• 제목/요약/키워드: Alternative chemicals

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바이오매스 유래 함산소 화합물의 수첨탈산소 촉매 반응: 총설 (Catalytic Hydrodeoxygenation of Biomass-Derived Oxygenates: a Review)

  • 하정명
    • 청정기술
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    • 제28권2호
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    • pp.174-181
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    • 2022
  • 바이오매스는 현재 석유, 천연가스, 석탄 등 화석 연료에서 얻을 수 있는 액체 연료와 유기 화합물을 생산할 수 있는 지속 가능한 대체 자원이다. 화석 연료를 사용하면 온실가스를 배출하기 때문에 바이오매스와 같은 탄소중립적 원료를 사용하는 것은 기후 변화 대응에 기여할 수 있다. 바이오매스 원료로부터 석유 대체 화학 제품과 연료를 생산하기 위한 생물학적 및 화학적 공정이 제안되었지만, 바이오매스에 포함된 높은 산소 함량때문에 화석 연료를 완전히 대체하기 어렵다. 석유와 유사한 연료와 화학 물질을 생산하려면 바이오매스 파생물에 존재하는 산소 원자를 제거하거나 산소 기능기를 전환해야 하며, 이는 촉매 화학적 수첨탈산소화에 의해 달성될 수 있다. 바이오매스 열분해 오일, 리그노셀룰로오스 유래 화학물질, 지질과 같은 원료를 탈산소 연료 및 화학물질로 전환하기 위해 수첨탈산소화가 진행되었다. 높은 표면적의 금속 산화물 또는 탄소에 지지된 귀금속 및 전이 금속으로 구성된 다기능성 촉매는 효율적인 수첨탈산소 촉매로 사용되었다. 본 총설에서는 문헌에서 제안된 촉매를 확인하고 이러한 촉매를 이용한 수첨탈산소 반응 시스템이 논의하였다. 문헌에 보고된 수첨탈산소화 방법을 기반으로, 실현 가능한 수첨탈산소화 공정 개발 방향이 제시하였다.

유류 오염지역 토양의 위해성 평가 및 사전복원목표 산정 사례연구 (Case Study of Health Risk Assessment and Preliminary Remediation Goals Calculation for the Petroleum Contaminated Site)

  • 정규혁
    • Environmental Analysis Health and Toxicology
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    • 제17권4호
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    • pp.347-355
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    • 2002
  • As concerns on the effects of soil contamination on human health have grown, more efforts have been made to quantify the effects. One of such efforts is the development of risk assessment methodology. The fundamental objectives of this approach is to investigate the alternative options that reduce the risk of hazardous chemicals results from environmental pollution, which will eventually lead to an accomplishment of removement of identified toxicants in polluted environment. The U.S. EPA Risk Assessment guidance for the superfund (RAGS) provides a methods for assessing the health risk of contaminated soils and determining the preliminary remediation goals (PRGs). Using this approach, we assessed the health risk and preliminary remediation goals of petroleum contaminated site in Kyounggi province.

식품조사(食品照射) 실용화(實用化)에 대한 배경(背景)과 전망(展望) (Background and Prospect for the Commercialization of Food Irradiation)

  • 권중호
    • 한국식품영양과학회지
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    • 제14권1호
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    • pp.88-94
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    • 1985
  • Food irradiation is increasingly recognized as the sole viable alternative to traditional method of food preservation in terms of reducing the overall quantity of spoiled food, reducing energy used in food storage, and reducing reliance on chemicals known to be hazardous but currently required for disinfestation. Irradiation with ionizing radiation can be applied in the fields of sprout inhibition, disinfestation of insects, sterilization, delay of ripening, and improvement of organoleptic properties in food. In order to back up the commercialization of food irradiation in Korea, this review not only dealt with the international background for food irradiation and wholesomeness of irradiated food, but also evaluated economic feasibility of irradiated food, irradiation facilities, and domestic status of food irradiation studies.

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친환경 실내마감재 한지의 도배공정 연구 (A study on the wall finishing process with 「Han-ji」, an eco-friendly material)

  • 장명희;이연숙
    • KIEAE Journal
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    • 제9권3호
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    • pp.29-36
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    • 2009
  • Interior material covering as the final process of house-building, critically influences not only aesthetic character but also air quality of indoor space. Wall covering today, however, caused a serious social problem because of chemicals contained in the industrial wallpaper and artificial glue. In this context, Korean traditional wall covering of Han-ji can be an alternative model due to it's ecological character. Recently 'Hanok' attracts public attention, since society and people become to appreciate the unique beauty and value of our traditional culture. The values include natural beauty, emotional character, and environment-friendliness. Recognizing this, this paper intended to scrutinize the operating process of Han-ji as an interior finish material. Historical research method was employed, tracing the related articles in old literature and interviewing with the witness of the experienced expert. Thereby, healthier and unique aesthetic indoor environment can be expected to be sustainable along with the rich cultural life of ancestors.

VOCs Concentrations of Indoor and Outdoor in Solvent Thinner-Using Occupation, and Application of TiO$_2$ Photocatalytic Air Cleaner

  • Wonho Yang;Joon Cho;Busoon Son;Park, Jongan
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2002년도 춘계 국제 학술대회
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    • pp.1.1-2
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    • 2002
  • Ultimate objective of industrial hygiene is the prevention of health impairment that may result from exposure to chemicals at workplaces. This implies the definition of permissible levels of exposure, that is, levels that according to the present status of knowledge are estimated to cause no adverse health effects during the lifetime of the workers, and the regular assessment of the possible health risk associated with exposure by comparing the current or the integrated exposure with the permissible exposure limits. Workers in solvent thinner-using occupation environment might be highly exposed to VOCs(volatile organic compounds) because solvent thinner has been used extensively such as painting, spraying, degreasing, coating and so on in Korea. The purpose of this study was to recognize, evaluate and propose the alternative control the VOCs from solvent thinner-using workplace.

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AHP기법 적용을 통한 수산양식장 평가방식 개선에 관한 연구 (A Study on the Improvement of the Aquaculture Evaluation Method by using AHP)

  • 서종석;서원철;옥영석
    • 수산해양교육연구
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    • 제26권4호
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    • pp.846-858
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    • 2014
  • The purpose of this study is to help domestic aquaculture farm by improved evaluation method. First, We analyzed evaluation method of domestic aquaculture certification, the greater retailer's supplier and global standard. Next, By using Analytic Hierarchy Process (AHP), We found priority and importance between criteria of SQF(Safety Quality Food) standard which is appled to alternative model for aquaculture evaluation. As a result is presented as follows: regarding pairwise comparison between System Element module and Good Aquaculture Practice(GAP) module, GAP is recognized to be more important than System Element. The highest priority criteria is presented 'Purchase and Use of Medications, Aquaculture Feeds and Aquaculture Chemicals.' Next, 'Management commitment', 'Attaining Food Safety', 'Location and Layout of Structures and Vessels', 'Stock Identification and Traceability are recognized high position. This study has major implications for research into development of evaluation method.

바이오 기반 경제를 위한 해조류 유래 바이오 연료 생산 (Biofuel production from macroalgae toward bio-based economy)

  • 임현규;곽동훈;정규열
    • 한국해양바이오학회지
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    • 제6권1호
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    • pp.8-16
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    • 2014
  • Macroalgae has been strongly touted as an alternative biomass for biofuel production due to its higher photosynthetic efficiency, carbon fixation rate, and growth rate compared to conventional cellulosic plants. However, its unique carbohydrate composition and structure limits the utilization efficiency by conventional microorganisms, resulting in reduced growth rates and lower productivity. Nevertheless, recent studies have shown that it is possible to enable microorganisms to utilize various sugars from seaweeds and to produce some energy chemicals such as methane, ethanol, etc. This paper introduces the basic information on macroalgae and the overall conversion process from harvest to production of biofuels. Especially, we will review the successful efforts on microbial engineering through metabolic engineering and synthetic biology to utilize carbon sources from red and brown seaweed.

인공습지의 수질개선 효과 분석모델 개발 (Development of Pollutant Removal Model in the Artificial Wetland)

  • 최지용
    • 한국습지학회지
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    • 제4권1호
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    • pp.51-61
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    • 2002
  • The wetland is a biologically integrated system consisting of water, soil, bacteria, plants, and animals. The wetland helps sustain the ecosystem, control the micro-climate and flood, maintain the ground water level, and provide fishing grounds. From the environmental standpoint, the wetland plays a vital role in reducing water pollution by filtering out sand and other polluted matters, producing oxygen, absorbing chemicals and nutrients. For these reasons, interest in restoring the wetlands has been steadily increasing. Artificial wetland, which is also referred to as created wetland or constructed wetland, is an alternative to natural wetland. Like natural wetland, artificial wetland is environmentally friendly and can effectively lower pollutant levels. The Korea government is actively reviewing the construction of artificial wetlands in mining and water supply areas to decrease nonpoint pollutant sources. This paper attempts to develop a pollutant removal model for the water quality improvement function of artificial wetlands. Artificial wetland can improve the quality of the water; however, depending on the type of water inflow, vegetation and hydrology, its effect can be different.

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식품중의 아질산염과 N-Nitrosamine에 관한 고찰 (Nitrite and Nitrosamine in food)

  • 우순자
    • 대한가정학회지
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    • 제23권3호
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    • pp.85-101
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    • 1985
  • 1. Nitrate and nitrite may contribute via nitrosation to the human exposure to N-nitroso compounds, especially nitrosamines, which are suspectd to be human carcinogens. 2. Since certain foods contain traces of nitrosamines, one should take the several points into consideration in evaluating the risk. 3. Nitrites, which can appear in the because of natural occurrence or deliberate addition, can react under the acidic conditions of the normal stomach with secondary amines to form nitrosamine. 4. Among the foods esamined, nitrate-nitrite treated meat products cooked bacon, and salted and dried fish are the main contributors of nitrosamines in our diet. 5. Consequently, in order to minimize human exposure to these chemicals, it is obviously essential to develop the alternative sources of nitrite in cured meat products. Thus the emphasis should be placed upon the most effective use of nitrite in curing with the use of acceptable inhibitors of nitrosation such as ascorbc acid or $\alpha$-tocopherol.

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Efficient Protection of Alcohols with Carboxylic Acids Using a Variety of Heteropolyoxometallates as Catalysts, Studying Effective Reaction Parameters

  • Tayebee, Reza;Cheravi, Fatemeh
    • Bulletin of the Korean Chemical Society
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    • 제30권12호
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    • pp.2899-2904
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    • 2009
  • Esterification is an important class of reactions in the preparation of perfumery and flavor chemicals, wherein homogeneous, solid acidic, and superacidic catalysts are normally used. Now, an efficient and selective protocol for protection of various functionalized alcohols employing carboxylic acids as protecting agents is realized through the catalytic mediation of simple heteropolyoxometallates. In this methodology, water is the only by-product and notably the aspect of effluent treatments does not arise. The advantages include the operational simplicity, recycle ability of the catalyst and mild reaction conditions. The present catalytic system may be a potential candidate not only for laboratory practice but also for commercial applications and offers an environmentally safer alternative to the existing processes.