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        검색결과 56

        41.
        2005.07 KCI 등재 서비스 종료(열람 제한)
        Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were investigated in soil and pine needle samples taken from 16 sites of industrial and residential areas in Changwon, Korea to assess their distribution levels and to suggest the influence of industrial activities. PCDDs/DFs levels in the soil samples ranged from 0.57 to 20.79 pg I-TEQ/g dry weight with a mean value of 4.20 pg I-TEQ/g dry weight. PCDDs/DFs levels in the pine needle samples ranged from 0.39 to 8.75 pg I-TEQ/g dry weight with a mean value of 4.09 pg I-TEQ/g dry weight. In both soil and pine needle samples, the PCDDs/DFs concentrations in the industrial area sites were higher than those in the residential area sites. Homologue profiles in pine needle samples showed different patterns compared with soil samples. Based on the results of principal component analysis (PCA), it was confirmed that pine needles reflected a direct influence from local potential sources of PCDDs/DFs, showing a much higher degree of reflection than in soils. Pine needles are very useful as an indicator for monitoring or estimating the contamination of PCDDs/DFs in other areas which have been impacted by point pollution sources.
        45.
        2005.01 KCI 등재 서비스 종료(열람 제한)
        Soil is one of the most fundamental elements as well as with water and air in studies associated with the environment, in addition, it is one of the important environmental mediums that constructs a basis of the biological system and performs various roles of matter circulation. This study was carried out in Seoul, in May 2000 to evaluate variation in the concentration levels and distribution characteristics for PAH compounds in soil. Soil samples were collected from 33 sites covering traffic, factory, incineration and mountain groups and the PAHs were analyzed. The results show a wide distribution range of PAHs concentrations between 14.66 ng/g and 1,219.35 ng/g. The highest concentration levels exist at Sungsu-2 of the factory group (FS-2). Daemo-3 of the Mountain group (MD-3) presents the lowest levels as compared with the other sites. PAH compounds including mutagenic and carcinogenic materials show high concentrations in the traffic and factory groups and a high ratio in the mountain group. Besides, these compounds absorbed with micro particles might be spread out over a wide region associated with particles' movement and diffusion. After principal component analysis of the soil samples, the results indicated that the sources of PAHs in the soil were divided into two groups, pesticides and vehicles.
        46.
        2004.12 KCI 등재 서비스 종료(열람 제한)
        Thirty-nine out of eighty-five barley varieties/strains survived until heading stage in the saline experimental field (0.03-0.05~%~;salt) and they were used for pollen study. Light and scanning electron microscopic observations revealed two distinctive types of barley pollens: one transparent and small in size and the other dark and larger. In addition, both types of pollens were stained with Alexander's stain and it was found that the smaller and transparent pollen was cytoplasm-devoid (CD) while the larger pollen was cytoplasm-rich (CR). Sixteen out of 39 barley varieties/lines grown in the saline soil had CR pollens, which were rarely observed in the barley plants grown in the non-saline soil. Moreover, it was observed that salt stress severely reduced seed setting in the varieties having degenerated pollens. These results suggest that salt stress affects the fertility of barley pollen. The sterile pollen was undersized and lack of cytoplasm probably due to abortion. Furthermore, a varietal difference existed in the response of pollen development to salt stress.
        47.
        2004.05 KCI 등재 서비스 종료(열람 제한)
        Atmospheric bulk (wet and dry) samples were monthly collected in an urban environment (Daeyeon-dong) of Busan over a year, to assess the deposition flux and seasonality of dioxin-like polychlorinated biphenyls (DLPCBs) using stainless steel pots. Deposition fluxes of DLPCBs in bulk samples were determined using high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). Particle deposition fluxes in the urban environment varied from 23 to 98 g/m2/year (mean 41 g/m2/year). DLPCB deposition fluxes in atmospheric bulk samples ranged from 0.09 to 0.77 ng-TEQ/m2/year (mean 0.35 ng-TEQ/m2/year). Seasonal atmospheric deposition fluxes of DLPCBs were high in winter and low in summer. Atmospheric deposition fluxes of particles and DLPCBs in this study were comparable to or slightly lower values than those of different locations in the world. Monthly DLPCB profiles in deposition bulk samples were similar over a year. Non-ortho PCBs were higher contributions to the total DLPCBs fluxes than mono-ortho PCBs. In particular, PCB 126 had the highest concentrartion (>75%) in all deposition samples, followed by PCB 169 and PCB 156. A highly positive correlation was found among the deposition fluxes of DLPCB species, suggesting the possibility of that the DLPCB contamination originated from one source. The deposition fluxes of DLPCBs were not significantly correlated with temperature and the amount of precipitation even though the summer season with the highest temperature and the largest amount of precipitation showed the lowest DLPCB deposition flux.
        48.
        2003.11 KCI 등재 서비스 종료(열람 제한)
        Polycyclic aromatic hydrocarbons (PAHs) are an important group of organic contaminants present in sewage sludge, due to their persistence, toxic, bioaccumulative and long range transfer. These characters make themselves as Persistent Organic Pollutants(POPs) in Long Range Transboundary Air Pollutions convention(LRTAP) of Europe. A method of the gas chromatographicmass spectrometric (GCMS) determination of PAHs present in sewage sludge was developed and applied to analyzed samples from five sewerage treatment plants (SWTPs), having different treatment types. PAHs were extracted from freeze-dried samples by toluene 16 hours in a soxhlet extraction system. The sludge extracts were cleaned-up by an activated silica gel column chromatography. The sum of the 16 US Environmental Protection Agency PAHs sewage sludge samples varied from 2.44 to 4.82 ㎍/ g. Concentration of emission carcinogen PAHs(PAHcarc), such as Benzo(a)anthracene, Benzo(b)fluoran- thene, Benzo(k)fluoranthene, Benzo(a)pyrene, Dibenzo(a,h)anthracene and Indeno(1,2,3-cd)pyrene ranged from 0.62 to 1.03 ㎍/g. The total amount of PAHs emission from sewage sludge in Korea was calculated as a top-down approach. PAHs and ∑PAHcarc from sewage treatment plants had emitted to environment by several pathway. The highest amount of emission to the environment was remarked in the ocean dumping(PAHs and ∑PAHcarc emissions were 1155.95 kg/year and 5040.32 kg/year, respectively).
        49.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        A new malting barley cultivar, “Sinho”, with a resistant gene (rym5) to barley yellow mosaic virus (BaYMV) was developed by the barley breeding team of National Crop Experiment Station (NCES), RDA in 1999. This cultivar was derived from the cross between
        50.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        “Jaeanchal” is a new six-rowed, naked and waxy barley cultivar developed by National Crop Experiment Station (NCES), RDA in 2001. This cultivar was derived from a cross between “Suwon261” and “SB881115-6” in 1989. The final selection was made at NCES in 1
        51.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        Sanglog', a new covered barley cultivar resistant to powdery mildew and barley yellow m osaic virus (BaYMV) was developed by the barley breeding team of the National Crop Experim ent Station (NCES), RDA in 1999. This variety was derived from a cross betwe
        52.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        A new two-rowed naked waxy barley cultivar, 'Pungsanchal', was developed for split polished grains by the National Crop Experiment Station(NCES), RDA in 2001. This cultivar was derived f rom a cross between 'SB901258GG-B' and 'Suwon212' in 1991. The f ina
        53.
        1999.04 KCI 등재 서비스 종료(열람 제한)
        To estimate the residence times of aerosols in air, the activities of 210Pb and 210Po in aerosols were measured at 4 sites in Pusan. All aerosol samples were collected by a high volume air sampler from January to October 1996. The activities 210Pb and 210Po in Pusan were varied from 11.77 to 67.57 dpm/1000㎥ and from 2.63 to 15.91 dpm/1000㎥, respectively. The mean activities were 34.62 dpm/1000㎥ for 210Pb and 8.24 dpm/1000㎥ for 210Po. The highest values of the activities of 210Pb and 210Po were appeared at P3 site and the lowest values at P4 site. During the sampling period, the trends of the activities of 210Po and 210Pb were similar to total suspended particulate matter(TSP) concentrations. The mean residence times of atmospheric aerosols calculated from 210Po/210Pb activity ratio was about 60∼80 days in Pusan. The longest residence time of atmospheric aerosols was in January because of the lack of rainout and washout, but the shortest residence time was in August, largely due to scavenging effect by frequent rains. The activities of 210Po and 210Pb in atmospheric aerosols were different in time and space, which seems that the distribution of 210Po and 210Pb activities and scavenging processes in air may be controlled by the local and meteorological conditions.
        54.
        1999.02 KCI 등재 서비스 종료(열람 제한)
        Chemical composition of atmospheric aerosols was measured at 4 sites in Pusan. All the samples were collected with a high volume air sampler from January to October 1996, to analyze major ions and heavy metals. Dominant ions of aerosols were SO42- in anion and Na+ in cation. Sulfate, nitrate and ammonium ions in aerosols showed high enrichmentfactor to soil and seawater composition. The concentrations of heavy metals in aerosols was lowest at the site P1 near the coast. The lowest concentrations of major ions and heavy metals mainly appeared in August, probably due to scavenging by frequent rains. Especially, the concentrations of total suspended particulate matter(TSP) and heavy metals in aerosols showed good correlations in Pusan. Based on crustal Al, enrichment factors for some metals(Zn, Cu, Pb, Cd) in aerosols were significantly greater than unity, and the order was Cd > Pb > Zn > Cu. This evidence suggests that Cd and Pb are derived predominantly from non-crustal sources.
        55.
        1998.10 KCI 등재 서비스 종료(열람 제한)
        The concentrations and wet deposition flux into the sea of heavy metals of precipitation in Pusan area were measured and estimated. The samples were collected by polyethylene bottle(30ℓ) from January to November in 1996, and heavy metals were analyzed by atomic absorption spectrometer. The concentration order of heavy metals was Al >Fe >Zn >Pb >Mn >Cu >Ni >Cd >Co, and they were high at inland sites and low at coastal sites. The enrichment factors for some metals(Zn, Cu, Pb, Cd), based on crustal Al, were significantly greater than unity, and the order was Cd > Pb > Zn > Cu. This evidence suggests Cd and Pb are derived predominantly from non-crustal sources. Al, Fe and Mn contents showed good correlation with each other. Therefore this enrichment factor indicates similar geochemical behavior of these elements. The annual wet depositional flux(㎎/㎡/yr) from P1 site was as follows: Al (121.1), Fe,(177.2), Zn(12.9), Mn(6.19), Pb(14.4), Cu(0.64), Ni(1.03), Cd(1.02) and Co(1.01).
        56.
        1998.10 KCI 등재 서비스 종료(열람 제한)
        The chemical characteristics of precipitation was investigated in Pusan area. Samples were collected from January to November in 1996 at 4 sites, and analyzed pH, mayor soluble ionic components(Cl^-, NO_3^-, SO_4^2-, Na^+, K^+, NH_4^+, Mg^2+, Ca^2+). The order of anion and cation concentrations for the initial precipitation were Cl^- > SO_4^2- > NO_3^- , and Ca^2+ > Na^+ > NH_4^+ > Mg^2+ > K^+, respectively. At coastal sites(P1 and P2) Cl^- and Na^+ of maritime sources (seasalt) were high, but at inland sites(P3 and P4) nss-Ca^2+ and nss-SO_4^2- were high. Calcium ion for the initial precipitation showed high value of enrichement factor(EF) relative to seawater composition. The contribution of seasalt to the composition of precipitation was higher at site P1 (53.5%) than those of the other sites. Throughout the year the concentrations of major ions for the initial precipitation were low in the heavy rain season. The mean pH for the initial precipitation was 5.4 and showed the negative relationship with the precipitaion amount. The SO_4^2- and NO_3^- do not play an important role in rain acidification due to the high(97%) neutralizing effect of amonia and calcium species.
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