• Journal of Species Research
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• v.2 no.1
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• pp.91-98
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• 2013

An investigation of the karyotypes of two species of the genus Brachymystax (B. lenok and B. tumensis) has been done for the Russia Primorye rivers running to the East Sea basin, and others belonging to Amur basin. Based on the analysis of two species chromosome characteristics, combined with original and literary data, four cytotypes have been described. One of these cytotypes (Cytotype I: 2n=90, NF=110-118) was the most common. This common cytotype belongs to B. tumensis from the rivers of the East Sea basin and B. lenok from the rivers of the Amur basin, i.e. extends to the zones of allopatry. In the rivers of the Amur river basin, in the zone of the sympatric habitat of two species, each taxon has karyotypes with different chromosome numbers, B. tumensis (2n=92) and B. lenok (2n=90). Because of the ability to determine a number of the chromosome arms for these two species, additional cytotype have been identified for B. tumensis: Cytotype II with 2n=92, NF=110-124 in the rivers basins of the Yellow sea and Amur river and for B. lenok three cytotypes: Cytotype I: 2n=90, NF=110 in the Amur river basin; Cytotype III with 2n=90, NF=106-126 in the Amur river basin and Cytotypes IV with 2n=92, NF=102 in the Baikal lake.

• Mycobiology
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• v.48 no.6
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• pp.450-463
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• 2020

The strains 17E-042, 17E-039, and NC13-171 belong to Ascomycota and were isolated from soil collected from Sancheong-gun and Yeongam-gun, Korea. The strain 17E-042 produced white mycelial colonies that developed a sienna color with a round margin on potato dextrose agar (PDA), and the reverse side developed a light sienna color. Morphologically, this strain was similar to the strains of Arthrinium phragmites and A. hydei, but the shorter conidial size of the newly identified strain (17E-042) was distinct. The strain 17E-039 produced macroconidia that were pale yellow to orange-brown, elongated-ellipsoid to oblong, round at both ends, primarily straight but sometimes slightly curved, 0-septate, thin-walled, and filled with numerous droplets, having diameters of 20.4-34.3 × 8.0-12.0 ㎛. And the strain NC13-171 formed hyaline to light brown chlamydospores, solitary or in a chain. Multigene phylogenetic analyses were conducted using sequence data obtained from internal transcribed spacer (ITS) regions, 28S rDNA large subunit (LSU), β-tubulin (TUB2), translation elongation factor 1-alpha (TEF1-α), and RNA polymerase II large subunit (RPB2) genes. The results of molecular phylogeny, the detailed descriptions and illustrations of each species strongly support our proposal that these strains from soil in Korea be designated as Arthrinium minutisporum sp. nov. and two new records of Pezicula neosporulosa and Acrocalymma pterocarpi.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.148.2-149
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• 2003

Cucumber fruit mottle mosaic tobamovirus (CFMMV) causes severe mosaic symptoms with yellow mottling on leaves and fruits, and occasionally severe wilting of cucumber plants. No genetic source of resistance against this virus has been identified. The genes coding for the coat protein or the putative 54-kDa replicase were cloned into binary vectors under control of the SVBV promoter. Agrobacterium-mediated transformation was peformed on cotyledon explants of a parthenocarpic cucumber cultivar with superior competence for transformation. R1 seedlings were evaluated for resistance to CFMMV infection by lack of symptom expression, back inoculation on an alternative host and ELISA. From a total of 14 replicase-containing R1 lines, 8 exhibited immunity, while only 3 resistant lines were found among a total of 9 CP-containing lines. Line 144 homozygous for the 54-kDa replicase was selected for further resistance analysis. Line 144 was immune to CFMMV infection by mechanical and graft inoculation, or by root infection following planting in CFMMV-contaminated soil. Additionally, line 144 showed delay of symptom appearance following infection by other cucurbit-infecting tobamoviruses. Infection of line 144 plants with various potyviruses and cucumber mosaic cucumovirus did not break the resistance to CFMMV. The mechanism of resistance of line 144 appears to be RNA-mediated, however the means is apparently different from the gene silencing phenomenon. Homozygote line 144 cucumber as rootstock demonstrated for the first time protection of a non-transformed scion from soil inoculation with a soil borne pathogen, CFMMV.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.3
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• pp.93-97
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• 1981

Laboratory experiment was carried out to investigate the changes in the amount of inorganic phosphorus fractions of native and applied phosphorus and to compare the some analytical methods of soil phosphorus in volcanic ash. The rates of inorganic phosphorus to total-pP were varied with the kinds of soil in the ranges of 6.9 to 28.8% for Al-P, 24.1 to 26.9% for Fe-P, 7.4 to 11.9% for Ca-P and 0.7 to 8.0% for available phosphorus. The composition of inorganic phosphorus after incubation for 60 days was in the order of Al-P>Fe-P>Ca-P in Black soil, Fe-P>Al-P>Ca-P in Very dark brown soil, Fe-P>Ca-P>Al-P in Dark brown soil and Fe-P Al-P>Ca-P on Red yellow soil. The amounts of phosphorus extracted from soil varied with the methods for available phosphorus estimation. The magnitute of available P measured by Bray No. 2 method was the greatest. In relationship between inorganic phosphorus forms and available phophorus, Bray No. 2 method was closely related to Ca-P only and Olsen method correlated to Al-P, Fe-P, Ca-P and Total-P.

• Journal of the Korean Geotechnical Society
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• v.17 no.2
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• pp.59-72
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• 2001

적황색토와 플라이애쉬의 혼합비율에 증가에 따라 건조밀도도 증가하며 최적함수비는 감소하는 경향이고 2차 첨가재인 소석회 및 시멘트 첨가에 의한 건조밀도의 증가는 보이나 처리토의 경량화의 범위는 1:03~1:0.5 정도임을 확인할 수 있었다. 프라이애쉬의 혼합비율이 증가해도 프라이애쉬의 고유산화칼슘(CaO)의 함유량이 적으면 유리산화칼슘의 증가도 크지 않으나, 2차 첨가재인 소석회 및 시멘트 첨가량의 증대에 따라 증가한다. 이는 첨가재에 의한 수화반응의 증가로 확인되며, 본 처리토는 Ion 교환작용과 Pozzolan 반응 생성물인 규산칼슘석회수화물(5CaO.6SiO$_2$.5$H_2O$, Tobermorite)과 알민산유산석회수화물(3CaO.Al$_2$O$_3$.3CaSO$_4$.32$H_2O$, Ettringite)가 주된 반응생성물이며 확인된 알민산유산석회수화물(Ettringite)의 회절 X-선 강도는 2차 첨가재의 첨가에 따른 수화반응으로 수화물은 점차 증가하며 상대적으로 일축압축강도도 상응한 강도발현을 하여 고결화 효과에 기여하고 있음을 보여준다.

• Korean Journal of Microbiology
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• v.53 no.1
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• pp.61-63
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• 2017

A Gram-negative, yellow-pigmented, long-rod shaped bacterium Spirosoma montaniterrae $DY10^T$ was isolated from a soil sample collected at Mt. Deogyusan, Jeonbuk Province, Republic of Korea. Cells showed extreme gamma radiation resistance with the $D_{10}$ value of 12 KGy. The complete genome sequence of strain $DY10^T$ is consist of a circular chromosome (5,797,678 bp) encoding 5,116 genes, 9 rRNA genes and 39 tRNA genes. The genomic features contain the key enzymes for gamma and UVC radiation.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.311-317
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• 2000

Acid sulfate soil and potential acid sulfate soil material are worldwide in distribution and are problematic in agriculture and environment due to their present and potential acidity developed by the oxidation of sulfides. Most of them are sedimentary origin and a few cases are reported as volcanic or metamorphic origin. We report a potential acid sulfate soil material originated from volcanic activity during Mesozoic. A profile of Bongsan series-weathered nonpyritic andesite-hydrothermally altered pyrite rich andesite was studied with field examination, chemistry, and mineralogy. Once, the pyrite rich andesite was exposed to atmosphere by excavation and leveling works for a residential area and the lay out site had subsequent acidification problem of soil and surface water. The parent material and soil profile of Bongsan series had no signs of presence of pyrite and acid sulfate weathering such as yellow mottles. However, the hydrothermally altered andesite substrata contained significant amount of pyrite showing characteristics of hydrothermal origin such as cubic and pyritohedron morphology and occurrence along cracks.

• Atmosphere
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• v.26 no.3
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• pp.357-372
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• 2016

Northeast Asian regions have recently become the main source of anthropogenic and natural aerosols. Measurement of aerosols on the sea in these regions have been rarely conducted since the experimental campaigns such as ACE-ASIA (Asian Pacific Regional Aerosol Characterization Experiment) in 2001. Research vessel observations of aerosol mass and chemical composition were performed on the Yellow and south sea around the Korean peninsula. The ship measurements showed six representative cases such as aerosol event and non-event cases during the study periods. On non-event cases, the anthropogenic chemical and natural soil composition on the Yellow sea were greater than those on the south sea. On aerosol event cases such as haze, haze with dust, and dust, the measured mass concentrations of anthropogenic chemical and element compositions were clearly changed by the events. In particular, methanesulfonate ($MSA^-$, $CH_3SO_3^-$), a main component of natural oceanic aerosol important for sulfur circulation on Earth, was first observed by the vessel in Korea, and its concentration on the Yellow sea was three times that on the south sea during the study period. Sea salt concentration important to chemical composition on the sea is related to wind speed. Coefficients of determination ($R^2$) between wind speed and sea salt concentration were 0.68 in $PM_{10}$ and 0.82 in $PM_{2.5}$. Maximum wave height was not found to be correlated to the sea salt concentration. When sea-salt comes into contact with pollutants, the total sea-salt mass is reduced, i.e., a loss of $Cl^-$ concentration from NaCl, the main chemical composing sea salt, is estimated by reaction with $HNO_3$(gas) and $H_2SO_4$(gas). The $Cl^-$ concentration loss by $SO_4^{2-}$ and $NO_3^-$ more easily increased for $PM_{10}$ compared to $PM_{2.5}$. The results of this study will be applied to verifying a dust-haze forecasting model. In addition, continued vessel measurements of aerosol data will become important to research for climate change studies in the future.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.6
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• pp.475-485
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• 2001

The presence of airborne particles in the earth atmosphere expert important controls on the global climate because of their effects on the radiative balance. However, there are major uncertainties associated with the direct and indirect radiative effects of aerosols. In addition, their physicochemical properties cannot only the decline of air quality but also damage human health. Airborne particles were collected by two different commercial air samples, high volume sampler(for TSP) and low volume sampler(for P $M_{10}$ ) at the campus of Kunsan National University during February to September, 2000. In most cases, TSP and P $M_{10}$ were sampled once a week for the duration of 24 hours from 9:00 a.m. In addition samples were collected more intenisve, when the yellow dust was expected. Each sample was analyzed for pH and major ions concentration (C $l^{[-10]}$ , S $O_4$$^{2-}$, N $O_3$$^{[-10]}$ , N $a^{+}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$) by ion chromatography and atomic absorption spectrophotometry. Acidity (pH) of TSP and P $M_{10}$ ranged from 5.09 to 8.51 and from 6.22 to 7.54, respectively. The concentrations of airborne particles were found to satisfy both the short and long-term air quality standards during the sampling period. If the ratio of ionic concentrations originating from None sea salt(Nss) to sea salt(ss) in aerosol samples was concerned, it was found that the ionic concentrations from marine environment contributed dominantly in total mass concentration in the airborne particles. When seasonal trends were examined, the TSP concentrations in spring were higher than those of other seasons. It may result form frequent occurrences of yellow dust and during the spring season. The concentration ratio of P $M_{10}$ to TSP ranged from 0.78 to 1 during the sampling period. pH in the airborne particle was highest during spring, but the other seasons maintained almost same level. These results suggest that alkaline species in yellow dust can directly neutralize aerosol acidity. During spring season, yellow dust could be a positive factor that can defer the acidification of surface soil and water by neutralizing acidic aerosols in the atmosphere.osphere.

• Journal of Conservation Science
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• v.25 no.3
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• pp.299-316
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• 2009

The Goryeo roof tiles from the Oegol site in Tangjeong, Asan are classified into three groups in color such as gray, red yellow and gray-yellow groups, respectively. While each group of tiles shows characteristic specific gravity, absorption ratio, LOI and vitrification degree, mineral content and distribution, and chemical composition are generally homogeneous among all groups of roof tiles. Also, all roof tiles and soils from the site show similar geochemical behavior of elements and clay-mineralization degree. This indicates that the soil from the site is probable to be a raw material of the roof tiles. Firing temperature of the roof tiles is estimated as 950 to $1,050^{\circ}C$ for the gray group, 800 to $900^{\circ}C$ for the red yellow group, and 900 to $950^{\circ}C$ for the gray-yellow group. In conclusion, roof tiles from the Oegol site is interpreted to be made of local clay without additive minerals, applying various firing conditions and standardized purifying process of raw clay materials.