• Journal of Life Science
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• v.18 no.6
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• pp.858-864
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• 2008

In the greenhouse fields for fruits and vegetables during the winter in Korea, there are serious damages by the sclerotium diseases due to the low temperature and humidity. This study was carried out to select an antagonic agent for the biological control of the sclerotium diseases. The 55 antagonic agents were selected from the rhizosphere in soil where the fruits and vegetables were cultivated in the green house fields, and strain AB02 among the tested isolates was estimated to be the strongest antagonist against the sclerotium disease. Using strain AB02, the antifungal spectrum was tested against 5 different plant pathogens. According to the results of the test, strain AB02 . showed the high antagonistic effect against Botrytis cinerea and Sclerotinia sclerotiorum. For the experiment of biological control against the sclerotium disease, it was estimated the suppression effect and the control effect by the strain in the pot experiment using the green perilla. According to the result of the pot experiments, the suppression effect was 40% and the control effect was 62%, respectively. For the stimulation effect of the tested plant growth by strain AB02 compared to the control, it was improved as 120% for the total length, 141% for the liveweight, 121% for the total number of leaves, 185% for the leaf area, and 327% for the liveweight of the root, respectively. Strain AB02 showing the antagonistic effect against the sclerotium disease and the stimulation effect for the plant growth was identified as Bacillus sp.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.943-951
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• 2004

As storing ginger roots under optimum conditions takes high cost, ginger roots are commonly stored in underground tunnels where the maintenance of optimum temperature and humidity is difficult. One of the methods fur long term storage of ginger roots is freezing. The objective of this research was to evaluate effect of storage temperatures and packaging methods on the quality of minced ginger prepared with frozen stored ginger. The minced ginger prepared with frozen stored ginger at $-20^{\circ}C$ was packed in bags, glass bottles and tubes, and then stored at 5 and $-20^{\circ}C$ for quality evaluation at 4 and 15 week-intervals. The changes of surface color, total free sugars, free amino acids and volatile compounds were less in the combined treatment samples than in control during storage, regardless of the storage temperature. The tube packing was the best for maintaining quality of minced ginger during storage among tested packaging methods. Sensory results showed that the minced ginger with the combined treatment and packed in tubes could be stored at 5 and $-20^{\circ}C$ for 12 and 45 weeks, respectively, without a significant drop in palatability.

• Korean Journal of Environmental Agriculture
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• v.35 no.4
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• pp.263-269
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• 2016

BACKGROUND: The personal protective equipments (PPEs) is the most important factor for reducing the pesticide exposure during the preparation and spraying of pesticides. This study was to investigate the retention, repellence and penetration of protective clothing of PPEs according to the ISO 22608 'Liquid penetration resistance-pipette test. Protective clothing for agriculture worker is very important for their health. However, test method for measurement of protective clothing is not presented in Korea. METHODS AND RESULTS: In order to measure the retention, repellence and penetration of protective clothing, a apparatus for pipette method in accordance with the ISO Guideline was prepared. The test was conducted at $25{\pm}5^{\circ}C$, $60{\pm}10%$ of relative humidity and pipette applied to a apparatus was validated to take exact amount(0.2 mL). The retention, repellence and penetration of five types of protective clothing and one type of shirt were analyzed by GC/MS. Pendimethalin(5% a.i, emulsion) was used as a test pesticide to measure above factors. The retention were less than 11.0% with the exclusion of two types(F4 and shirt) and the repellency was more than 67.0% with the exclusion of shirt material. The penetration was less than 5.4%, however, that of shirt was 66.7%. CONCLUSION: This results indicated that all protective clothing were suitable to use as PPEs according to the criteria specified by ISO Guide 22608. However, shirt was not suitable due to high penetration. This test method established for measurement the retention, repellence and penetration of protective clothing will help to establish the test notice of pipette method.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.65-72
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• 2007

The VOC (volatile organic compound) analyzer is devised to measure the four main aromatic hydrocarbon gases: toluene, ethylbenzene, xylene and styfene. It is not affected by ambient temperature and humidity. In addition, standby and measuring time of VOC Analyzer is a short as below 30 min and 8 min, respectively. Since the semiconductor gas sensor is supersensitive to gas components, it is not necessary to use a conventional gas concentrator or other complicated equipment. In this study, VOC emission behavior from 4 types paints (lacquer, urethane vanish, water-base paint, enamel paint) for wood-based panel was investigated using VOC Analyzer. After a specimen was spreaded on aluminum foil ($6.32{\times}6.32cm$) in $3{\ell}$ polyester bag, after 24 hours we could measure maximum VOC emission level that is a stabilized VOC value. Xylene of VOCs was high emitted from lacquer, urethane vanish and water-based paint, and TVOC (Toluene + Ethylbenzene + Xylene + Styrene) of lacquer was the highest emission concentration than another.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.3
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• pp.150-155
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• 2001

The hull dehydration in dough stage did not serious affect the rice yield though grain appearance texture may decline by severe occurrence of the symptom. As to white head in heading stage of rice, the occurrence of hull dehydration in 1998 was directly affected by high temperature, low air humidity and sometimes of strong wind and sunshine in early September. At harvest stage, 1,000-grain weight of brown rice was not found to be significantly different between the hull dehydrated grains and normal ones. That reason can be considered that the hull dehydration occurred hill was not injured on the leaf and rachis branches therefore the function of assimilation and translation of rice plant was not affected. The ratio of imperfect rice kernel such as green, cracked and white belly increased. The increase of cracked rice by the hull dehydration may caused by concurrent dehydration of kernel, or by insufficient water supply into kernel due to breaking of vascular bundles in glume.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.1
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• pp.1-11
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• 2002

This study was conducted to reveal the effects of local climatic conditions on the early growth of Korean white pine progeny test stands. For this, stand variables such as mean DBH, mean height, basal area per hectare, and volume per hectare by stand age and locality were first measured and summarized for each stand. Based on these statistics, annual increments for 10 years from stand age 10 to 20 were calculated for each of stand variables. The effects of local climatic conditions as one of environmental factors on the growth were then analyzed by both a topoclimatological method and a spatial statistical technique. From yearly climatic estimates,30 climatic indices which affect the tree growth were computed for each of the progeny test stand. The annual increments were then correlated with and regressed on the climatic indices to examine effects of local climatic conditions on the growth. Gapyung area provided the best conditions for the early growth of Korean white pine and Kwangju area ranked second. On the other hand, the growth pattern in Youngdong ranked last overall as expected. It is also found that the local growth patterns of Korean white pine in juvenile stage were affected by typical weather conditions. The conditions such as low temperature and high relative humidity provide favor environment for the early growth of Korean white pine. Especially, it was concluded that the low temperature is a main factor influencing the early growth of Korean white pine based on the results of correlation analysis and regression equations developed far the prediction of annual increments of stand variables.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.1
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• pp.9-16
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• 2008

In this study we investigated the effects of the microclimatic conditions on tree growth in different site types for natural deciduous forests in Korea. First, we classified all the sites into 36 types according to their aspect (east, west, south, and north), elevation (higher than 1,000 m, 700$\sim$1,000 m, and lower than 700 m), and topographical conditions (ridge, slope, and valley). For each site type, we measured diameter growth with increment borer, and then estimated periodic annual increment of diameter, height and volume. We applied a topoclimatological technique for estimating microclimatic conditions, and produced monthly climatic estimates from which 17 weather variables (including indices of warmth, coldness, and aridity) were computed for each site type. The periodic annual increments of diameter, height, and volume were then correlated by regression analysis with those weather variables to examine effects of microclimate on tree growth by site type. We found that the correlation of diameter growth by site type was significantly correlated with most weather variables except daily photoperiod. Water condition was the most important factor for the height growth. For volume growth, on the other hand, the conditions such as relatively high temperature and low humidity provided favorable environment. Our regression analysis shows that aridity index is a good predictor for tree growth including diameter, height and volume increments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.41-49
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• 2016

This study was conducted to evaluate maize downy mildew resistance using spreader row technique in Cambodia. A total of forty maize lines were used in this experiment. Seven Korean varieties and seven breeding lines showed high infection rates (80~100%) and highly susceptible (HS) to downy mildew disease in both spring and fall. Also most of nested association mapping (NAM) parent lines were highly susceptible (HS). Meanwhile three inbred lines, Ki3, Ki11, and CML228, showed highly resistant (HR) or resistant (R) in spring and moderately resistant (MR) in fall. These three lines were already known as resistant inbred lines against downy mildew disease. It appears that spreader row technique was suitable for selection of maize downy mildew resistance in Cambodia. The incidence of downy mildew was influenced by weather conditions, especially relative humidity and temperature. Among several inoculation methods to screen for downy mildew resistance, this spreader row technique is effectively and easily used in the field of Southeast Asia.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1104-1108
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• 1999

In this study it was focused that if the chrome could be removed in the shaving dust, the reusable protein resource could be recycled from the shaving dust. As the chrome forms a Cr-collagenate by cross linking of collagen in the shaving dust, the dust was steeped for swelling and plumping by $Ca(OH)_2$ solution and then chromium in dust was resolved out by $H_2SO_4$ solution in the first stage process. In the second stage one, dust was swelled and plumped by NaOH solution and then the chromium in dust was oxygenated to a hexavalent chrome, which has high solubility in $H_2O_2$ solution. And then the chromium was removed byt he steeping of $H_2SO_4$ solution as the last process. The first stage process was consisted of the sequential steeping of 3%-$Ca(OH)_2$ and $0.8%-H_2SO_4$. In the second stage the total chrome was effectively removed by the sequential steeping of 0.1%-NaOH, $3%-H_2O_2$ and $1%-H_2SO_4$. In the completely dechromated dust, the humidity was measured as 10.68% and the crude protein was contained by 79.81%. Steeping solutions were reused 3 times for chrome removal process, the chrome was entirely removed in shaving dust.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.267-277
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• 1997

The purpose of this study was to evaluate the shear bond strength of light-cured glass ionomer cements to dentin surface according to curing time induced by argon laser. In this study, 160 extracted human molars with sound crown were used. The dentin surface of these teeth were exposed with high speed diamond bur under water spray and polished with 120, 320, 400, 800, 1200 grits sand paper. 160 extracted human molars were randomly assigned into four groups (control, experimental 1, 2 & 3) with 40 teeth each. Control group used a visible light curing unit, XL 1000(3M Co., U.S.A) and experimental groups used argon laser($SPECTRUM^{TM}$). And then each group subdivided into two groups (A, B) according to filling materials. Subdivided A group used Fuji II LC(GC Co., Japan), B group used Vitremer(3M Co., U.S.A). The curing units and curing time of each group were as follows : Control group : visible light, 40 seconds Experimental group 1 Experimental group 2 Experimental group 3 : argon laser, 10 seconds : argon laser, 20 seconds : argon laser, 30 seconds The glass ionomer cements were bonded to dentin surface of each specimen. The specimens were stored in 100% relative humidity at 37"c for 7days. And then, the shear bond strength were measured by universal testing machine(Shimatzu Co. Japan) at crosshead speed of 5mm/min and 100kg in full scale and analyzed statistically. The following results were obtained : 1. Experimental group 2-A showed the highest shear bond strength with $9.87{\pm}1.24$ kgf and control group B showed the lowest shear bond strength with $4.08{\pm}0.78$ kgf(P<0.01). 2. The Fuji II LC showed higher shear bond strength with $9.49{\pm}1.24$ kgf than that of the Vitremer with $4.23{\pm}1.24$ kgf. There was significant difference between Fuji II LC and Vitremer(p<0.01). 3. There was no significant differences among experimental groups according to curing time induced by argon laser. 4. There was no significant differences between control group and experimental groups according to curing units.