• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.157-167
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• 1986

The study was carried out to identify several factors affecting isolation and culture of cotyledone and leaf mesophyll protoplasts of cabbage (Brassica oleraceae), petsai (B.campestris subsp. pekinensis) and rape (B.napus). High viable protoplasts could be obtained when the cotyledon and the leaf mesophyll tissue of all species were treated with enzyme solution composed of 1% macerozyme 'R-10', 1.5% Onozuka 'R-10', 10% mannitol and 50,0 mM $CaCl_22H_2O$ for 4 hours. The protoplasts which obtained from the cotyledon of all species except the cabbage and the leaf mesophyll tissue of all species were divided on NN culture medium supplemented with 9.1% mannitol, 1% glucose, 1% sucrose, $1mg/{\ell}$ 2,4-D, $0.5mg/{\ell}$ NAA and $0.5mg/{\ell}$ BA. The division of the rape leaf mesophyll protoplasts were continued and led to colony.

• Resources Recycling
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• v.2 no.2
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• pp.9-15
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• 1993

In this study, magnetite($Fe_3$$O_4$) from the converter dust of the Kwangyang steel making factory has been recove-red by means of the magnetic separation and the sedimentation column. The magnetite recovered from the dust is used for the preparation of Sr-ferrite instead of hematite. The results obtained in this study as follows : 1. The converter EP dust of the Kwangyang steel making factory are composed of $\alpha$-Fe, ($Fe_3$$O_4$) wustite etc. Magnetite in the converter EP dust is recovered by using sedimentation column and plastic bonding magnet. 2. It was confirmed that Sr-ferrite synthesis could be possible without oxidizing roasting of the magnetite. The steps of Sr-ferrite formation are proposed as follows : I$SrCO_3$ $+Fe_3$O$_4$+1/2(1-X)$O_2$longrightarrow$\alpha$ $-Fe _2$$O_3$ $+SrFeO _3$\ulcorner+$CO_2$II. $5.5\alpha$ $-Fe_2$$O_3$ $+SrFeO_3$\ulcornerlongrightarrowSrFe\ulcornerO\ulcorner+1/2(1/2-X)$O_2$3. By using magnetite from the dust insted of hematite, the hard Sr-ferrite magnet of (B.H)\ulcorner=2.64MGOe in the magnetic characteristics was succesfully prepared.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.12
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• pp.1027-1035
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• 2021

We presents a design of 3U cubesat MIMAN (Monochrome imaging for monitoring aerosol by nano-satellite) for aerosol monitoring mission with high spatial resolution. The main objective of MIMAN mission is to take images of aerosols around Korea and to provide auxiliary data for GK 2B cloud masking. For this mission, we derived mission requirements and constraints for the MIMAN mission. We designed the mission architecture and concept of operations. To reduce risk factors in space operation, we considered the safety of the communication. In every operation modes, UHF communication is available so that the cubesat can operate based on the ground commands. So, we can handle every problem at the ground station during mission operations. Based on the mission and concept of operations, we confirmed that the system design satisfied the system requirements. We designed the system interface considering data flow of each hardware, and evaluated the safety of the system with system budget analysis.

• Microbiology and Biotechnology Letters
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• v.29 no.1
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• pp.1-11
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• 2001

Lactic acid bacteria (LAB) are widely used for various food fermentation. With the recent advances in modern biotechnology, a variety of bio-products with the high economic values have been produced using microorganisms. For molecular cloning and expression studies on the gene of interest, E. coli has been widely used mainly because vector systems are fully developed. Most plasmid vectors currently used for E, coli carry antibiotic-resistant markers. As it is generally believed that the antibiotic resistance markers are potentially transferred to other bacteria, application of the plasmid vectors carrying antibiotic resistance genes as selection markers should be avoided, especially for human consump-tion. By contrast, as LAB have some desirable traits such that the they are GRAS(generally recognized as safe), able to secrete gene products out of cell, and their low protease activities, they are regarded as an ideal organism for the genetic manipulation, including cloning and expression of homologous and heterologous genes. However, the vec-tor systems established for LAB are stil insufficient to over-produce gene products, stably, limiting the use of these organisms for industrial applications. For a past decade, the two popular plasmid vectors, pAM$\beta$1 of Streptococcus faecalis and pGK12 theB. subtilis-E. coli shuttle vector derived from pWV01 of Lactococcus lactis ssp. cremoris wg 2, were most widely used to construct efficient chimeric vectors to be stably maintained in many industrial strains of LAB. Currently, non-antibiotic markers such as nisin resistance($Nis^{r}$ ) are explored for selecting recombi-nant clone. In addition, a gene encoding S-layer protein, slp/A, on bacterial cell wall was successfully recombined with the proper LAB vectors LAB vectors for excretion of the heterologous gene product from LAB Many food-grade host vec-tor systems were successfully developed, which allowed stable integration of multiple plasmid copies in the vec-mosome of LAB. More recently, an integration vector system based on the site-specific integration apparatus of temperate lactococcal bacteriophage, containing the integrase gene(int) and phage attachment site(attP), was pub-lished. In conclusion, when various vector system, which are maintain stably and expressed strongly in LAB, are developed, lost of such food products as enzymes, pharmaceuticals, bioactive food ingredients for human consump-tion would be produced at a full scale in LAB.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1497-1503
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• 2023

To address challenges in classifying clouds and snow cover when calculating ground reflectance in Near-UltraViolet (UV) wavelengths, this study introduces a methodology that combines cloud data from the Geostationary Environmental Monitoring Spectrometer (GEMS) and the Advanced Meteorological Imager (AMI)satellites for snow cover analysis. The proposed approach aims to enhance the quality of surface reflectance calculations, and combined cloud data were generated by integrating GEMS cloud data with AMI cloud detection data. When applied to compute GEMS surface reflectance, this fusion approach significantly mitigated underestimation issues compared to using only GEMS cloud data in snow-covered regions, resulting in an approximately 17% improvement across the entire observational area. The findings of this study highlight the potential to address persistent underestimation challenges in snow areas by employing fused cloud data, consequently enhancing the accuracy of other Level-2 products based on improved surface reflectivity.