• Title/Summary/Keyword: dusts

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Effects of SiO2 in Turkish Natural Stones on Cancer Development

  • Dal, Murat;Malak, Arzu Tuna
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.10
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    • pp.4883-4888
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    • 2012
  • In materials science, one of the new concerns in the construction industry, it is well established that mineral dust from rocks (stones) has adverse effects on human health. For instance, it is suspected that some mineral dusts in particular leads to occupational diseases, including lung cancer. The present research concerned the relationship between cancer and those workers who work in Turkish construction industry and quarries and are exposed to silica mineral dust from natural stones. One focus was cancer prevention methods applied in-site. In mining and construction industry where stone dust is widely used, silicosis induced lung cancer is frequently seen. Cancer cases which are seen across the regions mostly affected by silica containing dust in Turkey were identified and a survey was conducted of the methods to protect workers in the construction industry from exposure to silica dust.

Abnormal vibration of steam turbine due to carbon deposit at journal bearing in 500MW thermal power plant (탄소 고형물에 의한 터빈의 이상 진동)

  • 구재량;황재현;김연환;이우광
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.234-238
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    • 2002
  • Lubricating oil supply system is an essential instrument for safe turbine operation. A lubricating condition may cause the abnormal vibration of turbine. In this paper we have discussed the abnormal vibration of turbine due to lubricating oil. Dusts of the air usually attach to end of the oil deflector and contact particles of the bearing oil. Dusts which were contacted particles of the bearing oil were changed into carbon deposit because of high temperature. therefore, carbon deposits occur abnormal vibration of the turbine when they contact a rotor. So, we have solved this problems through the various maintenance.

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Preparation and Optical Characterization of Photonic Crystal Smart Dust Encoded with Reflection Resonance (반사공명으로 인코딩된 광결정 스마트 먼지의 제조방법 및 광학적 특징)

  • Lee, Boyeon;Hwang, Minwoo;Cho, Hyun;Kim, Hee-Cheol;Han, Jungmin
    • Journal of Integrative Natural Science
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    • v.3 no.2
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    • pp.84-88
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    • 2010
  • Photonic crystals containing rugate structures from a single crystalline silicon wafer was obtained by using a sinoidal alternating current during an electrochemical etch procedure. Photonic crystals were isolated from the silicon substrate by applying an electropolishing current and were then made into particles by using an ultrasonic fracture in an ethanol solution to give a smart dust. Smart dusts exhibited their unique nanostructures and optical characteristics. They exhibited sharp photonic band gaps in the optical reflectivity spectrum. The size of smart dust obtained was in the range of 10-20 nm.

Properties of Fine Dust Adsorption Matrix Based Blast Furnace Slag using Bentonite (벤토나이트를 활용한 고로슬래그 기반 미세먼지 흡착형 경화체의 특성)

  • Kim, Yeon-Ho;Kyoung, In-Soo;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.40-41
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    • 2019
  • Fine dust, which is emerging as a global problem, attracted much attention recently in Korea. One of the reasons is that recent factory relocation and expansion in China affected the increase of domestic fine dust concentration due to the influence of the Yangtze river battalion and westerlies. Fine dust is a big problem not only in outdoor but also indoors. The room requires periodic ventilation and is also essential for improving indoor air quality. The fine dusts are designated as Group 1 carcinogens in WHO and the risk of fine dusts on the human body due to respiratory diseases is also increasing. In this study, the characteristics of the fine dust adsorption matrix are examined and the actual application direction is derived.

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Characteristics of the Air-side Particulate Fouling Materials in Finned-Tube Heat Exchangers of Air Conditioners (공기조화기용 열교환기의 공기측 파울링 입자 분석 연구)

  • 안영철;신희수;황유진;이창건;이재근;이현욱;안승표;윤덕현;하삼철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.7
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    • pp.611-617
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    • 2003
  • The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the characteristics of the air-side particulate fouling materials in finned-tube heat exchangers of air conditioners. Air conditioners being used in the field such as inns, restaurants, and offices are collected in chronological order in use. Typical fouling materials on the heat exchangers include fibers and dusts ranged from 6.6 to 20.9 ${\mu}{\textrm}{m}$ in mass median diameter.

Wind-Tunnel Simulation of Windbreaks to Control Windblown Dusts in the Atmospheric Boundary layer (대기 경계층내에서 바람에 의해 발생되는 부유 물질 제어를 위한 Windbreaks의 풍동 시뮬레이션)

  • Kang, Kun
    • Journal of Environmental Science International
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    • v.4 no.1
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    • pp.29-40
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    • 1995
  • Transport rate of windblown dusts such as soil, sand, snow is proportionate to $U*_^3 and U_*$, friction velocity, approximately to flow velocity of ink Therefore, through measurement and the flow velocity of wind, it turned out that, considering different velocity distributions caused by downstream distance and porosity percent, windbreaks with appropriate porosity rate to the Protection area should be chosen for the optimal fence effect. In the economic respects better are fences with gap of 20%~30%. Among the windbreaks to have the optimal fence effect.

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Blood Levels of IL-Iβ, IL-6, IL-8, TNF-α, and MCP-1 in Pneumoconiosis Patients Exposed to Inorganic Dusts

  • Lee, Jong-Seong;Shin, Jae-Hoon;Lee, Joung-Oh;Lee, Won-Jeong;Hwang, Joo-Hwan;Kim, Ji-Hong;Choi, Byung-Soon
    • Toxicological Research
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    • v.25 no.4
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    • pp.217-224
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    • 2009
  • Inhaled inorganic dusts such as coal can cause inflammation and fibrosis in the lung called pneumoconiosis. Chronic inflammatory process in the lung is associated with various cytokines and reactive oxygen species (ROS) formation. Expression of some cytokines mediates inflammation and leads to tissue damage or fibrosis. The aim of the present study was to compare the levels of blood cytokines interleukin (IL)-$1\beta$, IL-6, IL-8, tumor necrosis factor (TNF)-$\alpha$ and monocyte chemoatlractant protein (MCP)-1 among 124 subjects (control 38 and pneumoconiosis patient 86) with category of chest x-ray according to International Labor Organization (ILO) classification. The levels of serum IL-8 (p= 0.003), TNF-$\alpha$ (p=0.026), and MCP-1 (p=0.010) of pneumoconiosis patients were higher than those of subjects with the control. The level of serum IL-8 in the severe group with the small opacity (ILO category II or III) was higher than that of the control (p=0.035). There was significant correlation between the profusion of radiological findings with small opacity and serum levels of IL-$1\beta$(rho=0.218, p<0.05), IL-8 (rho=0.224, p<0.05), TNF-$\alpha$ (rho=0.306, p<0.01), and MCP-1 (rho=0.213, p<0.01). The serum levels of IL-6 and IL-8, however, did not show significant difference between pneumoconiosis patients and the control. There was no significant correlation between serum levels of measured cytokines and other associated variables such as lung function, age, BMI, and exposure period of dusts. Future studies will be required to investigate the cytokine profile that is present in pneumoconiosis patient using lung specific specimens such as bronchoalveolar lavage fluid (BALF), exhaled breath condensate, and lung tissue.

HEPA Filter Tests Using PLS and Composite Nanospheres (PLS 및 복합 나노구체를 이용한 HEPA 필터 시험)

  • Hwang, Min-Jin;Sung, Dong Chan;Moon, Hee
    • Applied Chemistry for Engineering
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    • v.24 no.4
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    • pp.357-362
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    • 2013
  • Monodispersed polystyrene latex spheres (PLS) and PS-MPS/silica composite nanospheres were used to test high efficiency particulate air (HEPA) filters. Prior to filter tests, all nanospheres used in this work were characterized by measuring their average particle diameters and coefficients of variation (CV) for assessing them as artificial dusts. The average particle sizes of PLS and composite nanospheres could be well controlled in the range of 100~300 nm well by changing reaction temperature and the amount of a stabilizer during emulsion polymerization. The CV of all nanospheres were also in the range of 3~7%, lower than 15% that is the criterion for monodispersed particle distributions. Furthermore the results of HEPA filter tests show that all nanospheres used were quite proper as artificial dusts for testing air filters.

Survey of Globular Clusters with the AKARI FIS for the Intracluster Dusts

  • Pyo, Jeong-Hyun;Jeong, Woong-Seob;Kim, Eun-Hyeok;Lee, Myung-Gyoon;Hong, Seung-Soo
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.52.2-52.2
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    • 2010
  • In search of the intracluster dusts, we have made a survey of globular clusters (GCs) with the Far-Infrared Surveyor (FIS) aboard AKARI, the Japanese infrared space satellite. The GCs are thought to host dust particles that are condensed from the material injected by the cluster asymptotic giant branch (AGB) stars. However, attempts to detect dust emission from GCs had not been successful until a significant amount of far-infrared (FIR) emission was detected close to the NGC 7078 center by the ISO observations (Evans et al. 2003). Recent FIR observations by the AKARI (Matsunaga et al. 2008) and the Spitzer Space Telescope (Boyer et al. 2006; Barmpy et al. 2009) reported a tentative detection of the dusts in NGC 5024 and NGC 6341, and also confirmed the previous ISO dust detection from NGC 7078. We have observed 17 selected GCs in four FIS wavebands at 65, 90, 140, and 160 micrometers. Each observation covers about $10'{\times}10'$ area centered at each GC. The resulting images show extended structures and/or blobs around the GCs. The extended structures are very suggestive of the Galactic cirrus, while the blobs around NGC 288 and NGC 4833 seem to be related to the two clusters. In this presentation, we will report four representative cases of our survey results and discuss the properties of newly detected sources.

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