• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.17-24
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• 2001

Several underground cavities were found during construction of a road tunnel in 600m length . The area belong to Whasoon coalfield where extensive ground subsidences have occurred. It is necessary to find other underground cavities which might be located just near the road tunnel for safety, The field surveys and laboratory tests were conducted such as surface geological survey(672m), surface reflection seismic exploration(399m), drilling test(3 NX holes), 9 laboratory tests for rocks, 3 boreholes televiewer tests, reflection seismic exploration in tunnel(2, 342m). To estimate the effects of underground cavities on the road tunnel, 3 geological section were analysed with FLAC-2D modeling. The effects of the ground reinforcement were also analysed.

• Journal of Veterinary Science
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• v.21 no.2
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• pp.14.1-14.10
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• 2020

African swine fever (ASF) is a highly contagious disease of domestic pigs and wild boars (WBs). Without a vaccine, early antibody and antigen detection and rapid diagnosis are crucial for the effective prevention of the disease and the employment of control measures. In Sardinia, where 3 different suid populations coexisted closely for a long time, the disease persists since 1978. The recent ASF eradication plan involves more stringent measures to combat free-ranging pigs and any kind of illegality in the pig industry. However, critical issues such as the low level of hunter cooperation with veterinary services and the time required for ASF detection in the WBs killed during the hunting season still remain. Considering the need to deliver true ASF negative carcasses as early as possible, this study focuses on the evaluation and validation of a duplex pen-side test that simultaneously detects antibodies and antigens specific to ASF virus, to improve molecular diagnosis under field conditions. The main goal was to establish the specificity of the two pen-side tests performed simultaneously and to determine their ability to detect the true ASF negative carcasses among the hunted WBs. Blood and organ samples of the WBs hunted during the 2018/2019 hunting seasons were obtained. A total of 160 animals were tested using the pen-side kit test; samples were collected for virological and serological analyses. A specificity of 98% was observed considering the official laboratory tests as gold standards. The new diagnostic techniques could facilitate faster and cost-effective control of the disease.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.315-324
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• 2016

Background: Biocontrol agents are regarded as promising and environmental friendly approaches as agrochemicals for phytodiseases that cause serious environmental and health problems. Trichoderma species have been widely used in suppression of soil-borne pathogens. In this study, an endophytic fungus, Trichoderma gamsii YIM PH30019, from healthy Panax notoginseng root was investigated for its biocontrol potential. Methods: In vitro detached healthy roots, and pot and field experiments were used to investigate the pathogenicity and biocontrol efficacy of T. gamsii YIM PH30019 to the host plant. The antagonistic mechanisms against test phytopathogens were analyzed using dual culture, scanning electron microscopy, and volatile organic compounds (VOCs). Tolerance to chemical fertilizers was also tested in a series of concentrations. Results: The results indicated that T. gamsii YIM PH30019 was nonpathogenic to the host, presented appreciable biocontrol efficacy, and could tolerate chemical fertilizer concentrations of up to 20%. T. gamsii YIM PH30019 displayed antagonistic activities against the pathogenic fungi of P. notoginseng via production of VOCs. On the basis of gas chromatography-mass spectrometry, VOCs were identified as dimethyl disulfide, dibenzofuran, methanethiol, ketones, etc., which are effective ingredients for antagonistic activity. T. gamsii YIM PH30019 was able to improve the seedlings' emergence and protect P. notoginseng plants from soil-borne disease in the continuous cropping field tests. Conclusion: The results suggest that the endophytic fungus T. gamsii YIM PH30019 may have a good potential as a biological control agent against notoginseng phytodiseases and can provide a clue to further illuminate the interactions between Trichoderma and phytopathogens.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.563-570
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• 2005

The purposes of this study are to examine a field test on heavy metal removal efficiency for AMD(Acid Mine Drainage) using fish bone and apatite, and to compare those results of the laboratory & the field tests. The duration of the field test was about one month and flow rates of AMD varied from 2.53 l/min to 12.8 l/min. From the result of the field test, removal efficiencies of apatite and those of fish bone are high for As, Fe, and Pb while those of fish born is higher than those of apatite far Al, Cd, Cu and Zn which are similar to the result of the previous laboratory test. In particular, average arsenic removal efficiency of apatite is higher$(84\%)$ than that of fish bone$(75\%)$ like the result of the previous laboratory test. In case of precipitates of phosphate compounds which are generated from chemical reaction between apatite/fish bone and AMD, those generated from apatite/AMD reactionform powder-shape while those created from fish bone/AMD reaction seem to be sludge. Therefore, apatite will be used as a precipitant for mine drainages having wide range of pH based on previous studies while fish bone will be applied as a precipitantfor AMD having lower PH and high concentration of heavy metals.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.39-45
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• 2013

PURPOSES : The objective of this study is to evaluate the mechanical characteristics of castor oil based bio-polymer concrete for use of ultra thin overlays. METHODS : To evaluate the mechanical properties of bio-polymer concrete, the various laboratory tests including compressive, tensile, and flexural strength, and elongation tests were conducted on bio-polymer concrete specimens in this study. The mechanical characteristics of bio-polymer concretes were examined by changing the content of hardener and polymer binder to determine the optimum content for ultra-thin overlays. The bio-polymer concrete developed in this study was used for field trial test of the ultra-thin bridge deck pavement for verifying the workability and monitoring the long-term performance of materials. RESULTS : Test results showed that tensile and the flexural strength of bio-polymer concretes increase and the elongation of bio-polymer concrete decreases with increase of binder content. A field adhesive strength tests conducted on bridge deck pavement indicates the bio-polymer concrete has more than 2MPa of adhesive strength satisfy with the design criteria. CONCLUSIONS : The bio-polymer concrete with more than 20% content of castor oil was developed for ultra-thin overlays in this study. It is found from this study that the 35% of hardener content is most appropriate for maintaining the strength characteristics and flexibility.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.93-104
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• 2019

This study examined the relationship between the number of medical technologists and the medical test count. Data was obtained from 441 medical technologists in a hospital through a self-reported questionnaire. The Pearson correlation test, student's t-test, ANOVA or descriptive statistics were performed for data analysis. The distribution of medical technologist according to the size of hospitals was small 5.8, medium 14.9, large 25.8, and super 45.4. The analysis demonstrated a relationship between the number of medical technologists and the number of medical tests in the field, number of clinical tests per MT, and number of optimal medical test per MT according to the hospital size (P<0.001). The average time for quality control by the department at a higher hospital was less than two hours. In terms of the satisfaction of salary, work environment, test accomplishment, and welfare service, the dissatisfaction of medical technologists in small and medium hospitals was higher than those in large and super hospitals. Overall, a focus on intensifying systemic supplementation and improving the condition of medical technologists is needed to provide reliable data for medical examinations in medical areas.

• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.35-44
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• 2013

This paper presents the slope wall technique using soil improvement material for reinforced soil slope through laboratory scale model tests, and verifies the experimental results comparing with numerical analysis. In additional, case study in field has performed to investigate the deformation of reinforced soil slope for 6 months. As a result of laboratory scale model test, numerical analysis, and case study, the reinforcement effect of the slope wall technique using soil improvement material is sufficient to be constructed as reinforced soil slope. The technique shows the stable ratio (0.4%) of horizontal to vertical deformation in the surface loading.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.480-488
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• 2016

For the development of areas around railway lines, subsurface construction using the non-open cut method under the railway has recently been increased. However, when a structure under a railway is constructed, the stress release of the ground is not considered an important factor in the design. In this study, laboratory tests were conducted to determine a zone of stress relaxation. Field tests using an inclinometer were performed to measure the horizontal displacement of the ground during non-open cut construction. The stress release zone and the subgrade stiffness were investigated by numerical analysis. The results of the laboratory tests indicated that the failure zone in the ground was similar to a Rankine's active earth pressure zone. The measured data from the inclinometer in the field tests showed that displacements started when a steel pipe was pushed into the ground. The results of numerical analysis show that lateral earth pressure was also close to Rankine's active earth pressure. The roadbed support stiffness of the soil around the structure decreased to 40% of the original value. The ground around the subsurface structure constructed using nonopen cut methods should be reinforced to maintain the running stability of train.

• The Plant Pathology Journal
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• v.28 no.2
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• pp.185-190
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• 2012

Sclerotinia sclerotiorum is a serious pathogen which causes yield loss in many dicotyledonous crops including potato. The objective of this study was to assess the potential of biofumigation using three Brassica crops including Brassica napus, B. juncea and B. campestris against potato stem rot caused by S. sclerotiorum by in vitro tests. Both macerated and irradiated dried tissues were able to reduce radial growth and sclerotia formation of five pathogen isolates on PDA, but macerated live tissues were more effective. Compared with other tested crops, B. juncea showed more inhibitory effect against the pathogen. The volatile compounds produced from macerated tissues were identified using a gas chromatograph-mass spectrometer. The main identified compounds were methyl, allyl and butyl isothiocyanates. Different concentrations of these compounds inhibited mycelial growth of the pathogen in vitro when applied as the vapor of pure chemicals. A negative relationship was observed between chemicals concentrations and growth inhibition percentage. In this study, it became clear that the tissues of local Brassica crops release glucosinolates and have a good potential to be used against the pathogen in field examinations.

• Journal of Biosystems Engineering
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• v.34 no.3
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• pp.140-146
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• 2009

The garlic, along with the red pepper, is one of the major seasoning vegetables in Korea. Garlic clove planting is one of the most laborious operations. Labor cost is the main source of high production cost of the garlic. Because of the geometrical uniqueness and irregularity of garlic cloves, mechanization of garlic clove planting is very difficult. To overcome price competition against the imported garlic, however, there has been a need of development of a clove metering device and a planting device for the garlic clove planter. Computer simulation, laboratory tests and field tests were conducted to develop a garlic clove planter. This research was conducted to drop garlic cloves into a soil holes through a drum bucket metering system and a rotary type planting system. Followings are the major achievements from this study. 1. The metering device consisted of a drum, a guide, a bucket and a bucket cover. Opening positions of the metering hopper were evaluated at different positions and trajectories of planting hoppers. The simulation showed that the optimum positions of hopper was -15${\sim}$0 mm in the x direction. 2. When the planter was tested under different soil textures and water contents, the best performances were obtained in a upland field with 29.1% water content and a paddy field with 18.3% water content where single clove metering and missing rate were 88.4% and 1.3%, and 90.7% and 2.0%, respectively.