• Title/Summary/Keyword: Specific Harmful Substances

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A Study on the Performance and Particulate Emission Characteristics for the Hydrogen-Premixed Diesel Engine (수소 혼소 디젤 기관의 성능 및 미립자상 물질의 배출 특성에 관한 연구)

  • 채재우;한동성;이상만;전영남;정영식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.1 no.2
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    • pp.34-41
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    • 1993
  • In order to reduce harmful substances such as particulates and nitric oxides emitted from diesel engine, man kinds of methodology like high pressure spray of diesel fuel oil, exhaust gas recirculation, emulsified fuel usage and dual fuelling have been studied. Dual fuelling of a diesel engine with hydrogen which is well-known as the clean fuel and has excellent combustibility is expected to be effective in reducing harmful substances from diesel engine. This experimental study was conducted to investigate the effect of premixed hydrogen with intake air on the performance and particulate emission characteristics using a single cylinder, prechamber type diesel engine. As a result, it was clarified that a hydrogen-premixed diesel engine can be operated in the state of lower particulate emission and slightly aggravated fuel economy, compared with the conventional diesel engine.

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Characteristics of Organic Substances Produced from Cochlodiniumpolykrikoides (Dinophyceae) (Cochlodinium polykrikoides(Dinophyceae)에서 분비되는 유기물질의 특성)

  • Kang, Yang-Soon;Kwon, Jung-No;An, Kyoung-Ho
    • ALGAE
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    • v.21 no.2
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    • pp.253-259
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    • 2006
  • Organic substances are released from phytoplankton cells during all phases of growth. The type and amounts of organic substance excreted and the effects of nutrient limitation are often highly species-specific. Dinoflagellate, Cochlodinium polykrikoides grown in batch culture produced an exopolysaccharide. Exopolysaccharide and intracellular polysaccharide concentrations increased as C. polykrikoides cultures progressed from exponential phase, through stationary phase, to declining phase. In the exponential phase, the concentration of exopolysaccharide was relatively low, but in the stationary phase, it showed a rapid increase which seemed to coincide with the depletion of nitrate from the medium. Of the 20 amino acids analyzed, proline dominated in the organic matter of all cultures ranging from 48.2 to 79.9 nmol L–1, and constituting the 20-90% of total amino acids, and followed by histamine varying from 0.7 to 47.5 nmol L–1. Leucine and cysteine were also abundant in the stationary phase. The release rates of exopolysaccharide and intracellualr polysaccharide were higher the end of stationary phase than in the exponential phase. Exopolysaccharide concentration per cell was more than two times higher during the end of stationary phase than that in exponential phase. C. polykrikoides produced extracellular polysaccharide at a rate of 47.04 pg cell–1 day–1.

Establishment of Non-Drinking Groundwater Quality Standards: (1) Specific Harmful Substances (비음용 지하수 오염물질 기준설정체계 구축 연구: (1) 특정유해물질)

  • An, Youn-Joo;Nam, Sun-Hwa;Lee, Woo-Mi;Yoon, Sung-Ji;Yoon, Jin-Yul;Jeong, Seung-Woo;Kim, Hye-Jin;Kim, Huyn-Koo;Kim, Tae-Seung
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.9
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    • pp.630-635
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    • 2013
  • There is a need to establish systematic procedure of groundwater quality standards, however, there were no specified basis for establishing substances and values in Korean groundwater quality standards for non-drinking water. In this study, we reviewed basis for deriving groundwater quality standard in the developed countries, considering carcinogenic and non-carciongenic risk via inhalation and dermal contact exposure pathways. Also, we reviewed the prior systematic procedure of standards related to water quality (e.g. drinking water, surface water, and wastewater). USEPA RAGS, ASTM RBCA, and Massachusettes presented the formulas for deriving groundwater concentrations of chemicals and there were similarity and differences. We suggests systematic procedure of groundwater quality standards, as follows. (1) Selection of groundwater pollutants population, (2) Possibility of risk assessment, (3) Selection of monitoring priority substances, (4) Monitoring, (5) Risk assessment, (6) Selection of groundwater quality standard candidates, (7) Selection of new substances and values for groundwater quality standards. Especially, groundwater concentration of hazardous material were presented according to revised risk formulas via inhalation and dermal contact.

A Study on Combined Processes of Sliding Arc Plasma and Corona Dielectric Barrier Discharge for Improve the Efficiency Treatment of Harmful Substance (슬라이딩아크 방전과 코로나 방전의 복합공정을 통한 유해물질 처리효율 개선에 관한 연구)

  • Kwon, Woo-Taeg;Lee, Woo-Sik
    • Fire Science and Engineering
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    • v.28 no.6
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    • pp.108-113
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    • 2014
  • The combined process of Sliding Arc Plasma and corona dielectric barrier discharge process (CDBD) was used to efficiently improve harmful substance, which convert into OH radicals which have strong oxidation potential, and so have deodorization and sterilizing effects, by generating specific radicals and anion and then reacting with the moisture contained in harmful substance. As a result of experiment, even if the size of SAP reactor is reduced from 80 A to 50 A, there is no much change and therefore it is judged the size of reactor may be minimized. And it was confirmed that after the anion and ozone generated from CDBD rector react with harmful substance, a anion was reduced from 510,000 ppb to 470 ppb and ozone from 98 ppb to 22 ppb. It was also judged the stability and durability of plasma producer are excellent. Accordingly, it is considered the harmful substances which exist in indoor air quality will be efficiently improved and removed by using further plasma combined process through this study.

Chemical Ranking and Scoring Methodology for the Drinking and non-drinking Groundwater pollutants: CROWN (Chemical Ranking of Groundwater PollutaNts) (음용 및 비음용 지하수 우선관리대상 항목 선정기법: CROWN (Chemical Ranking of Groundwater PollutaNts))

  • An, Youn-Joo;Lee, Woo-Mi;Jeong, Seung-Woo
    • Journal of Soil and Groundwater Environment
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    • v.18 no.1
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    • pp.16-25
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    • 2013
  • The Korean groundwater law regulates 20 groundwater contamination parameters, including 14 specific harmful substances. Expanding the number of groundwater quality standards are needed to cope with recent groundwater quality deterioration due to the use of various chemicals. Chemical ranking and scoring system (CRS) is a scientific tool to sort priority chemicals by considering exposure and toxicity potentials. In this study, we developed a CRS for scoring and ranking of possible groundwater pollutants and screened priority substances to be later considered in the Korean standard expansion. Chemical Ranking Of groundWater pollutaNts (CROWN) incorporates important parameters consisting of exposure potential, human and water ecotoxicity, interests, and certainty. Furthermore, CROWN additionally evaluated existence of other media standards to consider impacts by contamination of other media. The 197 substances that were common to 9 countries were selected first. CROWN evaluated and ranked each chemical, and finally suggested priority substances. Suggested priority substances were classified into two groups according to the groundwater use purposes: drinking and non-drinking. The priority substances were further classified into $1^{st}$ and $2^{nd}$ group priorities. The $1^{st}$ group consists of 75 substances, including the all the Korean groundwater standard parameters. CROWN will be used in selecting groundwater pollutants for possible inclusion in the Korean standard expansion.

Fast Screening of Harmful Disinfectants in Household Products via Low-Temperature Plasma Ionization-Mass Spectrometry

  • Lee, Hyoung Jun;Kweon, Gi Ryang;Yim, Yong-Hyeon
    • Mass Spectrometry Letters
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    • v.8 no.2
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    • pp.44-47
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    • 2017
  • Isothiazolinone derivatives are widely used in consumer products as disinfectants or preservatives, but there are growing concerns about their impact on human health. Therefore, rapid screening of these biocides is very important for proper control and regulation of potentially hazardous substances. To this end, low-temperature plasma (LTP) ionization mass spectrometry (MS) was investigated to demonstrate its potential for direct and selective analysis of isothiazolinones from sprayed aerosol samples. Benzisothiazolinone (BIT) was clearly identified from a commercial fabric deodorant using LTP ionization MS and MS/MS. LTP allowed selective ionization of BIT directly from the simply sprayed aerosol sample and illustrated its potential for fast screening without sample pre-treatments. Selective nature of LTP ionization, on the other hands, implicates use of LTP ionization MS as a general screening method for specific groups of hazardous chemicals in commercial products.

Consideration of the Procedure for IMO Approval of Ballast Water Treatment System that Make Use of Active Substances (활성물질을 사용하는 선박평형수 처리장치의 IMO 승인 절차 고찰)

  • Kim, Eun-Chan
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.11 no.4
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    • pp.214-220
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    • 2008
  • The Ballast Water Management Convention provides that ballast water treatment systems which make use of active substances shall be approved from IMO according to the procedure developed by the IMO. The Convention described that active substance means a substance or organism, including a virus or a fungus, that has a general or specific action on or against harmful aquatic organisms and pathogens. The Marine Environment Protection Committee of IMO gave basic approval to 13 ballast water management systems and final approval to 4 systems until October 2008. This paper considered the matter of procedure and documents of the basic and final approval based on the "Procedure for approval of ballast water management systems that make use of Active Substances (G9)" and "The Methodology for information gathering and the conduct of work of the GESAMP-BWWG" and summarized the specifications of the treatment systems which was granted the basic or final approval from IMO and raised several points.

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The Trend of Cigarette Design and Tobacco Flavor System Development

  • Wu, Jimmy Z.
    • Journal of the Korean Society of Tobacco Science
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    • v.24 no.1
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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.

Characteristics of Micro-pore Structure of Foam Composite using Palm-based Activated Carbon (야자계 활성탄을 활용한 폼 복합체의 미세기공 구조특성)

  • Choi, Young-Cheol;Yoo, Sung-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.5
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    • pp.157-164
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    • 2021
  • Recently, a number of studies have been conducted on photocatalysts and adsorbents that can remove harmful substances to improve environmental problems related to fine particles. In this study, a porous foam composites were fabricated using palm-based activated carbon having a large amount of micro-pores and foam concrete with a significantly larger total pore volume compared to general construction materials. To evaluate the adsorption potential of fine particles, the pore structure of the foam composites were analyzed. For the analysis of the pore structure of the foam composite, BET and Harkins-jura theory were applied from the measured nitrogen adsorption isotherm. From the results of the analysis, the specific surface area and micro-pore volume of the foam composite containing activated carbon increased significantly compared to Plain. As thereplacement of activated carbon increased, the specific surface area and micro-pore volume of the foam composite tended to increase. It seems that the foam composite has high adsorption performance for gaseous fine particle precursor such as nitrogen oxides.

Development of Evaluation Criteria for Fashion Sustainability Focused on User Practice (사용자 실천 중심 의복지속가능성 평가항목 개발)

  • Kim, Ine;Ha, Jisoo
    • Fashion & Textile Research Journal
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    • v.23 no.2
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    • pp.174-185
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    • 2021
  • The purpose of the study is to establish sustainability evaluation items that can be applied to enhance clothing sustainability practice. The sustainability evaluation items related to clothing by product category, use, and disposal were derived through literature review. In order to evaluate the validity of the derived evaluation items, preliminary survey and two questionnaires were conducted for experts, and the importance and the possibility of change were measured. As a result, 39 evaluation items were constructed. Among the 39 evaluation items, 26 items related to the use and disposal were evaluated for 10 weeks in the 20s and 30s female consumers in terms of practice. The results of the study are as follows: First, items that have a high degree of importance and possibility of change are the items that can minimize resource saving, recycling, and the emission of harmful substances. Second, the participants' perceptions, attitudes, and outcomes of practicing the evaluation items of the use and disposal phase were proved to be positively affected, and the possibility of reducing resource saving and environmental impacts was proved. The clothing sustainability practice played a positive and developmental role in real life, while changing from small things to pursuing newness. The vagueness of sustainability was changed to specific perceptions and behaviors through the practice of the evaluation items.