• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.48-48
• /
• 2022

In recent, a demand for sweetpotato cultivation technology to expand the cultivated area of field crops in paddy fields is increasing. This research was carried out to establish suitable varieties and cultivation techniques for mass production of sweetpotato for processing raw materials. For the selection of varieties suitable for cultivation in rice fields for each processing purpose, 12 varieties in 2018 (8 varieties for starch, 4 as dried, chips and beverages), and 6 varieties in 2019 (4 varieties for starch including 'Daeyumi'; chips, semi-dried 'Pungwonmi'; beverage and coloring 'Shinjami') were used. Sweetpotato stems were planted in mid-May and harvested after 120 days to investigate the yield. Results revealed that the yield of sweetpotato (2019) for starch production, varied with variety as 'Gogeonmi' 3,926 > 'Jinhongmi' 3,428 > 'Daeyumi' 2,873 > 'Singeonmi' 2,752 kg/10a. The starch content was 20.2% in 'Daeyumi', 18.2 in 'Gogeonmi', 21.2 in 'Singeonmi', and 20.6% in 'Jinghongmi'. The total amount of starch was higher in 'Daeyumi' (730 kg/10a) and 'Gogeonmi' (731 kg/lOa). The yield of chips and edible varieties 'Pungwonmi' was 4,688 kg/10a. The yield of 'Shinjami' of purple variety such as beverages and powder was 3,139 kg/10a. Aaa result of evaluation sweetpotato yield by waterlogging treatments on different growing stages in paddy fields, the yields of 'Daeyumi' and 'Jinhongmi' varieties treated with waterlogging at the storage root formation stage decreased by 11.8% and 11.7%, respectively, compared to the control. In the case of waterlogging treatment at storage root swelling stage, Both varieties showed the lowest yield reduction at 7.0% and 4.8%, respectively. Based on these results, stable production and substitution effect of processing raw materials can be expected by cultivating sweetpotato varieties suitable for paddy cultivation.

• Tunnel and Underground Space
• /
• v.33 no.6
• /
• pp.561-573
• /
• 2023

Korea Atomic Energy Research Institute (KAERI) constructed the KURT (KAERI Underground Research Tunnel) to analyze the hydrogeological/geochemical characteristics of deep rock mass. Numerous boreholes have been drilled to conduct various field tests. The selection of suitable investigation intervals within a borehole is of great importance. When objectives are centered around hydraulic flow and groundwater sampling, intervals with sufficient groundwater flow are the most suitable. This study defines such points as hydraulic outliers and aimed to detect them using borehole geophysical logging data (temperature and EC) from a 1 km depth borehole. For systematic and efficient outlier detection, machine learning algorithms, such as DBSCAN, OCSVM, kNN, and isolation forest, were applied and their applicability was assessed. Following data preprocessing and algorithm optimization, the four algorithms detected 55, 12, 52, and 68 outliers, respectively. Though this study confirms applicability of the machine learning algorithms, it is suggested that further verification and supplements are desirable since the input data were relatively limited.

• Journal of Sensor Science and Technology
• /
• v.32 no.5
• /
• pp.290-294
• /
• 2023

Among various types of harmful gases, hydrogen sulfide is a strong toxic gas that is mainly generated during spillage and wastewater treatment at industrial sites. Hydrogen sulfide can irritate the conjunctiva even at low concentrations of less than 10 ppm, cause coughing, paralysis of smell and respiratory failure at a concentration of 100 ppm, and coma and permanent brain loss at concentrations above 1000 ppm. Therefore, rapid detection of hydrogen sulfide among harmful gases is extremely important for our safety, health, and comfortable living environment. Most hydrogen sulfide gas sensors that have been reported are electrical resistive metal oxide-based semiconductor gas sensors that are easy to manufacture and mass-produce and have the advantage of high sensitivity; however, they have low gas selectivity. In contrast, the electrochemical sensor measures the concentration of hydrogen sulfide using an electrochemical reaction between hydrogen sulfide, an electrode, and an electrolyte. Electrochemical sensors have various advantages, including sensitivity, selectivity, fast response time, and the ability to measure room temperature. However, most electrochemical hydrogen sulfide gas sensors depend on imports. Although domestic technologies and products exist, more research is required on their long-term stability and reliability. Therefore, this study includes the processes from electrode material synthesis to sensor fabrication and characteristic evaluation, and introduces the sensor structure design and material selection to improve the sensitivity and selectivity of the sensor. A sensor case was fabricated using a 3D printer, and an Ag reference electrode, and a Pt counter electrode were deposited and applied to a Polytetrafluoroethylene (PTFE) filter using PVD. The working electrode was also deposited on a PTFE filter using vacuum filtration, and an electrochemical hydrogen sulfide gas sensor capable of measuring concentrations as low as 0.6 ppm was developed.

• Journal of Mushroom
• /
• v.22 no.2
• /
• pp.60-66
• /
• 2024

This study was conducted to selection and investigate appropriate conditions for mass production of antagonistic microbes to control cobweb disease caused by Cladobotryum mycophilum. A grampositive bacterium was isolated from spent substrate of Agaricus bisporus and showed significant antagonistic activity against Cladobotryum mycophilum. The bacterium was identified as Bacillus altitudinis. based on the cultural, biochemical and physiological characteristics, and 16S rRNA sequence. The isolate is saprophytic, but not parasitic nor pathogenic to cultivated mushroom whereas it showed strong inhibitory effects against C. mycophilum cells in vitro. The control efficacy of B. altitudinis HC7 against cobweb disease of C. mycophilum was up to 78.2% on Agaricus bisporus. The suppressive bacterium may be useful for the development of biocontrol system. To define the appropriate conditions for the mass production of the Bacillus altitudinis HC7, we have investigated appropriate culture conditions and effects of various nutrient source on the bacterial growth. The appropriate initial pH and temperature were determined as pH 6.0 and 30℃, respectively. The appropriate concentration of medium elements for the growth of pathogen inhibitor bacterium(Bacillus altitudinis HC7) was determined as follows: 3.0% soluble startch, 10% soytone, 1.0% (NH₄)₂HPO₄, 1.0 mmol KCl, and 0.5% L-asparagine.

• Journal of Korean Society of Forest Science
• /
• v.77 no.4
• /
• pp.382-388
• /
• 1988

Improvement of productivity by forest tree breeding work in Korea was estimated for a few important tree species. Progenies of 17 plus trees of red pine (Pines densiflora) outgrew by 57 percentage compared with progenies of unselected trees at age 15. If best three families are selected among the 17, more than double in volume grow-th is expected. The hybrid Pinus rigida ${\times}$ P. taeda showed more than double volume growth compare to P. rigida at a southern plantation at age 15. However, the superiority of the hybrid decreased at northern plantations, mainly because of low coldhardiness of the hybrid. At a northern plantation, the hybrid grew less than the P. rigida on upper hill, while the hybrid grew much better than the P. rigida on flat area. Another hybrid Populus alba ${\times}$ P. glandulosa grew faster than both parents by two to two and half times according to planting sites at age 10. Introduction of Pinus rigida also showed increased volume growth. Volume increase by selection of best five provenances among 45 at age 12 was estimated as 53 percent compare to progenies of plus trees in Korea, Additional 19 percent of volume increase was expected by selection of the best families within the best provenances. Annual production of chestnuts reached about 70,000 M/T by planting resistant clones to chestnut gall wasp (Dryocosmus kuriphilus), which killed almost all susceptible trees. Although polyploid trees and mutants have been produced by colchicine treatments in over 10 tree species, none of them is economically important Remarkable improvement of productivity is expected by biotechnology in future through selection, hybridization, introduction of foreign genes at cell, cell organelle and gene level, and gene transformation. At present, mass propagation of superior planting materials by tissue culture will increase the productivity.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.3
• /
• pp.177-183
• /
• 2004

The discharge of waste nutrient solution from greenhouse to natural ecosystem leads to the accumulation of excess nutrients that results in contamination or eutrophication. There is a need to recycle the waste nutrient solution in order to prevent the environmental hazards. The amount and kind of nutrients in waste nutrient solution might be enough to grow photosynthetic microorganisms. Hence in the present study, we examined the growth and mass cultivation of cyanobacteria in the waste nutrient solution with an objective of removing N and P and concomitantly, its mass cultivation. Four photosynthetic filamentous cyanobacteria (Anabaena HA101, HA701 and Nostoc HN601, HN701) isolated from composts and soils of the Chungnam province were used as culture strains. Among the isolates, Nostoc HN601 performed faster growth rate and higher N and P uptake in the BG-II ($NO_3{^-}$) medium when compared to those of other cyanobacterial strains. Finally, the selected isolate was tested under optimum conditions (airflow at the rate of $1L\;min^{-1}$. in 15 L reactor, initial pH 8) in waste nutrient solution from tomato hydroponic in green house condition. Results showed to remove 100% phosphate from the waste nutrient solution in the tomato hydroponics recorded over a period of 7 days. The growth rate of Nostoc HN601 was $16mg\;Chl-a\;L^{-1}$ in the waste nutrient solution from tomato hydroponics with optimum condition, whereas growth rate of Nostoc HN601 was only $9.8mg\;Chl-a\;L^{-1}$ in BG-11 media. Nitrogen fixing capacity of Nostoc HN601 was $20.9nmol\;C_2H_4\;mg^{-1}\;Chl-a\;h^{-1}$ in N-free BG-11. The total nitrogen and total phosphate concentration of Nostoc HN601 were 63.3 mg N gram dry weight $(GDW)^{-1}$ and $19.1mg\;P\;GDW^{-1}$ respectively. Collectively, cyanobacterial mass production using waste nutrient solution under green house condition might be suitable for recycling and cleaning of waste nutrient solution from hydroponic culture system. Biomass of cyanobacteria, cultivated in waste nutrient solution, could be used as biofertilizer.

• Perspectives in Nursing Science
• /
• v.7 no.1
• /
• pp.10-22
• /
• 2010

Purpose: Through a thorough examination of the CCSC (Community Comprehensive Support Center) system in Japan, this study suggests a scheme to provide community-based preventive health care services for the elderly in Korea. Methods: The study inquired into the applicability of the Japanese model by reviewing the data related to the CCSC project, aided by both in-depth interviews with staff in the field and consultations with specialists. Results: Rearrangement of the Visiting Health Management Project system is needed to manage the collective or individual visiting care management for frailty prevention of the elderly in communities. The delegated service system for preventive care in the community, including direct management by one of the public health centers, also needs to be reviewed and the application of stricter standards for the selection of the agency or corporation to run the delegated service is necessary. Long-Term Care Insurance, along with national and local grants, is to be considered as a financial resource for the community-based preventive health care model for the elderly. By making active use of education rooms at district offices, senior citizen centers in neighborhoods for the elderly with easy access can be created. The project needs to raise active supports from communities, develop programs which can be absorbed into particular local cultures, and promote the understanding of the preventive project in local communities. The preventive program should focus on first solving the problems of depression, seclusion, and lack of mobility of the elderly. Second, the program should instruct physical self-management for exercise-nutrition-dental maintenance, and third, the program should strengthen the cognitive abilities of the elderly. In addition, it is necessary to systematize and implement counter-plans of the family and community to protect the elderly who has mental and cognitive problems. Finally, by establishing a network of public health welfare resources based upon research on a community level, assessment and planning for the health of the elderly should be one with their family, and comprehensive consultation and recommendations should be provided to the family. Conclusion: Taking into consideration the experience Japan has had with respect to a similar project, it is appropriate to develop and implement a service system which would combine the Visiting Health Management Project system which has already been established and a preventive health care model for the elderly on a community level.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.12 no.3
• /
• pp.191-198
• /
• 2014

Using results of groundwater flow system modeling for a hypothetical deep geological repository site, a distribution of groundwater flow rates at the disposal depth was analyzed and a method of applying this distribution to a safety assessment for a disposal of radioactive wastes was suggested. The distribution of groundwater flow rates was produced by hydraulic heads simulated from regional and local scale groundwater flow models for the hypothetical disposal site. The flow rates at the locations where deposition holes would be located were estimated. These rates were normalized by the maximum of the flow rates in order to probabilistically illustrate a possibility of canister failures at the deposition holes. From the normalized distribution, probabilistic expectations for mass discharges of radionuclides released from the canisters assumed to be failed were calculated and compared with those deterministically estimated under the assumption that the canisters at the same deposition holes were definitely failed. The suggested method can be contributed to constructing a methodology for safety assessment of a geological repository by reflecting natural conditions of a disposal site in more detail.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.5
• /
• pp.148-155
• /
• 2017

In this study, by using the international standards ISO TS 16774, Part 2 Test method for chemical resistance as a quality control method of injection type repair material used for leakage crack of underground concrete structure, the performance requirement against of chemical environment of underground concrete structures for repair materials was tested. For this testing 3 types for each of the 2 classes of repair materials(synthetic rubber, cement), with a total of 9 types repair materials, were selected and examined. As a result, the test results showed that the smallest performance deterioration by the change in the mass was with the synthetic rubber(RG) type as opposed to the cement type system, showing that the synthetic rubber type had the strongest relative resistance to chemical exposure. Furthermore, it is necessary to investigate the material with high resistance to chemical substances and to examine the material which can increase resistance to sodium hydroxide and sodium chloride in cement system. These results can be used as a basic index for the selection of repair materials with the strongest resistance to chemical environment found in concrete structures. In addition, it is expected that the test results derived in this study can be used as reference data that can be reflected in the quality improvement of the maintenance material to be developed later.

• Journal of Aquaculture
• /
• v.9 no.3
• /
• pp.195-203
• /
• 1996

Six strains (OKK, MOK, CHA, WON, 505 & PUA) of Korean rotifer, Brachionus plicatilis (S-type) were isolated from salt pond, and the resting egg production of these strains was investigated with the different salinities (10, 20, 30 put), Rotifer were cultured at $28^{\circ}C$ and 2,000 lux in 20 ml test tube with feeding Nannoohloris oculata. The maximum rotifer density was 2,050 inds./ml at 10 ppt for OKK strain, and MOK strain showed the highest specific growth rate (1.028) at 10 ppt. Mixis rate of CHA and WON strains increased with the lower salinity, while MOK strain increased the rate with salinity. PUA strain did not show the mixis rate even at the high rotifer density, and OKK strain showed the very low mixis rate ranging from 1.1 to $3.0\%$. Fertilization rate of CHA, MOK, SOS and WON strains was ranged from 10.4 to $68.8\%$, and OKK strain did not showed any fertilization rate. The highest production of resting egg in 20 ml test tube was 4,065 eggs at 10 ppt for WON strain. The results may suggest that the selection of rotifer strain and salinity are important factors for the mass production of resting egg.