• Journal of Ecology and Environment
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• v.48 no.1
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• pp.17-23
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• 2024

Background: Honey bees play a crucial role in pollination and ecological balance. Apis mellifera L. colonies, especially those located in specific geographic regions, such as the palm garden in Eastern Thailand, are susceptible to potential threats from microbial contaminants. Understanding and detecting microbial organisms in these beehives is essential for the preservation of bee health, honey production, and the broader ecosystem. However, the problem of microbial infection and antibiotic-resistant bacteria is more severe and continuously increasing, resulting in a health, economic, and social crisis. The purpose of this study is to determine the prevalence of microorganisms in A. mellifera beehives in palm gardens in Rayong province, Eastern Thailand. Results: Ten swabs in transport media were swabbed and obtained from different parts of each beehive (1 swab per beehive), for a total of 10 hives. Traditional microbial culture-based methods, biochemical tests, and antimicrobial susceptibility (disc-diffusion) tests were used to detect microbial organisms and antibiotic resistance in bacteria. The swab tests from nine beehives resulted in the detection of Gram-positive bacteria (63.64%), Gram-negative bacteria (27.27%), and fungi/yeast (9.09%). These microorganisms are classified as a group of coagulase-negative Staphylococcus spp. and made up 40.91% of the bacteria discovered. Other bacteria found were Coryneform bacteria (13.64%), Pantoea spp. (13.64%), Bacillus spp. (9.09%), yeast (9.09%), glucose non-fermentative Gram-negative bacilli (9.09%), and Pseudomonas spp. (4.55%). However, due to the traditional culture-based and 0biochemical tests usually used to identify the microbial organisms in clinical specimens and the limitation of identifying some environmental microbial species, the results of the antimicrobial susceptibility test cannot reveal if the organism is resistant or susceptible to the drug. Nevertheless, drug-sensitive inhibition zones were formed with each antibiotic agent. Conclusions: Overall, the study supports prevention, healthcare, and public health systems. The contamination of microorganisms in the beehives may affect the quality of honey and other bee products or even the health of the beekeeper. To avoid this kind of contamination, it is therefore necessary to wear personal protective equipment while harvesting honey and other bee products.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.3
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• pp.50-59
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• 2010

A pilot-scale test for production of biogas was conducted in an specially designed anaerobic digester (KH-ABC) in which the highly concentrated organic waste (food-waste and piggery-manure) was treated. The effect of inhibitive material to the reaction on anaerobic digestion and the feasibility of digested fluid for the liquefied fertilizer were investigated. The production rate of biogas, the concentration of methane($CH_4$) in biogas, and the digesting rate of volatile solid(VS) were analyzed in the variance of the operating conditions ; the influent rate, the mixture ratio of food waste and piggery manure, and the hydraulic retention time(HRT), etc. The production rate of biogas increased from 1.2 to $2.0kg-VS/m^3{\cdot}d$ with the organic loading rate(OLR). The most suitable operating conditions were recorded at $6m^3/day$ of an influent rate, 2:3 of the raw material mixture ratio(food waste : piggery manure) and 25 days of HRT, respectively. Under those conditions, the production rate of biogas, the concentration of methane($CH_4$) in biogas and the digesting rate of volatile solid(VS) were $220m^3/day$, 64%, and 70%, respectively. The concentration of inhibitive materials was below toxic standard and the anaerobic digested fluid(raw material mixture ratio of 3:7) could meet the condition of the liquefied fertilizer.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.230-240
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• 2015

An IOM sampler equipped with glass fiber filter has been recently utilized instead of solid adsorbent, which was used to measure the inhalation exposure of agricultural operator to pesticides. The aim of this study is to validate the efficacy of an IOM sampler by measuring the trapping efficiency and breakthrough using kresoxim-methyl water-dispersible granule and fenthion emulsifiable concentrate. On LC-MS/ MS, minimum detection level was 12.5 pg and method limit of detection was 5.0 ng/mL. Good linearity ($R^2$ > 0.999) for matrix matched standards was obtained. Recoveries of pesticides from glass fiber filter were 102-109% (kresoxim-methyl) and 97-104% (fenthion) while those from XAD-2 resin were 94-98% (kresoxim methyl) and 93-100% (fenthion). Trapping efficiency test was performed with personal air pumps and IOM sampler (glass fiber filter) connected with solid adsorbent (XAD-2 resin) with two types of formulation (solid and liquid) which were diluted by standard rate and sprayed to IOM sampler. Those pesticides were trapped only in glass fiber filter without any breakthrough to solid adsorbent. After spiking of pesticides to glass fiber filter, breakthrough test was carried out with IOM sampler (glass fiber filter) which was connected with solid adsorbent. As a results, 87-101% of kresoxim-methyl and 96-105% of fenthion remained in spiked glass fiber filter, however, no pesticides were detected in second glass fiber filter and solid adsorbent. In conclusion, IOM sampler which equipped with glass fiber filter can be applied widely for pesticide inhalation exposure study since it has good trapping efficiency and adsorption capacity, regardless of the solid or liquid formulation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1554-1559
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• 2008

This study was performed to investigate the hypoglycemic effect of single and repeated oral administration of medicinal herbal mixture (AD) in streptozotocin (STZ) induced diabetic rats. Angelica decursiva, Lycium chinense and Adenophora triphylla var. japonica Hara were selected by oral glucose tolerance test (OGTT) and mixed for AD mixture. In an oral glucose tolerance test, the AD inhibited the increase in blood glucose levels at 1 hr and 2 hr and decreased incremental glycemic response area under the curve. In a single administration of AD1 (100 mg/kg) and AD2 (500 mg/kg), significant reductions by 5.3% and 12.3% were observed in fasting blood glucose level for 4 hours. During the 1 month of the experimental period, AD1 and AD2 was given to the STZ induced diabetic rats. At 4th week, the fasting blood glucose levels of AD1 and AD2 caused a fall of 25.5% and 37.9%, respectively. In addition, the body weights were decreased by 7.7% (AD1) and 1.7% (AD2), respectively, compared with diabetic control (DC, decreasing of 10.2%). This study suggests that AD could be potentially useful for fasting and post-prandial hyperglycemia treatment and all these effects concluded to the use of this plant extract to manage diabetes mellitus.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.331-338
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• 2007

The major fungal diseases which effecting garlic storage are blue mold and dry rot, caused by Penicillium hirsutum and Fusarium oxysporum, respectively. In order to reduce the damage by the pathogenic fungi, here we report the effects of 11 fungicides tested to reduce spoilage during storage of garlics. In the in vitro antimicrobial activity test, the fungicides, diphenylamine, prochloraz and tebuconazole showed 0.3, 2.2, and 1.3 nun inhibition zone to F. oxysporium, and cyprodinil, diphenylamine, fenbuconazole, hexaconazole, penconazole, prochloraz, propiconazole, pyrimethanil and tebuconazole exhibited 0.2, 2.4, 0.8, 0.4, 1.2, 1.5, 1.2, 0.4 and 1.5 mm to P. hirsutum, respectively. To test the in vivo control effect, when the diphenylamine, prochloraz, and tebuconazole were treated by standard concentration, the fungal mycelium of F. oxysporium started to grow 5 days after inoculation, and 80, 63.3 and 83.3% of the inoculated cloves are infected 11 days after inoculation. When the tebuconazole were treated by standard concentration, the P. hirsutum was completely inhibited the growth of the fungi. In case of diphenylamine, penconazole and propiconazole treatment, the P. hirsutum was observed 7 days after inoculation and $20{\sim}23.3%$ of the cloves were infected 11 days after inoculation. When cyprodinil, prochloraz and pyrimethanil were treated, pathogens occurred 5 days after inoculation and $60{\sim}100%$ of the cloves infected 11 days after inoculation. Three fungicides such as diphenylamine, prochloraz and tebuconazole also suppressed remarkably the infection and growth of F. oxysporium and P. hirsutum on garlic when both of the pathogens are inoculated after the garlic cloves were dipped for 10 min in the suspension of each agrochemical. Overall, diphenylamine, prochloraz and tebuconazole showed effective control efficacy on dry rot and blue mold There was significant correlation between in vitro and in vivo assay in diphenylamine and prochloraz to F. oxysporum and cyprodinil, prochloraz and pyrimethanil to P. hirsutum.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.350-357
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• 2014

We studied on pesticide residue and pest control effect when using various types of sprayers on paprika cultivation. Additionally, a test was conducted to optimize chemical content per unit area in condition of optimum pest control. Two types of sprayer were tested (three times) on paprika cultivation which was divided into seven sections. Blind spots were also examined using a water sensitive paper when spraying chemical pesticide, remote controlled sprayer were confirmed to be not effective in terms of its spraying capacity. However, a U-shaped sprayer was confirmed that it sprayed enough on all the parts of a plant in green house including the blind spots. Additionally, it does not exceed the minimum residue limits on the all parts of pesticides residue conditions. When using remote controlled sprayer, water sensitive paper were changed to blue color (82.5% and 81.2%) in terms of controlling Bemisia tabaci and Aphis gossypii based on the two spraying manners. 53.0% and 42.6% of control effect were shown on the fair parts of the plants. However, on the poor parts on which pesticides were not well-sprayed, thus, not-remained, more number of pests increased. Meanwhile, on farming that only one type of pesticide has been used, resistance pests present with very low control effect, even though sufficient amount of pesticide was well-sprayed. On the test of the optimum amount of spraying per a unit area, which shows no differences in the two cases of using 5L and 2.5L of chemical pesticides on 9 plants of paprika that has 81.8% and 84.5% control effect, respectively.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.222-230
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• 1983

This study was designed to develop a process for the immobilization of xylose isomerase(D-xylose ketol isomerase, EC 5.3.1.5) from Streptomyces griseolus previously isolated by the authors and its application on a pilot plant scale for the production of high fructose corn syrup. The biomass which has endo-excreted xylose isomerase was homogenized under a pressure of $500kg/cm^2$ and 90.8% of the enzyme recovery of the native activity was obtained as compared to 54.7% recovery by the lysozyme treatment. Ionic bonding method was adopted for the enzyme immobilization due to its many reported merits. It was found that the porous resins such as Diaion HP 20, Duolite A-7, Amberlite IRA 93 and 94 were effective in immobilizing the enzyme. In addition, it was disclosed that the regeneration form of $BO_4--$ is effective for Amberlite IRA 93 and $HCO_3-$ for Diaion HP 20. Optimal immobilization condition for Amberlite IRA 93 was pH 8.0 and $55^{\circ}C$ yielding 80.6% of immobilization. Activity decay test showed half life of the immobilized enzyme with Amberlite IRA 93 was more than 24 days at $65^{\circ}C$. The carrier was evaluated to be resuable and its result showed the relative immobilization yields were 98.2, 93.3, 90.7 and 87.5%, respectively at second, third, forth and fifth rebinding test of the enzyme on Amberlite IRA 93. Optimal temperature of the immobilized enzyme was slightly lowered and the range widened to $60\sim70^{\circ}C$, while optimal pH moved toward $8.0\sim8.3$ in its isomerization reaction. The trial production result of high fructose corn syrup in pilot scale immobilization showed that one liter of immobilized xylose isomerase (350 IXIU/ml-R) is capable producing about 293l high fructose corn syrup(75% dry substance) in 30 days.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.514-520
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• 2014

In this study, the production potential of alternative coagulant ($Al_2(SO_4)_3$ solution) having the identical coagulation activity with respect to the commercial coagulant was investigated. The raw material of alternative coagulant was a spent catalyst including aluminium (waste activated alumina) generated in the manufacturing process of the polymer. The alternative coagulant was produced through a series of processes: 1) intense heat and grinding, 2) chemical polymerization and substitution with $H_2SO_4$ solution, 3) dissolution and dilution and 4) settling and separation. To determine the optimal operating conditions in the lab-scale autoclave and dissolver, the content of $Al_2O_3$ in alternative coagulant was analyzed according to changes of the purity of sulfuric acid, reaction temperature, injection ratio of sulfuric acid and water in the dissolver. The results showed that the alternative coagulant having the $Al_2O_3$ content of 7~8% was produced under the optimal conditions such as $H_2SO_4$ purity of 50%, reaction temperature of $120^{\circ}C$, injection ratio of $H_2SO_4$ of 5 times and injection ratio of water of 2.3 times in dissolver. In order to evaluate the coagulation activity of the alternative coagulant, the Jar-test was conducted to the effluent in aerobic reactor. As a result, in both cases of Al/P mole of 1.5 and 2.0, the coagulation activity of the alternative coagulant was higher than that of the existing commercial coagulant. When the production costs were compared between the alternative and commercial coagulant through economic analysis, the production cost reduction of about 50% was available in the case of the alternative coagulant. In addition, it was identified that the alternative coagulant could be applied at field wastewater treatment plant without environmental problem through ecological toxicity testing.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.235-249
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• 2011

A new form of I-type PSC bridge girder, which has hole in the web, is proposed in this paper. Three different concepts were combined and implemented in the design. First of all, a girder was precast at a manufacturing plant as divided pieces and assembled at the construction site using post-tensioning method, and the construction period at the site will be reduced dramatically. In this way, the quality of concrete can be assured at the manufacturing factory and concrete curing can be well controlled, and the spliced girder segments can be moved to the construction site without a transportation problem. Secondly, a numerous number of holes was made in the web of the girder. This reduces the self-weight of the girder. But more important thing related to the holes is that about half of the total anchorages can be moved from the girder ends into individual holes. The magnitude of negative moment developed at girder ends will be reduced. Also, since the longitudinal compressive stresses are reduced at ends, thick end diaphragm is not necessary. Thirdly, Prestressing force was introduced into the member through multiple stages. This concept of multi-stage prestressing method overcomes the prestressing force limit restrained by the allowable stresses at each loading stage, and maximizes the magnitude of applicable prestressing force. It makes the girder longer and shallower. Two 50 meter long full scale girders were fabricated and tested. One of them was non-spliced, or monolithic girder, made as one piece from the beginning, and the other one was assembled using post-tensioning method from five pieces of segments. It was found from the result that monolithic and spliced girder show similar load-deflection relationships and crack patterns. Girders satisfied specific girder design specification in flexural strength, deflection, and live load deflection control limit. Both spliced and monolithic holed web post-tensioned girders can be used to achieve span lengths of more than 50m with the girder height of 2 m.

• Journal of Korean Society of Forest Science
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• v.97 no.3
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• pp.215-220
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• 2008

Recently, there has been a great deal of interest in the applications of plant-based extracts to both cosmetic and medicinal industries. The objective of this study was to investigate the anti-inflammatory and antimicrobial effect of P. rigida extracts by water and ethyl acetate. Anti-inflammatory and anti-microbial effect of P. rigida extracts by water and EtOAc were investigated by using nitrite scavenging ability, nitric oxide production and anti-microbial ability. In the test of nitrite scavenging ability, P. rigida extracts by water and EtOAc showed 88.7% and 99% at 100 ppm concentration, respectively. The cell viability was measured using the MTT assay at 24 hours after P. rigida extracts as shown in over 80%. Anti-inflammatory effect was examined in LPS stimulated RAW 264.7 cells. NO productions in LPS and P. rigida extracts stimulated group were decreased in a concentration and were dependent on time as compared with LPS stimulated. The water extracts showed the highest inhibition at the 100 ppm concentration. In anti-microbial activity test, the water extract with 3.0 mg/disc resulted in the clear zone of 14 mm, and ethyl acetate with that of 15 mm for Staphylococcus aureus. However, P. rigida extracts didn't show any growth inhibitory effect on Esherichia coli. These results indicate that the extracts of P. rigida have anti-inflammatory activities as a cosmeceuticals.