• Title/Summary/Keyword: Elemental concentration

Search Result 294, Processing Time 0.024 seconds

Comparison of Diesel Exhaust Particle Concentration between Large Above-Underground Parking Lots (수도권 일부 대형상가 지상주차장 및 지하주차장의 공기중 디젤엔진배출 입자상물질의 공기중 농도 비교)

  • Kim, Boowook;Song, Dong-Woo
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.23 no.4
    • /
    • pp.323-332
    • /
    • 2013
  • Objectives: This study was conducted in order to investigate the diesel exhaust particle(DEP) concentrations in the thirteen parking lots of large shopping complex. Methods: The real-time black carbon(BC) concentration was determined using an Aethalometer, and elemental/organic carbon concentration was determined according to the method of the National Institute for Occupational Safety and Health(NIOSH) 5040. The particle number concentration(NC), lung deposited surface area concentration(LDSA) and geometric mean diameter(GMD) were determined using a DiSCmini aerosol monitor. Results: The average concentration of BC, EC, OC, NC, LDSA and GMD were $19.1{\mu}g/m^3$, $12.6{\mu}g/m^3$, $51.5{\mu}g/m^3$, $94,000particles/cm^{-3}$, $298{\mu}m^2/cm^{-3}$ and 57 nm in all parking lots, respectively, approximately 3-fold higher than those found in the urban outdoor. The average concentration of BC were $21.3{\mu}g/m^3$ in underground parking lots, 3-fold higher than above parking lots. Conclusions: Therefore, the parking lots at the large shopping complex can be considered a potentially dangerous environment with a high concentration of DEP nanoparticles.

Concentrations of Air Pollutants Measured at Kosan during ACE-Asia Intensive Observation Period (ACE-Asia 집중관측기간에 제주고산에서 측정한 대기오염물질의 농도 분포특성)

  • ;;;;Jianzhen Yu;Keith Bower
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.18 no.6
    • /
    • pp.487-501
    • /
    • 2002
  • The concentrations of gaseous (NO$_{x}$, SO$_2$, and $O_3$) and particulate (Elemental Carbon, EC and Organic Carbon, OC) pollutants were measured to evaluate the air quality of Kosan. Samples were taken at Kosan during ACE-Asia (Asian Pacific Regional Aerosol Characterization Experiment) IOP (Intensive Observation Period) (2001. 3. 21~2001. 5. 5). The mean concentrations of $O_3$(46.3$\pm$10.4 ppb) is higher than those at urban area such as Seoul and Busan in Korea. On the other hand, the mean concentrations of other gaseous species, NO$_{x}$(4.73$\pm$3.42 ppb) and SO$_2$(0.62$\pm$0.63 ppb) are lower than those at great cities. So we concluded that there are a few primary sources emitting atmospheric pollutants. The concentration of EC is higher and the concentration of OC is similar with or higher than those at other background sites. The recent EC concentration is higher than those measured before at Kosan. We concluded that there are more primary sources than other background sites and the amount of primary source have increased recently in Jeju. Backward trajectory and co..elation analysis were used to study where the air masses originated and distinguish the source of pollutants. While NO$_{x}$ and $O_3$ were mainly emitted and formed from Jeju inland area, concentrations of SO$_2$, OC and EC were affected by Asian Dust from China. Using the mean relative standard deviation of ozone, cleanness coefficient was obtained. The cleanness coefficient value, is 1.6 times larger than the value in 1992. Recently, the air quality of Kosan has been contaminated because of the Asian Dust events since spring and the rapid industrialization development.pment.

Quantitative Analysis of Silanization Degree of Silica Nanoparticles Modified with Bis[3-(trimethoxysilyl)propyl]amine Coupling Agent (Bis[3-(trimethoxysilyl)propyl]amine 커플링제로 개질된 실리카 나노입자의 실란화도 정량 분석)

  • Jeon, Ha-Na;Kim, Jung-Hye;Ha, Ki-Ryong
    • Polymer(Korea)
    • /
    • v.36 no.3
    • /
    • pp.372-379
    • /
    • 2012
  • In this study, we treated silica nanoparticles with bis[3-(trimethoxysilyl)propyl]amine (BTMA) silane coupling agent to modify their surfaces. We investigated the effects of BTMA hydrolysis time, BTMA concentration and BTMA treatment time on the degree of silanization reaction of silica nanoparticles. We used Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and solid state cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR) to obtain quantitative data. We found the decrease of isolated Si-OH peak intensity at 3747 $cm^{-1}$ and the increase of $-CH_2 $stretching and bending peaks with increasing hydrolysis time, concentration and treatment time of BTMA. EA analysis results also supported this trend. We found a strong effect of BTMA concentration on the degree of silanization of the silica particles, but weak effects of the hydrolysis time and the treatment time.

Effects of Short-term Feeding Magnesium before Slaughter on Blood Metabolites and Postmortem Muscle Traits of Halothane-carrier Pigs

  • Chen, Jing;Liu, XianJun;Bian, LianQuan
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.26 no.6
    • /
    • pp.879-885
    • /
    • 2013
  • Fifty-four, mixed-sex, halothane-carrier crossbred (Yorkshire${\times}$Landrace) pigs with an average initial BW of $108.2{\pm}0.8$ kg were randomly allotted to one of three dietary treatments for 5 d before slaughter: i) a control corn-soybean meal finisher diet devoid of supplemental magnesium; ii) a diet supplemented with 1.5 g/kg of elemental Mg from magnesium acetate; and iii) a diet supplemented with 1.5 g/kg of elemental Mg from magnesium sulfate heptahydrate. Serum creatine kinase (CK), lactate and glucose were analyzed at slaughter. Muscles from longissimus (LM) were packaged and stored to simulate display storage for muscle lactate and glycogen determinations at 0, 1, 2, 3, and 4 d. Mg supplementation reduced (p<0.05) serum CK and lactate concentration, but had no effect (p>0.05) on serum glucose. Daily change of muscle lactate concentration linearly increased (p<0.01), while glucose concentration linearly decreased (p<0.05) as storage time increased in all treatments. However, dietary Mg acetate and Mg sulfate supplementation in pigs elevated (p<0.05) muscle glycogen and reduced (p<0.05) muscle lactate concentrations, especially during the first 2 d of display, compared with pigs fed the control diet. This study suggests that short-term feeding of magnesium acetate and magnesium sulfate to heterozygous carriers of the halothane gene has beneficial effects on stress response and pork quality by improving blood and muscle biochemical indexes.

Activity of $V_2O_5-WO_3/TiO_2$-based SCR Catalyst for the Oxidation of Gas-phase Elemental Mercury ($V_2O_5-WO_3/TiO_2$ 계 SCR 촉매의 가스상 원소수은 산화 활성)

  • Hong, Hyun-Jo;Ham, Sung-Won
    • Clean Technology
    • /
    • v.17 no.4
    • /
    • pp.370-378
    • /
    • 2011
  • Catalytic activity of $V_2O_5-WO_3/TiO_2$-based SCR catalyst was examined for the oxidation of gas-phase elemental mercury to oxidized mercury. Mercury species was not detected on the commercial SCR catalyst after the oxidation reaction of elemental mercury, regadless of the presence of HCl acting as oxidant and the reaction conditions. This suggests that elemental mercury oxidation by HCl could occur via a Eley-Rideal mechanism with gas phase or weakly-bound mercury on the surface of $V_2O_5-WO_3/TiO_2$ SCR catalyst. The activity for mercury oxidation was significantly increased with the increase of $V_2O_5$ loading, which indicates that $V_2O_5$ is the active site. However, turnover frequency for mercury oxidation was decreased with the increase of $V_2O_5$ loading, indicating the activity for mercury oxidation was strongly dependent on the surface structure of vanadia species. The activity for oxidation of elemental mercury under SCR condition was much less than that under oxidation condition at the same HCl concentration and reaction temperature.

PIXE Analysis of Aerosol Particles - Preparation of Standard Samples and Calibration Test - (PIXE 분석에 의한 대기에어로졸의 원소분석 -표준시료의 작성 및 정량화-)

  • 崔琴簒
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.7 no.2
    • /
    • pp.114-118
    • /
    • 1991
  • Particle Induce X-Ray Emission (PIXE) analysis is one of the most useful methods which can determine the elemental concentration of aerosol particles in nano-gram range. The main purpose of this paper is to establish the measurement system and the procedure of PIXE analysis. The standard samples were prepared to calibrate the PIXE analysis by three different techniques. The linear relationships between the peak counts from PIXE spectra and the mass density from RBS spectra were obtained for each standardized element under the applied measurment geometry and conditions. The sensitivity curves for PIXE analysis were determined from these relationships.

  • PDF

One Pot Synthesis of Bioactive Novel Cyanopyridones

  • Khokhani, Kamlesh;Khatri, Taslimahemad;Patel, Praful
    • Journal of the Korean Chemical Society
    • /
    • v.57 no.4
    • /
    • pp.476-482
    • /
    • 2013
  • Cyanopyridone was prepared by the condensation of cyanoacetamide, substituted arylaldehydes and malononitrile in presence of pipyridine. The structure of the synthesized compound CP 1-20 was assigned on the basis of elemental analysis, IR, $^1H$-NMR and mass spectroscopy. These compounds were also screened for antimicrobial activity. The Minimum Inhibitory Concentration (MIC) of all the synthesized compounds was compared with standard drugs.

A Study on Properties of $CuInS_{2}$ thin films by Cu/In ratio (Cu/In 비에 따른 $CuInS_{2}$ 박막의 특성에 관한 연구)

  • Yang, Hyeon-Hun;Kim, Young-Jun;Jeong, Woon-Jo;Park, Gye-Choon
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2007.06a
    • /
    • pp.326-329
    • /
    • 2007
  • $CuInS_{2}$ thin films were synthesized by sulpurization of Cu/In Stacked elemental layer deposited onto glass Substrates by vacuum furnace annealing at temperature 200[$^{\circ}C$]. And structural and electrical properties were measured in order to certify optimum conditions for growth of the ternary compound semiconductor $CuInS_{2}$ thin films with non-stoichiometry composition. $CuInS_{2}$ thin film was well made at the heat treatment 200[$^{\circ}C$] of SLG/Cu/ln/S stacked elemental layer which was prepared by thermal evaporator, and chemical composition of the thin film was analyzed nearly as the proportion of 1 : 1 : 2. Physical properties of the thin film were investigated at various fabrication conditions substrate temperature, annealing and temperature, annealing time by XRD, FE-SEM and Hall measurement system. At the same time, carrier concentration, hall mobility and resistivity of the thin films was $9.10568{\times}10^{17}$ [$cm^{-3}$], 312.502 [$cm^{2}/V{\cdot}s$] and $2.36{\times}10^{-2}$ [${\Omega}{\cdot}cm$], respectively.

  • PDF

PHYSICOCHEMICAL CHARACTERIZATION OF UASB GRANULAR SLUDGE WITH DIFFERENT SIZE DISTRIBUTIONS

  • 안영희;송영진;이유진;박성훈
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2001.04a
    • /
    • pp.172-181
    • /
    • 2001
  • Upflow anaerobic sludge blanket (UASB) system employs granular sludge to treat various wastewaters including landfill leachate. CH$_4$ production of the granules determines overall performance of a UASB reactor. Sludge granules are developed by self-granulation of microorganisms and dynamic balance between granule growth and decay results in coexistence of granules with different sizes in the reactor. In this study, granules taken from a laboratory-scale UASB reactor were classified into 4 groups based on their diameters and their Physicochemical characteristics we were investigated. Each group was analyzed for settling ability, specific methanogenic activity (SMA), and elemental content. Settling ability was proportional to granule diameter. suggesting effective detainment of larger granules in the reactor. When acetate or glucose was used as a substrate, all groups showed relatively slight difference in SMA. However SMA with a volatile fatty acid mixture showed significant increase with granule diameter, suggesting better establishment of syntrophic relationship in larger granules. Larger granules showed higher value of SMA upon environmental changes (i.e., PH, temperature, or toxicant concentration). Comparative analysis of elemental contents showed that content (dry weight %) of most tested elements (iron, calcium, phosphorus, zinc, nickel. and manganese) deceased with granule diameter, suggesting importance of these elements for initial granulation. Taken together, this study verified experimentally that Physicochemical Properties of granules are related to granule size distributions. Overall results of physicochemical characterization supports that larger.

  • PDF