• Title/Summary/Keyword: harmful environments

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A Study on Air-Conditioning System for Excavator using Forced Exhaust (강제배기를 이용한 굴삭기 공기조화 시스템에 관한 연구)

  • Hwang, J.H.;Jeong, C.S.;Ko, J.H.;Yang, S.Y.
    • Journal of Drive and Control
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    • v.10 no.2
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    • pp.23-29
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    • 2013
  • The excavator is used in a variety of construction environments. There are many kinds of risk like falling rocks or harmful dust. The excavator cabin protects the operator not only from these harmful environments but also provides a comfortable working environment. By the way, the excavator cabin consumes a lot of energy for cabin air conditioner. For this reason, the research is required to reduce energy consumption. This study suggests the air conditioning system for excavator using forced exhaust. First, the forced exhaust system simulated by AMESim tool and surveyed the applicability. Using AMESim simulation, it was investigated the effect of cabin inside temperature by intake flow rate and intake air temperature. The experiment executed using the 1.5 ton excavator and field tested according to the intake flow rate. Finally, verified the applicability on the air conditioning system for excavator using forced exhaust.

New Algicidal Compounds from a Marine Algicidal Bacterium against Cochlodinium polykrikoides

  • Jeong, Seong-Yun;Kim, Min-Ju;Lee, Sang-Youb;Son, Hong-Joo;Lee, Sang-Joon
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2006.11a
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    • pp.285-289
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    • 2006
  • In screening of algicidal bacteria, we isolated a marine bacterium which had potent algicidal effects on harmful algal bloom (HAB) species. This organism was identified as a strain very close to Bacillus subtilisby 16S rRNA gene sequencing. This bacterium, Bacillus sp. SY-1, produces very active algicidal compounds against the harmful dinoflagellate Cochlodinium polykrikoides. We isolated three algicidal compounds (MS 1056, 1070, 1084) and identified them by amino acid analyses, fast atom bombardment mass spectrometry (FAB-MS), infrared spectroscopy (IR), $^1H$, $^{13}C$, and extensive two-dimensional nuclear magnetic resonance (2D NMR) techniques including $^1H-^{15}N$ HMBC analysis. One of them, MS 1056, contains a b-amino acid residue with an alkyl side chain of $C_{15}$. MS 1056, 1070, and 1084 showed algicidal activities against C. polykrikoides with an $LC_{50}$ (6 hrs) of 2.3, 0.8, $0.6\;{\mu}g/ml$, respectively. These compounds also showed significant algicidal activities against other harmful dinoflagellates and raphidophytes. In contrast, MS 1084 showed no significant growth inhibition against various organisms coexisting with HAB species in natural environments, including bacteria, eukaryotic microalgae, and cyanobacteria, although it inhibited growth of some fungi and yeasts. These observations imply that algicidal bacterium Bacillus sp. SY-1 and its algicidal compounds could play an important role in regulating the onset and development of HABs in the natural environments.

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The Protective Role of School Adjustment Between Risky Neighborhood Environment and Adolescent Drinking and Smoking (지역사회 유해환경과 청소년의 음주흡연 경험과의 관계에서 학교적응의 보호 작용)

  • Kim, Shinah;Han, Yoonsun
    • Korean Journal of Child Studies
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    • v.37 no.1
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    • pp.37-48
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    • 2016
  • Objective: To prevent adolescent drinking and smoking, this study proposed a strategy based on the ecological perspective. Methods: The study applied multilevel moderated logistic regression analysis on nationally representative individual-level (2,046 9th grade adolescents) and neighborhood-level (92 geographic areas) data. Results: There was a positive association between risky neighborhood environments (e.g., rate of smoking, drinking, and presence of saloon/bars accommodation) and rates of adolescent drinking and smoking. Furthermore, the interplay between risky neighborhood environments and school adjustment pointed to a possible protective effect of a high level of school adjustment in predicting smoking and drinking among adolescents. Conclusion: Findings highlighted the importance of considering multiple neighborhood social contexts surrounding adolescents to understand their risky behavior. Furthermore, positive intervention strategies that focus on adolescents' positive development within the school domain may act to protect adolescents from harmful neighborhood environments.

Harmful Materials treatment in Shipboard sewage by SBR process with BM (BM 미생물제제를 이용한 선박 오·폐수 내 유해물질처리)

  • Kim, In-Soo;Lee, Eon-Sung;Ha, Shin-Young;Jeong, Kyoung-Chul;Koh, Sung-Cheol
    • Journal of Navigation and Port Research
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    • v.38 no.6
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    • pp.601-606
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    • 2014
  • Lab scale experiment study was carried out for biological treatment process development in shipboard. SBR(Sequence Batch Reactor) process with BM(Beneficial Microorganisms) was investigated for practical application on shipboard sewage treatment. From the results it was suggested that SBR process with BM might be a suitable process in terms of harmful materials removal. By adding BM to SBR system, the useful species of microorganisms and EPS(Extracellar Polymetric Substances) in sludge was increased. It was found that the biodegrability and harmful organic compounds like VOCs and harmful inorganic compounds like heavy metals. was reduced over 70%. As far as reclamation water is considered, this process is very advantageous to special environments such as cruise ships, because the method of adding BM makes it unnecessary to add other facilities on the SBR system.

Review of Internet of Things-Based Artificial Intelligence Analysis Method through Real-Time Indoor Air Quality and Health Effect Monitoring: Focusing on Indoor Air Pollution That Are Harmful to the Respiratory Organ

  • Eunmi Mun;Jaehyuk Cho
    • Tuberculosis and Respiratory Diseases
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    • v.86 no.1
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    • pp.23-32
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    • 2023
  • Everyone is aware that air and environmental pollutants are harmful to health. Among them, indoor air quality directly affects physical health, such as respiratory rather than outdoor air. However, studies that have examined the correlation between environmental and health information have been conducted with public data targeting large cohorts, and studies with real-time data analysis are insufficient. Therefore, this research explores the research with an indoor air quality monitoring (AQM) system based on developing environmental detection sensors and the internet of things to collect, monitor, and analyze environmental and health data from various data sources in real-time. It explores the usage of wearable devices for health monitoring systems. In addition, the availability of big data and artificial intelligence analysis and prediction has increased, investigating algorithmic studies for accurate prediction of hazardous environments and health impacts. Regarding health effects, techniques to prevent respiratory and related diseases were reviewed.

Analysis of the integral fuel tank considering hygrothermal enviornmental factors (열습도 환경요소를 고려한 일체형 복합재 연료탱크의 해석)

  • Moon, Jin-Bum;Kim, Soo-Hyun;Kim, Chun-Gon
    • Composites Research
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    • v.20 no.5
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    • pp.64-69
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    • 2007
  • Matrix dominant properties of composites are largely degraded under harmful environments such as temperature and humidity. Therefore we should consider the harmful environmental factors in the design of an UAV integral fuel tank subjected to high temperature and high humidity. The harmful environment experiment was performed for carbon/epoxy composites made of a unidirectional prepreg USN175B, and a plain woven fabric prepreg WSN3. The immersion experiment was performed under $90^{\circ}C$. The specimens were tested when the weight gam of specimen was saturated. The specimens were tested under $74^{\circ}C$ to obtain tensile and inplane shear properties. The results showed that the matrix dominant properties were extremely degraded by hygrothermal environment. To consider the variability of load, the anti-optimization method was applied. By using this method, the worst load case was found by comparing the load convex model and stability boundary. The stability boundary was obtained by analysis of the integral wing fuel tank of UAV using degraded properties. To do this, it was known that the worst load case of the integral wing fuel tank was the hovering mode load case.

Study of the Density of Smoke and Harmful Gases of Adhesive Indirect Moxibustion (접착식 간접구의 연기 밀도 및 유해가스 발생 확인 연구)

  • Kim, Eun-Jung;Kim, Yu-Jong;Hwang, Ji-Hoo;Cho, Hyun-Seok;Kim, Kyung-Ho;Lee, Seung-Deok;Kim, Kap-Sung
    • The Journal of Korean Medicine
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    • v.33 no.1
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    • pp.42-51
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    • 2012
  • Objectives: We measured the density of smoke and harmful gases emitted from burning adhesive indirect moxa. Through the test we aimed to find out if there was an excessive amount of smoke emitted and if it included harmful gases. Methods: 9 types of adhesive indirect moxa were chosen. The buffer layers which do not burn during treatment were removed and 10g of each moxa were made into powder and put into a holder. A smoke density chamber (Smoke Density Chamber FTT. U.K) and Fourier transform infrared spectroscopy (FT-IR I 4001. MIDAC U.S.A.) were used to measure the density of smoke and harmful gases emitted from burning moxa by ISO 5659-2 test. Results: The result of measuring maximum smoke density showed that the regular indirect adhesive moxa (A-F) emitted high density smoke of 172.1-291.4Ds. The smokeless moxas, Seoam moxas, emitted the least amount of 3.4-5.5Ds. Concentrations of 7 typical harmful gases (CO, HCl, HCN, HBr, HF, SO2, NOx) were measured and all of the moxas emitted CO due to incomplete combustion. 4 types of moxa emitted NOx and all smokless moxas emitted NOx. HBr, HCN, HCl, HF, SO2 were not found in any of the moxas. Conclusions: The amount of harmful gases emitted from burning moxa was much lower than short-term exposure standards of chemical and physical factors (Ministry of Labor 2010-44). Further experiments measuring gases from moxa combustion should be done in larger environments similar to normal medical clinics.

The Reconstruction of Atmospheric Particle Size Distributions Using Optical Sensing Data and Some Regularization Methods l : Direct Methods (광측정 데이터와 최적화 방법들을 이용한 대기입자 크기분포 복원)

  • Kim, Seok-Seong;Yeon, Kyu-Hwang;Kim, Duck-Hyun
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.213-214
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    • 2003
  • Atmospheric particles have a great deal of influences on the climate and the air quality, which change the living and industrial environments of a specific area. Especially, the suspended dusts and aerosols can often have a harmful influences on workers' health, equipments at working places. For this reasons, the measurement of atmospheric particle size distributions is of considerable current interest. (omitted)

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A study on the Job Satisfaction Degree of Korean Dental Technicians (한국 치과기공사의 직무만족도에 대한 조사연구)

  • Park, Jong-Hee
    • Journal of Technologic Dentistry
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    • v.14 no.1
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    • pp.81-90
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    • 1992
  • 1. The dental technicians are worn to a frazzle by a hard work. Therfore, the term of manufacturing denture should be prolonged as 4$\sim$5 days. 2. The dental technicians work under the harmful environments. It should be improved the working conditions for the dental technicians. 3. In case of the women dental technicians, they feel like being treated discriminality. It should be take over a portion of the work in dental laboratory as the accountant' section and the technical section. 4. It should be abolished a pressent instruction dentist system.

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Students' Knowledge and Attitudes Towards Smoke-Free Universities: Changes Since Enactment of Vietnamese Tobacco Control Legislation

  • Nguyen, Ngoc Bich;Cook, Margaret;Johnstone, Kelly;Capra, Mike;Vu, Thi Hoang Lan
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup1
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    • pp.65-70
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    • 2016
  • Background: In 2013, legislation in Vietnam regulated smoking in public areas. Included was a ban on indoor smoking at universities. Objective: Since awareness and attitude are moderators of the effectiveness of smoke-free policy, ou aim was to assess changes in students' knowledge and attitude tosecond hand smoke (SHS) and awareness and support of smoke-free legislation at four Vietnamese universities, one year after legislative changes. Methods: A two-phase cross sectional study of undergraduate students using self-administered questionnaires (based on the Global Adult Tobacco Survey and the Thrasher survey) was conducted at the introduction of the legislation and one year thereafter. Results: One-year post legislation there were significant increases in knowledge of smoke-free legislation and awareness of universities as smoke-free environments. There was a significant increase in knowledge of harmful effects of SHS on diseases such as examples in the heart and lung, including lung cancer, and miscarriage. Students expressed strong support of smoke-free environments in universities, hospitals, schools, workplaces, public transport, libraries, cinemas and theatres; support was also increased post legislation. Changes were seen in attitude to SHS, and rights of non-smokers and smokers. Conclusions: Positive changes have occurred in knowledge and attitude toward smoke-free environments and SHS in universities since enactment of Vietnamese tobacco control legislation.