• Title/Summary/Keyword: mainstream

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Study of the Semi-volatile Components in Cigarette Mainstream Smoke (담배 Mainstream Smoke중 Semi-volatile 화합물 연구)

  • 김정열;신창호;김종열;김영호;이근회
    • Journal of the Korean Society of Tobacco Science
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    • v.20 no.1
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    • pp.115-123
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    • 1998
  • The semi-volatile fraction of cigarette mainstream smoke contains the most important aroma and taste that enhance smoke flavor. The components in mainstream smoke were analysed for commercially available cigarettes. To compare the semi-volatile components delivered from mainstream smoke of domestic cigarette with imported cigarette, we analyzed three types of filter cigarettes such as cellulose acetate mono filter, carbon dual filter and slim filter cigarette. Mainstream smoke was collected with a combination of Cambridge filter pad and liquid trap containing a small amount of acetone cooled by dry ice-methanol. We have identified 43 components from mainstream smoke by GC and GC/MS and found that benzene, toluene, 4-hydroxy-4-methyl-2-pentanone, 5-methyl-2-furaldehyde, acetic acids nicotine and triacetin were the main peaks in mainstream smoke. Also we have compared the relative amounts of semi-volatile compounds delivered from the domestic and imported cigarettes with three different filters. From the results of this study, the relative amounts of limonene, acetic acid, 5-methyl-Lfuraldehyde delivered from the imported cigarettes were generally higher than those of the domestic one's.

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Korean mainstream medical papers published in the 1980s

  • 이춘실
    • Journal of the Korean Society for information Management
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    • v.10 no.1
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    • pp.125-167
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    • 1993
  • A review of literature discussing the status and impact of mainstream Korean research revealed that there have been few studies carried out to investigate the status of Korean mainstream medical research and that we need to know exact status of Korean medical papers published in mainstream journals. Accordingly, a study is undertaken to measure mainstream medical publication output by authors at Korean institutions and its growth during the 1980s as recorded in MEDLINE. EMBASE and SCI. For comparison purpose, a measurement of mainstream publication output of chemistry, a scientific field which showed the best mainstream performance, is also made. The database searching is limited to SCI for chemistry records.

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A Study on the Delivery of Volatile Organic Compounds in Cigarette Mainstream Smoke with a Different Ventilation Rate (제품담배의 공기희석율에 따른 주류연중 휘발성 유기화합물의 이행특성)

  • Ji Sang-Un;Hwang Keon-Joong;Rhee Moon-Soo;Shin Chang-Ho;Kim Soo-Ho;Kim Jong-Yeol;Kim Mi-Ju
    • Journal of the Korean Society of Tobacco Science
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    • v.26 no.2 s.52
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    • pp.179-185
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    • 2004
  • This study was conducted to investigate the delivery pattern of volatile organic compounds(VOCs) in mainstream smoke generated by the combustion of a different ventilated cigarette. To compare the delivery pattern and the concentration of VOCs in mainstream smoke, the six different ventilated cigarette was manufactured and analyzed VOCs using the GC/MS. As a result of this experiments, cambridge filter used to trap the particulate matter in mainstream smoke did not affect on the trapping of VOCs components, and two impinger method among the trapping methods was the best condition to trap VOCs from mainstream smoke. As the slope of the delivery of VOCs such as isoprene, acrylonitrile and toluene were higher than 1, but that of benzene was lower than other VOCs.

Determination optimal ratio of ammonium to nitrite in application of the ANAMMOX process in the mainstream (Mainstream ANAMMOX 공정 적용시 암모니아성 질소 대비 아질산성 질소 비율 도출 연구)

  • Lee, Dawon;Lee, Jiwon;Gil, Kyungik
    • Journal of Wetlands Research
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    • v.23 no.1
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    • pp.60-66
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    • 2021
  • As the concentration of nitrogen in the sewage flowing into the sewage treatment plant increases due to urbanization and industrialization, the degree of adverse effects such as eutrophication and toxicity to the aquatic ecosystem is also increasing. In order to treat sewage containing high concentration of nitrogen, various studies on the biological nitrogen removal process are being conducted. Existing biological nitrogen removal processes require significant costs for supplying oxygen and supplementing external carbon sources. In this respect, as a high-level nitrogen removal process with economic improvement is required, an anaerobic ammonium oxidation process (ANAMMOX), which is more efficient and economical than the existing nitrification and denitrification processes, has been proposed. The purpose of this study is to confirm the stability of the ANAMMOX process in the water treatment process and to derive the ratio of ammonia nitrogen (NH4+) to nitrite nitrogen (NO2-) for the implementation of the mainstream ANAMMOX process. A laboratory-scale Mainstream ANAMMOX reactor was operated by applying the ratio calculated based on the substrate ratio suggested in the previous study. In the initial range, the removal efficiency of NH4+ was 58~86%, and the average removal efficiency was 70%. In the advanced range, the removal efficiency of NH4+ was 94~99%, and the average removal efficiency was 95%. As a result of the study, as the NH4+/NO2- ratio increased, the stability of the mainstream ANAMMOX process was secured, and it was confirmed that the NH4+ removal efficiency and the total nitrogen (TN) removal efficiency increased. As a result, the results of this study are expected to be used as basic data in the application of the ANAMMOX process in the mainstream.

A Comparison between Two Viewpoints of Agricultural Extension;A comparison between economic and non-economic method (농촌지도의 두 가지 관점의 비교;계량적 방법과 비(非)계량적 방법의 비교)

  • Lim, Hyung-Baek;Yoon, Jun-Sang
    • Journal of Agricultural Extension & Community Development
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    • v.6 no.2
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    • pp.105-118
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    • 1999
  • There are two viewpoints in agricultural extension. One is economics(econometrics) the is non-econometric social sciences. In Korea economic means mainstream economics. Most mainstream economists have tried to solve the social and economic problems of Korea using their basic principles and econometrics. This mainstream economics have been supported by the Korean government and many people due to its convenience, effectiveness, and clearness. However, Agriculture and agricultural extension should be studied through multidisciplinary approaches after considering their specific social structures. Especially, Korean agriculture and agricultural extension have many aspects that can not be easily explained by main stream economics. In this study, the researchers will; 1)identify the origin, growth, and limitation of mainstream economics, i.e. econometrics 2)identify the paradigm and the view of social sciences and out-of-mainstream economics to make up for the limitation of main stream economics in explain the agriculture and agricultural extension in Korea, and 3)suggest to use multidisciplinary approaches to solve the agriculture and agricultural extension in Korea.

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Effect of Mainstream Turbulence Intensity on Film Cooling of Combustor (연소기 벽면 막냉각에 주유동의 난류강도가 미치는 영향)

  • Kim Young Bong;Rhee Dong Ho;Cho Hyung Hee;Hahm Hee-Cheol;Bae Ju Chan;Oh Min Geun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.10a
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    • pp.132-136
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    • 2004
  • Experimental study has been conducted to investigate effect of mainstream turbulence intensity on film cooling performance of staggered rows of rectangular holes in combustor. Temperature fields and adiabatic film cooling effectiveness under $10\%$ mainstream turbulence intensity are measured. The results of temperature fields show that overall values are decreased and thicker film of coolant is formed downstream of rows of holes for high mainstream turbulence intensity. The results of film cooling effectiveness show that the values around the holes are smaller than the case of the low mainstream turbulence intensity, however, the difference of film cooing performance is decreasedforthefurtherdownstream.

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Academic Performance, Communication, and Psychosocial Development of Prelingual Deaf Children with Cochlear Implants in Mainstream Schools

  • Choi, Ji Eun;Hong, Sung Hwa;Moon, Il Joon
    • Journal of Audiology & Otology
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    • v.24 no.2
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    • pp.61-70
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    • 2020
  • Background and Objectives: To assess the academic performance, communication skills, and psychosocial development of prelingual deaf children with cochlear implants (CIs) attending mainstream schools, and to evaluate the impact of auditory speech perception on their classroom performance. Subjects and Methods: As participant, 67 children with CI attending mainstream schools were included. A survey was conducted using a structured questionnaire on academic performance in the native language, second language, mathematics, social studies, science, art, communication skills, self-esteem, and social relations. Additionally, auditory and speech performances on the last follow-up were reviewed retrospectively. Results: Most implanted children attending mainstream school appeared to have positive self-esteem and confidence, and had little difficulty in conversing in a quiet classroom. Also, half of the implanted children (38/67) scored above average in general academic achievement. However, academic achievement in the second language (English), social studies, and science were usually poorer than general academic achievement. Furthermore, half of the implanted children had difficulty in understanding the class content (30/67) or conversing with peers in a noisy classroom (32/67). These difficulties were significantly associated with poor speech perception. Conclusions: Improving the listening environment for implanted children attending mainstream schools is necessary.

Academic Performance, Communication, and Psychosocial Development of Prelingual Deaf Children with Cochlear Implants in Mainstream Schools

  • Choi, Ji Eun;Hong, Sung Hwa;Moon, Il Joon
    • Korean Journal of Audiology
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    • v.24 no.2
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    • pp.61-70
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    • 2020
  • Background and Objectives: To assess the academic performance, communication skills, and psychosocial development of prelingual deaf children with cochlear implants (CIs) attending mainstream schools, and to evaluate the impact of auditory speech perception on their classroom performance. Subjects and Methods: As participant, 67 children with CI attending mainstream schools were included. A survey was conducted using a structured questionnaire on academic performance in the native language, second language, mathematics, social studies, science, art, communication skills, self-esteem, and social relations. Additionally, auditory and speech performances on the last follow-up were reviewed retrospectively. Results: Most implanted children attending mainstream school appeared to have positive self-esteem and confidence, and had little difficulty in conversing in a quiet classroom. Also, half of the implanted children (38/67) scored above average in general academic achievement. However, academic achievement in the second language (English), social studies, and science were usually poorer than general academic achievement. Furthermore, half of the implanted children had difficulty in understanding the class content (30/67) or conversing with peers in a noisy classroom (32/67). These difficulties were significantly associated with poor speech perception. Conclusions: Improving the listening environment for implanted children attending mainstream schools is necessary.

Representation of Disabled Community in Mainstream Media

  • Teng, Chan Eang;Joo, Tang Mui
    • International Journal of Knowledge Content Development & Technology
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    • v.10 no.2
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    • pp.19-37
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    • 2020
  • There are limited research questioning the relationship between the disabled community and media, particularly in Malaysia. The lack of awareness and common assumption of specialty towards the disabled community have caused a small amount of local disability researches that question the relationship between the disabled community and the media. This research aims to find out the types of representation of disability in the Malaysian mainstream media, particularly press. Interview with visual disabled personnel and content analysis from news coverage of mainstream press are deployed in the study. The findings indicated the invalidity of disability culture as the misrepresentation of disabled community in Malaysia is not as severe as depicted by scholars because the news coverage focusing on them is getting more positive. Besides that, disabled people are not defensive towards the terms used to refer them as long as media practitioners do not over amplify their disability. The application of charity approach is still common in news coverage to portray the disabled community as victim, and therefore they are partially marginalized due to the misrepresentation in Malaysian mainstream press.

Media Sentiment Towards Chinese Investments in Malaysia: An Examination of the Forest City Project

  • Wang, Yicong;Reagan, James
    • Asian Journal for Public Opinion Research
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    • v.8 no.3
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    • pp.197-221
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    • 2020
  • We collected national newspaper articles on the largest Chinese investment project in Malaysia, Forest City, and examined media sentiment polarity using alternative automated sentiment analysis tools. We further checked the robustness of these results using content analysis, and consistently found that sentiment polarity for mainstream news is more volatile than independent online journalism. We also found that the sentiment polarity of Malaysian mainstream media towards Chinese investments is aligned with government interactions between the two countries. This suggests that the sentiment of Malaysian mainstream media towards Chinese investments complies with local government attitudes, while independent online media are less constrained by government control. In light of this, foreign investors looking to more effectively estimate risks should monitor both independent and mainstream media to calculate the sentiment of the host country towards their foreign direct investment projects.