• Journal of Ginseng Research
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• v.13 no.1
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• pp.114-118
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• 1989

Tolclofos-methyl applied as seed dipping at 1,000 ppm for 3 hrs before sowing and soil drenching at the rate of 300 g ai./10 a in the middle of April protected emerging seedlings of Panax ginseng from damping-off caused by Rhiiutonia solani(AG2-1) in Yangjik Soil artificially infested with the pathogen. Germination rates with tolclofos-methyl, pencycuron, and control were 53.7%, 45.8%, and 7.5%, respectively, while the rate of the seeds at non-infested soil was 62.6%. The effectiveness of Tolclofos-methyl against the pathogen in the soil lasted upto 32 days in vitro. However, the transpiratio of ginseng seedlings increased greatly with chemical treatment, showing 0.02, 0.12, and 0.24 m1/cm2 leaf area/day at 0, 1,2, and 4 ppm a.i. of the fungicide, respectively.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.87-88
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• 2006

To investigate the possibility of ceria abrasive-added slurry for the oxide-chemical mechanical polishing (oxide-CMP) application, two kinds of retreated methods were introduced as follows: First, the characteristics of mixed abrasive slurry (MAS) using $CeO_2$ powder as an abrasive added within diluted silica slurry (DSS) were evaluated to achieve the improvement of removal rates and non-uniformity. Second, the control of pH level due to the dilution of slurry was examined. And then, we have discussed the CMP characteristics as a function of abrasive dispersion time.

• The Korean Journal of Mycology
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• v.19 no.1
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• pp.85-87
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• 1991

Prochloraz of fungicide was applied on Mycogone perniciosa causing wet bubble in cultivated mushroom, Agaricus bisporus. In vitro, Prochloraz was an excellent fungicide on two strains of Mycogone, tolerant and non-tolerant to Benomyl, respectively. At the low dosage, Prochloraz more inhibited mycelial growth of mushrooms than Benomyl. At the higher dosage, Benomyl more inhibited the mycelial growth than prochloraz. The higher yield of sporophore of the mushroom with low inferction rate was abtained from several trial of Prochloraz. Prochloroz was concluded to be effective fungicide on Mycogone perniciosa on Agaricus cultivation.

• Journal of the Korean institute of surface engineering
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• v.23 no.3
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• pp.160-166
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• 1990

The effects of the variation of proedd varibles on the flow patterns and effects of the flow patterns on the deposition rate and uniformity in the Si-epitaxy CVD with SiH4 as the source of Si were studied through the calculation by use of control volume method. The reslts showed that the natural convection was undesirable to the uniformity of deposition rate, whose effects were decreased with the dercrese with the decrese of the pressure in the reactoor and with the increase of the flow rate. However. the excessive increase of flow rate caused the movement of the unreacted gas to the substrate. Therefore it resulted in the non-uniform depositions. The rotation of substrate was apperared to improve the uniformity. The resulte of this study could used in CVD process to design the reator and to find the optimum conditions of the process variables.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1364-1367
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• 2005

In this paper, a novel prototype topology of soft switching PWM controlled high frequency AC power conversion circuit without DC voltage smoothing chemical capacitor filter link from the voltage grid of utility frequency AC power supply source with 60Hz-100V or 60Hz-200V is proposed and introduced for innovative consumer induction heating(IH) boiler applications as hot water producer, steamer and super heated vapor steamer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.366-369
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• 2005

Electrochemical discharge machining (ECDM) has been found to be potential fur the micro-machining of non-conductive materials such as ceramics or glass. However this machining process has its own inherent problem that the reproducibility is too low to get the available geometric accuracy fur micromachining applications. One main challenge in reaching this goal is the control of the hydrogen built around the tool-electrode in which happen the discharges. This paper proposes the methods to improve the geometric accuracy using powder-mixed ECDM process. The experimental results show the effects of powder producing improved geometric accuracy by averaging and decreasing the concentration of spark energy.

• Journal of Environmental Health Sciences
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• v.38 no.2
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• pp.166-174
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• 2012

Introduction: After 17 years since the first production of humidifier disinfectants in Korea, Korea Centers for Disease Control and Prevention (KCDC) announced that the odds ratio of lung injury related with humidifier disinfectant usage was 47.3 (95% confidence interval 6.0-369.7) according to a case-control study with 18 adult cases, including 8 pregnant women at a university hospital in Seoul. Results: From September 2011 to April 2012, one-hundred and seventy four victim cases have been reported to an environmental non-governmental group (NGO). We summarized timetable of humidifier disinfectants accidents, analyzed health outcomes (death, lung or lung and heart transplantation, pulmonary disease) of reported victims, and classified some information for humidifier disinfectants with health outcomes, and government action for this accident. Among the victims, number of death cases are 52 (30.0%), including 26 babies less than 3 years old. Sixty-nine victims come from twenty-seven family with 2 to 4 members per family. About twenty types of humidifier disinfectant products and about 600,000 product items a year have been sold. Fifty-two death cases used 7 different types of disinfectant products, including imported goods and some private brands of well-known supermarkets. KCDC confirmed inhalation toxicity of 6 products through an animal experimental test, and based on this observation recalled disinfectants containing PHMG (polyhexamethylene guanidine) and PGH (Oligo(2-(2-ethoxy)ethoxyethyl guanidinium chloride). Discussions: The use of these biocides involved highly fatal consequences among biologically vulnerable victims, such as pregnant women, several family member victims after semi-acute exposure. This is the first biocide disaster in Korea with non-specific targets, and unknown scale of victims, warranting concerns on use of biocides in the living environment. Conclusions: Special administrative agency for chemical safety and compensation act for environmental health victims are needed to prevent similar problems.

• The Korean Journal of Physiology
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• v.4 no.2
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• pp.61-67
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• 1970

In view of the importance of sulfhydryl groups in producing a chemical protection against ionizing radiation, an attempt was made to evaluate the changes of intrinsic non-protein sulfhydryl (NP-SH) and non-Protein disulfide(NP-SS) of the lung and liver tissues of rabbits following the whole body X-irradiation with 900 r either in single or fractionated $(300\;r{\times}3)$ dose. NP-SH was measured by Ellman's method, and NP-SS was measured by the electrolytic reduction method described by Dohan. Experiment was performed at 1,3,5,24 and 48 hours post·irradiation, and the results were compared with the control. The results thus obtained are summarized as follows; 1) Intrinsic levels of NP-SH and NP-SS of normal rabbits were $0.77{\pm}0.10$ and $0.61{\pm}0.07\;{\mu}mol/gm$ wet weight in liver, and $0.28{\pm}0.03$ and $0.54{\pm}0.03$ in lung tissues respectively. 2) NP-SH of liver after single X-irradiation showed no significant change in general, but at 48 hours post·irradiation, it was elevated comparing with the normal value. 3) Levels of NP-SS in liver was decreased than the normal value in the irradiated groups, and the lowest level was observed at 3 hours after single X-irradiation and at 5 hours after fractionated irradiation. 4) In lung tissues, levels of NP-SS showed no significant change from the control at earlier experimental hours, but a great decrease was observed at later Part of the experiment.

• Journal of Forest and Environmental Science
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• v.33 no.4
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• pp.342-347
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• 2017

Since the first report of the oak wilt disease at 2004 in Korea, the disease distributed over Korean peninsula and are still giving severe damages. The management of oak wilt disease in Korea has mainly focused on the control of insect vector, Platypus koryoensis. Neverthless the effective method for evaluating the pathogenicity of the pathogen, Raffaelea quercus-mongolicae (Rqm), and for screening chemical or biological agents with strong inhibitory activity against the pathogen, is absolutely necessary, an reliable method is not available so far. This study was conducted to develop the effective method for evaluating the pathogenicity of Rqm in oak trees. The culture suspensions of Rqm were artificially injected to the saplings of Quercus acutissima by using ChemJet tree injector. Three months after treatments, the treated saplings were cut and dipped into 1% fuchsin acid solution. There were significant differences in non-conductive area (%), discoloration area (%) and vertical discoloration length between the pathogen-injected and distilled water-injected control treatments. These results indicated that the pathogen is the causal agent for the dysfunction of water conductive tissue, which will finally result in wilt symptom. Re-isolation of the pathogen and PCR detection using specific primers for the pathogen also confirmed the presence of Rqm in the sapwood chips of the pathogen-injected saplings. These observations would be greatly applied to other related researches for evaluating the pathogenicity of tree wilt pathogens and biocontrol efficacy of the selected antagonistic microorganisms, in case that the wilt symptom is not easily shown by artificial inoculation of the causal agent.

• The Plant Pathology Journal
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• v.25 no.3
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• pp.256-262
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• 2009

The potential of. nonpathogenic Fusarium oxysporum strain Avr5, either alone or in combination with chitosan and Bion, for inducing defense reaction in tomato plants inoculated with F. oxysporum f. sp lycopersici, was studied in vitro and glasshouse conditions. Application Bion at concentration of 5, 50, 100 and $500{\mu}g$/ml, and the highest concentration of chitosan reduced in vitro growth of the pathogen. Nonpathogenic F. oxysporum Avr5 reduced the disease severity of Fusarium wilt of tomato in split plants, significantly. Bion and chitosan applied on tomato seedlings at concentration $100{\mu}g$ a.i./plant; 15, 10 and 5 days before inoculation of pathogen. All treatments significantly reduced disease severity of Fusarium wilt of tomato relative to the infected control. The biggest disease reduction and increasing tomato growth belong to combination of nonpathogenic Fusarium and Bion. Growth rate of shoot and root markedly inhibited in tomato plants in response to tomato Fusarium wilt as compared with healthy control. These results suggest that reduction in disease incidence and promotion in growth parameters in tomato plants inoculated with nonpathogenic Fusarium and sprayed with elicitors could be related to the synergistic and cooperative effect between them, which lead to the induction and regulation of disease resistance. Combination of elicitors and non-pathogenic Fusarium synergistically inhibit the growth of pathogen and provide the first experimental support to the hypothesis that such synergy can contribute to enhanced fungal resistance in tomato. This chemical could provide a new approach for suppression of tomato Fusarium wilt, but its practical use needs further investigation.