• Journal of Microbiology and Biotechnology
• /
• v.7 no.1
• /
• pp.32-36
• /
• 1997

An adenosine deaminase inhibitor-producing bacterium was isolated from soil. An isolate exhibiting high adenosine deaminase inhibitory activity, was designated J-89, and classified as a strain of Bacillus subtilis on the basis of its morphological, phenotypic characteristics, the menaquinone content and cellular fatty acid composition. To confirm the taxonomic position of the strain we need more information such as DNA-DNA homology and other chemotaxonomic characteristics. In this paper we provisionally named strain J-89 as Bacillus sp. J-89 pending further chemotaxonomic study and analysis of adenosine deaminase inhibitor.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.40 no.4
• /
• pp.85-93
• /
• 1998

In the 2nd year study of a 5 year project to evaluate the soil quality and develop the best management practices for mountaineous soils, 11 runoff plots were treated and monitored with respect to physical property of the soil, runoff and sediment discharge, and the following results were obtained. 1. Bulk density and porosity did not show any siginificant difference between experimental treatments. 2. Runoff was basically dependent on the soil's physical property and tillage. Up-and-down plots showed the highest runoff while contour plots the lowest runoff. 3. Sediment yield in the mountaineous soils was directly related to tillage and residue cover. Residue covered plots showed the lowest sediment yield and up-and-down plots the highest sediment yield. And it is recommended that the best management practices using till_age and residue cover for the mountaineous soils must be developed to protect soil quality and maintain agricultural productivity.

• Journal of Biosystems Engineering
• /
• v.33 no.5
• /
• pp.355-361
• /
• 2008

As agricultural machinery has become larger and tillage practices have changed in recent decades, compaction as a result of wheel traffic and tillage has caused increasing concern. If strategies to manage compaction, such as deep tillage, could be applied only where needed, economic and environmental benefits would result. For such site-specific compaction management to occur, compacted areas within fields must be efficiently sensed and mapped. We previously developed an on-the-go soil strength profile sensor (SSPS) for this purpose. The SSPS measures within-field variability in soil strength at five soil depths up to 50 cm. Determining the variability structure of SSPS data is needed for site-specific field management since the variability structure determines the required intensity of data collection and is related to the delineation of compaction management zones. In this paper, soil bin data were analyzed by a spectral analysis technique to determine the variability structure of the SSPS data, and to investigate causes and implications of this variability. In the soil bin, we observed a repeating pattern due to soil fracture with an approximate 12- to 19-cm period, especially at the 10-cm depth, possibly due to cyclic development of soil fracture on this interval. These findings will facilitate interpretation of soil strength data and enhance application of the SSPS.

• Journal of Radiation Protection and Research
• /
• v.20 no.1
• /
• pp.8-15
• /
• 1995

An estimate of a change in radioactivity's circumstances around the nuclear power plant is validated with the results of the radioactivity measurements are compared. In this study, to further enhance the reliability of the results obtained from the environmental radioactivity measurements and analysis around the nuclear power plants that have been carried out up to the present. In the korea standard, there is the technical analysis guide for general stable chemical element's, but there is not the technical analysis guide for the radionuclei. therefore the environmental sample collection, the pretreatment of the sample and radionuclide analysis in the sample, the result's of the environmental radioactivity measurements by each organization, etc. are different. It is not sufficient for the database to forecasting a change in radioactivity's circumstances. A comparative study of collection and pretreatment techniques for the soil sample, the results by comparison, the method of minimizing the relative error are proposed. At one side of sample collection, there are going to considered that the surroundings of sample collection like the lay of the land, the provision of the selection standard for the area and pathway of radionuclide adhesion, the coherence of sample collection, etc.. at another side of pretreatment of the sample and measurement in the case of soil sample, how to do homogeneously the soil particle size and the standard tools, i.e. kinds of meshes, must to be selected.

• Economic and Environmental Geology
• /
• v.32 no.1
• /
• pp.43-51
• /
• 1999

In order to remediate hazardous waste site, a process of electrokinetically purging chemicals from saturated soil is examined by laboratory experiments. Electrokinetic soil remediation is one of the most promising soil decontamination processes that habe igh removal efficiency and time-effectiveness in low-permeability soils such as clay. Being combined with several mechanisms-electromigration, elec troosmosis, diffusion and electrolysis of water, electrokinetic soil processing can remove non-polar organics as well as ionic contaminants. The objectives of this study are; 1) the exploration of the feasibility of electrokinetic soil processing on the removal of heavy metals, 2) the investigation of applicability to the tailing-soils in aban doned mining area, 3) the examination of effects of soil pH and conductivity on the transport phenomena of elements in soils, and 4) the investigation of the applicability of the ionexchange membrance to the efficient collection of heavy metals removed from contaminated soils. With the result of this study, it is suggested that the removal efficiency is significantly influenced by applied voltage & current, type of purging solutions, soil pH, permeability and zeta potentials of soil. Although further study should be needed, it is possible to collect removed heavy metals with ion-exchange membrance in cathode compartment.

• The Korean Journal of Soil Zoology
• /
• v.3 no.1
• /
• pp.17-18
• /
• 1998

So far, two species, T. domestica(Clerk, 1757), T. secunda Paik, 1971 have been reported from Korea. In the present paper, the auther would like to describe a new species, T. daiamsanensis n. sp. The type of new species is deposited in the collection of the Arachnological Institute of Korea. Measurements are millimeter.

• Journal of Magnetics
• /
• v.10 no.3
• /
• pp.89-92
• /
• 2005

The analytic possibility of mobile lead contained in soil has been studied using carboxylated magnetic beads. Extraction of heavy metal was performed to contaminated soil that has been collected and supplied for tests. As experiment materials, soil sample, distilled water and magnetic beads were only used. It means that the lead was extracted under neutral condition. In this condition, only the mobile fraction of lead could be extracted by magnetic beads. The mobile lead in the soil was quickly combined with magnetic beads in the mixture process. Then, the magnetic beads were dissolved into acids after collection by external magnetic force, and the lead combined with the beads was eluted and analyzed by Graphite Furnace Atomic Absorption Spectroscopy (GFAAS). In the results of extraction experiments for 3 sandy soils, the efficiency using beads was similar to or higher than that of EDTA (Ethylendiamintetraacetic acid), which is normally used for analyzing mobile heavy metal concentration in soil. With this, it was shown that this method is a more accurate and simple method to analyze mobile lead when analyzing mobile heavy metal concentration in sandy soil, rather than conventional method using EDTA.

• Journal of Microbiology
• /
• v.40 no.1
• /
• pp.55-62
• /
• 2002

Biodiversity af yeasts in various natural environments including soils, swamps and plants was investigated. By molecular identification methods based on the partial sequences of 265 rDNA, 69 isolates were assigned to 44 taxa including 27 known species. The remaining 17 taxa could potentially form new species. All of them were classified into Ascomycota, Hymenomycetes, Urediniomycetes and Ustilaginomycetes. Ascomycetous and ustilaginomycetous yeasts were generally isolated from flower samples, and hymenomycetous and urediniomycetous yeasts were generally isolated from soil samples. Distribution of yeast groups exhibited geographical variation. Yeast biodiversity of root sail also varied according to the associated plant species.

• Mycobiology
• /
• v.33 no.2
• /
• pp.113-117
• /
• 2005

In this study, a total of 300 isolates of Penicillium and related teleomorphic genera were collected from soils of 17 locations in Korea from April to May, 2004. Ninety four isolates were identified as the species of Penicillium subgenus Furcatum based on cultural and morphological characteristics and ${\beta}-tubulin$ gene sequences. Among the specie's, Korean isolates of P. brasilianum Bat. and P. daleae K. M. Zalessky were phylogenetically identical to the reference species based on DNA sequence of the ${\beta}-tubulin$ gene. Here we described and illustrated P. brasilianum and P. daleae that are new in Korea.

• Mycobiology
• /
• v.34 no.1
• /
• pp.1-6
• /
• 2006

A Cordyceps species was found with a Beauveria anamorph state on larval insect cadavers on Obong mountains in Gangwon Provinces, Republic of Korea. Cultures from discharged ascospores formed an anamorph identifiable as Beauveria bassiana. This teleomorph-anamorph connection was also confirmed by the in vitro production of fertile ascomata from conidial cultures with morphology like that of field-collected specimen. This is the first report of in vitro production of a teleomorph for any Beauveria species. The Cordyceps species has been conspecified as Cordyceps bassiana, a species described from China with B. bassiana anamorph.