 제14권4호
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    • pp.184-190
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    • 2016
  • 본 연구는 하수오 표고균사(Lentinula edodes JMI-10079) 배양 최적조건 탐색을 목적으로 수행하였으며, 표고균사로 배양된 하수오의 일반성분, 아미노산, 무기성분을 분석하였다. 하수오 표고균사 배양 최적온도는 생장속도는 $25^{\circ}C$ 였으며, pH 5~8의 범위에서 균사생장이 양호하였다. 하수오 표고균사 배양 최적 탄소원은 glucose였으며, 질소원은 malt extract로 나타났다. 조단백질 함량은 적하수오 첨가량이 증가함에 따라 증가하는 경향을 보였다. 조지방 함량과 조회분 함량은 적하수오 발효물 첨가량에 비례하여 증가하는 경향을 보였다. 조섬유 함량은 대조구에서 36.39%로 가장 높게 나타났다. 16종의 아미노산이 검출되었으며, 총 구성아미노산 및 필수아미노산의 함량은 적하수오 발효물 첨가량에 비례하여 증가하는 경향을 확인 하였다. 본 연구는 하수오 100%에서도 표고균사배양이 원활하게 이루어져 향 후 대량생산을 시도할 때 공정조건이 간편할 것으로 보인다. 성분 분석 결과에서도 하수오 첨가량이 증가함에 따라, 조단백질, 조회분, 총 아미노산 및 potassium을 제외한 무기성분 함량이 증가함을 확인하여, 향 후 표고균사 배양 하수오를 이용한 식품개발이 기대되어 진다.

Spatial-temporal Assessment and Mapping of the Air Quality and Noise Pollution in a Sub-area Local Environment inside the Center of a Latin American Megacity: Universidad Nacional de Colombia - Bogotá Campus

  • Fredy Alejandro, Guevara Luna;Marco Andres, Guevara Luna;Nestor Yezid, Rojas Roa
    • Asian Journal of Atmospheric Environment
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    • 제12권3호
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    • pp.232-243
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    • 2018
  • The construction, development and maintenance of an economically, environmentally and socially sustainable campus involves the integration of measuring tools and technical information that invites and encourages the community to know the actual state to generate positive actions for reducing the negative impacts over the local environment. At the Universidad Nacional de Colombia - Campus $Bogot{\acute{a}}$, a public area with daily traffic of more than 25000 people, the Environmental Management Bureau has committed with the monitoring of the noise pollution and air quality, as support to the campaigns aiming to reduce the pollutant emissions associated to the student's activities and campus operation. The target of this study is based in the implementation of mobile air quality and sonometry monitoring equipment, the mapping of the actual air quality and noise pollution inside the university campus as a novel methodology for a sub-area inside a megacity. This results and mapping are proposed as planning tool for the institution administrative sections. A mobile Kunak$^{(R)}$ Air & OPC air monitoring station with the capability to measure particulate matter $PM_{10}$, $PM_{2.5}$, Ozone ($O_3$), Sulfur Oxide ($SO_2$), Carbon Monoxide (CO) and Nitrogen Oxide ($NO_2$) as well as Temperature, Relative Humidity and Latitude and Longitude coordinates for the data georeferenciation; and a sonometer Cirrus$^{(R)}$ 162B Class 2 were used to perform the measurements. The measurements took place in conditions of academic activity and without it, with the aim of identify the impacts generated by the campus operation. Using the free code geographical information software QGIS$^{(R)}$ 2.18, the maps of each variable measured were developed, and the impacts generated by the operation of the campus were identified qualitative and quantitively. For the measured variables, an increase of around 21% for the $L_{Aeq}$ noise level and around 80% to 90% for air pollution were detected during the operation period.

Hydrolysis of Agricultural Residues and Kraft Pulps by Xylanolytic Enzymes from Alkaliphilic Bacillus sp. Strain BK

  • Kaewintajuk Kusuma;Chon Gil-Hyong;Lee Jin-Sang;Kongkiattikajorn Jirasak;Ratanakhanokchai Khanok;Kyu Khin Lay;Lee John-Hwa;Roh Min-Suk;Choi Yun-Young;Park Hyun;Lee Yun-Sik
    • Journal of Microbiology and Biotechnology
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    • 제16권8호
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    • pp.1255-1261
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    • 2006
  • An alkaliphilic bacterium, Bacillus sp. strain BK, was found to produce extracellular cellulase-free xylanolytic enzymes with xylan-binding activity. Since the pellet-bound xylanase is eluted with 2% TEA from the pellet of the culture, they contain a xylan-binding region that is stronger than the xylan-binding xylanase of the extracellular enzyme. The xylanases had a different molecular weight and xylan-binding ability. The enzyme activity of xylanase in the extracellular fraction was 6 times higher than in the pellet-bound enzyme. Among the enzymes, xylanase had the highest enzyme activity. When Bacillus sp. strain BK was grown in pH 10.5 alkaline medium containing xylan as the sole carbon source, the bacterium produced xylanase, arabinofuranosidase, acetyl esterase, and $\beta$-xylosidase with specific activities of 1.23, 0.11, 0.06, and 0.04 unit per mg of protein, respectively. However, there was no cellulase activity detected in the crude enzyme preparation. The hydrolysis of agricultural residues and kraft pulps by the xylanolytic enzymes was examined at 50$^{\circ}C$ and pH 7.0. The rate of xylan hydrolysis in com hull was higher than those of sugarcane bagasse, rice straw, com cop, rice husk, and rice bran. In contrast, the rate of xylan hydrolysis in sugarcane pulp was 2.01 and 3.52 times higher than those of eucalyptus and pine pulp, respectively. In conclusion, this enzyme can be used to hydrolyze xylan in agricultural residues and kraft pulps to breach and regenerate paper from recycled environmental resources.

Rebamipide의 생식기관 내 흡수, 배설 및 항산화제로서 불임치료효과 (Absorption, Excretion and Antioxidative Effect of Rebamipide on Reproductive Organ)

  • 김종일;박현준;박남철
    • Clinical and Experimental Reproductive Medicine
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    • 제32권4호
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    • pp.301-314
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    • 2005
  • Objective: Rebamipide is a propionic acid derivative that has an action of the inhibition of superoxide production and removal of hydroxyl radical with the sperm incubation and cryopreservation. In the present study, to investigate whether rebamipide is useful to treat male infertility and sterility, the author observed the antioxidative effects in patient with male infertility and also examined its absorption and distribution in rat genital organ. Methods: To measure the distribution of rebamipide in reproductive organ in the rat, carbon indicated rebamipide, $^{14}C-OPC-12759$, was orally administered to 10 Spraque-Dawley rats and its organ concentration in serum, liver, kidney, stomach, duodenum, colon, urinary bladder, seminal vesicle, epididymis and testicle were measured each time after 0.5, 1, 2, 4, 8 and 24 hours by using HPLC fluorescent method. The concentrations in semen were measured by HPLC fluorescent method in a sample of 50 infertile males who took 900 mg of rebamipide daily for 3 months. To measure the antioxidative effect and fertility rate for 3 months, each month before and after the treatment, sperm motility, vitality, the oxygen free radical formation, level of peroxidation, fetilizing capacity of semen sample which were obtained from infertile male patients by masturbation after at least 48 hours abstinence were analyzed by computer assisted semen analyzer, eosin-nigrosin stain, chemiluminescence, thiobarbituric acid method and hypo-osmotic swelling test. Simultaneously in a sample that wanted baby, both pregnancy and delivery were researched. Results: The $^{14}C-OPC-12759$ concentration in the body of white rats was highest in gastrointestinal organ like stomach, smal intestine and duodenum and followed by genital organ like seminal vesicle, testis and epididymis. The rebamipide concentration in semen of infertile males was $220.77{\pm}327.84ng/mL$ (SD) which showed a large deviation but it was higher than serum which was $126{\pm}76ng/mL$ (SD). In the infertile males, after the treatment with rebamipide, the level of seminal reactive oxygen species (ROS) and lipid peroxidation have significantly decreased in duration of the treatment (p<0.05) and sperm vitality and fertilizing capacity except sperm motility significantly improved on post treatment of 2~3 months (p<0.05). Out of the 41 cases who hoped for pregnancy, 15 cases (36.6%) became pregnant and 12 cases had childbrith, 2 cases had miscarriage and one case is ongoing. The side effect was observed in 1 case (2%) which experienced diarrhea but it was lost spontaneously. Conclusions: We conclude from this study that rebamipide showed relatively high tendancy of absorption and excretion in the genital organ. In infertile males who had elevated ROS in semen, by specifically inhibiting the cell damage from the antioxidation, a way to preserve sperm motility, vitality and fertilizing capacity was confirmed.