• Title/Summary/Keyword: Micro dust

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Development of the stone surface process equipment by Water Jet System (워터젯 시스템을 이용한 석재표면처리장치 개발)

  • 강지호;장명환
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.26 no.3
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    • pp.31-38
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    • 2003
  • There is boner process of stone manufacturing to become quality down of stone to consolidated micro crack appearance of stone surface and biotite by fire that is to be route process in stone surface by flame of LPG. And then, it is develop that stone surface process equipment by automation for the work method of boner process can be substitute work method by water jet To development of equipment, There is to be down noise and dust. According to remove calamity growth hazardous substance in the work environment, there is to solve workplace avoidance factor.

Changes in consumer perception of fashion products in a pandemic - Effects of COVID-19 spead - (팬데믹 상황에서의 패션제품에 대한 소비자의 인식 변화 분석 - 코로나19 확산의 영향 -)

  • Choi, Yeong-Hyeon;Lee, Kyu-Hye
    • The Research Journal of the Costume Culture
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    • v.28 no.3
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    • pp.285-298
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    • 2020
  • This study aimed at examining fashion consumers' awareness during the COVID-19 pandemic. Big data analysis methods, such as text mining, social network analysis, and regression analysis, were applied to user posts about fashion on Korean portal websites and social media during COVID-19. R 3.4.4, UCINET 6, and SPSS 25.0 software were used to analyze the data. The results were as follows. In researching the popular fashion-related topics during COVID-19, the prevention of infection and prophylaxis were significant concerns in the early stage (Jan 1 to Jan 31, 2020), and changed to online channels and online fashion platforms. Then, various topics and fashion keywords appeared with COVID-19-related keywords afterwards. Fashion-related subjects concerned prophylaxis, home life, digital and beauty products, online channels, and fashion consumption. In comparing fashion consumers' awareness during COVID-19 with SARS and MERS, "face masks" was the common keyword for all three illnesses; yet, the prevention of infection was a major consumer concern in fashion-related subjects during COVD-19 only. As COVD-19 cases increased, the search volume for face masks, shoes, and home clothes also increased. Consumer awareness about face masks shifted from blocking yellow dust and micro-dust to the sociocultural significance and short supply. Keywords related to performance turned out to be the major awareness as to shoes, and home clothes were repurposed with an expanded range of use.

A Study of Emulsion Fuel of Cellulosic Biomass Oil (목본계 바이오매스오일의 에멀젼 연료화 연구)

  • Kim, Moon-Chan
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.4
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    • pp.836-847
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    • 2016
  • Water soluble oil was obtained by pyrolysis of biomass. The characteristics of emulsified fuel by mixing water soluble oil and MDO(marine diesel oil) and engine emissions were studied with engine dynamometer. Saw dust was used as biomass. Water soluble oil was obtained by condensing of water and carbon content with pyrolysis of saw dust at $500^{\circ}C$. Emulsion fuel was obtained by emulsifying MDO and water soluble oil by the water soluble oil mixing ratio of 10 to 20% of MDO. Exhaust gas detection was performed with engine dynamometer. While combustion, micro-explosion took place in the combustion chamber by water in the emulsion fuel, emulsion fuel scattered to micro particles and it caused to smoke reduction. The heat produced from water vapour reduce the temperature of internal combustion chamber and it caused to inhibition of NOx production. It can be verified by the lower exhaust temperature of each ND-13 mode using emulsion fuel than that of MDO fuel. The NOx and smoke concentration were reduced by increasing water soluble oil content in the emulsion fuel. The power also decreased according to the increment of water soluble oil content of emulsion fuel because emulsion fuel has low calorific value due to high water content than MDO. As a result of ND-13 mode test with 20% bio oil content, it was achieved 25% reduction in NOx production, 60% reduction in smoke density, and 15% reduction in power loss.

The performance of Bio-aerosol Detection System (BDS) with 405 nm laser diode (405 nm 광원을 이용한 생물입자탐지기의 에어로졸 분석성능)

  • Jeong, Young-Su;Chong, Eugene;Lee, Jong-Min;Choi, Kibong
    • Particle and aerosol research
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    • v.13 no.1
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    • pp.25-31
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    • 2017
  • This paper offer the characteristics for the detection and classification of biological and non-biological aerosol particles in the air by using laser-induced-fluorescence (LIF) based Bio-aerosol Detection System (BDS). The BDS is mainly consist of an optical chamber, in-outlet nozzle system, 405 nm diode laser, an avalanche photo detector (APD) for scattering signal and photomultiplier tubes (PMT) for fluorescence signals in two different wavelength range ; F1, 510-600 nm and F2, 435-470 nm. The detection characteristics, especially ratio of fluorescence signal intensity were examined using well-known components : polystylene latex (PSL), fluorescence PSL, $2{\mu}m$ of SiO2 micro sphere, dried yeast, NADH, ovalbumin, fungicide powder and standard dust. The results indicated that the 405 nm diode laser-based LIF instrument can be a useful bio-aerosol detection system for unexpected biological threaten alter in real-time to apply for dual-use technology in military and civilian fields.

Radical Mist Generator Using a Water Plasma Jet and Its Sterilization Effect

  • Huh, Jin Young;Ma, Suk Hwal;Kim, Kangil;Choi, Eun Ha;Hong, Yong Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.175.1-175.1
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    • 2016
  • In recent, tract infections such as atopic dermatitis, allergic rhinitis and a respiratory disease are increasing, giving rise to the atmospheric pollution, inflow of micro-size dust and side effect of humidifier disinfectant. In this context, the environment-friendly technology is required to eliminate airborne pathogens. We propose solution of the previous problems, making use of Radical Mist Generator (RMG). Existing technologies of air purification using a gas discharge produce harmful substances such as ozone, NOx, etc. However, the RMG uses a pure water as a plasma forming material. The RMG sprays the water mist, which contains reactive radicals to sterilize microorganisms. RMG is comprised of a power supply, plasma electrodes and a nozzle. In order to analyze the electrical characteristic and concentrations of reactive radicals, we employ an oscilloscope and a titration method. To test the sterilization effect of RMG, we used E.coli. We confirmed that E.coli was killed over 90%. Eventually, we expect that RMG can be promising tool for a purified system.

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Development of IoT based Real-Time Complex Sensor Board for Managing Air Quality in Buildings

  • Park, Taejoon;Cha, Jaesang
    • International Journal of Internet, Broadcasting and Communication
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    • v.10 no.4
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    • pp.75-82
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    • 2018
  • Efforts to reduce damages from micro dust and harmful gases in life have been led by national or local governments, and information on air quality has been provided along with real-time weather forecast through TV and internet. It is not enough to provide information on the individual indoor space consumed. So in this paper, we propose a IoT-based Real-Time Air Quality Sensing Board Corresponding Fine Particle for Air Quality Management in Buildings. Proposed board is easy to install and can be placed in the right place. In the proposed board, the air quality (level of pollution level) in the indoor space (inside the building) is easy and it is possible to recognize the changed indoor air pollution situation and provide countermeasures. According to the advantages of proposed system, it is possible to provide useful information by linking information about the overall indoor space where at least one representative point is located. In this paper, we compare the performance of the proposed board with the existing air quality measurement equipment.

Advances in the Field of Thermal Procedures in Direct Combination with Thin-layer Chromatography

  • Stahl, Egon
    • Korean Journal of Pharmacognosy
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    • v.7 no.1
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    • pp.3-13
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    • 1976
  • The hitherto existing gap in the field of chromatographic methods has been filled by the direct coupling of a suitable oven (TAS-oven) with TLC. The sample to be examined is heated either isothermally or linearly within the temperature gradient of $50{\sim}450^{\circ}C$. The volatile and/or thermolytically evolved substances are fractionated on the TLC-layer and subsequently chromatographed under standard conditions. Transport mechanisms from the sample to the TLC-layer, applications of the TAS-procedure and further developments are discussed. Thermofractography, developed from the TAS-procedure, is demonstrated on different groups of natural substances such as alkaloids, amino acids, nucleic acids. nucleosides, nucleotides, triglycerides and other lipids, pyrone glycosides and aglycon. Experimental work and results on the thermolysis of macromolecular natural and synthetic substances, natural polyphenols, tanning agents and leather and the possibilities of differentiating various lignins, carbohydrate and synthetic polymers are reported. Further, it is shown that classical reactions in the microgram range, e.g. zinc dust distillation, sulphur-and selenium dehydrogenation and catalytic dehydrogenation, can be coupled directly with TLC. Also described is a method which allows to investigate the gaseous compounds evolved during thermofractography in the range of up to $450^{\circ}C$. Thermal procedures coupled with TLC open up the following new possibilities for chemical microanalysis: fractionated separation of distillable and sublimable components, fractionated thermolysis and carrying out of thermal reactions in the ultra micro range.

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Evaluation of the Usability of Micro-Sensors for the Portable Fine Particle Measurement (생활 속 미세먼지 영향평가를 위한 소형센서의 신뢰성 및 활용성 평가)

  • Kim, Jinsu;Jang, Youjung;Kim, Jinseok;Park, Minwoo;Bu, Chanjong;Lee, Yungu;Kim, Younha;Woo, Jung-Hun
    • Journal of Environmental Impact Assessment
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    • v.27 no.4
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    • pp.378-393
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    • 2018
  • As atmospheric fine dust problems in Korea become more serious, there are growing needs to find the concentration of fine particles in indoor and outdoor areas and there are increasing demands for sensor-based portable monitoring devices capable of measuring fine dust concentrations instantly. The low-cost portable monitoring devices have been widely manufactured and used without the prescribed certification standards which would cause unnecessary confusion to the concerned public. To evaluate the reliability those devices and to improve their usability, following studies were conducted in this work; 1) The comparisons between sensor-based devices and comparison with more accurate devices were performed. 2) Several experiments were conducted to understand usefulness of the portable monitoring devices. As results, the absolute concentration levels need to be adjusted due to insensitivity of the tiny light scattering sensors in the portable devices, but their linearity and reproducibility seem to be acceptable. By using those monitoring devices, users are expected to have benefits of recognizing the changes of concentration more quickly and could help preventing themselves from the adverse health impacts.

Design and Development of Monitoring System for Subway Station based on USN (USN 기반의 지하역사 모니터링 시스템의 설계 및 개발)

  • Lee, Seok-Cheol;Jeong, Shin-Il;Kim, Chang-Soo
    • Journal of Korea Multimedia Society
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    • v.12 no.11
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    • pp.1629-1639
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    • 2009
  • This paper describes the environmental monitoring system for supporting comfortable subways based on USN. Our development system includes the sensor field based on integrated sensor, monitoring system for supporting the local and remote monitoring and middle-ware performs the collecting, analyzing, and storing the data. In this paper, we installed the temperature, humidity, micro-dust sensor and water-level sensor for supporting the rail-roads and make up the integrated sensor enables to reuse the analog device from 4~20mA output with connection of wireless sensor device. Middleware includes the modules of collecting, analysis, and storing the data and monitoring system supports the local for administrator and remote monitoring for citizen services based on web. The middleware and monitoring in this paper is comprised of some components can reuse and support the change of application and sensors. Our development system supports the mobility of sensor devices and distributes system. Data collection and management function supported by middleware will use assessment.

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Seasonal and Locational Concentrations of Particulate Air Pollutants in Indoor Air of Public Facilities in Taegu Area (대구지역 공중위생법 규제대상시설의 실내공기중 입자상 오염물질의 계절별 및 지점별 농도분포 특성)

  • 백성옥;송희봉
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.3
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    • pp.163-176
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    • 1998
  • In this study, airborne particle samples were obtained to determine the concentrations of particulate air pollutants in indoor and outdoor air of public facilities in Taegu area. Total of 12 public facilities, regulated by the Public Sanitary Law, were selected as sampling sites, which include three underground arcades, one railway and two bus terminals, three general hospitals, and three department stores. In each place, sampling was carried out seasonally during the period of October 1994 to July 1995, and four samples per each site per season were collected both indoors and outdoors simultaneously. After determination of suspended particulate matter (SPM) mass concentrations, the particle samples were divided into two parts for subsequent chemical analysis: one for the analysis of trace elements and the other for water soluble ions. Seasonal levels of SPM appeared to be the highest in spring and the lowest in summer both indoors and outdoors, while locational variations of highest in statioyterminals, and lowest in department stores . SPM concentrations indoors and outdoors did not show any significant differences each other in most places . However, there were significant correlations between indoor and outdoor levels of SPM and other chemical species . These results indicates that indoor SPM levels are likely to be significantly affected by outdoor sources in many places. The most significant source of SPM was estimated to be the resuspension of soil/road dust both indoors and outdoors . The concentrations of toxic heavy metals (Pb, Cd, Cr, Cu) in underground arcades appeared to be very much lower than the established air quality guidelines for underground environments. In addition, it is likely that micro-environmental parameters such as temperature, humidity, and air velocity, play a less significant role than outdoor air quality as a factor affecting the levels of particulate pollutants in indoor environments of public facilities in Taegu area.

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